Cationic surface sizing agent

Patent metadata

Field	Value
Publication number	US-10907307-B2
Application number	US-201616062550-A
Country	US
Kind code	B2
Filing date	Dec 28, 2016
Priority date	Dec 31, 2015
Publication date	Feb 2, 2021
Grant date	Feb 2, 2021

Abstract

Provided herein is an aqueous polymer dispersion (A) obtainable by free radical emulsion copolymerizing a first ethylenically unsaturated monomer blend having 15 to 100% by weight of at least one C1-C4-alkyl (meth)acrylate, in the presence of a water-soluble redox system having a first free radical initiator for free radical emulsion copolymerization and an aqueous prepolymer composition (B) obtainable by free radical emulsion copolymerizing in a polymerization solvent having C1-6-carboxylic acid and C1-6-carboxylic acid anhydride a second ethylenically unsaturated monomer blend with 5 to 50% by weight of at least one ethylenically unsaturated quaternary amine, and 10 to 95% by weight of at least one optionally substituted styrene, in the presence of a second free radical initiator.

First claim

The invention claimed is:

1. A process for preparation of an aqueous polymer dispersion (A), the method comprising:
free radical polymerizing, in a polymerization solvent having C 1-6 -carboxylic acid and C 1-6 -carboxylic acid anhydride, in a presence of a second free radical initiator a second ethylenically unsaturated monomer blend having:
(i) 5 to 50% by weight of at least one ethylenically unsaturated quarternary amine selected from quaternary salt of N,N,N-tri(C 1-4 -alkyl)amino C 1-4 -alkylmethacrylate or acrylate with a mineral acid or an organic acid and/or quaternary salt of N,N,N-tri(C 1-4 -alkyl)amino C 1-4 -alkyl(meth)acrylamide with a mineral acid or an organic acid,
(ii) 0 to 40% by weight of at least one ethylenically unsaturated tertiary amine selected from N,N-di(C 1-4 -alkyl)amino C 1-4 -alkylmethacrylate or acrylate and/or N,N-di(C 1-4 -alkyl)amino C 1-4 -alkyl(meth)acrylamide,
(iii) 10 to 95% by weight of at least one optionally substituted styrene,
(iv) 0 to 50% by weight of at least one C 1 -C 4 -alkyl methacrylate or acrylate, and
(v) 0 to 10% by weight of other ethylenically unsaturated copolymerizable monomers, wherein a sum of (i)+(ii)+(iii)+(iv)+(v) is 100%;
adding water to an obtained polymer composition to obtain an aqueous prepolymer composition (B); and
copolymerizing in a presence of said aqueous prepolymer composition (B) and a water-soluble redox system having a first free radical initiator for the free radical emulsion copolymerization of a first ethylenically unsaturated monomer blend having:
(a) 0 to 75% by weight of at least one optionally substituted styrene,
(b) 15 to 100% by weight of at least one C 1 -C 4 -alkyl methacrylate or acrylate, and
(c) 0 to 10% by weight of other ethylenically unsaturated copolymerizable monomers, wherein a sum of (a)+(b)+(c) is 100%,
to obtain the aqueous polymer dispersion (A).

2. The process as claimed in claim 1 , wherein a particle size D50 of the aqueous polymer dispersion (A) is less than 65 nm.

3. The process as claimed in claim 1 , wherein an amount of monomer component (i) is 15 to 30% by weight of a total weight of the second ethylenically unsaturated monomer blend.

4. The process as claimed in claim 1 , wherein the ethylenically unsaturated quaternary amine (i) is [2-(methacryloyloxy)ethyl] trimethylammonium chloride or [2-(acryloyloxy)ethyl]-trimethylammoniumchloride.

5. The process as claimed in claim 1 , wherein the C 1-6 -carboxylic acid is acetic acid.

6. The process as claimed in claim 1 , wherein the C 1-6 -carboxylic anhydride is acetic anhydride.

7. The process as claimed in claim 1 , wherein an amount of monomer component (ii) is 0%.

8. The process as claimed in claim 1 , wherein an amount of monomer component (iii) is 60 to 80% by weight of a total weight of the second ethylenically unsaturated monomer blend.

9. The process as claimed in claim 1 , wherein an amount of monomer component (iv) is 0%.

10. The process as claimed in claim 1 , wherein an amount of monomer component (v) is 0%.

11. The process as claimed in claim 1 , wherein monomer component (b) is a mixture of at least two isomeric butyl acrylates and monomer component (iv) is a mixture of at least two isomeric butyl acrylates.

12. The process as claimed in claim 1 , wherein monomer component (b) is at least one of tert-butyl acrylate and tert-butyl methacrylate.

13. The process as claimed in claim 1 , wherein an amount of monomer component (b) is over 50% by weight of a total weight of the first ethylenically unsaturated monomer blend.

14. The process as claimed in claim 1 , wherein the water-soluble redox system is a combination of hydrogen peroxide and at least one metal ion selected from a group consisting of cerium, manganese, and iron(II).

Assignees

• Kemira Oyj

Inventors

• Lepo Anneli
• Turunen Elsi
• Turkki Tarja

Classifications

• D21H11/14

  Secondary fibres (working-up waste paper D21C5/02) · CPC title

• C08F220/1803

  C3-(meth)acrylate, e.g. (iso)propyl (meth)acrylate · CPC title

• C08F220/1802

  C2-(meth)acrylate, e.g. ethyl (meth)acrylate · CPC title

• C08F212/08

  Styrene · CPC title

• C08F220/34

  Esters containing nitrogen {, e.g. N,N-dimethylaminoethyl (meth)acrylate} · CPC title