EP0101388A2 - Continuous process for the manufacture of decorated plastic floor or wall coverings and device for carrying out the process - Google Patents

Abstract

Floor and wall coverings having a pattern are made by coating a plastisol onto a sheet support, and simultaneously with a thermal activation of the plastisol to gelify it, bringing a transferable pattern on a paper layer into contact with the plastisol.

Description

The present invention relates to a continuous process for obtaining decorated plastic coatings for floors or walls and the installation provided for the implementation of this process as well as the coatings obtained.

It is known that polyvinyl chloride sheets, optionally comprising a frame such as a glass fiber mat, a grid, etc., intended to receive an impression are commonly produced by coating, that is to say by application, using conventional equipment (doctor blade, reverse-roll coater, curtain machine, etc.) of a liquid vinyl composition based on polyvinyl chloride added with plasticizers and various additives. This coating must then be solidified hot, generally between 150 and 180 ° C, so as to ensure its gelation. This gelling operation can be carried out in an oven; it is also advantageously in contact with a perfectly polished cylinder heated to the necessary temperatures, which makes it possible to achieve, at the same time as the gelation, a perfect surface condition of the plastic layer obtained. These gelification cylinders or drums are commonly used in the industry of plastic floor or wall coverings, and vinyl coating in general.

A large number of these plastic products based on coated or calendered polyvinyl chloride (PVC), such as tablecloths, blinds, curtains, tarpaulins, floor coverings, wall coverings, etc ... have a decoration brought by an impression in several colors. This printing can be carried out by various techniques: heliography, offset, serigraphy (flat or in the rotary frame), flexographic, etc ... and it is generally applied after gelation of the plastic support to be decorated.

Direct printing on a non-gelled plastic support can in fact pose a certain number of problems due, in particular, to the dimensional instability of said support resulting in deformations of the design.

It is of course possible to integrate, following the gelling device of the plastic support, a printing unit, in order to continuously manufacture the decorated coatings. However, and due not only to the high investment presented by a printing machine but also to the significant cost of engraving or preparing the frames or dies necessary to obtain each color of the design to be produced, this integration is not justified economically. only for obtaining important footage for the same drawing.

Finally, it should be noted that the use of conventional printing units for sampling designs, whether or not these units are integrated into a continuous production line, increases the cost of printing, in particular because of the high cost of certain plastic supports.

We quickly realized all the interest presented by the transfer printing process according to which the drawing to be produced is firstly printed on a low cost paper before being transferred, as by decal, on the plastic support.

The paper used for this purpose is treated, before printing, using compositions specially developed so that the inks normally used for printing polyvinyl chloride (generally based on copolymers of acetate and polyvinyl chloride ) adhere to it only weakly and can be completely transferred when hot on the plastic support to be decorated.

The actual transfer operation is usually done at a temperature between 100 ° and 180 ° C and under low pressure, the printed side of the paper and the face to be decorated of the plastic support are kept in contact for a very short time, but however sufficient to transfer the printing of the paper to the plastic support.

This operation is carried out on any equipment ensuring intimate contact at the necessary temperatures between the printed paper and the plastic support, for example on glazing machines, doublers, or doubling machines used in the plastics and rubber industry. , such as those commercially known as Auma, Rotodorn, Rotocurc, etc. The speed at which the transfer takes place is relatively high and is between 20 and 50 m / min. After moderate cooling (up to 50-80 ° C for example) the paper is separated from the plastic support onto which the printed design has been transferred.

The object of the present invention is to propose a continuous process for obtaining decorated plastic coatings which is applicable, under economic conditions, to low films and does not require significant investment.

Thus it has for its object a continuous process for obtaining decorated plastic coatings, in particular for floors and walls, and whose originality consists in that the coating step, using liquid plastisol , the support serving as a framework for said coatings is immediately followed by a transfer printing step during which the printed face of the transfer paper is brought into contact with the layer of liquid plastisol and in that the assembly thus constituted is subjected to the simultaneous action of heat and pressure in order to ensure in a single operation the transfer of the design and the gelling of the plastisol.

The paper used to carry out the transfer printing is advantageously provided, before its own printing, with a film-forming layer based on products capable of facilitating the subsequent transfer of said printing.

Among the products suitable for this use, mention may be made of zein, carboxymethylcelluloses, silicones and synthetic resins such as polyethylene, polypropylene and polyamide.

According to a preferred embodiment of the invention, the support serving as a reinforcement for the decorated floor or wall covering consists of a veil of fibers such as glass fibers, previously impregnated with a layer of plastisol and then gelled. There is thus a perfectly flat surface allowing, once the simultaneous gelling and transfer printing operation of this support coated with a new layer of liquid plastisol, to be obtained, a coating having no appearance irregularity. .

The installation used for implementing the method according to the invention essentially comprises a first plastisol storage station, means for supplying a veil of glass fibers to a first means of applying plastisol to said veil, means for gelling the veil coated with plastisol, a second plastisol storage station, means for supplying the coated and gelled veil constituting the support for a second means for applying plastisol, a storage station and unrolling '' a sheet of transfer paper previously impregnated, means making it possible to bring the coated face of the support and the new layer of plastisol into contact with the printed face of the transfer paper, means making it possible to simultaneously ensure the transfer of the dye from the support paper coated with liquid plastisol and the gelling of this plastisol, means for separating the gelled support decorated with the sheet of transfer paper, a storage and rewinding station for the foil uille of transfer paper devoid of its printing and of the means allowing the storage of the gelled and decorated support, possibly preceded by additional finishing means of the gelled and decorated support.

The present invention will be better understood moreover their and its advantages will emerge clearly from the examples which follow of different embodiments of the method according to the invention, with reference to the appended schematic drawing whose single figure represents an installation allowing the implementation of said method.

In the drawing (1) represents the support to be printed, (2) the plastisol, (3) the printed transfer paper and (4) the finished product, printed and gelled.

EXAMPLE 1 Obtaining an Expanded Flooring Coating embossed. Preparation of the support (1).

First of all, using a scraper means (14), a glass veil (6) of 50 g / m ² is coated (coming from an installation not shown in the drawing and which can constitute the head of line of the installation according to the invention) with 400g / m ² of plastisol (5) stored in the tank (7) and having the following composition:

The viscosity of the plastisol is adjusted to 2500 centipoise by the addition of 1 to 2% of dodecylbenzene.

Once coated, the veil (6) is gelled on the cylinder (8), the temperature of which is raised to 150-155 ° C. After cooling, in (15) is applied to this coated web, which constitutes the support (1), a coating (300 g / m ² ) of inflatable plastisol (2) stored in the tank (9) having the following composition:

The viscosity of this plastisol is adjusted to 4000 ccntipoises, with dodecylbenzene.

This coating can be indifferent: only applied to the doctor blade, as shown in the drawing, or using the so-called "reverse roll" device.

The support (1) coated with this liquid plastisol (2) is then brought into contact with the gel cylinder (11) at the same time as the printed transfer paper (3) coming from the roll (10), the printed side of the paper (3) being against the coated face of the support (1).

par CIBA CEIGY, selon le coloris 0,1 à 10 gThis transfer paper (3) is a coated paper of 50 g, previously coated with a layer called "rclease" of 20 g / m ² of a resin such as polypropylene; it was printed in rotogravure with an ink having the following composition:

by CIBA CEIGY, depending on the color 0.1 to 10 g

The viscosity was adjusted with methyl ethyl ketone to obtain, in use, a 15 second ink (FORD cut number 4).

Certain inks contain an expansion inhibitor making it possible to obtain relief drawings, such as trimellitic anhydride or benzotriazolo at a dose ranging from 2.5 to 10%, depending on the relief of the drawing.

The gel cylinder (11) is brought to a temperature which can be between 130 and 190 ° C and which, in the case of a line running at 20 m / minute, is around 170 ° C. The printed transfer paper (3) and the impregnated glass veil (2) and coated with inflatable plastisol (2) are pressed together against the hot cylinder (11) and remain in intimate contact over a large part of the circumference of the latter. At the outlet of the cylinder (11) the complex is cooled (2-3), then the paper which is no longer printed is separated and is taken up on the paper (12). You can optionally reprint it again for a subsequent operation. The print applied to the paper is then transferred to the inflatable plastisol layer (2) applied to the su ^p port (1) and a coating is obtained and coating printed (4).

It is then possible, and especially in the case where the printing ink contained an expansion inhibitor, to produce the printed coating (4), for example by means of a so-called "reverse-roll" installation (not shown in the drawing but located before the storage roller (13)) of 320 g / m ² of a deaerated transparent surface layer having the following composition:

The support (4) thus coated then passes through an oven at 200-210 ° C. At this temperature the blowing agent decomposes to form a chemical foam, except where the printing ink contains the inhibitor.

The surface is gelled.

The floor covering obtained printed and in relief may, in certain cases, receive an additional coating of mechanical foam upside down having the following composition:

This plastisol is mechanically foamed by incorporating dry air into a mechanical beater of the MONDOMIX type. Is applied to the squeegee 300 g / m ² of mechanical foam densi- _ty fresh 500 g per liter. It is gelled in an oven at 175 ° C. The gelled and decorated coating (4) is rolled up at (13).

Excmple 2 - Expanded relief wallcovering.

A glass veil (1) of 50 g / m ² is directly coated in (15) with the following composition (2):

The viscosity of the plastisol is adjusted to white spirit at 5000 centipoise. 400g / m ^{2 are} applied with a doctor blade.

The transfer paper (3) (coated paper of 50 g / m ² coated with a polyamide film of 20 g / m ² ) is prepared to provide the impression and the surface varnish at the same time. For this, we first print on paper an acrylic varnish of composition:

Optionally, 10% of micronized amorphous silica of the type sold by the company GRACE under the name Siloid is added to this composition. This will give a matt surface varnish.

The paper is then printed with an ink having the following composition:

One can also add to this ink an expansion inhibitor such as trimellitic anhydride at a dose of 5% for a medium relief and 10% for a more marked relief.

We simultaneously print and surface varnish and is carried out at the same time the _pre-S élification the inflatable plastisol by passing the carrier (1) coated with plastisol (2) and paper (3) on the gelifier cylinder (11).

The transfer paper is then removed and the inflatable plastisol (2) is expanded in an oven brought to 200-220 ° C (not shown).

A relief wall covering printed with a surface varnish is thus directly obtained which is stored in (13).

Example 3 - Unexpanded floor (or wall) covering. Preparation of the support (1).

On a glass veil (6) of 50 g / m ² , the following plastisol (5) is coated with a doctor blade in (14) 300 g / m ² :

The viscosity is adjusted to 3500 centipoise. After gelling of this plastisol on the heating drum (8) (140-145 ° C), 350 g of a plastisol (2) is applied using the doctor blade (15) on the support (1) thus obtained. the following composition:

The support (1) thus coated with plastisol (2) is pressed at the same time as the printed transfer paper (3) against the cylinder (11) brought to 180 ° C.

The paper is then removed and stored in (12) and a coating of plastisol with a transparent surface (100 g / m ² for a wall covering) is applied (to a part not shown of the installation) on the printed product (4). 250 g / m ² for a floor covering), having the following composition:

This plastisol is deaerated under vacuum, it is applied with a reverse-roll, it is gelled in an oven at 210 ° C. and a mechanical embossing is optionally carried out, making it possible to impart a certain relief to the surface of the coating before its storage on the roller ( 12).

As it goes without saying, and as appears from the above, the present invention is not limited to the single embodiments described above by way of examples; on the contrary, it embraces all variants, whatever the compounds in particular the plastisol (2) and the inks intended for printing the transfer paper (3), the nature of the latter and the additional devices added to the continuous installation described above. _-

Claims (10)

1 - Continuous process for obtaining decorated plastic coatings, in particular for floors and walls, characterized in that the step of coating, using liquid plastisol, the support serving as a reinforcement for said coatings is immediately followed by a transfer printing step during which the printed face of the transfer paper is brought into contact with the layer of liquid plastisol and in that the assembly thus formed is subjected to the simultaneous action of heat and pressure to ensure in a single operation the transfer of the drawing and the gelling of the plastisol. 2 - Method according to claim 1, characterized in that the liquid plastisol on which is applied the printed face of the transfer paper is an inflatable plastisol. 3 - Process according to claim 1 and claim 2, characterized in that the paper used for carrying out the transfer printing is provided, before its own printing with a layer of film-forming products capable of facilitating the subsequent transfer of said printing . 4 - Process according to claim 3, characterized in that the film-forming product is chosen from synthetic resins such as polyethylenes, polypropylenes and polyamides. 5 - Process according to claim 3, characterized in that the film-forming product is chosen from silicones. 6 - Process according to claim 3, characterized in that the film-forming product is chosen from the group comprising zein and carboxymethylcelluloses. 7 - Method according to any one of claims 1 to 6, characterized in that the support serving as a frame for the decorated floor covering or wall is constituted by a veil of fibers previously impregnated with a layer of plastisol and then gelled. 8 - Method according to claim 7, characterized in that the support serving as a frame is a veil of glass fibers. 9 - Installation for implementing the method according to any one of claims 1 to 8, characterized in that it essentially comprises a first storage station (7) of plastisol (5), means for supplying a veil of fibers (6) to a first means of application (14) of plastisol to said veil, means of gelling (8) of the veil coated with plastisol, a second storage station (9) of plastisol (2), means for feeding the coated and gelled veil constituting the support (1) to a second means for applying plastisol (15), a storage and unrolling station (10) of a sheet of previously printed transfer paper (3) , means making it possible to bring the coated face of the support of the new plastisol layer (2) into contact with the printed face of the transfer paper (3), means (11) making it possible simultaneously to transfer the dye from the paper to the support coated with liquid plastisol and the gelling of this plastisol, means for separating the support gelled and decorated (4) of the transfer paper sheet, a storage and winding station (12) of the transfer paper sheet devoid of its printing and means (13) allowing the storage of the gelled and decorated support, possibly preceded by additional finishing means of the gelled and decorated support. 10 - Decorated plastic coatings for floors and walls obtained according to any one of claims 1 to 9.

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