JP2002178462A - Sheet body and molded body manufactured from this sheet body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet body which dispenses with a primer and enables simplification of decorative coating and which brings about very strong adhesion of a decorative coating film when the decorative coating is to be applied on the surface of a sheet main body of which the surface layer at least is constituted of a thermoplastic olefin-series resin layer, and a formed body made of the sheet body. SOLUTION: The surface of the thermoplastic olefin-series resin layer (11) of the sheet main body (1) of which the surface layer at least is constituted of the layer (11) is treated with corona discharge and then coated with a film forming material containing a polyisocyanate so as to form a film (13). The sheet body obtained in this way is subjected to thermoforming to be made into the formed body.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet suitable for use as an interior material for a vehicle or a surface layer material of a furniture, and at least a surface layer of which is formed of a thermoplastic olefin resin layer, and a use thereof.

[Prior art]

The thermoplastic olefin resin has excellent moldability and recyclability and is used as a material in a wide range of fields. As one example, a sheet body in which a thermoplastic olefin-based resin layer is formed on a base cloth is widely used as an interior material of an automobile.

[0002] A sheet body or a molded body made of such a thermoplastic olefin resin is often subjected to surface coating for the purpose of improving scratch resistance, adjusting gloss, and coloring.

However, since the thermoplastic olefin resin is a non-polar material and has a low affinity with a paint (top coat) to be coated on the surface, the thermoplastic olefin resin has an affinity with the thermoplastic olefin resin at the time of coating. After coating and drying a primer such as a chlorinated polyolefin having the following formula, coating is performed.

[0004] The method of surface coating through such a primer treatment requires two steps of coating, which is complicated.

On the other hand, there is generally known a method in which an inactive surface of a thermoplastic olefin resin is subjected to a corona discharge treatment to activate the surface, thereby facilitating reception of a decorative paint.

For example, Japanese Patent Application Laid-Open No. 11-302983 discloses a technique in which at least a surface layer of a decorative sheet made of an olefin-based thermoplastic elastomer is subjected to a corona discharge treatment and then coated with a silicon-modified polycarbonate-based polyurethane solution. Is disclosed.

However, in this case, since the silicone-modified polycarbonate-based polyurethane solution is one-part,
The isocyanate component already mixed is used for urethane bonding for forming a film, and does not positively contribute to adhesion to an active surface subjected to corona discharge treatment.

[0008]

SUMMARY OF THE INVENTION According to the present invention, when decorative coating is performed on the surface of a sheet body in which at least the surface layer is made of a thermoplastic olefin resin layer, a primer can be easily prepared without requiring a primer, and the decorative coating film can be formed. An object of the present invention is to provide a sheet body that is very tightly adhered and a molded article manufactured from the sheet body.

[0009]

Thus, according to the invention of claim 1 of the present application, "the thermoplastic olefin-based resin of the sheet main body (1) having at least the surface layer composed of the thermoplastic olefin-based resin layer (11)" is described. After the surface of the layer (11) is subjected to a corona discharge treatment, a sheet (A1) "coated with a coating (13) made of a polyisocyanate-containing coating forming material is provided.

Further, according to the invention of claim 7 of the present application, there is provided "a molded article obtained by subjecting the sheet (1) of the present invention to thermoforming such as injection compression molding, vacuum molding". .

In the sheet body (A1) of the present invention, the surface of the thermoplastic olefin resin layer (11) is subjected to corona discharge treatment to generate a polar group such as a hydroxyl group on the surface. A urethane reaction occurs with the isocyanate contained in the material, whereby the coating (13) is formed in close contact with the resin layer (11).

In the molded article according to the present invention, the molded article is thermoformed from a sheet having a thermoplastic olefin-based resin layer having a surface firmly adhered to the surface thereof, so that the molded article is free from bending during molding. Also, the finished product has a beautiful finish without peeling or cracking, and the surface of the molded product has extremely improved scratch resistance, gloss control, coloring and the like, and has excellent durability.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION In the sheet (A1) of the present invention,
The sheet body (1) may be composed of a single resin layer as long as its surface layer is composed of the thermoplastic olefin resin layer (11), or may be a laminate of a plurality of resin layers. It may be. When laminated, it may be a non-foamed layer or a foamed layer.

In the sheet body (A1) of the present invention, the thermoplastic olefin resin layer (11) is composed of a thermoplastic olefin resin, an olefin thermoplastic elastomer and a mixture thereof, as described in claim 2 of the present application. One selected from
It is composed of

Examples of the thermoplastic olefin resin include polypropylene, low-density polyethylene, linear low-density polyethylene, high-density polyethylene, and ethylene-vinyl acetate copolymer, as described in claim 3 of the present application. One or a mixture of two or more selected from the following is used.

As the olefin-based thermoplastic elastomer, those known in the art can be used as they are, but as described in claim 4 of the present application, a mixture of polypropylene and ethylene-propylene-diene terpolymer is used. It is preferably used. However, the invention is not limited thereto. For example, a mixture of a partially crosslinked product of an ethylene α-olefin copolymer rubber and an olefin resin, a partially crosslinked product of an ethylene α-olefin copolymer and an olefin resin, ethylene α -A partially crosslinked product of an olefin copolymer rubber and an ethylene resin, a mixture of a rubber-like material such as a natural rubber or a synthetic rubber and an olefin resin, and the like can also be used.

The olefin-based thermoplastic elastomer may contain, if necessary, a softening agent such as paraffin-based oil and olefin-based wax, an inorganic filler such as calcium carbonate and talc, an antioxidant, a light stabilizer, and an ultraviolet absorber. Various additives such as an agent, an antistatic agent, a lubricant, and a colorant can be added.

In the sheet (A1) of the present invention, the corona discharge treatment for activating the surface of the thermoplastic olefin-based resin layer (11) is performed as described in claim 5 of the present application. It is preferable that the index is set so as to be 40 dyne / cm or more.

As the film-forming material used in the present invention, a topcoat paint known in the art can be used as it is, except that it contains a polyisocyanate. For example, a urethane paint or an acrylic paint can be prepared. Is mentioned. At this time, the 100% modulus is 40 to 50.
It is preferably prepared to be kg / cm2, but is not particularly limited to this.

The polyisocyanate may be any polyisocyanate having two or more isocyanate groups. Examples thereof include aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, diisocyanates having a cyclic group, and the like. Specifically, toluene diisocyanate (TDI), diphenylmethane-4,4′-diisocyanate (MDI), modified Examples include toluene diisocyanate and polymethylene polyphenylene isocyanate (PAPI). The polyisocyanate is used alone or in a mixture of two or more. Further, a prepolymer obtained by reacting an excess of isocyanate with a polyester polyol or a polyether polyol can also be used.

The film-forming material is preferably prepared as a urethane-based paint. In this case, as shown in claim 6 of the present application, the resin solid content of the urethane-based paint is 100%.
Those containing 6 to 20 parts by weight of polyisocyanate with respect to parts by weight are preferably used. When the content of the polyisocyanate is less than 6 parts by weight, the adhesiveness to the sheet surface is not stable (some portions having insufficient adhesiveness appear). It is not preferable in that it easily occurs and the cost increases. A more preferable content ratio is 8 to 10.
Parts by weight.

The urethane-based coating is preferably a carbonate-based coating. In this case, a modified acrylic product may be used.

The above film forming material is dissolved in an appropriate organic solvent. As the organic solvent, methanol, ethanol, isopropyl alcohol, isobutyl alcohol,
Butanol, toluene, xylene, methyl ethyl ketone, methyl-n-propyl ketone, methyl isobutyl ketone, diethyl ketone, methyl cellosolve, butyl cellosolve, cellosolve acetate, dimethylformamide,
Examples thereof include dimethylacetamide, dimethylsulfoxide, and N-methylpyrrolidone, and these are used alone or in a mixture of two or more.

The film-forming material may contain various additives such as a coloring agent, an antioxidant, a light stabilizer, an antistatic agent, a flame retardant, and a filler, if necessary. It can be added within a range that does not impair the properties and the like.

In the present invention, it is preferable that the above-mentioned film-forming material is applied by spraying when applied to the surface of the thermoplastic olefin-based resin layer (11). However, the present invention is not limited to this. It may be applied by an appropriate means such as a roll coater or a gravure roll coater.

The above-mentioned film-forming material is dried after application to form a film, and preferably has a film thickness after drying of about 5 to 10 μm.

The sheet (A1) of the present invention obtained as described above may be embossed by means known in the art. In this case, embossing may be performed before the coating material is applied.

Further, the sheet body (A1) of the present invention can be produced into molded articles of various shapes by subjecting the sheet body to known thermoforming such as injection compression molding and vacuum molding.

[0029]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited by these examples.

Example 1 (1) Production of Sheet Body An olefin-based thermoplastic elastomer composed of a mixture of polypropylene and ethylene-propylene-diene terpolymer (EPDM), and a linear low-density polyethylene (LLD)
The resin blended with (PE) is melted and extruded with a T-die, and the resulting molten sheet is passed through an embossing roll and squeezed and cooled while adhering a foamed polypropylene sheet thereto. As shown in FIG. 1, a sheet body (1) having a thermoplastic olefin-based resin layer (11) as a surface layer and a foamed polypropylene sheet (12) laminated on the back surface thereof was obtained. The thickness of the thermoplastic olefin-based resin layer (11) was 0.5 mm.

(2) Surface Treatment of Sheet Body (1) The surface of the thermoplastic olefin resin layer (11) of the sheet body (1) obtained above is subjected to a corona discharge treatment (c), The sheet body (1) was subjected to a surface treatment by applying a surface wetting index of 40 dyn / cm or more.

(3) Production of Sheets (A1) to (A4) Four types of top coats (film-forming materials) (a) to (f) having the following compositions were added to the sheet body (1) surface-treated as described above.
(D) spray coating and drying each to form a coating (coating) (13)
To form a sheet body (A) of the present invention having a configuration as shown in FIG.
1) to (A4) were obtained.

Composition of Topcoat (a) Polycarbonate polyurethane paint (resin solid content 13
%) [A1 component] Isocyanate [b component] Solvent [c component] Methyl ethyl ketone 20% Xylene 30% Methyl isobutyl ketone 20% Isobutyl alcohol 15% Isopropyl alcohol 15% [Blending ratio (weight ratio)] a1 component: b component: c Ingredient = 100: 4: 200

Composition of Top Coat (b) Polycarbonate polyurethane paint (resin solid content 13
%) [A1 component] Isocyanate [b component] Solvent [c component] Methyl ethyl ketone 20% xylene 30% methyl isobutyl ketone 20% isobutyl alcohol 15% isopropyl alcohol 15% Pigment / silica dispersion (solid content 20%) [d component] [Blending ratio (weight ratio)] a1 component: b component: c component: d component = 100: 4: 20
0:20

Composition of Topcoat (C) Acrylic-modified polycarbonate polyurethane paint (resin solid content 6%) [a2 component] Isocyanate [b component] Solvent [c component] Methyl ethyl ketone 20% Xylene 30% Methyl isobutyl ketone 20% Isobutyl alcohol 15% Isopropyl alcohol 15% [Blending ratio (weight ratio)] a2 component: b component: c component = 100: 4: 30

Composition of top coat (d) Acrylic-modified polycarbonate polyurethane paint (resin solid content 6%) [a2 component] Isocyanate [b component] Solvent [c component] Methyl ethyl ketone 20% Xylene 30% Methyl isobutyl ketone 20% Isobutyl alcohol 15% Isopropyl alcohol 15% Pigment / silica dispersion (solid content 20%) [d component] [Blending ratio (weight ratio)] a2 component: b component: c component: d component = 100: 4: 30:
20

As comparative examples, the following four types of topcoats (e) to (h) containing no isocyanate were prepared,
These were spray-coated and dried on a sheet body (1) similar to the above to form a film, and the sheet bodies (B1) to (B) of Comparative Examples
4) was obtained.

Composition of Topcoat (e) Polycarbonate polyurethane paint (resin solid content 13
%) [A1 component] Solvent [c component] Methyl ethyl ketone 20% Xylene 30% Methyl isobutyl ketone 20% Isobutyl alcohol 15% Isopropyl alcohol 15% [Blending ratio (weight ratio)] a1 component: c component = 100: 200

Composition of Top Coat (f) Polycarbonate polyurethane paint (resin solid content 13
%) [A1 component] Solvent [c component] Methyl ethyl ketone 20% Xylene 30% Methyl isobutyl ketone 20% Isobutyl alcohol 15% Isopropyl alcohol 15% Pigment / silica dispersion (solid content 20%) [d component] [Blending ratio (weight Ratio)] a1 component: c component: d component = 100: 200: 20

Composition of top coat (g) Acrylic-modified polycarbonate polyurethane paint (resin solid content 6%) [a2 component] Solvent [c component] Methyl ethyl ketone 20% xylene 30% methyl isobutyl ketone 20% isobutyl alcohol 15% isopropyl alcohol 15 % [Blending ratio (weight ratio)] a2 component: c component = 100: 30

Composition of Top Coat (H) Acrylic-modified polycarbonate-based polyurethane coating (resin solid content 6%) [a2 component] Solvent [c component] Methyl ethyl ketone 20% Xylene 30% Methyl isobutyl ketone 20% Isobutyl alcohol 15% Isopropyl alcohol 15 % Pigment / silica dispersion (solid content 20%) [d component] [Blending ratio (weight ratio)] a2 component: c component: d component = 100: 30: 20

With respect to the sheet bodies (A1) to (A4) of the present invention obtained as described above and the sheet bodies (B1) to (B4) of the comparative examples, a peeling test and a chemical resistance test were similarly performed. The evaluation was performed as follows.

<< Peeling Test >> 10 × 10 grids were formed on the coating (coating) surface at intervals of 2 mm with a cutter knife, and Nichiban cellophane tape was sufficiently adhered to this portion with a roller.
The number of grids remaining after peeling vigorously was counted.

<< Chemical Resistance Test >> About 30 mm in width and about 22 in length
Take a 0 mm test piece, attach it to the test bench of the Gakushin type friction tester specified in JIS-L-0823, and cover the contact surface of the friction element with white cotton cloth (Kanakin No. 3) impregnated with petroleum benzene. The test piece was reciprocated 200 times at a speed of reciprocating 30 times per minute between 100 mm test pieces under a load of 1.96 N (200 gf), and the frictional surface was visually judged.

<< Evaluation >>

[Table 1]

From the above results, it can be seen that the sheet (A1) of the present invention
In all of (A4), it can be seen that the coating film (coating film) is firmly adhered and the chemical resistance is good.

Example 2 Each of the sheet bodies (A1) to (A4) of the present invention obtained in Example 1 and Comparative Examples (B1) to (B4) was subjected to injection compression molding using a door lining mold. Do
The appearance of the obtained molded product was evaluated visually for cracks or peeling of the coating film (coating film), and the moldability was evaluated. The results shown in Table 2 below were obtained.

[0048]

[Table 2]

From the above results, the sheet (A1) of the present invention
It can be seen that (A4) has good thermoformability. Therefore, it is suitable for automotive interior materials.

[0050]

According to the sheet body of the present invention, the surface of the thermoplastic olefin resin layer constituting the surface layer of the sheet body is subjected to a corona discharge treatment and a polar group such as a hydroxyl group is generated on the surface. Since a film-forming material containing an isocyanate that undergoes a urethane reaction with the polar group is applied to form a film, the film (coating) of the decorative material can be very firmly adhered to the resin layer.

Accordingly, it is possible to provide a sheet body having extremely improved scratch resistance, gloss control, coloring and the like.

Further, the molded article of the present invention has scratch resistance, gloss control,
Since the sheet is thermoformed from a sheet whose coloring and the like have been greatly improved, it is possible to easily provide a molded article having excellent durability and excellent durability without cracks or peeling.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of an example of a sheet body used for a sheet body of the present invention.

FIG. 2 is a schematic cross-sectional view of an example of the sheet body of the present invention.

[Explanation of symbols]

 (A1) Sheet body (1) Sheet body (11) Thermoplastic olefin resin layer (surface layer) (12) Foamed polypropylene sheet (13) Film (coating)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08J 7/00 303 C08J 7/00 303 7/04 CES 7/04 CSE F-term (Reference) 4D075 BB44Y BB49Y CA02 CA13 CA32. BA10C CC00C DJ01A EJ40 EJ55B GB33 GB81 HB00C JB01 JB16B JL11

Claims (7)

[Claims] 1. A sheet body comprising at least a surface layer comprising a thermoplastic olefin resin layer, wherein the surface of the thermoplastic olefin resin layer is subjected to a corona discharge treatment and thereafter coated with a film comprising a polyisocyanate-containing film-forming material. Sheet body. 2. The thermoplastic olefin-based resin layer,
The sheet member according to claim 1, wherein the sheet member is formed of one selected from a thermoplastic olefin resin, an olefin-based thermoplastic elastomer, and a mixture thereof. 3. The thermoplastic olefin resin is one or a mixture of two or more selected from the group consisting of polypropylene, low-density polyethylene, linear low-density polyethylene, high-density polyethylene, and ethylene-vinyl acetate copolymer. The sheet according to claim 2. 4. The sheet according to claim 2, wherein the olefin-based thermoplastic elastomer is composed of polypropylene and an ethylene-propylene-diene terpolymer. 5. The sheet according to claim 1, wherein the corona discharge treatment is performed so that a surface wetting index after the treatment is 40 dyne / cm or more. 6. The film-forming material is a urethane-based paint containing an isocyanate and a urethane-based paint having a resin solid content of 10%.
The sheet according to any one of claims 1 to 5, having a composition in which the polyisocyanate is contained in a proportion of 6 to 20 parts by weight with respect to 0 parts by weight. 7. A molded product obtained by subjecting the sheet according to any one of claims 1 to 6 to thermoforming such as injection compression molding or vacuum molding.