Modified base material, heat insulation type room temperature vulcanized silicone rubber and preparation method thereof

Abstract

The invention discloses a modified base material, heat insulation type room temperature vulcanized silicone rubber and a preparation method of the heat insulation type room temperature vulcanized silicone rubber. The modified base material is prepared from simethicone, metal oxide and polyisocyanate according to the weight part ratio of 100: (95-105): (0.5-5). The heat insulation type room temperature vulcanized silicone rubber is prepared from 100 parts of alpha, omega-dihydroxy polydimethylsiloxane, 10 to 30 parts of silicon resin, 50 to 100 parts of a modified base material, 5 to 15 parts of a cross-linking agent, 1 to 5 parts of a silane coupling agent and 0.01 to 1 part of a catalyst. The silicone rubber prepared by the invention integrates a reflective heat-insulating functional material and a barrier heat-insulating functional material, so that the silicone rubber has reflective heat-insulating and barrier heat-insulating capabilities at the same time, and is low in heat conductivity coefficient and excellent in heat-insulating performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of RTV silicone rubber, and more specifically, the present invention relates to a modified base material, a heat-insulating room temperature vulcanized silicone rubber and a preparation method thereof. Background Art

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

[0003] Heat is mainly transferred in buildings through conduction, convection and radiation. The higher the thermal conductivity of the medium, the faster the heat transfer. Thermal insulation materials use materials with low thermal conductivity or porous materials to reduce the efficiency of heat transfer, thereby achieving the purpose of slowing down heat transfer. There are many types of thermal insulation materials on the market, and each has its own advantages and disadvantages. For example, fiberglass, asbestos, rock wool, etc. have good thermal insulation performance and are cheap, but they can cause damage to human skin and respiratory tract; vacuum insulation panels and aerogel felts have excellent thermal insulation performance but are fragile and expensive; polyurethane foam materials are brittle and flammable, and require professional equipment and personnel for construction. Summary of the invention

[0004] Based on this, the object of the present invention is to provide a heat-insulating room temperature vulcanized silicone rubber, which has a lower thermal conductivity and excellent heat insulation performance.

[0005] The specific technical solutions for achieving the above-mentioned invention objectives include the following.

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

[0007] The second aspect of the present invention provides a method for preparing a modified base material, comprising the following steps: vacuum stirring dimethyl silicone oil, metal oxide and polyisocyanate for 30 to 60 minutes, heating to 60°C to 100°C, continuing vacuum stirring for 60 to 90 minutes, cooling, discharging and grinding to obtain the modified base material.

[0008] The third aspect of the present invention provides a heat-insulating room temperature vulcanized silicone rubber, which is prepared from the following raw materials in parts by weight:

[0009]

[0010] The fourth aspect of the present invention provides a method for preparing a heat-insulating room temperature vulcanized silicone rubber, comprising the following steps: stirring α, ω-dihydroxypolydimethylsiloxane, silicone resin, modified base material, crosslinking agent, coupling agent and catalyst for 60 min to 120 min under a vacuum state to obtain the obtained product.

[0011] The present invention first prepares a modified base material with a certain weight ratio of dimethyl silicone oil, metal oxide and polyisocyanate. After the structure of nano titanium oxide or nano zinc oxide with heat reflectivity is reconstructed by polyisocyanate, it is added to the base rubber of room temperature vulcanized silicone rubber to form a porous material through stacking, interlacing and filling.

[0012] Furthermore, the present invention optimizes and obtains a heat-insulating room temperature vulcanized silicone rubber, which is prepared by adding the above-mentioned modified base material to the basic system of room temperature vulcanized silicone rubber (α, ω-dihydroxypolydimethylsiloxane, silicone resin, cross-linking agent, silane coupling agent, catalyst). The modified base material cooperates with the components of the basic system of room temperature vulcanized silicone rubber, so that the prepared silicone rubber has a porous structure filled with a large number of pores, which is equivalent to the silicone rubber integrating the reflective thermal insulation functional material and the barrier thermal insulation functional material, thereby having the ability of reflective thermal insulation and barrier thermal insulation at the same time. Therefore, the silicone rubber prepared by the present invention has low thermal conductivity and excellent thermal insulation performance. DETAILED DESCRIPTION

[0013] In order to facilitate the understanding of the present invention, the present invention will be described more fully below. The present invention 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 invention more thorough and comprehensive.

[0014] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in the present invention includes any and all combinations of one or more of the related listed items.

[0015] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods, and the materials, reagents, etc. used can be purchased from commercial channels unless otherwise specified.

[0016] In some embodiments of the present invention, 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, the metal oxide and the polyisocyanate is 100:98-102:0.5-3.

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

[0019] In some embodiments, the weight ratio of the dimethyl silicone oil, the metal oxide and the 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 100 m 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 300 cps to 400 cps.

[0025] In some embodiments, the dimethyl silicone oil is silicone oil that has been dehydrated.

[0026] In some of the embodiments, the dehydration condition is vacuum dehydration at 115° C. to 125° C. for 1.5 h to 2.5 h.

[0027] In other embodiments of the present invention, a method for preparing the modified base material is disclosed, comprising the following steps:

[0028] Mix dimethyl silicone oil, metal oxide and polyisocyanate, stir under vacuum for 30-60 minutes, heat to 60-100°C, continue to stir under vacuum for 60-90 minutes, cool down, discharge and grind to obtain the product.

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

[0030] In other embodiments of the present invention, a heat-insulating room temperature vulcanized silicone rubber is disclosed, which is prepared from the following raw materials in parts by weight:

[0031]

[0032]

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

[0034] 100 parts of α,ω-dihydroxy polydimethylsiloxane

[0035]

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

[0037] In some embodiments, the viscosity of the α,ω-dihydroxy polydimethylsiloxane at 25° C. is 1000 cps to 50000 cps.

[0038] In some embodiments, the α,ω-dihydroxy polydimethylsiloxane includes α,ω-dihydroxy polydimethylsiloxane with a viscosity of 10000cps and α,ω-dihydroxy polydimethylsiloxane with a viscosity of 50000cps, and the weight ratio of the α,ω-dihydroxy polydimethylsiloxane with a viscosity of 10000cps to the α,ω-dihydroxy polydimethylsiloxane with a viscosity of 50000cps 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 methyl phenyl silicone resin.

[0040] In some embodiments, the viscosity of the silicone resin is 100 cps to 10000 cps.

[0041] In some of the embodiments, the crosslinking agent is one or more of methyl triacetone oxime silane, methyl tributyl ketone oxime silane, propyl tributyl ketone oxime silane, phenyl tributyl ketone oxime silane, tetrabutyl ketone oxime silane, methyl tri(methyl isobutyl ketone oxime) silane, tetra(methyl isobutyl ketone oxime) silane, vinyl triacetone oxime silane, vinyl tributyl ketone oxime silane, and vinyl tri(methyl isobutyl ketone oxime) silane.

[0042] In some of the embodiments, the coupling agent is one or more of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β-aminoethylγ-aminopropyltrimethoxysilane, N-β-aminoethylγ-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, 3-isocyanatepropyltrimethoxysilane, epoxypropyltriethoxysilane, and mercaptopropyltrimethoxysilane.

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

[0044] In other embodiments of the present invention, a method for preparing the above-mentioned heat-insulating room temperature vulcanized silicone rubber is disclosed, comprising the following steps:

[0045] Under vacuum conditions, α,ω-dihydroxypolydimethylsiloxane, silicone resin, modified base material, crosslinking agent, coupling agent and catalyst are stirred for 60 to 120 minutes to obtain the product.

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

[0047] The present invention is described in detail below with reference to specific embodiments.

[0048] Example 1

[0049] The heat-insulating room temperature vulcanized silicone rubber of this embodiment includes the following preparation raw materials (by weight) and steps:

[0050] 1. Preparation of modified base material

[0051] 100 parts of 350cps dehydrated dimethyl silicone oil (120℃ vacuum dehydration for 2h), 100 parts of 2 / g of nano titanium oxide and 1 part of toluene diisocyanate were kneaded under vacuum conditions (-0.095MPa) for 30 minutes, then heated to 70°C and stirred under vacuum (-0.095MPa) for 60 minutes. The vacuum was maintained and the temperature was lowered to 48°C, the material was discharged, and then ground twice to obtain a modified base material.

[0052] 2. Preparation of heat-insulating room temperature vulcanized silicone rubber

[0053] 100 parts of 10000cps α,ω-dihydroxypolydimethylsiloxane (represented by 107 base glue in the following examples), 20 parts of 400cps methyl MQ silicone resin, 50 parts of modified base material, 12 parts of methyl tributylidene silane, 3 parts of γ-aminopropyltrimethoxysilane and 0.1 part of dibutyltin dilaurate were stirred and dispersed under vacuum (-0.095MPa) for 90 minutes to obtain the product.

[0054] Example 2

[0055] The heat-insulating room temperature vulcanized 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 350cps dehydrated dimethyl silicone oil (120℃ vacuum dehydration for 2h), 100 parts of 2 / g nano titanium oxide and 3 parts toluene diisocyanate were kneaded under vacuum conditions (-0.095MPa) for 30 minutes, then heated to 70°C and stirred under vacuum (-0.095MPa) for 60 minutes. The vacuum was maintained and the temperature was lowered to 47°C, the material was discharged, and then ground twice to obtain a modified base material.

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

[0059] 100 parts of 20,000 cps 107 base glue, 30 parts of 500 cps vinyl MQ silicone resin, 50 parts of modified base material, 12 parts of vinyl trisbutyl ketoxime silane, 3 parts of γ-aminopropyltrimethoxysilane and 0.1 parts of dibutyltin dilaurate were stirred and dispersed under vacuum (-0.095 MPa) for 90 minutes to obtain the product.

[0060] Example 3

[0061] The heat-insulating room temperature vulcanized 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 350cps dehydrated dimethyl silicone oil (120℃ vacuum dehydration for 2h), 100 parts of 2 / g nano titanium oxide and 3 parts of diphenylmethane diisocyanate were kneaded under vacuum conditions (-0.095MPa) for 30 minutes, then heated to 70°C and stirred under vacuum (-0.095MPa) for 60 minutes. The vacuum was maintained and the temperature was lowered to 49°C, the material was discharged, and then ground twice to obtain a modified base material.

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

[0065] 50 parts of 5000cps 107 base glue, 50 parts of 20000cps 107 glue, 30 parts of 500cps vinyl MQ silicone resin, 50 parts of modified base material, 12 parts of vinyl trisbutyl ketone oxime silane, 3 parts of γ-aminopropyltrimethoxysilane and 0.1 part of dibutyltin dilaurate were stirred and dispersed under vacuum (-0.095MPa) for 90 minutes to obtain the product.

[0066] Example 4

[0067] The heat-insulating room temperature vulcanized silicone rubber of this embodiment includes the following preparation raw materials (by weight) and steps:

[0068] 1. Preparation of modified base material

[0069] 100 parts of 350cps dehydrated dimethyl silicone oil (120℃ vacuum dehydration for 2h), 100 parts of 2 / g nano titanium oxide and 5 parts toluene diisocyanate were kneaded under vacuum conditions (-0.095MPa) for 30 minutes, then heated to 70°C and stirred under vacuum (-0.095MPa) for 60 minutes. The vacuum was maintained and the temperature was lowered to 49°C, the material was discharged, and then ground twice to obtain a modified base material.

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

[0071] 70 parts of 50000cps 107 base glue, 30 parts of 1500cps 107 glue, 40 parts of 500cps vinyl MQ silicone resin, 50 parts of modified base material, 12 parts of vinyl trisbutyl ketone oxime silane, 3 parts of γ-aminopropyltrimethoxysilane and 0.1 part of dibutyltin dilaurate were stirred and dispersed under vacuum state (-0.095MPa) for 90 minutes to obtain.

[0072] Example 5

[0073] The heat-insulating room temperature vulcanized silicone rubber of this embodiment includes the following preparation raw materials (by weight) and steps:

[0074] 1. Preparation of modified base material

[0075] 100 parts of 350cps dehydrated dimethyl silicone oil (120℃ vacuum dehydration for 2h), 100 parts of 2 / g nano titanium oxide and 3 parts toluene diisocyanate were kneaded under vacuum conditions (-0.095MPa) for 30 minutes, then heated to 70°C and stirred under vacuum (-0.095MPa) for 60 minutes. The vacuum was maintained and the temperature was lowered to 48°C, the material was discharged, and then ground twice to obtain a modified base material.

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

[0077] Stir and disperse 60 parts of 10000cps 107 base glue, 40 parts of 20000cps 107 glue, 30 parts of 550cps methylphenyl silicone resin, 80 parts of modified base material, 10 parts of vinyltributylidene oxime silane, 3 parts of N-βaminoethyl γ-aminopropyltriethoxysilane and 0.1 part of dibutyltin diacetate under vacuum (-0.095MPa) for 90 minutes to obtain the product.

[0078] Example 6

[0079] The heat-insulating room temperature vulcanized silicone rubber of this embodiment includes the following preparation raw materials (by weight) and steps:

[0080] 1. Preparation of modified base material

[0081] 100 parts of 350cps dehydrated dimethyl silicone oil (120℃ vacuum dehydration for 2h), 100 parts of 2 / g nano titanium oxide and 3 parts toluene diisocyanate were kneaded under vacuum conditions (-0.095MPa) for 30 minutes, then heated to 70°C and stirred under vacuum (-0.095MPa) for 60 minutes. The vacuum was maintained and the temperature was lowered to 47°C, the material was discharged, and then ground twice to obtain a modified base material.

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

[0083] 60 parts of 10000cps 107 base glue, 40 parts of 20000cps 107 glue, 30 parts of 400cps methyl silicone resin, 100 parts of modified base material, 6 parts of vinyl trisbutyl ketone oxime silane, 4 parts of phenyl trisbutyl ketone oxime silane, 3 parts of N-β-aminoethyl γ-aminopropyl triethoxy silane and 0.15 parts of dibutyl tin diacetate were stirred and dispersed under vacuum (-0.095MPa) for 90 minutes to obtain the product.

[0084] Example 7

[0085] The heat-insulating room temperature vulcanized silicone rubber of this embodiment includes the following preparation raw materials (by weight) and steps:

[0086] 1. Preparation of modified base material

[0087] 100 parts of 350cps dehydrated dimethyl silicone oil (120℃ vacuum dehydration for 2h), 100 parts of 2 / g nano titanium oxide and 1 part triphenylmethane triisocyanate were kneaded under vacuum conditions (-0.095MPa) for 30 minutes, then heated to 70°C and stirred under vacuum (-0.095MPa) for 60 minutes. The vacuum was maintained and the temperature was lowered to 46°C, the material was discharged, and then ground three times to obtain a modified base material.

[0088] 2. Preparation of heat-insulating room temperature vulcanized silicone rubber

[0089] 50 parts of 5000cps 107 base glue, 50 parts of 20000cps 107 base glue, 30 parts of 400cps methyl MQ silicone resin, 80 parts of modified base material, 8 parts of methyl tributyl ketone oxime silane, 4 parts of phenyl tributyl ketone oxime silane, 3 parts of N-β-aminoethyl γ-aminopropyl triethoxy silane and 0.2 parts of dibutyl tin diacetate were stirred and dispersed under vacuum (-0.095MPa) for 90 minutes to obtain the product.

[0090] Example 8

[0091] The heat-insulating room temperature vulcanized silicone rubber of this embodiment includes the following preparation raw materials (by weight) and steps:

[0092] 1. Preparation of modified base material

[0093] 100 parts of 350cps dehydrated dimethyl silicone oil (120℃ vacuum dehydration for 2h), 100 parts of 2 / g nano titanium oxide and 2 parts of triphenylmethane triisocyanate were kneaded under vacuum conditions (-0.095MPa) for 30 minutes, then heated to 70°C and stirred under vacuum (-0.095MPa) for 60 minutes. The vacuum was maintained and the temperature was lowered to 50°C, the material was discharged, and then ground three times to obtain a modified base material.

[0094] 2. Preparation of heat-insulating room temperature vulcanized silicone rubber

[0095] 100 parts of 20000cps 107 base glue, 30 parts of 550cps methylphenyl silicone resin, 80 parts of modified base material, 8 parts of methyltributylacetonato silane, 4 parts of phenyltributylacetonato silane, 3 parts of N-βaminoethylγ-aminopropyltriethoxysilane and 0.2 parts of dibutyltin diacetate were stirred and dispersed under vacuum (-0.095MPa) for 90 minutes to obtain the product.

[0096] Example 9

[0097] The heat-insulating room temperature vulcanized silicone rubber of this embodiment includes the following preparation raw materials (by weight) and steps:

[0098] 1. Preparation of modified base material

[0099] 100 parts of 350cps dehydrated dimethyl silicone oil (120℃ vacuum dehydration for 2h), 100 parts of 2 / g nano titanium oxide and 3 parts of triphenylmethane triisocyanate were kneaded under vacuum conditions (-0.095MPa) for 30 minutes, then heated to 70°C and stirred under vacuum (-0.095MPa) for 60 minutes. The vacuum was maintained and the temperature was lowered to 47°C. The material had a distinct granular feel and was ground four times to obtain a modified base material.

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

[0101] Stir and disperse 60 parts of 10000cps 107 base glue, 40 parts of 50000cps 107 base glue, 30 parts of 550cps methylphenyl silicone resin, 80 parts of modified base material, 8 parts of methyltributylacetonato silane, 4 parts of phenyltributylacetonato silane, 3 parts of N-βaminoethylγ-aminopropyltriethoxysilane and 0.15 parts of dibutyltin diacetate under vacuum (-0.095MPa) for 90 minutes to obtain.

[0102] Example 10

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

[0104] 1. Preparation of modified base material

[0105] 100 parts of 350cps dehydrated dimethyl silicone oil (120℃ vacuum dehydration for 2h), 100 parts of 2 / g nano zinc oxide and 3 parts of triphenylmethane triisocyanate were kneaded under vacuum conditions (-0.095MPa) for 30 minutes, then heated to 70°C and stirred under vacuum (-0.095MPa) for 60 minutes. The vacuum was maintained and the temperature was lowered to 49°C, the material was discharged, and then ground three times to obtain a modified base material.

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

[0107] 80 parts of 10000cps 107 base glue, 20 parts of 50000cps 107 base glue, 30 parts of 550cps methylphenyl silicone resin, 80 parts of modified base material, 8 parts of methyltributylacetonato silane, 4 parts of phenyltributylacetonato silane, 3 parts of N-βaminoethylγ-aminopropyltriethoxysilane and 0.15 parts of dibutyltin diacetate were stirred and dispersed under vacuum (-0.095MPa) for 90 minutes to obtain the product.

[0108] Comparative Example 1

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

[0110] 60 parts of 10000cps 107 base glue, 40 parts of 50000cps 107 base glue, 30 parts of 550cps methylphenyl silicone resin, 40 parts of 350cps dehydrated dimethyl silicone oil (120℃ vacuum dehydration for 2h), 40 parts of 200m 2 / g titanium oxide, 8 parts of methyltributylacetonato silane, 4 parts of phenyltributylacetonato silane, 3 parts of N-βaminoethylγ-aminopropyltriethoxysilane and 0.15 parts of dibutyltin diacetate were stirred and dispersed under vacuum (-0.095MPa) for 90 minutes to obtain.

[0111] Comparative Example 2

[0112] The room temperature vulcanized silicone rubber of this comparative example comprises the following preparation raw materials (by weight) and steps:

[0113] 1. Preparation of modified base material

[0114] 100 parts of 350cps dehydrated dimethyl silicone oil (120℃ vacuum dehydration for 2h), 100 parts of 2 / g nano calcium carbonate and 3 parts triphenylmethane triisocyanate were kneaded under vacuum conditions (-0.095MPa) for 30 minutes, then heated to 70°C and stirred under vacuum (-0.095MPa) for 60 minutes. The vacuum was maintained and the temperature was lowered to 48°C, the material was discharged, and then ground three times to obtain a modified base material.

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

[0116] Stir and disperse 60 parts of 10000cps 107 base glue, 40 parts of 50000cps 107 base glue, 30 parts of 550cps methylphenyl silicone resin, 80 parts of modified base material, 8 parts of methyltributylacetonato silane, 4 parts of phenyltributylacetonato silane, 3 parts of N-βaminoethylγ-aminopropyltriethoxysilane and 0.15 parts of dibutyltin diacetate under vacuum for 90 minutes to obtain the product.

[0117] Comparative Example 3

[0118] The room temperature vulcanized silicone rubber of this comparative example comprises the following preparation raw materials (by weight) and steps:

[0119] 60 parts of 10000cps 107 base glue, 40 parts of 50000cps 107 base glue, 30 parts of 550cps methylphenyl silicone resin, 40 parts of 350cps dehydrated dimethyl silicone oil (120℃ vacuum dehydration for 2h), 40 parts of aerogel (bulk density 60~120kg / m 3), 8 parts of methyl tributylacetonato silane, 4 parts of phenyl tributylacetonato silane, 3 parts of N-β-aminoethyl γ-aminopropyl triethoxysilane and 0.15 parts of dibutyltin diacetate were stirred and dispersed under vacuum (-0.095MPa) for 90 minutes to obtain silicone rubber.

[0120] Comparative Example 4

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

[0122] 60 parts of 10000cps 107 base glue, 40 parts of 50000cps 107 base glue, 30 parts of methylphenyl silicone resin, 40 parts of 350cps dehydrated dimethyl silicone oil (120℃ vacuum dehydration for 2h), 20 parts of titanium oxide, 20 parts of aerogel (bulk density 60~120kg / m 3 ), 8 parts of methyl tributylacetonato silane, 4 parts of phenyl tributylacetonato silane, 3 parts of N-β-aminoethyl γ-aminopropyl triethoxysilane and 0.15 parts of dibutyltin diacetate were stirred and dispersed under vacuum (-0.095MPa) for 90 minutes to obtain silicone rubber.

[0123] Comparative Example 5

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

[0125] 1. Preparation of modified base material

[0126] 100 parts of 350cps dimethyl silicone oil (120℃ vacuum dehydration for 2h), 50 parts of 2 / g titanium oxide, 50 parts aerogel (bulk density 60~120kg / m 3 ) and 3 parts of triphenylmethane triisocyanate were kneaded under vacuum conditions (-0.095 MPa) for 30 minutes, then heated to 70°C and stirred under vacuum (-0.095 MPa) for 60 minutes. The vacuum was maintained and the temperature was lowered to 48°C, the material was discharged, and then ground three times to obtain a modified base material.

[0127] 2. Preparation of silicone rubber

[0128] Stir and disperse 60 parts of 10000cps 107 base glue, 40 parts of 50000cps 107 base glue, 30 parts of 550cps methylphenyl silicone resin, 80 parts of modified base material, 8 parts of methyltributylacetonato silane, 4 parts of phenyltributylacetonato silane, 3 parts of N-βaminoethylγ-aminopropyltriethoxysilane and 0.15 parts of dibutyltin diacetate under vacuum (-0.095MPa) for 90 minutes to obtain.

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

[0130] 1. Surface drying 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: Soak the cured silicone rubber in clean water for 168 hours, weigh its weight before soaking (m1), and its weight after removing the water droplets on the surface with an absorbent paper towel (m2). There are 6 specimens, and the results are averaged. Calculate the water absorption rate W of the silicone rubber according to formula (1).

[0135] W=(m2-m1) / m1×100% (1)

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

[0137] Table 1 Comparison of properties of silicone rubber prepared in various embodiments and comparative examples

[0138] Surface drying time / min Tensile strength / MPa Elongation at break / % Thermal conductivity / W / (mk) 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, as the amount of silicone resin in the raw material increases, the mechanical properties of the prepared silicone rubber will be enhanced, but its curing speed will slow down. After the addition amount exceeds 30 parts, the silicone rubber will be difficult to cure, which will not be easy to construct (Examples 1, 2, and 4). In Example 2 and Example 3, base materials modified with different diisocyanates are used, and the overall performance of the silicone rubber prepared is similar, which shows that the modification effects of different diisocyanates are relatively close; in Example 5 and Example 9, base materials modified with diisocyanate and triisocyanate are used respectively, and the thermal conductivity of the silicone rubber prepared with the base material modified with triisocyanate is lower, indicating that the modification effect of triisocyanate is better than that of diisocyanate. Comparing the thermal conductivity of the silicone rubber of Examples 3, 5, and 6, it can be found that as the amount of the modified base material increases, the thermal conductivity of the prepared silicone rubber decreases, indicating that the thermal insulation performance is enhanced, and the water absorption rate of the silicone rubber is also strengthened, indicating that the gaps in the silicone rubber are more, and therefore, more water vapor can be absorbed and accommodated. As the amount of modified base material increases, the mechanical properties of silicone rubber will decrease, which may be because a large number of pore structures will affect the compactness of silicone rubber. Compared with the modified base material added in an amount of 80 parts, when the modified base material is added in an amount of 100 parts, the thermal conductivity is only slightly reduced, and the heat-increasing performance of silicone rubber is not significantly increased. Therefore, considering the thermal insulation performance and mechanical properties, the effect is best when the modified base material is added in an amount of 80 parts. Comparing the performance of silicone rubber in Examples 7, 8 and 9, it is found that as the amount of modifier triisocyanate increases, the thermal conductivity of silicone rubber will decrease, indicating that the thermal insulation performance of silicone rubber is better. When the amount of modifier added is too much, it is easy to cause the appearance of the modified base material to be poor, affecting the mechanical properties of silicone rubber. Considering comprehensively, the optimal amount of modifier added is 3 parts. In summary, the heat-insulating room temperature vulcanized silicone rubber optimized by the present invention has good thermal insulation performance and good mechanical properties. Among them, Example 9 has the best comprehensive performance.

[0140] Compared with Example 9, Comparative Example 1 uses an unmodified base material (including dimethyl silicone oil and nano-titanium oxide), and its thermal conductivity is significantly increased and its water absorption is significantly decreased, indicating that the base material obtained by modifying nano-titanium oxide can be added to the silicone rubber system to increase its porosity and thus improve its thermal insulation performance.

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

[0142] The thermal insulation material used in Comparative Example 3 is aerogel, and the thermal conductivity of the silicone rubber prepared therefrom is greater than that of Example 9, indicating that the silicone rubber prepared using the modified base material of the present invention has superior thermal insulation performance and lower cost.

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

[0144] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0145] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A modified base material, characterized in that: The invention is prepared from dimethyl silicone oil, metal oxide and polyisocyanate in a weight ratio of 100:95-105:0.5-5.

2. The modified base material according to claim 1, characterized in that: The weight ratio of the dimethyl silicone oil, the metal oxide and the polyisocyanate is 100:98-102:0.5-3, preferably 100:99-101:1-3, and more preferably 100:100:2-3.

3. The modified base material according to claim 1, characterized in that: The metal oxide is nano titanium oxide or nano zinc oxide; And / or, the polyisocyanate is one or more of diphenylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, and triphenylmethane triisocyanate; preferably triphenylmethane triisocyanate.

4. The modified base material according to any one of claims 1 to 3, characterized in that: The specific surface area of ​​the nano titanium oxide or nano zinc oxide is 100 m 2 / g~300m 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 silicone oil that has been dehydrated, and the dehydration conditions are vacuum dehydration at 115° C. to 125° C. for 1.5 h to 2.5 h.

5. A method for preparing the modified base material according to any one of claims 1 to 4, characterized in that: The following steps are involved: Mix dimethyl silicone oil, metal oxide and polyisocyanate, stir under vacuum for 30-60 minutes, heat to 60-100°C, continue to stir under vacuum for 60-90 minutes, cool down, discharge and grind to obtain the product.

6. The method for preparing the modified base material according to claim 5, characterized in that: The vacuum degree of the vacuum is -0.09MPa to -0.1MPa.

7. A heat-insulating room temperature vulcanized silicone rubber, characterized in that: It is prepared from the following raw materials in parts by weight: 100 parts of α,ω-dihydroxy polydimethylsiloxane 8. The heat-insulating room temperature vulcanized silicone rubber according to claim 7, characterized in that: It is prepared from the following raw materials in parts by weight:

9. The heat-insulating room temperature vulcanized silicone rubber according to claim 7 or 8, characterized in that: The viscosity of the α,ω-dihydroxy polydimethylsiloxane at 25° C. is 100 cps to 100,000 cps; preferably 1,000 cps to 50,000 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 cross-linking agent is one or more of methyl triacetone oxime silane, methyl tributylacetonate oxime silane, propyl tributylacetonate oxime silane, phenyl tributylacetonate oxime silane, tetrabutyl ketone oxime silane, methyl tris(methyl isobutyl ketone oxime) silane, tetra(methyl isobutyl ketone oxime) silane, vinyl triacetone oxime silane, vinyl tributylacetonate oxime silane, vinyl tris(methyl isobutyl ketone oxime) silane; And / or, the coupling agent is one or more of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β-aminoethylγ-aminopropyltrimethoxysilane, N-β-aminoethylγ-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, 3-isocyanatepropyltrimethoxysilane, epoxypropyltriethoxysilane, and mercaptopropyltrimethoxysilane; And / or, the catalyst is one or more of dibutyltin dilaurate, dibutyltin diacetate, dioctyltin dilaurate, stannous octoate, and tin dibutyl acetylacetonate.

10. A method for preparing the heat-insulating room temperature vulcanized silicone rubber according to any one of claims 7 to 9, characterized in that: The following steps are involved: Under vacuum conditions, α,ω-dihydroxypolydimethylsiloxane, silicone resin, modified base material, crosslinking agent, coupling agent and catalyst are stirred for 60 to 120 minutes to obtain the product.

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