JP5015996B2 - Sheet for simultaneous injection molding - Google Patents

Description

  The present invention relates to a sheet for simultaneous injection-molding with a picture which can be laminated with good adhesion to a resin molded product made of polyolefin resin. In particular, the present invention relates to a sheet for simultaneous injection molding with little curling.

  Conventionally, a molded article with a picture of the surface of a resin molded product has been used for various purposes. For example, in the injection molding simultaneous painting method disclosed in Patent Document 1, Patent Document 2, etc., the injection molding simultaneous painting sheet is disposed between both male and female molds for injection molding, and then molten resin is injected and filled into the cavity. Thus, a method is disclosed in which simultaneously with the molding of a resin molded product, an injection-molded simultaneous painting sheet is bonded and laminated on the surface thereof to obtain a molded article with a picture painted on the sheet.

  By the way, conventionally, as the injection molding resin used for the resin molding by the injection molding simultaneous painting method, there are many ABS resins (acrylonitrile-butadiene-styrene copolymer), acrylic resins, polycarbonate resins and the like. For this reason, a laminate type injection molding simultaneous painting sheet used for laminating on the surface of a resin molded article by the injection molding simultaneous painting method is generally of a specification that has good adhesion to these injection molding resins. . In addition, a surface sheet is used as the outermost surface layer in order to give a sense of quality by imparting a design feeling such as a feeling of painting and surface gloss to the resulting molded molded article and to obtain sufficient surface properties such as scratch resistance and weather resistance. An acrylic resin sheet or the like was used.

  (1) For example, as described in Patent Document 3, (1) A transparent acrylic resin sheet such as polymethyl methacrylate (PMMA) having excellent transparency is used for the top sheet, and the base sheet on the back side is used. This is a sheet for injection-molded simultaneous painting using an ABS resin sheet and having a decorative layer or the like formed between them. However, the adhesiveness was poor particularly for injection molding resins of inexpensive polyolefin resins such as polypropylene, which have been demanded recently.

  (2) Also, for example, as described in Patent Document 4, a transparent acrylic resin sheet is used as a base sheet and a front sheet, a decorative layer is printed on the back side, and a polyolefin is used as the backmost layer. In the sheet for injection-molded simultaneous painting having a configuration in which an adhesive that adheres to a resin is applied and formed, the adhesion to the polyolefin resin is improved. However, since the acrylic resin sheet has a thickness of 0.1 to 0.2 mm in terms of film formation technology and cost of the acrylic resin sheet, there is no waist as a base sheet, and it is difficult to handle the sheet. Was also big.

  (3) Therefore, the present inventor, in Japanese Patent Application No. 11-91537, used an acrylic resin for the top sheet, a polyolefin resin for the base sheet, and provided a decoration layer or the like therebetween. A sheet for simultaneous injection molding with composition was proposed.

Japanese Patent Publication No. 50-19132

Japanese Patent Publication No.43-27488

Japanese Patent Laid-Open No. 11-91041

JP-A-10-128789

  However, the injection-molded simultaneous painting sheet having the configuration (3) has improved adhesion to the polyolefin resin, but may cause curling. For this reason, when conveying a sheet at the time of injection molding simultaneous painting, a problem that the curled sheet is caught in the apparatus occurred. Further, if the sheet is curled when the sheet is fixed to the injection mold, the positioning of the sheet may be inaccurate. Also, in the case of simultaneous injection molding with an off-line preforming method in which the sheet is preformed separately from the injection mold, after the preforming, the sheet is removed from the preforming mold and then set in the injection mold. The problem of curling was particularly large because it was necessary to do so.

  However, as a curl reduction measure, a measure to leave the acrylic resin of the top sheet and the polyolefin resin of the base sheet as it is without changing to another resin was desired. To the last, the surface sheet that is the outermost surface is excellent in acrylic resin in terms of transparency, weather resistance, etc., and the base material sheet that is the outermost surface is in close contact with the polyolefin resin. This is because polyolefin resin is excellent. Therefore, it is necessary to reduce curl on the premise that acrylic resin is used for the top sheet and polyolefin resin is used for the base sheet.

  Therefore, the object of the present invention is to provide a laminate-type injection-molded sheet for simultaneous painting with sufficient transparency and surface physical properties to the resulting molded article, and use an polyolefin resin such as polypropylene as the injection-molding resin. However, it is possible to laminate on a resin molded article with good adhesion, and furthermore, curl is less and simultaneous injection molding can be performed smoothly.

Therefore, in order to solve the above-mentioned problems, in the injection-molded simultaneous painting sheet of the present invention, in the laminate-type injection-molded simultaneous painting sheet, at least as a surface sheet that becomes the outermost surface layer, a decoration layer is formed on one surface. A decorative sheet made of a polymethylmethacrylate ( excluding one containing a fluorine-based resin ) sheet, and a base sheet made of polyolefin resin on the decorative layer surface of the decorative sheet, and the top sheet and the base material The total thickness of the sheet is 400 μm or more, the thickness ratio of the surface sheet to the base sheet is surface sheet thickness / base sheet thickness ≦ 0.35, and the thickness of the surface sheet is 30 μm or more. The sheet is a sheet for injection-molded simultaneous painting that can be preformed with another mold .

In this way, a transparent acrylic resin is used for the surface sheet that becomes the outermost surface layer after lamination, while a polyolefin-based resin is used for the base sheet that becomes the outermost surface layer in contact with the resin molded product. By providing them in between, excellent transparency and surface physical properties can be imparted to the resulting molded article with a picture, and in particular, it can be laminated with good adhesion to a resin molded product of polyolefin resin. In addition, the thickness ratio between the top sheet and the base sheet is specified as described above, and the thickness of the top sheet is less than the specific thickness ratio compared to the thickness of the base sheet, so curling can be reliably reduced. Therefore, mechanical injection of the sheet for simultaneous injection molding and accurate positioning can be performed smoothly, especially in the case of simultaneous injection molding with a form such as offline preforming, which is preformed with a mold different from the injection mold. Are better. Moreover, the sheet for simultaneous injection-molding painting of the present invention has a configuration in which the base sheet has a multilayer configuration in the configuration.

  According to the injection-molded simultaneous painting sheet of the present invention, excellent transparency and surface physical properties are imparted to the resulting molded article, and in particular, it can be laminated with good adhesion to a resin molded product of a polyolefin-based resin. Curling can be reliably reduced when using the sheet. Therefore, mechanical injection of the sheet for simultaneous injection molding and accurate positioning can be performed smoothly, especially in the case of simultaneous injection molding with a form such as offline preforming, which is preformed with a mold different from the injection mold. Are better.

The conceptual diagram which shows the relationship between the thickness ratio of a surface sheet and a base material sheet, and curl. Sectional drawing which illustrates some layer structures of the sheet | seat for injection molding simultaneous painting of this invention. Sectional drawing which illustrates some layer structures of the sheet | seat for injection molding simultaneous painting of this invention. The conceptual diagram explaining an example of the injection molding simultaneous painting method. Sectional drawing which illustrates the molded article with a picture obtained by this invention. Explanatory drawing of the measuring method of curl.

  Embodiments of the present invention will be described below. 1 is an explanatory view conceptually showing the relationship between the thickness ratio of the topsheet and the base sheet and the degree of curling, and FIGS. 2 and 3 show the layer structure of the injection-molded simultaneous painting sheet of the present invention. Cross-sectional views illustrating some of them, FIG. 4 is a conceptual diagram illustrating an injection molding simultaneous painting method that is an application of the injection molding simultaneous painting sheet of the present invention, and FIG. 5 shows the injection molding simultaneous painting sheet of the present invention. Sectional drawing which illustrates the molded article with a picture obtained by using, FIG. 6 is explanatory drawing of the measuring method of curl.

[Thickness ratio of surface sheet and substrate sheet]
In the present invention, the thickness ratio between the transparent acrylic resin surface sheet and the polyolefin resin substrate sheet, that is, the ratio of the thickness of the surface sheet to the thickness of the substrate sheet, The “thickness” is 0.35 or less. FIG. 1 is a knowledge obtained as a result of the prototype experiment, and is a conceptual diagram conceptually showing the relationship between the thickness ratio of the top sheet and the base sheet and the degree of curling. As shown in FIG. When the ratio is 0.35, the degree of curling changes abruptly before and after the ratio, and when the thickness ratio is 0.35 or less, the curl becomes good enough that the sheet for simultaneous painting with injection molding can be used.

  This phenomenon is presumed that when the ratio of the surface sheet of the transparent acrylic resin to the thickness of the base sheet is large, it is likely to be affected by the size of the heat shrinkage of the surface sheet, and the curl will increase. It is. For this reason, if it is said specific thickness ratio, it will be thought that the influence of the magnitude | size of the heat shrinkage rate of the surface sheet which consists of a transparent acrylic resin can be reduced, and curl can be reduced reliably.

  The lower limit of the thickness ratio is of course not zero (a configuration without a surface sheet), but is subject to the limitation of the lower limit of the thickness of a transparent acrylic resin sheet that can be prepared in practice. Incidentally, the thickness of the surface sheet of the transparent acrylic resin is 30 μm or more, more preferably 50 μm or more from the viewpoint of weather resistance, surface wear resistance, and the like. Therefore, in order to use a sheet having a thickness of 35 μm as the top sheet, a sheet having a thickness of 100 μm or more may be used as the base sheet in order to make the thickness ratio 0.35 or less. Conversely, when a sheet having a thickness of 400 μm is used as the base sheet, a sheet having a thickness of 140 μm or less may be used as the top sheet.

[Layer structure of sheet for simultaneous injection molding]
Here, some of the layer structures of the injection-molded simultaneous painting sheet of the present invention are illustrated by the cross-sectional views of FIGS. 2 and 3.

  An injection-molded simultaneous painting sheet S illustrated in FIG. 2A is composed of a transparent acrylic resin surface sheet 1 as an outermost surface layer, a decoration layer 2, a primer layer 4, an adhesive layer 5, and a polyolefin resin. The base sheet 3 has a configuration in which the base sheets 3 are laminated in this order. As described above, the injection-molded simultaneous painting sheet of the present invention basically has a configuration in which the top sheet 1, the decorative layer 2, and the base sheet 3 are laminated, but if necessary, other layers ( In the figure, a primer layer 4 and an adhesive layer 5) may be provided between the layers. Moreover, the sheet S for injection molding simultaneous picture illustrated in FIG. 2 (B) has a configuration in which the adhesive layer 5 is omitted from the configuration of FIG. 2 (A), and is made of a transparent acrylic resin that becomes the outermost surface layer. A decorative sheet 2, a primer layer 4, and a base material sheet 3 made of a polyolefin resin are laminated on the top sheet 1 in this order.

  Further, like the injection-molded simultaneous painting sheet S illustrated in FIG. 3A, the base sheet 3 may be a multilayer. Incidentally, the sheet S for simultaneous injection molding with pictures in FIG. 3A is an example of the two-layer base sheet 3. The other layer structure is the same as FIG. 2 (B), and is composed of a top sheet 1, a decoration layer 2, a primer layer 4, a base sheet 3A on the front side, and a base sheet 3B on the back side. 3 is a laminated sheet. FIG. 3B is a diagram for simultaneous injection molding of a layer configuration example in which the base sheet 3 is laminated with the base sheet 3A and the base sheet 3B through the adhesive layer 6 in FIG. 3A. Sheet S.

  Next, each layer will be described in detail.

[Surface sheet]
The top sheet 1 is a transparent resin sheet made of a transparent acrylic resin. Examples of the transparent acrylic resin include acrylic resins such as polymethyl (meth) acrylate, polybutyl (meth) acrylate, methyl (meth) acrylate-butyl (meth) acrylate copolymer, methyl (meth) acrylate-styrene copolymer [ However, (meth) acrylate means acrylate or methacrylate] as a single substance or a mixture of two or more. In order to impart good scratch resistance to the top sheet, it is preferable to add a lubricant such as a hydrocarbon lubricant or a fatty acid lubricant as a lubricant to the transparent acrylic resin. However, if too much lubricant is added, the sheet slips in the mold during simultaneous injection molding, and wrinkles, distortion, etc. are likely to occur. Therefore, the lubricant is preferably added so that the dynamic friction coefficient of the top sheet becomes 0.2 to 0.9. In terms of addition amount, it is about 0.1 to 0.5% by weight. In addition, you may use a surface sheet as a transparent acrylic resin sheet | seat of a laminated body of two or more layers other than a single layer. Moreover, although transparent is normally non-colored transparent, it may be colored transparent by appropriately adding a known colorant as necessary. By using a transparent acrylic resin for the top sheet and using the decorative layer as a lower layer, it is possible to impart a high-quality design such as a feeling of painting and surface gloss due to the excellent transparency of the transparent acrylic resin. In addition, surface properties such as weather resistance and scratch resistance can be improved as compared with polyolefin resins and the like.

  The thickness of the top sheet is not particularly limited as long as the above-described thickness ratio condition is satisfied. The surface sheet is usually about 20 to 200 μm. However, as described above, the thickness of the top sheet is preferably 30 μm or more, more preferably 50 μm or more in terms of weather resistance, surface wear resistance, and the like.

[Decoration layer]
The decoration layer 2 is a layer that expresses, for example, a pattern or the like by printing or the like. There is no restriction | limiting in particular as a material of a decoration layer. What is necessary is just to be able to be laminated | stacked on the adjacent layers, such as a surface sheet and a base material sheet, with sufficient adhesion. The pattern by the decoration layer 2 is arbitrary, for example, wood grain, stone grain, cloth grain, grained grain, leather-drawn pattern, geometric pattern, character, symbol, whole surface solid, and the like.

  The decorative layer 2 is usually formed of printing ink or paint, and is formed by a known printing or coating method (when the coating method is a solid pattern). Usually, the decorative layer 2 is formed on the top sheet 1. Then, the surface sheet on which the decoration layer is formed is laminated with the base sheet 3 by a known laminating method such as a dry lamination method through the primer layer 4 or further the adhesive layer 5 as necessary. To make a sheet for simultaneous injection molding.

  The colorant used in the printing ink (or paint) may be a known dye or pigment, for example, inorganic pigments such as titanium white, carbon black, petal, yellow lead, cobalt blue, aniline black, phthalocyanine blue, isoindo. Organic pigments such as linone and quinacridone, metal pigments such as aluminum foil powder, pearlescent pigments such as titanium dioxide-coated mica, and other dyes are used.

  Moreover, what is necessary is just to use an appropriate thing from well-known resins, such as an acrylic resin, a vinyl chloride-vinyl acetate copolymer, and a urethane resin, as resin of the binder of the decoration layer 2 (or printing ink or paint).

  As the binder resin, a mixture of a vinyl chloride-vinyl acetate copolymer and an acrylic resin, or an acrylic urethane resin is used as a main component. This is a preferred embodiment in terms of sex. By the way, the combination of the mixture of vinyl chloride-vinyl acetate copolymer and acrylic resin, acrylic resin contributes to improved adhesion to the surface sheet, and vinyl chloride-vinyl acetate copolymer improves printability and moldability. Contribute. Moreover, acrylic urethane resin can satisfy those suitability by itself.

  As the vinyl chloride-vinyl acetate copolymer, those having a vinyl acetate content of about 5 to 20% by weight and an average degree of polymerization of about 350 to 900 are usually used. The vinyl chloride-vinyl acetate copolymer may be further copolymerized with a carboxylic acid such as maleic acid or fumaric acid, if necessary.

  Examples of the acrylic resin include acrylic resins such as polymethyl (meth) acrylate, polybutyl (meth) acrylate, methyl (meth) acrylate-butyl (meth) acrylate copolymer, methyl (meth) acrylate-styrene copolymer, Alternatively, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate, cyclohexyl (meth) acrylate, and the like, 2-hydroxyethyl (meth) acrylate, 2-hydroxy-3-phenoxy An acrylic resin such as an acrylic polyol obtained by copolymerizing a (meth) acrylic acid ester having a hydroxyl group in a molecule such as propyl (meth) acrylate is used alone or in combination of two or more. (Meth) acrylate means acrylate or methacrylate. The mixing ratio of the vinyl chloride-vinyl acetate copolymer and the acrylic resin is about vinyl chloride-vinyl acetate copolymer / acrylic resin = 1/9 to 9/1 (weight ratio).

  As the acrylic urethane resin, a two-component curable acrylic urethane resin or a thermoplastic acrylic urethane resin may be used.

  For example, a two-component curable urethane urethane resin is a urethane resin whose main component is acrylic polyol and whose crosslinking agent (curing agent) is isocyanate. Examples of the acrylic polyol include methyl (meth) acrylate-2hydroxyethyl (meth) acrylate copolymer, octyl (meth) acrylate-ethylhexyl (meth) acrylate-2 hydroxyethyl (meth) acrylate copolymer, methyl (meth) ) Acrylate-butyl (meth) acrylate-2hydroxyethyl (meth) acrylate-styrene copolymer or the like is used alone or in admixture of two or more. As the isocyanate, a polyvalent isocyanate having two or more isocyanate groups in the molecule is used. For example, aromatic isocyanate such as 2,4-tolylene diisocyanate, xylene diisocyanate, 4,4'-diphenylmethane diisocyanate, or 1,6-hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate, etc. Aliphatic (or alicyclic) isocyanates, or adducts or multimers of the above-mentioned various isocyanates can also be used. For example, there are tolylene diisocyanate adducts, tolylene diisocyanate trimers, and the like. The thermoplastic acrylic urethane resin is made of a linear polymer such as that obtained by urethane bonding of divalent acrylic polyol and divalent isocyanate.

  In addition, when using a mixture of a vinyl chloride-vinyl acetate copolymer and an acrylic resin, or an acrylic urethane resin as the main component of the binder resin, as a subcomponent resin, if necessary, Other resins than the resin to be used, for example, a thermoplastic polyester resin, a resin such as a thermoplastic resin or a urethane resin (other than an acrylic urethane resin) such as a two-component curable resin may be used in combination.

  The decorative layer is a functional layer such as a conductive layer in which a thin film layer of a metal such as chrome or aluminum, or a conductive powder such as silver powder is dispersed in a binder, in addition to a layer for decorative purposes such as a grain pattern. But it ’s okay.

[Base material sheet]
The base material sheet 3 is a layer that becomes the backmost layer of the injection-molded simultaneous painting sheet. By using a sheet made of a polyolefin-based resin for the base sheet, the injection-molded simultaneous painting sheet is made of a polyolefin-based resin. It becomes possible to laminate with good adhesion to the resin molded product. Of course, a sheet having a thickness that satisfies the above-described specific thickness ratio relationship with the surface sheet is used as the base sheet in that the curl of the sheet for simultaneous injection molding is reliably reduced.

  Examples of the polyolefin resin include high crystalline non-crystalline materials such as polyethylene (low density, medium density, or high density), polypropylene, polymethylpentene, polybutene, ethylene-propylene copolymer, propylene-butene copolymer, and the like. Elastomeric polyolefin resins or various olefinic thermoplastic elastomers are used. As the olefin-based thermoplastic elastomer, for example, the following can be used.

  (1) As described in Japanese Patent Publication No. 6-23278, (A) as a soft segment, the number average molecular weight Mn is 25,000 or more and the ratio Mw / Mn ≦ 7 of the weight average molecular weight Mw and the number average molecular weight Mn 10 to 90% by weight of atactic polypropylene soluble in boiling heptane, and (B) 90 to 10% by weight of isotactic polypropylene insoluble in boiling heptane having a melt index of 0.1 to 4 g / 10 min as a hard segment. Soft polypropylene made of a mixture of In particular, in order to improve the moldability and achieve both printability (registration accuracy), the mixing ratio of isotactic polypropylene and atactic polypropylene is the weight ratio of atactic polypropylene and the lower limit is 5% by weight or more. Is preferably 50% by weight or less, more preferably 40% by weight or less.

(2) A thermoplastic elastomer comprising an ethylene-propylene-butene copolymer resin. Here, as the butene, any of three structural isomers of 1-butene, 2-butene, and isobutylene can be used. As the copolymer, the following (i) to (iii) may be mentioned as preferred specific examples of the ethylene-propylene-butene copolymer which is a random copolymer and partially contains an amorphous portion.
(I) Those described in JP-A-9-1111055. This is a random copolymer of a terpolymer of ethylene, propylene and butene. The weight ratio of the monomer component is 90% by weight or more of propylene. The melt flow rate is preferably 1 to 50 g / 10 min at 230 ° C. and 2.16 kg. Then, 0.01 to 50 parts by weight of a transparent nucleating agent mainly composed of a phosphoric acid aryl ester compound and a fatty acid amide having 12 to 22 carbon atoms is added to 100 parts by weight of such a ternary random copolymer. 003 to 0.3 parts by weight are melt kneaded.
(Ii) Those described in JP-A-5-77371. This is a terpolymer of ethylene, propylene and 1-butene, and 20 to 100% by weight of amorphous polypropylene having a propylene component content of 50% by weight or more, and 80 to 0% by weight of crystalline polypropylene. % Addition.
(Iii) Those described in JP-A-7-316358. This is a terpolymer of ethylene, propylene, and 1-butene, and the content of propylene and / or 1-butene is 50 to 100% by weight of the low crystalline polymer. 0.5% by weight of an oil gelling agent such as N-acylamino acid amine salt or N-acylamino acid ester is added to a composition in which 80 to 0% by weight of crystalline polyolefin such as isotactic polypropylene is mixed. It will be.

  In addition, ethylene-propylene-butene copolymer resin may be used independently and may mix and use other polyolefin resin further as needed to said (i)-(iii).

  (3) As described in JP-B 53-21021, (A) an olefin polymer (crystalline polymer) such as polyethylene, polypropylene, polymethylpentene or the like is used as a hard segment, and (B) a partially crosslinked ethylene Monoolefin copolymer rubber such as propylene copolymer rubber and unsaturated ethylene-propylene-nonconjugated diene terpolymer rubber is used as a soft segment, and these are uniformly blended and mixed. In addition, it mixes in the ratio of monoolefin rubber / olefin polymer = 50 / 50-90 / 10 (weight ratio).

  (4) (B) Uncrosslinked monoolefin copolymer rubber (soft segment) and (A) Olefin copolymer (crystalline, hard segment) and crosslinked as described in JP-B-53-34210 An olefin-based elastomer that is mixed with an agent, heated, and partially dynamically crosslinked while applying shear stress. Note that (B) monoolefin rubber / (A) olefin copolymer = 60/40 to 80/20 (weight ratio).

  (5) As described in Japanese Examined Patent Publication No. 56-15741, etc. (A) Mixing and heating with peroxides such as isotactic polypropylene, propylene-ethylene copolymer, propylene-butene-1 copolymer, the molecular weight is reduced. Mixing and heating with peroxide-decomposable olefin polymer (hard segment) to increase fluidity and (B) peroxides such as ethylene-propylene copolymer rubber and ethylene-propylene-nonconjugated diene terpolymer rubber Peroxide-crosslinked monoolefin copolymer rubber (soft segment) that crosslinks to reduce fluidity, (C) Crosslinks with peroxides such as polyisobutylene, butyl rubber, etc. will not crosslink, and fluidity will remain unchanged. Peroxide non-crosslinked hydrocarbon rubber (soft segment and fluidity modifying component), and (D) para Fin, napthenic mineral oil-based softening agent for aromatic and the like, mixed with the city, olefin elastomer obtained by dynamically heat-treated in the presence of an organic peroxide. (A) is 90 to 40 parts by weight, (B) is 10 to 60 parts by weight, and (A) + (B) = 100 parts by weight, and (C) and / or (D) is 5 The blending ratio is ˜100 parts by weight.

  (6) An olefinic thermoplastic elastomer comprising an ethylene-styrene-butylene copolymer as described in JP-A-2-139232.

  (7) The olefinic thermoplastic elastomer according to the above (1) to (6), which has a hydroxyl group and / or a carboxyl group as a polar group. For example, an olefinic thermoplastic elastomer into which a hydroxyl group is introduced by graft polymerization of an ethylene-vinyl alcohol copolymer or the like and a carboxyl group is introduced by a copolymer of maleic acid, fumaric acid, itaconic acid or the like is used. Either one or both of these hydroxyl groups and carboxyl groups may be used together, and these polar groups (polar functional groups) have the effect of improving the adhesion with other layers such as a primer layer and an adhesive layer. .

  The type of polyolefin resin to be used may be appropriately selected depending on the resin on which the sheet for simultaneous injection molding is provided. For example, when the resin to be laminated is polypropylene, it is preferable to use polypropylene, and when it is polyethylene, it is preferable to use polyethylene. When polyethylene or polypropylene is employed, advantages such as availability of the base sheet, versatility, and low cost can be obtained. Moreover, when an olefinic thermoplastic elastomer is used, it is easy to bend and handling becomes easy. In addition, since the olefinic thermoplastic elastomer is composed of a hard segment made of a crystalline polyolefin resin and a soft segment made of a rubber (elastomer) component, the sheet of crystalline polyolefin resin (high density polyethylene, isotactic polypropylene, etc.) In this case, it is difficult to cause necking (locally concentrated sheet elongation is concentrated), which is advantageous in terms of formability.

  The base sheet may be either a stretched sheet or an unstretched sheet, but the unstretched sheet is preferable in terms of formability. The base sheet may be a sheet already formed by a known film-forming method such as a T-die extrusion method, but a laminated sheet in which a decorative layer, a primer layer, and the like are appropriately formed on a transparent acrylic resin surface sheet On the other hand, it may be laminated simultaneously with film formation as a sheet by a T-die extrusion method or the like. In the former case, lamination may be performed by a known lamination method such as dry lamination.

  The thickness of the base material sheet is about 80 μm to 2 mm, although it depends on the application, the relationship of the thickness ratio with the surface sheet, the required thickness of the entire sheet for simultaneous injection molding and painting. In addition, it is preferable that the total thickness of the entire sheet for injection-molded simultaneous painting is 200 μm or more from the viewpoint of ease of handling and the like. In particular, when performing off-line preforming, the total thickness is preferably 400 μm or more.

  Various additives such as a flame retardant, a lubricant, an antioxidant, an ultraviolet absorber, a light stabilizer, and a filler may be further added to the base sheet as necessary.

  For example, aluminum hydroxide, magnesium hydroxide, or the like is used as the flame retardant. As the ultraviolet absorber, benzotriazole, benzophenone, or the like is used. Further, as the light stabilizer, a hindered amine radical scavenger or the like is used. Examples of the filler include extender pigments such as mica, talc, calcium carbonate, barium sulfate, silica, alumina, and kaolinite.

  Further, by adding a colorant, it is possible to impart color concealment to the base sheet, conceal the color of the resin for laminating the sheets for simultaneous injection-molding, and adjust the base color of the decoration layer. As the colorant, a known colorant may be used as described in the decoration layer.

  In addition, as already outlined with reference to FIG. 3, the base sheet may have a multilayer structure such as two layers. In the case of two layers, two layers may be directly laminated by heat fusion as shown in FIG. 3A, or may be laminated via an adhesive layer 6 between layers as shown in FIG. . A known adhesive such as urethane resin may be used for the adhesive layer 6. Also. In order to form a multilayer structure such as two layers without interposing an adhesive layer between layers, for example, it can be laminated simultaneously with film formation by a co-extrusion method using a T die. In order to laminate through the adhesive layer, for example, lamination may be performed by a dry lamination method. In this case, if it demonstrates in FIG. 3 (B), in addition to laminating | stacking the base material sheet 3A and the base material sheet 3B and once making it the base material sheet 3, the surface sheet 1, the decoration layer 2, the primer layer 4, The base sheet 3B may be laminated on the decorative sheet (laminated sheet) on which the base sheet 3A is laminated. The decorative layer in the decorative sheet is formed by printing or the like on the surface sheet or the base sheet 3A on which the primer layer 4 has been formed.

  In addition, it is meaningful from the meaning which ensures the printing suitability to make a base material sheet into 2 layer structure etc. and multilayer structure. This is because when a decorative layer is printed on a base sheet as a continuous belt-like sheet, a sheet that is too thick, such as 500 μm, can only be printed on a single sheet. For this reason, after printing on this sheet as a sheet having a thickness (about 50 to 100 μm) capable of printing the base material sheet 3A on the front side, the base material sheet 3B on the back side is interposed, for example, with the adhesive layer 6 interposed therebetween. If it laminates | stacks by the dry lamination method, the required total thickness as the base material sheet 3 is securable. The decorative layer may be printed on the top sheet, but the base sheet is generally better in solvent resistance and the problem of sheet deterioration due to the solvent during printing is less likely to occur. is there. However, the base sheet generally has a problem of poor adhesion, and as illustrated in FIG. 3, the primer layer 4 made of urethane resin or the like is previously provided on the base sheet 3 and then the decoration layer 2 is provided. Can be solved.

  In the case of a two-layer base sheet, it is also effective for improving adhesion. For example, in the case of FIG. 3 (A), as the base material sheet 3, the base material sheet 3 </ b> A having a polar functional group in the molecule is arranged on the side in contact with the primer layer 4 to adhere the primer layer 4. The base material sheet 3B having no polar functional group in the molecule is arranged on the side in contact with the resin molded product to secure the total thickness of the base material sheet 3 necessary for simultaneous injection molding, and the increase in price is minimal. The configuration is limited to the limit. In order to impart a polar functional group to the polyolefin resin molecule, for example, an olefin monomer such as ethylene or propylene is used as an unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic acid or fumaric acid. To give a carboxyl group in the polymer molecule, or once the olefin monomer is copolymerized with vinyl acetate and then saponified to give a hydroxyl group in the polymer molecule. .

  Further, by forming the base sheet in a two-layer structure, for example, the base sheet 3B on the resin molded product side is a thickness necessary for providing colored concealment, moldability, and simultaneous injection molding as a colored concealment layer. The front side base sheet 3A can be used as a layer that ensures adhesion with the primer layer and the adhesive layer without adding a colorant or the like, thereby minimizing the cost. And a plurality of required physical properties can be satisfied. And by the said concealment property, the color tone expression by painting can be stabilized irrespective of the color of injection molding resin.

[Primer layer]
The primer layer 4 may be provided in order to improve interlayer adhesion by interposing between layers as necessary. The primer layer 4 illustrated in FIG. 3 is a case between the decorative layer 2 and the base sheet 3. A known primer agent or the like may be appropriately selected and used as the primer layer 4, and the resin is not particularly limited. Especially, it is preferable to use a urethane resin as a main component resin. By using a urethane resin for the primer layer 4, interlayer adhesion can be improved.

  As the urethane resin, a two-component curable urethane resin, a one-component moisture curable urethane resin, a thermoplastic urethane resin, or the like may be used.

  For example, a two-component curable urethane resin is a urethane resin having a polyol as a main component and an isocyanate as a crosslinking agent (curing agent). As the polyol, one having two or more hydroxyl groups in the molecule, for example, polyethylene glycol, polypropylene glycol, acrylic polyol, polyester polyol, polyether polyol, polycarbonate polyol, polyurethane polyol and the like are used. As the isocyanate, a polyvalent isocyanate having two or more isocyanate groups in the molecule is used. For example, aromatic isocyanate such as 2,4-tolylene diisocyanate, xylene diisocyanate, 4,4'-diphenylmethane diisocyanate, or 1,6-hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate, etc. Aliphatic (or alicyclic) isocyanates, or adducts or multimers of the above-mentioned various isocyanates can also be used. For example, there are tolylene diisocyanate adducts, tolylene diisocyanate trimers, and the like.

  The one-component moisture-curable urethane resin is a composition containing a prepolymer having an isocyanate group at the molecular end as an essential component. The prepolymer is usually a polyisocyanate prepolymer having one or more isocyanate groups at both molecular ends, and is in a state of a solid thermoplastic resin at room temperature. Isocyanate groups react with each other by moisture in the air to cause chain extension reaction. As a result, a reaction product having a urea bond in the molecular chain is generated, and the isocyanate group at the molecular end further reacts with this urea bond. , Biuret bond is caused to branch, causing a crosslinking reaction. The skeleton structure of the molecular chain of the prepolymer having an isocyanate group at the molecular terminal is arbitrary, and specific examples include a polyurethane skeleton having a urethane bond, a polyester skeleton having an ester bond, and a polybutadiene skeleton. One or more of these skeleton structures are employed as appropriate. In addition, when there is a urethane bond in the molecular chain, the terminal isocyanate group is contrary to this urethane bond to form an allophanate bond, and this allophanate bond also causes a crosslinking reaction.

  The thermoplastic urethane resin is composed of a linear polymer obtained by urethane-bonding a divalent polyol and a divalent isocyanate.

  In addition, what is necessary is just to form a primer layer by the well-known printing method or the coating method by using the ink or coating liquid using the above-mentioned specific resin as a primer agent.

[Adhesive layer]
In addition, the adhesive layer 5 is appropriately interposed between the primer layer 4 and the base sheet 3 with respect to the primer layer 4 provided between the decoration layer 2 and the base sheet 3 so as to adhere them. You may provide as a layer to make. There is no restriction | limiting in particular as resin of an adhesive bond layer, What is necessary is just to use well-known various thermoplastic resins, thermosetting resins, etc. suitably. However, when a urethane resin is used for the primer layer 4 and the binder resin of the decoration layer is a mixture of vinyl chloride-vinyl acetate copolymer and an acrylic resin or an acrylic urethane resin is used as a main component resin, When this adhesive layer is composed mainly of chlorinated polypropylene, a favorable result can be obtained for improving the interlayer adhesion between the primer layer 4 and the substrate sheet 3. In addition, what is necessary is just to form an adhesive bond layer with the well-known printing method or the coating method with the ink or coating liquid using the above-mentioned resin. Although there is no restriction | limiting in particular in the thickness of an adhesive bond layer, For example, it is about 5-20 micrometers.

  The reason why the adhesive layer 5 is also provided and the two layers of the primer layer 4 and the adhesive layer 5 are interposed between the decorative layer 2 and the base sheet 3 is mainly as follows. There are two.

  (1) For the purpose of easy adhesion treatment of the substrate sheet; that is, in this case, the adhesive layer 5 has a single-layer configuration of the substrate sheet 3 described in detail later, and from the viewpoint of cost, In the case of a resin sheet in which a polar functional group contributing to improvement in adhesion is not introduced, the adhesive property between the primer layer 4 and the base sheet 3 can be used as a resin layer in place of the base sheet with the polar functional group introduced. Can be strengthened. In this case, the adhesive layer 5 is preferably formed on the surface of the base sheet 3 in terms of improving the adhesive strength. The adhesive layer 5 is formed by a known coating method such as gravure roll coating or melt extrusion coating. Needless to say, an adhesive layer may be used even when a polyolefin-based resin having a polar functional group is used for the base sheet 3.

  (2) When aiming at off-line of the printing / coating process on the topsheet 1 and the lamination process with the base sheet 3; that is, in this case, the decorative layer 2 and the primer layer 4 on the topsheet 1 Until the film is formed, the processing is continuously completed in-line by a conventional printing / coating machine. On the other hand, since the lamination (laminate) of the base sheet 3 is performed by a laminating machine different from the printing / coating machine, the management of the actual production process includes the process of the printing / coating machine. In many cases, it is more efficient to carry out the process that each machine is responsible for when the machines are vacant independently and independently from the laminating machine process, without being simultaneously continuous. In this case, the time from when the primer layer 4 is formed on the top sheet 1 using the decorative layer 2 and the one-component or two-component curable urethane resin until the substrate sheet 3 is laminated is It may be longer than the curing reaction completion time (pot life) of the urethane resin used for the layer 4. If the pot life is exceeded, the primer layer no longer loses adhesion. Therefore, after the primer layer 4 is formed, the pot life is infinite by continuously forming the adhesive layer 5 using a thermoplastic resin on the primer layer 4 within the in-line continuous and less than the pot life. The adhesive force with the base material sheet 3 is unlimited in time by the adhesive layer 5 of a thermoplastic resin such as chlorinated polypropylene. In that case, it is rather possible to use chlorinated polypropylene for the primer layer 4 and omit the addition of the adhesive layer 5, but the conclusion is impossible. This is because the mixture of the acrylic resin and vinyl chloride-vinyl acetate copolymer or the acrylic urethane resin constituting the decorative layer 2 and the chlorinated polypropylene have insufficient adhesion. The term “adhesiveness” as used herein means that even if the initial adhesive strength is sufficient, the adhesive strength after environmental resistance tests such as heat resistance test and weather resistance test will drop, and it will easily peel off between layers. Say that. Therefore, in order to make the printing / coating process and the lamination process off-line, the surface sheet 1 in which the decoration layer 2, the primer layer 4 and the thermoplastic resin adhesive layer 5 are formed in-line appropriately, A method of laminating the base sheet 3 by hot bonding with the adhesive layer 5 by the hot press is optimal. In this case, the adhesive layer 5 is formed on the surface side of the primer layer 4 of the surface sheet 1 by a known printing method or coating method such as gravure roll coating, using an ink or a coating liquid using the specific resin. It is formed continuously with the decoration layer 2 and the primer layer 4.

[Injection molding simultaneous painting method]
Here, the injection molding simultaneous painting method, which is a use application of the above-described injection molding simultaneous painting sheet of the present invention, will be described once. The injection molding simultaneous painting method here is a laminating form, and as described in Japanese Patent Publication No. 50-19132, Japanese Patent Publication No. 43-27488, etc., a sheet for injection molding simultaneous painting is used as a pair of molds. After being placed between the two molds, both molds are clamped, the resin in a fluid state is injected into the cavities formed by both molds, solidified by solidification, and simultaneously with injection molding on the surface of the resin molding This is a method of painting resin sheets by laminating picture sheets.

  Basically, various methods known in the art can be used as the method of simultaneous injection molding. For example, a form in which the injection molding simultaneous painting sheet is preformed or not. Moreover, the form which pre-heats the sheet | seat for injection molding simultaneous painting, and the form which does not perform. In addition, the sheet for simultaneous injection-molding is usually preheated at the time of preliminary molding. However, in the case of the sheet for simultaneous injection-molded painting of the present invention, among these, the form in which the preforming with an increased handling operation is performed off-line is preferable in that the curl reduction performance of the sheet is fully exhibited. One of the forms.

  Of course, it is preferable to perform preliminary molding when the drawing of the sheet for simultaneous injection molding is large. On the other hand, when the injection molding simultaneous painting sheet has a small aperture, the sheet may be molded with the resin pressure of the injected resin in a fluid state. At this time, if the aperture is shallow, the injection-molded simultaneous painting sheet may be molded with the resin pressure of the resin in a fluid state filled in the mold simultaneously with the resin injection without pre-molding. Even when a sheet for simultaneous injection molding is molded with resin pressure, the heat of the injection resin may be used without preheating the sheet. In addition, the preliminary molding of the sheet for simultaneous injection molding is usually performed by using the injection mold as a vacuum mold, but before supplying the sheet between the molds, a separate vacuum mold is used outside the mold. It may be preformed such that the sheet is vacuum formed. In addition, the pre-molding is preferable in that an injection mold is also used as a vacuum mold so that lamination can be performed efficiently and accurately. However, in the case where the preformed injection-molded simultaneous painting sheet is manufactured in advance at a different location, the pre-molding is preferably in the form of off-line pre-molding performed by a mold different from the injection mold. In the description of the present invention, vacuum forming includes vacuum / pressure forming.

  Incidentally, FIG. 4 is a conceptual diagram illustrating the injection molding simultaneous painting method in one form. In the form shown in FIG. 4, the injection mold is a vacuum mold that is another mold, and after the injection molding simultaneous painting sheet is heated and softened and pre-molded, the molded injection molding simultaneous painting sheet is injection molded. After insertion into the mold, the mold is clamped and the resin is injected. Then, next, the injection molding simultaneous painting method of this embodiment will be further described with reference to FIG.

  First, as shown in FIG. 4A, using a vacuum forming die Mv having suction means such as suction holes 31 on the die surface, the injection-molded simultaneous painting sheet softened by heating with the heater 32 is preformed by vacuum forming. . The vacuum forming die Mv is made of a metal such as iron or aluminum, or ceramics. Further, the injection-molded simultaneous painting sheet S is appropriately fixed by a frame-shaped sheet clamp 33. At this time, the base sheet side of the injection-molded simultaneous painting sheet is oriented to the injection resin side (upward in the drawing). The heat softening by the heater 32 is, for example, non-contact radiation heating, but may be conductive heating by contact. In the preliminary molding, vacuum injection is performed by sucking from the suction holes, and the injection-molded simultaneous painting sheet is vacuum-formed along the mold surface of the vacuum-forming mold Mv. Note that the vacuum forming may be vacuum / pressure forming using pressure air together, and includes this.

  Next, the preformed injection-molded simultaneous painting sheet S is supplied between a pair of injection molds Ma and Mb as shown in FIG. Here, the injection mold Ma has a runner and a gate that communicate with the injection nozzle, and the injection mold Mb has the same or substantially the same cavity surface as that of the preforming mold Mv. It has a shape and becomes a mold for fixing a preformed injection-molded simultaneous painting sheet. These molds are made of metal such as iron or ceramics. In the mold open state, the injection molding simultaneous painting sheet S is supplied between the molds Ma and Mb, and the injection molding simultaneous painting sheet S is fixed to the mold Mb by pressing it with a frame-shaped sheet clamp 42. In this case, of course, the base sheet side of the injection-molded simultaneous painting sheet is the injection resin side on the right side of the drawing. Next, both molds are clamped as shown in FIG. 4C, and a resin formed in a fluid state such as a heat-melted state is filled in a cavity formed by both molds. If there is an unnecessary portion of the sheet for simultaneous injection-molding, if it is appropriately trimmed, a molded product with a picture can be obtained.

[Injection molding resin]
In addition, in the injection molding simultaneous painting method, as a resin which is injection molded into a resin molded product, basically known ones in the injection molding simultaneous painting method can be used, and there is no particular limitation. It is selected according to the required physical properties and cost. However, since the injection-molded simultaneous painting sheet of the present invention is configured to have good adhesion to the polyolefin-based resin, a polyolefin-based resin is preferable. Examples of polyolefin resins include high crystalline non-elastomeric polyolefin resins such as polyethylene, polypropylene, polybutene, polymethylpentene, ethylene-propylene copolymer, propylene-butene copolymer, or various olefinic thermoplastics. An elastomer is used.

  The injection-molded simultaneous painting sheet of the present invention is configured so as to have good adhesion with these polyolefin resins. However, when it is necessary to further improve the adhesion, Propylene rubber should be added. The ethylene propylene rubber is a rubber (EPR) made of an ethylene-propylene copolymer, and is an amorphous random copolymer. In addition to the pure ethylene-propylene copolymer, ethylene-propylene-diene terpolymer (EPDM) can be used as the ethylene-propylene rubber. The ethylene propylene rubber is preferably added in an amount of 1 to 40 parts by weight with respect to 100 parts by weight of the polyolefin resin from the viewpoint of improving adhesion and maintaining rigidity.

  Note that as the injection molding resin, a resin colored by adding a colorant may be used as appropriate according to the application. As the colorant, a known colorant as described in the decoration layer can be used. In addition, the injection molding resin appropriately contains various known additives such as inorganic powders such as silica, alumina, calcium carbonate, and aluminum hydroxide, fillers such as glass fibers, stabilizers, and lubricants as necessary. .

[Molded product with picture]
By laminating the injection-molded simultaneous painting sheet of the present invention on a resin molded product, a molded product P as illustrated conceptually in the cross-sectional view of FIG. 5 is obtained. That is, it is a molded article having a structure in which the above-described sheet S for simultaneous injection molding of the present invention is laminated on the surface of the resin molded product 7. As the resin of the resin molding 7, a polyolefin resin is suitable. Of course, the injection-molded simultaneous painting sheet S is laminated so that the base sheet is in contact with the resin molded product. The polyolefin resin used for the resin molded product is a resin as described in the injection molding resin. In order to laminate the injection molding simultaneous painting sheet S on the surface of the resin molded product 7, the above-described injection molding simultaneous painting method is suitable. A picture-molded product in which a sheet for injection-molded simultaneous painting is laminated on a resin-molded product made of polyolefin resin is a molded product with excellent adhesion between the sheet for simultaneous painting with injection-molding and the resin-molded product, and excellent surface transparency. It becomes.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

  A sheet S for simultaneous injection molding with a structure as shown in FIG. 2A was produced as follows. An uncolored polymethyl methacrylate (PMMA) sheet (thickness: 0.125 mm) is used as a transparent acrylic resin topsheet 1, and on one side, a binder resin is a pair of a vinyl chloride-vinyl acetate copolymer and an acrylic resin. A 1-weight ratio mixture is used to print a colored ink using a colorant mainly composed of a petiole to form a grain-patterned decorative layer 2, and further two liquids consisting of acrylic polyol and 1,6-hexamethylene diisocyanate A primer ink mainly composed of a curable urethane resin was printed on the entire surface to form the primer layer 4 with a thickness of 2 μm to obtain a printed sheet. Next, on one side of the base material sheet 3 (thickness 0.4 mm) made of opaque polypropylene colored yellowish brown by adding a colorant mainly composed of petal, carbon black, chrome lead and titanium white. The adhesive layer 5 having a thickness of 4 μm is formed by applying an adhesive mainly composed of chlorinated polypropylene, and then the adhesive layer 5 and the uncured primer layer 4 of the printed sheet are in contact with each other. In this manner, the base sheet 3 was laminated on the above printed sheet by a dry lamination method to obtain an injection-molded simultaneous painting sheet S of the present invention. Incidentally, the thickness ratio between the top sheet and the base sheet, the top sheet thickness / the base sheet thickness is 0.125 / 0.40 = 0.31. The contents are shown in Table 1 together with other examples and comparative examples.

  In Example 1, the thickness of the top sheet was changed to 0.075 mm, and the thickness of the base sheet was 0.38 mm (however, the front base sheet having a thickness of 0.08 mm and the back base sheet having a thickness of 0.30 mm) A sheet for simultaneous injection molding was obtained in the same manner as in Example 1 except that the base sheet was changed into a two-layer laminate by dry lamination via an adhesive layer of a two-component curable urethane resin. . The thickness ratio is 0.20.

  In addition, the said base material sheet uses the sheet | seat which consists of a non-colored transparent polypropylene which introduce | transduced the carboxyl group into the molecule | numerator by graft copolymerization of maleic acid for the front side base material sheet of thickness 0.08mm, and thickness 0.30mm The back side base material sheet is a sheet made of an opaque polypropylene colored with a colorant as in Example 1, and a two-component curable urethane resin consisting of acrylic polyol and 1,6-hexamethylene diisocyanate as a main component. A sheet laminated by a dry lamination method with an adhesive layer of the adhesive to be used in between was used.

  In Example 1, the thickness of the surface sheet was changed to 0.050 mm, and the base sheet was injection molded in the same manner as in Example 1 except that a sheet having the same thickness of 0.38 mm as in Example 2 was used. A sheet for simultaneous painting was obtained. The thickness ratio is 0.13.

  In Example 1, except that the base material sheet was changed to the base material sheet used in Example 2, a sheet for simultaneous injection molding was obtained in the same manner as in Example 1. The thickness ratio is 0.33.

[Comparative Example 1]
In Example 1, except that the thickness of the base material sheet was changed to 0.20 mm, a sheet for simultaneous injection molding and painting was obtained in the same manner as Example 1. The thickness ratio is 0.63.

[Comparative Example 2]
In Example 1, except that the thickness of the base material sheet was changed to 0.30 mm, an injection-molded simultaneous painting sheet was obtained in the same manner as in Example 1. The thickness ratio is 0.42.

[Performance evaluation]
The evaluation of curl was made by cutting each of the injection-molded simultaneous painting sheets of the above examples and comparative examples into squares of 120 mm in length and width, leaving them in an oven at 160 ° C. for 1 minute, taking them out, and cooling the sheet temperature to 20 ° C. Then, as shown in FIG. 6, the sheet S for simultaneous injection molding was placed on the horizontal plane E, and the (maximum) height H from the horizontal plane of the curved sheet was measured to evaluate the degree of curling. When the (maximum) height was 20 mm or less, it was judged as good, and when it exceeded 20 mm, it was judged as bad. As a result, as shown in Table 1, each of the comparative examples having a thickness ratio exceeding 0.35 had a curl degree of 40 mm or more and was poor and strong, but in each example having a thickness ratio of 0.35 or less, The curl degree was 5 to 18 mm, and the curl was good and the curl was weak. In addition, when the thickness ratio was around 0.35, the difference in the degree of curling was different by 20 mm or more, and a critical effect (thickness ratio ≦ 0.35 significance) was recognized with a thickness ratio = 0.35.

  Next, simultaneous injection painting by off-run preforming as described in the conceptual diagram of FIG. 4 was performed to evaluate the presence or absence of defects during handling due to curling. As the injection molding resin, a polypropylene resin to which 10% by weight of ethylene-propylene copolymer rubber was added was used, and an injection molding simultaneous painting sheet S was laminated on the resin molding 7 as shown in FIG. A molded article P with a picture was produced. As a result, in each example, the handling and positioning accuracy when the injection-molded simultaneous painting sheet after the pre-molding was set in the injection mold were also good. In addition, a picture-molded article is obtained which is painted with a wood grain pattern and has good transparency and has a sense of design full of luxury. However, in each comparative example, the curl is large, and the curl is generated on the injection-molded sheet with pre-molding, the handling is not performed smoothly when set in the injection mold, and the positioning accuracy to the injection mold For this reason, some of the molded articles with paintings had defects in the appearance due to the wrinkles of the sheet for simultaneous injection molding on the surface.

DESCRIPTION OF SYMBOLS 1 Surface sheet 2 Decoration layer 3 Base material sheet 3A (Front side) Base material sheet 3B (Back side) Base material sheet 4 Primer layer 5 Adhesive layer 6 Adhesive layer 7 Resin molding 31 Suction hole 32 Heater 33 Sheet clamp E Horizontal surface H Curl height Ma Injection mold (male)
Mb injection mold (female)
Mv Vacuum Mold P Molded Product S Sheet for Injection Molding Simultaneous Painting

Claims (2)

In a laminate type injection-molded simultaneous painting sheet, at least as a surface sheet to be an outermost surface layer, a decorative sheet made of a polymethyl methacrylate (excluding one containing a fluorine-based resin) sheet having a decorative layer formed on one surface; The base sheet made of polyolefin resin is laminated on the decorative layer surface of the decorative sheet, and the total thickness of the top sheet and the base sheet is 400 μm or more, and the thickness ratio between the top sheet and the base sheet However, the surface sheet thickness / substrate sheet thickness ≦ 0.35, and the thickness of the surface sheet is 30 μm or more, and a sheet for injection molding simultaneous painting that can be preformed in another mold . The sheet for simultaneous injection molding and painting according to claim 1, wherein the base sheet has a multilayer structure.

Images