Silicone elastomer material and preparation method therefor

Abstract

The present invention provides a silicone elastomer material. The silicone elastomer comprises a grafted VMQ polysiloxane; and the grafted VMQ polysiloxane is α,ω-divinyl polydimethylvinylsiloxane which is grafted with methyl thioglycolate, has a grafting ratio of >70%, and is end-capped with (CH2=CH)(CH3)2SiO1 / 2. The present invention further provides a preparation method for the silicone elastomer material. The silicone elastomer material has the advantages of low swelling ratio, high retention rate of mechanical properties, etc.

Description

An organosilicon elastomer material and its preparation method Technical Field

[0001] This invention belongs to the field of polymer materials, and more specifically, this invention relates to an organosilicon elastomer material and its preparation method. Background Technology

[0002] Thermoplastic silicone elastomer (TPSIV) is a high-performance material that combines the advantages of silicone and thermoplastic materials. With its adjustable color, stain resistance, and excellent UV protection, TPSIV is ideal for outdoor applications. Furthermore, TPSIV is easy to process and supports various secondary processing techniques, meeting the diverse product demands of the market.

[0003] In terms of physical properties, TPSIV materials exhibit exceptional high strength and elasticity, along with good abrasion resistance, hydrolysis resistance, and excellent chemical resistance. These properties also give TPSIV materials an advantage in terms of environmental friendliness, as they can be recycled and reused, reducing their environmental impact. The wide range of applications for TPSIV materials spans consumer electronics, medical, and automotive fields. In consumer electronics, TPSIV materials can be used to manufacture high-performance components for devices such as smartwatches; in the medical field, it is suitable for the production of various medical devices; and in the automotive field, TPSIV materials can be used to manufacture various automotive parts. Furthermore, the unique ergonomic feel of TPSIV materials also makes them an ideal material for everyday consumer products, such as baby products and sports equipment.

[0004] While TPSIV materials excel in versatility and high performance, they have limitations in oil and solvent resistance. The structural characteristics of TPSIV materials make them less resistant to certain oils and solvents; prolonged contact with these substances may cause swelling or performance degradation, thus failing to meet the requirements of some products. Therefore, there is an urgent need to develop a new type of oil- and solvent-resistant thermoplastic silicone elastomer material to overcome this limitation of existing TPSIV materials and meet the needs of a wider range of industrial applications.

[0005] Patent application number 201580060822.1 discloses a thermoplastic silicone elastomer blend and its preparation method. The patent uses thermoplastic polyolefin organic polymers, silicone matrix materials, plasticizers, catalysts, coupling agents, etc., to prepare a thermoplastic silicone elastomer vulcanized composition, which exhibits high mechanical properties, wear resistance, scratch resistance, and chemical stability, making it suitable for automotive interiors, medical devices, and sporting goods. However, the patent does not evaluate its oil resistance, solvent resistance, or other properties.

[0006] Patent application number 202210324334.9 discloses an oil- and solvent-resistant rubber composite material, its preparation method, and its application in cables. The invention controls the chlorine content in a ternary copolymer chloroprene rubber, enabling the rubber composite material to possess both oil and solvent resistance and good processability. However, this material contains halogens, has poor environmental friendliness, and is unsuitable for high-end applications such as daily cosmetics. Furthermore, this material is a thermosetting material. Summary of the Invention

[0007] To address the aforementioned problems, this invention provides an organosilicon elastomer material and its preparation method, which has advantages such as low swelling degree and high retention of mechanical properties.

[0008] To better solve the above problems, the present invention adopts the following technical solution:

[0009] An organosilicon elastomer material, wherein the organosilicon elastomer comprises a grafted VMQ polysiloxane, wherein the grafted VMQ polysiloxane is α,ω-divinyl polydimethylvinylsiloxane, grafted with methyl mercaptoacetate, with a grafting rate >70%, (CH2=CH)(CH3)2SiO 1 / 2 Link end.

[0010] As a preferred technical solution, the molar mass fraction of (CH3)2SiO links in the grafted VMQ polysiloxane is >90%, and the molar mass fraction of (CH2=CH)(CH3)SiO links is 0.5-10%. 1 / 2 Links are closed, with an aggregation degree of 2000-10000.

[0011] As a preferred technical solution, the material comprises the following components by weight:

[0012] 20-70 parts of grafted VMQ polysiloxane, 8-20 parts of VMQ silicone resin, 1-10 parts of hydroxyl silicone oil, 20-50 parts of polyolefin resin, 1-20 parts of filler, 0.1-1 part of vulcanizing agent, and 0.1-1 part of antioxidant.

[0013] As a preferred technical solution, the VMQ silicone resin is a vinyl MQ silicone resin with an M / Q value of 0.1-0.9, a vinyl content of 0.1-3.0% by mass, and a solid content of >50%.

[0014] As a preferred technical solution, the hydroxyl silicone oil is a hydroxyl-terminated methyl vinyl silicone oil with a hydroxyl content >3% and a vinyl content >3%.

[0015] As a preferred technical solution, the polyolefin resin is polyethylene and ethylene-α-olefin copolymer.

[0016] As a preferred technical solution, the filler is one or more of precipitated silica, fumed silica, diatomaceous earth, calcium carbonate, quartz powder, calcium silicate, zirconium silicate, titanium dioxide, zinc oxide, iron oxide, kaolin, or nano clay.

[0017] As a preferred technical solution, the vulcanizing agent is a peroxide vulcanizing agent or a hydrosilylation vulcanizing agent.

[0018] To better address the aforementioned technical problems, the present invention also discloses the following technical solutions:

[0019] A method for preparing an organosilicon elastomer material as described in any of the above claims includes the following steps:

[0020] VMQ polysiloxane was added to a glass reactor and allowed to dissolve completely in the solvent; the solution was stirred for 5-8 hours to prepare a homogeneous gel; a measured amount of methyl mercaptoacetate was added to the gel to make the molar ratio of C=C and HS groups reach 1:1.5; stirring was continued for 30-60 minutes; initiator DMPA was added to the glass reactor; the mixture was irradiated with ultraviolet light for 1-3 hours to complete the grafting reaction; the grafted VMQ polysiloxane was obtained by separation.

[0021] As a preferred technical solution, the preparation method further includes the following steps:

[0022] The grafted VMQ polysiloxane, VMQ organosilicon resin, hydroxyl silicone oil, polyolefin resin, filler, vulcanizing agent, and antioxidant are mixed in an internal mixer at 180-220°C for 8-15 minutes, and then granulated to obtain the organosilicon elastomer material.

[0023] The beneficial effects of this invention are as follows: This invention provides an oil- and solvent-resistant thermoplastic silicone elastomer material, which utilizes the click chemical reaction between mercapto (-SH) and alkenyl (such as vinyl) groups to functionalize VMQ polysiloxane. Under mild conditions, the modification of the polysiloxane molecular chain is achieved, introducing polar groups into the polysiloxane molecular chain, improving the compatibility of the components in the formulation, and endowing the prepared thermoplastic silicone elastomer material with excellent oil and solvent resistance. Detailed Implementation

[0024] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to specific examples and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0025] While TPSIV materials exhibit excellent performance in many aspects, they have certain limitations in oil and solvent resistance. Their structural characteristics result in weak resistance to some oils and solvents; prolonged contact may lead to swelling or performance degradation, failing to meet product application requirements. To address this issue, this application provides an organosilicon elastomer material comprising a grafted VMQ polysiloxane, wherein the grafted VMQ polysiloxane is α,ω-divinyl polydimethylvinylsiloxane, grafted with methyl mercaptoacetate at a grafting rate >70%, and (CH2=CH)(CH3)2SiO 1 / 2 Link end.

[0026] Specifically, in one embodiment, the molar mass fraction of (CH3)2SiO links in the grafted VMQ polysiloxane is >90%, and the molar mass fraction of (CH2=CH)(CH3)SiO links is 0.5-10%. 1 / 2 The link is capped, with a cohesion degree of 2000-10000 and a grafting rate of >70%.

[0027] In one embodiment, the material comprises, by weight, the following components:

[0028] 20-70 parts of grafted VMQ polysiloxane, 8-20 parts of VMQ silicone resin, 1-10 parts of hydroxyl silicone oil, 20-50 parts of polyolefin resin, 1-20 parts of filler, 0.1-1 part of vulcanizing agent, and 0.1-1 part of antioxidant.

[0029] In one embodiment, the VMQ silicone resin is a vinyl MQ silicone resin with an M / Q value of 0.1-0.9, a vinyl content of 0.1-3.0% by mass, and a solid content of >50%.

[0030] In one embodiment, the hydroxyl silicone oil is a hydroxyl-terminated methyl vinyl silicone oil with a hydroxyl content >3% and a vinyl content >3%.

[0031] In one embodiment, the polyolefin resin is polyethylene and an ethylene-α-olefin copolymer. For example, the polyolefin resin may be one or more of the following: ethylene-vinyl acetate copolymer, ethylene-acrylic acid or acrylate copolymer, polypropylene and propylene-α-olefin copolymer, poly-1-butene, poly-4-methyl-1-pentene, and cyclic olefin polymers.

[0032] In one embodiment, the filler is one or more of precipitated silica, fumed silica, diatomaceous earth, calcium carbonate, quartz powder, calcium silicate, zirconium silicate, titanium dioxide, zinc oxide, iron oxide, kaolin, or nanoclay. For example, the filler is spherical precipitated silica with a sphericity >96%.

[0033] In one embodiment, the vulcanizing agent is a peroxide vulcanizing agent or a hydrosilylation vulcanizing agent.

[0034] In one embodiment, the antioxidant is one or more of phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants, and polymeric phenol antioxidants.

[0035] To better address the aforementioned technical problems, the present invention also discloses the following technical solutions:

[0036] A method for preparing an organosilicon elastomer material as described in any of the above claims includes the following steps:

[0037] VMQ polysiloxane was added to a glass reactor and allowed to dissolve completely in the solvent; the solution was stirred for 5-8 hours to prepare a homogeneous gel; a measured amount of methyl mercaptoacetate was added to the gel to make the molar ratio of C=C and HS groups reach 1:1.5; stirring was continued for 30-60 minutes; initiator DMPA was added to the glass reactor; the mixture was irradiated with ultraviolet light for 1-3 hours to complete the grafting reaction; the grafted VMQ polysiloxane was obtained by separation.

[0038] As a preferred technical solution, the preparation method further includes the following steps:

[0039] The grafted VMQ polysiloxane, VMQ organosilicon resin, hydroxyl silicone oil, polyolefin resin, filler, vulcanizing agent, and antioxidant are mixed in an internal mixer at 180-220°C for 8-15 minutes, and then granulated to obtain the organosilicon elastomer material.

[0040] In one embodiment, a method for preparing an organosilicon elastomer material includes the following steps:

[0041] (1) Preparation of grafted VMQ polysiloxane: VMQ polysiloxane was added to a 500L glass reactor and dissolved in THF. After stirring for 5 hours, a uniform solution was prepared. Then, a certain amount of methyl mercaptoacetate was added to make the molar ratio of C=C and HS groups 1:1.5. After stirring for another 30 minutes, the initiator DMPA was added. After irradiation with ultraviolet light for 1 hour, the grafting reaction was completed. The solution was precipitated with ethanol solution and then dried to obtain grafted VMQ polysiloxane.

[0042] (2) The grafted VMQ polysiloxane from step 1 is mixed with other components in a mixer at 180°C for 8 minutes, and then granulated by a single screw at a granulation temperature of 170-180°C to obtain an oil-resistant and solvent-resistant thermoplastic silicone elastomer material.

[0043] The technical solution of this application is further illustrated below with reference to the embodiments:

[0044] Unless otherwise specified, the raw materials used in the following examples and comparative examples were all purchased commercially.

[0045] Preparation of grafted VMQ polysiloxane:

[0046] Grafted VMQ polysiloxane A: 100 parts of VMQ polysiloxane a (α,ω-divinyl polydimethylvinylsiloxane, wherein the molar mass fraction of (CH3)2SiO links is >90%, the molar mass fraction of (CH2=CH)(CH3)SiO links is 3.2%, (CH2=CH)(CH3)2SiO1 / 2 links are end-capped, and the degree of polymerization is 3500) were added to a 500L glass reactor and fully dissolved in THF. The mixture was stirred for 5 hours to prepare a homogeneous solution. Then, a certain amount of methyl mercaptoacetate was added to make the molar ratio of C=C to HS groups 1:1.5. After stirring for another 30 minutes, the initiator DMPA was added, and the mixture was irradiated with ultraviolet light for 1 hour. After the grafting reaction was completed, the solution was precipitated with ethanol solution and dried to obtain grafted VMQ polysiloxane with a grafting rate of 85%.

[0047] Grafted VMQ polysiloxane B: 100 parts of VMQ polysiloxane b (α,ω-divinyl polydimethylvinylsiloxane, wherein the molar mass fraction of (CH3)2SiO links is >90%, the molar mass fraction of (CH2=CH)(CH3)SiO links is 6.0%, (CH2=CH)(CH3)2SiO1 / 2 links are end-capped, and the degree of polymerization is 5000) were added to a 500L glass reactor and fully dissolved in THF. The mixture was stirred for 5 hours to prepare a homogeneous solution. Then, a certain amount of methyl mercaptoacetate was added to make the molar ratio of C=C to HS groups 1:1.5. After stirring for another 30 minutes, the initiator DMPA was added, and the mixture was irradiated with ultraviolet light for 1 hour. After the grafting reaction was completed, the solution was precipitated with ethanol solution and dried to obtain grafted VMQ polysiloxane with a grafting rate of 85%.

[0048] Grafted VMQ polysiloxane C: 100 parts of VMQ polysiloxane C (α,ω-divinyl polydimethylvinylsiloxane, wherein the molar mass fraction of (CH3)2SiO links is >90%, the molar mass fraction of (CH2=CH)(CH3)SiO links is 8.5%, (CH2=CH)(CH3)2SiO1 / 2 links are end-capped, and the degree of polymerization is 5000) were added to a 500L glass reactor and fully dissolved in THF. The mixture was stirred for 5 hours to prepare a homogeneous solution. Then, a certain amount of methyl mercaptoacetate was added to make the molar ratio of C=C to HS groups 1:1.5. After stirring for another 30 minutes, the initiator DMPA was added, and the mixture was irradiated with ultraviolet light for 1 hour. After the grafting reaction was completed, the solution was precipitated with ethanol solution and dried to obtain grafted VMQ polysiloxane with a grafting rate of 85%.

[0049] Grafted VMQ polysiloxane D: 100 parts of VMQ polysiloxane b (α,ω-divinyl polydimethylvinylsiloxane, wherein the molar mass fraction of (CH3)2SiO links is >90%, the molar mass fraction of (CH2=CH)(CH3)SiO links is 6.0%, (CH2=CH)(CH3)2SiO1 / 2 links are end-capped, and the degree of polymerization is 5000) were added to a 500L glass reactor and fully dissolved in THF. The mixture was stirred for 5 hours to prepare a homogeneous solution. Then, a certain amount of methyl mercaptoacetate was added to make the molar ratio of C=C and HS groups 1:1.5. After stirring for another 30 minutes, the initiator DMPA was added, and the mixture was irradiated with ultraviolet light for 1 hour. After the grafting reaction was completed, the solution was precipitated with ethanol solution and dried to obtain grafted VMQ polysiloxane with a grafting rate of 91%.

[0050] The preparation methods of the materials in Examples 1-5 and Comparative Example 1 are as follows:

[0051] Grafted VMQ polysiloxane and other components were mixed sequentially in a 180°C internal mixer for 8 minutes, and then granulated by a single screw at a temperature of 170-180°C to obtain an oil- and solvent-resistant thermoplastic silicone elastomer material.

[0052] Table 1

[0053] Components Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Grafted VMQ polysiloxane A 200 200 Grafted VMQ polysiloxane B 200 Grafted VMQ polysiloxane C 200 Grafted VMQ polysiloxane D 200 VMQ polysiloxane a 200 VMQ polysiloxane c 200 VMQ Organosilicon Resin (M / Q=0.8, Vi%=2.5%, Solid Content=70%) 50 50 50 50 60 50 50 Hydroxy Silicone Oil (OH%: 6.5%, Vi%: 7%) 10 10 1010101010 Spherical silica (98% sphericity) 50505050505050 Polyolefin resin VLDPE (VST: 105℃) 123.2123.2123.2123.2120123.2123.2 Polyolefin resin EMA (ester content 17%) 61.661.661.661.66061.661.6 Vulcanizing agent 2.52.52.52.52.52.5 Antioxidant B2152.52.52.52.52.52.52.52.5

[0054] The materials obtained above were subjected to performance tests, and the test results are shown in Table 2.

[0055] Table 2

[0056]

[0057] The examples and comparative examples show that Examples 1 to 5 have excellent oil and solvent resistance.

[0058] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An organosilicon elastomer material, characterized in that, The organosilicon elastomer comprises a grafted VMQ polysiloxane, wherein the grafted VMQ polysiloxane is α,ω-divinyl polydimethylvinylsiloxane, grafted with methyl mercaptoacetate, with a grafting rate >70%, (CH2=CH)(CH3)2SiO 1 / 2 Link end.

2. The organosilicon elastomer material according to claim 1, characterized in that, In the grafted VMQ polysiloxane, the molar mass fraction of (CH3)2SiO links is >90%, and the molar mass fraction of (CH2=CH)(CH3)SiO links is 0.5-10%. 1 / 2 Links are closed, with an aggregation degree of 2000-10000.

3. The organosilicon elastomer material according to claim 1, characterized in that, The material, by weight, comprises the following components: 20-70 parts of grafted VMQ polysiloxane, 8-20 parts of VMQ silicone resin, 1-10 parts of hydroxyl silicone oil, 20-50 parts of polyolefin resin, 1-20 parts of filler, 0.1-1 part of vulcanizing agent, and 0.1-1 part of antioxidant.

4. The organosilicon elastomer material according to claim 3, characterized in that, The VMQ silicone resin is a vinyl MQ silicone resin with an M / Q value of 0.1-0.9, a vinyl content of 0.1-3.0% by mass, and a solid content of >50%.

5. The organosilicon elastomer material according to claim 3, characterized in that, The hydroxyl silicone oil is a hydroxyl-terminated methyl vinyl silicone oil with a hydroxyl content >3% and a vinyl content >3%.

6. The organosilicon elastomer material according to claim 3, characterized in that, The polyolefin resin is a copolymer of polyethylene and ethylene-α-olefin.

7. The organosilicon elastomer material according to claim 3, characterized in that, The filler is one or more of the following: precipitated silica, fumed silica, diatomaceous earth, calcium carbonate, quartz powder, calcium silicate, zirconium silicate, titanium dioxide, zinc oxide, iron oxide, kaolin, or nanoclay.

8. The organosilicon elastomer material according to claim 3, characterized in that, The vulcanizing agent is a peroxide vulcanizing agent or a hydrosilylation vulcanizing agent.

9. A method for preparing an organosilicon elastomer material as described in any one of claims 1-8, characterized in that, Includes the following steps: VMQ polysiloxane was added to a glass reactor and allowed to dissolve completely in the solvent; the solution was stirred for 5-8 hours to prepare a homogeneous gel; a measured amount of methyl mercaptoacetate was added to the gel to make the molar ratio of C=C and HS groups reach 1:1.5; stirring was continued for 30-60 minutes; initiator DMPA was added to the glass reactor; the mixture was irradiated with ultraviolet light for 1-3 hours to complete the grafting reaction; the grafted VMQ polysiloxane was obtained by separation.

10. The method for preparing the organosilicon elastomer material according to claim 9, characterized in that, It also includes the following steps: The grafted VMQ polysiloxane, VMQ organosilicon resin, hydroxyl silicone oil, polyolefin resin, filler, vulcanizing agent, and antioxidant are mixed in an internal mixer at 180-220°C for 8-15 minutes, and then granulated to obtain the organosilicon elastomer material.

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