JPH06192576A - One-pack type organopolysiloxane composition - Google Patents

Abstract

(57) [Summary] The present invention is an addition-curable type comprising an alkenyl group-containing organopolysiloxane, an organohydrogenpolysiloxane having a hydrogen atom bonded to a silicon atom, a curing catalyst, an amine compound and an inorganic filler. The composition is characterized by containing β-diketone or β-ketoester. [Effect] In the presence of an inorganic filler, an amine compound compounded as an inhibitory control agent for an addition curing reaction does not exhibit its inhibitory effect effectively because it is adsorbed to the filler.
By blending the β-diketone or β-ketoester according to the present invention, its adsorption is effectively prevented,
The addition-cure suppressing action of the amine compound is effectively exhibited.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an organopolysiloxane composition, and more particularly to an organopolysiloxane composition having good long-term storage stability at room temperature.

[0002]

2. Description of the Related Art Conventionally, a hydrogen atom (S
(iH group) -containing organohydrogenpolysiloxane and an organopolysiloxane having an aliphatic unsaturated hydrocarbon group (for example, vinyl group) bonded to a silicon atom, and addition reaction of the SiH group to a vinyl group or the like. Curable organopolysiloxane compositions that utilize (hydrosilylation) are well known. Incorporating various reaction inhibitors into such a composition to suppress the curing reaction at temperatures near room temperature to improve long-term storage stability, and at the time of use, accelerate the hydrosilylation reaction to cure the composition. Organopolysiloxane compositions capable of achieving the above have been proposed.

For example, acetylene compounds (US Pat. No. 3,445,420), sulfoxide compounds (US Pat. No. 3,453,234), or hydroperoxide compounds (US Pat. No. 4,061,609) as reaction inhibitors.
No.)) has been proposed. However, when an organohydrogenpolysiloxane having (H) (R ′) SiO _0.5 units (in the formula, two R ′'s are the same or different monovalent hydrocarbon groups) is used In addition, even if the above reaction inhibitor is blended, it effectively suppresses the curing of the hydrogen atom in this unit by the hydrosilylation reaction of the aliphatic unsaturated hydrocarbon group bonded to the silicon atom near room temperature. Therefore, the storage stability of the organopolysiloxane composition was not sufficient.

[0004]

In order to solve these problems, U.S. Pat. No. 4,584,361 discloses a hydrogen atom bonded to a silicon atom at the end of the molecular chain of an organohydrogenpolysiloxane and a silicon atom. N-butylamine, N, N-dibutylaminopropylamine, N, N, as a reaction inhibitor that suppresses the hydrosilylation reaction near the room temperature with the bonded aliphatic unsaturated hydrocarbon group
It has been proposed to use amine compounds such as N ', N'-tetramethylethylenediamine. However, these amine compounds are adsorbed on the surface of the inorganic filler when the composition contains the inorganic filler,
It has a drawback that its reaction suppressing effect is significantly reduced.

Therefore, an object of the present invention is to provide a one-part composition in which the curing reaction at room temperature is effectively suppressed and the storage stability is maintained for a long period of time even when the composition contains an inorganic filler. A type organopolysiloxane composition is provided.

[0006]

According to the present invention, by blending a β-diketone or a β-ketoester, the above-mentioned drawbacks of an amine compound as a reaction inhibitor are ameliorated, and even in the presence of an inorganic filler, It has succeeded in effectively exhibiting the reaction suppressing effect of the amine compound.

According to the present invention, (A) an alkenyl group-containing organopolysiloxane, (B) the following formula (1): (H) (R ¹ ) ₂ SiO _0.5 unit (1) [in the formula, two R ¹ may be the same or different and is a substituted or unsubstituted monovalent hydrocarbon group other than an aliphatic unsaturated group.] An organohydrogenpolysiloxane having at least two siloxane units in one molecule. , (C) platinum group metal-based catalyst, (D) the following general formula (2): (R ² ) ₂ N—R ⁴ —N (R ³ ) ₂ (2) [In the formula, two R ² are the same. But it may be different, a lower alkyl group having not more than 4 carbon atoms, the two R ³ may be the same or different, a lower alkyl group or a hydrogen atom having 4 or less carbon atoms, R ⁴ Has 2 carbon atoms
Is an alkylene group of 4 to 4] and the following formula (3): R ⁵ —NH ₂ (3) [wherein, R ⁵ is an alkyl group having 2 to 4 carbon atoms]
At least one reaction inhibitor selected from the group consisting of amine compounds represented by: (E) β-diketone and β-
1 containing at least one compound selected from the group consisting of ketoesters and (F) an inorganic filler
A liquid organopolysiloxane composition is provided.

Component (A) The alkenyl group-containing organopolysiloxane which is the component (A) of the composition of the present invention has, for example, the following average composition formula (4): (R ⁶ ) _a (R ⁷ ) _b SiO ₍₄ ) _{-ab) / 2} (4) In the average composition formula (4), R ⁶ is an alkenyl group, preferably an alkenyl group having 2 to 8 carbon atoms, and examples thereof include a vinyl group, an allyl group, a 1-butenyl group, and a 1-hexenyl group. . R ⁷ may be a substituted or unsubstituted monovalent hydrocarbon group, or two R ⁷ may combine together to form a lower alkylene group. Examples of the monovalent hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group and octyl group; cycloalkyl groups such as cyclopentyl group, cyclohexyl group and cyclobutyl group; phenyl group , An aryl group such as a tolyl group, a xylyl group, and a naphthyl group; an aralkyl group such as a benzyl group, a phenylethyl group, and a phenylpropyl group; or a part or all of the hydrogen atoms bonded to these hydrocarbon groups is chlorine,
Groups substituted with halogen atoms such as fluorine and bromine, cyano groups, etc., such as halogenated hydrocarbon groups such as chloromethyl group, trifluoropropyl group, chlorophenyl group, dibromophenyl group, tetrachlorophenyl group, difluorophenyl group, etc. A cyanoalkyl group such as β-cyanoethyl group, γ-cyanopropyl group, β-cyanopropyl group, etc., and a lower alkylene group formed from two R ⁷ includes an ethylene group and a trimethylene group. , Methylmethylene group, tetramethylene group, hexamethylene group and the like. Also, a is 0 <a <3
, B is a number 0 <b <3, where 0 <a + b <
It is 4. The organopolysiloxane represented by the average composition formula (4) may be linear or branched, or may be a mixture thereof. Such organopolysiloxanes may be used alone or in combination of two or more.

The organopolysiloxane as the component (A) has an average of 0.05 mol% or more, preferably 0.1 to 2 of all organic groups bonded to silicon atoms contained in one molecule.
Mol% is an alkenyl group. When the alkenyl group bonded to the silicon atom is less than 0.05 mol% on the average of all the organic groups bonded to the silicon atom in one molecule, the resulting composition does not cure sufficiently and is cured into a gel or May not be elastomeric. Further, this alkenyl group may be bonded to either a silicon atom in the middle of the molecular chain or a silicon atom at the end of the molecular chain, but it is bonded to the silicon atom at the end of the molecular chain in terms of curing rate of the resulting composition. It is preferable that The viscosity of the organopolysiloxane (A) is determined by casting, potting, or
When used for coating, impregnation, adhesion, etc., the composition usually has a suitable fluidity before curing and can exhibit stable physical properties after curing.
It is preferably 00 cP.

Specific examples of the component (A) used in the present invention include those represented by the following formulas). In the formulas below, l, m, o, p and q each represent a positive integer.

[0011]

[Chemical 1]

[0012]

[Chemical 2]

[0013]

[Chemical 3]

[0014]

[Chemical 4]

[0015]

[Chemical 5]

[0016]

[Chemical 6]

Component (B) The organohydrogenpolysiloxane which is the component (B) contains at least two siloxy units represented by the above formula (1) in one molecule. That is, in this organohydrogenpolysiloxane, a hydrogen atom is bonded to at least the terminal silicon atom of the molecule. Examples of the organohydrogenpolysiloxane include those represented by the following average composition formula (5): (H) _c (R ⁸ ) _d SiO _{(4-cd) / 2} (5).

In this average composition formula (5), R ⁸ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms which is not an aliphatic unsaturated hydrocarbon group, or R 2 is 2. R ⁸ is taken together to form a lower alkylene group, and examples thereof include the same ones exemplified for R ⁷ in the formula (4). Further, c is a number of 0 <c ≦ 2, d is a number of 0 <d ≦ 3, and 0 <c + d <4. These organohydrogenpolysiloxanes may be linear or branched and may be used alone or in combination of two or more.

In the present invention, examples of the straight-chain organohydrogenpolysiloxane of the component (B) include those represented by the following formula. (In the formula, R ⁸ has the same meaning as described above, and r 8
Is a positive integer and s is 0 or a positive integer. )

[0020]

[Chemical 7]

Examples of the branched organohydrogenpolysiloxane include those having R ⁸ SiO _3/2 units, SiO ₂ units and units represented by the following formula as a branching source.

[0022]

[Chemical 8]

The organohydrogenpolysiloxane of the component (B) described above is 25 in view of ease of synthesis and the like.
The viscosity at 1000C is preferably 1000 cP or less.
The blending ratio of the component (B) in the composition of the present invention is usually (B) because the cured product of the resulting composition has good physical properties such as heat resistance and mechanical strength and does not foam when cured. The number of hydrogen atoms bonded to silicon atoms contained in one molecule of component (A) is 0.5 to 4.0, particularly 0.8 to 1.5, per alkenyl group contained in the organopolysiloxane (A).
It is preferable that the ratio is that of individual pieces.

The platinum group metal-based catalyst which is the component (C) of the composition of the present invention is used to accelerate the addition curing reaction between the alkenyl group in the component (A) and the SiH group in the component (B). There are platinum-based, palladium-based and rhodium-based ones, but generally platinum-based catalysts such as platinum, chloroplatinic acid, platinum-olefin complex, platinum-alcohol complex, A platinum coordination compound or the like is preferably used. The composition ratio of the component (C) in the composition of the present invention is usually 1 ppm based on the component (A) in terms of platinum group metal in terms of good curability of the resulting composition.
Above all, a ratio of 3 to 100 ppm is particularly preferable.

Component (D) The amine compound which is the component (D) of the composition of the present invention is used as a reaction control agent for suppressing the addition curing reaction between the above-mentioned components (A) and (B). The use of this amine compound maintains the storage stability of the organopolysiloxane composition. As the amine compound, the above-mentioned formula (2), that is, (R ² ) ₂ N—R ⁴ —N (R ³ ) ₂ (2) [In the formula, two R ² may be the same or different. , A lower alkyl group having 4 or less carbon atoms, two R ^{3 s} may be the same or different, a lower alkyl group having 4 or less carbon atoms or a hydrogen atom, and R ⁴ has 2 carbon atoms.
Is an alkylene group of 4 to 4], or the above formula (3), that is, R ⁵ —NH ₂ (3) [In the formula, R ⁵ is an alkyl group having 2 to 4 carbon atoms]
Are used alone or in combination of two or more.

For example, as the amine compound represented by the above formula (2), N, N, N ', N'-tetramethylethylenediamine, N, N-dimethylethylenediamine, N,
N-diethylethylenediamine, N, N-dibutylethylenediamine, N, N-dibutyl-1,3-propanediamine, N, N-dimethyl-1,3-propanediamine, N, N, N ', N'-tetraethylethylenediamine , N, N-dibutyl-1,4-butanediamine and the like. Examples of the amine compound represented by the formula (3) include ethylamine, propylamine and butylamine. In the present invention, among these,
N, N, N ', N'-tetramethylethylenediamine is preferably used.

The blending ratio of the component (D) in the composition of the present invention can moderately suppress the catalytic action of the platinum group metal-based catalyst of the component (C) and ensure the storage stability of the resulting composition for a long period of time. In this respect, the ratio is usually 1 mol or more, preferably 2 to 20 mol, per 1 mol of the platinum atom in the platinum group metal-based catalyst of the component (C).

Component (E) In the present invention, at least one of β-diketone and β-ketoester is used as component (E). These are amine compounds of component (D) that act as reaction inhibitors. Has a function of preventing the adsorbent to the inorganic filler. That is, by using these (E) components,
Even in the presence of the inorganic filler, the reaction suppressing effect of the component (D) is sufficiently effectively exhibited, and the storage stability of the composition is secured.

Examples of such β-diketones and β-ketoesters include those represented by the following formulas "Chemical formula 9" to "Chemical formula 20".

[0030]

[Chemical 9]

[0031]

[Chemical 10]

[0032]

[Chemical 11]

[0033]

[Chemical 12]

[0034]

[Chemical 13]

[0035]

[Chemical 14]

[0036]

[Chemical 15]

[0037]

[Chemical 16]

[0038]

[Chemical 17]

[0039]

[Chemical 18]

[0040]

[Chemical 19]

[0041]

[Chemical 20]

The compounding amount of the compound used as the component (E) is largely influenced by the properties of the inorganic filler of the component (F) compounded in the composition, but it is difficult to unconditionally specify. , Generally 10 for component (F)
It is preferred to use at a rate of ~ 30,000 ppm.

Component (F) In the present invention, various inorganic fillers known per se can be used as the inorganic filler of component (F). Generally, at least aluminum oxide powder and silica powder are used. One kind is used. For example, as the aluminum oxide powder, spherical or non-spherical aluminum oxide, and those obtained by surface-treating these with a silylating agent such as methylchlorosilane, organopolysiloxane, silazane, and silylketene acetal are preferable. Further, as the silica powder, fumed silica, precipitated silica, and those surface-treated with the above silylating agent, and fused silica,
Quartz powder and the like are suitable. These inorganic fillers are used in a proportion of 5 to 90% by weight, particularly 10 to 80% by weight, based on the whole composition.

Other Ingredients In addition to the above components (A) to (F), the composition of the present invention comprises
As long as the storage stability of the composition is not impaired, an organopolysiloxane containing only one dimethylhydrogensiloxy unit or methylhydrogensiloxane unit in one molecule, or the above formula (1 An organohydrogenpolysiloxane containing no siloxy unit represented by the formula (1) may be appropriately blended. Further, the composition of the present invention may be blended with silicone oil such as dimethylpolysiloxane or raw rubber in order to adjust or modify the flowability, the hardness of the cured product of the composition and the like.

Organopolysiloxane Composition The composition of the present invention is easily prepared by uniformly mixing the above-mentioned components. This composition has excellent long-term storage stability, and exhibits curability that is the same as immediately after production even after long-term storage. The composition of the present invention comprises an adhesive,
It is used in various fields as a sealing agent and the like.

[0046]

EXAMPLES In the following examples, unless otherwise specified, "part"
Indicates "parts by weight", and the viscosity indicates a value measured at 25 ° C.

EXAMPLE 1 Vinyl group-containing organopolysiloxane (composed of 94.24 mol% of Me ₂ SiO unit, 0.52 mol% of ViMePhSiO _0.5 unit, 2.24 mol% of Me ₃ SiO _0.5 unit and 3 mol% of MeSiO _1.5 unit, and viscosity of 1500 cP) 71 parts, dimethylpolysiloxane (94 mol% Me ₂ SiO unit, ₃ mol% Me ₃ SiO _0.5 unit and 3 mol% MeSiO _1.5 unit, viscosity 500 cP) 29 parts, alumina (specific surface area 1.5 m ² / g) 350 parts and 0.3 part of acetylacetone were uniformly mixed. Then, to this mixture, 0.1 part of chloroplatinic acid-vinyl siloxane complex (platinum content; 1% by weight), 1-ethynyl-1-cyclohexanol 0.06 part, tetramethylethylenediamine 0.0012 part, dimethyl poly A mixture of 4.3 parts of siloxane (terminated with _0.5 unit of HMe ₂ SiO and a viscosity of 18 cP), which was stored at room temperature for 12 hours, was added and uniformly mixed.

Further added to this mixture was methylhydrogenpolysiloxane (HMe ₂ SiO _0.5 unit 2.5 mol%, Me ₂ SiO unit 95 mol%, Me ₃ SiO _0.5 unit 2.5 mol%, viscosity 35 cP). 6.7 parts was added and mixed uniformly to obtain an organopolysiloxane composition. The storage stability of this composition at 40 ° C.
It was measured by a viscosity measuring method. The results are shown in Table 1.

Example 2 Instead of 350 parts of alumina, quartz powder (specific surface area 2 m ²
/ G) An organopolysiloxane composition was prepared in the same manner as in Example 1 except that 20 parts were used, and the storage stability at 40 ° C. was measured. The results are shown in Table 1.

Comparative Example 1 An organopolysiloxane composition was prepared in the same manner as in Example 1 except that acetylacetone was not used, and the composition was prepared at 40 ° C.
The storage stability was measured. The results are shown in Table 1.

Comparative Example 2 An organopolysiloxane composition was prepared in the same manner as in Example 2 except that acetylacetone was not used, and the composition was prepared at 40 ° C.
The storage stability was measured. The results are shown in Table 1.

[0052]

[Table 1]

[0053]

EFFECTS OF THE INVENTION According to the present invention, in a one-pack addition-curing type organopolysiloxane composition, even when an inorganic filler is added, its storage stability can be secured for a long period of time.

Claims (2)

[Claims] 1. (A) an alkenyl group-containing organopolysiloxane, (B) the following formula (1): (H) (R ¹ ) ₂ SiO _0.5 unit (1) [in the formula, even if two R ^1's are the same, Which may be different, and is a substituted or unsubstituted monovalent hydrocarbon group other than an aliphatic unsaturated group] having at least two siloxane units in one molecule, (C) Platinum group metal catalyst, (D) General formula (2): (R ² ) ₂ N—R ⁴ —N (R ³ ) ₂ (2) [In the formula, two R ^{2 s} may be the same or different. May be a lower alkyl group having 4 or less carbon atoms, two R ^{3 s} may be the same or different, are a lower alkyl group having 4 or less carbon atoms or a hydrogen atom, and R ⁴ is a carbon atom number. Two
Is an alkylene group of 4 to 4] and the following formula (3): R ⁵ —NH ₂ (3) [wherein, R ⁵ is an alkyl group having 2 to 4 carbon atoms]
At least one reaction inhibitor selected from the group consisting of amine compounds, (E) at least one compound selected from the group consisting of β-diketones and β-ketoesters, and (F) inorganic A one-pack type organopolysiloxane composition containing a filler. 2. A cured product obtained by curing the composition according to claim 1.