阅读说明：本技术 一种液体硅橡胶及其制备方法 (Liquid silicone rubber and preparation method thereof ) 是由 叶忠平 于 2020-04-29 设计创作，主要内容包括：本发明公开了一种液体硅橡胶及其制备方法,包括A组分、B组分,所述A组分、B组分的配比为3:2；其中所述A组分以重量百分比计,包括以下原料：二甲基硅氧烷25-30%、二氧化硅微粉40-45%、聚二甲基硅氧烷20-30%、扩链剂5-8%；所述B组分以重量百分比计,包括以下原料：硫化剂10-25%、稀释剂15-30%、催化剂1-5%、抗粘剂10-26%。本发明的液体硅橡胶采用高活性化学物质配方,对电气设备底部缝隙形成充分密封；能耐受自然温度冻融循环和各种恶劣环境,不变形、不变质、不开裂,效果持久免维护,与各种金属材质、电缆护套材质均可紧密粘合,而且不产生任何不良化学反应。(The invention discloses a liquid silicone rubber and a preparation method thereof, wherein the liquid silicone rubber comprises a component A and a component B, wherein the ratio of the component A to the component B is 3: 2; wherein the component A comprises the following raw materials in percentage by weight: 25-30% of dimethyl siloxane, 40-45% of silicon dioxide micro powder, 20-30% of polydimethylsiloxane and 5-8% of chain extender; the component B comprises the following raw materials in percentage by weight: 10-25% of vulcanizing agent, 15-30% of diluent, 1-5% of catalyst and 10-26% of anti-sticking agent. The liquid silicone rubber adopts a high-activity chemical substance formula, and fully seals a gap at the bottom of electrical equipment; can endure natural temperature freeze-thaw cycle and various severe environments, has no deformation, deterioration and cracking, has lasting effect and no maintenance, can be tightly bonded with various metal materials and cable sheath materials, and does not generate any adverse chemical reaction.)

1. The liquid silicone rubber is characterized by comprising a component A and a component B, wherein the ratio of the component A to the component B is 3: 2; wherein the component A comprises the following raw materials in percentage by weight: 25-30% of dimethyl siloxane, 40-45% of silicon dioxide micro powder, 20-30% of polydimethylsiloxane and 5-8% of chain extender; the component B comprises the following raw materials in percentage by weight: 10-25% of vulcanizing agent, 15-30% of diluent, 1-5% of catalyst and 10-26% of anti-sticking agent.

2. A liquid silicone rubber according to claim 1, wherein the vulcanizing agent is dibenzoyl peroxide.

3. A liquid silicone rubber according to claim 1, wherein the anti-tack agent is stearamide.

4. A liquid silicone rubber according to claim 1, wherein the catalyst is dibutyltin dilaurate.

5. A liquid silicone rubber as claimed in claim 1, wherein the chain extender is 1, 4' -butanediol.

6. The liquid silicone rubber of claim 4, wherein the catalyst comprises dibutyltin dilaurate in an amount of from 10% to 17%.

7. A method of preparing a liquid silicone rubber as claimed in any one of claims 1 to 6, comprising the steps of:

(1) weighing the raw materials according to the proportion to respectively prepare a component A and a component B;

(2) adding the component A and the component B into a reaction kettle in proportion, uniformly stirring, and reacting for 20-30 minutes at 30-40 ℃ to obtain a mixed solution;

(3) and curing the mixed solution at room temperature to obtain the liquid silicone rubber.

Technical Field

The invention relates to the technical field of silicone rubber, in particular to liquid silicone rubber and a preparation method thereof.

Background

Liquid silica gel is relative to solid high-temperature vulcanized silicone rubber, is liquid gel, has the characteristics of good fluidity and fast vulcanization, is safer and more environment-friendly, can completely meet the requirements of food grade, and is usually divided into two categories according to the position of a functional group (namely a cross-linking point) contained in a molecular structure: one is called as remote claw type liquid rubber with functional groups at two ends of a molecular structure; the other is that the active functional groups are distributed randomly in the main chain, namely the functional groups are carried in the molecular structure, which is called non-telechelic liquid rubber, the liquid silicone rubber can be used for trademarks, products, nipples, medical supplies, coating, dipping and pouring, etc., can be used for forming dies of crystal glue, polyurethane, epoxy resin, etc., injection molding process, cake dies, etc., and is widely used as the coating and encapsulating material for moisture protection, transportation and insulation of electronic components in the electronic industry, and plays a role in dust prevention, moisture prevention, shock prevention and insulation protection for the electronic components and assemblies, and if the transparent gel is used for encapsulating the electronic components, the liquid silicone rubber not only plays a role in shock prevention and water prevention.

With the development of advanced equipment towards high performance, precision and integration, higher requirements are put forward on the curing speed, viscosity and mechanical property of the liquid silicone rubber, the liquid silicone rubber is required to have lower viscosity so as to be convenient for injection molding, and the liquid silicone rubber is also required to have good mechanical property so as to ensure that cable accessories are not damaged in the actual use process.

The existing liquid silicone rubber is easy to deteriorate and crack when being subjected to natural temperature freeze-thaw cycle and various severe environments, and the moisture-proof effect of the existing liquid silicone rubber is influenced.

Therefore, the prior art is in need of improvement.

Disclosure of Invention

In order to solve the technical problems, the invention provides liquid silicone rubber and a preparation method thereof. The liquid silicone rubber prepared by the invention can resist natural temperature freeze-thaw cycle and various severe environments, is not deformed, deteriorated or cracked, has lasting effect and is free from maintenance, and the problems can be effectively solved.

The specific technical scheme of the invention is as follows: the liquid silicone rubber comprises a component A and a component B, wherein the ratio of the component A to the component B is 3: 2; wherein the component A comprises the following raw materials in percentage by weight: 25-30% of dimethyl siloxane, 40-45% of silicon dioxide micro powder, 20-30% of polydimethylsiloxane and 5-8% of chain extender; the component B comprises the following raw materials in percentage by weight: 10-25% of vulcanizing agent, 15-30% of diluent, 1-5% of catalyst and 10-26% of anti-sticking agent.

The liquid silicone rubber prepared by the method can fully flow on a sealing operation surface and automatically level, is nontoxic, environment-friendly, corrosion-resistant, resistant to various severe environments, waterproof, damp-proof, dustproof, durable in effect and free of maintenance.

In the liquid silicone rubber, the vulcanizing agent is dibenzoyl peroxide.

The liquid silicone rubber, wherein the anti-sticking agent is stearic acid amide.

The liquid silicone rubber, wherein the catalyst is dibutyltin dilaurate.

The liquid silicone rubber, wherein the chain extender is 1, 4' -butanediol.

The chain extender is added, so that a finished product is of a flexible molecular closed cell matrix structure, and the finished product is flexible, light in weight and free from breakage or collapse after being formed.

The liquid silicone rubber, wherein the content of dibutyltin dilaurate in the catalyst is 10-17%.

The preparation method of the liquid silicone rubber comprises the following steps:

(1) weighing the raw materials according to the proportion to respectively prepare a component A and a component B;

(2) adding the component A and the component B into a reaction kettle in proportion, uniformly stirring, and reacting for 20-30 minutes at 30-40 ℃ to obtain a mixed solution;

(3) and curing the mixed solution at room temperature to obtain the liquid silicone rubber.

The liquid silicone rubber can be widely applied to distribution network outer ring main units, box-type transformers, cable branch boxes, distribution network control cabinets, outdoor transformer terminal boxes, mechanism operation boxes, electric knife switch boxes, high-low voltage switch cabinets, convergence control unit cabinets and the like.

When in use, liquid silicon rubber is used as a main plugging material (main material), and auxiliary materials (main material: auxiliary material =10: 1) in a certain proportion are added and stirred uniformly, and then poured into an operation part to be plugged. The liquid silicone rubber is automatically leveled through good fluidity and is solidified within 1-2 hours, so that the flexible plugging effect is achieved.

The invention has the beneficial effects that: the liquid silicone rubber disclosed by the invention is prepared by applying a high-molecular polymer mixing technology and adopting a high-activity chemical substance formula, so that a gap at the bottom of electrical equipment is fully sealed; the cable sheath can resist natural temperature freeze-thaw cycle and various severe environments, is not deformed, deteriorated or cracked, has lasting effect and no maintenance, can be tightly bonded with various metal materials and cable sheath materials, and does not generate any adverse chemical reaction; the method is the preferred scheme for safe operation and moisture-proof sealing operation of electric equipment of a power grid.

Detailed Description

The present invention will be further described with reference to the following examples.