Aqueous emulsion of a sizing agent

Patent metadata

Field	Value
Publication number	US-2016010282-A1
Application number	US-201414771868-A
Country	US
Kind code	A1
Filing date	Feb 24, 2014
Priority date	Mar 1, 2013
Publication date	Jan 14, 2016
Grant date	—

Abstract

A method of preparing an aqueous emulsion of a sizing agent for use in a papermaking process comprising, emulsifying the sizing agent into an aqueous liquid, in which an aqueous dispersion of a water-soluble polymer of N-vinylformamide and/or N-vinylacetamide units is added to either the sizing agent or the aqueous liquid before, during or after emulsification, wherein the dispersion contains, based on 100 parts by weight of water, (A) from 0.1 to 80 parts by weight of a water-soluble polymer containing N-vinylformamide units and/or N-vinylacetamide units, and (B) from 0.02 to 50 parts by weight of at least one polymeric dispersant.

First claim

1 . A method of preparing an aqueous emulsion of a sizing agent for use in a papermaking process comprising,
emulsifying the sizing agent into an aqueous liquid,
in which an aqueous dispersion of a water-soluble polymer of N-vinylformamide and/or N-vinylacetamide units is added to either the sizing agent or the aqueous liquid before, during or after emulsification,
wherein the dispersion contains, based on 100 parts by weight of water,
(A) from 0.1 to 80 parts by weight of the water-soluble polymer containing N-vinylformamide units and/or N-vinylacetamide units, and
(B) from 0.02 to 50 parts by weight of at least one polymeric dispersant.

2 . The method according to claim 1 , wherein the sizing agent is alkenyl succinic anhydride (ASA).

3 . The method according to claim 1 , wherein the dispersion contains, based on 100 parts by weight of water,
(A) from 5 to 80 parts by weight of the water-soluble polymer containing N-vinylformamide units and/or N-vinylacetamide units and (B) from 1 to 50 parts by weight of the at least one polymeric dispersant.

4 . The method according to claim 3 , wherein the dispersion contains, based on 100 parts by weight of water,
(A) from 10 to 50 parts by weight of the water-soluble polymer containing N-vinylformamide units and/or N-vinylacetamide units and (B) from 5 to 40 parts by weight of the at least one polymeric dispersant.

5 . The method according to claim 1 , wherein the polymeric dispersant (B) is selected from the group consisting of carboxymethylcellulose, water soluble starch, starch esters, starch xanthates, starch acetates, dextran, polyalkylene glycols, polyvinyl acetate, polyvinyl alcohol, polyvinylpyrrolidone, polyvinylpyridine, polyethylenimine, polyvinylimidazole, polyvinylsuccinimide and polydiallyl dimethyl ammonium chloride.

6 . The method according to claim 1 , wherein the dispersion contains as component (A) a homopolymer of N-vinylformamide.

7 . The method according to claim 1 , wherein the N-vinylformamide units and/or vinylacetamide units of the polymer (A) have been partially or completely converted into a polymer containing vinyl amine units by hydrolysis.

8 . The method according to claim 1 wherein 5 to 30 mol % of the N-vinylformamide units and/or vinylacetamide units of the polymer (A) have been converted into vinyl amine units by hydrolysis.

9 . The method according to claim 1 wherein the polymer (A) has an average molar mass M w of at least 1 million daltons.

10 . An aqueous emulsion of a sizing agent obtainable by the method of claim 1 .

11 . A method of using an aqueous dispersion of a water-soluble polymer of N-vinylformamide and/or N-vinylacetamide units for the preparation of an aqueous emulsion of a sizing agent, comprising:
adding the aqueous dispersion of the water-soluble polymer of N-vinylformamide and/or N-vinylacetamide units to either the sizing agent or an aqueous liquid, before, during or after emulsification of the sizing agent into the aqueous liquid, wherein the dispersion contains, based on 100 parts by weight of water, (A) from 0.1 to 80 parts by weight of the water-soluble polymer containing N-vinylformamide units and/or N-vinylacetamide units and having a particle size of from 1 to 10 μm, and (B) from 0.02 to 50 parts by weight of at least one polymeric dispersant.

Assignees

• Basf Se

Inventors

• Haufe Ingrid
• Möller Klaus
• Kurucz Attila

Classifications

• D21H21/16 Primary

  Sizing or water-repelling agents · CPC title

• D21H17/34

  obtained by reactions only involving carbon-to-carbon unsaturated bonds · CPC title

• D21H17/15

  Polycarboxylic acids, e.g. maleic acid · CPC title

• D21H17/72

  of organic material · CPC title

• D21H17/37

  Polymers of unsaturated acids or derivatives thereof, e.g. polyacrylates · CPC title