JP2019163385A - Epoxy-containing modified silicone resin composition - Google Patents

Abstract

To obtain a resin composition that allows epoxy-containing modified silicone to cure without addition of a tin catalyst, with a moderate curing speed and excellent storage stability, the cured product having sufficient adhesive strength.SOLUTION: A resin composition contains a modified silicone compound having a urethane bond represented by formula (1), a diglycidyl ether compound having one to three bisphenol A repeating units, and a ketimine compound.SELECTED DRAWING: None

Description

  The present invention relates to an epoxy-containing modified silicone adhesive.

Conventionally, epoxy resin adhesives are used as heat-resistant adhesives. However, epoxy resin-based adhesives are known to have a cured product lacking in flexibility, and those in which rubber is added and those in which the main chain or side chain of the epoxy compound is modified with a urethane group or various rubbers are known. However, it was not satisfactory in terms of heat resistance.

In recent years, in order to relieve stress of this epoxy resin adhesive, an adhesive added with modified silicone has been developed.

  Patent Documents 1 and 2 show examples in which a modified silicone in which a hydrolyzable silyl group is directly bonded to the terminal of polyglycol is used. An example of a two-component type composed of this modified silicone, a hydrolysis catalyst, an epoxy resin, and an epoxy curing agent is shown. Since it is two liquids, it was necessary to stir immediately before use, which put a load on the consumer. In addition, when this hydrolyzable silyl group is condensed, this modified silicone cures slowly, so that a tin catalyst is essential, which places a burden on the environment.

JP2007-99806 JP 2014-227427 A JP 2010-77226 A JP2012-509374

Patent Document 3 describes an example in which a modified silicone of a type different from Patent Document 1 and Patent Document 2 is used.
This modified silicone utilizes Michael addition when reacting 3-aminopropyltrimethoxysilane with methyl acrylate. Therefore, it took a long time to synthesize the modified silicone. Moreover, when condensing a hydrolyzable silyl group, a fluorine compound is selected instead of a tin catalyst. Although a tin catalyst was not included, the fluorine compound was not preferable from the viewpoint of the water pollution prevention method.

  In Patent Document 4, a modified silicone similar to that of the present application is used, a tin catalyst is not added, and measures are taken with respect to environmental load, but there is room for improvement in terms of adhesive strength.

  Even without adding a tin catalyst, the epoxy-containing modified silicone is cured, has an appropriate curing speed and good storage stability, and obtains a resin composition in which the cured product has sufficient adhesive strength.

  The present inventors include a modified silicone compound having a urethane bond represented by the formula (1), a bisphenol diglycidylate compound represented by the bisphenol A type epoxy compound represented by the formula (2), and a ketimine compound. It came to provide the resin composition. In particular, it has been found that this composition does not hold for amine compounds other than ketimine compounds.

  Since the epoxy-containing modified silicone resin composition of the present invention does not contain a tin catalyst, it is environmentally friendly, has an appropriate reaction speed and good storage stability, and its cured product has sufficient adhesive strength. It can be used as an adhesive for various applications.

  Provided is a resin composition comprising a modified silicone compound having a urethane bond represented by the formula (1), a bisphenol diglycidylate compound represented by the bisphenol A type epoxy compound represented by the formula (2), and a ketimine compound. .

FIG. 1 shows the basic structure of the modified silicone of the present application. The modified silicone of the present application is made of a polyalkylene glycol such as polyethylene glycol or polypropylene glycol, a polyester polyol, or a part (I ), Part (II) which is a urethane bond obtained by reacting isocyanate and alcohol, and part (III) consisting of alkylene and a hydrolyzable silyl group.
A diol that is a basic skeleton, a compound having a hydrolyzable silyl group at one end of an alkylene chain having 1 to 3 carbon atoms, and an isocyanate attached at the other end, and the latter being added twice as much as the latter Can do.

Such a compound is commercially available, and from Wacker Chemie Aktiengesellschaft, Z is propylene glycol and m is 1 carbon compound having the basic skeleton represented by formula (1). -E10, trade name: STP-E30, m is 3 carbon number 3 compound, trade name: STP-E15, trade name: STP-E35 is sold.
In any case, formula R1 is methyl, n is 1, and X is methoxy.

  Examples of bisphenol diglycidylate compounds represented by the bisphenol A type epoxy compound used in the present composition include bisphenol A diglycidylate (BPAE), bisphenol F diglycidylate, bisphenol E diglycidylate, bisphenol S diglycidylate and the like. And may be a hydrogenated (hydrogenated) type. As for the molecular weight, the epoxy basic structural formula is shown in the formula (1), but it is not always necessary to use n = 0 isomer. When a viscosity other than n = 0 is used and the viscosity is high and the workability is not satisfactory, the dilution ratio may be increased.

  Examples of commercially available ketimine compounds used in the composition of the present application include Adeka Corp., trade name: Adeka Hardener EH-235R-2, Nitto Kasei Co., Ltd., product name: Eponit K-100, and the like.

If necessary, the composition of the present application may contain a diluent, a plasticizer, an inorganic and organic filler, a thixotropic agent, a silane coupling agent having no amino group, and an antioxidant.
Examples of the diluent include glycidylated aliphatic compounds and glycidylated ether compounds, and the number of glycidylated compounds is arbitrary. Representative examples include Yokkaichi Gosei Co., Ltd., trade name: DY-BP (butyl glycidyl ether), trade name: CY-BP (butyl glycidyl ether), trade name: EPOGOSE EN (C12-13 mixed alcohol glycidyl ether), product Name: Epogosay AN (C12-13 mixed alcohol glycidyl ether), trade name: Epogosay 2EH (2-ethylhexyl glycidyl ether), trade name: Epogosay HD (M) (1,6-hexanediol diglycidyl ether), etc. .

  Examples of the plasticizer include compounds that are compatible with the composition of the present application, such as glycol-based, (hydrogenated) phthalate-based, and xylene resin-based.

Inorganic fillers include calcium carbonate, silica, calcium oxide, kaolin, calcined kaolin, clay, calcium silicate, calcium sulfate, aluminum oxide (alumina), aluminum hydroxide, aluminum silicate, titanium oxide, zinc oxide, magnesium carbonate, silicic acid Examples include magnesium, talc, zeolite, glass beads, and shirasu balloon.
Examples of the organic filler include polyethylene, polypropylene, polymethyl methacrylate, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer, ethylene-vinyl acetate copolymer, nylon, polyethylene terephthalate. , Polybutylene terephthalate, polystyrene, ABS resin, acrylonitrile-styrene copolymer, polycarbonate and the like.
Examples of thixotropic agents include fumed silica, amide wax, polyvinyl alcohol, butyral resin, methylcellulose, carboxymethylcellulose, carboxyethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, polyacrylamides, starch, gelatin, casein and metal salts thereof, Arabic Examples thereof include rubber, polyethylene oxide, guar gum and the like.

  Examples of silane coupling agents having no amino group include epoxy silanes such as 3-glycidoxypropylmethyldimethoxysilane and 3-glycidoxypropyltrimethoxysilane, vinylsilanes such as vinyltriethoxysilane and vinyltrimethoxysilane. And methacryl silanes such as 3-methacryloxypropylmethyldimethoxysilane and 3-acryloxypropyltrimethoxysilane and acrylic silanes, and mercaptosilanes such as 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane.

  Examples of the antioxidant include phosphorus-based, hydroquinone-based, bis-tris-polyphenol-based, thiobisphenol-based and hindered phenol-based antioxidants.

  In the present application composition, a catalyst containing no tin can be added to adjust the reaction rate. As the catalyst, a bismuth catalyst, a titanium catalyst, a metal complex, a platinum catalyst, a basic substance, an organic phosphorous oxide, or the like is used. Examples of the bismuth catalyst include Nitto Kasei Co., Ltd., trade name: Neostan U-600, and the like.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and demonstrated in detail about this invention, a specific example is shown and it does not specifically limit to these. All the parts are parts by weight.

Liquid preparation STP-E10 of Example 1 : 77.5 parts by weight, BPAE: 15 parts by weight, and Eponit K-100: 7.5 parts by weight were weighed and stirred until uniform.

Liquid preparation of Examples 2 to 5 and Comparative Examples 1 to 4 The liquids of Examples 2 to 5 and Comparative Examples 1 to 4 were prepared in the same proportions as the liquid preparation of Example 1 at the mixing ratio shown in Table 1. did.
Note that EST-280 is a modified silicone manufactured by Kaneka Co., Ltd., and does not contain part (II) at the end of polyglycol, which is part (I) in FIG. 1, and does not contain the alkylene part of part (III). It is a modified silicone with a hydrolyzable silyl group.
Neostan U-600 is a bismuth catalyst manufactured by Nitto Kasei Co., Ltd., Baxodur EC 201 is an isophorone diamine manufactured by BASF, and OFS 6020 is an aminosilane manufactured by Toray Dow Corning.

Viscosity measurement Measured according to JIS Z 8803. Using a cone plate viscometer manufactured by Toki Sangyo Co., Ltd., trade name: RE550R, the viscosity at 3 ° R7.7, 10 rpm, 60 sec was measured. The measurement temperature is 25 ± 1 ° C. The composition viscosity is in the proper range of 5 to 50 Pa · s.

Storage Stability The liquids of Examples 1 to 5 and Comparative Examples 1 to 4 were packed in an aluminum tube and allowed to stand in a 50 ° C. thermostat, and the state of the liquid was confirmed after 1 week. The case where it was not gelled was indicated as (◯), and the case where it was gelled was indicated as (x).

Skin coating test Examples 1 to 5 and Comparative Examples 1 to 4 were bead-coated on a release paper in a width of 8 mm and a length of 150 mm, left in a 23 ± 1 ° C. environment, and touched with a finger. The time at which no sticks to the finger was defined as the skinning time. The case where the skinning time was shorter than 10 hours was (◯), and the case where it was 10 hours or longer was taken as (x). In this test, the evaluation sample (x) is not subjected to hardness measurement or adhesive strength measurement.

Hardness measurement Measured according to JIS K 6253. On the polytetrafluoroethylene sheet, a mold of 50 mm × 50 mm × 10 mm thickness was prepared with silicone rubber, and the liquids of Examples 1 to 5 and Comparative Examples 1 to 4 were poured into the liquid so that the liquid level was horizontal. . The sample was cured at 23 ° C./50% RH for one week, and the test piece was taken out of the mold and used as a hardness measurement test piece.
The initial value was measured with a type A hardness meter manufactured by Teclock. The measurement temperature is 23 ° C. ± 2 ° C. As for composition hardness, type A hardness is 20-50.

Adhesive strength test The shear strength of Lauan plywood was measured.
A 50 μm thick cellophane tape was attached to a 70 mm × 25 mm × 4 mm thick lauan plywood so that the short-side line of the lauan plywood and the end-side line of the cellophane tape were parallel to form a masking material. Apply the liquids of Examples 1 to 5 and Comparative Examples 1 to 4 to the lauan plywood with the masking material, using a spatula, and apply the masking material to the lauan plywood with another masking material The applied parts were overlapped so as to be in contact with the liquid, adjusted so that the distance between the masking material and the masking material was 25 mm, and fixed with clips. This was left still at 23 ± 2 ° C. for 1 week, the clip was removed, and the protruding cured product was scraped off with a cutter knife to obtain a shear strength measurement test piece.
The shear strength of this test piece for measuring the shear strength was measured in a 23 ± 2 ° C. environment at a pulling speed of 50 mm / min. The case where the shear strength was 0.8 MPa or more was indicated by (◯), and the case where the shear strength was less than 0.8 MPa was indicated by (×).

  In Examples 1 to 5, in which (A), (B), and (C) were added to the composition, the viscosity, storage stability, skin test, hardness, and adhesive strength test were all within the appropriate ranges.

  In FIG. 1, a modified silicone having a hydrolyzable silyl group directly without hydrolyzable silyl groups, which does not contain part (II) and does not contain the alkylene part of part (III) at the end of polyglycol, which is part (I). Although the comparative example 1 used had good storage stability, the curing was slow, the skin test could not be cleared, and the hardness and adhesive strength of the previous test could not be measured.

In Comparative Example 2 using isophoronediamine and Comparative Example 3 using aminosilane instead of the ketimine compound of (C), although there is no problem in physical properties, both were gelated in the storage stability confirmation. It was shown that the stability of the liquid was very bad.
In general, amines at the silane coupling agent level rarely contribute to liquid stability, and it was strongly shown that this combination must be a ketimine compound.

  In Comparative Example 5 in which the bisphenol diglycidylate compound (B) was not added, the adhesive strength was low, indicating that there was difficulty in using it as a general-purpose adhesive.

Claims (2)

A resin composition comprising a modified silicone compound (A) having a urethane bond represented by formula (1), a bisphenol-based diglycidylate compound (B) represented by formula (2), and a ketimine compound (C).
... (1)
In the formula (1), X represents a hydrolyzable group, R 1 represents a hydrocarbon group having 1 to 20 carbon atoms or a hydrocarbon group having a substituent, and n represents 0, 1 or 2. m is 1 to 3, and Z is a polyalkylene glycol, polyester polyol, or a moiety obtained by condensing an alkylene diol having 5 to 60 carbon atoms and an isocyanate compound.

... (2) An article bonded using the resin composition according to claim 1.