CN113444369B

CN113444369B - Bi-component liquid silicone rubber and preparation method thereof

Info

Publication number: CN113444369B
Application number: CN202110717085.5A
Authority: CN
Inventors: 徐旋; 卢杭; 陈丽云; 金政御; 李露
Original assignee: Zhejiang Xinan Chemical Industrial Group Co Ltd
Current assignee: Zhejiang Xinan Chemical Industrial Group Co Ltd
Priority date: 2021-06-28
Filing date: 2021-06-28
Publication date: 2022-09-27
Anticipated expiration: 2041-06-28
Also published as: CN113444369A

Abstract

The invention belongs to the technical field of silicone rubber, and particularly relates to bi-component liquid silicone rubber and a preparation method thereof. The bi-component liquid silicone rubber provided by the invention comprises a component A and a component B; the component A comprises the following raw materials in parts by mass: 50-100 parts of base rubber, 5-15 parts of a hardness control agent, 20-50 parts of a filler, 5-15 parts of a structural control agent and 0.1-1 part of a catalyst; the component B comprises the following raw materials in parts by mass: 50-100 parts of base rubber, 5-15 parts of a hardness control agent, 20-50 parts of a filler, 20-40 parts of a cross-linking agent, 5-15 parts of a structural control agent and 0.01-1 part of an inhibitor. According to the invention, through the optimized design of the raw material formula of the liquid silicone rubber, the liquid silicone rubber material provided by the invention has excellent performances of low viscosity, low hardness, high strength, smooth hand feeling and the like, can better meet the use requirements in the field of medical health, and has a wide market prospect.

Description

Bi-component liquid silicone rubber and preparation method thereof

Technical Field

The invention belongs to the technical field of silicone rubber, and particularly relates to bi-component liquid silicone rubber and a preparation method thereof.

Background

Liquid silicone rubber is widely used as a care product and a medical health product in medical health because of its heat resistance, cold resistance, safety, good appearance (transparency), and good skin touch. In the field of health care products at present, on one hand, a user wants a liquid silicone rubber product to have better tensile strength and tearing strength, so that the liquid silicone rubber product is not easy to damage in the using process; meanwhile, the user wants the liquid silicone rubber product to have lower hardness and a dry and comfortable surface, so that the experience of patients in use is improved. Therefore, the development of a liquid silicone rubber with low viscosity, low hardness, high strength and smooth hand feeling can better meet the demand of the current market.

For achieving low viscosity of liquid silicone rubber, the existing technical means can be mainly divided into three categories: 1) adding a diluent to the rubber compound to meet the requirement of low viscosity, wherein the diluent comprises low-viscosity methyl silicone oil, white oil, toluene, n-hexane, n-heptane and the like; the diluent volatilizes in the vulcanization process, has larger smell and higher requirements on safety and environmental protection, and most of organic solvents have larger damage to human bodies, and partial solvents, such as toluene, belong to a class A chemical product and are strictly controlled. 2) A large amount of low-viscosity terminal vinyl silicone oil is adopted as a main polymer, and the purpose of reducing the overall viscosity is achieved by reducing the viscosity of the main silicone oil; however, in a conventional formula, the lower the viscosity of the terminal vinyl silicone oil is, the higher the vinyl content is, so that the crosslinking density of the product is too high, and finally the mechanical properties of the material are difficult to be considered, namely, the hardness is high, the elongation at break is low, and the material is generally brittle as a whole; 3) the filler with a relatively thick particle size is used, the conventional filler is fumed silica, but the fumed silica has an obvious thickening effect, so that the viscosity of the rubber material is relatively high; if the precipitated silica is used, although the thickening effect is low, the precipitated silica has poor reinforcing effect, and the mechanical properties of the material are poor under general conditions.

For achieving low hardness of liquid silicone rubber, which generally means hardness of shore 5A to 25A, the following three main prior art approaches are available: 1) adjusting the crosslinking density and the silicon-hydrogen ratio (H/Vi) in the rubber material; wherein the si-to-H ratio includes but is not limited to H/Vi of 1.5, 1.4, 1.3, 1.2, 1.1, 1.0, etc.; if the silicon-hydrogen ratio is too high, the crosslinking density is improved, the hardness of the rubber material is too high, and if the silicon-hydrogen ratio is too low, the rubber material is incompletely vulcanized, oil is produced, the hand feeling is sticky, the surface of the material is not dry and comfortable, and the like. 2) The reduction of the filler part in the rubber material has an obvious effect on the adjustment of the hardness by reducing the filler, such as white carbon black, in the rubber material, but the performance of the rubber material after vulcanization is deteriorated due to the reduction of the filler content. 3) Adding common hardness control agent, wherein the hardness control agent comprises low-viscosity methyl silicone oil, white oil, DMC and other solvents; the hardness control agent is added to effectively reduce the hardness of the vulcanized rubber, but the hardness control agent does not participate in the reaction, so that the vulcanized rubber still dissociates in the rubber, and the phenomena of oil seepage and stickiness can occur after long-term use; and if the sizing material added with the solvent is baked at high temperature, the solvent is volatilized, the hardness of the sizing material is obviously improved, and the shrinkage phenomenon of different degrees occurs.

For realizing high strength of liquid silicone rubber, generally, the liquid silicone rubber has good tensile strength, elongation and right-angle tear strength, and the prior art means are mainly as follows: 1) the filler part in the rubber material is improved, the reinforcing effect is improved, and the tensile strength and the tearing strength of the product are improved; 2) improving the quality of the filler, for example, selecting high-quality fumed silica as the filler; 3) polysiloxane with different composition structures is selected to participate in the crosslinking reaction, so that the crosslinking network structure of the rubber material is enriched, and the tensile strength and the tearing strength of the product are improved; 4) the reinforcing effect is further enhanced by treating the filler with a structuring agent, such as divinyltetramethylsilazane.

Although there are many reports on "low hardness", "low viscosity" and "high strength" in the prior art relating to liquid silicone rubber, it is also difficult to find out from the above description that the following contradiction points occur if the three properties of low viscosity, low hardness and high strength are satisfied at the same time: 1) the selection of the types of the fillers, namely, the strength can be improved by adding the fumed silica, but the viscosity can be improved at the same time, and the viscosity can be reduced by using the precipitated silica, but the performance can be reduced at the same time; 2) the selection of the amount of the filler can improve the performance of the product by increasing the amount of the filler, but correspondingly, the hardness and the viscosity can also obviously increase; 3) the addition of the hardness control agent and the viscosity control agent can effectively reduce the hardness and the viscosity, but the viscosity control agent and the hardness control agent do not participate in the reaction, so that a certain negative effect is generated on the formation of a cross-linked network in the silicone rubber, the physical properties of the product are influenced, and the strength of the product is reduced.

For example, in the patents currently referred to, in order to meet the requirement of "low viscosity", some patents have specifically added thereto methyl-, alkoxy-or epoxy-containing terminated linear polysiloxanes as viscosity control agents. The addition of the viscosity control agent has the defect that the silicone rubber can generate oil in the long-term use process, so that the use hand feeling of the silicone rubber product is influenced; in some patents, a relatively large amount of low-viscosity vinyl silicone oil is added to reduce the viscosity, and the method for reducing the viscosity has the defects that the crosslinking degree of the product is too high, the rubber material is brittle and the physical property is poor due to the addition of a large amount of low-viscosity vinyl silicone oil. In some of the patents, viscosity is controlled by adding an organic solvent, and the disadvantage of this method is that the organic solvent does not participate in the crosslinking reaction, and the rubber material becomes oily and sticky after long-term use, and if the rubber material added with the solvent is baked at high temperature, the solvent volatilizes, the hardness of the rubber material becomes high, and shrinkage of the rubber material occurs to different degrees.

For another example, some liquid silicone rubbers with low hardness have mechanical properties that are difficult to achieve at a high level because of their low hardness. In the prior patents, in order to reduce the hardness, methyl polysiloxane or organic group polysiloxane is added, but the defects of oil yielding and stickiness of the product exist; in some patents, vinyl polysiloxane and bismaleimide resin are used as main raw materials, and fillers such as tetramethyl thiuram disulfide, GRT fiber and nano clay are added, so that the product achieves higher performance by adding the high-performance fillers, but the hardness of the product is higher due to higher content of the fillers.

In conclusion, it is an urgent technical problem to be solved by those skilled in the art how to make a liquid silicone rubber material have low hardness, low viscosity, high strength and smooth hand feeling.

Disclosure of Invention

In view of the above, the present invention provides a two-component liquid silicone rubber and a preparation method thereof, and the liquid silicone rubber provided by the present invention has low hardness, low viscosity and high strength, has smooth hand feeling, and is very suitable for injection molding.

The invention provides a bi-component liquid silicone rubber, which comprises a component A and a component B;

the component A comprises the following raw materials in parts by mass: 50-100 parts of base rubber, 5-15 parts of a hardness control agent, 20-50 parts of a filler, 5-15 parts of a structural control agent and 0.1-1 part of a catalyst;

the component B comprises the following raw materials in parts by mass: 50-100 parts of base rubber, 5-15 parts of a hardness control agent, 20-50 parts of a filler, 20-40 parts of a cross-linking agent, 5-15 parts of a structural control agent and 0.01-1 part of an inhibitor;

in the component A and the component B, the base adhesive is vinyl-terminated silicone oil with the viscosity of 200-5000 mPa.s at 25 ℃;

in the component A and the component B, the hardness control agent is non-vinyl-terminated vinyl silicone oil with the viscosity of 100-2000 mPa.s at 25 ℃;

in the component A and the component B, the structural control agent is selected from a plurality of hexamethyldisilazane, divinyl tetramethyl silazane, diphenyl silanediol, hydroxyl silicone oil and vinyl hydroxyl silicone oil; the total content of divinyl tetramethyl silazane and vinyl hydroxyl silicone oil in the structural control agent is 10-25 wt%;

the cross-linking agent is a mixture of side chain hydrogen-containing silicone oil and terminal hydrogen-containing silicone oil; the content of the hydrogen-terminated silicone oil in the cross-linking agent is 60-90 wt%.

Preferably, the vinyl-terminated silicone oil has a vinyl content of 0.1 to 10 wt%.

Preferably, the vinyl content of the non-vinyl-terminated vinyl silicone oil is 0.1 to 10 wt%.

Preferably, the non-vinyl terminated vinyl silicone oil is a methyl terminated vinyl silicone oil.

Preferably, in the component A and the component B, the filler is selected from one or more of precipitated silica, fumed silica and vinyl silicone resin.

Preferably, the specific surface area of the precipitated white carbon black is 100-400 m ² /g。

Preferably, the specific surface area of the fumed silica is 100-200 m ² /g。

Preferably, the vinyl content of the vinyl silicone resin is 0.1 to 10 wt%.

Preferably, the hydrogen atom content of the crosslinking agent is 0.01 to 1 wt%.

Preferably, the catalyst is a platinum catalyst.

Preferably, the inhibitor is selected from one or more of 1-ethynyl-1-cyclohexanol, 2-methyl-3-butyn-2-ol, 3-methyl-1-ethynyl-3-ol and 3, 5-dimethyl-1-hexyn-3-ol.

Preferably, the raw materials of the component A and the component B both contain 0-5 parts of other auxiliary agents; the other auxiliary agent is water and/or an antibacterial agent.

The invention provides a preparation method of the bi-component liquid silicone rubber, which comprises the following steps:

A) kneading the base rubber, the hardness control agent, the filler, the structural control agent and the catalyst to obtain a component A of the liquid silicone rubber;

B) kneading the base rubber, the hardness control agent, the filler, the crosslinking agent, the structural control agent and the inhibitor to obtain a component B of the liquid silicone rubber;

there is no chronological restriction between step A) and step B).

Compared with the prior art, the invention provides a bi-component liquid silicone rubber and a preparation method thereof. The bi-component liquid silicone rubber provided by the invention comprises a component A and a component B; the component A comprises the following raw materials in parts by mass: 50-100 parts of base rubber, 5-15 parts of a hardness control agent, 20-50 parts of a filler, 5-15 parts of a structural control agent and 0.1-1 part of a catalyst; the component B comprises the following raw materials in parts by mass: 50-100 parts of base rubber, 5-15 parts of a hardness control agent, 20-50 parts of a filler, 20-40 parts of a cross-linking agent, 5-15 parts of a structural control agent and 0.01-1 part of an inhibitor; in the component A and the component B, the base adhesive is vinyl-terminated silicone oil with the viscosity of 200-5000 mPa.s at 25 ℃; in the component A and the component B, the hardness control agent is non-vinyl-terminated vinyl silicone oil with the viscosity of 100-2000 mPa.s at 25 ℃; in the component A and the component B, the structural control agent is selected from a plurality of hexamethyldisilazane, divinyltetramethylsilazane, diphenylsilanediol, hydroxyl silicone oil and vinyl hydroxyl silicone oil; the total content of divinyl tetramethyl silazane and vinyl hydroxyl silicone oil in the structural control agent is 10-25 wt%; the cross-linking agent is a mixture of side chain hydrogen-containing silicone oil and terminal hydrogen-containing silicone oil; the content of the hydrogen-terminated silicone oil in the cross-linking agent is 60-90 wt%. According to the invention, through the optimized design of the raw material formula of the liquid silicone rubber, the liquid silicone rubber material provided by the invention has excellent performances of low viscosity, low hardness, high strength, smooth hand feeling and the like, can better meet the use requirements in the field of medical health, and has a wide market prospect. The experimental results show that: after the two components of the liquid silicone rubber A, B are mixed according to the mass ratio of 1:1, the viscosity at 25 ℃ before curing can be as low as 4000-8500 mPa & s; after curing and forming, the hand feeling is smooth, the Shore hardness is less than 25A, the tearing strength can reach 6.5-15.2 KN/m according to the difference of hardness, the tensile strength can reach 2.5-6 MPa, and the elongation can reach 450-600%.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

the component B comprises the following raw materials in parts by mass: 50-100 parts of base rubber, 5-15 parts of a hardness control agent, 20-50 parts of a filler, 20-40 parts of a cross-linking agent, 5-15 parts of a structural control agent and 0.01-1 part of an inhibitor.

In the two-component liquid silicone rubber provided by the invention, in the component A and the component B, the base adhesive is vinyl-terminated silicone oil, the viscosity of the vinyl-terminated silicone oil at 25 ℃ is 200-5000 mPa.s, and specifically can be 200mPa.s, 250mPa.s, 300mPa.s, 350mPa.s, 400mPa.s, 450mPa.s, 500mPa.s, 550mPa.s, 600mPa.s, 700mPa.s, 800mPa.s, 900mPa.s, 1000mPa.s, 1500mPa.s, 2000mPa.s, 2500mPa.s, 3000mPa.s, 4000mPa.s or 5000 mPa.s; the vinyl-terminated silicone oil preferably has a vinyl content of 0.1 to 10wt%, more preferably 0.2 to 2wt%, and specifically may be 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1wt%, 1.1 wt%, 1.2 wt%, 1.3 wt%, 1.4 wt%, 1.5 wt%, 1.6 wt%, 1.7 wt%, 1.8 wt%, 1.9 wt%, or 2 wt%. In one embodiment provided by the present invention, the chemical structure of the vinyl-terminated silicone oil is represented by formula (I):

in the formula (I), Me represents a methyl group, Vi represents a vinyl group, and n represents a polymerization degree.

In the bi-component liquid silicone rubber provided by the invention, the content of the base rubber in the component A and the component B can be the same or different, and can be independently selected from 50-100 parts by mass, specifically 50 parts by mass, 55 parts by mass, 60 parts by mass, 65 parts by mass, 70 parts by mass, 75 parts by mass, 80 parts by mass, 85 parts by mass, 90 parts by mass, 95 parts by mass or 100 parts by mass.

In the bi-component liquid silicone rubber provided by the invention, in the component A and the component B, the hardness control agent is non-vinyl-terminated vinyl silicone oil; the viscosity of the non-vinyl-terminated vinyl silicone oil at 25 ℃ is 100-2000 mPa.s, specifically 100mPa.s, 200mPa.s, 300mPa.s, 400mPa.s, 500mPa.s, 600mPa.s, 700mPa.s, 800mPa.s, 900mPa.s, 1000mPa.s, 1100mPa.s, 1200mPa.s, 1300mPa.s, 1400mPa.s, 1500mPa.s, 1600mPa.s, 1700mPa.s, 1800mPa.s, 1900mPa.s or 2000 mPa.s; the vinyl content of the non-vinyl-terminated vinyl silicone oil is preferably 0.1 to 10wt%, more preferably 0.1 to 1wt%, and specifically may be 0.1wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, or 1 wt%. In one embodiment provided by the present invention, the non-vinyl terminated vinyl silicone oil is preferably a methyl terminated vinyl silicone oil, and the chemical structure of the methyl terminated vinyl silicone oil is preferably as shown in formula (II):

in the formula (II), Me represents a methyl group, Vi represents a vinyl group, and m and n represent a polymerization degree.

In the two-component liquid silicone rubber provided by the invention, the content of the hardness control agent in the component A and the component B can be the same or different, and is independently selected to be 5-15 parts by mass, specifically 5 parts by mass, 6 parts by mass, 7 parts by mass, 8 parts by mass, 9 parts by mass, 10 parts by mass, 11 parts by mass, 12 parts by mass, 13 parts by mass, 14 parts by mass or 15 parts by mass.

In the two-component liquid silicone rubber provided by the invention, in the component A and the component B, the filler is preferably one or more of precipitated white carbon black, gas-phase white carbon black and vinyl silicone resin; the specific surface area of the precipitated white carbon black is preferably 100-400 m ² A specific value of 100 m/g ² /g、120m ² /g、150m ² /g、170m ² /g、200m ² /g、230m ² /g、250m ² /g、270m ² /g、300m ² /g、320m ² /g、350m ² /g、380m ² G or 400m ² (ii)/g; the specific surface area of the fumed silica is preferably 100-200 m ² A specific value of 100 m/g ² /g、110m ² /g、120m ² /g、130m ² /g、140m ² /g、150m ² /g、160m ² /g、170m ² /g、180m ² /g、190m ² (ii)/g or 200m ² (iv) g; the viscosity of the vinyl silicon resin at 25 ℃ is preferably 5000-20000 mPa.s, and specifically can be 5000mPa.s, 6000mPa.s, 7000mPa.s, 8000mPa.s, 9000mPa.s, 10000mPa.s, 12000mPa.s, 15000mPa.s, 17000mPa.s or 20000mPa mPa.s; the vinyl content of the vinyl silicone resin is preferably 0.1 to 10wt%, and specifically may be 0.1wt%, 0.5 wt%, 1wt%, 2wt%, 3 wt%, 4 wt%, 5wt%, 6wt%, 7 wt%, 8 wt%, 9 wt%, or 10 wt%. In one embodiment provided by the present invention, the filler is preferably precipitated silica and vinyl silicone resin, and the mass ratio of the precipitated silica to the vinyl silicone resin is preferably2: (0.5 to 2), and more preferably 2: 1.

In the two-component liquid silicone rubber provided by the invention, the content of the filler in the component A and the component B can be the same or different, and is independently selected to be 20-50 parts by mass, specifically 20 parts by mass, 23 parts by mass, 25 parts by mass, 27 parts by mass, 30 parts by mass, 32 parts by mass, 35 parts by mass, 37 parts by mass, 40 parts by mass, 42 parts by mass, 45 parts by mass, 47 parts by mass or 50 parts by mass.

In the two-component liquid silicone rubber provided by the invention, in the component A and the component B, the structural control agent is selected from a plurality of hexamethyldisilazane, divinyltetramethylsilazane, diphenylsilanediol, hydroxysilicone oil and vinyl hydroxysilicone oil, preferably from a plurality of hexamethyldisilazane, divinyltetramethylsilazane and vinyl hydroxysilicone oil, and more preferably from hexamethyldisilazane and divinyltetramethylsilazane; the total content of divinyltetramethylsilazane and vinylhydroxysilicone oil in the structural control agent is preferably 10 to 25wt%, and specifically may be 10wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, or 25 wt%. In an embodiment of the present invention, which does not contain vinylhydroxysilicone oil, i.e., the vinyl-containing structural chemical control agent is only divinyltetramethylsilazane, the total content of divinyltetramethylsilazane and vinylhydroxysilicone oil in the structural chemical control agent is the content of divinyltetramethylsilazane in the structural chemical control agent.

In the two-component liquid silicone rubber provided by the invention, the content of the structural control agent in the component A and the component B can be the same or different, and is independently selected to be 5-15 parts by mass, preferably 5-10 parts by mass, specifically 5 parts by mass, 6 parts by mass, 7 parts by mass, 8 parts by mass, 9 parts by mass, 10 parts by mass, 11 parts by mass, 12 parts by mass, 13 parts by mass, 14 parts by mass or 15 parts by mass.

In the bi-component liquid silicone rubber provided by the invention, the cross-linking agent is a mixture of side chain hydrogen-containing silicone oil and terminal hydrogen-containing silicone oil; the content of the hydrogen-terminated silicone oil in the cross-linking agent is 60-90 wt%, and specifically can be 60 wt%, 62 wt%, 65 wt%, 67 wt%, 70 wt%, 72 wt%, 75 wt%, 78 wt%, 80 wt%, 81 wt%, 82 wt%, 83 wt%, 84 wt%, 85 wt%, 86 wt%, 87 wt%, 88 wt%, 89 wt% or 90 wt%. In the invention, the hydrogen atom content of the cross-linking agent is preferably 0.01 to 1wt%, more preferably 0.05 to 0.5 wt%; more specifically, the hydrogen atom content of the side chain hydrogen-containing silicone oil is preferably 0.1 to 0.6wt%, and specifically may be 0.1wt%, 0.15 wt%, 0.2 wt%, 0.25 wt%, 0.3 wt%, 0.35 wt%, 0.4 wt%, 0.45 wt%, 0.5 wt%, 0.55 wt%, or 0.6 wt%; the hydrogen atom content of the hydrogen-terminated silicone oil is preferably 0.01-0.1 wt%, and specifically can be 0.01 wt%, 0.02 wt%, 0.03 wt%, 0.04 wt%, 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, 0.09 wt%, or 0.1 wt%. In the invention, the viscosity of the cross-linking agent at 25 ℃ is preferably 10-150 mPa.s, and more preferably 20-100 mPa.s; more specifically, the viscosity of the side chain hydrogen-containing silicone oil at 25 ℃ is preferably 10-60 mPa.s, and specifically can be 10mPa.s, 15mPa.s, 20mPa.s, 25mPa.s, 30mPa.s, 35mPa.s, 40mPa.s, 45mPa.s, 50mPa.s, 55mPa.s or 60 mPa.s; the viscosity of the hydrogen-terminated silicone oil at 25 ℃ is preferably 80-150 mPa.s, and specifically can be 80mPa.s, 85mPa.s, 90mPa.s, 95mPa.s, 100mPa.s, 105mPa.s, 110mPa.s, 115mPa.s, 120mPa.s, 125mPa.s, 130mPa.s, 135mPa.s, 140mPa.s, 145mPa.s or 150 mPa.s. In one embodiment provided by the present invention, the chemical structures of the side chain hydrogen-containing silicone oil and the terminal hydrogen-containing silicone oil are respectively represented by formula (III) and formula (IV):

in the formula (III), Me represents methyl, and m and n represent polymerization degrees.

In the formula (IV), Me represents a methyl group, and n represents a polymerization degree.

In the two-component liquid silicone rubber provided by the invention, the content of the cross-linking agent in the component B is 20-40 parts by mass, specifically 20 parts by mass, 21 parts by mass, 22 parts by mass, 23 parts by mass, 24 parts by mass, 25 parts by mass, 26 parts by mass, 27 parts by mass, 28 parts by mass, 29 parts by mass, 30 parts by mass, 31 parts by mass, 32 parts by mass, 33 parts by mass, 34 parts by mass, 35 parts by mass, 36 parts by mass, 37 parts by mass, 38 parts by mass, 39 parts by mass or 40 parts by mass.

In the two-component liquid silicone rubber provided by the invention, the catalyst is preferably a platinum catalyst; the components of the platinum catalyst preferably comprise polysiloxane and platinum (0) divinyltetramethyldisiloxane, the content of the polysiloxane in the platinum catalyst is preferably more than or equal to 80 wt%, more preferably 95 wt%, and the content of the platinum (0) divinyltetramethyldisiloxane in the platinum catalyst is preferably 0.1-20 wt%, more preferably 5 wt%; the content of the catalyst in the component A is 0.1-1 part by mass, and specifically may be 0.1 part by mass, 0.2 part by mass, 0.3 part by mass, 0.4 part by mass, 0.5 part by mass, 0.6 part by mass, 0.7 part by mass, 0.8 part by mass, 0.9 part by mass or 1 part by mass.

In the two-component liquid silicone rubber provided by the invention, the inhibitor is preferably one or more of 1-ethynyl-1-cyclohexanol, 2-methyl-3-butynyl-2-ol, 3-methyl-1-ethynyl-3-ol and 3, 5-dimethyl-1-hexynyl-3-ol; the content of the inhibitor in the component B is 0.01-1 part by mass, preferably 0.01-0.1 part by mass, and specifically may be 0.01 part by mass, 0.02 part by mass, 0.03 part by mass, 0.04 part by mass, 0.05 part by mass, 0.06 part by mass, 0.07 part by mass, 0.08 part by mass, 0.09 part by mass, or 0.1 part by mass.

In the two-component liquid silicone rubber provided by the invention, raw materials of the component A and the component B preferably further comprise other auxiliary agents, and the other auxiliary agents are water and/or antibacterial agents; the content of the other auxiliary agents in the component A and the component B can be the same or different, and is independently preferably 0-5 parts by mass, specifically 0 part by mass, 0.5 part by mass, 1 part by mass, 1.5 parts by mass, 2 parts by mass, 2.5 parts by mass, 3 parts by mass, 3.5 parts by mass, 4 parts by mass, 4.5 parts by mass or 5 parts by mass.

The invention also provides a preparation method of the bi-component liquid silicone rubber, which comprises the following steps:

there is no chronological restriction between step A) and step B).

In the preparation method provided by the invention, the step A) specifically comprises the following steps:

A1) kneading the hardness control agent, the structural control agent and part of base gum to obtain a first kneaded material;

A2) combining the first kneaded mass and a filler to obtain a second kneaded mass;

A3) continuously kneading the second kneaded mass under the conditions of heating and vacuumizing to obtain a third kneaded mass;

A4) and kneading the third kneadate, a catalyst and the balance of base rubber to obtain a component A of the liquid silicone rubber.

In the specific preparation step of the component a provided by the invention, in the step a1), the kneading temperature is preferably 10 to 40 ℃, and specifically may be 10 ℃, 15 ℃, 20 ℃, 25 ℃ (room temperature), 30 ℃, 35 ℃ or 40 ℃; the kneading time is preferably 5-30 min, and specifically can be 5min, 10min, 15min, 20min, 25min or 30 min.

In the specific preparation step of the component a provided by the invention, in the step a2), the kneading temperature is preferably 10 to 40 ℃, and specifically may be 10 ℃, 15 ℃, 20 ℃, 25 ℃ (room temperature), 30 ℃, 35 ℃ or 40 ℃; the kneading time is preferably 0.2 to 2 hours, and specifically may be 0.2 hour, 0.5 hour, 0.7 hour, 1 hour, 1.2 hour, 1.5 hour, 1.7 hour or 2 hours.

In the specific preparation step of the component a provided by the invention, in the step a3), the heating temperature is preferably 150-200 ℃, and specifically can be 150 ℃, 155 ℃, 160 ℃, 165 ℃, 170 ℃, 175 ℃, 180 ℃, 185 ℃, 190 ℃, 195 ℃ or 200 ℃; the pressure of the vacuumizing is preferably less than or equal to 0MPa, and more preferably less than or equal to-0.1 MPa; the kneading time is preferably 0.5-5 h, and specifically may be 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h or 5 h.

In the specific preparation step of the component a provided by the invention, in the step a4), the kneading temperature is preferably 10 to 40 ℃, and specifically may be 10 ℃, 15 ℃, 20 ℃, 25 ℃ (room temperature), 30 ℃, 35 ℃ or 40 ℃; the kneading time is preferably 0.2 to 2 hours, and specifically may be 0.2 hour, 0.5 hour, 0.7 hour, 1 hour, 1.2 hour, 1.5 hour, 1.7 hour or 2 hours.

In the specific preparation step of the component a provided by the present invention, if the raw materials of the component a all contain other additives, the other additives are added in step a1) to participate in kneading.

In the preparation method provided by the invention, the step B) specifically comprises the following steps:

B1) kneading the hardness control agent, the structural control agent and part of base gum to obtain a first kneaded material;

B2) combining the first kneaded material with a filler to obtain a second kneaded material;

B3) continuously kneading the second kneaded material under the conditions of heating and vacuumizing to obtain a third kneaded material;

B4) kneading the third kneadate, the inhibitor, the cross-linking agent and the balance of base rubber to obtain a component B of the liquid silicone rubber.

In the specific preparation step of the component B provided by the present invention, in the step B1), the kneading temperature is preferably 10 to 40 ℃, and specifically may be 10 ℃, 15 ℃, 20 ℃, 25 ℃ (room temperature), 30 ℃, 35 ℃ or 40 ℃; the kneading time is preferably 5-30 min, and specifically may be 5min, 10min, 15min, 20min, 25min or 30 min.

In the specific preparation step of the component B provided by the present invention, in the step B2), the kneading temperature is preferably 10 to 40 ℃, and specifically may be 10 ℃, 15 ℃, 20 ℃, 25 ℃ (room temperature), 30 ℃, 35 ℃ or 40 ℃; the kneading time is preferably 0.2 to 2 hours, and specifically may be 0.2 hour, 0.5 hour, 0.7 hour, 1 hour, 1.2 hour, 1.5 hour, 1.7 hour or 2 hours.

In the specific preparation step of the component B provided by the present invention, in the step B3), the heating temperature is preferably 150 to 200 ℃, and specifically may be 150 ℃, 155 ℃, 160 ℃, 165 ℃, 170 ℃, 175 ℃, 180 ℃, 185 ℃, 190 ℃, 195 ℃ or 200 ℃; the pressure of the vacuumizing is preferably less than or equal to 0MPa, and more preferably less than or equal to-0.1 MPa; the kneading time is preferably 0.5-5 h, and specifically may be 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h or 5 h.

In the specific preparation step of the component B provided by the present invention, in the step B4), the kneading temperature is preferably 10 to 40 ℃, and specifically may be 10 ℃, 15 ℃, 20 ℃, 25 ℃ (room temperature), 30 ℃, 35 ℃ or 40 ℃; the kneading time is preferably 0.2 to 2 hours, and specifically may be 0.2 hour, 0.5 hour, 0.7 hour, 1 hour, 1.2 hour, 1.5 hour, 1.7 hour or 2 hours.

In the specific preparation step of the component B provided by the present invention, if the raw materials of the component B all contain other additives, the other additives are added in step B1) to participate in kneading.

In the invention, the use method of the two-component liquid silicone rubber comprises the following steps: mixing the component A and the component B in proportion, and then pouring or injection molding; wherein the mass ratio of the component A to the component B is preferably 1: (0.5 to 2), and more preferably 1:1. In the invention, the component B contains a cross-linking agent, the component A contains a catalyst corresponding to the cross-linking agent of the component B, and the component B and the component A can be vulcanized and cross-linked to form at room temperature or under heating after being uniformly mixed.

According to the technical scheme provided by the invention, the raw material formula of the liquid silicone rubber is optimally designed, so that the liquid silicone rubber material provided by the invention has multiple excellent performances, can better meet the use requirements in the field of medical health, and has wide market prospect. More specifically, the technical scheme provided by the invention has the following advantages:

1) the liquid silicone rubber material provided by the invention has the advantages of heat resistance, cold resistance, safety, good appearance (transparency), good skin touch, dry and comfortable hand feeling and the like.

2) The liquid silicone rubber material provided by the invention has the advantages of low viscosity, low hardness, high strength, excellent comprehensive performance, low energy loss and good quality of rubber material, and can be poured and molded only by simple mixing; in particular, 2.1) low viscosity and low hardness: according to the invention, solvents such as methyl silicone oil, DMC, organic solvent and the like are not added as viscosity and hardness control agents, but a combined mode of adding different types of low-viscosity vinyl silicone oil, vinyl silicone resin and hydrogen-terminated silicone oil is adopted, and a chain extension method is adopted to achieve the effect of the high-viscosity silicone oil, so that the effects of reducing viscosity and hardness are achieved, and the problem of oil yielding and stickiness of a vulcanized product is avoided; 2.2) high strength: the invention particularly adds divinyl tetramethyl silazane and vinyl hydroxyl silicone oil as the components of the structural control agent for treating the filler, increases the crosslinking points in the system, forms a better crosslinking network, and has better mechanical strength compared with other liquid glue products with low viscosity and low hardness.

3) The invention is different from the liquid silicon rubber of a common silicon oil-white carbon black system, particularly adds hydrogen-containing silicone oil as a cross-linking agent component, uses divinyl tetramethyl silazane and vinyl hydroxy silicone oil as a structural control agent component to treat white carbon black, and prepares the liquid silicon rubber with low viscosity, low hardness and high strength under the condition of not adding hardness and viscosity control agents such as organopolysiloxane, organic solvent and the like. Due to the characteristics of low viscosity, low hardness, high strength, dry and comfortable hand feeling and good affinity with human bodies, the material can be applied to the fields of health care and medical health.

4) Compared with the common low-viscosity high-strength liquid silicone rubber, the material disclosed by the invention does not add a viscosity control agent (such as methyl silicone oil and the like) for adjusting the viscosity, but reduces the viscosity of the liquid rubber material by adding a cross-linking agent (such as terminal hydrogen-containing silicone oil) for chain extension reaction; the measure has the advantages that the vulcanized rubber material does not produce oil due to the addition of viscosity control agents such as methyl silicone oil and the like, and the long-term use of the silicone rubber is not influenced.

5) Compared with the liquid silicone rubber material in the currently disclosed patent of 'a preparation method of low-viscosity liquid silicone rubber', the currently disclosed patent uses vinyl polysiloxane as a liquid silicone rubber matrix, uses white carbon black as an inorganic filler, mixes the materials, then adds an inhibitor, a platinum complex and hydrogen-containing silicone oil, fully stirs and defoams in vacuum to obtain the transparent liquid silicone rubber. According to the patent technology, the white carbon black (filler) is not added with a structural control agent, so that the integral performance deviation of the rubber material can be caused. In the liquid silicone rubber material, especially divinyl tetramethyl silazane and vinyl hydroxy silicone oil are added as the components of the structural control agent for treating white carbon black, so that the crosslinking points in the rubber material are increased, and the tensile strength (more than 5 MPa) and the tear strength (more than 13 KN/m) of the material can be well improved.

6) The present invention provides an addition-curable liquid silicone rubber composition containing (a) an alkenyl group-containing organopolysiloxane having 2 or more silicon atom-bonded alkenyl groups in 1 molecule, having an average degree of polymerization of 1500 or less, and being liquid at 25 ℃; (B) (B-1) an organohydrogenpolysiloxane having no aromatic group and containing 6 or more silicon atoms to hydrogen atoms in 1 molecule, (B-2) an organohydrogenpolysiloxane having no aromatic group and containing 3 to 5 silicon atoms to hydrogen atoms in 1 molecule, (B-3) an organohydrogenpolysiloxane having no aromatic group and containing 1 to 2 silicon atoms to hydrogen atoms in 1 molecule; (C) BET specific surface area of 130m ² (ii) fumed silica of greater than/g; and (D) an addition reaction catalyst. The patent technology also does not add divinyl tetramethyl silazane or vinyl silane coupling agent for processing white carbon black, and the tearing performance of the white carbon black is only 10 KN/m; compared with the invention, the performance is poorer, and the standard of high performance can not be achieved.

7) Compared with the liquid silicone rubber material in the currently disclosed patent of low-viscosity high-strength addition type liquid silicone rubber, the currently disclosed patent provides an addition curing liquid silicone rubber composition which comprises the following raw materials in parts by weight: 60-140 parts of vinyl polysiloxane, 4-24 parts of white carbon black, 1-4 parts of inhibitor, 0.1-0.24 part of catalyst, 15-25 parts of hydrogen-containing silicone oil, 40-160 parts of bismaleimide resin, 15-35 parts of GRT fiber, 0.5-2.5 parts of tetramethyl thiuram disulfide and 2.5-4.5 parts of nano argil. The main materials of the invention adopt vinyl polysiloxane and bismaleimide resin, and in addition, tetramethyl thiuram disulfide, GRT fiber and nano argil are added. In the invention, auxiliary fillers such as bismaleimide resin, GRT fiber, tetramethyl thiuram disulfide, nano argil and the like are particularly added for reinforcing the silicone rubber material. Because the tetramethyl thiuram disulfide has certain chemical toxicity, the tetramethyl thiuram disulfide is not suitable for manufacturing products contacting with human bodies, and the application range of the tetramethyl thiuram disulfide is reduced. The preparation method needs to be carried out in high-speed stirring equipment at 1200 ℃, and the experimental method is complicated and has poor process stability. The liquid silicone rubber material does not need to be added with other special auxiliary agents and fillers, and has simple preparation method and good production process stability.

8) Compared with the liquid silicone rubber material in the currently disclosed patent of low-viscosity high-strength addition type room temperature curing liquid silicone rubber and a preparation method thereof, the currently disclosed patent discloses a low-viscosity high-strength addition type room temperature curing liquid silicone rubber and a preparation method thereof, wherein the low-viscosity high-strength addition type room temperature curing liquid silicone rubber comprises a component A and a component B in parts by mass: the component A comprises: 45-72 parts of a base polymer, 11-25 parts of a filler, 5-15 parts of a hardness control agent, 2.7-9 parts of a viscosity control agent, 2-6 parts of a cross-linking agent and 1-2 parts of an inhibitor; the component B comprises: 4.5-9 parts of a base polymer, 1.3-4.3 parts of a filler and 1-2 parts of a platinum catalyst; the silicone rubber elastomer is prepared by separately preparing a component A and a component B, mixing the component A and the component B according to the mass ratio of 9:1, and curing for 8-10 hours at the temperature of 20-25 ℃. In the invention, linear polysiloxane containing methyl, alkoxy or epoxy end capping is specially added as a viscosity control agent. The method can cause oil leakage in the process of long-term use of the material, and the normal use of the material is influenced. In the invention, assistants such as methyl, alkoxy or epoxy-containing end-capped linear polysiloxane and the like are not added as viscosity control agents, but the viscosity is adjusted by a chain extension method through a combination mode of adding different types of low-viscosity vinyl silicone oil, vinyl silicone resin and hydrogen-containing end-capped silicone oil, so that oil seepage is avoided after vulcanization is completed, and the vulcanized material has good hand feeling and is suitable for long-term use.

9) Compared with the liquid silicone rubber material in the patent of low-viscosity flame-retardant insulating liquid silicone rubber and the preparation method thereof which are disclosed at present, the invention discloses addition type liquid silicone rubber and the preparation method thereof.A liquid silicone rubber base rubber A is prepared from linear polysiloxane, a reinforcing filler and a reinforcing filler surface treating agent; the cross-linking agent B consists of hydrogen-containing silicone oil; the component C consists of titanium dioxide, carbon black, azo compounds, catalysts and polymerization inhibitors; the viscosity of the liquid silicone rubber is less than 20Pa.s before curing, the fluidity is improved through low viscosity, the liquid silicone rubber is easy to inject and mold, and the flame retardance is embodied by adding proper flame retardant, so that the liquid silicone rubber can be used in the field of high-voltage insulators. In the invention, the viscosity of the silicon rubber at 25 ℃ before curing is less than 20000mPa.s, while the viscosity of the silicon rubber at 25 ℃ before curing is 4000-8500 mPa.s, the viscosity is smaller, and the operation process is simpler.

For the sake of clarity, the following examples and comparative examples are given in detail below.

Example 1

The embodiment provides a liquid silicone rubber with low hardness, low viscosity, high strength and smooth hand feeling, which comprises the following raw materials in parts by mass:

the vinyl-terminated silicone oil with the viscosity of 500mPa & s at 25 ℃ and the vinyl content of 0.5 wt% is selected as the base adhesive, and the chemical structure of the vinyl-terminated silicone oil is shown as the formula (I);

the specific surface area of the filler is 200m ² Precipitated silica,/g;

the structural control agent is a composition of hexamethyldisilazane and divinyltetramethylsilazane, and the composition comprises the following components in percentage by mass: hexamethyldisilazane: divinyltetramethylsilazane 5: 1;

the hardness control agent is methyl-terminated vinyl silicone oil with the viscosity of 1000mPa & s and the vinyl content of 0.3 wt% at 25 ℃, and the chemical structure of the methyl-terminated vinyl silicone oil is shown as a formula (II);

the cross-linking agent is a composition which is selected from side chain hydrogen-containing silicone oil H1 with the viscosity of 50 mPas at 25 ℃ and the hydrogen content of 0.2 wt% in the formula (III) and a terminal hydrogen-containing silicone oil H2 with the viscosity of 100 mPas at 25 ℃ and the hydrogen content of 0.05 wt%, wherein the mass ratio of the composition is H1: H2-1: 3;

the catalyst is selected from platinum catalyst, and the components of the platinum catalyst comprise 95 wt% of polysiloxane and 5wt% of platinum (0) divinyltetramethyldisiloxane;

the inhibitor is selected from 1-ethynyl-1-cyclohexanol;

distilled water is selected as the other auxiliary agents;

the preparation steps of the component A are as follows:

step 1) adding 50 parts of base rubber, 10 parts of structured control agent, 10 parts of hardness control agent and 1 part of other auxiliary agent into a kneader, and kneading for 10 minutes at room temperature; step 2) adding 40 parts of filler into a kneader in batches, mixing the filler and the kneader for kneading for 1 hour at room temperature; step 3) heating the kneader to 170 ℃, vacuumizing to less than-0.1 MPa, keeping the vacuum, and kneading for 2.5 hours under the vacuum; step 4), cooling to room temperature, adding 20 parts of base adhesive and 0.1 part of catalyst into a kneading machine, closing the kettle, and kneading for 1 hour at room temperature; and step 5) stopping kneading to obtain the component A.

The preparation steps of the component B are as follows:

step 1) adding 50 parts of base rubber, 10 parts of structured control agent, 10 parts of hardness control agent and 1 part of other auxiliary agent into a kneader, and kneading for 10 minutes at room temperature; step 2) adding 40 parts of filler into a kneader, mixing the filler and the kneader, and kneading the mixture for 1 hour at room temperature; step 3) heating the kneader to 170 ℃, vacuumizing to less than-0.1 MPa, keeping the vacuum, and kneading for 2.5 hours under the vacuum; step 4), cooling to room temperature, adding 20 parts of base adhesive, 0.02 part of inhibitor and 20 parts of cross-linking agent into a kneader, closing a kettle, and kneading for 1 hour at room temperature; and step 5) stopping kneading to obtain a component B.

Example 2

the vinyl-terminated silicone oil with the viscosity of 1000mPa & s at 25 ℃ and the vinyl content of 0.8 wt% is selected as the base adhesive, and the chemical structure of the vinyl-terminated silicone oil is shown as the formula (I);

the specific surface area of the filler is 150m ² Precipitated silica,/g;

the hardness control agent is methyl-terminated vinyl silicone oil with viscosity of 2000mPa & s at 25 ℃ and vinyl content of 0.2 wt%, and the chemical structure of the methyl-terminated vinyl silicone oil is shown as a formula (II);

the cross-linking agent is a composition which is selected from side chain hydrogen-containing silicone oil H1 with the viscosity of 50 mPas at 25 ℃ and the hydrogen content of 0.3 wt% in the formula (III) and a terminal hydrogen-containing silicone oil H2 with the viscosity of 100 mPas at 25 ℃ and the hydrogen content of 0.05 wt%, wherein the mass ratio of the composition is H1: H2-1: 1.5;

the inhibitor is selected from 1-ethynyl-1-cyclohexanol;

distilled water is selected as the other auxiliary agents;

the preparation steps of the component A are as follows:

step 1) adding 60 parts of base rubber, 12 parts of a structured control agent, 15 parts of a hardness control agent and 1.5 parts of other auxiliary agents into a kneader, and kneading for 10 minutes at room temperature; step 2) adding 50 parts of filler into a kneader in batches, mixing the filler and the kneader, and kneading the mixture for 1 hour at room temperature; step 3) heating the kneader to 170 ℃, vacuumizing to less than-0.1 MPa, keeping the vacuum, and kneading for 2.5 hours under the vacuum; step 4), cooling to room temperature, adding 20 parts of base adhesive and 0.1 part of catalyst into a kneading machine, closing the kettle, and kneading for 1 hour at room temperature; and step 5) stopping kneading to obtain the component A.

The preparation steps of the component B are as follows:

step 1) adding 60 parts of base rubber, 12 parts of a structural control agent, 15 parts of a hardness control agent and 1.5 parts of other auxiliary agents into a kneader, and kneading for 10 minutes at room temperature; step 2) adding 50 parts of filler into a kneader, mixing the filler and the kneader, and kneading the mixture for 1 hour at room temperature; step 3) heating the temperature of the kneader to 170 ℃, vacuumizing to less than-0.1 MPa, maintaining vacuum, and kneading for 2.5 hours under vacuum; step 4), cooling to room temperature, adding 20 parts of base adhesive, 0.02 part of inhibitor and 28 parts of cross-linking agent into a kneader, closing a kettle, and kneading for 1 hour at room temperature; and step 5) stopping kneading to obtain a component B.

Example 3

the vinyl-terminated silicone oil with the viscosity of 200mPa & s at 25 ℃ and the vinyl content of 1.6 wt% is selected as the base adhesive, and the chemical structure of the vinyl-terminated silicone oil is shown as the formula (I);

the specific surface area of the filler is 150m ² The weight ratio of the precipitated silica to the vinyl silicon resin is 2:1, and the chemical structure of the vinyl silicon resin is as follows:

the cross-linking agent is a composition which is selected from side chain hydrogen-containing silicone oil H1 with a structure shown in formula (III) and viscosity of 50 mPas at 25 ℃ and hydrogen content of 0.3 wt%, and hydrogen-containing silicone oil H2 with a structure shown in formula (IV) and viscosity of 100 mPas at 25 ℃ and hydrogen content of 0.05 wt%, wherein the mass ratio of the composition is H1: H2: 1: 4;

the inhibitor is selected from 1-ethynyl-1-cyclohexanol;

distilled water is selected as the other auxiliary agents;

the preparation steps of the component A are as follows:

step 1) adding 40 parts of base rubber, 8 parts of a structural control agent, 8 parts of a hardness control agent and 1.5 parts of other auxiliary agents into a kneader, and kneading for 10 minutes at room temperature; step 2) adding 50 parts of filler into a kneader in batches, mixing the filler and the kneader, and kneading the mixture for 1 hour at room temperature; step 3) heating the kneader to 170 ℃, vacuumizing to less than-0.1 MPa, keeping the vacuum, and kneading for 2.5 hours under the vacuum; step 4), cooling to room temperature, adding 20 parts of base adhesive and 0.1 part of catalyst into a kneading machine, closing the kettle, and kneading for 1 hour at room temperature; and 5) stopping kneading to obtain the component A.

The preparation steps of the component B are as follows:

step 1) adding 40 parts of base rubber, 8 parts of structured control agent, 8 parts of hardness control agent and 1.5 parts of other auxiliary agent into a kneader, and kneading for 10 minutes at room temperature; step 2) adding 50 parts of filler into a kneader, mixing the filler and the kneader, and kneading the mixture for 1 hour at room temperature; step 3) heating the kneader to 170 ℃, vacuumizing to less than-0.1 MPa, keeping the vacuum, and kneading for 2.5 hours under the vacuum; step 4), cooling to room temperature, adding 20 parts of base adhesive, 0.02 part of inhibitor and 30 parts of cross-linking agent into a kneader, closing a kettle, and kneading for 1 hour at room temperature; and step 5) stopping kneading to obtain a component B.

Example 4

the base adhesive is vinyl-terminated silicone oil with the viscosity of 1000mPa & s at 25 ℃ and the vinyl content of 1wt%, and the chemical structure of the vinyl-terminated silicone oil is shown as the formula (I);

the specific surface area of the filler is 200m ² Precipitated silica,/g;

the structural control agent is a composition of hexamethyldisilazane and divinyltetramethylsilazane, and the composition comprises the following components in percentage by mass: hexamethyldisilazane: divinyltetramethylsilazane ═ 9: 1;

the cross-linking agent is a composition which is selected from side chain hydrogen-containing silicone oil H1 with the viscosity of 20 mPas at 25 ℃ and the hydrogen content of 0.5 wt% in the formula (III) and a terminal hydrogen-containing silicone oil H2 with the viscosity of 100 mPas at 25 ℃ and the hydrogen content of 0.05 wt%, wherein the mass ratio of the composition is H1: H2-1: 8;

the inhibitor is selected from 1-ethynyl-1-cyclohexanol;

distilled water is selected as the other auxiliary agents;

the preparation steps of the component A are as follows:

step 1) adding 40 parts of base rubber, 7 parts of a structured control agent, 15 parts of a hardness control agent and 1 part of other auxiliary agents into a kneader, and kneading for 10 minutes at room temperature; step 2) adding 30 parts of filler into a kneader in batches, mixing the filler and the kneader, and kneading the mixture for 1 hour at room temperature; step 3) heating the kneader to 170 ℃, vacuumizing to less than-0.1 MPa, keeping the vacuum, and kneading for 2.5 hours under the vacuum; step 4), cooling to room temperature, adding 30 parts of base adhesive and 0.1 part of catalyst into a kneading machine, closing the kettle, and kneading for 1 hour at room temperature; and step 5) stopping kneading to obtain the component A.

The preparation steps of the component B are as follows:

step 1) adding 40 parts of base rubber, 7 parts of a structural control agent, 15 parts of a hardness control agent and 1 part of other auxiliaries into a kneading machine, and kneading for 10 minutes at room temperature; step 2) adding 30 parts of filler into a kneader, mixing the filler and the kneader, and kneading the mixture for 1 hour at room temperature; step 3) heating the kneader to 170 ℃, vacuumizing to less than-0.1 MPa, keeping the vacuum, and kneading for 2.5 hours under the vacuum; step 4), cooling to room temperature, adding 30 parts of base adhesive, 0.02 part of inhibitor and 35 parts of cross-linking agent into a kneading machine, closing a kettle, and kneading for 1 hour at room temperature; and 5) stopping kneading to obtain the component B.

Example 5

the vinyl-terminated silicone oil with the viscosity of 550mPa & s at 25 ℃ and the vinyl content of 1.4 wt% is selected as the base adhesive, and the chemical structure of the vinyl-terminated silicone oil is shown as the formula (I);

the specific surface area of the filler is 200m ² Precipitation in gWhite carbon black;

the structural control agent is a composition of hexamethyldisilazane and divinyltetramethylsilazane, and the composition comprises the following components in percentage by mass: hexamethyldisilazane: divinyltetramethylsilazane ═ 7: 1;

the hardness control agent is methyl-terminated vinyl silicone oil with viscosity of 2000mPa & s and vinyl content of 0.2 wt% at 25 ℃, and the chemical structure of the methyl-terminated vinyl silicone oil is shown as the formula (II);

the cross-linking agent is a composition which is selected from side chain hydrogen-containing silicone oil H1 with the viscosity of 50 mPas at 25 ℃ and the hydrogen content of 0.5 wt% in the formula (III) and a terminal hydrogen-containing silicone oil H2 with the viscosity of 100 mPas at 25 ℃ and the hydrogen content of 0.05 wt%, wherein the mass ratio of the composition is H1: H2: 1: 7;

the inhibitor is selected from 1-ethynyl-1-cyclohexanol;

distilled water is selected as the other auxiliary agents;

the preparation steps of the component A are as follows:

step 1) adding 40 parts of base rubber, 7 parts of a structural control agent, 12 parts of a hardness control agent and 1 part of other auxiliary agents into a kneader, and kneading for 10 minutes at room temperature; step 2) adding 35 parts of filler into a kneader in batches, mixing the filler with the kneader, and kneading the mixture for 1 hour at room temperature; step 3) heating the kneader to 170 ℃, vacuumizing to less than-0.1 MPa, keeping the vacuum, and kneading for 2.5 hours under the vacuum; step 4), cooling to room temperature, adding 25 parts of base adhesive and 0.1 part of catalyst into a kneading machine, closing the kettle, and kneading for 1 hour at room temperature; and step 5) stopping kneading to obtain the component A.

The preparation steps of the component B are as follows:

step 1) adding 40 parts of base rubber, 7 parts of a structural control agent, 12 parts of a hardness control agent and 1 part of other auxiliary agents into a kneader, and kneading for 10 minutes at room temperature; step 2) adding 35 parts of filler into a kneading machine, mixing the materials in a kettle, and kneading the materials at room temperature for 1 hour; step 3) heating the kneader to 170 ℃, vacuumizing to less than-0.1 MPa, keeping the vacuum, and kneading for 2.5 hours under the vacuum; step 4) cooling to room temperature, adding 25 parts of base rubber, 0.02 part of inhibitor and 32 parts of cross-linking agent into a kneading machine, closing a kettle, and kneading for 1 hour at room temperature; and step 5) stopping kneading to obtain a component B.

Example 6

the vinyl-terminated silicone oil with the viscosity of 350mPa & s at 25 ℃ and the vinyl content of 1.5 wt% is selected as the base adhesive, and the chemical structure of the vinyl-terminated silicone oil is shown as the formula (I);

the specific surface area of the filler is 200m ² Precipitated silica in g;

the hardness control agent is methyl-terminated vinyl silicone oil with the viscosity of 1000mPa & s and the vinyl content of 0.1wt% at 25 ℃, and the chemical structure of the methyl-terminated vinyl silicone oil is shown as a formula (II);

the cross-linking agent is a composition which is selected from side chain hydrogen-containing silicone oil H1 with the viscosity of 20 mPas at 25 ℃ and the hydrogen content of 0.3 wt% in the formula (III) and a terminal hydrogen-containing silicone oil H2 with the viscosity of 100 mPas at 25 ℃ and the hydrogen content of 0.05 wt%, wherein the mass ratio of the composition is H1: H2-1: 6;

the inhibitor is selected from 1-ethynyl-1-cyclohexanol;

distilled water is selected as the other auxiliary agents;

the preparation steps of the component A are as follows:

step 1) adding 40 parts of base rubber, 5 parts of a structural control agent, 10 parts of a hardness control agent and 1 part of other auxiliary agents into a kneader, and kneading for 10 minutes at room temperature; step 2) adding 37 parts of filler into a kneader in batches, mixing the filler with the kneader, and kneading the mixture for 1 hour at room temperature; step 3) heating the kneader to 170 ℃, vacuumizing to less than-0.1 MPa, keeping the vacuum, and kneading for 2.5 hours under the vacuum; step 4), cooling to room temperature, adding 20 parts of base adhesive and 0.1 part of catalyst into a kneading machine, closing the kettle, and kneading for 1 hour at room temperature; and step 5) stopping kneading to obtain the component A.

The preparation steps of the component B are as follows:

step 1) adding 40 parts of base rubber, 5 parts of a structural control agent, 10 parts of a hardness control agent and 1 part of other auxiliaries into a kneading machine, and kneading for 10 minutes at room temperature; step 2) adding 37 parts of filler into a kneader, mixing the filler and the kneader, and kneading the mixture for 1 hour at room temperature; step 3) heating the kneader to 170 ℃, vacuumizing to less than-0.1 MPa, keeping the vacuum, and kneading for 2.5 hours under the vacuum; step 4), cooling to room temperature, adding 20 parts of base adhesive, 0.02 part of inhibitor and 31 parts of cross-linking agent into a kneader, closing a kettle, and kneading for 1 hour at room temperature; and 5) stopping kneading to obtain the component B.

Comparative example 1

The comparative example provides a liquid silicone rubber with low hardness, low viscosity, high strength and smooth hand feeling, which comprises the following raw materials in parts by mass:

the specific surface area of the filler is 200m ² Precipitated silica,/g;

the structural control agent is only hexamethyldisilazane;

the hardness control agent is methyl-terminated vinyl silicone oil with the viscosity of 1000mPa & s at 25 ℃ and the vinyl content of 0.3 wt%, and the chemical structure of the methyl-terminated vinyl silicone oil is shown as a formula (II);

the cross-linking agent is a composition which is selected from side chain hydrogen-containing silicone oil H1 with the viscosity of 50 mPas at 25 ℃ and the hydrogen content of 0.2 wt% in the formula (III) and a terminal hydrogen-containing silicone oil H2 with the viscosity of 100 mPas at 25 ℃ and the hydrogen content of 0.05 wt%, wherein the mass ratio of the composition is H1: H2-1: 9;

the inhibitor is selected from 1-ethynyl-1-cyclohexanol;

distilled water is selected as the other auxiliary agents;

the preparation steps of the component A are as follows:

step 1) adding 50 parts of base rubber, 7 parts of a structural control agent, 6 parts of a hardness control agent and 1 part of other auxiliary agents into a kneader, and kneading for 10 minutes at room temperature; step 2) adding 40 parts of filler into a kneader in batches, mixing the filler and the kneader, and kneading the mixture for 1 hour at room temperature; step 3) heating the kneader to 170 ℃, vacuumizing to less than-0.1 MPa, keeping the vacuum, and kneading for 2.5 hours under the vacuum; step 4), cooling to room temperature, adding 20 parts of base adhesive and 0.1 part of catalyst into a kneading machine, closing the kettle, and kneading for 1 hour at room temperature; and step 5) stopping kneading to obtain the component A.

The preparation steps of the component B are as follows:

step 1) adding 50 parts of base rubber, 7 parts of a structural control agent, 6 parts of a hardness control agent and 1 part of other auxiliary agents into a kneader, and kneading for 10 minutes at room temperature; step 2) adding 40 parts of filler into a kneader, mixing the filler and the kneader, and kneading the mixture for 1 hour at room temperature; step 3) heating the kneader to 170 ℃, vacuumizing to less than-0.1 MPa, keeping the vacuum, and kneading for 2.5 hours under the vacuum; step 4), cooling to room temperature, adding 20 parts of base adhesive, 0.02 part of inhibitor and 20 parts of cross-linking agent into a kneader, closing a kettle, and kneading for 1 hour at room temperature; and step 5) stopping kneading to obtain a component B.

Comparative example 2

the specific surface area of the filler is 200m ² Precipitated silica,/g;

the inhibitor is selected from 1-ethynyl-1-cyclohexanol;

distilled water is selected as the other auxiliary agents;

the preparation steps of the component A are as follows:

step 1) adding 50 parts of base rubber, 6 parts of a structured control agent and 1 part of other auxiliary agents into a kneading machine, and kneading for 10 minutes at room temperature; step 2) adding 40 parts of filler into a kneader in batches, mixing the filler and the kneader, and kneading the mixture for 1 hour at room temperature; step 3) heating the temperature of the kneader to 170 ℃, vacuumizing to less than-0.1 MPa, maintaining vacuum, and kneading for 2.5 hours under vacuum; step 4), cooling to room temperature, adding 20 parts of base adhesive and 0.1 part of catalyst into a kneading machine, closing the kettle, and kneading for 1 hour at room temperature; and step 5) stopping kneading to obtain the component A.

The preparation steps of the component B are as follows:

step 1) adding 50 parts of base rubber, 6 parts of structured control agent and 1 part of other auxiliary agent into a kneading machine, and kneading for 10 minutes at room temperature; step 2) adding 40 parts of filler into a kneader, mixing the filler and the kneader, and kneading the mixture for 1 hour at room temperature; step 3) heating the kneader to 170 ℃, vacuumizing to less than-0.1 MPa, keeping the vacuum, and kneading for 2.5 hours under the vacuum; step 4), cooling to room temperature, adding 20 parts of base adhesive, 0.02 part of inhibitor and 20 parts of cross-linking agent into a kneader, closing the kneader, and kneading for 1 hour at room temperature; and step 5) stopping kneading to obtain a component B.

Comparative example 3

the specific surface area of the filler is 200m ² Precipitated silica,/g;

the solvent is methyl polysiloxane with the viscosity of 100mPa & s at 25 ℃;

the inhibitor is selected from 1-ethynyl-1-cyclohexanol;

distilled water is selected as the other auxiliary agents;

the preparation steps of the component A are as follows:

step 1) adding 50 parts of base adhesive, 4 parts of structured control agent and 1 part of other auxiliary agent into a kneading machine, and kneading for 10 minutes at room temperature; step 2) adding 40 parts of filler into a kneader in batches, mixing the filler and the kneader for kneading for 1 hour at room temperature; step 3) heating the kneader to 170 ℃, vacuumizing to less than-0.1 MPa, keeping the vacuum, and kneading for 2.5 hours under the vacuum; step 4), cooling to room temperature, adding 20 parts of base adhesive, 15 parts of solvent and 0.1 part of catalyst into a kneader, closing the kneader, and kneading for 1 hour at room temperature; and step 5) stopping kneading to obtain the component A.

The preparation steps of the component B are as follows:

step 1) adding 50 parts of base rubber, 4 parts of structured control agent and 1 part of other auxiliary agent into a kneading machine, and kneading for 10 minutes at room temperature; step 2) adding 40 parts of filler into a kneader, mixing the filler and the kneader, and kneading the mixture for 1 hour at room temperature; step 3) heating the kneader to 170 ℃, vacuumizing to less than-0.1 MPa, keeping the vacuum, and kneading for 2.5 hours under the vacuum; step 4), cooling to room temperature, adding 20 parts of base adhesive, 15 parts of solvent, 0.02 part of inhibitor and 20 parts of cross-linking agent into a kneader, closing a kettle, and kneading for 1 hour at room temperature; and step 5) stopping kneading to obtain a component B.

Comparative example 4

the specific surface area of the filler is 200m ² Precipitated silica in g;

the structural control agent is a composition of hexamethyldisilazane and divinyltetramethylsilazane, and the composition comprises the following components in percentage by mass: hexamethyldisilazane: divinyltetramethylsilazane 2: 1;

the cross-linking agent is a composition which is selected from side chain hydrogen-containing silicone oil H1 with a structure shown in formula (III) and viscosity of 50 mPas at 25 ℃ and hydrogen content of 0.2 wt%, and hydrogen-containing silicone oil H2 with a structure shown in formula (IV) and viscosity of 100 mPas at 25 ℃ and hydrogen content of 0.05 wt%, wherein the mass ratio of the composition is H1: H2: 1: 3;

the inhibitor is selected from 1-ethynyl-1-cyclohexanol;

distilled water is selected as the other auxiliary agents;

the preparation steps of the component A are as follows:

The preparation steps of the component B are as follows:

step 1) adding 50 parts of base rubber, 10 parts of structured control agent, 10 parts of hardness control agent and 1 part of other auxiliary agent into a kneader, and kneading for 10 minutes at room temperature; step 2) adding 40 parts of filler into a kneader, mixing the filler and the kneader, and kneading the mixture for 1 hour at room temperature; step 3) heating the kneader to 170 ℃, vacuumizing to less than-0.1 MPa, keeping the vacuum, and kneading for 2.5 hours under the vacuum; step 4) cooling to room temperature, adding 20 parts of base adhesive, 0.02 part of inhibitor and 20 parts of cross-linking agent into a kneading machine, closing a kettle, and kneading for 1 hour at room temperature; and step 5) stopping kneading to obtain a component B.

Comparative example 5

the specific surface area of the filler is 200m ² Precipitated silica,/g;

the structural control agent is a composition of hexamethyldisilazane and divinyltetramethylsilazane, and the composition comprises the following components in percentage by mass: hexamethyldisilazane: divinyltetramethylsilazane ═ 5: 1;

the hardness control agent selects methyl-terminated vinyl silicone oil with the viscosity of 1000 mPas at 25 ℃ and the vinyl content of 0.3 wt%, and the chemical structure of the methyl-terminated vinyl silicone oil is shown as the formula (II);

the cross-linking agent is a composition which is selected from side chain hydrogen-containing silicone oil H1 with the viscosity of 50 mPas at 25 ℃ and the hydrogen content of 0.2 wt% in the formula (III) and a terminal hydrogen-containing silicone oil H2 with the viscosity of 100 mPas at 25 ℃ and the hydrogen content of 0.05 wt%, wherein the mass ratio of the composition is H1: H2-2: 1;

the inhibitor is selected from 1-ethynyl-1-cyclohexanol;

distilled water is selected as the other auxiliary agents;

the preparation steps of the component A are as follows:

step 1) adding 50 parts of base rubber, 10 parts of structured control agent, 10 parts of hardness control agent and 1 part of other auxiliary agent into a kneader, and kneading for 10 minutes at room temperature; step 2) adding 40 parts of filler into a kneader in batches, mixing the filler and the kneader, and kneading the mixture for 1 hour at room temperature; step 3) heating the kneader to 170 ℃, vacuumizing to less than-0.1 MPa, keeping the vacuum, and kneading for 2.5 hours under the vacuum; step 4), cooling to room temperature, adding 20 parts of base adhesive and 0.1 part of catalyst into a kneading machine, closing the kettle, and kneading for 1 hour at room temperature; and step 5) stopping kneading to obtain the component A.

The preparation steps of the component B are as follows:

step 1) adding 50 parts of base rubber, 10 parts of structured control agent, 10 parts of hardness control agent and 1 part of other auxiliary agent into a kneader, and kneading for 10 minutes at room temperature; step 2) adding 40 parts of filler into a kneader, mixing the filler and the kneader, and kneading the mixture for 1 hour at room temperature; step 3) heating the kneader to 170 ℃, vacuumizing to less than-0.1 MPa, keeping the vacuum, and kneading for 2.5 hours under the vacuum; step 4), cooling to room temperature, adding 20 parts of base adhesive, 0.02 part of inhibitor and 20 parts of cross-linking agent into a kneader, closing the kneader, and kneading for 1 hour at room temperature; and 5) stopping kneading to obtain the component B.

Comparative example 6

the specific surface area of the filler is 200m ² Precipitated silica,/g;

the cross-linking agent is a composition which is selected from side chain hydrogen-containing silicone oil H1 with the viscosity of 50 mPas at 25 ℃ and the hydrogen content of 0.2 wt% in the formula (III) and a terminal hydrogen-containing silicone oil H2 with the viscosity of 100 mPas at 25 ℃ and the hydrogen content of 0.05 wt%, wherein the mass ratio of the composition is H1: H2: 1: 12;

the inhibitor is selected from 1-ethynyl-1-cyclohexanol;

distilled water is selected as the other auxiliary agents;

the preparation steps of the component A are as follows:

step 1) adding 50 parts of base rubber, 10 parts of structured control agent, 10 parts of hardness control agent and 1 part of other auxiliary agent into a kneader, and kneading for 10 minutes at room temperature; step 2) adding 40 parts of filler into a kneader in batches, mixing the filler and the kneader for kneading for 1 hour at room temperature; step 3) heating the kneader to 170 ℃, vacuumizing to less than-0.1 MPa, keeping the vacuum, and kneading for 2.5 hours under the vacuum; step 4), cooling to room temperature, adding 20 parts of base adhesive, 0.1 part of catalyst and 1 part of other auxiliary agents into a kneading machine, closing a kettle, and kneading for 1 hour at room temperature; and 5) stopping kneading to obtain the component A.

The preparation steps of the component B are as follows:

step 1) adding 50 parts of base rubber, 10 parts of structured control agent, 10 parts of hardness control agent and 1 part of other auxiliary agent into a kneader, and kneading for 10 minutes at room temperature; step 2) adding 40 parts of filler into a kneader, mixing the filler and the kneader, and kneading the mixture for 1 hour at room temperature; step 3) heating the kneader to 170 ℃, vacuumizing to less than-0.1 MPa, keeping the vacuum, and kneading for 2.5 hours under the vacuum; step 4), cooling to room temperature, adding 20 parts of base adhesive, 0.02 part of inhibitor and 20 parts of cross-linking agent into a kneader, closing the kneader, and kneading for 1 hour at room temperature; and step 5) stopping kneading to obtain a component B.

Evaluation of Performance

Respectively mixing the component A and the component B in the examples 1-6 and the comparative examples 1-6 according to the mass ratio of 1:1, measuring the viscosity at 25 ℃, vulcanizing at 150 ℃ for 400 seconds, molding, and measuring the performance of the molded material; the viscosity and after-formation property profiles of the different examples and comparative examples are shown in the following table:

as can be seen from comparison of comparative example 1 with example 1, after the rubber compound is formed, the data of hardness, tear strength and tensile strength of the rubber compound are obviously different from those of example 1, so that the addition of the vinyl-containing treating agent similar to divinyltetramethylsilazane, vinylhydroxysilane and the like can be proved to improve the physical properties of the rubber compound;

as can be seen from comparison between the comparative example 2 and the example 1, the hardness control agent is not added, the hardness of the rubber material is obviously higher after the rubber material is formed, and the performance values of tensile strength, tear strength and the like are slightly lower than those of the data in the example 1, so that the addition of the methyl-terminated vinyl silicone oil as the hardness control agent can obviously reduce the hardness of the rubber material and improve the tensile strength and the tear strength;

as can be seen from comparison between the comparative example 3 and the example 1, the methyl silicone oil is added as the solvent, although the viscosity is obviously reduced, the poor performances of the rubber compound can be obviously seen after the rubber compound is formed, and after the rubber compound is placed for 2 hours, the phenomena of oil generation and stickiness begin to appear on the surface of the rubber compound;

as can be seen from comparison of comparative example 4 with example 1, when the amount of divinyltetramethylsilazane added is outside the range specified in the invention, the resulting compound has a higher hardness, is brittle, and has a higher viscosity before vulcanization;

as can be seen from comparison of the comparative example 5 and the example 1, the mass percentage content ratio of the lateral hydrogen-containing silicone oil to the terminal hydrogen-containing silicone oil is not within the range of the invention, wherein the mass percentage content ratio of the terminal hydrogen-containing silicone oil is too low, so that the prepared rubber material has obviously higher hardness and relatively deviated performance compared with the example 1;

as can be seen from comparison of comparative example 6 with example 1, the ratio of the content of the side hydrogen-containing silicone oil to the content of the end hydrogen-containing silicone oil in percentage by mass is out of the range described in the present invention, wherein the ratio of the content of the end hydrogen-containing silicone oil in percentage by mass is too high, so that the resulting compound has a slightly decreased hardness and relatively deviated properties compared with example 1, and the compound has a sticky phenomenon after vulcanization due to incomplete crosslinking;

the foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A two-component liquid silicone rubber comprises a component A and a component B;

in the component A and the component B, the base adhesive is vinyl-terminated silicone oil with the viscosity of 200-5000 mPa.s at 25 ℃; the vinyl content of the vinyl-terminated silicone oil is 0.2-2 wt%;

in the component A and the component B, the hardness control agent is methyl-terminated vinyl silicone oil with the viscosity of 100-2000 mPa.s at 25 ℃; the vinyl content of the methyl-terminated vinyl silicone oil is 0.1-1 wt%;

in the component A and the component B, the structural control agent is selected from a plurality of hexamethyldisilazane, divinyltetramethylsilazane, diphenylsilanediol, hydroxyl silicone oil and vinyl hydroxyl silicone oil; the total content of divinyl tetramethyl silazane and vinyl hydroxyl silicone oil in the structural control agent is 10-25 wt%;

in the component A and the component B, the filler is precipitated white carbon black, or precipitated white carbon black and vinyl silicone resin;

the cross-linking agent is a mixture of side chain hydrogen-containing silicone oil and terminal hydrogen-containing silicone oil; the hydrogen atom content of the side chain hydrogen-containing silicone oil is 0.1-0.6 wt%, and the hydrogen atom content of the terminal hydrogen-containing silicone oil is 0.01-0.1 wt%; the content of the hydrogen-terminated silicone oil in the cross-linking agent is 60-90 wt%.

2. The two-component liquid silicone rubber according to claim 1, wherein the precipitated silica has a specific surface area of 100 to 400m ² (ii)/g; the vinyl silicone resin has a vinyl content of 0.1 to 10 wt%.

3. The two-component liquid silicone rubber according to claim 1, wherein the catalyst is a platinum catalyst.

4. The two-component liquid silicone rubber according to claim 1, wherein the inhibitor is selected from one or more of 1-ethynyl-1-cyclohexanol, 2-methyl-3-butyn-2-ol, 3-methyl-1-ethynyl-3-ol, and 3, 5-dimethyl-1-hexyn-3-ol.

5. The two-component liquid silicone rubber according to claim 1, wherein the raw materials of the component A and the component B both contain 0-5 parts of other auxiliary agents; the other auxiliary agent is water and/or an antibacterial agent.

6. A method for preparing the two-component liquid silicone rubber of claim 1, comprising the steps of:

there is no chronological restriction between step A) and step B).