Oil-resistant agent for paper

Patent metadata

Field	Value
Publication number	US-11851822-B2
Application number	US-202117169842-A
Country	US
Kind code	B2
Filing date	Feb 8, 2021
Priority date	Sep 14, 2018
Publication date	Dec 26, 2023
Grant date	Dec 26, 2023

Abstract

An oil-resistant agent for paper, which contains a non-fluorine copolymer that has a repeating unit formed from (a) an acrylic monomer having a long-chain hydrocarbon group with 7-40 carbon atoms and a repeating unit formed from (b) an acrylic monomer having a hydrophilic group. The oil-resistant agent for paper also contains a liquid medium that is composed of water and/or an organic solvent, preferably of water or a mixture (aqueous medium) of water and an organic solvent. The non-fluorine copolymer preferably has a repeating unit formed from (c) a monomer having an ion donor group in addition to the repeating units formed from the monomers (a) and (b). Also disclosed is an oil-resistant paper having an oil-resistant layer including the oil-resistant agent for paper, and starch or modified starch, on a surface of the paper as well as a method of treating paper.

First claim

The invention claimed is:

1. An oil-resistant agent for paper, comprising a fluorine-free copolymer having:
(a) a repeating unit formed from an acrylic monomer having a long-chain hydrocarbon group having 7 to 40 carbon atoms, and
(b) a repeating unit formed from an acrylic monomer having a hydrophilic group,
wherein
the acrylic monomer having a hydrophilic group (b) is at least one compound represented by the formula selected from the group consisting of:
CH 2 ═CX 2 C(═O)—O—(RO) n X 3   (b1),

CH 2 ═CX 2 C(═O)—O—(RO) n —C(═O)CX 2 ═CH 2   (b2), and

CH 2 ═CX 2 C(═O)—NH—(RO) n —X 3   (b3)

wherein
X 2 each is independently a hydrogen atom or a methyl group,
X 3 each is independently a hydrogen atom, an unsaturated or saturated hydrocarbon group having 1 to 22 carbon atoms,
R is an alkylene group having 2 to 6 carbon atoms, and
n is an integer of 1 to 90,
wherein
an amount of the repeating unit formed from the monomer (b) is 5 to 70% by weight, based on the copolymer.

2. The oil-resistant agent for paper according to claim 1 , wherein the acrylic monomer having a long-chain hydrocarbon group (a) is a monomer represented by the formula:
CH 2 ═C(—X 1 )—C(═O)—Y 1 (R 1 ) k

wherein
R 1 each is independently a hydrocarbon group having 7 to 40 carbon atoms,
X 1 is a hydrogen atom, a monovalent organic group, or a halogen atom,
Y 1 is a divalent to tetravalent group composed of at least one selected from a hydrocarbon group having one carbon atom, —C 6 H 4 —, —O—, —C(═O)—, —S(═O) 2 —, or —NH—, provided that a hydrocarbon group is excluded, and
k is 1 to 3.

3. The oil-resistant agent for paper according to claim 2 , wherein Y 1 or Y 4 is a group represented by:
—Y′—, —Y′—Y′—, —Y′—C(═O)—, —C(═O)—Y′—, —Y′—C(═O)—Y′—, —Y′—R′—, —Y′—R′—Y′—, —Y′—R′—Y′—C(═O)—, —Y′—R′—C(═O)—Y′—, —Y′—R′—Y′—C(═O)—Y′—, or —Y′—R′—Y′—R′—
wherein
Y′ each is independently a direct bond, —O—, —NH—, or —S(═O) 2 —, and
R′ is —(CH 2 ) m — wherein m is an integer of 1 to 5, a linear hydrocarbon group having 1 to 5 carbon atoms and an unsaturated bond, a hydrocarbon group having 1 to 5 carbon atoms and a branched structure, or —(CH 2 ) l —C 6 H 4 —(CH 2 ) l — wherein 1 each is independently an integer of 0 to 5, and —C 6 H 4 — is a phenylene group.

4. The oil-resistant agent for paper according to claim 1 , wherein, in the acrylic monomer having a long-chain hydrocarbon group (a), X 1 is a hydrogen atom, and the long-chain hydrocarbon group has 18 to 40 carbon atoms.

5. The oil-resistant agent for paper according to claim 1 , wherein the acrylic monomer having a long-chain hydrocarbon group (a) is:
(a1) an acrylic monomer represented by the formula:
CH 2 ═C(—X 4 )—C(═O)—Y 2 —R 2

wherein
R 2 is a hydrocarbon group having 7 to 40 carbon atoms,
X 4 is a hydrogen atom, a monovalent organic group, or a halogen atom, and
Y 2 is —O— or —NH—, and/or
(a2) an acrylic monomer represented by the formula:
CH 2 ═C(—X 5 )—C(═O)—Y 3 —Z(˜Y 4 —R 3 ) n

wherein
R 3 each is independently a hydrocarbon group having 7 to 40 carbon atoms,
X 5 is a hydrogen atom, a monovalent organic group, or a halogen atom,
Y 3 is —O— or —NH—,
Y 4 each is independently a direct bond, or a group composed of at least one selected from —O—, —C(═O)—, —S(═O) 2 —, or —NH—,
Z is a direct bond or a divalent or trivalent hydrocarbon group having 1 to 5 carbon atoms, and
n is 1 or 2.

6. The oil-resistant agent for paper according to claim 1 , wherein the fluorine-free copolymer further comprises a repeating unit formed from (c) a monomer having an olefinic carbon-carbon double bond and having an anion-donating group or a cation-donating group, other than the monomers (a) and (b).

7. The oil-resistant agent for paper according to claim 6 , wherein the anion-donating group is a carboxyl group, or the cation-donating group is an amino group.

8. The oil-resistant agent for paper according to claim 1 , wherein an amount of the repeating unit formed from the acrylic monomer having a long-chain hydrocarbon group (a) is 30 to 95% by weight, based on the copolymer.

9. The oil-resistant agent for paper according to claim 1 , wherein an amount of the repeating unit formed from the acrylic monomer having a long-chain hydrocarbon group (a) is 30 to 90% by weight, based on the copolymer, an amount of the repeating unit formed from the monomer having an anion-donating group or a cation-donating group (c) is 0.1 to 30% by weight, based on the fluorine-free copolymer, and the fluorine-free copolymer is a random copolymer.

10. The oil-resistant agent for paper according to claim 1 , wherein the fluorine-free copolymer has a melting point or a glass transition point of 20° C. or higher, and/or the fluorine-free copolymer has a dynamic viscoelasticity (a complex viscosity) of 10 to 5,000 Pa·s at 90° C.

11. The oil-resistant agent for paper according to claim 1 , further comprising a liquid medium that is water or a mixture of water and an organic solvent.

12. The oil-resistant agent for paper according to claim 1 , comprising no emulsifier, and being a self-dispersive product.

13. The oil-resistant agent for paper according to claim 1 , wherein the amount of the repeating unit formed from the monomer (b) is 8 to 50% by weight, based on the copolymer.

14. The oil-resistant agent for paper according to claim 1 , wherein the amount of the repeating unit formed from the monomer (b) is 16 to 70% by weight, based on the copolymer.

15. The oil-resistant agent for paper according to claim 1 , wherein the acrylic monomer having a hydrophilic group (b) is at least one compound represented by the formula selected from the group consisting of (b2) and (b3).

16. Oil-resistant paper having an oil-resistant layer comprising the oil-resistant agent for paper according to claim 1 , and starch or modified starch, on a surface of the paper.

17. The oil-resistant paper according to claim 16 , wherein the oil-resistant agent for paper in the oil-resistant layer has a solid content of 2 g/m 2 or less.

18. Oil-resistant paper comprising the fluorine-free copolymer of the oil-resistant agent for paper according to claim 1 inside the paper.

19. The oil-resistant paper according to claim 16 , which is a food packaging material or a food container.

20. A method of treating paper, comprising treating paper with the oil-resistant agent for paper according to claim 1 by an external application treatment or an internal application treatment.

Assignees

• Daikin Ind Ltd

Inventors

• Yamamoto Yuuki
• Matsuda Michio
• Uehara Tetsuya
• Sakashita Hirotoshi

Classifications

• D21H21/18 Primary

  Reinforcing agents · CPC title

• C08F220/1812

  C12-(meth)acrylate, e.g. lauryl (meth)acrylate · CPC title

• C08F220/1818

  C13or longer chain (meth)acrylate, e.g. stearyl (meth)acrylate · CPC title

• C08F220/36

  containing oxygen in addition to the carboxy oxygen {, e.g. 2-N-morpholinoethyl (meth)acrylate or 2-isocyanatoethyl (meth)acrylate} · CPC title

• C09D5/00

  Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced {(electrically insulating plastics, resins or waxes H01B3/30)}; Filling pastes · CPC title