Materials having a textured surface and methods for producing same

TECHNICAL FIELD [0001] The invention relates to materials with a textured surface and methods of making such products.

BACKGROUND Textured surfaces, such as e.g. three-dimensional patterns, can be transferred to materials in the form of a sheet or tape in a process in which the tape is covered with a curable coating, where the texture is transferred to a curable coating through a projection surface having the form of engraved metal roller, and the coating is cured in contact with the roller by passing radiation through the tape. In the case of transparent tape, the coating can be cured using UV radiation, while in the case of opaque tape, electron radiation is usually used. The substrates (tape) that can be used in this process are limited to substrates thin enough to allow radiation to pass through them, and, in the case of opaque substrates, suitable for exposure to electron radiation. In some cases, releasing the engraved roller is a problem and / or causes problems with the quality of the coating, e.g. trapped air or smudging.

[0003] Sheets or tapes resulting from this process can be used as release sheets or films in processes in which a plastic coating or sheet is formed on a release sheet and then separated from the release sheet after cooling or curing. The release sheet creates a surface from which the plastic material can be easily separated, and transfers the surface quality of the release layer to the plastic surface. For example, the desired textured surface may be made on the surface of the plastic material by forming the plastic material on a release sheet having a textured surface being a mirror image of the desired textured surface.

[0004] An example of this process is "casting", ie a process in which a resinous material, such as, for example, polyvinyl chloride or a liquid polyurethane resin, is deposited or "cast" on the surface of the release sheet, heated, cured and cooked for consolidating the resin material into a continuous, self-supporting coating, and then separated from the release sheet. Usually, the release sheet has the desired surface, e.g. glossy, textured or embossed, which is reproduced on the cast coating.

[0005] US Patent Pat. No. 4,289,821 (Gray et al.) and US Pat. No. 4,322,450 (Gray et al.), the disclosure of which is incorporated herein by reference, disclose techniques for producing surface effects on a release coating on a release sheet for use in casting processes. One of the disclosed methods involves applying a coating of electron-curable material to one of the substrate surfaces in the form of a tape, pressing the coated side of the substrate against a mapping surface (embossing agent) having the desired surface to cause the coating to conform to

This technique allows the coating and the mapping surface expressions, exposing the coating to electron radiation to harden it and separating the substrate from the mapping surface, with a cured coating adhering to the substrate. Preferably, the projection surface is formed by a metal cylinder with an engraved pattern or accurately smoothed surface. An important advantage of this technique is that the pattern or finish of the mapping layer is mapped onto the cured coating with 100% mapping fidelity.

reproduction of very delicate textures, such as, for example, wood or leather texture, on the surface of plastic cast on a release sheet.

SUMMARY OF THE INVENTION [0006] The disclosure includes processes and apparatus for producing materials with a textured molded surface by applying a texture to the curable then curing the coating. The texture used here "and" textured surface "include delicate textures, including textures with topography below the wavelength of light. However, the textures described here are predetermined, i.e. are textures intentionally transferred to the surface, not textures naturally occurring on any surface due to its natural topography, pollution, etc.

[0007] Thus, textured materials so formed include both non-stick coatings for use in casting processes and finished sheet, tray, plate or tape products, e.g. floor materials, wallpapers, textured laminates and the like. In the processes described herein, a textured band is used instead of the engraved roll as the texture forming agent, thereby allowing the curing radiation to pass through the texture medium rather than the substrate containing the textured and medium cured coating.

[0008] Curing by a texturing agent provides a number of advantages. Thicker substrates, such as foils, plates or trays, enable the production of a wider range of products. Furthermore, the occurrence of radiation damage to substrates is reduced or eliminated, and the use of substrates that could be damaged by radiation, e.g. cellulosic substrates, is used. Thus, in some embodiments, after curing the coating, virtually no changes in the mechanical properties (tensile and tear resistance) occur in the substrate relative to its mechanical properties prior to the curing process.

[0009] The processes disclosed herein also relate to some of the problems associated with their control that may occur during their course, e.g. separation from the extrusion agent, formation of air bubbles and smudging, providing a finished product of consistent quality.

[0010] The use of a texturizing agent in the form of a tape instead of an engraved roller provides a number of significant advantages. For example, it is generally easier to change the texture center, e.g. to change the texture, than to replace the engraved roller. In addition, because the engraved roller is rarely, if ever used (as a pattern for creating a texture agent), damage problems on the engraved roller are minimized or eliminated. In addition, faithful texture reproduction is easier. It is easier textured, including:

also apply a coating on the texture agent in the form of a tape than coating the engraved roller, therefore the whole process can be faster without causing difficulties in the form of air bubbles in the coating.

[0011] In one aspect, the invention relates to a method of producing a material with a surface (a) providing a means comprising a flexible band and a surface layer with a three-dimensional texture defining a mapping surface, (b) providing a substrate on which the textured surface is to be placed, (c) covering the mapping surface and / or substrate with a curable coating, (d) arranging the substrate and texturing agent in such a way, that the coating is between the substrate and the texturing agent, (e) curing the coating, and (f) separating the texturing agent from the substrate so that the cured coating remains on the substrate.

[0012]

Some embodiments incorporate one or more of the following features.

[0013]

The curing step may include passing radiation, e.g., UV or electron radiation through the texturing agent. Preferably, radiation is applied to the side of the texture medium. In some embodiments, curing is performed without applying pressure to the substrate or texturing agent.

[0014] The step of providing a texturing agent may include applying a curable coating to an elastic band, transferring the texture to the coating, and curing the coating to obtain a surface layer. When forming the texture medium, the texture may be transferred to the coating on the elastic band through a roller having an engraved pattern, or, alternatively, the texture may be applied to the coating on the elastic band through the main texture agent (i.e. a medium containing an elastic band and a textured, hardened coating).

[0015] The texture medium may be a continuous tape. In this case, the method may also involve drawing the texture agent from the feed roller to the take-up roller during the coating, curing and separation steps. The coating process may involve passing the coated texture and substrate through the pressure. The texturing agent may be, for example, paper or foil tape.

[0016] The substrate may be a polymer film, multiple individual plates or trays, or other desired materials. The substrate is usually in the form of a tape, sheet, tray or plate.

[0017] The coating may comprise a release agent that allows the cured substrate to act as a release layer during the subsequent casting process.

[0018] Preferably, the coating consists of 100% solids that minimize or eliminate shrinkage of the coating during curing and thus allow the inside to faithfully transfer the texture of the textured surface to the coating. In preferred embodiments, the reverse side of the mapping surface texture is mapped onto the cured coating with 100% fidelity. In embodiments where an engraved cylinder is initially used to form a texture agent, preferably the pattern on the engraved cylinder is reproduced on a hardened substrate with 100% accuracy.

[0019] Preferably, the texture agent is essentially reusable. Thus, in some embodiments, the method also includes switching the take-up roller, on which the texturing medium is wound, to the position of the feed roller and reusing the texturing medium.

[0020] In another embodiment, the textured product comprises a substrate in the form of a sheet, plate or tape, wherein the exposed side of the product is provided with a radiation curable coating having a three-dimensional texture. Importantly, the physical properties (tensile and tear resistance) of the coating are essentially the same as the physical properties of the substrate prior to application and curing of the coating. This advantageous solution is obtained by subjecting the radiation curable coating to radiation during the production process, through a texturizing agent and not through a substrate.

[0021] Some embodiments may include one or more of the following features. The substrate may contain a graphic pattern, e.g. a pattern printed on the substrate below the cured coating. In some embodiments, the pattern coincides with the texture of the substrate. In some cases, the substrate may be a disc. Sticky substance may be present on the surface of the substrate opposite the exposed surface, for example when the product is wallpaper or flooring. In some cases, the cured coating contains a release agent that allows the cured substrate to act as a release layer during the subsequent casting process.

[0022] Details regarding one or more embodiments of the invention are provided below with the accompanying drawings. Other features and advantages of the invention will become apparent from the description, drawings and claims.

DESCRIPTION OF THE DRAWINGS [0023]

<td>FIG. 1 shows schematically</td><td>throw</td><td>side</td><td>process</td>

<td colspan="3">making textured release film.</td><td></td>

<td>FIG. 2 shows schematically producing a laminated product.</td><td>throw</td><td>side</td><td>process</td>

<td>FIG. 3 shows schematically manufacturing a texturing agent.</td><td>throw</td><td>side</td><td>process</td>

FIG. 4 schematically illustrates various possibilities of using the processes shown in FIG. 1-3.

DETAILED DESCRIPTION [0024] In the following we will first describe how the texturing processes disclosed in the description can be used to make non-adhesive tapes, i.e. materials in the form of a tape or sheet, which can be used in the casting processes described above in the section entitled "Prior art", or in other processes such as stamping, laminating, vulcanization and rotary curing. For example, the release tape thus produced can then be used as a mold for casting the finished product with the desired texture on the release film. Next, we will describe how the processes discussed here can be used to directly produce a finished substrate product, and to form - on the exposed surface of the substrate - a cured coating having a texture that is the reverse of the texture on the texture medium. Finally, we describe the preferred ways of making a texturizing agent using the processes discussed here.

Manufacture of release tape [0025] Referring to FIG. 1, the device 10 for producing a release tape comprises a textured tape 12 provided from a feed roller 14 and wound on a take-up roller 16. The textured tape 12 provides a mapping surface 18 against which the substrate for the release tape is pressed. At the curing point 20, a curable coating is applied to the mapping surface 18. The textured tape and curable coating are selected so that the curable coating after curing can separate from the textured tape.

[0026] The substrate 22 is supplied from the feed roller 23 and enters the device at pressure 24 between the pressure rollers 26, 28. The pressure presses the coated surface of the textured tape 12 against the surface of the substrate 22. The resulting "sandwich" then passes through the curing point 30 containing devices that generate 32 radiation, e.g., UV lamps.

[0027] In the case of an opaque substrate, or when it is desired, radiation generating devices can - instead of UV radiation - generate electron radiation. Preferably, the radiation generating devices are positioned as shown, i.e. on the side of the textured band 12, and not on the side of the substrate 22. As a result, the radiation does not need to pass, and does not pass, through the substrate. Because the radiation does not pass through the substrate, the physical properties of the substrate do not deteriorate during the curing process.

[0028] After curing, the substrate on which the cured coating is located (finished release tape 34) is separated from the textured tape 12, the cured coating remaining on the substrate 22. Then, the finished release tape 34 is wound onto the take-up roller 36. Textured tape 12 is wound onto the take-up roller

16. Basically, textured tape can be used multiple times, i.e. more than 50 times, and in some cases up to 70 and more times.

Manufacture of finished products [0029] Referring to FIG. 2, as in the case of the device 10 described above, the device 10 'for the production of finished products comprises a textured band 12 supplied from a feed roller 14 and wound on a take-up roller 16. The textured band 12 provides a mapping surface 18 against which the substrate for the finished product is pressed . At the curing point 20, a curable coating is applied to the mapping surface 18. The textured tape and curable coating are selected so that the curable coating after curing can separate from the textured tape. An important advantage of the technique shown in FIG. 2 and described below is that the surface texture of the mapping surface 18 is mapped with 100% fidelity. Thus, this technique allows the reproduction of very delicate patterns on the surface of the cured coating while maintaining substantially 100% accuracy.

[0030] Substrate 22 'shown in FIG. 2 as a series of separate plates enters the device at pressure 24, where it is pressed against the shaft 26 '. The plates are supported by a conveyor or series of rollers (not shown). Roller 26 'presses the coated surface of the textured band 12 against the surface of the substrate 22'. The resulting "sandwiches" then pass through a curing point 30 equipped with devices for generating radiation 32, e.g. UV lamps or devices for generating electron radiation. In this case, in contrast to the machine 10 shown in FIG. 1, the radiation generating devices are mounted above the "sandwiches" and the texturing medium is above the substrate 22 ', whereby the coating can be cured by the texturing medium while the plates are supported by a conveyor or rollers. Preferably, as shown in FIG. 2, no pressure is applied to "sandwiches" during curing. This can reduce the processing cost and minimize damage to the textured tape 12, so that it can be reused, in many cases even repeatedly.

[0031] After curing, the textured tape 12 is separated from the substrate on which the cured coating is located by winding the textured tape through the separation roller 13. The cured textured coating remains on the substrate 22 to form the finished product 35. In the embodiment shown in FIG. The mass of the plates causes them to adhere to the conveyor or rollers during the separation process. Other separation techniques may be used in other embodiments. The textured tape 12 is wound on the take-up shaft 16 and can be reused more than 50 or even 70 times.

[0032] If desired, the boards or other substrate 22 'may comprise a pre-printed graphic pattern. In this measure, FIG. 1) it is the case if it is desirable that the graphic pattern coincide with the texture of the textured coating, convergence can be ensured by using fit marks on the substrate and the textured medium or by using fit techniques such as optical devices.

[0033] Preferably, since the curing takes place from the textured strip side, the substrate can be any material, for example cellulosic, ceramic, metal or textile material, of any thickness. Thanks to this, you can produce a wide range of finished products. In some embodiments, if metal is used, the finished product can be a spacer plate or aluminum panels or wallpaper - when using flexible tape.

Manufacture of the texturizing agent [0034] In some embodiments, the texturizing agent (e.g., textured band 12 with a fluid, curable liquid produced by coating the substrate, e.g., a forming roller, transferring the pattern onto the coating, and separating the substrate and the cured coating from the pattern transferring surface.

[0035] In the process shown in FIG. The 2 pattern on the texture center is the reverse of the desired texture of the finished product. Thus in this case (option A in FIG. 4) the pattern on the engraved roller will be identical to the pattern that will appear on the finished product. In the process shown in FIG. 1, the texture of the finished, cast product (see option B in FIG. 4) will be the reverse of the release tape, so the pattern on the forming roller will be the reverse of the pattern on the finished product, and the pattern on the texture center will be the same as the pattern on the finished product.

[0036] Preferably, the entire process of producing the texturing agent through the engraved roller is carried out on a continuous web of material passed through a series of processing points, e.g. 3. The process shown in FIG. 3 provides a large, substantially 100% faithful reproduction of the desired pattern.

[0037] Referring to FIG. 3, in one process, tape 110, e.g., polymeric film, first passes through the feed roller 102, up to the coating point 112 where the head 114 applies a wet coating 116 to the surface 117 of the tape. The coated belt then passes through the pressure 118 between the supporting roller 120 and the engraved roller 122, the belt facing the wet coating 116 towards the engraved roller 122. On the engraved roller there is a pattern, the reverse of which is transferred to a wet coating. The clamping force is usually relatively small, and is selected according to the viscosity of the coating to prevent it from peeling off the tape. Typically, coatings with a higher degree of viscosity and deeper patterns require relatively more pressure.

[0038] After releasing the pressure, the coated and textured tape passes through a curing point 124, e.g. an electron or UV curing device. The coating is hardened while remaining in contact with the engraved roller. Electron or actinic radiation is usually applied from the back side of the tape 126 and passes through the tape hardening the coating 116 to form a hardened but flexible textured coating 128 firmly adhering to the tape 110. The tape 110 and the cured coating 128 can be separated from the engraved roller of the examples used for the take-up roller 130. In the case of UV curing, the tape should be transparent if curing is to occur from the back of the tape as shown.

[0039] Coating 116 can be applied by any suitable methods such as offset gravure, direct gravity, knife coating, curtain coating and other printing and coating techniques.

[0040] An engraved roller is one of the mapping surfaces that can be transferring a pattern to a wet coating. You can also use other pattern transfer devices. However, it is usually preferred to arrange the mapping surface on a rotating and endless surface, such as a cylinder or drum, or other cylindrical surface. The coating may be applied directly to the tape before the substrate comes into contact with the roller as shown in FIG. 3, or alternatively, the coating can be applied directly to the roller. The substrate is then pressed against the coated roller.

[0041] The coating may be cured by thermal curing or, preferably, by curing by radiation (e.g. electron or UV radiation). Electron radiation is preferred in some cases because it is able to penetrate the thick coatings required for some of the desired patterns. Devices for generating electron radiation are readily available and usually consist of a transformer capable of increasing the line voltage, and an electron accelerator.

Devices for generating electron radiation are manufactured by Sciences, Inc. PCT Engineered The manufacturer of suitable UV radiation is, for example, Maryland.

among others by: Energy Systems, LLC, Davenport, Iowa. curing equipment

Fusion, Inc., Gaithershurg, [0042] Coating materials and substrates are discussed in the section titled "Materials".

[0043] Another method may be used to form the texture agent. For example, the texturizing agent may be produced by the process shown in FIG. The fabric of claim 1, wherein the pattern of textured tape 12 is the negative of the pattern desired for the new texture agent (option C in FIG. 4). In this case, the textured band 12 acts as a matrix. The texturizing agent can also be produced by traditional extrusion techniques.

Materials [0044] The substrate 22 used in the process shown in FIG. 1 may be any material in the form of a sheet or tape to which a curable coating may adhere, e.g. paper or foil. The polymer to which the coating usually adheres can be administered, e.g., flame treatment, corona discharge or precoating using an adhesive activator. Suitable substrates can be: paper, polyester films, cellulose triacetate films, biaxially oriented polystyrene and acrylics. These and other substrates referred to above are suitable for use in the process shown in FIG. 2.

[0045] Preferably, the curable coatings referred to above include acrylated oligomers, monofunctional monomers, and multifunctional monomers for crosslinking reactions. If UV radiation is used to cure the functional acrylic coating, the coating will also contain a photoinitiator, as is known in the art. Preferably, acrylated oligomers include acrylated urethanes, epoxies, polyesters, acrylics and silicones. The oligomer essentially contributes to the final properties of the coating. Experts in the field know how to choose the right oligomers to achieve the desired end properties. The desired end properties for the release tapes described herein usually require an oligomer that provides flexibility and durability. Cytec Surface Specialties Corporation offers a wide range of acrylated oligomers such as Ebecryl 6700, 4827, 3200, 1701 and 80, while Sartomer Company, Inc. offers e.g. CN-120, CN999 and CN-2920.

[0046] Typical multifunctional monomers include acrylic acid, N-vinylpyrrolidone, ethyl (ethoxyethoxy) acrylate or isodecyl acrylate. Preferably, the isodecyl acrylate is a multifunctional monomer. The multifunctional monomer works like a thinner, i.e. it reduces the viscosity of the coating and increases its elasticity. Examples of multifunctional monomers are: SR-395 and SR-440, offered by Sartomer Compnany, Inc., as well as Ebecryl 111 and ODA-N (octyl / decyl acrylate), offered by Cytec Surface Specialties Corporation.

[0047] Commonly used multi-functional monomers for cross-linking are trimethylpropyl triacrylate (TMPTA), propoxylated glyceryl triacrylate (PGTA), tripropylene glycol diacrylate (TPGDA) and di-propylene glycol diacrylate (DPGA). Preferably, the multifunctional monomer is selected from the group consisting of TMPTA, TPGDA and mixtures thereof. The preferred multifunctional monomer acts as a crosslinker. Examples of multifunctional monomers are: SR-9020, SR-351, SR-9003 and SR-9209, manufactured by

Sartomer Company, Inc., and TMPTA-N, OTA-480 and DPGDA, manufactured by Cytec Surface Specialties Corporation.

[0048] Preferably, before curing, the coating consists of 20-50% acrylated oligomer, 15-35% monofunctional monomer, and 20-50% multifunctional monomer. The composition of the coating depends on the final target viscosity and the desired physical properties of the cured coating. In some embodiments, the preferred viscosity coefficient is from 0.2 to 5 Pascal seconds, and the more preferred viscosity coefficient is 0.3 to 1 Pascal seconds measured at room temperature (21-24 ° C). [0049] The coating may also contain other ingredients such as opacifiers, dyes, glidants / spreaders and anti-static or anti-abrasive agents. The degree of opacity of the coating can be changed, for example, by the addition of various pigments, such as titanium dioxide, barium sulfate and calcium carbonate, or the addition of an incompatible liquid, such as water. The degree of opacity can be adjusted by changing the amount of added funds.

[0050] As mentioned above, in the case where the coating is to be cured by UV radiation, a photoinitiator or photoinitiators package may be included. Suitable photoinitiators named KTO-46^TM offers Sartomer Company. The photoinitiator may be added in an amount of e.g. 0.5-2%.

[0051] In the event that the process is not used to produce a release tape but a finished product, the coating need not provide release properties.

[0052] For example, when desired, instead of coating the textured tape 12 in the process shown in FIG. 1 and 2, substrate 22 or 22 'may be coated before being placed in the clamp.

[0053] Furthermore, in some embodiments, a thermal curing process may be used instead of the radiation curing process. Then the curable material is a material suitable for thermal curing. Thermal energy is fed from the side of the texturing agent and can be, for example, infrared energy (IR).

[0054] Therefore, accordingly, other embodiments fall within the scope of the following claims.