Silicone composition containing carbinol-functionalized polyorganosiloxane

Abstract

The present invention relates to a composition comprising thermally conductive filler particles, a compound of formula 1, and a compound of formula 2, wherein R, R', R'', R'''; m; n; p; x; and y are defined herein. The composition of the present invention is useful as a thermally conductive composite material exhibiting high thixotropy and polyorganosiloxane compatibility. [Formula 1] JPEG2026513972000034.jpg67170

Description

[Technical Field]

[0001] This invention relates to a composition comprising a carbinol-functionalized polyorganosiloxane and a thermally conductive filler material. The composition of this invention provides an excellent balance between low shear viscosity and high shear viscosity. [Background technology]

[0002] Balancing distributiveness / fluidity with storage stability presents an ongoing challenge for thermally conductive polyorganosiloxane composites. Thermally conductive gap fillers require a balance of distributiveness, compressive force, and fluid separation, while thermally conductive encapsulants or potents require a balance of fluidity, reduced filler sedimentation, and reduced cake formation. The desired balance of properties in fillers and encapsulants is theoretically achievable by increasing the ratio of low shear viscosity to high shear viscosity, also known as the thixotropy index. However, this challenge has not been overcome by conventional thixotropic agents (e.g., fumed silica, carbon black, aluminum silicate, calcium carbonate, polyethers, hydrogenated castor oil, and polyamide waxes) because they increase both low and high shear viscosity and / or are incompatible with siloxanes.

[0003] International Publication No. 2022 / 164640(A1) discloses the use of succinic anhydride-functionalized siloxanes as effective thixotropic agents in conductive compositions. However, these agents have been found to inhibit hydrosilylation curing. Therefore, in the field of thermally conductive polyorganosiloxane composites, there is a need to find effective thixotropic agents that are compatible with polyorganosiloxanes and do not inhibit hydrosilylation curing. [Overview of the project]

[0004] The present invention is a composition, a) 60-95 weight percent of thermally conductive filler particles, b) 4.9 to 39.9 weight percent of the polysiloxane of formula 1,

[0005] [Chemical formula] c) 0.01 to 1 weight percent of the compound of formula 2, and provides a composition containing the same to address the needs in the art.

[0006] [Chemical formula] In the formula, each R is independently C1 - C 10 alkyl or phenyl, each R' is C1 - C4 - alkyl, vinyl or H, R'' and R'''' are each independently C1 - C 10 - alkyl or C3 - C 22 carbino group, each R''' is independently C1 - C4 - alkyl, phenyl, or H, m is 5 - 150, n is 0 - 20, p is 40 - 800, provided that when each R'' is C1 - C 10 - alkyl, n is 2 - 20, R'''' is C3 - C 22 carbino group, and further, when n is 0, each R'' is C3 - C 22 carbino group, and the weight percent is based on the weights of the thermally conductive filler, the compound of formula 1, and the compound of formula 2.

[0007] The composition of the present invention is useful as a thermally conductive composite material showing high thixotropic properties and polyorganosiloxane compatibility. Further, the composite material does not inhibit hydrosilylation curing. [Embodiments for Carrying Out the Invention]

[0008] The present invention is a composition comprising a) 60 to 95 weight percent of thermally conductive filler particles, and b) 4.9 to 39.9 weight percent of the polysiloxane of formula 1,

[0009] [Chemical formula] c) A composition comprising 0.01 to 1 weight percent of a compound of formula 2,

[0010] [Chemical formula] wherein each R is independently C1 - C 10 alkyl or phenyl, each R' is C1 - C4 - alkyl, vinyl or H, R'' and R'''' are each independently C1 - C 10 - alkyl or C3 - C 22 carbinol group, each R''' is independently C1 - C4 - alkyl, phenyl, or H, m is 5 - 150, n is 0 - 20, p is 40 - 800, provided that when each R'' is C1 - C 10 - alkyl, n is 2 - 20, R'''' is a C3 - C 22 carbinol group, and further, when n is 0, each R'' is a C3 - C 22 carbinol group, and the weight percent is based on the weights of the thermally conductive filler, the compound of formula 1, and the compound of formula 2.

[0011] Examples of suitable thermally conductive fillers include alumina, alumina trihydrate, zinc oxide, boron nitride, aluminum nitride, magnesium oxide, silicon carbide, and aluminum. The thermally conductive filler preferably comprises alumina, alumina trihydrate, or zinc oxide, or a combination thereof. The concentration of the thermally conductive filler ranges from 60 or 65 weight percent to 95 weight percent based on the weights of the thermally conductive material, the compound of formula 1, and the compound of formula 2.

[0012] The D 50 volume - average diameter particle size of the filler particles generally ranges from 80 nm to 200 μm. To maximize packing, it is advantageous to use a multimodal particle size distribution. For example, D 50Alumina particles typically have particle sizes of 0.2 μm to 0.8 μm, 1 μm to 5 μm, and 10 μm to 30 μm. For zinc oxide, the D range is 100 nm to 200 nm. 50 The particle size is typical, and for alumina trihydrate, D is in the range of 30 μm to 70 μm. 50 The particle size is typical.

[0013] The compound of chemical formula 1 is preferably represented by the following chemical formula 1a or chemical formula 1b:

[0014] [ka] In the formula, p is in the range of 40 to 800, or ~400, or ~300, or ~200, and each R and each R''' is preferably independently phenyl or methyl.

[0015] The compound of formula 2 can be represented by any of formulas 2a, 2b, and 2c.

[0016] [ka] In the formula, R a is C1~C 20 It is a carbinol group. As used herein, "carbinol group" refers to a branched or linear alkyl group containing one or more hydroxyl groups or thiol groups, preferably one or more hydroxyl groups and optionally an ether, ester, or amine functional group. R'' is CH2CH2, and R a Compounds of formula 2a, in which the group is a non-functionalized carbinol group or a carbinol group functionalized with an ether or ether-amine group, can be prepared according to scheme 1.

[0017] [ka]

[0018] Appropriate = -R aExamples of starting materials include the following compounds:

[0019] [ka]

[0020] The above compound corresponds to the carbinol group R a The following applies:

[0021] [ka] In the formula, the dashed line represents the bonding point to the ethylene bridge.

[0022] R a Compounds of formula 2a, in which is a non-functionalized carbinol group, can also be prepared according to scheme 2.

[0023] [ka]

[0024] R a Compounds of formula 2a, in which the compound is functionalized with an ester group, can be prepared according to scheme 3.

[0025] [ka]

[0026] The compounds of formulas 2b and 2c are precursors of the following compounds, formula 2b o and 2c o It can be formed via any of the hydrosilylations.

[0027] [ka]

[0028] If n > 0, R aC1-C12 contains 1 or 2, and up to 20, 10, or 7 ether, ester, or amine groups, but does not contain a carbinol group. 20 It may further contain structural units of a hydrocarbyl group. For example, formula 2b using a mixture of 2-allyloxyethanol and 3-ethoxyprop-1-ene. o Hydrosilylation of forms the compound of formula 2d,

[0029] [ka] In the formula, r is between 1 and 20, or between 10 and 7.

[0030] The concentration of the compound of formula 2 ranges from 0.01, 0.05, or 0.1 weight percent to 1, 0.8, or 0.6 weight percent, based on the weights of the thermally conductive filler, the compound of formula 1, and the compound of formula 2.

[0031] The compositions of the present invention may be curable or non-curable. Curable compositions include, for example, compounds of formula 1b and formula 1c o It can be formed by hydrosilylation of the compound,

[0032] [ka] In the formula, R o is methyl or H. The composition can be cured under hydrosilylation conditions in the presence of a hydrosilylation catalyst such as a platinum catalyst. The presence of a carbinol group in the compound of formula 2 does not adversely affect the hydrosilylation reaction.

[0033] The composition of the present invention may further contain one or more filler treatment agents, for example, C-1 to C 16 -Alkyl-tri-C1~C6-alkoxysilane, or C-1~C6 such as methyltrimethoxysilane or n-decyltrimethoxysilane 16-alkyl-trimethoxysilane: or a compound of formula (3),

[0034] [ka] In the formula, the compound is one in which p' is in the range of 20 to 200. When used, the concentration of the filler treatment agent is in the range of 0.5 or 1 weight percent to 5 or 3 weight percent, based on the weight of the composition.

[0035] Preferably, the thermally conductive filler, the compound of formula 1, and the compound of formula 2 constitute at least 90, 95, or 97 to 100 percent by weight of the composition.

[0036] While not bound by theory, the compound in Equation 2 is thought to increase the thixotropy index by crosslinking thermally conductive filler particles via hydrogen bonding, which is considered to be the cause of the significant increase in low-shear viscosity. At high shear, it is presumed that the hydrogen bonds are broken, thereby resulting in little to no increase in high-shear viscosity.

[0037] As demonstrated in the following examples, the compositions of the present invention provide an improved thixotropy ratio compared to compositions that do not contain the compound of Formula 2. In the following examples, dp refers to the degree of polymerization. [Examples]

[0038] Intermediate Example 1 - Preparation of ether alcohol polymer (dp=7) of formula 2a DOWSIL (trademark) 1-8114 SiH crosslinking agent (36.98 g, dp=7, trademark of The Dow Chemical Company or its affiliates) was added to an oven-dried 100 mL three-necked round-bottom flask fitted with a condenser and N2 flow on the central neck. A thermocouple was inserted into the flask through a septum attached to another neck, and the flask was heated to 60°C while stirring. Using a syringe inserted through a septum attached to the remaining neck, 2-allyloxyethanol (additive 1) was metered into the flask at a rate of 200 μL / min. After feeding for 4 minutes, a solution of platinum(0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex in toluene (Pt catalyst, 30 μL) was added to the round-bottom flask. After continuing to feed additive 1 for 35 minutes, an additional Pt catalyst (2.5 ppm) was added. After continuing the supply for another 10 minutes, an additional Pt catalyst (2.5 ppm) was added, and after continuing the supply for another 30 minutes, an additional Pt catalyst (2.5 ppm) was added. After another 10 minutes, the supply of 2-allyloxyethanol was completed (15.93 g from the start of supply), and then an additional Pt catalyst (2.5 ppm) was added. The contents of the flask were stirred for about 3 hours, the heat was allowed to cool, and 5 wt% activated carbon (DARCO KB-G) was added. The mixture was stirred at room temperature under an N2 atmosphere for about 21 hours, and then the mixture was filtered through a 0.45 μm nylon membrane (47 mm in diameter) using N2. The filtrate was collected in a flask, and then a distillation apparatus was attached to it and heated at 60°C for 1.5 hours under vacuum to remove unreacted additive 1. The final product was 1 H, 13 C, and 29 Analysis using Si NMR spectroscopy confirmed that the compound has the structure shown in formula 2a.

[0039] [ka]

[0040] Intermediate Example 2 - Preparation of ether alcohol polymer of formula 2a (dp=118) The preparation procedure for intermediate Example 1 was used with the following differences: hydride-terminated polydimethylsiloxane (53.30 g, dp=118, available from Gelest); and additive 1 (1.59 g). Additive 1 was metered into a flask for 1 minute (200 μL), and then Pt catalyst (31 μL) was added to the flask. After another 10 minutes, the supply of additive 1 was completed. Heating was continued for a further 30 minutes, and then the mixture was stirred under N2 at room temperature for 16 hours. The product (50.50 g) was isolated. 1 H, 13 C, and 29 Analysis by Si NMR spectroscopy confirmed that the compound has the structure shown in formula 2a.

[0041] [ka]

[0042] Intermediate Example 3 - Preparation of ether-amine alcohol polymer of formula 2a (dp=118) 53.33 g of hydride-terminated polydimethylsiloxane (dp=118) was added to an oven-dried 100 mL three-necked round-bottom flask fitted with a condenser and N2 stream in the middle neck. A thermocouple was inserted into the flask through a septum attached to another neck, and the flask was heated to 80°C while stirring. Using a syringe inserted through a septum attached to the remaining neck, 1,1'-[[2-hydroxy-3-(2-propen-1-yloxy)propyl]imino]bis[2-propanol] (additive 2) was metered into the flask at a rate of 200 μL / min.

[0043] After weighing additive 2 for 1 minute, Pt catalyst (33 μL) was added to the flask with more rapid stirring. After 25 minutes, additive 2 was complete. Heating was continued for 1.5 hours, after which additional Pt catalyst (33 μL) was added. Heating was continued for 25.5 hours, after which additional Pt catalyst (33 μL) was added. Heating was continued for 2 hours, after which the heat source was removed. The mixture was stirred under N2 at room temperature for 4 days. The crude product was dissolved in toluene and washed with deionized water. Carbon black was added to the isolated toluene layer, and the mixture was stirred under N2. The carbon black was filtered under pressure through a 5 μm nylon membrane and a Celite layer. The headspace of the filtrate was swept with N2 for 16 hours. The filtrate was filtered again under pressure, and residual toluene was removed at 90°C in vacuum for 2 hours. 1 H, 13 C, and 29 Analysis using Si NMR spectroscopy confirmed that the polymer is represented by the following formula 2a.

[0044] [ka]

[0045] In particular, for the low molecular weight polymer of formula 2a, it has sometimes been found to be advantageous to prepare the ether-amine functionalized polymer of formula 2a by a two-step method. Intermediate 4 exemplifies such an approach.

[0046] Intermediate Example 4 - Preparation of ether-amine alcohol polymer of formula 2a (dp=7) A. Preparation of glycidyl ether-functionalized polymers DOWSIL (trademark) 1-8114 SiH crosslinking agent (36.98 g) was added to the central neck attached to a condenser with a nitrogen flow. A thermocouple was inserted into the flask through a septum attached to another neck, and the flask was heated to 70°C while stirring. Allyl glycidyl ether (additive 3) was metered into the flask at a rate of 200 μL / min using a syringe inserted through a septum attached to the remaining neck.

[0047] After weighing additive 3 for 1 minute, Pt catalyst (31 μL) was added to the flask. After completing the addition of additive 3 (total 17.66 g), heating was continued for 16 hours. The glycidyl ether functionalized polymer was transferred to a 250 mL single-neck round-bottom flask, and unreacted allyl glycidyl ether was removed under vacuum at 60°C for 1 hour, followed by 90°C for 2 hours.

[0048] B. Preparation of etheramine alcohol intermediate Example 3 Bis(2-hydroxypropyl)amine (9.40 g) and 2-propanol 1 (9.70 g) were added to a 250 mL three-necked round-bottom flask equipped with a stirring rod and a heating mantle. The contents were heated to 44°C, and the glycidyl ether-functionalized polymer of Part A was added dropwise to the flask under N2 conditions through an addition funnel attached to the neck of the flask. After 17 minutes, the addition was completed (total 29.46 g), and stirring was intensified. After 1 hour, the temperature was raised to 60°C. After 16 hours, the product mixture was transferred to a flask, and volatile substances were removed under vacuum at 60°C. The final product was collected, 1 H, 13 C, and 29 Si NMR spectroscopy confirmed that the polymer is as shown in equation 2a below.

[0049] [ka]

[0050] Intermediate Example 5 - Preparation of ether-amine alcohol polymer of formula 2b (m=113.9, n=6.5) formula 2b oTrimethylsiloxy-terminated methylhydrosiloxane-dimethylsiloxane copolymer (117.8 g, m=113.9, n=6.5, CAS#68037-59-2) and additive 1 (11.95 g) were added to an oven-dried 250 mL three-necked round-bottom flask fitted with a condenser and N2 flow on the central neck. A thermocouple was inserted into the flask through a septum attached to another neck, and a septum was attached to the remaining neck. The flask was heated to 60°C with stirring. Next, Pt catalyst (74 μL) was added to the flask, and the mixture was heated and stirred for 100 minutes, after which the reaction temperature was raised to 70°C. After 22 hours of heating and stirring, additional Pt catalyst (5 ppm) and additional additive 1 (2.39 g) were added. Heating and stirring were continued for a further 24.5 hours, after which additional Pt catalyst (5 ppm) was added. After continuing heating and stirring for a further 105 minutes, the reaction temperature was raised to 90°C. After further heating and stirring for 2 hours, an additional Pt catalyst (5 ppm) was added. The contents of the flask were stirred for 23 hours, the mixture was cooled, and the mixture was filtered through a Celite pad and a 0.45 μm nylon membrane (47 mm in diameter) under N2. Unreacted additive 1 was removed under vacuum at 90°C for 1 hour. The final product was 1 H, 13 C, and 29 Analysis using Si NMR spectroscopy confirmed that the compound has the structure shown in formula 2b.

[0051] [ka]

[0052] General preparation procedure for a thermally conductive masterbatch containing alumina filler Polymer of formula 1a or polymer of formula 1b and A1000 SGD alumina particles (A1 SGD , D 50 Diameter = 0.5 μm, manufactured by Almatis) was added to a MAX100 dental cup and mixed in a Flacktek Speed ​​mixer at 2000 rpm for 20 seconds. Then, CB-P02 spherical alumina particles (Al P02 , D 50A-SF-20 spherical alumina particles (Al) were added to a cup and mixed at 2000 rpm for 20 seconds. SF20 , D 50 A 20μm diameter (Chalco) particle was added to the cup, and mixing was continued at 2000 rpm for another 20 seconds. The mixture was then manually mixed using a spatula, followed by mixing at 2500 rpm for 20 seconds, and then a second manual mixing followed by high-speed mixing for 20 seconds. The mixture was transferred to an aluminum pan and heated at 150°C, 23 Torre for 1 hour to form a heat-conductive masterbatch.

[0053] Viscosity measurement of thermally conductive composite materials Vibration-strain amplitude sweep measurements were performed on thermally conductive silicone composites using an ARES G2 rheometer (TA Instruments) under a parallel plate configuration (25 mm diameter sawtooth steel plates). The samples were placed in the rheometer, and excess material was trimmed from the plate edges at plate gaps of 2.0 mm, 1.5 mm, 1.1 mm, and exactly 1.05 mm, as needed. Tests were performed with a 1.0 mm gap. The material was equilibrated for at least 5 minutes before each measurement. The vibration frequency of each sample was fixed at 10 rad / s, and the strain amplitude was swept in the range of 0.01% to 300%, with 20 sampling points between 0.01% to 0.1%, 0.1% to 1%, 1% to 10%, and 10% to 100%, and 10 sampling points between 100% to 300%. All measurements were performed at 25°C. During these measurements, the storage modulus G', loss modulus G'', and complex viscosity η were measured. * This was recorded as a function of vibration strain amplitude.

[0054] Table 1 shows the formulations of the three thermally conductive masterbatches (TC-1, TC-2, and TC-3). PDMS refers to DOWSIL® 510 Fluid, and PDVS 119 This refers to DOWSIL (trademark) SFD-119 polymer, and PDVS- 128 This refers to SILASTIC® SFD-128 polymer. (SILASTIC and DOWSIL are trademarks of The Dow Chemical Company or its affiliates.)

[0055] [Table 1]

[0056] General procedure for preparing a blend of alumina-containing composite material and thixotropic additive. Masterbatch material (20g) was added to a MAX20 dental cup, followed by the addition of the thixotropy additive of intermediate example 1, 2, 3, or 5. The components were mixed at 1000 rpm for 20 seconds, followed by manual mixing, then further mixing at 1000 rpm for 20 seconds, and finally manual mixing. After storing the mixture at room temperature for 2 days, vibration strain amplitude sweep measurements were recorded. Table 2 shows the thixotropy index (TI) of thermal conductive composites with and without the thixotropy additive. Symbol η max and η min These represent the maximum low shear viscosity and the minimum high shear viscosity, respectively. TI = η max / η min .

[0057] [Table 2]

[0058] General preparation procedure for a thermally conductive masterbatch (TC-4) containing ZnO, alumina, and alumina trihydrate. Vinyldimethyl-terminated dimethylsiloxane (6.3g), n-decyltrimethoxysilane (0.5g), and trimethylsilyl-terminated polydimethylsiloxane (1.2g, dp=110), all having a kinematic viscosity of 60 mPa·s, were added to a MAX100 dental cup and mixed in a Flacktek Speed ​​mixer at 2000 rpm for 30 seconds, followed by ZOCO102 ZnO (19.6g, D 50 Add (0.12 μm) and mix at 2000 rpm for 30 seconds. Then, add A-CF-3 alumina (26.5 g, D 50Add (3μm) to the cup, mix the contents further at 2000rpm for 30 seconds, then add MX-200 alumina trihydrate (45.9g, D 50 The mixture was added to a cup (45 μm). The mixture was further mixed at 2000 rpm for 30 seconds, then manually mixed with a spatula, followed by another 30 seconds of mixing at 2000 rpm, and then a second manual mixing followed by 30 seconds of high-speed mixing. The mixture was transferred to an aluminum pan and heated at 150°C, 23 Torre for 1 hour to form a heat-conductive masterbatch. Table 3 shows the thixotropy index (TI) of TC-4 with and without the thixotropy additive.

[0059] [Table 3]

Claims

1. A composition, a) 60-95 weight percent of thermally conductive filler particles, b) comprising 4.9 to 39.9 weight percent of the polysiloxane of formula 1, 【Chemistry 1】 In the formula, each R is independently C １ ~C １０ alkyl or phenyl, each R' is C １ ~C ４ -alkyl, vinyl or H, R'' and R'''' are each independently C １ ~C １０ -alkyl or C ３ ~C ２２ a carbinol group, each R''' is independently C １ ~C ４ -alkyl, phenyl, or H, m is 5 to 150, n is 0 to 20, p is 40 to 800, provided that when each R'' is C １ ~C １０ -alkyl, n is 2 to 20, R'''' is C ３ ~C ２２ a carbinol group, and further, when n is 0, each R'' is C ３ ~C ２２ a carbinol group, and the weight percentage is based on the weights of the thermally conductive filler, the compound of formula 1, and the compound of formula 2, a composition.

2. The thermally conductive filler particles are one or more thermally conductive filler particles selected from the group consisting of alumina, alumina trihydrate, and zinc oxide, and formula 2 is represented by any of the following formulas 2a, 2b, and 2c. 【Chemistry 2】 In the formula, R ａ C contains optionally an ether, ester, or amine functional group. １ ~C ２０ The composition according to claim 1, wherein the group is a carbinol group, p is 40 to 400, each R' is methyl or vinyl; each R''' is independently methyl or phenyl, provided that when formula 2 is formula 2b, n > 2, and when formula 2 is formula 2c, n > 1.

3. p is between 40 and 300, and equation 2 is expressed by equation 2a or equation 2b, R ａ C contains an ether or ether-amine functional group. ３ ~C ２２ The composition according to claim 2, wherein the carbinol group and thermally conductive filler particles are alumina particles, or a combination of alumina, alumina trihydrate, and zinc oxide particles, and the thermally conductive filler, the compound of formula 1, and the compound of formula 2 constitute at least 90 percent by weight of the composition.

4. Each Ra is independently selected from the following group: 【Transformation 3】 The composition according to claim 3, wherein the thermally conductive filler particles are alumina particles.

5. Each R ａ They became independent, 【Chemistry 4】 The composition according to claim 3.

6. Based on the weight of the aforementioned composition, C- １ ~C １６ -Alkyl-tri-C １ ~C ６ - Further comprising 0.5 to 5 weight percent of one or more filler treatment agents selected from the group consisting of alkoxysilanes and compounds of formula 3, 【Transformation 5】 The composition according to claim 3, wherein each R is independently methyl or phenyl, p' is 20 to 200, and the thermally conductive filler, the compound of formula 1, and the compound of formula 2 constitute at least 95 percent by weight of the composition.

7. Based on the weight of the above composition, the composition further comprises 0.5 to 5 weight percent of one or more filler treatment agents selected from the group consisting of methyltrimethoxysilane, n-decyltrimethoxysilane, or compounds of formula 3. 【Transformation 6】 The composition according to claim 4, wherein each R is independently methyl or ethyl, and p' is 40 to 300.

8. Based on the weight of the above composition, the composition further comprises 1 to 3% by weight of one or more filler agents selected from the group consisting of methyltrimethoxysilane, n-decyltrimethoxysilane, or compounds of formula 3. 【Transformation 7】 The composition according to claim 5, wherein each R is independently methyl or ethyl, and p' is in the range of 20 to 200.

9. A curable composition comprising a compound of formula 1, a mixture of compounds of formulas 1b and 1c, 【Transformation 8】 In the formula, each R is independently CH ３ or phenyl, each R ｏ The composition according to any one of claims 1 to 8, wherein is methyl or H, and the composition further comprises a hydrosilylation catalyst.

10. The hydrosilylation catalyst is a platinum catalyst, R ａ but 【Chemistry 9】 The composition according to claim 9, which is any of the following.

11. n is 1 to 10, and R'''' optionally contains an ether, ester, or amine group, but does not contain a carbinol group. １ ~C ２０ The composition according to claim 1 or 2, further comprising 1 to 10 structural units of a hydrocarbyl group.

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