阅读说明：本技术 一种聚氨酯-有机硅合成革涂层用反应型增容剂的制备方法 (Preparation method of reactive compatibilizer for polyurethane-organic silicon synthetic leather coating ) 是由 范浩军 孙哲 陈意 颜俊 向均 文嘉婷 王文凯 于 2020-07-13 设计创作，主要内容包括：本发明公开了一种聚氨酯-有机硅合成革涂层用反应型增容剂的制备方法。利用硅氢键与双键的配位加成反应,将聚乙二醇烯丙基甲基醚接枝于含氢硅油侧链,合成了一种带有硅氢键的反应型增容剂,并将其用于聚氨酯-有机硅互穿网络涂层体系的增容。本发明制备的反应型增容剂在有机硅和聚氨酯间起到“互溶”作用,能够有效降低聚氨酯、有机硅两相间界面张力,进而改善相容性。用其增容后的聚氨酯-有机硅涂层与增容前相比,二者互容程度提高,相分离程度减轻,互穿网络更易形成,涂层力学性能、表面极性等得到显著提升。另外,在增容剂的制备过程中不使用任何溶剂,实现了制备过程绿色化。(The invention discloses a preparation method of a reactive compatibilizer for a polyurethane-organic silicon synthetic leather coating. By utilizing the coordination addition reaction of a silicon-hydrogen bond and a double bond, polyethylene glycol allyl methyl ether is grafted on a hydrogen-containing silicone oil side chain to synthesize a reactive compatibilizer with the silicon-hydrogen bond, and the reactive compatibilizer is used for compatibilization of a polyurethane-organic silicon interpenetrating network coating system. The reactive compatibilizer prepared by the invention plays a role in mutual solubility between organic silicon and polyurethane, can effectively reduce the interfacial tension between polyurethane and organic silicon, and further improves the compatibility. Compared with the polyurethane-organic silicon coating before compatibilization, the polyurethane-organic silicon coating after compatibilization by using the composite material has the advantages that the mutual compatibility degree of the polyurethane-organic silicon coating is improved, the phase separation degree is reduced, an interpenetrating network is easier to form, and the mechanical property, the surface polarity and the like of the coating are obviously improved. In addition, no solvent is used in the preparation process of the compatibilizer, so that the preparation process is green.)

1. A preparation method of a reactive compatibilizer for a polyurethane-organic silicon synthetic leather coating is characterized by comprising the following steps of:

(1) preparation of reactive compatibilizer:

adding 6-20 parts of hydrogen-containing polysiloxane and 6-30 parts of polyethylene glycol allyl methyl ether into a reaction kettle, controlling the molar ratio of-C = C/Si-H of a system to be 0.3-0.6, heating to 85 ℃, adding 1-2 parts of chloroplatinic acid catalyst under stirring, and reacting at 100-120 ℃ for 1-2 hours to prepare a reactive compatibilizer containing a polyethylene glycol side chain;

(2) preparing a polyurethane-organic silicon synthetic leather coating:

60-95 parts of vinyl polysiloxane, 1-7 parts of hydrogen-containing polysiloxane, 2-5 parts of liquid diisocyanate, 20-45 parts of liquid polyol, 0-0.2 part of organic bismuth catalyst, 2-8 parts of the prepared reactive compatibilizer (1), 1-2 parts of chloroplatinic acid catalyst, 0.2-0.4 part of methyl butynol and 10-20 parts of white carbon black are quickly mixed at normal temperature, then the mixture is injected and coated on the surface of release paper, the mixture is reacted in an oven at 120-130 ℃ for 8-10 min, then the mixture is transferred to the surface of base cloth for bonding, and the solvent-free polyurethane-organosilicon synthetic leather coating is obtained after further curing.

2. The method for preparing the reactive compatibilizer for the polyurethane-organic silicon synthetic leather coating according to claim 1, wherein the hydrogen-containing polysiloxane is hydrogen-containing silicone oil with the hydrogen content of 0.8-1.6%, and the hydrogen atoms are positioned on the side chain of the polysiloxane.

3. The preparation method of the reactive compatibilizer for the polyurethane-organic silicon synthetic leather coating according to claim 1, wherein the molecular weight of the polyethylene glycol allyl methyl ether is 290-1000 g/mol, and the general structural formula is as follows: CH (CH)₂=CHCH₂O(CH₂CH₂O)_nCH₃Wherein n =5~ 20.

4. The method for preparing the reactive compatibilizer for polyurethane-organic silicon synthetic leather coating according to claim 1, wherein the vinyl polysiloxane is double-ended vinyl silicone oil (vinyl content: 0.05-0.43%, structural general formula: CH)₂=CH(CH₃)₂Si-O-[(CH₃)₂Si-O]_nSi(CH₃)₂CH=CH₂Wherein n =200 to 3000), polyvinyl silicone oil (vinyl content: 0.2-2.3% of vinyl, mainly located in a branched chain).

5. The method for preparing the reactive compatibilizer for polyurethane-silicone synthetic leather coating according to claim 1, wherein the liquid diisocyanate is one or a combination of hexamethylene diisocyanate, isophorone diisocyanate, 4-dicyclohexylmethane diisocyanate, 2, 4-toluene diisocyanate and diphenylmethane diisocyanate (MDI-50).

6. The method for preparing the reactive compatibilizer for polyurethane-organic silicon synthetic leather coating according to claim 1, wherein the liquid polyalcohol is one of polyethylene glycol with number average molecular weight of 600-1000, polypropylene glycol with number average molecular weight of 1000-4000, poly adipic acid-1, 3-butanediol glycol with number average molecular weight of 1000-2000 or a combination thereof.

Technical Field

The invention relates to a preparation method of a reactive compatibilizer for a polyurethane-organic silicon synthetic leather coating, belonging to the field of modification of high polymer materials.

Background

Organic silicon is a chemical material produced independently of petrochemical resources, and has been widely applied to the industries of textile auxiliaries, automobiles, daily chemicals, biomedicine and the like because of the excellent characteristics of environmental protection, no toxicity, good weather resistance, hydrophobicity, flame retardancy, physiological inertia and the like. With the development of the organic silicon industry, organic silicon resin based on a solvent-free two-component silicon-hydrogen addition system has entered the fields of textile, synthetic leather coating and the like. For example, chinese patent CN205688265U discloses a super soft silicone leather, which comprises a first silicone rubber layer, a second silicone rubber layer, a super soft silicone rubber layer and a base material, which are sequentially arranged from top to bottom, so as to endow the leather with soft and plump texture. However, although the organosilicon coating has many advantages, due to the structural characteristics of the material, when the organosilicon coating is used as a coating material such as synthetic leather, the organosilicon coating has the problems of insufficient mechanical strength (tensile strength is less than or equal to 5MPa and elongation is less than or equal to 400%), low surface tension, poor adhesion with a base material and the like, and further development and application of the organosilicon coating in the field of synthetic leather are limited. Therefore, it is a hot point of research to develop a composite material which not only has excellent performance of organic silicon, but also simultaneously gives consideration to or satisfies various performances required by a synthetic leather coating material.

Polyurethane is a polar high molecular material containing repeated carbamate bond structure (-NHCOO-) formed by polyaddition reaction of polyisocyanate and polyol (including polyester polyol and polyether polyol). The polyurethane resin can be regarded as a block copolymer in which soft segments and hard segments are alternately connected. The soft segment determines the adhesion, elongation at break, etc. of the resin, and the hard segment determines the modulus, strength, etc. of the resin, and the molecular chain often contains polar groups such as ester group, ether group, urea bond, urethane bond, etc. Due to the specific structure, the polyurethane resin has a plurality of excellent properties, such as excellent mechanical properties, adhesive force, wide hardness and hardness adjustable range, and the like, and is widely applied to synthetic leather coatings. And is therefore also very suitable for modifying silicone coating materials. For example, chinese patent CN109722917A discloses a method for improving the surface tension and recoatability of an organic silicon synthetic leather coating. The polar polyurethane chain segment capped by the double bond is introduced into the organic silicon synthetic leather coating material by utilizing the coordination addition reaction of the silicon-hydrogen bond and the double bond, so that the surface tension and the coating property of the organic silicon synthetic leather coating are improved, and the technical problems of poor adhesion with a base cloth, poor wetting and leveling property of after finishing and poor recoatability caused by low surface energy of a single organic silicon synthetic leather coating are effectively solved. The polyurethane is introduced into the organic silicon, so that the advantages of the organic silicon and the polyurethane material can be complemented, and the defects of the organic silicon coating in mechanical property, surface tension and base material bonding force can be effectively overcome while the excellent performance of the organic silicon coating is kept.

However, since the chemical structures and polarities of silicone and polyurethane are different greatly, the direct mixing of the two tends to cause delamination due to poor compatibility, and the unstable two-phase morphology may cause a decrease in the final overall properties, which is not the intended purpose.

Disclosure of Invention

The invention aims to provide a preparation method of a reactive compatibilizer for a polyurethane-organic silicon synthetic leather coating aiming at the defects of the prior art. The coordination addition reaction of silicon-hydrogen bonds in hydrogen-containing polysiloxane and double bonds in polyethylene glycol allyl methyl ether is utilized to graft semi-polar polyether side chains into the hydrogen-containing polysiloxane to prepare the reactive compatibilizer, and the reactive compatibilizer is used for compatibilization of a polyurethane-organosilicon interpenetrating network coating system.

The invention provides a preparation method of a reactive compatibilizer for a polyurethane-organic silicon synthetic leather coating, which is characterized by comprising the following steps of:

(1) preparation of reactive compatibilizer:

adding 6-20 parts of hydrogen-containing polysiloxane and 6-30 parts of polyethylene glycol allyl methyl ether into a reaction kettle, controlling the molar ratio of-C = C/Si-H of a system to be 0.3-0.6, heating to 85 ℃, adding 1-2 parts of chloroplatinic acid catalyst under stirring, and reacting at 100-120 ℃ for 1-2 hours to prepare a reactive compatibilizer containing a polyethylene glycol side chain;

(2) preparing a polyurethane-organic silicon synthetic leather coating:

60-95 parts of vinyl polysiloxane, 1-7 parts of hydrogen-containing polysiloxane, 2-5 parts of liquid diisocyanate, 20-45 parts of liquid polyol, 0-0.2 part of organic bismuth catalyst, 2-8 parts of the prepared reactive compatibilizer (1), 1-2 parts of chloroplatinic acid catalyst, 0.2-0.4 part of methyl butynol and 10-20 parts of white carbon black are quickly mixed at normal temperature, then the mixture is injected and coated on the surface of release paper, the mixture is reacted in an oven at 120-130 ℃ for 8-10 min, then the mixture is transferred to the surface of base cloth for bonding, and the solvent-free polyurethane-organosilicon synthetic leather coating is obtained after further curing.

The preparation method of the reactive compatibilizer for the polyurethane-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 0.8-1.6%, and the hydrogen atoms are positioned on the side chain of the polysiloxane.

The preparation method of the reactive compatibilizer for the polyurethane-organic silicon synthetic leather coating is characterized in that the molecular weight of the polyethylene glycol allyl methyl ether is 290-1000 g/mol, and the structural general formula is as follows: CH (CH)₂=CHCH₂O(CH₂CH₂O)_nCH₃Wherein n =5~ 20.

The preparation method of the reactive compatibilizer for the polyurethane-organic silicon synthetic leather coating is characterized in that the vinyl polysiloxane is double-ended vinyl silicone oil (the vinyl content is 0.05-0.43%, and the structural general formula is CH)₂=CH(CH₃)₂Si-O-[(CH₃)₂Si-O]_nSi(CH₃)₂CH=CH₂Wherein n =200 to 3000), polyvinyl silicone oil (vinyl content: 0.2-2.3% of vinyl, mainly located in a branched chain).

The preparation method of the reactive compatibilizer for the polyurethane-organic silicon synthetic leather coating is characterized in that the liquid diisocyanate is one or a combination of hexamethylene diisocyanate, isophorone diisocyanate, 4-dicyclohexylmethane diisocyanate, 2, 4-toluene diisocyanate and diphenylmethane diisocyanate (MDI-50).

The preparation method of the reactive compatibilizer for the polyurethane-organic silicon synthetic leather coating is characterized in that the liquid polyalcohol is one or a combination of polyethylene glycol with the number average molecular weight of 600-1000, polypropylene glycol with the number average molecular weight of 1000-4000 and poly adipic acid-1, 3-butanediol glycol with the number average molecular weight of 1000-2000.

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

(1) according to the invention, the polyethylene glycol allyl methyl ether is grafted on the side chain of the hydrogenous polysiloxane to synthesize the reactive compatibilizer, so that the problem of phase separation of a polar polyurethane component and a nonpolar polysiloxane component in the mixing and reaction processes is effectively solved, and the preparation process of the compatibilizer does not need any solvent, so that the reactive compatibilizer meets the requirements of green and environmental protection;

(2) the reactive compatibilizer prepared by the invention can be covalently bonded into a polymer coating in the curing process while playing a role in compatibilization, so that a compatibilized polyurethane-organosilicon interpenetrating network coating system is more stable, and the reactive compatibilizer also has the functions of plasticizing and softening the coating;

(3) the reactive compatibilizer prepared by the invention can effectively reduce the interfacial tension between the organic silicon and the polyurethane, realizes the fusion of the organic silicon and the polyurethane at the molecular level, and obviously improves the mechanical property, the surface tension and the bonding property with a base material of the polyurethane modified organic silicon coating.

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.