JPH0119715B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an adhesive composition, and more particularly to an adhesive composition that is used for adhesion to rubber underwater or on a wet surface, and particularly has excellent adhesive properties and flexibility. Conventionally, epoxy resins have been widely used in various fields such as various paints and adhesives because of their excellent chemical resistance, adhesive properties, and electrical properties. However, in terms of adhesives that harden in water or on wet surfaces and have sufficient bonding strength, for example, adhesives made of polybutadiene-modified epoxy resin and polyamide amine have only been used for bonding concrete in the civil engineering field, and epoxy Because these resins have high hardness, poor adhesion, and lack flexibility, they cannot be used underwater or on wet surfaces, and are especially useful for fenders, marine hoses, rubber bags for oil recovery, rubber water storage tanks, etc. There was no material that could be used as a repair material for marine rubber products. In view of these problems, the present invention aims to improve the adhesion and flexibility of adhesion to rubber underwater or on wet surfaces, and particularly for marine rubber products, such as fenders, water tanks, etc. that can be repaired underwater. Used as a repair material for work. As a result of intensive research to achieve the above object, the present inventors have found that epoxy resins containing epoxy resins (A) obtained by reacting long-chain dibasic acids and epoxy resins
(B) is a poorly water-soluble amine and/or amide (C)
The present invention was accomplished by discovering that an adhesive composition containing a specific amount of the following can improve adhesiveness and flexibility when adhering rubber in water or on wet surfaces. That is, the present invention provides a compound represented by the general formula HOOC-(CH ₂ ) ₅ -R-(CH ₂ ) ₅ -COOH (where R is an alkyl group or alkenyl group having 2 to 8 carbon atoms in the straight chain portion). It contains at least 50% by weight of an epoxy resin (A) obtained by reacting a long-chain dibasic acid with an epoxy resin having at least two epoxy groups in the molecule, and the number of epoxy groups/the number of carboxyl groups. 100 parts by weight of an epoxy resin (B) with a number ratio of 2.0 to 7.0;
Poorly water-soluble amine and/or amide (C)4-430
The adhesive composition is characterized in that it contains parts by weight. The long-chain dibasic acid used in the present invention has the general formula: HOOC-( _CH2 ) ₅ -R-( _CH2 ) ₅ -COOH (where R is an alkyl group having 2 to 8 carbon atoms in the straight chain portion) or alkenyl group). Specifically, as a saturated linear dibasic acid, for example, R is -(CH ₂ ) ₄ -, -(CH ₂ ) ₈ -,

【formula】

【formula】

[Formula] Saturated branch 2 As a basic acid, for example R is

【formula】

[Formula] As an unsaturated linear dibasic acid, for example, R is -CH ₂ -CH=CH-CH ₂ -, -CH ₂ -CH=CH(CH ₂ ) ₂ -CH=CH-CH ₂ -,

[Formula] Unsaturated branch As a dibasic acid, for example, R is

【formula】

【formula】

[Formula] etc. can be mentioned. These dibasic acids may be used alone or in combination of two or more. The epoxy resin to be reacted with the long-chain dibasic acid in the present invention includes those having at least two epoxy groups in the molecule, such as bisphenol type epoxy resins and hydrogenated products thereof, cycloaliphatic epoxy resins, phenols, or cresols. Commonly used epoxy resins include novolac type epoxy resin, phthalate glycidyl ester type epoxy resin, dimer acid type epoxy resin, and polyglycol type epoxy resin. These epoxy resins may be used alone, or
Two or more types may be used in combination. General formula of epoxy resin (A) having at least two epoxy groups obtained by reacting the long-chain dibasic acid obtained in this way with a general-purpose epoxy resin, and epoxy resin (A)
Chemical formula of a compound (epoxy resin (A) -
1 to 6) are shown in Table 2 below. In the present invention, the epoxy resin (A) having at least two epoxy groups in the molecule obtained by reacting the long-chain dibasic acid with the epoxy resin is used as the epoxy resin (B) in the adhesive composition. At least 50% by weight of the ingredients
or more. As the epoxy resin (B) component, the epoxy resin (A) may be used alone or in combination of two or more types, or the epoxy resin (A) and the above-mentioned general-purpose epoxy resins may be used in combination. In any case, the epoxy resin (A) must be contained in the epoxy resin (B) component at 50% by weight or more, and if the content of the epoxy resin (A) is less than 50% by weight, it will High adhesion and flexibility cannot be obtained. In this epoxy resin (B), the ratio of the number of epoxy groups/the number of carboxyl groups needs to be 2.0 to 7.0. If the ratio of the number of epoxy groups/the number of carboxyl groups is less than 2.0, free carboxyl groups remain and water resistance deteriorates, and if it exceeds 7.0, adhesiveness and flexibility deteriorate. The adhesive composition of the present invention can be obtained by blending a specific amount of poorly water-soluble amine and/or amide (C) into the epoxy resin (B). The amount of poorly water-soluble amine and/or amide (C) is the same as the epoxy resin (B).
It is mixed at a ratio of 4 to 430 parts by weight per 100 parts by weight. If the amount is less than 4 parts by weight, curing will be insufficient, and if it is more than 430 parts by weight, unreacted curing agent will remain, and both will reduce the cohesive strength of the adhesive, resulting in poor adhesive strength. It is not preferable because it has a low water resistance and also reduces water resistance. In the present invention, the poorly water-soluble amine and/or amide (C) refers to aromatic amines that are poorly soluble in water and have the ability to replace water molecules, polyalkylene polyamines, polyamides, amide polyamines, NBR-modified amines, etc. for epoxy resins. One or more types of curing agents are used. Specifically, aromatic amines include m-phenylenediamine, 4,4'-methylenedianiline, etc., polyamides include polyamides made from linoleic acid dimer and ethylenediamine, and polyamides made from linoleic acid dimer and diethylenetriamine. etc., amide polyamines from tall oil and triethylenetetramine, amide polyamines from ricinoleic acid and triethylenetetramine, etc., dibutylaminopropylamine, bis(hexamethylene)triamine, etc. as polyalkyl polyamines, NBR modified amines, etc. Examples include reactants of carboxylated NBR and N-aminopiperazine. In the present invention, an ordinary room temperature curing agent can also be used together with the poorly water-soluble amine and/or amide (C). Examples of these room temperature curing agents include aliphatic polyamines, amine adducts, tertiary amines, and modified polymercaptans. For example, aliphatic polyamines include triethylenetetramine and dimethylaminopropylamine, amine adducts include diethylenetriamine and bisphenol A type epoxy resin adducts, triethylenetetramine and ethylene oxide, etc., tertiary amines include 2, 4, 6-Tris (dimethylaminomethyl)
Examples of modified polymercaptans include phenol, benzyldimethylamine, and trimercaptomethyltrioxane. The rubber used as the adherend of the adhesive composition in the present invention is natural rubber, butadiene rubber, styrene rubber, etc.
Examples include butadiene rubber, ethylene propylene rubber, chloroprene rubber, nitrile butadiene rubber, epichlorohydrin rubber, acrylic rubber, and chlorinated polyethylene, among which good adhesion is shown to chloroprene rubber. The adhesive composition of the present invention may contain appropriate amounts of extenders, reinforcing agents, fillers, pigments, and the like, as required. These include, for example, coal tar, glass fiber, asbestos fiber,
Carbon fiber, cellulose, polyethylene powder, quartz powder, mica, activated alumina, kaolin, bentone,
Examples include silica titanium dioxide, carbon black, iron oxide, and aluminum powder, and any of them can be used effectively depending on the purpose. Furthermore, a silane coupling agent can be mixed into the adhesive composition of the present invention for the purpose of improving its adhesiveness. For example, vinyltriethoxysilane, γ-methacrylooxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane Examples include silane and γ-mercaptopropyltrimethoxysilane. Next, a detailed description will be given based on examples and comparative examples of the present invention. Note that all formulations in Tables 1 and 3 are parts by weight. Examples 1 to 9 and Comparative Examples 1 to 2 The compositions shown in the main component column of Table 1 were mixed on a paint mill to prepare a main component. Similarly, a curing agent was prepared by mixing on a paint mill with the formulation shown in the column of curing agent components in Table 1. An adhesive composition was obtained by mixing this base agent and a curing agent. The general formula of epoxy resin (A) obtained by reacting a long-chain dibasic acid with an epoxy resin and the chemical formulas of epoxy resins (A)-1 to 6 listed in Table 1 used in the examples are as follows. It is shown in Table 2. On the other hand, vulcanized chloroprene rubber with a JIS hardness of 45 obtained by the formulation and vulcanization conditions shown in Table 3 was
A test piece with a thickness of 25.4 mm x 150 mm was prepared using sandpaper (AA-120 manufactured by Riken Corundum) in seawater.
After buffing with water, the adhesive composition described above was applied to a thickness of 3 mm, and a plain weave cloth was layered on top to form a sample for adhesion testing. This adhesive test sample was cured in seawater at 20°C for one week, and the adhesive strength was measured. Adhesive strength was measured using Shimadzu Autograph S500 at 20° C. and at a tensile speed of 50 mm/min. In addition, to measure the hardness of adhesive compositions,
Apply the above adhesive composition on release paper 3mm x 50mm x 50mm
Casting with dimensions of mm and placed in seawater at 20℃ x 1
After being cured for a week, the hardness was measured using a JIS hardness meter. The results are shown in Table 1.

【table】

【table】

【table】

【table】

[Table] As shown in Table 1, Examples 1 to 9 using the adhesive composition of the present invention all had good adhesion to chloroprene rubber even after adhesive treatment in seawater, and It can be seen that the flexibility is also good. On the other hand, it was found that Comparative Examples 1 and 2 in which a general-purpose epoxy resin was used had low adhesion to chloroprene rubber and lacked flexibility. As explained above, an epoxy resin (B) containing an epoxy resin (A) obtained by reacting a long-chain dibasic acid with an epoxy resin having at least two epoxy groups in its molecule has a slightly water-soluble Amine and/or
The adhesive composition of the present invention, in which a specific amount of amide (C) is added, uses an amine and/or amide that is poorly soluble in water and has the ability to replace water molecules, so it can be used in water or on wet surfaces. Since it uses epoxy resin (A) obtained by curing and then reacting a long-chain dibasic acid with an epoxy resin having at least two epoxy groups in the molecule, it has excellent adhesiveness and flexibility when adhering to rubber. As a result, it can be used as a repair material for rubber products used in the ocean, as well as paints, lining materials, and other materials used in the ocean.
It can also be used as a sealant.

Claims (1)

[Claims] 1 Represented by the general formula HOOC-(CH ₂ ) ₅ -R-(CH ₂ ) ₅ -COOH (wherein R is an alkyl group or alkenyl group having 2 to 8 carbon atoms in the straight chain portion) Contains at least 50% by weight of an epoxy resin (A) obtained by reacting a long-chain dibasic acid with an epoxy resin having at least two epoxy groups in the molecule, and the number of epoxy groups/carboxylic groups. 100 parts by weight of an epoxy resin (B) having a number ratio of 2.0 to 7.0,
Poorly water-soluble amine and/or amide (C)4-430
An adhesive composition characterized in that it contains parts by weight.