GB2161720A

GB2161720A - Wallcoverings

Info

Publication number: GB2161720A
Application number: GB08418519A
Authority: GB
Inventors: George Frederick Urry; Rodney John Briston
Original assignee: Reed International Ltd
Current assignee: Reed International Ltd
Priority date: 1984-07-20
Filing date: 1984-07-20
Publication date: 1986-01-22
Also published as: GB8418519D0

Abstract

A wallcovering is provided with a surface having high and low areas by heating a foamable plastisol with or without embossing. In line with this, and prior to cooling, pigmented heat-expandable microcapsules are applied to at least some of the high areas. The microcapsules are then caused to expand, preferably by residual heat from the initial heating operation.

Description

SPECIFICATION Wallcoverings This invention relates to wallcoverings.

There is a problem, in the manufacture of wall coverings, in obtaining strong colourations against a background of different colour and gloss and the present invention provides a solution to this problem.

According to the present invention a wallcovering is made by the following process steps: (a) Generating on a substrate by a heating process a surface having high and low areas; (b) in line with step (a), and prior to cooling to ambient, applying pigmented heat expandable microcapsules or microspheres on at least some of the high areas; and (c) allowing heat, which is either wholly residual from step (a) or is supplemented, to expand the microcapsules or microspheres.

The generation of a surface having high and low areas (step (a)) could be achieved by heating a foamable plastisol with or without embossing generated either by chemical or mechanical means.

This step typically requires a temperature of about 21 0 C, and cooling to 1300C can be allowed to take place before the pigmented materials are applied.

The residual heatfrom step (a) is adequate to cause these materials to expand as the wallcovering advances along its manufacturing line. Cooling to, or near, ambient can then take place prior to reeling or piece winding. Expansion without bursting is preferred although some bursting (say up to 10%) can be accepted.

The microcapsules or microspheres can be applied as a very thin coating so that the emboss is not significantly altered.

Thus a heat efficient on-line process of manufacture is obtained. At the same time an added advantage arises in that pigments, which can undesirably depress foaming, can be kept out of the foamable plastisol. The principal object of obtaining a strong colouration against a background of different colour and gloss can also be achieved.

The use of microspheres or microcapsules to give decoration effects is not in itself new. For example, reference is made to USP 3,908,059 where clumps of microspheres in a binder are applied to ceiling tiles and to GB 1,422,823 where microspheres are incorporated into a printing ink to give 3D effects.

In one way of carrying the invention into effect a manufacturing line is set up starting with a conventional paper substrate to which is applied a foamable plastisol layer (which may be total or partial). The plastisol is heated to gell it and then passed to a foaming oven. At this stage, typically, a white or pale coloured irregular surfaced article is produced having high and low areas.

From the foaming oven the product is cooled in temperature to 1300C and is advanced to a tipping roll which applies resin, pigments, and heat expandable microspheres to the higher areas of the foamed surface without marking the lower surfaces.

A small degree of radiant heat is applied to ensure the expansion of the microspheres. At this stage, typically, the product has deep coloured matt high areas contrasting with more glossy and lighter coloured or white low areas.

The product is cooled and reeled or piece wound.

Metallic powders could be included with the microspheres.

The process of the invention could also be used in conjunction with the process of our co-pending application No. 84 16733. This discloses a process forthe manufacture ofawallcovering of the kind in which emboss effects are produced from a foamable base, and said process involving heating the base to gell it, printing the gelled base (whole or part) with an activator, and then printing a part of the activator with an inhibitor, allowing the activator to migrate into the foamable material and heating to generate a relief product in which the foamable base printed with activator devoid of inhibitor expands the most and the base printed with activator and inhibitor expands less to leave sharply defined recessed areas in the foam expanded by the activator. The microcapsules are applied to the higher areas of the foam.

1. A process for the manufacture of a wallcovering comprising the steps of (a) Generating on a substrate by a heating process a surface haying high and low areas; (b) in line with step (a), and priorto cooling to ambient, applying pigmented heat expandable microcapsules or microspheres on at least some of the high area; and (c) allowing heat, which is either wholly residual from step (a) or is supplemented, to expand the microcapsules or microspheres.

2. A process as claimed in Claim 1 in which expansion of the microcapsules or microspheres takes place with less than 10% bursting.

3. A process as claimed in Claim 1 or 2 in which the microcapsules or microspheres are applied as a thin coating so that surface of high areas is not significantly altered.

4. A process as claimed in any one of claims 1 to 3 in which the surface having high and low areas is that of a foam devoid of pigments which could have depressed the foam.

5. A process as claimed in any preceding claim in which the microcapsules or microspheres are applied when said surface having high and low areas is at a temperature of about 1300C.

6. A process of manufacturing a wallcovering of the kind in which emboss effects are produced from a foamable base, and said process involving heating the base to gell it, printing the gelled base (whole or part) with an activator (8) and then printing a part of the activator with an inhibitor allowing the activator to migrate into the foamable material and heating to generate a relief product in which the foamable base printed with activator devoid of inhibitor expands the most and the base printed with activator and inhibitor expands less to leave sharply defined recessed areas in the foam expanded by the activator and, in which, in line with heating to

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Wallcoverings This invention relates to wallcoverings. There is a problem, in the manufacture of wall coverings, in obtaining strong colourations against a background of different colour and gloss and the present invention provides a solution to this problem. According to the present invention a wallcovering is made by the following process steps: (a) Generating on a substrate by a heating process a surface having high and low areas; (b) in line with step (a), and prior to cooling to ambient, applying pigmented heat expandable microcapsules or microspheres on at least some of the high areas; and (c) allowing heat, which is either wholly residual from step (a) or is supplemented, to expand the microcapsules or microspheres. The generation of a surface having high and low areas (step (a)) could be achieved by heating a foamable plastisol with or without embossing generated either by chemical or mechanical means. This step typically requires a temperature of about 21 0 C, and cooling to 1300C can be allowed to take place before the pigmented materials are applied. The residual heatfrom step (a) is adequate to cause these materials to expand as the wallcovering advances along its manufacturing line. Cooling to, or near, ambient can then take place prior to reeling or piece winding. Expansion without bursting is preferred although some bursting (say up to 10%) can be accepted. The microcapsules or microspheres can be applied as a very thin coating so that the emboss is not significantly altered. Thus a heat efficient on-line process of manufacture is obtained. At the same time an added advantage arises in that pigments, which can undesirably depress foaming, can be kept out of the foamable plastisol. The principal object of obtaining a strong colouration against a background of different colour and gloss can also be achieved. The use of microspheres or microcapsules to give decoration effects is not in itself new. For example, reference is made to USP 3,908,059 where clumps of microspheres in a binder are applied to ceiling tiles and to GB 1,422,823 where microspheres are incorporated into a printing ink to give 3D effects. In one way of carrying the invention into effect a manufacturing line is set up starting with a conventional paper substrate to which is applied a foamable plastisol layer (which may be total or partial). The plastisol is heated to gell it and then passed to a foaming oven. At this stage, typically, a white or pale coloured irregular surfaced article is produced having high and low areas. From the foaming oven the product is cooled in temperature to 1300C and is advanced to a tipping roll which applies resin, pigments, and heat expandable microspheres to the higher areas of the foamed surface without marking the lower surfaces. A small degree of radiant heat is applied to ensure the expansion of the microspheres. At this stage, typically, the product has deep coloured matt high areas contrasting with more glossy and lighter coloured or white low areas. The product is cooled and reeled or piece wound. Metallic powders could be included with the microspheres. The process of the invention could also be used in conjunction with the process of our co-pending application No. 84 16733. This discloses a process forthe manufacture ofawallcovering of the kind in which emboss effects are produced from a foamable base, and said process involving heating the base to gell it, printing the gelled base (whole or part) with an activator, and then printing a part of the activator with an inhibitor, allowing the activator to migrate into the foamable material and heating to generate a relief product in which the foamable base printed with activator devoid of inhibitor expands the most and the base printed with activator and inhibitor expands less to leave sharply defined recessed areas in the foam expanded by the activator. The microcapsules are applied to the higher areas of the foam. CLAIMS

6. A process of manufacturing a wallcovering of the kind in which emboss effects are produced from a foamable base, and said process involving heating the base to gell it, printing the gelled base (whole or part) with an activator (8) and then printing a part of the activator with an inhibitor allowing the activator to migrate into the foamable material and heating to generate a relief product in which the foamable base printed with activator devoid of inhibitor expands the most and the base printed with activator and inhibitor expands less to leave sharply defined recessed areas in the foam expanded by the activator and, in which, in line with heating to generate the relief product pigmented heat expandable microcapsules or microspheres are applied on at least some of the high areas of the relief are allowing heat which is wholly residual,or is residual and supplemented, to expand the microcapsules or microspheres.