阅读说明：本技术 一种高耐久抗菌防霉聚氨酯合成革及其制备方法 (High-durability antibacterial mildew-proof polyurethane synthetic leather and preparation method thereof ) 是由 赵建明 陈清 徐青 徐雪明 朱继元 邹建峰 于 2020-04-14 设计创作，主要内容包括：本发明公开了一种高耐久抗菌防霉聚氨酯合成革,包括基布层和面层,面层的制备原料按质量份数包括以下组分：聚氨酯树脂100份、DMF 50～70份、环糊精3～12份、抗菌防霉剂3～10份、甲苯1～10份、流平剂1～3份、表面活性剂0～3份；抗菌防霉剂为核壳结构的二氧化硅包覆银纳米颗粒与羧甲基壳聚糖复合而成的复合抗菌防霉剂；二氧化硅包覆银纳米颗粒中的外壳为多孔结构；复合抗菌防霉剂具体是将羧甲基壳聚糖进行烷基化处理,然后将核壳结构的二氧化硅包覆银纳米颗粒负载于烷基化羧甲基壳聚糖上制备而成。本发明还公开了高耐久抗菌防霉聚氨酯合成革的制备方法。本发明的聚氨酯合成革透气透湿性好,产品档次高,且具有较优异和持久的抗菌防霉效果。(The invention discloses a high-durability antibacterial mildew-proof polyurethane synthetic leather which comprises a base cloth layer and a surface layer, wherein the surface layer comprises the following raw materials in parts by weight: 100 parts of polyurethane resin, 50-70 parts of DMF (dimethyl formamide), 3-12 parts of cyclodextrin, 3-10 parts of antibacterial and mildewproof agent, 1-10 parts of toluene, 1-3 parts of flatting agent and 0-3 parts of surfactant; the antibacterial mildew preventive is a composite antibacterial mildew preventive which is formed by compounding silicon dioxide coated silver nanoparticles with a core-shell structure and carboxymethyl chitosan; the shell in the silicon dioxide coated silver nano-particles is of a porous structure; the composite antibacterial mildew inhibitor is prepared by alkylating carboxymethyl chitosan and then loading silica-coated silver nanoparticles with a core-shell structure on the alkylated carboxymethyl chitosan. The invention also discloses a preparation method of the high-durability antibacterial mildew-proof polyurethane synthetic leather. The polyurethane synthetic leather has good air permeability and moisture permeability, high product grade and excellent and lasting antibacterial and mildewproof effects.)

1. The high-durability antibacterial mildew-proof polyurethane synthetic leather comprises a base cloth layer and a surface layer, and is characterized in that the surface layer comprises the following raw materials in parts by mass: 100 parts of polyurethane resin, 50-70 parts of DMF (dimethyl formamide), 3-12 parts of cyclodextrin, 3-15 parts of antibacterial and mildewproof agent, 1-10 parts of toluene, 1-3 parts of flatting agent and 0-3 parts of surfactant;

the antibacterial mildew preventive is a composite antibacterial mildew preventive which is formed by compounding silicon dioxide coated silver nanoparticles with a core-shell structure and carboxymethyl chitosan;

wherein the shell of the silicon dioxide coated silver nano-particles is of a porous structure; the composite antibacterial mildew inhibitor is prepared by alkylating carboxymethyl chitosan and then loading silica-coated silver nanoparticles with a core-shell structure on the alkylated carboxymethyl chitosan.

2. The high-durability antibacterial mildewproof polyurethane synthetic leather according to claim 1, which is characterized in that: the flatting agent is one or the combination of two or more of acrylic flatting agent, organic silicon flatting agent and fluorocarbon flatting agent.

3. The high-durability antibacterial mildewproof polyurethane synthetic leather according to claim 1, which is characterized in that: the alkylated carboxymethyl chitosan is prepared by adopting 3-glycidyl ether trimethoxy silane to carry out alkylation treatment on carboxymethyl chitosan.

4. The high-durability antibacterial mildewproof polyurethane synthetic leather according to claim 1, which is characterized in that: the silicon dioxide coated nano silver particle with the core-shell structure is prepared by reducing silver nitrate by hydrazine hydrate under the condition of taking CTAB as a surfactant and then coating a silicon dioxide layer by CEOS.

5. The high-durability antibacterial mildewproof polyurethane synthetic leather according to claim 1, which is characterized in that: the surfactant is a nonionic surfactant.

6. The method for preparing the polyurethane synthetic leather with high durability, antibiosis and mildewproof as claimed in any one of claims 1 to 5, which is characterized by comprising the following steps:

(1) manufacture of surface layer

Dissolving polyurethane resin in a mixed solvent of DMF and toluene, adding cyclodextrin, an antibacterial mildew preventive, toluene, a flatting agent and a surfactant, and stirring and mixing uniformly to obtain a surface layer slurry; uniformly scraping the surface layer slurry on release paper, and drying to obtain a surface layer;

(2) bonding of surface layer and base cloth

And (2) uniformly scraping and coating the adhesive on the surface layer prepared in the step (1), then adhering the surface layer on the base cloth, drying, and stripping the release paper from the surface layer to prepare the high-durability antibacterial mildew-proof polyurethane synthetic leather.

7. The preparation method of the highly durable antibacterial mildewproof polyurethane synthetic leather according to claim 6, wherein the drying temperature in the step (1) and the drying temperature in the step (2) are both 160-210 ℃.

8. The preparation method of the polyurethane synthetic leather with high durability, antibacterial property and mildew resistance as claimed in claim 6, wherein the preparation process of the antibacterial and mildew resistant agent added in the step (1) is as follows: under the condition of taking CTAB as a surfactant, reducing silver nitrate by hydrazine hydrate to prepare nano silver colloid, and then wrapping a layer of silicon dioxide with a porous structure outside the nano silver by using CEOS to prepare silicon dioxide coated silver nanoparticles with nano silver as a core and the porous silicon dioxide as a shell; 3-glycidyl ether trimethoxy silane is adopted to carry out alkylation treatment on carboxymethyl chitosan, so as to prepare alkylated carboxymethyl chitosan; adding the silicon dioxide coated silver nanoparticles into an alkylated carboxymethyl chitosan solution, loading the silicon dioxide coated silver nanoparticles with a core-shell structure on the alkylated carboxymethyl chitosan, and performing centrifugal treatment and freeze-drying to obtain the composite antibacterial mildew preventive.

Technical Field

The invention belongs to the technical field of synthetic leather, and particularly relates to high-durability antibacterial mildew-proof polyurethane synthetic leather and a preparation method thereof.

Background

The polyurethane synthetic leather is a high polymer material with special performance, has appearance, hand feeling and mechanical properties similar to those of natural leather, and is the most popular and mainstream product in the prior synthetic leather. However, the special molecular structure of polyurethane, the fiber components in the synthetic leather base cloth, the auxiliary agents contained in the synthetic leather and the like can provide rich nutrient sources for the growth of microorganisms, so that the polyurethane synthetic leather is extremely easy to be corroded by the microorganisms to rot and deteriorate, the service life of the synthetic leather is greatly shortened, and meanwhile, the growth and reproduction of surface pathogenic microorganisms can seriously threaten the health and safety of users. Therefore, the antibacterial and mildewproof functions are necessary prerequisites for improving the quality of the synthetic leather. The antibacterial mildew preventive is added in the production process of the polyurethane synthetic leather, so that the growth and the propagation of microorganisms can be effectively controlled, and the problems can be avoided.

The antibacterial and antifungal agent mainly comprises inorganic antibacterial agent, synthetic organic antibacterial agent and natural organic antibacterial agent. The inorganic antibacterial agent has many kinds, and the inorganic antibacterial agent is widely applied and is represented by metal or metal ion antibacterial agents such as silver, copper, zinc and the like and metal oxides (such as TiO)₂ZnO, etc.) inorganic nano antibacterial agents. Inorganic antibacterial agents have many advantages such as safety in use, heat resistance, good persistence, broad antibacterial spectrum, etc., and thus have become a research hotspot in the field of antibacterial agents. Among them, the silver-based antibacterial agent is an inorganic antibacterial agent having the highest antibacterial efficiency. However, silver-based antibacterial agents are liable to be discolored, and are difficult to produce and complicated in the process of using them in materials. Generally, silver ions of a silver-based antibacterial agent need to be loaded on an inorganic carrier, but the silver ions are easily discolored under illumination, and the silver ions are released too fast to realize the long-lasting antibacterial effect. The synthetic organic antibacterial agent used for synthetic leather mainly comprises compounds such as quaternary ammonium salts, biguanides, alcohols, phenols, aldehydes, organic acids, peroxides, halogens, imidazoles, thiophenes, pyridines and the like. The organic antibacterial agent has the advantages of high sterilization speed, strong sterilization capability, no toxicity of partial antibacterial agents, convenient processing, good color stability and poor heat resistance. The natural organic antibacterial agent mainly has a shellPolysaccharide, serum protein, cassia oil, thujoram oil, garlicin, natural phenols and the like, wherein most of the antibacterial agents are refined from animals and plants; the natural antibacterial agent has advantages of environmental friendliness and better biocompatibility unlike other antibacterial agents, and has disadvantages of poor stability and heat resistance.

At present, most of antibacterial agents are used independently in synthetic leather, and the antibacterial effect has certain limitations, such as narrow bactericidal spectrum of single component, large using amount, short time effect, high cost, poor biodegradability of some antibacterial agents, poor use safety and great influence on environment. If different antibacterial agents are compounded according to the antibacterial characteristics of the different antibacterial agents, the respective advantages can be exerted, and the cost for developing new antibacterial agents is saved.

Disclosure of Invention

In order to solve the technical problems, the invention aims to provide the high-durability antibacterial mildew-proof polyurethane synthetic leather and the preparation method thereof.

In order to achieve the technical purpose and achieve the technical effect, the invention is realized by the following technical scheme:

the high-durability antibacterial mildew-proof polyurethane synthetic leather comprises a base cloth layer and a surface layer, wherein the surface layer is prepared from the following raw materials in parts by mass: 100 parts of polyurethane resin, 50-70 parts of DMF (dimethyl formamide), 3-12 parts of cyclodextrin, 3-15 parts of antibacterial and mildewproof agent, 1-10 parts of toluene, 1-3 parts of flatting agent and 0-3 parts of surfactant;

the antibacterial mildew preventive is a composite antibacterial mildew preventive which is formed by compounding silicon dioxide coated silver nanoparticles with a core-shell structure and carboxymethyl chitosan;

wherein the shell of the silicon dioxide coated silver nano-particles is of a porous structure; the composite antibacterial mildew inhibitor is prepared by alkylating carboxymethyl chitosan and then loading silica-coated silver nanoparticles with a core-shell structure on the alkylated carboxymethyl chitosan.

Further, the leveling agent is one or a combination of two or more of an acrylic leveling agent, an organic silicon leveling agent and a fluorocarbon leveling agent.

Furthermore, the alkylated carboxymethyl chitosan is prepared by alkylating the carboxymethyl chitosan by using 3-glycidyl ether trimethoxy silane.

Further, the silica-coated nano silver particles with the core-shell structure are prepared by reducing silver nitrate by hydrazine hydrate under the condition that CTAB is taken as a surfactant, and then coating a silica layer by CEOS.

Further, the surfactant is a nonionic surfactant.

The invention also provides a preparation method of the high-durability antibacterial mildew-proof polyurethane synthetic leather, which comprises the following steps:

(1) manufacture of surface layer

Dissolving polyurethane resin in a mixed solvent of DMF and toluene, adding cyclodextrin, an antibacterial mildew preventive, toluene, a flatting agent and a surfactant, and stirring and mixing uniformly to obtain a surface layer slurry; uniformly scraping the surface layer slurry on release paper, and drying to obtain a surface layer;

(2) bonding of surface layer and base cloth

And (2) uniformly scraping and coating the adhesive on the surface layer prepared in the step (1), then adhering the surface layer on the base cloth, drying, and stripping the release paper from the surface layer to prepare the high-durability antibacterial mildew-proof polyurethane synthetic leather.

Further, the drying temperature in the step (1) and the drying temperature in the step (2) are both 160-210 ℃.

Further, the preparation process of the antibacterial and mildewproof agent added in the step (1) is as follows: under the condition of taking CTAB as a surfactant, reducing silver nitrate by hydrazine hydrate to prepare nano silver colloid, and then wrapping a layer of silicon dioxide with a porous structure outside the nano silver by using CEOS to prepare silicon dioxide coated silver nanoparticles with nano silver as a core and the porous silicon dioxide as a shell; 3-glycidyl ether trimethoxy silane is adopted to carry out alkylation treatment on carboxymethyl chitosan, so as to prepare alkylated carboxymethyl chitosan; adding the silicon dioxide coated silver nanoparticles into an alkylated carboxymethyl chitosan solution, loading the silicon dioxide coated silver nanoparticles with a core-shell structure on the alkylated carboxymethyl chitosan, and performing centrifugal treatment and freeze-drying to obtain the composite antibacterial mildew preventive.

The invention has the beneficial effects that:

the antibacterial mildew inhibitor in the raw materials for preparing the polyurethane synthetic leather is a composite antibacterial mildew inhibitor formed by compounding silicon dioxide coated silver nanoparticles with a core-shell structure and carboxymethyl chitosan. The silver nanoparticle coated with the silicon dioxide of the core-shell structure is prepared by reducing silver nitrate by hydrazine hydrate under the condition of taking CTAB as a surfactant and then coating a silicon dioxide layer by CEOS. The prepared silicon dioxide coated silver nano-particle is of a core-shell structure with a silicon dioxide layer as a shell and nano silver as a core, and the silicon dioxide shell is of a porous structure, so that silver ions can be released through holes of the silicon dioxide shell to realize an antibacterial effect; the silver particles are coated in the silicon dioxide shell layer, so that the silver particles can be prevented from falling off quickly, and the silver ions can be prevented from discoloring under illumination, thereby ensuring the durability of the antibacterial effect;

the invention selects chitosan as the organic antibacterial agent, which has better biocompatibility, biological nontoxicity and biodegradability, and the carboxymethyl chitosan adopted by the invention is obtained by utilizing the reaction of chitosan and monochloroacetic acid under the alkaline condition, compared with the conventional chitosan, the carboxymethyl chitosan has enhanced water solubility, enhanced antibacterial activity and enlarged antibacterial range;

according to the invention, 3-glycidyl ether trimethoxy silane is adopted to carry out alkylation treatment on carboxymethyl chitosan to prepare alkylated carboxymethyl chitosan, and then silicon dioxide coated silver nanoparticles are loaded on the alkylated carboxymethyl chitosan to prepare the composite antibacterial mildew preventive, so that the composite antibacterial mildew preventive has the advantages of an organic antibacterial agent and an inorganic antibacterial agent, overcomes the defect of a single antibacterial component, produces a synergistic effect of the organic component and the inorganic component, enhances the antibacterial effect, improves the antibacterial stability and the long-acting property, and can enable the antibacterial mildew preventive effect to have the same period and the same service life as those of a synthetic leather product.

In addition, the cyclodextrin in the raw materials for preparing the polyurethane synthetic leather is matched with the toluene, so that the air permeability and the moisture permeability of the polyurethane synthetic leather can be improved, specifically, the toluene enters cyclodextrin cup-shaped molecules during the preparation of the slurry, and the toluene is volatilized during drying, so that cavities of the cyclodextrin molecules are left, and the moisture permeability of the synthetic leather is improved. Moreover, the hydrophilic chain segment can be introduced by adding the surfactant, and the moisture permeability of the synthetic leather is improved to a certain extent.

Detailed Description

The technical solutions in the present invention will be described clearly and completely with reference to specific embodiments, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.