JPH04135716A - Manufacture of molded object with covering layer - Google Patents

Abstract

PURPOSE:To obtain a laminate with strong adhesive force at low temperature by using vinylchloride resin and ABS resin as surface layer materials and by using modified amorphous propylene copolymer as an adhesive layer material. CONSTITUTION:An adhesive layer 2 is formed of an adhesive containing copolymers of modified amorphous propylene as a main component. The covering layer 3 made of vinylchloride resin or ABS resin is laminated on the surface of the formed object 4 made of polypropylene by strong adhesive strength by using the adhesive layer 2. The perform 3' for covering provided with the adhesive layer 2 is arranged in a mold along the inner surface of the stationary mold 5 for injection molding, and the movable mold 6 corresponding to the stationary mold is brought into close contact with the stationary mold, thereby closing the molds. Molten polypropylene is injected into the mold, and simultaneously with injection molding, the covering layer 3 formed of the perform is laminated on the surface of an injection molded object through the adhesive layer 2, whereby the molded object 1 with the covering layer is molded.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is a method in which a coating layer made of vinyl chloride resin or ABS resin is laminated on the surface of a polypropylene molded body through a special adhesive layer. The present invention relates to a method of manufacturing a molded article with a coating layer.

[Prior art and issues]

Molded objects made of polypropylene have excellent mechanical strength and chemical resistance and are used in various fields, but it is extremely difficult to print or paint the surface of the molded objects. Therefore, it was not possible to produce various figures and patterns on the surface of the molded product, and it was not possible to use it for decorative purposes.

Therefore, the surface of the polypropylene molded object has printability and
Vinyl chloride resin or A with excellent paintability and design properties
It has been proposed to laminate a covering layer made of BS resin.

However, polypropylene and vinyl chloride resin or ABS resin do not bond even if they are directly laminated, and no adhesive has been found that can strongly bond the two. It has been almost impossible to form a coating layer made of vinyl chloride resin or ABS resin that is strongly bonded to the surface.

To improve this point, Japanese Patent Application Laid-Open No. 56-10976
No. 0 is disclosed. This is made of vinyl chloride in the adhesive layer.
Although ethylene-vinyl acetate copolymer or the like is used, there are drawbacks such as insufficient adhesive strength and the need to raise the temperature of the molten polypropylene.

1. Means for Solving the Problem] The present inventors have developed a molded article with a coating layer, in which a vinyl chloride resin or ABS resin coating layer is strongly bonded to the surface of a polypropylene molded article. As a result of extensive research, the inventors discovered that the above object could be achieved by using a special adhesive used in the present invention, and completed the present invention.

That is, a coating preform made of vinyl chloride resin or ABS resin and provided with an adhesive layer containing a modified amorphous propylene copolymer as a main component is mixed with polypropylene supplied in a molten state and the adhesive. as possible in contact with the layer,
A movable mold corresponding to the fixed mold is placed along the inner surface of the fixed mold of the injection mold, and the mold is closed by closely contacting the fixed mold, and the molten state is transferred to the inside of the mold. A molded article with a coating layer, characterized in that, at the same time as the polypropylene is injected and injection molded, a coating layer formed from the preformed article is laminated on the surface of the injection molded article via the adhesive layer. This is the manufacturing method.

The molded article with a coating layer obtained by the method of the present invention has the coating layer laminated on the surface of the polypropylene molded article via the adhesive layer described above, and has excellent durability. It has the following.

According to the method of the present invention, even when the surface of a molded article made of polypropylene having a complicated curved surface is coated, wrinkles, uplifts, tears, etc. do not occur in the coating layer, and the above-mentioned excellent molded article with a coating layer can be obtained. is obtained.

Hereinafter, this invention will be described in more detail with reference to the drawings.

FIG. 1 is a sectional view showing an example of a molded article with a coating layer obtained by the method of the present invention, and FIG. FIG. 2 is a cross-sectional view schematically showing the manufacturing situation.

The adhesive layer 2 used in this invention is formed from an adhesive whose main component is a modified amorphous propylene copolymer.

In addition to the above-mentioned resin, the adhesive contains other thermoplastic resins that are dissolved in the solvent of the modified amorphous propylene copolymer.
It may be contained in a proportion of up to about 50% by weight, particularly up to 30% by weight.

In addition, in the present invention, the modified amorphous propylene copolymer of the present invention used as the main component of the adhesive layer is a non-copolymer of propylene produced for the purpose and other α-olefins such as ethylene and butene-1. A crystalline copolymer having a propylene component of 71 to 95 mol % and a number average molecular weight of 3.500 to 30.000 is preferable.

Further, the modifier of the copolymer is one in which an unsaturated carboxylic acid derivative component consisting of an unsaturated carboxylic acid, its anhydride, metal salt, ester, etc. is grafted.

Specifically, acrylic acid, methacrylic acid, maleic acid,
Fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, bicyclo(2,2,1)hept-2-ene-
Unsaturated carboxylic acids such as 5,6-dicarboxylic acid, maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, bicyclo(2,2,1)hept-2
Anhydrides of unsaturated carboxylic acids such as -ene 5.6-dicarboxylic anhydride, methyl acrylate, methyl methacrylate,
Dimethyl maleate, monomethyl maleate, diethyl fumarate, dimethyl itaconate, diethyl citraconate, dimethyl tetrahydrophthalate, bicyclo(2,
2,1) Esters of unsaturated carboxylic acids such as dimethyl hept-2-ene-5,6-dicarboxylate. Among these, maleic acid, itaconic acid, or anhydrides thereof are preferred.

The amount of grafting is 0.01 to 100 parts by weight of the copolymer.
It is 40 parts by weight.

In addition, chlorinated or chlorosulfonated products can be similarly used as modified products.

Known methods can be used for these modifications.

In the present invention, by using an adhesive layer mainly composed of the above-mentioned copolymer, a coating layer 3 made of vinyl chloride resin or ABS resin is applied to the surface of the polypropylene molded body 4 with a strong adhesive layer. It can be laminated by adhesive strength, and with an adhesive layer mainly composed of another resin that is 144 m thick with the above-mentioned resin, as shown in Comparative Examples 1 and 2, the surface of the polypropylene molded body is A molded article with a coating layer having a strongly bonded coating layer cannot be obtained.

The preformed body 3' for coating with vinyl chloride resin or ABS resin provided with an adhesive layer in the method of this invention is as follows:
For example, a solution prepared by dissolving an adhesive mainly composed of the above-mentioned resin in a heated organic solvent such as toluene, heptane, hexane, benzene, or perchloromethane is applied to one side of a sheet or film of vinyl chloride resin or ABS resin. The organic solvent is removed by evaporation from a thin film of the adhesive solution to form a sheet or film with an adhesive layer, or the copolymer is formed into a film containing an adhesive as the main component and the organic solvent is removed by evaporation from the thin film of the adhesive solution. A sheet (film) of resin or ABS resin is thermally laminated on one side to form an adhesive layer, and then the sheet (film) with the adhesive layer is heated under pressure. It can be manufactured by molding, vacuum forming, or other sheet forming methods into a preformed body (having a shape corresponding to the shape of the inner layer of a mold for producing a polypropylene molded body).

In the method of the present invention, the preformed body 3' for coating of vinyl chloride resin or ABS resin provided with the adhesive layer 2 is formed by supplying molten polypropylene and applying pressure to form the polypropylene. Although it is preferable that the molding die 5 has a shape that allows them to be brought into close contact with each other along the inner surface of the mold 5, it is not necessary that the molding die 5 and the preform 3' match in detail.

In the present invention, vinyl chloride resin refers to a vinyl chloride polymer, a copolymer of vinyl chloride containing 60% or more of vinyl chloride units and other monomers, 50% by weight or more, especially 6
It is a thermoplastic resin containing 0% by weight or more, and in addition to the above-mentioned vinyl chloride polymer or copolymer, it also contains other synthetic resins,
For example, the amount of the mixture of one or more of ethylene-vinyl acetate copolymer, ABS resin, MBS resin, acrylic resin, etc. is less than about 50% by weight, especially 40% by weight.
It may be contained in the following proportions. Preforms molded using vinyl chloride resin are molded from vinyl chloride resin containing various additives such as plasticizers, fillers, reinforcing agents, dyes, pigments, etc. It may be something that has been done.

In addition, in the present invention, ABS resin refers to 50% by weight of acrylonitrile-butadiene-styrene copolymer.
The above is a thermoplastic resin containing 60% by weight or more, and in addition to the ABS copolymer, other synthetic resins such as polyvinyl chloride, ethylene-vinyl acetate copolymer, M
One type or a mixture of two or more types of BS resin, acrylic resin, etc. may be contained in a proportion less than 50% by weight, particularly 40% by weight or less. Note that the preform molded using ABS resin may be molded from ABS resin mixed with various additives as appropriate.

The sheet (film) made of vinyl chloride resin or ABS resin used for molding the above-mentioned preform has an average thickness of about 0.01 to 2 m, especially 0.1 to 1 m. is preferable, and the surface of the sheet may be decorated by printing a pattern such as wood grain.

In this invention, the average thickness of the adhesive layer provided on the sheet is preferably about 5 to 500 microns, particularly about 10 to 300 microns. If the thickness of the adhesive layer is too small, it is not preferable because a coating layer that is strongly adhered to the surface of the polypropylene molded article cannot be laminated.

In the second invention, the polyethylene in the present invention is
These include polymers of monomers such as propylene, ethylene, and butene-1, crystalline copolymers, and mixtures and modified products thereof. Specifically, they include polypropylene, polyethylene, propylene/ethylene block, random copolymer, and the like. Conventionally known additives, fillers, etc. may be blended with the polypropylene.

In the method of the present invention, a preformed body 3' made of a vinyl chloride resin or ABS resin provided with the adhesive layer 2 described above is prepared so that the polypropylene supplied in a molten state can come into contact with the adhesive layer. The polypropylene is placed along the inner surface of the molding die 5, and molten polypropylene is supplied into the mold and pressurized, so that the preform is molded at the same time as the polypropylene is molded. The coating layer 3 is laminated on the surface of the molded article using an adhesive layer to produce a molded article with a coating layer.

In the method of the present invention, an injection molding method is most suitable, in which a molded article made of polypropylene can be formed by supplying molten polypropylene into a mold and pressurizing it.

In the method of the present invention, for example, the coating preform 3' provided with the adhesive layer 2 described above is placed in the mold along the inner surface of the fixed mold 5 for injection molding. The movable mold 6 corresponding to the fixed mold is brought into close contact with the fixed mold, and the mold is closed.
Polypropylene in a molten state heated to about 180 to 320°C is injected into the mold, and at the same time, the coating layer 3 formed from the preform is applied to the surface of the injection molded product. Laminated via the adhesive layer 2,
A method for molding the molded article 1 with a coating layer can be mentioned.

In the method of the present invention, by injecting the heated polypropylene as described above, a molded article with a coating layer is obtained in which the preformed article arranged as described above and the injection molded article of polypropylene are firmly adhered to each other. I can do it.

According to the method of this invention, vinyl chloride resin or AB
A beautiful coated molded article having an S-based resin coating layer can be obtained.

The molded article with a coating layer obtained by the method of the present invention is a polypropylene molded article having a beautiful coating layer with excellent durability, so it can be used for various decorative purposes, such as cases for furniture, electrical appliance cases, bags, etc. It can be used for the following purposes.

〔Example〕

Examples and comparative examples are shown below. In the following description, parts indicate parts by weight.

Example I 100 parts of ABS resin (acrylonitrile content: 25% by weight, butadiene content: 30% by weight, styrene content: 45% by weight) and higher alcohol (carbon number: 16-18
) ABS resin sheet formed by a calendar roll method using a resin composition consisting of 1 part (average thickness: approximately 0
．． 5 m) was printed with wood grain on the surface, and the back side of the sheet was coated with propylene content of 80 mol% and ethylene content of 2.
A hot toluene solution (concentration, 20%) of a modified amorphous copolymer grafted with 7.1% maleic anhydride was applied to a 0 mol% amorphous copolymer and dried to give an average thickness. is about 1
An adhesive layer of 5μ was provided.

The ABS resin sheet provided with this adhesive layer is vacuum-formed so that it can fit on the inner surface of an injection mold.
A preformed article for coating made of ABS resin and provided with an adhesive layer was formed.

This preform is placed along the inner surface of a fixed mold for injection molding, the mold is closed, and approximately 190″C2
Polypropylene in a molten state heated to 230° C. was injected to perform injection molding, the mold was cooled, the mold was opened, and the molded article with the coating layer was taken out.

This molded article with a coating layer had a beautiful wood grain pattern in which the ABS resin coating layer was integrally laminated on the surface of the polypropylene molded article.

A part of this molded article with a coating layer was cut out and the adhesive force between the ABS resin coating layer and the polypropylene molded article was measured. The peel strength at a peeling speed of 50 mm/min (180
degree) is 2.3 kg/cm (molten resin temperature approximately 190°
C), 3.1 kg/cm (molten resin temperature approx. 230
°C).

Comparative Example 1 Instead of the copolymer of Example 1, vinyl chloride-ethylene-
A solution of vinyl acetate copolymer (vinyl chloride content: 19%, ethylene content: 57%, vinyl acetate content: 24%) in a mixed solvent of toluene and n-hexane (polymer concentration: 31% by weight) A molded article with a coating layer was obtained in the same manner as in Example 1, except for using the same method.

This molded product with a covering layer has a covering layer with a beautiful wood grain pattern laminated on the surface of a polypropylene molded product, and when the adhesive strength was measured in the same manner as in Example 1, it was found to be similar to that of a polypropylene molded product. The peel strength (180 degrees), which indicates the adhesive strength with the ABS resin coating layer, is 0.7 kg/
cm (molten resin temperature approx. 190°C), 1.6 kg
/cm (molten resin temperature about 230''C).

Example 2 Example 1 except that the amorphous copolymer in Example 1 was replaced with a chlorinated modified copolymer (chlorine content, approximately 25%)
I did the same thing. Peel strength was 2.8 kg/cm (molten resin temperature of about 190°C), 3.3 kg/cm (molten resin temperature of about 230°C) Comparative Example 2 In Example 2, the modified amorphous copolymer The same procedure as in Example 2 was carried out except that chlorinated polypropylene (chlorination rate of about 25%) was used instead of chlorinated polypropylene.

The peel strengths were 1.1 kg/cm (molten resin temperature of about 190°C) and 2.6 kg/cm (molten resin temperature of about 230''C), respectively.

〔Effect of the invention〕

The present invention uses a vinyl chloride or ABS resin with good printability as the surface layer and a modified amorphous propylene copolymer as the adhesive layer to achieve stronger adhesive strength at a lower temperature than the conventional technology. A laminate containing the following properties is obtained.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of a molded article with a coating layer obtained by the method of the present invention, and FIG. FIG. 2 is a cross-sectional view schematically showing the manufacturing situation. 1.-Molded article with coating layer, 2...Adhesive layer, 3...Coating layer made of vinyl chloride resin or ABS resin, 3'.
... Preformed body, 4... Molded body made of thermoplastic resin, 5
...Fixed mold, 6...Movable mold. Ryo-ichikobi molded body

Claims (1)

[Claims] A coating preform made of vinyl chloride resin or ABS resin and provided with an adhesive layer mainly composed of a modified amorphous propylene copolymer is combined with polypropylene supplied in a molten state and the adhesive layer. A movable mold corresponding to the fixed mold is placed along the inner surface of the fixed mold so that contact is possible, and the movable mold corresponding to this fixed mold is closely contacted with the fixed mold to close the mold. It is characterized by injecting polypropylene in a molten state into a mold and performing injection molding, and at the same time, laminating a coating layer formed from the preform onto the surface of the injection molded product via the adhesive layer. A method for producing a molded article with a coating layer.