JPH0365364B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an anaerobic curable composition having improved storage stability and containing acrylate and/or methacrylate as a main monomer component. An anaerobic curable composition is a curable composition that is stable for a long period of time while in contact with air or oxygen, but easily polymerizes and cures by blocking air or oxygen between two adjacent surfaces. This composition is used for adhesion, sealing, loosening prevention, fixing of fitting parts, etc. of metal parts, etc. This type of anaerobic curable composition is usually commercially available in polyethylene containers filled to about half the container's capacity. Polymerization and curing of this anaerobic curable composition is prevented by oxygen in the space within the container and oxygen permeating through the walls of the container, and the composition is stored in a liquid state. However, anaerobic curable compositions generally contain an organic peroxide polymerization initiator and further contain a curing accelerator. The curing accelerator is
It acts with the metal on the surface of the object to be adhered or fixed to promote curing when the composition is applied to those surfaces. Therefore, if trace amounts of metals are mixed into the raw materials used in such anaerobic curable compositions or during the manufacturing process, there is a risk that the composition will become unstable and polymerize or harden in the storage container, making it unusable. There is. In the past, several methods have been proposed to solve this problem that adversely affects storage stability. For example, a method of adding quinone or phenols, a method of adding a metal chelating agent to inactivate metal impurities that adversely affect stability (Japanese Patent Publication No.
20555 (see Japanese Patent Publication No. 20555) and a method using a combination of hydroquinone and a metal chelating agent (see Japanese Patent Publication No. 54-36954). It has been difficult to obtain an anaerobic curable composition that satisfies long-term storage stability and curing properties at the same time, as those with high curing speeds have poor storage stability. As a result of various studies aimed at improving the above-mentioned drawbacks of conventional anaerobic curable compositions, the present inventors have discovered that organic peroxidation of radically polymerizable monomers containing acrylates and/or methacrylates as main components. The present invention was achieved by discovering that the objective can be achieved by adding a specific stabilizer compound to a composition containing a quinone polymerization initiator and a quinone polymerization inhibitor. That is, the anaerobic curable composition of the present invention contains a radical polymerizable monomer mainly composed of acrylate and/or methacrylate, an organic peroxide polymerization initiator, a quinone polymerization inhibitor, and the following general formula ( ), general formula (), and at least one stabilizer selected from compounds represented by general formula (). [Wherein, X is _-CH3 , -COOM (M represents a hydrogen atom or an alkali metal atom), -OH, -COH
or -CH ₂ OH, and M represents a hydrogen atom or an alkali metal atom. ] [Wherein, X is _-CH3 , -COOM (M represents a hydrogen atom or an alkali metal atom), -OH, -COH
or -CH ₂ OH, and M represents a hydrogen atom or an alkali metal atom. ] [Wherein, X is _-CH3 , -COOM (M represents a hydrogen atom or an alkali metal atom), -OH, -COH
or -CH ₂ OH, and M represents a hydrogen atom or an alkali metal atom. ] The anaerobic curable composition of the present invention can exhibit the following characteristics and effects. (i) By adding the specific stabilizer compounds represented by the above-mentioned general formulas () to (), storage stability is good, and polymerization and hardening do not occur during storage. (ii) Moreover, the addition of the same compound has no adverse effect on the curing properties. In other words, although the storage stability is improved by adding the same compound, the curing properties are not deteriorated. (iii) As a result of improved storage stability, highly active curing accelerators that could not be used in the past can be used, and the curing rate can be improved. The monomer in the present invention is a radically polymerizable monomer containing acrylate and/or methacrylate as a main component, and preferably consists only of acrylate and/or methacrylate. The acrylate and/or methacrylate [hereinafter may be collectively referred to as (meth)acrylate. ] Examples include alkylene type bifunctional (meth)acrylates such as neopentyl glycol di(meth)acrylate; diethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, triethylene glycol Ether-type bifunctional (meth)acrylates such as di(meth)acrylate and tetraethylene glycol di(meth)acrylate; trimethylolpropane tri(meth)acrylate;
Trifunctional (meth)acrylates such as trimethylolethane tri(meth)acrylate; polyfunctional (meth)acrylates such as pentaerythritol tetra(meth)acrylate, dipentaerythritol poly(meth)acrylate, and tetramethylolmethanetetra(meth)acrylate ;2-hydroxyethyl (meth)acrylate, tetramethylolmethane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, 2,3-
(meth)acrylates containing polar groups or substituted atoms such as diprompropyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-chloroethyl (meth)acrylate, dimethylaminoethane (meth)acrylate; 2,2'-bis (4-acryloxy-diethoxyphenyl)propane di(meth)acrylate, bisoxypolyethyleneated bisphenol A-di(meth)acrylate, bisoxypropylenated bisphenol A
-di(meth)acrylate, bisoxy-2-hydroxyethylated bisphenol A-di(meth)
Examples include epoxy (meth)acrylates such as acrylate; polyester type di(meth)acrylates such as adipic acid-1,6-hexane diol di(meth)acrylate; and urethane (meth)acrylates. These (meth)acrylates may be used alone or in combination of two or more. Further, in some cases, monomers other than (meth)acrylates may be used in combination with these (meth)acrylates. Other monomers that can be used in combination include styrene, tetraethylene glycol dicrotonate, diallyl phthalate, alkyl vinyl ether, butadiene acrylonitrile rubber with vinyl groups at both ends (VTBN rubber), triallyl isocyanurate,
Examples include triallyl trimellitate, N,N'-methylene-bis-acrylamide, N-methylol acrylamide, N-n-butoxymethyl acrylamide, etc. When the cured product is required to have flexibility, VTBN rubber is used. Available. Examples of the organic peroxide polymerization initiator in the present invention include ketone peroxides, diacyl peroxides, peroxy esters, dialkyl peroxides, hydroperoxides, peroxy esters, etc. is described in Japanese Patent Application No. 50-9686. Particularly preferred polymerization initiators are hydroperoxides such as cumene hydroperoxide and t-butyl hydroperoxide. It is also possible to use two or more types of these polymerization initiators in combination. The blending ratio of the polymerization initiator is 0.01 to 10.0% by weight, preferably 0.1 to 7.0% by weight, based on the total amount of radically polymerizable monomers. Examples of the quinone polymerization inhibitor in the present invention include hydroquinone, benzoquinone, naphthoquinone, and hydroquinone monomethyl ether. When added to an anaerobic curable composition, these have the effect of improving storage stability, but at the same time they also have the effect of slowing down the curing rate. Therefore, it is difficult to obtain an anaerobic curable composition that satisfies both storage stability and curing properties using only a quinone polymerization inhibitor. The preferred amount of the quinone polymerization inhibitor added to the anaerobic curable composition in the present invention is based on the total amount of radically polymerizable monomers.
0.001-0.5% by weight, preferably 0.01-0.1% by weight
It is. The amount of the quinone polymerization inhibitor must be such that it does not harm the curing speed of the anaerobic curable composition, and from the viewpoint of storage stability, it is preferable that the amount be slightly insufficient. The most distinctive feature of the present invention is the use of specific storage stabilizers, specific stabilizer compounds represented by the general formulas () to () above. It is possible to impart good storage stability to an anaerobic curable composition with insufficient storage stability, in which the amount of the quinone polymerization inhibitor added is kept low with emphasis on In other words, by incorporating these specific stabilizer compounds,
An anaerobic curable composition with excellent balance of stability and curing speed can be obtained. Compounds represented by the general formula () (i.e. 2-pyridinecarboxylic acids), the general formula ()
Specific examples of compounds represented by (i.e., 2-quinolinecarboxylic acids) and compounds (i.e., 2-pyridinecarboxylic acids) represented by the general formula () include α-picolinic acid (i.e., pyridine-2-carboxylic acid). ), quinolinic acid (i.e. pyridine-2,3-dicarboxylic acid), dipicolinic acid (i.e. 2,6-pyridinedicarboxylic acid), 2,4-pyridinedicarboxylic acid monohydrate, 2,5-pyridinedicarboxylic acid, etc. 2-pyridinecarboxylic acids and their alkali metal salts; quinaldic acid (i.e., quinoline-2-carboxylic acid), kynurenic acid (i.e., 4-oxyquinaldic acid), acridic acid (i.e., quinoline-2-carboxylic acid),
2-quinolinecarboxylic acids such as 2,3-dicarboxylic acid), quinoline-2,8-dicarboxylic acid and alkali metal salts thereof; 2-pyrazinecarboxylic acid, 2,3-pyrazinedicarboxylic acid, 2,5-
Examples include 2-pyrazinecarboxylic acids such as pyrazinedicarboxylic acid and alkali metal salts thereof. One type of these compounds may be used. Several types may be used together. The amount of these compounds used is based on the total amount of radically polymerizable monomers.
0.0001-0.1% by weight, preferably 0.0005-0.05% by weight. Furthermore, it is a known stabilizing agent. Polymerization inhibitors such as phenothiazine, phenolic antioxidants such as butylated hydroxytoluene, nitroso compounds such as o-nitrosophenol, cuperone, N-methyl-N-nitrosoaniline, picric acid,
Aromatic nitro compounds such as 2,4-dinitrophenol, galbinoxyl, 1,1-diphenyl-2
-Picrylhydrazyl, 2,2-diphenyl-1
- By using one or more radical scavengers such as picrylhydrazyl in combination with the stabilizer of the present invention, a specific stabilizer compound represented by the above general formulas () to (). , it is also possible to further improve stability. In this case, it is necessary that the amounts added do not harm the curing speed of the anaerobic curable composition. Various substances can further be added to the composition of the present invention for various purposes. For example, dyes and pigments are used for the purpose of coloring, thixotropic agents are used for the purpose of imparting thixotropy, soluble polymers such as urethane rubber and phenoxy resin are used for the purpose of thickening and improving strength, and the breaking torque/escape torque ratio is 1. ~3, an epoxidized plasticizer such as epoxidized soybean oil, a non-reactive acrylic oligomer with a hydroxyl group (for example, the product name Nicalite XK type resin, manufactured by Nippon Carbide Industries Co., Ltd.), etc.
Plasticizers such as dibutyl phthalate and butylbenzyl phthalate are used to adjust the adhesion strength, and silane coupling agents such as vinylsilane, aminosilane, and epoxysilane, acid phosphoxyethyl methacrylate, and 3-chloro- are used to improve adhesive strength.
A phosphorus-containing (meth)methacrylate such as 2-acidophosphoxypropyl methacrylate may be blended with a filler for the purpose of thickening or increasing the volume, and a known curing accelerator for the purpose of increasing the curing speed. The anaerobic curable composition of the present invention can be easily prepared by mixing and dissolving the above-mentioned components at room temperature or under heating. Next, Examples and Comparative Examples of the present invention will be described in detail. Parts in these examples indicate parts by weight. In addition, the performance tests for each composition obtained in these examples were conducted in accordance with the Japan Adhesive Industry Association standard "Anaerobic Adhesive Test Method JAI6-1979" (hereinafter referred to as "JAI Standard").
It is abbreviated as. ) was carried out using the following simple method. (1) Measurement of curing speed Based on the JAI standard, the test specimen was
Bolts and nuts (M10) with (coarse thread), thread grade 2, and a joint length (nut thickness) of 8 mm were used and were cleaned with trichlorethylene. The measurement method is to apply the composition to be tested to the thread between the bolt and nut mentioned above, tighten the nut with zero tightening torque (a state in which it can be moved with fingers without resistance), and then It was left in a constant temperature room at ℃ and the fixation time (time until it could no longer be moved with a finger) was measured. (2) Measurement of adhesive strength The same bolts and nuts as above were coated with the composition and left in a constant temperature room at 20°C for 24 hours, and the breaking torque and escape torque were measured based on JAI standards. (3) Measurement of storage stability A storage test was conducted at 50°C for 10 days, and gelation time was measured at 80°C. The 10-day storage test at 50°C is based on the JAI standard, in which half of the composition to be tested is placed in a 100 c.c. polyethylene container, and this is placed in a thermostatic oven with hot air circulation at 50±2°C. After storage for 10 days, the appearance of the composition was measured. If there is little change before and after storage under these conditions, the shelf life is said to be one year or more at room temperature. In addition, to measure gelation time at 80°C, half of the composition to be tested is placed in a 5 c.c. polyethylene container, and this is placed in a hot air circulation thermostat at 80±2°C until the sample gels. The time it took for it to change was measured. It is said that if the gelation time at 80°C is 60 minutes or more, it can be stored at room temperature for more than a year. Examples 1 to 18 Comparative Examples 1 to 10 90 parts of triethylene glycol dimethacrylate, 10 parts of 2-hydroxyethyl methacrylate, 15 parts of phenoxy resin (manufactured by Ciel Chemical Co., Ltd.), and vinyl-terminated butadiene acrylonitrile rubber (trade name: BF Gutdoritsu Co., Ltd.) hiker VT polymer
VTBN 1300 -80'') added 3 parts;
Furthermore, each of the various compounds listed in Table 1 is
1 was added to prepare each composition of Examples and Comparative Examples. Each of these compositions was tested for curing speed, storage stability, and adhesive strength according to the test methods described above. The results are shown in Table 1, and Comparative Examples 2, 4, and 2 without adding stabilizers
The stabilizer compound of the present invention was added in comparison to each composition of Comparative Examples 3, 5, 8, and 10 in which the compositions of Comparative Examples 6, 7, and 9 and the known stabilizer tetrasodium ethylenediaminetetraacetate were added. Each of the compositions of Examples 1 to 18 has excellent storage stability and is comparable in other properties. This tendency is remarkable when a highly active curing accelerator is used, and it has become possible to use highly active curing accelerators, which were previously impossible to use in this type of anaerobic curable composition. Although the speed is extremely high, it is possible to supply an anaerobic curable composition with good storage stability.

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【table】

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[Table] Examples 19 to 25 90 parts of triethylene glycol dimethacrylate, 10 parts of 2-hydroxyethyl methacrylate, 0.05 part of 1,4-benzoquinone, 15 parts of phenoxy resin (manufactured by Ciel Chemical Co., Ltd.), and vinyl-terminated butadiene acrylonitrile rubber ( BF Gutudoritsuchi product name: “Hiker VT Polymer VTBN1300×22”)
5 parts of 3-chloro-2-acid phosphoxypropyl methacrylate (product name "Hosmer C1" by Yushi Products Co., Ltd.), 0.3 parts of pyrazole, and 0.3 parts of lauryl mercaptan were added, and Table 2 was further added as a stabilizer. The formula described in

Various compounds containing the structural unit shown by [Formula] in the molecule
Various anaerobic curable compositions (Examples 19-25) were prepared by adding 0.03 parts of each. The results of measuring the curing rate, storage stability, and adhesive strength of each of these compositions are shown in Table 2. Although the curing rate was fast, all of the compositions of the examples had poor storage stability. Good and has great adhesion strength.

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Claims (1)

[Scope of Claims] 1 A radically polymerizable monomer containing acrylate and/or methacrylate as a main component, an organic peroxide polymerization initiator, a quinone polymerization inhibitor, and the following general formula (), general formula ( ) and general formula ()
An anaerobic curable composition containing at least one stabilizer selected from the compounds represented by: [Wherein, X is _-CH3 , -COOM (M represents a hydrogen atom or an alkali metal atom), -OH, -COH
or -CH ₂ OH, and M represents a hydrogen atom or an alkali metal atom. ] [Wherein, X is _-CH3 , -COOM (M represents a hydrogen atom or an alkali metal atom), -OH, -COH
or -CH ₂ OH, and M represents a hydrogen atom or an alkali metal atom. ] [Wherein, X is _-CH3 , -COOM (M represents a hydrogen atom or an alkali metal atom), -OH, -COH
or -CH ₂ OH, and M represents a hydrogen atom or an alkali metal atom. ]