Use of a single-component laminating adhesive for composite film lamination

Patent metadata

Field	Value
Publication number	US-11015091-B2
Application number	US-201716069320-A
Country	US
Kind code	B2
Filing date	Jan 10, 2017
Priority date	Jan 18, 2016
Publication date	May 25, 2021
Grant date	May 25, 2021

Abstract

A description is given of the use of a one-component laminating adhesive for composite film lamination, and also of a method for composite film lamination. The laminating adhesive comprises an aqueous polymer dispersion preparable by radical emulsion polymerization of monomers comprising (a) at least 60 wt %, based on the total amount of monomers, of at least one monomer selected from the group consisting of C1 to C20 alkyl acrylates, C1 to C20 alkyl methacrylates, vinyl esters of carboxylic acids comprising up to 20 carbon atoms, vinylaromatics having up to 20 carbon atoms, vinyl halides, vinyl ethers of alcohols comprising 1 to 10 carbon atoms, aliphatic hydrocarbons having 2 to 8 carbon atoms and one or two double bonds, and mixtures of these monomers, and (b) at least 0.1 wt %, based on the total amount of monomers, of at least one monomer having at least one acid group, and (c) 0.1 to 5 wt %, based on the total amount of monomers, of at least one ethylenically unsaturated compound having at least one functional group selected from keto groups and aldehyde groups; where the aqueous polymer dispersion comprises at least one compound A which has at least two functional groups that are able to enter into a crosslinking reaction with keto groups or with aldehyde groups; where the molar ratio of the groups of the compound A that are reactive with keto groups or with aldehyde groups to the keto and aldehyde groups of the monomer (b) is from 1:10 to 2:1; and where, in the composite film lamination, at least two films are bonded to one another with the laminating adhesive so firmly that the peel strength is 2.5 N/15 mm or more or that the films bonded to one another are partable only with destruction of at least one of the films. The composite films can be used for the packing of foods.

First claim

The invention claimed is:

1. A method for producing a composite film, comprising:
bonding, without UV cross-linking, at least two films together with a one-component laminating adhesive that comprises no UV-crosslinkable components;
wherein the laminating adhesive being present in the form of an aqueous polymer dispersion, and the aqueous polymer dispersion comprising polymer particles in dispersion in water that are obtained by radical emulsion polymerization of monomers comprising
a) 90 to 99.4 wt %, based on the total amount of monomers, of a mixture of C1 to C8 alkyl acrylates and styrene,
b) 0.1 to 5 wt %, based on the total amount of monomers, of at least one monomer having at least one acid group, and
c) 0.1 to 5 wt %, based on the total amount of monomers, of at least one ethylenically unsaturated compound having at least one functional group selected from the group consisting of keto groups and aldehyde groups;
where the aqueous polymer dispersion comprises at least one compound A which has at least two functional groups that are able to enter into a crosslinking reaction with the keto groups or with the aldehyde groups, and is present in an amount of up to 1.6 wt % based on the total amount of the monomers;
where the molar ratio of the groups of the compound A that are reactive with keto groups or with aldehyde groups to the keto and aldehyde groups of the monomer c) is in a range from 1:1.3 to 1.3:1;
where, in the composite film, the at least two films are bonded to one another with the laminating adhesive so firmly that the peel strength, measured 24 h after laminate production and at 23° C., is 2.5 N/15 mm or more or that the films bonded to one another are partable only with destruction of at least one of the films.

2. The method according to claim 1 , wherein the laminating adhesive has a tack of less than 1.7 N/25 mm, measured as loop tack in an applied thickness of 20 μm, applied to a polyester film 12 μm thick, and measured on steel at room temperature (20° C.) with a removal velocity of 300 mm/min.

3. The method according to claim 1 , wherein the polymer particles are produced from monomers further comprising
d) 0 to 10 wt %, based on the total amount of monomers, of other monomers, different from the monomers a) to c).

4. The method according to claim 3 , wherein the other monomers d) are present, and are selected from the group consisting of acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, phenyloxyethyl glycol mono(meth)acrylate, monomers comprising hydroxyl groups, monomers comprising amino groups, nitriles of alpha,beta-monoethylenically unsaturated C3-C8 carboxylic acids, bifunctional monomers which as well as an ethylenically unsaturated double bond have at least one glycidyl group, oxazoline group, ureido group or ureido-analogous group, and crosslinking monomers which have more than one radically polymerizable group.

5. The method according to claim 3 , wherein the monomers b) are selected from the group consisting of acrylic acid, methacrylic acid, and itaconic acid, and the other monomers d) are present, and are selected from the group consisting of hydroxyalkyl (meth)acrylates having 1 to 10 carbon atoms in the alkyl group.

6. The method according to claim 1 , wherein the monomers c) are selected from the group consisting of acrolein, methacrolein, vinyl alkyl ketones having 1 to 20 carbon atoms in the alkyl radical, formylstyrene, alkyl (meth)acrylates having one or two keto or aldehyde groups or having one aldehyde and one keto group in the alkyl radical, N-oxoalkyl(meth)acrylamides, acetoacetyl (meth)acrylate, acetoacetoxyethyl (meth)acrylate, and diacetoneacrylamide.

7. The method according to claim 1 , wherein the compound A comprises a compound having hydrazide, hydroxylamine, oxime ether, or amino groups.

8. The method according to claim 1 , wherein compound A is a dicarboxylic dihydrazide having 2 to 10 carbon atoms, and monomer c) is selected from the group consisting of acetoacetyl (meth)acrylate, acetoacetoxyethyl (meth)acrylate, and diacetoneacrylamide.

9. The method according to claim 1 , wherein compound A is adipic dihydrazide and monomer c) is diacetoneacrylamide.

10. The method according to claim 1 , wherein the polymer particles are produced from monomers comprising
b) 0.5 to 3 wt %, based on the total amount of monomers, of at least one monomer selected from the group consisting of acrylic acid, methacrylic acid, and itaconic acid,
c) 0.1 to 5 wt %, based on the total amount of monomers, of at least one ethylenically unsaturated compound having at least one keto group, selected from the group consisting of acetoacetyl (meth)acrylate, acetoacetoxyethyl (meth)acrylate, and diacetoneacrylamide, and
d) 0 to 5 wt %, based on the total amount of monomers, of other monomers, different from the monomers a) to c), selected from the group consisting of acrylamide, methacrylamide, N-methylolacrylamide and N-methylolmethacrylamide, phenyloxyethyl glycol mono(meth)acrylate, monomers comprising hydroxyl groups, monomers comprising amino groups, nitriles of alpha,beta-monoethylenically unsaturated C3-C8 carboxylic acids, bifunctional monomers which as well as an ethylenically unsaturated double bond have at least one glycidyl group, oxazoline group, ureido group or ureido-analogous group, and crosslinking monomers which have more than one radically polymerizable group,
and where compound A is a dicarboxylic dihydrazide having 2 to 10 carbon atoms.

11. The method according to claim 1 , wherein the material of the films to be bonded is selected from the group consisting of polyethylene, oriented polypropylene, undrawn polypropylene, polyamide, polyethylene terephthalate, polyacetate, cellophane, metalized films, and metal foils.

12. The method according to claim 1 , wherein the polymer particles have a glass transition temperature of −40 to +15° C.

13. The method according to claim 1 , wherein less than 1 part by weight of emulsifier is used per 100 parts by weight of monomers in the emulsion polymerization.

14. The method according to claim 1 , wherein the monomers comprise:
b) 0.5 to 3 wt %, based on the total amount of monomers, of at least one monomer selected from the group consisting of acrylic acid, methacrylic acid, and itaconic acid,
c) 0.1 to 5 wt %, based on the total amount of monomers, of at least one ethylenically unsaturated compound selected from the group consisting of acetoacetyl (meth)acrylate, acetoacetoxyethyl (meth)acrylate, and diacetoneacrylamide, and
d) 0.1 to 5 wt % of a hydroxyalkyl (meth)acrylate having 1 to 10 carbon atoms in the alkyl group or 0.1 to 4 wt % of a chain transfer agent having a thiol group;
and where compound A is a dicarboxylic dihydrazide having 2 to 10 carbon atoms and the films are polyester films.

15. The method according to claim 14 , wherein compound A is adipic dihydrazide and monomer c) is diacetoneacrylamide.

16. The method according to claim 1 , wherein the monomers comprise:
b) 1.0 to 3 wt %, based on the total amount of monomers, of at least one monomer selected from the group consisting of acrylic acid, methacrylic acid, and itaconic acid,
c) 1.0 to 5 wt %, based on the total amount of monomers, of at least one ethylenically unsaturated compound selected from the group consisting of acetoacetyl (meth)acrylate, acetoacetoxyethyl (meth)acrylate, and diacetoneacrylamide, and
d) 1.0 to 5 wt % of a hydroxyalkyl (meth)acrylate having 1 to 10 carbon atoms in the alkyl group or 1.0 to 4 wt % of a chain transfer agent having a thiol group;
and where compound A is adipic dihy

Assignees

• Basf Se

Inventors

• Schumacher Karl-Heinz
• Tonhauser Christine
• Kiener Christoph
• Preishuber-Pfluegl Peter
• Kuntz Andrea

Classifications

• C09J4/00 Primary

  Adhesives based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond {; adhesives, based on monomers of macromolecular compounds of groups C09J183/00 - C09J183/16} · CPC title

• B32B23/042

  of metal · CPC title

• C09J133/06

  of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical · CPC title

• B32B2307/4023

  on the layer surface, e.g. ink · CPC title

• B32B23/08

  of synthetic resin · CPC title