CN-121992682-A - Water-repellent and oil-repellent agent for coated type bending-resistant paper, and preparation method and application thereof

Abstract

The invention provides a water-repellent and oil-repellent agent for coating type bending-resistant paper, and a preparation method and application thereof, and belongs to the technical field of material chemistry. The invention discloses a water-repellent and oil-repellent agent for coated bending-resistant paper, which comprises, by mass, 8-10 parts of O-carboxymethyl chitosan, 1.5-4.5 parts of nanocellulose, 1-3 parts of nanocellulose crystals, 0.5-0.7 part of nanosilicon dioxide, 5-15 parts of ammonium citrate buffer solution, 2-6 parts of polycarbodiimide solution, 0.1-2 parts of glycerol and 40-100 parts of water. According to the invention, a crosslinking system is formed on the surface of paper by utilizing the reaction crosslinking characteristic of the polycarbodiimide and the carboxyl structure and the esterification reaction of the carboxyl and the hydroxyl structure, the O-carboxymethyl chitosan is used for providing oil resistance, the polycarbodiimide, the nano silicon dioxide and other structures are used for providing water resistance, and the surface water-repellent and oil-repellent coating is formed, so that the oil-repellent coating has the characteristic of small reduction of the oil-repellent performance after bending.

Inventors

• Bai Shuoao
• Tu Weiwen

Assignees

• 福可新材料(上海)有限公司

Dates

Publication Date

20260508

Application Date

20260320

Claims (10)

1. 1. The water-repellent and oil-repellent agent for the coated bending-resistant paper is characterized by comprising the following components in parts by mass: 8-10 parts of O-carboxymethyl chitosan; 1.5-4.5 parts of nanocellulose; 1-3 parts of nano cellulose crystal; 0.5-0.7 parts of nano silicon dioxide; 5-15 parts of ammonium citrate buffer solution; 2-6 parts of polycarbodiimide solution; 0.1-2 parts of glycerol; 40-100 parts of water.
2. 2. The water-and oil-repellent agent for coated type bending-resistant paper according to claim 1, wherein the substitution degree of the O-carboxymethyl chitosan is 0.6-1.2, and the deacetylation degree of the chitosan used for preparing the O-hydroxymethyl chitosan is more than or equal to 90%.
3. 3. The water and oil repellent agent for coated type bending-resistant paper according to claim 1, wherein the nanocellulose is cotton seed hull nanocellulose, and the nanocellulose has a length of 1-10 μm; The nano cellulose crystal is cotton seed hull nano cellulose crystal, and the length of the nano cellulose crystal is 100-500 nm.
4. 4. The water-and oil-repellent agent for coated type bending-resistant paper according to claim 1, wherein the nano silica is silane coupling agent modified nano silica, and the particle size of the nano silica is 10-50 nm.
5. 5. The water-and oil-repellent agent for coated flex paper according to claim 1, characterized in that the mass concentration of said polycarbodiimide solution is 20-30%, and the molecular weight of said polycarbodiimide is not less than 5000.
6. 6. The method for preparing the water-repellent and oil-repellent agent for coated bending-resistant paper according to any one of claims 1 to 5, comprising the steps of: Mixing nanocellulose, nanocellulose crystals and a first part of water to obtain nanocellulose-nanocellulose crystal dispersion; mixing O-carboxymethyl chitosan, ammonium citrate buffer solution, nano cellulose-nano cellulose crystal dispersion liquid, glycerol, nano silicon dioxide, polycarbodiimide solution and the rest of water, and performing dispersion treatment to obtain the water and oil repellent agent for the coated type bending-resistant paper.
7. 7. The method according to claim 6, wherein the mass ratio of the first part of water to the remaining part of water is 10-30:30-70; the dispersion treatment is ultrasonic treatment and/or homogenization treatment.
8. 8. The application of the water-repellent and oil-repellent agent for coated bending-resistant paper according to any one of claims 1 to 5 or the water-repellent and oil-repellent agent for coated bending-resistant paper prepared by the preparation method according to claim 6 or 7 in packaging materials.
9. 9. The water-repellent and oil-repellent slurry for the coated type bending-resistant paper is characterized by comprising the following components in parts by mass: 40-60 parts of water-repellent and oil-repellent agent; 1-5 parts of starch; 80-120 parts of water; The water-repellent and oil-repellent agent is the water-repellent and oil-repellent agent for coated bending-resistant paper according to any one of claims 1 to 5 or the water-repellent and oil-repellent agent for coated bending-resistant paper prepared by the preparation method according to claim 6 or 7.
10. 10. The water-repellent and oil-repellent coated paper is characterized by comprising a paper substrate and water-repellent and oil-repellent slurry coated on the surface of the paper substrate, wherein the water-repellent and oil-repellent slurry is the water-repellent and oil-repellent slurry for coated bending-resistant paper according to claim 9, and the coating amount of the water-repellent and oil-repellent slurry is 10-30 g/m 2 .

Description

Water-repellent and oil-repellent agent for coated type bending-resistant paper, and preparation method and application thereof Technical Field The invention relates to the technical field of material chemistry, in particular to a water-repellent and oil-repellent agent for coating type bending-resistant paper, a preparation method and application thereof. Background For a long time, fluorine-containing compounds, particularly copolymers containing perfluoroalkyl groups, are "gold standards" for achieving high efficiency in water and oil repellency, and the principle is to form a barrier on the surface of fibers that is both hydrophobic and oleophobic by utilizing the extremely low surface energy of the fluorocarbon chains. As early as 1978, a patent by dupont proposed a composition of a non-water soluble fluorochemical and a film forming polymer such as nitrocellulose for use in barrier coatings for paper and paperboard. However, with increasing environmental and health risks of perfluoro and polyfluoroalkyl materials, the development of fluorine-free environmental-friendly water-and oil-repellent agents is becoming an absolute mainstream of the industry. In addition, the paper product needs to undergo folding and bending processes in use, if the water-repellent and oil-repellent agent has poor bending resistance, the bending part can crack, so that the water-repellent and oil-repellent performance is invalid. The prior art discloses a scheme for preparing a water-repellent and oil-repellent agent for paper by taking PLA, chitosan and the like as raw materials, but has the defect of insufficient bending-resistant stability, and the oil-repellent performance is obviously reduced after bending. Disclosure of Invention In view of the above, the present invention aims to provide a water-repellent and oil-repellent agent for coated type bending-resistant paper, and a preparation method and application thereof. The water-repellent and oil-repellent agent for the coated bending-resistant paper has good bending-resistant stability, and can keep oil-resistant performance after bending. In order to achieve the above object, the present invention provides the following technical solutions: The invention provides a water-repellent and oil-repellent agent for coating type bending-resistant paper, which comprises the following components in parts by mass: 8-10 parts of O-carboxymethyl chitosan; 1.5-4.5 parts of nanocellulose; 1-3 parts of nano cellulose crystal; 0.5-0.7 parts of nano silicon dioxide; 5-15 parts of ammonium citrate buffer solution; 2-6 parts of polycarbodiimide solution; 0.1-2 parts of glycerol; 40-100 parts of water. Preferably, the substitution degree of the O-carboxymethyl chitosan is 0.6-1.2, and the deacetylation degree of the chitosan used for preparing the O-hydroxymethyl chitosan is more than or equal to 90%. Preferably, the length of the nanocellulose is 1-10 mu m; The length of the nano cellulose crystal is 100-500 nm. Preferably, the nano silicon dioxide is silane coupling agent modified nano silicon dioxide, and the particle size of the nano silicon dioxide is 10-50 nm. Preferably, the mass concentration of the polycarbodiimide solution is 20-30%, and the molecular weight of the polycarbodiimide is more than or equal to 5000. The invention provides a preparation method of the water-repellent and oil-repellent agent for coated bending-resistant paper, which comprises the following steps: Mixing nanocellulose, nanocellulose crystals and a first part of water to obtain nanocellulose-nanocellulose crystal dispersion; mixing O-carboxymethyl chitosan, ammonium citrate buffer solution, nano cellulose-nano cellulose crystal dispersion liquid, glycerol, nano silicon dioxide, polycarbodiimide solution and the rest of water, and performing dispersion treatment to obtain the water and oil repellent agent for the coated type bending-resistant paper. Preferably, the mass ratio of the first part of water to the rest of water is 10-30:30-70; the dispersion treatment is ultrasonic treatment and/or homogenization treatment. The invention provides application of the water-repellent and oil-repellent agent for coated bending-resistant paper in packaging materials. The invention provides water-repellent and oil-repellent slurry for coating type bending-resistant paper, which comprises the following components in parts by mass: 40-60 parts of water-repellent and oil-repellent agent; 1-5 parts of starch; 80-120 parts of water; the water-repellent and oil-repellent agent is the water-repellent and oil-repellent agent for the coated bending-resistant paper. The invention provides water-repellent and oil-repellent coated paper which comprises a paper base material and water-repellent and oil-repellent slurry coated on the surface of the paper base material, wherein the coating weight of the water-repellent and oil-repellent slurry is 10-30 g/m 2. The invention provides a water-repellent and oil-repellent agent for coa