CA2198203C - Plastic siding panels with outdoor weatherable embossed surfaces - Google Patents

Abstract

An outdoor weatherable decorative clad plastic siding panel. The panel has a plastic substrate sheet and a decorative and protective coating bonded to the substrate sheet. The decorative and protective coating comprises a weatherable polymer that includes an exterior coat formed as a continuous cast film and containing substantially uniformly dispersed pigment at a level sufficient to retard UV degradation of the underlying plastic substrate sheet. The coating includes one or more print coats formed by an ink in a level sufficient to limit heat build-up in the finished panel.

Description

PLASTIC SIDING PANELS
WITH OUTDOOR WEATHERABLE EMBOSSED SURFACES
This application is a division of Canadian Patent No. 2,045,651, issued March 18, 199i', the parent application.
This invention relates to an outdoor weatherable plastic siding panel useful for the surfacing of frame buildings.
The present invention will be described with relation to its use in the building and construction industry using weatherable plastic riding panels made from vinyl (polyvinylchloride or PVC). The following description relating to vinyl siding panels is an example of outdoor weatherable embossed decorative surfaces on extruded plastic sheets.
Wood, metal and vinyl are materials commonly used as boards or shingles for siding in th~= construction and remodeling of commercial and residential structures.
Painted wood is perhaps the most aesthetically pleasing of these materials to the consumer, but wood suffers from deterioration by rotting and attack by insects, rodents and birds. Wood surfaces need constant reprotection with paint, stains and water sealants.
Advantages of metal over wood include the ability to provide a baked-on finish which is more resistant to the elements than coatings applied to wood, thus eliminating subsequent material and labor costs to the consumer.
However, metal-based siding has less thermal insulation value and is sensitive to scratching and denting by hail and other blows to the surface. In. addition, it does not have the pleasing look of a wood surface.
Vinyl siding has an economic advantage over most high quality wood and metal siding. It has better _ 2 _ insulating qualities than metal, and it is more resistant to denting and scratching. However, vinyl is sensitive to degradation from ultraviolet rays of the sun and has inadequate solventresistance. Previously, vinyl siding has suffered aesthetically compared to wood because of the generally higher gloss or uniform sheen of vinyl siding, which has a rather unnatural or plastic look. In addition, it is difficult to decorate vinyl surfaces with a natural-looking wood grain pattern that is pleasing to the consumer. --:
The present invention overcomes the drawbacks of presently available vinyl siding by providing a vinyl-based siding panel with a superior outdoor weatherable surface having the look of either a painted wood surface or natural unpainted wood grain.
A vinyl siding presently on the market is made by a process in which an extruded sheet of PVC is decorated and embossed to produce a wood grain-appearance. A
silicone-coated release paper is used in this process to transfer a-printed wood grain pattern to the vinyl.
Typically, an aciylic clear coat and a color coat with a wood grain pattern are coated on the paper carrier sheet and then transfer-laminated onto the vinyl extrusion under heat and pressure. The wood grain color coat can simulate the appearance of painted or unpainted wood. The clear coat and wood grain color coat bond to the extrusion and release from the paper carrier sheet so that the clear coat forms a protective outer coating for the underlying wood grain color coat. During the transfer pr~c2as, the release paper-is pressed into contact with the extrusion by an embossing roll which transfers deep-embossments to the-surface of the transferred decarative wood grain. The deep embossments or indentations produce a "shadow~~ effect in the finished surface that more truly resembles the sheen of natural 2Ig82~3 wood. Without these embossments, the vinyl wood grain-simulating surface has a flat appearance at different light angles - an unnatural look that gives the unsatisfactory appearance of a plastic simulated wood panel . -- , , , --, --There are several drawbacks to this prior art process of making vinyl wood grain y~anels. A principal disadvantage is that gloss levels produced by this process are too high. Surface,gloss. can be measured by various techniques; and according to one technique (ASTM
designation D 3679-86, 5.11), surface gloss levels produced by the-prior art process generally have a 75~
gloss reading from about 40 to-about 50 gloss units. A
much lower matte surface with a gloss reading below about 20 gloss units, and preferably below about 12 gloss units, is desirable to produce a more natural looking simulated wood grain finish_-In addition to its surface gloss problem, the silicone-coated-paper carrier sheet-of the prior art can prevent carefully controlled printing of the decorative coatings. The-carrier sheet also should release freely from the decorative layer transferred to the extruded vinyl sheet. Transfer of-the decorative wood grain layer to the vinyl sheet takes place at high temperatures, since the decorative coating may be transferred to the heated vinyl extrusion immediately after it exits the extruder die opening. The vinyl sheet is also embossed when the wood grain coat is transferred, and embossing temperatures should be high in order to physically form the embossments. A substantial reduction in temperature of the vinyl extrusion prior to embossing can inhibit forming the deep embossments. If the transferred wood grain coat hasa highly roughened surface, in order to produce lower gloss, the surface roughness can interfere with proper release of the carrier sheet. At the high 2'198203 transfer and embossing temperatures, certain coatings on the-carrier sheet can preferentially adhere to the carrier-rather than properly releasing from it.
The decorative coatings transferred to a vinyl sheet to provide a wood grain or other surface finish also should protect the underlying vinyl panel from UV
degradation, delamination, and other weather problems.
Thus, there is a need for a process for decorative wood grair~ vinyl sheets with a sufficiently low gloss surface to resemble the appearance of natural wood grain, painted or unpainted. In a-transfer process in which the wood grain coating is printed on a carrier and transferred from the carrier to a vinyl extrusion, while the vinyl is being deeply embossed, there is a need to I5 ensure that the decorative wood grain coat properly releases from the carrier and bonds to the vinyl. The deep embossing step must not the adversely affected; the low matte surface of the decorative wood grain must not adversely affect proper release from the carrier; and these steps must be carried out at the high temperatures and pressures necessary for proper embossing.
The parentapplication describes and claims a process for making plastic panels with an embossed decorative surface.
In a first aspect, the present invention is an outdoor weatherable decorative clad-plastic siding panel comprising a substrate panel containing an extrudable thermoplastic material, the substrate panel having an outer surface area, and a decorative and protective exterior coating bonded to and covering the outer surface area of the substrate panel and comprising a top coat formed as a continuous cast film on an underlying color coat formed as a continuous cast film and visible through 2'198203 the top coat, the top coat and color coat each containing a weatherable fluoropolymer resin, the color coat containing a sufficient amount of dispersed pigment to cover the surface area of the substrate panel and thereby retard W degradation of the underlying substrate panel, the top coat having an exterior surface with a transferred microroughness providing a 75° gloss level of less than about 20 gloss units covering a major surface area of the top coat.
In a further aspect the invention is an outdoor weatherable decorative clad plastic siding panel comprising a plastic substrate sheet having an outer surface area, and a decorative and protective exterior coating bonded to the exterior surface area of the substrate sheet, the decorative coating comprising a weatherable thermoplastic polymer having embossed indentations formed depthwise in the thermoplastic coating and permanently set therein to form a pattern of surface emboseinents in an exterior surface thereof, in which the decorative coating includes a weatherable outer clear coat formed as a continuous cast film and an underlying color coat formed as a continuous cast film visible through the clear coat and containing a sufficient amount of a dispersed pigment to cover the surface area ~f the substrate sheet and thereby retard W
degradation of-the substrate sheet.
In a further aspect the invention is an outdoor weatherable decorative clad plastic siding panel comprising a plastic substrate sheet, and a decorative and protective coating bonded to the substrate sheet, the decorative and protective coating-comprising a weatherable polymer which includes an exterior paint coat formed as a continuous cast film containing a substantially uniformly dispersed gigment at a level sufficient to retard W degradation of the underlying plastic substrate sheet, and in which the coating includes one or-more print coats formed by an ink in a level sufficient to limit heat build-up in the finished panel.
In a further aspect the invention is an outdoor weatherable decorative clad plastic siding panel comprising a plastic substrate sheet containing a vinyl polymer, and a decorative and protective exterior coating bonded to the substrate sheet, the decorative coating comprising a weatherable thermoplastic polymer different from the polymer comprising the substrate, in which the decorative coating includes a weatherable outer clear coat formed as a continuous cast film visible through the clear coat and containing a sufficient amount of a I5 dispersed pigment to cover the surface area of the substrate sheet and thereby retard UV degradation of the -substrate sheet.
In a further aspect the invention is a transfer sheet for forming a decorative outer surface.coat on a substrate panel, the transfer sheet comprising a flexible carrier sheet having coated thereon (a) a matte release layer bonded to the carrier sheet, and (b) a decorative coating on the matte release layer for facing toward the substrate panel, the decorative coating being releasable from the matte release layer under heat and pressure for bonding it to the substrate panel and for applying a Iow gloss surface to the transferred decorative costing from the matte release layer, the matte release layer comprising (1) a synthetic resinous coating dried to a film thickness and containing therein a thermosetting resinous component bonding the resinous coating to the carrier sheet, (2) a fine particulate filler dispersed in the resinous coating so that when the resinous coating is dried to its film thickness, the dispersed filler transfers a low gloss surface to the surface of the ~~~98~~3 transferred decorative coating, (3) a wax component contained in the synthetic resinous coating for enhancing release of the matte release layer from the transferred decorative coating, and (4) a silicone resin component in the synthetic resinous coating further enhancing release properties.
Good results are obtained when a cast fluoropolymer resin is used in an underlying color coat of the printed wood grain pattern. A pigmented color coat is especially useful in preventing UV degradation and delamination of the clear coat/color coat paint layers-from an extruded vinyl substrate.
These and other aspects of the-invention will be more fully understood by referring to the following 15detailed description and the accompanying drawings.
FIG. 1 is a schematic diagram illustrating an in-line decorative transfer and embossing step in a process for making extruded plastic siding=panels with embossed decorative wood grain surfaces according to this invention;
FIG. 2 is a schematic diagram illustrating a first step in the process;
FIG. 3 is a schematic diagram illustrating a second step in the process, prior to the decorative transfer and embossing step;
FIG.-4 is=a schematic cross-sectional view illustrating components of one embodiment of a decorative wood grain foil according to this invention;
FIG. 5 is- a schematic cross-sectional view illustrating components of a finished plastic siding panel; and FIG. 6 is a schematic cross-sectional view illustrating components of another..embodiment of a decorative wood grain foil that retards W degradation according to the principles of this invention.

~~9$~(~3 _8_ FIG.-1 schematically illustrates one process for making extruded plastic aiding panels with embossed decorative wood grain surfaces. The process is useful in the manufacture of outdoor weatherable embossed plastic siding panels used for the surfacing of frame buildings or other outdoor structures. The invention will be described in relation to the manufacture of extruded vinyl (PVC) aiding panels, although the invention is also relates to panels made from other e~trudable plastic substrate materials such as polystyrene, acrylonitrile-butadiene-styrene(ABS), nylon, ethylene-vinyl acetate (EVA), polycarbonate, polyethylene, polypropylene, polyethylene terepthalate, thermoplastic olefins, acrylonitrile-styrene-acrylic (ASA), and alloys, blends or coextrusiona of these resins.
The invention solves-the problem of providing outdoor weatherable surfaces closely resembling natural wood grain on extruded plastic sheets. Exterior panels of.the invention have the look of either painted or unpainted wood.
Referring briefly to FIG. l, a painted wood-like plastic siding panel is produced by a dry paint transfer and embossing process in which a transfer laminate in the form of a decorative wood grain foil 10 is transferred to a surface of a thin, flexible extruded plastic sheet or film 12 which is continuously extruded-from the exit die opening of an extruder.l4.using conventional plastic extrusion-techniques.
The decorative foil is made by a multistage coating process described below and illustrated in FIGS. 2 and 3.
The wood grain printed foil zncludea multiple synthetic resinous paint coats printed or cast on a temporary flexible carrier sheet. The resinous paint coats are molecularly unoriented in the sense that they are castor ~~~~~~3 roller coated on the carrier or casting sheet. The wood grain-printed transfer fail produced by the coating process ie installed as a supply roll 16 in the transfer and embossing process depicted in FTCf. 1. The plastic sheet 12 continuously extruded from the extruder 14 and the foil 10 unwound from the roll 16 are passed through the nip of a decorative transfer and embossing station 18 which includes a metal embossing roller 20 and a rubber backup roller 21. A multilayer wood grain-printed synthetic resinous coating is simultaneously transferred from the foil carrier to the surface-of the extrudate while a three-dimensional wood grain texture is embossed in the surface=of the laminate. The transferred coating is an outdoor weatherable multilayer synthetic resinous coating that simulates the appearance of natural wood grain, painted or unpainted. Following the embossing step, the temporary carrier sheet portion 26 of the foil is then stripped away and wound on a carrier take off roll 23. Further steps in the process are described below.
In one embodiment used for the production of vinyl siding, the extruded sheet 12 preferably comprises an impact-modified PVC suspension ream:. Tn one embodiment, the extruded vinyl sheet material contains a pigment that forms the background color for the finished siding panel.
The extruded sheet is preferably extruded to a uniform film thickness from about 30 to about SO mils and is extruded from the die exit opening at a temperature from about 385° to about 400°F_ The transfer and embossing station 18 is located sufficiently close to the extruder die opening so that the extrusion is embossed, using the heat of extrusion at elevated temperatures sufficient to form deep three-dimensional embossments in the laminated extrusion. In-one embodiment, the embossing roller is located a distance of about five inches downstream from the extruder die exit opening. This maintains the temperature of=the extruded film during transfer and embossing near its natural extruder die exit temperature.
By embossing at such elevated temperatures, the natural temperature drop of the extrusion which occurs after it exits the extruder die opening is sufficiently limited so the embossments-can be.formed in the pliable sheet without requiring reheating of the extrusion prior to embossing.
The metal embossing roller 20 has a pattern of surface protrusions for simulating the texture and pattern of-a natural wood grain surface. The embossing roller applies pressure to the foilto transfer the wood grain-simulating coating to the extrusion 12, while embossing three-dimensional indentations in the exterior of-the decorative coating transferred to the extrusion.
By maintaining the embossing temperature of the extrudate substantially near its temperature at the extruder die opening, the extrusioQ-is sufficiently pliable that embossed indentations are permanently formed in the transferred decorative layer.
The transfer process also produces a low gloss surface on the transferred decorative wood grain coating which, combined with the embossments formed in the coating, closely resembles the appearance of a natural wood grain surface: The low glosssurface is transferred-by replicating the surface of a matte release coat adhered to the-temporary carrier film. Details of the techniques for forming the low gloss surface on the transferred wood grain coat are more fully understood by the description to follow.
FIG. 2 schematically illustrates a first step in a coating process for forming the decorative wood grain foil. FIG. 3 schematically illustrates a second step in the coating process for making the fail. FIG. 4 is a 21J82~3 -z~-schematic cross-sectional view illustrating components of the decorative foil during its use in the transfer and embossing step of the process.
Referring to FIG. 2, a first step in the process includes coating a matte release coat 24 in thin film form onto a surface of the flexible, foldable, heat-resistant, substantially inelastic, self-supporting temporary carrier film 26. The carrier is preferably an oriented polyester casting film such as Mylar (a IO trademark of DuPont), Hoechst Celanese Hostaphan (trade-mark) 2000 polyester film, or the like. The film thickness of the carrier sheet is less than one mil, and is preferably about 0.48 to about 0.75 mil thick. Since the wood grain-printed coat on the carrier is embossed I5 through the depth of the carrier -film, the carrier film does not have a thickness which inhibits forming the embossed three-dimensional impressions in the wood grain printed coat. The carrier film also has a film thickness which provides-sufficient-strength to permit its release 20 from the wood grain-printed coat at the elevated temperatures described below.
The carrier film 26 is contained on a supply roll 28 from which the carrier is-unwbiznd, passed around an idler roller 30, and then passed to a gravure print station 32 25 where the matte release coat 24 is gravure-coated onto the carrier film by a conventional gravure cylinder. The carrier film containing the matte release coat 24 is then passed through a first drying oven 34, preferably a 20-foot long impinging air oven operated at a temperature 30 from about 325°-to about 350°F, sufficient for drying and cross-linking the matte release coat. In the first stage drying oven, the matte release coat is sufficiently cross-linked to permanently bond it to the carrier sheet.
Preferably, the matte release coat is coated and dried to 35 produce a coat weight (dry) from about 3 to about 5 gr/m'.

The carrier--containing the matte release coat 24 which has been-dried and cross-linked exits the first stage oven 34 and is-then passed to a reverse-roll coater station 3fi for_.coating an outdoor weatherable protective clear coat or top coat 38 onto the dried matte release coat. The top coat is preferably transparent, although it can be pigmented, but in this -case, it is preferred that any pigmentation be at a sufficiently low level that underlying print coats are visible:through the top coat.
The cast top coat 38 is then passed to a second drying oven 40, preferably a 120-foot long impinging air oven.
This_ oven can be in multiple stages with drying zones of different controlled temperatures, depending upon the drying characteristics of the-top coat. Preferably, a cast top coat comprising an acrylic/polyvinylidene fluoride blend;-described below, is dried and used at an oven air temperature of about 340°F to form a weatherable clear coat on the matte release film.
The dried, clear-coated film 41 is removed from the second drying oven 40 and wound onto a rewind roll 42 at the output of the first coating stage.
The dried, coated film 41 produced from the first coating stage is then removed and installed at an unwind station 44 of a second coating stage schematically illustrated in FIG. 3-. In the second stage coating system, the clear-coated side of the film 41 is gravure printed with aaex-iesof synthetic resinous print coats to provide a-selected wood grain print pattern on the film. FIG. 3 is an example of one embodiment in which the clear--coated side of the film is printed with a aeries of-two wood grain print coats, followed by a size coat for use in Later bonding the decorative foil to the extruded sheet 12 during the transfer and embossing stage of the pracess:

Referring to FIG. 3, the dried, coated film 41 passes from the unwind station 44 through a tension-control stage 46, after which the foil passes to a first wood grain print station 48 where afirst-synthetic-resinous wood grain ink is gravure-printed onto the clear coated aide of the foil. This forms a first wood grain print coat 50on the exterior of-,the foil.- The first print coat is typically in adiacontinuoua wood grain print pattern. The foil is then passed to a first drying oven 52 .for drying the first wood grain print coat 50 at an air temperature of about 250°F.
The foil then travels to a second gravure print station 54 for-printing a second synthetic resinous wood grain ink pattern on the foil-- This forms a second wood grain print coat 56 on the dried first print coat 50.
The foil is then passed to a second drying oven 58, also operated at anair temperature of about 250°F for drying the second print coat.
In the illustrated embodiment; two wood grain print stages are shown, although further wood grain print coats or continuous color coats and corresponding drying steps can be used, depending upon the desired print pattern.
The wood grain inks used in the illustrated print coats comprise a pigmented synthetic resinous coating composition which can be coated in-thin-film farm in a discontinuous print pattern onto the surface of the cast top coat by conventional coating te-chniques. The wood grain coatings, can be produced by any conventional pigmented lacquer, typically blended with a suitable solvent and containing a pigment dispersion to provide the desired coloration. Pigmentation for the underlying color of the wood grain-simulating panel can be contained in the extruded vinyl sheet; however, pigmentation for the wood grain print coats, such as by an underlying color coat described below, makes it possible to avoid - i4 -use of larger, more costly amounts of pigment in the vinyl extrusion.
The wood grain print coats can be formulated from a thermoplastic synthetic resinous coating composition containing an acrylic resin, such as polymethylmethacrylate or polyethylmethacrylate, or mixtures thereof, including methacrylate copolymer resins and minor amounts of other cpmonomers; or the print coats can be made from a fluoropolymer resin, such as polyvinylidenefluoride (PVDF) or polyvinylfluoride (PVF);
or the print coats can ba formulated of blends of fluoropolymer and acrylic resins. The level of pigmentation-i~the coating-can range-up to about 40~ by volume, depending upon the depth of color needed for the particular wood grain pattern being printed I3owever, less than about 10~ pigment by volume is preferred. The dry coat weight of the-wood grain print coats ranges from about 0.1 to about 2 gr/m'. Example 6 below describes in more detail the pigments that can be used in the wood grain printing inks.
Referring again to FIG. 3, the foil containing the dried wood grain print coats passes from the second drying oven 58 to a gravure print station 60 where a size coat 62 is coated on the dried second wood grain print coat. {If additional color coats-are used, then the size coat is coated on the finished, dried color coat.) The size coat is then passed through an impinging air oven 64 operated at a temperature of about 250°F for drying the size coat. The size coat is applied using a gravure cylinder and cah contain pigment-up to about 25~ by volume, although less than 10~ by volume is preferred.
The dried coat weight of the size coat ranges from about-1 to about 3 gr/ma.

The size coat 62 comprises any of various suitable coating compositions to provide adhesion of the decorative foil to the extruded sheet 12- during the transfer and embossing step carried out later during the process. The size coat preferably comprises a suitable thermoplastic resinous material such as an acrylic resin.
In oneembodiment, the size coat comprises a polymethylmethacrylate-or polyethylmethacrylate-containing resin. Such a aize:coat formulation is sufficient-for. providing a-good boridto an extrusion made from a PVC resin.
In certain instances in which a backing sheet may be made from a thermoplastic olefin such ae polypropylene or polyethylene, a differentaize coat-can be used. In this instance, the size coat is preferably made from a coating composition of-a solution of a thermoplastic chlorinated polyolefin (CPO). A preferred CPO size-coat preferably is a chlorinated polypropylene or chlorinated polyethylene,- in-which the coating composition contains about 10~ to about 60~ by weight of the CPO, and correspondingly, about 50~ to about 90g by weight solvent.
Following drying of the size coat 62, the foil exits the drying oven 64 and is passed through a second tension control system 66 prior to being wound on a supply roll 67. The completed foil is then removed from the second coating system and installed at the unwind station 16 of the extruder-laminator shown in FIG. 1.
FIG. 6 shows an embodiment in-which a continuous color coat 80 is cast on the dried print coat to provide background color for the decorative-wood grain coating.
The color--coat 80 contains a sufficient level of pigment to improve resistance to W degradation of the vinyl sheet and resulting delamination, as described in more ~~~8'~f~3 detail below. The color coat 80 preferably comprises a coating containing a fluoropolymer resin. A cast, weatherable color coat containing PVDF is preferred; in one embodiment, the color coat contains a blend of PVDF
and an acrylic resin, such as polymethylmethacrylate or polyethylmethacrylate. - Coloration canbe produced with pigments comprisingmixed metal oxides(MMO's), although organic pigments alsomay be,used._ Referring again to FIG. 1, during the transfer-embossing step,the wood grain printed transfer foil 10 is fed to the nip of the embossing roll 20 so that the carrier film 26 is in pressure contact with the metal embossing roller and the size coat 62 on the foil is in pressure contact with the extrudedp-lastic film 12. The embossing roll 2D imprints a three-dimensional pattern of impressions 67-(see FIG. 5) in the outer surface of the top coat 38. Embossing is done through the depth of the carrier film 26-. Since embossing is carried out when the extruded sheet 12 is at a temperature below, but reasonably close to, its extrusion--die exit temperature, the extrusion is sufficiently pliable to facilitate embossing deep-three dimensional impressions (up to an average depth of about 120 microns)-through the carrier film and into the depth of the top-coat 38, on the surface of the extruded sheet. The carrier film is sufficiently thin (about 0.48 to about 0.75 mil) to cause the metal embossing roller pattern to be physically transferred through the carrier film to the top coat, while still maintaining a carrier film strength sufficient to be hot stripped fromthe embossed top coat at the-stripping station 23 downstream from the embossing station 18.
When the decorative foil is pressed into contact with the extruded sheet, the extrusion temperature is also sufficiently elevated to bond the foil to the extruded sheet. The polyester carrier sheet has a heat resistance well above the extrusion die exit temperature, so the carrier.resiata elongation or deformation during the transfer and embossing step.
Following the embossing and transfer step, the flexible, laminated extruded film 68 (see FIG. 1) undergoes controlled cooling from the nip of the embossing rollto the point where the carrier is stripped from the laminate. A series of water-cooled chill a rollers 70 produce a controlled temperature reduction in the laminate 68_ The laminate is cooled to a temperature in the range from about 295° to about 340°F occurring at the point where.the carrier film 26 is stripped from the laminate. The preferred stripping temperature is 308°F.
Cooling to the lower temperature also sets the impressions embossed in the laminate. If the temperature stays too high, flowability of the laminate can cause the impressions to smooth out. The temperature drop also enhances freely removing the carri-er from the laminate.
The matte release coat 24, which has been cross-linked and permanently bonded to the carrier sheet 26, remains adhered to the carrier film during the stripping process. The matte release coat has a chemical matte outer surface with a micro-roughness which transfers a low gloss surface 71 (see FIG_ 5) to the top coat. The micro-roughness of the matte coat is replicated to transfer a sufficiently low gloss to resemble the appearance of natural wood grain. -However, other gloss levels also can be produced. The formulation of the matte release coat (described below) provides a combination of the desired low gloss surface, together with a smooth or free release of the carrier sheet from the replicated low gloss surface at-elevated stripping temperatures .

2'198203 -1a-Following stripping of the carrier sheet, the decorated, embossed sheet 72 passes from the cooling rolls 70 to a forming station 74 using forming dies to shape the edges of the sheet and punch mounting holes at desired intervals. Further cooling occurs between stripping of the carrier and the forming station. The formed sheet is then passed to a cutting station 76 for cutting the sheet into separate panels. A finished panel 78 is illustrated schematically in FIG. 5.
The matte release coat formulation comprises a coating which can be applied-tothe=carrier by conventional casting techniques, such as roller coating.
The preferred coating composition is a-thermosetting resinous material which, when exposed to heat for drying it, also crbsslinks and permanently bonds as a surface film adhered to the carrier sheet.- The solids contained in the matte release coat preferably include, as a principal component, one or more crosslinking agents to provide good-adhesion of the dried=crosslinked coating to the polyester-carrierfilm. In one embodiment, the matte releas-a coat formulation includes a primary crosslinking resin such as a vinyl resin-that bonds to the polyester film. A suitable vinyl resin is a medium molecular weight vinylchloride-vinylacetate resin known as VAGH, -described iii more detail in Example 1-below. This-vinyl resin can be present in an amount up to about 20~ of the total solids iri the matte release coat. In addition, the matte release coat can include a secondary crosalinking resin to improve release of the clear coat from the matte release coat. In one embodiment, the secondary crosslinking resin can be an acrylic modified alkyd resin such as the resin known as Chemtpol (trade-mark) 13 1501 also described in more detail in Example 1. This secondary crosslinking resin comprises from about 1~ to about 15~ of the total solids of the matte release coat.
The matte release coat further includes a suitable 2I9~203 catalyst for accelerating the crosslinking process, typically comprising from about 1~ to 2~ of the total solids in the matte release coat.
The resinous components of the matte release coat composition are-mixed-with suitable solvents. In one embodiment, the resins are mixed with a primary resin solvent such as methyl isobutyl ketone-(MIBK) which comprises about 65$ to about 85~ of the total solvent in the formulation_ A secondary resin solvent such as isopropylalcohol (IPOH)is useful -in retarding crosslinking of the resins in solution. The secondary resin solvent preferably comprises from about 5~ to about 20~ of the total of solvent.
The matte release coat formulation-is prepared by dissolving the primary crosslinking reslii in the primary and secondary resin solvents by mixing and then adding the secondary croselinking resin, together with a primary matting agent,-preferably in the foam of a filler comprising a fine-particulate inertinorganic-material.
In one embodiment, the filler comprises aluminum silicate with an average particle size of about 4.8 microns. The filler contained in the formulation comprises up to about 25~ of the total solids in the matte release coat. The fine particulate filler is thoroughly dispersed in the resin and resin solvent blend, preferably under elevated temperatures from about 100° to about 120°F.
In use, when the matte release layer dries and cross-links, it forms a chemical matte 10 coating on the surface of the carrier sheet. The matte surface is controlled by the amount and particle size of the filler.-The fine particles project through the dried exterior surface of the matte release coat to form, on a microscopic scale, a surface with a micro-roughness that transfers to the surface of the dried top coat a replicated micro-roughness that produces light-scattering, resulting in a low surfs-ce gloss on the top coat.
The matte release coat formulation also includes a release agent to enhance freely releasing the carrier and its matte release coat from the top coat during the transfer process. The release agent preferably includes a wax component such as a polyethylene wax which melts at elevated temperatures to allow easy hot- release of the release coat. The wax component is normally suspended in the matte release coat at temperatures below the transfer-embossing temperature and the wax component, in its suspended or particulate form,acts as a matte agent to enhance transfer of the low surface gloss to the clear coat. The temperature of_the extension at the transfer-embosaing point of the process heats the laminate (including the release coat) to melt-the wax sufficiently for it to enhance the release properties of the matte release coat. -Preferably, the melting point of the wax is below the temperature at which the release-coated carrier stripped from the laminate. In a preferred polyethylene wax known as Shamrocks-381-N1 (trade-mark described in Example 1 below), the melting point of the wax is about 206°F. Stripping of the release-coated carrier is preferably carried out at temperatures more than about 80°F above the melting point of the wax, to enhance release properties. The wax, which melts at relatively higher temperatures as it dries,-can have a crystalline or-semi-crystalline structure; the wax, at relatively lower temperatures, is believed to crystallize and reform particles which affect the matte transferred to the laminate. In one preferred form of the release coat formulation, the polyethylene wax comprises from about 12~ to about 25~ of the solids contained in the matte release coat.

The release agent contained in the matte release coat formulation further includes a silicone resin component which-combines with the polyethylene wax to enhance free release o~ the clear cos~,t. "from ,the matte release-coat at elevated temperatures. In one embodiment, the silicone resin comprises from about 2.5~
to about 25~ of_the solids contained in the matte release coat formulation. Release is improved_and lower gloss is transferred when the wax and silicone resin are used in combination in-the matte release coat.
In one embodiment, the clear coat or top coat 38 is a transparent, or substantially transparent, thermoplastic synthetic resinous coating composition.
The preferred dry film thickness of-the top coat is about 0.3 to ahout_1_5_mils. Preferably, the top coat lacquer formulation produces a dry film form exterior outdoor weatherable coating having desired:properties of hardness and abrasion resistance, along with weatherability properties ouch as W resistance and resistance to water and humidity eacpoaure= -The top coat formulation also enhances having transferred to-it a.-law-gloss surface from the matte release coat. In one embodiment, the top coat is formulated from a thermoplastic synthetic resinous coating which, in dry film form, softens and deforms under-elevated temperatures so that the three-dimensional impressions can be formed in its exterior surface during the embossing step, while replicating the micro-roughness from the matte release coat to produce the low gloss.aurface. The top coat preferably comprises a blend of a thermoplastic fluorinated polymer and an acrylic resin as its principal components. The fluorinated polymer component is preferably a thermoplastic fluorocarbon resin, such as polyvinylidene fluoride (PVDF) or polyvinyl. fluoride (PVF). The fluorinated polymer resin also can include copolymers and terpolymers of vinylidene fluoride-or polyvinyl fluoride, or mixtures thereof.. One--thermoplastic fluorocarbon useful as the top coatis the PVDF-known as Kynar, a trademarkof Atochem, formerly Pennwalt Corp. This polymeric-a high molecular weight polymer which provides a useful blend-of durability and chemical resistance properties. The PVDF component preferably comprises from about 65~ to about 90~ of the total solids present in the top coat_ The acrylic resin component of the top coat can be a polymethylmethacrylate or a polyethylmethacrylate resin, or mixtures thereof, including methacrylate copolymer resins, and minor amounts of other comonomers. The top coat also can include minor amounts of block copolymers and other compatibilizers to stabilize the blended PVDF
and acrylic resin system and provi-de compatibility with the underlying film.
In one embodiment, a principal component of the acrylic resin contained in a top coat is a medium molecular weight polyethylmethacrylate resin such as Elvacite 2042, a trademark of DuPont. This acrylic resin clarifies the top coat, hardens the top coat, and-improves adhesion to the underlying print coat. In its preferred form, acrylic component comprises from about 10~ to about 35g of the total solids contained in the top coat formulation.
The PVDF and acrylic based top coat formulation can be prepared as a dispersion of the PVDF and a solution of the acrylic resin. In one embodiment, the top coat formulation is prepared by mixing the acrylic resin with a suitable organic solvent and applying heat to dissolve the resin. The mixture is then allowed to cool sufficiently before adding the PVDF component, so that the PVDF will not dissolve, but will be maintained as a dispersion in the acrylic-solvent based mixture_ By maintaining the PVDF component as a dispersion in the top coat, solvent evaporation during drying of the top coat can be improved. In one formulation,-a primary solvent can be cyclohexanone, a latent solvent for the PVDF, comprising from about 92% toabout 100 of the solvent component. A secondary solvent such as n-methyl-2-pyrrollindona, preferably coiitprising up to about 8% of the total solvent component, can be used in the formulation as-a solvent for the PVpF to aid in the film formation.
Other minor components of the top coat formulation can include W absorbers compris-ing up to about 3% of the total solids and a dispersing agent-such as Solsperse 17000 (trademark of ICI America) useful for reducing the viscosity of the dispersion coating. The dispersing agent preferably comprises up to about 4% of the P~IDF
component.

Example -Matte release coats 1 and 2 were formulated from the following components:

Component _ Parts Composition - 38.3 1: Methyl isobutyl ketone (MIBK) Isopropyl alcohol (IPOH 6.7 VAGH 4.8 ASP400 - 44.3 Chempol 13-150* - 5.9 100. 0 Composition 56.7 2: Methyl isobutyl ketone Isopropyl alcohol- - _- 9.0 VAGH 15.1 Chempol 13-1501* -.__ 19-.2.2 __ 100.0 Release .l: . Composition 1 41.8 Coat Composition 2 2i.1 SR107 1.2 5381-N1 5.D

- - MIBK/IPOH Blend (85/15) 21.4 Cycat 4040* 3.8 Cymel 303* 5.7 100.0 Release 2: - Composition I 39.7 Coat ~.omposition 2 20.0 SR107 _. 2.0 5381-N1 9.0 MIIBK/IPOH Blend (85/15) - 20.3 Cycat 4040* 3.6 _. _ Cymel 3D3* - . 5.4 100.0 *Trade-mark 1. VAGH is a medium molecular weight, partially hydrolyzed vinyl chloride-vinyl acetate resin (approximately 90g vinyl chloride, 4~ vinyl acetate and a hydroxyl content of 2.3~) sold by Union Carbide, Somerset, New Jersey.
2. ASP400 is an aluminum silicate._of average particle size 4.8 microns made by 45 Engelhafd Corp, Edison, New Jersey, and sold by Jensen-Souder,- Itaeca; lllinois.

3. Chempol 13-15-O1 is an acrylic modified alkyd resin solution (50~ resin, 50~ xylol) sold by Freeman Chemical Co., Port Washington, Wisconsin.

4. SR-107 is a silicone resin manufactured by General Electric,-Waterford, Connecticut, and sold by Fitzchem, Chicago, lllinbis.

5. 5381-Nl is a polyethylene wax sold by Shamrock Chemicals Corp., Newark, New Jersey.

6. Cycat 404D* is a para toluene sulfonic acid catalyst (40~ by weight in isopropanol) sold by American Cyanamid Co., Walingford, Connecticut.

7. Cymel 303*-is a liquid hexamethoxy-methylmelamine cross-linking agent sold by American Cyanamid.
Composition 1 was produced by dissolving the VAGH
resin--iu MIBK and IPOH blend by mixing in a Cowles* mixer and then adding the Chempol i3-1501*; and ASP400 while mixing. This -mixture was then sandmilled at a temperature of--about 110°F to disperse the ASP400.
An exterior top coat was formulated from the following components:
Component Parts Cyclohexanone 40.0 Elvacite 2042* 10.5 Solsperse 17000* 0.1 Tinuvin 234* 0.6 Kynar ~O1F (PVDF)* 27.0 35- n-methyl-2-pyrollidone 2.5 Cyclohexanone-(2) 19.3 100.0 *Trade-mark - 2fi -8. Elvacite 2042*, is a polyethylmethacrylate resin with a weight-average molecular weight of 3DD,000, sold by DuPont, Wilmington, Delaware.

9. Solsperse I7000* is a Polymeric fatty ester dispersing agent sold by IC1 Americas Inc., Wilmington, Delaware.

10. Tinuvin2.3_4*.. is a 2- (31, 5l,bis (1-methyl 1-phenylethyl)-23 hydraxyphenyl) benzotriazole U.V. light stabilizer soldby Ciba Geigy, Hawthorne, New York.
11_ . Kyriar-3~1F~ is a polyvinylidene-floride polymer sold by Pennwalt Corp., Philadelphia, Pennsylvania.
The Elvacite 2042*, Solaperse 17000* and Tinuvin 234* were first dissolved in the cyclohexanone (1) solvent at a temperature ofi30°F and allowed to cool to room temperature. The PVDF wasthen dispersed in the resin solution-using a 14 inch,Cowles blade at 1800 RPMl.
The temperature. of the PVDF dispersion was kept below 110°F toavoid gelation of the dispersion. Next, the n-methyl-2-pyrollidone and the remaining cyclohexanone (2) were preblended before mixing into the PVDF dispersion_ In this embodiment, the top coat was not Pigmented.
Preparation of the Wood Grain Printed Transfer Foil The matte release coat was gravure coated with a 100 HK gravtire-cylinder pattern at a coat weight of 3 gr/m2 onto a 75 gauge orientedgloss polyester carrier sheet (Hostaphan 2000*, sold by lloechst Celanese, Greer, South Carolina) at 200 feet per minute and dried and cross-linked in a 2D_ ~oot.impinging-air oven {Oven No. 1 in FIG. 2) at an air temperature of 34D°F (web temperature approximately 220°F). _ Next, the--clear coat was coated at a coating weight (dried) of lfi-gr/ma onto the dried matte release coat in a reverse-roll water station on the same coater and dried and used in a 120 foot three-zone impinging air oven with the air temperatures in the three zones being 240°F, *Trade-mark ~~98203 27 _ 340°F, and 340°F (see FIG. 2).-- This formed a transparent clear coat on the matte release coat of the carrier film.
To minimize web shrinkage and avoid distortion of the carrier film, web tension was 5 maintained below 0.8 lbs/linear inch of web width through the drying ovens.
The dried, coated film was wound as a roll, removed from the first coater and set up on the unwind station of a second water (FIG. 3).-- The clear-coated side of the coated film was then gravure printed at a speed of 200 feet per minute with a seriss of two grain prints and then a size coat. The drying oven temperature was 25-0°F.
The grain inksand the size coat were made bypigmenting a 25~ solution of DuPont's Elvacite 201D (trade-mark) polymethylmethacrylate, in a MIBK/toluene blend with pigment dispersions such as GCW-46-39000made by Gibraltar Chemical, South Holland, lllinois. The size coat was applied using a I37 HR graS~ure-cylinder and contained Pigment of about 10~ by volume. The dried coat weight of the grain coats ranged from 0.1-2 gr/mz and the size coat was about 2 gr/m'. After-drying, the roll of wood grain printedtransferfoil was removed-from the second water and installed on-an unwind station of the extruder-laminator line (FIG. 1).
Production of Experimental Painted Wood-Like Vinvl Sidinct A 50~ inorganic particle-filled ethylene-vinyl acetate/PVC material with a glass transition temperature of 61°C (142°F) was extruded at a temperature of about 400°F at a speed of 35 ft/min and a thickness of about 44 mils. The cross web width was approximately 18 inches.
The vinyl sheet contained a pigment to provide the background color of the vinyl siding panel. ,The previously produced wood grain-printed transfer foil was passed, along with the extruded film, through the nip of an embossing station, which included a 12_5 inch diameter metal embossing roller. The embossing station was approximately five inches from the extruder die exit opening so that the extruded film during transfer and embossing had essentially the same temperature as the temperature ofthe extruded film at the extruder die exit opening. The polyester carrier sheet surface was in contact with the metal embossing roller, and the size coat was in contact with the extruded film.
The embossing roll imprin;ed a three-dimensional pattern in thetransfer-decorated film which simulated wood grain in the form of painted wood with random lines generally in one direction of,various lengths, widths and depths spaced about 1 to 2 mm apart with an average peak-to-valley height of about 2D to 120microns. There were some deeper embossed lines. When viewed in oblique light, the embossing cast shadows similar to those found with natural painted wood viewed the same way.
The extruded sheet was cooled to a temperature of about 30B°F before stripping the carrier film from the decorated vinyl sheet at a stripping station downstream from the.. transfer and embossing station., The carrier film had a sufficient-thickness {75 gauge or 0.75 mil) to allow the metal-embossing roller pattern to be transferred,- while maintaining the film strength to be hot strippedfrom the clearcoat at atemperature of 308°F. Therelease-coated carries sheet was wound for disposal, and fhe clear-coated, wood grain decorated embossed extruded vinyl material proceeded to forming dies where the siding was formed by shaping the edges, punching mounting holes, and then cutting to size.
Vinyl siding produced by this-process using both Release coatings 1 and 2 had 75° gloss readings of 14-15 gloss units, giving the look of natural painted or stained wood, compared to the 40-50 gloss units obtained with silicone coated paper release-backings. Surface gloss was measured by ASTM test D 3679-86. 5.11.

Release coat 1 had a tight release during the stripping step, whereas Release coat 2 had an easy release, similar to the silicone coated release paper.
When a 100 gauge polyester film was, substituted for the 75 gauge film used in the,previous-example, the embossing depth was not deep enoughand did not-give a pleasing wood-like appearance.
Example 2 Vinyl siding was produced experimentally as described .in.the previous example using a 75 gauge polyester-carrierfilmand using-the following release coat:
Release Coat 3: Parts Composition 1 40.7 Compbsition 2 20.6 SR107 9.0 5381-Nl 0.4 MBK/IPOH blend 20.1 Cycat 4040* 3.7 Cymel 303* S.5 100.0 Despite the high level of aili~one inthe release coat, the hot release of the release-coated carrier was unacceptably high, and the 75° gloss also increased to 25 gloss units. Release was at a temperature of about 308°F. -Example 3 To teat the effect of changes in the concentration of SR107 silicone resin and 5381-NIwax in the release coat on both the gloss and the hot release, a series of formulations-were prepared, as shov~n in Table 1. For convenience, lab draw-downs of these-formulations were made on a Mylar* carrier, overcoated with the PVDF/acrylic clear-coat, and then transferred to a flat AES panel. Hod release was done-manually at a temperature of 290° to 300°F, and 85° gloss was then *trade-mark measured. The gloss x-eadinge were-taken with a -tri-gloss meter sold by SYK-Chemie, Walingford, Connecticut. The data indicated that increasing levels of silicone increases the gloss and decreases the release force, whereas increasing the wax level decreases the gloss and the release force. Optimum formulations include both the silicone and the wax. The 75°-gloss measured on production samples is significantly lower than the 85°
gloss measured-on lab samples of the same formulation.
Table 1 Release Formulations -Comp. 1 50.2 47.8 45.6 45.3 43.5=41.741.9 40.2 38.7 =

Comp. 2 25.4 24-.223.0 23.0 22.0-21.1 -21.220.3 19.5 15. SR107 0.0 4.7 9.0 0.0 4.3 8.2 D.D 4.0 7.6 5381-N1 0.0 0.0 0.0 4.5 4.3~4.1 8.3 8.0 7.6 MIBK/IPOH 14.2 13.6 13.1-18.0 17.1.16.5 20.1 -19.3 -18.8 Cycat 4040* 4.2 3.9 3.7 3.7 3.5 3.4 3.4 3.3 3.1 Cymel 303*- -..E-33==-.~-8.. . .~. .~ ~ - 4-9 4-7 -, -~ ~

85Gloss 49.0 57.0 54.0 25.0 30.0--35.035.0 .25.0 29.0 -Hot Rel. Fail T T T EasyEasy T Easy Easy Fail - Adhesive failure-between the release coat and the polyester film T - Tightness (would not be-acceptable in production) Easy - Releases freely In a test considered a failure, the release coat transfers-with the clear coat during stripping.
-In a test-involving tight release, the vinyl tends to transfer with the laminateduring stripping.
*Trade-mark 2'198203 Example 4 A vinyl siding foil was prepared from formulations similar to Example 1. The resulting coatings were coated onto different types of flexible carrier sheets, after which the laminates were transferred to flat plastic panels. Eighty-five degree gloss was measured with the following results:
Table 2 Carrier 85° Gloss Units Gloss polyester film 96 Hoechst Sp-23 - Super matte polyester film 45 Gloss polyester film with the matterelease of this invention 16 Example 5 Test panels were subjected to accelerated weatherability tests. Accelerated Uv resistance, also referred to as QW, was measured using a standard accelerated tesf procedure to determine long-term W
resistance and other weatherability properties. One test includes exposure to W light and humidity exposure (from water condensation on the test panel) to test surface deterioration, color change, gloss-change, and loss of coating adhesi-on. Weatherability also was measured with a Modified Sunshine Arc Weatherometer test. A standard Sunshine Carbon Arc-Weatherometer uses exposure to two carbon arc light sources: the modified teat procedure used three-Light sources. The bulbs were contained in a cabinet which included a drum for revolving the panel around the light sources. The test panel-was exposed to the light sources periodically and to a water spray cycle at selected time intervals.
Delamination between the decorative wood grain paint coat and the extruded vinyl sheet was observed when wood grain decorated vinylsiding test panels were exposed to 2'198203 these accelerated weathering tests. The-siding panels initially tested for weatherability consisted of the PVDF/acrylic-clear coat, acrylic wood grain print inks, and an acrylic size (adhesion) coat. The extruded vinyl sheet was pigmented to provide the underlying color coat.
Delamination of-these vinyl siding panels was proceeded by UV degradation of the vinyl sheet, since discoloration of the vinyl was observed whenever delamination occurred.
The hours of failure in these teats depended upon ink coverage and pigmentation levels. The-composition of the vinyl siding also was found to be factor in how soon delamination occurred. The following accelerated weathering test results were produced with these vinyl siding panels__ s 1e 3 Exposure time to Failure - Modified QW Sunshine No. Description -_____, . Hours - - Arc 1 Grey wood grain 10D0 Not Tested 2 Grey/green wood grain 1500 43 cycles 3 Milky oak wood grain 2000 43 cycles 4 Barn red wood grain 1500 43 cycles a pigmented acrylic.color-coat-was_coatad,behind the wood grain inks to test its protection of the PvC sheet from W degradation. - This color coatis shown, for example, at 80- in the laminate illustrated in FIG. 6.
Laboratory samples were prepared using acrylic color coats pigmented with exterior grade titanium dioxide and mixed metal oxide ((MMO) pigments. These samples exceeded 3500-hours of QW testing without delamination.
However; these same samples were to delaminate when exposed to the specially modified Sunshine Arc Weatherometer (trade-mark) (one cycle is one hour "on"
and one hour "off"). The delamination occurred between the PVDF/acrylixi clear coat and the color coat, with the grain inks splitting. Test results were as follows:
_: s>..._.

2I9820~

Table 4 ~cposure time to Failure Color Coat Modified Test Grain - -Pig. - QUV Sunshine No. Ink Resin , Vol. ____, _-Hours Arc 5 Acrylic Acrylic 35% - 3500 - 109 cycles (Fail) 6 Acrylic - Acrylic 45% 3500 239 cycles -I - -lFai1) t As a follow-up to these tests, the addition of more W absorber to..the clear coat and including U,V absorbers in the grain and color coats was found to retard delamination failure in QW testing, but improvement was I5 -limited.
Replacing-the acrylic resin in the grain ink coats and color coats with blends of fluoropolymer resin and acrylic resin was evaluated. The two fluoropolymer Pennwalt's Kynar 7201*, and Kynar 9301* (also known as Kynar ADS*). The Kynar 7201*-constructions with the fluoropolymer in both the grain inks and color coats producedthe best resistance to delamination. Laboratory samples were exposed to 700 cycles in the specially modified Sunshine Arc test and 3500 hours in the QW teat with no delamihation or tape-off. -~Lynar 9301 constructions with the fluoropolymer in both the grain inks and color-coats showed only slight tape-off after 700-cycles in the specially modified Sunshine Arc Weatherometer, and no failure after 3500 hours in the QW
test. The test results were as-follows:-*Trade-mark 21.98203 r Table 5 Exposure time t0 Failure Color Modified Coat Test Grain .. Pig. QUV Sunshine No - . Luk ..Resin...vol. _.. ~.. .Arc ...
.. __ 7 Acrylic Kynar* 35DD 7DD cycles 7201/ (Slight Acrylic 35% - -Tape-off) 8 Acrylic Kynar*

7201/ 35D0 700 cycles Acrylic 45% (Fail) 9 Kynar* Kynar* -720I/ 7201/ ~ 3500 700 cycles Acrylic -Acrylic 45% (Good) .

10 Kynar* Kynar*

7201/ 7201/ - 35D0 - 7D0 cycles Acrylic Acrylic 45% (Good) -11 -Kynar* Kynar* 350D. 700 cycles 9301/ -.9301/ - . (Slight) Acrylic - Acrylic35% - - (Tape-off) T2~.e test results showed good long-term weatherability o~ uinyl siding panelshaving a.decorative coating which includes at least.an,underlying color coat containing at least a weatherable ~luoropolymer resin containing a level of pigment sufficient to block UV-radiation and thereby retard delamination by inhibiting W degradation-of the vinyl sheet.
Example 6 The use of mixed metal oxide (MME) pigments in the wood grain print inks is desirable ~ecauae of the excellent durability of mixed metal oxides and the availability of an I_R. reflective, mixed metal black pigment which minimizes heat build-up in the-wood grain decorated vinyl siding. However, the mixed metal oxide pigments can result in excessive gravure cylinder wear *Trade-mark when the grain ink print patterns are coated by a gravure cylinder. This can increase manufacturing costs and disrupt production by requiring the cylinders to be rechromed at less than 50,000 linear feet intervals. An attempt was made to use carbon-black, along with exterior durable organic-pigments to resolve the cylinder wear problem. The wood grain decorated vinyl siding made in this way exceeded the acceptable heat build-up temperature and could resulting warpage-or "oil canning"
i 7 of the vinyl siding during use: To=resolve this problem, grain inlc pigments were produced rematching the original color standards by using a blend of organic pigments comprising Chromophatal Brown 5R and Chromophatal Blue A3R (both trademarks of Ciba Geigy). These organic pigments were used-in-place-of- the carbon black, along with other durable organic pigments. Vinyl aiding made using inks made with this aII-organic system had acceptable heat-build-up temperatures. (Temperatures of 140°F and above are considered unacceptable.) Heat build-up test results were as follows:
Table 6 Infra-Red Heat Lamp Heat Build-Up (°F) Carbon Grey/ GreyJGreenGrey/Green White Black Green wJCarb. Blk No Carb Blk Min. Std.- sta. W MMO's No MMO's No MMO's 1 89 110 86 99 ~ 89 --9 116 .150 107 - 129 - 110 -.-15 124 164 119_ 139 120 -40 128 Z72 126. - 141 127 --In certain-instances, the invention can be carried out to produce outdoor weatherable panels that do not have an embossed wood grain or a low gloss surface finish resembling natural wood or the like. For instance, it has been found that weatherable coatings containing a fluoropolymer resin, such as the PVDF-or PVF resins, can be coated onto a carrier sheet and later-transferred to an extruded plastic sheet or panel as described above.
These fluoropolymer resin coatings can be blended with acrylic-coatings, such as polymethylmethacrylate or polyethylmethacrylate resins. These coatings are cast on the carrier sheet, preferably in a dry coating thickness in the range of about 0.5 to about 1.5 mil. The preferred weatherable film is a clear coat/color coat combination with the color coa~ containing a pigment at a level to provide opacity sufficient to retard W
degradation of the extruded sheet during use. The extruded sheet can be made from a-v3ny1 polymer, although polyester, polyolefins, and the otherextrudable materials described above for the extruded film 12 also can be used. The weatherable decorative coating is transferred to the extruded sheet under the pressure and temperature levels described above with respect to the process illustrated in FIG. 1. The hot laminating of the weatherable polymer cladding to the heated extruded sheet as it comes out of the extruder die opening produces a good bond-between the weatherable decorative coating and the extruded sheet.
The invention has been described-in relation to its use with extruded plastic siding panels, although other similar uses are contemplated, such as window and door moldings, rain gutters, and other outdoor structures, for example. -

Claims (51)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An outdoor weatherable decorative clad plastic siding panel comprising a substrate panel containing an extrudable thermoplastic material, the substrate panel having an outer surface area, and a decorative and protective-exterior coating bonded-to and covering the outer surface area of the substrate panel and comprising a top coat formed as a continuous cast film on an underlying color coat formed as a continuous cast film and visible through the top coat, the top coat and color coat each containing a weatherable fluoropolymer resin, the color coat containing a sufficient amount of dispersed pigment to cover the surface area of the substrate panel and thereby retard UV degradation of the underlying substrate panel, the top coat having an exterior surface with a transferred microroughness providing a 75° gloss level of less than about 20 gloss units covering a major surface area of the top coat.

2. The panel according to claim 1 in which the top coat and the color coat each contain a blended PVDF and acrylic resin.

3. The panel according to claim 1 in which the color coat contains a uniformly dispersed pigment level of at least about 35% by volume.

4. The panel according to claim 3 in which the pigment level is at least about 45% by volume.

5. An outdoor weatherable decorative clad plastic siding panel comprising a plastic substrate sheet having an outer surface area, and a decorative and protective exterior coating formed as a continuous cast film bonded to and covering the outer surface area of the substrate sheet, the decorative and protective coating forming an exterior surface of the siding panel and comprising a weatherable thermoplastic-polymer having a dispersed pigment to provide a layer of coloration, said exterior surface of the siding panel having a transferred microroughness providing a 75° gloss level of less than about 20 glow units distributed essentially uniformly across said exterior surface.

6. The panel according to claim 5 in which the exterior coating contains a blended PVDF and acrylic resin and contains a level of pigment sufficient to cover the surface area of the underlying substrate panel and retard UV degradation thereof.

7. An outdoor weatherable decorative clad plastic siding panel comprising a plastic substrate sheet having an outer surface area, and a decorative and protective exterior coating bonded to the exterior surface area of the substrate sheet, the decorative coating comprising a weatherable thermoplastic polymer having embossed indentations formed depthwise in the thermoplastic coating and permanently set therein to form a pattern of surface embossments in an exterior surface thereof, in which the decorative coating includes a weatherable outer clear coat formed as a continuous cast film and an underlying color coat formed as a continuous cast film visible through the clear coat and containing a sufficient amount of a dispersed pigment to cover the surface area of the substrate sheet and thereby retard UV
degradation of the substrate sheet.

8. The product according to claim 7 in which the top coat has an exterior surface with a transferred microroughness providing a 75° gloss level of less than about 20 gloss unite.

9. An outdoor weatherable decorative clad plastic siding panel comprising a plastic substrate sheet, and a decorative and protective coating bonded to the substrate sheet, the decorative and protective coating comprising a weatherable polymer which includes an exterior paint coat formed as a continuous cast film containing a substantially uniformly dispersed pigment at a level sufficient-to-retard UV degradation of the underlying plastic substrate sheet, and in which the coating includes one or more print coats formed by an ink in a level sufficient to limit heat build-up in the finished panel.

10. An outdoor weatherable decorative clad plastic aiding panel having the appearance of natural woodgrain, comprising a plastic substrate sheet containing a vinyl polymer, the substrate sheet having an outer surface area, and a decorative and protective exterior coating bonded to the outer surface area of the substrate sheet, the decorative and protective coating comprising a weatherable polymer different from the polymer comprising the substrate sheet and having embossed indentations formed depthwise in the thermoplastic coating and permanently set therein to form a pattern of surface embossments in an exterior surface thereof simulating the appearance of natural woodgrain, in which the decorative and protective coating includes a weatherable outer clear coat formed as a continuous cast film and at least one underlying color coat visible through the clear coat and formed as a continuous cast film containing a sufficient amount of substantially uniformly dispersed pigment to cover the surface area of the substrate sheet and thereby significantly retard UV degradation of the substrate sheet, said dispersed pigment including one or more print coats comprising an ink dispersed at a level sufficient to significantly limit heat build-up in the panel.

11. The panel according to claim 10 in which the weatherable outer clear coat has an exterior surface with a transferred microroughness providing a 75° gloss level of less than about 20 gloss units covering a major surface area thereof.

12. The panel according to claim 10 in which the outer clear coat and the color coat each contain a fluoropolymer resin.

13. The panel according to claim 12 in which the clear coat and color coat contain a blended PVDF and acrylic resin.

14. An outdoor weatherable decorative clad plastic siding panel comprising a substrate panel made from an extrudable thermoplastic polymeric material, the substrate panel having an outer surface area, and a decorative and protective exterior coating bonded to and covering the surface area of the substrate panel and comprising a continuous cast film comprising a weatherable polymer containing a sufficient amount of dispersed pigment to cover the surface area of the substrate panel and thereby retard UV degradation of the underlying substrate panel, the exterior coating including one or more print coats formed by an ink at a dispersed level sufficient to retard heat build-up in the finished panel, the exterior coating further having an exterior surface with a transferred microroughness providing a 75° gloss level of less than about 20 gloss units covering a major surface area of said exterior surface.

15. The panel according to claim 14 in which the exterior coating and the print coat contain a fluoropolymer resin.

16. The panel according to claim 14 in which the exterior coating and the print comprise a blended PVDF
and acrylic resin.

17. The panel according to claim 16 in which the substrate panel is made from a vinyl polymer.

18. An outdoor weatherable decorative clad plastic panel comprising a substrate panel containing a vinyl polymer, and a decorative and protective exterior coating bonded to and covering the surface area of the substrate panel and comprising a top coat formed as a continuous cast film on an underlying color coat formed as a continuous cast film and visible-through the top coat, the top coat and color coat each comprising a polymer different from the substrate panel and containing a weatherable fluoropolymer resin, the color coat containing a sufficient amount of dispersed pigment to cover the surface area of the substrate panel and thereby retard UV degradation of the underlying substrate panel, the top coat having an exterior surface with a transferred microroughness providing a 75° gloss level of less than about 20 gloss units covering a major surface area of the top coat.

19. The panel according to claim 18 in which the top coat and the color coat each contain a blended PVDF
and acrylic resin.

20. The panel according to claim 18 in which the color coat contains one or more print coats formed by an ink having a dark pigment which consists essentially of an organic pigment which appreciably limits temperature build-up in the finished panels.

21. The panel according to claim 20 in which the organic pigment, when substituted for carbon black, produces a 40 minute infrared heat lamp temperature build-up of less than about 140°F.

22. The panel according to claim 18 in which the color coat contains a uniformly dispersed pigment level of at least about 35% by volume.

23. The panel according to claim 22 in which the pigment level is at least 45% by volume.

24. An outdoor weatherable decorative clad plastic siding panel comprising a plastic substrate sheet, and a decorative and protective exterior coating formed as a continuous cast film bonded to and covering the surface area of the substrate sheet, the decorative and protective coating comprising a weatherable thermoplastic polymer different from the polymer comprising the substrate panel and having a dispersed pigment to provide a layer of coloration, and embossed indentations formed depthwise in the coating and permanently set therein to form a pattern of surface embossments in the exterior surface of said coating simulating the appearance of natural woodgrain said exterior surface having a transferred microroughness providing a 75° gloss level of less than about 20 gloss units distributed essentially uniformly across said exterior surface area.

25. A product according to claim 24 in which the 75°
gloss level is less than about 12 gloss units.

26. The panel according to claim 25 in which the embossments have an average peak-to-valley depth of about 20 to 120 microns.

27. The panel according to claim 24 in which the embossments have an average peak-to-valley depth of about 20 to 120 microns.

28. The panel according to claim 24 in which the exterior coating contains a blended PVDF and acrylic resin-and contains a level of pigment sufficient to cover the surface area of the underlying substrate panel and retard UV degradation thereof.

29. The panel according to claim 28 in which the color coat contains one or more print coats formed by an ink having a dark pigment which consists essentially of an organic pigment which appreciably limits temperature build-up in the finished panel.

30. An outdoor weatherable decorative clad plastic siding panel comprising a plastic substrate sheet containing a vinyl polymer, and a decorative and protective exterior coating bonded to the substrate sheet, the decorative coating comprising a weatherable thermoplastic polymer different from the polymer comprising the substrate, in which the decorative coating includes a weatherable outer clear coat formed as a continuous cast film visible through the clear coat and containing a sufficient amount of a dispersed pigment to cover the surface area of the substrate sheet and thereby retard UV degradation of the substrate sheet.

31. The product according to claim 30 in which the clear coat and the color coat each contain a fluoropolymer resin.

32. The product according to claim 31 in which at least the clear coat and the color coat contains a blended fluoropolymer and acrylic resin.

33. The product according to claim 30 in which the top coat has an exterior surface with a transferred microroughness providing a 75° gloss level of less than about 20 gloss units.

34. An outdoor weatherable decorative clad plastic siding pane-1comprising a plastic substrate sheet containing a vinyl polymer, and a decorative and protective coating bonded to the substrate sheet, the decorative and protective coating comprising a weatherable polymer different from the polymer comprising the substrate sheet, in which the decorative and protective coating includes an exterior paint coat formed as a continuous cast film containing a substantially uniformly dispersed pigment at a level sufficient to retard UV degradation of the underlying vinyl plastic substrate sheet, and in which the coating includes one or more print coats formed by an ink having a dark pigment which consists essentially of an organic pigment.

35. The product according to claim 34 in which the decorative coating includes a weatherable outer clear coat and an underlying color coat containing a dispersed pigment in an amount sufficient to retard UV degradation of the substrate sheet, and in which the clear coat and color each contain a fluoropolymer resin.

36. The product according to claim 35 in which at least the outer clear coat contains a blended fluoropolymer arid acrylic resin.

37. The product according to claim 35 in which the decorative coating contains one or more printing inks having a pigment component consisting essentially of an organic pigment.

38. The product according to claim 34 in which decorative coating has a 75° gloss level of less than about 20 gloss units.

39. The product according to claim 38 in which the 75° gloss level is less than about 12 gloss units.

40. An outdoor weatherable decorative clad plastic siding panel comprising a substrate panel made from an extrudable thermoplastic polymeric material, and a decorative and protective exterior coating bonded to and covering the surface area of the substrate panel and comprising a continuous cast film made from a polymer different from the substrate panel and comprising a weatherable polymer containing a sufficient amount of dispersed pigment to cover the surface area of the substrate panel and thereby retard UV degradation of the underlying substrate panel, the exterior coating having an exterior surface with a transferred microroughness providing a 75° gloss level of less than about 20 gloss units covering a major surface area of said exterior surface.

41. The panel according to claim 40 in which the exterior coating and the print coat contain a fluoropolymer resin.

42. The panel according to claim 40 in which the exterior coating and the print coat comprise a blended PVDF and acrylic resin.

43. The panel according to claim 42 in which the substrate panel is made from a vinyl polymer.

44. A transfer sheet for forming a decorative outer surface coat on a substrate panel, the transfer sheet comprising a flexible carrier sheet having coated thereon (a) a matte release layer bonded to the carrier sheet, and (b) a decorative coating on the matte release layer for facing toward the substrate panel, the decorative coating being releasable from the matte release layer under heat and pressure for bonding it to the substrate panel and for applying a low gloss surface to the transferred-decorative coating from the matte release layer, the matte release layer comprising (1) a synthetic resinous coating dried to a film thickness and containing therein a thermosetting resinous component bonding the resinous coating to the carrier sheet, (2) a fine particulate filler dispersed in the resinous coating so that when the resinous coating is dried to its film thickness, the dispersed filler transfers a low gloss surface to the surface of the transferred decorative coating, (3) a wax component contained in the synthetic resinous coating for enhancing release of the matte release layer from the transferred decorative coating, and (4) a silicone resin component in the synthetic resinous coating further enhancing release properties.

45. The transfer sheet according to claim 44 in which the surface gloss transferred to the decorative coating has a 75° gloss level of less than about 20 gloss units.

46. The transfer sheet according to claim 45 in which the 75° gloss level is less than about 12 gloss units.

47. The transfer sheet according to claim 44 in which the decorative coating includes a weatherable fluoropolymer resin.

48. The transfer sheet according to claim 44 in which the wax component is a polyethylene wax.

49. The transfer sheet according to claim 44 in which the wax component is in suspended form in the matte release layer at a transfer temperature, for enhancing transfer of said low surface gloss to the decorative layer; and in which the wax component can be melted at a temperature lower than the transfer temperature to enhance releasing the matte release coat from the transferred low gloss surface.

50. the transfer sheet according to claim 44 in which the decorative coating comprises a continuous paint coat containing a pigment at a level sufficient to retard UV degradation of the extruded sheet.

51. The transfer sheet according to claim 44 in which the decorative sheet contains one or more printing inks in which the pigment component consists essentially of an organic pigment.