One-component dealcoholized room temperature vulcanized silicone rubber and preparation method thereof

Abstract

The application provides a single-component dealcoholized room-temperature vulcanized silicone rubber and a preparation method thereof. The single-component dealcoholized room-temperature vulcanized silicone rubber is prepared from raw materials including the following components by weight: alkoxyl-terminated polydimethylsiloxane 100 parts, organic titanate catalyst 0.1-5 parts, diluent 10-20 parts, inorganic filler 100-150 parts, alcohol type crosslinking agent 0.5-5 parts and silane coupling agent 0.1-0.5 parts; wherein the organic titanate catalyst is a tetraalkoxy titanate catalyst. The alkoxyl-terminated polydimethylsiloxane is used in combination with the tetraalkoxy titanate catalyst, so that the viscosity peak in the production process can be effectively avoided, the storage stability is improved, the surface drying time of the single-component dealcoholized room-temperature vulcanized silicone rubber can be greatly prolonged, the operation is simple, and the continuous process in the industrial production process can be met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of silicone rubber, more particularly to a single-component dealcoholized room temperature vulcanized silicone rubber and a preparation method thereof. BACKGROUND

[0002] Silicone rubber has excellent weather resistance, ultraviolet resistance, high and low temperature resistance and electrical insulation, and can be widely used in the fields of building, electronics and electrical appliances, automobiles, new energy and the like. Room temperature vulcanized silicone rubber can be divided into dealcoholized type, deoxime type, deacetone type, deamide type and deacid type according to the small molecules released during curing. Among them, the dealcoholized room temperature vulcanized silicone rubber has been widely used in many fields, such as printed circuit board coating, bonding and fixing of electronic and electrical appliance parts, automobile, LED lamp assembly, sealing of doors and windows, bonding and sealing of mirrors or handicrafts, and has very promising development prospects.

[0003] The traditional dealcoholized silicone rubber is generally prepared by using 107 silicone rubber as base glue, and by adding fillers, cross-linking agents, catalysts, coupling agents and plasticizers. Since organic tin is used as the catalyst, single alkoxy polymer without cross-linking activity is easily generated, and the storage stability is poor. If titanium ester is used as the catalyst, the viscosity peak phenomenon will occur due to the reaction between the titanium ester and the terminal hydroxyl group of the 107 silicone rubber to form a false cross-linking state, which seriously affects the production efficiency. SUMMARY

[0004] In order to overcome the problems of viscosity peak, difficulty in production, fast surface drying, difficulty in construction operation and modification of the single-component dealcoholized glue in the prior art, the present application provides a single-component dealcoholized room temperature vulcanized silicone rubber with low viscosity, long surface drying time and storage resistance, and a preparation method thereof.

[0005] The single-component dealcoholized room temperature vulcanized silicone rubber provided by the present application is prepared from raw materials including the following components by weight: alkoxy-terminated polydimethylsiloxane 100 parts, organic titanate catalyst 0.1-5 parts, diluent 10-20 parts, inorganic filler 100-150 parts, alcohol type cross-linking agent 0.5-5 parts and silane coupling agent 0.1-0.5 parts; wherein the organic titanate catalyst is a tetraalkoxy titanate catalyst.

[0006] The alkoxy-terminated polydimethylsiloxane is used instead of α, ω-dihydroxy polydimethylsiloxane, and the tetraalkoxy titanate is used as the catalyst at the same time, which can effectively avoid the viscosity peak in the production process, improve the storage stability of the finished product, greatly prolong the surface drying time of the single-component dealcoholized room temperature vulcanized silicone rubber, and is simple to operate, and can meet the continuous process in the industrial production process.

[0007] In a preferred embodiment of the present application, the tetraalkoxy titanate catalyst is one or more of tetraethyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, tetra-t-butyl titanate.

[0008] In a preferred embodiment of the present application, the viscosity of the alkoxyl-terminated polydimethylsiloxane (at 25°C, the viscosity herein refers to the viscosity value at 25°C if not otherwise specified) is in the range of 100-500000 mPa·s, preferably 5000-100000 mPa·s. In a preferred embodiment of the present application, the alkoxyl-terminated polydimethylsiloxane can be preferably methoxyl-terminated polydimethylsiloxane, and further can be trimethoxyl-terminated polydimethylsiloxane.

[0009] In a preferred embodiment of the present application, the diluent is one or more of dimethyl silicone oil, white oil, aspartate, caprolactone acrylate. Among them, the viscosity of the dimethyl silicone oil is preferably in the range of 100-500 mPa·s.

[0010] In a preferred embodiment of the present application, the inorganic filler is at least one or more of fumed white carbon black, light or heavy calcium carbonate, alumina, silicon powder, white corundum, preferably light calcium carbonate and / or heavy calcium carbonate. When the inorganic filler is light calcium carbonate and heavy calcium carbonate, the weight ratio of light calcium carbonate to heavy calcium carbonate is preferably (2-10):1.

[0011] In a preferred embodiment of the present application, the alcohol type crosslinking agent is at least one or more of methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, propyltrimethoxysilane.

[0012] In a preferred embodiment of the present application, the silane coupling agent is one or more of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, N-β-aminoethyl-γ-aminopropyltriethoxysilane, bisamino silane oligomer.

[0013] In one preferred embodiment of the present application, the single-component dealcoholized room temperature vulcanized silicone rubber is prepared from raw materials comprising 100 parts of trimethoxyl terminated polydimethylsiloxane, 0.1-5 parts of tetra-n-butyl titanate, 10-20 parts of dimethyl silicone oil, 100-150 parts of inorganic filler, 0.5-5 parts of alcohol type crosslinking agent and 0.1-0.5 parts of silane coupling agent; wherein the viscosity of the trimethoxyl terminated polydimethylsiloxane is 10000-100000 mPa·s, the viscosity of the dimethyl silicone oil is 100-500 mPa·s, the inorganic filler is light calcium carbonate and heavy calcium carbonate with a mass ratio of (5-10):1, the alcohol type crosslinking agent is methyltrimethoxysilane, and the silane coupling agent is γ-aminopropyl triethoxysilane. In this embodiment, the single-component dealcoholized room temperature vulcanized silicone rubber has more excellent elongation at break while meeting other performance requirements.

[0014] In one preferred embodiment of the present application, the single-component dealcoholized room temperature vulcanized silicone rubber is prepared from raw materials comprising 100 parts of trimethoxyl terminated polydimethylsiloxane, 0.1-5 parts of tetra-n-butyl titanate, 10-20 parts of dimethyl silicone oil, 100-150 parts of inorganic filler, 0.5-5 parts of alcohol type crosslinking agent and 0.1-0.5 parts of silane coupling agent; wherein the viscosity of the trimethoxyl terminated polydimethylsiloxane is 10000-100000 mPa·s, the viscosity of the dimethyl silicone oil is 100-500 mPa·s, the inorganic filler is light calcium carbonate and heavy calcium carbonate with a mass ratio of (5-10):1, the alcohol type crosslinking agent is methyltrimethoxysilane, and the silane coupling agent is γ-aminopropyl triethoxysilane. In this embodiment, the single-component dealcoholized room temperature vulcanized silicone rubber has more excellent elongation at break while meeting other performance requirements.

[0015] In one preferred embodiment of the present application, the single-component dealcoholized room temperature vulcanized silicone rubber is prepared from raw materials comprising 100 parts of trimethoxyl terminated polydimethylsiloxane, 0.1-5 parts of tetra-n-butyl titanate, 10-20 parts of dimethyl silicone oil, 100-150 parts of inorganic filler, 0.5-5 parts of alcohol type crosslinking agent and 0.1-0.5 parts of silane coupling agent; wherein the viscosity of the trimethoxyl terminated polydimethylsiloxane is 10000-100000 mPa·s, the viscosity of the dimethyl silicone oil is 100-500 mPa·s, the inorganic filler is light calcium carbonate and heavy calcium carbonate with a mass ratio of (5-10):1, the alcohol type crosslinking agent is methyltrimethoxysilane, and the silane coupling agent is γ-aminopropyl triethoxysilane. In this embodiment, the single-component dealcoholized room temperature vulcanized silicone rubber has more excellent elongation at break while meeting other performance requirements.

[0016] In a preferred embodiment of the present application, the single-component dealcoholized room temperature vulcanized silicone rubber is prepared from raw materials including 100 parts of trimethoxyl terminated polydimethylsiloxane, 2-5 parts of tetraisopropyl titanate, 10-20 parts of dimethyl silicone oil, 100-150 parts of inorganic filler, 0.5-5 parts of alcohol type crosslinking agent and 0.1-0.5 parts of silane coupling agent, by weight; wherein the viscosity of the trimethoxyl terminated polydimethylsiloxane is 20,000-100,000 mPa·s, the viscosity of the dimethyl silicone oil is 100-500 mPa·s, the inorganic filler is light calcium carbonate and heavy calcium carbonate with a mass ratio of (2-5):1, the alcohol type crosslinking agent is methyltrimethoxysilane, and the silane coupling agent is γ-aminopropyltriethoxysilane. In this embodiment, the single-component dealcoholized room temperature vulcanized silicone rubber has better adhesion to concrete while maintaining other properties, and is more suitable for use in the construction field.

[0017] In a preferred embodiment of the present application, the single-component dealcoholized room temperature vulcanized silicone rubber is prepared from raw materials including alkoxyl terminated polydimethylsiloxane, tetraalkoxyl titanate catalyst, diluent, inorganic filler, alcohol type crosslinking agent and silane coupling agent, by weight.

[0018] In the present application, the weight parts can be μg, mg, g, kg and other weight units known in the art, and can also be multiples thereof, such as 1 / 10, 1 / 100, 10 times, 100 times, etc. In the present application, the amount of each substance is determined according to the above-mentioned proportions, and the total mass parts of the substances are not necessarily 100 weight parts, and can be less than 100 mass parts or greater than 100 mass parts, as long as they are within the above-mentioned proportion values.

[0019] Another object of the present application is to provide a preparation method of the single-component dealcoholized room temperature vulcanized silicone rubber, which comprises the following steps:

[0020] (1) The alkoxyl terminated polydimethylsiloxane, diluent and inorganic filler are added to a kneader, kneaded uniformly, heated to 75±5°C, vacuumized to above -0.095 MPa, kneaded for 30 minutes to 1 hour, cooled to room temperature in a closed state, and a uniformly dispersed base rubber is obtained;

[0021] (2) The alcohol type crosslinking agent, silane coupling agent and titanate catalyst are mixed at room temperature to obtain a premix, and the mixing time is 10-20 minutes;

[0022] (3) Finally, the base rubber and the premix are added to a planetary mixer, stirred at high speed under vacuum for 30-60 minutes, discharged after vacuum removal, and packaged to obtain the single-component dealcoholized room temperature vulcanized silicone rubber.

[0023] Another object of the present application is to provide the application of the single-component dealcoholized room temperature vulcanized silicone rubber in the construction field.

[0024] The present application has the following advantages:

[0025] The single-component dealcoholized room temperature vulcanized silicone rubber provided by the present application has a long surface drying time. The use of alkoxyl-terminated polydimethylsiloxane and tetraalkoxyl titanate catalyst in combination with other ingredients not only ensures the curing speed of the obtained single-component dealcoholized room temperature vulcanized silicone rubber, but also prolongs the open time, facilitating construction operation and modification. DETAILED DESCRIPTION

[0026] The specific embodiments of the present application will be further described in detail below in combination with examples. The following examples are used to illustrate the present application, but not to limit the scope of the present application.

[0027] Example 1

[0028] The present embodiment provides a single-component dealcoholized room temperature vulcanized silicone rubber, and the preparation method comprises the following steps: taking 100 parts of trimethoxyl-terminated polydimethylsiloxane with a viscosity of 20000 mPa·s, 15 parts of dimethyl silicone oil with a viscosity of 100 mPa·s, 95 parts of light calcium carbonate, and 20 parts of heavy calcium carbonate, mixing the trimethoxyl-terminated polydimethylsiloxane, dimethyl silicone oil, light calcium carbonate, and heavy calcium carbonate uniformly in a kneader, heating to 75℃, vacuumizing to above-0.095 MPa, high-speed kneading for 30 minutes, and closed cooling to room temperature to obtain a uniformly dispersed base glue, and transferring the base glue to a planetary stirrer.

[0029] The trimethoxyl-terminated polydimethylsiloxane, dimethyl silicone oil, light calcium carbonate, and heavy calcium carbonate are mixed uniformly in a kneader, heated to 75℃, vacuumized to above-0.095 MPa, high-speed kneaded for 30 minutes, and closed cooled to room temperature to obtain a uniformly dispersed base glue, and transferred to a planetary stirrer; 2.5 parts of methyltrimethoxysilane, 0.5 parts of vinyltrimethoxysilane, 0.15 parts of γ-aminopropyltrimethoxysilane, and 0.8 parts of tetra-n-butyl titanate are pre-mixed at room temperature for 15 minutes and then added to the base glue, vacuumized to-0.09 MPa, stirred at a speed of 800 rpm for 30 minutes, and sealed after discharging.

[0030] Example 2

[0031] The present embodiment provides a single-component dealcoholized room temperature vulcanized silicone rubber, and the preparation method comprises the following steps: taking 100 parts of trimethoxyl-terminated polydimethylsiloxane with a viscosity of 20000 mPa·s, 15 parts of dimethyl silicone oil with a viscosity of 100 mPa·s, 95 parts of light calcium carbonate, and 20 parts of heavy calcium carbonate, mixing the trimethoxyl-terminated polydimethylsiloxane, dimethyl silicone oil, light calcium carbonate, and heavy calcium carbonate uniformly in a kneader, heating to 75℃, vacuumizing to above-0.095 MPa, high-speed kneading for 30 minutes, and closed cooling to room temperature to obtain a uniformly dispersed base glue, and transferring the base glue to a planetary stirrer.

[0032] The 10000 mPa-s trimethoxyl terminated polydimethylsiloxane 100 parts, the viscosity of 500 mPa-s dimethyl silicone oil 18 parts, light calcium carbonate 110 parts, heavy calcium carbonate 15 parts are weighed, the trimethoxyl terminated polydimethylsiloxane, dimethyl silicone oil, light calcium carbonate and heavy calcium carbonate are added into the kneader and uniformly mixed, heated to 80 DEG C, vacuumized to-0.095 MPa or more, high-speed kneaded for 30 minutes, closed cooling to room temperature, to get the uniformly dispersed base glue, transfer to the planetary mixer; 2.9 parts of methyl trimethoxysilane, 0.1 parts of γ-aminopropyl triethoxysilane, 0.83 parts of titanium tetrabutoxide are premixed at room temperature for 20 minutes and then added into the base glue, vacuumized to-0.09 MPa, stirring speed 800 rpm, stirring for 45 minutes, sealed after discharging.

[0033] Example 3

[0034] The present embodiment provides a single-component dealcoholized room temperature vulcanized silicone rubber, and the preparation method comprises the following steps: taking weight parts,

[0035] The 20000 mPa-s trimethoxyl terminated polydimethylsiloxane 70 parts, 5000 mPa-s trimethoxyl terminated polydimethylsiloxane 30 parts, No. 3 white oil 15 parts, light calcium carbonate 80 parts, heavy calcium carbonate 40 parts are weighed, the trimethoxyl terminated polydimethylsiloxane, No. 3 white oil, light calcium carbonate and heavy calcium carbonate are added into the kneader and uniformly mixed, heated to 70 DEG C, vacuumized to-0.095 MPa or more, high-speed kneaded for 30 minutes, closed cooling to room temperature, to get the uniformly dispersed base glue, transfer to the planetary mixer; 2 parts of methyl triethoxysilane, 1 part of vinyl triethoxysilane, 1 part of γ-aminopropyl triethoxysilane, 1.2 parts of titanium tetrabutoxide are premixed at room temperature for 20 minutes and then added into the base glue, vacuumized to-0.09 MPa, stirring speed 800 rpm, stirring for 60 minutes, sealed after discharging.

[0036] Example 4

[0037] The present embodiment provides a single-component dealcoholized room temperature vulcanized silicone rubber, and the preparation method comprises the following steps: taking weight parts,

[0038] Weigh 100 parts of 20000 mPa-s trimethoxyl terminated polydimethylsiloxane, 20 parts of 150 mPa-s dimethyl silicone oil, 90 parts of light calcium carbonate, 25 parts of heavy calcium carbonate, mix the trimethoxyl terminated polydimethylsiloxane, dimethyl silicone oil, light calcium carbonate and heavy calcium carbonate in a kneader, mix uniformly, knead for 30 minutes, heat to 80℃, vacuum above -0.095 MPa, high speed knead for 30 minutes, close cooling to room temperature, get uniformly dispersed base glue, transfer to planetary mixer; add 4 parts of methyl trimethoxysilane, 0.5 parts of γ-aminopropyl triethoxysilane, 3 parts of titanium acid tetraisopropylate in room temperature, pre-mix for 20 minutes, then add to the base glue, vacuum -0.09 MPa, stirring speed 800 rpm, stir for 50 minutes, seal after discharging.

[0039] Comparative Example 1

[0040] This comparative example provides a single-component dealcoholization type room temperature vulcanized silicone rubber, the preparation method comprises the following steps: in parts by weight,

[0041] Weigh 100 parts of 20000 mPa-s trimethoxyl terminated polydimethylsiloxane, 20 parts of 150 mPa-s dimethyl silicone oil, 90 parts of light calcium carbonate, 25 parts of heavy calcium carbonate, mix the trimethoxyl terminated polydimethylsiloxane, dimethyl silicone oil, light calcium carbonate and heavy calcium carbonate in a kneader, mix uniformly, knead for 30 minutes, heat to 80℃, vacuum above -0.095 MPa, high speed knead for 30 minutes, close cooling to room temperature, get uniformly dispersed base glue, transfer to planetary mixer; add 4 parts of methyl trimethoxysilane, 0.5 parts of γ-aminopropyl triethoxysilane, 3 parts of titanium acid tetraisopropylate in room temperature, pre-mix for 20 minutes, then add to the base glue, vacuum -0.09 MPa, stirring speed 800 rpm, stir for 50 minutes, seal after discharging.

[0042] Use dynamic viscosity instrument, No. 52 rotor, test the viscosity of dealcoholization glue under the condition of 25℃, test the dry time under the condition of 23℃ / 50%, deep curing, test the tensile property after the room temperature sample is cured for 7 days according to GB / T528-2009. The test performance of examples 1-4 and comparative example 1 is shown in table 1 and table 2.

[0043] Table 1: product performance result table

[0044]

[0045] Table 2: adhesion performance test results

[0046]

[0047] Note: 2 pieces of each substrate were tested, the test environment conditions were 23±2℃, 50±5% relative humidity, AF means adhesive failure, CF means cohesive failure.

[0048] As can be seen from Tables 1 and 2, the viscosity of the adhesives of Examples 1-4 is significantly lower than that of Comparative Example 1, and the adhesives are easier to produce and apply in practice; the surface drying time of the alcohol-removing adhesives can be greatly prolonged, while the internal curing speed does not change significantly, which is convenient for modification operation after practical adhesive application; the hardness, tensile properties and substrate adhesion properties are close to those of Comparative Example 1.

[0049] Finally, the method of the present application is only a preferred embodiment, and is not intended to limit the protection scope of the present application. 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 one-component dealcoholized room temperature vulcanizing silicone rubber, characterized by, The raw materials include trimethoxyl terminated polydimethylsiloxane 100 parts, tetraisopropyl titanate 2-5 parts, dimethyl silicone oil 10-20 parts, inorganic filler 100-150 parts, alcohol type crosslinking agent 0.5-5 parts and silane coupling agent 0.1-0.5 parts by weight; wherein the viscosity of the trimethoxyl terminated polydimethylsiloxane is 20000-100000 mPa·s, the viscosity of the dimethyl silicone oil is 100-500 mPa·s, the inorganic filler is light calcium carbonate and heavy calcium carbonate with a mass ratio of (2-5):1, the alcohol type crosslinking agent is methyl trimethoxysilane, and the silane coupling agent is γ-aminopropyl triethoxysilane.

2. The one-part dealcoholized room temperature vulcanizing silicone rubber according to claim 1, characterized by, The raw materials include trimethoxyl terminated polydimethylsiloxane, tetraisopropyl titanate, dimethyl silicone oil, inorganic filler, alcohol type crosslinking agent and silane coupling agent.

3. The process for the preparation of one-component dealcoholized room temperature vulcanizing silicone rubber according to claim 1 or 2, characterized in that, The method includes the following steps: (1) trimethoxyl terminated polydimethylsiloxane, dimethyl silicone oil and inorganic filler are added into a kneader, kneaded uniformly, heated to 75±5℃, vacuumized to above -0.095MPa, high-speed kneaded for 30 minutes-1 hour, closed cooling to room temperature, to obtain uniformly dispersed base glue; (2) alcohol type crosslinking agent, silane coupling agent and tetraisopropyl titanate are mixed at room temperature to obtain a premix, the mixing time is 10-20 minutes; (3) finally, the base glue and the premix are added into a planetary stirrer, high-speed stirred for 30-60 minutes under vacuum, discharged and packaged after vacuum removal.

4. The application of the one-component dealcoholized room temperature vulcanized silicone rubber in claim 1 or 2 in the field of building.

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