JPH06299120A - Fixing agent composition for screw - Google Patents

Abstract

PURPOSE:To obtain a fixing agent composition useful for fixing of fastening parts of automobiles, etc., having highly fixing performances, excellent loosening prevention effect by blending an anaerobically curable composition with fluororesin powder and/or microballons. CONSTITUTION:(A) A anaerobically curable composition consisting essentially of a (meth)acryloyl group-containing monomer [preferably di(meth)acrylate of ethylene oxide adduct of bisphenol A] and an organic peroxide (preferably capsulated benzoyl peroxide) is blended with (B) fluororesin powder and/or microballoons (preferably microballoons of sodium borosilicate) to give the objective composition. The blending ratio of the component A and the component B is preferably 100/7-100/25.

Description

Detailed Description of the Invention

[0001]

The present invention relates to an acryloyl group and / or a methacryloyl group (hereinafter referred to as "(meth) acryloyl group").
Called. And a anaerobic curable composition mainly containing an organic peroxide and a fluororesin powder and / or microballoons. The composition of the present invention is used by being applied to various screws, and by fastening the screws, a monomer having an anaerobic curable (meth) acryloyl group is polymerized to fix the fastening parts of the screws. It has an anti-loosening effect and is widely used in industries such as automobiles, transportation machines, industrial machines, construction and electric machines.

[0002]

2. Description of the Related Art Conventionally, a fixing agent containing an anaerobic curable composition as a main component has been used for fixing, preventing loosening, and preventing falling of fastening parts such as bolts. As such a fixing agent, a one-pack type in which an anaerobic curable polymerizable monomer is mixed with an organic peroxide has been used. However, it is necessary to apply it at the time of screw tightening and uneven application in the application work. However, there were problems such as skin irritation of workers and odors, and a long curing time.

As a solution to the above-mentioned problems, a microcapsule type adhesive agent has been developed in which either or both of an anaerobic curable polymerizable monomer and an organic peroxide are encapsulated. The fixing agent not only solves the above-mentioned problems, but also makes it possible to dissolve or disperse a curable component in an organic solvent or water and apply the so-called precoat to the screw fastening portion in advance. Tightening the precoated screws destroys the inactivated microcapsules,
The monomer having a (meth) acryloyl group is polymerized and solidified to fix the fastening component.

[0004]

Some of the inventors of the present invention are
A composition suitable for preventing loosening of screws, which is already excellent in stability and has high adhesion breaking strength, has been proposed (JP-A-2-160).
881). However, a fixing agent containing such an anaerobic curable composition as a main component usually has a strong fixing force after fastening and has a high breaking strength at the time of loosening and returning, but also has a high escape torque and a returning torque after being loosened and returned. However, the screw may be broken or the mating female screw surface may be damaged, which makes it difficult to replace the screw.

Also, due to variations in screw precision, breaking strength is reduced when the gap between the male and female screws is large, and the applied adhesive agent is peeled off or scraped when the gap is small. was there. Usually, a steel material is used as the screw material, but when an aluminum material such as aluminum die cast is applied as the mating female screw material, there is a large possibility that the female screw material is damaged as described above.

The object of the present invention is to solve the above-mentioned problems, to exert excellent breaking torque strength when applied to a wide range of male screw members / female screw members, and to damage the fastening parts at the time of loosening and returning. To obtain a fixing composition for screws which does not cause

[0007]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a composition containing a monomer having a (meth) acryloyl group and an organic peroxide as main components. The present invention has completed the present invention by discovering a fixing composition for screws, which is characterized by containing a fluororesin powder and / or a microballoon.

Monomer having a (meth) acryloyl group The monomer having a (meth) acryloyl group in the present invention has one or more acryloyl groups and / or methacryloyl groups in one molecule. It is a monomer, for example, methyl acrylate and / or methyl methacrylate (hereinafter referred to as “methyl (meth) acrylate”).
same as below. ), Ethyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth)
Acrylate, tetrahydrofurfuryl (meth) acrylate, 2-hydroxyethyl (meth) acrylate,
Allyl (meth) acrylate, glycidyl (meth) acrylate, methoxyethyl (meth) acrylate, sulfopyropyl (meth) acrylate, 2-hydroxyethylacryloyl phosphite, acetoxyethyl (meth) acrylate, methylcarbitol (meth) acrylate, etc. (Meth) acrylate; ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, acrylic acid and / or methacrylic acid (hereinafter referred to as “(meth) acrylic acid”). Polyester di (meth) acrylate, diisocyanate, diol, and hydroxyalkyl (meth) acrylate obtained by polyesterification reaction by dehydration condensation of polybasic acid and polyol. The resulting polyurethane di (meth) acrylate, di (meth) acrylate of ethylene oxide adduct of bisphenol A, di (meth) acrylate of propylene oxide adduct of bisphenol A; and glycerin, trimethylolpropane Alternatively, a compound containing two or more (meth) acrylate structures obtained from a polyhydric alcohol such as pentaerythritol and (meth) acrylic acid may be used.

Of these (meth) acrylate monomers, di (meth) acrylate of an ethylene oxide adduct of bisphenol A and di (meth) acrylate of a propylene oxide adduct of bisphenol A are used in the case of the adhesive composition. It has excellent adhesive strength and is preferable.

Organic Peroxide A powdery or liquid organic peroxide can be used as it is if it is physically homogeneously mixed with other components constituting the present invention, but by encapsulating it. In addition, the pot life is improved, and a more excellent composition as a one-pack type adhesive can be obtained.

The encapsulation method is not particularly limited,
A fine powdery organic peroxide is dispersed in a urea-formalin prepolymer obtained by a methylolation reaction having a pH of 7.5 to 9, and then the pH is lowered to 2 to 3 and the reaction temperature is set to 3
The method of maintaining the temperature at 5 to 45 ° C. and encapsulating the produced polymer in the peroxide powder by the methylation reaction while encapsulating it is preferable because the water resistance and oil resistance of the capsule are excellent.

The organic peroxide used in the present invention includes hydroperoxide, ketone peroxide,
Dialkyl peroxide, peroxy ester oxide, diacyl peroxide and the like can be mentioned. An organic peroxide having a strong redox reactivity such as benzoyl peroxide has a high adhesive strength but has a short pot life. Therefore, it is particularly preferable to use by encapsulating according to the above method.

The amount of the organic peroxide used is 0.2 to 100 parts by weight of the (meth) acryloyl group-containing monomer.
It is preferably 5 parts by weight, and more preferably 0.5 to 3 parts by weight. If the amount is less than 0.2 parts by weight, the adhesive performance will not be sufficiently exhibited. On the other hand, if the amount is more than 5 parts by weight, the adhering performance will be deteriorated because the amount exceeds the appropriate amount and is mixed as a foreign substance, which is not preferable.

Fluorine Resin Powder Examples of the fluorine resin powder used in the present invention include powders of polytetrafluoroethylene, polyvinylidene fluoride, polytetrafluoroethylene / ethylene copolymer, fluorinated perfluoroalkyl ether and the like. . The type of such fluororesin powder is not particularly limited, but polytetrafluoroethylene is preferable for the purpose of reducing the escape torque, which is the object of the present invention, and has a low molecular weight of 25,000 to 250,000. More preferred is polytetrafluoroethylene. In addition, the particle size of the fluororesin powder is 20 from the viewpoint of being uniformly dispersed in the composition.
It is preferably 0 μm or less, more preferably 0.1 to 30 μm.
m. It is also possible to use a dispersant or the like together to disperse the fluororesin.

Microballoon The microballoon used in the present invention is a microsphere having a hollow inside, and is produced by a method such as a heat foaming method, a core material melting method, or a melt spraying method. Specific examples include inorganic microballoons such as sodium borosilicate, alumina, shirasu, fly ash and borax, and organic microballoons such as phenolic resins. Particularly preferred in the present invention are sodium borosilicate microballoons. The size of such a microballoon is preferably one having an average particle diameter of 1 mm or less, more preferably 1 to 200 μm, and particularly preferably 10 to 100 μm. If the particle size is too large, it will not be sufficiently filled in the groove of the screw, and if it is too small, the compounding effect of the microballoon will not be fully exerted. The true specific gravity is preferably 0.1 to 0.8.

○ Blending ratio The blending ratio of the monomer having a (meth) acryloyl group to the fluororesin powder and / or microballoon in the composition of the present invention is 100/1 to 100/50 by weight.
Is preferred, and more preferably 100/7 to 100/25
Is. If the blending ratio of the fluororesin powder and / or microballoon is small with respect to the monomer having a (meth) acryloyl group, it is difficult to obtain these blending effects, and if the blending ratio is too large, the composition after curing will be Easily becomes brittle,
In addition, there is a risk that an appropriate viscosity may not be obtained when applying to the screw.

Preparation Method As a preparation method of the composition of the present invention, a fluororesin powder and / or a anaerobic curable composition containing a monomer having a (meth) acryloyl group and an organic peroxide as main components is used. Any method can be used as long as it can uniformly mix and disperse the microballoons, and a known mixing method can be adopted.

For example, a monomer having a (meth) acryloyl group is surface-active and has a number average molecular weight of 3,000.
There is a method in which it is added dropwise to an aqueous solution of a polymer of about 50,000 with high stirring, and the resulting emulsion is mixed with a fluororesin powder and / or microballoons. In addition, there is also a method in which a fluororesin powder and / or microballoons are mixed in advance with a monomer having a (meth) acryloyl group, and the mixture is dropped into the above polymer aqueous solution under high stirring to prepare an emulsion.

As a polymer having a surface activity capable of emulsifying a monomer having a (meth) acryloyl group in water,
Acrylic ester-based resin obtained by copolymerizing 20 to 50% by weight of (meth) acrylic acid, polyvinyl alcohol having a saponification degree of 70 to 90 mol%, polyvinylpyrrolidone, ethylene-maleic anhydride copolymer, ethyl cellulose, methoxyhydroxypropyl Water-soluble polymers such as cellulose, hydroxypropyl cellulose, water-soluble nylon resin, urea resin, melamine resin, polyethylene oxide, polyethylene oxide-propylene oxide copolymer; acrylic ester resin emulsion, urethane emulsion, chloroprene polymer emulsion, butadiene Water-dispersible polymers such as acrylonitrile polymer emulsions. Among these polymers, the saponification degree is 70-9.
It is preferable to use 0 mol% of polyvinyl alcohol, a water-soluble or a nylon polymer which is soluble in a mixed solvent of water and alcohol, or a mixture thereof, because a tack-free film is formed after application to a screw.

In addition, a reducing agent may be added for the purpose of enhancing the curing performance and fixing performance of the anaerobic curable composition. Preferred types include organic acid salts such as copper, cobalt, and manganese for organic hydroperoxides or peroxyesters when they correspond to organic peroxides used at the same time; ethylenethiourea, tetramethylthiourea, and 2- Hydrophobic mercapto compounds such as mercaptobenzimidazole; hydrazine derivatives such as hydrazine, 2-hydroxyhydrazine and benzoylhydrazine; and others such as sodium p-toluenesulfinate, L-ascorbic acid and triethylenediamine.
Of these, use of ethylenethiourea or L-ascorbic acid is preferable because the reactivity is increased.

For diacyl peroxide, dimethylaniline, dimethyl-p-toluidine, diethyl-p-toluidine, N, N-dimethyl-p-anisidine, o-sulfobenzoic acid imide, mercaptoethanol, thiomalic acid. , Α-thiobutyric acid, thiolactic acid, mercaptoethylamine, o-salicylic acid and the like. Of these, dimethyl-p-toluidine or o-
The use of sulfobenzoic acid imide is preferable because the reactivity is increased.

The amount of the reducing agent used is 0.1 to 100 parts by weight of the (meth) acryloyl group-containing monomer.
It is preferably 5 parts by weight, and more preferably 0.3 to 2 parts by weight. If the amount is less than 0.1 part by weight, the redox reactivity is weak and the fixing performance is not exhibited at room temperature or below. If the amount is more than 5 parts by weight, the redox reaction mechanism loses balance and the fixing performance and pot life are lost. The performance tends to decrease, and each is unsuitable.

When chlorophylls are allowed to coexist in an anaerobic curable composition consisting of a monomer having a (meth) acrylate group and an organic peroxide, it is extremely stable when stored and stored under high temperature and high humidity conditions. A composition can be obtained.
Specific examples of chlorophylls include chlorophyll and compounds in which magnesium in chlorophyll is replaced with a metal such as copper, zinc or sodium, and a mixture of these two. Of these, copper chlorophyll sodium is preferred because of its high stability itself.

The amount of chlorophylls to be used is 0. 0 with respect to 100 parts by weight of the monomer having a (meth) acryloyl group.
01 to 5 parts by weight is preferable, and more preferably 0.1 to 5 parts by weight.
2 parts by weight. If it is less than 0.01 parts by weight, the effect of improving pot life is small, and if it exceeds 5 parts by weight, the effect hardly increases. The chlorophylls can be used as they are if they are uniformly mixed with the composition of the present invention, but it is more preferable to use them after being dissolved or dispersed in the water-soluble polymer.

Other Additives The adhesive composition of the present invention may contain appropriate additives for various purposes. Such additives are widely used in the art, and include, for example, carbon black, titanium oxide, zinc white, lead white, yellow lead, aluminum hydroxide, calcium carbonate, talc, clay, kaolin, white carbon, and carbon dioxide. Various additives such as pigments such as molybdenum sulfide, alumina, mica, glass fiber, zinc powder, and aluminum powder, fillers, reinforcing agents, viscosity modifiers, defoamers, leveling agents, antioxidants, and ultraviolet absorbers. To be Such additives can be added at an appropriate stage during production. Further, for the purpose of maintaining a long-term pot life property, hydroquinone, methylhydroquinone, 2,4-dinitriloanisole, 2,6-di-t-
It is also possible to add butyl-p-cresol and the like.

○ Screw The screw of an object to which the composition of the present invention is applied includes all those having a threaded portion such as a bolt, a screw and a nut. As its material, metals such as iron, brass, copper, aluminum, and stainless steel, metal base materials obtained by subjecting various metal materials to chemical conversion treatment, heat treatment, etc., metal base materials plated with zinc, chromium, nickel, etc., Further, a metal base material or the like which is subjected to chromate treatment or the like on such plating can be applied. In particular, a material obtained by subjecting an iron material to zinc plating and chromate treatment is inexpensive and has corrosion resistance, and is widely used in the industry.

For the purpose of improving the adhesion to a metal substrate and imparting rustproofness, various coating films should be provided on the screws in advance before applying the composition of the present invention. Is preferred. Examples of such coating film include epoxy resin type, acrylic resin type, phenol resin type, silicon resin type, and epoxy silicon resin type. The coating liquid can be applied by a method such as dip coating or spray coating, and a coating film is formed by heating and drying at an appropriate temperature.

○ Coating method The method of applying the composition of the present invention to a screw may be a known method. After adjusting the coating viscosity to an appropriate value, the screw shape, coating position, coating amount and other conditions Dip coating, flow coating,
A method such as spray coating or roll coating can be selected. The screw coated by such a method may be dried by heating to volatilize the solvent.

[0029]

The adhesive composition of the present invention comprises an anaerobic curable composition containing a (meth) acryloyl group-containing monomer and an organic peroxide as main components, and a fluororesin powder and / or microballoons. By doing so, it is possible to reduce the escape torque at the time of loosening and returning while maintaining the breaking strength of the adhesive, and the reason for this has not been clarified, but it is presumed as follows. When the anaerobic curable composition is polymerized and cured, the fluororesin powder is uniformly dispersed in the cured product. The breaking strength at the time of loosening and returning retains a high level of strength, but when it is continuously returned, the fluororesin powder has a lubricating action inside the cured product and at the screw metal interface, and an excessive amount of excess of the required amount is applied. It is possible to reduce the excessive torque strength at the time of returning generated by the composition or the like, and smoothly loosen and perform the returning operation. An anaerobic curable composition is needed to fill the gap between the male and female screws for fixing, but in reality, more than the required amount of the composition is applied, and excess composition should be loosened. This will cause extra torque between the female and male threads when returning. However, in the case of blending microballoons, even if the coated amount is large, the microballoons are destroyed and the volume decreases when the screws are fastened, so the coating amount during coating is an apparent amount, Since the amount of coating is adjusted to the amount that is truly required for fixing, no extra torque is generated when returning to loosen.

[0030]

The present invention will be described in more detail with reference to specific examples. The adhesive composition of the present invention was evaluated by the following test methods.

Application of Adhesive Composition to Screws Adhesive Composition 1 was applied to the thread groove of a hexagonal bolt having a diameter of 8 mm and a length of 40 mm, which had been treated with zinc-plated yellow chromate.
00mg is applied 20mm width in the circumferential direction, then 80
After heat-drying at 20 ° C. for 20 minutes, a locking screw having a tack-free coating formed on the threaded portion was obtained.

○ Adhesion test The above-mentioned coated screw was subjected to a torque of 250 kgfcm at a torque of 250 kgfcm, and a zinc-plated colored chromate-treated hexagon nut (8 mm
Diameter) and an aluminum die-cast female screw (8 mm diameter), and after standing at 23 ° C. for 2 hours, breaking torque, escape torque and returning torque were measured. The breaking torque is the torque strength when the torque wrench starts to rotate, the escape torque is the torque strength when the torque wrench makes 1/4 rotation, and the return torque is the rotation until the female screw is completely disengaged. Is the maximum return torque strength.

○ Pot life test of coated screws The above-mentioned coated screws were left in a humidifier at 50 ° C. and 95% RH for 5 days, and then the above adhesion test was conducted.

EXAMPLE 1 Preparation of Monomer Emulsion Having (Meth) acryloyl Group 860 g of pure water and Gohsenol GM were placed in a 2 liter beaker.
An aqueous solution was prepared by adding 100 g of -14 (partially saponified polyvinyl alcohol having a saponification degree of 86 mol% and an average polymerization degree of 1400, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.). Then, while stirring at 650 rpm with a propeller type stirring device, NK
BPE-200 {2,2-bis [4- (methacryloxydiethoxy) phenyl] propane, manufactured by Shin-Nakamura Chemical Co., Ltd.} 1000 g and AQ nylon A-70 (dimethylamino type substituted nylon manufactured by Toray Industries, Inc.) 66.7 g of a methanol solution containing 30% by weight of
Stirring was continued to obtain an aqueous emulsion. This emulsion had emulsion particles with a particle diameter of 2 to 6 μm and had a viscosity of 6000 cps.

Encapsulation of Organic Peroxide A 1 liter flask was charged with 350 g of a 37% by weight aqueous formalin solution, 131 g of urea and triethanolamine, and charged at 70 ° C. with a propeller-type stirring device for 30 minutes.
The mixture was stirred and reacted at 0 rpm for 2 hours to obtain a prepolymer having a pH of 8.1 and a viscosity of 775 cps. Next, 609 g of the above prepolymer aqueous solution and 609 g of pure water were charged into a 2 liter beaker, the pH was adjusted to 2.3 with 1N sulfuric acid, 12.8 g of benzoyl peroxide fine powder was added, the temperature was raised to 40 ° C., and the homogenizer was used. At 4000 rpm
After the reaction was carried out for 6 hours under stirring of No. 1, the reaction was continued for 14 hours under stirring at 300 rpm using a propeller-type stirring device. The resulting slurry was neutralized with a 1N aqueous solution of caustic soda, washed with pure water and methanol, and the filtered solid matter was dried at 40 ° C. As a result, 25% by weight of benzoyl peroxide was contained, and a urea resin was used as a wall film. Particle size of 20 to 50
51.2 g of μm capsules were obtained.

Preparation of Adhesive Composition The total amount of the (meth) acrylate monomer emulsion obtained above, 40 g of encapsulated organic peroxide (containing 10 g as benzoyl peroxide), 7 g of dimethylparatoluidine, 5 g of chlorophyll and 50 g of Lubron L-2 (low molecular weight polytetrafluoroethylene fine powder, manufactured by Daikin Industries, Ltd.) were placed in a 2 liter beaker and stirred with a homogenizer at 2000 rpm for 5 minutes to give an aqueous adhesive composition. Obtained. The results of evaluation of the adhesive composition according to the above method are shown in Table 1.

Examples 2 to 11 and Comparative Examples 1 to 3 The kinds and amounts of the fluororesin powder in Example 1 were changed, and microballoons were used instead of the fluororesin powder, and the kinds and the amounts were changed. The evaluation results of the adhesive composition prepared and prepared in exactly the same manner as in Example 1 are shown in Tables 1 and 2.

Examples 12 to 16 The kinds and amounts of the (meth) acryloyl group-containing monomer, organic peroxide, reducing agent and chlorophyll in Example 1 were changed as shown in Table 3, and other conditions were the same as those of Example 1. Table 3 shows the evaluation results of the adhesive composition obtained by preparing in the same manner as in 1.

Example 17, Comparative Example 4 As a screw, a hexagonal bolt having a diameter of 8 mm and a length of 40 mm was subjected to a zinc-plated colored chromate treatment and an anticorrosive coating agent K.
Coat K-103 (weight concentration: 17% by weight, manufactured by Toagosei Chemical Industry Co., Ltd.) was applied by dip coating, and dried by heating at 80 ° C. for 20 minutes, and the composition of Example 2 was applied. Further, the composition of Example 2 was applied by changing the material to galvanized bright chromate, iron, and stainless steel (SUS304). A fixation test was conducted using a zinc-plated colored chromate treated nut as the female screw material. Similarly, the composition of Comparative Example 1 was applied and a sticking test was conducted. These results are shown in Table 4.
Note.

Examples 18 and 19 and Comparative Example 5 As a screw, a hexagonal bolt having a diameter of 8 mm and a length of 40 mm was treated with zinc-plated colored chromate and treated with an anticorrosive coating agent K.
Coat K-103 (weight concentration: 17% by weight, manufactured by Toagosei Chemical Industry Co., Ltd.) was applied by dip coating, and dried by heating at 80 ° C. for 20 minutes, and the composition of Example 2 was applied. Tighten this to the zinc plated colored chromate treated nut, 1
After standing for a day, it was subjected to a salt spray test (JIS-Z2371). The generation state of white rust after 360 hours was evaluated. Similarly, a salt spray test test was performed on such a screw without an anticorrosion coating and also on a screw without a coating of a fixing agent. The results are shown in Table 5.

[0041]

[Table 1]

[0042]

[Table 2]

[0043]

[Table 3]

[0044]

[Table 4]

[0045]

[Table 5]

[0046]

EFFECTS OF THE INVENTION The adhesive composition of the present invention has a long pot life even under conditions of high temperature and high humidity, has a high degree of adhesiveness to various base materials, and has a mating screw that is used even when loosened and returned. It is extremely easy to handle without damage. The composition of the present invention is suitable for the use of a screw in which the thread part is pre-coated in advance and a film is formed with the adhesive composition. The adhesive composition of the present invention is most suitable for use in locking and fixing in applications such as automobiles, electric equipment, office equipment, etc., and greatly contributes to various industries.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Asaji Isobe 1 Toago, 1 Funami-cho, Minato-ku, Nagoya-shi, Aichi Toagosei Chemical Industry Co., Ltd. Nagoya Research Institute

Claims (1)

[Claims] 1. Fixing for screws, which is obtained by blending a fluororesin powder and / or microballoons into an anaerobic curable composition containing a monomer having an acryloyl group and / or a methacryloyl group and an organic peroxide as a main component. Agent composition.