Heat-resistant silicone oil composition

Abstract

To provide a silicone oil composition having excellent heat resistance without the occurrence of separation, sedimentation, etc., even during long-term storage.SOLUTION: This heat resistant silicone oil composition includes (A) 100 pts.mass of an organopolysiloxane having a kinematic viscosity of 50-5,000 mm2 / s at 25°C as measured using a Cannon-Fenske viscometer according to the method stipulated in JIS Z 8803: 2011, and (B) 10-100 pts.mass of a (poly)thiophene-(poly)siloxane block copolymer including the structure represented by formula (1). (In the formula, R1's are each independently a hydrogen atom or a hydrocarbon group having 1-10 carbon atoms, R2's are each independently a hydrocarbon group having 1-10 carbon atoms, a is 1-3, b is 2-200, and c is 1-40).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a heat-resistant silicone oil composition. [Background technology]

[0002] Traditionally, silicone oils have been used for applications such as lubricants and hydraulic oils. In particular, for applications requiring heat resistance, phenyl silicone oils with phenyl groups or 2-phenylpropyl groups are often used. However, even these phenyl silicone oils do not have sufficient heat resistance and generate aromatic hydrocarbons during thermal decomposition, which poses problems in terms of both performance and safety.

[0003] In addition, methods of blending various heat resistance improvers with silicone oil have been studied. Heat resistance improvers used in hydrocarbon lubricants, such as metal soaps and aromatic amines, are also used in silicone oil. However, these heat resistance improvers are not sufficiently compatible with silicone oil, and the effect of improving heat resistance is not satisfactory.

[0004] Patent Document 1 discloses an attempt to improve heat resistance by blending fullerene with silicone oil. However, fullerene is a solid and is not sufficiently compatible with silicone oil, resulting in problems such as separation and sedimentation during long-term storage.

[0005] For these reasons, there has been a demand for the development of a silicone oil composition that is free from separation or sedimentation even during long-term storage and has excellent heat resistance. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2005-206761 A Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, an object of the present invention is to provide a silicone oil composition which is free from separation or sedimentation even during long-term storage and has excellent heat resistance. [Means for solving the problem]

[0008] As a result of intensive research conducted by the present inventors to solve the above problems, it was discovered that a silicone oil composition containing a silicone oil and a heat-resistant (poly)thiophene-(poly)siloxane block copolymer does not separate or settle even during long-term storage and has excellent heat resistance, thereby completing the present invention.

[0009] The present invention provides the following heat-resistant silicone oil composition.

[0010] [1] (A) The kinetic viscosity at 25°C measured using a Cannon-Fenske viscometer according to the method described in JIS Z8803:2011 is 50 to 5,000 mm 2 / s: 100 parts by mass of organopolysiloxane, and (B) a (poly)thiophene-(poly)siloxane block copolymer containing a structure represented by the following formula (1): 10 to 100 parts by mass [ka] [In the formula, R 1 are each independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms; R 2 are each independently a hydrocarbon group having 1 to 10 carbon atoms, a is a number from 1 to 3, b is a number from 2 to 200, and c is a number from 1 to 40. A heat resistant silicone oil composition comprising: [2] The heat-resistant silicone oil composition according to [1], wherein component (A) is a dimethylpolysiloxane. [3] The component (B) is represented by the following formula (2): [ka] [In the formula, R 1 are each independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms; R 2 are each independently a hydrocarbon group having 1 to 10 carbon atoms, each a is independently a number from 1 to 3, b is a number from 2 to 200, and c is a number from 1 to 40. The heat-resistant silicone oil composition according to [1] or [1], wherein the silicone oil composition is a (poly)thiophene-(poly)siloxane block copolymer represented by the following formula: Effect of the Invention

[0011] According to the present invention, it is possible to provide a silicone oil composition that does not separate or settle even during long-term storage and has excellent heat resistance even at high temperatures of 300° C. or higher. The silicone oil composition of the present invention is useful for applications such as a heat transfer medium, a mold release agent, and a resin modifier. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present invention will be described in detail below.

[0013] [(A) Organopolysiloxane] The organopolysiloxane of the present invention, component (A), has a kinetic viscosity of 50 to 5,000 mm at 25°C as measured using a Cannon-Fenske viscometer according to the method described in JIS Z8803:2011. 2 / s, preferably 100 to 1,000 mm 2 / s, and more preferably, 100 to 500 mm 2 / s. The kinetic viscosity is 50mm 2 If the kinematic viscosity is less than 5,000 mm / s, the component (A) itself may be prone to volatilization at high temperatures, or the desired properties as a silicone oil may not be obtained. 2 If it exceeds this ratio, compatibility with the component (B) described below may decrease, or handling may become difficult.

[0014] The molecular structure of the organopolysiloxane may be linear or partly branched, but linear organopolysiloxanes represented by the following formula (3) are preferred. [ka] (In the formula, R is independently a group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms, and n is a number from 30 to 700.)

[0015] Here, R is independently a group selected from an alkyl group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, preferably 6 to 8 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms, preferably 7 to 8 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the aryl group include a phenyl group and a tolyl group. Examples of the aralkyl group include a benzyl group and a 2-phenylpropyl group. Among them, an alkyl group is preferable, and a methyl group is particularly preferable. R may be the same or different, but it is preferable that 90% or more of all R are methyl groups, and it is more preferable that all R are methyl groups.

[0016] In addition, the component (A) of the present invention may be one that has a reduced content of low molecular weight siloxanes, including cyclic siloxanes, in order to reduce the amount of volatile components at high temperatures. Specifically, the total amount of cyclopolysiloxanes (D3-D20) having 3 to 20 silicon atoms is preferably 3,000 ppm or less, and more preferably 100 to 2,000 ppm. Within this range, it is possible to prevent the occurrence of problems such as contamination of the surrounding environment and electrical contact failure.

[0017] [(B) (Poly)thiophene-(poly)siloxane block copolymer] The (poly)thiophene-(poly)siloxane block copolymer which is component (B) of the present invention contains a structure represented by the following formula (1), and is preferably a (poly)thiophene-(poly)siloxane block copolymer represented by the following formula (2). This component (B) is a component which imparts heat resistance to the heat-resistant silicone oil composition of the present invention. [ka]

[0018] In formulas (1) and (2), R 1 are each independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. Examples of the hydrocarbon group having 1 to 10 carbon atoms include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; aryl groups such as phenyl and tolyl; and alkenyl groups such as vinyl and allyl. Among these, a hydrogen atom or an alkyl group is preferred, and a hydrogen atom is more preferred.

[0019] In formulas (1) and (2), R 2 are each independently a hydrocarbon group having 1 to 10 carbon atoms. Examples of the hydrocarbon group having 1 to 10 carbon atoms include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl groups; cycloalkyl groups such as cyclopentyl and cyclohexyl groups; aryl groups such as phenyl and tolyl groups; and alkenyl groups such as vinyl and allyl groups. Among these, alkyl groups are preferred, and methyl groups are more preferred.

[0020] In formulas (1) and (2), a's are each independently a number from 1 to 3, preferably 1 or 2, and more preferably 1. In formulas (1) and (2), b's is a number from 2 to 200, preferably 4 to 200, and more preferably 4 to 100. In formulas (1) and (2), c's is a number from 1 to 40, preferably 1 to 30, and more preferably 1 to 20. Within these ranges, compatibility with the organopolysiloxane of component (A) is excellent, and the composition of the present invention has excellent heat resistance.

[0021] In the present invention, the bonding mode of the (poly)thiophene-(poly)siloxane units (formulas (1) and (2)) is linear or cyclic.

[0022] In addition, the (B) component of the present invention may be one that has a reduced content of low molecular weight siloxanes, including cyclic siloxanes, in order to reduce the amount of volatile components at high temperatures. Specifically, the total amount of cyclopolysiloxanes (D3-D20) having 3 to 20 silicon atoms is preferably 3,000 ppm or less, more preferably 100 to 2,000 ppm. Within this range, it is possible to prevent problems such as contamination of the surrounding environment and electrical contact failure.

[0023] The blending amount of component (B) is 10 to 100 parts by mass, and preferably 15 to 50 parts by mass, per 100 parts by mass of the organopolysiloxane of component (A). If it is less than 10 parts by mass, it is not possible to impart sufficient heat resistance to the composition of the present invention, and if it exceeds 100 parts by mass, there is a risk that compatibility with component (A) will be poor or that the inherent properties of the silicone oil of component (A) will be impaired. The total content of the components (A) and (B) in the composition of the present invention is preferably from 90 to 100%, more preferably from 95 to 100%, and even more preferably from 98 to 100%.

[0024] [Other ingredients] The heat-resistant silicone oil composition of the present invention may contain components other than the above-mentioned components (A) and (B) as long as the effects of the present invention are not impaired. Examples of components other than the above-mentioned components (A) and (B) include heat resistance improvers such as metal soaps and aromatic amines.

[0025] [Method of producing heat-resistant silicone oil composition] The heat-resistant silicone oil composition of the present invention can be produced by any known method for mixing liquid substances. In particular, since component (B) of the present invention has excellent compatibility with the organopolysiloxane of component (A), a homogeneous composition can be obtained by simply mixing at room temperature (25°C). When components other than components (A) and (B) are added to the composition of the present invention, it is preferable to disperse the components in silicone oil in advance by a known method, and then simply mix them at room temperature (25°C). EXAMPLES

[0026] The present invention will be described in more detail below with reference to examples and comparative examples, but they can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited to the specific examples shown below.

[0027] The kinematic viscosity of the organopolysiloxane is a value at 25° C. measured using a Cannon-Fenske viscometer according to the method described in JIS Z8803:2011.

[0028] The silicone oil compositions of the present invention were evaluated as having heat resistance if they met the following criteria: "After heating in an air atmosphere at 300°C for 6 hours, the weight loss of the silicone oil composition is 10% or less, the composition maintains its oily appearance, and no phenomena such as separation or sedimentation are observed." Those that did not meet these criteria were evaluated as not having heat resistance.

[0029] Example 1 Kinematic viscosity at 25°C is 100mm 2To 100 parts by mass of dimethylpolysiloxane having a molecular weight of 1000 g / s, 18 parts by mass of a (poly)thiophene-(poly)siloxane block copolymer represented by the following formula (4) was added, and the mixture was stirred at room temperature (25°C) for 15 minutes. The obtained silicone composition was placed in an oven at 300°C in an air atmosphere and heated for 6 hours, resulting in a weight loss rate of 8.2%. After the heating test, the composition remained oily, and no separation or precipitation occurred. The silicone composition of Example 1 had heat resistance. [ka]

[0030] Example 2 Kinematic viscosity at 25°C is 100mm 2 To 100 parts by mass of dimethylpolysiloxane having a molecular weight of 1000 g / s, 33 parts by mass of the (poly)thiophene-(poly)siloxane block copolymer represented by the above formula (4) was added, and the mixture was stirred at room temperature (25°C) for 15 minutes. The obtained silicone composition was placed in an oven at 300°C in an air atmosphere and heated for 6 hours, resulting in a weight loss rate of 6.8%. After the heating test, the composition remained oily, and no separation or precipitation occurred. The silicone composition of Example 2 had heat resistance.

[0031] Example 3 Kinematic viscosity at 25°C is 2,000mm 2 To 100 parts by mass of dimethylpolysiloxane having a molecular weight of 1000 g / s, 18 parts by mass of the (poly)thiophene-(poly)siloxane block copolymer represented by the above formula (4) was added, and the mixture was stirred at room temperature (25°C) for 15 minutes. The obtained silicone composition was placed in an oven at 300°C in an air atmosphere and heated for 6 hours, resulting in a weight loss rate of 4.0%. After the heating test, the composition remained oily, and no separation or sedimentation occurred. The silicone composition of Example 3 had heat resistance.

[0032] Comparative Example 1 Kinematic viscosity at 25°C is 100mm 2When the dimethylpolysiloxane of Comparative Example 1 was placed in an oven at 300°C in an air atmosphere and heated for 6 hours, the weight loss rate was 29.5%. After the heating test, the composition lost its fluidity and turned into a gel. The dimethylpolysiloxane of Comparative Example 1 did not have heat resistance.

[0033] Comparative Example 2 Kinematic viscosity at 25°C is 2,000mm 2 When the dimethylpolysiloxane of Comparative Example 2 was placed in an oven at 300°C in an air atmosphere and heated for 6 hours, the weight loss rate was 17.5%. After the heating test, the composition lost its fluidity and turned into a gel. The dimethylpolysiloxane of Comparative Example 2 did not have heat resistance.

Claims

1. (A) The kinematic viscosity at 25 ° C. measured with a Cannon-Fenske viscometer according to the method described in JIS Z8803:2011 is 50 to 5,000 mm 2 / s: 100 parts by mass of organopolysiloxane, and (B) a (poly)thiophene-(poly)siloxane block copolymer having a structure represented by the following formula (1): 10 to 100 parts by mass 【Chemistry 1】 [In the formula, R 1 are each independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms; R 2 are each independently a hydrocarbon group having 1 to 10 carbon atoms, a is a number from 1 to 3, b is a number from 2 to 200, and c is a number from 1 to 40. A heat resistant silicone oil composition comprising:

2. 2. The heat-resistant silicone oil composition according to claim 1, wherein component (A) is a dimethylpolysiloxane.

3. The component (B) is represented by the following formula (2): 【Chemistry 2】 [In the formula, R 1 are each independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms; R 2 are each independently a hydrocarbon group having 1 to 10 carbon atoms, each a is independently a number from 1 to 3, b is a number from 2 to 200, and c is a number from 1 to 40.

3. The heat-resistant silicone oil composition according to claim 1, which is a (poly)thiophene-(poly)siloxane block copolymer represented by the formula:

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