JPH01165682A - Adhesive composition - Google Patents

Abstract

PURPOSE:To obtain a cold-setting one-pack adhesive composition having excellent oil resistance, heat resistance, and adhesiveness to various materials, by mixing a plurality of specified monomers, an organic peroxide, and a reducing agent that forms a redox catalyst with this organic peroxide. CONSTITUTION:This adhesive composition consists of 100 pts.wt. monomer mixture comprising 20-98wt.% monomer of formula I (wherein R1 and R2 are each 1-5C alkyl; R3 and R4 are each 2-4C alkylene; and m and n are each 2-8) and/or monomer of formula 11 (wherein R1 and R2 are each 1-5C alkyl; R5 is H, Cl, CH3 or C2H5; R6, R7, and R8 are each H, CH3, C2H5 or a group of formula III or IV; l is 1-8; q is 1-20; and p is o or 1) and 80-2wt.% monomer of formula V (wherein R9 is 1-12C alkyl); 0.2-3 pts.wt. organic peroxide (e.g., hydroperoxide); and 0.1-2 pts.wt. reducing agent that forms a redox catalyst with said organic peroxide (e.g., ethylenethiourea). It is a cold-setting anaerobic one-pack adhesive composition having a long pot life, excellent oil resistance, heat resistance, and adhesiveness to various materials; therefore, it is suitable especially as an adhesive for prevention of loosening of a screw when the resistance to oil and heat is required.

Description

Detailed Description of the Invention (a) Purpose of the Invention [Field of Industrial Application] The present invention relates to a one-component adhesive composition, which particularly exhibits oil resistance, heat resistance, and adhesion ability to a wide variety of materials. The present invention relates to an excellent anaerobic adhesive composition that cures at room temperature and has a long pot life.

This adhesive composition is particularly suitable as an adhesive for locking screws, which requires oil resistance and heat resistance.

[Conventional technology]

Anaerobic curable compositions made of monomers having acryloyl groups and/or methacryloyl groups have conventionally been used as one-component cold-curing adhesives that harden rapidly.

[Problem that the invention seeks to solve]

Conventional anaerobic curing adhesives are mainly composed of monomers with methacryloyl groups, so the curing components after reaction are inferior in oil resistance or heat resistance, and adhesive performance is also inferior to materials mainly composed of stainless steel or nickel. However, they lacked versatility because they had drawbacks such as low adhesive strength and, when used on metal materials, a short pot life from the time the adhesive was applied until the time the adhesive was processed.

g) Structure of the invention [Means for solving the problems] The present invention comprises the following monomers [A] and/or monomers [B], monomers [C],
Consisting of an organic peroxide and a reducing agent that forms a redox system with the organic peroxide, ■ A total of 100 monomers consisting of monomer [A], monomer [B] and monomer [C] 0 organic peroxides per part by weight
．． 2 to 3 parts by weight, and 0.1 to 2 parts by weight of the reducing agent that forms a redox system with the organic peroxide; (2) The proportion of each monomer is monomer [A] and/or Monomer (B) is 20 to 98% by weight, and monomer [C] is 80 to 98% by weight.
2% by weight of the adhesive composition.

Monomer [A] In the above formula, R1 and R2 represent an alkyl group having 1 to 5 carbon atoms, R3 and R4 each represent an alkylene group having 2 to 4 carbon atoms, and m and n each represent 2
Indicates an integer of ~8.

Monomer [B] In the above formula, R7 and R2 represent an alkyl group having 1 to 5 carbon atoms, R6 represents H, Cf, -CHff or -Cg Hs, and R6, R1 and R3 each represent Hl- CH3, Cz H
s, -CHtOH or I represents an integer of 1 to 8, q represents an integer of 1 to 20, and p represents 0 or 1.

Monomer [C] CH,=C-CN In the above formula, R1 represents an alkyl group having 1 to 12 carbon atoms.

The present inventor has solved the above problem by using monomer [C] together with monomer [A] and/or monomer [B] as monomer components, that is, after the reaction. The present invention was completed by discovering that the oil resistance or heat resistance of the curing component can be improved and the adhesion ability to various materials can be stabilized.

[Monomer]

Specific examples of the monomer [A] used in the adhesive composition of the present invention include 2,2bis[4-(methacryloxy-jetoxy)phenyl]propane, 2,2bis[4-(methacryloxy-tetraethoxy) ) Phenyl]propane, 2
, 2bis[4-(methacryloxy octaethoxy)phenyl]propane, 2.2bis(4-(methacryloxydipropoxy)phenyl)propane, 2.2bis[4
-(methacryloxy octabutoxy)phenyl]propane, 2 (4-(methacryloxy jetoxy) phenyl) -2(4-(methacryloxy triethoxy) phenyl] propane, 2 (4-(methacryloxy dipropoxy) phenyl) -2( 4-(methacryloxytriethoxy)phenyl]propane, 2゜2bis[4-(α
-ethyl acryloxy jetoxy) phenyl]propane, 2,2bis[4-(α-propylacryloxy jetoxy) phenyl]propane, 2 (4-(α-ethyl acryloxy jetoxy) phenyl)-2(4 −(
Examples include methacryloxy (jetoxy) phenyl] propane.

Among these, 2,2bis[4-(methacryloxy-jetoxy)phenyl]propane and 2.2-bis[4-(methacryloxy-tetraethoxy)phenyl]propane are preferred because they have good radical polymerizability.

Specific examples of monomer (B) include ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, octaethylene glycol dimethacrylate, di(pentamethylene glycol) dimethacrylate, diglycerol dimethacrylate, glycerin trimethacrylate, and trimethylolpropane. Examples include trimethacrylate.

Among these, triethylene glycol dimethacrylate and trimethylolpropane tritacrylate are preferred because they have good radical polymerizability.

Specific examples of monomer [C] include methacrylonitrile,
d-ethyl acrylonitrile, α-butylacrylonitrile, α-(2-ethylhexyl)acrylonitrile,
Examples include α-dodecyl acrylonitrile.

Among these, methacrylonitrile is preferred because it has good radical polymerizability and is inexpensive.

As the mixing ratio of the above monomers, the total amount of all monomers is 100
It is necessary to mix 80 to 2% of monomer [C] per part by weight.

When it exceeds 80% by weight, monomer [A] or monomer [
Since the copolymerization reactivity with B] decreases, the adhesive ability decreases,
On the other hand, if the amount is less than 2% by weight, the oil resistance and heat resistance of the cured component after reaction will be reduced, and adhesive ability will not be exhibited to a wide variety of materials, making each of them inappropriate.

A more preferable blending amount is 50 to 5%.

Each monomer in the present invention can be used as it is if it is physically uniformly mixed with other components constituting the present invention, but if it is emulsified in water using the method described below, there is a risk of chemical injury. It is preferable because it can reduce the amount and the coating properties can be significantly improved.

That is, a method of emulsifying the monomer mixture by gradually adding the monomer to an aqueous solution of a polymer that has surface activity in an aqueous solution state and has a number average molecular weight of about 3,000 to 50,000 under high stirring. be.

At this time, if a water-soluble polymer and/or water-dispersible polymer having film-forming ability is added at the same time as the monomer is emulsified or added after emulsification, the resulting adhesive composition It is preferable because a resin film is formed after coating and a coated surface with a dry touch can be obtained.

Furthermore, it is also possible to use a polymer that has the ability to form a film as described below and is capable of emulsifying the monomer mixture.

Examples of polymers that have film-forming ability and can emulsify the monomer mixture in water include acrylic ester resins having 20 to 50% by weight of acrylic acid in the copolymer composition, or methyl vinyl ether copolymers; polyvinylpyrrolidone,
polyvinyl alcohol with a saponification degree of 70 to 98 mol%,
Ethylcellulose, hydroxypropylcellulose, methoxyhydroxypropylcellulose, ethylene-maleic anhydride copolymer, water-soluble nylon polymer, urea-
Water-soluble polymers such as formaldehyde polymers or block copolymers of polyethylene oxide and polypropylene oxide; acrylic ester resin emulsions;
Examples include water-dispersible polymers such as urethane emulsion, chloroprene polymer emulsion, and butadiene-acrylonitrile emulsion.

Among these polymers, polyvinyl alcohol having a degree of saponification of 70 to 98 mol % is preferred because it has a high emulsifying power for the monomer mixture, and a water-soluble nylon polymer has a high film-forming ability.

Among these polymers, it is preferable to use a mixture of a polymer with a high emulsifying power and a polymer with a high film-forming ability in the monomer mixture, since this provides suitable conditions for the method of the present invention.

(Organic peroxide) Powdered or liquid organic peroxide can be used as it is if it is physically uniformly mixed with the other components constituting the present invention, but by encapsulating it, the pot life can be improved. It is possible to obtain a more excellent composition as a one-component adhesive composition.

The encapsulation method involves dispersing a finely powdered organic peroxide in a urea-formaldehyde prepolymer obtained by a methylolation reaction at a pH of 7.5 to 9, and then dispersing the organic peroxide at a pH of 7.5 to 9.
The method of encapsulation while lowering the temperature to 2 to 3 and maintaining the reaction temperature at 35 to 45 °C and depositing the produced polymer in peroxide powder by methylenation reaction improves the water resistance and oil resistance of the produced capsules. is excellent and preferable.

As the organic peroxide used in the present invention, hydroperoxide, ketone peroxide, dialkyl peroxide, peroxy ester, diacyl peroxide, etc. can be used, but benzoyl peroxide or meta-toluoyl peroxide is particularly suitable. When used in an adhesive composition, organic peroxides with a strong redox reaction, such as organic peroxides, have a high adhesive ability, but have a short pot life, so it is desirable to encapsulate them according to the above-mentioned method.

The amount of organic peroxide used is 0.2 to 3 parts by weight, preferably 0.5 to 2 parts by weight, based on 100 parts by weight of the monomer mixture.

If the amount is less than 0.2 parts by weight, the adhesion ability will not be fully exhibited, while if it exceeds 3 parts by weight, more than the appropriate amount may be mixed in as foreign matter and reduce the adhesion ability, so each is inappropriate. .

[Reducing agent that forms a redox system with an organic peroxide] The compound can be used by dissolving or uniformly dispersing it in the monomer mixture, but it can also be used by emulsifying the monomer mixture. In this case, it is preferable to add it at the time of emulsification and emulsify it at the same time, or add it to the dispersion after emulsification and disperse it uniformly.

Specific examples of such compounds include organic acid salts of copper, cobalt, manganese, etc.: ethylenethiourea, tetramethylthiourea, etc. for organic hydroperoxides or peroxyesters, when combined with organic peroxides used at the same time. , 2-mercaptobenzimidazole, and other hydrophobic mercapto compounds; hydrazine, 2-hydroxyethylhydrazine, benzoylhydrazine, and other hydrazine derivatives; p-) sodium luenesulfinate, L-ascorbic acid, triethylenediamine, and the like.

Among these, it is preferable to use ethylene thiourea or L-ascorbic acid because the reactivity increases.

For diacyl peroxides, dimethylaniline, dimethyl-p-1 luidine, diethyl-p-toluidine, N,N dimethyl-p-anisidine, 0-sulfobenzoic acid imide; and also mercaptoethanol, thiomalic acid, thioglycolic acid. Water-soluble mercapto compounds such as , thiolactic acid, α-thiobutyric acid, mercaptoethylamine, or 0- or m-thiosalicylic acid are used.

Among these, it is preferable to use dimethyl-P-)luidine or 0-sulfobenzoic acid imide because the reactivity increases.

The amount of the compound to be used is 0.1 to 2 parts by weight per 100 parts of the monomer mixture, preferably 0.1 to 2 parts by weight.
It is 3 to 2 parts by weight.

When the amount is less than 0.1 part by weight, the redox reaction is weak (
However, if the amount exceeds 2 parts by weight, the redox reaction mechanism will be unbalanced and the adhesive ability will tend to decrease, which is inappropriate.

[Other substances that may be employed in the adhesive composition of the present invention] Talc, silica, alumina or calcium carbonate which are commonly used for the purpose of improving the properties of the adhesive composition, for example to impart thixotropic properties; In order to maintain a long pot life, hydroquinone, methylhydroquinone, 2,4-dinitroanisole or 2. 6-ditertiary-butyl p-cresol, etc. can be added.

[Function] The adhesive composition of the present invention is a one-component room temperature curing type using a mixture of the above monomer [A] and/or monomer [B], and monomer [C]. , the oil resistance and heat resistance of the cured component after reaction are improved, and the adhesive strength is improved on a wide range of materials including stainless steel and nickel, and even when used on metal materials, it is possible to improve the adhesive strength even after application to the adherend. It has a long pot life during adhesive processing.

Monomer [A] and/or monomer [B]
The reason why these excellent effects are exhibited by adding C] is not necessarily clear, but it is thought that the cyano group in the monomer [C] is involved.

[Examples and comparative examples]

The present invention will be explained in more detail by giving examples and comparative examples below.

As an evaluation method, the adhesion performance to bolts and screws was conducted using the following test method.

(Application of adhesive composition to bolts and screws) Yellow chromate and stainless steel (SUS3) with a diameter of 8 mm and a length of 40 mm.
04) Apply 0.15 g of the water-free adhesive composition evenly so as to fill the groove of the screw,
Coated adhesive fasteners obtained type screws.

On the other hand, 0.2 g of the aqueous adhesive composition was uniformly applied and then dried at 80°C for 20 minutes to obtain a screw with a tack-free film formed on the surface.

(Adhesive Performance and Other Evaluation Tests) (a) Adhesiveness Test The coated screws described above were tightened with a torque of 230 kg/cm, and after being left at 23° C. for 1 hour, the start-up return torque was measured.

(b) Adhesive performance pot life test After continuing to heat the above-mentioned coated screw at 40°C for 60 days, it was tightened with a torque of 230 kg/cm.
The starting return torque after being left at °C for 1 hour was measured.

[C] Oil resistance test The coated screws were tightened with a torque of 230 kg/cm and immersed in gasoline at 40°C for 7 days.

The starting return torque was measured immediately after removal.

(d) Heat resistance test The coated screws described above were tightened with a torque of 230 kg/cm, heated at 120°C for 1 hour, and heated to 120°C.
The starting return torque was measured while the engine was held at .

Example 1 A 11 beaker equipped with a homogenizer was equipped with a 2°2 screw.
4-(methacryloxyjethoxy)phenyl]propane s o g, methacrylonitrile 200 g, cumene hydroperoxide 10 g, and dimethyl para-toluidine 7 g were added and stirred for 30 minutes.

The obtained oily liquid was tested according to the evaluation method described above, and the results are shown in Table 1.

Examples 2 to 5, Comparative Examples 1 to 2 In Example 1, the type and amount of the monomer, organic peroxide, or reducing agent that forms a redox system with the organic peroxide were changed as shown in Table 1. However, the test results were shown in Table 1 when the other conditions were exactly the same as in Example 1.

Example 6 A urea-formaldehyde resin was used to encapsulate benzoyl peroxide as a core material by the following method, and the monomer mixture was further emulsified in an aqueous polyvinyl alcohol solution by the following method.

(Encapsulation of benzoyl peroxide) II with reflux condenser! , 350 g of formalin aqueous solution with a concentration of 37% by weight, 131 g of urea, and 1.7 g of triethanolamine were placed in a flask, stirred at 300 rpm and 70°C for 2 hours to react, and the pH was determined by H7.7 and B-type viscometer. Urea whose viscosity at 60 rpm is 9.1 cps
An aqueous prepolymer solution of formaldehyde resin was obtained.

Next, add 240 ml of the above prepolymer aqueous solution to 22 beakers.
Prepare 520 g of pure water and 500 g of pure water using a homogenizer.
By adding 12 cc of an aqueous solution of IN hydrochloric acid under stirring in an Orpm, p! (is set to 2°3.

Next, fine powder of benzoyl peroxide (average particle size 2
0μm) 12.8g and 500Orp at 40°C.
The reaction was maintained for 6 hours under stirring.

Further, 300 g of pure water was added thereto, the stirring speed was reduced, and the reaction was continued at 200 rpm and 40° C. for 15 hours to obtain a slurry.

As a result of washing and drying, polynuclear capsule particles containing 20% by weight of benzoyl peroxide and having an average particle size of 40 μm were obtained.

(Emulsification of monomer in water) 2! In a beaker, 860 g of pure water, Gohsenol CM-
14 (partially saponified polyvinyl alcohol with a degree of saponification of 86 mol% and an average degree of polymerization of 1400, manufactured by Nippon Gosei Kagaku Kogyo ■)
86 g of 2,2 bis[4-(methacryloxy jetoxy) phenyl]propane and 200 g of methacrylonitrile were added thereto while stirring with a homogenizer at 400 rpm, followed by stirring for 2 hours to obtain an emulsion.

This emulsion had emulsified particles with a particle size of 2 to 6 μm, and had a viscosity of 8500 cps as measured by a B-type viscometer at 6 rpm.

(Preparation of adhesive composition) The total amount of the monomer emulsion obtained above, 50 g of benzoyl peroxide capsules obtained above (containing 10 g as benzoyl peroxide), and 7 g of dimethyl para-toluidine were placed in a 21 beaker. The mixture was then stirred using a homogenizer at 300 rpm for 5 minutes to obtain an aqueous adhesive composition.

Table 1 shows the results obtained for the liquid according to the evaluation method described above.

Examples 7 to 8 In Example 6, the type and amount of the monomer, the organic peroxide, or the reducing agent that forms a redox system with the organic peroxide were changed as shown in Table 1, and the other conditions were Table 1 shows the test results when the test was carried out in exactly the same manner as in Example 6. - (C) Effects of the invention The adhesive composition of the present invention has improved oil resistance and heat resistance of the cured components after reaction, and improved adhesive strength to a wide variety of materials including stainless steel and nickel. Moreover, even when used on metal materials, it is a one-component anaerobic curing composition that has a long pot life from the time it is applied to the adherend to the time it is bonded.

The adhesive composition of the present invention is particularly suitable as a self-lock adhesive for bolts or nuts.

Claims (1)

[Claims] 1. The following monomer [A] and/or monomer [B], monomer [C], an organic peroxide, and a reducing agent that forms a redox system with the organic peroxide. (1) 0.2 to 3 parts by weight of organic peroxide per 100 parts by weight of monomers [A], monomer [B], and monomer [C]; , the reducing agent that forms a redox system with the organic peroxide is 0.1 to 2 parts by weight, and (2) the proportion of each monomer is monomer [A] and/or monomer [B]. ] is 20 to 98% by weight, and monomer [C] is 80 to 98% by weight.
2% by weight of an adhesive composition. Monomer [A] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ In the above formula, R_1 and R_2 represent an alkyl group having 1 to 5 carbon atoms, and R_3 and R_4 each represent an alkylene group having 2 to 4 carbon atoms. represents a group, and m and n each represent an integer of 2 to 8. Monomer [B] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ In the above formula, R_1 and R_2 represent an alkyl group having 1 to 5 carbon atoms, R_5 represents H, Cl, -CH_3 or -C_2H_5, R_6, R_7 and R_8 are H, -CH_3, respectively
-C_2H_5, -CH_2OH or ▲There are mathematical formulas, chemical formulas, tables, etc.▼, l represents an integer from 1 to 8, q represents an integer from 1 to 20, and p represents 0 or 1. Monomer [C] ▲ Numerical formulas, chemical formulas, tables, etc. are available▼ In the above formula, R_9 represents an alkyl group having 1 to 12 carbon atoms.