JP2006522233A - Method for producing fiber composition - Google Patents

Abstract

A method for producing a fiber composition, the method comprising a first component comprising plant fibers and a second component comprising a synthetic conductive polymer. According to the method, the plant fiber comprises porous loosely separated fibers, and the conductive polymer is a self-conducting conductive polymer doped to generate charge carriers in the polymeric material, the synthetic polymer Is produced by in-situ polymerization on the interior and surface of the fiber. The doping agent is an organic sulfonic acid, which is absorbed by the fiber in an aqueous medium and then polymerized by bringing a monomer corresponding to the polymer into contact with the fiber. According to the present invention, the conductive polymer adheres firmly to the fibers so that it is not substantially washed away with water.

Description

  The present invention relates to a method for producing a fiber composition according to the preamble of claim 1.

  Such a composition generally comprises a plant-derived porous fiber and a synthetic conductive polymer, and is produced by polymerization of the conductive polymer in the fiber.

  Papers and paper products containing conductive polymers are known from the patent literature. That is, US Pat. No. 5,421,959 discloses a composite material composed of paper and a conductive polymer, for example, as an electrode for a primary or secondary battery, as an antistatic packaging material, and as an electromagnetic radiation. Suitable for use in products that shut off. The composite material is obtained by immersing the paper in a solution containing a conductive conjugated polymer precursor, impregnating the solution into the paper, and subsequently heat treating the paper to form a polymer on the surface of the paper. Manufactured.

  German Published Patent Publication No. 19826800 discloses a security paper containing a linear pigment or a transparent conductive polymer. The pigment or polymer can be mixed into the paper by adding it to the furnish in the paper machine headbox in order to distribute it uniformly throughout the papermaking pulp.

  A wallpaper that protects against electromagnetic radiation is disclosed in EP 1 139 710, which is produced by covering the wallpaper with a mixture comprising a matrix polymer, a conductive polymer and additional components mixed therewith. Is done.

  In such known paper products, the polymer adheres somewhat loosely to the fiber matrix. When the polymer is mechanically mixed with the fiber, the polymer is generally hydrophobic and the fiber is hydrophilic, so the adhesion of the polymer to the fiber is weak. By polymerizing the precursor impregnated in the paper, the polymer precipitates mainly on the fibers because the penetration of the precursor into the fiber matrix of the ready-made paper is minimal. This means that the polymerization takes place on the surface of the fiber matrix. Furthermore, when the paper is covered with a layer containing a conductive polymer, the conductive polymer adheres directly to the matrix polymer rather than to the cellulosic fibers, leaving the conductive polymer on the surface of the product, Leave with the coating dye. In the context of the present invention, it has been found that a practical method for producing a product in which the conductive polymer adheres firmly to the cellulosic fibers and the use of the product are important. Any polymer that leaves the fiber will impair the recovery and recirculation of the aqueous circulation stream in the paper machine, resulting in weak product functionality at the appropriate time. In addition, it is preferred to introduce the conductive polymer directly into the textile during the manufacturing process. Therefore, from a technical point of view, to avoid a decrease in conductivity below the detection limit under the general conditions of a paper machine due to washing of the polymer, only when the polymer adheres to the fiber sufficiently firmly, It is advisable to produce conductive paper or paperboard on a paper machine.

  U.S. Pat. No. 5,211,810 discloses a wrapping paper containing fibers that can be used for cooking in an electronic oven and have a conductive polymer attached to the surface. Polymerization takes place in situ in the presence of a strong mineral acid, ie 1N hydrochloric acid. The publication does not mention the electrical conductivity of the fibers or products made from the fibers.

  Furthermore, this known solution exhibits considerable disadvantages. That is, as a result of the polymerization conditions, a significant portion of the polymer is produced by homopolymerization in solution. This homopolymer separates from the reaction mixture. Under the conditions described in the above US patents, the low pH of the mineral acid is even more detrimental to the physical properties of cellulosic and lignocellulosic fibers. That is, the acid modifies the amorphous region of cellulose, for example. When the pH drops below 2, the potential strength of the textile product is significantly reduced. Low pH keratinizes the fiber and reduces the water retention capacity of the fiber. Such keratinized fibers also require a significant amount of beating energy. Furthermore, the fibers become stiffer. Treatment at low pH is almost inferior to drying of cellulosic pulp.

  It is an object of the present invention to provide a new paper or paperboard product comprising a conductive polymer that adheres firmly to the fiber network so that it is not substantially washed away. In the present invention, even if the conductivity of the product temporarily decreases while the doping agent is dissolved during wet cleaning, this can be recovered.

  According to the present invention, the polymer adheres to the free porous natural fibers before forming the fiber web on a paper or paperboard machine. A fiber composition in which the porous fiber is in intimate contact with the conductive polymer in an aqueous intermediate, and then the conductive polymer is adhered to the fiber, so that the polymer is firmly adhered to the fiber so that it is not substantially washed away with water. The composition can be produced in such a way as to yield a product. If necessary, the fiber composition is recovered.

  In the process according to the invention, the polymerization of the conductive polymer takes place “in situ” in the porous fibre. This is accomplished by first impregnating the porous fibers with both the monomer to be polymerized and the conducting polymer doping agent and then forming these salts. Thereafter, a catalyst or oxidant that enables the polymerization reaction is added to effect polymerization of the monomer doped inside and on the fiber and adhesion of the monomer to the fiber. The doping agent used is an organic sulfonic acid, which is first impregnated into the fiber to be treated, then a monomer corresponding to the polymer is introduced into the reaction mixture, and this monomer is polymerized to form the surface of the fiber. And in particular it is very important for the present invention to adhere to the inside of the fiber.

  That is, the method according to the invention is characterized by what is specified in the characterizing part of claim 1.

Significant benefits are obtained by the present invention. That is, a mixture that can be used to form a conductive network on paper and paperboard webs can be formed by the present invention. By adjusting the amount of conductive polymer, a selected level of conductivity can be achieved, for example, in the range of 10 ⁴ to 10 ¹¹ ohm / square, typically about 10 ⁴ to 10 ⁸ ohm / square. it can. When the square resistance is 10 ⁸ or less, it is easy to distinguish the product from the non-conductive product. A variety of different types of functions are achieved by including a conductive network on paper or paperboard, and these functions are linked to antistatic applications, registered identity information, security signs, etc., depending on the level of conductivity.

  In particular, the present invention provides a textile product having a long-lasting conductivity suitable for wires. Only a very small amount of non-adherent polymer is transferred to waste and circulating water for each of the fiber web composition and manufacture.

If the conductive polymer is firmly attached to the fibers, for example, already in the head box of a paper machine, the polymer is distributed uniformly and homogeneously throughout the furnish. This has the advantage of achieving adequate conductivity with a small amount of polymer compared to the situation where the polymer is present, for example, in a dispersed form between the fibers. As shown in the examples below, a good conductivity of about 10 ⁴ ohms can be achieved in advance with a total of 10% by weight of polyaniline (for pulp).

  From EP-A-0783015 it is known to coat microfibrils with polypyrrole. The size of such fibrils is on the order of micrometers and the diameter is usually 2-30 nanometers. However, according to the present invention, the microfibrils are not modified but made into “plant fibers” such as natural fibers, ie cellulosic or lignocellulosic fibers. This type of fiber structure usually consists of five different wall layers, the length of which is soft, typically about 3 mm. Such wall layers include lignin, hemicellulose and cellulose. For these components, the cellulose molecules are bonded together by hydrogen bonds to form short microfibrils, which in turn are organized like bundles to form fibrils that are oriented in different directions in various fiber wall layers. In the present invention, the conductive polymer penetrates into the fiber.

  The modified cellulose and lignocellulosic fibers according to the invention can be used as is, in other words they can be recovered, dried and mixed with some other matrix material, or the fibers can be separated and A fiber web can be formed from pulp containing these fibers without recovery. Conductive fibers can be tied to different types of fiber products such as paper, paperboard, fiberboard (eg MDF and HDF) and other compression products such as compression molded articles. They can also be used in the manufacture of composite products, for example together with thermoplastics and cold sets, and in combination with inorganic fillers and building materials. Therefore, according to this invention, it becomes possible to manufacture the building board which can be identified, for example by an electrical measurement.

  The conductive polymer can be doped with an organic doping agent without lowering the pH of the fiber dispersion to 2 or lower. In this way, keratinization of the fibers and a decrease in durability of the sheet to be formed can be avoided. In addition, organic acids, in particular aromatic sulfonic acids, can be selected depending on the fiber to be treated so that the conductive polymer can be adhered to the fiber.

  In the following, the invention will be examined more closely with the help of a detailed description and some practical embodiments.

  In the examples, reference is made to the accompanying drawings which include micrographs showing the cross-sections of fibers treated with polyaniline, from which it can be seen how polyaniline penetrated into the interior of the fibers in the presence of different counterions. it can.

  1 and 2 represent cross sections of fibers treated with polyaniline doped with toluene sulfonic acid (TSA) shown magnified 200 times (FIG. 1) and 500 times, respectively. FIGS. 3 and 4 show corresponding micrographs of polyaniline doped with dodecylbenzenesulfonic acid (DBSA), and FIGS. 5 and 6 show micrographs of polyaniline doped with hydrochloric acid (comparative example).

The fiber composition of the present invention comprises a substrate made of porous natural fibers and a conductive polymer attached to the substrate. As mentioned above, the concentration of the conductive polymer is adjusted to the substrate resistivity (surface resistivity) at a level of 10 ¹¹ ohms, preferably below that value, most preferably at a level of 10 ⁸ ohms as needed. It should be sufficient as to be able to reduce further the level of 10 ⁴ ohm. Therefore, about 0.1 to 150%, preferably about 1 to 100% by weight of polymer can be added based on the amount of fiber. The amount of conductive polymer is preferably about 5-70% of the total weight of the fiber material, and most preferably about 7.5-50%.

  According to the present invention, the polymer adheres to the substrate made of fibers so that it is not substantially washed away. As a result of this, the polymer does not enter the short circulating water of, for example, a paper or paperboard machine.

  In general, in the solutions described above, the conductivity of the fiber containing the conductive polymer can be substantially restored to the first level after washing, even if the polymer counterion is washed away as a result of wet washing. Conceivable. Preferably, the conductivity of the conductive polymer can be restored to a level that is more than 30 times weaker than the initial level (ie, the surface resistivity is 30 times greater). To restore conductivity, the same counter ion or some other material can be used, as described in more detail below.

  Typically, up to about 20%, preferably less than about 10%, and even less than 5% by weight of the conductive polymer is washed away with water at a temperature of 25 ° C. and a pH of 7 ± 0.3 per wash. It is. In the wet cleaning, the fibers are immersed and mixed in water under the pH and temperature conditions described above, and after about 10 minutes, the water is removed to separate and dry the fibers.

Depending on the doping agent and the fixing state, the conductivity (in terms of surface resistivity) can be reduced by a factor of 4 to 8 each time it is washed, for example after washing with water 10 ⁴ after washing the doping agent. To 10 ⁸ ohms.

  The conductivity of the fiber can be determined by forming a uniform fiber layer of the fiber suspension, then sucking water by vacuum filtration and drying the fiber layer at a temperature of up to 50 ° C. before measurement ( See Examples 7 and 8.) Conductivity can also be determined from sheets prepared by standard methods (eg, SCAN C26: 76).

  In order to prevent the conductive polymer adhering to the fibers from being washed away, the fibers are made from porous natural fibers, which are in the form of separate, loose fibers before optionally forming a uniform fiber matrix. Should be. Polymer precursors, such as salts formed with monomers and doping agents, first penetrate into the pores of the fibers (inside the fibers) and then undergo a polymerization reaction to adhere the polymer to the fibers on the fibers. To achieve both inside and outside. If the fiber matrix is formed using, for example, a paper or paperboard machine with separated and loosened fibers, and the matrix is provided with a uniform fiber layer, for example in the form of paper or paperboard, it is conductive. The polymer penetrates into the fibers, and the majority of the polymer is located inside the fiber matrix. As a result, the polymer is homogeneously dispersed in the fiber layer. Homogeneous dispersion changes the surface resistivity of the paper or paperboard as a function of position up to about 10%, preferably up to about 5%.

Weight per square web forming the fibrous matrix is generally from about 5~700g / ^{m 2,} typically about 20 to 500 g / ^{m 2,} and the example for paper about 30 to 150 g / ^{m 2,} and paperboard Is 80 to 300 g / m ² .

  The porous fibers used in the present invention are cellulose fiber, lignocellulose fiber, cellulose fiber of cereal, pentosan of cereal, cotton lint, manila hemp fiber, sisal fiber, ramie fiber, flax fiber, kusayoshi fiber or bastose. ). Most preferably, cellulose or lignocellulose pulp obtained by disaggregating annual or perennial plants such as chemical or mechanical pulp or mechanical chemical pulp is used. Chemical pulping methods can include sulfate pulping, continuous sulfate pulping, sulfite pulping, sulfide pulping, organosolv-pulping (eg Milox pulping) and soda pulping. The most important mechanical pulping methods are grinding (GW), pressure grinding (PGW), thermomechanical pulping (TMP) and beating (RMP), and the most important mechanical chemical pulping methods are CTMP and CMP methods. It is. The pulp may or may not be bleached.

  It is characterized by using a porous fiber that can absorb at least an amount of water corresponding to its own amount (before impregnating the polymer and / or its precursor). Most suitably, the fiber to be used can absorb an amount of water 1.5 to 20 times its weight. In general, the fiber size is about 0.01 to 10 mm. Depending on the desired dewatering efficiency, the fiber is generally beaten to a drainage capacity of generally 80-650 ml CSF, preferably about 120-560 ml CSF. The fiber is “separated and loosened”, which means that it can be dried into fluff. Compared to known solutions where the polymer adheres to the fabric, the present invention achieves significantly better homogeneity.

In the present invention, “conductive polymer” means an essentially conductive polymer (ICP) that is “doped” (supplied, processed) to generate charge carriers (holes and electrons). Common to all conducting polymers is a conjugated double bond in the main chain (alternating single and double bonds, delocalized silicone electronic system) that allows the movement of charge carriers. Conductive polymers have both ionic and electronic conductivity and can be used in a variety of applications. The conductivity of the conductive polymer can be adjusted by varying within the entire conductivity range from the insulator to the metal conductor. In general, if the maximum resistance is 10 ¹¹ ohms (as surface resistance), the polymer is considered conductive.

  The conductive polymer can be bonded to the fiber in both conductive and non-conductive forms. Thus, the term “conductive polymer” in the claims also means a polymer that is non-conductive at the time of reference but can be rendered conductive, for example, by treatment with a suitable doping agent.

  Polyaniline, polypyrrole, polyacetylene, polyparaphenylene, polythiophene, or derivatives or mixtures thereof are used as the conductive polymer. Among the derivatives, especially the alkyl and aryl derivatives of the above polymers and the chlorine and bromine substituted derivatives are worth mentioning. If necessary, conductive particles such as graphite or carbon black can also be added.

  In the present invention, polyaniline is particularly preferred. The monomer in the aniline polymer is aniline or a derivative thereof, and the nitrogen atom is usually bonded to the para-position carbon of the benzene ring of the next unit. Unsubstituted polyaniline can be in different forms, in which the emeraldine form is commonly used for conductive polymer applications, characterized by a bright emerald green representing this name.

  By doping, an electrically neutral polyaniline can be converted into a conductive polyaniline complex. The doping agent used in the present invention can vary widely and is commonly used when doping a conjugated polymer into a conductive or semiconductor form.

Protonic acids are known as doping agents in the field of intrinsically conductive polymers, as is evident in the literature of J.-C.Chiang and Alan G. MacDiarmid and the citation of WRSalaneck.
・ Chiang et al., Synth.Metals (1986) 13: 193-205
・ MacDiarmid et al., Papers from the 6th European Physical Society Industrial Workshop Eur. Phys. Soc.
・ Salaneck et al., Synth.Metals (1986) 13: 291-297 No Month Available

  Such doping agents consist of organic acids and their derivatives, of which sulfonic acid, picric acid, n-nitrobenzoic acid, dichloroacetic acid and polymeric acids are typical examples. If necessary, two or more doping agents can be used.

  A functional acid is preferably used for doping, for example sulfonic acid, especially aromatic sulfonic acid. The aromatic sulfonic acid comprises one aromatic ring or two fused rings, wherein at least one ring is a polar or nonpolar ring substituent, such as a functional group (eg, a hydroxyl group) or 1-20 carbons. It has a hydrocarbon chain such as an alkyl chain having Examples of these are alkyl benzene sulfonic acids and dialkyl benzene sulfonic acids (wherein the alkyl comprises 1 to 20 carbon atoms), other branched benzene sulfonic acids, and aromatic diesters of phosphoric acid.

The details can be mentioned as follows.
MSAs (Methylsulfonic acid)
Ethylsulfonic acid BSAs (benzenesulfonic acid)
TSAs (Toluenesulfonic acid)
DBSAs (dodecylbenzenesulfonic acid)
Ethylbenzenesulfonic acid PSAs (phenol sulfonic acid or hydroxybenzene sulfonic acid)
CSAs (Camphorsulfonic acid)
AMPSA (2-acrylamide-1-propanesulfonic acid)
Vinylsulfonic acid isophthalsulfonic acid ester PPA (phenylphosphinic acid)
Phosphonoacetic acid DIOHP (bis (2-ethylhexyl) hydrogen phosphate)
Chlorobenzene sulfonic acid pyridine sulfonic acid anisidine sulfonic acid aniline sulfonic acid quinoline sulfonic acid naphthalene sulfonic acid sulfosalicylic acid phosphonic acid

  Polymers end-functionalized with sulfonic acids (polystyrene (PSSA), polyolefins, polyethylene oxide, polyvinyls), sulfonated polyparaphenylenes, sulfonated aromatic polyamides and similar materials can be converted into polymer acids. Can be cited as an example.

  Preferred acids are dodecylbenzene sulfonic acid (DBSA), camphor sulfonic acid, paratoluene sulfonic acid and phenol sulfonic acid.

  The preparation of polyaniline complexes is described in great detail, for example in European Patent Publication Nos. 545729 and 582919, and Finnish Patent Applications 932557, 932578 and 940626, the contents of which are described here. Included for reference.

  According to a preferred embodiment of the present invention, a salt formed of a parent substance (monomer) of a conductive polymer and a doping agent can be dissolved in a medium such as water used for attaching the polymer. Next, a conductive polymer doping agent is selected. This is particularly relevant when the conductive polymer is attached to fibers produced by chemical pulping.

  When the fiber to be treated contains lignin, a doping agent having surface activity and / or hydrophobicity should be used even though the salt formed from the doping agent and the parent material of the conductive polymer is slightly soluble in the intermediate agent. it can. In this case, the fibers are lignocellulose fibers obtained from mechanical pulping. Dodecylbenzenesulfonic acid (DBSA) can be mentioned as an example of the doping agent.

  In general, an oxidizing agent is used for the polymerization of the monomer compound to the corresponding conductive polymer. Preferred oxidants are polyatomic metal salts such as peroxides, peracids, persulfates, perborates such as perborates, permanganates and perchlorates, and chlorates, nitrates and It is a salt of quinone and iron (III). The amount of oxidant to monomer is generally from 10: 1 to 1: 1, most preferably from about 5: 1 to 2: 1 (parts by weight), ie mole fraction (oxidant / monomer) 4: 1 to 1: 1.

  Polyaniline can be attached to the fiber in both conductive and non-conductive forms. In order to convert polyaniline to a conductive form, it is necessary to dope with a counter ion. As will be described in more detail below, it is particularly preferred to attach the polyaniline to the fiber in a conductive form, as it can be assumed that the bonding of the polyaniline occurs at least in part with the aid of a doping agent.

The resistivity of fiber compositions made according to the present invention is generally about 50 to 10 ⁸ ohms.

  The product can be produced by bringing the monomer forming the conductive polymer into intimate contact with the porous fibers in a suitable medium, in particular an aqueous medium. In addition to water and aqueous solutions, polar and non-polar organic solvents can be used. “Intimate” means that fiber and polymer monomer precursors and / or fine pulp containing polymer doping agent are vigorously mixed to efficiently distribute the monomer and / or doping agent to the fiber material. It means that Thus, “aqueous medium” refers to both water and aqueous solutions in which the fibers are slurried. Typically, the viscosity of the aqueous slurry is 0.1 to 50% (weight / weight), preferably about 0.5 to 30%, particularly about 0.7 to 20%. Thereafter, the counterion or the monomer of the conductive agent to be polymerized can each be dissolved in the aqueous phase. The amount of doping agent varies with the amount of monomer. Generally, the amount of monomer is about 0.1 to 200%, typically about 1 to 150%, preferably about 5 to 120%, especially about 10 to 100% by weight of the amount of fiber. %. In general, the amount of counterion can be equimolar to the amount of monomer, but can also be about ± 30% of the molar amount of monomer.

  The temperature is usually 0 ° C. or higher and normal temperature or lower. Typically, the temperature is about 1-18 ° C, preferably about 2-15 ° C.

  In general, by using an acidic counter ion, the pH of the aqueous phase used for pairing the fiber and the polymer / monomer becomes the most appropriate and clear acid, and the pH is preferably 5 or less, preferably 2 or more. Most preferably. A pH value that is too low can adversely affect the mechanical properties of the fiber, but for this reason the preferred pH environment is about 2-5, most suitably 2-3.

As described above, according to the present invention, an aggregate (complex or salt) formed of a monomer and a doping agent is first introduced between the fibers, and then is not washed away under severe papermaking conditions. The monomer is polymerized for the purpose of attaching the polymer to the fiber. Regarding the mutual adhesion, the affinity of the porous fiber and the conductive polymer can be improved by considering the following.
a) Types of counter ions
b) Solubility of salts formed by monomers and counterions
c) Concentration of monomer and counter ion
d) Fiber type

  The latter item has already been discussed. In order to increase the mutual adhesive affinity between the porous fiber and the conductive polymer, it is possible to attach the polymer formed by polymerization to the porous fiber by conducting a polymerization reaction in an aqueous medium containing the porous fiber. To. Typically, the monomer to be polymerized into the conductive polymer and the doping agent react with each other to form a salt or complex in the aqueous solution, which is then contacted with the porous fiber and allowed to penetrate the fiber. Thereafter, the monomer is polymerized in the fiber, resulting in a polymer that is homogeneously dispersed throughout the pulp. The reaction between the monomer and the polymerization catalyst can be performed in the presence of fibers. Further, the doping agent can be added before the monomer, and this (ie, the doping agent) can be absorbed by the fiber before the monomer. This solution can further improve monomer adhesion and thereby polymer adhesion to the fiber.

  When selecting a doping agent, the aim is to reach a situation where the affinity for the adhesion between the porous fiber and the conductive polymer is as strong as possible. In the present invention, it has been found that the selection of the doping agent depends on the surface of the cellulose fiber. According to one preferred embodiment, the affinity of the porous fibers and the conductive polymer for mutual adhesion is increased by selecting fibers whose surfaces are at least partially covered with lignin. This means, for example, mechanical or mechanochemical pulp fibers with lignin from the laminated interlayer on the surface. Lignin is known to contain phenyl and phenolic structures, and thus it has been observed that it is preferable to have a doping agent having an aliphatic hydrocarbon structure that increases the hydrophobicity of the doping agent. As a result of experiments, it was found that polyaniline can be sufficiently bonded to mechanical pulp fibers by using dodecylbenzenesulfonic acid or a similar compound as a doping agent. “Similar compound” means a compound with an alkyl or dialkyl side chain having 4 or more, preferably about 5 to 20 carbon atoms attached to an aromatic group. It is clear that the bond can be strengthened by placing aliphatic and aromatic hydrocarbon structures adjacent to the bond surface.

  In Examples described later, ordinary chemical pulp (bleached softwood cellulose digested by a sulfate method) was also used. The surface of this type of pulp is rich in aliphatic anhydrous hexose or anhydrous pentose chains originating from cellulose or hemicellulose, which chains have typical aliphatic properties. In order to improve the bond to these, it is advantageous to use doping agents that are more hydrophilic than alkylbenzene sulfonic acids, ie agents that have at most a lower alkyl group as a substituent on the aromatic ring. Alternatively, the ring can contain functional groups that increase the hydrophilicity of the material. According to this, para-toluenesulfonic acid and similar substances are particularly preferred as the doping agent described above. Even in this case, it is considered that each of the adjacent aliphatic hydrocarbon structure and aromatic hydrocarbon structure is formed at the bonding site between the doping agent and the fiber.

  According to the invention, it is advantageous to use conductive cellulose and lignocellulosic fibers for the production of conductive paper or paperboard products. The fibers can be collected after production, dried, and then used in a dried form for the desired application or reused as a suspension. After treatment according to the invention, the fibers can be further transferred to the production of paper or paperboard. The fibers are then advanced into the most suitable aqueous pulp and mixed with other fibers, for example in a paper machine headbox. It is extremely important to obtain a conductive fiber composition containing a uniformly dispersed conductive component by mixing conventional plant fibers that do not contain a conductive polymer component and fibers according to the present invention. In general, the fibers according to the invention are added in an amount of about 1 to 50%, preferably about 2 to 30% by weight of the dry matter of the textile. When a product is produced on a paper or paperboard machine, a fiber matrix in which the conductive polymer is completely dispersed is obtained.

  The product to be manufactured can be used for ESD applications or to make security signs.

  The following examples illustrate the invention. These show more details of the preferred embodiment of the present invention.

Example Summary In this study, aniline was polymerized using different counterions in the presence of ground conifer cellulose fibers. The purpose of the study was to deposit polyaniline supplied primarily by polymerization on the surface of the fiber and then to produce a conductive paper of the fiber that absorbed polyaniline.

  The parent substances used in this study were water, aniline, dodecylbenzenesulfonic acid (A), p-toluenesulfonic acid (B), citric acid (C), ammonium persulfate (manufactured by Degussa), and crushed softwood cellulose pulp (TKK). Helsinki Institute of Technology). In order to keep the temperature of the exothermic reaction stable during the whole reaction, the emulsion polymerization was conducted in a 5-liter glass sphere cooled in an ice-water bath. The polymerization was carried out in the same way for all three counter ions.

  For comparison, hydrochloric acid was used as a counter ion.

  Pulp having a 5-30% viscosity was added to the water to form a 1% mixture for the fibers (eg, 30 grams of fiber in 3000 grams of water). To this, the counter ion (A, B or C) was dissolved using an amount corresponding to the molar amount of aniline. Subsequently, aniline (for example, 3 g) of 10 to 100% by weight of the fiber amount was added. The mixture was then cooled to a temperature below 10 ° C. APS aqueous solution (7.4%) was used as an oxidizing agent, and the amount of APS was equivalent to 1.03 times the molar amount of aniline. Thereafter, the oxidizing agent was gradually added to the mixture within about 3 hours, and then the temperature was raised to room temperature.

Next, the pulp press water of the mixture consisting of polyaniline, chemical pulp fiber and water was centrifuged. If the APS salt residue was washed away, the product was once slurried in water and centrifuged again. The finished washed product was transferred to a paper sheet manufacturing TKK. The surface resistivity of the fiber filtered at the top of the filter paper and the dried fiber was as follows:

100% PAN-DBSA amount of fiber: 10 ³ ohm fiber amounts of 10% PAN-DBSA: 10 ⁴ ohm fibers in an amount of 10% PAN-TSA: 10 ⁷ ohm fiber amounts of 25% PAN-TSA: 10 50% PAN-TSA in the amount of ⁴ ohm fiber: 10 10% PAN-citric acid in the amount of ³ ohm fiber: 10 ^{5... 11} ohm (PAN = polyaniline)

  The micrograph shows the cross section of the PAN treated fiber, ie how the PAN penetrated into the fiber in the presence of different counterions. 1, 3 and 5 are 200 × magnified photographs using toluene sulfonic acid (TSA) and dodecylbenzene sulfonic acid (DBSA) as counterions and HCl as a counter example. 2, 4 and 6 are 500 times magnified photographs of each.

  It seems as follows based on the figure. DBSA forms a water-insoluble salt with aniline when PAN partially stays as particles on the surface and between the fibers. TSA is very well impregnated into the fiber structure as a water-soluble aniline salt. HCl forms a water-soluble salt, while PAN stays on the surface of the fiber as an obvious layer. Actually, almost no PAN can be seen inside the fiber, in other words, in the lumen, together with the counter ion. Thus, a mineral acid similar to strong hydrochloric acid not only keratinizes the fiber, but also specifies that the mineral acid will leave the polyaniline on the fiber surface if the organic doping agent allows the polyaniline to polymerize inside the fiber. can do. As a result, polyaniline stays better in the fiber even when there is mechanical erosion.

The surface resistivity measured by VTT was measured by an apparatus that placed two parallel metal rods each having a length of 6.5 cm on the surface of the sample and measured the electric resistance therebetween. The bars are 4 cm apart from each other. Measured voltage in the conductive region, 10V in the region of less than 10 ⁵ ohms and a 100V 10 ⁵ ohms or more regions.

  Since the retention mechanism between the counter ion and the fiber and the mechanism leading to it are still unclear at present, more polymerization was performed on both the chemical pulp fibers and the TMP rejection and TMP / GW lignin fibers. Such polymerization was performed in a manner corresponding to that described above, except that phenol sulfonic acid (PSA), camphor sulfonic acid (CSA) and methane sulfonic acid (MSA) were used as counterions. The product was washed by filtration and pouring back into water. For filtration, a filter cake was prepared directly from the reaction mixture and after the third and sixth washes. The product was washed until the pH rose to 6 or higher. The surface resistivity was measured from the dry filter cake, and samples taken from the pulp were analyzed for adhesion of the polymer in KCl to the fibers by optical microscopy. A micrograph is presented in Appendix II. A summary of treatments performed with different counterions and fibers is shown in Table 1.

  In addition to the reactions shown in Table 1, a reaction using sulfuric acid as a counter ion was performed. When the reaction was achieved with both water-insoluble and water-soluble aniline salts, the reaction was performed using two different aniline-counter ion concentrations.

  The reaction according to Table 2 showed that the solubility of the salt could also be determined by the salt concentration. The purpose of the test was to demonstrate that the water-insoluble aniline-counter ion salt does not adhere to the fiber as does the water-soluble salt. However, this demonstration failed because the amount of insoluble salt was more than 10 times that of the treated chemical pulp fiber. Other reactions used up to 25% aniline based on the amount of fiber. This led to a situation where there was a large amount of polyaniline that made it difficult to wash out the fibers. Moreover, high concentration sulfuric acid could be loaded into the fiber structure before the aniline was polymerized.

  In the examples of Table 1, only the DBSA aniline salt becomes water insoluble and at a lower concentration. Due to its solid state, large molecular structure and surface activity of dodecylbenzene sulfonic acid (DBSA), the penetration of polyaniline into chemical pulp fibers was weak. Secondly, the wood fibers also contain a plurality of different types of active groups that are easy to attach even to long chain DBSA.

  For water-soluble aniline-counter ions, attachment to and impregnation of fibers with water was easy. Moreover, impregnation into chemical pulp fibers is easier than wood fibers due to the chemical and physical properties of lignin.

  If polyaniline is simply mixed with the fiber (Example 13, 25% of the amount of fiber mixed with chemical pulp fiber), the polyaniline does not properly impregnate into the fiber. Thus, the polyaniline is washed out of the fiber mixture very easily compared to a mixture of polyaniline synthesized in the presence of fibers.

  Depending on the type of fiber (cellulosic pulp or wood), the choice of counterion (water-soluble / solid, counterion size and shape), the amount of aniline-counterion salt relative to the amount of fiber, and the slight amount of water-soluble salt In some cases, the conductivity of the conductive fiber product can be influenced by the concentration of salt in the reaction mixture. In the post-treatment, when a part of the counter ion is washed away with water to cause dedoping of the product, the effect can be returned to the beginning depending on the amount of washing water used and the number of washings.

Production example
Example 1
Polymerization of aniline using dodecylbenzenesulfonic acid as a counter ion in the presence of chemical pulp fiber. The amount of aniline is equal to the amount of fiber.

A total of 1500 ml of water was poured into the flask and 52.5 g of dodecylbenzenesulfonic acid was added. Next, after dissolving dodecylbenzenesulfonic acid in water, 1015 g of fine pulp was added. Fine pulp contains 15 g of softwood chemical pulp fiber per 1000 g of water. After 15 minutes, 15 g of aniline was added. Aniline and dodecylbenzenesulfonic acid are mixed for 30 minutes to form a water-insoluble salt. The mixture was cooled to a temperature of 12 ° C. with an ice-water bath. Thereafter, 36.8 g of ammonium persulfate was dissolved in 200 ml of water and this solution was added to the mixture during 3 hours. After the addition of ammonium persulfate, mixing was continued for 2.5 hours to obtain an extremely dark green, almost black chemical pulp fiber-polyaniline aqueous suspension. The reaction water was washed away from the product by centrifugation and re-watered into a suspension with about 7.4% dry matter. The surface resistivity of the fiber containing about 100% polyaniline to chemical pulp fiber was 10 ³ ohms. The product was transferred to TKK for paper production testing.

Example 2
Polymerization of aniline using dodecylbenzenesulfonic acid as a counter ion in the presence of chemical pulp fiber. The amount of aniline was 10% of the amount of fiber.

A total of 400 ml of water was poured into the flask and 5.25 g of dodecylbenzenesulfonic acid was added. Next, after dodecylbenzenesulfonic acid was dissolved in water, 1.5 g of aniline was added to the mixture. Aniline and dodecylbenzenesulfonic acid are mixed for 15 minutes to form a water-insoluble salt. A total of 983.3 g of cold dispersed chemical pine pulp at pH 5.5 was added into the mixture. This fine pulp contained 15 g of fiber per liter of pulp. The mixture was cooled to a temperature of 8 ° C. with an ice water bath. Thereafter, 3.7 g of ammonium persulfate was dissolved in 50 ml of water and this solution was added to the mixture during 1.5 hours. Mixing continued for 5 hours after the addition of ammonium persulfate to obtain an aqueous suspension of very dark green, almost black chemical pulp fiber-polyaniline. The reaction water was rinsed from the product by centrifugation and re-watered into a suspension with about 1.6% dry matter. The surface resistivity of the chemical pulp fiber washed once and containing about 10% polyaniline was 10 ⁴ ohms. The product was transferred to TKK for paper production testing.

Example 3
Polymerization of aniline using dodecylbenzenesulfonic acid as a counter ion in the presence of chemical pulp fiber. The amount of aniline was 10% of the amount of fiber. The fiber was added before the counter ion.

A total of 500 g of water was poured into the flask and 1000 g of cold dispersed chemical pine pulp was added. The pulp contained 15 g fiber per 1000 g pulp. Next, 5.3 g of dodecylbenzenesulfonic acid was added and dissolved for 10 minutes. Thereafter, when 1.5 g of aniline was added, a water-insoluble white aniline-dodecylbenzenesulfonate was formed. The mixture was cooled to a temperature of 8 ° C. with an ice water bath. Thereafter, 3.7 g of ammonium persulfate was dissolved in 50 ml of water and this solution was added to the mixture during 1.5 hours. After the addition of ammonium persulfate, mixing was continued for 4 hours to obtain an extremely dark green, almost black chemical pulp fiber-polyaniline aqueous suspension. The reaction water was rinsed from the product by centrifugation and re-watered into a suspension with about 1.6% dry matter. The surface resistivity of the chemical pulp fiber washed once and containing about 10% polyaniline was 10 ⁴ ohms.

Example 4
Polymerization of aniline using dodecylbenzenesulfonic acid as a counter ion in the presence of chemical pulp fiber. The amount of aniline was 10% of the amount of fiber. A more dilute reaction mixture.

  A total of 2780 g of water was poured into the flask and 300 g of cold dispersed chemical pine pulp was added. The pulp contained 10 g of fiber per 100 g of pulp. Next, 10.5 g of dodecylbenzenesulfonic acid was added and dissolved for 20 minutes. Thereafter, when 3 g of aniline was added, a water-insoluble white aniline-dodecylbenzenesulfonate was formed. The mixture was cooled to a temperature of 11 ° C. with an ice-water bath during mixing. Thereafter, 7.4 g of ammonium persulfate was dissolved in 100 ml of water and this solution was added to the mixture during 2.5 hours. Mixing continued for 5 hours after the addition of ammonium persulfate to obtain an aqueous suspension of very dark green, almost black chemical pulp fiber-polyaniline. The reaction water was washed away from the product by centrifugation and re-watered into a suspension with about 2.3% dry matter. Paper sheets containing different amounts of treated cellulosic pulp were prepared from chemical pulp fibers containing 10% polyaniline in TKK.

Example 5
Polymerization of aniline using p-toluenesulfonic acid as a counter ion in the presence of chemical pulp fiber. The amount of aniline was 10% of the amount of fiber.

A total of 1970 g of water was poured into the flask, and 295 g of cold-dispersed fine pine pulp was added. The pulp contained 10 g of fiber per 100 g of pulp. Next, 6.13 g of p-toluenesulfonic acid was added and dissolved for 50 minutes. Thereafter, when 3 g of aniline was added, a water-soluble aniline-p-toluenesulfonate was formed, and the mixture was slightly brownish. The mixture was cooled to a temperature of 9 ° C. with an ice-water bath during mixing. Thereafter, 7.4 g of ammonium persulfate was dissolved in 100 ml of water and this solution was added to the mixture during 1 hour. After the addition of ammonium persulfate, mixing was continued for 5 hours and left overnight. This resulted in an almost black, slightly greenish chemical pulp fiber-polyaniline suspension in water. The reaction water was washed away from the product by centrifugation. The product was washed once by filtration and re-watered with water to a suspension with about 7.1% dry matter. The surface resistivity of the sheet obtained by filtration of chemical pulp fibers containing about 10% polyaniline was 10 ⁷ ohms. Paper sheets containing different amounts of treated cellulosic pulp were prepared from the product with TKK.

Example 6
Polymerization of aniline using citric acid as counter ion in the presence of chemical pulp fiber. The amount of aniline was 10% of the amount of fiber.

A total of 1970 g of water was poured into the flask and 294.8 g of cold-dispersed fine pine pulp was added. The pulp contained 10 g of fiber per 100 g of pulp. Next, 6.19 g of citric acid was added and dissolved for 40 minutes. Thereafter, when 3 g of aniline was added, a water-soluble aniline-citrate was formed. The mixture was cooled to a temperature of 9 ° C. with an ice-water bath during mixing. Thereafter, 7.4 g of ammonium persulfate was dissolved in water (100 ml) and this solution was added to the mixture during 1.5 hours. Mixing continued for 6 hours after the addition of ammonium persulfate to give a brown product. After leaving the mixture overnight, an aqueous suspension of black chemical pulp fiber-polyaniline was obtained. The reaction water was washed away from the product by centrifugation. The product was elutriated with water again to a suspension with about 6.1% dry substance. The surface resistivity of the sheet obtained by the filtration of chemical pulp fibers containing about 10 percent of the polyaniline was 10 ⁵ ohms. Paper sheets containing different amounts of treated cellulosic pulp were prepared from the product with TKK.

Example 7
Polymerization of aniline using p-toluenesulfonic acid as a counter ion in the presence of chemical pulp fiber. The amount of aniline was 25% of the amount of fiber.

A total of 1700 g of water was poured into the flask and 300 g of cold dispersed fine pine pulp was added. The pulp contained 10 g of fiber per 100 g of pulp. Next, 15.3 g of p-toluenesulfonic acid was added and dissolved for 15 minutes. Thereafter, 0.02 g of phenyldiamine was added and mixed for 15 minutes, and then 7.5 g of aniline was added. A water soluble aniline-p-toluenesulfonate was formed and the mixture was slightly brownish. The mixture was cooled to a temperature of 9 ° C. with an ice-water bath during mixing. Thereafter, ammonium persulfate (18.5 g) was dissolved in 200 ml of water and this solution was added to the mixture during 1 hour. After the addition of ammonium persulfate, mixing was continued for 3 hours and allowed to stand overnight to obtain an almost black, slightly greenish chemical pulp fiber-polyaniline aqueous suspension. The reaction water was washed away from the product by centrifugation. The product was washed once by filtration, and the pH of the washing water at this time was 2.0. The product was elutriated with water again to a suspension with about 5.5% dry substance. The surface resistivity of the sheet obtained by filtration of chemical pulp fibers containing about 25% polyaniline was 10 ⁴ ohms. Paper sheets containing different amounts of treated cellulosic pulp were prepared from the product with TKK.

Example 8
Polymerization of aniline using p-toluenesulfonic acid as a counter ion in the presence of chemical pulp fiber. The amount of aniline was 50% of the amount of fiber.

A total of 1700 g of water was poured into the flask and 300 g of cold dispersed fine pine pulp was added. The pulp contained 10 g of fiber per 100 g of pulp. Next, 30.6 g of p-toluenesulfonic acid was added and dissolved for 15 minutes. Thereafter, 0.04 g of phenyldiamine was added and mixed for 15 minutes, and then 15 g of aniline was added. A water soluble aniline-p-toluenesulfonate was formed and the mixture was slightly brownish. The mixture was cooled to a temperature of 9 ° C. with an ice-water bath during mixing. Thereafter, ammonium persulfate (37 g) was dissolved in 400 ml of water and this solution was added to the mixture during 2 hours. Following the addition of ammonium persulfate, mixing was continued for 2 hours and allowed to stand overnight to obtain an almost black, slightly greenish chemical pulp fiber-polyaniline aqueous suspension. The reaction water (pH = 1.3) was washed away from the product by centrifugation. The product was washed once by filtration, and the pH of the washing water at this time was 1.7. The product was elutriated with water again to a suspension with about 7.0% dry substance. The surface resistivity of the sheet obtained by filtration of chemical pulp fibers containing about 50% polyaniline was 10 ³ ohms. Paper sheets containing different amounts of treated cellulosic pulp were prepared from the product with TKK.

Example 9
Polymerization of aniline using p-toluenesulfonic acid as a counter ion in the presence of chemical pulp fiber. The amount of aniline was 25% of the amount of fiber.

A total of 2400 g of wood fiber pulp (TMP rejection) containing 4.27 g of fiber per liter of water, ie a total of 20 g of fiber, was placed in the flask. Next, 10.2 g of p-toluenesulfonic acid was added and dissolved for 25 minutes. Thereafter, 5 g of aniline was added. A water-soluble aniline-p-toluenesulfonate was formed, and the mixture became light yellow. The mixture was cooled to a temperature of 9 ° C. with an ice-water bath during mixing. Thereafter, 14.7 g of ammonium persulfate was dissolved in 150 ml of water and this solution was added to the mixture during 3.5 hours. Mixing was continued for 2 hours after the addition of ammonium persulfate and the mixture was left overnight. In this phase, blond fibers were present in the brown solution of the product. The product was left in the refrigerator and reacted little by little to the almost black, slightly greenish mixture within a week. The reaction water was washed away from the product by centrifugation. The product was washed once with water (the pH of the wash water was 2.2), and a sheet having a surface resistance of 10 ⁴ ohms was obtained from a portion of the product that had been filtered. In addition to this, the product was washed eight times to see how the polyaniline separated from the fiber surface. The pH of the eighth wash water was 6.34, and the surface resistivity of the sheet obtained by filtration was 10 ⁹ ohms. Micrographs of fibers treated after the first and eighth wash were taken.

Example 10
Polymerization of aniline using p-toluenesulfonic acid as a counter ion in the presence of chemical pulp fiber. The amount of aniline was 25% of the amount of fiber.

A total of 200 g of cold-dispersed wood fine pulp containing 20 g of pine fibers was placed in a flask. Next, 1400 g of water was added to the pulp. A total of 10.21 g of p-toluenesulfonic acid was added into the mixture and dissolved for 15 minutes. Thereafter, 5 g of aniline was added to form a water-soluble aniline-p-toluenesulfonate. The mixture was cooled to a temperature of 10 ° C. with an ice-water bath during mixing. Thereafter, 12.9 g of ammonium persulfate was dissolved in 120 ml of water and this solution was added to the mixture during 1 hour and 15 minutes. Mixing continued for 3.5 hours after the addition of ammonium persulfate and the mixture was allowed to stand overnight. This resulted in a black, slightly greenish reaction mixture. The reaction water was washed away from the product by centrifugation. The product was washed once with water (the pH of the wash water was 1.8), and a sheet having a surface resistance of 10 ⁴ ohms was obtained from a portion of the product that had been filtered. In addition to this, the product was washed 10 times to see how the polyaniline separated from the fiber surface. The pH of the 10th wash water was 5.0 and the surface resistivity of the sheet obtained from the corresponding fiber by filtration was 10 ⁶ ohms. After this, 2% ammonia solution was added and the fiber was left overnight to dedope the fiber. The ammonia solution was filtered off and the fiber was washed once with water. At this time, the sheet made of fibers through filtration did not conduct electricity. A total of 30 ml of 0.2 MH ₂ SO ₄ was added to the remaining pulp (about 10 g) and allowed to work overnight. The surface resistivity of the sheet made of fibers again doped through filtration was 10 ⁵ ohms. After the first and tenth washes, micrographs of the treated fibers, both undoped and redoped, were taken.

Example 11
Polymerization of aniline using dodecylbenzenesulfonic acid as a counter ion in the presence of chemical pulp fiber. The amount of aniline was 20% of the amount of fiber.

A total of 100 g of cold dispersed chemical pulp containing 10 g of fiber was placed in the flask. Next, 7.0 g of dodecylbenzenesulfonic acid was added and dissolved for 1 hour. Thereafter, 2.0 g of aniline was added to form a water-soluble white aniline-dodecylbenzene sulfonate. The mixture was cooled to a temperature of 7 ° C. during mixing with an ice-water bath. Thereafter, 5.15 g of ammonium persulfate was dissolved in 60 ml of water and this solution was added to the mixture during 0.5 hours, after which the product turned very light blue. Mixing was continued for 5 hours after the addition of ammonium persulfate during which time the reaction was complete and the product became very dark green. The reaction mixture was left to stand overnight. The reaction water was washed away from the product by centrifugation. The product was washed once with water, and a sheet having a surface resistance of 10 ^{4... 5} ohms was obtained from a portion of the filtered product. In addition to this, the product was washed five times to see how the polyaniline separated from the fiber surface. The pH of the fifth wash water was 6.2 and the surface resistivity of the filtered sheet was 10 ¹² ohms. After this, the fibers were further dedoped with 2% ammonia solution overnight. Micrographs of the treated fibers were taken after the first and fifth wash and after undoping.

Example 12
Polymerization of aniline using dodecylbenzenesulfonic acid as a counter ion in the presence of woody chemical pulp fibers. The amount of aniline was 20% of the amount of fiber.

A total of 2000 g of wood fiber pulp (TMP rejection) containing 10 g of fiber per liter of water, ie a total of 20 g of fiber, was placed in the flask. Next, 17.5 g of dodecylbenzenesulfonic acid was added and dissolved overnight (15 hours). Thereafter, 5 g of aniline was added to form water-insoluble aniline-dodecylbenzene sulfonate, and the mixture became light yellow. The mixture was cooled to a temperature of 7 ° C. during mixing with an ice-water bath. Thereafter, 14.1 g of ammonium persulfate was dissolved in 150 ml of water and this solution was added to the mixture during 1 hour. Mixing was continued for 5 hours after the addition of ammonium persulfate, after which the reaction mixture became dark green. The mixture was left overnight. The reaction water was washed away from the product by centrifugation. The product was washed three times with water, and a sheet having a surface resistance of 10 ⁴ ohms was obtained from a portion of the filtered product. The surface resistivity after 5 washes was still 10 ⁴ ohms. The product was washed nine times to see how the polyaniline separated from the fiber surface. The pH of the ninth wash water was 6.24, and the surface resistivity of the sheet obtained from the product by filtration was 10 ¹¹ ohms. Micrographs of the treated fibers were taken after the fifth and ninth washes.

Example 13
Mixture of polyaniline paste and chemical pulp fiber

A total of 100 g of cold-dispersed chemical pulp containing 10 g of fiber per liter of water, ie a total of 10 g of fiber, was placed in the flask. Next, 1250 g of water with 8.2% dry matter was added along with 30.5 g of polyaniline polymerized with p-toluenesulfonic acid. The mixture was mixed for 24 hours. Thereafter, pH 3.3 water was removed by filtration, and a sheet having a surface resistance of 10 ^{7... 8} ohms was obtained from a part of the filtered product. The remaining pulp was washed a total of 5 times. The pH of the fifth wash water was 6.4 and the surface resistivity of the sheet obtained from the product by filtration was 10 ¹² ohms. After the first and fifth washes, micrographs can be taken to examine the adhesion of polyaniline on the fiber surface.

Example 14
Polymerization of aniline using p-toluenesulfonic acid as a counter ion in the presence of woody chemical pulp fibers. The amount of aniline was 25% of the amount of fiber. The fiber was added after the addition of aniline.

  A total of 1000 g of water was poured into the flask to dissolve 7.66 g of p-toluenesulfonic acid. Next, 3.75 g of aniline was added to form a reddish solution. After a total of 1500 g woody chemical pulp fiber was added to the solution to contain 15 g fiber, the mixture turned yellow. The mixture was cooled to a temperature of 11 ° C. with an ice-water bath during mixing. Thereafter, 9.1 g of ammonium persulfate was dissolved in 95 ml of water and this solution was added to the mixture during 50 minutes. Mixing was continued for 5 hours after the addition of ammonium persulfate. This was followed by the presence of blond fibers in the brown solution of the product. The product was left overnight to react very slowly to the darkened and slightly greenish mixture. The purpose of the experiment was to investigate whether in the presence of woody cellulosic pulp, the polymerization was promoted by changing the order in which the reagents were added prior to the addition of the oxidizing agent. At the end of the experiment, it can be stated that the reaction did not accelerate.

Example 15
Polymerization of aniline using phenolsulfonic acid as a counter ion in the presence of woody thermomechanical fibers. The amount of aniline was 25% of the amount of fiber.

A total of 2000 g of thermomechanical pulp (TMP / GW) containing 20 g of fibers was placed in a flask. Next, 14.4 g of 65% phenolsulfonic acid aqueous solution and 0.02 g of phenylenediamine were added to the pulp, and the mixture became light yellow. After mixing for 30 minutes, 5 g of aniline was added to form a water-soluble aniline-phenol sulfonate, and the reaction mixture became light yellow. The mixture was cooled to a temperature of 9 ° C. with an ice-water bath during mixing. Thereafter, 12.3 g of ammonium persulfate was dissolved in 120 ml of water and this solution was added to the mixture during 40 minutes. Mixing was continued for 5 hours after the addition of ammonium persulfate. At this stage, the product was black and slightly greenish, meaning that the reaction was complete. The product was left overnight. The next day, pulp press water was filtered off from the product, and at the same time, a cake was prepared through filtration and drying. The surface resistivity of the cake was 10 ³ Ω. Washing of the product was continued by immersing in water again and filtering until the pH of the wash water was 6 or higher. This required a total of 10 washes. The surface resistivity of the cake prepared from the third washing was 10 ⁴ Ω, and the surface resistivity of the cake from the sixth washing was 10 ⁵ .

  Micrographs were taken from the reaction mixture and 6th washed fine pulp (Appendix II). The photo shows that the polymer adheres well to the fiber, gives the entire fiber a typical green polyaniline, and the color changes to blue as the amount of counterion is reduced by washing. .

Example 16
Polymerization of aniline using phenolsulfonic acid as a counter ion in the presence of woody thermomechanical fibers. The amount of aniline was 25% of the amount of fiber.

A total of 1000 g of thermomechanical pulp (TMP rejection) containing 7 g of fiber was placed in a flask. Next, 5.1 g of 65% phenolsulfonic acid aqueous solution and 0.008 g of phenylenediamine were added to the pulp. After the reaction mixture was mixed for 30 minutes, 1.75 g of aniline was added to form a water-soluble aniline-phenol sulfonate, and the reaction mixture became light yellow. The mixture was cooled to a temperature of 9 ° C. with an ice-water bath during mixing. Thereafter, 4.6 g of ammonium persulfate was dissolved in 50 ml of water and this solution was added to the reaction mixture in 25 minutes. Mixing was continued for 4 hours after the addition of ammonium persulfate. At this stage, the product was black and slightly greenish, meaning that the reaction was complete. The product was left overnight. The next day, pulp press water was removed from the product by filtration, and at the same time, a cake was obtained through filtration and drying. The surface resistivity of the cake was 10 ⁴ Ω. Washing of the product was continued by immersing in water again and filtering until the pH of the wash water was 6 or higher. This required a total of 6 washes. The surface resistivity of the cake prepared from the third washing was 10 ^{5... 6} Ω, and similarly the surface resistivity of the cake from the sixth washing was 10 ⁷ Ω. Micrographs were taken from the reaction mixture and 6th washed fine pulp (Appendix II).

  The photomicrograph shows that most of the fibers and fine fibers are colored green of polyaniline. However, among these, there are fibers for which no reaction occurred on the surface. These unreacted fibers are colored yellow anyway, and it can be seen that aniline-counter ion salts adhere. In any case, the amount of oxidant was not sufficient to polymerize at the site in question, and therefore some oxidative consumption such as lignin oxidation consumed the oxidant in the reaction mixture. By washing, the counter ions are also washed away from the fibers, and the polyaniline becomes undoped and turns blue, which can be seen from the fiber photograph of the sixth wash. However, the color of the fiber is clearly lighter than the color of polyaniline attached to the chemical pulp fiber of Example 17.

Example 17
Polymerization of aniline using phenolsulfonic acid as a counter ion in the presence of crushed woody chemical pulp fibers. The amount of aniline was 25% of the amount of fiber.

A total of 100 g of woody chemical pulp fiber containing 10 g of fiber was placed in a flask. Next, 900 g of water and 7.2 g of 65% phenolsulfonic acid aqueous solution were added. After the reaction mixture was mixed for 10 minutes, 2.5 g of aniline was added to form a water-soluble aniline-phenol sulfonate. At this stage, the mixture was still white. The mixture was cooled to a temperature of 9 ° C. with an ice-water bath during mixing. Thereafter, 6.4 g of ammonium persulfate was dissolved in 60 ml of water and this solution was added to the reaction mixture during 35 minutes. Mixing was continued for 4 hours after the addition of ammonium persulfate. At this stage, the product was black and slightly bluish. The product was left overnight. The next day, pulp press water was removed from the product by filtration, and at the same time, a cake was obtained through filtration and drying. The surface resistivity of the cake was 10 ⁴ Ω. Washing of the product was continued by immersing in water again and filtering until the pH of the wash water was 6 or higher. This required a total of 10 washes. The surface resistivity of the cake prepared from the third washing was 10 ⁵ Ω, and similarly the surface resistivity of the cake from the sixth washing was 10 ⁷ Ω. A micrograph of the reaction mixture and the 10th wash was taken (Appendix II).

  The micrograph shows that the fibers and fine fibers are completely colored with the typical polyaniline green color, and that the reduction in surface resistivity is determined by the polyaniline undoping rather than the separation of the polyaniline from the fiber. Show that sometimes keep.

Example 18
Polymerization of aniline using camphorsulfonic acid as a counter ion in the presence of woody thermomechanical fibers. The amount of aniline was 25% of the amount of fiber.

A total of 1000 g of thermomechanical pulp (TMP reject) containing 10 g of fiber was placed in a flask. Next, 4.4 g of camphor sulfonic acid was added and the mixture became light yellow. After the reaction mixture was mixed for 20 minutes, 1.75 g of aniline was added to form a water-soluble aniline-camphor sulfonate, and the mixture became light yellow. The mixture was cooled to a temperature of 10 ° C. with an ice-water bath during mixing. Thereafter, 4.6 g of ammonium persulfate was dissolved in 45 ml of water and this solution was added to the reaction mixture during 20 minutes. Mixing was continued for 4 hours after the addition of ammonium persulfate. At this stage, the product was brown. The product was left overnight. The next day, the product turned dark green and pulp press water was filtered out of the product. At the same time, a cake was obtained through filtration and drying, and the surface resistivity was 10 ⁵ Ω. Washing of the product was continued by immersing in water again and filtering until the pH of the wash water was 6 or higher. This required a total of 6 washes. The surface resistivity of the cake obtained from the third washing was 10 ⁷ Ω, and similarly the surface resistivity of the cake from the sixth washing was 10 ¹² Ω. A micrograph of the reaction mixture and the sixth wash was taken (Appendix II).

  The micrograph shows a number of non-green blonde areas of polyaniline. Even in the reaction mixture, the color of the fiber / polyaniline is greyish green, and after the sixth wash, we observe that the fiber becomes a blonde indigo green, and there are also uncolored areas. Here, as in Example 16, the fact that the non-colored region is yellow is related to the fact that the aniline-counter ion salt adheres to the fiber, and when the oxidizing agent is consumed in a part of the competitive reaction by lignin. The polymerization is not complete.

Example 19
Polymerization of aniline using camphor sulfonic acid as a counter ion in the presence of ground woody chemical pulp fiber. The amount of aniline was 25% of the amount of fiber.

A total of 100 g of crushed softwood chemical pulp fiber containing 10 g of fiber was placed in a flask. Next, 6.3 g of camphor sulfonic acid was added. After the reaction mixture was mixed for 20 minutes, 2.5 g of aniline was added to form a water-soluble aniline-camphor sulfonate. The mixture was cooled to a temperature of 8 ° C. with an ice-water bath during mixing. Thereafter, 6.4 g of ammonium persulfate was dissolved in 62 ml of water and this solution was added to the reaction mixture during 30 minutes. Mixing was continued for 5 hours after the addition of ammonium persulfate. At this stage, the product was black and slightly reddish. The product was left overnight. The next day, pulp press water was removed by filtration from the black-green mixture, and at the same time, a cake was obtained through filtration and drying. The surface resistivity of the cake was 10 ⁴ Ω. Washing of the product was continued by immersing in water again and filtering until the pH of the wash water was 6 or higher. This required a total of 8 washes. The surface resistivity of the cake obtained from the third washing was 10 ⁶ Ω, and similarly the surface resistivity of the cake from the sixth washing was 10 ⁷ Ω. A micrograph of the cellulosic pulp was taken from the reaction mixture and the sixth wash (Appendix II).

  The micrograph shows that the fibers and microfibers are completely colored with the typical polyaniline green color, and that the decrease in surface resistivity is not due to the separation of the polyaniline from the fiber but simply due to the undoping of the polyaniline. Indicates that it is maintained even during cleaning.

Example 20
Polymerization of aniline using methanesulfonic acid as a counter ion in the presence of woody thermomechanical pulp. The amount of aniline was 50% of the amount of fiber.

A total of 500 g of thermomechanical pulp (TMP / GW) containing 5 g of fiber was placed in a flask. Next, 2.6 g of methanesulfonic acid was added. Thereafter, 2.5 g of aniline was added to form a water-soluble aniline-methanesulfonate salt, and the reaction mixture became bright yellow. The mixture was cooled to a temperature of 6 ° C. with an ice-water bath during mixing. Thereafter, 6.14 g of ammonium persulfate was dissolved in 60 ml of water and this solution was added to the reaction mixture during 15 minutes. Mixing was continued for 3 hours after the addition of ammonium persulfate. At this stage, the product was dark orange. The product was left overnight. The next day, pulp press water was filtered out of the black-green mixture. At the same time, the cake was obtained through filtration and drying, and the surface resistivity was 10 ³ Ω. Washing of the product was continued by immersing in water again and filtering until the pH of the wash water was 6 or higher. This required a total of 7 washes. The surface resistivity of the cake obtained from the third washing was 10 ⁵ Ω, and the surface resistivity of the cake from the sixth washing was similarly 10 ⁶ . A micrograph of the cellulosic pulp was taken from the reaction mixture and the sixth wash (Appendix II).

  The micrograph shows that the fine fibers and some fibers are clearly polyaniline green, but some fibers remain yellow, i.e. the aniline salt is in the fibers but before the polymerization of aniline is finished. This indicates that the lignin consumed the oxidant and the reaction remained incomplete. However, the polymer formed stays well in the fibers during washing and simply reduces the surface resistivity of the filter cake by undoping.

Example 21
Polymerization of aniline using methanesulfonic acid as a counter ion in the presence of ground chemical pine pulp fiber. The amount of aniline was 25% of the amount of fiber.

A total of 100 g of thermomechanical pulp (TMP / GW) containing 10 g of fiber was placed in a flask. Next, 900 g of water and 2.6 g of methanesulfonic acid were added to the pulp. Thereafter, 2.5 g of aniline was added to form a water-soluble aniline-methanesulfonate. The mixture was cooled to a temperature of 6 ° C. with an ice-water bath during mixing. Thereafter, 6.14 g of ammonium persulfate was dissolved in 60 ml of water and this solution was added to the reaction mixture during 35 minutes. Mixing was continued for 4 hours after the addition of ammonium persulfate. At this stage, the product was greenish black. The product was left overnight. The next day, pulp press water was filtered from the product. At the same time, a cake was obtained through filtration and drying. The surface resistivity of the cake was 10 ⁴ Ω. Washing of the product was continued by immersing in water again and filtering until the pH of the wash water was 6 or higher. This required a total of 7 washes. The surface resistivity of the cake obtained from the third washing was 10 ⁶ Ω, and similarly the surface resistivity of the cake from the sixth washing was 10 ⁹ Ω.

Conductive paper sheet TKK (Helsinki Institute of Technology) made from fiber, producing paper sheet directly from pulp treated according to Examples 1 and 2 or from a sample obtained by adding untreated softwood cellulosic pulp did. Sheets were prepared using standard SCAN-C 26:76 for sheet preparation. The surface resistivity was measured from both sides of the sheet in KCl according to standard method ASTM D257-93, which is used to measure the resistivity of the paper. In this method, a sample is applied between two electrodes. Surrounding the lower circle center electrode with another circle electrode, while the higher electrode eliminates the error due to the vertical paper conductivity, the surface difference from the potential difference between the lower center electrode and the circle electrode Measure resistivity. The apparatus consists of HP4339A type high resistivity meter and HP1600B type shape measurement. The measurement temperature was 23 ° C., the relative humidity of air was 20% RH, the measurement voltage was 100 VDC, and the charging time was 30.0 seconds.

A paper sheet containing the same amount of polyaniline as the chemical pulp fiber obtained directly from Sample 1 was too brittle to make paper. When 50% pure chemical pulp fiber was added thereto, a sheet having a surface resistivity of 10 ⁵ to 10 ⁶ Ω / square level was obtained. When the fiber-treated polyaniline was mixed with 25% pure fiber, the surface resistivity increased to 10 ⁹ to 10 ¹⁰ Ω / square level.

The surface resistivity of a paper sheet made directly from Sample 2 containing 10% polyaniline attached to chemical pulp fibers was at a level of 10 ⁷ Ω / square. Adding 50% pure chemical pulp fiber to the fiber increased the surface resistivity of the paper sheet to a level of 10 ¹⁰ Ω / square (5% polyaniline inside the fiber).

  In addition, the paper sheets of the samples of Examples 4, 5, 6, 7 and 8 were obtained with TKK. Paper sheets were made directly from the fiber samples of Samples 4, 5 and 6 obtained by mixing half pure fibers with chemical pulp fibers treated with different counterions.

  Paper sheets of Samples 7 and 8 were obtained directly from the treated fibers without adding any pure fibers. In these samples, 25% and 30% polyaniline were present inside the fiber. However, because some of the polyaniline was washed away during sheet manufacture, the amount of bound polyaniline was 17% (Sample 7) and 30% (Sample 8).

  The surface resistivity was measured from the paper sheet at a temperature of 23 ° C., a relative humidity of 20% and a voltage of 100V. The surface resistivity was measured both from the upper end (ts) of the sheet and from the lower end (bs) of the sheet.

  Furthermore, the surface resistivity was measured from a sheet made of pure pine cellulose-based pulp. The results are shown in Table 3, which shows the surface resistivity measured on a paper sheet obtained from chemical pulp fibers treated with polyaniline polymerized using different counterions. A paper sheet made of pure pine cellulosic pulp was used for reference.

  Prior to obtaining the paper sheet, there was 5%, 10%, 25% or 50% polyaniline inside the fiber. The measurement voltage was 100V and 10V for the two measurements. Measurements were taken from both the upper end (ts) of the sheet and the lower end (bs) of the sheet. This result showed the average of a total of 10 measurements except that it was a total of 9 measurements in Example 6 + 50% chemical pulp fiber bottom measurement.

  Table 3 shows that a suitable conductivity can already be achieved with a polyaniline concentration of 5% when obtaining paper sheets containing polyaniline polymerized with dodecylbenzene sulfonic acid. This good electrical conductivity can be exploited especially through this type of fiber (eg through thermomechanical pulp), since proper adhesion to the wood fiber of dodecylbenzene-acid-polyaniline is achieved.

  In the presence of p-toluenesulfonic acid, the polymerized polyaniline adheres very well to the chemical pulp fibers and therefore reduces the risk of washing away. This polyaniline needs to be slightly more than dodecylbenzenesulfonic acid-polyaniline inside the fiber to achieve the appropriate conductivity for the fiber, preferably 10% or more.

  Thus, with the aid of the correct fiber type and polyaniline-counter ion combination, it is possible to produce conductive chemical pulp fibers and further produce a conductive paper sheet from the fibers.

  However, in paper production, the mechanical properties of the finished paper must also be considered: density (SCAN-P7: 75), tensile strength (SCAN-P38: 80), Scottbond Z-axis strength ( TAPPI T569pm-00 method) was measured. Table 4 shows the results of the mechanical properties.

  In the production of the sheet, attention was paid to the weak retention of polyaniline on paper when dodecylbenzenesulfonic acid is used as a counter ion. This was observed as an intensely patchy sheet above all. Instead, this type of problem was not observed when p-toluenesulfonic acid or citric acid was used.

  Table 2 shows that apparently low paper resistivity is achieved by using a 10% dose of p-toluenesulfonic acid as a counterion compared to that using citric acid.

  From all the counterions used it can be seen from the results that the paper adhesion and its associated strength (tensile index and Scott bond) are clearly reduced compared to the reference sample without polyaniline.

1 represents a cross section of a fiber treated with polyaniline doped with toluene sulfonic acid (TSA) shown magnified 200 times. 1 represents a cross section of a fiber treated with polyaniline doped with toluene sulfonic acid (TSA), magnified 500 times. Figure 5 shows corresponding micrographs of polyaniline doped with dodecylbenzene sulfonic acid (DBSA). Figure 5 shows corresponding micrographs of polyaniline doped with dodecylbenzene sulfonic acid (DBSA). The micrograph of the polyaniline doped with hydrochloric acid (comparative example) is shown. The micrograph of the polyaniline doped with hydrochloric acid (comparative example) is shown.

Claims (16)

In producing a fiber composition comprising a first component comprising a plant fiber and a second component comprising a synthetic conductive polymer,
-The plant fiber comprises porous loosely separated fibers,
-The conductive polymer used is a self-conducting conductive polymer doped to generate charge carriers in the polymeric material;
-Synthetic polymers are produced by in-situ polymerization inside and on the fiber,
A method of attaching the conductive polymer to the fiber tightly so that it is not substantially washed away with water, using an organic sulfonic acid that can be absorbed into the fiber in an aqueous medium as a doping agent, and then corresponding to the polymer A method for producing a fiber composition, which comprises polymerizing a monomer in contact with a fiber.   A monomer or polymer doping agent is absorbed into the fiber to form a salt or complex, and then the salt or complex is polymerized at an increased temperature as necessary by adding a polymerization catalyst. Item 2. The method according to Item 1.   3. An aromatic ring or two condensed rings, wherein at least one of the rings is used to dope an aromatic sulfonic acid optionally having a polar or nonpolar substituent. The method described in 1.   4. The method of claim 3, wherein the method is used to dope an aromatic sulfonic acid containing at least one ring with a functional group or an alkyl group having 1 to 20 carbons.   Characterized by increasing the mutual affinity between the porous fiber and the conductive polymer by forming adjacent aliphatic and aromatic hydrocarbon structures on the adhesive surface between them The method according to claim 1 to 4.   6. A method according to claim 5, characterized in that the affinity of the porous fibers and the conducting polymer for mutual adhesion is increased by selecting fibers whose surfaces are at least partly covered with lignin.   The use of doped polyaniline whose counter ion contains an aromatic hydrocarbon group as a conductive polymer increases the affinity between the porous fibers and the conductive polymer for mutual adhesion. Item 6. The method according to Item 5.   By conducting the polymerization of the conductive polymer in an aqueous medium containing the porous fiber so that the polymer formed by the polymerization adheres to the porous fiber, the porous fiber and the conductive weight are prepared for mutual adhesion. 6. The method of claim 5, wherein the affinity of the coalescence is increased.   The method according to any one of claims 1 to 8, wherein a doping agent soluble in a medium for attaching the polymer to fibers made of chemical cellulose pulp is used.   A maximum of 10% by weight, preferably up to 5% by weight, of a conductive polymer attached to the fibers produces a fiber composition that can be washed away with water at a pH of 7 ± 0.3 and a temperature of 25 ° C. Item 10. The method according to any one of Items 1 to 9.   11. A method according to any one of the preceding claims, characterized in that the porous fibers comprise separated and loose fibers.   12. A method according to any one of the preceding claims, characterized in that the pH of the aqueous phase is 2-3 in the presence of an organic counter ion or doping agent that can render the polymer formed conductive.   13. A process according to any one of the preceding claims, characterized in that the fiber mixture is recovered from the aqueous phase and dried.   14. A method according to claim 1, wherein the fiber mixture is used for the production of paper or paperboard without intermediate drying.   A doping agent selected from para-toluene sulfonic acid, phenol sulfonic acid and camphor sulfonic acid is dissolved in the aqueous phase, then fibers are added to form a fiber suspension, and aniline is mixed into the fiber suspension. Forming a salt of aniline and a doping agent, adding a polymerization catalyst, raising the temperature of the suspension to produce polyaniline and attaching it to the fiber, thereby converting the polyaniline into a fiber made of chemical cellulose pulp. 15. A method according to any one of claims 1 to 14, characterized in that it is deposited.   Dodecylbenzenesulfonic acid is dispersed in the aqueous phase as a doping agent, then fibers are added to form a fiber suspension, and aniline is added to the fiber suspension to form a salt of aniline and the doping agent, then The polyaniline is attached to the fiber made of mechanical cellulosic wood pulp by adding a polymerization catalyst to the suspension, raising the temperature of the suspension to produce polyaniline, and attaching the polyaniline to the fiber. The method according to any one of 1 to 15.

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