Modified base, heat-insulating room temperature vulcanized silicone rubber and preparation method thereof

Abstract

The application discloses a modified base material, a heat-insulating room temperature vulcanized silicone rubber and a preparation method thereof. The modified base material is prepared from dimethyl silicone oil, metal oxide and polyisocyanate in a weight ratio of 100:95-105:0.5-5. The heat-insulating room temperature vulcanized silicone rubber is prepared from 100 parts of alpha, omega-dihydroxypolydimethylsiloxane, 10-30 parts of silicone resin, 50-100 parts of the modified base material, 5-15 parts of a crosslinking agent, 1-5 parts of a silane coupling agent and 0.01-1 part of a catalyst. The silicone rubber prepared by the application combines a reflective heat-insulating functional material and a barrier heat-insulating functional material, thereby simultaneously having the abilities of reflective heat insulation and barrier heat insulation, low thermal conductivity and excellent heat-insulating performance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of RTV silicone rubber, and more particularly, the present application relates to a modified base material, a heat insulation type room temperature vulcanized silicone rubber and a preparation method thereof. BACKGROUND

[0002] In the 21st century, energy and environment have become two major constraints for the continued development of mankind. In order to solve the energy crisis, in addition to developing new energy, the utilization rate of energy should also be improved, and energy waste should be reduced. With the development and progress of society, a large number of high-rise buildings have sprung up, and urbanization has become more and more obvious. The energy consumption caused by urban heat island effect has increased sharply. Among the entire energy consumption, the energy consumption of buildings accounts for 30% to 40% of the entire energy consumption, more than half of which is consumed by building heating and cooling. In order to reduce the energy consumption in this regard, heat insulation and heat preservation treatment of buildings is a relatively effective way.

[0003] Heat in buildings is mainly transferred through conduction, convection and radiation. The higher the thermal conductivity of the medium, the faster the heat propagation. Heat insulation materials are materials with low thermal conductivity or porous materials that can reduce the efficiency of heat propagation, thereby slowing down heat transfer. There are many types of heat insulation materials on the market, each with its own advantages and disadvantages. For example, glass fiber, asbestos, rock wool, etc. have good heat insulation performance and are inexpensive, but they can cause harm to the skin and respiratory tract of the human body; vacuum insulation panels and aerogel blanket have excellent heat insulation performance but are fragile and expensive; polyurethane foam is brittle and flammable, and requires professional equipment and personnel for construction. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a heat insulation type room temperature vulcanized silicone rubber with low thermal conductivity and excellent heat insulation performance.

[0005] The specific technical solutions to achieve the above-mentioned purposes include the following.

[0006] In a first aspect of the present application, a modified base material is provided, which is prepared from dimethyl silicone oil, metal oxide and polyisocyanate in a weight ratio of 100:95-105:0.5-5.

[0007] In a second aspect of the present application, a preparation method of the modified base material is provided, comprising the following steps: vacuum stirring dimethyl silicone oil, metal oxide and polyisocyanate for 30-60 minutes, heating to 60-100 DEG C, continuing vacuum stirring for 60-90 minutes, cooling and discharging, and grinding to obtain the modified base material.

[0008] In a third aspect of the present application, a heat insulation type room temperature vulcanized silicone rubber is prepared from raw materials including the following weight parts:

[0009]

[0010] In a fourth aspect of the present application, a preparation method of the heat insulation type room temperature vulcanized silicone rubber is provided, comprising the following steps: stirring α, ω-dihydroxyl polydimethylsiloxane, silicone resin, modified base material, crosslinking agent, coupling agent and catalyst for 60-120 minutes under vacuum, and obtaining the product.

[0011] The present application first prepares a modified base material with a certain weight ratio of dimethyl silicone oil, metal oxide and polyisocyanate. After the structure of the nano titanium oxide or nano zinc oxide with heat reflectivity is restructured by the polyisocyanate, the nano titanium oxide or nano zinc oxide is added to the base glue of the room temperature vulcanized silicone rubber, and can form a porous material by stacking, inserting and filling each other.

[0012] Further, the present application optimizes a heat insulation type room temperature vulcanized silicone rubber, which is prepared by adding the modified base material to the base system (α, ω-dihydroxyl polydimethylsiloxane, silicone resin, crosslinking agent, silane coupling agent, catalyst) of the room temperature vulcanized silicone rubber. The components of the modified base material and the base system of the room temperature vulcanized silicone rubber cooperate with each other, so that the prepared silicone rubber has a porous structure, in which a large number of pores are filled. This is equivalent to that the silicone rubber is fused with the reflective type heat insulation functional material and the barrier type heat insulation functional material, so as to have the ability of reflective heat insulation and barrier heat insulation at the same time. Therefore, the prepared silicone rubber has low thermal conductivity and excellent heat insulation performance. DETAILED DESCRIPTION

[0013] In order to facilitate the understanding of the present application, the present application will be described more fully below. The present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0014] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The use of the terms "and / or" includes a combination of one or more of the associated listed items.

[0015] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The use of the terms "and / or" includes a combination of one or more of the associated listed items.

[0016] In some embodiments of the present application, a modified base material is disclosed, which is prepared from dimethyl silicone oil, metal oxide and polyisocyanate in a weight ratio of 100:95-105:0.5-5.

[0017] In some embodiments, the weight ratio of the dimethyl silicone oil, metal oxide and polyisocyanate is 100:98-102:0.5-3.

[0018] In some embodiments, the weight ratio of the dimethyl silicone oil, metal oxide and polyisocyanate is 100:99-101:1-3.

[0019] In some embodiments, the weight ratio of the dimethyl silicone oil, metal oxide and polyisocyanate is 100:100:2-3.

[0020] In some embodiments, the metal oxide is nano-titanium oxide or nano-zinc oxide.

[0021] In some embodiments, the specific surface area of the nano-titanium oxide or nano-zinc oxide is 100m 2 / g-300m 2 / g.

[0022] In some embodiments, the polyisocyanate is one or more of diphenylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, and triphenylmethane triisocyanate.

[0023] In some embodiments, the polyisocyanate is triphenylmethane triisocyanate.

[0024] In some embodiments, the viscosity of the dimethyl silicone oil at 25°C is 300cps-400cps.

[0025] In some embodiments, the dimethyl silicone oil is a silicone oil treated by dehydration.

[0026] In some embodiments, the dehydration conditions are 115°C-125°C vacuum dehydration for 1.5h-2.5h.

[0027] In other embodiments of the present application, a preparation method of the modified base material is disclosed, which comprises the following steps:

[0028] The dimethyl silicone oil, metal oxide and polyisocyanate are vacuum stirred for 30min-60min, heated to 60°C-100°C, and then vacuum stirred for 60min-90min, and then cooled and discharged, and then ground to obtain the product.

[0029] In some embodiments, the vacuum degree of the vacuum is -0.09 MPa to -0.1 MPa.

[0030] In some embodiments of the present application, a heat-insulating room temperature vulcanized silicone rubber is prepared from raw materials including the following components by weight:

[0031]

[0032]

[0033] In some embodiments, the heat-insulating room temperature vulcanized silicone rubber is prepared from raw materials including the following components by weight:

[0034] α, ω-dihydroxypolydimethylsiloxane 100 parts

[0035]

[0036] In some embodiments, the viscosity of the α, ω-dihydroxypolydimethylsiloxane at 25°C is 100 cps to 100,000 cps.

[0037] In some embodiments, the viscosity of the α, ω-dihydroxypolydimethylsiloxane at 25°C is 1,000 cps to 50,000 cps.

[0038] In some embodiments, the α, ω-dihydroxypolydimethylsiloxane includes α, ω-dihydroxypolydimethylsiloxane with a viscosity of 10,000 cps and α, ω-dihydroxypolydimethylsiloxane with a viscosity of 50,000 cps, and the weight ratio of the α, ω-dihydroxypolydimethylsiloxane with a viscosity of 10,000 cps to the α, ω-dihydroxypolydimethylsiloxane with a viscosity of 50,000 cps is 1 to 4:1.

[0039] In some embodiments, the silicone resin is one or more of methyl MQ silicone resin, vinyl MQ silicone resin, methyl silicone resin, and methylphenyl silicone resin.

[0040] In some embodiments, the viscosity of the silicone resin is 100 cps to 10,000 cps.

[0041] In some embodiments, the cross-linking agent is one or more of methyltrisacetone oxime silane, methyltributanone oxime silane, propyltributanone oxime silane, phenyltributanone oxime silane, tetrabutanone oxime silane, methyltris(methylisobutanone oxime) silane, tetrakis(methylisobutanone oxime) silane, vinyltrisacetone oxime silane, vinyltributanone oxime silane, and vinyltris(methylisobutanone oxime) silane.

[0042] In some embodiments, the coupling agent is one or more of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, N-β-aminoethyl-γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, 3-isocyanatopropyltrimethoxysilane, glycidoxypropyltriethoxysilane, mercaptopropyltrimethoxysilane.

[0043] In some embodiments, the catalyst is one or more of dibutyltin dilaurate, dibutyltin diacetate, dioctyltin dilaurate, stannous octoate, dibutyltin acetylacetate.

[0044] In some embodiments of the present application, a method for preparing the heat-insulating RTV silicone rubber is disclosed, comprising the following steps:

[0045] The α, ω-dihydroxypolydimethylsiloxane, silicone resin, modified base material, cross-linking agent, coupling agent and catalyst are stirred for 60-120 minutes under vacuum, and the heat-insulating RTV silicone rubber is obtained.

[0046] In some embodiments, the vacuum degree of the vacuum is -0.09 MPa to -0.1 MPa.

[0047] The present application is described in detail below in conjunction with specific embodiments.

[0048] Embodiment 1

[0049] The heat-insulating RTV silicone rubber of the present embodiment comprises the following raw materials (by weight) and steps:

[0050] 1. Preparation of modified base material

[0051] 100 parts of 350 cps dehydrated dimethyl silicone oil (120°C vacuum dehydration for 2 hours), 100 parts of nano-titanium oxide with a specific surface area of 200 m 2 / g and 1 part of toluene diisocyanate are kneaded under vacuum (-0.095 MPa) for 30 minutes, and then heated to 70°C, and vacuum (-0.095 MPa) stirring is continued for 60 minutes. The vacuum is maintained to cool to 48°C, the material is discharged, and then ground twice to obtain the modified base material.

[0052] 2. Preparation of heat-insulating RTV silicone rubber

[0053] 100 parts of 10,ω-dihydroxypolydimethylsiloxane (referred to as 107-based adhesive in the following examples), 20 parts of 400 cps methyl MQ silicone resin, 50 parts of modified base material, 12 parts of methyl tributanone oxime silane, 3 parts of γ-aminopropyltrimethoxysilane, and 0.1 parts of dibutyltin dilaurate were stirred and dispersed under vacuum (-0.095 MPa) for 90 min to obtain the final product.

[0054] Example 2

[0055] The heat-insulating room temperature vulcanizing silicone rubber of this embodiment includes the following preparation raw materials (by weight) and steps:

[0056] 1. Preparation of modified base material

[0057] 100 parts of 350 cps dehydrated dimethyl silicone oil (vacuum dehydrated at 120℃ for 2 hours) and 100 parts of specific surface area 200 m² 2 / g of nano-titanium oxide and 3 parts of toluene diisocyanate were kneaded under vacuum (-0.095MPa) for 30 min, then heated to 70℃ and stirred under vacuum (-0.095MPa) for 60 min. The mixture was then cooled to 47℃ while maintaining vacuum, discharged, and then ground twice to obtain the modified base material.

[0058] 2. Preparation of heat-insulating room temperature vulcanizing silicone rubber

[0059] The following mixtures were prepared by stirring and dispersing 100 parts of 20,000 cps 107 base adhesive, 30 parts of 500 cps vinyl MQ silicone resin, 50 parts of modified base material, 12 parts of vinyl tributanone oxime silane, 3 parts of γ-aminopropyltrimethoxysilane, and 0.1 parts of dibutyltin dilaurate under vacuum (-0.095 MPa) for 90 min to obtain the final product.

[0060] Example 3

[0061] The heat-insulating room temperature vulcanizing silicone rubber of this embodiment includes the following preparation raw materials (by weight) and steps:

[0062] 1. Preparation of modified base material

[0063] 100 parts of 350 cps dehydrated dimethyl silicone oil (vacuum dehydrated at 120℃ for 2 hours) and 100 parts of specific surface area 200 m² 2 / g of nano-titanium oxide and 3 parts of diphenylmethane diisocyanate were kneaded under vacuum (-0.095MPa) for 30 min, then heated to 70℃ and stirred under vacuum (-0.095MPa) for 60 min. The mixture was then cooled to 49℃ while maintaining vacuum, discharged, and then ground twice to obtain the modified base material.

[0064] 2. Preparation of heat-insulating room temperature vulcanizing silicone rubber

[0065] Disperse 50 parts of 5000 cps 107 base gum, 50 parts of 20000 cps 107 gum, 30 parts of 500 cps vinyl MQ silicone resin, 50 parts of modified base, 12 parts of vinyl tributanone oxime silane, 3 parts of γ-aminopropyl trimethoxysilane and 0.1 part of dibutyl tin dilaurate under vacuum condition (-0.095 MPa) for 90 min to obtain the product.

[0066] Example 4

[0067] The heat-insulating room temperature vulcanized silicone rubber of the present example comprises the following raw materials (by weight) and steps:

[0068] 1. Preparation of modified base

[0069] Disperse 100 parts of 350 cps dehydrated dimethyl silicone oil (dehydrated at 120℃ for 2 h), 100 parts of nano titanium oxide with specific surface area of 200 m 2 / g and 5 parts of toluene diisocyanate under vacuum condition (-0.095 MPa) for 30 min, then heat to 70℃, continue to stir under vacuum (-0.095 MPa) for 60 min. Keep vacuum and cool to 49℃, discharge, then pass through 2 times of grinding to obtain the modified base.

[0070] 2. Preparation of heat-insulating room temperature vulcanized silicone rubber

[0071] Disperse 70 parts of 50000 cps 107 base gum, 30 parts of 1500 cps 107 gum, 40 parts of 500 cps vinyl MQ silicone resin, 50 parts of modified base, 12 parts of vinyl tributanone oxime silane, 3 parts of γ-aminopropyl trimethoxysilane and 0.1 part of dibutyl tin dilaurate under vacuum condition (-0.095 MPa) for 90 min to obtain the product.

[0072] Example 5

[0073] The heat-insulating room temperature vulcanized silicone rubber of the present example comprises the following raw materials (by weight) and steps:

[0074] 1. Preparation of modified base

[0075] Disperse 100 parts of 350 cps dehydrated dimethyl silicone oil (dehydrated at 120℃ for 2 h), 100 parts of nano titanium oxide with specific surface area of 200 m 2 / g and 3 parts of toluene diisocyanate under vacuum condition (-0.095 MPa) for 30 min, then heat to 70℃, continue to stir under vacuum (-0.095 MPa) for 60 min. Keep vacuum and cool to 48℃, discharge, then pass through 2 times of grinding to obtain the modified base.

[0076] 2. Preparation of heat-insulating room temperature vulcanized silicone rubber

[0077] Disperse 60 parts of 10,000 cps 107 base gum, 40 parts of 20,000 cps 107 gum, 30 parts of 550 cps methylphenyl silicone resin, 80 parts of modified base, 10 parts of vinyl tributanoxime silane, 3 parts of N-beta aminoethyl gamma-aminopropyl triethoxysilane and 0.1 part of dibutyl tin diacetate under vacuum (-0.095 MPa) for 90 min to obtain the product.

[0078] Example 6

[0079] The heat-insulating room temperature vulcanized silicone rubber of the present example comprises the following raw materials (by weight) and steps:

[0080] 1. Preparation of modified base

[0081] Disperse 100 parts of 350 cps dehydrated dimethyl silicone oil (dehydrated at 120°C for 2 h), 100 parts of nano titanium oxide with specific surface area of 200 m 2 / g and 3 parts of toluene diisocyanate under vacuum (-0.095 MPa) for 30 min, then heat to 70°C, continue to stir under vacuum (-0.095 MPa) for 60 min. Keep vacuum and cool to 47°C, discharge, then pass through 2 times of grinding to obtain the modified base.

[0082] 2. Preparation of heat-insulating room temperature vulcanized silicone rubber

[0083] Disperse 60 parts of 10,000 cps 107 base gum, 40 parts of 20,000 cps 107 gum, 30 parts of 400 cps methyl silicone resin, 100 parts of modified base, 6 parts of vinyl tributanoxime silane, 4 parts of phenyl tributanoxime silane, 3 parts of N-beta aminoethyl gamma-aminopropyl triethoxysilane and 0.15 part of dibutyl tin diacetate under vacuum (-0.095 MPa) for 90 min to obtain the product.

[0084] Example 7

[0085] The heat-insulating room temperature vulcanized silicone rubber of the present example comprises the following raw materials (by weight) and steps:

[0086] 1. Preparation of modified base

[0087] Disperse 100 parts of 350 cps dehydrated dimethyl silicone oil (dehydrated at 120°C for 2 h), 100 parts of nano titanium oxide with specific surface area of 200 m 2 / g and 1 part of triphenyl methane triisocyanate under vacuum (-0.095 MPa) for 30 min, then heat to 70°C, continue to stir under vacuum (-0.095 MPa) for 60 min. Keep vacuum and cool to 46°C, discharge, then pass through 3 times of grinding to obtain the modified base.

[0088] 2. Preparation of the heat-insulating RTV silicone rubber

[0089] 100 parts of 20000 cps 107-based gum, 30 parts of 550 cps methylphenyl silicone resin, 80 parts of the modified base, 8 parts of methyltriketoxime silane, 4 parts of phenyltriketoxime silane, 3 parts of N-β-aminoethyl γ-aminopropyl triethoxysilane and 0.2 parts of dibutyl tin diacetate are stirred and dispersed under vacuum (-0.095 MPa) for 90 min to obtain the heat-insulating RTV silicone rubber.

[0090] Example 8

[0091] The heat-insulating RTV silicone rubber of the present example comprises the following raw materials (by weight) and steps:

[0092] 1. Preparation of the modified base

[0093] 100 parts of 350 cps dehydrated dimethyl silicone oil (vacuum dehydrated at 120°C for 2 h), 100 parts of nano titanium oxide with a specific surface area of 200 m 2 / g and 2 parts of triphenylmethane triisocyanate are kneaded under vacuum (-0.095 MPa) for 30 min, and then heated to 70°C, and stirred under vacuum (-0.095 MPa) for 60 min. The temperature is lowered to 50°C while maintaining the vacuum, and the product is discharged and ground for 3 times to obtain the modified base.

[0094] 2. Preparation of the heat-insulating RTV silicone rubber

[0095] 100 parts of 20000 cps 107-based gum, 30 parts of 550 cps methylphenyl silicone resin, 80 parts of the modified base, 8 parts of methyltriketoxime silane, 4 parts of phenyltriketoxime silane, 3 parts of N-β-aminoethyl γ-aminopropyl triethoxysilane and 0.2 parts of dibutyl tin diacetate are stirred and dispersed under vacuum (-0.095 MPa) for 90 min to obtain the heat-insulating RTV silicone rubber.

[0096] Example 9

[0097] The heat-insulating RTV silicone rubber of the present example comprises the following raw materials (by weight) and steps:

[0098] 1. Preparation of the modified base

[0099] 100 parts of 350 cps dehydrated dimethyl silicone oil (vacuum dehydrated at 120°C for 2 h), 100 parts of nano titanium oxide with a specific surface area of 200 m 2The modified base was obtained by kneading 3 parts of triphenylmethane triisocyanate with 60 parts of 10,000 cps 107 base gum, 40 parts of 50,000 cps 107 base gum, 30 parts of 550 cps methylphenyl silicone resin, 80 parts of modified base, 8 parts of methyltris(butanone oxime) silane, 4 parts of phenyltris(butanone oxime) silane, 3 parts of N-β-aminoethyl γ-aminopropyl triethoxysilane and 0.15 parts of dibutyl tin diacetate under vacuum (-0.095 MPa) for 90 min, and then cooling to 47°C under vacuum, and discharging the product.

[0100] 2. Preparation of the heat-insulating room temperature vulcanized silicone rubber

[0101] The modified base was obtained by kneading 3 parts of triphenylmethane triisocyanate with 60 parts of 10,000 cps 107 base gum, 40 parts of 50,000 cps 107 base gum, 30 parts of 550 cps methylphenyl silicone resin, 80 parts of modified base, 8 parts of methyltris(butanone oxime) silane, 4 parts of phenyltris(butanone oxime) silane, 3 parts of N-β-aminoethyl γ-aminopropyl triethoxysilane and 0.15 parts of dibutyl tin diacetate under vacuum (-0.095 MPa) for 90 min, and then cooling to 47°C under vacuum, and discharging the product.

[0102] Example 10

[0103] The heat-insulating room temperature vulcanized silicone rubber of this example comprises the following raw materials (by weight) and steps:

[0104] 1. Preparation of the modified base

[0105] The modified base was obtained by kneading 3 parts of triphenylmethane triisocyanate with 60 parts of 10,000 cps 107 base gum, 40 parts of 50,000 cps 107 base gum, 30 parts of 550 cps methylphenyl silicone resin, 80 parts of modified base, 8 parts of methyltris(butanone oxime) silane, 4 parts of phenyltris(butanone oxime) silane, 3 parts of N-β-aminoethyl γ-aminopropyl triethoxysilane and 0.15 parts of dibutyl tin diacetate under vacuum (-0.095 MPa) for 90 min, and then cooling to 47°C under vacuum, and discharging the product. 2 The modified base was obtained by kneading 3 parts of triphenylmethane triisocyanate with 60 parts of 10,000 cps 107 base gum, 40 parts of 50,000 cps 107 base gum, 30 parts of 550 cps methylphenyl silicone resin, 80 parts of modified base, 8 parts of methyltris(butanone oxime) silane, 4 parts of phenyltris(butanone oxime) silane, 3 parts of N-β-aminoethyl γ-aminopropyl triethoxysilane and 0.15 parts of dibutyl tin diacetate under vacuum (-0.095 MPa) for 90 min, and then cooling to 47°C under vacuum, and discharging the product.

[0106] 2. Preparation of the heat-insulating room temperature vulcanized silicone rubber

[0107] The modified base was obtained by kneading 3 parts of triphenylmethane triisocyanate with 60 parts of 10,000 cps 107 base gum, 40 parts of 50,000 cps 107 base gum, 30 parts of 550 cps methylphenyl silicone resin, 80 parts of modified base, 8 parts of methyltris(butanone oxime) silane, 4 parts of phenyltris(butanone oxime) silane, 3 parts of N-β-aminoethyl γ-aminopropyl triethoxysilane and 0.15 parts of dibutyl tin diacetate under vacuum (-0.095 MPa) for 90 min, and then cooling to 47°C under vacuum, and discharging the product.

[0108] Comparative Example 1

[0109] The room temperature vulcanized silicone rubber of this comparative example comprises the following raw materials (by weight) and steps:

[0110] Example 1 60 parts of 10,000 cps 107 base gum, 40 parts of 50,000 cps 107 base gum, 30 parts of 550 cps methylphenyl silicone resin, 40 parts of 350 cps dehydrated dimethyl silicone oil (vacuum dehydrated at 120°C for 2 hours), 40 parts of titanium oxide with a specific surface area of 200 m 2 / g, 8 parts of methyltriketoximosilane, 4 parts of phenyltriketoximosilane, 3 parts of N-β-aminoethyl γ-aminopropyl triethoxysilane, and 0.15 parts of dibutyl tin diacetate were dispersed by stirring under vacuum (-0.095 MPa) for 90 minutes.

[0111] Comparative Example 2

[0112] The room temperature vulcanizing silicone rubber of the present comparative example was prepared from the following raw materials (by weight) and steps:

[0113] 1. Preparation of modified base

[0114] 100 parts of 350 cps dehydrated dimethyl silicone oil (vacuum dehydrated at 120°C for 2 hours), 100 parts of nano calcium carbonate with a specific surface area of 200 m 2 / g, and 3 parts of triphenylmethane triisocyanate were kneaded under vacuum (-0.095 MPa) for 30 minutes, and then the temperature was raised to 70°C and stirring was continued under vacuum (-0.095 MPa) for 60 minutes. The temperature was lowered to 48°C while maintaining the vacuum, and the product was discharged and ground three times to obtain the modified base.

[0115] 2. Preparation of room temperature vulcanizing silicone rubber

[0116] 60 parts of 10,000 cps 107 base gum, 40 parts of 50,000 cps 107 base gum, 30 parts of 550 cps methylphenyl silicone resin, 80 parts of modified base, 8 parts of methyltriketoximosilane, 4 parts of phenyltriketoximosilane, 3 parts of N-β-aminoethyl γ-aminopropyl triethoxysilane, and 0.15 parts of dibutyl tin diacetate were dispersed by stirring under vacuum for 90 minutes.

[0117] Comparative Example 3

[0118] The room temperature vulcanizing silicone rubber of the present comparative example was prepared from the following raw materials (by weight) and steps:

[0119] 60 parts of 10,000 cps 107 base gum, 40 parts of 50,000 cps 107 base gum, 30 parts of 550 cps methylphenyl silicone resin, 40 parts of 350 cps dehydrated dimethyl silicone oil (vacuum dehydrated at 120°C for 2 hours), 40 parts of aerogel (bulk density 60-120 kg / m 38 parts of methyl tributanone oxime silane, 4 parts of phenyl tributanone oxime silane, 3 parts of N-β-aminoethyl γ-aminopropyltriethoxysilane and 0.15 parts of dibutyltin diacetate were stirred and dispersed under vacuum (-0.095 MPa) for 90 min to obtain silicone rubber.

[0120] Comparative Example 4

[0121] The room temperature vulcanizing silicone rubber of this comparative example includes the following preparation materials (by weight) and steps:

[0122] 60 parts of 107-based adhesive with a density of 10000 cps, 40 parts of 107-based adhesive with a density of 50000 cps, 30 parts of methylphenyl silicone resin, 40 parts of 350 cps dehydrated dimethyl silicone oil (vacuum dehydrated at 120℃ for 2 hours), 20 parts of titanium dioxide, and 20 parts of aerogel (bulk density 60-120 kg / m³) were mixed. 3 8 parts of methyl tributanone oxime silane, 4 parts of phenyl tributanone oxime silane, 3 parts of N-β-aminoethyl γ-aminopropyltriethoxysilane and 0.15 parts of dibutyltin diacetate were stirred and dispersed under vacuum (-0.095 MPa) for 90 min to obtain silicone rubber.

[0123] Comparative Example 5

[0124] The room temperature vulcanizing silicone rubber of this comparative example includes the following preparation materials (by weight) and steps:

[0125] 1. Preparation of modified base material

[0126] 100 parts of 350 cps dimethyl silicone oil (vacuum dehydrated at 120℃ for 2 hours) and 50 parts of a specific surface area of ​​200 m² were mixed. 2 / g titanium dioxide, 50 parts aerogel (bulk density 60-120kg / m³) 3 The mixture was kneaded with 3 parts of triphenylmethane triisocyanate under vacuum (-0.095 MPa) for 30 min, then heated to 70 °C and stirred under vacuum (-0.095 MPa) for 60 min. The mixture was then cooled to 48 °C while maintaining vacuum, discharged, and then ground three times to obtain the modified base material.

[0127] 2. Preparation of silicone rubber

[0128] The following mixtures were prepared by stirring and dispersing 60 parts of 107-based adhesive with a viscosity of 10000 cps, 40 parts of 107-based adhesive with a viscosity of 50000 cps, 30 parts of 550 cps of methylphenyl silicone resin, 80 parts of modified base material, 8 parts of methyl tributanone oxime silane, 4 parts of phenyl tributanone oxime silane, 3 parts of N-β-aminoethyl γ-aminopropyltriethoxysilane, and 0.15 parts of dibutyltin diacetate under vacuum (-0.095 MPa) for 90 min to obtain the final product.

[0129] The silicone rubbers of Examples 1-10 and Comparative Examples 1-5 were subjected to the following performance tests:

[0130] 1. Tack-free time: tested according to the method specified in GB / T 13477.5-2002;

[0131] 2. Tensile strength: tested according to the method specified in GB / T 528;

[0132] 3. Elongation at break: tested according to the method specified in GB / T 13477.8-2002;

[0133] 4. Thermal conductivity: tested according to the method specified in IS022007-2.2008;

[0134] 5. Water absorption test: the cured silicone rubber was soaked in clean water for 168 h, and the weight of the silicone rubber before soaking m1 and the weight after removing the water droplets on the surface with a water absorption paper towel m2 were measured. The sample specimens were 6, and the average value was taken as the result. The water absorption W of the silicone rubber was calculated according to formula (1).

[0135] W = (m2-m1) / m1 x 100% (1)

[0136] The test results are shown in Table 1.

[0137] Table 1 Comparison of properties of silicone rubbers prepared in each example and comparative example

[0138] Surface dry time / min Tensile strength / MPa Elongation at break / % Thermal conductivity / W / (m.k) Water absorption / % Example 1 25 1.56 262 0.223 0.21 Example 2 45 1.89 330 0.215 0.32 Example 3 47 1.84 325 0.213 0.33 Example 4 120 2.06 380 0.195 0.52 Example 5 38 1.72 295 0.184 0.78 Example 6 39 1.33 205 0.180 0.79 Example 7 40 1.84 305 0.182 0.80 Example 8 35 1.70 288 0.175 0.97 Example 9 40 1.59 211 0.173 1.01 Example 10 43 1.61 220 0.178 0.98 Comparative Example 1 44 2.31 355 0.235 0.07 Comparative Example 2 46 1.85 312 0.336 0.95 Comparative Example 3 47 2.44 468 0.238 0.65 Comparative Example 4 46 2.02 310 0.236 0.38 Comparative Example 5 45 1.38 199 0.279 0.40

[0139] As can be seen from Table 1, with the increase of the amount of the silicone resin in the raw material, the mechanical properties of the prepared silicone rubber are enhanced, but the curing speed is slowed down, and when the amount of the additive is more than 30 parts, the silicone rubber is difficult to cure, which is not conducive to construction (Examples 1, 2 and 4). Examples 2 and 3 use the base modified by different diisocyanates, and the prepared silicone rubber has similar overall performance, which shows that the modification effect of different diisocyanates is relatively close; Examples 5 and 9 use the base modified by diisocyanate and triisocyanate respectively, and the thermal conductivity of the silicone rubber prepared by using the base modified by triisocyanate is lower, which shows that the modification effect of triisocyanate is better than that of diisocyanate. By comparing the thermal conductivities of the silicone rubbers of Examples 3, 5 and 6, it can be found that with the increase of the amount of the modified base, the thermal conductivity of the prepared silicone rubber is reduced, which shows that the heat insulation performance is enhanced, and the water absorption of the silicone rubber is also enhanced, which shows that the voids of the silicone rubber are increased, and thus the absorbed water vapor is increased. With the increase of the amount of the modified base, the mechanical properties of the silicone rubber are reduced, which may be because a large number of pore structures affect the compactness of the silicone rubber. Compared with the case where the amount of the modified base is 80 parts, when the amount of the modified base is 100 parts, the thermal conductivity is only slightly reduced, and the heat generation performance of the silicone rubber is not obviously increased. Therefore, by comprehensively considering the heat insulation performance and the mechanical properties, when the amount of the modified base is 80 parts, the effect is optimal. By comparing the properties of the silicone rubbers of Examples 7, 8 and 9, it can be found that with the increase of the amount of the modifier triisocyanate, the thermal conductivity of the silicone rubber is reduced, which shows that the heat insulation performance of the silicone rubber is better. Since too much addition of the modifier can easily cause poor appearance of the modified base and affect the mechanical properties of the silicone rubber, the optimal amount of the modifier is 3 parts. It can be known from the above that the heat insulation type room temperature vulcanized silicone rubber obtained by optimization has good heat insulation performance and good mechanical properties. Among them, the comprehensive performance of Example 9 is the best.

[0140] Compared with Example 9, the base used in Comparative Example 1 is not modified (including dimethyl silicone oil and nano titanium oxide), and the thermal conductivity is significantly increased, and the water absorption is significantly reduced, which shows that the base obtained by modifying the nano titanium oxide can increase the porosity of the silicone rubber system, and thus improve the heat insulation performance.

[0141] The modified base used in Comparative Example 2 is prepared by modifying nano calcium carbonate with triisocyanate, and the water absorption of the prepared silicone rubber is similar to that of the silicone rubber of Example 9, but the thermal conductivity is greater than that of Example 9, and the heat insulation performance is much worse.

[0142] The heat insulation material used in Comparative Example 3 is aerogel, and the thermal conductivity of the prepared silicone rubber is greater than that of Example 9, which shows that the heat insulation performance of the silicone rubber prepared by using the modified base of the application is more superior, and the cost is lower.

[0143] The base material used in Comparative Example 4 includes unmodified nano-titanium oxide and aerogel, and the base material used in Comparative Example 5 is modified both nano-titanium oxide and aerogel. The heat conductivity of the sealant prepared from the base material of Comparative Example 5 is significantly greater than that of the sealant of Example 9, and the heat insulation performance of the silicone rubber of Comparative Example 5 is worse than that of Comparative Example 4, because the porosity of the aerogel is destroyed under high-speed kneading in vacuum, which greatly reduces the heat insulation performance of the aerogel.

[0144] The technical features of the above-described embodiments can be combined in any manner. For the sake of brevity, not all possible combinations of the technical features in the above-described embodiments are described, but it should be understood that any combination of the technical features is within the scope of the present disclosure as long as the combination does not result in a contradiction.

[0145] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, and these are within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A modified base material, characterized in that, It is prepared from dimethyl silicone oil, metal oxide and polyisocyanate in a weight ratio of 100:95~105:0.5~5; the metal oxide is nano titanium oxide or nano zinc oxide.

2. The modified base material according to claim 1, characterized in that, The weight ratio of the dimethyl silicone oil, metal oxide and polyisocyanate is 100:98~102:0.5~3.

3. The modified base material according to claim 2, characterized in that, The weight ratio of the dimethyl silicone oil, metal oxide, and polyisocyanate is 100:99~101:1~3.

4. The modified base material according to claim 3, characterized in that, The weight ratio of the dimethyl silicone oil, metal oxide, and polyisocyanate is 100:100:2~3.

5. The modified base material according to claim 1, characterized in that, The polyisocyanate is one or more of diphenylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, and triphenylmethane triisocyanate.

6. The modified base material according to any one of claims 1 to 5, characterized in that, The specific surface area of ​​the nano-titanium oxide or nano-zinc oxide is 100 m². 2 / g~300 m 2 / g; And / or, the viscosity of the dimethyl silicone oil at 25°C is 300 cps to 400 cps; And / or, the dimethyl silicone oil is a silicone oil that has undergone dehydration treatment, wherein the dehydration conditions are vacuum dehydration at 115℃~125℃ for 1.5 h~2.5 h.

7. A method for preparing the modified base material according to any one of claims 1 to 6, characterized in that, Includes the following steps: Dimethyl silicone oil, metal oxide and polyisocyanate are vacuum stirred for 30 min to 60 min, heated to 60℃ to 100℃, and vacuum stirred for another 60 min to 90 min. The mixture is then cooled, discharged, and ground to obtain the final product.

8. The method for preparing the modified base material according to claim 7, characterized in that, The vacuum level is -0.09 MPa to -0.1 MPa.

9. A heat-insulating room temperature vulcanizing silicone rubber, characterized in that, It is prepared from the following raw materials in parts by weight: 100 parts of α,ω-dihydroxypolydimethylsiloxane 10 to 30 parts of silicone resin 50 to 100 parts of the modified base material according to any one of claims 1 to 6 5 to 15 parts of crosslinking agent 1 to 5 parts of silane coupling agent Catalyst: 0.01 to 1 part.

10. The heat-insulating room temperature vulcanizing silicone rubber according to claim 9, characterized in that, It is prepared from the following raw materials in parts by weight: 100 parts of α,ω-dihydroxypolydimethylsiloxane 20 to 30 parts of silicone resin 50-80 parts of modified base material 5 to 12 parts of crosslinking agent 1 to 3 parts of silane coupling agent Catalyst 0.1 to 0.2 parts.

11. The heat-insulating room temperature vulcanizing silicone rubber according to claim 9 or 10, characterized in that, The viscosity of the α,ω-dihydroxypolydimethylsiloxane at 25°C is 100 cps to 100,000 cps. And / or, the silicone resin is one or more of methyl MQ silicone resin, vinyl MQ silicone resin, methyl silicone resin, and methyl phenyl silicone resin; And / or, the viscosity of the silicone resin is 100 cps to 10000 cps; And / or, the crosslinking agent is one or more of methyltriacetone oxime silane, methyltributanone oxime silane, propyltributanone oxime silane, phenyltributanone oxime silane, tetrabutanone oxime silane, methyltris(methylisobutylone oxime) silane, tetra(methylisobutylone oxime) silane, vinyltriacetone oxime silane, vinyltributanone oxime silane, and vinyltris(methylisobutylone oxime) silane; And / or, the coupling agent is one or more of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltriethoxysilane, γ-glycidyl etheroxypropyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, 3-isocyanate-propyltrimethoxysilane, glycidyltriethoxysilane, and mercaptopropyltrimethoxysilane; And / or, the catalyst is one or more of dibutyltin dilaurate, dibutyltin diacetate, dioctyltin dilaurate, and stannous octoate.

12. The heat-insulating room temperature vulcanizing silicone rubber according to claim 11, characterized in that, The viscosity of the α,ω-dihydroxypolydimethylsiloxane at 25°C is 1000 cps to 50000 cps.

13. A method for preparing a heat-insulating room temperature vulcanizing silicone rubber according to any one of claims 9 to 12, characterized in that, Includes the following steps: Under vacuum, α,ω-dihydroxypolydimethylsiloxane, silicone resin, modified base material, crosslinking agent, coupling agent and catalyst are stirred for 60 min to 120 min to obtain the product.

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