JPS6237658B2 - - 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 a vulcanized rubber adhesive 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 is prepared by mixing 10 to 300 parts by weight of a diisocyanate compound to 100 parts by weight of liquid rubber to obtain Compound I, which contains glycerin, 2-ethylhexanediol, 3,3'-dichlorobenzidine,
4,4′-methylene-bis-2-chloroaniline,
N,N-bis-(2-hydroxypropanol)
A liquid rubber chain extender selected from the group consisting of aniline and lauroguanamine is added to the liquid rubber 100.
1 to 500 parts by weight per part by weight, and 0.1 to 10 parts by weight of an ultraviolet absorber or an antioxidant selected from the group consisting of aromatic secondary amines, alkylphenols, thioureas, and benzimidazole per 100 parts by weight of the liquid rubber. This is a vulcanized rubber adhesive obtained by mixing two parts to obtain a blend, and then mixing the above blend and the other blends. 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. Examples of the diisocyanate compound include tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and polymethylene polyphenyl diisocyanate. Next, in the present invention, glycerin, 2-ethylhexanediol,
3,3'-dichlorobenzidine, 4,4'-methylene-bis-2-chloroaniline, N,N-bis-
(2-Hydroxypropanol) selected from the group consisting of aniline and lauroganamine is used. In addition, examples of ultraviolet absorbers or antioxidants include 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.), benzimidazole (2-mercaptobenzimidazole, etc.), and the like can be used. Appropriate amounts of the above components are 10 to 300 parts by weight of the diisocyanate compound, 1 to 500 parts by weight of the liquid rubber chain extender, and 0.1 to 10 parts by weight of the ultraviolet absorber or antioxidant per 100 parts by weight of the liquid rubber. It is. The above components are blended by first mixing a liquid rubber and a diisocyanate compound to obtain a blend I, then mixing a chain extender and an anti-aging agent for the liquid rubber to obtain a blend, and then blending with the above blend I. The procedure is to mix the ingredients, and the mixture thus obtained is used as an adhesive. In the present invention, the curing reaction can normally be carried out without using a catalyst. However, if shortening of the curing time is desired, the usual urethane curing catalysts stannous chloride, dimethyltin dichloride, trimethyltin hydroxide, di-n-butyltin dilaurate, dibutyltin diacetate, dibutyltin sulfide can be used. , metal compounds such as ferric chloride, iron acetylacetonate, cobalt naphthenate, bismuth nitrate, lead oleate, and antimony trichloride, and amines such as triethylamine and tetramethylbutanediamine. In this case, these catalysts are preferably used in an amount of 0.001 to 1 part by weight per 100 parts by weight of liquid rubber. Additionally, inorganic fillers can be added to strengthen the strength of the liquid rubber. Examples of inorganic fillers include carbon black, white carbon,
Examples include metal oxides (such as aluminum hydroxide), metal carbonates (such as magnesium carbonate), and metal sulfates (such as magnesium sulfate); It is desirable to use the same one. The inorganic filler is added in a proportion of 5 to 300 parts by weight per 100 parts by weight of liquid rubber. 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
Examples include propylene rubber, and it is possible to strongly bond not only vulcanized rubbers of the same or different types, but also vulcanized rubber and cotton cloth, etc. 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 Liquid polybutadiene having hydroxyl groups at both ends of the molecule (manufactured by ARCO Chemical Co., Ltd., trade name: Pqly bdR-
45HT, hydroxyl group content 0.83meq/g, viscosity 50 poise/30℃) 1000g tolylene diisocyanate
Add 318g and mix well at room temperature.
A time-reacted formulation I was obtained. Formulation I had a free NCO content of 9.2% and a viscosity of 50 poise/30°C. Next, 1000 g of 2-ethyl-1,3-hexanediol as a chain extender for liquid rubber, 1.15 g of dibutyltin laurate as a curing reaction catalyst, and 2,2' methylene bis(4- Methyl-6-tertiary-phenol) (Product name: Nokratsuku NS-6, manufactured by Ouchi Shinko Chemical Co., Ltd.)
Add 115 g and 57.5 g of 2(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole (trade name: Tinuvin 327, manufactured by Nippon Ciba Geigy) and mix well. I prepared something. For 100g of Formulation I, 204.2g of Formulation
g, mix well to obtain a mixture, use this mixture as an adhesive, and use #60 sandpaper.
Various buffed vulcanized rubbers (conformed under heat and pressure according to ASTMD-15-77 under specified conditions; ethylene propylene rubber is compounded and vulcanized according to "Introduction to New Rubber Technology" (published by Japan Rubber Association)) mold it,
150 x 300 x 2 mm sample) and cotton fabric (JIS L3102 regular cotton canvas No. 9).
After applying 1200 g/m ² and stacking them to avoid trapping air bubbles and curing at 50℃ for 24 hours, IS
Adhesive strength was measured using -500 Autograph (manufactured by Shimadzu Corporation). The results are shown in the table. Example 2 Same as Example 1 except that 248 g of N,N-bis(2-hydroxypropyl)aniline was used for 1000 g of Formulation I instead of 2-ethyl-1,3-hexanediol. I did the same thing. The results are shown in the table. Example 3 Liquid styrene-butadiene copolymer having hydroxyl groups at both ends of the molecule (manufactured by Alco Chemical Co., Ltd.)
297 g of tolylene diisocyanate was added to 1000 g of Polybd CS-15 (hydroxyl group content 0.65 meq/g, viscosity 150 poise/30° C.), mixed well at room temperature, and reacted at room temperature for 24 hours to obtain Formulation I. The properties of this formulation I are: free NCO content 8.9%, viscosity
It was 150 poise/30℃. Same formulation as Example 1 for 1000g of formulation
204.2 g was added and mixed well to prepare a blend, and this blend was used as an adhesive and the same procedure as in Example 1 was carried out. Example 4 Same as Example 3 except that 248 g of N,N-bis(2-hydroxypropyl)aniline was used for 1000 g of the formulation instead of 2-ethyl-1,3-hexanediol. I did the same thing. The results are shown in the table.

[Table] Example 5 A test piece prepared in the same manner as in Example 1 was cured at 50°C for 24 hours, and then tested using a gear aging tester.
A heat aging test was conducted at 90°C for 96 hours and then cooled to room temperature. Thereafter, the adhesive strength of this test piece was measured in the same manner as in Example 1. Comparative Example A blend was obtained by mixing 1000 g of liquid polybutadiene having hydroxyl groups at both ends of the molecule as used in Example 1, 75.8 g of tolylene diisocyanate, and 0.5 g of dibutyltin dilaurate. A test piece was prepared using the method described above.
Next, this test piece was subjected to a heat aging test in the same manner as in Example 5, and the adhesive strength was measured. The results are shown in the table below.

【table】

Claims (1)

[Claims] 1 Mix 10 to 300 parts by weight of a diisocyanate compound to 100 parts by weight of liquid rubber to form a compound I.
from glycerin, 2-ethylhexanediol, 3,3'-dichlorobenzidine, 4,4'-methylene-bis-2-chloroaniline, N,N-bis-(2-hydroxypropanol)aniline and lauroguanamine. A chain extender for liquid rubber selected from the group consisting of 1 per 100 parts by weight of the liquid rubber.
~500 parts by weight and 0.1 to 10 parts by weight of an ultraviolet absorber or an antioxidant selected from the group consisting of aromatic secondary amines, alkylphenols, thiourea and benzimidazole per 100 parts by weight of the liquid rubber. A vulcanized rubber adhesive obtained by preparing a compound by preparing a compound and then mixing the compound and the compound.