阅读说明：本技术 一种具有防水和自消光功能的水性聚氨酯制备方法 (Preparation method of waterborne polyurethane with waterproof and self-extinction functions ) 是由 范浩军 林智贤 章爱琴 黄国栋 陈意 向均 颜俊 于 2021-02-03 设计创作，主要内容包括：本发明公开了一种具有防水和自消光功能的水性聚氨酯制备方法,属于皮革化工材料领域。首先由含氟丙烯酸酯和醇胺反应制备有机氟醇扩链剂,然后通过分子设计控制水性聚氨酯分子量和亲水基含量,合成出以有机氟/硅为核,内交联水性聚氨酯为壳、乳液粒径4-6μm、具有防水和自消光功能的水性聚氨酯。该制备方法解决了外添加消光剂易沉降,涂层易出现折叠发白或拉伸泛白的问题。引入的有机硅/氟在成膜过程中,向表面迁移、富集,赋予涂层持久的防水性,解决了目前外添加有机氟/硅材料与水基聚氨酯相容性差和易迁移的技术难题。所制备水性聚氨酯用于合成革表面处理,涂层光泽度可低至0.5,接触角高达120～°,兼具优异的防水和自消光性。(The invention discloses a preparation method of waterborne polyurethane with waterproof and self-extinction functions, belonging to the field of leather chemical materials. Firstly, fluorine-containing acrylate reacts with alcohol amine to prepare an organic fluorine alcohol chain extender, and then molecular design is used to control the molecular weight and the hydrophilic group content of the waterborne polyurethane so as to synthesize the internally crosslinked waterborne polyurethane with organic fluorine/silicon as a coreIs water-based polyurethane with a shell, an emulsion particle size of 4-6 mu m and waterproof and self-extinction functions. The preparation method solves the problems that the external addition of the flatting agent is easy to settle, and the coating is easy to have folding blushing or stretching whitening. The introduced organic silicon/fluorine migrates and is enriched to the surface in the film forming process, so that the coating is endowed with lasting water resistance, and the technical problems of poor compatibility and easy migration of the organic fluorine/silicon material added externally and water-based polyurethane at present are solved. The prepared waterborne polyurethane is used for the surface treatment of synthetic leather, the glossiness of the coating can be as low as 0.5, and the contact angle can reach as high as 120 ° And has excellent waterproof and self-extinction properties.)

1. The method for preparing waterborne polyurethane with waterproof and self-extinction functions according to claim 1, wherein the fluorine-containing acrylate is one or a combination of hexafluorobutyl acrylate, perfluorohexylethyl acrylate, perfluorooctyl acrylate, tetrafluoropropyl acrylate and octafluoropentyl acrylate.

2. The method for preparing waterborne polyurethane with waterproof and self-extinction functions according to claim 1, wherein the alcohol amine is one or a combination of diethanolamine, diisopropanolamine, 1, 3-bis (hydroxymethyl) urea, 3-amino-1, 2-propanediol, [ (2-aminoethyl) imino ] dimethanol and 2-hydroxymethylaminoethanol.

3. The method for preparing waterborne polyurethane with waterproof and self-extinction functions according to claim 1, wherein the catalyst is one or a combination of sodium ethoxide, sodium hydride, sodium methoxide and triethylamine.

4. The method for preparing the waterborne polyurethane with the functions of water resistance and self-extinction according to claim 1, wherein the solvent is one of ethyl acetate, butyl acetate, dichloromethane, petroleum ether, N-methyl pyrrolidone and dipropylene glycol dimethyl ether.

5. The method for preparing the waterborne polyurethane with the functions of water resistance and self-extinction according to claim 1, wherein the macrodiol is one or a combination of poly (1.4-butanediol adipate), polytetrahydrofuran diol, poly (neopentyl glycol adipate) diol, polypropylene glycol, polycarbonate diol, polycaprolactone diol and hydroxyl-terminated polytetramethylene glycol.

6. The method for preparing waterborne polyurethane with waterproof and self-extinction functions according to claim 1, wherein the isocyanate is one or a combination of toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate and dicyclohexylmethane diisocyanate.

7. The method for preparing waterborne polyurethane with waterproof and self-extinction functions according to claim 1, wherein the amount of the dimethylolbutyric acid hydrophilic chain extender is 1.5-2.0 wt% of the amount of the macrodiol used in the prepolymerization of the waterborne polyurethane.

Technical Field

The invention relates to a preparation method of waterborne polyurethane with waterproof and self-extinction functions, belonging to the field of leather chemical materials.

Background

The waterborne polyurethane takes water as a dispersion medium, is nontoxic and environment-friendly, has excellent comprehensive performance, and has been widely regarded by researchers in recent years. With the continuous progress of science and technology, waterborne polyurethane is widely applied to the manufacturing fields of artificial leather/synthetic leather, furniture paint, automotive interior and the like. For synthetic leather products, besides good fastness, flexibility, extensibility and good hand feeling, the coating is also required to have various properties such as self-cleaning property, antibacterial property, water resistance, yellowing resistance and adjustable glossiness. In recent years, delustering synthetic leather products are favored by consumers and have wide market prospects in the application fields of home decoration leather, automobile leather, luggage leather, sofa leather and the like. Consumers desire a delustering synthetic leather product that has good water resistance while maintaining an excellent delustering effect.

Chinese patent publication No. CN 105462403A discloses a compound aqueous woodware single-component semi-gloss top-coat paint and a preparation method thereof, and a silicon dioxide delustering agent with good compatibility and high porosity is selected to be compounded with acrylic acid modified aqueous polyurethane to prepare the aqueous delustering top-coat paint. The semi-dull finish paint is only suitable for dull of hard substrates (such as wood paint), can not solve the problem of whitening of a coating when being used for soft substrates (such as leather and synthetic leather), and can not effectively solve the problem of easy sedimentation of a dulling agent added externally. Chinese patent publication No. CN103740250A provides a preparation method of a self-extinction leather waterborne polyurethane finishing agent. The component A with larger grain diameter and the component B with smaller grain diameter are physically blended to prepare the extinction waterborne polyurethane, when the emulsion is formed into a film, the component A can float on the surface of the coating film to form a rough surface, and the extinction effect is achieved. However, the gloss of the extinction emulsion is difficult to control below 0.5 degrees (60 degrees gloss meter, GB/T9754-2007), and the coating has no hydrophobicity, so that the application of the self-extinction aqueous polyurethane material is limited.

In conventional documents and patents, many studies have been made at home and abroad to improve the water resistance of synthetic leather. Chinese patent publication No. CN 108103797A discloses an environment-friendly polyurethane waterproof material and a preparation method thereof, wherein a component A is obtained by adopting vegetable oil polyalcohol as monomer alcohol for polymerization, and a component B is composed of diphenylmethane diisocyanate, polypropylene glycol, a filling agent, a plasticizer, chlorinated paraffin and the like to prepare a solvent-free two-component waterproof polyurethane coating. Chinese patent publication No. CN 108103797A discloses a soft and water-repellent superfine fiber synthetic leather and a preparation method thereof, the superfine fiber synthetic leather is padded in a softening treatment agent, and then hydrophobic water-based emulsion is printed on the surface of the superfine fiber synthetic leather. However, the hydrophobic component is only printed on the surface of the synthetic leather in a physical mode, and the hydrophobic component is easy to migrate and separate out in the use process, so that the waterproof effect is reduced, and the durability is insufficient.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a preparation method of waterborne polyurethane with waterproof and self-extinction functions. Firstly, preparing an organic fluoroalcohol chain extender through the reaction of fluorine-containing acrylate and alcohol amine, and then controlling the molecular weight and the hydrophilic group content of the waterborne polyurethane through molecular design to synthesize the waterborne polyurethane emulsion which takes organic fluorine/organic silicon as a core, takes the internally crosslinked waterborne polyurethane as a shell, has the emulsion particle size of 4 mu m-6 mu m and has the waterproof and self-extinction functions. The preparation method solves the problems that the external addition of the flatting agent is easy to settle, and the soft coating is easy to fold and pull white (the phenomenon of whitening in folding or stretching) and the like. The introduced organosilicon and organofluorine waterproof components migrate and enrich to the surface in the process of film formation, so that the coating is endowed with lasting waterproof property, and the technical problems that the existing externally added organofluorine/silicon waterproof material is poor in compatibility with water-based polyurethane and easy to migrate and separate out are solved. The preparation method specifically comprises the following process steps of:

a preparation method of waterborne polyurethane with waterproof and self-extinction functions specifically comprises the following process steps of:

(1) preparing an organic fluorine alcohol chain extender: reacting 2-6 parts of fluorine-containing acrylate, 1-3 parts of alcohol amine, 0.02 part of catalyst and 10-30 parts of solvent for 2-3 hours under the protection of nitrogen at 85 ℃, and removing the redundant solvent by vacuum distillation after cooling to 20-30 ℃ to obtain an organic fluorine alcohol chain extender;

(2) preparing a water-based polyurethane emulsion with waterproof and self-extinction functions: adding 50-70 parts of polyether or polyester diol, 1-3 parts of hydroxyl-terminated polysiloxane and 0.5-1 part of trimethylolpropane into a reaction bottle, adding 25-35 parts of isocyanate and 0-0.3 part of organic bismuth catalyst at 40 ℃, stirring and reacting for 1-2 hours at the temperature of 85-90 ℃, then adding 3-5 parts of organic fluorine alcohol chain extender prepared in the step (1) and metered dimethylolbutyric acid hydrophilic chain extender into the reaction bottle for reacting for 2-3 hours, cooling to 60-70 ℃, adding 1-3 parts of 1, 4-cyclohexanedimethanol for continuously reacting for 1.5-2 hours, then cooling the prepolymer to 40 ℃, adding metered triethylamine for neutralizing, adding deionized water for emulsifying and dispersing under the condition of high-speed stirring, finally adding 0.3-0.5 part of hydrazine hydrate for chain extending and reacting for 2-3 hours to obtain the polyurethane/silicone rubber with organic fluorine/organic silicon as a core, The water-based polyurethane emulsion has a shell of the internal crosslinking water-based polyurethane, has an emulsion particle size of 4-6 mu m, and has waterproof and self-extinction functions.

The fluorine-containing acrylate is one or a combination of hexafluorobutyl acrylate, perfluorohexyl ethyl acrylate, perfluorooctyl acrylate, tetrafluoropropyl acrylate and octafluoropentyl acrylate.

The secondary amine is one or the combination of diethanolamine, diisopropanolamine, 1, 3-bis-hydroxymethyl urea, 3-amino-1, 2-propanediol, [ (2-aminoethyl) imino ] dimethanol and 2-hydroxymethyl aminoethanol.

The catalyst is one or combination of sodium ethoxide, sodium hydride, sodium methoxide and triethylamine.

The solvent is one or combination of ethyl acetate, butyl acetate, dichloromethane, petroleum ether, N-methyl pyrrolidone and dipropylene glycol dimethyl ether.

The macrodiol is one or a combination of poly adipic acid-1, 4-butanediol, polytetrahydrofuran diol, poly neopentyl glycol adipate diol, polypropylene glycol, polycarbonate diol, polycaprolactone diol and hydroxyl-terminated polytetramethylene glycol.

The isocyanate is one or a combination of toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate and dicyclohexylmethane diisocyanate.

The dosage of the dimethylolbutyric acid hydrophilic chain extender is 1.5 to 2.0 weight percent of the dosage of all macromolecular diols in the waterborne polyurethane prepolymerization.

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

(1) aiming at the problem of lack of organic fluorine alcohol raw materials for the water-based polyurethane, a class of organic fluorine alcohol chain extenders are prepared, and a key material is provided for development of waterproof self-extinction water-based polyurethane;

(2) organic fluorine and organic silicon chain extenders are introduced into a water-based polyurethane molecular chain through molecular design, and organic fluorine and organic silicon hydrophobic chains migrate and enrich to the surface in the emulsion film forming process, so that the coating is endowed with lasting waterproof performance, and the technical problems that the existing externally added organic fluorine/organic silicon waterproof material is poor in compatibility with water-based polyurethane and easy to migrate and separate out are solved;

(3) by controlling the molecular weight and the hydrophilic group content of the waterborne polyurethane, the waterborne polyurethane emulsion which takes organic fluorine/organic silicon as a core, takes the internally crosslinked waterborne polyurethane as a shell, has the particle size of 4-6 mu m and has the waterproof and self-extinction functions is obtained, and the problems that the external flatting agent is easy to settle, and the coating is easy to turn white and pull white (the phenomenon of whitening during folding or stretching) and the like are solved.

Drawings

FIG. 1 is a schematic structural diagram of an aqueous polyurethane emulsion with waterproof and self-extinction functions.

Detailed Description

The invention is described in detail below with reference to examples, which are intended to be illustrative only and not to be construed as limiting the scope of the invention, and many insubstantial modifications and variations of the invention can be made by an engineer skilled in the art based on the teachings of the invention.

Example 1:

(1) preparing an organic fluorine alcohol chain extender: reacting 2 parts of octafluoropentyl acrylate, 1 part of diisopropanolamine, 0.02 part of triethylamine and 10 parts of ethyl acetate for 2 hours under the protection of 85 ℃ nitrogen, and removing excess solvent by vacuum distillation after cooling to 20-30 ℃ to obtain an organic fluorine alcohol chain extender;

(2) preparing a water-based polyurethane emulsion with waterproof and self-extinction functions: 15 parts of polycarbonate diol, 35 parts of polytetrahydrofuran diol, 1 part of hydroxyl-terminated polysiloxane and 0.5 part of trimethylolpropane are charged into a reaction flask, adding 25 parts of isophorone diisocyanate and 0.1 part of organic bismuth catalyst at 40 ℃, controlling the temperature to be 85-90 ℃, stirring and reacting for 1 hour, then 3 parts of organic fluorine alcohol chain extender and 1.5wt% of dimethylolbutyric acid hydrophilic chain extender are added into a reaction bottle for reaction for 2 hours, then cooling to 60 ℃, adding 1 part of 1.4-cyclohexanedimethanol to continue reacting for 1.5 hours, cooling to below 40 ℃, adding metered triethylamine to neutralize, adding deionized water under the condition of high-speed stirring, emulsifying and dispersing, finally adding 0.3 part of hydrazine hydrate, chain extending and reacting for 2 hours to obtain the product which takes organic fluorine/organic silicon as a core, the water-based polyurethane emulsion has a shell of the internal crosslinking water-based polyurethane, has an emulsion particle size of 4 mu m and has waterproof and self-extinction functions.

The emulsion prepared in the embodiment is used for surface treatment of a synthetic leather coating, the glossiness of the coating is 0.5 (60-degree glossiness instrument, GB/T9754-^。And the paint shows excellent hydrophobic and extinction effects.

Example 2:

(1) preparing an organic fluorine alcohol chain extender: reacting 6 parts of perfluorooctyl acrylate, 3 parts of 3-amino-1, 2-propylene glycol, 0.02 part of sodium ethoxide and 30 parts of butyl acetate under the protection of nitrogen at 85 ℃ for 3 hours, and cooling to 20-30 ℃ to remove redundant solvent by vacuum distillation to obtain an organic fluorine alcohol chain extender;

(2) preparing a water-based polyurethane emulsion with waterproof and self-extinction functions: adding 30 parts of polypropylene glycol, 10 parts of polytetrahydrofuran glycol, 30 parts of poly adipic acid-1.4-butanediol, 3 parts of hydroxyl-terminated polysiloxane and 1 part of trimethylolpropane into a reaction bottle, adding 35 parts of dicyclohexylmethane diisocyanate and 0.3 part of organic bismuth catalyst at 40 ℃, stirring and reacting for 2 hours at the temperature of 90 ℃, adding 5 parts of organic fluorine alcohol chain extender and 2.0wt% of dimethylolbutyric acid hydrophilic chain extender into the reaction bottle, continuing to react for 2 hours after cooling to 70 ℃, adding 3 parts of 1, 4-cyclohexanedimethanol to continue to react for 2 hours, cooling the prepolymer to below 40 ℃, adding metered triethylamine to neutralize, adding deionized water under the condition of high-speed stirring for emulsifying and dispersing, finally adding 0.5 part of hydrazine hydrate, performing chain extension reaction for 3 hours to obtain the polyurethane with organic fluorine/organic silicon as a core and internally crosslinked water-based polyurethane as a shell, The emulsion particle size is 6 mu m, and the water-based polyurethane emulsion has waterproof and self-extinction functions.

The emulsion prepared in the embodiment is used for surface treatment of a synthetic leather coating, the glossiness of the coating is 0.4 (60-degree glossiness instrument, GB/T9754-^。And the paint shows excellent hydrophobic and extinction effects.

Example 3:

(1) preparing an organic fluorine alcohol chain extender: 4 parts of perfluorohexyl ethyl acrylate, 2 parts of [ (2-aminoethyl) imino ] dimethanol, 0.02 part of triethylamine and 20 parts of N-methyl pyrrolidone, reacting for 2.5 hours under the protection of nitrogen at 85 ℃, and removing redundant solvent by vacuum distillation after cooling to 20-30 ℃ to obtain an organic fluorine alcohol chain extender;

(2) preparing a water-based polyurethane emulsion with waterproof and self-extinction functions: adding 20 parts of polytetrahydrofuran diol, 20 parts of poly neopentyl glycol adipate diol, 20 parts of polycaprolactone diol, 2 parts of hydroxyl-terminated polysiloxane and 0.75 part of trimethylolpropane into a reaction bottle, adding 8 parts of toluene diisocyanate, 20 parts of dicyclohexylmethane diisocyanate and 0.3 part of organic bismuth catalyst at 40 ℃, stirring and reacting for 1.5 hours at the temperature of 90 ℃, adding 4 parts of organic fluorine alcohol chain extender and 1.8wt% of dimethylolbutyric acid hydrophilic chain extender for continuous reaction for 2.5 hours, cooling to 65 ℃, adding 2 parts of 1, 4-cyclohexanedimethanol for continuous reaction for 2 hours, cooling the prepolymer to below 40 ℃, adding metered triethylamine for neutralization, adding deionized water under the condition of high-speed stirring for emulsification and dispersion, finally adding 0.4 part of hydrazine hydrate for chain extension reaction for 2.5 hours to obtain the product with organic fluorine/organic silicon as a core, the water-based polyurethane emulsion has a shell of the internal crosslinking water-based polyurethane, has an emulsion particle size of 5 mu m and has waterproof and self-extinction functions.

The emulsion prepared in the embodiment is used for surface treatment of a synthetic leather coating, the glossiness of the coating is 0.45 (60-degree gloss instrument, GB/T9754-^。And the paint shows excellent hydrophobic and extinction effects.