Use of a coating layer with a styrene-butadiene copolymer on a paper substrate for blocking oxygen transfer

Patent metadata

Field	Value
Publication number	US-10837140-B2
Application number	US-201615574714-A
Country	US
Kind code	B2
Filing date	May 13, 2016
Priority date	May 18, 2015
Publication date	Nov 17, 2020
Grant date	Nov 17, 2020

Abstract

The invention relates to a use of a coating layer on a paper substrate for blocking oxygen transfer through the coated paper substrate, wherein the coating layer on the paper substrate is obtainable by a process, which comprises the steps of (a) providing a paper substrate with a surface, (b) applying onto the surface of the provided paper substrate an aqueous coating mass, and (c) drying of the paper substrate with the applied aqueous coating mass to obtain the coated paper substrate, wherein the aqueous coating mass contains an aqueous dispersion of a copolymer P, which is obtainable by radically initiated emulsion polymerization of at least 40 parts by weight of styrene and 22 to 49 parts by weight of butadiene and optionally other monomers based on the sum total of the parts by weight of all monomers, which is always 100, in the presence of a first degraded starch. It relates further to a coated paper substrate obtainable with a coating mass comprising the aqueous dispersion of the copolymer P and a further saccharide, which is added after the polymerization of the monomers. It relates also to a process for manufacturing the coated paper substrate obtainable with a coating mass comprising the aqueous dispersion of the copolymer P and the further saccharide.

First claim

The invention claimed is:

1. A process for manufacturing a coated paper substrate, the process comprising:
applying onto a surface of a paper substrate an aqueous coating mass; and
drying of the paper substrate with the applied aqueous coating mass to obtain the coated paper substrate, wherein the coated paper substrate has an oxygen permeability rate of lower than 85 cm 3 oxygen per square meter and per day;
wherein:
the aqueous coating mass comprises an aqueous dispersion of a polymer P, which is obtainable by radically initiated emulsion polymerization of:
(i) at least 40 parts by weight of styrene;
(ii) 22 to 49 parts by weight of butadiene;
(iii) 0 to 5 parts by weight of an acidic monomer, which contains one ethylenically unsaturated group and at least one acid group;
(iv) 0 to 20 parts by weight of acrylonitrile;
(v) 0 to 5 parts by weight of an acrylate monomer, which is a C 1 -C 18 alkyl acrylate or a C 1 -C 18 alkyl methacrylate;
(vi) 0 to 20 parts by weight of a further monomer, which contains an ethylenically unsaturated group and which is different to the acrylate monomer, styrene, the acidic monomer, or butadiene;
the sum total of the parts by weight of the monomers (i), (ii), (iii), (iv), (v) and (vi) is 100; and
in the presence of a first degraded starch in an amount of from 30 to 80 parts by weight based on the sum total of the parts by weight of the monomers (i), (ii), (iii), (iv), (v) and (vi).

2. The process of claim 1 , wherein the aqueous mass when dried exhibits a glass transition temperature below 40° C. as determined by the norm ISO 11357-2.

3. The process of claim 1 , wherein the aqueous mass further comprises a further saccharide.

4. The process of claim 3 , wherein the weight ratio of the sum of the monomers (i), (ii), (iii), (iv), (v) and (vi) and the first degraded starch to the further saccharide is from 5 to 0.25.

5. The process of claim 3 , wherein the amount of the further saccharide is from 21 to 720 parts by weight based on the sum total parts by weight of the monomers (i), (ii), (iii), (iv), (v), and (vi).

6. The process of claim 3 , wherein the further saccharide is a native starch, a second degraded starch, which can chemically be similar to the first degraded starch, a chemically modified starch, a cellulose, a hemicellulose, or a xyloglucane.

7. A coated paper substrate comprising a paper substrate and a coating layer thereon that is configured to block oxygen transfer through the paper substrate,
wherein the coating layer comprises:
a first degraded starch; and
a polymer P which is the polymerization product of a radically initiated emulsion in the presence of 30 to 80 parts by weight of the first degraded starch, the emulsion comprising:
(i) at least 40 parts by weight of styrene;
(ii) 22 to 49 parts by weight of butadiene;
(iii) 0 to 5 parts by weight of an acidic monomer, which contains one ethylenically unsaturated group and at least one acid group;
(iv) 0 to 20 parts by weight of acrylonitrile;
(v) 0 to 5 parts by weight of an acrylate monomer, which is a C 1 -C 18 alkyl acrylate or a C 1 -C 18 alkyl methacrylate; and
(vi) 0 to 20 parts by weight of an ethylenically unsaturated monomer other than styrene, butadiene, the acidic monomer, and acrylate monomer;
wherein:
the sum total of the parts by weight of (i), (ii), (iii), (iv), (v) and (vi) is 100; and
the coated paper substrate has an oxygen permeability rate of lower than 85 cm 3 oxygen per square meter and per day.

8. The coated paper substrate of claim 7 , wherein the coating layer exhibits a glass transition temperature below 40° C. as determined by the norm ISO 11357-2.

9. The coated paper substrate of claim 7 , wherein the coating layer comprises from 5 to 80 parts by weight of the first degraded starch based on the sum total parts by weight of the monomers (i), (ii), (iii), (iv), (v) and (vi).

10. The coated paper substrate of claim 7 , wherein the emulsion comprises at least 45 parts by weight of styrene.

11. The coated paper substrate of claim 7 , wherein the emulsion comprises 30 to 45 parts by weight of butadiene.

12. The coated paper substrate of claim 7 , wherein the acidic monomer is an α,β-ethylenically unsaturated C 3 -C 6 carboxylic acid.

13. The coated paper substrate of claim 7 , wherein the emulsion comprises 0 parts by weight of the acrylonitrile, 0 parts by weight of the acrylate monomer, or 0 parts by weight of acrylonitrile and acrylate monomer.

14. The coated paper substrate of claim 7 , wherein the emulsion comprises 0 to 5 parts by weight of the further monomer.

15. The coated paper substrate of claim 7 , wherein the coating layer further comprises an auxiliary ingredient in an amount of 0 to 15 parts by weight based on the sum total of the parts by weight of the monomers (i), (ii), (iii), (iv), (v) and (vi).

16. The coated paper substrate of claim 7 , wherein the paper substrate is a paper or a cardboard.

17. The coated paper substrate of claim 7 , wherein the coated paper substrate is a segment of a wall of a container suitable for packaging which possesses an interior room completely surrounded by the wall, wherein from 45% to 100% of the area of the wall based on the overall area of the wall is the segment.

18. The coated paper substrate of claim 7 , wherein the aqueous dispersion further comprises a further saccharide which is added after the polymerization of the monomers (i), (ii), (iii), (iv), (v), and (vi).

19. The coated paper substrate of claim 18 , wherein the amount of the further saccharide is from 21 to 720 parts by weight based on the sum total parts by weight of the monomers (i), (ii), (iii), (iv), (v), and (vi).

20. The coated paper substrate of claim 18 , wherein the weight ratio of the sum of the monomers (i), (ii), (iii), (iv), (v), and (vi) and the amount of the first degraded starch to the amount of the further saccharide is from 5 to 0.25.

21. The coated paper substrate of claim 18 , wherein the further saccharide is a native starch, a second degraded starch, which can chemically be similar to the first degraded starch, a chemically modified starch, a cellulose, a hemicellulose, or a xyloglucane.

Assignees

• Basf Se

Inventors

• Seyffer Hermann
• Cimpeanu Carmen-Elena
• Smit Theo
• Veling Nico
• Schmidt-Thuemmes Juergen
• Lawrenz Dirk
• Blum Rainer

Classifications

• C09D109/06 Primary

  Copolymers with styrene · CPC title

• D21H19/54

  Starch · CPC title

• D21H27/18

  Paper- or board-based structures for surface covering · CPC title

• C08F236/10

  with vinyl-aromatic monomers · CPC title

• D21H19/22

  Polyalkenes, e.g. polystyrene · CPC title