阅读说明：本技术 一种氰基改性的有机硅合成革涂层制备方法 (Preparation method of cyano-modified organic silicon synthetic leather coating ) 是由 范浩军 王文凯 孙哲 李静 陈意 颜俊 向均 文嘉婷 于 2020-07-13 设计创作，主要内容包括：本发明公开了一种氰基改性的有机硅合成革涂层制备方法。利用含氢聚硅氧烷(含氢硅油)中活性氢与乙烯基腈单体中双键的配位加成反应,合成了一种侧链带极性氰基的含氢硅油,然后将其共价引入到有机硅合成革涂层中,有效提升了有机硅合成革涂层的表面张力、再涂性、粘接性及耐溶剂性。另外,本发明所提出的改性有机硅涂层在制备过程中不使用任何有机溶剂,可实现生产过程的清洁化,符合消费者的绿色、健康需求和行业发展趋势,对皮革、合成革、纺织涂层及低能表面的涂层、粘接具有指导意义。(The invention discloses a preparation method of a cyano-modified organic silicon synthetic leather coating. Active hydrogen in hydrogen-containing polysiloxane (hydrogen-containing silicone oil) is utilized to perform coordination addition reaction with double bonds in vinyl nitrile monomers to synthesize hydrogen-containing silicone oil with polar cyano groups on side chains, and then the hydrogen-containing silicone oil is covalently introduced into the organic silicon synthetic leather coating, so that the surface tension, recoatability, adhesiveness and solvent resistance of the organic silicon synthetic leather coating are effectively improved. In addition, the modified organic silicon coating provided by the invention does not use any organic solvent in the preparation process, can realize the cleanness of the production process, meets the green and health requirements of consumers and the industry development trend, and has guiding significance for the coating and bonding of leather, synthetic leather, textile coatings and low-energy surfaces.)

1. A preparation method of a cyano-modified organic silicon synthetic leather coating is characterized by comprising the following steps of:

(1) preparation of cyano-modified hydrogenpolysiloxane: adding 10-20 parts of hydrogen-containing polysiloxane and 1-3 parts of vinyl nitrile monomer into a reaction kettle, controlling the molar ratio of C = C and Si-H to be 0.5-0.8, heating to 75-85 ℃, adding 0.3-0.6 part of platinum catalyst and 0.1-0.2 part of polymerization inhibitor, reacting for 3-4H at 75-85 ℃, determining the residual Si-H group by bromoacetic acid titration to react to a theoretical value, preparing cyano-modified hydrogen-containing polysiloxane, and sealing for later use;

(2) preparation of cyano-modified organosilicon synthetic leather coating: adding 1-5 parts of cyano-modified hydrogen-containing polysiloxane prepared in the step (1) into a mixed solution of 10-20 parts of vinyl polysiloxane, 1-2 parts of platinum catalyst and 0.1-0.2 part of inhibitor, fully mixing, coating the mixed solution on the surface of release paper, vulcanizing in a vacuum oven at 120 ℃, transferring the coating to the surface of base cloth, and attaching to obtain the cyano-modified organic silicon synthetic leather coating.

2. The method for preparing a cyano-modified organosilicon synthetic leather coating according to claim 1, wherein the hydrogen-containing polysiloxane is hydrogen-containing silicone oil with hydrogen content of 1.0-1.6%, and the hydrogen atom is located at the side chain of polysiloxane.

3. The method for preparing a cyano-modified organosilicon synthetic leather coating according to claim 1, wherein the vinyl nitrile monomer is one or a combination of acrylonitrile, 3-butenenitrile, 5-hexenenitrile and 3, 7-dimethyl-6-octenenitrile.

4. The method for preparing a cyano-modified organosilicon synthetic leather coating according to claim 1, wherein the platinum catalyst is chloroplatinic acid (H)₂PtCI₆·6H₂O) isopropanol solution (Sphaer catalyst), complexes of platinum-1, 3-divinyl-1, 1,3, 3-tetramethyldisiloxane (Kalset catalyst) or combinations thereof.

5. The method for preparing a cyano-modified organosilicon synthetic leather coating according to claim 1, wherein the polymerization inhibitor is one or a combination of hydroquinone, phenothiazine and p-hydroxyanisole.

6. The method for preparing the cyano-modified organic silicon synthetic leather coating according to claim 1, wherein the vinyl polysiloxane is double bond terminated vinyl silicone oil (vinyl content: 0.05-0.43%, structural general formula: CH)₂=CH(CH₃)₂-Si-O-[(CH₃)₂SiO]_nSi(CH₃)₂CH=CH₂Wherein n =200 to 3000), tetramethyltetravinylcyclotetrasiloxane (vinyl content: 30%, the structural formula is: [ CH ]₃(CH₂=CH)SiO]₄) And polyvinyl silicone oil (vinyl content: 0.2-2.3% of vinyl, mainly located in a branched chain).

7. The method for preparing a cyano-modified silicone synthetic leather coating according to claim 1, wherein the inhibitor is one or a combination of methylbutynol, phenylbutynol and ethynylcyclohexanol.

Technical Field

The invention relates to a preparation method of a cyano-modified organic silicon synthetic leather coating, belonging to the technical field of organic silicon materials.

Background

Silicon is the most abundant element in the earth crust, does not depend on petrochemical resources, and organic silicon is an environment-friendly material, has the excellent performances of no toxicity, environmental protection, weather resistance, water resistance, wear resistance, physiological inertia and the like, and is widely applied to industries such as leather/synthetic leather finishing, automobile polishing, daily chemicals, textile and the like in the form of additives or modifiers. With the development of the silicone industry and manufacturing technology, silicone gradually begins to enter the coating fields of leather/synthetic leather, textile and the like as a coating material.

Chinese patent CN108221396B discloses a healthy and safe silicone rubber leather and a coating process thereof, and the raw materials of the composition comprise a silicone rubber raw material which is safe for human health and a bright hand feeling oil. The addition type silicon rubber has the advantages that the active groups only contain vinyl and silicon hydrogen bonds, belong to a two-component addition reaction system, have no byproducts, and have no adverse reaction on human bodies; chinese patent CN108035161B discloses a silicone rubber leather without volatile organic compounds, which comprises a silicone rubber raw material without volatile organic compounds and a bright coating raw material without volatile organic compounds. The method can directly coat and produce the synthetic leather without adding any organic solvent, has zero discharge amount of VOCs, and belongs to environment-friendly materials.

Although the organic silicon material has many advantages, the low polarity (low surface tension) caused by the weak intermolecular interaction force due to the shielding effect of a large amount of methyl groups on the side chain of the polysiloxane and the low polarity (low surface tension) causes the problems of insufficient adhesion with polar substrates, poor surface recoatability, poor solvent resistance and the like when the organic silicon is used as leather, synthetic leather and textile coatings. Poor recoatability is shown in that coatings such as organic silicon synthetic leather are difficult to wet and spread by a surface treatment agent in surface treatment procedures such as brightening, delustering, printing, color changing and the like, so that the appearance and style diversification of products are not facilitated; poor adhesion is shown by the difficulty in bonding the organic silicon coating with the base cloth/material, and low peel strength, for example, the adhesion with the sole material is low when the shoe leather is made into a product; organic silicon synthetic leather coatings with poor solvent resistance are easy to swell or peel when meeting solvents, and further the finished leather performance is reduced. These problems limit the further popularization and application of the organic silicon coating material in the fields of synthetic leather and the like.

Disclosure of Invention

The invention aims to provide a preparation method of a cyano-modified organic silicon synthetic leather coating aiming at the defects of the prior art. Firstly, the coordination addition reaction of active hydrogen in hydrogen-containing siloxane (hydrogen-containing silicone oil) and double bonds in vinyl nitrile monomers is utilized to synthesize hydrogen-containing polysiloxane with a side chain containing polar cyano groups, and then the modified hydrogen-containing polysiloxane is introduced into the organic silicon synthetic leather coating, so that the surface tension, the base cloth bonding force and the solvent resistance of the organic silicon synthetic leather coating are improved, and no organic solvent is used in the production process, so that the requirements of green and environment-friendly development are met.

The invention provides a preparation method of a cyano-modified organic silicon synthetic leather coating, which is characterized by comprising the following steps:

(1) preparation of cyano-modified hydrogenpolysiloxane: adding 10-20 parts of hydrogen-containing polysiloxane and 1-3 parts of vinyl nitrile monomer into a reaction kettle, controlling the molar ratio of C = C and Si-H to be 0.5-0.8, heating to 75-85 ℃, adding 0.3-0.6 part of platinum catalyst and 0.1-0.2 part of polymerization inhibitor, and reacting for 3-4 hours at 75-85 ℃. Measuring the residual Si-H group by bromoacetic acid titration to react to a theoretical value, preparing cyano modified hydrogen-containing polysiloxane, and sealing for later use;

(2) preparation of cyano-modified organosilicon synthetic leather coating: adding 1-5 parts of cyano-modified hydrogen-containing polysiloxane prepared in the step (1) into a mixed solution of 10-20 parts of vinyl polysiloxane, 1-2 parts of platinum catalyst and 0.1-0.2 part of inhibitor, fully mixing, coating the mixed solution on the surface of release paper, curing in a vacuum oven at 120 ℃, transferring the coating to the surface of base cloth, and attaching to obtain the cyano-modified organic silicon synthetic leather coating.

The preparation method of the cyano-modified organic silicon synthetic leather coating is characterized in that the hydrogen-containing polysiloxane in the method is hydrogen-containing silicone oil with the hydrogen content of 1.0-1.6%, and the hydrogen atoms are positioned on the side chain of the polysiloxane.

The preparation method of the cyano-modified organic silicon synthetic leather coating is characterized in that the vinyl nitrile monomer in the method is one or a combination of acrylonitrile, 3-butenenitrile, 5-hexenenitrile and 3, 7-dimethyl-6-octenenitrile.

The preparation method of the cyano-modified organic silicon synthetic leather coating is characterized in that the platinum catalyst is chloroplatinic acid (H)₂PtCI₆·6H₂O) isopropanol solution (Sphaer catalyst), complexes of platinum-1, 3-divinyl-1, 1,3, 3-tetramethyldisiloxane (Kalset catalyst) or combinations thereof.

The preparation method of the cyano-modified organic silicon synthetic leather coating is characterized in that the polymerization inhibitor is one or a combination of hydroquinone, phenothiazine and p-hydroxyanisole.

The preparation method of the cyano-modified organic silicon synthetic leather coating is characterized in that the vinyl polysiloxane is double-bond end-capped vinyl silicone oil (the vinyl content is 0.05-0.43%, and the structural general formula is CH)₂=CH(CH₃)₂-Si-O-[(CH₃)₂SiO]_nSi(CH₃)₂CH=CH₂Wherein n =200 to 3000), tetramethyltetravinylcyclotetrasiloxane (vinyl content: 30%, the structural formula is: [ CH ]₃(CH₂=CH)SiO]₄) And polyvinyl silicone oil (vinyl content: 0.2-2.3% of vinyl, mainly located in a branched chain).

The preparation method of the cyano-modified organic silicon synthetic leather coating is characterized in that the inhibitor is one or a combination of methyl butynol, phenyl butynol and ethynyl cyclohexanol.

Compared with the prior art, the invention has the following positive effects:

(1) according to the invention, strong polar cyano groups are introduced into the organic silicon synthetic leather coating in a chemical bonding manner through a hydrosilylation reaction, so that the advantages of wear resistance, scratch resistance, weather resistance, cold resistance and the like of the organic silicon coating are maintained, the bonding force and surface recoatability of the organic silicon synthetic leather coating and the base cloth are effectively improved, and a foundation is laid for the performance improvement and appearance diversification of products;

(2) the introduction of the cyano can effectively improve the solvent resistance of the organic silicon synthetic leather coating, and the carbon atoms and the nitrogen atoms in the cyano are connected through triple bonds, so that the cyano is endowed with higher stability, and the swelling or peeling of the coating caused by a solvent is reduced;

(3) the invention increases the variety of hydrogen-containing polysiloxane, does not use any organic solvent in the coating process, can realize the cleanness of the production process, and the prepared modified organic silicon coating is an environment-friendly product, meets the green and healthy requirements of consumers and accords with the development trend of the industry.

Detailed Description

The present invention is described in detail by the following embodiments, it should be noted that the following embodiments are only used for further illustration of the present invention, and should not be construed as limiting the scope of the present invention, and those skilled in the art can make some insubstantial modifications and adaptations based on the above disclosure, and still fall within the scope of the present invention.