JP2003313206A - Anaerobic curable composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a storage-stable anaerobic curable composition which thermally cures the resin component forced out of an adhered part at a low temperature for a short time. <P>SOLUTION: This anaerobic curing composition consists of (a) a compound having at least one radically polymerizable functional group, (b) an organic peroxide, (c) o-benzoic sulfimide, and (d) carbon powder. Preferably the composition contains 100 pts.wt. (a), 0.1-5 pts.wt. (b), 0.5-5 pts.wt. (c), and 0.01-50 pts.wt. (d). <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an anaerobic curable composition having the properties of conventional anaerobic curable adhesives and having the property of being cured by heating even in the presence of air.

[0002]

2. Description of the Related Art An anaerobic curable composition is stable in a liquid state without gelation for a long time while being in contact with air or oxygen (hereinafter simply referred to as "air") containing a (meth) acrylic acid ester monomer as a main component. The composition has a property of being rapidly cured when air is blocked or excluded, and by utilizing such a property, the composition is adhered, fixed, fixed to fitting parts such as screws and bolts, It is used for adhesion between flange surfaces, sealing, filling of cavities that occur in cast parts, etc.

[Problems to be Solved by the Invention]

The anaerobic curable composition is cured by starting the polymerization reaction by cutting off the contact with air by sticking or fitting the applied parts. Therefore, there is a drawback in that the anaerobic composition is applied in a large amount and the portion protruding from the adhesive portion is in contact with air and is not cured but remains uncured as it is. The uncured anaerobic composition that squeezes out and drips to other sites may contaminate the surroundings, or volatile components may be generated due to natural evaporation, which may adversely affect other sites. In order to solve such a problem, a method of imparting photocurability to the anaerobic curable composition and applying ultraviolet rays to the protruding portion which is anaerobic and does not cure to cure the composition has been considered. Also, an adhesive or the like has been used which has a resistance to drooping such as increasing the viscosity so that the protruding portion does not run down.

However, in the case of imparting photocurability, a light irradiator must be prepared, and the protruding portion is not always exposed to the light, and the portion which is not exposed or is hard to contact is still uncured. Met. Further, when the viscosity is increased so that the composition does not run down, the workability during application is deteriorated, and an anaerobic curable composition that can satisfy the drawbacks has not been obtained.

An anaerobic curable composition to which heat-curability is imparted can cure the protruding portion. However, the mechanism of anaerobic curing is achieved by coexisting a component for polymerizing a radically polymerizable compound and a factor for suppressing the polymerization of the radically polymerizable compound, and appropriately balancing the two components. Therefore, if a large amount of peroxide is added in order to impart heat-curability, or if a peroxide with a low decomposition temperature (half-life temperature) is used,
The storability of the anaerobic curable composition is extremely deteriorated and the storability as an industrial product cannot be achieved.

Even if a large amount of peroxide is added to impart heat-curability at the expense of storage stability, the surface of the protruding portion remains unhardened due to the inhibition of hardening by oxygen. I will follow you.

[0007]

The present invention overcomes the above-mentioned conventional problems, namely, (a) a compound having at least one radically polymerizable functional group in the molecule, (b) an organic compound. An anaerobic curable composition comprising a peroxide, (c) o-benzoxulfimide and (d) carbon powder. Is provided.

The compound (a) having at least one radically polymerizable functional group in the molecule used in the present invention is a monomer, oligomer or polymer having a vinyl group such as acrylic acid or methacrylic acid in the molecule. Is mentioned. More specific examples of the polymerizable monomer include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth). Monoesters such as acrylates; 2-hydroxyethyl (meth) acrylate, 2
Hydroxyalkyl esters such as hydroxypropyl (meth) acrylate; ethylene glycol diacrylate, polyethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate,
Polyvalent esters such as trimethylolpropane tri (meth) acrylate, pentaerythritol tetraacrylate, etc. are not limited to these and are generally used in the field of anaerobic adhesives. These polymerizable monomers can be used alone or as a mixture of two or more kinds.

Examples of the polymerizable oligomer include a curable resin having a maleate group, a fumarate group, an allyl group and a (meth) acrylate group, an isocyanate modified acrylic oligomer, an epoxy modified acrylic oligomer, a polyester acrylic oligomer, a polyether acrylic. Oligomer and the like can be mentioned, and these oligomers can be used alone or as a mixture of two or more kinds. The polymerizable oligomer can be appropriately contained for the purpose of adjusting the viscosity of the anaerobic curable composition or adjusting the characteristics of the cured product.

Examples of the polymerizable polymer include polymerizable unsaturated polymers such as unsaturated polyester resins and unsaturated acrylic resins. This polymerizable unsaturated polymer is preferably used in combination with the above polymerizable monomer.

The (b) organic peroxide used in the present invention has been conventionally used in an anaerobic curable composition.
It is not particularly limited, and for example, cumene hydroperoxide, t-butyl hydroperoxide,
p-menthane hydroperoxide, methyl ethyl ketone peroxide, cyclohexane peroxide,
Examples thereof include hydroperoxides such as dicumyl peroxide and diisopropylbenzene hydroperoxide, and organic peroxides such as ketone peroxides, diallyl peroxides and peroxyesters.

These organic peroxides can be used alone or as a mixture of two or more kinds. The blending amount of the component (b) is 0.1 with respect to 100 parts by weight of the component (a).
~ 5 parts by weight. In this case, if the amount is less than 0.1 part by weight, the polymerization reaction is insufficient, and if the amount is more than 5 parts by weight, the stability of the anaerobic curable composition decreases.

The component (c) used in the present invention is o
-Benzoxulfimide, a component commonly used in anaerobic compositions. o-Benzoxulfimide is so-called saccharin, and the amount of component (c) added is 0.5 to 5 parts by weight per 100 parts by weight of component (a).

The component (d) used in the present invention is carbon powder, and examples thereof include graphite powder such as artificial graphite and natural graphite, carbon black, pyrolytic carbon and coke powder. The particle size of the carbon powder is 0.1 to 50 μm. (D)
The component may be added in an amount of 0.01 to 50 parts by weight based on 100 parts by weight. If it is less than 0.01, the heat-curability cannot be expected, and if it is more than 50 parts by weight, the physical properties of the cured product become hard.

The component (d) may be added, for example, in order to impart conductivity to the resin, but it has been considered that it does not contribute to the curability, but it is usually added to the anaerobic composition. It did not contribute to the anaerobic curability and was not expected to have the effect of improving the heat curability and the surface curability. Further, the heat curability can be improved, but the storage stability is not deteriorated.

In addition to the above-mentioned components, the composition may further contain a small amount of components that promote polymerization. Examples of the polymerization accelerator include amine compounds, mercaptan compounds, and hydrazine derivatives. Amine compounds are 1, 2,
Heterocyclic secondary amines such as 3,4-tetrahydroquinoline and 1,2,3,4-tetrahydroquinaldine, heterocyclic tertiary amines such as quinoline, methylquinoline, quinaldine and quinoxalinephenazine, N, N-dimethyl -Aromatic tertiary amines such as anisidine, N, N-dimethylaniline, 1,2,4-triazole, oxazole, oxadiazole, thiadiazole, benzotriazole, hydroxybenzotriazole, benzothiazole, benzoxazole, 1 , 2,3 benzothiadiazole, 3-mercaptobenzotrizole and other azole compounds. Examples of the mercaptan compound include linear mercaptans such as n-dodecyl mercaptan, ethyl mercaptan and butyl mercaptan. Ethylcarbazate, N as the hydrazine derivative
-Aminolhodanine, acetylphenylhydrazine, p
-Nitrophenylhydrazine, p-trisulfonylhydrazide and the like can be mentioned, but the invention is not limited thereto.

The mixing ratio of these polymerization accelerators is such that the weight of the polymerizable monomer or the polymerizable monomer and oligomer and / or
Alternatively, the weight of the mixture with the polymerizable unsaturated polymer is 0 to 1 part by weight, preferably 0.1 to 100 parts by weight.
0.5 parts by weight. If the blending ratio of the polymerization accelerator is less than 0.1 part by weight, the effect as the polymerization accelerator is not obtained, and the content of 0.
When it exceeds 5 parts by weight, the storage stability of the anaerobic composition is deteriorated.

The present invention can further use various additives.
For example, in order to obtain storage stability, radical absorbers such as benzoquinone, hydroquinone and hydroquinone monomethyl ether, ethylenediaminetetraacetic acid or 2-
It is also possible to add a metal chelating agent such as sodium salt, oxalic acid, acetylacetone, o-aminophenol and the like.

Further, conventionally used polymerization accelerators such as mercaptans and amines may be added to such an extent that the storage stability of the composition is not deteriorated. In addition, in order to adjust the properties of the anaerobic curable resin and the properties of the cured product, a thickener, a filler, a plasticizer, a colorant and the like can be used if necessary.

[0020]

DETAILED DESCRIPTION OF THE INVENTION

EXAMPLES Hereinafter, the excellent effects of the present invention will be proved by Examples. All formulations in the table are parts by weight.
Polyethylene glycol # 200 dimethacrylate as component (a): product name 4G (manufactured by Shin-Nakamura Chemical Co., Ltd.), dipentaerythritol hexaacrylate: product name: DPH
-A (manufactured by Nippon Kayaku Co., Ltd.) was used. As the organic peroxides 1 and 2 of the component (b), cumene hydroperoxide and perbutyl I (NOF: tert-dimethyl-
2,5-bis (m-toluol peroxy) h
exane) and (c), o-benzoxulfimide is used as the other component, and EDTA.
2Na, using Aerosil # 200 (manufactured by Nippon Aerosil Co., Ltd.) as a filler, using NICABEADS: MC-0520 (Nippon Carbon) and carbon powder (Soekawa Rikagaku) as the carbon powders 1 and 2 of the component (d). An anaerobic adhesive was prepared with the compounding amounts shown in Table 1. The test piece used for the test is a material SPCC-SD, 100 mm x 25 m
m (JIS G 3141) was used.

100 m of each composition prepared as described above
Drop two drops on an mx25mm iron test piece at each temperature,
Each time was evaluated. The evaluation results are shown in Table 1. The standard of curability was set as follows. On a scale of 0 to 5, 0: no cured product, 1: some cured product, 2: half cured, 3: almost cured, surface not yet cured, 4: surface also cured, slightly tacky, 5: complete Hardened. Further, the storage stability test was stored at 40 ° C. for 3 months, and it was confirmed whether a gelled product was formed. Those that did not thicken or gel were evaluated as ◯, those that did not gel but increased in viscosity were evaluated as Δ, and those that gelled were evaluated as x. Further, the curability test of the sample subjected to the storage stability test was performed. The degree of curing was measured by heating at 120 ° C. for 2 hours. The results are shown in Table 1. As can be seen from the table, it was confirmed that the addition amount of the carbon powder and the curability were almost the same, and a large difference could be confirmed between those with and without addition of carbon.

[0022]

[Table 1]

[0023]

EFFECT OF THE INVENTION Until now, the protruding portion of the anaerobic adhesive could not be cured unless a primer or UV curability was applied. Further, although it was possible to impart the heat curability at the sacrifice of the storage stability of the anaerobic curability, it cannot be sufficiently cured unless it is performed at a high temperature for a long time,
Further, depending on the composition, it was difficult to cure the surface even by heating at high temperature for a long time. However, in the present invention, it is possible to perform heat curing at a low temperature in a short time without deteriorating the storage stability of anaerobic curability.

Claims (2)

[Claims] 1. A compound having at least one radically polymerizable functional group in a molecule, (b) an organic peroxide, (c) an o-benzoxulfimide and (d).
An anaerobic curable composition comprising a carbon powder. 2. Each component of (a) is 100 parts by weight,
(B) 0.1 to 5 parts by weight, (c) 0.5 to 5 parts by weight,
(D) 0.01 to 50 parts by weight, the anaerobic curable composition according to claim 1.