WO1991006705A1

WO1991006705A1 - Method for manufacturing a decorative laminate

Info

Publication number: WO1991006705A1
Application number: PCT/FR1990/000780
Authority: WO
Inventors: Jean Le Stum; Jean Chort; André SEGALA
Original assignee: Polyrey
Priority date: 1989-10-30
Filing date: 1990-10-29
Publication date: 1991-05-16
Also published as: FR2653706B1; NO904589L; FI905308A0; PT95703A; FR2653706A1; NO904589D0

Abstract

A method for manufacturing a decorative laminate, wherein a collection of sheets are laminated under pressure, said collection of sheets being saturated with phenolic resin and comprising core sheets, at least one decorative sheet and optionally a covering sheet. A suspension of a pigment and/or an ink in a thickener is sprayed onto the saturated decorative sheet and/or the saturated covering sheet.

Description

PROCESS FOR PRODUCING A DECORATIVE LAMINATE

The invention relates to decorative laminates obtained by assembling under pressure an assembly of sheets impregnated with resin comprising core sheets, at least one decor sheet, and possibly a cover sheet called overlay.

In the usual technique for manufacturing decorative laminates - high or low pressure the decorative aspect is obtained by the use of a "decor" sheet or paper, either mass-dyed or printed, which is impregnated with aminoplast resin - preferably a "melamine-formaldehyde" resin and then laminated on a "core" (or core) made up of a number of sheets of Kraft paper, and impregnated with phenolic resin, or on a particle board. This laminating operation is carried out either in multi-stage heating presses for the laminate on

Kraft at a pressure close to 100 bats, either in single or multi-stage heating presses, for laminate on particle board at a pressure of the order of 20 bars. In both cases, the "decor" comes into contact with a metal plate in stainless steel or chrome-plated brass, which gives it the desired surface appearance: gloss, satin, mat or texture.

The "decor" papers are generally manufactured by specialists - papermakers or printers - who deliver to the manufacturer of decorative laminates, ready-to-use papers, that is to say, ready to be printed. pregnated in aminoplast resin. This supposes, for the laminate manufacturer, to order relatively large quantities of the same decor, because these papers are manufactured industrially. In addition, the laminate manufacturer is not completely in control of the decorative pattern, since it is not he who prints or realizes said pattern, even if he can, of course, order the design.

To overcome this drawback, some laminate manufacturers have equipped themselves with screen printing machines with their own decorative patterns. This process has some drawbacks, however, such as having to formulate or buy screen printing inks and requiring relatively expensive investments for frames.

The object of the invention is to overcome these drawbacks, and in particular to propose a method for manufacturing laminates by means of which it is possible to produce decor sheets at will in small series, allowing a wide variety of decorations, and at a price. cost significantly lower than that of conventional processes (gravure, screen printing, etc.).

This object is achieved according to the invention in the context of a process of the type cited at the head of this thesis of the fact that a spray is sprayed onto the impregnated decor sheet and / or the impregnated cover sheet pigment and / or ink in a thickener.

One can thus realize, in a simple way, without using sophisticated material, laminates presenting a very beautiful decorative and personalized aspect. The possibilities of creating a decor are innumerable, varying the basic colors, the choice of pigments, the projection densities, the shapes of the graphics. In certain cases, by a judicious choice of the products, one obtains a good fixing of the pigment on the decoration, which can be used without protective overlay, which gives a great freshness to the colors. This is made possible due to the formulation of the dispersion projected onto the paper thanks to which no "patterns" are observed on the veneer sheet. On the contrary, in conventional printing methods on impregnated paper, it is almost always necessary to protect the printing with an overlay to avoid the transfer of the decorative pattern onto the veneer, causing unacceptable soiling; although this overlay becomes transparent, it partially alters the freshness of the prints. Among the thickeners, one can choose polyvinyl alcohol, carboxymethylcellulose, an alginace. However, the preferred thickener is microcris¬ talline cellulose, which proves to be an excellent fixer for pigments and therefore avoids the aforementioned transfers. As pigments, use is preferably made of mother-of-pearl and metallic powders (such as bronze, copper, aluminum) which give very aesthetic effects.

As for inks, they can be used in different ways: depending on the projection density and the contrast of the ink projected with the background color, you can obtain various effects: a grain can appear, or on the contrary a fine projection modifies at leisure the shade of the basic decor. The method is therefore particularly effective for modifying the color of a decoration on demand.

The viscosity of the inks is advantageously of the order of 20 to 30 s at 20 ° C. determined in the Ford n ° 4 cut. The method according to the invention will be better understood on reading the following examples given by way of illustration but in no way limiting. EXAMPLE 1 A 2% dispersion of microcrystalline cellulose, AVICEI® RC 581, is prepared in water. AVICEli © RC 581, supplied by FMC CORP, PHILADELPHIA, UNITED STATES, contains, in addition to microcrystalline cellulose, approximately 1% of carboxymethylcellulose to promote dispersion.

To 100 g of this dispersion, 3 g of MEARL INT pearlescent pigment are added. HI-LIT violet 539 X, with simple stirring.

This mixture is sprayed, using conventional compressed air guns, on a decorative paper already impregnated with aminoplast resin. The pistols are of type A 20 supplied by KREMLIN and have a nozzle of 0.9 mm in diameter. They are mounted in an automatic spraying and drying machine of the "MAP" type 120 A2 S6 (D7) manufactured by CHARvO. The paper scrolls at 3 / min at 30 cm from the guns, and is dried for 2 minutes at 135 ° C. This paper is then laminated, like an ordinary decoration, without overlay, in contact with a sheet of veneer. There is no transfer of impression on the sheet and we obtain a very beautiful decorative effect. EXAMPLE 2:

To 100 g of the AVICEL® RC 581 dispersion, 1 g of metallic pigment LAC LT LEMON from ECKART is always added by simple stirring. The dispersion is then projected, as in Example 1, onto a decorative paper impregnated with aminoplast, which is then laminated without overlay. A laminate is thus obtained which has metallic reflections. EXAMPLE 3:

As a variant, the preceding dispersions are projected onto an overlay paper, pre-impregnated with aminoplast resin. This overlay is then laminated on decorations of different colors, which makes it possible to obtain pearly or metallic reflections, on different shades. EXAMPLE 4:

A 3% dispersion of AVICEL ^ RC 581 microcrystalline cellulose is prepared in water. To 100 g of this dispersion, we add:

- 2.5 g of White BAS0FLEX 0022 supplied by BASF;

- 0.1 g of LUCONYL 0060 BLACK BASE pigment paste.

The viscosity of the ink, measured using a Brookfield viscometer, at 20 ° C (rotor no. 2, 12 rpm) is 1000 cps.

This gray ink is projected onto a gray decor, already "impregnated with aminoplast resin. This paper is then laminated with an overlay, like an ordinary printed decor.

A laminate is obtained, the original color of which is changed and which has all the physical characteristics of a laminate which meets the standards. EXAMPLE 5

To 100 g of the dispersion of AVICEli-V RC 581 at 3%, the following is added:

- 5 g of BASOFLEX 0022 White (BASF); - 0.3 g of LUCONYL 9360 GREEN (BASF).

This ink is projected onto a green decor already pre-impregnated with aminoplast resin. This decoration is then laminated with an overlay as in Example 4.

We obtain a laminate with a new color and meeting standards.

Claims

1. Method for manufacturing a decorative laminate, of the type according to which an assembly of sheets impregnated with phenolic resin comprising pressure sheets is laminated under pressure, comprising core sheets, at least one decor sheet, and optionally a cover sheet, characterized in that sprayed onto the impregnated decor sheet and / or the impregnated cover sheet a suspension of a pigment and / or an ink in a thickener.

2. Method according to claim 1, characterized in that micro-crystalline cellulose is used as thickener.

3. Method according to any one of claims 1 or 2, characterized in that a pigment chosen from mother of pearl or metallic powders is used.