Oil-proofing agent for paper and preparation method of oil-proofing agent

Abstract

The invention discloses an oil-proofing agent for paper and a preparation method thereof, and the preparation method is characterized by comprising the following steps: firstly, adding ethanol, an acylamino monomer, vinyl acetate, a vinyl monomer and a cationic monomer into a reaction tank, then adding a certain amount of an initiator, then raising the temperature to 70-80 DEG C, carrying out heat preservation reaction for 4-8 hours, then cooling to 30-40 DEG C, and carrying out heat preservation reaction for 4-8 hours; and adding a certain amount of sodium hydroxide, reacting for 2-4 hours, adding a certain amount of deionized water, heating to 80-90 DEG C to evaporate ethanol and reaction byproducts, and after the solvent is evaporated, adding water, heating and dissolving to obtain the product. The oil-proofing agent does not contain fluorine harmful substances, and does not cause harm when being used as an oil-proofing agent in paper pulp molding or other food packaging products; by adding acylamino, hydroxyl after vinyl acetate is hydrolyzed and a cationic group, better bonding performance with a fiber-based product is achieved, and a better oil-proof effect can be achieved.

Description

Technical Field

[0001] The invention relates to an oil-proof agent for paper, in particular to an oil-proof agent for paper and a preparation method thereof. Background Art

[0002] In order to have good water and oil resistance, the oil-repellent coating in the prior art has fluorine added to the oil-repellent coating. However, fluorine is a potential carcinogen and poses a potential threat to human health. In the process of using tableware made of fluorine-containing oil-repellent, fluoride may penetrate into food or beverages and then be ingested by the human body, posing a hidden danger to human health. Therefore, an oil-repellent agent for paper and a preparation method thereof are proposed. Summary of the invention

[0003] The purpose of the present invention is to solve the above problems and to provide an oil-proofing agent for paper and a preparation method thereof.

[0004] In order to achieve the above object, the present invention provides the following technical solution: a method for preparing an oil-proofing agent for paper, characterized in that the preparation process is as follows: First, add ethanol, amide monomer, vinyl acetate, vinyl monomer, cationic monomer into the reaction tank, then add a certain amount of initiator, and then raise the temperature to 70-80°C, keep the reaction for 4-8 hours, then cool to 30-40°C, add a certain amount of sodium hydroxide, react for 2-4 hours, then add a certain amount of deionized water, raise the temperature to 80-90°C to evaporate the ethanol and reaction by-products, after the solvent is evaporated, add water and heat to dissolve to obtain the product.

[0005] More preferably, the amide monomer is at least one of acrylamide and methacrylamide, and is used in combination with sodium methacrylamide isopropyl sulfonate.

[0006] More preferably, the cationic monomer is at least two of 2-methyl-5-vinylpyridine, 1-vinylimidazole, 1-vinyl-2-methylimidazole, 2-vinylpyridine and 4-vinylpyridine.

[0007] More preferably, the oily initiator is any one of an azo initiator and azobisisobutylnitrile, and the amount used is 0.05-1% of the total weight of the monomers.

[0008] More preferably, the vinyl monomer is at least one of dodecyl vinyl ether, hexadecyl vinyl ether and octadecyl vinyl ether.

[0009] More preferably, the mass ratio of the amide monomer, vinyl acetate, vinyl monomer and cationic monomer is 5-10:100:10-30:5-10.

[0010] Further preferably, the number average molecular weight Mn of the product polymer is between 50,000 and 150,000.

[0011] Further preferably, the alcoholysis degree of the product polymer is higher than 99%.

[0012] Beneficial effects of the present invention: (1) The present invention does not contain fluorine-related harmful substances and will not cause harm when used as an oil-proof agent in pulp molding or other food packaging products; (2) By adding amide groups, hydroxyl groups after hydrolysis of vinyl acetate, and cationic groups, better binding properties with fiber-based products can be achieved, thus achieving better oil-proof effects; (3) By introducing vinyl acetate to hydrolyze hydroxyl groups and amide groups, the product molecular structure has better bonding, better film-forming properties, and better oil resistance. The paper-based material can withstand hot oil at 40°C, 80°C, and 100°C without absorption and penetration; (4) The raw materials of the product are mainly composed of vinyl raw materials. The product has better polymerization and better cationic distribution. When added to the pulp molding system and surface coating system, it can be better retained in the material with less loss. DETAILED DESCRIPTION

[0013] The following is a further description of the oil-proofing agent for paper and the preparation method thereof according to the present invention. Example 1

[0014] Add ethanol, acrylamide, 5 g of sodium methacrylamide isopropyl sulfonate, 100 g of vinyl acetate, 30 g of dodecyl vinyl ether, and 10 g of 1-vinylimidazole and 1-vinyl-2-methylimidazole to the reaction tank, add a certain amount of initiator, raise the temperature to 80°C, keep the reaction for 8 hours, cool to 30°C, add a certain amount of sodium hydroxide, react for 4 hours, add a certain amount of deionized water, raise the temperature to 80 degrees to evaporate the ethanol and reaction by-products, and after the solvent is evaporated, add water to heat and dissolve to obtain the product. Example 2

[0015] Add ethanol, acrylamide, methacrylamide, 7.5g of methacrylamide isopropyl sulfonic acid sodium salt, 100g of vinyl acetate, 50g of octadecyl vinyl ether, 5g of 1-vinyl-2-methylimidazole, 2-vinylpyridine and 4-vinylpyridine in a reaction tank, add a certain amount of initiator, raise the temperature to 75°C, keep the reaction for 4h, cool to 40°C, add a certain amount of sodium hydroxide, react for 3h, add a certain amount of deionized water, raise the temperature to 85°C to evaporate ethanol and reaction by-products, and after the solvent is evaporated, add water to heat and dissolve to obtain the product. Example 3

[0016] Add ethanol, methacrylamide, 10 g of methacrylamide isopropyl sulfonic acid sodium salt, 100 g of vinyl acetate, 40 g of hexadecyl vinyl ether, 2-methyl-5-vinylpyridine, and 7.5 g of 2-vinylpyridine to the reaction tank, add a certain amount of initiator, raise the temperature to 70°C, keep the reaction for 6 hours, cool to 35°C, add a certain amount of sodium hydroxide, react for 2 hours, add a certain amount of deionized water, raise the temperature to 90°C to evaporate the ethanol and reaction by-products, and after the solvent is evaporated, add water to heat and dissolve to obtain the product.

[0017] Application examples of the present invention when applied:

[0018] The oil-proofing agent prepared by the present invention can be applied to food paper surface coating oil-proofing treatment, pulp molding pulp internal or surface coating oil-proofing treatment, and can obtain good oil-proofing effect; Surface coating process, add sizing process on the surface of paper, add it to the sizing feeding trough according to the flow rate, two sizing processes on the front and back sides, the added amount is 10-20kg / ton of paper, and then dried and finished. The oil-proof grade can reach 12 levels, and it can withstand hot oil below 100℃; In the pulp molding process of sugarcane pulp, straw pulp, etc., the oil-proof agent is added to the mixing tank at a rate of 40-80kg / ton of paper. After mixing, it is put into the mold and the moisture content is controlled at 50-60% during molding. After drying and molding, the oil-proof agent is solidified and the oil-proof grade reaches 12, which can withstand 80-100℃ hot oil without absorption and penetration.

[0019] The protection scope of the present invention is not limited to the above embodiments and their variations. Conventional modifications and replacements made by those skilled in the art based on the contents of this embodiment all fall within the protection scope of the present invention.

Claims

1. A method for preparing an oil-proofing agent for paper, characterized in that The preparation process is as follows: First, add ethanol, amide monomer, vinyl acetate, vinyl monomer, cationic monomer into the reaction tank, then add a certain amount of initiator, and then raise the temperature to 70-80°C, keep the reaction for 4-8 hours, then cool to 30-40°C, add a certain amount of sodium hydroxide, react for 2-4 hours, then add a certain amount of deionized water, raise the temperature to 80-90°C to evaporate the ethanol and reaction by-products, after the solvent is evaporated, add water and heat to dissolve to obtain the product.

2. The oil-proofing agent prepared by the method for preparing an oil-proofing agent for paper according to claim 1, characterized in that: The amide monomer is at least one of acrylamide and methacrylamide, and is used in combination with methacrylamide isopropyl sulfonic acid sodium salt.

3. The oil-proofing agent prepared by the method for preparing an oil-proofing agent for paper according to claim 1, characterized in that: The cationic monomer is at least two of 2-methyl-5-vinylpyridine, 1-vinylimidazole, 1-vinyl-2-methylimidazole, 2-vinylpyridine and 4-vinylpyridine.

4. The oil-proofing agent prepared by the method for preparing an oil-proofing agent for paper according to claim 1, characterized in that: The oily initiator is any one of an azo initiator and azobisisobutylnitrile, and the amount used is 0.05-1% of the total weight of the monomers.

5. The oil-proofing agent prepared by the method for preparing an oil-proofing agent for paper according to claim 1, characterized in that: The vinyl monomer is at least one of dodecyl vinyl ether, hexadecyl vinyl ether and octadecyl vinyl ether.

6. The oil-proofing agent prepared by the method for preparing an oil-proofing agent for paper according to claim 1, characterized in that: The mass ratio of the amide monomer, vinyl acetate, vinyl monomer and cationic monomer is 5-10:100:10-30:5-10.

7. The oil-proofing agent prepared by the method for preparing an oil-proofing agent for paper according to claim 1, characterized in that: The number average molecular weight Mn of the product polymer is between 50,000 and 150,000.

8. The oil-proofing agent prepared by the method for preparing an oil-proofing agent for paper according to claim 1, characterized in that: The alcoholysis degree of the product polymer is higher than 99%.

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