JP2014210893A - Self-adhesive filling resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a self-adhesive filling resin composition which comprises a room temperature-curable silicone rubber composition capable of being curable in a short time under room temperature, a cured material of which shows extremely little yellowing even when kept at a high temperature for a long period of time and which has good transparency and adhesiveness.SOLUTION: The self-adhesive filling resin composition comprises a diorganopolysiloxane (A) with both molecular chain terminals capped with silanol groups or alkoxy groups, an organosilane represented by the general formula (R)SiXor a partial hydrolysis condensate thereof (B), and an epoxyalkylalkoxysilane (C) represented by the general formula Q-R-Si-(R)(OR).

Description

The present invention is a condensation reaction curable silicone resin composition that can be used as an encapsulant for an optical semiconductor substrate such as an LED, and has good adhesion to a glass epoxy substrate serving as an LED substrate at room temperature. The present invention relates to a self-adhesive filling resin composition that can be cured in a short time and has good transparency and yellowing resistance.

Conventionally, an addition reaction curable silicone resin composition has been used as a sealant for an optical semiconductor substrate such as an LED (Patent Documents 1 to 4). However, the addition reaction curing type requires a long time to cure at room temperature, and heating is necessary to accelerate the curing, resulting in high energy costs and the need for dedicated equipment for heat curing.

  On the other hand, it is a room temperature curable silicone rubber composition that can be cured in a short time by room temperature curing and has good adhesion to substrates such as glass, aluminum, concrete and plastic. A silicone rubber composition has been proposed (Patent Document 5).

Japanese Patent Laid-Open No. 2004-2784 JP 2004-266134 A Special table 2007-502346 gazette JP 2007-63538 A Japanese Patent Publication No. 7-86172

  However, the room temperature curable silicone rubber composition disclosed in Patent Document 5 may turn yellow when it is placed at a high temperature of about 150 ° C. for a long time. D) Since the organosilicon group-containing isocyanuric acid ester represented by the general formula (III) is expensive, there is a problem that a sealing agent for an optical semiconductor substrate such as an LED using the organosilicon group is also expensive.

  As a result of earnest research to solve the above-mentioned problems, the present inventor does not use the organosilicon group-containing isocyanuric acid ester as an adhesion-imparting component of the self-adhesive filling resin composition, and can be obtained at a lower cost. Self-adhesive filling resin with extremely low degree of yellowing of cured product and good transparency and adhesiveness even when it is used for a long time at a high temperature of about 150 ° C. It is to provide a composition.

The invention described in claim 1 includes a diorganopolysiloxane (A) having both molecular chain ends blocked with silanol groups or alkoxy groups, and a general formula (R ¹ ) _a SiX _4-a (wherein R ¹ is 1). X represents an organic group selected from the group consisting of an alkoxy group, an enoxy group, an organoketoxime group and an organoamide group bonded to a silicon atom, and a represents 0 or Or a partially hydrolyzed condensate thereof (B) and a general formula Q—R ² —Si— (R ³ ) _b (OR ⁴ ) _{3 -b} (wherein R ² is carbon) Represents a divalent hydrocarbon group having 1 to ⁴ carbon atoms, R ³ and R ⁴ represent a monovalent hydrocarbon group having 1 to ⁴ carbon atoms, Q represents a glycidoxy group or an epoxycyclohexyl group, and b represents 0 or 1) It provides a self-adhesive potting composition characterized by containing an epoxy alkyl alkoxysilane (C) that.

The invention according to claim 2 is based on 100 parts by weight of the organopolysiloxane (A), 0.5 to 25 parts by weight of the organosilane or a partial hydrolysis condensate (B) thereof, and the epoxyalkylalkoxysilane ( The self-adhesive filling resin composition according to claim 1, wherein 0.1 to 20 parts by weight of C) is contained.

The resin composition for self-adhesive filling of the present invention can be cured for a short time at room temperature, and the degree of yellowing of the cured product even when placed at a high temperature of about 150 ° C. for a long time. There is an effect that it is extremely small and has excellent transparency and adhesiveness. And it can be manufactured at a lower cost by using only the components that are available at a lower cost without using the organosilicon group-containing isocyanuric acid ester as an adhesiveness-imparting component of the resin composition for self-adhesive filling. effective.

The present invention will be described in detail below.

The self-adhesive filling resin composition according to the present invention comprises a diorganopolysiloxane (A) in which both molecular chain ends are blocked with silanol groups or alkoxy groups, and a general formula (R ¹ ) _a SiX _4-a (formula Wherein R ¹ represents a monovalent substituted or unsubstituted hydrocarbon group, and X represents an organic group selected from the group consisting of an alkoxy group, an enoxy group, an organoketoxime group and an organoamide group bonded to a silicon atom. And a partial hydrolysis-condensation product (B) thereof represented by the general formula Q—R ² —Si— (R ³ ) _b (OR ⁴ ) _{3 -b} (formula) R ² represents a divalent hydrocarbon group having 1 to ⁴ carbon atoms, R ³ and R ⁴ represent a monovalent hydrocarbon group having 1 to ⁴ carbon atoms, and Q represents a glycidoxy group or an epoxycyclohexyl group. B is 0 May be formulated contains an epoxy alkylalkoxysilane represented by representing the 1) (C), the silanol condensation catalyst if necessary, silicone oil, a thixotropic agent, an additive such as a rust preventive.

Diorganopolysiloxane (A) in which both ends of the molecular chain are blocked with silanol groups or alkoxy groups
The diorganopolysiloxane (A) in which both ends of the molecular chain used in the present invention are blocked with a silanol group or an alkoxy group is generally used in a room temperature curable condensation type polyorganosiloxane composition. The diorganopolysiloxane (A) is blended in order to give an appropriate fluidity to the composition before curing and to give excellent mechanical properties to the rubber-like elastic body after curing, and the viscosity at 25 ° C. is 100 Desirably ˜500,000 cSt. If the viscosity is less than 100 cSt, the mechanical properties of the rubber-like elastic body after curing are insufficient, and if it exceeds 500,000 cSt, it is difficult to obtain a uniform composition and the fluidity is deteriorated. More preferably, the viscosity at 25 ° C. is 2,000 to 100,000 cSt. If it is less than 2000 cSt, the rubber-like elastic body after curing tends to have insufficient mechanical properties, and if it exceeds 100,000 cSt, a uniform composition is obtained. There is a tendency to become difficult to obtain, and fluidity tends to be poor.

  Organic groups directly bonded to silicon atoms include alkyl groups such as methyl, ethyl, propyl, butyl and hexyl, alkenyl groups such as vinyl and allyl, chloromethyl groups, β-cyanoethyl groups, 3, 3, 3 -A monovalent substituted hydrocarbon group such as a trifluoropropyl group is exemplified, but a methyl group and a vinyl group are generally used for ease of synthesis.

  In particular, the methyl group is not only easily obtained as a raw material intermediate, but also has a low viscosity even when the degree of polymerization of the siloxane is high, and the fluidity of the composition before curing and the physical properties of the rubber-like elastic body after curing. The balance of is made good. It is preferable that 85% or more of all organic groups are methyl groups, and it is more preferable that substantially all organic groups are methyl groups.

Organosilane or its partial hydrolysis condensate (B)
The organosilane or its partial hydrolysis condensate (B) used in the present invention has the general formula (R ¹ ) _a SiX _4-a (wherein R ¹ represents a monovalent substituted or unsubstituted hydrocarbon group). X represents an organic group selected from the group consisting of an alkoxy group bonded to a silicon atom, an enoxy group, an organoketoxime group, and an organoamide group, and a represents 0 or 1, or an organosilane It is a partially hydrolyzed condensate, which is hydrolyzed by moisture and easily undergoes a condensation reaction with the silanol group or alkoxy group of component (A).

(R ¹ ) _{a The} monovalent substituted or unsubstituted hydrocarbon group of R1 in SiX _4-a is, for example, a methyl group, an ethyl group, a propyl group, or a butyl group from the viewpoint of ease of synthesis and crosslinking speed. Desirable are alkyl groups having 1 to 8 carbon atoms, alkenyl groups having 2 to 3 carbon atoms such as vinyl groups, and the like.

  X should be a material that does not release a substance that corrodes the adherend during curing by giving an appropriate curing speed and good adhesion. Examples of such X include alkoxy groups such as methoxy group, ethoxy group, propoxy group and isopropoxy group, enoxy groups such as propenoxy group, and organoketoxime groups such as acetone oxime group and butanone oxime group. .

Examples of the general formula (R ¹ ) _a SiX _4-a include alkoxy compounds such as tetraethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, and ethyl orthosilicate. And enoxy compounds such as methyltripropenoxysilane and vinyltriisopropenoxysilane.

  (B) The compounding quantity of component is 0.5-25 weight part with respect to 100 weight part of said (A) component, More preferably, it is 2-10 weight thing. If it is less than 0.5 part by weight, the condensation reaction is not carried out, and if it exceeds 25 parts by weight, the mechanical performance of the rubber-like elastic body of the cured product of the present composition is lowered. If it is less than 2 parts by weight, the condensation reaction tends to be insufficient, and if it exceeds 10 parts by weight, the mechanical performance of the rubber-like elastic body of the cured product of the present composition tends to be lowered.

Epoxy alkyl alkoxy silane (C)
The epoxyalkylalkoxysilane (C) used in the present invention has a general formula Q—R ² —Si— (R ³ ) _b (OR ⁴ ) _{3 -b} (wherein R ² is ² having 1 to 4 carbon atoms). R ³ and R ⁴ each represent a monovalent hydrocarbon group having 1 to ⁴ carbon atoms, Q represents a glycidoxy group or an epoxycyclohexyl group, and b represents 0 or 1). Epoxyalkylalkoxysilane, which is blended for the purpose of improving the adhesion of the composition.

The general formula _{^{Q-R 2 -Si- (R 3}} ) b (OR 4) 3-b (2 divalent hydrocarbon group having 1 to 4 carbon atoms ^{R 2} in the formula, alkylene of 1 to 4 carbon atoms As the monovalent hydrocarbon group having 1 to ⁴ carbon atoms of R ³ and R ⁴ , an alkyl group having 1 to 4 carbon atoms is preferable.

  Examples of component (C) include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, 3,4-epoxycyclohexylethyltrimethoxysilane, and 3,4-epoxycyclohexylethylmethyldimethoxysilane. can do.

  (C) The compounding quantity of a component is 0.1-20 weight part with respect to 100 weight part of (A) component. If 0.1 part by weight, the adhesion to the glass epoxy substrate becomes insufficient, and if it exceeds 20 parts by weight, the mechanical performance of the rubber-like elastic body of the cured product of the present composition is lowered. The more preferable blending amount is 0.5 to 5 parts by weight, and if it is less than 0.5 parts by weight, the adhesion to the glass epoxy substrate tends to be insufficient, and if it exceeds 5 parts by weight, the cured product of the composition is rubbery. There exists a tendency for the mechanical performance of an elastic body to fall.

Silanol condensation catalyst A silanol condensation catalyst can be blended in the present invention if necessary. Silanol condensation catalysts are tin octylate, tin neodecanoate, tin naphthenate, tin stearate, dibutyltin dioctoate, dibutyltin dilaurate, dioctyltin diversate, dibutyltin bistriethoxysilicate, dibutyltin dioleyl malate, dibutyltin diacetate 1,1,3,3-tetrabutyl-1,3-dilauryloxycarbonyl-distannoxane, dibutyltinoxybisethoxysilicate, dibutyltin oxide, reaction product of dioctyltin salt and normal ethyl silicate, dibutyltin salt Examples include reaction products of normal ethyl silicate, reaction products of dibutyltin oxide and phthalate, reaction products of dibutyltin oxide and maleic diester, and organic tin compounds such as dibutyltin diacetylacetonate. By using such a component, the internal curability of the composition is also improved.

  The blending amount of the silanol condensation catalyst with respect to the component (A) is 0.3 to 1.5 parts by weight with respect to 100 parts by weight of the component (A), and if it is less than 0.3 parts by weight, the curing rate may be slow. If it exceeds 1.5 parts by weight, the pot life may be shortened. A commercially available dioctyltin dilaurate is U-810 (manufactured by Nitto Kasei Co., Ltd., trade name).

Silicone oil A silicone oil can be mix | blended with this invention as needed. Silicone oil is blended for the purpose of improving workability when using the present composition, improving foam removal properties, etc., and adjusting the hardness and elongation of the rubber-like elastic body after curing. Silicone oil is a non-reactive silicone oil that does not have a reactive group such as an alkoxy group or silanol group in the molecule, and the end of the molecular chain is blocked with a triorganosiloxy group such as a trimethylsiloxy group. Most preferably used is polydimethylsiloxane blocked at both ends with trimethylsiloxy groups.

  The viscosity of the silicone oil is preferably 5 to 50,000 cSt at 25 ° C. If the viscosity is less than 5 cSt, the mechanical properties of the rubber-like elastic body after curing of the composition may be insufficient, exceeding 50,000 cSt. Then, the fluidity | liquidity of this composition may worsen. More preferably, it is 50 to 5,000 cSt, and if it is less than 50 cSt, the mechanical properties of the rubber-like elastic body after curing of the composition tend to be insufficient, and if it exceeds 5,000 cSt, the extrusion workability of the composition Tend to get worse.

  The compounding amount of the silicone oil is 0.1 to 100 parts by weight, preferably 0.2 to 80 parts by weight per 100 parts by weight of the component (A). If it is less than 0.1 part by weight, the fluidity of the composition is insufficient, and if it exceeds 100 parts by weight, the mechanical strength of the cured product is lowered. If it is less than 0.2 parts by weight, the extrusion workability of the composition tends to be insufficient, and if it exceeds 80 parts by weight, the mechanical strength of the cured product tends to decrease.

  Hereinafter, it demonstrates concretely in an Example and a comparative example.

EXAMPLE In the formulation shown in Table 1, as the component (A), dimethylpolysiloxane having a viscosity of 750 cSt / 25 ° C. and silanol groups at both ends of the molecular chain is used, and tetraethoxy is used as the organosilane or its partial hydrolysis condensate (B) Silane is used, dimethylpolysiloxane having both ends of a viscosity of 100 cSt / 25 ° C. sealed with trimethylsiloxy groups is used as silicone oil, and 3,4-epoxycyclohexylethyltrimethoxysilane is used as epoxyalkylalkoxysilane, The above-mentioned U-810 (manufactured by Nitto Kasei Co., Ltd., trade name) was used as a silanol condensation catalyst, and all materials were uniformly mixed to obtain a self-adhesive filling resin composition of the example.

Comparative Examples 1 to 3
(A) Component, organosilane or its partially hydrolyzed condensate (B), silicone oil, and silanol condensation catalyst are the same as in the examples except that the same materials are used. The self-adhesive filling resin compositions of Comparative Examples 1 to 3 were obtained.

Evaluation items and evaluation methods

Adhesiveness Under the conditions of 23 ° C. and 50% RH, the self-adhesive filling resin compositions of Examples and Comparative Examples 1 to 3 were applied on a glass epoxy substrate at 2 mm and cured for 7 days. Furthermore, what was left to stand at 150 degreeC for 200 hours was used as the test body after a heating. The self-adhesive filling resin composition cured on the glass epoxy substrate was pulled up until it was broken in the direction of peeling from the glass epoxy substrate by grasping with a finger, and the fracture state was evaluated visually. The cohesive failure of this composition was evaluated as ○, and the interface failure was evaluated as ×.

Under normal conditions, the self-adhesive filling resin compositions of Examples and Comparative Examples 1 to 3 were molded into 25 mm × 80 mm × thickness 2 mm and cured for 7 days under a total light transmittance of 23 ° C. and 50% RH. Further, a sample that was allowed to stand at 150 ° C. for 200 hours was used as a test specimen after heating. Each specimen was measured for total light transmittance according to ISO13468-1 (JISK7361). 99.9% or more was evaluated as ○, and less than 99.9% was evaluated as ×.

Color value (b *)
A self-adhesive filling resin composition of Examples and Comparative Examples 1 to 3 was molded into 25 mm × 80 mm × thickness 2 mm and cured for 7 days at 23 ° C. and 50% RH. The test specimen after heating was allowed to stand at 200 ° C. for 200 hours. The color values (b *) of each test specimen were measured with a spectrocolorimeter CM-700d (trade name, manufactured by Konica Minolta). When b * was less than 0.2, it was evaluated as ○, 0.2 or more and less than 3.0 as Δ, and 3.0 or more as ×.

Appearance Under conditions of 23 ° C. and 50% RH, the self-adhesive filling resin compositions of Examples and Comparative Examples 1 to 3 were molded into 25 mm × 80 mm × thickness 10 mm and cured for 7 days. A specimen that was allowed to stand at 150 ° C. for 200 hours was used as a test specimen after heating. Each test specimen was visually evaluated, and those that were colorless and transparent were evaluated as ◯, those that were slightly yellowish as Δ, and those that were yellow as ×.

Evaluation results The evaluation results are shown in Table 2.

In the summary examples, all evaluation items were “good”, and the adhesiveness, total light transmittance, color value (b *) and appearance were good.

Claims (2)

Diorganopolysiloxane (A) having both ends of the molecular chain blocked with silanol groups or alkoxy groups, and a general formula (R ¹ ) _a SiX _4-a (wherein R ¹ is a monovalent substituted or unsubstituted carbonization) X represents an organic group selected from the group consisting of an alkoxy group bonded to a silicon atom, an enoxy group, an organoketoxime group, and an organoamide group, and a represents 0 or 1. Silane or a partially hydrolyzed condensate thereof (B) and a general formula Q—R ² —Si— (R ³ ) _b (OR ⁴ ) _{3 -b} (wherein R ² is a divalent divalent having 1 to 4 carbon atoms) R ³ and R ⁴ each represent a monovalent hydrocarbon group having 1 to ⁴ carbon atoms, Q represents a glycidoxy group or an epoxycyclohexyl group, and b represents 0 or 1). Alkyria Kokishishiran (C) and self-adhesive potting composition characterized by containing a. The organosilane or its partially hydrolyzed condensate (B) is 0.5 to 25 parts by weight and the epoxyalkylalkoxysilane (C) is 0.1 to 20 parts per 100 parts by weight of the organopolysiloxane (A). The self-adhesive filling resin composition according to claim 1, wherein the resin composition is contained in parts by weight.