阅读说明：本技术 一种室温固化弹塑性硅树脂组成物 (Room temperature solidified elastic-plastic silicon resin composition ) 是由 赵淑辉 于 2020-07-14 设计创作，主要内容包括：本发明公开了一种室温固化弹塑性硅树脂组成物。该组合物成分包括：A)烷氧基封端的嵌段的含有双硅脲结构的有机硅树脂；B)一种室温固化催化剂；C)至少一种如甲苯、二甲苯、乙酸乙酯、石油醚、氯仿、环己烷等的有机烃类溶剂。该组合物具有可室温固化、弹塑性、力学强度佳、电性能好的特点。本发明硅树脂组成物储存期可达3年。本发明所述室温固化弹塑性硅树脂组成物的制备方法简单易操作,适合中试放大和工业化生产。(The invention discloses a room temperature curing elastoplastic silicon resin composition. The composition comprises the following components: A) an alkoxy-terminated blocked silicone resin containing a bis-silicon urea structure; B) a room temperature curing catalyst; C) at least one organic hydrocarbon solvent such as toluene, xylene, ethyl acetate, petroleum ether, chloroform, cyclohexane, etc. The composition has the characteristics of room temperature curing, good elastoplasticity, good mechanical strength and good electrical property. The storage life of the silicon resin composition can reach 3 years. The preparation method of the room temperature curing elastoplasticity silicon resin composition is simple and easy to operate, and is suitable for pilot scale and industrial production.)

1. The room temperature curing elastic-plastic silicon resin composition is characterized in that: the silicone resin composition comprises the following components in percentage by weight:

the component A is as follows: the silicone resin is prepared by reacting and blocking a hydroxyl-blocked silicone resin intermediate with a block structure with alkoxysilane; the hydroxyl-terminated silicone resin intermediate with a block structure is prepared by copolymerizing hydroxyl-terminated linear polysiloxane and a silicone resin prepolymer containing a bis-silicon urea structure in a solvent; the mass fraction of the alkoxy-terminated silicone resin in the room-temperature-cured elastoplastic silicone resin composition is 10-90%;

and (B) component: the room temperature curing elastic-plastic silicon resin composition also comprises a room temperature curing catalyst, which comprises a basic compound and a metal-containing compound; the mass fraction of the room temperature curing catalyst for curing the elastoplastic silicon resin composition at room temperature is 0.05-5%;

and (C) component: the room temperature curing elastic-plastic silicon resin composition also comprises at least one organic solvent, wherein the organic solvent is any one of organic hydrocarbon solvents such as toluene, xylene, ethyl acetate, petroleum ether, chloroform, cyclohexane and the like; the mass ratio of the organic solvent to the solid in the room-temperature curing elastoplastic silicon resin composition is 10-90: 90-10.

2. The room temperature-curable elastoplastic silicone resin composition of claim 1, wherein: the hydroxyl-terminated linear polysiloxane is represented by structure I:

wherein R is¹Is methyl, ethyl, propyl, phenyl or a hydrocarbon radical having a carbon number of 4 or more, preferablyA methyl or phenyl group; r²Is methyl, ethyl, propyl, phenyl or a hydrocarbon group with a carbon atom of 4 or more, preferably methyl or phenyl; n is an integer greater than 0; the viscosity of the hydroxyl-terminated linear polysiloxane is 10-1000 mpa.s.

3. The room temperature-curable elastoplastic silicone resin composition of claim 2, wherein: the viscosity is 20-200 mPas.

4. The room temperature-curable elastoplastic silicone resin composition of claim 2, wherein: r²Is methyl or phenyl.

5. The room temperature-curable elastoplastic silicone resin composition of claim 1, wherein: the silicone resin prepolymer containing the bis-silicon urea structure is prepared by cohydrolysis of a bis-silicon urea containing compound shown in a structural formula II and alkoxy silane shown in a structural formula III;

R³ _4-mSi(OR⁴)_mIII

in the formula III, R³Is methyl, phenyl, ethyl, propyl or a hydrocarbon group with a carbon atom of more than or equal to 4; r⁴Is methyl, ethyl, propyl;

the content of bis-silicon urea chain links in the silicone resin prepolymer accounts for 10-90 wt% of the solid content in the silicone resin prepolymer composition, and the solid content of alkoxy silane with the structural characteristics shown in formula III accounts for 10-90 wt%.

6. The room temperature-curable elastoplastic silicone resin composition of claim 5, wherein: the R is³Methyl or phenyl, R⁴Is methyl or ethyl.

7. The room temperature-curable elastoplastic silicone resin composition of claim 1, wherein: the end-capping alkoxysilane is methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, ethyltriethoxysilane, ethyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, or the like, and methyltrimethoxysilane, ethyltrimethoxysilane, and vinyltrimethoxysilane are preferred.

8. The room temperature-curable elastoplastic silicone resin composition of claim 1, wherein: the room temperature curing catalyst is a titanium or tin compound, or a titanate compound or a chelate.

9. The room temperature-curable elastoplastic silicone resin composition of claim 1, wherein: the organic solvent is toluene or xylene.

Technical Field

The invention belongs to the technical field of chemical industry, relates to organic silicon resin in the field of silicon resin, and particularly relates to an elastic-plastic silicon resin composition cured at room temperature.

Background

The common silicone resin is prepared by hydrolytic polycondensation of hydrolyzable condensed hydrocarbyl chlorosilane or hydrocarbyl alkoxy silane, the contained hydrocarbyl group generally refers to methyl or phenyl, the curing active group can be hydroxyl or alkoxy, and most silicone resins are cured by heating, dehydrating and polycondensing. The organic silicon resin is a high polymer with Si-O bond as a main chain, and the Si-O bond has high energy and a stable structure, so the organic silicon resin has good temperature resistance, weather resistance and corrosion resistance, the service cycle of the coating can be effectively prolonged, and the maintenance cost is reduced.

Room temperature curing silicones are generally polysiloxanes containing reactive methoxy groups which can undergo condensation reactions with water in the air, which cure to form a cross-linked network linked by siloxane bonds. However, the random polymethoxy silicone resin is condensed and cured into a highly crosslinked three-dimensional network structure, and the rotation in a molecular chain is seriously hindered, so that the polymethoxy silicone resin shows high hardness, but has lower mechanical properties. In order to overcome the defects of the polymethoxy silicone resin and expand the development and application range of the polymethoxy silicone resin, a great deal of research is carried out on the polymethoxy silicone resin by organic silicon enterprises at home and abroad so as to improve the mechanical strength of the polymethoxy silicone resin.

The elastic plastic silicone material has the characteristics of both resin and rubber, and has the flexibility of rubber and a smooth surface after being cured. The resin takes linear polysiloxane and chlorosilane as raw materials, has better mechanical and electrical properties, but has the problems of short operation time, easy sagging on the surface, difficult construction and the like, and directly influences the use process. But the preparation process provides reference for the later. In 2011, Mianyang Huili discloses a patent (CN102304323A) of a room temperature curing phenyl silicone resin conformal coating, which has the characteristics of good elasticity, tough and wear-resistant surface, high and low temperature resistance, water resistance, heat resistance, cold resistance and the like. 2018, institute of New Material research, academy of sciences in Shandong province, and discloses a room temperature curing radiation-resistant silicone resin composition and a preparation method thereof (CN 108441115A). according to the invention, co-hydrolysate of phenyltrichlorosilane and arylidetetramethyldichlorodisilane is firstly prepared, then the co-hydrolysate is copolymerized with hydroxyl silicone oil to prepare hydroxyl-terminated phenylsilicone resin, and after a cross-linking agent, a catalyst and a metal radiation-resistant agent are added into the resin, the resin can be cured at room temperature to form an elastoplastic radiation-resistant silicone resin material. In 2019, Zhonglan Chen photo-chemical Co., Ltd discloses a single-component room temperature curing silicone resin containing MQ structural units and a preparation method thereof, the silicone resin is obtained by performing condensation reaction on hydrogen-containing MQ silicone resin and phenyl hydroxyl silicone oil or phenyl hydroxyl silicone resin, and then adding alkyl alkoxy silane to perform end capping in the presence of a catalyst, the silicone resin prepared by the method can remarkably increase the strength of the room temperature curing silicone resin, and the silicone resin has better mechanical property, electrical property and excellent three-proofing property after being completely cured. However, the silicone resin prepared in the prior art has low mechanical property and poor adhesive force.

Disclosure of Invention

Aiming at the defects of low mechanical property, poor adhesive force and the like of the silicone resin, the invention aims to prepare the room-temperature-curable silicone resin with elastoplasticity, good mechanical property and good adhesive force by introducing the bis-silicon urea compound and a block copolymerization technology. The invention selects a bis-silicon urea compound and an alkoxy silane monomer containing methyl or phenyl to carry out cohydrolysis to prepare a silicon resin prepolymer, and the silicon resin prepolymer and hydroxyl-terminated polysiloxane are subjected to block copolymerization to prepare a hydroxyl-terminated silicon resin intermediate with a block structure. Trialkoxysilane is added into the silicone resin intermediate in a certain proportion, and the single-component room-temperature curing elastoplastic silicone resin composition is obtained by blocking under the action of a catalyst. The resin has the characteristics of good elasticity and plasticity, good mechanical property and good adhesive force.

In order to achieve the above purpose, the specific technical solution is as follows:

the room temperature curing elastic-plastic silicon resin composition comprises the following components in percentage by weight:

the component A is as follows: the silicone resin is prepared by reacting and blocking a hydroxyl-blocked silicone resin intermediate with a block structure with alkoxysilane; the hydroxyl-terminated silicone resin intermediate with a block structure is prepared by copolymerizing hydroxyl-terminated linear polysiloxane and a silicone resin prepolymer containing a bis-silicon urea structure in a solvent; the mass fraction of the alkoxy-terminated silicone resin in the room-temperature-cured elastoplastic silicone resin composition is 10-90%;

and (B) component: the room temperature curing elastic-plastic silicon resin composition also comprises a room temperature curing catalyst, which comprises a basic compound and a metal-containing compound; the mass fraction of the room temperature curing catalyst for curing the elastoplastic silicon resin composition at room temperature is 0.05-5%;

and (C) component: the room temperature curing elastic-plastic silicon resin composition also comprises at least one organic solvent, wherein the organic solvent is organic hydrocarbon solvents such as toluene, xylene, ethyl acetate, petroleum ether, chloroform, cyclohexane and the like; the mass ratio of the organic solvent to the solid in the room-temperature curing elastoplastic silicon resin composition is 10-90: 90-10.

Specifically, the method comprises the following steps: the hydroxyl-terminated linear polysiloxane is represented by structure I:

wherein R is¹Is methyl, ethyl, propyl, phenyl or a hydrocarbon group with a carbon atom of 4 or more, preferably methyl or phenyl; r²Is methyl, ethyl, propyl, phenyl or alkyl with carbon atom more than or equal to 4; n is an integer greater than 0; the viscosity of the hydroxyl-terminated linear polysiloxane is 10-1000 mpa.s.

Preferably, the viscosity is 20-200 mpas.

Preferably, R²Is methyl or phenyl.

Specifically, the method comprises the following steps: the silicone resin prepolymer containing the bis-silicon urea structure is prepared by cohydrolysis of a bis-silicon urea containing compound shown in a structural formula II and alkoxy silane shown in a structural formula III;

R³ _4-mSi(OR⁴)_mIII

in the formula III, R³Is methyl, phenyl, ethyl, propyl or a hydrocarbon group with a carbon atom of more than or equal to 4; r⁴Methyl, ethyl and propyl.

Preferably, said R is³Methyl or phenyl, R⁴Is methyl or ethyl.

The content of the bis-silicon urea chain link in the silicone resin prepolymer accounts for 10-90 wt% of the solid content in the silicone resin prepolymer composition, and the solid content of the alkoxy silane with the structural characteristic shown in formula III accounts for 10-90 wt%.

Specifically, the method comprises the following steps: the end-capping alkoxysilane is methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, ethyltriethoxysilane, ethyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, or the like, and methyltrimethoxysilane, ethyltrimethoxysilane, and vinyltrimethoxysilane are preferred.

Specifically, the room temperature curing catalyst is a titanium or tin-containing compound, or a titanate compound or a chelate.

Specifically, the method comprises the following steps: the organic solvent is toluene or xylene.

Component A is synthesized by itself in the present invention, and component B, C can be obtained by a known method. The room temperature curing elastoplasticity silicon resin composition provided by the invention has high adhesive force, mechanical strength and good electrical property; the product has smooth surface and good flexibility after being cured; meanwhile, the composition has excellent high and low temperature resistance, weather resistance, waterproof performance and flame retardance, and in addition, the composition has good storage stability, and the shelf life of the product can reach 3 years.

Detailed Description

The following provides a more detailed description of the present invention.