JPH0321584B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a two-component adhesive that cures quickly and has high adhesive strength by combining a main agent and an auxiliary agent in air. Conventionally, a solution of chlorosulfonated polyethylene dissolved in at least one monomer selected from the group consisting of acrylic monomers and methacrylic monomers, as well as a free radical generator, a reaction accelerator, a reaction initiator, and a reaction promoter are used. Adhesive compositions containing at least one polymerization catalyst selected from the group consisting of adhesives are known. (Special Publication No. 53-41699) Also called second generation acrylic adhesive (SGA adhesive), it is expected to be used as a structural adhesive for bonding metals, plastics, etc. However, this adhesive requires several minutes to several tens of minutes to harden after bonding, and the disadvantage is that the initial adhesive strength during this time is insufficient. Furthermore, the final adhesive strength after curing is not fully satisfactory as a structural adhesive, and an adhesive with even higher adhesive strength has been desired. An object of the present invention is to improve such drawbacks and provide an adhesive having a higher initial adhesive strength and a higher final adhesive strength. That is, the present invention provides (a) a copolymer produced by chlorinating and chlorosulfonating an ethylene-vinyl acetate copolymer having a vinyl acetate content of 6% by weight or more and a melt index of 0.1 to 300 g/10 minutes; Chlorine content 5
~65% by weight, sulfur content 0.3-3.3% by weight of chlorosulfonated ethylene-vinyl acetate copolymer 5
~45% by weight (a) 30~90% by weight of a monomer having one unsaturated bond containing at least one monomer selected from acrylic acid, acrylic ester, methacrylic acid, and methacrylic ester ) Crosslinkable monomer containing two or more unsaturated double bonds
0.5 to 20% by weight (d) Organic peroxide 0.1 to 3% by weight (e) Stabilizer 0.1 to 3% by weight An auxiliary agent containing the main agent (A) consisting of (a) to (e) and an electron-donating compound It is a two-component adhesive consisting of (B). The chlorosulfonated ethylene-vinyl acetate copolymer used in the present invention is produced by chlorinating and chlorosulfonating the ethylene-vinyl acetate copolymer by reacting chlorine and sulfur dioxide gas or chlorine and sulfuryl chloride or sulfuryl chloride alone. Manufactured more than that. However, in consideration of the stability of the main ingredient (A) of the adhesive during storage or the stability of the hue, it is preferable to react with sulfuryl chloride alone. The raw material ethylene-vinyl acetate copolymer is
The vinyl acetate content must be at least 6% by weight, and the melt index must be between 0.1 and 300 g/10 min. Preferably the vinyl acetate content is 15
~45% by weight, melt index 1.0~30g/
It is 10. Chlorination and chlorosulfonation of this raw material are important in carrying out the present invention. If the vinyl acetate content is less than 6% by weight,
This is similar to adhesives using chlorosulfonated polyethylene, and it is not possible to obtain adhesives that are the object of the present invention. The chlorosulfonated ethylene-vinyl acetate copolymer is chlorinated and chlorosulfonated to contain 5 to 65% by weight of chlorine and 0.3 to 3.3% by weight of sulfur. Preferably chlorine content 17-37% by weight
It is. The chlorine content of the chlorosulfonated ethylene-vinyl acetate copolymer is 17% by weight or less or 37% by weight
If it is more than that, the impact resistance after adhesion will not be sufficiently exhibited. The sulfur content of the chlorosulfonated ethylene-vinyl acetate copolymer influences the initial adhesive strength or final adhesive strength after bonding, and the higher the sulfur content, the higher the initial adhesive strength and the higher the final adhesive strength. However, if the sulfur content is extremely high, the stability of the base ingredient (A) will be poor; therefore, if the sulfur content is 0.8
~2.2% by weight is preferred. More preferably, it is 1.5 to 2.0% by weight. This is particularly important in practicing the invention. This chlorosulfonated ethylene-vinyl acetate copolymer is contained in the base ingredient (A) in an amount of 5 to 45% by weight. The content of the chlorosulfonated ethylene-vinyl acetate copolymer contained in the base material (A) is preferably 15 to 35% by weight in view of the balance between impact resistance and adhesive strength. (b) Monomers with one unsaturated bond, including at least one monomer selected from acrylic acid, acrylic esters, methacrylic acid, and methacrylic esters, are adhesive because they polymerize and harden during bonding. The root of. Although the polymerization mechanism is not clear, the electron-donating compound contained in the auxiliary agent (B) and the organic peroxide contained in the main agent (A) cause a redox reaction, and the generated radicals undergo radical polymerization of the monomer or chlorosulfone. This is thought to cause graft polymerization to the ethylene-vinyl acetate copolymer. Examples of acrylic esters and methacrylic esters include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, and glycidyl methacrylate. . In addition to acrylic acid, acrylic ester, methacrylic acid, and methacrylic ester, it is also effective to add other monomers as necessary. Examples include vinyl chloride, styrene, acrylonitrile, vinyl acetate, vinyltoluene, and acrylamide. These acrylic acids, acrylic esters,
The monomer having one unsaturated bond containing at least one kind of monomer selected from methacrylic acid and methacrylic acid ester is contained in the base ingredient (A) in an amount of 30 to 90% by weight. (c) Crosslinkable monomers containing two or more unsaturated double bonds include, for example, ethylene dimethacrylate and divinylbenzene, and the addition of such monomers increases adhesive strength. It is contained in the base ingredient (A) in an amount of 0.5 to 20% by weight, preferably 1 to 5% by weight. Examples of organic peroxides include cumene hydroperoxide, t-butyl hydroperoxide, diisopropylbenzene monohalodroperoxide, di-t-butyl peroxide, benzoyl peroxide, dicumyl peroxide, and the like. . Preferably, it is an organic peroxide with a 10-hour half-life exceeding 100°C and excellent stability during storage. Furthermore, it is particularly effective to use an organic peroxide having an unsaturated double bond in its molecule for the purpose of increasing adhesive strength. For example, t-butyl peroxyallyl carbonate. These organic peroxides are contained in the base agent (A) in an amount of 0.1 to 3
Contains % by weight. The stabilizer is the aforementioned acrylic monomer,
A compound generally known as a polymerization inhibitor is used to prevent spontaneous polymerization of methacrylic monomers. Examples include phenols and quinones such as 2,6 di-t-butyl-4-methylphenol, hydroquinone, and p-benzoquinone.
These stabilizers are used in the base ingredient (A) in an amount of 0.1 to 3% by weight, preferably 0.1 to 1.5% by weight. In addition, other polymer components such as epoxy resin, polyvinyl chloride, polyvinyl acetate, polyaclonitrile, polystyrene may be added as necessary for the purpose of improving wetting to the adherend, improving adhesive strength, and adjusting the viscosity of the main resin. It is also within the scope of the present invention to add such substances to the main ingredient (A). (A) to (E) must be thoroughly mixed to form a uniform solution before use. In order to dissolve the chlorosulfonated ethylene-vinyl acetate copolymer, the base agent (A) becomes a highly viscous liquid. This viscosity is influenced by the content of the chlorosulfonated ethylene-vinyl acetate copolymer, the amount of chlorine and sulfur, the composition of the solution, etc., but preferably
It is 100~30000cps. The auxiliary agent (B) containing an electron-donating compound is prepared as a separate agent from the main agent (A). When the auxiliary agent (B) containing an electron-donating compound comes into contact with the main agent (A), it causes a redox reaction and starts polymerization of the acrylic monomer or methacrylic monomer contained in (A). . For this reason, it is possible to use a mixture of the main agent (A) and the auxiliary agent (B), but it is possible to apply the main agent (A) on one side to be bonded and use the auxiliary agent containing an electron-donating compound on the other side. It is desirable to apply (B) and bond the two pieces together. Examples of electron-donating compounds include compounds having heteroatoms such as nitrogen, phosphorus, oxygen, and sulfur, which generally have a large chlorinating property and a small ionization potential. The most commonly known are nitrogen-containing amine compounds. For example, N,N-dimethylaniline, aniline ethylamine, butylamine, hexylamine,
Examples include N,N-dimethyl-p-toluidine. These compounds generate radicals through redox reactions with organic peroxides. (Chemistry of Free Radicals by WApryor, Tokyo Kagaku Dojin) However, since these amine compounds have a strong odor and are highly toxic, it is effective to use a condensation product of an amine compound and an aldehyde. For example, there are condensates of n-butyraldehyde and aniline and condensates of butyraldehyde and monobutylamine. These auxiliary agents (B) are used in an amount of 1 to 30 parts by weight per 100 parts by weight of the main agent (A). Preferably 3~
15 parts by weight. The adhesive obtained by the present invention is characterized by a high initial adhesive strength and a high final adhesive strength. The adhesive of the present invention can be applied to steel, aluminum, copper, brass, wood, glass, paper, ceramics, plastics, etc., but it is particularly effective in adhering metals. Regarding plastics, polyvinyl chloride, polyamide, polyamideimide,
Effective for adhering polar materials such as polyester and polyurethane. The adhesive according to the invention cures at room temperature without requiring any heating operations for bonding. Furthermore, it can be bonded regardless of the presence or absence of air, and since it is a two-liquid non-mixable type, it has practical advantages such as having no restrictions on pot life, and therefore has great industrial value. Next, the present invention will be described in more detail based on Examples, but these are examples to help understand the present invention, and the present invention is not limited in any way by these Examples. Note that the numerical values used in the present invention were obtained based on the following measurement method. Vinyl acetate content: JIS K 6730 Melt index: ASTM D 1238-73 Chlorine/sulfur analysis: Combustion flask method Mooney viscosity: JIS K6300ML ₁₊₄ (100℃) Solution viscosity: B-type viscometer 25℃ Tensile shear strength; (1) Test piece Cold rolled steel plate (100 x 25 x 1.4 mm)
It was sanded with Cw400-2C sandpaper and degreased with a 1:1 toluene/acetone solvent. (2) Lamination and adhesion Apply the main agent (A) to one side of the test piece and the auxiliary agent (B) to the other side. Lightly rub both pieces together
After making sure that they have an overlapping area of 25 x 25 mm, they are fixed with clips. (3) Measurement Autograph the test piece after the specified time has passed.
Determine the tensile shear strength using IS-5000 at a speed of 50 mm/min. Example 1 Vinyl acetate content at melt index 14 g/10 min in 10 glass lined autoclave
15% by weight ethylene-vinyl acetate copolymer 1.0Kg
Dissolved in 10Kg of carbon tetrachloride, 100℃, 3.3Kg/cm ²
(gauge pressure), a chlorosulfonated ethylene-vinyl acetate copolymer was synthesized by reacting with 1620 g of sulfuryl chloride using 30 g of α,α'-azobisisobutyronitrile as a catalyst and 0.35 g of pyridine as a co-catalyst. did. After the reaction, nitrogen gas was blown into the reflux of carbon tetrachloride to discharge hydrogen chloride and sulfur dioxide gas remaining in the liquid. After adding 13 g of 2,2'-bis(4-glycidyloxyphenyl)propane as a stabilizer, the product was isolated by feeding the solution into a drum dryer in a conventional manner. As a result of analysis, this chlorosulfonated ethylene-
The vinyl acetate copolymer was found to contain 29.4% chlorine and 1.8% sulfur by weight. Further, the Mooney viscosity (ML ₁₊₄ 100°C) was 30. These results are shown in Table-1. This chlorosulfonated ethylene-vinyl acetate copolymer was dissolved according to the following formulation to obtain a base material (A). (Blend) Chlorosulfonated ethylene-vinyl acetate copolymer 30% by weight Methyl methacrylate 51.5% by weight Methacrylic acid 15% by weight Ethylene dimethacrylate 2% by weight Cumene hydroperoxide 1% by weight 2,6-di-t-butyl- 4-Methylphenol 0.5% by weight Noxela-8 (manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.), which is a condensate of n-butyraldehyde and aniline, was used as the auxiliary agent (B) containing an electron-donating compound. 0.20 g of the main agent (A) was applied to one side of the test piece, and 0.015 g of the auxiliary agent (B) was applied to the other side. After rubbing them together lightly, I secured them with clips. Tensile shear strength was measured after 10 minutes and 24 hours. These results are summarized in Table 2. Example 2 Chlorosulfonated ethylene used in Example 1
Vinyl acetate copolymer was used, but the proportion of the main ingredient (A) was changed as shown in Table 2. The adhesive strength was tested in the same manner as in Example 1. The results are summarized in Tables 1 and 2. Example 3 Chlorosulfonated ethylene used in Example 1
Vinyl acetate copolymer is used, but t-butyl peroxyallyl carbonate (Pelomer AC, manufactured by NOF Corporation), which is an organic peroxide with an unsaturated double bond in the molecule, is added as an organic peroxide. did. The adhesive strength was tested in the same manner as in Example 1. The results are summarized in Tables 1 and 2. Example 4 A reaction was carried out in the same manner as in Example 1 except that the ethylene-vinyl acetate copolymer used in Example 1 was used and the amount of sulfuryl chloride used was reduced to 1020 g, and the amount of chlorine was 20.7% by weight and the amount of sulfur was 1.6. % by weight of chlorosulfonated copolymer was obtained. Adhesion tests were carried out using the formulations shown in Table 2 in the same manner as in Example 1, and the results are summarized in Tables 1 and 2. Example 5 In the chlorosulfonated ethylene-vinyl acetate copolymer obtained in Example 4, t-butyl peroxyallyl carbonate ((Pelomer AC)), which is a peroxide having an unsaturated double bond, was further added. The adhesive strength was tested by coating in the same manner as in Example 1. The results are summarized in Tables 1 and 2. Example 6 Ethylene-vinyl acetate copolymer with a melt index of 20 g/10 minutes and a vinyl acetate content of 20% by weight The reaction was carried out in the same manner as in Example 1 to obtain a chlorosulfonated ethylene-vinyl acetate copolymer containing 29.4% by weight of chlorine and 1.7% by weight of sulfur. This chlorosulfonated ethylene-vinyl acetate copolymer A liquid (A) was prepared using the formulation shown in Table 2, and an adhesion test was conducted by applying it in the same manner as in Example 1. The results are summarized in Tables 1 and 2. Example 7 Melt index 1.5 g/10 Since an ethylene-vinyl acetate copolymer with a vinyl acetate content of 20% by weight was reacted with sulfuryl chloride in the same manner as in Example 1, chlorosulfonated ethylene-vinyl acetate with a chlorine content of 29.6% by weight and a sulfur content of 1.6% was obtained. A copolymer was obtained. The formulation shown in Table 2 was applied and an adhesion test was conducted in the same manner as in Example 1. These results are summarized in Table 2.
Shown in 1 and 2. Comparative example 1 Melt index 12g/0 min, density
Chlorosulfonated polyethylene was obtained by reacting 0.921 g/cm ³ of high-pressure polyethylene with sulfuryl chloride in the same manner as in Example 1. Analysis revealed that the chlorosulfonated polyethylene contained 29.1% chlorine and 1.0% sulfur by weight. The formulations shown in Table 2 were applied and adhesion tests were conducted in the same manner as in Example 1, but the results are summarized in Table 2.
Shown in 1 and 2. From these facts, it is clear that the present invention has excellent characteristics as a two-component fast-curing adhesive composition.

[Table] * Value of chlorosulfonated polyethylene

【table】

Claims (1)

[Scope of Claims] 1 (a) Produced by chlorinating and chlorosulfonating an ethylene-vinyl acetate copolymer having a vinyl acetate content of 6% by weight or more and a melt index of 0.1 to 300 g/10 min. Chlorine content: 5-65% by weight, Sulfur content: 0.3-3.3% by weight
5 to 45% by weight of chlorosulfonated ethylene-vinyl acetate copolymer. (a) 30 to 90% by weight of a monomer having one unsaturated bond, including at least one monomer selected from acrylic acid, acrylic ester, methacrylic acid, and methacrylic ester. (c) Crosslinkable monomer containing two or more unsaturated double bonds
0.5-20% by weight (d) 0.1-3% by weight of organic peroxide. (e) Stabilizer 0.1-3% by weight. A two-component adhesive consisting of a main agent (A) consisting of the above (A) to (E) and an auxiliary agent (B) containing an electron-donating compound. 2 A chlorosulfonated ethylene-vinyl acetate copolymer is melted with a vinyl acetate content of 15 to 45% by weight.
Ethylene with an index of 1.0 to 30g/10 minutes
The claim is a chlorosulfonated ethylene-vinyl acetate copolymer having a chlorine content of 17 to 37% by weight and a sulfur content of 0.8 to 22% by weight, which is produced by chlorinating and chlorosulfonating a vinyl acetate copolymer. The two-component adhesive according to item 1. 3. The two-component adhesive according to claim 1 or 2, wherein an organic peroxide having an unsaturated double bond is used as the organic peroxide.