JP2000043087A - Injection molding in-mold decorating sheet, injection molding in-mold decorating method, and molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the molding properties and the adhesion of a in-mold decorating sheet for moldings of polyolefin resin when a in-mold decoration is to be performed by lamination or transfer, in an injection molding in-mold decoration method. SOLUTION: A decorating sheet S consisting of at least a base sheet 1 and an adhesive sheet 2 is formed of the base sheet 1 which is a thermoplastic resin sheet cut to the width of 10 mm with a stress value, when the base sheet 1 is pulled at a rate of 30%/sec. under 50 deg.C environments, indicating 0.6 kg or more after a yielding point in case the yielding point exists and 0.6 kg or more after 10% elongation in the case the yielding point does not exist. Further the adhesive layer 2 is formed of a chlorinated polyolefin resin with 90-100 deg.C softening point. A decorative layer 3 or the like may be formed in addition to the adhesive layer 2. When the sheet S is used for transfer, the adhesive layer 2 and the decorative layer 3 or the like become the transfer layer 2. The injection molding in-mold decoration method is performed using this decorating sheet to obtain moldings.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminate type or transfer type painting sheet used in a simultaneous injection molding painting method, a method of simultaneous injection molding painting using the sheet, and a molded product. In particular, the present invention relates to a painting sheet having excellent moldability, capable of performing deep drawing, and having excellent adhesion to a polyolefin-based resin, a method of simultaneous painting by injection molding using the sheet, and a molded article.

[0002]

2. Description of the Related Art Conventionally, molded articles obtained by painting the surface of a resin molded article by a simultaneous painting method for injection molding have been used for various purposes. The injection molding simultaneous painting method is an excellent decoration method in which painting can be performed even when the painting surface is a three-dimensional uneven surface by forming a painting sheet using, for example, an injection mold. Therefore, in the case where the unevenness of the painting surface is deep, a sheet having formability capable of deep drawing is used as the painting sheet. For example, in Japanese Patent No. 2690258, as a painting sheet used as a transfer sheet or a laminate sheet having good moldability, the sheet is formed of a material having a yield point, and is cut at a temperature of 50 ° C. Discloses a sheet for simultaneous painting with injection molding having a stress value of 0.6 kg or more after the yield point when the film is pulled at a rate of 30% / sec under the environment described above.

[0003] However, even in the simultaneous injection molding painting method, when obtaining a painted molded product, an injection molding resin generally used is an acrylic resin, an ABS resin, a polycarbonate resin, or a polymer blend thereof. Is the main resin. However, when obtaining a molded product in which the surface of a resin molded product made of an inexpensive polyolefin resin is painted, the resin has poor adhesion. No) After the resin molded product is manufactured by injection molding or the like, the surface of the resin molded product is painted and decorated, or subjected to a base treatment such as a primer treatment and then painted by a hydraulic transfer method or the like. In most cases, it is a desired molded product.

[0004]

However, the sheet for painting as disclosed in the above-mentioned publication has good moldability and can be deep-drawn, but uses an inexpensive polyolefin resin such as a polypropylene resin as an injection resin. When used, sufficient adhesion was not obtained. Therefore, in the case of a molded article of a polyolefin resin, if the painted surface is an irregular surface that can be a deep drawing of a painting sheet, it has been decorated by painting or hydraulic transfer method as described above. However, painting cannot make complicated, delicate, or highly designed designs. Further, in the hydraulic transfer method, in addition to the pattern flowing and being easily distorted, the number of steps such as a base treatment and the removal of a water-swellable sheet was increased, resulting in an increase in cost.

[0005] Therefore, an object of the present invention is to provide a painting sheet which can be painted simultaneously with the molding of a resin molded article and which is used in an injection molding simultaneous painting method which is efficient in the process, and which is particularly excellent in moldability and deep. An object of the present invention is to provide a sheet for painting that can be drawn and has excellent adhesion to a polyolefin-based resin. Another object of the present invention is to provide a simultaneous painting method for injection molding and a molded product using such a painting sheet.

[0006]

Therefore, in order to solve the above problems, in the sheet for simultaneous painting with injection molding of the present invention, at least a base sheet and an outermost layer are laminated on the resin molded product side of the base sheet. In the painting sheet used in the simultaneous molding method for injection molding, which comprises an adhesive layer to be formed, the base sheet cut at a speed of 30% / sec in an environment of 50 ° C. A thermoplastic resin sheet having a stress value of 0.6 kg or more after a yield point at the time of pulling, or a base sheet cut to a width of 10 mm without a yield point at an environment of 50 ° C. at a rate of 30% / sec. 1 when pulling
It is made of a thermoplastic resin sheet having a stress value of 0.6 kg or more after 0% elongation, and the adhesive layer has a softening point of 90 to 100 ° C.
Of a chlorinated polyolefin resin. As a result, a sheet for painting having excellent moldability capable of deep drawing and excellent adhesion to inexpensive polyolefin-based resins is obtained.

In addition, the method of simultaneous painting by injection molding of the present invention
After inserting the above-described sheet for simultaneous injection molding and painting between a pair of molds, both molds are clamped, and a cavity formed by both molds is filled with a resin in a fluid state and solidified, and molding is performed. At the same time, the sheet for simultaneous painting with injection molding was brought into close contact with and laminated on the surface of the resin molded product, and then both molds were opened. In the case of laminating, all layers of the sheet for simultaneous painting with injection molding were directly laminated on the resin molded product. As a molded product, in the case of transfer, at least a decorative layer between the substrate sheet and the adhesive layer, of the sheet for simultaneous painting with injection molding having a transfer layer together with the adhesive layer,
Only the base sheet was peeled off, so that a molded article in which the transfer layer including the adhesive layer was laminated on the resin molded article. as a result,
Painting can be performed even if the painting sheet has a deep drawing surface, and even if the resin molded product is an inexpensive polyolefin resin, painting can be performed with good adhesion.

Further, the molded article of the present invention is characterized in that all the layers of the sheet for simultaneous painting with injection molding are laminated on the surface of a resin molded article made of a polyolefin resin by an adhesive layer. did. As a result, even if the painted surface of the inexpensive polyolefin-based resin molded product has an uneven surface such as a deep drawing, the laminated molded sheet has good adhesion to the painted sheet. .

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view illustrating some examples of the embodiment of the sheet for simultaneous painting with injection molding of the present invention, FIG. 2 is a conceptual diagram for explaining the simultaneous painting method for injection molding of the present invention, and FIG. FIG. 4 is a cross-sectional view illustrating a molded article of FIG.
FIG. 3 is a cross-sectional view illustrating another embodiment of the sheet for simultaneous painting with injection molding of the present invention.

[Sheet for simultaneous painting with injection molding] The sheet for simultaneous painting with injection molding of the present invention is roughly classified into laminating
Transfer sheet and transfer sheet. In the case of the laminate sheet, the whole of the painting sheet remains laminated on the resin molded product. In the transfer sheet, after the painting sheet is laminated on the resin molded product, the base sheet is peeled off, and only a transfer layer including a decorative layer and the like in addition to the adhesive layer is finally laminated on the resin molded product. You. The sheet S for simultaneous painting with injection molding of the present invention illustrated in FIG. 1 (A) is a laminate sheet, and comprises a base sheet 1 and an adhesive layer 2 in FIG. The sheet S for simultaneous painting with injection molding of the present invention illustrated in FIG. 1 (B) is a transfer sheet, in which a decorative layer 3 is provided between the base sheet 1 and the adhesive layer 2. And
The adhesive layer 2 and the decoration layer 3 become the transfer layer 4.

(Base Sheet) In the present invention, the base sheet 1 having a yield point and cut to a width of 10 mm in the present invention is produced at a rate of 30% / sec in an environment of 50 ° C. Thermoplastic resin sheet whose stress value after the yield point at the time of pulling is 0.6 kg or more, no yield point, and 10 mm
The substrate sheet cut into a width of 30% /
The stress value after 10% elongation when pulled at a speed of 0.2 seconds is 0.
Any of thermoplastic resin sheets weighing 6 kg or more is used. By defining such physical properties, it is possible to impart excellent moldability capable of deep drawing to the sheet for simultaneous painting with injection molding. Because the other layers such as the adhesive layer and the decorative layer are considerably thinner than the base sheet in the total thickness of the sheet for simultaneous injection molding and painting, the formability of the entire sheet for simultaneous injection molding and painting is not sufficient. This is because it is governed by the base sheet. Basically, the lower the stress value is, the lower the sheet is, the easier it is to stretch and it becomes easy to follow the surface unevenness that becomes deep drawing, but the sheet for simultaneous painting with injection molding usually comes in contact with the heated and melted injection resin, so the It is also necessary to have heat resistance so as not to cause breakage or wrinkles due to heat or shearing force. For this purpose, the above stress value is preferably set to 0.6 kg or more. When the weight is less than 0.6 kg, the sheet for simultaneous painting with injection molding is excessively stretched particularly in the vicinity of a gate portion which is easily subjected to heat and shearing force, so that the sheet is liable to bite into the resin molded product. However, if the stress value is too large, the suitability for molding into a mold is reduced. The upper limit of the stress value varies depending on the drawing ratio of the mold, the drawing shape, the resin injection conditions, and the like, and is appropriately adjusted according to the situation.

The stress value referred to here is not a force per unit cross-sectional area, but a width of 10 mm width, and a thickness is a tension of a test piece of a thickness of a substrate sheet actually used. means. The reason is that the problem in the present invention is, to the last, how much resistance the substrate sheet of the thickness actually used exhibits to displacement and heat applied at the time of preforming or injection molding. Therefore, the thickness is the actual base sheet thickness. In addition, the width varies widely for each shape and size of the molded product, and cannot be compared under the same conditions.
Use the same width. It happens that the unified width is 10 in the present invention.
mm. The reason why the measurement condition is set to 50 ° C. is that the stress value measured under the condition at 50 ° C. has a correlation with the behavior of the base sheet during actual injection molding or preforming. .

In addition, in order to obtain good moldability particularly during preforming, in addition to the above-mentioned stress value, the base sheet may have a thickness of 10 mm.
200% at a speed of 7% / sec.
Sheets having a value when stretched to 200% (200% modulus value) and having a value at 100 ° C. to 120 ° C. of 0.3 kg or less are preferred. That is, there is a correlation between the stress value and the numerical range of the 200% modulus value, the excessive elongation and deformation of the painting sheet during injection molding, and the quality of the formability of the painting sheet during preliminary molding. By using the painting sheet having the physical property values as described above, it is possible to implement an injection-molding simultaneous painting method capable of providing good painting.

The thermoplastic resin is not particularly limited as long as it exhibits the above physical properties. For example, acrylic resins such as polymethyl (meth) acrylate, polybutyl (meth) acrylate, methyl (meth) acrylate-butyl (meth) acrylate copolymer, methyl (meth) acrylate-styrene copolymer [provided that
(Meth) acrylate means acrylate or methacrylate], polyolefin resins such as polyethylene, polypropylene, polymethylpentene, polybutene, ethylene-propylene copolymer, ethylene-propylene-butene copolymer, and olefin-based thermoplastic elastomer. And polyester resins such as polybutylene terephthalate, vinyl chloride resins, polystyrene resins, ABS resins (acrylonitrile-butadiene-styrene copolymer), polycarbonate resins, polyamide resins and the like. As the base sheet, a single layer or a laminate of two or more layers of these resin sheets (films) is used. In addition, in the thermoplastic resin sheet, various additives such as a plasticizer and a stabilizer,
It may be added for adjusting physical properties.

Here, the design guidelines for the stress value and the 200% modulus value will be described. In a base sheet having a yield value,
As a method for giving a stress value and a 200% modulus value after a desired yield point, a known method for adjusting mechanical and thermal properties of a resin may be applied.

For example, taking the case of a vinyl chloride resin as an example, the degree of polymerization, the amount (and type) of plasticizer, and / or the copolymerization (with vinyl acetate, etc.) are adjusted. As shown in Table 1, in general, when the amount of plasticizer is increased, when the degree of polymerization is decreased, and when the copolymerization ratio of monomers other than vinyl chloride is increased, the above 200% modulus value decreases, and the yield point Subsequent stress values decrease. Conversely, when the amount of plasticizer is reduced, when the degree of polymerization is increased, and when the copolymerization ratio of monomers other than vinyl chloride is reduced, the above 200% modulus increases, and the stress value after the yield point increases. Increases. However, the plasticity also depends on the type of plasticizer, and in general, dioctyl phthalate tends to show a yield value more clearly than tricresyl phosphate, and the above value increases. Then, if the plasticizer is completely non-plastic or the amount of the plasticizer is extremely small, there is no yield value.

[0017]

[Table 1]

In the case of polyethylene resin, as shown in Table 2, when a (low crystallinity) high-pressure polyethylene is used, the above 200% modulus value decreases, and the stress value after the yield point decreases. When (high crystallinity) low-pressure polyethylene is used, the 200% modulus increases, and the stress after the yield point increases.

[0019]

[Table 2]

Further, in the case of thermoplastic linear polyester resins such as polyethylene terephthalate and polybutylene terephthalate, as shown in Table 3, when the draw ratio is reduced, the above 200% modulus value decreases, and after the yield point, The stress value decreases. Conversely, when the stretching ratio is increased, the 200% modulus increases, and the stress after the yield point increases.

[0021]

[Table 3]

On the other hand, in the case of a base sheet having no yield point, for example, polystyrene is selected and the degree of polymerization is increased to increase the stress value after 10% elongation and the above-mentioned 20%.
The 0% modulus value will increase and lower the degree of polymerization or
Alternatively, by copolymerizing acrylonitrile, butadiene, or the like, the stress value after 10% elongation and the 200%
The modulus value decreases. However, as the copolymerization ratio of acrylonitrile or butadiene is gradually increased, the base sheet has a yield point. Further, when a vinyl chloride resin is selected, no yield point is obtained if the amount of plasticizer is non-plastic or a very small amount. As for the plasticizer, the yield point is more likely to disappear in tricresyl phosphate than in dioctyl phthalate.

The thickness of the base sheet is not particularly limited, but is generally about 30 to 500 μm, and about 20 to 200 μm when used for a transfer sheet.

In the case of a transfer sheet, a sheet having a releasability from a transfer layer including an adhesive layer and a decorative layer is used as the base sheet. For this reason, if necessary, a sheet provided with a known release layer as a component of the base sheet is provided on the transfer layer side of the base sheet in order to improve releasability from the transfer layer. The release layer is removed from the transfer layer integrally with the base sheet when the base sheet is peeled off. For the release layer, for example, silicone resin, wax or the like is used. The release layer has a thickness of about 0.1 to 4 μm, and the influence on the mechanical properties of the entire base sheet described above is very small.

(Adhesive Layer) As the adhesive layer 2, a chlorinated polyolefin resin having a softening point of 90 to 100 ° C. is used. The softening point is Vicat softening temperature (JIS K7206)
Regulation). As the chlorinated polyolefin resin, chlorinated polyethylene, chlorinated polypropylene or the like is used alone or in combination of two or more. By using a chlorinated polyolefin resin, even when the resin molded product is a polyolefin resin, a sheet for simultaneous painting with injection molding can be laminated with good adhesion.
Particularly, by setting the softening point in the range of 90 to 100 ° C., excellent adhesion can be obtained. When the softening point is less than 90 ° C., the heat resistance is insufficient even if the adhesive is adhered, and the softening point is 10 ° C.
If the temperature exceeds 0 ° C., the adhesion of the injection resin due to heat during simultaneous painting by injection molding becomes insufficient.

The thickness of the adhesive layer may be appropriately determined according to the method of use and the like, but is usually about 1 to 10 μm. The method for forming the adhesive layer is not particularly limited, but is usually a known printing or coating means such as gravure printing or roll coating as an ink or coating liquid composed of a resin liquid obtained by diluting the above resin with a diluting solvent. Is formed. The adhesive layer may be composed of only a chlorinated polyolefin resin. However, in order to adjust and improve various physical properties such as printing (or coating) suitability of the ink (or coating liquid), if necessary, And various additives such as extender, preservative stabilizer and the like.

(Other Layers) When the sheet for simultaneous painting with injection molding is used as a laminate sheet, a sheet for painting such as a structure composed of a base sheet and an adhesive layer is used without a decorative layer. In some cases, only the base sheet is laminated on the adherend (of course, an adhesive layer is interposed).
Usually, it is a sheet for painting on which a decorative layer is also formed. Also, without a decorative layer in this manner, even when only the base sheet is laminated, by kneading the pigment or the like into the base sheet itself,
If the base sheet itself is subjected to a decoration treatment, the base sheet itself becomes a decoration layer, and the adherend is painted. Further, even when the transparent base sheet itself imparts a feeling of painting, the adherend is painted. In addition, when the sheet for simultaneous painting with injection molding is used as the transfer sheet, if the adhesive layer contains a coloring agent and is used as a decorative layer, the adhesive layer alone may be transferred. But usually
A painting sheet having a decorative layer that does not double as an adhesive layer is formed between the base sheet and the adhesive layer.

(Other Layers: Decorative Layer) The sheet for simultaneous painting with injection molding of the present invention is the same as the conventionally known sheet for simultaneous painting with injection molding except that the base sheet and the adhesive layer are composed of the above-mentioned specific ones. In this case, various layer configurations can be adopted. For example, when a decorative layer is further formed on the base sheet, the decorative layer is basically not particularly limited. The decorative layer is usually formed of printing ink or paint. Alternatively, a metal thin film layer or the like can be used as the decoration layer. The decorative layer is formed on the surface of the base material sheet on the side of the adhesive layer or, in the case of a laminate sheet, on the surface of the base material sheet on the side opposite to the side of the adhesive layer or on both the front and back surfaces of the base material sheet. . In the case of the adhesive layer side of the base sheet, the base sheet can be used as a protective layer for the decorative layer. Of course, the base sheet in this case is a transparent (colorless or colored) sheet, but the base sheet can also be used for imparting a feeling of painting.

When the decorative layer is formed of printing ink or paint, the binder resin of the printing ink (or paint) may be acrylic resin, vinyl chloride-vinyl acetate copolymer, polyester resin, urethane resin, or chlorinated resin. Chlorinated polyolefins such as polyethylene and chlorinated polypropylene may be used alone or as a mixture of two or more. The colorant used in the printing ink (or paint) may be a known dye or pigment, for example, titanium white, red iron oxide, graphite, ultramarine, carbon black, isoindolinone, quinacridone, phthalocyanine blue, or the like. The pattern of the decoration layer is wood grain, stone grain, cloth grain, sand grain, geometric pattern, letters,
It is optional such as solid on the whole surface.

The metal thin film layer serving as the decorative layer includes:
It is formed by a vacuum evaporation method, a sputtering method, or the like using aluminum, brass, gold, silver, copper, chromium, or the like. In addition, the metal thin film layer is an entire surface or a partial (picture-like or the like) layer.

(Other layers: release layer) When the sheet for simultaneous painting with injection molding is used as the transfer sheet, the surface in contact with the base sheet is adjusted for releasability from the base sheet so that surface protection after transfer is performed. A release layer may be provided as a layer or a layer giving a feeling of painting. As the release layer, in addition to the various binder resins listed with the printing ink for forming the decorative layer, an ionizing radiation curable resin made of an acrylic resin, an epoxy resin, or the like, which is cured by ultraviolet rays or electron beams can be used. The release layer is formed by a known printing method or coating method similar to the decoration layer. The thickness of the release layer is usually about 1 to 100 μm.

(Other Layers: Primer Layer) In the base sheet, adhesive layer, decorative layer, release layer, etc., a primer layer may be provided between the layers in order to improve the interlayer adhesion. good. The resin of the primer layer is not particularly limited, and may be appropriately selected from known ones. For example, a urethane resin may be used. As urethane resin, 2
A liquid-curable urethane resin or a thermoplastic urethane resin may be used. Further, the primer layer may be formed by a known printing method or coating method using an ink or coating liquid made of such a resin.

For example, a base sheet 1 such as a sheet S for simultaneous painting with injection molding which becomes a laminate sheet shown in FIG.
Alternatively, a configuration in which the decorative layer 3, the primer layer 6, and the adhesive layer 2 are laminated in this order may be used. With such a configuration, it is possible to decorate with the decorative layer, and it is possible to widen the selection range of the resin that can be used for the decorative layer and the base sheet with the primer layer. As a specific example of such a sheet for simultaneous painting with injection molding having the configuration illustrated in FIG. 4, for example, a base sheet 1 mainly composed of an acrylic resin and having the above-described physical properties is prepared by adding a binder resin of an acrylic resin and a vinyl chloride resin. A decorative layer 3 mainly composed of a mixture with a vinyl acetate copolymer, a primer layer 6 mainly composed of urethane resin, and a softening point of 90 to
This is a painting sheet in which an adhesive layer 2 mainly composed of a chlorinated polyolefin resin at 100 ° C. is laminated in this order.

[Injection Simultaneous Painting Method] The simultaneous injection molding simultaneous painting method of the present invention uses the above-described simultaneous injection molding simultaneous painting method of the present invention to laminate the surface of a resin molded product by the so-called simultaneous injection molding painting method. Then, in the case of transfer, the base sheet is further peeled off (when the base sheet has a release layer as a constituent element as described above, the release is performed as a part of the base sheet. This is a method of obtaining a molded article painted with the painting sheet.

Incidentally, the simultaneous painting method for injection molding is described in JP-B-50-19132, JP-B-43-27488, JP-A-6-315950 and JP-B-2-420.
As described in Japanese Patent Publication No. 80, etc., after a painted sheet is placed between both male and female molds for injection molding, a resin in a flowing state is injected and filled into the mold, and simultaneously with the molding of the resin molded product, a picture is painted on the surface. This is a method in which sheets are laminated and painted by lamination or transfer.

The simultaneous injection molding simultaneous painting method of the present invention takes various forms in the conventionally known simultaneous injection molding simultaneous painting method except that the above-mentioned injection molding simultaneous painting sheet of the present invention is used as the painting sheet to be used. What you get. For example, the pre-forming of the painting sheet may or may not be performed. Further, the prepainting sheet may or may not be preheated. In addition, the sheet for painting is usually preheated at the time of preforming. Of course, when the drawing sheet has a large drawing, it is preferable to perform preforming. On the other hand, when the drawing sheet has a small amount of drawing, the drawing sheet can be formed by the resin pressure of the resin in the fluidized state to be injected. At this time, if the drawing is shallow, the painting sheet may be formed by the resin pressure of the resin in a flowing state that is filled into the mold at the same time as the resin injection without the preliminary molding. Further, even when the painting sheet is formed by the resin pressure, the painting sheet may utilize the heat of the injection resin without preheating. In addition, the preforming of the painting sheet is usually performed by using the injection mold also as the vacuum forming mold, but before supplying the painting sheet between the molds, the outside of the mold is used for painting with another vacuum forming mold. Preforming such as vacuum forming the sheet may be used. In addition, the vacuum forming includes vacuum pressure forming.

The injection molding simultaneous painting method of the present invention will be described with reference to a conceptual diagram of FIG. In addition, the form described here is a form in which the painting sheet is heated and softened between the molds, pre-molded by vacuum molding with an injection mold, and then resin is injected by clamping before the mold is clamped. .

First, as shown in FIG. 2A, as an injection mold, a mold Ma having a runner and a gate (gate) communicating with the injection nozzle, and a sheet having a suction hole 41 on the mold surface. And a pair of molds of the mold Mb also serving as the preliminary mold. These molds are made of metal such as iron or ceramics. In the mold opened state, the sheet S for simultaneous painting with injection molding is supplied between the two molds Ma and Mb, and the sheet S for painting is fixed to the mold Mb by pressing with a frame-shaped sheet clamp 42 or the like. At this time, it goes without saying that the adhesive layer side of the painting sheet is the injection resin side on the right side of the drawing. Next, the painting sheet is appropriately heated and softened by a heater inserted between both molds. The heating is, for example, non-contact radiation heating, but may be contact heating. Then, it is sucked through the suction hole and vacuum formed, and the painting sheet is preformed along the cavity surface of the mold Mb. In addition, vacuum forming may be vacuum press forming using both pressure and air, and this is also included. Next, the heater is retracted from between the two dies, the two dies are clamped as shown in FIG. 2B, and a cavity formed by the two dies is filled with a resin in a flowing state such as a heated and molten state. After the resin is solidified, the mold is opened and the molded product is taken out. In the case where the sheet for simultaneous painting with injection molding is a laminate sheet, if there is an unnecessary portion of the sheet for painting, trimming is appropriately performed as shown in FIG.
The sheet S for simultaneous painting with injection molding is laminated on the sheet to obtain a molded article P on which painting is performed. When the sheet for simultaneous painting with injection molding is a transfer sheet, the molded article is taken out with the base sheet left on the mold Mb side, or after the molded article is taken out with the whole sheet for painting laminated. Then, the base sheet is peeled off to obtain a painted product in which only the transfer layer is laminated and painted.

In the simultaneous injection molding painting method of the present invention, the resin to be injection-molded is basically any known resin in the injection molding simultaneous painting method, and is not particularly limited. The injection molding resin is selected according to the required physical properties and cost of the product. For example, in the case of a thermoplastic resin, ABS (acrylonitrile-butadiene-styrene copolymer) resin, styrene resin, vinyl chloride resin, acrylic resin, polycarbonate resin, or polyethylene, polypropylene, polybutene, polymethylpentene, ethylene-propylene copolymer Polyolefin resins such as polymers, ethylene-propylene-butene copolymers, and olefin-based thermoplastic elastomers. In addition, in the case of a curable resin, a material which has been conventionally known as a two-part curable resin, such as an uncured resin liquid such as a urethane resin, an unsaturated polyester resin, or an epoxy resin, is used for simultaneous injection molding and painting. Can be used. The thermoplastic resin is melted by heating and injected in a fluid state, and the curable resin is injected at room temperature or appropriately heated and flowed. However, in the simultaneous injection molding painting method of the present invention, the above-described method of using the simultaneous injection molding painting sheet of the present invention is used, and the most advantageous effect of the painting sheet of the present invention is obtained by using polypropylene. And the above-mentioned various polyolefin-based resins.

[Molded Article] In the molded article of the present invention, like the molded article P illustrated in FIG. 3, the above-mentioned sheet S for simultaneous painting with injection molding of the present invention is formed by bonding a laminate sheet made of a specific resin as a laminate sheet. The molded article has a configuration in which all layers including the base sheet are laminated on the surface of the resin molded article 5 made of a polyolefin resin via the agent layer. Examples of the polyolefin-based resin include polyethylene, polypropylene, polybutene, polymethylpentene, ethylene-propylene copolymer, ethylene-propylene-butene copolymer, and olefin-based thermoplastic elastomer. The molded product is usually a three-dimensional object in which the laminated surface of the sheet for painting is non-planar with an uneven surface or the like. However, as the molded article of the present invention, a three-dimensional object in which the laminated surface of the sheet for painting is flat but the other surface is non-planar,
It does not exclude a plate-like material having a flat lamination surface. Excellent adhesion due to the specific adhesive layer can be enjoyed.

In order to obtain the molded article of the present invention, it is essential to use the sheet for simultaneous painting with injection molding of the present invention for the sheet for painting. However, the method of laminating the sheet for simultaneous painting with injection molding on the resin molded product is preferably, but not necessarily limited to, the method for simultaneous painting with injection molding. The irregular use of the sheet for simultaneous painting with injection molding will be an irregular use, but the method may be appropriately determined according to the resin molded article to be adhered (the shape of the adhered surface of the sheet for painting in) and the available manufacturing equipment. May be adopted. For example, Japanese Patent Publication No. 56-457
No. 68 (overlay method), Japanese Patent Publication No. 60-5801
A so-called vacuum forming and laminating method described in Japanese Unexamined Patent Publication No. 4 (vacuum pressing method) or the like may be used. Of course, the simultaneous injection molding and painting method of the present invention can be applied to a three-dimensional surface with a deep squeeze by closely laminating a painting sheet and painting. In addition, molding and painting can be performed simultaneously in one step. This is preferable in that the production efficiency is good.

[0042]

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

Example 1 A transparent acrylic resin sheet having a thickness of 125 μm (a sheet having a width of 10 mm was pulled at a rate of 30% / sec in an environment of 50 ° C. at a rate of 30% / sec. (Thermoplastic resin sheet having properties) (K-623, manufactured by Sumitomo Chemical Co., Ltd.) as a base sheet, and on one side thereof, a binder resin is one-to-one of an acrylic resin and a vinyl chloride-vinyl acetate copolymer. The mixture is in a weight ratio, and the coloring pigment is a red ink, carbon black, and a coloring ink mainly composed of graphite, and a 2 μm thick decorative layer having a wood grain pattern is formed by gravure printing. A primer layer having a thickness of 1 μm is formed by gravure printing using a primer ink composed of a base resin, followed by chlorinated polypropylene (softening point 90 ° C .;
t softening point. A modified chlorinated polypropylene adhesive (solution) having the following composition mainly containing
After forming an adhesive layer having a thickness of μm, a sheet for simultaneous painting with injection molding of the present invention was obtained as a laminate sheet.

Modified chlorinated polypropylene adhesive composition Chlorinated polypropylene (softening point 90 ° C.) 16 parts by weight Storage stabilizer (epoxy resin) 1.6 parts by weight Silica 1.6 parts by weight Ethyl acetate 5.7 parts by weight Methyl ethyl ketone 5. 7 parts by weight Toluene 69.4 parts by weight

FIG. 4 is a cross-sectional view of the sheet S for simultaneous painting with injection molding obtained above. The decorative layer 3, the primer layer 6, and the adhesive layer 2 are laminated on the transparent base sheet 1 in this order. This is a sheet having a different configuration.

Then, by the simultaneous injection molding and painting method of the present invention as shown in the conceptual diagram of FIG. 2, the above-mentioned sheet for simultaneous injection molding and painting is laminated on the surface of the adherend made of the resin molded product at the same time. As a result, as shown in FIG. 3, a molded product P of the present invention having a layer configuration in which the whole sheet S for simultaneous painting with injection molding was laminated on the resin molded product 5 was obtained. The painting sheet showed good moldability. In addition, as an injection molding resin, a polypropylene resin (HIP-145, manufactured by Mitsui Toatsu Chemicals, Inc.) was used. In the simultaneous injection molding painting method, the painting sheet was formed by using an injection mold as a vacuum mold, supplying between the molds, softening by heating, and preforming by vacuum molding. As the injection molding die, a die having a suction hole for preforming the sheet on the female die side, which is a die from which a resin molded product to be a box-shaped panel was obtained was used.

Further, when the obtained molded article was subjected to the following durability test, the molded article showed no particular change and exhibited excellent heat resistance and the like. The molded article was painted with a wood grain pattern and was excellent in design.

[Performance Evaluation Test] In addition to the moldability of the sheet for painting at the same time as the injection molding, the adhesiveness of the sheet for painting in a molded product and its durability properties such as heat resistance, moisture resistance and hot water resistance were evaluated. evaluated. Table 4 shows the durability test results,
The content of the chlorinated polypropylene used and the moldability of the sheet for painting are shown together with other examples and comparative examples.

Formability: It is visually confirmed whether or not the sheet for painting is sufficiently formed to follow the irregularities on the surface of the painted surface. Insufficient ones were bad. Adhesion: As a grid test, cuts were made in a grid pattern at 2 mm intervals on the surface of the molded product (sheet surface for painting) in a grid pattern to make 10 × 10 grids in a matrix of 100 in total. , Cellophane adhesive tape (Nichiban Co., Ltd.,
"Cellotape" (registered trademark) 24 mm width, industrial)
After adhering at 5 ° C., it was vigorously peeled off, and it was evaluated whether the painting sheet was peeled off together with the tape. A sample without any squares was evaluated as good, and a sample with squares was evaluated as poor. Heat resistance: The molded article was placed in an oven at 70 ° C. for 500 hours, taken out and cooled to room temperature, and then visually evaluated for the presence or absence of abnormalities in the appearance. Moisture resistance: After placing the molded article in a thermo-hygrostat at 50 ° C. and 95% RH for 500 hours, take it out, cool it down to room temperature, and visually evaluate the appearance for abnormalities.
Anything that was abnormal was determined to be defective. Warm water resistance: After placing the molded product in warm water of 40 ° C. for 24 hours, take it out, wipe off the surface moisture, cool to room temperature, visually evaluate the appearance for abnormalities,
Anything that was abnormal was determined to be defective.

Example 2 In Example 1, the chlorinated polypropylene used for the adhesive layer had a softening point of 10%.
A sheet for simultaneous painting with injection molding was obtained in the same manner as in Example 1 except that the temperature was changed to 0 ° C. Then, a molded article was obtained by the same simultaneous injection molding and painting method as in Example 1 using this painting sheet. The formability of the sheet for simultaneous painting with injection molding and the durability of the molded product were also good.

Example 3 A sheet for painting was produced as in Example 1 except that the substrate sheet was replaced with a vinyl chloride resin sheet having a thickness of 80 μm. However, as the base sheet, a vinyl chloride resin having an average degree of polymerization of 700 and a plasticizer containing 18 parts by weight of tricresyl phosphate relative to 100 parts by weight of the resin were used. The substrate sheet is at 50 ° C.
When the sample having a width of 10 mm was pulled at a pulling rate of 30% / sec in Example 1, there was no yield point, and the stress value after 10% elongation was 0.64 to 2.1 kg. Other than that, the same thing as Example 1 was made, and it was set as the sheet for simultaneous painting with injection molding. Then, a molded article was obtained by the same simultaneous injection molding and painting method as in Example 1 using this painting sheet. The formability of the sheet for simultaneous painting with injection molding and the durability of the molded product were also good.

Comparative Example 1 In Example 1, the chlorinated polypropylene used for the adhesive layer had a softening point of 85.
A sheet for simultaneous painting with injection molding was obtained in the same manner as in Example 1 except that the temperature was changed to ° C. Then, a molded article was obtained by the same simultaneous injection molding and painting method as in Example 1 using this painting sheet. Although the moldability of the sheet for simultaneous painting with injection molding was good, in the heat resistance test of the molded product, surface irregularities occurred in the sheet for painting, resulting in poor heat resistance.

Comparative Example 2 In Example 1, the chlorinated polypropylene used for the adhesive layer had a softening point of 10
A sheet for simultaneous painting with injection molding was obtained in the same manner as in Example 1 except that the temperature was changed to 4 ° C. Then, a molded article was obtained by the same simultaneous injection molding and painting method as in Example 1 using this painting sheet. The moldability of the sheet for simultaneous painting with injection molding was good, but the adhesion in the molded product was poor.

Comparative Example 3 In Example 1, the chlorinated polypropylene used for the adhesive layer had a softening point of 11
A sheet for simultaneous painting with injection molding was obtained in the same manner as in Example 1 except that the temperature was changed to 3 ° C. Then, an attempt was made to obtain a molded product by the same simultaneous injection molding and painting method as in Example 1 using this painting sheet. However, although the preforming of the painting sheet was successfully performed, the painting sheet did not adhere to the resin molded product due to the hot pressure of the injection resin, and a molded product in a state where the painting sheet was laminated was not obtained. Was.

[0055]

[Table 4]

[0056]

According to the sheet for simultaneous painting with injection molding of the present invention, when laminated on a resin molded article at the same time as injection molding and painted by lamination or transfer, the unevenness of the painted surface is deep. However, excellent moldability that allows deep drawing of the sheet is obtained, and excellent adhesion is obtained even when the resin molded product is made of a polyolefin-based resin that is difficult to adhere to. Further, in the simultaneous injection molding and painting method of the present invention, by using the above-described sheet for simultaneous injection molding and painting, the sheet is deep drawn even in the case of a painted surface having a large unevenness, and the resin molded product is hardly adhered. Even in the case of using a polyolefin resin, excellent adhesion can be obtained. In addition, the surface of the resin molded product can be efficiently painted in one step by laminating or transferring the surface of the resin molded product in one step with excellent adhesion at the same time as the molding. According to the molded article of the present invention, even if the painted surface of the inexpensive polyolefin resin molded product is an uneven surface such as a deep drawing, the lamination of the injection-molded simultaneous painting sheet can be achieved. It becomes a painted molded product with good properties.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a form example of a sheet for simultaneous painting with injection molding of the present invention.

FIG. 2 is a conceptual diagram illustrating an injection molding simultaneous painting method of the present invention in one embodiment.

FIG. 3 is a cross-sectional view illustrating an example of a form of a molded article of the present invention.

FIG. 4 is a cross-sectional view illustrating another embodiment of the sheet for simultaneous painting with injection molding of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base sheet 2 Adhesive layer 3 Decorative layer 4 Transfer layer 5 Resin molding 6 Primer layer 41 Suction hole 42 Sheet clamp Ma Injection mold (male) Mb Injection mold (female) P Molded article S Simultaneous injection molding Painting sheet

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 4F100 AK01A AK03B AK07B AK25 AL06B AT00A BA02 BA10A BA10B BA15 CC00 EA061 EC042 EC182 EH312 EH362 EJ303 GB90 HB00 HB31 JA04B JB16A JK01A JK06 JK10AJAAD03 JB13 JB19 JB22 JF05 JN43 JQ81

Claims (3)

[Claims] 1. A painting sheet for use in a simultaneous painting method for injection molding, comprising at least a base sheet and an adhesive layer laminated as an outermost layer on the resin molded product side of the base sheet, Thermoplastic sheet having a yield point and a stress value after the yield point of 0.6 kg or more when the base sheet cut into a width of 10 mm is pulled at a rate of 30% / sec in an environment of 50 ° C. When the resin sheet or the substrate sheet having no yield point and cut to a width of 10 mm is pulled at a rate of 30% / sec in an environment of 50 ° C., the stress value after 10% elongation is 0.6 k.
g. of a thermoplastic resin sheet having a softening point of 90 to 100 ° C. and a chlorinated polyolefin resin having a softening point of 90 to 100 ° C. 2. The sheet for simultaneous painting with injection molding according to claim 1 is inserted between a pair of molds, and then both molds are clamped, and a cavity formed by both molds is filled with a resin in a flowing state. After solidifying and laminating the sheet for simultaneous painting with injection molding on the surface of the resin molded product at the same time as the molding and laminating, open both molds. In the case of laminating, complete the sheet for simultaneous painting with injection molding as it is. In the case of transfer, in the case of transfer, at least a decorative layer is provided between the base material sheet and the adhesive layer as a transfer layer together with the adhesive layer. Injection molding simultaneous painting method in which only a material sheet is peeled off to form a molded article in which a transfer layer including an adhesive layer is laminated on a resin molded article. 3. A molded product obtained by laminating all layers of the sheet for simultaneous painting with injection molding according to claim 1 on the surface of a resin molded product made of a polyolefin resin by an adhesive layer.