JPS6135946B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color resin board used for signboards, display materials, architectural glazing materials, and the like. The term "color resin board" as used herein refers to a resin board colored in a single color.

Conventionally, plastic boards such as PVC boards and acrylic resin boards have been used in large quantities in the field of signs and displays. Particularly in recent years, acrylic resin boards have come to be used mostly for this purpose because of their weather resistance and beauty. Currently, methods for producing acrylic resin plates can be roughly divided into monomer casting methods and extrusion methods, but in the past, most acrylic resin plates were so-called cast plates manufactured by the monomer casting method. Cast plates have the advantage of having a cleaner surface than extruded plates. Moreover, color resin plates colored in various colors by the cast method have the advantage that they can be produced in relatively small lots, that is, they can be produced in small quantities of a wide variety of products. However, on the other hand, there was a problem in manufacturing control that variations between lots were unavoidable and it was difficult to obtain products with the same color tone. In recent years, as extrusion manufacturing technology has been established, the difference in quality between cast plates and extruded plates has become smaller, and at the same time there has been a gap in productivity and price, so the quantity of advantageous extruded plates has gradually increased. It's coming. However, the extrusion method is originally a method suitable for mass production, and has the disadvantage that it is difficult to meet market demands for color resin plates produced in small quantities in a wide variety of products. This is because it is necessary to clean the extruder every time the color is changed, which is laborious and costly. Cleaning the extruder requires flowing a large amount of new resin into the extruder.

The present invention is an epoch-making color resin plate and its manufacturing method that meet the market demand for color resin plates produced in small quantities in a wide variety of products using an extrusion method, and has almost no variation in color tone between lots of the same color. It provides:

That is, the first invention of the present application is such that a transparent thermoplastic synthetic resin plate-shaped extrusion molded body 2 and a transparent thermoplastic synthetic resin film 3 are laminated and thermally fused via a resin thin layer 4 containing a uniform color pigment. This is a light-transmissive color resin plate 1 made of a resin film.

A detailed explanation will be given below with reference to the drawings. FIG. 1 shows an enlarged sectional view of a color resin plate 1 of the present invention, in which a plate-shaped extrusion molded body 2 and a film 3 are interposed with a thin resin layer 4 containing a uniform color pigment interposed therebetween. Laminated and heat fused. In addition, since the thickness ratio of the plate-shaped extrusion molded body 2 and the film 3 can be as much as 50 times, the thickness of the plate-shaped extrusion molded body 2 is drawn with the middle portion omitted. In addition, in the figure, for convenience, the plate-shaped extrusion molded body 2 and the resin thin layer 4 containing a uniformly colored pigment are drawn as though they are in close contact with each other but exist independently. As can be expected from the method, it is thought that the thin resin layer 4 containing the pigment and the surface portion of the film 3 often melt into the surface layer of the extruded plate 2 to a considerable extent and are in close contact with it.

The plate-shaped extrusion molded body 2 referred to in the present invention is preferably made of thermoplastic and transparent synthetic resin, such as methyl methacrylate resin, polystyrene, or polycarbonate. In particular, polymethyl methacrylate resin, commonly referred to as acrylic resin, is a preferred material in terms of weather resistance, beauty, and processability. The film 3 is made of a thermoplastic and transparent synthetic resin, that is, an acrylic film (for example, the product name "Koratsudo", manufactured by Koratsudo Co., Ltd., or the product name "Sanjiyuren", manufactured by Kanekabuchi Kagaku Kogyo Co., Ltd.). , polystyrene film (for example, product name “Styro Film” manufactured by Asahi Dow Co., Ltd.)
(manufactured by Teijin Kasei Ltd.), polycarbonate film (for example, "Panlite Film" manufactured by Teijin Kasei Ltd.), etc. are preferred, but it is preferable that the film 3 and the plate-shaped extrusion molded body 2 are made of the same material. For example, an acrylic film and an extruded acrylic resin plate may be combined. The thickness of the plate-shaped extrusion molded body 2 is 1 to 10
mm, preferably 2 to 6 mm. Further, the thickness of the film 3 is preferably 20 to 150 microns.

The thin resin layer 4 containing uniformly colored pigments has the composition of an ink commonly used for gravure printing of plastic films. The uniformly colored pigment is preferably one that exhibits a light-transmitting hue when the thin resin layer 4 is formed. The pigment is uniformly dispersed in a color vehicle containing, for example, an acrylic resin. The thickness of this thin resin layer 4 is usually around 10 microns, but it can be made thinner to make the brightness brighter, and thicker to make it darker. The brightness can also be adjusted by adjusting the amount of pigment relative to the resin.

The uniformly colored pigment contained in the thin resin layer 4 is required to have sufficient weather resistance due to its intended use. However, in reality, it is difficult to obtain materials that exhibit excellent weather resistance, light transmittance, and beautiful hues. Considering that the colored resin board of the present invention is often used outdoors, the product must be resistant to fading. Sunlight contains a large amount of ultraviolet rays. Ultraviolet light generally has the effect of deteriorating or fading materials in the presence of oxygen. Although it is possible to block UV rays and oxygen to some extent by trapping the thin resin layer 4 containing pigment between the extruded plate 2 and the film 3, it is extremely insufficient for the purpose of imparting weather resistance. It is. Therefore, by incorporating an ultraviolet absorber into the transparent thermoplastic synthetic resin that is the material of the plate-shaped extrusion molded body 2 and the film 3, it is possible to almost completely prevent ultraviolet rays from reaching the thin resin layer 4 containing the pigment. It can be prevented. As the ultraviolet absorber, for example, Tinuvin P (trade name, manufactured by Ciba Geigy) is contained in a proportion of about 2% by weight in the case of a 50 micron film. Since the plate-shaped extrusion molded product is relatively thicker than the film, it is sufficient to use the amount of about 0.2% by weight or less.

The surface of the color resin plate of the present invention may be smooth, or may have an uneven structure on one or both sides. FIG. 2 shows an enlarged cross-sectional view of a color resin plate of the present invention having uneven structures 5, 5 on both sides. A light-transmitting color resin plate having an uneven structure on its surface has a solid feel due to diffuse reflection of transmitted light. Here, as shown in FIG. 2, the uneven structure 5 on the laminated side of the film 3 is formed by integrating the surface layer of the extruded plate 2 with the film 3 and a thin resin layer 4 containing pigment interposed in the middle. By forming an uneven structure, the adhesion between the extruded plate 2, the film 3, and the thin resin layer 4 is stronger than in the case shown in FIG.

The second invention of the present application is a method of manufacturing the light-transmitting color resin plate 1 of the first invention. That is, a transparent thermoplastic synthetic resin film 3 coated with a resin thin layer 4 containing a uniformly colored pigment is placed on a plate-shaped extrusion molded body 2 made of a molten transparent thermoplastic synthetic resin, with the resin thin layer 4 on the inside. This is a method for manufacturing a light-transmissive color resin plate 1, in which a plate-shaped extrusion molded body 2 and a film 3 are heat-sealed by laminating them in the following manner and then passing them between a pair of rolls 6, 6. . FIG. 3 is a process diagram showing an outline of this manufacturing method. In FIG. 3, reference numeral 7 denotes a roll of film 3 on which a thin resin layer 4 containing a uniform color pigment is coated over the entire surface using a gravure printing machine or a roll coater. While extruding a transparent thermoplastic synthetic resin into a plate shape using an extruder 8, a film 3 whose surface is coated with a resin containing a uniform color pigment is laminated thereon so that the coated resin layer is on the inside. 2 rolls 6,
This laminate is passed through the space between the layers 6 and 6 to bring them into close contact. In this way, the color resin plate 1 of the first invention of the present application is obtained. Since the film 3 is laminated and adhered while the plate-shaped extrusion molded body is in a molten state, heat fusion is possible without using any particular adhesive.
The thin resin layer 4 containing the applied pigment and the surface portion of the film 3 are melted into the surface layer of the extruded plate 2, and the film 3 and the extruded plate 2 are separated by a conventional method. It cannot be removed. By providing embossing with an appropriate pattern on the surface of one or both of the rolls 6, 6, a color resin plate having an uneven structure on the surface can be manufactured.

Example 1 A transparent blue ink composition (vehicle) consisting of a blue pigment, a color vehicle, and a solvent was applied to a transparent acrylic film (product name: CORAD, manufactured by CORAD Co., Ltd.) with a thickness of 50 microns and a width of 1000 mm using a gravure printing machine. was coated with acrylic resin (prepared by Company D) twice. This acrylic film has a UV absorber incorporated into it, so it has UV blocking properties as a film. Furthermore, analysis revealed that the acrylic resin that is the material of this acrylic film is a copolymer resin consisting of a large amount of methyl methacrylate and a small amount of normal butyl ester in the acrylic part. Next, an acrylic resin consisting of a copolymer of 95% by weight of methyl methacrylate and 5% by weight of acrylic acid methyl ester, and containing 0.1% by weight of an ultraviolet absorber, was heated to 1000% by weight using an extruder.
It was extruded into a plate with a width of 3 mm and a thickness of 3 mm. The acrylic film was placed so that the surface on which the transparent blue ink composition was applied faced the extruded plate.

The plate-shaped body and the film were passed through two embossing rolls having an amorphous uneven pattern with a depth of 0.2 to 0.5 mm on the surface while being overlapped. Then, this was cooled and cut into a predetermined size.
The obtained color acrylic resin plate was a beautiful light-transmitting plate in which the plate-shaped extrusion molded product and the film adhered well, and the appearance was such that it was hard to tell at first glance that the film was laminated.

The above color acrylic resin plate was exposed to sunlight to examine its weather resistance (Arizona, USA).
EMMAQUA method at DSET Institute).

Even after irradiation with 1 million Langleys, no changes in appearance such as discoloration or fading were observed, proving that the color acrylic resin board has extremely high weather resistance. In addition,
1 million Langley is 45 southbound in Choshi, Japan.
This is the amount of sunlight equivalent to 10 years when exposed outdoors at a slant.

Example 2 Transparent polystyrene film with a thickness of 50 microns and a width of 1000 mm (trade name: Stylo Film, Asahi Dow Co., Ltd.)
A transparent yellow ink composition (manufactured by Company D) was coated on one side of the paper (manufactured by Company D) twice using a gravure printing machine. Polystyrene (trade name: Styron, manufactured by Asahi Dow Co., Ltd.) having the same composition as the above polystyrene film was extruded using an extruder, and the above film was laminated thereon so that the surface coated with the yellow ink composition was on the inside. . By passing it between two embossing rolls in the same manner as in Example 1, a solid color resin plate having a concavo-convex structure on both sides was obtained.

Since the present invention is manufactured by the manufacturing method described above, if colored films of each color whose surfaces are coated with pigment-containing resin are kept in stock, colored resin plates of various colors can be manufactured according to market demands. The extrusion method makes it possible to produce in small batches with small turns, and resin plate manufacturers are freed from the uneconomical burden of stocking large quantities of resin plates. There is no need to spend time cleaning the extruder after each color change. This makes it possible to accommodate a variety of plans in the field of sign and display. In addition, while conventional color resin boards are colored throughout the board whether cast or extruded, the color resin board of the present invention is different in that a colored layer exists inside the board near one surface. There is. Due to these differences, the color resin board of the present invention has a clearly more elegant surface gloss than the conventional extruded color resin board made by mixing a colorant. Furthermore, if the same lot of the above-mentioned colored films are used, there will be no difference in color tone between batches.

The colored resin board of the present invention, which is made from methyl methacrylate resin containing an ultraviolet absorber, has unparalleled weather resistance, so it can be used not only for signs and displays, but also for hiding openings in houses, balconies, handrails, etc. It can also be used in parts of buildings facing outdoors.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of a color resin plate according to an embodiment of the present invention. FIG. 2 is an enlarged sectional view of a color resin plate according to another embodiment of the present invention.
FIG. 3 is a process diagram showing an outline of a method for manufacturing a color resin plate of the present invention. 1...Color resin plate, 2...Plate-shaped extrusion molded body,
3...Film, 4...Resin thin layer, 5...Irregular structure, 6...Roll.

Claims (1)

[Scope of Claims] 1. A transparent thermoplastic synthetic resin plate-like extrusion molded body 2 and a transparent thermoplastic synthetic resin film 3 are laminated and heat-sealed via a thin resin layer 4 containing a uniformly colored pigment. Light-transparent color resin plate 1. 2. The color resin board 1 according to claim 1, which has an uneven structure 5, 5 on one or both sides. 3 The transparent thermoplastic synthetic resin of the plate-shaped extrusion molded body 2 and the film 3 is a methyl methacrylate resin,
The color resin board 1 according to claim 1 or 2, which is made of polystyrene or polycarbonate. 4. The color resin plate 1 according to any one of claims 1 to 3, in which the transparent thermoplastic synthetic resin plate-shaped extruded body 2 and the transparent thermoplastic synthetic resin film 3 both contain an ultraviolet absorber. 5. A transparent thermoplastic synthetic resin film 3 coated with a resin thin layer 4 containing a uniform color pigment is placed on a plate-shaped extrusion molded body 2 made of a molten transparent thermoplastic synthetic resin so that the resin thin layer 4 is on the inside. A method for producing a light-transmissive color resin plate 1, in which a plate-shaped extrusion molded body 2 and a film 3 are thermally fused by laminating the same and then passing between a pair of rolls 6, 6. 6. The manufacturing method according to claim 5, wherein the color resin plate 1 according to claim 2 is manufactured by providing embossing on the surface of at least one of the pair of rolls 6, 6.