LU86014A1 - PROCESS FOR PRODUCING CRACKED FLOOR OR WALL COVERINGS AND PRODUCT OBTAINED - Google Patents

Description

* 1 *} b PROCESS FOR PRODUCING FLOOR COVERINGS OR WALLS WITH A CRACKED EFFECT AND PRODUCT OBTAINED The present invention relates to a process for the production of floor coverings or wall coverings, 05 of the synthetic coverings type, with cracked effect. It also extends to the products obtained by this process.

In the production of synthetic decorative coatings for floors and walls, it is increasingly sought to approach the decorations obtained with conventional materials such as ceramic and the like. A particular decorative effect achieved by ceramic materials lies in cracks which are difficult to obtain with synthetic materials deposited in the coating state, for example, on a conventional support. The reproduction of cracks by printing has the disadvantage of not allowing a good imitation of the "natural" cracked effect and the patterns obtained are necessarily repetitive without randomness. In addition, printing does not allow to give an effect 20 depth (relief) to the material.

Document FR-A-2 126 658 discloses a method for applying an emulsion coating material to produce cracking patterns. In this case, a lower coating synthetic material containing a mineral material having a high swelling property is deposited, this lower coating material is dried, and then a cured coating material containing a silicon dioxide sol is applied. In the process according to the above document, the lower coating material absorbs the water contained in the hardened coating material, simultaneously causing its contraction, and also, jointly, cracking. A disadvantage of the process lies in the fact that there are two different layers of particular composition to be used, which require intermediate drying. This process is necessarily slow and expensive.

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An object of the present invention is to provide a process for the production of floor coverings or wall coverings, with a cracked effect requiring only a single layer to obtain said cracked effect.

Another object of the present invention is to provide a method for producing deep cracked floor or wall coverings, that is to say in substantially the whole mass of at least one layer of the covering.

According to another aspect of the present invention, it is aimed at providing a new product, that is to say a new floor or wall covering having a cracked effect, of random nature.

According to the invention, the process for the production of floor coverings or wall coverings, with a cracked effect, is characterized in that a coating composition of a PVC plastics floor containing a coating is deposited on any support. couple consisting of a solid sorbent and a solvent which causes the swelling-20 by absorption of the solvent in and on the sorbent, in that a thermal treatment of film formation is then carried out at a sufficient temperature so that an irreversible process of pregelification of the coating and a change of state of the sorbent agent / solvent couple occur by desorption of the solvent of the sorbent agent and in what is then carried out, optionally, conventional finishing operations.

The method of the invention achieves the aims of the invention and in particular makes it possible to produce a coating with a cracked effect, in which the | s cracks spread randomly, deeply; deur, in the mass.

j "The invention also resides in the choice of the sorbent agent / solvent pair used in the particular conditions of the process of the invention. Advantageously, the solvent does not disturb the plasticizing effect of the other additives of the synthetic material used. - \ [* / 3

Used for manufacturing the coating according to the invention. It is obvious that a solvent which does not participate in the plasticization is preferably used, although the use of such a solvent cannot be excluded. 05 According to one embodiment of the invention, the support on which a composition is applied for coating a plastisol containing said couple of sor-bant agent / solvent can consist of a conventional support which optionally already comprises one or several deposits of synthetic material, possibly provided with a print.

According to the invention, it is possible, in order to obtain particular decorative effects, to apply the PVC plastisol coating composition containing the sorbent / solvent couple discontinuously so that only part of the decorative pattern has a "cracked" appearance. Can this discontinuous application be done by well known techniques? for example by a screen printing technique. It should be:::> ·] * - 20 to imitate in particular coatings and s-cd with cracked effect tiles and .. seen: -an ”joints imitating cement joints which are not cracked .

According to an advantageous embodiment of the; 25 present invention, it is possible, after formation of cracked lures, scrape a coating of plastisol for example on the coating obtained, so as to fill the cracks with a suitable material. According to a particularly preferred embodiment, it is possible to scrape a plas-30 tisol containing up to 30% of carbon black on the product obtained or optionally an aqueous emulsion of. Plasticized PVC and conductive carbon black, so as to fill the cracks with a material; conductive of the electric current. Such a coating is particularly suitable for avoiding the formation of static electricity for coatings intended for operating rooms, computer rooms, etc.

4 The use of such a composition containing carbon black makes it possible to increase the electrical transverse resistance of the coating obtained, which is normally 10 ^ -4 05 ohm.cm.

It is also advantageous, depending on the desired effects, to carry out a printing or any other conventional operation on the cracked product. According to one embodiment, it is also possible to coat in = 10 cracks a conventional foamable paste which, during the heat treatment, undergoes swelling by producing a veining leaving the surface by imitating a wall plaster.

Finally, a coating of a conventional wear layer can be deposited on the surface which further improves the service life of such a coating obtained according to the various embodiments mentioned above of the invention.

According to a particularly preferred embodiment of the invention, the absorbent agent is a silier or a silicate, preferably having a specific surface according to BET of between 250 and 700 m 2 / g, preferably of 1 'around 300 to 400 m ^ / g. The coating composition advantageously comprises 0.5 to 15% by weight of sorbent agent.

Preferably, a solvent is used which has a very high vapor pressure at the temperature of formation of the synthetic film, so that the sorbent shrinks by desorption of the solvent once the film is formed, in order to form it. "tear" by forming cracks. It is understood that the temperature at which the solvent has a high vapor pressure, or the boiling temperature of the solvent, must be close to the film-forming temperature, because, if this temperature is too high, there is no 'there will be no j:'> 5 formation of cracks, due to the fusion and the surface tension of the synthetic coating. On the other hand, if this temperature is too low, there is evaporation before the film is formed. Care must be taken, while stretched, to ensure that the retraction force is greater than the cohesive force of the film. Advantageously, a solvent such as the hydrocarbon fractions and in particular white spirit is used at a rate of the order of 15 to 35% by weight of the plastic coating.

The following products can also be used as solvent: (r)

- solvents of the SHELLSOL TD or AB type

- hydrocarbon fractions other than white spi-15 rit having suitable evaporation / retention properties (R) - solvents of the POLYSOLVAN type, namely n-butyl esters of glycol - solvents of the DOWANOL DPN type , namely dipropylene glycol methyl ether.

The shape, depth and opening of the cracks can be controlled by the temperature of the heat treatment, by the choice of the sor-bant agent / solvent couple and by the rate of solvent used. It has just been noted, however, that the depth and the opening of the cracks can be modified subsequently markedly by a heat treatment in particular, unless there has been prior coating of these.

Advantageously, the temperature for forming the plastisol coating film is chosen between 110 and 160 ° C. The coating can be subjected subsequently, for example to a temperature of the order of 20 ° C. for 1 minute to 2 minutes 30 seconds if it is desired to modify the initial opening of the cracks without acting on their number.

The other steps of a conventional type which can be carried out on the cracked product obtained according to the present invention should not be described in more detail in the present specification. Let us simply note, by way of example, the deposits of pigmented or non-pigmented coating, the prints, the wear layer deposits, the conventional heat treatments and the final baking.

The present invention is described in more detail on the basis of the following examples in which all the proportions are expressed by weight unless otherwise indicated: Example 1;

A gel is prepared beforehand composed of: - 100 parts of butyl glycol acetate - 10 parts of fumed silica (300 m2 / g) -

Aerosil ®300.

A so-called "compact" plastisol composition is also prepared containing: - 650 parts of emulsion PVC (for example: value K 72).

- 100 parts of PVC in suspension (for example: K value 66).

- 540 parts of phthalate plasticizer - 500 parts of carbonated fillers (calcium carbonate) - 25 parts of titanium oxide 25 - 2 parts of tin stabilizer.

The compact composition and the gel previously prepared are then mixed as follows: - 70 parts of "compact" - 35 parts of gel

30 - 10 parts of TXIB

(texanol isobutyrate - secondary plasticizer) i - 3.5 parts of barium and zinc stabilizer.

: i The levels of Aerosil 300 vfyet of solvent are respectively 2.68% and 26.31% in the plastisol coating. The coating thus obtained is applied to a conventional support having possibly already received at least one coating and / οι an impression.

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The product thus obtained is subjected to a heat treatment so as to create the cracks, which advantageously consists of passing, for 2 minutes 30 seconds, at a temperature between 110 and 05 120 ° C., obtained by heating in particular using a forced air oven or infrared radiation or a combination of the two, for example.

i | The product obtained is then, possibly,! subjected to an impression of a decoration, according to a process “10 known per se.

The product can also be subjected to a second heat treatment which allows the opening of already formed cracks. Such a heat treatment consists in passing, for 1 minute to 2 minutes 30 seconds, at a temperature of the order of 200 ° C.

The product is then passed under a rubber doctor blade which penetrates, inside the cracks, a pigmented fluid plastisol which then undergoes a pre-lamination.

It is surprisingly found that after coating with a plastisol, the cracks no longer open during this pregelification.

The whole is covered with a coating of PVC plastisol serving as a wear layer and the product obtained is subjected to a gelling operation, for 2 minutes 30 seconds, at a temperature of the order of 190 ° C.

It is also possible to use a crosslinkable polyurethane varnish by any suitable means, for example UV or by electron beam.

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Example 2

We prepare a gel composed of: \ - 80 parts of White Spirit! - 35 parts of barium silicate such as 35 Dutch Boy BAROSIL ^^ (product of the National

Lead Inc. USA) I *

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A compact composition similar to that of Example 1 is also prepared and the gel previously prepared is incorporated therein at the rate of: - 50 parts of compact composition, 05 - 35 parts of gel.

The rate of BarosilCS ^ and white spirit in the coating is, respectively, 12.5% and 28.7%.

The coating thus obtained is deposited on a conventional support which is subjected to a heat treatment 10 so as to create the cracks. Said heat treatment consists of a passage of 2 minutes at 110 -120 ° C, in an oven for example. The product thus obtained? is then passed under a doctor blade so as to penetrate, inside the cracks, a paste 15 containing 30% carbon black. A final baking heat treatment is then carried out. A so-called "homogeneous" coating is obtained, the transverse electrical resistance of which is lowered to a value of the order of 10 ^ ohm.cm (whereas it is 10 ^ - ^ ohm.cm. 20 for the PVC) and which therefore makes it possible to disperse local electrical charges. Such a coating could be! used in an environment with high sensitivity to local loads such as computer rooms.

i | Example 3! 25 A gel composed of: - 10 parts by weight of Aerosil ^ 5 ^ 300 | - 100 parts by weight of white spirit.

j A "compact" plastisol composition is prepared according to Example 1.

! 30 Then mix: - 70 parts of "compact" J - 37 parts of gel

- 10 parts of TXIB

We then proceed as in Example 1.

35 Example 4

We proceed as in example 1 or 2 but we | - coated in the cracks obtained with a foamable paste ï of the following composition:! 9 ”*” - 30 parts of PVC suspension of value K = 66 - 70 parts of PVC emulsion of value K = 70 - 32 parts of phthalate plasticizer

- 20 parts of TXIB

05 - 25 parts of fillers (calcium carbonate) - 2 parts of TiC> 2 - 4 parts of batch of blowing agent (DOP-Report 1/2)

The attached diagrams show the results of laboratory tests using the ring pumping technique.

Figures 1 to 3 represent, on the abscissa, the frequencies (in Hz) and, on the ordinate, the module G "(dissipation module) in N / m ^.

Figures 4 to 6 represent, on the abscissa, the frequencies (in Hz), the module K (stiffness module) in N / ra.

Figures 1 and 4 relate to a composition according to Example 3.

Figures 2 and 5 relate to a campes- tion s

Compact according to example 1 1 4fi0

Aerosil® 300 63

White spirit 637 TXIB 200 25 Figures 3 and 6 relate to a composition:

Compact according to example 1 1 400

Premix 700 TXIB 200 (r) 30 The premix consists of 63 parts of Aerosil 300 and 637 parts of white spirit.

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Claims (10)

1. Process for the production of floor coverings or wall coverings with a cracked effect, comprising at least the coating of a PVC plastisol on a support, characterized in that a coating composition is deposited on a support. a PVC plastisol containing a couple consisting of a solid sorbent and a solvent which causes swelling by absorption of the solvent in and on the sorbent, in that a formation heat treatment is then carried out of film at a temperature sufficient for an irreversible process of pregelification of the coating to occur simultaneously and a change in state of the sorbent / solvent couple by desorption of the solvent from the sorbent agent and in what is then carried out , possibly conventional finishing operations. 2. Method according to claim 1 characterized in that the solvent which is part of said pair does not disturb the plasticizing effect of the other additives of the synthetic material used. 3. Method according to claim 1 or 2 characterized in that the support consists of a conventional support which optionally comprises at least one deposit of synthetic material and / or at least one impression. 4. Method according to any one of the preceding claims, characterized in that the plastisol coating composition containing the sorbent / solvent couple is applied discontinuously. 5. Method according to any one of the preceding claims, characterized in that the sorbent is a silica or a silicate having a surface area specific to BET between 250 and 700 m2 / g, preferably between 300 and 400 m2 / g. 6. Method according to any one of the preceding claims, characterized in that the coating composition contains 0.5 to 15% by weight of silica, preferably 2 to 13% by weight. ! m * - - i 11 7. Method according to any one of the preceding claims, characterized in that the solvent used in said pair has a very high vapor pressure 05, at the temperature of formation of the coating film. 8. Method according to any one of the preceding claims, characterized in that the coating composition contains 15 to 35% by weight, preferably from 10 20 to 30% by weight, of solvent. * 9. Method according to any one of the preceding claims, characterized in that the treatment = thermal film formation consists in passing at a temperature of 110 to 160 ° C, for 1 minute to 2 minutes 30 seconds . 10. Method according to any one of the preceding claims, characterized in that, after the formation of the cracks, a second heat treatment operation is carried out intended to open the cracks. 11. Method according to claim 10 characterized in that said second heat treatment operation consists in passing at a temperature of the order of 200 ° C for 1 minute to 2 minutes 30 seconds. 12. Method according to any one of the preceding claims, characterized in that at least one coating is applied to the doctor blade so as to fill the cracks. 13. Method according to any one of the preceding claims, characterized in that a composition containing conductive carbon black is applied to the doctor blade so as to fill the cracks. - 14. Method according to any one of the preceding claims, characterized in that the cracks are coated with a foamable paste. 15. Method according to any one of the preceding claims, characterized in that an impression is applied according to a method known per se. • N f / / 12 m ^ * * 16. Method according to any one of the preceding claims, characterized in that a final wear layer is applied to the product. 17. Method according to any one of the preceding claims, characterized in that a final cooking operation is carried out at a temperature of the order of 190 ° C, for 1 minute to 2 minutes 30 seconds. 10. Product obtained according to the method of any one of claims 1 ί>] 7. "10 * / / ύ '' y / 1 r '25 30! · *