One-step process for making a polymer composite coating with high barrier

Patent metadata

Field	Value
Publication number	US-2017183468-A1
Application number	US-201515313091-A
Country	US
Kind code	A1
Filing date	May 21, 2015
Priority date	May 21, 2014
Publication date	Jun 29, 2017
Grant date	—

Abstract

This invention relates to a a one-step process for making a polymer composite suspension for coating plastic films characterized in that a first polymer is synthesized in-situ optionally in the presence of other polymers and in the presence of clay. Preferably the polymer composite suspension comprises a) 1.0 to 11.0 wt % of clay or silane modified clay, b) 0.1 to 10.0 wt % of poly (acrylic acid), which is a copolymer of acrylic acid (AA) with at least one other monomer selected from 2-ethylhexyl acrylate (EHA), β-carboxyethyl acrylate (β-CEA), methacrylamidoethyl ethylene urea (WAM II) and ethoxylated behenyl methacrylate (β-EM), c) 1.0 to 15.0 wt % of other polymers, preferably poly (vinyl alcohol) and d) 70 to 97 wt % of water or mixture of water with 2-propanol. The coating films made from the suspensions show good barrier capabilities against water vapor and oxygen can be used to make barrier layers on or within plastic films for packaging applications. The invention also relates to methods for making silane modified clay usable in the process for making the suspensions.

First claim

1 . A one-step process for making a polymer composite suspension for coating plastic films wherein a poly (acrylic acid) copolymer synthesized in-situ optionally in the presence of other polymers end in the presence of clay.

2 . The process according to claim 1 wherein the other polymer is selected from poly (vinyl alcohol) or copolymer of ethylene and vinyl alcohol.

3 . The process according to claim 1 wherein the suspension comprises:
a) 1.0-10.0 wt % of clay,
b) optionally 0.05-1.0 wt % of silanes,
c) 0.1-10.0 wt % of poly (acrylic acid),
d) 1.0-15.0 wt % poly (vinyl alcohol),
e) 70-97 wt % of water or mlkture of water with 25wt % of 2-propanol.

4 . The process according to claim 3 wherein the poly (acrylic acid) copolymer is a block copolymer synthesized from various acrylic monomers or monomer blocks.

5 . The process according to claim 4 wherein the acrylic monomers or monomer blocks comprise acrylic add, 2-ethylhexyl acrylate, β-carboxyethyl acrylate, methacrylamidoethyl ethylene urea and ethoxylated behenyl methacrylate.

6 . The process according to claim 4 wherein the weight percentage of various monomers or monomer blocks in the polymer comprises:
a) 50 to 90 wt % of acrylic acid,
b) 5 to 30 wt % of 2-ethylhexyl acrylate,
c) 0.5 to 10 wt % of β-carboxyethyl acrylate,
d) 0.5 to 10 wt % of methacrylamidoethyl ethylene urea,
e) 0.5 to 10 wt % of ethoxylated behenyl methacrylate.

7 . The process according to claim 1 comprising:
a) optionally dissolving the other polymers in water,
b) adding the acrylic monomers of the poly (acrylic acid) into water or into the aqueous polymer solution under stirring,
c) adding a dispersion of clay in water,
d) starting a radical polymerisation in the presence of ea starter and inert gas under elevated temperature to obtain a suspension.

8 . The process according to claim 7 wherein the starter is selected from benzoyl peroxide, butyl hydro peroxide, azobisisobutyronitril or a combination of butyl hydro peroxide and isoascorbic acid.

9 . The process according to claim 1 , wherein the clay is a silane modified clay.

10 . The process according to claim 9 , wherein the clay is modified with a mixture of amino silanes and glycidoxy silanes through slow injection of the mixture into clay suspension under high speed homogenization.

11 . (canceled)

12 . A polymeric: coating suspension that comprises:
a) 1.0 to 11.0 wt % of clay or silene modified clay, b) 0.1 to 10.0 wt % of poly (acrylic acid) copolymer, which is a copoiymer of acrylic acid (AA) with at least one other monomer selected from 2-ethylhexyl acrylate (EHA), β-carboxyethyl acrylate (β-CEA), methacrylamidoethyl ethylene urea (WAM II) and ethoxylated behenyl methacrylate (β-EM), c) 1.0 to 15.0 wt % of other polymers and d) 70 to 97 wt % of water or mixture of water with 2-propanol.

13 . The suspension according to claim 12 , wherein poly (acrylic acid) is dived from a monomer mixture that comprises:
a) 50 to 90 wt % of acrylic acid, b) 5 to 30 wt % 2ethylhexyl acrylate, c) 0.5 to 10 wt % of β-carboxyethyl acrylate, d) 0.5 to 10 wt % of methecrylamidoethyl ethylene urea, e) 0.5 to 10 wt % of ethoxylated beheny methacrylate.

14 . A method for making silane modified clay by dispersing the clay in an aqueous solution and adding a silane or a mixture of silanes at a slow injection speed under high homogenization speed.

15 . The method according to claim 14 wherein the silane or silane mixture is added by injection with a flow rate of to 3.0 ml/min.

16 . The method according to claim 14 wherein the speed of homogenization is in the range of 10000 to 20000 rpm.

17 . The method according to claim 14 which comprises a heating step after the addition of the silanes.

18 - 25 . (canceled)

Assignees

• Agency Science Tech & Res

Inventors

• Li Xu
• Chieng Yu Yuan
• Wong Siew Yee
• Zhang Xikui

Classifications

• C08J7/0427

  with only one layer of a composition containing a polymer binder (with more layers C08J7/042) · CPC title

• C08F20/06 Primary

  Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof · CPC title

• C09D133/02

  Homopolymers or copolymers of acids; Metal or ammonium salts thereof · CPC title

• C09D4/06

  {Organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond} in combination with a macromolecular compound other than an unsaturated polymer of groups C09D159/00 - C09D187/00 · CPC title

• C08F2/44

  Polymerisation in the presence of compounding ingredients, e.g. plasticisers, dyestuffs, fillers · CPC title