JP2008120975A - Catalyst for addition reaction - Google Patents

Abstract

The present invention provides an addition reaction catalyst which is excellent in storage stability and does not have a poor appearance over time and a decrease in catalyst activity.
A catalyst for addition reaction is (A) a polyorganosiloxane having two or more silicon-bonded alkenyl groups in one molecule and having a viscosity at 23 ° C. of 0.01 to 3 Pa · s, (B) A catalyst for addition reaction comprising a platinum complex having a vinyl group-containing organosiloxane as a ligand and (C) a stabilizer having a nitrogen atom, wherein the blending amount of the component (C) is the component (B) It is 0.001-0.5 mol with respect to 1 mol of platinum atoms of the component.
[Selection figure] None

Description

  The present invention relates to an addition reaction catalyst which is excellent in storage stability and suitable as a curing catalyst for use in curing an addition reaction curable polyorganosiloxane composition.

  Conventionally, a curing rate as a catalyst for an addition reaction of a polyorganosiloxane composition containing a polyorganosiloxane having a vinyl group bonded to a silicon atom and a polyorganohydrogensiloxane having a hydrogen atom bonded to a silicon atom. From the point of being good, platinum-based catalysts, in particular, platinum complexes having a vinyl group-containing organosiloxane as a ligand are frequently used (see, for example, Patent Document 1).

  However, a platinum complex having a vinyl group-containing organosiloxane as a ligand is inferior in long-term storage stability at room temperature as well as at high temperatures.

  Therefore, a catalyst for an addition reaction obtained by blending a specific vinyl group-containing polyorganosiloxane with a platinum complex having a vinyl group-containing organosiloxane as a ligand and heat-treating it has been proposed (for example, Patent Documents). 2).

However, even when such an addition reaction catalyst is used, the storage stability is not sufficient. For example, when the appearance changes to black over time and it is formulated as a curing catalyst for an addition reaction curable polyorganosiloxane composition, the catalytic activity is significantly reduced, and the curing rate is important. Was inappropriate.
Japanese Examined Patent Publication No. 46-28795 Japanese Patent Laid-Open No. 11-128748

  An object of the present invention is to provide a catalyst for addition reaction that is excellent in storage stability and does not have a poor appearance over time and a decrease in catalyst activity.

  As a result of intensive studies to achieve the above object, the present inventors have converted (C) a stabilizer having a nitrogen atom into (B) a platinum atom of a platinum complex having a vinyl group-containing organosiloxane as a ligand. On the other hand, by adding a predetermined amount, it has been found that an addition reaction catalyst excellent in storage stability without poor appearance over time and a decrease in catalyst activity can be obtained, and the present invention has been made.

That is, the catalyst for addition reaction of the present invention is
(A) a polyorganosiloxane having two or more silicon-bonded alkenyl groups in one molecule and having a viscosity at 23 ° C. of 0.01 to 3 Pa · s,
(B) a platinum complex having a vinyl group-containing organosiloxane as a ligand, and (C) a catalyst for addition reaction containing a stabilizer having a nitrogen atom,
The amount of the component (C) is 0.001 to 0.5 mol with respect to 1 mol of the platinum atom of the component (B).

  According to the above configuration, it is possible to provide an addition reaction catalyst that is excellent in storage stability and does not have a poor appearance over time and a decrease in catalyst activity.

  Hereinafter, the addition reaction catalyst of the present invention will be described in detail.

[(A) component]
Component (A) is a component that imparts excellent storage stability by preventing poor appearance over time, and has one alkenyl group bonded to two or more silicon atoms in one molecule, preferably one molecule. It has an alkenyl group bonded to 2 to 5 silicon atoms.

  Examples of the alkenyl group bonded to the silicon atom include a vinyl group, an allyl group, a butenyl group, a petenyl group, and a hexenyl group, and a vinyl group is preferable. The alkenyl group may be bonded to the silicon atom at the end of the molecular chain, may be bonded to the silicon atom in the middle of the molecular chain, or may be bonded to both, but at least the silicon atom at the end of the molecular chain, Bonding to silicon atoms at both ends of the molecular chain is preferred.

  Examples of the organic group bonded to the silicon atom other than the alkenyl group as the component (A) include alkyl groups such as methyl group, ethyl group and propyl group, cycloalkyl groups such as cyclopentyl group and cyclohexyl group, phenyl group, and tolyl. Group, aryl group such as xylyl group, or halogenated hydrocarbon group in which these hydrogen atoms are partially substituted with chlorine atom, fluorine atom or the like, usually 1 to 12 carbon atoms, preferably 1 carbon atom From the viewpoint of ease of synthesis and storage stability of the resulting catalyst, an alkyl group and an aryl group are preferable, and a methyl group and a phenyl group are more preferable.

  The molecular structure of the component (A) is not particularly limited, and examples thereof include linear, cyclic, and branched chains, and preferably are linear. Moreover, (A) component can also be used individually by 1 type or in combination of 2 or more types.

  The viscosity of the component (A) at 23 ° C. is 0.01 to 3 Pa · s, preferably 0.1 to 1.0 Pa · s, from the viewpoint of workability of adding and blending the catalyst solution.

[Component (B)]
The component (B) is a platinum complex having a vinyl group-containing organosiloxane as a ligand, and a known one can be used.

で示されるものが挙げられる。 Examples of the vinyl group-containing organosiloxane serving as a ligand include the following general formula:

The thing shown by is mentioned.

In the above formula, R ¹ is the same or different substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms. R ¹ includes, for example, an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, and an octyl group, an alkenyl group such as a vinyl group, an allyl group, a propenyl group, and a butenyl group, a phenyl group, a tolyl group, An aryl group such as a xylyl group, an aralkyl group such as a benzyl group and a phenylethyl group, a halogen-substituted alkyl group such as a chloromethyl group, a bromoethyl group, a trifluoropropyl group, and a chlorophenyl group, and a halogen-substituted aryl group are preferable. A methyl group and a phenyl group;

  n is an integer greater than or equal to 1, m is an integer greater than or equal to 0, and n + m is 3-8.

The component (B) can be obtained by a known production method. For example, a platinum compound such as chloroplatinic acid (H ₂ PtCl ₆ ) and a vinyl group-containing organosiloxane are mixed with a diluent such as ethanol, sodium bicarbonate. It can obtain by making it react for 2 to 6 hours by heating at 60-80 degreeC in presence of neutralizing agents, such as.

  (B) Although the compounding quantity of a component is not specifically limited, Usually, it is 1000-10000 ppm as platinum amount in the catalyst for addition reaction obtained, Preferably it is 2000-5000 ppm.

[Component (C)]
Component (C) is a component that imparts the characteristics of the present invention, and gives the resulting addition reaction catalyst excellent storage stability without poor appearance over time and a decrease in catalyst activity.

  (C) A component contains a nitrogen atom and can be used individually by 1 type or in mixture of 2 or more types.

で示されるアミン化合物を用いることができる。 As the component (C), for example, a general formula:

The amine compound shown by can be used.

In the above formula, R ² is the same or different alkyl group having 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, and a propyl group. R ³ is the same as R ² or a hydrogen atom. R ⁴ is an alkylene group having 2 to ⁴ carbon atoms, and examples thereof include an ethylene group, a propylene group, and a trimethylene group.

  Examples of the component (C) represented by the above general formula include N, N, N ′, N′-tetramethylethylenediamine, N, N-dimethylethylenediamine, N, N-diethylethylenediamine, and 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- Examples thereof include butanediamine, and N, N, N ′, N′-tetramethylethylenediamine is preferable.

で示されるエチレン系不飽和イソシアヌレートを用いることもできる。 Examples of the component (C) include the following general formula:

It is also possible to use an ethylenically unsaturated isocyanurate represented by

In the above formula, R ⁵ is the same or different substituted or unsubstituted monovalent hydrocarbon group, and at least one R ⁵ is an alkenyl group. R ⁵ is, for example, an alkyl group having 1 to 20 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a pentyl group, or a hexyl group, a vinyl group, an allyl group, or a butenyl group. , An alkenyl group having 2 to 6 carbon atoms such as an isobutenyl group, an aryl group such as a phenyl group, a tolyl group and a xylyl group, an aralkyl group such as a benzyl group and a phenylethyl group, and a hydrogen atom bonded to the carbon atom of these groups Are partially substituted with a halogen atom such as a chlorine atom or a fluorine atom, a polycyclic aryl group, a heterocyclic aryl group, etc., preferably, at least one R ⁵ is an allyl group, Preferably all R ⁵ are allyl groups.

  Examples of the component (C) represented by the above general formula include triallyl isocyanurate, diallyl isocyanurate, diallyl ethyl isocyanurate, tributenyl isocyanurate, diallyl phenyl isocyanurate, and preferably triallyl isocyanurate. Diallyl isocyanurate, more preferably triallyl isocyanurate.

  (C) The compounding quantity of a component is the range of 0.001-0.5 mol with respect to 1 mol of platinum atoms of (B) component, Preferably it is 0.01-0.1 mol. When the amount is less than 0.001 mol, it is difficult to prevent the appearance failure of the obtained catalyst over time and the color is easily changed to black. On the other hand, if it exceeds 0.5 mol, it is possible to sufficiently prevent the appearance failure over time, but it is not suitable for applications that require short-time curing, where the catalytic activity tends to decrease and the curing speed is important. It is.

  Examples of the method for producing an addition reaction catalyst of the present invention include a method in which the components (A) to (C) are uniformly mixed at a room temperature of about 23 ° C.

  The resulting catalyst for addition reaction is free from poor appearance over time and reduced in catalytic activity, has excellent storage stability, and is suitable as a curing catalyst for known addition reaction curable polyorganosiloxane compositions. The addition reaction curable polyorganosiloxane composition includes an alkenyl group-containing polyorganosiloxane containing at least two silicon-bonded alkenyl groups in one molecule and at least two, preferably three or more silicons in one molecule. It is a well-known composition containing polyorganohydrogensiloxane containing an atomic bond hydrogen atom (SiH group), and various components such as various fillers can be blended as required.

  When the addition reaction catalyst of the present invention is used as a curing catalyst for the above addition reaction curing type polyorganosiloxane composition, the addition amount of the addition reaction catalyst may be an amount required for curing, It can adjust suitably according to a cure rate. Usually, the platinum amount is 1 to 500 ppm, preferably 3 to 100 ppm, based on the total amount of the alkenyl group-containing polyorganosiloxane having a silicon atom-bonded alkenyl group and the polyorganohydrogensiloxane.

  Therefore, in applications where the curing speed is important, for example, in a heat-dissipating sheet interposed between a heat-generating electronic component and a heat-dissipating body, from the heat conductive filler blended in the addition reaction curable polyorganosiloxane composition In the case where curing delay occurs, the curing delay can be prevented by using the catalyst for addition reaction of the present invention.

  Examples The present invention will be described in detail by examples, but the present invention is not limited to the examples. The addition reaction catalysts obtained in Examples and Comparative Examples were evaluated as follows, and the results are shown in Table 1. The characteristics shown in Table 1 are values measured at 23 ° C.

[appearance]
30 g of the resulting catalyst for addition reaction was placed in a 50 ml glass bottle and allowed to stand at room temperature of 23 ° C. for 1 day, and then the appearance was visually observed. Similarly, the appearance after aging at 70 ° C. for 1 week was also observed.

で示されるメチルハイドロジェンシロキサン１．３ｇを混合、攪拌して付加反応硬化型ポリオルガノシロキサン組成物をつくり、１００℃の熱板上での硬化時間を測定した。 [Catalytic activity]
0.5 g of the obtained catalyst for addition reaction, 100 g of polydimethylsiloxane containing vinyl groups at both ends having a viscosity at 23 ° C. of 3.0 Pa · s, 0.02 g of 1-ethynyl-1-cyclohexanol, formula:

The hydrogenated polyorganosiloxane composition was prepared by mixing and stirring 1.3 g of methylhydrogensiloxane, and the curing time on a hot plate at 100 ° C. was measured.

で示されるジビニルテトラメチルジシロキサン２４ｇを７０℃で４時間加熱して反応させた。この後、反応混合物を２３℃の室温で攪拌しながら、炭酸水素ナトリウム１９ｇを徐々に加えて２時間中和した。反応混合物を吸引ろ過し、ろ液を減圧留去し、エタノールと過剰のジビニルテトラメチルジシロキサンを除去した後、オクタメチルテトラシロキサンで希釈して、（Ｂ−１）ジビニルテトラメチルジシロキサンを配位子とする白金錯体（白金含有量５．０％）を１００ｇ得た。
この（Ｂ−１）白金錯体４．０ｇ（白金量として２０００ｐｐｍ）を、（Ａ‐１）２３℃における粘度が０．４Ｐａ・ｓの両末端にビニル基を含有したポリジメチルシロキサン９６ｇに加え、室温で攪拌した後、さらに、（Ｃ−１）テトラメチルエチレンジアミン０．５９ｍｇを加え、付加反応用触媒を得た。
この付加反応用触媒の特性を測定し、結果を表１に示した。 [Example 1]
In a 100 ml reaction flask equipped with a reflux condenser, a thermometer and a stirrer, 13.3 g of chloroplatinic acid represented by H ₂ PtCl ₂ .6H ₂ O, 30 g of ethanol, formula:

Was reacted by heating at 70 ° C. for 4 hours. Thereafter, while stirring the reaction mixture at room temperature of 23 ° C., 19 g of sodium hydrogen carbonate was gradually added to neutralize for 2 hours. The reaction mixture was suction filtered, the filtrate was distilled off under reduced pressure, ethanol and excess divinyltetramethyldisiloxane were removed, then diluted with octamethyltetrasiloxane, and (B-1) divinyltetramethyldisiloxane was disposed. 100 g of platinum complex (platinum content 5.0%) as a ligand was obtained.
4.0 g of this (B-1) platinum complex (2000 ppm as the amount of platinum) was added to (A-1) 96 g of polydimethylsiloxane containing vinyl groups at both ends having a viscosity at 23 ° C. of 0.4 Pa · s, After stirring at room temperature, 0.59 mg of (C-1) tetramethylethylenediamine was further added to obtain an addition reaction catalyst.
The characteristics of this addition reaction catalyst were measured and the results are shown in Table 1.

[Example 2]
A catalyst for addition reaction was obtained in the same manner as in Example 1 except that 0.59 mg of (C-1) tetramethylethylenediamine of Example 1 was changed to 5.9 mg.
The characteristics of this addition reaction catalyst were measured and the results are shown in Table 1.

[Example 3]
A catalyst for addition reaction was obtained in the same manner as in Example 1 except that 0.59 mg of (C-1) tetramethylethylenediamine of Example 1 was changed to 11.8 mg.
The characteristics of this addition reaction catalyst were measured and the results are shown in Table 1.

[Example 4]
A catalyst for addition reaction was obtained in the same manner as in Example 1 except that 0.59 mg of (C-1) tetramethylethylenediamine of Example 1 was changed to 12.7 mg of (C-2) triallyl isocyanurate.
The characteristics of this addition reaction catalyst were measured and the results are shown in Table 1.

[Comparative Example 1]
An addition reaction catalyst was obtained in the same manner as in Example 1 except that (C-1) tetramethylethylenediamine of Example 1 was not added.
The characteristics of this addition reaction catalyst were measured and the results are shown in Table 1.

[Comparative Example 2]
An addition reaction catalyst was obtained in the same manner as in Example 1 except that 0.59 mg of (C-1) tetramethylethylenediamine in Example 1 was changed to 118 mg.
The characteristics of this addition reaction catalyst were measured and the results are shown in Table 1.

[Comparative Example 3]
Except that 0.59 mg of (C-1) tetramethylethylenediamine in Example 1 was changed to 6.4 mg of (C-3) 3,5-dimethyl-1-hexyn-3-ol, the same procedure as in Example 1 was carried out. Thus, a catalyst for addition reaction was obtained.
The characteristics of this addition reaction catalyst were measured and the results are shown in Table 1.

で示されるメチルビニルテトラマー１７．７ｍｇとした以外は、実施例１と同様にして、付加反応用触媒を得た。
この付加反応用触媒の特性を測定し、結果を表１に示した。 [Comparative Example 4]
0.59 mg of (C-1) tetramethylethylenediamine of Example 1 is replaced with (C-4) formula:

A catalyst for addition reaction was obtained in the same manner as in Example 1 except that 17.7 mg of methylvinyltetramer represented by
The characteristics of this addition reaction catalyst were measured and the results are shown in Table 1.

[Comparative Example 5]
In Example 1, (A-1) 96 g of polydimethylsiloxane containing vinyl groups at both ends with a viscosity at 23 ° C. of 0.4 Pa · s was used, and (A-2) the viscosity at 23 ° C. of 0.1 Pa · s was 0.1 Pa · s. An addition reaction catalyst was obtained in the same manner as in Example 1 except that 96 g of polydimethylsiloxane containing no vinyl group was used.
The characteristics of this addition reaction catalyst were measured and the results are shown in Table 1.

  As is clear from Table 1, (C) tetramethylethylenediamine or (C-2) triallyl isocyanurate as a stabilizer having a nitrogen atom is added to 1 mol of platinum atom in the component (B). On the other hand, the catalyst for addition reaction of each example blended in the range of 0.001 to 0.5 mol does not have a poor appearance over time, and even if blended into an addition reaction curable polyorganosiloxane composition, There is no decline over time.

  Therefore, the catalyst for addition reaction of the present invention has no poor appearance over time, no reduction in catalytic activity, has excellent storage stability, and is suitable as a curing catalyst for an addition reaction curable polyorganosiloxane composition, It is particularly suitable for applications where the curing rate is important.

Claims (4)

(A) a polyorganosiloxane having two or more silicon-bonded alkenyl groups in one molecule and having a viscosity at 23 ° C. of 0.01 to 3 Pa · s,
(B) a platinum complex having a vinyl group-containing organosiloxane as a ligand, and (C) a catalyst for addition reaction containing a stabilizer having a nitrogen atom,
The addition reaction catalyst, wherein the compounding amount of the component (C) is 0.001 to 0.5 mol with respect to 1 mol of the platinum atom of the component (B). The vinyl group-containing organosiloxane of the component (B) has the following general formula:

The addition according to claim 1, wherein the siloxane is represented by the formula: wherein R ¹ is the same or different substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms. Catalyst for reaction. The component (C) has the following general formula:

(Wherein, ^{R 2} is identical or different alkyl groups having 1 to 4 carbon atoms, ^{R 3} is identical or hydrogen atom and ^{R 2, R 4} is an alkylene group having 2 to 4 carbon atoms. The catalyst for addition reaction according to claim 1 or 2, wherein   The catalyst for addition reaction according to claim 1 or 2, wherein the component (C) is an ethylenically unsaturated isocyanurate.