JPS6150115B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an adhesive for vulcanized rubber, and more particularly to an adhesive for vulcanized rubber that has excellent water resistance, low temperature resistance, and high temperature resistance. BACKGROUND ART Conventionally, as a method for adhering vulcanized products of natural rubber or synthetic rubber, a method is known in which a compound consisting of liquid rubber and an isocyanate compound is used as an adhesive. However, since this adhesive has poor properties such as water resistance, low temperature resistance, and high temperature resistance, it has not always been satisfactory in adhesive strength. The present invention provides an adhesive for vulcanized rubber that eliminates the drawbacks of the conventional adhesive by blending specific components in a specific procedure, although it is an adhesive based on liquid rubber like the above adhesive. The purpose is to The adhesive of the present invention contains (a) 100 parts by weight of liquid rubber, and (b) 5 to 50% of an inorganic filler selected from the group consisting of carbon black, white carbon, metal oxides, metal carbonates, and metal sulfates. 300 parts by weight and
(c) an ultraviolet absorber or antioxidant selected from the group consisting of aromatic secondary amines, alkylphenols, thioureas and benzimidazoles from 0.1 to 10;
This adhesive for vulcanized rubber is prepared by adding 5 to 100 parts by weight of (d) diisocyanate compound to a mixture obtained by adding and kneading parts by weight. Examples of liquid rubbers that are the main ingredient of the adhesive of the present invention include functional groups capable of forming crosslinks such as carboxyl groups, hydroxyl groups, mercapto groups, halogen atoms, amino groups, aziridino groups, and epoxy groups at both ends of the molecule. polybutadiene, polyisoprene, polychloroprene, butadiene/isoprene copolymer, acrylonitrile/
Preferred are so-called telechelic liquid rubbers such as butadiene copolymers and styrene/butadiene copolymers. Inorganic fillers are used as reinforcing agents and are from the group consisting of carbon black, white carbon, metal oxides (such as aluminum hydroxide), metal carbonates (such as magnesium carbonate), and metal sulfates (such as magnesium sulfate). Although a selected reinforcing agent may be used, it is desirable to use the same reinforcing agent that is blended into the vulcanized rubber to be bonded. In addition, specific examples of ultraviolet absorbers or antioxidants include ultraviolet absorbers and antioxidants, and aromatic secondary amines (n・n'-di-2-naphthyl-
P-phenylenediamine, etc.), alkylphenol (2,2'-methylenebis(4-methyl-6-
tert-butylphenol), thiourea (1,3-bis(dimethylaminopropyl)-2-
thiourea, etc.), and benzimidazole (2-mercaptobenzimidazole, etc.). The diisocyanate compound is used as a curing agent, and examples include tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and polymethylene polyphenyl diisocyanate. The appropriate amounts of the above components are 5 to 300 parts by weight of the inorganic filler, 0.1 to 10 parts by weight of the ultraviolet absorber or antioxidant, and 5 to 100 parts by weight of the diisocyanate compound per 100 parts by weight of the liquid rubber. The above-mentioned components are blended by kneading the three components except the diisocyanate compound to obtain a blend, then adding the diisocyanate compound to the blend, and after kneading, the adhesive is used. In the present invention, the curing reaction can normally be carried out without using a catalyst. However, when shortening the curing time is desired, the usual urethane curing catalysts such as stannous chloride, dimethyltin dichloride, trimethyltin hydroxide, di-n-butyltin dilaurate, dibutyltin diacetate, dibutyltin sulfide, Metal compounds such as ferric chloride, iron acetylacetonate, cobalt naphthenate, bismuth nitrate, lead oleate, and antimony trichloride, and amines such as triethylamine and tetramethylbutanediamine can be used. In this case, these catalysts are preferably used in an amount of 0.01 to 1 part by weight per 100 parts by weight of liquid rubber. In order to further improve the strength of the liquid rubber, if necessary, general polyols, short chain polyols, polyamines, polycarboxylic acids, etc., such as glycerin, 2-ethylhexanediol,
3,3'-dichlorobenzidine, 4,4'-methylene-bis-2-chloroaniline, N,N-bis(2
-Hydroxypropanol) aniline, lauroguanamine, etc., from 0 to 20% per 100 parts by weight of liquid rubber.
It can also be added in parts by weight. Furthermore, oil extenders such as aromatic process oils, naphthenic process oils, and phthalate esters are added to liquid rubber.
It is also possible to improve workability by adding 0 to 100 parts by weight per 100 parts by weight. The vulcanized rubber to be bonded using the adhesive of the present invention is generally vulcanized with a vulcanizing agent, a crosslinking agent, and a vulcanization accelerator, and also contains compounds such as carbon black and white carbon. It may be something that does. Examples of vulcanized rubber to which the adhesive of the present invention can be applied include natural rubber, butadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber,
Chloroprene rubber, isoprene rubber, ethylene-
Adhesion between the same or different types of vulcanized rubber, such as propylene rubber, is of course possible.
Strong adhesion can also be achieved between vulcanized rubber and cotton cloth. When adhering, after polishing the surface of the vulcanized rubber to be adhered using sandpaper as necessary, apply adhesive to the adherend, and superimpose and adhere, being careful not to introduce air bubbles. . In the present invention, the curing reaction is usually carried out at room temperature without heating. However, if it is desired to increase the initial adhesive strength, sufficient results can be achieved by allowing the curing reaction to proceed under heating. After bonding, room temperature to 150℃, preferably 50 to 80℃
Adhesion is completed by curing for a predetermined period of time at a temperature of .degree. Since the adhesive of the present invention contains an ultraviolet absorber or an antioxidant, it has excellent properties such as water resistance, low temperature resistance, and high temperature resistance, and has the same adhesive strength even when used under various conditions. is large, and can maintain strong adhesive strength even under conditions where vulcanized rubber deteriorates. Furthermore, unlike the case of ordinary rubber-based adhesives, bonding using the adhesive of the present invention does not require a solvent, so the bonding work can be carried out safely without worrying about the generation of pollution or the risk of fire. I can do it. Moreover, since heating and pressure are not necessarily required for adhesion, the adhesion work is easy and can be carried out in a short time. Therefore, the adhesive of the present invention can be advantageously used in manufacturing industrial parts such as conveyor belts, various balls, etc., and can also be widely used as an adhesive for shoe making, an adhesive for manufacturing sheet waterproofing agents, and the like. Furthermore, it can also be used for gluing, repairing, and connecting rubber products such as tires, tubes, and lining materials. Next, examples of the present invention will be shown. Example 1 1000 g of a liquid butadiene-styrene copolymer having hydroxyl groups at both ends (manufactured by Alco Chemical Co., Ltd., hydroxyl group content 0.65 meq/g, viscosity 150 poise/30°C) was added as an adhesive main ingredient, and carbon black was added as an inorganic filler. ISAF-LS (manufactured by Tokai Carbon Co., Ltd., Seast 600) 500g, 2,2'-methylenebis(4-methyl-6-tert-phenol) as an ultraviolet absorber or antioxidant (Nokrac NS-6, Ouchi) 20g (manufactured by Shinko Kagaku Co., Ltd.) and 2(2'-hydroxy-3'.
10 g of 5'-di-tert-butylphenyl)-5-chlorobenzotriazole (Tinuvin 327, manufactured by Nippon Ciba Geigy) was added and sufficiently kneaded with a paint mill roll to obtain a mixture. This formulation 1560
68 g of tolylene diisocyanate and 1 g of dibutyltin laurate as a curing reaction catalyst were added and mixed to prepare an adhesive. Next, various vulcanized rubbers ((
Heat and pressure mold under specified conditions according to ASTMD15-77 (for ethylene-propylene rubber, compound, vulcanize and mold according to "Introduction to New Rubber Technology" (published by Japan Rubber Association)), 150 x 300 x 2 mm. 1200 g/m ² of the above adhesive was applied to the surface of each of the sample) and cotton fabric (JIS L3102 regular cotton canvas No. 9), overlapped to avoid trapping air bubbles, and heated at 50°C.
After curing for 24 hours, tensile speed according to JIS K6854
Adhesion strength was measured using an IS-500 autograph (manufactured by Shimadzu Corporation) at 50 mm/min for a 25 mm width sample. The results are shown in the table. In addition, the table shows the adhesive strength after being immersed in hot water at 100°C for one week, the adhesive strength after being treated with gear at 100°C for one week, and the adhesive strength when heated at 80°C for the samples bonded in this example at -20°C. The adhesive strength under cooling is also shown. Examples 2 to 5 Types of carbon black in Example 1
ISAF (Example 2), HAF- instead of ISAF-LS
The same procedure as in Example 1 was conducted except that HS (SEAST 3H, Example 3), HAF-LS (SEAST 300, Example 4), and GPF (SEAST V, Example 5) were used. The results are shown in the table. Example 6 Modified 4,4'-diphenylmethane diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., Millionate) was used in place of tolylene diisocyanate in Example 1.
Example 1 was repeated except that 96 g of MTL, free NCO content 29%, viscosity 40 centipoise/25° C.) was used. The results are shown in the table. Example 7 Carbon black ISAF-LS in Example 6
GPF (same as used in Example 5) instead of
The same procedure as in Example 6 was carried out except that .
The results are shown in the table. Example 8 1000g of liquid butadiene-styrene copolymer having hydroxyl groups at both ends as the main adhesive agent, 1000g of calcium carbonate (Shiraishi Calcium Co., Ltd., 1:1 mixture of Hakuenhana CC/Hakuenhana PC), and 2 as an ultraviolet absorber or antioxidant・2'-methylenebis(4-methyl-6-tert-phenol) (Nokrac NS-
6) Add 20g and 10g of 2(2'-hydroxy-3'-5'-di-tert-butylphenyl)-5-chlorobenzotriazole (Tinuvin 327) and knead well with a paint mill roll to form a mixture. Obtained.
Add tolylene diisocyanate to 2030g of this formulation.
68 g and 1 g of dibutyltin laurate as a curing reaction catalyst were thoroughly mixed to prepare an adhesive. Using this adhesive, the same procedure as in Example 1 was carried out. The results are shown in the table. Example 9 The same procedure as in Example 8 was carried out except that 96 g of modified 4,4'-diphenylmethane diisocyanate was used in place of tolylene diisocyanate. The results are shown in the table.

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【table】

Claims (1)

[Claims] 1 (a) per 100 parts by weight of liquid rubber, (b) 5 to 300 parts by weight of an inorganic filler selected from the group consisting of carbon black, white carbon, metal oxides, metal carbonates and metal sulfates; ) A UV absorber or antioxidant selected from the group consisting of aromatic secondary amines, alkylphenols, thioureas and benzimidazoles is added in a proportion of 0.1 to 10 parts by weight to a blend obtained by kneading (d) An adhesive for vulcanized rubber containing 5 to 100 parts by weight of a diisocyanate compound.