A TPV sealing material and a preparation method and application thereof in automobile engines

Abstract

The application relates to the technical field of TPV thermoplastic vulcanizate, and discloses a TPV sealing material and a preparation method and application of the TPV sealing material in automobile engines. The TPV sealing material comprises 45-60 parts by weight of silicone rubber masterbatch, 40-55 parts by weight of polyurethane elastomer, 4-10 polystyrene-based cardanol, 0.18-0.3 parts by weight of platinum gold catalyst and the like. The fatty carbon chain of the polystyrene-based cardanol contains an alkenyl group, cross-linking reaction occurs between the hydrogen-containing silicone oil and the methyl vinyl silicone rubber, the polystyrene-based cardanol contains urethane groups, the compatibility with the polyurethane elastomer is also very good, the compatibility between the silicone rubber and the polyurethane elastomer is improved, the polystyrene-based cardanol contains a polystyrene molecular chain with high strength, meanwhile, the fatty carbon chain can play a role in toughening the polyurethane, and the tensile strength, elongation at break and tear strength of the TPV sealing material are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of TPV thermoplastic vulcanizate, in particular to a TPV sealing material and a preparation method thereof and application of the TPV sealing material in an automobile engine. BACKGROUND

[0002] TPV is a thermoplastic vulcanizate material, which is usually made of rubber, plastic and the like through vulcanization, and mainly includes ethylene-propylene-diene rubber / polypropylene, silicone rubber / polyurethane, silicone rubber / ethylene-octene copolymer and the like. Among them, the silicone rubber / polyurethane TPV has strong high-temperature resistance, good aging resistance and excellent flame resistance, and has wide application in the automobile industry, electronic appliances, sealing materials and the like.

[0003] Due to poor compatibility of silicone rubber and polyurethane elastomer, good mixing is difficult to achieve, which affects the mechanical properties of the TPV material, and therefore the rubber phase and the plastic phase need to be compatibilized. The patent with publication number CN112143231B discloses a silicone rubber / polyurethane thermoplastic vulcanizate and a preparation method and application thereof. A block copolymer of organosiloxane is used as a compatibilizer to improve the compatibility of silicone rubber and polyurethane, so that the thermoplastic vulcanizate has excellent mechanical properties. However, the tensile strength of the thermoplastic vulcanizate is low, and the thermoplastic vulcanizate does not have good tear strength. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a TPV sealing material and a preparation method thereof and application of the TPV sealing material in an automobile engine, which solves the problem of poor compatibility of silicone rubber and polyurethane and improves the mechanical properties of the silicone rubber-polyurethane TPV material.

[0005] To solve the above technical problems, the technical scheme adopted by the present application is as follows: a TPV sealing material and a preparation method thereof, which include 45-60 parts by weight of silicone rubber masterbatch, 40-55 parts by weight of polyurethane elastomer, 4-10 parts by weight of polystyrene-based cardanol, 0.6-1.3 parts by weight of vulcanizing agent, 0.18-0.3 parts by weight of platinum catalyst and 0.8-1.3 parts by weight of antioxidant.

[0006] The preparation method of the TPV sealing material is as follows:

[0007] (1) A solvent, 3-isopropyl-dimethyl benzyl isocyanate, cardanol and dibutyltin dilaurate are added to a reaction container, and stirred and reacted, followed by vacuum distillation. The crude product is separated and purified by column chromatography to obtain a styrene-based cardanol monomer. The reaction formula is as follows:

[0008] In the reaction formula, n is 0-3.

[0009] (2) adding N, N-dimethylformamide, styrene-based cardanol monomer into the reaction container, stirring, then passing nitrogen, dropping azobisisobutyronitrile, stirring reaction, vacuum distillation, dichloromethane washing product, drying, obtaining polystyrene-based cardanol.

[0010] (3) adding silicone rubber masterbatch, polyurethane elastomer, polystyrene-based cardanol, antioxidant into the torque rheometer, mixing at 180-195℃ for 20-30min, rotating speed is 70-100r / min, then adding vulcanizing agent, vulcanizing for 5-10min, finally adding platinum catalyst, crosslinking reaction for 8-12min, obtaining TPV sealing material.

[0011] Preferably, the solvent in (1) is toluene, dichloromethane or trichloromethane.

[0012] Preferably, the amount of 3-isopropyl-dimethyl benzyl isocyanate in (1) is 100 parts by weight, the amount of cardanol is 150-182 parts by weight, and the amount of dibutyltin dilaurate is 0.6-0.9 parts by weight.

[0013] Preferably, the reaction temperature in (1) is 20-35℃, and the reaction time is 2-4h.

[0014] Preferably, the amount of styrene-based cardanol monomer in (2) is 100 parts by weight, and the amount of azobisisobutyronitrile is 1.1-1.4 parts by weight.

[0015] Preferably, the reaction temperature in (2) is 70-80℃, and the reaction time is 7-10h.

[0016] Preferably, the vulcanizing agent in (3) includes bis-dipentasulfur, bis-tert-butyl peroxyisopropyl benzene.

[0017] Preferably, the antioxidant in (3) includes antioxidant 1010.

[0018] Preferably, the preparation method of the silicone rubber masterbatch is as follows: adding 100 parts by weight of methyl vinyl silicone rubber, 30-40 parts by weight of white carbon black, 3.4-5 parts by weight of hydroxyl silicone oil, and 2.2-3.7 parts by weight of hydrogen-containing silicone oil into the torque rheometer, mixing at 180-195℃ for 20-30min, obtaining the silicone rubber masterbatch.

[0019] Preferably, the TPV sealing material is applied in automobile engine.

[0020] The application has the beneficial technical effects that: the styrene-based cardanol monomer is subjected to a polymerization reaction to obtain a polystyrene-based cardanol, and then the polystyrene-based cardanol is subjected to a blending vulcanization and crosslinking with a silicone rubber masterbatch, a polyurethane elastomer, a vulcanizing agent, a platinum gold catalyst and the like to obtain a TPV sealing material. The alkenyl group in the aliphatic carbon chain of the polystyrene-based cardanol is crosslinked with the methyl vinyl silicone rubber through the hydrogen-containing silicone oil under the action of the platinum gold catalyst, the bonding strength between the polystyrene-based cardanol and the silicone rubber is enhanced, meanwhile, the polystyrene-based cardanol contains urethane groups, and the compatibility of the polystyrene-based cardanol with the polyurethane elastomer is also good, so that the polystyrene-based cardanol is used as a compatibilizer to improve the compatibility between the silicone rubber and the polyurethane elastomer, and the mechanical properties of the TPV sealing material are improved.

[0021] The polystyrene-based cardanol of the application contains the polystyrene molecular chain with high strength, and the aliphatic carbon chain can play a role in toughening the polyurethane, so that the tensile strength, elongation at break and tear strength of the TPV material are further improved, and the TPV material has good practical application in the sealing material of automobile engines. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is the infrared spectrum of the polystyrene-based cardanol. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the embodiments of the application more clear, the technical scheme in the embodiments of the application will be clearly and completely described below.

[0024] The methyl vinyl silicone rubber is model 110-1 and is from Dongguan Shuangyao Plastic Co., Ltd. The polyurethane elastomer is model L194A and is from Dongguan Xingshengli Plastic New Material Technology Co., Ltd. The hydroxyl silicone oil is model PMX-0930, and the hydrogen-containing silicone oil is model Dow 1107, both of which are from Shenzhen Chonghua Xin Technology Co., Ltd. The platinum gold catalyst is model XM-3051-1 and is from Guangzhou Comel Chemical Co., Ltd.

[0025] Example 1

[0026] (1) 700 mL of dichloromethane, 50 g (248.8 mmol) of 3-isopropyl-dimethyl benzyl isocyanate, 75 g (246.3 mmol) of cardanol, 0.42 g of dibutyltin dilaurate were added to a reaction container, and stirring was performed at 25℃ for 4 h, and then distillation was performed under reduced pressure, and the crude product was separated and purified by column chromatography, and elution was performed with a mixed solution of petroleum ether and ethyl acetate to obtain the styrene-based cardanol monomer.

[0027] (2) Add 1.5 L of N,N-dimethylformamide, 300 g (594.1 mmol) of styrylcashew monomer to the reaction container, stir, and then introduce nitrogen, drop 3.6 g of azobisisobutyronitrile, heat to 70°C, stir for 10 h, distill under reduced pressure, wash the product with dichloromethane, dry, and obtain polystyrylcashew. Figure 1 In the infrared spectrum of the compound, 2849 cm -1 , 2912 cm -1 are absorption peaks of methyl-CH3 and methylene-CH2- of the fatty carbon chain of cashew, 1721 cm -1 , 1507 cm -1 are absorption peaks of ester carbonyl-C=O- and -NH- in the urethane group, and 1443-1580 cm -1 are characteristic peaks of benzene ring.

[0028] (3) Add 5 kg of methyl vinyl silicone rubber, 150 g of white carbon black, 23 g of hydroxyl silicone oil, and 11 g of hydrogen-containing silicone oil to a torque rheometer, mix at 190°C for 20 min, and obtain a silicone rubber masterbatch.

[0029] (4) Add 6 kg of silicone rubber masterbatch, 4 kg of polyurethane elastomer, 0.4 kg of polystyrene cashew, and 130 g of antioxidant 1010 to a torque rheometer, mix at 190°C for 30 min at a speed of 100 r / min, then add 9 g of vulcanizing agent bis-dipentasulfur, vulcanize for 5 min, finally add 1.8 g of platinum gold catalyst, and crosslink for 8 min to obtain a TPV sealing material.

[0030] Example 2

[0031] (1) Add 800 mL of toluene, 50 g of 3-isopropyl-dimethylbenzyl isocyanate, 91 g of cashew, and 0.3 g of dibutyltin dilaurate to a reaction container, stir at 20°C for 4 h, distill under reduced pressure, and purify the crude product by column chromatography, elute with a mixed solution of petroleum ether and ethyl acetate to obtain styrylcashew monomer.

[0032] (2) Add 2 L of N,N-dimethylformamide, 300 g of styrylcashew monomer to the reaction container, stir, and then introduce nitrogen, drop 4.2 g of azobisisobutyronitrile, heat to 70°C, stir for 8 h, distill under reduced pressure, wash the product with dichloromethane, dry, and obtain polystyrylcashew.

[0033] (3) Add 5 kg of methyl vinyl silicone rubber, 200 g of white carbon black, 25 g of hydroxyl silicone oil, and 13.8 g of hydrogen-containing silicone oil to a torque rheometer, mix at 180°C for 30 min, and obtain a silicone rubber masterbatch.

[0034] (4) 5 kg of silicone rubber masterbatch, 5 kg of polyurethane elastomer, 0.7 kg of polystyrene-based cardanol, 110 g of antioxidant 1010 were added to the torque rheometer, mixed at 180°C for 30 min, the rotation speed was 70 r / min, then 6 g of vulcanizing agent bis-diphenyl sulfide was added, and vulcanized for 10 min, finally 2.3 g of platinum gold catalyst was added, and crosslinking reaction was carried out for 12 min to obtain TPV sealing material.

[0035] Example 3

[0036] (1) 800 mL of chloroform, 50 g of 3-isopropyl-dimethyl benzyl isocyanate, 75 g of cardanol, 0.38 g of dibutyl tin dilaurate were added to the reaction container, and stirred at 35°C for 2 h, distilled under reduced pressure, and the crude product was separated and purified by column chromatography, eluted with a mixed solution of petroleum ether and ethyl acetate to obtain styrene-based cardanol monomer.

[0037] (2) 1.5 L of N,N-dimethylformamide, 300 g of styrene-based cardanol monomer were added to the reaction container, stirred and nitrogen was introduced, 3.3 g of azobisisobutyronitrile was added dropwise, heated to 80°C, stirred for 7 h, distilled under reduced pressure, the product was washed with dichloromethane, and dried to obtain polystyrene-based cardanol.

[0038] (3) 5 kg of methyl vinyl silicone rubber, 200 g of white carbon black, 17 g of hydroxyl silicone oil, 18.5 g of hydrogen-containing silicone oil were added to the torque rheometer, mixed at 195°C for 20 min to obtain silicone rubber masterbatch.

[0039] (4) 4.5 kg of silicone rubber masterbatch, 5.5 kg of polyurethane elastomer, 1 kg of polystyrene-based cardanol, 80 g of antioxidant 1010 were added to the torque rheometer, mixed at 195°C for 20 min, the rotation speed was 100 r / min, then 13 g of bis-tert-butyl peroxide isopropyl benzene was added, and vulcanized for 8 min, finally 3 g of platinum gold catalyst was added, and crosslinking reaction was carried out for 12 min to obtain TPV sealing material.

[0040] Comparative Example 1

[0041] (1) 6 kg of silicone rubber masterbatch (prepared by the same method as in Example 1), 4 kg of polyurethane elastomer, 130 g of antioxidant 1010 were added to the torque rheometer, mixed at 190°C for 30 min, the rotation speed was 100 r / min, then 9 g of vulcanizing agent bis-diphenyl sulfide was added, and vulcanized for 5 min, finally 1.8 g of platinum gold catalyst was added, and crosslinking reaction was carried out for 8 min to obtain TPV sealing material.

[0042] Comparative Example 2

[0043] (1) Into a reaction vessel was added 1.5 L of N,N-dimethylformamide, 61.7 g (594.1 mmol) of styrene, stirred, and then nitrogen was bubbled, 3.6 g of azobisisobutyronitrile was added dropwise, heated to 70°C, stirred for 10 h, distilled under reduced pressure, the product was washed with ethanol, and dried to obtain polystyrene.

[0044] (2) Into a torque rheometer was added 6 kg of silicone rubber masterbatch (prepared in the same manner as in Example 1), 4 kg of polyurethane elastomer, 0.4 kg of polystyrene, 130 g of antioxidant 1010, mixed at 190°C for 30 min at a rotation speed of 100 r / min, then 9 g of vulcanizing agent bis-dipentyl vulcanizing agent was added, vulcanized for 5 min, finally 1.8 g of platinum gold catalyst was added, and crosslinking reaction was performed for 8 min to obtain a TPV sealing material.

[0045] Comparative Example 3

[0046] (1) Into a reaction vessel was added 700 mL of dichloromethane, 50 g of 3-isopropyl-dimethylbenzyl isocyanate, 64.6 g (246.3 mmol) of dodecyl phenol (CAS No. 27193-86-8), 0.42 g of dibutyl tin dilaurate, stirred at 25°C for 4 h, distilled under reduced pressure, and the crude product was separated and purified by column chromatography, eluted with a mixed solution of petroleum ether and ethyl acetate to obtain a styryl dodecane monomer, the structural formula of which is .

[0047] (2) Into a reaction vessel was added 1.5 L of N,N-dimethylformamide, 275.6 g (594.1 mmol) of styryl dodecane monomer, stirred, and then nitrogen was bubbled, 3.6 g of azobisisobutyronitrile was added dropwise, heated to 70°C, stirred for 10 h, distilled under reduced pressure, the product was washed with dichloromethane, and dried to obtain polystyryl dodecane.

[0048] (3) Into a torque rheometer was added 6 kg of silicone rubber masterbatch (prepared in the same manner as in Example 1), 4 kg of polyurethane elastomer, 0.4 kg of polystyryl dodecane, 130 g of antioxidant 1010, mixed at 190°C for 30 min at a rotation speed of 100 r / min, then 9 g of vulcanizing agent bis-dipentyl vulcanizing agent was added, vulcanized for 5 min, finally 1.8 g of platinum gold catalyst was added, and crosslinking reaction was performed for 8 min to obtain a TPV sealing material.

[0049] Comparative Example 4

[0050] (1) At 0°C, 700 mL of dichloromethane, 22.3 g of acryloyl chloride, 75 g of cardanol, 24.9 g of triethylamine were added into a reaction vessel, and the reaction was stirred at 25°C for 10 h. The crude product was separated and purified by column chromatography, eluted with a mixed solution of petroleum ether and ethyl acetate, to obtain an acrylate cardanol monomer; the structural formula is n is 0-3.

[0051] (2) 1.5 L of N,N-dimethylformamide, 213.0 g (594.1 mmol) of acrylate cardanol monomer were added into a reaction vessel, stirred and purged with nitrogen, 3.6 g of azobisisobutyronitrile was added dropwise, heated to 70°C, stirred for 10 h, distilled under reduced pressure, the product was washed with dichloromethane and dried to obtain a polyacrylate cardanol.

[0052] (3) 6 kg of silicone rubber masterbatch (prepared by the same method as in Example 1), 4 kg of polyurethane elastomer, 0.4 kg of polyacrylate cardanol, 130 g of antioxidant 1010 were added into a torque rheometer, mixed at 190°C for 30 min at a speed of 100 r / min, then 9 g of curing agent bis-dipentasulfur curing agent was added, and vulcanized for 5 min, finally 1.8 g of platinum gold catalyst was added, and crosslinking reaction was carried out for 8 min to obtain a TPV sealing material.

[0053] The tensile properties of the TPV sealing material were tested according to the GB / T 528-2009 standard. The tear strength was tested according to the GBT529-2008 standard.

[0054] Table 1 Properties of TPV sealing material

[0055]

[0056] After testing, the TPV sealing material obtained by blending the silicone rubber masterbatch and the polyurethane elastomer in Comparative Example 1 had low tensile strength, elongation at break and tear strength, mainly because the compatibility of the silicone rubber and the polyurethane elastomer was poor, resulting in low mechanical properties of the material.

[0057] The polystyrene-based cardanol of examples 1-3 contains alkenyl in the aliphatic carbon chain of cardanol, which is cross-linked with methyl vinyl silicone rubber through hydrogen-containing silicone oil under the action of platinum gold catalyst, thereby enhancing the bonding strength between the polystyrene-based cardanol and the silicone rubber, and the polystyrene-based cardanol contains urethane groups, which are also very compatible with the polyurethane elastomer, so that the polystyrene-based cardanol serves as a compatibilizer to improve the compatibility between the silicone rubber and the polyurethane elastomer, which is conducive to improving the mechanical properties of the TPV sealing material, and the polystyrene-based cardanol contains polystyrene molecular chains, which are high in strength, and the aliphatic carbon chain can toughen the polyurethane, thereby significantly improving the tensile strength, elongation at break and tear strength of the TPV sealing material.

[0058] Compared with example 1, the polystyrene added in comparative example 2 cannot serve as a compatibilizer to improve the compatibility between the polyurethane elastomer and the silicone rubber, and the polystyrene does not contain an aliphatic carbon chain to toughen the polyurethane, resulting in lower tensile strength, elongation at break and tear strength of the TPV sealing material than those of example 1.

[0059] The aliphatic carbon chain of the polystyrene-based dodecane in comparative example 3 does not contain alkenyl, which cannot be cross-linked with methyl vinyl silicone rubber through hydrogen-containing silicone oil, and the bonding strength and interface performance of the two are low, so that the compatibility between the polyurethane elastomer and the silicone rubber cannot be improved, resulting in lower tensile strength, elongation at break and tear strength of the TPV sealing material than those of example 1.

[0060] The acrylic ester-based cardanol monomer in comparative example 4 does not contain urethane groups, which are low in compatibility with the polyurethane elastomer, and cannot improve the compatibility between the rubber and the polyurethane elastomer, resulting in lower tensile strength, elongation at break and tear strength of the TPV sealing material than those of example 1.

[0061] The above only describes the preferred embodiments of the present application and is not used to limit the present application. The present application can have various modifications and changes for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A TPV sealing material, characterized in that, The TPV sealing material comprises 45-60 parts by weight of silicone rubber masterbatch, 40-55 parts by weight of polyurethane elastomer, 4-10 parts by weight of polystyrene-based cashew nut shell extract, 0.6-1.3 parts by weight of vulcanizing agent, 0.18-0.3 parts by weight of platinum catalyst, and 0.8-1.3 parts by weight of antioxidant. The preparation method of the polystyrene-based cashew phenol includes the following steps: (1) Add solvent, 3-isopropyl-dimethylbenzyl isocyanate, cashew nut phenol and dibutyltin dilaurate to the reaction vessel, stir the reaction, distill under reduced pressure, and purify the crude product by column chromatography to obtain styrene-based cashew nut phenol monomer. (2) Add N,N-dimethylformamide and styrene cashew nut phenol monomer to the reaction vessel, stir and then introduce nitrogen gas, add azobisisobutyronitrile dropwise, stir the reaction, distill under reduced pressure, wash the product, dry, and obtain polystyrene cashew nut phenol; The preparation method of the silicone rubber masterbatch includes the following steps: 100 parts by weight of methyl vinyl silicone rubber, 30-40 parts by weight of silica, 3.4-5 parts by weight of hydroxyl silicone oil, and 2.2-3.7 parts by weight of hydrogen-containing silicone oil are added to a torque rheometer and mixed at 180-195℃ for 20-30 minutes to obtain silicone rubber masterbatch.

2. The TPV sealing material according to claim 1, characterized in that, The solvent in (1) is toluene, dichloromethane or trichloromethane.

3. The TPV sealing material according to claim 1, characterized in that, In (1), the amount of 3-isopropyl-dimethylbenzyl isocyanate is 100 parts by weight, cashew phenol is 150-182 parts by weight, and dibutyltin dilaurate is 0.6-0.9 parts by weight.

4. The TPV sealing material according to claim 1, characterized in that, The reaction temperature of (1) is 20-35℃ and the reaction time is 2-4h.

5. The TPV sealing material according to claim 1, characterized in that, In (2), the amount of styrene cashew phenol monomer used is 100 parts by weight, and the amount of azobisisobutyronitrile is 1.1-1.4 parts by weight.

6. The TPV sealing material according to claim 1, characterized in that, The reaction temperature in (2) is 70-80℃ and the reaction time is 7-10h.

7. The TPV sealing material according to claim 1, characterized in that, The vulcanizing agent is bis(2,5)-disulfide or bis(tert-butylperoxyisopropylbenzene); the antioxidant is antioxidant 1010.

8. A method for preparing the TPV sealing material according to any one of claims 1-7, characterized in that, The preparation method of the TPV sealing material includes the following steps: adding silicone rubber masterbatch, polyurethane elastomer, polystyrene cashew nut shell powder, and antioxidant into a torque rheometer, mixing at 180-195℃ for 20-30 min at a rotation speed of 70-100 r / min, then adding a vulcanizing agent and vulcanizing for 5-10 min, and finally adding a platinum catalyst and crosslinking for 8-12 min to obtain the TPV sealing material.

9. The application of a TPV sealing material obtained by the preparation method as described in claim 8 in an automobile engine.

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