CN-119930900-B - Degradable environment-friendly paper cup interior coating and preparation method thereof

CN119930900BCN 119930900 BCN119930900 BCN 119930900BCN-119930900-B

Abstract

The invention relates to the technical field of environment-friendly materials and preparation thereof, in particular to a degradable environment-friendly paper cup interior coating and a preparation method thereof. The method comprises the steps of firstly synthesizing a polymerizable quaternary ammonium salt surfactant (RPKO-X), and then introducing the polymerizable quaternary ammonium salt surfactant and a bio-based polymer solution into a polyacrylate molecular chain simultaneously by a redox initiation polymerization mode, so as to obtain the degradable acrylic ester emulsion for coating the inside of the paper cup. According to the invention, the hydrophobic monomer RPKO-X with the characteristic of an emulsifier is introduced to form a stronger cross-linked network, so that the water resistance and oil resistance of the paint can be obviously improved, and meanwhile, the introduction of the bio-based material polyvinyl alcohol 2688 is utilized to enhance the environmental friendliness of the paint and promote the rapid degradation of the paint after use. The method is simple to prepare through a redox initiation polymerization system, can prepare under mild conditions, and has uniform and stable emulsion particle size.

Inventors

Xue Xinyan
LAI XIAOJUAN
LIU GUIRU
WANG LEI
WEN XIN
DANG ZHIQIANG
LI PENG
LIU SIYAN

Assignees

陕西科技大学

Dates

Publication Date: 20260508
Application Date: 20250110

Claims (7)

1. The preparation method of the degradable environment-friendly paper cup interior coating is characterized by comprising the following steps of: Step one, stirring 12-18 parts of long carbon chain amido dimethyl tertiary amine and 24-36 parts of absolute ethyl alcohol in a water bath, introducing nitrogen for protection, slowly dripping a mixed solution of 3-5 parts of halogenated propylene and 6-10 parts of absolute ethyl alcohol, and then heating for reaction; Step two, uniformly mixing 70-80 parts of methacrylate monomers, 2-4 parts of silane coupling agents and 1-3 parts of acrylic monomers containing hydrophilic groups to prepare a solution A; Weighing 1-2 parts of anionic emulsifier, 1-2 parts of nonionic emulsifier, 0.5-1 part of polymerizable quaternary ammonium salt surfactant, 10-20 parts of 5% polyvinyl alcohol 2688 solution, 2-4 parts of reducing agent and 100 parts of water, and mixing and dissolving to obtain solution B; weighing 2-4 parts of oxidant, and adding water for dissolution to obtain a solution C; Step five, adding the component A into the component B, and pre-emulsifying to obtain uniform acrylic resin pre-emulsion; Step six, introducing nitrogen gas 1-1.5 h into the pre-emulsion, slowly dripping the solution C by using a microinjection pump, and then controlling the temperature for reaction to obtain the degradable acrylic ester emulsion for coating the inside of the paper cup; In the step six, slowly dripping the solution C for 1-2 h hours, then controlling the temperature to be 40-50 ℃, and carrying out heat preservation reaction for 4-5 h hours; The long carbon chain amido dimethyl tertiary amine is oleic acid amido dimethyl tertiary amine, erucic acid amido dimethyl tertiary amine or palm kernel oil amido dimethyl tertiary amine; The methacrylate monomer is methyl methacrylate; the acrylic monomer containing hydrophilic groups is one or two of hydroxyethyl acrylate and hydroxypropyl acrylate.
2. The method for preparing the degradable environment-friendly paper cup interior coating according to claim 1, which is characterized by comprising the following steps: In the first step, the water bath temperature is 40-50 ℃, and the stirring speed is constant at 500-800r/min; slowly dripping the mixed solution for 3-4 h ℃, heating to 5-10 ℃ and reacting 24-30 h.
3. The method for preparing the degradable environment-friendly paper cup interior coating according to claim 2, wherein the halopropene in the first step is chloropropene or bromopropene.
4. The method for preparing the degradable environment-friendly paper cup interior paint according to claim 3, wherein in the fifth step, the pre-emulsification is performed by stirring 10-15 min at 10000-12000 r/min by a high-speed stirrer.
5. The method for preparing the degradable environment-friendly paper cup interior coating as claimed in claim 4, wherein the reducing agent is one or a mixture of two or more of sodium bisulphite, sodium sulfite, sodium thiosulfate and sodium metabisulfite in any proportion.
6. The method for preparing the degradable environment-friendly paper cup interior coating as claimed in claim 5, wherein the oxidant is one or a mixture of two or more of potassium persulfate, ammonium persulfate, sodium persulfate and tert-butyl peroxide in any proportion.
7. The degradable environment-friendly paper cup interior coating prepared by the preparation method according to claim 1.

Description

Degradable environment-friendly paper cup interior coating and preparation method thereof Technical Field The invention relates to the technical field of environment-friendly materials and preparation thereof, in particular to a degradable environment-friendly paper cup interior coating and a preparation method thereof. Background Paper cups are made of paper components and have the characteristics of portability and portability, so that the paper cups are widely applied to cold drinks and hot drinks in dining industries such as restaurants, fast food restaurants, popular milky tea shops and the like. The inner walls of the paper cups are generally coated with a layer of Polyethylene (PE) plastic film, and PE materials are uniformly coated on the inner walls of the paper cups through PE film coating technology, so that waterproof and leak-proof functions are realized, the paper cups are not easy to leak when liquid is contained, and the structural strength of the paper cups is maintained. However, with the global increased awareness of environmental protection, the problem of plastic contamination is becoming more serious. Not only is the conventional PE coating difficult to degrade, but it can have long-term negative effects on soil, water sources and organisms after the plastic waste is deposited. In order to solve the above problems, research into degradable materials as interior paper cup coatings has been paid attention, and particularly, bio-based materials are widely available and environmentally friendly. Biodegradable materials such as polylactic acid (PLA), polyhydroxyalkanoate (PHA), starch-based materials and the like have shown good application prospects in various fields. The document of application number "202280086854.9" discloses a "bio-based coating, and methods of forming and using it", a degradable bio-based coating that can be used, for example, in packaging and food containers or as a sacrificial layer, which may be formed on the outer surface of a substrate including paper or pulp starch, corrugated board, mushrooms (including mycelium), seaweed, fabric, concrete or metal. However, the high cost of raw materials results in high production cost of the bio-based material, and under some extreme environmental conditions, the performance (such as temperature resistance, chemical resistance and the like) of the bio-based coating is not ideal, so that the application range of the bio-based coating is limited. Therefore, it is important to develop a degradable environment-friendly paper cup interior coating with excellent performance and strong environmental adaptability. Disclosure of Invention The invention aims to provide a preparation method of novel degradable environment-friendly paper cup interior coating, which aims to solve the problems that the production cost of bio-based materials is high due to high raw material cost in the prior art, and the performance of bio-based coatings is not ideal and the application range of the bio-based coatings is limited under some extreme environmental conditions. In order to achieve the aim, the invention provides the following technical scheme that the preparation method of the degradable environment-friendly paper cup internal coating comprises the following steps: Step one, stirring 12-18 parts of long carbon chain amido dimethyl tertiary amine and 24-36 parts of absolute ethyl alcohol in a water bath, introducing nitrogen for protection, slowly dropwise adding a mixed solution of 3-5 parts of halogenated propylene and 6-10 parts of absolute ethyl alcohol, and then heating for reaction; Step two, uniformly mixing 70-80 parts of methacrylate monomers, 2-4 parts of silane coupling agents and 1-3 parts of acrylic monomers containing hydrophilic groups to prepare a solution A; Weighing 1-2 parts of anionic emulsifier, 1-2 parts of nonionic emulsifier, 0.5-1 part of polymerizable quaternary ammonium salt surfactant, 10-20 parts of 5% polyvinyl alcohol 2688 solution, 2-4 parts of reducing agent and 100 parts of water, and mixing and dissolving to obtain solution B; weighing 2-4 parts of oxidant, and adding water for dissolution to obtain a solution C; Step five, adding the component A into the component B, and pre-emulsifying to obtain uniform acrylic resin pre-emulsion; and step six, introducing nitrogen into the pre-emulsion for 1 to 1.5 hours, slowly dripping the solution C by using a microinjection pump, and then controlling the temperature for reaction to obtain the degradable acrylic ester emulsion for coating the inside of the paper cup. Further, in the first step, the water bath temperature is 40-50 ℃, and the stirring speed is constant at 500-800r/min. Further, in the first step, the time for slowly dripping the mixed solution is 3-4 hours, the temperature is raised to 5-10 ℃ and the reaction is carried out for 24-30 hours. In the fifth step, the pre-emulsification is performed by stirring for 10-15min with a high-speed stirrer at 10000-1200