JPS58189276A - Two-pack adhesive - Google Patents

Abstract

PURPOSE:To provide the titled adhesive excellent in storage stability, workability and adhesion property, prepared by packing organic solvent solutions of a water-crosslinkable polyolefin and a silanol condensation catalyst in separate containers. CONSTITUTION:Solution A prepared by dissolving water-crosslinkable polyolefin (e.g., organic silane-graftd polyethylene) in an organic solvent, pref. one having a boiling point of (t-20 deg.C)-(t+70 deg.C)(where t is the melting point of the polyolefin), and solution B prepared by dissolving a silanol condensation catalyst (e.g. dibutyltin dilaurate) in an organic solvent are packed in separate containers. Preferred blend ratio of the two solutions in application is 100pts.vol. A to at least 1pt.vol. B.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to two-component adhesives based on water-crosslinkable polyolefins.

Known water-crosslinkable polyolefin-based adhesives contain a 7-lanoyl condensation catalyst that promotes the crosslinking reaction of the water-crosslinked polyolefin with water, but due to the coexistence of this 7-lanoyl condensation catalyst, Furthermore, since crosslinking of known adhesives rapidly progresses with the presence of a small amount of moisture, they must be stored in a sufficiently dry state when not in use.

Water-crosslinkable polyolefins are generally solid at room temperature and have a high melt viscosity when heated and melted, so they cannot be used in the form of coating on adhesive surfaces.

In view of the above, the present invention proposes a water-crosslinked adhesive that can be applied and used and has good storage stability. It is a two-liquid type, characterized in that it consists of a B component consisting of a mixture of a catalyst and an organic solvent, and the A component and B component are stored and stored in separate containers.

When using the adhesive of the present invention, components A and B are taken out in predetermined amounts as described below and mixed. However, since the coexistence of an organic solvent lowers the melt viscosity of the water-crosslinkable polyolefin, it is used by coating. becomes possible.

In addition, organic solvents, especially inexpensive industrial organic solvents, generally contain a small amount of water, so it is difficult to store water-crosslinkable polyolefins by dissolving them in an organic solvent together with the ranol gold condensation catalyst. Crosslinking progresses due to the water contained in the organic solvent, but in the present invention, the water-crosslinkable polyolefin and the 7-lanol condensation catalyst are kept separated when not in use, so the above-mentioned problem is solved. . It also has the advantage that it can also be used as an organic solvent in inexpensive industrial products with a high water content.

Component A in the present invention is liquid, semi-solid, or solid at room temperature depending on the concentration of the water-crosslinkable polyolefin in the component, but even if it is solid at room temperature, it can be coated by heating. It becomes liquid.

Generally, the amount of the ranol condensation catalyst mixed into the water-crosslinkable polyolefin is a small amount of about 1 part or less per 100 parts (parts by weight, hereinafter the same) of the above polyolefin, and such a small amount can be quickly and uniformly added to the A component. Mixing is surprisingly difficult, but in the present invention, the 7-ranoyl condensation catalyst is diluted with an organic solvent and used in an increased amount, that is, included in component B, so uniform mixing is possible. It is easy and there is no problem mentioned above.

The water-crosslinkable polyolefin in component A may include polyolefins such as polyether, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polybutene-1, or other α-olefins. Examples include homopolymers and copolymers obtained by grafting 7-runs using an organic 7-run compound such as vinyltrimethoquinonerane and an organic peroxide such as dicumyl peroxide.

Other examples of 7-ran grafted polyolefins, organic/ran compounds, and organic peroxides of this type can be found in, for example, JP-A-50-126789 and JP-B-Sho 50-359.
40 etc. As a water-crosslinkable polyolefin, a copolymer of an organosolane compound such as the above-mentioned vinyltritquinone 7ran and an a-olefin can also be used. Examples of water-crosslinkable copolymers include, for example. The material shown in Japanese Patent Application Laid-Open No. 56-88446 can also be used.

The 7-lanol condensation catalyst in component B is, for example, cyphthyl-tin-dilaurate, and other examples include those shown in JP-A-56-88446.

As the organic solvent used in component A, it is preferable to use one that has a large dissolving power for water-crosslinkable polyolefin.
In addition, excessively volatile materials will make it difficult to mix component A and component B in a liquid or semi-solid state, as well as to apply the resulting mixture. is preferred. The specific organic solvent is a mixture of the above,
Whether or not it is excessively volatile during the coating process depends on the viscosity when mixing components A and B and the difficulty of the coating process, but in general, the melting point of the water-crosslinkable polyolefin is set to t.
Where 'c' is (t-20)'C or more, those having a boiling point of t'c or more are preferred.

The adhesive of the present invention has an adhesive function even when organic solvent remains, but in order to achieve even stronger adhesion, it is necessary to It is preferable that the amount of residual organic solvent in the adhesive be as small as possible during the subsequent time period. From this point of view, it is not preferable to use an excessively non-volatile organic solvent in component A;
Particularly preferred are those having a boiling point of 0 ) °C or less, especially (t +50 )'C or less.

Examples of organic solvents include benzene, toluene, quinreno, durene, menthylene, tecarin, tetralin, nitrogen-containing hydrocarbons such as olefin oliamide and dimethylacetamide, which are liquid at room temperature, tetrahydrofuran, formic acid, malonic acid ester, and methyl isobutyl. Oxygenated hydrocarbons such as ketones, 7-chlorohexanone, diphenyl ether, di-ethylhexanol, various esters, or other organic compounds such as dimetersulfoquinde, hexamethylphosphaamide, 0-dichlorobenze/, and triclev. It is a kind. Among the above, particularly preferred are:
They are hydrocarbons because they have particularly good solubility.

The amount of organic solvent used in component A varies depending on its solubility in water-crosslinkable polyolefin, but (t-
20) It is sufficient to use an amount that can form a liquid or semi-solid with a viscosity or consistency that allows easy application in a temperature range of approximately 'C to (t+70)'C. The optimum amount to be used can be determined by trial and error depending on the purpose of use, but generally it is 10 to 2 parts per 100 parts by volume of water-crosslinkable polyolefin.
000 parts by volume, in particular from 50 to 1000 parts by volume.

In the B component, the reason for using a solvent is mainly to dilute and increase the amount of the /ranol condensation catalyst, as described above. Therefore, in general, the range of organic solvent selection is wider than in the case of component A, but since component B is used in combination with component A, it is important to select the organic solvent according to the explanation regarding the organic solvent for component A. preferable. It is particularly preferred in practice to use the same organic solvent as for component A.

When mixing component B and component A, the larger the amount of component B used, the easier the mixing, so the amount of component B used is 10% of component A.
0 part by volume, 1 part by volume or more": It is particularly preferable to use 10 parts by volume or more. On the other hand, use of an excessive amount of component I3 will increase the amount of organic solvent in the mixture of both components A and B. Therefore, the amount of component B used is 200 parts per 100 parts by volume of component A.
It is preferable to make it less than the capacity part.

As mentioned above, since the amount of the /ranol condensation catalyst used is about 0.001 to 1 part by weight per 100 parts by weight of water-crosslinkable polyolefin, taking into account that the mixing ratio of component A and component B is as described above. , the amount of the nranol condensation catalyst mixed in component B may be determined as appropriate.

Cans, tubes, or other containers are used to hold the A and B components, but the A component is often solid at room temperature, and in that case, it must be heated and melted before use. Therefore, containers that allow such heating to be easily performed, such as cans with lids that can be opened and closed, metal tubes, etc., are preferred.

The adhesive of the present invention can be used to bond wood, metal, plastic, rubber, ceramic, etc., but is particularly suitable for bonding and joining polyolefin molded products, such as polyethylene pipes and water-crosslinkable polyethylene pipes.

The present invention will be explained in more detail with reference to Examples below.

Table 1 shows the compositions of various examples. Component A in each example was prepared by heating a mixture of a water-crosslinkable polyolefin and an organic solvent to a high temperature above the melting point of the polyolefin to form a homogeneous solution, then pouring it into a can with a lid that can be opened and closed and leaving it to cool. Manufactured.

On the other hand, since the B component of each Example is a liquid at room temperature, it was stored in a glass bottle.

Examples 1 to 8 Compositions A and B of each example were retained, and Table 1
After each storage period, both were heated to a temperature higher than the melting point of the water-crosslinkable polyethylene and the water-crosslinkable ethylene-vinyl acetate copolymer, and the two were uniformly mixed at the mixing ratio shown in Table 1. Next, the mixture was applied to the outer end of a water-crosslinkable polyethylene pipe having an outer diameter of 26 mm and a wall thickness of 3 which had been heated to 240° C., and to the inner surface of a socket joint that had been heated to the same temperature to connect the pipes.

All of Examples 1 to 8 had good workability and good adhesion even after one year of storage.

(Note 1) Density (p) 0.929/am, melt index (MI) 2. (1100 parts by weight, 20 parts by weight of vinyltrimethquine 7 run, dikumi-bridged polyethylene.

(Note 2) ρ0.95. 7 runs of MI5 high density polyethylene as in Note 1 (Note 3) ρ0.92. M11
．． 5 low-density polyethylene in the same manner as Note 1 (Note 4)
ρ0.935, MI 0.5 medium density polyethylene was used in the same manner as Note 1 (Note 5) ρ0.92. MI0
．． 8 ethylene-7 run copolymer.・(Note 6) ρ0
．． 93. MI3. Ethylene with 15% vinyl acetate content
Ethylene acetate-vinyl acetate copolymer.

/10 minutes, water-crosslinkable polyethylene grafted with resin run and water-dyed with 0.1 part by weight of linear low-density polyethylene rubber oxide 7 having a melting point (M, P) of 124°C.

Crafted water-crosslinkable polyethylene.

Run-grafted water-crosslinkable polyethylene.

Water-crosslinking property obtained by grafting 7 runs of vinyl copolymer as in Note 1 Applicant: Dainichi Nippon Electric Cable Co., Ltd. Representative Director: Yukio Aoyama

Claims (1)

[Claims] 1 A component consisting of a mixture of a water-crosslinkable polyolefin and an organic solvent, and a B component consisting of a mixture of a /ranol condensation catalyst and an organic solvent, and the mA acid component and the B component are placed in a separate container. A two-component adhesive that can be stored and stored.