Multilayer polymeric sheets and light weight laminates produced therefrom

Patent metadata

Field	Value
Publication number	US-2016167348-A1
Application number	US-201414906139-A
Country	US
Kind code	A1
Filing date	Jul 22, 2014
Priority date	Jul 22, 2013
Publication date	Jun 16, 2016
Grant date	—

Abstract

A multilayer polymeric sheet comprising three layers is provided. The two outer layers of the multilayer polymeric sheet comprise an ionomeric composition and are positioned on either side of the inner layer of the multilayer polymeric sheet, which comprises an ethylene vinyl acetate (EVA) composition. Further provided is a laminate comprising the multilayer polymeric sheet, for example, a glass laminate. Preferred laminates exhibit a sound transmission class of greater than 25, as measured by ASTM E314, or an effective stiffness by bending of about 3.0 mm to about 5.0 mm, as measured by ASTM C158. Also preferably, the laminate has an areal density that is lower than that of a glass monolith of comparable thickness.

First claim

What is claimed is:

1 . A laminate comprising a multilayer polymeric sheet and at least one additional layer;
wherein the multilayer polymeric sheet comprises two outer layers and an inner layer, wherein the two outer layers are positioned on either side of the inner layer;
wherein the inner layer comprises an ethylene vinyl acetate composition; and
wherein the two outer layers are the same or different and comprise an ionomeric composition; the ionomeric composition comprises an ionomer; and the ionomer is a product of neutralizing an acid copolymer;
wherein the acid copolymer comprises copolymerized repeat units derived from an alpha-olefin, about 0.1 to about 30 wt % of copolymerized repeat units derived from a first alpha,beta-ethylenically unsaturated carboxylic acid having 3 to 8 carbon atoms, and optionally about 2 to about 25 wt % of copolymerized repeat units derived from an ester of a second alpha,beta-ethylenically unsaturated carboxylic acid, said ester having 4 to 12 carbon atoms; and the first and the second alpha,beta-ethylenically unsaturated carboxylic acids are the same or different;
wherein the weight percentages are based on the total weight of the acid copolymer and the sum of the weight percentages of the copolymerized residues in the acid copolymer is 100 wt %; and wherein about 5% to about 100% of the carboxylic acid groups in the acid copolymer are neutralized with one or more bases that contain a metal cation; and

wherein the laminate has a sound transmission class of greater than 25, as measured by ASTM E314; or wherein the laminate has an effective stiffness by bending of about 3.0 mm to about 5.0 mm, as measured by ASTM C158.

2 . The laminate of claim 1 , wherein the outer layers have a thickness between about 0.1 mm and about 1.5 mm;
wherein the inner layer has a thickness between about 0.1 mm and about 1.5 mm; and wherein the total thickness of the multilayer polymeric sheet is between about 0.3 mm and about 2.0 mm.

3 . The laminate of claim 1 , wherein the ratio of the thicknesses of the layers of the multilayer polymeric sheet, given in the order “outer layer/inner layer/outer layer”, is selected from the group consisting of 1/1/1, 2/5/2, and 4/1/4.

4 . The laminate of claim 1 , wherein the ethylene vinyl acetate composition comprises a poly(ethylene-co-vinyl acetate) polymer, and the poly(ethylene-co-vinyl acetate) polymer comprises at least about 25 wt % of copolymerized repeat units derived from vinyl acetate, based on the total weight of the poly(ethylene-co-vinyl acetate) polymer.

5 . The laminate of claim 4 , wherein the poly(ethylene-co-vinyl acetate) polymer comprises between 30 and 50 wt % of copolymerized repeat units derived from vinyl acetate; or wherein the poly(ethylene-co-vinyl acetate) polymer has a melt flow index of about 14 g/10 min before crosslinking and a melt flow index of less than or equal to 2 g/10 min after crosslinking, as measured by ASTM Method No. D1238-13 at a temperature of 190° C. and under a weight of 2.16 kg.

6 . The laminate of claim 1 , wherein the acid copolymer is an acid terpolymer comprising copolymerized repeat units derived from ethylene, about 20 to about 25 wt % of copolymerized repeat units derived from acrylic acid or methacrylic acid, and about 7 to about 15 wt % of copolymerized repeat units derived from an alkyl ester of acrylic acid or methacrylic acid.

7 . The laminate of claim 1 , wherein the acid copolymer is an acid dipolymer comprising from about 70 to about 79 wt % of copolymerized residues of ethylene and from about 21 to about 30 wt % of copolymerized residues of the first alpha,beta-ethylenically unsaturated carboxylic acid.

8 . The laminate of claim 1 , wherein the acid copolymer has a melt index of about 100 g/10 minutes or less; or wherein the ionomer has a melt flow index of from about 0.1 to about 50 g/10 min, as measured by ASTM Method No. D1238-13 at a temperature of 190° C. and under a weight of 2.16 kg.

9 . The laminate of claim 1 , wherein about 15% to about 35% of the carboxylic acid groups in the first alpha,beta-ethylenically unsaturated carboxylic acid are neutralized; or wherein the acid copolymer is neutralized with a base that contains sodium ions to form the ionomer.

10 . The laminate of claim 1 , wherein the ethylene vinyl acetate composition or the ionomeric composition(s) comprise one or more additives selected from the group consisting of colorants, pigments, silane coupling agents, thermal stabilizers, UV absorbers, hindered amine light stabilizers (HALS), additives that reduce the melt flow rate of the ethylene vinyl acetate composition or the ionomeric composition(s) composition, plasticizers, processing aides, flow enhancing additives, lubricants, dyes, flame retardants, impact modifiers, nucleating agents to increase crystallinity, antiblocking agents, UV stabilizers, dispersants, surfactants, chelating agents, coupling agents, adhesives and primers.

11 . The laminate of claim 10 that comprises the pigment, wherein the pigment is a transparent pigment comprising nanoparticles having a nominal particle size of less than about 200 nm.

12 . The laminate of claim 1 , wherein the at least one additional layer is a layer of glass.

13 . The laminate of claim 12 , further comprising a second layer of glass;
wherein said multilayer polymeric sheet is placed between said two layers of glass and laminated to form the laminate.

14 . The laminate of claim 13 , wherein each layer of glass has a thickness between about 0.7 mm and about 3.0 mm; and wherein the total thickness of the laminate is between about 1.5 mm and about 7.5 mm.

15 . The laminate of claim 13 , wherein the areal density of the laminate is lower than that of a glass monolith, said glass monolith having a thickness approximately equal to the thickness of the laminate; and wherein the bending stiffness of the laminate is greater than or equal to the bending stiffness of the glass monolith.

Assignees

• Du Pont

Inventors

• Bennison Stephen J
• Kobayashi Toshikazu
• Meerscheidt Shannon D
• Nakata Kazuyuki
• Pesek Steven C
• Shaffer W Alexander
• Shitanoki Yuki
• Smith Charles Anthony

Classifications

• B32B2307/412

  Transparent · CPC title

• B32B27/308

  comprising acrylic (co)polymers · CPC title

• B32B17/10036

  comprising two outer glass sheets · CPC title

• B32B27/30

  comprising vinyl {(co)polymers; comprising acrylic (co)polymers} · CPC title

• B32B17/10788

  containing ethylene vinylacetate · CPC title