JPH07314553A - Shaped sheet - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a shaped sheet which can surely form an uneven pattern on the surface of a molded product. [Constitution] 0-2 based on 100 parts by weight of polyvinyl chloride
It contains 5 parts by weight of a plasticizer and has an average degree of polymerization of 700 to 200.
A concave-convex pattern is formed on the surface of the polyvinyl chloride resin sheet of 0 to obtain a patterning sheet. The shaping sheet 10 is placed between the female die 20 and the male die 30 and preformed, and then the sprue 3
The molten resin is injected from No. 2, and after the injected resin is solidified, the shaping sheet is peeled off to form an uneven pattern on the surface of the molded product.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shape-imparting sheet for use in a simultaneous injection-molding method, and more particularly, to molding an uneven pattern having an excellent design effect on the surface of various injection-molded products simultaneously with injection molding. The present invention relates to a shaped sheet.

[0002]

2. Description of the Related Art As a method of imparting a surface texture, that is, a concavo-convex pattern to an injection-molded product, there is a method of imparting concavities and convexities to an injection-molding die to impart irregularities to the surface of the molded product during injection molding. However, according to this method, it is difficult to form an accurate concavo-convex shape on the curved surface of the mold, and thus it is difficult to provide a desired concavo-convex pattern on the curved surface of the injection molded product. Further, since only one surface uneven pattern can be applied to one mold, it is necessary to make a plurality of molds for each different uneven pattern, which is a troublesome work and uneconomical.

As a means for avoiding the above-mentioned drawbacks, Japanese Patent Laid-Open No. Sho 6-62 is known.
In Japanese Patent Laid-Open No. 4-53823, a synthetic resin is injection-molded by using a mold in which a shaping sheet having an uneven pattern is mounted, and after shaping, the shaping sheet is peeled off to form an uneven pattern on the surface of a molded product. The method is described.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
According to the method described in No. 823, it is possible to give various concave and convex patterns to an injection-molded product only by changing the shaping sheet mounted inside the mold without preparing a plurality of molds. It was found that the uneven pattern that should have been applied to the surface of the injection-molded product disappeared due to heat and pressure during molding, and the desired uneven pattern could not be applied.

In order to avoid this drawback, an ink is prepared by adding a matting agent such as silica or calcium carbonate to the surface of the thermoplastic resin sheet, if necessary, to a cross-linking curable resin such as acrylic resin, urethane resin or epoxy resin. A shape-imparting sheet made by printing an uneven pattern and cross-linking and curing the ink with heat, ultraviolet rays or electron rays was also devised, but these cross-linking type inks are hard and cracked during injection molding, or ink and sheet. There was a problem that the ink layer was not sufficiently adhered to the molded product and the uneven pattern ink layer was taken on the molded product side when peeled from the molded product.

According to the present invention, it is possible to surely form an uneven pattern on the surface of a molded product by removing the above-mentioned drawbacks, by injection molding a synthetic resin in a state of being mounted inside a mold, and peeling after molding. The purpose is to provide a mold sheet.
Further, the present invention is a shaping sheet which can surely form an uneven pattern on a surface of a molded product and at the same time, by injection molding a synthetic resin in a state of being mounted inside a mold and peeling the molded resin after molding. The purpose is to provide.

[0007]

Means for Solving the Problems The present inventor pays attention to the injection molding conditions such as the material of the shaping sheet, the embossing temperature, and the time, temperature, and pressure of the injection molding process, and selects these conditions. The inventors have found that the above objects can be achieved and completed the present invention. In the present invention,
The thermoplastic resin sheet constituting the patterning sheet contains 0 to 25 parts by weight, preferably 0 to 8 parts by weight, of a plasticizer with respect to 100 parts by weight of polyvinyl chloride, and has an average degree of polymerization of 700.
Above, preferably 700-2000, thickness 50
.About.200 .mu.m, preferably 80 to 100 .mu.m polyvinyl chloride resin sheet is used.

If necessary, additives such as a heat stabilizer, a filler and a release agent may be added to the polyvinyl chloride resin. Examples of the heat stabilizer include carboxylic acid salts of magnesium, lead, zinc, cadmium, barium, epoxidized soybean oil, metal soap and the like. The filler is an inorganic fine powder such as calcium carbonate, aluminum hydroxide, kaolinite, barium sulfate, etc., and the addition amount is usually 0 to
It is about 50 parts by weight. As the plasticizer, dioctyl phthalate (DOP), butyl benzyl phthalate (BB
P), phthalic acid esters such as dibutyl phthalate, tricresyl phosphate, phosphoric acid esters such as alkyldiphenyl phosphate, chlorinated paraffin, and the like are used.

In general injection molding of thermoplastic resin, the injection resin temperature (nozzle temperature) is 150 to 280 ° C., the mold temperature is 20 to 100 ° C., the molding time is 1 to 30 seconds, and the injection pressure is 500 to 2000 kg / cm ² . is there. Under the molding conditions in this range, it was found that the imprinted sheet having the above-mentioned design does not cause the disappearance of the unevenness which can be visually confirmed at the time of injection molding. If the average degree of polymerization of the polyvinyl chloride resin is less than 700, the softening temperature of the resin becomes low, and the uneven pattern is likely to disappear due to heat and pressure of the injection resin during injection molding (low emboss fastness). Further, if the average degree of polymerization is too high, the emboss fastness is good, but the moldability and followability to the mold shape of the sheet during injection molding or preliminary molding prior to it become low, so about 2000 is preferable. . Also,
If the amount of the plasticizer exceeds 25 parts by weight, the softening temperature becomes too low and the emboss fastness becomes low, which is not preferable. Thickness is 5
If it is less than 0 μm, the sheet will be easily broken when it is molded into a mold shape, and if it exceeds 200 μm, the heat of the injection resin is insulated and is difficult to be cooled to the mold, and the sheet temperature rises due to heat accumulation. Since the uneven pattern disappears, it is not preferable to make the thickness too thick because the uneven pattern is promoted to disappear.

On the surface of the patterning sheet, a concavo-convex pattern having the same shape as the concavo-convex pattern to be formed on the surface of the molded article and the reverse concavo-convex pattern is formed. The method of forming the uneven pattern is the embossing method by hot pressing,
Alternatively, the casting method is used. The depth of the unevenness (the height difference between the concave portion and the convex portion) is at most about the thickness of the shaping sheet. It is possible to form an uneven pattern having a depth equal to or greater than the thickness of the shaping sheet, but in that case, the object of the present invention cannot be achieved because the uneven pattern is crushed and dented by the pressure of the injection resin. .

The embossing of the uneven pattern on the shape-imparting sheet is a temperature between the softening temperature and the melting temperature of the thermoplastic resin, for example, 130 to 170 in the case of the polyvinyl chloride sheet having the above composition.
It is performed by pressing with an embossing plate at a sheet temperature of about ℃. The plate temperature is set high (about 40 to 90 ° C.), the softened resin flows into the uneven shape of the embossed plate, and the mold is released after waiting for the internal stress to be sufficiently relaxed. Cool to room temperature. The casting method is a method in which an organosol or plastisol of polyvinyl chloride resin is applied onto a mold having an uneven pattern, and the sol is solidified by solvent drying or heat gelation, and the mold is released from the mold. This method is good in that the residual of internal stress is small.

The pre-molding is carried out when the unevenness of the mold has a large difference in level and curvature, and prior to the injection molding, the cavity mold of the injection-molding mold is vacuum-pressure air-molded. The preforming temperature depends on the shape of the mold, but is usually 10 to 40 ° C. higher than the softening point of the shaping sheet. In the case of the polyvinyl chloride sheet having the above composition, the preforming time is 5 to 30 seconds and the pressure is 0.05 to 1.0 kg / c.
m ² , the preforming temperature is 80 to 120 ° C. When the curvature and the unevenness are small, the preforming may be omitted.

Thereafter, the injection resin is injected into the cavity, the injection resin is cooled and solidified, and then the patterning sheet is peeled off to obtain a molded product having an uneven pattern on the surface. As the injection resin, generally any resin can be used as long as it does not adhere to the shaping sheet, and polystyrene, ABS, polypropylene, polyvinyl chloride or the like is usually used. The injection temperature of the injection resin may be the above-mentioned normal injection molding temperature. For example, a polystyrene resin is injected at an injection pressure of 0.02 to 1.0 kg / cm ² and an injection time of 1 to 10 so that the temperature of the surface of the shaped sheet becomes 100 to 130 ° C.
It is injected from the gate at a nozzle temperature of 220 to 250 ° C. in seconds.

In order to improve the releasability from the injection resin, a silicone resin, a fluorine resin, waxes such as wax, a water-dispersible urethane emulsion or a resin layer containing these is formed on the surface of the shaping sheet, if necessary. A release layer is formed. Painting can also be done at the same time as injection molding. In this case, on the surface of the imprint sheet made of the polyvinyl chloride resin sheet, as a transfer layer, a pattern is directly printed by gravure printing, silk screen printing, or the like, and the ink is formed simultaneously with imprinting. Painting can be performed by transferring the layer to the molded article.

Alternatively, as a transfer layer, in addition to the pattern layer,
A release layer (a layer that is peeled from the patterning sheet and transferred to the molded article side and that functions as a protective layer on the surface of the pattern layer after transfer) may be provided between the patterning sheet and the pattern layer. Further, an adhesive layer may be provided on the pattern layer.

[0016]

[Operation] Using the shaped sheet, by selecting the injection molding conditions such as time, temperature and pressure of the injection molding process within the range of the usual thermoplastic resin according to the injection molded resin, the shaped sheet It becomes possible to perform injection molding without losing the concavo-convex pattern, and it becomes possible to surely impart a desired concavo-convex pattern to the surface of the injection-molded article. Further, by providing a transfer layer composed of a pattern ink layer or the like on the imprinting sheet, it is possible to imprint a concavo-convex pattern on the surface of the injection-molded article and at the same time, paint.

[0017]

EXAMPLES Examples of the present invention will be described below. First, as Example 1, 8 parts by weight of a plasticizer DOP (dioctyl phthalate), an average degree of polymerization of 1000, and a polyvinyl chloride (PVC) sheet having a thickness of 80 μm were used to form a satin-like concavo-convex pattern with an embossing depth of 2 μm by an embossing machine. , Seat temperature 16
The embossing plate was placed at a plate surface temperature of 65 ° C. to form a shaped sheet.

Next, using the apparatus schematically shown in FIG. 1, the imprinting sheet 10 is mounted in the cavity 24 of the female die 20 of the die with the concavo-convex pattern surface facing the male die 30 side, and a heater. Female suction hole 22 while heating with a heating plate 40
Was vacuum-sucked from and was preformed on the female die surface of the die at a sheet temperature of 110 ° C. After that, as shown in FIG. 2, both male and female molds 20 and 30 are closed, molten polystyrene resin at a temperature of 230 ° C. is injected from the male sprue 32, and the surface temperature of the shaping sheet becomes 120 ° C. Injection pressure is 1 for 5 seconds
It was molded under the condition of 50 g / cm ² .

After that, the injection resin is cooled by a mold at a temperature of 40 ° C., the mold is opened and the solidified injection resin P is taken out, and then the pattern forming sheet 10 is peeled off as shown in FIG.
A molded product P having a satin surface was obtained. The shape of the molded product P is shown in FIG.
The cross-sectional shape is like, and the depth of the step (diaphragm) is 15 m.
m and the radius of curvature of the cusps were 8 mm. The surface unevenness pattern of the molded product P at this time faithfully reproduces the unevenness pattern of the shape-imparting sheet 10 in detail, and even if the surface of the shape-imparting sheet and the surface of the molded product are visually compared, the difference in the unevenness shape is particularly noticeable. Was not recognized.

[0020] In the following, various types of polyvinyl chloride constituting the shaping sheet were changed in various parameters, and simultaneous molding was performed. The results are summarized in the following table, including the results of Example 1 above.

[0021]

[Table 1]

Next, as shown in FIG. 4, the plasticizer DOP
(Dioctyl phthalate) 8 parts by weight, average degree of polymerization 100
0, polyvinyl chloride (PVC) sheet 5 with a thickness of 80 μm
A sheet was prepared by laminating the release layer 54 and the pattern layer 56 on the sheet 2. An embossing machine was used to form a matte textured uneven pattern with an embossing depth of 2 μm at a sheet temperature of 160 ° C. and a plate surface temperature of the embossing plate of 65 ° C. to form a shaped sheet.

The release layer 54 comprises a mixture of a vinyl chloride / vinyl acetate copolymer and an acrylic resin in a ratio of 1: 1 (weight ratio).
It was applied to a thickness of μm, and a binder having the same composition as that of the release layer and a coloring pigment added thereto was used as an ink, and a wood grain pattern was printed by a gravure printing method to form a pattern layer 56. An acrylic resin as an adhesive layer was applied on the pattern layer 56 to a thickness of 3 μm.

After that, injection molding was performed under the same molding conditions as in Example 1 using the apparatus schematically shown in FIG. 1, and after the solidified injection resin was taken out, a PVC sheet 52 was formed as shown in FIG. When peeled off, a grain pattern was formed on the surface of the molded product P by the transfer of the pattern layer, and at the same time, the uneven pattern was faithfully reproduced.

[0025]

EFFECTS OF THE INVENTION According to the present invention, since a shaping sheet suitable for the usual injection molding condition range of a thermoplastic resin is selected,
It is possible to provide a clear and faithful concavo-convex pattern without causing the concavo-convex pattern to disappear due to heat and pressure during injection molding.
In the case of using a shaped sheet in which a picture layer is laminated, it is possible to apply a picture at the same time as providing the uneven pattern.

Further, it is possible to form various kinds of uneven patterns on the surface of the injection resin molded product with one die. Furthermore, since the shape-imparting sheet is a thermoplastic resin sheet and can be molded into any shape including a three-dimensional solid shape, it is possible to impart a concavo-convex pattern to the surface of a molded product of any shape.

[Brief description of drawings]

FIG. 1 is a diagram illustrating one step of a simultaneous injection molding method.

FIG. 2 is a diagram illustrating one step of a simultaneous injection molding method.

FIG. 3 is a diagram illustrating one step of a simultaneous injection molding method.

FIG. 4 is a schematic cross-sectional view of a laminated sheet.

FIG. 5 is a diagram illustrating one step of a method for simultaneously applying an uneven pattern and painting.

[Explanation of symbols]

10 ... Molding sheet, 20 ... Female mold, 22 ... Intake hole, 24 ...
Cavity, 30 ... Male type, 32 ... Gate, 40 ... Hot plate, 5
2 ... Polyvinyl chloride resin sheet, 54 ... Release layer, 56 ...
Design layer, P ... Molded product

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display area C08K 5/10 C08L 27/06 KGY

Claims (2)

[Claims] 1. 0 for 100 parts by weight of polyvinyl chloride
Containing 25 to 25 parts by weight of a plasticizer and having an average degree of polymerization of 700 to 2
000, a polyvinyl chloride resin sheet having a thickness of 50 to 200 μm, and an uneven pattern formed on the surface thereof. 2. Zero per 100 parts by weight of polyvinyl chloride.
Containing 25 to 25 parts by weight of a plasticizer and having an average degree of polymerization of 700 to 2
000, a polyvinyl chloride resin sheet having a thickness of 50 to 200 μm, and a transfer layer laminated on the polyvinyl chloride resin sheet, and an uneven pattern is formed on the surface thereof.