JP2009215377A - Curable silsesquioxane composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable silsesquioxane composition excellent in strength of adhesion to metals, ceramics, plastics, glasses, semiconductors and the like. <P>SOLUTION: The curable silsesquioxane composition contains a silsesquioxane having at least two 2-12C hydrocarbon groups that contain a carbon-carbon double bond and a phosphoric acid compound containing a 3-12C hydrocarbon group that contains a carbon-carbon double bond and may contain an oxygen atom, such as a phosphate added with triallyl phosphate or trimethoxysilane. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a curable silsesquioxane composition having excellent adhesion to inorganic materials such as metals and ceramics, plastics and the like.

  Conventionally, a transparent epoxy resin has been frequently used as a sealing resin for an optical element such as an LED. However, it tends to yellow over time due to heat generated during LED operation and exposure to short wavelength light emitted from the LED element. was there. Since yellowing causes a decrease in luminance of the optical element, it is difficult to apply an epoxy resin as a sealant for an optical element whose luminance is increasing. In order to overcome the drawbacks of this epoxy resin, an optical element sealant composed of a curable silsesquioxane composition has been proposed (for example, see Patent Document 1). However, silicone compositions often lack adhesion to substrates such as metals and plastics.

As a technique for improving the adhesiveness of a silicone composition, a curable organo compound containing a copolymer of a (meth) acrylate monomer, a vinyl monomer having an alkoxysilyl group, a vinyl monomer having a hydrosilyl group, etc. A polysiloxane composition (for example, see Patent Document 2), a curable organopolysiloxane composition containing an organosilicon compound having an epoxy group (for example, see Patent Document 3), a titanium catalyst and a silane coupling agent. A polysiloxane composition using a mixed and aged adhesive component (for example, see Patent Document 4), a technique using an adhesion promoter composed of a reaction product of aminoalkylsilane and glycidoxyalkylsilane (for example, see Patent Document 5) ), (Meth) acryloxyalkyl-modified organopolysiloxane as an adhesive component ( In example, there is Patent Document 6 refer.) And the like. However, even if these techniques are applied to a curable silsesquioxane composition, sufficient adhesive strength cannot always be obtained.
JP 2004-359933 A JP 2006-63092 A JP-A-6-145525 JP 2007-2088 A JP-A-8-31346 Japanese Patent Laid-Open No. 2007-9189

  In view of the above-mentioned present situation, the present invention provides a curable silsesquioxane composition that is excellent in adhesion strength to metals, plastics, ceramics, glass, semiconductors, etc. while maintaining transparency without being easily yellowed. With the goal. Such a composition can be used for sealing, bonding and the like of optical elements and the like.

  The present invention relates to a silsesquioxane having at least two hydrocarbon groups having 2 to 12 carbon atoms containing a carbon-carbon double bond, and a carbon-carbon double represented by the following general formula (1): It is a curable silsesquioxane composition containing a C3-C12 hydrocarbon group-containing phosphoric acid compound which contains a bond and may contain an oxygen atom.

  In formula (1), X represents a C3-C12 monovalent hydrocarbon group containing a carbon-carbon double bond and optionally containing an oxygen atom, and R is a C1-C12 carbon atom. Represents a monovalent hydrocarbon group which may contain a silyl group. a represents an integer of 1 to 3, c represents 0 or 1, and is 0 or a positive integer satisfying b = 3- (a + c).

In another embodiment of the present invention, a compound having at least two H—Si bond-containing groups may be further blended as a curing agent.
In still another embodiment of the present invention, a carbon-carbon double bond-containing silane and a hydrous alcohol may be further contained.

The curable silsesquioxane composition of the present invention (hereinafter also simply referred to as the composition of the present invention) exhibits high adhesive strength due to the above-described configuration, and is used as a sealing agent, an adhesive, a sealing adhesive, and the like. Useful.
The composition of the present invention can exhibit high adhesive strength without using a silane coupling agent, and can also exhibit further adhesive strength even when used in combination with a carbon-carbon double bond-containing silane. . Conventionally, this has been observed to reduce the adhesive strength when a silane coupling agent such as vinyltrimethoxysilane is added to the curable silsesquioxane composition, but this disadvantage is overcome. .
The composition of the present invention can be sealed, bonded, etc. by applying it to metals, ceramics, glass, semiconductors, plastics, etc., which have been poor in adhesion.
Since the composition of the present invention has both high transparency stability and high adhesiveness that transparency hardly deteriorates even when exposed to heat or light, a sealant using the composition has a high temperature and high humidity. Under the conditions, it is possible to produce an optical element having high durability and high brightness. For example, it can be used as a sealing resin or an adhesive resin for light emitting elements such as LEDs.
The present invention will be described in detail below.

The curable silsesquioxane composition of the present invention contains, as a main component, a silsesquioxane having at least two C2-C12 hydrocarbon groups containing a carbon-carbon double bond. Examples of the C2-C12 hydrocarbon group containing a carbon-carbon double bond include a vinyl group, allyl group, 3-butenyl group, 3-cyclohexenyl group, 3-cyclohexenylethyl group, 5- ( Bicycloheptenyl) group, cyclopentenyl group, CH ₂ ═CH— (CH ₂ ) ₈ —, styryl group and the like can be mentioned.

Silsesquioxane is usually a polysiloxane synthesized by hydrolysis and polycondensation of a trifunctional organosilicon compound and has ASiO _3/2 units (A is a hydrogen atom or a substituent). The shape of the molecular arrangement of silsesquioxane is typically an amorphous structure, a ladder structure, a cage structure (fully condensed cage structure) or a partially cleaved structure thereof (from a cage structure to a part of silicon atoms). In which a silicon-oxygen bond is partially broken in a structure lacking or a saddle type structure). The silsesquioxane in the present invention may have any structure among these silsesquioxane compounds, or a mixture thereof.

  In the present invention, the silsesquioxane has at least two, preferably at least three, hydrocarbon groups having 2 to 12 carbon atoms containing a carbon-carbon double bond. The above hydrocarbon group is a functional group necessary for forming a crosslinked product of silsesquioxane, and forms a cured product in combination with an appropriate curing agent, or in a self-condensation or self-addition manner. can do.

  In the present invention, silsesquioxane has other substituents as long as the object of the present invention is not impaired, in addition to the hydrocarbon group having 2 to 12 carbon atoms containing the carbon-carbon double bond. Also good. Examples of such other substituents include alkyl groups having 1 to 20 carbon atoms, cycloalkyl groups having 5 to 12 carbon atoms, aryl groups, aralkyl groups, alkoxyl groups, and halogens. Specific examples include, for example, methyl group, isobutyl group, octyl group, isooctyl group, phenyl group, phenethyl group, cyclohexyl group, cyclopentyl group, adamantyl group, adamantylethyl group and the like.

  Among the silsesquioxanes, a method for synthesizing a cage silsesquioxane includes a method of introducing a substituent such as the hydrocarbon group into a synthesized skeleton structure of a cage silsesquioxane, or a substitution A method by hydrolysis of a trifunctional organosilicon monomer having a group is known, and any of these methods may be used.

  The method for producing the ladder structure is not particularly limited, and for example, a method of producing an alkyltrialkoxysilane or alkyltrichlorosilane by cohydrolysis condensation is known, and this can be utilized. As reaction temperature, it is 20-100 degreeC, for example, and reaction time is 1 to 24 hours. In order to improve the regularity of the ladder structure, the first hydrolysis reaction is performed at a relatively low temperature of 20 to 60 ° C. for 0.5 to 1 hour, and then the temperature is continuously raised to react at 70 to 90 ° C. for 1 to 23 hours. It is preferable to make it. If this condition is not met, the appearance of amorphous materials will increase. Further, the polymerization degree of the ladder-type silsesquioxane can be adjusted by adjusting the pH at which the organosilicon monomer is hydrolyzed and the pH at which the condensation reaction is carried out.

  In the present invention, silsesquioxane may be cured by silsesquioxane self-condensation reaction or self-addition reaction. Such a reaction is made possible by a combination of substituents that can react with each other. For example, a hydrosilylation reaction between a vinyl group and a hydrogen atom directly bonded to a Si atom, or a partially cleaved structure of a cage structure silsesquioxane. Typical examples thereof include hydrolysis / condensation of silanol groups and reaction of a hydrocarbon group containing an epoxy ring with a silanol group.

  In the present invention, a curing agent may be used to form a cured product of silsesquioxane. Examples of such a curing agent include compounds having at least two H-Si bond-containing groups in one molecule. Examples of such a compound include 1,4-bis (dimethylsilyl) benzene and tetramethyldisiloxane. Further, it may be a compound having three or more Si—H bond-containing groups in one molecule such as tetramethylcyclotetrasiloxane. Of these, 1,4-bisdimethylsilylbenzene is preferred from the viewpoint of heat resistance, toughness, and compatibility. In the present specification, the Si—H bond-containing group refers to a group formed by bonding at least one H atom to a Si atom, such as a hydrosilyl group.

  The compounding amount of the curing agent is such that the ratio of the number of moles of carbon-carbon double bonds contained in silsesquioxane and the number of moles of hydrogen of Si—H bond-containing groups contained in the curing agent is 1: 0.9. It is preferable to add so that it may become -1: 1.05, and it is more preferable to add so that it may become 1: 0.99-1: 1.01.

  In the present invention, a curing catalyst is used together with the curing agent. Examples of such curing catalysts include platinum-containing catalysts such as platinum-divinylsiloxane complex, platinum cyclic vinylmethylsiloxane complex, tris (dibenzylideneacetone) diplatinum, chloroplatinic acid, bis (ethylene) tetrachlorodiplatinum. Hydrosilylation catalysts such as cyclooctadiene dichloroplatinum, bis (cyclooctadiene) platinum, bis (dimethylphenylphosphine) dichloroplatinum, tetrakis (triphenylphosphine) platinum, and platinum carbon can be used.

  It is preferable to add such a curing catalyst so that the platinum content in the composition is 3 to 100 ppm, more preferably 8 to 30 ppm.

  In the composition of the present invention, a hydrocarbon group-containing phosphoric acid compound having 3 to 12 carbon atoms, which contains a carbon-carbon double bond and may contain an oxygen atom, represented by the general formula (1). (Hereinafter, also simply referred to as “the phosphoric acid compound in the present invention”) is a component for improving adhesiveness. Examples of the hydrocarbon group having 3 to 12 carbon atoms, which contains the carbon-carbon double bond and may contain an oxygen atom, include, for example, an ether bond and an ester in addition to the exemplified hydrocarbon group described above. A carbon-carbon double bond-containing group containing a bond, for example, a group having a skeleton such as C═C—CO—O—C—C— or C═C—C—O—C—C— Of these, an allyl group, a methacryloyloxyethyl group, and a 3-cyclohexenyl group are preferable. In the general formula (1), R represents a monovalent hydrocarbon group having 1 to 12 carbon atoms which may contain a silyl group (for example, trimethoxysilane or the like). Examples of R include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and a group in which a silyl group is bonded to these groups. For example, the above-described corresponding groups (methyl group, isobutyl group) Group, propyl group, phenyl group, cyclohexyl group, etc.), trimethoxysilylethyl, trimethoxysilylpropyl and the like, and trimethoxysilylpropyl is preferable. a represents an integer of 1 to 3, c represents 0 or 1, and is 0 or a positive integer satisfying b = 3- (a + c). Specific examples include, for example, a compound in which a is 3, b and c are 0, a is 2, b is 1, and c is 0, a is 2, b is 0, c is 1, and a is 1 , B is 2, and c is 0, a is 1, b is 1, and c is 1. Of these, compounds in which a is 3, b and c are 0, a is 2, b is 1, c is 0, a is 2, b is 0 and c is 1, and a is 3, A compound in which b and c are 0, a compound in which a is 2, b is 0, and c is 1 is more preferable.

  Examples of the phosphoric acid compound containing a C3-C12 hydrocarbon group containing a carbon-carbon double bond and optionally containing an oxygen atom represented by the general formula (1) include phosphorus. Acid triallyl ester, phosphoric acid diallyl ester, trimethoxysilane addition-type diallyl phosphate, for example, trimethoxysilylpropyl phosphate diallyl ester, di (trimethoxysilylpropyl) phosphate allyl ester, di (methacryloyloxyethyl) phosphorus Examples include acid esters, tri (2-cyclohexenylmethyl) phosphate, and di (2-cyclohexenylmethyl) phosphate. These can be used alone or in combination of two or more.

  The blending amount of the phosphoric acid compound in the present invention is preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of silsesquioxane or 100 parts by weight in total with the curing agent, if applicable. 2 parts by weight is more preferred.

  The composition of the present invention can further contain a carbon-carbon double bond-containing silane and a hydrous alcohol. Examples of the carbon-carbon double bond-containing silane include allyltrimethoxysilane, allyltriethoxysilane, diethoxymethylvinylsilane, triethoxyvinylsilane, vinyltrimethoxysilane, vinyltris (2-methoxyethoxy) silane, and the following general formula. The silicate oligomer etc. which are represented by (2) can be mentioned.

  In formula (2), Y represents a vinyl group, an allyl group, a styryl group, or a cyclohexenylethyl group, and Z represents an alkyl group having 1 to 12 carbon atoms, an aryl group, or an aralkyl group. n and m are 0 or a positive integer in which the ratio of n: m is 10: 0 to 1: 9 and m + n = 2 to 40 is satisfied. Preferably, it is an oligomer of m = 5-15 and n = 5-15.

  Of these, the carbon-carbon double bond-containing silane is preferably vinyltrimethoxysilane, allyltrimethoxysilane, or a silicate oligomer represented by the general formula (2) (Y is preferably a vinyl group or an allyl group). Z is preferably a phenyl group or a cyclohexyl group, Y is a vinyl group, and Z is more preferably a phenyl group. The said silane can use together 1 type, or 2 or more types.

  Examples of the water-containing alcohol include water-containing methanol, water-containing ethanol, and water-containing isopropanol. The water content of the hydrous alcohol is preferably about 10 to 50%.

  The compounding amount of the carbon-carbon double bond-containing silane and the hydrous alcohol is 100 parts by weight of silsesquioxane or, if applicable, 100 parts by weight of the total amount of silsesquioxane and curing agent. The carbon double bond-containing silane is preferably 0.1 to 5 parts by weight, and the water-containing alcohol is added so that the number of moles of water contained does not exceed the number of moles of the alkoxy group.

Other additives can be used in the composition of the present invention as long as the object of the present invention is not impaired. Examples of such additives include hindered amine light stabilizers, hindered phenol antioxidants, and the like. Examples of the hindered amine light stabilizer include TINUVIN (registered trademark) 770, TINUVIN (registered trademark) 622LD (both manufactured by Ciba Specialty Chemicals), and Adekastab (registered trademark) LA-57 (manufactured by Asahi Denka Kogyo Co., Ltd.). Etc. Examples of the hindered phenol antioxidant include IRGANOX (registered trademark) 1010 (manufactured by Ciba Special Te Chemicals), NOCRACK NS-30 (trade name) (manufactured by Ouchi Shinsei Chemical Co., Ltd.), Tominox TT (product) Name) (manufactured by Yoshitoyo Fine Chemical Co., Ltd.).
However, it is preferable not to use a solvent.

The blending amount of the hindered amine light stabilizer is preferably 0.01 to 0.5 phr, more preferably 0.1 to 0.3 phr in the composition.
The blending amount of the hindered phenolic antioxidant is preferably 0.01 to 0.5 phr, more preferably 0.1 to 0.3 phr in the composition.

  The composition of the present invention is usually used after blending each component at a predetermined ratio, stirring for 5 to 10 minutes, and then degassing under reduced pressure. At this time, while removing bubbles entrained during stirring, alcohol released by the reaction between the alkoxy group contained in the carbon-carbon double bond-containing silane and the water in the hydrous alcohol, and the alcohol component in the hydrous alcohol Can be efficiently distilled off under reduced pressure, and foaming during heat curing can be effectively suppressed.

  The composition of this invention can use 120-150 degreeC and about 1 to 5 hours as hardening conditions. Further, first, initial curing is performed at a relatively low temperature, for example, about 60 to 90 ° C. for a relatively short time, for example, 1 to 3 hours, and thereafter, higher temperature and a long time, for example, 120 to 180 ° C., 1 It is also possible to use a step cure method in which a curing treatment for ˜5 hours is performed.

  The composition of the present invention can form a thin film having a cured thickness of about 0.5 to 4 μm by coating and curing on a glass substrate, a metal substrate, a semiconductor substrate or the like, for example. Alternatively, it can be used as a sealant or adhesive for light emitting elements such as LEDs and LDs. Therefore, the present invention provides a sealing body (for example, a semiconductor sealing body) or an adhesive body (for example, a semiconductor bonding body or a semiconductor sealing bonding) using a thin film or a cured product obtained by curing the composition of the present invention. Body).

  The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples.

Examples 1-9 and 1A-1B and Comparative Examples 1-5 and 1A-1B
Each component and composition (parts by weight) shown in Table 1 were blended and mixed at room temperature to prepare a uniform composition. However, the compounding amount of the platinum-divinylsiloxane complex is such that platinum is 21 ppm on a mass basis with respect to the solid content (total amount of vinyl group-containing silsesquioxane and 1,4-bisdimethylsilylbenzene). Calculated and added.
Each composition obtained was applied onto an aluminum plate and two aluminum plates were bonded together, and then cured under the following conditions to obtain a cured product.
Curing conditions: 80 ° C. × 1 hour + 150 ° C. × 3 hours Measurement conditions are as follows.
Measurement of tensile shear bond strength (N / mm2): Measurement of bond strength was based on JIS K6850. The results are shown in Table 1.
Tensile shear adhesive strength under constant temperature and humidity test conditions: Examples 1A and 1B and Comparative Examples 1A and 1B were measured under the conditions shown in Table 2 before being measured. The results are shown in Table 2 together with Example 1 and Comparative Example 1.

The meanings of the terms in the table are as follows.
Silsesquioxane 1: Silsesquioxane-based resin YOH-1-1A manufactured by Nagase ChemteX Corporation (vinyl equivalent = 324 g / eq, weight average molecular weight Mw = 1400)
Silsesquioxane 2: Silsesquioxane resin YOH-1-2A manufactured by Nagase ChemteX Corp. (vinyl equivalent = 194 g / eq, weight average molecular weight Mw = 1500)
Platinum-divinylsiloxane complex: 0.21% platinum-divinyldisiloxane xylene solution Trimethoxysilane-added phosphate ester: 1 mol of trimethoxysilane per 1 mol of triallyl phosphate, hydrosilylation using platinum-divinylsiloxane complex as a catalyst And synthesized.
Silicate oligomer: In the above formula (2), Y is a vinyl group, Z is a phenyl group, and average n and m are m = 10 and n = 10, respectively.

From the above examples, a phosphate ester or a carbon-carbon double bond-containing silane and a hydrous alcohol are added to a resin composition for curing a vinyl group-containing silsesquioxane with 1,4-bis (dimethylsilyl) benzene. The aluminum plates bonded with the resins of Examples 1 to 9 as adhesives had high adhesiveness. In addition, Examples 1A to 1B to which triallyl phosphate was added had high moisture-resistant adhesive properties such that the decrease in adhesive strength was small or rather large even after exposure to high temperature and high humidity conditions. I understand.
On the other hand, in Comparative Examples 1 to 5 in which only a carbon-carbon double bond-containing silane such as vinyltrimethoxysilane or an oligomer thereof was added as an adhesion-imparting agent, the addition of the carbon-carbon double bond-containing silane resulted in no addition. The adhesive strength was lower than that of the system. Further, as can be seen from Comparative Examples 1A to 1B, it was greatly reduced by exposure to high temperature and high humidity conditions.

Claims (8)

Silsesquioxane having at least two hydrocarbon groups having 2 to 12 carbon atoms containing a carbon-carbon double bond, and a carbon-carbon double bond represented by the following general formula (1) A curable silsesquioxane composition comprising a hydrocarbon group-containing phosphate compound having 3 to 12 carbon atoms, which may contain an oxygen atom.

(In Formula (1), X represents a C3-C12 monovalent hydrocarbon group which contains a carbon-carbon double bond and may contain an oxygen atom, and R represents C1-C12. Represents a monovalent hydrocarbon group which may contain a silyl group, a represents an integer of 1 to 3, c represents 0 or 1, and 0 or a positive value satisfying b = 3- (a + c) (It is an integer.) The composition according to claim 1, wherein the phosphoric acid compound is a triallyl phosphate, a diallyl phosphate, or a trimethoxysilane-added phosphate diallyl ester. Furthermore, the composition of Claim 1 or 2 formed by mix | blending the compound which has at least 2 H-Si bond containing group as a hardening | curing agent. Furthermore, the composition in any one of Claims 1-3 containing a carbon-carbon double bond containing silane and a hydrous alcohol. The composition according to claim 4, wherein the carbon-carbon double bond-containing silane is at least one selected from the group consisting of vinyltrimethoxysilane, allyltrimethoxysilane, and a silicate oligomer represented by the following general formula (2). object.

(In Formula (2), Y represents a vinyl group, an allyl group, a styryl group, or a cyclohexenylethyl group, Z represents a C1-C12 alkyl group, an aryl group, or an aralkyl group. (The ratio of n: m is 10: 0 to 1: 9, and m + n is 0 or a positive integer that satisfies 2 to 40.) The sealing agent formed by containing the composition in any one of Claims 1-5. The adhesive agent containing the composition in any one of Claims 1-5. The sealing body or adhesive body formed by hardening | curing the composition in any one of Claims 1-5.