JP2019123772A - Flame-retardant room temperature-curable organopolysiloxane composition, electric or electronic component, and method for improving heat-resistant adhesiveness of electric or electronic component - Google Patents

Abstract

[Problem] A flame-retardant, room-temperature-curing organopolysiloxane composition that is highly reliable because no air bubbles are generated from the cured product even when exposed to high temperatures, and has excellent storage stability with no deterioration in curability over time. I will provide a. [Solution] (A) diorganopolysiloxane in which both ends of the molecular chain are blocked with hydroxyl groups and/or hydrolyzable siloxy groups bonded to silicon atoms, (B) water with an average particle diameter of 0.4 to 5 μm. Magnesium oxide, (C) curing catalyst, (D) formula (1): R1aSi(OR2)4-a (R1 is a substituted monovalent hydrocarbon group containing N, S and O, R2 is an ethyl group, a is 1 or 2.) Hydrolyzable organosilicon compound and/or partially hydrolyzed condensate thereof (E) Formula (2): R3bSi(OR4)4-b (R3 is an unsubstituted or halogen-substituted monovalent hydrocarbon group, R4 is a methyl group, and b is 0, 1 or 2.) and/or a partially hydrolyzed condensate thereof. [Selection diagram] None

Description

  The present invention relates to a flame retardant room temperature curable organopolysiloxane composition useful as a silicone based sealing agent or adhesive. In particular, a flame retardant room temperature curable organopolysiloxane composition having excellent storage stability and high heat resistance temperature, and an electric or electronic part sealed, fixed or adhered with a cured product of the composition, and electric or electronic The present invention relates to a method for improving heat-resistant adhesion in parts.

  Organopolysiloxane compositions are used for electric or electronic parts because they are excellent in heat resistance, electrical properties and adhesion. Furthermore, the composition is often required to be flame retardant in consideration of safety. It is known to blend a platinum compound and an inorganic filler in order to impart flame retardancy to the organopolysiloxane composition (patent documents 1 to 3: JP-A-4-18451, JP-A-5-125285). (Japanese Patent Application Laid-Open No. 5-230376).

  Among the mineral fillers, aluminum hydroxide is particularly useful because of the high endothermic effect of the water of crystallization. However, aluminum hydroxide is a problem in terms of heat resistance because crystal water is gradually lost even at temperatures lower than 200 ° C. In other words, when the organopolysiloxane cured product is used at high temperature, water (steam) is generated from aluminum hydroxide added to the organopolysiloxane cured product, which causes a problem that air bubbles are generated in the organopolysiloxane cured product. . When air bubbles are generated in the cured organopolysiloxane, not only the appearance may be deteriorated, but also the waterproof and moisture proof properties may be lowered and the electrical insulation properties may be lowered.

  Therefore, methods using magnesium hydroxide having a decomposition temperature of about 350 ° C. or boehmite (aluminum hydroxide oxide) having a decomposition temperature of about 500 ° C. as a flame retardant filler have been proposed (Patent Documents 4 and 5: Patents No. 3297014, Unexamined-Japanese-Patent No. 2010-132865). Although the heat resistance problem can be solved by using these fillers, the flame retardant effect is lower than aluminum hydroxide, so in order to obtain the same flame retardancy, a large amount of these flame retardant fillers should be used. It is necessary to blend it. However, since these compounds have surface activity and may have a large water content, volatile components such as methanol are formed over time, and cracking reaction and catalyst deactivation occur due to additives and catalysts. Therefore, there was a concern for the curability to decrease with time, that is, the storage stability. Then, use of the magnesium hydroxide which held down the water content is proposed (patent documents 6: Unexamined-Japanese-Patent No. 2017-002213). The use of these special magnesium hydroxides improves the storage stability, but limits the types of flame retardant fillers.

Japanese Patent Application Laid-Open No. 4-18451 JP-A-5-125285 Unexamined-Japanese-Patent No. 5-230376 Patent No. 3297014 Unexamined-Japanese-Patent No. 2010-132865 JP, 2017-002213, A

  The present invention has been made in view of the above-mentioned circumstances, and in particular, even when exposed to high temperatures, no bubbles are generated from the cured product, so that the reliability is high and the storage stability does not decrease the curability over time. The present invention provides a flame retardant room temperature curable organopolysiloxane composition excellent in the above, and a method for improving the heat-resistant adhesion in electric or electronic parts and electric or electronic parts sealed, fixed or adhered with the cured product of the composition. The purpose is

  As a result of intensive studies to achieve the above object, the present inventors have found that magnesium hydroxide used as a flame retardant filler by using an adhesion imparting component having a specific hydrolyzable functional group and a crosslinking agent. It has been found that it is possible to obtain a flame-retardant room-temperature curable organopolysiloxane composition which does not require water content management, is excellent in storage stability, and does not generate bubbles from the cured product even when exposed to high temperatures. I came to

That is, the present invention relates to the following flame retardant room temperature curing type organopolysiloxane composition and heat resistance in electric or electronic parts and electric or electronic parts sealed, fixed or bonded with a cured product (silicone rubber) of the composition. The present invention provides a method for improving adhesion.
1. (A) 100 parts by mass of a diorganopolysiloxane blocked by a hydroxyl group and / or a hydrolyzable siloxy group in which both ends of a molecular chain are bonded to a silicon atom,
(B) 5 to 500 parts by mass of magnesium hydroxide having an average particle size of 0.4 to 5 μm,
(C) Curing catalyst 0.001 to 30 parts by mass,
(D) the following general formula (1):
R ¹ _a Si (OR ² ) _4-a (1)
(Wherein, R ¹ represents a substituted monovalent hydrocarbon group containing one or more atoms of at least one atom selected from a nitrogen atom, a sulfur atom and an oxygen atom, and each R ² independently represents ² to 4) A monovalent alkyl group containing a carbon atom, a is 1 or 2, provided that when a is 2, R ¹ may be the same or different)
0.05 to 20 parts by mass of a hydrolyzable organosilicon compound represented by and / or a partial hydrolysis condensate thereof
(E) the following general formula (2):
R ³ _b Si (OR ⁴ ) _4-b (2)
(Wherein, R ³ represents an unsubstituted or halogen-substituted monovalent hydrocarbon group, R ⁴ is a monovalent alkyl group each independently containing 2 to 4 carbon atoms, and b is 0) , 1 or 2, provided that when b is 2, R ³ may be the same or different.)
A flame-retardant room-temperature-curable organopolysiloxane composition comprising 0.5 to 30 parts by mass of a hydrolyzable organosilicon compound represented by and / or a partial hydrolysis condensate thereof.
2. The flame-retardant room-temperature-curable organopolysiloxane composition according to 1, wherein the average particle diameter of magnesium hydroxide as the component (B) is 0.6 to 3 μm.
3. In the formula (1) of the component (D), R ¹ is 3-methacryloxypropyl group, 2- (3,4-epoxycyclohexyl) ethyl group, 2- (2,3-epoxycyclohexyl) ethyl group, 3-glyl. And sidoxypropyl group, N-2 (aminoethyl) -3-aminopropyl group, 3-aminopropyl group, 3-mercaptopropyl group, 3-acryloxypropyl group, or N-phenyl-3-aminopropyl group. The flame-retardant room-temperature-curable organopolysiloxane composition according to 1 or 2.
4. The flame-retardant room-temperature-curable organopolysiloxane composition according to any one of 1 to 3, wherein the curing catalyst of the component (C) is an organotin catalyst.
5. A two-component mixed flame-retardant room-temperature-curable organopolysiloxane composition obtained by mixing the following first composition and second composition in a mass ratio of 100: 10 to 100: 100, respectively. , (C) curing catalyst in an amount corresponding to 0.001 to 30 parts by mass with respect to a total of 100 parts by mass of the first composition and the component (A) of the second composition, the first composition or the second composition The flame-retardant room-temperature-curable organopolysiloxane composition according to any one of 1 to 4, which is obtained by blending it with any one of the above.
First component (A) 100 parts by mass of a diorganopolysiloxane blocked by a hydroxyl group and / or a hydrolyzable siloxy group in which both molecular chain ends are bonded to a silicon atom,
(B) 5 to 500 parts by mass of magnesium hydroxide having an average particle size of 0.4 to 5 μm,
(D) the following general formula (1):
R ¹ _a Si (OR ² ) _4-a (1)
(Wherein, R ¹ represents a substituted monovalent hydrocarbon group containing one or more atoms of at least one atom selected from a nitrogen atom, a sulfur atom and an oxygen atom, and each R ² independently represents ² to 4) A monovalent alkyl group containing a carbon atom, a is 1 or 2, provided that when a is 2, R ¹ may be the same or different)
The hydrolyzable organosilicon compound represented by and / or its partial hydrolytic condensate equivalent to 0.05 to 20 parts by mass with respect to a total of 100 parts by mass of the first composition and the component (A) of the second composition Amount to be
(E) the following general formula (2):
R ³ _b Si (OR ⁴ ) _4-b (2)
(Wherein, R ³ represents an unsubstituted or halogen-substituted monovalent hydrocarbon group, R ⁴ is a monovalent alkyl group each independently containing 2 to 4 carbon atoms, and b is 0) , 1 or 2, provided that when b is 2, R ³ may be the same or different.)
The hydrolyzable organosilicon compound represented by and / or its partial hydrolytic condensate equivalent to 0.5 to 30 parts by mass with respect to a total of 100 parts by mass of the first composition and the component (A) of the second composition A composition comprising an amount of
Second composition (A) 100 parts by mass of a diorganopolysiloxane blocked by a hydroxyl group and / or a hydrolyzable siloxy group in which both molecular chain ends are bonded to a silicon atom,
(B) A composition comprising 5 to 500 parts by mass of magnesium hydroxide having an average particle size of 0.4 to 5 μm.
6. An electrical or electronic component sealed, fixed or adhered with a cured product of the flame retardant room temperature curable organopolysiloxane composition according to any one of 1 to 5.
7. Heat-resistant adhesion in electric or electronic parts characterized by sealing, fixing or adhering a cured product of the flame-retardant room-temperature-curable organopolysiloxane composition according to any of 1 to 5 to electric or electronic parts How to improve.
8. 7. The method for improving heat-resistant adhesion in an electric or electronic component according to 7, wherein the object to be sealed, fixed or bonded in the electronic or electronic component is a flame retardant polycarbonate resin.

According to the present invention, a flame-retardant room-temperature curable organopolysiloxane composition excellent in storage stability in which no bubbles are generated in a cured product even when exposed to high temperatures, and a cured product of the composition (silicone rubber) It is possible to obtain an electrical or electronic component or the like sealed, fixed or bonded.
In the present invention, room temperature means 23 ° C. ± 10 ° C.

Hereinafter, the present invention will be described in more detail.
[(A) component]
The diorganopolysiloxane of component (A) is a hydroxyl group (ie, silanol group) and / or a hydrolyzable siloxy group (eg, a diorganohydroxysiloxy group and / or a tri (organo) having both molecular chain terminals bonded to a silicon atom. Blocked with a hydrolyzable group having 1 to 3 hydrolyzable groups such as (oxy) siloxy, di (organooxy) organosiloxy and (organooxy) diorganosiloxy groups), and the main chain is basically a diorgano. It is a linear diorganopolysiloxane composed of repeating siloxane units, and is a base polymer (main agent) component constituting the flame retardant room temperature curable organopolysiloxane composition of the present invention, and silicon atoms at both ends of molecular chain The hydroxyl group and / or the hydrolyzable group are bonded to

  As the hydrolyzable group, an alkoxy group having 1 to 6 carbon atoms such as methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, isobutoxy group, sec-butoxy group, tert-butoxy group, etc .; methyl ethyl ketoxime group And a ketoxime group having 3 to 8 carbon atoms such as diethyl ketoxime group and dimethyl ketoxime group; an acyloxy group having 2 to 6 carbon atoms such as acetoxy group; an alkenyloxy group such as vinyloxy group, allyloxy group and isopropenyloxy group; Organoxy such as substituted or unsubstituted aminooxy group is exemplified.

  In addition, as other groups (preferably substituted or unsubstituted monovalent hydrocarbon groups having 1 to 20 carbon atoms) bonded to the silicon atom of this organopolysiloxane, methyl group, ethyl group, propyl group, isopropyl group, Alkyl groups such as butyl group, 2-ethylbutyl group and octyl group; cycloalkyl groups such as cyclohexyl group and cyclopentyl group; alkenyl groups such as vinyl group and allyl group; phenyl group, tolyl group, xylyl group, naphthyl group, biphenylyl group Aryl groups such as phenanthryl group; aralkyl groups such as benzyl group and phenylethyl group; chloromethyl group, trichloropropyl group, trifluoropropyl group, bromophenyl group, halogenated alkyl groups such as chlorophenyl group, aryl or cycloalkyl group 2-cyanoethyl group, 3-cyano Nopuropiru groups include cyanated alkyl groups such as 2-cyanobutyl group, a methyl group, a vinyl group, a phenyl group, a trifluoropropyl group are preferred, a methyl group is particularly preferred. In addition, it is preferable that they are groups which do not contain a nitrogen atom, a sulfur atom, and an oxygen atom as another group couple | bonded with a silicon atom.

The viscosity at 23 ° C. of the component (A) organopolysiloxane is preferably in the range of 10 to 500,000 mPa · s, more preferably 100 to 100,000 mPa · s, and still more preferably 200 to 50,000 mPa · s. is there. If the viscosity is too low, sufficient mechanical properties may not be obtained for the cured product. If the viscosity is too high, the viscosity of the composition may be increased and the workability may be reduced. The degree of polymerization (or the number of repeating difunctional diorganosiloxane units present in the molecule) is usually 10 to 1,500, as the range in which the organopolysiloxane (A) can obtain the above viscosity. Preferably, it is about 30 to 1,200, more preferably 50 to 1,000, and still more preferably 100 to 800 or so. Here, the viscosity can be measured by a rotational viscometer (for example, BL type, BH type, BS type, cone plate type, rheometer, etc.). The degree of polymerization (or molecular weight) can be determined, for example, as a polystyrene-equivalent number average degree of polymerization (or number average molecular weight) in gel permeation chromatography (GPC) analysis using toluene or the like as a developing solvent.
The organopolysiloxanes of component (A) may be used alone or in combination of two or more.

[(B) component]
Magnesium hydroxide having an average particle diameter of 0.4 to 5 μm as component (B) imparts flame retardancy to a cured silicone rubber obtained by curing the composition of the present invention as a flame retardant filler Is formulated into The magnesium hydroxide of the component (B) is a flame-retardant filler having a thermal decomposition temperature of 300 ° C. or higher, so it has excellent heat resistance as well as flame retardancy to the composition of the present invention and its cured product (silicone rubber). It can be made to have sex.

  The flame retardant filler having a thermal decomposition temperature of 300 ° C. or higher includes, in addition to magnesium hydroxide, boehmite, zinc carbonate, calcium hydroxide and the like, but in the present invention, the obtained cured product ( In particular, magnesium hydroxide having a specific average particle size is selectively used as the flame retardant filler of the component (B) from the viewpoint of achieving both flame retardancy and heat resistance of silicone rubber).

That is, the magnesium hydroxide of the component (B) needs to have an average particle diameter of 0.4 to 5 μm, preferably 0.6 to 3 μm, in order to develop flame retardancy. Moreover, it is preferable that the specific surface area by BET method is 11 m < ² > / g or less. The average particle diameter can be determined by a particle size distribution measuring apparatus by laser light diffraction, and is a value measured as the accumulated mass average diameter D50 (that is, the particle diameter or median diameter when the accumulated mass is 50% by mass). is there.

Component (B) magnesium hydroxide may be surface-hydrophobicized with organosilicon compounds such as organochlorosilanes, organoalkoxysilanes and organosilazanes, fatty acids and paraffins as its flame retardant filler. Good.
The component (B) may be used alone or in combination of two or more.

  In addition, the water content in particular of 150 degreeC of magnesium hydroxide of (B) component is not restrict | limited. That is, the water content at 150 ° C. (the ratio of the water content to the total mass of the hydrous magnesium hydroxide) is not limited to 1.0 mass% or less, and may be more than 1.0 mass%. The upper limit of the water content at 150 ° C. is also not particularly limited as long as the material is commercially available, but, for example, 2.0 mass% or less is preferable, 1.5 mass% or less is more preferable, and 1.2 mass% The following is more preferable. The water content can be stopped with an infrared moisture meter and is a value measured at 150 ° C.

  The compounding quantity of (B) component is 5-500 mass parts with respect to 100 mass parts of organopolysiloxane of (A) component, and it is preferable that it is 10-300 mass parts. If the amount is less than 5 parts by mass, sufficient flame retardancy can not be obtained. If the amount is more than 500 parts by mass, the viscosity of the composition obtained is too high, and the workability and the dischargeability deteriorate.

[(C) ingredient]
The curing catalyst which is the component (C) of the present invention is a condensation reaction, particularly a condensation reaction between the component (A) and the component (E) described later or the component (A) and the components (D) and (E) described later And a curing catalyst for a condensation reaction which is added to accelerate the condensation reaction (crosslinking reaction) and accelerate gum formation.
Examples of the curing catalyst include organic titanates such as tetrabutyl titanate and tetraisopropyl titanate; organic titanium chelate compounds such as diisopropoxy bis (acetylacetonate) titanium and diisopropoxy bis (ethyl acetoacetate) titanium; aluminum Organic aluminum compounds such as tris (acetylacetonate), aluminum tris (ethylacetoacetate); organic zirconium compounds such as zirconium tetra (acetylacetonate), zirconium tetrabutyrate; dibutyltin dioctoate, dibutyltin dilaurate, dibutyltin di (2 Organotin compounds such as -ethylhexanoate) and dioctyltin dineodecanoate; tin naphthenate, tin oleate, tin butylate, Koval naphthenate Metal salts of organic carboxylic acids such as zinc stearate; amine compounds such as hexylamine and dodecylamine phosphate, and salts thereof; quaternary ammonium salts such as benzyltriethylammonium acetate; lower alkali metals such as potassium acetate and lithium nitrate Examples thereof include fatty acid salts; dialkylhydroxylamines such as dimethylhydroxylamine and diethylhydroxylamine; and guanidyl group-containing organic silicon compounds such as tetramethylguanidine propyltrimethoxysilane. In particular, the use of an organotin catalyst is preferred in view of the curing speed.

The component (C) can be used alone or in combination of two or more.
The compounding amount of the curing catalyst is 0.001 to 30 parts by mass, preferably 0.002 to 20 parts by mass, and more preferably 0.004 to 10 parts by mass with respect to 100 parts by mass of the component (A). It is an extent. When the amount of the curing catalyst is too small, curing is insufficient, and when it is too large, curing is too fast and handling is difficult.

[(D) component]
In the present invention, a specific hydrolyzable organosilicon compound and / or a partial hydrolytic condensate thereof is used as an adhesive in order to improve the adhesive strength, prevent the decrease in the curability of the composition over time, and maintain the storage stability. It is blended as a imparting component (adhesion aid).
That is, the component (D) has the following general formula (1):
R ¹ _a Si (OR ² ) _4-a (1)
(Wherein, R ¹ represents a substituted monovalent hydrocarbon group containing one or more atoms of at least one atom selected from a nitrogen atom, a sulfur atom and an oxygen atom, and each R ² independently represents ² to 4) A monovalent alkyl group containing a carbon atom, a is 1 or 2, preferably 1, provided that when a is 2, R ¹ may be the same or different)
Hydrolyzable organosilicon compounds such as hydrolysable silanes represented by and / or their partial hydrolytic condensates (i.e. hydrolysable siloxane oligomers). The term "partially hydrolyzed condensate" means an organopolysiloxane (siloxane oligomer) having two or more residual hydrolyzable groups in the molecule formed by partial hydrolysis of the hydrolyzable silane compound. .

In the above formula (1), R ¹ is a substituted monovalent hydrocarbon group containing one or more atoms of at least one atom selected from nitrogen atom, sulfur atom and oxygen atom, and specifically, 3-methacryloxypropyl Group, 2- (3,4-epoxycyclohexyl) ethyl group, 3-glycidoxypropyl group, N-2 (aminoethyl) -3-aminopropyl group, 3-aminopropyl group, 3-mercaptopropyl group, 3 -An alkyl group having 1 to 10 carbon atoms, such as an acryloxypropyl group or an N-phenyl-3-aminopropyl group, substituted by at least one atom selected from a nitrogen atom, a sulfur atom and an oxygen atom; And substituted monovalent hydrocarbon groups.

And R ² is a monovalent alkyl group each containing independently 2 to 4 carbon atoms, preferably 2 or 3 carbon atoms, more preferably 2 carbon atoms, and is an ethyl group And a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group etc., among which the reactivity (hydrolysis rate) as a hydrolyzable group (-OR ² ) is exemplified. And ethyl group, propyl group and isopropyl group because they can achieve outstanding compatibility of storage requirements (cracking resistance and catalyst deactivation resistance) and contradictory requirements such as flame retardancy and adhesiveness after curing. Preferably, the ethyl group is more preferred. When R ² is a methyl group having 1 carbon atom, the reactivity is too fast, methanol is generated in the composition during storage, and cracking reaction and catalyst deactivation reaction occur, so storage stability and curing And the flame retardancy and adhesiveness of the cured product are reduced.
a is 1 or 2, preferably 1.

Specific examples of the component (D) include 3-methacryloxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 2- (2,3-epoxycyclohexyl) ethyltriethoxysilane, 3-glycidoxypropyltriethoxysilane, N-2 (aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltriethoxysilane, 3-mercaptopropyltriethoxysilane, 3-glycidoxypropyltriisopropanol Penoxysilane, 3-glycidoxypropylmethyldiisopropenoxysilane, 3-acryloxypropyltriethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, partial hydrolytic condensates of these silanes, etc. It is illustrated. In particular, the use of an amino group-containing silane coupling agent is preferred.
The component (D) may be used alone or as a mixture of two or more.

  The compounding amount of the component (D) is 0.05 to 20 parts by mass, preferably 0.1 to 15 parts by mass, and particularly preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the component (A). When the amount is less than 0.05 parts by mass, sufficient adhesiveness can not be obtained, and when the amount is more than 20 parts by mass, the weather resistance and the mechanical properties become inferior.

[(E) ingredient]
In the present invention, in addition to the above component (D), a specific hydrolyzable organosilicon compound and / or a partial hydrolytic condensate thereof is crosslinked in order to prevent the decrease in the curability of the composition over time and maintain storage stability. It mixes as an agent component.
That is, the component (E) has the following general formula (2):
R ³ _b Si (OR ⁴ ) _4-b (2)
(Wherein, R ³ represents an unsubstituted or halogen-substituted monovalent hydrocarbon group, R ⁴ is a monovalent alkyl group each independently containing 2 to 4 carbon atoms, and b is 0) , 1 or 2, provided that when b is 2, R ³ may be the same or different.)
And / or a partial hydrolytic condensate thereof.

In the above formula (2), R ³ is an unsubstituted or halogen-substituted monovalent hydrocarbon group, and as the unsubstituted or halogen-substituted monovalent hydrocarbon group of R ³ , a methyl group, an ethyl group, a propyl group An alkyl group such as a vinyl group, an alkenyl group such as a vinyl group, an aryl group such as a phenyl group, a chloromethyl group, a 3,3,3-trifluoropropyl group, etc. It is preferable that it is a monovalent hydrocarbon group, particularly an unsubstituted monovalent hydrocarbon group having about 1 to 6 carbon atoms, and in particular, a methyl group, an ethyl group, a propyl group, a vinyl group and a phenyl group are preferable.

And R ⁴ is a monovalent alkyl group each containing independently 2 to 4 carbon atoms, preferably 2 or 3 carbon atoms, more preferably 2 carbon atoms, and is an ethyl group And a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group etc., among which the reactivity (hydrolysis rate) as a hydrolyzable group (-OR ⁴ ) is exemplified. And ethyl group, propyl group and isopropyl group because they can achieve outstanding compatibility of storage requirements (cracking resistance and catalyst deactivation resistance) and contradictory requirements such as flame retardancy and adhesiveness after curing. Preferably, the ethyl group is more preferred. When R ⁴ is a methyl group having 1 carbon atom, the reactivity is too fast, methanol is generated in the composition during storage, and cracking reaction and catalyst deactivation reaction occur, so storage stability and curing And the flame retardancy and adhesiveness of the cured product are reduced.
b is 0, 1 or 2, preferably 0 or 1.

Specific examples of the component (E) include tetraethoxysilane, tetrapropoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, ethyltriethoxysilane, diethyldiethoxysilane, vinyltriethoxysilane, divinyldiethoxysilane, and phenyltriethoxysilane. Various hydrolysable silanes such as ethoxysilane, (organo) alkoxysilanes such as methyltripropoxysilane, and partial hydrolytic condensates of these silanes can be mentioned.
The component (E) may be used alone or as a mixture of two or more.

  When the component (E) is blended, the blending amount is 0.5 to 30 parts by mass, preferably 0.5 to 20 parts by mass, particularly preferably 1 to 15 parts by mass with respect to 100 parts by mass of the component (A) Used in the range of If the amount is less than 0.5 parts by mass, sufficient crosslinking may not be obtained, and it may be difficult to obtain a composition having a suitable rubber elasticity. If the amount exceeds 30 parts by mass, the resulting cured product tends to have reduced mechanical properties.

[Other additives]
The flame-retardant room-temperature-curable organopolysiloxane composition of the present invention includes reinforcing fillers such as fumed silica, wet silica, precipitated silica, calcium carbonate, pigments, dyes, anti-aging agents, antioxidants, charge Inhibitors, platinum compounds, antimony oxides, and flame retardants such as chlorinated paraffin can be blended. Furthermore, a polyether as a thixotropic agent, a fungicide, an antibacterial agent and the like can be blended. The blending amount of these additives is optional as long as the object of the present invention is not impaired.

  The flame-retardant room-temperature-curable organopolysiloxane composition of the present invention preferably comprises the components (A) to (E) and the above-mentioned various additives, preferably in a dry atmosphere (substantially without moisture). Can be obtained by mixing uniformly.

  The flame-retardant room-temperature-curable organopolysiloxane composition of the present invention is separately prepared and stored as a two-component mixture type composition, and the two-component composition is uniformly mixed immediately before using it. Flame retardant room temperature curable organopolysiloxane composition. In this case, for example, the following first composition and second composition are separately prepared, and further, (C) 0.002 to 60 parts by mass of a curing catalyst (that is, the first composition and the second composition) The first composition or the second composition is blended with an amount corresponding to 0.001 to 30 parts by mass with respect to a total of 100 parts by mass of the component (A). Immediately before using the second composition and the second composition, it is preferable to uniformly mix them in a mass ratio of 100: 10 to 100: 100 to obtain a flame-retardant room-temperature-curable organopolysiloxane composition.

First composition 100 parts by mass of the above component (A),
5 to 500 parts by mass of the component (B)
An amount corresponding to 0.05 to 20 parts by mass with respect to a total of 100 parts by mass of the component (A) of the component (D), the first composition and the second composition,
(E) component The composition formed by containing the quantity corresponded to 0.5-30 mass parts with respect to a total of 100 mass parts of (A) component of a 1st composition and a 2nd composition.

Second composition 100 parts by mass of the above component (A),
A composition comprising 5 to 500 parts by mass of the component (B).

  In addition, when mix | blending other additives, although both a 1st composition and a 2nd composition can be mix | blended, the mixing | blending to either one is preferable on performance, and the mixing | blending to a 1st composition is more preferable .

  The flame-retardant room-temperature-curable organopolysiloxane composition of the present invention is cured by moisture in the air by coating or molding at room temperature and in the air, and the curing conditions and the like are usually room temperature commercially available. It may be the same as the curable organopolysiloxane composition.

  The flame-retardant room-temperature-curable organopolysiloxane composition of the present invention can be suitably used for sealing, fixing or bonding of electric or electronic parts, and is sealed, fixed or adhered with a cured product of the composition. As an electric or electronic component, the frame of a solar cell, a terminal box, the capacitor of an electronic board, etc. can be illustrated.

  Further, the method for improving heat-resistant adhesion in electric or electronic parts according to the present invention comprises sealing, fixing or bonding a cured product of the flame-retardant room temperature-curable organopolysiloxane composition of the present invention to the electric or electronic parts. It is characterized by doing.

  Here, it is preferable that the object to be sealed, fixed or adhered in the electronic or electronic component is made of a flame retardant resin material such as a flame retardant polycarbonate resin.

  EXAMPLES Hereinafter, the present invention will be specifically described by showing Examples and Comparative Examples, but the present invention is not limited to the following Examples. In addition, a viscosity shows the measured value in the rotational viscometer in 23 degreeC in the following example. Further, the average particle diameter is the cumulative mass average value D50 in the particle size distribution measurement by the laser light diffraction method, and the water content is a value measured by an infrared moisture meter at 150 ° C.

Example 1
100 parts by mass of polydimethylsiloxane in which both ends of the molecular chain having a viscosity of 30,000 mPa · s at 23 ° C. are blocked with a trimethoxysiloxy group, an average particle diameter of 0.7 μm as a flame retardant filler and a moisture amount of 150 ° C. 60 parts by mass of 1.2% by mass of magnesium hydroxide, 2 parts by mass of fumed silica having a surface treated with dimethyldichlorosilane as a reinforcing filler, and a mixture of alcohol solutions of chloroplatinic acid as a flame retardancy improver The mixture was added in such an amount that the amount of platinum was 20 ppm with respect to and completely mixed under reduced pressure to obtain a mixture. Next, 3 parts by mass of vinyltriethoxysilane, 1 part by mass of 3-aminopropyltriethoxysilane, and 0.15 parts by mass of dioctyltin dineodecanoate were thoroughly mixed with this mixture under reduced pressure to obtain Sample 1. The

Example 2
Sample 2 was prepared under the same conditions as in Example 1 except that the flame retardant filler was changed to silanized magnesium hydroxide having an average particle diameter of 1.1 μm and a water content of 0.4% by mass at 150 ° C. I got

[Example 3]
A sample 3 was obtained under the same conditions as in Example 1 except that 0.15 parts by mass of dioctyltin dineodecanoate was changed to 3 parts by mass of diisopropoxybis (acetylacetonate) titanium.

Example 4
100 parts by mass of polydimethylsiloxane in which both ends of the molecular chain having a viscosity of 30,000 mPa · s at 23 ° C. are blocked with a trimethoxysilyl group, an average particle diameter of 0.7 μm as a flame retardant filler and a moisture amount of 150 ° C. 60 parts by mass of 1.2% by mass of magnesium hydroxide, 2 parts by mass of fumed silica having a surface treated with dimethyldichlorosilane as a reinforcing filler, and a mixture of alcohol solutions of chloroplatinic acid as a flame retardancy improver The mixture was added in such an amount that the amount of platinum was 20 ppm with respect to and completely mixed under reduced pressure to obtain a mixture. Next, 1 part by mass of vinyltriethoxysilane and 3 parts by mass of 3-aminopropyltriethoxysilane were added to this mixture, and thoroughly mixed under reduced pressure to obtain a first composition.
In 100 parts by mass of polydimethylsiloxane in which both ends of the molecular chain having a viscosity of 5,000 mPa · s at 23 ° C. are blocked with silanol groups, the average particle diameter 0.7 μm as a flame retardant filler and the amount of water at 150 ° C. 60 parts by mass of 1.2% by mass of magnesium hydroxide, 5 parts by mass of fumed silica having a surface treated with dimethyldichlorosilane as a reinforcing filler, and a mixture of alcohol solutions of chloroplatinic acid as a flame retardancy improver The mixture was added in such an amount that the amount of platinum was 20 ppm with respect to and completely mixed under reduced pressure to obtain a mixture. Next, 0.15 parts by mass of dioctyltin dineodecanoate was added to the mixture, and thoroughly mixed under reduced pressure to obtain a second composition.
The first composition and the second composition were mixed at a mass ratio of 1: 1 to obtain Sample 4 immediately before use in the following adhesion test.

[Example 5]
Sample 5 was prepared under the same conditions as in Example 1 except that the flame retardant filler was changed to magnesium hydroxide having an average particle diameter of 0.4 μm and a water content of 1.5% by mass at 150 ° C. .

Comparative Example 1
A sample 6 was obtained under the same conditions as Example 1 except that vinyltriethoxysilane was changed to vinyltrimethoxysilane.

Comparative Example 2
A sample 7 was obtained under the same conditions as in Example 1 except that 3-aminopropyltriethoxysilane was changed to 3-aminopropyltrimethoxysilane.

Comparative Example 3
Sample 8 was prepared under the same conditions as in Example 1 except that the flame retardant filler was changed to magnesium hydroxide having an average particle diameter of 7.0 μm and a water content of 0.2 mass% at 150 ° C. .

Comparative Example 4
Sample 9 was prepared under the same conditions as in Example 1 except that the flame retardant filler was changed to aluminum hydroxide having an average particle diameter of 1.2 μm and a water content of 0.4 mass% at 150 ° C. .

[Evaluation]
As storage stability evaluation, tack free time after initial and heating accelerated deterioration (5 days at 70 ° C.) and flame-retardant polycarbonate resin (trade name: Eupiron FPR3500, manufactured by Mitsubishi Engineering Plastics) used for electric parts Simple adhesion was confirmed. In addition, heat resistance and flame retardancy were also evaluated. The obtained results are shown in Tables 1 and 2.

Tack free time:
It measured by the finger touch method. Specifically, the sample was placed flat in an atmosphere of 23 ° C./50% RH, the surface was touched with a fingertip cleaned with ethyl alcohol, and the time until the sample did not adhere to the fingertip was measured.

Simple adhesion:
The sample is applied in a shape of 20 mm × 30 mm × 5 mm on a flame retardant polycarbonate resin, left to be cured for 7 days in a 23 ° C./50% RH environment, and then cured silicone rubber is 0 ° from each resin surface It pulled in the direction of, and checked adhesion by visual observation. After the above pulling, the bonded silicone rubber (cohesive failure 100%) adheres ○, partially peeled (cohesive failure 80 to 99%) Δ, peeled (cohesive failure 0%) x evaluated.

Heat-resistant:
The sample was filled to a thickness of 5 mm in a glass petri dish having a diameter of 25 mm and a depth of 10 mm, and was cured for one week in an atmosphere of 23 ± 2 ° C. and 50 ± 5% RH. Each glass petri dish was left to stand at 200 ° C. for 2 hours, and those which were not foamed were evaluated as ○, and those which were foamed were evaluated as ×.

Flame retardance:
The sample was allowed to stand for 7 days in a 23 ° C./50% RH environment to prepare a 3.0 mm thick test body, which was evaluated by the method defined in UL-94.

From the above results, it can be seen that the compositions of the present invention (samples 1, 2, 3, 4 and 5 of Examples 1 to 5) show little change in tack free time after accelerated heating deterioration and are excellent in storage stability . Furthermore, it is understood that the heat resistance and the flame retardance are also excellent. On the other hand, Sample 6 of Comparative Example 1 using the component (E) outside the scope of the present invention and Sample 7 of Comparative Example 2 using the component (D) outside the scope of the present invention have tack after heating accelerated deterioration. It can be seen that the free time change is large, the adhesiveness is also reduced, and the storage stability is reduced. Moreover, in the sample 8 of the comparative example 3 which uses the flame-retardant filler besides the range of this invention, it became a result inferior to a flame retardance. In addition, in sample 9 of Comparative Example 4 in which aluminum hydroxide having a thermal decomposition temperature of about 200 ° C. is used as a flame retardant filler, since it foams after a heat resistance test, its reliability as a sealing agent or adhesive is descend.
According to the present invention, the moisture content at 150 ° C. of the magnesium hydroxide of the component (B) is not only 1.0 mass% or less, but is excellent in storage stability even if it exceeds 1.0 mass%. It became.

Claims (8)

(A) 100 parts by mass of a diorganopolysiloxane blocked by a hydroxyl group and / or a hydrolyzable siloxy group in which both ends of a molecular chain are bonded to a silicon atom,
(B) 5 to 500 parts by mass of magnesium hydroxide having an average particle size of 0.4 to 5 μm,
(C) Curing catalyst 0.001 to 30 parts by mass,
(D) the following general formula (1):
R ¹ _a Si (OR ² ) _4-a (1)
(Wherein, R ¹ represents a substituted monovalent hydrocarbon group containing one or more atoms of at least one atom selected from a nitrogen atom, a sulfur atom and an oxygen atom, and each R ² independently represents ² to 4) A monovalent alkyl group containing a carbon atom, a is 1 or 2, provided that when a is 2, R ¹ may be the same or different)
0.05 to 20 parts by mass of a hydrolyzable organosilicon compound represented by and / or a partial hydrolysis condensate thereof
(E) the following general formula (2):
R ³ _b Si (OR ⁴ ) _4-b (2)
(Wherein, R ³ represents an unsubstituted or halogen-substituted monovalent hydrocarbon group, R ⁴ is a monovalent alkyl group each independently containing 2 to 4 carbon atoms, and b is 0) , 1 or 2, provided that when b is 2, R ³ may be the same or different.)
A flame-retardant room-temperature-curable organopolysiloxane composition comprising 0.5 to 30 parts by mass of a hydrolyzable organosilicon compound represented by and / or a partial hydrolysis condensate thereof.   The flame-retardant room-temperature-curable organopolysiloxane composition according to claim 1, wherein the average particle diameter of magnesium hydroxide as the component (B) is 0.6 to 3 μm. In the formula (1) of the component (D), R ¹ is 3-methacryloxypropyl group, 2- (3,4-epoxycyclohexyl) ethyl group, 2- (2,3-epoxycyclohexyl) ethyl group, 3-glyl. And sidoxypropyl group, N-2 (aminoethyl) -3-aminopropyl group, 3-aminopropyl group, 3-mercaptopropyl group, 3-acryloxypropyl group, or N-phenyl-3-aminopropyl group. A flame retardant room temperature curable organopolysiloxane composition according to claim 1 or 2.   The flame-retardant room-temperature-curable organopolysiloxane composition according to any one of claims 1 to 3, wherein the curing catalyst of the component (C) is an organotin catalyst. A two-component mixed flame-retardant room-temperature-curable organopolysiloxane composition obtained by mixing the following first composition and second composition in a mass ratio of 100: 10 to 100: 100, respectively. , (C) curing catalyst in an amount corresponding to 0.001 to 30 parts by mass with respect to a total of 100 parts by mass of the first composition and the component (A) of the second composition, the first composition or the second composition The flame-retardant room-temperature-curable organopolysiloxane composition according to any one of claims 1 to 4, which is obtained by blending it with any one of the above.
First component (A) 100 parts by mass of a diorganopolysiloxane blocked by a hydroxyl group and / or a hydrolyzable siloxy group in which both molecular chain ends are bonded to a silicon atom,
(B) 5 to 500 parts by mass of magnesium hydroxide having an average particle size of 0.4 to 5 μm,
(D) the following general formula (1):
R ¹ _a Si (OR ² ) _4-a (1)
(Wherein, R ¹ represents a substituted monovalent hydrocarbon group containing one or more atoms of at least one atom selected from a nitrogen atom, a sulfur atom and an oxygen atom, and each R ² independently represents ² to 4) A monovalent alkyl group containing a carbon atom, a is 1 or 2, provided that when a is 2, R ¹ may be the same or different)
The hydrolyzable organosilicon compound represented by and / or its partial hydrolytic condensate equivalent to 0.05 to 20 parts by mass with respect to a total of 100 parts by mass of the first composition and the component (A) of the second composition Amount to be
(E) the following general formula (2):
R ³ _b Si (OR ⁴ ) _4-b (2)
(Wherein, R ³ represents an unsubstituted or halogen-substituted monovalent hydrocarbon group, R ⁴ is a monovalent alkyl group each independently containing 2 to 4 carbon atoms, and b is 0) , 1 or 2, provided that when b is 2, R ³ may be the same or different.)
The hydrolyzable organosilicon compound represented by and / or its partial hydrolytic condensate equivalent to 0.5 to 30 parts by mass with respect to a total of 100 parts by mass of the first composition and the component (A) of the second composition A composition comprising an amount of
Second composition (A) 100 parts by mass of a diorganopolysiloxane blocked by a hydroxyl group and / or a hydrolyzable siloxy group in which both molecular chain ends are bonded to a silicon atom,
(B) A composition comprising 5 to 500 parts by mass of magnesium hydroxide having an average particle size of 0.4 to 5 μm.   An electric or electronic part sealed, fixed or adhered by the cured product of the flame-retardant room-temperature-curable organopolysiloxane composition according to any one of claims 1 to 5.   A heat resistant electric or electronic component characterized by sealing, fixing or adhering a cured product of the flame retardant room temperature curable organopolysiloxane composition according to any one of claims 1 to 5 to an electric or electronic component. How to improve adhesion.   The method according to claim 7, wherein the object to be sealed, fixed or bonded in the electronic or electronic component is a flame retardant polycarbonate resin.