Method of making foamed, opacifying elements

Patent metadata

Field	Value
Publication number	US-2016354804-A1
Application number	US-201615144911-A
Country	US
Kind code	A1
Filing date	May 3, 2016
Priority date	Jun 4, 2015
Publication date	Dec 8, 2016
Grant date	—

Abstract

A foamable aqueous composition can be used to form foamed, opacifying elements. These compositions have: (a) 0.5 to 20 weight % of porous particles having a continuous polymeric phase and discrete pores dispersed therein. The porous particles have a mode particle size of 2 to 50 μm; (b) at least 20 weight % of a binder material; (c) 0.1 to 30 weight % of additives including dispersants, plasticizers, inorganic or organic pigments and dyes, thickeners, flame retardants, biocides, fungicides, optical brighteners, tinting colorants, metal flakes, and inorganic or organic fillers; (d) water; and (e) at least 0.001 weight % of an opacifying colorant different from (c). The foamable aqueous composition is suitably aerated, disposed on a porous substrate, dried, and crushed on the porous substrate. The method can be used to provide such elements with one or more dry foamed layers.

First claim

1 . A method for providing a foamed, opacifying element, the method comprising:
providing a foamable aqueous composition comprising:
(a) at least 0.05 weight % and up to and including 20 weight % of porous particles, each porous particle comprising a continuous polymeric phase and a first set of discrete pores dispersed within the continuous polymeric phase, the porous particles having a mode particle size of at least 2 μm and up to and including 50 μm;
(b) at least 20 weight % of a binder material;
(c) at least 0.1 weight % and up to and including 30 weight % of one or more additives selected from the group consisting of dispersants, plasticizers, inorganic or organic pigments and dyes, flame retardants, optical brighteners, tinting colorants, thickeners, biocides, fungicides, metal flakes, and inorganic or organic fillers;
(d) water; and
(e) at least 0.001 weight % of an opacifying colorant different from all of the one or more additives of (c), which opacifying colorant absorbs predetermined electromagnetic radiation,
all amounts being based on the total weight of the foamable aqueous composition;
aerating the foamable aqueous composition to provide a foamed aqueous composition having a foam density of at least 0.1 g/cm 3 and up to and including 0.5 g/cm 3 ; disposing the foamed aqueous composition onto a surface of a porous substrate; drying and at least partially curing, simultaneously or in any order, the foamed aqueous composition on the surface of the porous substrate to provide a dry foamed composition on the surface of the porous substrate, and densifying the dry foamed composition on the surface of the porous substrate to provide the foamed, opacifying element.

2 . The method of claim 1 , comprising:
aerating the foamable aqueous composition by introducing air or an inert gas in a controlled manner.

3 . The method of claim 1 , further comprising:
cooling the foamable aqueous composition below ambient temperature during aerating.

4 . The method of claim 1 , comprising:
disposing the aqueous foamed composition on the surface of the porous substrate by a coating process.

5 . The method of claim 1 , comprising:
densifying the dry foamed composition on the porous substrate by a compression calendaring, pressing, or embossing operation.

6 . The method of claim 1 , comprising:
aerating the foamable aqueous composition to provide a foamed aqueous composition having a foam density of at least 0.15 g/cm 3 and up to and including 0.4 g/cm 3 .

7 . The method of claim 1 , wherein aerating is carried out by introducing air under pressure into the foamable aqueous composition.

8 . The method of claim 1 , wherein the foamable aqueous composition further comprises an optical brightener.

9 . The method of claim 1 , wherein the foamable aqueous composition comprises at least 0.5 weight % and up to and including 10 weight % of the porous particles that have a mode particle size of at least 3 μm and up to and including 40 μm, the amount based on the total weight of the foamable aqueous composition.

10 . The method of claim 1 , wherein the opacifying colorant is present within the porous particles.

11 . The method of claim 1 , wherein the foamable aqueous composition comprises a carbon black as the opacifying colorant that is present in an amount of at least 0.002 weight % and up to and including 1 weight %, based on the total weight of the foamable aqueous composition.

12 . The method of claim 1 , wherein the opacifying colorant is present within: the continuous polymeric phase of the porous particles; a volume of the first set of discrete pores; or both the first set of discrete pores and the continuous polymeric phase of the porous particles.

13 . The method of claim 1 , wherein the porous substrate comprises a porous textile web, porous polymer film, porous cellulosic material, porous ceramic material, or porous glass material, or combination thereof.

14 . The method of claim 1 , wherein the binder material has a T g of 25° C. or less.

15 . The method of claim 1 , wherein the foamable aqueous composition comprises one or more tinting colorants in an amount of at least 0.0001 weight % and up to and including 3 weight %, based on the total weight of the foamable aqueous composition.

16 . The method of claim 15 , wherein the one or more tinting colorants are present in at least the porous particles.

17 . The method of claim 1 , wherein the foamable aqueous composition comprises an optical brightener, carbon black as the opacifying colorant, or both an optical brightener and carbon black as the opacifying colorant.

18 . The method of claim 1 , wherein densifying provides an embossed design on the dry foamed composition.

19 . The method of claim 1 , further comprising, after densifying:
providing a printed image on the dry foamed composition or a backside of the porous substrate, or on both of the dry foamed composition and the backside of the porous substrate.

20 . The method of claim 1 , comprising:
densifying the dry foamed composition on the porous substrate to form a first dry foamed layer, and further comprising: forming a second dry foamed (outer) layer on the first dry foamed layer.

Assignees

• Eastman Kodak Co

Inventors

• Brick Mary Christine
• Nair Mridula
• Lindner Kimberlv S
• Bessey Peter G

Classifications

• C08J9/236

  using binding agents · CPC title

• C08J9/30

  by mixing gases into liquid compositions or plastisols, e.g. frothing with air · CPC title

• C08J2400/00

  Characterised by the use of unspecified polymers · CPC title

• C08J9/122 Primary

  Hydrogen, oxygen, CO2, nitrogen or noble gases · CPC title

• C08J2300/00

  Characterised by the use of unspecified polymers · CPC title