JP7175249B2 - Alkynyl group-containing organopolysiloxane and hydrosilylation reaction control agent - Google Patents

Description

The present invention relates to novel alkynyl group-containing organopolysiloxanes useful as hydrosilylation reaction control agents.

Platinum-catalyzed addition reactions between aliphatic unsaturated bonds and hydrosilyl groups are applied in many fields, and in the field of silicone industry in particular, it is widely used as a means of cross-linking addition reaction type resins and rubbers.

Since the reaction proceeds even at room temperature in addition reaction-type silicone resin compositions that apply such hydrosilylation reactions, reaction inhibitors are generally added for the purpose of adjusting the curing speed and improving storage stability. Examples of reaction control agents include 3-methyl-1-butyn-3-ol, 2,5-dimethyl-3-hexyne-2,5-diol (Patent Document 1), 3-methyl-trideca-1-yne Acetylene alcohols such as -3-ol (Patent Document 2) are used.

However, since the above acetylene alcohols are composed only of a hydrocarbon skeleton, there is a problem that when they are added to a resin composition as a hydrosilylation control agent, the resulting resin is colored in a reliability test after curing.

As a countermeasure, for example, Patent Document 3 describes the use of an organosiloxane modified with an alkoxy group having an acetylenically unsaturated group as a reaction controller.

Japanese Patent Publication No. 44-31476 JP-A-8-269339 JP-A-64-51466

However, the organosiloxane described in Patent Document 3 has poor compatibility with a composition containing a phenyl group-modified silicone, and may not provide sufficient reaction controllability.

The present invention has been made in view of the above problems, and is capable of functioning as a hydrosilylation reaction inhibitor in an addition-curable organopolysiloxane resin composition, exhibiting excellent storage stability at room temperature and resistance after curing. An object of the present invention is to provide an alkynyl group-containing organopolysiloxane that gives a composition excellent in discoloration.

In order to achieve the above objects, the inventors have found that an organopoly having alkynyl groups at both ends and at least one aromatic hydrocarbon group bonded to a silicon atom represented by the following formula (1): The present inventors have synthesized siloxane and found that the organopolysiloxane can solve the above-mentioned problems, thereby completing the present invention.

（式中、Ｒ^１及びＲ^２は、互いに独立に、炭素数１～６の飽和脂肪族炭化水素基、または炭素数６～１２の芳香族炭化水素基であり、Ｒ^３は互いに独立に、水素原子または炭素数１～６の飽和脂肪族炭化水素基であり、ｘは０～４の整数であり、ｎは夫々１～３の整数であり、ａは互いに独立に０～６の整数であり、及びｂは互いに独立に０または１であり、上記式（１）は少なくとも１の芳香族炭化水素基を有し、ｘが０のとき上記ｎの少なくとも一つは１又は２である）。
更には、上記アルキニル基含有オルガノポリシロキサンからなるヒドロシリル化反応制御剤を提供する。 Specifically, the present invention provides an alkynyl group-containing organopolysiloxane represented by the following formula (1).

(wherein R ¹ and R ² are each independently a saturated aliphatic hydrocarbon group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and R ³ is each independently a hydrogen atom or a saturated aliphatic hydrocarbon group having 1 to 6 carbon atoms, x is an integer of 0 to 4, n is an integer of 1 to 3, and a is an integer of 0 to 6 independently of each other and b are each independently 0 or 1, the above formula (1) has at least one aromatic hydrocarbon group, and when x is 0, at least one of the above n is 1 or 2 ) .
Furthermore, there is provided a hydrosilylation reaction control agent comprising the alkynyl group-containing organopolysiloxane.

The addition reaction-curable silicone composition containing the alkynyl group-containing organopolysiloxane of the present invention as a hydrosilylation reaction inhibitor has excellent storage stability at room temperature and can give a cured product with excellent discoloration resistance.

1 is a ¹ H-NMR spectrum chart of the compound synthesized in Example 1. FIG. 2 is a ¹ H-NMR spectrum chart of the compound synthesized in Example 2. FIG. 3 is a ¹ H-NMR spectrum chart of the compound synthesized in Example 3. FIG.

（式中、Ｒ^１及びＲ^２は、互いに独立に、炭素数１～６の飽和脂肪族炭化水素基、または炭素数６～１２の芳香族炭化水素基であり、Ｒ^３は互いに独立に、水素原子または炭素数１～６の飽和脂肪族炭化水素基であり、ｘは０～４の整数であり、ｎは夫々１～３の整数であり、ａは互いに独立に０～６の整数であり、及びｂは互いに独立に０または１であり、上記式（１）は少なくとも１の芳香族炭化水素基を有し、ｘが０のとき上記ｎの少なくとも一つは１又は２である）。 The present invention will now be described in more detail.
The present invention is an alkynyl group-containing organopolysiloxane represented by the following formula (1).

(wherein R ¹ and R ² are each independently a saturated aliphatic hydrocarbon group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and R ³ is each independently a hydrogen atom or a saturated aliphatic hydrocarbon group having 1 to 6 carbon atoms, x is an integer of 0 to 4, n is an integer of 1 to 3, and a is an integer of 0 to 6 independently of each other and b are each independently 0 or 1, the above formula (1) has at least one aromatic hydrocarbon group, and when x is 0, at least one of the above n is 1 or 2 ) .

R ¹ and R ² are each independently a saturated aliphatic hydrocarbon group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, provided that n of at least 1 is 1 or 2 At least one of R ¹ and R ² is an aromatic hydrocarbon group having 6 to 12 carbon atoms. A group selected from a saturated aliphatic hydrocarbon group having 1 to 3 carbon atoms and an aromatic hydrocarbon group having 6 to 8 carbon atoms is preferable. In particular, it is preferable to have at least one aromatic hydrocarbon group whenever n is 1 to 3. Examples of saturated aliphatic hydrocarbon groups include alkyl groups such as methyl group, ethyl group, propyl group and butyl group; cycloalkyl groups such as cyclopentyl group and cyclohexyl group; Among these, a methyl group is preferred. Examples of aromatic hydrocarbon groups include aryl groups such as phenyl group, tolyl group, naphthyl group and biphenyl group, and aralkyl groups such as benzyl group, phenylethyl group and phenylpropyl group. Among these, a phenyl group is preferred.

Each R ³ is independently a hydrogen atom or a saturated aliphatic hydrocarbon group having 1 to 6 carbon atoms, preferably a hydrogen atom or a saturated aliphatic hydrocarbon group having 1 to 3 carbon atoms. Examples of saturated aliphatic hydrocarbon groups include alkyl groups such as methyl group, ethyl group, propyl group and butyl group; cycloalkyl groups such as cyclopentyl group and cyclohexyl group; Of these, methyl groups are preferred, and most preferably all R3 ^are methyl groups. When R ³ is a methyl group, the effect of suppressing the reaction can be improved.

x is an integer of 0-4, n is an integer of 1-3, and b is 0 or 1; Here, when x is 0, n is preferably 2 or 3, and when x is 1 to 4, b is preferably 0. a is an integer of 0-6, preferably an integer of 0-3. More preferably, each n is 2 or 3. By having adjacent acetylene groups, the effect of suppressing addition reaction due to the chelating action of the acetylene groups can be further improved.

（ｘは１～４の整数であり、好ましくは１又は２であり、ａは０～６の整数であり、好ましくはaは０である。Ｒ^１、Ｒ^２、及びＲ^３は上記の通りであり、好ましくは少なくとも１のＲ^１が芳香族炭化水素基であるのがよく、より好ましくはフェニル基であり、Ｒ^２は好ましくは飽和脂肪族炭化水素基であり、より好ましくはメチル基であり、Ｒ^３は好ましくは水素原子又はメチル基であり、より好ましくはメチル基である） When x=1 to 4, the following structures can be mentioned.

(x is an integer of 1 to 4, preferably 1 or 2; a is an integer of 0 to 6; preferably a is 0; R ¹ , R ² and R ³ are as described above; , preferably at least one R ¹ is an aromatic hydrocarbon group, more preferably a phenyl group, R ² is preferably a saturated aliphatic hydrocarbon group, more preferably a methyl group and R ³ is preferably a hydrogen atom or a methyl group, more preferably a methyl group)

（ａは０～６の整数であり、好ましくはａは０であり、ｂは０または１であり、Ｒ^２及びＲ^３は上記の通りであり、Ｒ^２の少なくとも１は芳香族炭化水素基であり、より好ましくはフェニル基であり、Ｒ^３は好ましくは水素原子又はメチル基であり、より好ましくはメチル基である）
When x=0, the following structures are included.

(a is an integer of 0 to 6, preferably a is 0, b is 0 or 1, R ² and R ³ are as described above, and at least one of R ² is an aromatic hydrocarbon group , more preferably a phenyl group, R ³ is preferably a hydrogen atom or a methyl group, more preferably a methyl group)

More specific examples of the alkynyl group-containing organopolysiloxane include compounds represented by the following formulas.

[Method for Producing Alkynyl Group-Containing Organopolysiloxane]
The alkynyl group-containing organopolysiloxane of the present invention can be produced, for example, by dehydrogenating acetylene alcohol and hydrosilyl group-containing organosiloxane in the presence of a catalyst such as trispentafluoroborane. The production method using the dehydrogenation reaction using a borane catalyst is desirable because it can prevent an unwanted increase in the molecular weight of the organopolysiloxane chain and yield the desired alkynyl group-containing organopolysiloxane in high yield. Conditions for the dehydrogenation reaction may be adjusted as appropriate. For example, the reaction ratio of hydrosilyl groups and acetylene alcohol is 1:1.1 in terms of molar ratio.

The alkynyl group-containing organopolysiloxane can exhibit excellent effects as a reaction control agent for the hydrosilylation reaction. When the alkynyl group-containing organopolysiloxane is used as a reaction controller, it should be 0.001 to 5 parts by mass per 100 parts by mass of the alkenyl group-containing organopolysiloxane contained in the addition reaction curing silicone composition. is preferred, and 0.01 to 3 parts by mass is more preferred. The composition of the addition reaction-curable silicone composition is not particularly limited. The alkynyl group-containing organopolysiloxane of the present invention preferably has an aromatic hydrocarbon group, and the siloxane has good compatibility with a composition having a phenyl-modified silicone, and is excellent in storage stability. can give.

EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.
In the following examples, ¹ H-NMR measurements were carried out using a BRUKER apparatus (apparatus name: AVANCE III 400M) using deuterated chloroform as solvent and chloroform as internal standard.

滴下終了後、更に７０℃で７時間加熱撹拌した。加熱終了後、室温（２５℃）まで冷却し、前記トリスペンタフルオロフェニルボランを吸着除去するためにマグネシウム・アルミニウム系固溶体３ｇ（商品名：ＫＷ－２２００、協和化学工業株式会社製）を添加して１時間室温で撹拌した。加圧濾過によりＫＷ－２２００を除去し、減圧化で残存溶剤を留去し下記式（Ｂ）で表されるアルキニル基含有オルガノポリシロキサン（化合物１）を得た。^１Ｈ－ＮＭＲチャートを図１に示す。

^１Ｈ－ＮＭＲのケミカルシフト（ＴＭＳ基準、ｐｐｍ）と積分比は以下のとおりである。
δ０．２０（ＯＳｉ（ＣＨ _３ ）_２）１２Ｈ
δ１．４９（Ｃ－ＣＨ _３ ）１２Ｈ
δ２．３１（Ｃ≡ＣＨ）２Ｈ
δ７．３２－７．６９（ＳｉＣ_６ Ｈ _５ ）１０Ｈ [Example 1]
0.3 g (5.9×10 ⁻⁴ mol) of trispentafluorophenylborane was added to a four-necked flask equipped with a stirrer, condenser, dropping funnel and thermometer and dissolved in 100 g of toluene. 33.3 g (0.40 mol) of 2-methyl-3-butyn-2-ol was added thereto, and the temperature was raised to 70°C. To this, 60.0 g (0.18 mol) of a compound represented by the following formula (A) was added dropwise over 30 minutes using a dropping funnel.

After completion of the dropwise addition, the mixture was further heated and stirred at 70° C. for 7 hours. After heating, the mixture was cooled to room temperature (25° C.), and 3 g of a magnesium-aluminum solid solution (trade name: KW-2200, manufactured by Kyowa Chemical Industry Co., Ltd.) was added to adsorb and remove the trispentafluorophenylborane. Stir at room temperature for 1 hour. KW-2200 was removed by pressure filtration, and the remaining solvent was distilled off under reduced pressure to obtain an alkynyl group-containing organopolysiloxane (compound 1) represented by the following formula (B). ^{A 1} H-NMR chart is shown in FIG.

¹ H-NMR chemical shift (TMS standard, ppm) and integral ratio are as follows.
δ0.20( OSi ( _CH3 ) ₂ )12H
δ 1.49(C—C H ₃ )12H
δ2.31(C≡C H )2H
δ7.32-7.69(SiC ₆ H ₅ )10H

[Example 2]
0.3 g (5.9×10 ⁻⁴ mol) of trispentafluorophenylborane was added to a four-necked flask equipped with a stirrer, condenser, dropping funnel and thermometer and dissolved in 100 g of toluene. 27.8 g (0.33 mol) of 2-methyl-3-butyn-2-ol was added thereto, and the temperature was raised to 70°C. To this, 80.0 g (0.15 mol) of a compound represented by the following formula (C) was added dropwise over 30 minutes using a dropping funnel.

^１Ｈ－ＮＭＲのケミカルシフト（ＴＭＳ基準、ｐｐｍ）と積分比は以下のとおりである。
δ０．０７（ＯＳｉ（ＣＨ _３ ）_２）１２Ｈ
δ１．４０（Ｃ－ＣＨ _３ ）１２Ｈ
δ２．２１（Ｃ≡ＣＨ）２Ｈ
δ７．２５－７．６２（ＳｉＣ_６ Ｈ _５ ）２０Ｈ After completion of the dropwise addition, the mixture was further heated and stirred at 70° C. for 7 hours. After heating, the mixture was cooled to room temperature (25° C.), and 3 g of a magnesium-aluminum solid solution (trade name: KW-2200, manufactured by Kyowa Chemical Industry Co., Ltd.) was added to adsorb and remove the trispentafluorophenylborane. Stir at room temperature for 1 hour. KW-2200 was removed by pressure filtration, and the remaining solvent was distilled off under reduced pressure to obtain an alkynyl group-containing organopolysiloxane (compound 2) represented by the following formula (D). ^{A 1} H-NMR chart is shown in FIG.

¹ H-NMR chemical shift (TMS standard, ppm) and integral ratio are as follows.
δ0.07( OSi ( _CH3 ) ₂ )12H
δ 1.40(C—C H ₃ )12H
δ2.21(C≡C H )2H
δ7.25-7.62 (SiC ₆ H ₅ ) 20H

滴下終了後、更に７０℃で３時間加熱撹拌した。加熱終了後、室温（２５℃）まで冷却し、前記トリスペンタフルオロフェニルボランを吸着除去するためにマグネシウム・アルミニウム系固溶体１ｇ（商品名：ＫＷ－２２００、協和化学工業株式会社製）を添加して１時間室温で撹拌した。加圧濾過によりＫＷ－２２００を除去し、減圧化で残存溶剤を留去し下記式（Ｆ）で表されるアルキニル基含有オルガノポリシロキサン（化合物３）を得た。^１Ｈ－ＮＭＲチャートを図３に示す。

^１Ｈ－ＮＭＲのケミカルシフト（ＴＭＳ基準、ｐｐｍ）と積分比は以下のとおりである。
δ０．１４，０．１７（ＯＳｉ（ＣＨ _３ ）_２）２４Ｈ
δ１．４６（Ｃ－ＣＨ _３ ）２４Ｈ
δ２．３０（Ｃ≡ＣＨ）４Ｈ
δ７．２６－７．７０（ＳｉＣ_６ Ｈ _５ ）１０Ｈ [Example 3]
0.08 g (1.7×10 ⁻⁴ mol) of trispentafluorophenylborane was added to the reactor and dissolved in 12 g of toluene. 7.4 g (0.09 mol) of 2-methyl-3-butyn-2-ol was added thereto, and the temperature was raised to 70°C. To this, 5.0 g (0.01 mol) of a compound represented by the following formula (E) was added dropwise over 30 minutes.

After completion of the dropwise addition, the mixture was further heated and stirred at 70° C. for 3 hours. After heating, the mixture was cooled to room temperature (25° C.), and 1 g of a magnesium-aluminum solid solution (trade name: KW-2200, manufactured by Kyowa Chemical Industry Co., Ltd.) was added to adsorb and remove the trispentafluorophenylborane. Stir at room temperature for 1 hour. KW-2200 was removed by pressure filtration, and the remaining solvent was distilled off under reduced pressure to obtain an alkynyl group-containing organopolysiloxane (compound 3) represented by the following formula (F). ^{A 1} H-NMR chart is shown in FIG.

¹ H-NMR chemical shift (TMS standard, ppm) and integral ratio are as follows.
δ0.14, 0.17( OSi ( _CH3 ) ₂ )24H
δ1.46(C—C H ₃ )24H
δ2.30(C≡C H )4H
δ7.26-7.70 (SiC ₆ H ₅ ) 10H

[Preparation of addition-curable silicone resin composition]
[Example 4]
157 parts by mass of linear dimethylpolysiloxane (viscosity: 5,000 Pa s, vinyl group equivalent: 0.006 mol/100 g) having both ends of the molecular chain blocked with vinyl groups, and CH ₂ =CH(CH ₃ ) ₂ SiO _{Resin -} like _{organopolysiloxane} (weight _average molecular weight: ₅₂₀₀ , vinyl 50 parts by mass (group equivalent: 0.095 mol/100 g) and 8.1 parts by mass of an organohydrogenpolysiloxane whose average structural formula is represented by the following formula (G) were mixed until uniform. To this mixture, 0.1 part by mass (2.6×10 ⁻⁴ mol, amount of acetylene: 5.2×10 ⁻⁴ mol) of compound 1 obtained in Example 1 was added as a hydrosilylation reaction controller and mixed. After that, 0.2 parts by mass of 1,3-divinyltetramethyldisiloxane platinum (0) complex (platinum content 1.0% by mass) was added and mixed to prepare a silicone resin composition.

[Example 5]
Except for using 0.2 parts by mass (2.6×10 ⁻⁴ mol, amount of acetylene: 5.2×10 ⁻⁴ mol) of compound 2 obtained in Example 2 instead of compound 1 in Example 4. Example 4 was repeated to prepare a silicone resin composition.

[Example 6]
Except that 0.1 part by mass (1.2×10 ⁻⁴ mol, acetylene amount: 5.2×10 ⁻⁴ mol) of compound 3 obtained in Example 3 was used instead of compound 1 in Example 4. Example 4 was repeated to prepare a silicone resin composition.

[Comparative Example 1]
0.044 parts by mass (5.2×10 ⁻⁴ mol, amount of acetylene: 5.2×10 ⁻⁴ mol) of 2-methyl-3-butyn-2-ol instead of compound 1 in Example 4 Example 4 was repeated except that a silicone resin composition was prepared.

[Storage stability]
The viscosities at 23° C. of the silicone resin compositions prepared in Examples 4 to 6 and Comparative Example 1 were measured immediately after preparation, 4 hours, and 7 hours after preparation to evaluate storage stability. Viscosity was measured using a Brookfield rotational viscometer. Table 1 shows the results.

[Discoloration resistance]
The silicone resin compositions prepared in Examples 4 to 6 and Comparative Example 1 were heat-molded at 150° C. for 4 hours to obtain cured products (10 mm×15 mm×5 mm). These cured products were subjected to heat and moisture resistance tests under conditions of 135° C. and 85% RH for 30 hours. The appearance and total transmittance of the cured product after the heat and moisture resistance test were compared with the initial appearance (before the test) and total transmittance to evaluate discoloration resistance.
For the heat/humidity resistance test, an unsaturated type highly accelerated life test device (device name: HASTEST PC-242HSR2) manufactured by Hirayama Seisakusho Co., Ltd. was used. Further, the total transmittance was measured using a spectrophotometer (apparatus name: U-4100) manufactured by Hitachi High-Technologies Corporation. Table 2 shows the results.

As shown in Table 1 above, the addition reaction curable composition of Comparative Example 1, in which the hydrosilylation reaction inhibitor is acetylene alcohol, gelled 4 hours after preparation. Furthermore, as shown in Table 2, the cured product obtained by curing the composition turned yellow after the heat and moisture resistance test, and both the composition and the cured product were inferior in storage stability.
In contrast, the addition reaction curable composition containing the alkynyl group-containing organopolysiloxane of the present application as a reaction control agent does not gel 4 hours after preparation, and the resulting cured product is colorless even after heat and moisture resistance tests. It is transparent and has improved storage stability and transparency. In particular, the composition containing compound 3, which has two alkynyl groups at both ends, as a reaction control agent, exhibited significantly improved storage stability, with the increase in viscosity being suppressed even after 4 hours and 7 hours after preparation. Furthermore, the obtained cured product has high transparency before and after the heat and moisture resistance test. The compound is particularly preferred as a reaction controller for addition-curable organopolysiloxane compositions used for optical applications.

The alkynyl group-containing organopolysiloxane of the present invention exhibits excellent effects as a reaction control agent for hydrosilylation reactions. In particular, since it has an aromatic hydrocarbon group in its molecule, it is particularly useful as a reaction controller for addition-curable organopolysiloxane compositions used in optical applications such as LED sealants.

Claims (3)

A hydrosilylation reaction controller which is an alkynyl group-containing organopolysiloxane represented by the following formula (1)

(wherein R ¹ and R ² are each independently a saturated aliphatic hydrocarbon group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and R ³ is each independently a hydrogen atom or a saturated aliphatic hydrocarbon group having 1 to 6 carbon atoms, x is an integer of 0 to 4, n is an integer of 1 to 3, and a is an integer of 0 to 6 independently of each other and b are each independently 0 or 1, the above formula (1) has at least one aromatic hydrocarbon group, and when x is 0, at least one of the above n is 1 or 2 ) . 2. The hydrosilylation reaction controller according to claim 1, wherein x is an integer of 1 to 4 and b is 0 in the formula (1). 2. The hydrosilylation reaction inhibitor according to claim 1, wherein in formula (1), x is 0 and n is 2 or 3, provided that at least one of n is 2 .

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