JP3422966B2 - Ink and painting sheet for painting at the same time as molding - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink used for painting a molded article when molding an article by injection molding or the like, and more particularly to an ink containing a metal powder.

[0002]

2. Description of the Related Art As a method of decorating the surface of a synthetic resin molded product, a design sheet printed in advance with ink is installed in a molding die, and a synthetic resin is injected into the mold to print a design on the design sheet. There is known a method of integrating a resin into a synthetic resin. With this method, it is possible to form a pattern even on a molded product in which it is difficult to directly form a pattern on the surface by printing, and moreover, the adhesive strength is large compared to printing on the surface of the molded body, It also has the advantage of being less prone to change, and is used to decorate the surface of various devices, including small electronic devices such as mobile phones and personal computers.

However, in the injection molding method, the molten synthetic resin for molding is injected into the mold after the printed pictured sheet is mounted inside the mold.
Since it melts at a temperature of ℃ to 300 ℃ and is injected at high pressure, problems such as flowing of the pattern printed on the painting sheet and deformation of the painting sheet occur, and the product quality is improved. In some cases, the product was inferior and could not be used as a product, and in some cases, the adhesive strength between the painting sheet and the molded synthetic resin was insufficient due to the picture flow. Therefore, in order to solve these problems, it has been proposed to change the position of the gate of the mold used for injection molding or change the distance between the gate and the painting sheet. However, there is a problem in that the amount of material wasted during molding increases.

Further, it has been practiced to use an ink having a property of expanding along with the deformation of the painting sheet caused by the flow of the molten synthetic resin, and a two-part printing ink which intermolecularly crosslinks is used. ing. Further, as a printing ink having high heat resistance, a printing ink containing a thermoplastic aromatic polycarbonate has been proposed in Japanese Patent No. 2997636. However, even if these printing inks are used, the flow of the printing ink occurs in an environment where the injection molding conditions such as the injection speed of the molten synthetic resin are high and the conditions are severe. In particular, there is a problem that the flow of the printing ink largely appears in the case of the printing ink containing metal particles such as aluminum particles.

Since metal particles such as aluminum are widely used for imparting metallic luster and a high degree of hiding property to a molded product, in a painting sheet printed with a printing ink containing metal particles such as aluminum particles. The problem that occurred was a big one.

[0006]

DISCLOSURE OF THE INVENTION The present invention prevents the flow of a pattern printed by a printing ink containing metal particles on a painting sheet which is placed in a mold and integrated with a synthetic resin in injection molding, It is an object of the present invention to provide a printing ink that does not cause defective products during injection molding.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ink for painting at the same time when molding is used for printing a painting sheet which is integrated with a molten synthetic resin in a synthetic resin molding process. This can be solved by an ink containing a resin binder and metal particles whose surface is coated with a coupling agent or a synthetic resin. Further, in the above ink, the metal particles are flat particles of aluminum coated with an acrylic resin. A binder made of polycarbonate resin on the synthetic resin film, and a coupling agent on the surface,
Alternatively, it is a printed sheet printed with an ink containing metal particles coated with a synthetic resin. Also,
In the injection molding method, a painting sheet printed with an ink containing metal particles whose surface is coated with a coupling agent or a synthetic resin is placed inside a metal mold, and a molten synthetic resin is used to melt the resin at 200 ° C. This is an injection molding method in which injection molding is performed at the above temperature.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, when a painting sheet printed with an ink containing fine metal particles such as silver ink is provided in a mold and injection-molded, the surface of the fine metal particles is a coupling agent or a synthetic resin. It has been found that the use of the metal particles coated by means does not affect the molten resin injected into the mold, and the image deletion painted on the printing sheet does not occur. .

In other words, the inventors of the present invention not only relate to the heat resistance of the binder contained in the ink and the like to cause the flow of images during injection molding, but also to the ink such as silver ink. Paying attention to the fact that it largely depends on the metal fine particles used in the above, it has been found that it is possible to greatly improve the flow of pictures by using metal fine particles surface-treated with a synthetic resin or the like. Is. For the metal fine particles added to the ink, flat fine particles such as scales are used in order to enhance the shielding effect by the metal fine particles and to obtain a metallic luster, but the surface of these metal fine particles is preliminarily coupled with a coupling agent. Alternatively, by applying a coating treatment with a synthetic resin, the flow of pictures is prevented.

Although it is not clear why the method of the present invention can prevent the flow of pictures, the metal surface is coated with the coupling agent or the synthetic resin, and as a result, the affinity with the binder in the ink is increased. , It seems that it is less affected by the flow of the molten synthetic resin injected during injection molding. As the binder used in the painting ink of the present invention, it is preferable to use a polycarbonate resin having high heat resistance, and 2,2-bis (4-hydroxyphenyl) propane together with a generally known polycarbonate resin. Units, and 2,
Examples thereof include a copolymer composed of 2-bis (4-hydroxy-3-methylphenyl) propane units and an aromatic polycarbonate resin modified with a dialkylsiloxane unit. Specifically, Mitsubishi Gas Chemical's Iupilon FPC-2136 (copoly (2,2-bis (4-hydroxyphenyl) propane / 2,2-bis (4-hydroxy-3-methylphenyl) propane) carbonate), Z -200, Teijin Kasei Panlite TS-20
20 and thermoplastic resins having large heat resistance such as the resins described in Japanese Patent No. 2997636.

As the aluminum particles coated with synthetic resin or the aluminum particles treated with a coupling agent, Toyo Aluminum White Silver FZ-
7160N, FZ-Q65, FZ-Q95, 97-25
15 can be mentioned.

The ink of the present invention can be produced by mixing these components with a pigment and other components generally added to an ink, adding an organic solvent and kneading. In addition, the ink of the present invention is not limited to the case where the components are mixed together as described above, but the commercially available heat-resistant ink for forming a painted sheet may be added with a synthetic resin or a coupling agent. It can also be produced by adding treated metal particles. For example, NORIPHANHTR (manufactured by Prel) sold for making a painted sheet can be cited.

The picture-added sheet produced using the ink of the present invention can be printed on a film of a base material such as polycarbonate by a method such as screen printing to form a predetermined pattern. Examples of the synthetic resin integrated with the decorative sheet of the present invention include a polycarbonate resin, an acrylonitrile-butadiene-styrene copolymer, and a polymer alloy of a polycarbonate resin / acrylonitrile-butadiene-styrene copolymer.

[0014]

EXAMPLES The present invention will be described below with reference to examples. Example 1A (Preparation of Ink 1) polycarbonate resin (manufactured by Mitsubishi Gas Chemical IUPILON FPC-2136) 20 parts by weight, synthetic resin-coated aluminum particles paste (Toyo Aluminum FZ-7160N particle size D _50: 13 .mu.m) 2
0 parts by weight, antifoaming agent (BYK-057 manufactured by BYK Chemie) 1
By weight, 20 parts by weight of cyclohexanone as a solvent, 20 parts by weight of propylene glycol monomethyl ether acetate, and 20 parts by weight of Solvesso # 150 were mixed and kneaded with a rotary stirrer to obtain an ink 1.

(Preparation of Picture Sheet) Ink 1 was used to form a solid print pattern by screen printing on a polycarbonate resin film having a size of 150 mm × 70 mm and a thickness of 500 μm, and thereafter 10
It dried at 0 degreeC for 2 hours, and produced the pictured sheet.

(Injection molding) The obtained sheet with a picture was placed in a mold for injection molding, and a polymer alloy consisting of a polycarbonate / acrylonitrile / butadiene / styrene copolymer was prepared from an injection molding machine in which the cylinder temperature was set to 250 ° C. (Mitsubishi Gas Chemical's Iupilon PM1210N)
Was supplied at 116 cm ³ / sec to prepare an injection-molded sample having a thickness of 1.5 mm.

(Measurement of Amount of Picture Flow) In the injection-molded sample 1 shown in plan view in FIG. 1, the maximum moving distance 5 of the image forming section from the end 4 of the printing section 3 by the ink on the picture-added sheet 2 was measured. It was measured and shown in Table 1 as the amount of picture flow.

(Measurement of Peel Strength) A 1 cm-wide cut is made on the painted sheet side of the injection-molded sample, peeled off from the injection-molded resin, and peeled off at a pulling speed of 300 mm / min to obtain a 180 ° peel strength tensile tester. It was measured at.

Example 1B A synthetic resin for injection molding was used at a cylinder temperature of 305 ° C.
In the same manner as in Example 1A except that a polycarbonate resin (Upilon S3000 manufactured by Mitsubishi Gas Chemical Co., Inc.) was supplied at 116 cm ³ / sec to prepare an injection molded sample having a thickness of 1.9 mm, and The amount of picture flow and the peel strength measured were shown in Table 2.

Example 2A (Preparation of Ink 2) Paste of aluminum particles coated with synthetic resin (FZ manufactured by Toyo Aluminum Co., Ltd.)
-Q65 particle size D _50: in the same manner as in Example 1A except that a 20 [mu] m) to prepare an ink 2. After injection molding was performed in the same manner as in Example 1A to prepare an injection molded sample, the amount of picture flow and the peel strength were measured, and the results are shown in Table 1.

Example 2B Except that ink 2 was used, injection molding was carried out in the same manner as in Example 1B to prepare an injection molded sample, and then the flow rate and peel strength were measured. The results are shown in Table 2.

Example 3A (Preparation of Ink 3) Same as Example 1A except that a paste of aluminum particles having aluminum particles surface-treated with a coupling agent (Toyo Aluminum 97-2515, particle diameter D ₅₀ : 9 μm) was used. To prepare Ink 3. After injection molding was performed in the same manner as in Example 1A to prepare an injection molded sample, the amount of picture flow and the peel strength were measured, and the results are shown in Table 1.

Example 3B Except that ink 3 was used, injection molding was carried out in the same manner as in Example 1B to prepare an injection molded sample, and then the flow rate and peel strength were measured. The results are shown in Table 2.

Comparative Example 1A (Preparation of Ink 4) As aluminum particles, particles not surface-treated (TD280T manufactured by Toyo Aluminum Co., Ltd.)
Particle size D ₅₀ : 20 μm), except that Example 1A was used.
Ink 4 was prepared in the same manner as in.

Injection molding was carried out in the same manner as in Example 1A to prepare an injection molded sample, and then the amount of picture flow and the peel strength were measured. The results are shown in Table 1.

COMPARATIVE EXAMPLE 1B The flow rate and the peel strength were measured after injection molding was carried out in the same manner as in Example 1B except that the ink 4 was used, and the results are shown in Table 2.

[0027]

Table 1 Example 1A Example 2A Example 3A Comparative Example 1A Picture flow rate (mm) 1.07 1.02 1.10 4.22 Peel strength (kN / m) 2.30 2.82 2.51 1.75

[0028]

[Table 2] Example 1B Example 2B Example 3B Comparative Example 1B Picture flow amount (mm) 1.54 1.65 1.47 7.5 7.5 Peel strength (kN / m) 2.98 2.96 2.94 1.44

[0029]

EFFECT OF THE INVENTION A molded article obtained by mounting a painting sheet produced by using the ink of the present invention on an injection molding die can reduce the amount of painting flow due to the flow of synthetic resin at the time of injection. Therefore, the yield of products can be improved.

[Brief description of drawings]

FIG. 1 shows a plan view of an injection-molded sample produced in an example of the present invention.

[Explanation of symbols]

1 ... Injection-molded sample, 2 ... Picture sheet, 3 ... Printing section, 4
... ends, 5 ... movement distance

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C09D 11/00-11/20 C09C 1/00-3/12 B29C 45/14

Claims (4)

(57) [Claims] 1. An ink for painting at the same time when molding is used for printing a painting sheet which is integrated with a synthetic resin melted in a synthetic resin molding step, and a surface coupling with a binder made of a polycarbonate resin. An ink containing metal particles coated with an agent or a synthetic resin. 2. The metal particles are flat aluminum particles coated with an acrylic resin.
Ink described. 3. A paint sheet, which is integrated with a synthetic resin melted in a synthetic resin molding step, has a binder made of a polycarbonate resin on a synthetic resin film, and a metal whose surface is coated with a coupling agent or a synthetic resin. A printed sheet, which is printed with an ink containing particles. 4. In the injection molding method, a painted sheet printed with an ink containing metal particles whose surface is coated with a coupling agent or a synthetic resin is placed inside a metal mold to melt the synthetic resin. An injection molding method characterized by performing injection molding at a temperature of 200 ° C. or higher.