Bisphenol-cyclic polymethylhydrogensiloxane compounds and their preparations

Abstract

The present invention relates to the compound of formula 1: [Formula 1] JPEG2026525399000013.jpg32170 (wherein n is 1, 2, or 3). The compounds of the present invention are useful as adhesion promoters in thermally conductive compositions. The present invention also relates to a method for preparing the compounds of formula 1.

Description

[Technical Field]

[0001] In recent years, efficient methods for bonding silicone rubber to incompatible materials such as organic resins have been reported. For example, U.S. Patent No. 6,887,932 discloses the preparation and use of cyclic polymethylhydrogensiloxanes containing mono-, di-, or triphenylene skeletons that are not directly bonded to silicon atoms. Examples of such compounds include BPA derivatives bonded to terminal cyclic polymethylhydrogensiloxane groups via propoxyl linkage groups, as shown below:

[0002] [ka] (wherein n is 1, 2, 3, or 4).

[0003] Unfortunately, when preparing such an adhesion promoter, one D H A considerable amount of the following by-products, which are terminated by only four units, are formed.

[0004] [ka]

[0005] Furthermore, the preparation of such adhesion promoters requires the use of a Pt catalyst, which is difficult to remove and thus negatively affects the shelf life of the part B addition-curing formulation. Therefore, there is a need to find a reactive adhesion promoter that can be prepared in high yield and high purity without using a Pt catalyst. [Overview of the project]

[0006] In one embodiment, the present invention relates to a compound of formula 1:

[0007] [ka] The present invention addresses the needs of the art by providing compounds (wherein each n is 1, 2, or 3) in the formula. The compounds of the present invention, which can be prepared in high purity and high yield without the use of a platinum catalyst, are useful as adhesion promoters in thermally conductive compositions. [Modes for carrying out the invention]

[0008] The present invention relates to the compound of formula 1:

[0009] [ka] (wherein each n is 1, 2, or 3)

[0010] The compound of formula 1 can be prepared in a single step by dehydrogenating condensation of bisphenol A and the cyclic polymethylhydrogensiloxane of formula 2 in the presence of a catalytic amount of Lewis acid, such as tris(pentafluorophenyl)borane (BCF).

[0011] [ka]

[0012] The reaction temperature is preferably controlled within the range of 20°C to 40°C. The BCF catalyst can be easily removed by treatment with Al2O3, or completely deactivated at 100°C for 10 minutes. The compounds of the present invention do not require a platinum catalyst, which is a significant advantage for the reasons mentioned above.

[0013] The compound of Formula 1 is useful as an adhesion promoter in thermally conductive compositions. Therefore, in another embodiment, the present invention relates to a composition comprising: a) the compound of Formula 1; b) a divinyl-terminated poly(di-C1~C6-alkyl)siloxane having a degree of polymerization (dp) in the range of 8 to, or 20 to, or 100 to 600, or 300, preferably a divinyl-terminated polydimethylsiloxane; c) an organohydrogenpolysiloxane (Si-H-containing polysiloxane) having preferably 10 to 100 dp; d) thermally conductive filler particles such as alumina or zinc oxide particles; e) a first filler treatment agent which is trimethoxysilyl-terminated polydimethylsiloxane (PDMS), preferably having dp in the range of 10 to 150; and f) a C6~C such as n-decyltrimethoxysilane. 20 - A composition comprising a second filler treatment agent which is alkyltrimethoxysilane, and g) a platinum catalyst. The composition may further contain a platinum catalyst inhibitor such as phenylbutynol and a pigment such as STAN-TONE 40SP03 Blue pigment.

[0014] The concentration of the thermally conductive filler particles is preferably in the range of 1000 or 1200 pbw to 1600 or ~1450 pbw per 100 parts by weight (pbw) of divinyl-terminated poly(di-C1~C6-alkyl)siloxane. The thermally conductive filler particles preferably have a multimodal distribution in the ranges of 200 nm to 800 nm, 1 μm to 10 μm, and 20 μm to 100 μm when measured by laser diffraction. 50 The particles present in the composition are alumina or zinc oxide particles having a specific particle size, or both.

[0015] The concentrations of the first and second filler treatment agents are preferably in the range of 0.5 to 3 pbw per 100 pbw of thermally conductive filler particles. The ratio of Si-H groups in the organohydrogenpolysiloxane to vinyl groups in the divinyl-terminated poly(di-C1-C6-alkyl)siloxane is preferably in the range of 0.5:1 to 1.1:1, and the concentration of the ratio of Si-H groups in the organohydrogenpolysiloxane to Si-H groups in the compound of formula 1 is preferably in the range of 0.1:1 to 1:1.

Example

[0016] Preparation of Compound of Formula 1 (n = 1) in Example 1

[0017]

Chem.

[0018] Bisphenol A (BPA, 100.3 g), anhydrous toluene (295.2 g, ACS grade), heptane (77.0 g), and 809 g of D H 4 (809 g, available from Gelest) was charged into a 2 L flask. The solvent was distilled off, and residual water (from D H 4) was removed by recharging and returning anhydrous toluene (160.0 g) to the flask. The mixture was stirred overnight, and tris(pentafluorophenyl)borane / toluene catalyst (4.46% BCF 248 μL) was added to the flask. The pot temperature was controlled in the range of 22 °C to 38 °C using a heating block cooled with dry ice, and stirring was continued for 3 hours and 50 minutes. Then, Al2O3 (23 g) was added to the flask to remove BCF. Stirring was continued for an additional 1.5 hours, and then the contents of the flask were filtered through a 0.45 μm membrane. Residual volatiles were removed at 1 torr and 60 °C for 50 minutes to obtain the desired product (278.0 g). 1 H, 13 C, and 29 Si The structure was confirmed by 1H, 13C, and 29

[0019] Preparation of Compounds of Formula 1 (n = 1, 2, and 3) in Example 2

[0020]

Chem.

[0021] BPA (104.3 g), anhydrous toluene (494.5 g, ACS grade), and DOWSIL™ MH-1109 Fluid (791.2 g, a trademark of The Dow Chemical Company or its affiliates) were charged into a 2 L flask equipped with a thermocouple, a mechanical stirrer, and an adapter to a N2 bubbler. The headspace of the flask was purged with N2 for 5 minutes, and then BCF / toluene catalyst (4.46% BCF 199 μL) was added to the flask. The pot temperature was controlled in the range of 22 °C to 30 °C using a heating block cooled with dry ice. Gas evolved during this time, and when the evolution subsided, an additional amount of BCF / toluene catalyst (57 μL) was added and repeated 5 times. The contents of the flask were stirred for an additional 3 hours, and then Al2O3 (47 g) was added. Stirring was continued for an additional 2 hours, and then the contents of the flask were filtered through a 0.45 μm membrane. Residual volatiles were removed at 1 torr and 60 °C for 50 minutes to obtain the desired product (438.6 g). 1 H, 13 C, and 29 Si The structure was confirmed by NMR spectroscopy.

[0022] Example 3 - Preparation of a Thermal Conductivity Compound Vinyl-terminated polydimethylsiloxane (60 mPa·s, 6.5 pbw), trimethoxysiloxy-terminated polydimethylsiloxane (dp=30; 0.7 pbw), and n-decyltrimethoxysilane (0.2 pbw) were placed in a 1 L planetary mixer, followed by the addition of AES-12 alumina (18.8 pbw) and AL-M734 alumina (20.8 pbw). The mixture was stirred at room temperature for 10 minutes, after which DAM-40K alumina particles (25 pbw) were added. Stirring was continued for another 10 minutes, during which an additional amount of DAM-40K alumina particles (25 pbw) was added. Stirring was continued for another 10 minutes, followed by scraping and further mixing for an additional 10 minutes. The contents were heated at 160°C under vacuum for 60 minutes, and then cooled to room temperature over 30 minutes. STAN-TONE 40SP03 Blue (0.2 pbw), SiH-terminated polyorganosiloxane (dp=14, 2.62 pbw), the compound of Formula 1 from Example 2 (0.06 pbw), and phenylbutynol (0.01 pbw) were added to a mixer and mixed for 15 minutes, then scraped off and mixed further under vacuum for an additional 15 minutes. The contents of the mixer were removed, and then platinum 85 catalyst (0.1 pbw, 6000 ppm Pt) was added to the mixture.

[0023] Measurement of hardness A mold with plate dimensions of 120mm x 120mm x 2mm was used, with PTFE sheets placed between each plate of the mold. The composition was placed inside the mold to form a sheet with a thickness of 2mm, which was then cured by hot pressing at 120°C for 60 minutes. After that, the JIS Type A hardness was measured using a JIS Type A hardness tester. Hardness was measured by stacking three sheets. Furthermore, the hardness of each thermally conductive component was measured again after aging at 200°C for 72 hours.

[0024] Thermal conductivity (hot disk) In a mold with plate dimensions of 50 mm × 30 mm × 6 mm, test specimens of thermally conductive samples were prepared with PTFE sheets between each plate of the mold. Each composition was placed in the mold to form a sheet with a thickness of 6 mm, which was then cured by hot pressing at 120°C for 60 minutes. The sheets were removed from the mold and stored at 25°C for 24 hours. Subsequently, the thermal conductivity of two samples was measured and averaged using a Hot Disk TPS 500S manufactured by Hot Disk AB (Goteborg, Sweden).

[0025] Wrap shear strength and cohesive failure rate First, the adhesive strength (MPa) and cohesive failure rate (%) of each thermally conductive component were measured by cleaning the aluminum die-cast substrate (ADC12) with isopropyl alcohol. The composition was filled into an overlapping region defined by the aluminum die-cast substrate, which had dimensions of 10 mm × 24 mm × 1 mm. The composition was cured by hot pressing at 120°C for 60 minutes while placed in the overlapping region defined by the substrate. After curing, excess curing product was removed from around the overlapping region using a cutter, and the properties were measured by tensile testing at a measurement speed of 50 mm / min.

[0026] Table 1 summarizes the hardness, adhesive strength, and cohesive failure rate of the composition of Example 3.

[0027] [Table 1]

Claims

1. Compound of formula 1: 【Chemistry 1】 (In the formula, each n is 1, 2, or 3).

2. A compound of formula I, where each n is 1.

3. A method comprising the step of contacting bisphenol A and a compound of formula 2 under conditions that form a compound of formula 1 in the presence of a Lewis acid catalyst, wherein the compound of formula 2 has the following structure: 【Chemistry 2】 The compound of formula 1 is represented by the following structure: 【Transformation 3】 A method expressed by (wherein each n is 1, 2, or 3).

4. The method according to claim 3, wherein the Lewis acid catalyst is tris(pentafluorophenyl)borane and the reaction temperature is maintained in the range of 20°C to 40°C.

5. The method according to claim 4, wherein each n is 1.

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