TWI725104B - Release web, method of forming release web, method of imparting texture to release web, substrate - Google Patents

Abstract

The present disclosure features processes and equipment for manufacturing materials that have a textured surface formed by applying a first three-dimensional texture to a curable coating, curing the coating, and then embossing a second, different texture over the first three-dimensional texture. The disclosure also features textured materials, including both release webs for use in replicative casting processes and finished products in sheet, board, plate or web form.

Description

Release template, method of forming release template and impart texture to release template Board method, base material

Surface texture (such as a three-dimensional pattern) can be imparted to the template through the process. During the process, a curable coating is applied to the template, and the curable coating texture is imparted through the replication surface (such as a metal engraving roller), and radiation is passed through the template So that the coating is cured while contacting the roller.

The template material produced by this process can be used as a release template in the subsequent process, such as forming (for example: casting) a plastic film on the release template or against the release template, and after the plastic material is cooled or solidified, it can be used as a release template. Template separation. The release template provides a surface from which the cured plastic material can be easily separated and can give the plastic material the texture of the release surface. For example, by forming a plastic sheet on a release template with a textured surface, the desired textured surface can be provided on the surface of the plasticized material, and the textured surface on the release template is the desired textured surface Mirror.

U.S. Patent Nos. 4,289,821 and 4,322,450 disclose techniques for producing surface effects in a release coating on a release template used in a casting process, the disclosures of which are incorporated herein by reference. One disclosed method includes applying a coating of an electron beam radiation curable material to a surface of a template substrate, and pressing the coated side of the substrate against a replication surface such as gold. It is an engraving roller, irradiates the coating with electron beam radiation to cure the coating, and then peels off the cured coating adhered to the substrate from the replication surface. Using these methods, the replicated surface can be replicated in the cured coating with substantially 100% fidelity. Other replica casting methods are disclosed in U.S. Patent Nos. 6,355,343 and 7,964,243, the disclosures of which are incorporated herein by reference.

The replication casting process can be used to form very fine, even nanoscale textures. One example of a micron-scale texture is called "Sharklet" in the art. Sharklet texture can be applied to plastic sheet products to provide the product with a structured surface that prevents the growth of bacteria. The micron-scale texture of the surface replicates like shark skin teeth, which are arranged in a diamond pattern with millions of fine ribs. Sharklet materials are widely discussed in applications, such as: U.S. Patent Nos. 7,650,848 and 8,997,672, the entire disclosures of which are incorporated herein by reference. This material is important in providing non-toxic bioadhesion control and anti-fouling properties, and has been proposed for use in the medical device industry. Other micro-scale textures include lenticular textures, drag reducing textures (eg, Riledt features), and cube corner textures that produce reflective surfaces.

Nanoscale textures include diffraction gratings, hydrophobic surfaces (for example, a lotus leaf-like surface with micron and nanoscale structures on the surface, which minimizes the adhesion of droplets to the surface) and laser interference rainbow patterns, which Shows that the reflected light is the color of the visual spectrum. One example of a nanoscale texture is a diffraction grating, which has a series of raised ridges about 400 nm wide, about 800 nm apart, and about 100 nm deep.

The present invention is characterized by a process and equipment for manufacturing a material with a textured surface by applying a first three-dimensional texture to a curable coating, curing the coating, and then embossing and the first three-dimensional texture on the first three-dimensional texture. A second three-dimensional texture with different textures. This disclosure is more involved And texture materials, including release templates used to replicate the casting process and finished products in the form of sheets, strips, ribbons or plates.

In some embodiments, the methods disclosed herein can be used to impart micron, nanoscale (such as Sharklet materials) to macroscale (thus observable by the naked eye) material texture. Doing so can enhance the appreciation quality of the material, and can also provide other advantages, such as improved wear resistance and tactile properties.

In one aspect, the invention features a release template for replicating casting of a curable system. The release template includes a substrate and a coating provided on at least one surface of the substrate, the coating having a surface effect that is replicated during casting. Surface effects include a first three-dimensional texture on a micron or nanometer scale and a second three-dimensional texture on a macro scale. Wherein, the second three-dimensional texture is superimposed on the first three-dimensional texture, and the first three-dimensional texture and the second three-dimensional texture are coextensive.

In some embodiments, the release template may include one or more of the following technical features.

During the manufacture of the release template, the second three-dimensional texture can be post-embossed on the first three-dimensional texture. The first three-dimensional texture may be composed of diffraction gratings, hydrophobic surface textures, laser interference rainbow patterns, and combinations thereof; or may be composed of lenticular lens textures, drag reduction textures, cube corner textures, and combinations thereof. In some embodiments, the second three-dimensional texture has a characteristic depth of about 50 to 300 microns. The first three-dimensional texture may have a feature length of about 1 to 100 microns, a feature width of about 1 to 10 microns, a feature pitch of about 1 to 10 microns, and a feature depth or height of about 1 to 10 microns.

In another aspect, the technical feature of the present invention lies in a method, which includes applying a coating to a flexible substrate, and imparting a first three-dimensional texture on a micron or nanometer scale to the coating and a second three-dimensional texture on a macro scale. , To form a release template with a textured surface.

In some embodiments, the method may include one or more of the following features.

The method may further include curing the coating after imparting the first three-dimensional texture and before imparting the second three-dimensional texture. The imparting of the second three-dimensional texture may include embossing a cured coating. At least one texture can be applied by clamping the coating against the surface of the engraving roller. For example, the cured coating can be imprinted by pressing the cured coating against a heated replication surface. In some embodiments, the replication surface may be heated to a temperature greater than the glass transition temperature of the cured coating.

The method may further include casting a polymer film on a release template, and in some embodiments, laminating a sheet material such as fabric, board, paper, or foil onto the cast polymer film. The polymer film may contain a polyurethane resin.

In another aspect, the present disclosure features an article that includes a flexible template having a textured surface including micrometer, nanometer-scale features, and macro-scale features, the micrometer or nanoscale features and The macro-scale features are arranged on the same area of the template and are coextensive with each other in such a way that the texture of the micron or nano-scale feature is under the texture of the macro-scale feature.

In some embodiments, the article may include one or more of the following features.

The flexible template may include, for example, a textured polymer layer of polyurethane, thermoplastics such as polypropylene or silicone. The article may include a silicone mold. In some cases, The flexible template further includes sheet materials such as fabric, board, paper or foil laminated to a textured polymer layer.

In another aspect, the present disclosure features a method of manufacturing an article with a textured surface, the method comprising mechanically embossing a macro-scale three-dimensional texture on the surface of a template having a micron or nano-scale three-dimensional texture.

Another feature of the present disclosure lies in a method, which includes (a) casting a silicone resin on a textured release template with a macro-scale texture and a micro- or nano-scale texture provided on the same surface of the template to form a textured release template. Silicon replication template; (b) forming a mold containing a textured silicon replication template; (c) using a mold to form a nickel sleeve; and (d) using a nickel sleeve as a replication surface to give the second release template a macroscopic view and Micron or nanometer scale structure.

As used herein, the terms "texture" and "texture surface" include very fine textures, for example, including textures with topography below the wavelength of light. The texture discussed in this article is a predetermined texture, that is, a texture that is deliberately given to a surface, not just the natural appearance of the surface, surface pollution, and other textures that are inherently present on any surface.

The term “feature spacing distance” used in this article distance)" refers to the distance between adjacent features of a three-dimensional texture. A confocal microscope or a scanning electron microscope (SEM) can be used to observe and measure the distance between features.

The term "nanoscale" as used herein refers to features having a characteristic scale of less than 1000 nanometers.

The term "micro-scale" as used herein refers to features having a characteristic scale of less than 50 μm.

The term "macro-scale" as used herein refers to features that can be distinguished by the naked eye.

"Web" as used herein in the singular and plural forms includes continuous templates and discrete sheets.

Unless otherwise stated, all are percentages by weight.

Other features and advantages of the present invention will be apparent from the following detailed description, drawings and scope of patent application.

10: Release template

12: Substrate

14: Coating

16: micron scale

18: Macro scale

100, 200: Process

139: Template

110, 120, 130, 140, 210, 220: steps

141: roll gap

142: engraving roller

143: Elastic back roller

Figure 1 is a partial schematic side sectional view of a release template according to an embodiment.

FIG. 1A is a partial schematic side sectional view of a release template according to an alternative embodiment.

FIG. 2 is a flowchart of a manufacturing process of a release template according to an embodiment.

FIG. 2A is a schematic diagram showing the manufacturing process of FIG. 2.

FIG. 3 is a flow chart of a process for imprinting a template after manufacturing according to an embodiment.

Fig. 4 and Fig. 4A are the photomicrographs of release paper taken with a confocal microscope and a polyurethane fabric made of release paper, respectively. Release paper and fabrics include leather macro-scale patterns superimposed on Sharklet micro-scale patterns.

The process described herein involves post-imprinting the texture on the fine-scale texture below. In some cases, the features of the underlying texture are invisible to the naked eye, and the features of the embossed texture can be seen with the naked eye. An example of such an arrangement is schematically shown in FIG. 1 and FIG. 1A, in which the release template 10 includes a substrate 12 carrying a coating layer 14. The coating 14 includes a micro-scale 16 and a macro-scale 18. As shown in Figure 1, the substrate 12 may be deformed due to the imprinting process that imparts the macro-scale 18, or as shown in Figure 1A, the macro-scale 18 may only affect the surface of the substrate. Although the features are evenly spaced in Figures 1 and 1A, other textures that may use micro-scale and/or nano-scale features are irregularly spaced.

In some embodiments, the underlying texture is a micron or nanoscale texture, such as a functional texture such as a Sharklet texture, and the post-imprint texture is a larger-scale, such as macro-scale texture. As will be discussed below, these processes can be used to form a release template with two superimposed textures, or can be used to post-imprint a textured product, such as a paper or plastic template with a textured surface. For example, the textured product can be a printed decorative paper with a Sharklet micro-scale pattern, and then the substrate is post-imprinted with a macro-scale pattern such as a "woodcut" pattern.

Macro-scale textures can be applied to micro- or nano-scale textured products, otherwise the products may be visually unattractive and do not have the originally expected aesthetic appearance. For example, the macro-scale texture can be leather or wood grain, or other visually appealing textures.

Adding macro-scale textures tends to hide seams in micro- or nano-scale textures, which may result from the process used to create a replicated surface that obtains micro- or nano-scale textures. For example, a master micron or nanoscale pattern can be produced on a flat master shim, and the pattern on the shim is transferred to a roller used as a replication surface. A finite-scale flat pattern from the main gasket is set on the surface to give a relatively continuous pattern around the circumference and length of the roll pattern. During this tiling process, visible seams are formed between each pattern area. These seams are more aesthetically objectionable, so it is advantageous that the post-embossing minimizes the visibility of the seams.

In the case of a texture such as Sharklet, the macro-scale pattern can also reduce the visual intensity of the iridescent appearance of the finished product made using the release template, which may appear as an iridescent texture due to the use of a diffraction grating.

Surprisingly, the post-imprint process does not deleteriously affect the fidelity of micron or nanoscale textures, and therefore usually does not negatively affect the functional properties provided by micron or nanoscale textures. For example, if the underlying texture is designed to hinder the growth of bacteria, this property will remain in the post-imprinted product.

The macro-scale texture can also improve the durability and abrasion resistance of the finished product by preferentially abrading the raised areas of the macro-scale texture, and protect the micron or nano-scale texture below.

Texture template

Examples of micron-scale textures include the Sharklet pattern described in US Patent 7,145,709 B2. These patterns consist of a series of ridges that can be above or below the plane of the substrate coating. The micron feature size can be in the range of 0.5 to 50 microns. In some embodiments, the feature length can be about 1 to 50 microns, the feature width can be about 1 to 10 microns, the feature pitch can be about 1 to 10 microns, and the feature depth or height (the distance perpendicular to the plane of the substrate) can be It is about 1 to 10 microns. In one embodiment, the length of the ridge varies between 4 and 16 microns, with a width of 2 microns, a pitch of 2 microns, and a height/depth of 2 to 3 microns. In another embodiment, the length of the ridge varies between 20 and 80 microns, and the width is 10 microns, the spacing is 2 microns, The height/depth is 2 to 3 microns. For these two examples, the angle of the sidewall of each feature is less than 85 degrees. In some embodiments, the angle of the sidewall is about 10 to 90 degrees, for example, about 50 to 85 degrees. If the angle of the sidewall is greater than about 85 degrees, the peeling force of the cured coating from the replication surface (e.g., engraving roller) can be very high.

Nanoscale textures can have characteristic scales (length, width, and depth/height) in the range of 10 to 999 nanometers.

In some embodiments, micron or nanoscale textures may include features in the positive and negative z directions, as an example, such as certain Sharklet materials.

The macro-scale texture can be, for example, any texture among the many textures on Sappi/Warren release paper. These Sappi/Warren release papers have obtained the trademark ULTRACAST® or the trade name Classic, which is produced by SDWarren Corporation d/b/a Sappi North America production. An example of a macro-scale pattern is a replica of natural leather particles with a characteristic depth of about 50 to 300 microns. Any other desired macro-scale texture can also be used.

In addition to macro-scale features, post-embossed textures may include micro-scale features that contribute to the texture's tactile or aesthetic properties (e.g., surface gloss/brightness) that are not visible to the naked eye.

Manufacturing process of release template

In Figures 2 and 2A, examples of the manufacturing process 100 for manufacturing the release template and the finished product made from the release template are shown.

Referring to Figure 2, the process 100 includes applying a coating to the surface of a template substrate that will become a release template, or to a replication surface that will be used to apply micron or nanoscale textures to the coating (step 110). For example, the coating can be applied to the substrate before it reaches the replication surface On; or applying the coating to the replication surface, when the substrate is pressed against the replication surface, the coating is transferred to the substrate.

The base template can be any flexible sheet-like substrate, such as paper, metal foil, and plastic film. In some embodiments, the base template is preferably paper with a primer layer to prevent excessive penetration of the coating composition. The replication surface can be, for example, the surface of an engraved roller, the surface of a textured template conveyed from a supply roller and wound on a take-up roller, or any other suitable textured surface such as a textured sleeve, belt, cylinder or plate.

The base template is clamped on the replication surface, and a coated template having a surface with a texture opposite to the replication surface is produced (step 120). Then, the coated template passes through a curing station to cure the coating to form a textured template (step 130). The replicated surface remains in contact with the coated template during curing, and the textured template is peeled from the replicated surface after curing. The curing station may include a radiation delivery device such as a UV lamp or an electron beam device. The coating composition is selectively cured using the equipment in the curing station. Generally, no heat or pressure is applied during this step.

The second replication surface (step 140) is then used to post-imprint the textured fabric with a larger-scale (e.g., macro-scale) texture. As shown in detail in Figure 2A, the post-imprinting step can be performed, for example, by passing the template 139 through the nip 141, in which the textured surface of the template is pressed against a heated engraving roller (or other replication surface) 142, For example in hydraulic presses. The nip defined by the engraving roller 142 and the elastic backing roller 143 is pressurized to a desired pressure. The engraving roller can be heated, for example, by steam or oil. Heat and pressure are applied at the nip during the mechanical embossing step to impart the surface texture of the engraving roller to the texture template. The heat and pressure that are selectively applied in a particular process will be discussed in the process parameters section below. The post-imprint template leaving the nip is ready to be used as a release template.

After post-imprinting, the finished release template can be used to form the desired final product, for example, by casting a plastic film on the release template (step 150).

Coating composition

Generally, a suitable coating composition can be mechanically imprinted in the post-imprinting process after curing, and can withstand the expected conditions of the subsequent copy casting process without suffering unacceptable damage. The composition of the coating composition used in a particular process will depend on many factors, including the depth of the macro-scale pattern to be applied, post-imprint conditions (e.g., temperature and pressure), and the chemicals that will be used to replicate the casting process.

The radiation-curable acrylate composition has chemical resistance during curing and excellent flexibility when used as a coating, so it is a preferred choice in many embodiments.

In some embodiments, the coating composition contains a monofunctional acrylate monomer to impart release properties and flexibility to the cured coating, and is used as a diluent, a multifunctional acrylate monomer for crosslinking, and in some cases Next, the acrylated oligomer provides flexibility in the cured coating.

In some embodiments, the ratio between monofunctional and multifunctional acrylates is about 15:85 to 85:15. In some embodiments, the monofunctional acrylate material provides at least 15% of the total acrylate material in the coating composition, such as at least 25%, 35%, 45%, 55%, 65%, or 75%. In some embodiments, about 15% to about 85%, or about 33% to about 66% of the total acrylate materials are monofunctional acrylate monomers. The chain length of the monofunctional acrylate material also affects the release properties of the coating composition. In some embodiments, the molecular weight is about 120 to 380, such as about 128 to about 212, or about 212 to 324.

Monofunctional monomers include, for example, acrylic acid, N-vinylpyrrolidone, (ethoxyethoxy) ethyl acrylate, and isodecyl acrylate.

Multifunctional monomers include, for example, trimethylolpropane triacrylate (TMPTA), propoxylated glycerol triacrylate (PGTA), tripropylene glycol diacrylate (TPGDA), and dipropylene glycol diacrylate (DPGDA). Preferably, the multifunctional monomer is selected from TPGDA, TMPTA and mixtures thereof.

Acrylic oligomers include, for example, acrylated urethanes, epoxy resins, polyesters, acrylates, and silicones. In some embodiments, it is preferably urethane acrylate. The acrylic oligomer contributes to the mechanical properties of the coating. The inclusion of acrylated oligomers can impart toughness and flexibility to the cured formulation, which can help the cured coating to withstand post-imprinting without cracking. Acrylated oligomers are commercially available from, for example, Allnex, under the trade name EBECRYL® UV/EB curable resin.

As an example, a composition that can be used to form the release coating used in the method described herein can include (prior to curing) 20-50% acrylated oligomer, 15-35% monofunctional monomer, and 20 -50% of multifunctional monomers.

The composition may include reactive or non-reactive silicones, such as amino-functional silicones as a release agent. If the coating is cured while in contact with the replicated surface, it will help the cured coating to peel off from the replicated surface.

The coating composition may include materials other than acrylic functional materials, such as viscosity control additives such as colloidal silica or volatile solvents, or surface texture materials such as starch particles or silica. If UV curing is used, the composition will generally include a photoinitiator. In addition, filler materials such as conventional paper coating dispersants may be included to reduce the cost of the coating. However, the amount of acrylic functional material in the coating composition must be sufficient in the area where it is coated Provide a continuous polymerization layer. Preferably, the acrylic functional material accounts for at least about 30% of the total weight of the total coating composition, and more preferably, provides at least about 40%.

Replicated Surfaces (Replicative Surfaces)

The replication surface is usually provided on a rotating cylindrical member, such as a roller or drum with a patterned or engraved sleeve or surface, but it can also be provided on a plate, belt or a textured release template.

The first replication surface used to impart the first three-dimensional texture on the micrometer or nanometer scale is usually set on a metal roller or sleeve, and can use photolithography, ion deposition, laser interference or other to make the surface micrometer or nanometer scale. The characteristic technology forms the first replication surface. Other types of replication surfaces can be used, including textured release templates, strips, tapes, etc., but it is usually necessary to use technology that can form very fine (for example, micron or nanoscale) features to make the main body.

The second replication surface can be produced using various techniques, such as those well known in the field of imprinting. The second replication surface is usually selected to have a surface that can withstand the process parameters used in the post-imprint process.

Process parameters

The temperature of the template at the nip (imprint temperature (Te)) during the post-imprint step may be important, especially to allow accurate, high-fidelity reproduction of the post-imprint texture. For example, conventional techniques such as passing or recirculating steam and/or hot oil through the nip rolls can be used to heat one or both of the nip rolls to heat the template as it passes through the nip. The optimal template temperature for a particular process will depend on various factors, including the composition of the coating, the thickness of the coating, the dynamics of the nip, the speed at which the template travels through the nip, and the depth of the texture after imprinting. The template temperature is sufficiently higher than the glass transition temperature (Tg) of the cross-linked coating to obtain sufficient coating flow to allow precise imprinting. The degree to which the template temperature exceeds Tg can be empirically determined based on the above factors. In some embodiments, the template temperature is about 100 to 200°F, for example, about 140 to 170°F, depending on the equipment available, temperatures as high as 500°F or higher, for example, may also be used.

The temperature of the die plate is generally lower than the temperature of the heated press roll. In some embodiments, the temperature of the template after leaving the heated nip is about 60 to 100°F lower than the surface temperature of the heated nip roll. This temperature difference can vary according to various factors that affect heat transfer.

Generally, the template temperature should be high enough to enable uniform, high-fidelity macro-size patterns to be imprinted on the entire template side-to-side. If the coating used is prone to cracking, a sufficiently high temperature can also help minimize cracking of the coating during post-imprinting.

A high hardness crosslinked coating with a relatively high Tg (e.g., 120°F) may be more susceptible to cracking during post-imprinting. In some cases, in order to minimize or avoid cracking, it may be desirable to impart greater flexibility to the coating, for example, by changing the composition of the coating or reducing the thickness of the coating, and/or increasing the post-imprint temperature.

The pressure applied at the nip is also important to obtain a good post-imprint texture. If the pressure is too high, in some cases, this may result in uneven imprinting across the width of the template. If the pressure is too low, the desired characteristic depth of the embossed texture may not be obtained. In some embodiments, the nip pressure is at least 1000 pounds per linear inch (PLI), for example about 1000 to 2000 PLI. The appropriate pressure is the same as that used in standard macro-scale imprinting methods; it seems that the pressure used does not affect the underlying micron or nanoscale patterns.

In some cases, the nip includes an elastic back roller, which may have a Shore D hardness of, for example, about 80 to 90.

In some embodiments, the coating weight of the coating is about 10 to 15 g/m ² . The stiffness of the coating is directly proportional to the thickness of the coating (the stiffness is proportional to the cube of the thickness), so if other factors remain constant, the smaller the weight of the coating usually provides greater flexibility, so the coating can be imprinted.

Process of Post-Embossing Textured Films

In the alternative embodiment shown in Figure 3, once post-imprinting is performed on the template, it will be made into an intermediate product or finished product (rather than a release template). Referring to FIG. 3, in the process 200, a first three-dimensional texture (for example, a micron or nanoscale texture) is applied to a plastic template or a plastic coating of a paper template using a first replication surface (step 210). Any desired technique may be used to apply the first three-dimensional texture, such as using a release template bearing the first three-dimensional texture as the first replication surface, or using any of the above-mentioned techniques.

Then, for example, using an engraving roller, the desired texture is post-imprinted on the textured template to provide a second replication surface (step 220).

The plastic film or coating can be formed, for example, by extrusion or other techniques used to form a sheet-shaped plastic substrate. In some cases, the template includes a polypropylene sheet. In other cases, the template includes a paper template, for example, by extruding polypropylene onto a cooling roll textured with a micron or nanoscale texture while holding the paper template to deposit polypropylene on the paper template coating. As another example, a polypropylene film can be extruded or laminated to a paper template, and then micron or nanoscale textures are applied to the polypropylene surface.

Thermoplastics other than polypropylene can be used, such as vinyl, polymethyl methacrylate and other thermoplastics used in the embossing process.

The embossing temperature for initial and post embossing will be selected based on the softening temperature and melting temperature of the particular thermoplastic used. The temperature of the template during post-imprinting should generally be low enough so that the micron or nanoscale patterns are not harmfully affected and the coating does not melt. This temperature will depend on the melting temperature of the thermoplastic used. For polypropylene, the preferred temperature for subsequent embossing is usually a temperature higher than the softening temperature of polypropylene but less than 200°F.

The imprint pressure is usually the same as the pressure discussed above in the process parameters section.

In some cases, polypropylene and/or paper may be pre-printed with a desired pattern, for example, the paper may be a decor paper.

The post-imprint template may be a finished product or an intermediate product. For example, the post-imprint template may be subjected to further processing steps, such as adhering it to the base plate and/or cutting it into pieces.

Example 1

The release template shown in Figure 4 was manufactured using the following process: a 158 g/m2 fiber base paper was coated with a clay coating that provided acrylic coating retention and adhesion. An offset gravure coating assembly was used to coat the acrylic paint (the composition of which is shown in Table 1 below) on the substrate at a coating speed of ^{18 g/m 2 and 60 ft/min.} The coated paper was then wrapped around the nickel sleeve with a micron-scale Sharklet pattern, and cured using an electron beam at a dose of 4 Mrads. The micron-scale Sharklet pattern has a feature pitch of 2 microns, a feature width of 10 microns, and a feature depth of 2.1 microns.

The cured paper with micron-scale texture is wound into a finished roll.

The paper is post-embossed in a separate process step as follows: the template passes through the tension control roller and is between the embossing roller and the elastic backing roller. The engraved embossing roller is preheated to 220°F, and the nip is closed and loaded to a pressure of 1800RPI. The paper was run at a speed of 60 feet per minute to impart the macro-scale texture of the impression roller to the paper substrate, and the micron/macro-scale textured paper release template (shown in Figure 4) was wound into a roll.

Example 2

The texture of the polyurethane coated fabric (fabric) shown in Figure 4A was prepared using the following method: a polyurethane surface coating with a thickness of about 75 microns was cast onto the release paper formed in Example 1 shown in Figure 4, and Heat to 140°C for 2 minutes to remove the solvent. The coating composition includes 80% by weight of Stahl Holdings' SU 10-104 (product name) polyurethane resin, 8% DMF (dimethylformamide) and 15% Stahl VP-048-031 dispersant (pigment).

The urethane adhesive coating (120 microns thick) was cast onto the pre-cured cast polyurethane surface coating. The paint composition is 80% by weight of IMAPUR 5105 Polyurethane resin, 8% DMF (dimethylformamide) and 15% Stahl VP-048-031 dispersant.

Then the non-woven fabric is sandwiched into the wet polyurethane adhesive coating, heated to 140°C for two minutes and allowed to cool.

The resulting fabric/urethane composite has a micron/macro surface texture that replicates the release paper and is peeled from the release paper as shown in Figure 4A.

Other embodiments

A number of embodiments have been described. However, it should be understood that various modifications can be made without departing from the spirit and scope of the present disclosure.

For example, there are many other examples of coatings that can be used in the processes discussed herein. In addition to the well-known examples of free radical cured acrylates described above, other radiation (UV or electron beam) coatings are also available. Examples of radiation curable coatings are generally divided into three main groups: "radical polymerization", "ionic polymerization" and "donor-acceptor polymerization".

As mentioned above, typical resins cured by radiation-induced free radical polymerization: (meth)acrylate resins are sold by Arkema (Sartomer) Inc.; free radical-induced progressive polymerization can also be achieved by using mercaptans- Ethylene unsaturated polyester: NOVOC® Performance Resins, which is provided from Andara Inc.; with mercaptans such as trimethylolpropane tris(3-mercaptopropionate) as curing agent: THIOCURE® TMPMP, which is provided from Evans Chemetics Bruno Bock).

Free radical polymerization can be charge transfer or donor-acceptor polymerization with donors such as vinyl ethers and acceptors such as maleate functional resins. This type of composition (formulation) is Examples include: vinyl ether from BASF, triethylene glycol divinyl ether DVE-3 as donors; unsaturated maleate-terminated resin from Piedmont Chemical as acceptors.

Ionic polymerization usually follows radiation-induced anionic or cationic catalysis. Typical resins cured by base-catalyzed radiation-induced ionic polymerization are epoxy-thiol or Michael additions of mercaptans and acrylates, but many other base-catalyzed polymerization systems are known. Photobase generators such as CGI-90 from BASF generate a strong base when absorbing radiation, which induces thiol for anion curing toward Michael reaction or direct anion curing. A well-known example of acid-catalyzed ionic polymerization is the cationic polymerization of cycloaliphatic epoxy resins such as Dow's CYRACURE ^™ UVR-6110 and acid catalysts such as BASF's IRGACURE® 250. Glycidyl epoxy resins, such as EPOTUF® 31-127, can also be polymerized by acid catalysis under UV or electron beam radiation with appropriately selected catalysts. In each case, proper screening of catalysts and radiation sources should be performed to form free radicals or acids/bases to induce polymerization.

For each of the above general examples, various combinations and/or "hybrids" can be made to adjust the reaction rate and final mechanical properties. The coating systems described above can generally be thermally polymerized with a suitable catalyst, although generally slower than UV or electron beam curing resins. Those skilled in the art should understand that the various proportions of oligomers, diluents, additives (such as wetting agents, catalysts, photoinitiators, fillers, etc.) can be adjusted to meet the specific requirements of the coating. Curing rate and mechanical properties.

The release templates discussed in this article can be used to cast textured silicone sheets or templates. The sheets of textured silicone can then be joined together to form a mold that can be used to produce nickel sleeves. The resulting nickel sleeve can be used as a replication surface as a further release template, For example: by embossing a polypropylene-coated paper template to carry the micro- or nano-scale and macro-scale textures of the original release template.

In summary, other embodiments are also included in the scope of the patent application of the present invention.

10: Release template

12: Substrate

14: Coating

16: micron scale

18: Macro scale

Claims (25)

A release template for replicating casting of a curable system. The release template includes: a substrate; and, a coating disposed on at least one surface of the substrate. A surface effect replicated during the period, wherein the surface effect includes a first three-dimensional texture on a micron or nanometer scale, and a second three-dimensional texture on a macro-scale; wherein the second three-dimensional texture is superimposed on the first three-dimensional texture and the The first three-dimensional texture and the second three-dimensional texture are coextensive. The release template according to claim 1, wherein during the manufacturing of the release template, the second three-dimensional texture is then embossed on the first three-dimensional texture. The release template according to claim 1, wherein the first three-dimensional texture is selected from the group consisting of diffraction gratings, hydrophobic surface textures, laser interference rainbow patterns, and combinations thereof. The release template according to claim 1, wherein the first three-dimensional texture is selected from the group consisting of lenticular lens texture, drag reduction texture, cube corner texture, and combinations thereof. The release template according to claim 1, wherein the second three-dimensional texture has a characteristic depth of about 50 to 300 microns. The release template according to claim 1, wherein the first three-dimensional texture has a characteristic length of about 1 to 100 microns and a characteristic width of about 1 to 10 microns. The release template according to claim 1, wherein the first three-dimensional texture has a feature pitch of about 1 to 10 microns, and a feature depth or height of about 1 to 10 microns. The release template according to claim 1, wherein the coating layer comprises acrylate. The release template according to claim 1, wherein the coating includes polypropylene. The release template according to claim 1, wherein the substrate comprises paper or plastic. A method for forming a release template with a textured surface, which includes: applying a coating to a flexible substrate; imparting a first three-dimensional texture of micrometer or nanometer scale; after imparting the first three-dimensional texture , Curing the coating; and after curing, imparting a macro-scale second three-dimensional texture on the coating to form the release template. The method of claim 11, wherein setting the second three-dimensional texture includes embossing the cured coating. The method according to claim 11, wherein the at least one texture is made by pressing the coating against the surface of an engraving roller. The method according to claim 12, wherein the embossing is performed by pressing the cured coating against a heated replication surface. The method of claim 14, wherein the replication surface is heated to a temperature greater than the glass transition temperature of the cured coating. The method according to claim 14, wherein a pressure of at least 1000 PLI is applied at the nip. The method of claim 11, wherein the first three-dimensional texture is selected from the group consisting of diffraction gratings, hydrophobic surface textures, laser interference rainbow patterns, and combinations thereof. The method according to claim 11, wherein the first three-dimensional texture is selected from the group consisting of a lenticular lens texture, a drag reducing texture, a cube corner texture, and a combination thereof. A substrate comprising: a flexible template having a surface including micro- or nano-scale features and a texture of macro-scale features, the texture of the micro- or nano-scale features and the texture of the macro-scale features are arranged on On the same area as the flexible template, the micro-scale or nano-scale feature texture is coextensive with each other in such a way that the macro-scale feature texture is under the texture. The substrate according to claim 19, wherein the flexible template includes a textured polymer layer. The substrate according to claim 20, wherein the flexible template further comprises a sheet-like material laminated on the textured polymer layer. The substrate according to claim 21, wherein the sheet material is selected from the group consisting of fabric, board, paper, and foil. The substrate according to claim 19, wherein the texture of the nanoscale feature is selected from the group consisting of diffraction grating, hydrophobic surface texture, laser interference rainbow pattern, and combinations thereof. The substrate according to claim 19, wherein the micro-scale feature texture is selected from the group consisting of lenticular lens texture, drag reduction texture, cube corner texture, and combinations thereof. A method for imparting texture to a release template, which includes: pouring a silicone resin on a textured release template to form a textured silicon replication template, the release template being arranged on the same surface of the release template Macro-scale texture and micron or nano-scale texture; forming a mold containing the textured silicon replication template; using the mold to produce a nickel sleeve; and using the nickel sleeve as a replication surface to combine the macro-scale, micron Nanoscale The texture is given to a second release template.

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