WO2005108041A1 - Mold cleaning solution, mold cleaning method and mold cleaning apparatus - Google Patents

Abstract

A method for cleaning a mold, wherein a main cleaning solution for use in the electrolytic cleaning as a main cleaning comprises a strongly alkaline component containing one or more selected from sodium hydroxide, potassium hydroxide and sodium carbonate, a chelating agent comprising EDTA 4-sodium salt, an oxidized material removing component comprising an organic or inorganic nitrogen, and sodium gluconate, wherein a purified water is used for the preparation of said main cleaning solution, which results in that the present method is suitable for the cleaning of a nickel mold used for molding a fine molded article, and wherein when a pre-cleaning is carried out before the electrolytic cleaning as a main cleaning, use is made of a pre-cleaning solution comprising a nonionic, cationic or anionic surfactant, sodium metasilicate and/or sodium orthosilicate and a chelating agent.

Description

 Specification

 Mold cleaning liquid, mold cleaning method and mold cleaning device

 Technical field

 The present invention relates to a cleaning liquid, a cleaning method, and a cleaning apparatus for cleaning and removing deposits such as resin residue, rubber residue, glass residue, and gas burns adhering to a molding die such as resin, rubber, and glass. In particular, the improvement of the cleaning liquid suitable for using the cleaning of the microstructured mold in the main cleaning for electrolytic cleaning and the auxiliary cleaning liquid used for the pre-cleaning before the main cleaning and, if necessary, for the post-cleaning. It is intended.

 Background art

 [0002] In recent years, with the improvement of molding materials for resins and rubbers and the advancement of molding technology!部品 Metal and glass parts, which have been formed by conventional pressing, etc., are also shifting to resin parts molded with molds that can be mass-produced.

 For example, resin products and rubber products are said to have poorer strength, heat resistance, oil resistance, and abrasion resistance than metal products and glass products, but the above properties are improved by modifying the resin products and rubber products. Distributor cases, which are attached and installed in the hood of automobiles that require heat resistance and oil resistance, are also replacing metal products with resin products.

 In addition, advances in ultra-precision molding technology have transformed television screens and lenses into glass-based resins. Ultra-precision parts such as light guide plates for flat panel displays, lenses for ultra-small precision cameras for mobile phones, lenses for goggles, gears, connectors, etc. are also mass-produced by resin molding by injection molding using molds. .

 [0003] In the mold used for molding the resin, rubber, glass, or the like, a resin residue, a rubber residue, or a glass residue adheres to an inner surface of the mold according to a molding amount, and a gas generated when the resin is dissolved. Adheres. These deposits accumulate on the mold surface as the number of shots increases when molding shots are repeated, and cannot be easily removed. If these are not reliably removed while pressing, inconveniences such as poor molding will occur. Therefore, the mold must be periodically removed and washed to remove the deposits.

[0004] Especially, light guide plates for flat panel displays, ultra-small precision camera lenses for mobile phones Injection molds for lenses for goggles, reflectors for vehicles, etc. are molds with a pure nickel plating layer or a nickel alloy plating layer containing phosphorus or boron on the surface of iron or brass, or It is a mold in which a nickel plate or a nickel alloy plate is adhered to the surface, or a mold formed of only nickel or only a nickel alloy (hereinafter referred to as a nickel mold). In this type of nickel mold, nickel has a V-characteristic that makes it easy for substances to be adsorbed, so that metal fine particles, minute resin fragments, and foreign matter that precipitate in the electrolyte are likely to adhere. If these ultrafine particles remain in a state attached to the nickel plating surface, there is a problem that the quality of the light guide plate, lens, and reflector formed by the nickel mold cannot be maintained. In particular, if the light guide plate does not remove the resin that has entered the fine pattern that requires precision and the dirt such as the edge of a part where gas easily accumulates, the light guide plate can respond to increasing precision. I can't.

 Conventionally, mold cleaning has been performed by immersing in trichlene or hydrocarbon petroleum or the like, and then rubbing it with a brush swab. It has a negative effect on the human body.

 [0006] Due to the above-mentioned problem, the present applicant uses Japanese Patent Application Laid-Open No. 7-214570 (Patent Document 1) as a cleaning device using a cleaning liquid containing a strong alkali component such as sodium hydroxide as a cleaning device for a molding die. The electrolytic cleaning apparatus shown in FIG. 8 is provided in the literature 1).

 This cleaning apparatus has an advantage that the cleaning of the mold can be efficiently performed in a short time by using both electrolytic cleaning and ultrasonic cleaning. In FIG. 8, reference numeral 1 denotes a cleaning tank, 2 denotes a mold holding basket which is removably inserted into the cleaning tank, and 3 denotes a plus-side electrode suspended in the washing tank, and the above-described mold holding basket on the minus pole side. An electric current flows between the mold 5 held in 2 and the ultrasonic vibrator 4 attached to the bottom of the cleaning tank 1 to generate ultrasonic vibrations in the electrolytic cleaning liquid in the cleaning tank, thereby performing electrolytic cleaning. The mold 5 is cleaned by using both the ultrasonic cleaning and the ultrasonic cleaning.

[0007] Further, in Japanese Patent Application Laid-Open No. 2001-241000 (Patent Document 2), a degreasing tank 6 for performing pre-cleaning of a main cleaning tank 1 'for performing electrolytic cleaning and a main cleaning tank for performing main cleaning shown in FIG. A mold cleaning apparatus provided with a rinse tank 7 for performing post-cleaning later is provided. The mold cleaning apparatus is provided with a main cleaning apparatus for performing electrolytic cleaning similar to the mold cleaning apparatus of Patent Document 1 and a degreaser for performing pre-cleaning. It is configured to have a tank and a rinsing tank for post-washing.

 [0008] Patent Document 1 provides an alkaline solution containing sodium hydroxide or Z and potassium hydroxide, an alkali salt of EDTA, and sodium dalconate as a cleaning solution used in the main cleaning for performing electrolytic cleaning. are doing. In addition, a temperature control device is attached to heat the temperature of the cleaning liquid to 30 to 70 ° C.

 Also in Patent Literature 2, as the electrolytic solution used in the main cleaning for performing electrolytic cleaning, the same cleaning liquid as in Patent Literature 1 is used, which has sodium hydroxide, EDTA, a surfactant, and hydraulic power.

 In the pre-cleaning degreasing tank, an organic degreasing solvent such as ether or alcohol is used as the pre-cleaning liquid, and the mold is mounted in a basket in the degreasing tank, immersed, and pre-cleaning is performed in an open configuration that is not sealed with a lid or the like. We are! / Puru.

Patent Document 1: JP-A-7-214570

 Patent Document 2: JP 2001-241000

 Disclosure of the invention

 Problems to be solved by the invention

[0010] Since the mold cleaning apparatus of Patent Document 1 uses both electrolytic cleaning and ultrasonic cleaning, it is possible to very efficiently remove deposits on the mold in a short time, and has an advantage of excellent cleaning effect. You. Recently, as described above, recently, ultra-precision molded parts such as light guide plates of flat panel displays have rapidly increased. In the molds of these ultra-small precision parts, the irregularities are also fine, and ultra-fine resin particles and the like that easily adhere to minute concave portions, particularly, resin residue and the like adhering to the corners of the concave portions are likely to remain. Recently, resin with improved properties such as heat resistance, oil resistance, and abrasion resistance has increased in strength tl. In these resin molding dies, it is difficult to remove resin residue. ing.

 [0011] In order to solve the above problem, it is necessary to increase the detergency.

 However, in particular, in a resin mold having improved heat resistance, oil resistance, and wear resistance, the resin residue does not easily melt and swell even when the temperature of the cleaning liquid is increased and time is taken.

However, it is difficult to remove these resin residues.

In addition, when a cleaning liquid containing an increased amount of a strongly alkaline substance such as sodium hydroxide is used, Corrosion trouble occurs.

 In addition, it is considered that the cleaning performance is physically increased by stirring the cleaning liquid in combination with the ultrasonic vibration. The lower the frequency of the ultrasonic wave, for example, from 50 KHz to 20 KHz, the stronger the power to remove dirt, but the greater the destructive force due to ultrasonic vibration, and the longer the cleaning time, the more damage to the mold. . In particular, a nickel mold for forming a light guide plate or the like of the flat panel display has a problem that the nickel layer on the surface is easily damaged by ultrasonic waves.

[0012] Also, as a method for increasing the cleaning ability, Patent Literature 2 describes, and the pre-filing method of Patent Literature 2 is also an improvement of the pre-cleaning and post-cleaning methods performed by those skilled in the art. However, it is also possible to adopt a method to increase the cleaning capacity in total of pre-cleaning, main cleaning and post-cleaning.

 In addition, in the degreasing tank for performing pre-cleaning described in Patent Document 2, even if a pre-cleaning solution consisting of an organic degreasing solvent such as ether or alcohol is used, the applicant's follow-up test And the cleaning power was not recognized.

 In addition, washing with water in a rinsing tank after the main washing of electrolytic washing has been conventionally performed, but there is a problem that the mold is likely to generate 鲭 if it is washed with water! /.

[0013] The present invention has been made in view of the above-described problems, and the pre-cleaning liquid used in pre-cleaning and the main cleaning liquid used in main cleaning in which electrolytic cleaning is performed are modified to enhance the cleaning performance, and the like, thereby improving the ultra-fine mold. Therefore, it is an object of the present invention to increase the cleaning ability so that even if a resin residue having heat resistance, oil resistance, and abrasion resistance adheres, it can be removed without fail.

 Means for solving the problem

[0014] In order to solve the above-mentioned problems, the present invention firstly provides a pre-cleaning solution used for pre-cleaning before main cleaning for performing electrolytic cleaning, and a post-cleaning solution used for post-cleaning performed as necessary. The present invention provides a mold cleaning solution characterized by containing a surfactant, a cationic or arnone-based surfactant, sodium metasilicate or Z and sodium orthosilicate, and a chelating agent.

The present inventor prepared a cleaning solution containing various components as an auxiliary cleaning solution consisting of the pre-cleaning solution and the post-cleaning solution, and repeated experiments using the same. As a result, the pre-cleaning solution was also used as a surfactant and a chelating agent. Mixing agent and oxide removing component, and especially Was obtained by knowing that the addition of Z and sodium orthosilicate can increase the pre-cleaning ability.

 Examples of the chelating agent include EDTA4 sodium salt, carboxylic acid-containing sodium salt and the like. Examples of the oxide removing component include organic nitrogen and inorganic nitrogen including nitrate and ammonium salt.

[0016] In particular, when the pre-cleaning liquid is used in a state of being heated to about 40 ° C to 100 ° C, the cleaning ability can be enhanced.

 Furthermore, at the time of the pre-cleaning, the upper opening of the pre-cleaning tank is closed with a lid and heated. In other words, when heated in the state of a pressure cooker, the boiling point rises and the temperature can be raised to a higher temperature. It is possible to improve the safety of workers because it is sealed with a lid.

 Even if the pre-cleaning solution is not closed and boiled, the pre-cleaning solution comprising the above components can be used to increase the cleaning ability even if the pre-cleaning solution is used. It is preferred to heat to about ° C.

If the pre-cleaning is performed using the auxiliary cleaning liquid before the main cleaning, the following effects can be particularly exhibited.

 Heat conduction grease (for example, heat conduction grease KS-609 manufactured by Shin-Etsu Chemical Co., Ltd.) and heat conduction paste (Infracoat 1KB sold by Japan Mold Industry Co., Ltd.) to improve the heat conduction of the heater attached to the mold When used, metal powder that causes trouble during cleaning, especially during electrolytic cleaning, is contained in the thermal conductive agent. Specifically, the heat conductive grease contains 75% zinc oxide, and the heat conductive paste contains 30% copper, 25% graphite, and 10% aluminum.

 When the heat conductive grease and the metal powder contained in the heat conductive paste flow out into the cleaning solution and are attached to the mold surface by a substitution reaction or electrolytic deposition, they can be easily removed with sodium hydroxide. Cause trouble.

In addition, the heat conductive agent contains copper and zinc oxide which are easily precipitated on the surface of an iron mold by a substitution reaction, and further contains aluminum which corrodes iron when electrolyzed. In addition, because it contains porous graphite that adsorbs organic substances, it can be used in cleaning solutions. The contained surfactant is also adsorbed and loses the effect of preventing re-adhesion of stains to the mold and prevention of mist generated during electrolysis.

 In order to prevent the above troubles, before the electrolytic cleaning of sodium hydroxide as a main component, a surfactant such as a non-one or a sodium metasilicate or sodium orthosilicate which mainly oxidizes the thermally conductive grease or paste is mainly used. As a component, pre-cleaning is performed in advance using an auxiliary cleaning liquid composed of a chelating agent such as sodium EDTA, and after removing the thermal conductive agent, an electrolytic cleaning liquid composed of a strong alkali such as sodium hydroxide is used. This has the effect of shortening the main cleaning time for removing resin with excellent heat, oil and abrasion resistance.

[0018] Second, the present invention provides a main cleaning liquid used in electrolytic cleaning,

 A main cleaning solution for performing electrolytic cleaning, which comprises a strong alkali component containing at least one selected from sodium hydroxide, potassium hydroxide, and sodium carbonate; a chelating agent comprising sodium salt of EDTA4; The present invention provides a mold cleaning liquid characterized by containing a component for removing an oxidizing substance which also has nitrogen or inorganic nitrogen power and sodium dalconate.

A nitrate or an ammonium salt is used as the inorganic nitrogen,

 As the organic nitrogen, ethylene diamine, diethylene triamine, triethylene tetramine, pentaethylene bexamine using ethylene diamines also selected power,

 As the chelating agent, it is preferable to use sodium hydroxyethyliminodiacetic acid, trisodium ditrilotrisetate (ΝΤΑ · 3Na), and tetrasodium disodium dicarboxymethyl-glutamate (GLDA′4Na)! /.

[0020] As described above, the present washing solution contains a strong alkali component containing at least one selected from sodium hydroxide, potassium hydroxide, and sodium carbonate, and a chelating agent having sodium dalconate and sodium salt of EDTA4. By adding an organic or inorganic nitrogen-added component to the mixture, the performance of removing the oxide is further improved as compared with the case where the chelating agent is used alone.

 [0021] Further, nonionic, cationic, and anionic surfactants When one or more selected surfactants are included, the cleaning power can be further increased, and the resin residue removed from the mold can be further improved. It has the function of suppressing the re-adhesion of the metal to the mold and the generation of mist.

[0022] Specifically, the main cleaning solution contains a strong alkali component of 30 to: LOOgZ liter, 4 Sodium salt: 30 to: LOOgZ liter, sodium dalconate to 10 to 60 gZ liter, and 30 to 150 gZ liter of an oxidizing substance removing component composed of organic nitrogen or inorganic nitrogen are preferable.

 In addition, when one or more surfactants selected from the nonionic, cationic, and anionic surfactants are also blended, it is preferable that the surfactant be blended in an amount of 1 to 3 cc / liter. The compounding amount was found by the present inventor by repeating experiments.

Further, it is preferable that the main cleaning liquid is provided with a heating means and is heated to 30 ° C. to 60 ° C. in terms of the ability to enhance the cleaning ability.

 At the time of the main cleaning using electrolytic cleaning using the main cleaning liquid, and preferably also using ultrasonic cleaning, it is necessary to cover the upper opening of the cleaning tank with a hood to perform the cleaning, thereby controlling the temperature of the cleaning liquid and controlling the mist. A point that prevents the scattering and diffusion of off-flavors.

[0024] The main cleaning solution and the pre-cleaning solution are included! / ヽ is Z and water is mixed in the cleaning solution used in the post-cleaning performed after the main cleaning, and tap water is used as the water to remove impurities through a purification means. It is preferable to mix water!

 As the purifying means, a purifying means employing distillation, ion exchange or Z and filtration methods is used.

 This is because tap water contains foreign substances such as silica and calcium, and when the mold to be cleaned is a high-density mold such as the above-mentioned nickel mold, foreign substances such as silica and calcium contained in the cleaning liquid are removed from the mold. , Which may cause mold precision to deteriorate and cause molding failure. Therefore, it is preferable that tap water has been subjected to removal of foreign substances such as silica and calcium by the purification means.

 [0025] As a second invention, a mold cleaning method is provided.

 The mold is characterized in that the main cleaning liquid is used during the main cleaning in the electrolytic cleaning, and the pre-cleaning liquid is used when performing the pre-cleaning, and the post-cleaning is performed when performing the post-cleaning liquid as needed. Provide cleaning method!

Depending on the mold to be cleaned, it is preferable to perform only main cleaning, pre-cleaning → main cleaning → post-cleaning.In some cases, it is preferable to eliminate pre-cleaning and perform only main cleaning and post-cleaning. You. In the main cleaning, it is preferable to use ultrasonic cleaning in combination with electrolytic cleaning, so that the cleaning power can be enhanced.

 In the ultrasonic cleaning, it is preferable that an ultrasonic generator is attached to the bottom of the main cleaning tank, and the ultrasonic oscillator is switched to two or more kinds of frequencies to generate ultrasonic waves. As described above, if the ultrasonic vibration is switched to a different frequency, for example, 34 KHz and 44 KHz, instead of setting the ultrasonic vibration to a constant frequency, and the alternating ultrasonic vibration is generated, an appropriate stirring action is generated in the electrolytic cleaning liquid. And the cleaning power can be increased. Instead of ultrasonic waves, a single wave of 30 to 100 KHz may be used.

 If the mold to be cleaned is for dense molded products such as light guide plates for flat panel displays, ultra-small precision lenses, reflectors for automobiles, etc.If the mold is a nickel mold, the ultrasonic frequency is 30KHz to 100KHz. , Preferably in the range of 40 to 70 KHz. Within this range, it is possible to clean the nickel coating layer without damaging the balance of the metal bond on the surface of the nickel plating and without damaging the nickel coating layer.

After the pre-cleaning using the pre-cleaning solution, after the main cleaning using the main cleaning solution, or after the post-cleaning using Z and the post-cleaning solution, the following methods (1) to (3) are used. The cleaning solution has been removed.

 (1) Only wash with clean water.

 (2) After washing with clean water, rinse with alcohol, ethanol, acetone, or a mixture of these with water.

 (3) Rinse with alcohol, ethanol, acetone, or a mixture of these and water directly, without washing with water.

 Thus, by removing the cleaning liquid, it is possible to prevent the occurrence of water stain on the mold surface due to the influence of the composition and impurities contained in the water of the cleaning liquid.

 [0028] In the mold cleaning, the cleaning intensity is changed according to the amount of the resin residue adhering to the mold, the adhesive force, the adhesion position, the type of the resin, and the like, and the entire cleaning process is performed. For example, the following (1) to (5) forces are preferably selected.

 (1) Main cleaning → cleaning liquid removal

(2) Main cleaning → cleaning liquid removal → anti-scratch treatment (3) Pre-cleaning → removal of cleaning liquid → main cleaning → removal of cleaning liquid → prevention treatment

 (4) Main cleaning → cleaning liquid removal → post-cleaning → cleaning liquid removal → anti-treatment

 (5) Pre-cleaning → cleaning solution removal → main cleaning → cleaning solution removal → post-cleaning → cleaning solution removal → prevention treatment.

 For nickel molds, (1) is preferred.

[0029] By performing pre-cleaning using a pre-cleaning liquid before main cleaning or performing post-cleaning using a post-cleaning liquid after Z and main cleaning before performing the electrolytic cleaning, the heat-resistant material strongly adhered to the mold surface can be obtained.

Oil and abrasion resistant resin residue can be reliably removed.

Regardless of which of the above steps is adopted, the main cleaning can be performed by using ultrasonic cleaning in combination with electrolytic cleaning to improve the cleaning ability, and adjusting the cleaning time according to the degree of contamination of the mold, and performing main cleaning. The components of the washing solution and the washing solution for pre-washing and post-washing are adjusted within the above ranges.

[0031] The water washing may be performed as shower washing by discharging water from a nozzle or the like, or a mold may be immersed in a washing tank storing water. In the rinsing, the volatile component or a mixture of the volatile component and water may be applied to a mold such as a nozzle or the like, or the mold may be immersed in a washing tank containing the liquid.

 [0032] After the post-cleaning, the post-cleaning liquid is preferably removed, and then a heat-proofing treatment for applying a heat-proofing agent to the mold surface is preferably performed. The water-proofing treatment may be performed by dipping the mold in a liquid tank containing a water-proofing agent, or by another coating method.

 As the water-proofing agent, an aqueous water-proofing agent such as a lower amine is used, and morpholine is particularly preferably used.

 In addition, in a nickel mold for a light guide plate, a plastic lens, and a reflector, a residue is likely to remain on the nickel-coated surface, and therefore, it is preferable to perform a water-proof treatment.

[0033] As described above, when the water-based waterproofing agent is used, it evaporates and volatilizes at about 100 ° C and spontaneously evaporates in 2 to 3 days without heating, thereby preventing a molded article molded with a mold. The agent can be prevented from adhering.

On the other hand, since the water-based protection agent has a relatively short protection period, if there is no problem even if the protection agent adheres to the surface of the molded article, the water-based protection agent can be used instead of the water-based protection agent, The oil-based protective agent may be applied again on the surface of the mold to which the protective agent has been applied. [0034] The present invention, as a third invention, comprises a pre-cleaning tank for performing pre-cleaning or a post-cleaning tank for performing Z and post-cleaning, and a main cleaning tank for performing main cleaning by electrolytic cleaning means. A die cleaning apparatus is provided, wherein the pre-cleaning liquid is supplied to the cleaning tank, and the main cleaning liquid is supplied to the main cleaning tank.

[0035] Needless to say, a shower or cleaning tank for performing washing with water for rinsing off the cleaning liquid, rinsing with volatile components, and further a protection means may be provided.

In the case of performing pre-cleaning, a mold is immersed in a pre-cleaning tank supplied with a pre-cleaning liquid for a required time.

 Examples of the cleaning tank for the main cleaning which also performs electrolytic cleaning, preferably ultrasonic cleaning, include the cleaning apparatus described in Patent Document 1 or the like, which was previously filed by the present applicant, Japanese Patent Application No. 2004-101.

The cleaning device described in No. 361 is suitably used.

[0037] The transfer of the mold from the pre-cleaning tank to the main cleaning tank and from the main cleaning tank to the post-cleaning may be performed by holding the mold holding tool by a guide rail installed above, or by an operator. The mold may be held by a holder and transported.

[0038] In particular, the pre-cleaning tank is provided with a lid for closing the upper opening of the pre-cleaning tank at the time of cleaning, and a means for heating the auxiliary cleaning tank with the lid closed is provided. It is preferable that the cleaning tank is configured as a pressure cooker.

Mold power to be cleaned For precision molded products such as light guide plates for flat panel displays, lenses, and reflectors for automobiles, when a nickel mold is used, the pre-cleaning is eliminated as described above. In the main cleaning tank, it is most preferable to use a cleaning method using the main cleaning liquid and a combination of electrolytic cleaning and ultrasonic cleaning. When the washing is performed by the washing method, the most severely required washing performance can be obtained, including prevention of attachment of the ultrafine particles and removal of the attached ultrafine particles.

When cleaning the nickel mold, the positive electrode used for electrolytic cleaning of the main cleaning tank is made of platinum (platinum), palladium, rhodium, iridium, ruthenium, osmium, gold, and silver. It is preferable that the precious metal is made of a precious metal or an alloy of one or more of these precious metals, or is plated with the metal. Further, the metal on the positive electrode side is formed by attaching or affixing the metal to titanium. As a matter of fact, things are better! / ,.

 Further, it is preferable that the voltage applied to the electrode for electrolytic cleaning in the main cleaning tank is in the range of 2 to 5 V!

 The invention's effect

 As described above, according to the present invention, as for the cleaning liquid, as a pre-cleaning liquid before the main cleaning for electrolytic cleaning (preferably in combination with ultrasonic cleaning), a non-ion, a cation, or a cation is not used as a cleaning liquid containing an organic solvent. -Pre-cleaning is performed using a cleaning solution containing a chelating agent with an on-surfactant, sodium metasilicate or Z and sodium orthosilicate, and the resin that has heat resistance, oil resistance, and abrasion resistance is made of gold. In the case where it adheres as a resin residue to the mold surface, especially at the corners of the minute recesses, even if these conventional electrolytic methods are used, they cannot be removed by Z and ultrasonic mold cleaning. Can be reliably removed.

 Furthermore, in the case of a severely dirty mold, after cleaning with electrolytic cleaning and ultrasonic cleaning using the post-cleaning liquid of the same component as the pre-cleaning liquid, post-cleaning almost completely removes grease dust that is difficult to remove. Can be removed.

 [0042] Further, the main cleaning solution for performing electrolytic cleaning includes a strong alkali component containing at least one selected from sodium hydroxide, potassium hydroxide, and sodium carbonate, a chelating agent composed of sodium salt of EDTA4, Using water containing an organic nitrogen or inorganic nitrogen-containing oxidizing substance removing component and sodium dalconate, the water is purified by a purification means to remove foreign substances such as silica and calcium contained in tap water. are doing. Therefore, in the case of a nickel mold for precision component molding, foreign matter adheres even when observed with an electron microscope at a magnification of LOOOOO times. can do.

 Therefore, when a nickel mold for molding a light guide plate of a flat panel display, a lens, a reflector of an automobile, and the like is washed, the nickel mold can be effectively used due to its high washing ability.

 Brief Description of Drawings

 FIG. 1 is an overall schematic diagram of an embodiment of the present invention.

 FIG. 2 is a perspective view showing a holding basket of the mold.

FIG. 3 is a plan view showing the present cleaning device. FIG. 4 is a perspective view of FIG. 3.

 FIG. 5 is a cross-sectional view of another embodiment.

 [FIG. 6] (A) to (D) are drawings showing a cleaning step.

 [FIG. 7] (A) to (D) are drawings showing another cleaning step.

 FIG. 8 is a drawing showing a conventional example.

 FIG. 9 is a drawing showing another conventional example.

 Explanation of symbols

[0044] 10 Pre-cleaning tank

 12 washing tanks

 13 Rinse tank

 14 Waterproof treatment tank

 21 Mold

 22 Holding basket

 Q1 Pre-cleaning liquid

 Q2 main cleaning solution

 Q3 Waterproofing agent

 BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.

 FIG. 1 shows an overall schematic view of a mold cleaning apparatus according to a first embodiment, in which 10 is a pre-cleaning tank, 11 is a water washing tank, 12 is a main cleaning tank, 13 is a rinsing tank, and 14 is a waterproof coating tank.

 The mold to be cleaned by the cleaning apparatus of the first embodiment is a general steel mold instead of a nickel mold coated with nickel.

 Of the cleaning tanks, the pre-cleaning tank 10 and the main cleaning tank 12 are provided with lids 16 and 17 for closing the upper openings of the cleaning tanks 10 and 12, and the cleaning is performed by closing the lids 16 and 17 during cleaning. It is.

The lid may be a single continuous lid instead of being provided separately for each tank. In addition, washing may be performed without sealing with a lid, but pre-washing tank 10 is preferably sealed with lid 16 for pre-washing. [0046] The cleaning tanks 10 to 14 are provided side by side, and a guide rail 2 is provided above the cleaning tanks 10 to 14.

A metal holding cage 22 holding a synthetic resin mold 21 to be mounted and washed with the arm 23 is detachably attached to the arm 23, and is sequentially conveyed! /

 In addition, the above-mentioned transport mechanism is not always necessary, and the worker inserts a holder for holding the mold into the cleaning tank sequentially.

[0047] The pre-cleaning tank 10 has a box shape with an upper surface opening and stores a pre-cleaning liquid Q1 therein. As shown in FIG. The basket 22 made of steel is immersed for a required time (preferably 15 to 30 minutes).

 The pre-cleaning liquid Q1 is obtained by mixing a non-on, cationic or a-on type surfactant, sodium metasilicate or Z and sodium orthosilicate, and a chelating agent in water. The water is pure water purified by tap water.

 In the pre-cleaning solution Q1 of the present embodiment, the surfactant is 2 cc Z liter and the sodium metasilicate is 50 g.

A chelating agent consisting of Z liter to 100 gZ liter and a sodium salt of EDTA4 is blended at 100 g / liter to 50 gZ liter, and the rest is water.

[0048] The pre-cleaning tank 10 is provided with a heating means 18 having a heater or the like at a lower portion thereof.

At 16, the upper opening of the pre-cleaning tank 10 is closed to form a pressure cooker. In this state, the pre-cleaning solution Q1 in the pre-cleaning tank 10 is boiled by the heating means 18, and the mold 21 is pre-cleaned by the pre-cleaning solution Q1.

 [0049] After the pre-cleaning in the pre-cleaning tank 10, a water washing tank 11 for washing the mold with water is provided, and the pre-cleaning liquid adhering to the mold surface is washed and dropped. In this washing tank 11, water is flowed from a chassis 15 arranged at an upper portion to easily wash the mold. In addition, it may be immersed in a tank storing clean water and washed.

 The mold washed with water in the washing tank 11 is transferred to the main washing tank 12 shown in FIGS. 3 and 4. The main cleaning tank 12 is configured to perform cleaning using both the electrolytic cleaning method and the ultrasonic cleaning method.

The main cleaning tank 12 has a box shape with an upper opening, and a surface heater (not shown) which also has a silicon rubber heater is attached along substantially the entire outer peripheral surface thereof, and the main cleaning liquid Q2 in the main cleaning tank 12 is supplied at 30 to 60 °. Heat to C. [0051] The main cleaning solution Q2 (that is, the electrolytic cleaning solution) comprises a strong alkali component containing at least one selected from sodium hydroxide, potassium hydroxide, and sodium carbonate, and a clean solution composed of sodium salt of EDTA4. Agent, an oxidizing substance removing component that also has an organic nitrogen or inorganic nitrogen force, sodium dalconate, and a nonionic, cationic, or anionic surfactant. One or more surfactants selected from the group consisting of: Tap water is mixed with pure water purified by purification means.

 At that time, the compounding amount of the strong alkali component is 30 to: LOOgZ liter, EDTA4 sodium salt is 30 to: LOOgZ liter, sodium dalconate is 10 to 60 gZ liter, the oxide removing component is 30 to 150 gZ liter, One or more surfactants selected from on-type, cationic-type, and a-on-type surfactants are combined in l to 3 ccZ liters and the rest as pure water.

 [0052] The main cleaning solution Q2 is contained in the main cleaning tank 12 to a required level according to the amount of the mold 21, and is not shown, but is provided on the bottom wall of the main cleaning tank 12 when required. The water is discharged from the outlet into a circulation pipe, guided into a purification tank, filtered, sucked up by a circulation pump, and charged into the upper opening of the main cleaning tank 11 for circulation.

 In the main cleaning tank 12, an insulating base 21 is attached to the upper surface of an outer peripheral flange portion surrounding the upper surface opening, and the support arm 22a of the mold holding cage 22 is hung on the insulating base 21 to perform the main cleaning. The holding basket 22 is detachably suspended inside the tank 12, and the basket 22 is prevented from contacting the bottom surface and the inner peripheral surface in the main cleaning tank 12.

 The mold holding basket 22 has a support arm 22a protruding from a bottom portion 22b which also has a punching metal force, and an upper bending portion 22c provided on the support arm 22a is mounted on the insulating base 21 and attached. At this time, a part of the support arm 22a is positioned and mounted on a stainless steel power supply plate 23 attached on two opposite sides of the insulating base 21. The support arm 22a of the mold holding cage 22 is coated with an insulating coating so as not to contact with the inner surface of the cleaning tank 12 so as not to be energized, and is provided with an insulating coating only at a contact portion with the power supply plate 23.

 The power supply plate 23 is fixed to the insulating base 21 with a long current-carrying bolt (not shown) penetrating the inside of the insulating base 21, and the lower end of the current-carrying bolt is connected to a minor of the electrolytic converter via a bus bar. Connected to the ground electrode.

Similarly, attach a similar power supply plate 27 on the other two opposite sides of the insulating base 21. A conductive support rod 28 is mounted between the power supply plates 27, and the power supply plate 27 is connected to the positive electrode of the exchange gas for electrolysis via a bus bar.

 [0055] The conductive support rod 28 is provided with mounting holes 28a at regular intervals in the length direction, and the lower end of the upper vertical axis 29a is bifurcated in the mounting hole 28a in the horizontal direction. An electrode material 29 having a circular electrode plate 29c swingably attached to the lower end of the 29b with the tip end bent downward and the vertical length adjustable is attached, and the electrode material 29 is suspended in parallel with a gap between the conductive support rods 28. The soldered electrode plate 29c is brought into contact with the mold and the holding basket 22 in such a manner as to be removed.

 The converter for electrolysis is connected to an AC power supply, converts current from AC to DC, and supplies current to the electrode for electrolytic cleaning and the mold holding basket 22. In this way, by connecting the electrode material 29 to the positive side of the electrolytic converter and the mold holding basket 22 to the negative side, electricity is supplied through the main cleaning liquid Q2, which is an electrolytic cleaning liquid, to perform electrolytic cleaning. To do this.

 Further, a vibrator (not shown) for generating ultrasonic waves for performing ultrasonic cleaning is attached to the bottom surface of the main cleaning tank 12, and ultrasonic vibration is applied to the main cleaning liquid Q2 in the main cleaning tank 12. Is generated.

 In the main cleaning tank 12, after the main cleaning liquid is heated to a required temperature, a current is supplied to the mold holding basket 22 and the electrode material 29 from the power supply plates 23 and 27, and the mold holding basket 22 is passed through the main cleaning liquid Q 2. In addition to performing the electrolytic cleaning of the mold 5 held at the same time, the ultrasonic vibration is generated and the ultrasonic cleaning is also used.

 In the main cleaning tank, which uses both the electrolytic method and the ultrasonic cleaning method, the ultrasonic cleaning method applies vibrations to the adhered matter such as resin residue from outside the mold 21 to destroy the adhered matter. Then, the deposits are lifted from the mold 21 by hydrogen gas generated from the surface of the metal mold by the electrolytic cleaning method, and the deposits are separated from the mold 21 and removed. At this time, since the main cleaning liquid Q2 is heated as required, a strong cleaning power can be exhibited.

The mold 21 that has been subjected to the main cleaning in the main cleaning tank 12 is transported to the rinsing tank 13. The rinsing tank 13 is provided with a shower 19 to apply a mixed solution of ethanol and water to the holding basket 22 while holding the mold, thereby performing rinsing. In this embodiment, alcohol and water are used. Rinse and wash with a mixture of.

 After being rinsed in the rinsing tank 13, the rinsing tank 13 is transferred to the water-proofing treatment tank 14. The water-proofing agent Q3 composed of lower amine carbonate is stored in the water-proofing treatment tank 14, and the mold 21 held by the holding basket 22 is immersed in the water-proofing treatment tank 15 to form the mold 21. A water-based waterproofing agent is applied to the surface.

 In the present embodiment, morpholine is used as an aqueous water-proofing agent that also forms lower amine moths. If the resin molded product to be molded by the mold is a product to which a protective agent may be attached to the surface, it is further immersed in a second protective tank in which an oil-based protective agent is stored.

[0061] According to the above-described embodiment, the mold to be cleaned is firstly subjected to the pre-cleaning liquid Q in the pre-cleaning tank 10.

After washing in step 1, the pre-cleaning solution Q2 is washed out in the washing tank 11 with clean water, and then the main washing is performed in the main washing tank 12 by using both the electrolytic cleaning and the ultrasonic cleaning in the main cleaning liquid Q2.

 At this time, the resin residue adhering to the mold 21 has heat resistance, oil resistance and wear resistance due to the pre-cleaning with the pre-cleaning liquid Q1 and the electrolytic cleaning and ultrasonic cleaning with the main cleaning liquid Q2. However, even if they adhere to the corners of the fine recesses, they can be reliably removed and the cleaning ability can be increased.

 [0062] The mold cleaning apparatus of the present invention is not limited to the above embodiment, and is disclosed in Japanese Patent Application Laid-Open No. 2004-101361, which is a prior application filed by the present applicant, as a main cleaning tank using both electrolytic cleaning and ultrasonic cleaning. Alternatively, the cleaning apparatus shown in FIG. 5 may be used.

 [0063] The main cleaning tank may be configured as shown in Fig. 5. In the main cleaning tank 35, a side plate 31 made of resin is erected in a rectangular frame shape on a bottom plate 30 that also has a conductive metal plate strength, and a mold 21 is directly placed on the bottom plate 30, and the bottom plate 30 is turned into a mold. The power is on. The electrode 29 is suspended on the side wall 31 in the same manner as in the above embodiment. The main cleaning liquid Q2 is supplied into a cleaning tank 35 composed of a bottom plate 30 and a side plate 31.

The first embodiment includes the steps shown in FIG. 6 (A). That is, pre-cleaning with pre-cleaning liquid → water cleaning with clean water → main cleaning by electrolytic cleaning and ultrasonic cleaning → rinsing cleaning with a mixed solution of ethanol and water → post-cleaning with post-cleaning liquid Omitted. The cleaning step is not limited to the above (A), and as shown in (B), after the pre-cleaning, After the washing, rinsing may be further performed with ethanol alone to completely remove the pre-cleaning solution, and then the main washing may be performed.

 [0065] In the first embodiment, the post-cleaning with the post-cleaning liquid is not performed. However, if the resin residue of the mold is not easily removed, as shown in FIG. After washing with water, it is filled with the post-cleaning solution and then dipped in the cleaning tank for post-cleaning. In this post-washing as well, it is preferable to heat the post-washing liquid to the extent of boiling as in the pre-washing. After the cleaning with the post-cleaning liquid, washing with clean water is performed, followed by rinsing with ethanol alone. In FIG. 6 (D), after the post-washing with the post-washing solution, the washing with water is omitted, and the rinsing with the mixed solution of ethanol and water is performed.

 Further, as shown in FIGS. 7A and 7B, the pre-cleaning with the pre-cleaning liquid may be omitted.

 In 07 (A), main cleaning → rinse cleaning with a mixture of ethanol and water → protective coating.

 In Fig. 7 (B), the post-washing with the post-washing liquid is performed, and the main cleaning → water washing with the cleaning liquid → post-washing with the post-cleaning liquid → water washing with the cleaning liquid → rinsing cleaning with ethanol alone → water-proof coating ing.

 Further, as shown in FIG. 7 (C), main washing → water washing → rinse washing, and as shown in FIG. 7 (D), main washing → water washing → drying, thereby eliminating the final step of protective coating. Is also good. FIG. 7D is suitable for cleaning the nickel mold for molding the light guide plate, lens, and the like! / Puru.

 The second embodiment of the present invention is for cleaning a nickel mold for forming a light guide plate of a flat display. The washing is performed by the main washing → water washing →→ drying step of FIG. 7 (D) described above, and nickel gold is placed on the mold holding basket 22 shown in FIG. 2 in the washing tank 12 shown in FIGS. 3 and 4 shown in the first embodiment. The mold is mounted and washed. Therefore, the illustration of the cleaning device of the second embodiment is omitted, and will be described with reference to FIGS.

 The main cleaning liquid Q 2 is supplied in the cleaning tank 12. The water to be added to the main washing liquid is distilled water of tap water.

The electrode plate 29c to be attached to the lower end of the electrode material 29 suspended for electrolytic cleaning in the main cleaning tank 12 has a titanium surface coated with platinum, and is provided between the electrode plate 29c and the mold holding force 22. The voltage applied to is about 5V. The vibration frequency of the ultrasonic vibrator disposed on the bottom of the main cleaning tank 12 is set in the range of 40 to 70 KHz.

In the second embodiment, the mold is easily damaged by the nickel mold! Therefore, the mold is not transported for water washing and drying after the main washing, but is left in a state of being immersed in the washing tank 12. After the main cleaning, the main cleaning liquid is drained, and after the draining, water for rinsing is supplied to the cleaning tank 12.The supply of the water for rinsing is repeated about twice, and then alcohol or acetone is applied to the required pressure. It is sprayed on the mold and dried.

In the second embodiment, when the nickel mold is cleaned in the main cleaning tank 12 by using both the electrolytic cleaning and the ultrasonic cleaning, the surfactant contained in the cleaning liquid Q2 is coated on the nickel-coated surface with fine metal particles or fine particles. Establish a barrier to prevent the attachment of fine fat particles, and prevent the attachment of foreign matter such as metal fine particles.

 Also, since the electrode material 29 is made of platinum, the amount of precipitation is reduced, and the frequency of the ultrasonic vibration is set to 40 to 70 KHz so as not to disturb the metal bonding balance of the nickel plating layer! Damage to the plating surface can be prevented.

 Therefore, it is most suitable for cleaning nickel molds for fine resin molded products such as light guide plates for flat panel displays, ultra-small precision camera lenses for mobile phones, reflectors (light reflectors) for vehicles, etc. It becomes.

 Industrial applicability

[0072] The cleaning liquid, cleaning method and cleaning apparatus according to the present invention are not limited to the synthetic resin mold described in the embodiment, but are also suitably used for cleaning molds for rubber molding, glass molding and the like. You can do it.

Also, when used for cleaning a nickel mold for forming a precision molded product such as a light guide plate of a flat display, the present invention can exhibit high-precision cleaning ability. Therefore, advanced precision products such as CD-ROM, DVD-ROM, spur multi-drive RAM, HDDVD pickup lens, Blu-ray disc pickup lens, liquid display hologram; prism, digital camera liquid hologram 'prism, mobile phone CCD Suitable for cleaning molds for molding precision parts for molding camera lenses, various light guide plates, etc. Can be used.

Claims

The scope of the claims  [1] Pre-cleaning prior to main cleaning with electrolytic cleaning ヽ is a cleaning solution used for Z and post-cleaning performed after main cleaning, and is a non-, cation- or a-on-based surfactant, sodium metasilicate. A mold cleaning liquid characterized by containing Z, sodium orthosilicate, and a chelating agent.  [2] The mold cleaning liquid according to claim 1, wherein the pre-cleaning liquid or Z and the post-cleaning liquid are heated to about 40 ° C to 100 ° C. [3] A main cleaning solution for performing electrolytic cleaning, comprising a strong alkali component containing at least one selected from sodium hydroxide, potassium hydroxide, and sodium carbonate, and a chelating agent comprising EDTA4 sodium salt A mold washing liquid comprising: a component for removing an oxidizing substance that also has an organic nitrogen or inorganic nitrogen power; and sodium dalconate. [4] As the inorganic nitrogen, there is a nitrate!  As the organic nitrogen, ethylenediamine, diethylenetriamine, triethylenetetramine Using ethylenediamines, pentaethylene bexamine power is also selected,  Examples of the chelating agent include hydroxyethyliminodiacetic acid sodium salt, trisodium ditrilotrisetate (ナ ト リ ウ ム · 3Na), tetrasodimu dicarboxymethyl-glutamic acid The mold cleaning solution according to claim 3, wherein tetrasodium (GLDA'4Na) is used. [5] The mold cleaning liquid according to claim 3 or 4, comprising one or more surfactants whose nonionic, cationic or anionic surfactant power is also selected. [6] The method according to any one of claims 1 to 5, wherein tap water is purified through a purification means to remove impurities, and water is added to the cleaning liquid used in the main cleaning, pre-cleaning or Z and post-cleaning. Mold cleaning liquid as described in item 1. [7] The mold washing liquid according to claim 6, wherein a purifying means employing distillation, ion exchange, or Z and filtration methods is used as the purifying means. [8] The strong alkali component is 30-: LOOgZ liter, and the EDTA4 sodium is 30-: LOOg 8. The composition according to claim 3, wherein Z liter, 10 to 60 g Z liter of sodium dalconate, and 30 to 150 g Z liter of an oxidized substance removing component composed of organic nitrogen or inorganic nitrogen. V, the mold cleaning liquid according to item 1. [9] The mold cleaning liquid according to claim 8, wherein 1 to 3 ccZl of one or more surfactants whose nonionic, cationic or anionic surfactant power is also selected are blended. [10] The mold cleaning liquid according to any one of claims 3 to 9, wherein the cleaning liquid used for the main cleaning is heated to about 30 ° C to 60 ° C. [11] A mold cleaning method, wherein the main cleaning of electrolytic cleaning is performed using the cleaning liquid according to any one of claims 3 to 10. [12] A method of cleaning a mold, wherein the cleaning liquid according to claim 1 or 2 is used for pre-cleaning before the main cleaning of electrolytic cleaning or post-cleaning after the main cleaning of electrolytic cleaning. Law.  13. The mold cleaning method according to claim 11, wherein ultrasonic cleaning is used in combination with the main cleaning.  14. The mold cleaning method according to claim 13, wherein the frequency of the ultrasonic cleaning is in a range of 30 KHz to 100 KHz.  [15] After the pre-cleaning using the pre-cleaning liquid, after the main cleaning using the main cleaning liquid, or after the post-cleaning using the Z and the post-cleaning liquid, the following methods (1) to (3) are used. 15. The mold cleaning method according to claim 11, wherein the cleaning liquid is removed.  (1) Only wash with clean water.  (2) After rinsing with clean water, rinse with alcohol, ethanol, acetone, or a mixture of these and water.  (3) Rinse and wash directly with alcohol, ethanol, acetone, or a mixture of these and water without washing.  [16] The mold cleaning method according to any one of claims 11 to 15, wherein the cleaning step is selected from the following (1) to (5).  (1) Main cleaning → cleaning liquid removal  (2) Main cleaning → cleaning liquid removal → anti-scratch treatment  (3) Pre-cleaning → removal of cleaning liquid → main cleaning → removal of cleaning liquid → prevention treatment  (4) Main cleaning → cleaning liquid removal → post-cleaning → cleaning liquid removal → anti-treatment (5) Pre-cleaning → cleaning liquid removal → main cleaning → cleaning liquid removal → post-cleaning → cleaning liquid removal → prevention processing.  17. The mold cleaning according to claim 16, wherein the water-proofing treatment is performed by applying a water-proofing agent to the surface of the mold, and using an aqueous water-proofing agent having a lower amine power as the heat-proofing agent. Method.  [18] The mold cleaning method according to claim 17, wherein morpholine is used as the lower amine.  19. The mold cleaning method according to claim 12, wherein the cleaning tank is covered with a lid at the time of the pre-cleaning to heat the mold to about 40 ° C. to 100 ° C.  [20] At least a cleaning tank for performing pre-cleaning and / or post-cleaning, and a main cleaning tank for performing main cleaning with electrolytic cleaning means, wherein the pre-cleaning or Z and post-cleaning cleaning tanks are claimed in claim 1 or claim Item 11. A method comprising: supplying the pre-cleaning liquid according to Item 2; and supplying the main cleaning liquid according to any one of Claims 3 to 10 to the main cleaning tank. Mold cleaning device.  [21] The pre-cleaning tank is provided with a lid for closing an upper opening of the pre-cleaning tank during cleaning, and is provided with a unit for heating the pre-cleaning tank in a state of being sealed with the lid. Item 20: Mold cleaning device according to Item 20.  [22] The mold to be cleaned in the main cleaning tank provided with at least the electrolytic cleaning means and the ultrasonic cleaning means is a nickel plating die, a nickel alloy plating die, a nickel plate surface bonding die, or a nickel alloy plate surface bonding. This is a nickel mold consisting of a mold or a mold made of nickel.  11. A mold cleaning apparatus, characterized in that the main cleaning tank is supplied with the main cleaning liquid according to any one of claims 3 to 10, and the main cleaning tank is supplied with the main cleaning liquid. 23. The mold according to claim 22, wherein the nickel mold is a mold for injection molding of a light guide plate of a flat panel display, a mold for injection molding of a lens, and a mold for injection molding of a reflector for a vehicle. Mold cleaning equipment.  [24] The positive electrode used for electrolytic cleaning of the main cleaning tank is a noble metal of platinum (platinum), palladium, rhodium, iridium, ruthenium, osmium, gold, silver, or an alloy of one of these noble metals. 24. The mold cleaning apparatus according to claim 22, wherein the mold cleaning apparatus is made of one or more kinds of metals, or a metal plated with the metals. [25] The electrode on the positive electrode side may be formed by plating the metal on titanium. The mold cleaning device according to any one of the above.  26. The mold cleaning apparatus according to claim 22, wherein a voltage applied to the electrode for electrolytic cleaning in the main cleaning tank is in a range of 2 to 5V.