LU85728A1 - METHOD FOR LOCAL MATIFICATION OF SYNTHETIC COATINGS AND PRODUCTS OBTAINED - Google Patents

Description

P.EUR.22 / LU

Process of local matification of svnthé-tick coatings and products obtained.

The present invention relates to a process for locally mattering a synthetic covering surface, more particularly a PVC-based floor or wall covering and the products obtained.

5 The majority of plastic coatings do not have a sufficient difference in gloss-mattness at their surface to give certain areas of the surface a particular appearance. Said zones can for example be a pattern applied by printing on a covering or an imitation of a joint, in the case of a covering imitating a ceramic tile.

In US-A-4,273,819, or. arrives at a matification of the joint between the tiles c * an imitation of ceramic tiles by adding a monomer vmvli-15 that and a thermal initiator in all the cuckoo of j ^ ~ ei_ pat groin age and chauo C6 this surplus. The s-prints containing a catalyst lowering the decomposition temperature of the thermal initiator keep the mat appearance (seed), while the other areas lose zô ur ^ graining during gelation.

This process has the disadvantage of being strong —not said at the graining temperature. A slight overshoot at this temperature may initiate cross-linking to the entire surface of the product, and maintain a look to the entire product. A barter temperature hasSS - * against does not result in a matte appearance, even at the level of the joints. Given the cmetioue aspect of the _ decomposa.t; ion of the initiator, a dull of crainaas barter lon- '^ âis at good temperature riscue crtser ·' - · * 30 same Problem (total graining).

In document US-A-4 298 64o, or: knows a procedure j - „....

^ ^ Qe matit ication icc ~ j_e ce revetenents t 1 '“' -iques in ieauei in print according to a —r * / 2 pattern determined on a basis of resinous material rr.ous-sable, pre-gelified, certain parts of the printing containing a urethane polymerization catalyst and these or other parts containing a foaming inhibitor; a resinous wear layer is applied to the printed pattern, the wear layer is pregelified and the resinous materials foam and gel; applying a urethane coating composition containing no urethane polymerization catalyst to the wear layer; heating to polymerize the portions of the urethane coating composition directly superimposed on the portions containing the urethane polymerization catalyst to create interdispersed areas of high gloss polymerized surface. Then the entire surface of the urethane coating composition is powdered with a particulate or granular material containing a urethane polymerization catalyst, the excess of this material is removed from the aforementioned shiny areas and heated in order to polymerizing the remaining surfaces of the urethane coating composition to create low gloss surfaces thereon due to the presence of occluded particulate or granular material.

25 This relatively complicated process has, however, significant drawbacks. On the one hand, it involves high consumption of 1 to 1 v of different types and requires several times the action of heat; on the other hand, it is ^ o'r * ement 30 linked to the temperature of first this lyménsa-1 -r g · 1 * if it is bartered high, crovooue la c-n * e___ I the whole surface.

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Finally, document US-A-4,167,131 mentions a process for the local mattification of synthetic coatings in which the differences in mattness do not result solely from the difference in viscosity, but in which a mechanical graining of the entire surface is carried out. a temperature allowing the initiation of polymerization using the thermal initiator, before causing the polymer to melt, which makes the surface smooth, except in the areas containing the merly and / or crosslinked pcly-10 monomer. The drawbacks are similar to those of the abovementioned methods and in particular the consumption of the monomer is relatively high.

The present invention aims to simplify known production methods and to provide an improved method of local mattification of a synthetic coating surface.

Another object of the present invention is to provide a method of the above-mentioned type which is linked to a precise temperature for initiating a chemical process and which allows a widening of the working range.

On the other hand, we are also looking to provide a proceoe this local pulling of synthetic coatings, which allows a significant saving in mono-mother and which avoids or strongly limits the problems this toxicity linked to the evaporation of certain monomers .

According to the present invention, the aim is achieved by a process in which a 3G deposit of plsstisol containing a crosslinkable monomer is applied at least locally to a foamable support or not; 4 is gelled by any suitable means, for example by infrared or by air chaua; the surface is then uniformly covered with a varnish of plastisol * it is co-received and seeded at least locally; the crosslinking of the monomer is initiated in order to fix the seed appearance of the layer I of varnish in the areas before receiving a deposit containing i / _ 4 * of the monomer; and a gelation is carried out which, by causing the plastisol varnish to fluidize, causes the disappearance of the seed appearance in the non-crosslinked zones. Optionally, expansion can still be carried out as long as the support is foamable.

According to a first embodiment, the deposit of crosslinkable monomer is also suitable for a polymerization initiator, such as a thermal initiator or a radiative initiator, which is decomposed or modified by energetic radiation, for example by UV rays, for forming free radicals or ions necessary for chain propagation in a polymerization reaction.

According to another embodiment, the crosslinking of the monomer is initiated by means of ur. energy beam of accelerated electrons. In this case, the monomer need not contain an initiator.

Preferably, the plastisci containing the monomer is applied locally by a printing technique such as screen printing for example. However, any other suitable technique can be used.

It should be noted that after the initiation of the crosslinking, this remains localized in the areas which contain monomer and that, consequently, the fixing of the mat seed appearance is local and that this local matification is maintained during the following operations.

It is suprenar.t to note that the zones superimposed on the impression containing the reticulable minomer-30 remain gramees lins your itérât * tr.s of celifi-cation subsequent. 2 is explained by the migration of the monomer towards the surface which makes it possible to fix on the surface the seed appearance which has been imparted to the product. It should be noted that this effect takes place practically without or with very little longitudinal diffusion which does not practically affect the location of the aramea. It is fixed in this way.

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A non-negligible advantage of the present invention lies in a significant saving in monomer which is only deposited locally, in accordance with a desired decoration. It therefore falls well below the conventional monomer values of about 20 g / ir. , necessary according to the prior techniques.

This monomer being incorporated in a printed mass covered with a varnish presents lesser dangers with regard to its toxicity.

Another advantage of the process of the present invention resides in the fact that it is sufficient to use at most an initiator, either thermal, or radiative (i.e. UV or others), or ionic. However, it is also possible to initiate crosslinking without any input of an initiating molecule, for example by an accelerated electron beam.

The implementation of the process of the invention has yet another advantage, namely that the graining temperature can be chosen in a largely arbitrary den. In the case where a thermal initiator is not used, it has in any case no or fear of influence on the crosslinking of the monomer.

On the other hand, it may also be advantageous to carry out the graining and the pre-gelation simultaneously. In this case, it is also possible to seed at a temperature such that the crosslinking of the monomer is initiated, in the presence of a thermal initiator.

The method of the invention also has the advantage of allowing graining of the entire surface of the coating, without having to provide a particular grinding cylinder controlled in accordance with the pattern or the decoration of the coating, since the area which is not pciymérisée after graining will be fluidized during the subsequent treatment of gelling erse will smooth by surface tension.

By way of examples of monomers suitable for the implementation of the invention, the following compounds may be cited (non-limiting list): y * »/ /» 6 ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethyleneglycol triethylacrylate, polyethyleneglycol dimethacrylate, polyethylene glycol dimethylacrylate, polyethylene glycol dimethacrylate, polyethylene glycol dimethacrylate 1,3-butylene glycol, 1,4-butylene glycol diacrylate, 15 1,4-butanediol diacrylate, 1,6-hexanedicl dimethacryate, 1,6-hexanediol diacrylate, neopentylglyccl diacrylate, neopentylglycol dimethacrylate, 20 tisphenol A (ethoxylated) dimethacrylate, divinylbenzene, divinyltoluene, trimethylclprcpane trimethacrylate, tr imethvlolpropane triacryate, d triacrylate e pentaerythritol, giyceryl trimethacrylate, pentaerythritcl tetracrylate, pentaerythritis 1 tetrametnacrylate, 1,4-butanecicl dimethacrylate.

To these compounds yes have at the r: ir.s two propagation sites, one can add a certain quantity this monomeric compounds having a site this propagation.

Particularly preferred compounds are 1,4-butylene glycol dimethacrylate and trimetha-35d. trim.ethylolprcpane cryiate.

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Advantageously, when the support to which the crosslinkable monomer is applied is foamable, at least one step of expansion of the support is carried out, after or during gelation.

It is obvious that the steps of the process of the present invention can be combined with all the conventional steps in the manufacture of synthetic coatings, the process of the invention concerning steps, generally final, to obtain an appearance 10 of particular surface.

If the matt effect is desired at the joints of a covering imitating ceramic tiles, the deposit containing the monomer and possibly the initiator may also contain an expansion inhibitor.

In the case where the matt effect is desired at the location of a pattern applied to a fused area, said deposit of monomer obviously does not contain c: expansion inhibitor.

In particular, conventional expansion inhibitors can be used, preferably trimellitic anhydride (TMA /.

As the UV polymerization initiator, the Merci products are preferably used: DAROCUF® 1173 25 or DAROCUR® 1116 at 0.01 to 50%, preferably of the order of 5.5% by weight, the hoop or the cut.

Other compounds such as the following are also suitable (non-exhaustive list;: 30 benzophenone, 2 - ch 1 oro -1 hicxa η th ο ne, 2-methyl-thioxanthone, 2-i sopropy 1 -th io>: an thone , benzoin, t 35 fi 4,4 '—dimethcxvbenzci'ne,

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f - 1 s * 8 benzoin-ethyl-ether, benzoin-isopropyl-ether, benzylaimethyl ketal, 1,1,1-trichloroacetophenone, 5 1-phenyl-1,2,2-propanedione-2- (etnoxvcarbonvl) -oxime , di ethoxyacetophenone, dibenzcsuberone,

Darocur ® 1398,

Darocur ® 1174, 10 Darocur ^ 1020.

The plastisol deposit containing the crosslinkable monomer contains 1 to 50%, preferably 1 to 45% by weight, of monomer comprising at least two chain propagation sites, optionally in admixture with monomers having a propagation site of cnain.

Several successive deposits of rlastiscis are possible according to the invention. In this case it is necessary to carry out an icatior pre-gel, for example by infrared or in the oven between each print head.

The invention will be described in more detail with the aid of the appended figures in which: - Figure 1 represents the support used for the method of the invention, - Figure 2 represents the first step of the method, - Figure 3 represents the coating by means of a varnish after the deposition of the monomer in a plastisol, FIG. 4 represents the step of crainage,

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- Figure 5 shows the radiative initiation of crosslinking, and - Figure 6 shows the finished product.

It should be noted that the description using this particularly preferred embodiment of the invention is only given by way of example and or is in no way intended to limit the scope of the present invention.

The matification process applied to products a f. reliefs obtained by screen printing also falls under one invention.

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f en 9 EXAMPLE 1

Preferably, the support consists of a sut- 2 jectile 1 and a coating at the rate of 000 g / m of a foamable plastisol 2. On this coating of foamable plastisol 5, it is deposited (FIG. 2) one or more stages, locally, according to a decor imitating the design of a tiling joint 3, a plastisol having the following composition: PVC LUCOVYL PB 1702 100 parts by weight

Acrylic monomer ROCRYL ®980 80 "" "(r) 10 Darocur ^ 1173 (Merck) 10" ""

Pigments 2 11 ""

Since the monomer also acts as a plasticizer, it is nevertheless possible to add an adequate fraction of plasticizer such as, for example, dioctyl phthalate (DOP) to improve the flexibility of the product.

Preferably, the above composition also contains an expansion inhibitor.

According to the desired decor, we also deposit, in one or more stages, locally <4 i a ctnp: otherwise ana-20 is logue to the previous one, but which does not contain an expansion inhibitor.

Next, a coating of transparent plastisol 5 is applied (FIG. 3) as a wear layer over the entire surface. Then a pre-cooling is carried out at a conventional temperature of the order of 100 to 16 ° C.

FIG. 4 represents the graining stage by means of a graining cylinder, over the entire surface, at a temperature usually practiced for this operation, that is to say at a temperature above 30 ° C., under pressure however of the desired degree of dullness. The stages of pregeif ica tï g.c and graining can be carried out in a single operation, by means of a graining cylinder 6 heated from rar. 1st adequate.

Going under a UY 7 lamp> Figure 5; allows 35, to crosslink the zone containing the monomer and the initiator fj UV so that the grained state of the wear layer t * 10 * * of this zone is fixed by the crosslinking.

Then, the product obtained is passed, for 1 minute to 2 minutes 30 seconds, in an oven at approximately 200 ° C., intended to expand the foamable coating 2 at the 5 places which do not contain an expansion inhibitor to gel. and fluidizing the area which has not been polymerized during UV initiation by causing a fluidization which has the effect of smoothing the grained surface, while the grained and crosslinked area during UV initiation maintains its grained (matt) state.

The product shown in FIG. 6 is obtained.

This step can also be performed under a UV lamp.

Advantageously, the initiation of the crosslinking 15 by direct radiative route or via an energy transfer agent can be carried out by X-ray radiation, by an electron beam or by isf radiation.

For the practice of techniques involving the use of electron beams, one can in particular (p) use the "ELECTROCURTAIN" apparatus ^ manufactured by the Ateliers de Charmilles (Energy Sciences International) in Geneva 'Switzerland; by applying sufficient energy to penetrate deep into the layer to be crosslinked, for example of the order of 175 KV for doses of 2Mrad.

According to a variant of the invention, it is also possible to complete the smoothing by surface tension ‘occurring during gelation, either by a mechanical smoothing treatment by roller, or by a graining, preferably light, hot.

Xi also rexeve this invention this z revo ir exposure to infrared radiation at the end of treatment, for example at the exit of ur. expansion furnace to assist 1 Smoothing operation on the surface of the 35 ^ product.

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It is therefore found that there is a low consumption of monomer since it is deposited, unlike conventional methods, only locally according to a desired decoration. Furthermore, the monomer is enclosed in the product since it is covered with a wear layer unlike the known methods in which it is contained in the coating. The possible toxicity risks that its evaporation may present, are therefore greatly reduced.

Many operating variants are of course possible within the framework of the invention, while retaining the same advantages.

It is thus possible to carry out the crosslinking in a single step using a decomposing initiator at low temperature, close to the temperature oe gramace. In this regard, the benzyl peroxide mashed in a plasticizer, the peroxide of 3,3,5-trimethyl-hexanoye, the perival of terbutyie, are suitable.

The monomer can be included in a localized plsstisol deposit and the initiator in the plastisol of the wear layer and crosslink in two stages or carry out celification-crosslinking. i%

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Claims (13)

4 12 "* Claims 1. A method of local mattification of synthetic coatings, characterized in that by applying, on a foamable or non-foamable support, at least locally, a plastisol deposit containing a re11culab 1e monomer, in that it gels, in that 'we cover the surface a: f: r ~ enent of a plastisol varnish, in that we pre-gel and burn at least v locally, in that we initiate the crosslinking of the monomer in order to fix the grease appearance. é of the layer of varnish in the zones having received a deposit 10 containing monomer, and in this au'el a gelation which, causing the fluidization of the varnish of plastisol, causes the disappearance of the grainy appearance in the non-crosslinked zones . 2. Method according to claim 1, characterized in that the crosslinking of the monomer is initiated by means of an energetic beam of very accelerated electr. 3. Process according to the resell! coastal-r. 1, characterized in that the reticulaticr is initiated. of the monomer by means of a polymerization initiator contained in the 2o plastisol deposit comprising said monomer. 4. Method according to claim 3, characterized in that the polymerization initiator is a thermal, ionic or radiative initiator (X-rays, £ rays, 5. Method according to any one of the preceding claims, characterized in that an additional step of expansion of the foamable support is carried out. 6. Method according to which one of the preceding cisterns resells, characterized in that the plastisol containing the monomer is applied thereto and optionally the polymerization polymerization method is used. ic- i t-ressi cr. serloraphicue. f. X- é. 13k 7. Method according to any one of the preceding claims, characterized in that the pregelling and the graining is carried out in a single step by means of a graining cylinder heated between 100 and 5,200 ° C, which seeds the entire surface . 8. Method according to any one of the preceding claims, characterized in that the deposit of plastisol containing monomer also contains an expansion inhibitor. 9. Method according to any one of the preceding claims, characterized in that the plastisol deposit containing monomer contains 0.01 to 50 p, of reference approximately 5.5% by weight of poly- (R) initiator (UV meritization, DAROCUR ^ 1173 or EAFQCL'F ^ 1116. 10. Method according to any one of the preceding claims, characterized in that the deposit of plastisol containing the monomer contains 1 to 5G%, preferably approximately 1 to 45% in ooids of r: r. ; r t r e before at least two sites of spread of cnaîr.e. 11. Method according to any one of the preceding claims, characterized in that the graining is carried out at a temperature above 100cC, under a pressure depending on the desired degree of dullness. 12. A method according to any one of the preceding claims, characterized in that the effect of irssaoe is supplemented by surface tension resulting from the fluidization, by a mechanical treatment with a roller. 13. Products obtained using the 3C process any of the above reverses. / 1 ^