阅读说明：本技术 电子用高纯度、粘度可控的硅树脂的制备方法 (Preparation method of high-purity and viscosity-controllable silicone resin for electronics ) 是由 伊港 刘海龙 高梓寒 张明 石科飞 孙晓雷 张帅 张海雷 邢松松 周磊 周玲 于 2021-08-25 设计创作，主要内容包括：本发明涉及一种硅树脂的制备方法,具体涉及一种电子用高纯度、粘度稳定可控的硅树脂的制备方法。包括以下步骤：a、采用氯硅烷水解制备硅树脂或者采用烷氧基硅树脂水解物进行静置,油水分离,得到硅树脂预聚物A；b、将硅树脂预聚物A采用溶剂溶解,进行油水分离,分出水层后,得到硅树脂预聚物B；c、加入醇后搅拌均匀,加热进行回流；d、蒸馏去除溶剂和醇,得到硅树脂产品。采用该方法制备的硅树脂产品粘度可控,纯度高,不含金属离子和氯离子,可以应用于电子领域,具有非常优异的稳定性和电气性能。(The invention relates to a preparation method of silicone resin, in particular to a preparation method of high-purity, stable and controllable-viscosity silicone resin for electronics. The method comprises the following steps: a. preparing silicon resin by hydrolyzing chlorosilane or standing an alkoxy silicon resin hydrolysate, and performing oil-water separation to obtain a silicon resin prepolymer A; b. dissolving the silicon resin prepolymer A by using a solvent, carrying out oil-water separation, and separating a water layer to obtain a silicon resin prepolymer B; c. adding alcohol, stirring uniformly, heating and refluxing; d. and distilling to remove the solvent and the alcohol to obtain the silicone resin product. The silicone resin product prepared by the method has controllable viscosity and high purity, does not contain metal ions and chloride ions, can be applied to the field of electronics, and has excellent stability and electrical properties.)

1. A preparation method of high-purity and viscosity-controllable silicone resin for electronics is characterized by comprising the following steps: the method comprises the following steps:

a. preparing silicon resin by hydrolyzing chlorosilane or standing an alkoxy silicon resin hydrolysate, and performing oil-water separation to obtain a silicon resin prepolymer A;

b. dissolving the silicon resin prepolymer A by using a solvent, carrying out oil-water separation, and separating a water layer to obtain a silicon resin prepolymer B;

c. adding alcohol, stirring uniformly, heating and refluxing;

d. and distilling to remove the solvent and the alcohol to obtain the silicone resin product.

2. The method of preparing high purity, viscosity-controlled silicone resin for electronics according to claim 1, wherein: in the step b, the solvent is one or more of toluene, xylene, n-heptane or petroleum ether.

3. The method of preparing high purity, viscosity-controlled silicone resin for electronics according to claim 2, wherein: in step b, the solvent is toluene or xylene.

4. The method of preparing high purity, viscosity-controlled silicone resin for electronics according to claim 1, wherein: in the step c, the alcohol is one or more of methanol, ethanol or isopropanol.

5. The method of preparing high purity, viscosity-controlled silicone resin for electronics according to claim 4, wherein: in step c, the alcohol is ethanol or isopropanol.

6. The method of preparing high purity, viscosity-controlled silicone resin for electronics according to claim 1, wherein: in step c, an inert gas is bubbled while heating and refluxing.

7. The method of preparing high purity, viscosity-controlled silicone resin for electronics according to claim 6, wherein: in step c, the inert gas comprises nitrogen, helium or argon.

8. The method of preparing high purity, viscosity-controlled silicone resin for electronics according to claim 7, wherein: in step c, the inert gas is nitrogen.

Technical Field

The invention relates to a preparation method of silicone resin, in particular to a preparation method of high-purity and viscosity-controllable silicone resin for electronics.

Background

Silicone resin is one of the most important products of electronic materials, and the products have diverse forms and structures, especially good weather resistance and electrical properties, and are widely used in the electronic field. The solvent-based, solvent-free, emulsion-based, and the like are generally used. Generally, the resin material is used as an adhesive or protective coating to protect electronic elements and has the functions of fixing, bonding, moisture prevention, dust prevention, salt mist resistance and the like, and the resin material is in contact with the electrical elements for a long time, so that the requirement on the purity of the resin material is high, and the electrical performance of the resin material is met.

Many electronic silicones have very high demands on the ion content of the product, requiring that it be absent or contained in very low amounts (ppb level). However, the existing preparation method of the silicon resin mainly adopts a hydrolysis method, raw materials are chlorosilane and alkoxy silane, the preparation of the silicon resin by adopting a chlorosilane product is a relatively common method, the complete hydrolysis of the chlorosilane is very difficult, a certain amount of chloride ions are difficult to remove, and particularly, a resin prepolymer after the hydrolysis is incompatible with water, and the chlorosilane and the resin prepolymer are separated, so that a small amount of silicon-chlorine bonds contained in the silicon resin are difficult to hydrolyze. The silicon resin is prepared by hydrolyzing alkoxy silane, acid or alkali is generally used as a catalyst for catalyzing hydrolysis, common acid comprises hydrochloric acid, sulfuric acid, trifluoromethanesulfonic acid and other products, nonvolatile acid is very difficult to remove, and metal ions are inevitably brought in if sodium carbonate, sodium bicarbonate, potassium carbonate, calcium carbonate and other products are used for neutralization. The use of volatile acids still produces silicon-chlorine bonds which are difficult to remove. Alkaline catalysis, such as sodium hydroxide, potassium hydroxide and the like, is adopted, and metal ions are also brought in.

In addition to the above problems, since the prepolymer of the silicone resin contains acid and alkali substances, in the process of removing volatile components such as solvent and alcohol, it is generally necessary to remove the volatile substances relatively cleanly, and it is necessary to remove the volatile substances under vacuum, so that the acid or alkali substances contained in the prepolymer of the silicone resin start to act, the silicone resin is further reacted and condensed, the molecular weight of the silicone resin is further increased, and the molecular weight of the silicone resin is difficult to control.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a preparation method of a high-purity and viscosity-controllable silicone resin for electrons, and the silicone resin product prepared by the method has controllable viscosity and high purity, does not contain metal ions and chloride ions, can be applied to the field of electrons, and has excellent stability and electrical properties.

In order to achieve the purpose, the invention adopts the technical scheme that:

the preparation method of the silicon resin with high purity and controllable viscosity for the electrons comprises the following steps:

a. preparing silicon resin by hydrolyzing chlorosilane or standing an alkoxy silicon resin hydrolysate, and performing oil-water separation to obtain a silicon resin prepolymer A;

b. dissolving the silicon resin prepolymer A by using a solvent, carrying out oil-water separation, and separating a water layer to obtain a silicon resin prepolymer B;

c. adding alcohol, stirring uniformly, heating and refluxing;

d. and distilling to remove the solvent and the alcohol to obtain the silicone resin product.

Wherein:

in the step b, the solvent is one or more of toluene, xylene, n-heptane or petroleum ether, and toluene or xylene is preferred.

In step c, the alcohol is one or more of methanol, ethanol or isopropanol, preferably ethanol or isopropanol.

In step c, an inert gas is bubbled during heating for reflux, wherein the inert gas comprises nitrogen, helium or argon, and preferably nitrogen.

Compared with the prior art, the invention has the beneficial effects that:

1. because a certain amount of Si-Cl bonds are remained in the silicone resin prepolymer, the Si-Cl bonds can not be well contacted with water for hydrolysis due to phase separation, and after the alcohol is added, the prepolymer and the alcohol have good compatibility, and can easily generate the following reaction and be taken away by inert gas.

2. As the Si-Cl bond of water in the prepolymer is hydrolyzed to be removed by hydrogen chloride, the further condensation reaction of the silicone resin can be prevented in the process of removing the Si-Cl bond due to the existence of alcohol, and other metal ions are not introduced in the reaction process, in the subsequent process of removing the solvent and the alcohol, the silicone resin can not be further condensed in the process of removing the solvent and low-molecular volatile matters because the system is neutral and has no other acid, alkali or salt with a catalytic effect, so that the multi-batch production is realized, the viscosity between batches is stable, and the control is easy.

3. The silicon resin product prepared by the invention does not contain metal ions and chloride ions, can be applied to the field of electronics, and has excellent stability and electrical properties.

Detailed Description

The invention is further described below with reference to the following examples, but without limiting the invention thereto.

This example takes methyl MQ silicone resin and methyl phenyl silicone resin as examples.

Preparation of silicone prepolymer a (alkoxysilane preparation method): placing ethyl orthosilicate in an elevated tank, adding dilute hydrochloric acid (prepared by deionized water and concentrated hydrochloric acid, the concentration of which is 1%) and hexamethyldisiloxane into a reaction kettle, slowly adding the ethyl orthosilicate in the elevated tank under a stirring state, controlling the temperature of a reaction system to be lower than 65 ℃, continuing stirring and reacting for 4 hours after the dropwise addition is finished, standing and layering to separate out a silicone resin prepolymer, then adding toluene accounting for 20% of the mass of the prepolymer, further standing, and removing a water layer to obtain a silicone resin prepolymer A.

Preparation of silicone prepolymer B (chlorosilane method): firstly, adopting phenyl trichlorosilane and hexamethyldisiloxane according to a molar ratio of 1:3, placing the mixture in an elevated tank, adding deionized water and toluene into a reaction kettle, slowly adding the mixture of the phenyl trichlorosilane and the hexamethyldisiloxane in the elevated tank under a stirring state, controlling the temperature of a reaction system to be lower than 60 ℃, continuing stirring and reacting for 2 hours after the dropwise addition is finished, standing and layering to separate out a silicone resin prepolymer, then adding toluene accounting for 20% of the mass of the prepolymer, further standing, and removing a water layer to obtain a silicone resin prepolymer B.

Example 1

Taking the silicone resin prepolymer A with the mass of 500g, adding 300g of ethanol, bubbling and introducing nitrogen, heating to a reflux state, refluxing for 2h, carrying out reduced pressure distillation to remove toluene and ethanol to obtain a product, and repeating for three times to respectively obtain products 1-1, 1-2 and 1-3.

Example 2

Taking the mass of the silicone resin prepolymer B as 500g, adding isopropanol as 300g, bubbling and introducing nitrogen, heating to a reflux state, refluxing for 2h, carrying out reduced pressure distillation to remove toluene and isopropanol to obtain a product, and repeating for three times to respectively obtain products 2-1, 2-2 and 2-3.

Example 3

Taking the silicone prepolymer A with the mass of 500g, introducing nitrogen, distilling under reduced pressure to remove volatile components to obtain a product, and repeating the steps for three times to respectively obtain products 3-1, 3-2 and 3-3.

Example 4

Taking the mass of the silicone resin prepolymer A as 500g, adding 1000g of toluene, washing for 5 times by adopting 1000g of deionized water, removing a water layer by layering, introducing nitrogen for bubbling, reducing pressure, distilling and removing volatile components to obtain a product, and repeating for three times to respectively obtain products 4-1, 4-2 and 4-3.

Example 5

Taking the mass of the silicone resin prepolymer B as 500g, adding 1000g of toluene, washing for 5 times by adopting 1000g of deionized water, removing a water layer by layering, introducing nitrogen for bubbling, and distilling under reduced pressure to remove volatile components to obtain a product, and repeating for three times to respectively obtain products 5-1, 5-2 and 5-3.

Example 6

Putting tetraethoxysilane in an elevated tank, adding sodium hydroxide aqueous solution (prepared by deionized water and sodium hydroxide and having the concentration of 1%) and hexamethyldisiloxane into a reaction kettle, slowly adding tetraethoxysilane in the elevated tank under the stirring state, controlling the temperature of a reaction system to be lower than 65 ℃, continuously stirring for reacting for 4 hours after the dropwise addition is finished, standing for layering, separating out a silicone resin prepolymer, then adding toluene with the mass of 20% of that of the prepolymer, further standing, removing a water layer to obtain the silicone resin prepolymer, taking 500g of the silicone resin prepolymer, adding 300g of ethanol, bubbling and introducing nitrogen, heating to the reflux state, refluxing for 2 hours, carrying out reduced pressure distillation to remove the toluene and the ethanol to obtain a product, repeating for three times, and respectively obtaining products 6-1, 6-2 and 6-3.

Example 7

Putting tetraethoxysilane in an elevated tank, adding aqueous hydrogen chloride solution (prepared by deionized water and concentrated hydrochloric acid and having the concentration of 1%) and hexamethyldisiloxane into a reaction kettle, slowly adding tetraethoxysilane in the elevated tank under the stirring state, controlling the temperature of a reaction system to be lower than 65 ℃, continuing to stir and react for 4 hours after the dropwise addition is finished, standing for layering, separating out a silicone resin prepolymer, then adding toluene with the mass of 20% of that of the prepolymer, further standing, removing a water layer to obtain the silicone resin prepolymer, taking the mass of the silicone resin prepolymer to be 500g, adding toluene, adding sodium carbonate powder for neutralization, filtering to remove solids, carrying out reduced pressure distillation to remove toluene to obtain products, repeating the steps for three times, and respectively obtaining products 7-1, 7-2 and 7-3.

Example 8

Placing tetraethoxysilane in an elevated tank, adding dilute sulfuric acid (prepared by deionized water and concentrated sulfuric acid and having the concentration of 1%) and hexamethyldisiloxane into a reaction kettle, slowly adding tetraethoxysilane in the elevated tank under the stirring state, controlling the temperature of a reaction system to be lower than 65 ℃, continuously stirring for reacting for 4 hours after the dropwise addition is finished, standing for layering, separating out a silicone resin prepolymer, then adding toluene with the mass of 20% of the prepolymer, further standing, removing a water layer to obtain the silicone resin prepolymer, taking the silicone resin prepolymer with the mass of 500g, adding 300g of ethanol, bubbling, introducing nitrogen, heating to a reflux state, refluxing for 2 hours, removing the toluene and the ethanol through reduced pressure distillation to obtain a product, repeating for three times, and respectively obtaining the products 8-1, 8-2 and 8-3.

Example 9

Taking the mass of the silicone prepolymer A as 500g, adding 1000g of toluene, washing for 5 times by adopting 1000g of 1% sodium carbonate aqueous solution, removing a water layer by layering, distilling under reduced pressure to remove volatile components to obtain a product, and repeating for three times to respectively obtain products 9-1, 9-2 and 9-3.

Example 10

Preparation of silicone prepolymer a (alkoxysilane preparation method): putting tetraethoxysilane in an elevated tank, adding dilute hydrochloric acid (prepared by deionized water and concentrated hydrochloric acid, the concentration of which is 1%) and hexamethyldisiloxane into a reaction kettle, slowly adding tetraethoxysilane in the elevated tank under the stirring state, controlling the temperature of a reaction system to be lower than 65 ℃, continuing to stir and react for 4 hours after the dropwise addition is finished, standing and layering to separate out a silicone resin prepolymer, taking 500g of the silicone resin prepolymer, adding 300g of ethanol, bubbling and introducing nitrogen, heating to a reflux state, refluxing for 2 hours, and removing ethanol and other low-boiling-point substances by reduced pressure distillation to obtain a product, and repeating the steps for three times to respectively obtain 10-1, 10-2 and 10-3 of the product.

Example 11

Taking the mass of the silicone prepolymer A as 500g, adding 300g of ethanol, heating to a reflux state, refluxing for 2h, introducing no nitrogen in the refluxing process, then carrying out reduced pressure distillation to remove toluene and ethanol to obtain a product, and repeating for three times to respectively obtain products 11-1, 11-2 and 11-3.

The silicone resins prepared in the above examples were tested and the results are shown in table 1.

Table 1 results of examples