Method of forming three dimensional patterns

Abstract: The improved method of forming a three-dimensional pattern comprises attaching a pattern forming mold to the work surface where a desired pattern is to be formed, casting a surfacing material comprising an acrylic resin concrete composition onto said work surface, allowing said surfacing material to harden, and detaching and removing said pattern forming mold from the work surface. Also disclosed are a mold for use in this method to form a three-dimensional pattern and a tool for removing said mold after the desired pattern has been formed.

Description: This invention relates to a method of forming three-dimensional patterns. More particularly, this invention relates to a method of forming desired three-dimensional patterns on the surfaces of walls, floors, etc., molds for use in that methods for forming three-dimensional patterns, as well as a tool for removing the molds used in that method. For the purpose of beautifying the asphalt concrete or cement concrete surfaces of floors or walls of buildings, platforms of railroad stations, concourses, pedestrian overpasses and pavements, the practice of forming brick or tile patterns or various other geometrical figures on those surfaces is gaining increasing acceptance these days. Also gaining wide acceptance is forming three-dimensional directional signs directly on walls, floors, etc. Three most common methods proposed so far for forming three-dimensional patterns or geometrical figures on walls, floors, road surfaces, etc. include: (a) a method comprising attaching an expanded polyethylene mold to the work surface, applying a projection forming material to fill in the mold, allowing the applied material to harden, and removing the mold by either burning or dissolving it away so as to form a pattern with intended projections and grooves (see Japanese Patent Publication No. 47593/1987); (b) a method comprising attaching a two-layered mold (having a releasable covering material on its top) to the work surface, applying a projection forming material to fill in the mold, removing the releasable covering material before the projection forming material solidifies or hardens and, after the projection forming material hardens completely, removing the mold to form a pattern with intended projections and grooves [see Japanese Patent Application (kokai) No. 233264/1985]; and (c) a method which is the same as method (b) except that the mold remaining after the releasable covering material is removed is left intact as a joint filler on the work surface [see Japanese Patent Application (kokai) No. 111062/1987]. The three methods described above have their own defects. In method (a), the appearance of the final pattern is considerably damaged by burning the mold. Even if the mold is dissolved away with the aid of a solvent, solvent staining will occur. In method (c), the mold in the joint can later be damaged or shed from the work surface. In both methods (b) and (c), the releasable covering material has to be removed while the projection forming material remains incompletely hardened, so the unhardened projection forming material deposited on the surface of the covering material can drip in areas where projections are to be formed, which either damages the appearance of the finished pattern or presents difficulty in the pattern forming operation. Further, method (b) requires two removing steps, one for removing the releasable covering material and the other for removing the mold, and this renders the overall operation cumbersome. A common problem to these conventional methods is that no special tool has been developed for use in removing the mold after the surfacing material hardens and the only tools available today are common screwdrivers with a thin wedge-shaped end and scrapers. However, it has not been easy to remove the mold with conventional screwdrivers or scrapers. For instance, in order to remove the mold with a conventional screwdriver, the latter is inserted between the mold and the work surface and the mold is pried to be detached from the work surface. Further, the screwdriver must be kept pushed during the operation but precise removal of the mold is difficult to achieve in this way. Scrapers are suitable for the purpose of removing burrs and other projections from the work surface but not suitable for removing the mold embedded in the surfacing material. EP-A-0 160 315 reveals a method of forming a decorative rugged surface pattern on a wall, a panel or the like, characterized in that a thick and soft main body of a molding frame having been adhered with a covering material which can be peeled off later on its top surface is stuck on an area to be processed, where the recessed surface of said pattern is to be formed, and after the spraying or trowelling material for forming protruding portion is applied, the covering material is removed together with a protrusion forming material laid on it, and said molding frame is removed in a later stage when the protrusion part material becomes dried and solidified. A first object, therefore, of the present invention is to provide a method by which three-dimensional patterns can be formed in a simple and easy-to-implement manner. A further object of the present invention is to provide a method using a mold that is capable of preventing the dripping of a surfacing material so as to facilitate pattern forming operation and produce a satisfactory finished surface and which therefore is suitable for the purpose of forming a desired three-dimensional pattern on the surface of a wall, floor, etc. The above objects of the present invention can be attained by a method which comprises attaching a pattern forming mold to the work surface where a desired pattern is to be formed, said pattern forming mold being formed from an expanded polyethylene, casting onto the work surface a surfacing material of an acrylic resin concrete composition, allowing the surfacing material to harden, and detaching and removing the pattern forming mold from the work surface. The acrylic resin concrete composition used as a surfacing material comprises: (A) at least one monomer component selected from among (meth)acrylic acid and esters thereof, in an amount of 45-85 parts by weight; (B) a polymer that can dissolve in said monomer component (A) or that is swollen by said monomer component (A), in an amount of 5-20 parts by weight; and (C) an aggregate in a proportion of 1-6 times the amount of (A) + (B) by volume. In a preferred embodiment of the present invention the pattern forming mold comprises a substrate layer made of an expanded polyethylene and at least one release layer formed as the topmost layer on the surface of said substrate layer. Preferably, a rigid protective layer is provided between the release layer and the substrate layer. Fig. 1 shows the major steps of forming a three-dimensional pattern by the method of the present invention; Fig. 2 shows an example of the mold which is used in forming a three-dimensional pattern by said method; Fig. 3 is a partial enlarged cross-sectional view of said mold; Fig. 4 is a perspective view showing a preferred example of the mold for use in forming a three-dimensional pattern by the method of the present invention; Fig. 5 is a cross section that shows schematically the mold of Fig. 4; Fig. 6 is a cross section showing schematically a more preferred example of the mold. The method of the present invention for forming three-dimensional patterns on flat surfaces such as those of pavements and walls is described below in detail with reference to Figs. 1A - 1D. First, the area around the work surface on which a pattern is to be formed is masked. Preferably, the same area is protected against staining by covering it with a sheet. Masking may be performed by attaching adhesive tape or a commercial polyethylene masking film. A polyethylene sheet may be used as an anti-stain sheet. In the next step, a preliminary treatment is conducted to remove grease, foreign matter like mud and water, as well as any other dirt and deposits from the work surface. When the work surface is a cement concrete or cement mortar paved surface, the preliminary treatment may be performed using a surface treating machine such as a scrabbling machine (e.g. LINAX®) or a demarcation line remover, and if the work surface is an asphalt paved surface, a polisher fitted with wire brushes may be used. If necessary, a primer may be coated on the work surface in order to improve adhesion to an undercoat material and a joint filler that are described hereinafter. Useful primers include methyl methacrylate (MMA) or urethane modified MMA primers such as R41, R51B of Mitsui Petrochemical Industrial Products, Ltd. When primers are to be coated on the work surface, the coat weight is typically in the range of from about 100 to 500 g/m². If the work surface has steps, roughness, cracks and other surface flaws, a pavement material may preliminarily be applied to make the work surface completely level. A suitable pavement material may be selected in accordance with the severity of surface flaws. If they are moderate, a resin mortar consisting of a resin composition comprising methyl methacrylate and a methacrylate polymer, mixed silica sand as an aggregate, as well as a pigment and a curing agent (e.g.R64SL of Mitsui Petrochemical Industrial Products, Ltd.) may be used. If surface flaws are severe, a resin concrete consisting of a resin composition comprising methyl methacrylate and a methacrylate polymer, gravel and silica sand as aggregates, and fillers such as calcium carbonate and a pigment (e.g. R17 of Mitsui Petrochemical Industrial Products, Ltd.) may be used. These pavement materials can be applied to the work surface by ruling, raking or troweling. In the next step, a joint filler for forming the joint of a brick pattern is applied as an undercoat to the level work surface. A joint filler is applied to provide a completely level coated surface so that good adhesion is insured between the work surface and a pattern forming mold which is to be attached thereto in a subsequent stage. A suitable joint filler may be selected in consideration of color contrast from the surface layer that is to be formed of a surfacing material to be discussed hereinafter which is made of an acrylic resin concrete composition. An illustrative example is a resin paste that comprises 5 - 15 parts by weight of an inorganic pigment as a colorant, 5 - 50 parts by weight of a filler such as talc, calcium carbonate or a silica sand powder, and 100 parts by weight of a resin composition chiefly made of methacrylic acid and a methyl methacrylate resin (e.g. Silical®R61 of Mitsui Petrochemical Industrial Products, Ltd.) The joint filler is typically coated in a thickness of about 0.1 - 2mm. After the joint filler hardens, marking is preferably conducted in order to insure that a pattern forming mold can be attached to an exact position on the work surface in the next step. In this case, longitudinal and transverse reference lines are preferably marked in an exact way. After the preliminary treatments described above, a mold 3 for forming a three-dimensional pattern (see Fig. 2) is attached to the hardened layer of joint filler 2 on top of the work surface 1 in accordance with the marked reference lines as shown in Fig. 1A. As shown in Figs. 2 and 3, the mold 3 has an adhesive coated on its bottom surface 5 with which the mold is to be bonded to the hardened layer of joint filler 2. When not in use, the adhesive is protected with release paper 6 that is applied to the bottom surface 5. The mold 3 is preferably formed of an expanded polyethylene having a blow ratio of ca. 3 - 7. An expanded polyethylene is used since it does not adhere to acrylic resin concrete and because it is not attacked by resin concrete. The thickness of the mold is not limited to any particular value and may be selected as appropriate for such factors as the shape and size of the pattern to be formed. As a guide figure, the range of ca. 1 - 2 mm may be adopted. If the particle size of the aggregate that is incorporated as a component of the acrylic resin concrete composition which is used as the surfacing material to be described hereinafter is to be taken in account, the thickness of the mold is preferably at least 3 - 4 times as much the maximum particle size of the aggregate, with the range of ca. 1 - 5 mm being mentioned as a guide figure. The mold 3 is preferably attached to the work surface in such a way that the two members adhere strongly to prevent lifting of the mold. If the surface of the hardened layer of joint filler 2 remains tuck, the mold 3 will sometimes fail to adhere strongly to the work surface. Hence, it is recommended that the work surface be examined and any defect such as tuck should be removed before the mold is attached. After the mold 3 is attached to the work surface in the manner described above, the surfacing material 7 is applied or cast to fill in the open spaces 8 in the mold as shown in Fig. 1B. An acrylic resin concrete composition is used as the surfacing material 7. The composition comprises: (A) at least one monomer component selected from among (meth) acrylic acid and ester compounds thereof; (B) a polymer that can dissolve in said monomer component (A) or that is swollen by said monomer component; and (C) an aggregate. Examples of the monomer component (A) include: alkyl (meth)acrylates such as methyl acrylate, ethyl acrylate, methyl mathacrylate and ethyl methacrylate; as well as acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, hexylene glycol di(meth)acrylate, 2,2-bis[4-(meth)acryloyloxyphenyl]propane, 2,2-bis[4-(meth)acryloyloxycyclohexyl]propane, 2,2-bis[3-(meth)acryloyloxy-2-hydroxypropoxyphenyl]propane, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and dipentaerythritol hexa(meth)acrylate. These compounds may be used either on their own or as admixtures. The polymer (B) may be exemplified by homo- or copolymers of the monomers listed above, in particular, (meth)acrylate esters. Examples of the aggregate (C) include silica sand, alumina, white Japanese marble (calcite), emery, ceramic sand and glass beads. In order to produce a colored surface layer, these aggregates may be colored. Such colored aggregates may be prepared by forming a colored layer consisting of a silane coupling agent, a pigment and a binder component over all or part of the surfaces of aggregates. Pigments may be organic or inorganic. Exemplary organic pigments include Benzidine Yellow, Hansa Yellow, Lithol Red, alizarin lake, Pigment Scarlet 3B, Brilliant Carmine 6B, Permanent Red F-5R, Permanent Red 4R, Rhodamine B Lake, Rhodamine Y Lake, Lake Red C, Para Red, Peacock Blue Lake, Phthalocyanine Blue, Aniline Black, Permanent Yellow HR, PV Violet BL, quinacridone, perinone, anthraquinone, Chrome Phthal Yellow 6G, Chrome Phthal Yellow 3G and Chrome Phthal Yellow GR. Exemplary inorganic pigments include titanium oxide, zinc white, lithopone, white lead, cadmium yellow, chrome yellow, titanium yellow, zinc chromate, yellow ochre, chrome vermillion, vermillion, amber, yellow iron oxide, red iron oxide, cadmium red, red lead, prussian blue, ultramarine blue, cobalt blue, chromium oxide green, mineral violet, carbon black and iron black. While any of these organic and inorganic pigments can be used, suitable ones are selected as appropriate depending on the resin component of resin concrete. Suitable binder components include emulsions or solutions of resins such as epoxy, urethane and acrylic urethane resins. Preferred examples of silane coupling agents include vinyl trimethoxysilane, vinyl triethoxysilane, vinyl tris (β-methoxyethoxy)silane, vinyl triacetylsilane, and γ-methacryloxypropyl trimethoxysilane. Other silane coupling agents that can be used include vinyl trichlorosilane, and γ-[N-β-methacryloxyethyl)-N,N-dimethylammonium(chloride)]propyl trimethoxysilane. Colored aggregates can be prepared using the aggregate, pigment, binder component and silane coupling agent described above by permitting the silane coupling agent to be present during the coating of the colorant so that it is baked to the aggregate simultaneously. The aggregate (C) is incorporated in a proportion of ca. 1 - 6, preferably ca. 2 - 4, per unit volume of liquid. The acrylic resin concrete composition that comprises monomer component (A), polymer (B) and aggregate (C) may further contain a plasticizer (D) and a polymerizable unsaturated bond containing compound (E). Exemplary plasticizers (D) are phthalic acid esters including dimethyl phthalate, dibutyl phthalate, dicyclohexyl phthalate, dipentyl phthalate, dioctyl phthalate, di-2-ethylhexyl phthalate, diisodecyl phthalate and butylbenzyl phthalate. Internal plasticizers can also be used as exemplified by α, β-unsaturated carboxylic acid esters that are copolymerizable with monomer component (A) and more specific examples are diethyl maleate, dibutyl maleate, dioctyl maleate, dibutyl fumarate and dioctyl fumarate. Examples of the polymerizable unsaturated bond containing compound (E) include: alkanediol di(meth)acrylates such as ethylene glycol di(meth)acrylate, 1,2-propylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate and 1,4-butylene glycol di(meth)acrylate; and (meth)acrylic acid modified epoxy resins such as 2,2-bis[3-(meth)acryloyloxy-2-hydroxypropoxyphenyl]propane, and commercial products available under the trade names "Ripoxy VR-60" and "Ripoxy VR-90" from Showa Highpolymer Co., Ltd. If components (A), (B), (D) and (E) described above are to be used in combination, their respective proportions are such that monomer component (A) is 45 - 85 parts by weight, polymer (B) is 5 - 20 parts by weight and plasticizer (D) is 1 - 25 parts by weight, with (E) being the balance. The acrylic resin concrete composition can be hardened by incorporating a polymerization initiator together with the optional amine used as a cold curing accelerator. Exemplary polymerization initiators include azo compounds and peroxides such as diacyl peroxides, alkyl peroxides, aralkyl peroxides, peracids and peracid esters, with diacyl peroxides being preferred. Exemplary diacyl peroxides include dibenzoyl peroxide, diacetyl peroxide, dicapryl peroxide, dilauroyl peroxide, and distearoyl peroxide. Amines may be primary, secondary or tertiary, with tertiary amines being used advantageously. Exemplary amines include aniline, toluidine, xylidine, phenylenediamine, N,N-dimethylaniline, N,N-diethylaniline, N,N-di(β-hydroxyethyl)aniline, N,N-dimethyltoluidine, N,N-diethyltoluidine, N,N-dimethylanisidine, N,N-diethylanisidine, N,N-dimethyl-p-t-butylaniline, N,N-diethyl-p-t-butylaniline, N,N-dimethyl-p-chloroaniline, diphenylamine, and N,N-(β-hydroxyethyl)-p-toluidine Among these, tertiary amines having an electron donating substituent at least in the p-position of the benzene ring such as N,N-dimethyl-p-toluidine, N,N-dimethyl-p-butylaniline, N,N-dimethylanisidine, N,N-dimethyl-p-chloroaniline and N,N-bis(β-hydroxyethyl)-p-toluidine are preferred, with N,N-dimethyl-p-toluidine and N,N-dimethyl-p-t-butylaniline being particularly preferred. The polymerization initiator and amines are generally used in such amounts that each is 0.1 - 20 parts by weight per 100 parts by weight of the sum of components (A), (B), (D) and (E). In order to prevent insufficient progress of a surface hardening reaction due to the trapping of radicals by aerial oxygen, solid paraffins, preferably paraffin waxes having melting points of 40 - 60°C are preferably added. Such paraffins are incorporated in amounts of 0.1 - 1.0 part by weight per 100 parts by weight of the sum of components (A), (B), (D) and (E). The surfacing material should be cast or applied to fill in the spaces in the mold immediately after the preparation of the acrylic resin concrete composition and in such a gentle way as to prevent the lifting of the mold from the work surface. To this end , troweling or some other techniques of application may be performed in conformity with the shape and other features of the work surface and the surface layer to be formed, with care being taken to minimize unwanted coverage of the mold with the surfacing material. The surfacing material is typically applied in a coat weight of ca. 4 kg/m² if a surface layer 2 mm thick is to be formed. The applied surfacing material is then cured to harden. The curing time typically ranges from ca. 30 to 90 min, preferably ca. 40 - 60 min. After the surfacing material hardens, the mold 3 is gently pulled up starting at one end, as shown in Fig. 1C, so that it is detached and removed from the work surface. Preferably, the mold 3 is removed from the work surface immediately after the surfacing material has hardened in order to insure that the unhardened surfacing material on the mold will not drip to either foul or disfigure the finally produced pattern. If extensive coverage with the surfacing material makes it difficult to remove the mold 3 efficiently, a blade toll such as a scraper may be used to assist in the removal step. The operator is recommended to put on clean shoes or take any other precautions necessary to prevent the surface layer from being fouled during the removal of the mold. After the mold removal is completed, shedding of the surfacing material, burring of the joint and any other minor defects that can impair the appearance of the final pattern are preferably remedied. The above-described steps lead to the formation of a brick patterned surface layer over the work surface 1 as shown in Fig 1D. After removing the mold, the surface layer and the joint over the work surface are thoroughly cleaned and provided with a uniform topcoat in order to prevent staining and give an appealing finish. Specific examples of the topcoat that can be applied include R81 Clear and R71 Clear of Mitsui Petrochemical Industrial Products, Ltd. The topcoat may be applied by various methods such as roller coating, brush coating or spray coating that may be properly selected depending upon the surface to be coated. Since the topcoat being applied is prone to collect in the joint, care should be taken to insure that the topcoat is evenly applied over the surface layer with standing topcoat being absorbed by a highly absorbent roller or brush. The applied topcoat is cured for ca. 30 min until it hardens completely. After the topcoat has hardened. the masking tape or film as well as the protective sheet are removed to complete the process of forming a desired three-dimensional pattern by the method of the present invention. The foregoing description concerns an embodiment in which a three-dimensional pattern is formed using a single-layered mold. A preferred example of the mold is described below with reference to Figs. 4 and 5. Fig. 4 is a perspective view of the preferred mold which is generally indicated by 9 and which consists basically of a substrate layer 10 and a release layer 11 on its top. Below the substrate layer 10 is provided an adhesive layer 12 which permits the substrate layer 10 to be firmly adhered to the hardened layer of joint filler. When not in use, the adhesive layer 12 is preferably protected with release paper 13 that is applied to its underside. Release paper 13 has a release agent applied to those areas which correspond to the adhesive layer 12. The substrate layer 10 of the mold 9 is formed of an expanded polyethylene. It is particularly preferred that the substrate layer 10 is formed of an expanded polyethylene having a blow ratio of ca. 3 - 7 since it does not adhere to the acrylic resin concrete used as a surfacing material and because it is not attacked by resin concrete. The thickness of the substrate layer is not limited to any particular value and may be selected as appropriate for such factors as the shape and size of the pattern to be formed. As a guide figure, the range of ca. 1 - 2 mm may be adopted. If the particle size of the aggregate that is incorporated as a component of the acrylic resin concrete composition which is used as the surfacing material is to be taken into account, the thickness of the substrate layer is preferably at least 3 - 4 times as much as the maximum particle size of the aggregate, with the range of ca. 1 - 5 mm being mentioned as a guide figure. The mold 9 has at least one release layer 11 as the topmost layer on the substrate layer 10. The release layer 11 may be formed of any release agent that is releasable from the surfacing material used, and useful release agents include silicone rubber (in solvent) based compounds, wax (in solvent) based compounds and PVA based compounds. These release agents may be used either on their own or as admixtures and suitable compounds may be selected as appropriate for such factors as the material of the substrate layer. The release layer 11 may be formed by applying a suitable release agent to the surface of the substrate layer 10. An appropriate coating method may be selected from among known techniques including spray coating and brush coating. The adhesive layer 12 may be formed of any known adhesives including aliphatic petroleum resin (e.g. Hi-rez®), aromatic petroleum resin (e.g. Petrozin®) and petroleum resin (e.g. Tackace®). The release paper 13 applied to the underside of the adhesive layer 12 comprises a release agent coated at least onto those surfaces which contact the substrate layer, and such release paper serves to protect the adhesive layer when it is not in use. The release paper 13 is separated as required and the exposed adhesive layer 12 is bonded to the work surface. The release paper 13 may be of any type that is commonly used in a class of applications as contemplated by the present invention and kraft paper may be mentioned as an example. Suitable release paper may be selected as appropriate for the adhesive agent of which the adhesive layer 12 is made. Another example of the mold 9 is shown in Fig. 6, in which a rigid protective layer 14 is provided between the substrate layer 10 and the release layer 11 formed on top of the substrate layer 10. Since the protective layer 14 imparts appropriate rigidity to the substrate layer, the mold for forming a three-dimensional pattern can be attached to the hardened layer of joint filler with such high efficiency that even a mold having a large area can be handled without deformation. Hence the advantage of the mold having the construction shown in Fig. 6 (i.e., providing high operational efficiency) is enhanced as the area of the three-dimensional pattern to be formed increases. The rigid protective layer 14 may be made of paper or a synthetic resin such as polyethylene and it can be formed by bonding or thermally fusing a rigid sheet of kraft paper (120 µm) onto the top surface of the substrate layer with an adhesive layer 15 being interposed. While the method of the present invention has been described above in relation to the formation of a brick-shaped three-dimensional pattern on a flat surface, it should be noted that this is not the sole case for the applicability of the present invention and that it is also applicable to the formation of three-dimensional patterns in other situations such as tile facing, stone masonry and natural stone setting. It should also be noted that the shape of three-dimensional patterns that can be formed by the present invention are in no way limited to brick-shaped patterns and three-dimensional patterns of any other shapes can be formed using molds having corresponding shapes including those of animals, plants, designed pictures of scenery, characters, symbolic marks and numerals. Using the method of the present invention, three-dimensional patterns of various shapes can be easily formed on the surfaces of walls, floors, etc. If a mold having the construction shown in Fig. 2 is used in forming a three-dimensional pattern by this method, the following two advantages will result: the mold has a simple structure and hence can be fabricated at low cost; secondly, the method of forming a desired three-dimensional pattern can be practiced in a convenient manner. Further, by using a mold having the construction shown in Fig. 4 which has at least two layers, i.e., a substrate layer and a release layer, the dripping of a surfacing material over the mold can be prevented so as to facilitate the pattern forming operation and produce a satisfactory finished surface. The mold is therefore suitable for the purpose of forming a desired three-dimensional pattern on the surface of a wall, floor, etc.

Claims: A method of forming a three-dimensional pattern from an acrylic resin concrete composition which comprises: attaching a pattern forming mold (3) to a work surface (1) where a three-dimensional pattern is to be formed, said pattern forming mold (3) being formed from an expanded polyethylene; casting onto said work surface (1) a surfacing material (7) of an acrylic resin concrete composition comprising: (A) at least one monomer compound selected from the group consisting of acrylic acid, methacrylic acid and esters thereof, in an amount of 45-85 parts by weight, (B) a polymer that dissolves in said monomer component (A) or that is swollen by said monomer component (A), in an amount of 5-20 parts by weight, and (C) an aggregate in a proportion of 1-6 times the amount of (A) + (B) by volume; allowing said acrylic resin concrete composition of said surfacing material (7) to harden; and then detaching and removing said pattern forming mold (3) from said work surface (1) and said hardened surfacing material (7). The method according to claim 1, wherein said pattern forming mold (9) comprises a substrate layer (10) made of an expanded polyethylene and at least one release layer (11) formed as the topmost layer on the surface of said substrate layer (10). The method according to claim 2, wherein a rigid protective layer (14) is provided between said release layer (11) and said substrate layer (10).

Inventors: SUZUKI YASUYUKI C O MITSUI PET, TSUCHIDA KATSUNORI C O MITSUI, WATANABE YASUO C O MITSUI PETR, SUZUKI, YASUYUKI, C/O MITSUI PETROCHEMICAL, TSUCHIDA, KATSUNORI, C/O MITSUI PETROCHEMICAL, WATANABE, YASUO, C/O MITSUI PETROCHEMICAL
Applicants: MITSUI PETROCHEMICAL IND, MITSUI PETROCHEMICAL INDUSTRIES, LTD.
Application year: 1991
Main classification: E04F13
IPC codes: E04F21, B29C39