JP2023011269A - Resin sheet, laminate, molding and method for manufacturing molding - Google Patents

Abstract

A resin sheet having a high color saturation and a deep appearance is provided.
A resin sheet containing polypropylene containing smectic crystals and an interference pearl pigment.
[Selection figure] None

Description

TECHNICAL FIELD The present invention relates to a resin sheet, a laminate, a molded article, and a method for producing a molded article.

BACKGROUND ART Painting is used as a method for improving appearance design in various fields such as automobiles, home appliances, building materials, daily necessities, and information communication equipment. However, since painting emits a large amount of VOC, it is a method with a large environmental load. Furthermore, the temperature and humidity control of the painting booth and the baking process consume a large amount of energy and emit a large amount of carbon dioxide. Especially in the production of new cars, paint accounts for 20% of the carbon dioxide emitted. In order to reduce these environmental loads, construction methods that replace painting are actively being developed.

As a method for substituting the coating of molded articles, for example, Patent Document 1 discloses a technique for obtaining a molded article having a flip-flop appearance by using a resin composition having a specific composition containing a pearl pigment or the like. It is

JP-A-2006-9034

However, in the method disclosed in Patent Document 1, since the color development of the pearl pigment is impaired, the chroma of the molded product is low, and the depth of the design is poor. In addition, although it is necessary to increase the amount of the pearl pigment added in order to improve the color development, it has been difficult to improve the depth of the design even if the concentration of the pearl pigment is increased.
An object of the present invention is to provide a resin sheet having a high color saturation and a deep appearance.

According to the present invention, the following resin sheet and the like are provided.
1. A resin sheet containing polypropylene containing smectic crystals and an interference pearl pigment.
2. 2. The resin sheet according to 1, wherein the polypropylene has an isotactic pendant fraction of 85 mol % to 99 mol %.
3. 3. The resin sheet according to 1 or 2, wherein the polypropylene has a crystallization speed at 130° C. of 2.5 min ⁻¹ or less.
4. 4. The resin sheet according to any one of 1 to 3, wherein the polypropylene has an exothermic peak of 1 J/g or more on the low temperature side of the maximum endothermic peak in a curve obtained by differential scanning calorimetry.
5. 5. The resin sheet according to any one of 1 to 4, wherein the interference pearl pigment is one or more selected from the group consisting of titanium oxide-coated mica, titanium oxide-coated glass, and titanium oxide-coated alumina.
6. 6. The resin sheet according to any one of 1 to 5, wherein the content of the interference pearl pigment is 0.01% by mass or more and 20% by mass or less.
7. A laminate comprising a first layer comprising polypropylene containing smectic crystals and a second layer comprising the resin sheet according to any one of 1 to 6.
8. 8. Laminate according to 7, comprising a third layer comprising a thermoplastic resin and a colorant on the side of the second layer opposite the first layer.
9. A laminate comprising the resin sheet according to any one of 1 to 6 and an easy-adhesion layer.
10. 10. The laminate according to 9, wherein the easy-adhesion layer contains one or more resins selected from the group consisting of urethane, acrylic, polyolefin and polyester.
11. 11. The laminate according to 9 or 10, which has a printed layer on the surface of the easy-adhesion layer opposite to the resin sheet.
12. A molded article produced using the resin sheet described in any one of 1 to 6 or the laminate described in any one of 7 to 11.
13. A method for producing a molded body by molding the resin sheet according to any one of 1 to 6 or the laminate according to any one of 7 to 11.
14. placing the resin sheet or laminate on a mold; and feeding molding resin toward the resin sheet or laminate to conform the resin sheet or laminate to the mold. 14. The method for producing a molded article according to 13, comprising integrating the molding resin and the resin sheet or the laminate while shaping as in the above.
15. shaping the resin sheet or the laminate so as to match a mold; and supplying a molding resin toward the shaped resin sheet or the shaped laminate. 14. The method for producing a molded article according to 13, comprising integrating a resin with the shaped resin sheet or the shaped laminate.
16. heating the resin sheet or the laminate and placing it on the cavity surface of a mold to shape the resin sheet or the laminate so as to match the shape of the mold; Integrating the molding resin with the shaped resin sheet or the shaped laminate by supplying it toward the shaped resin sheet or the shaped laminate. 14. The method for producing a molded article according to 13, comprising:
17. A core material is arranged in a chamber box, the resin sheet or the laminate is arranged above the core material, the resin sheet or the laminate is heated and softened, and the pressure in the chamber box is reduced to perform the heating. 14. The method for producing a molded article according to 13, wherein the softened resin sheet or the heat-softened laminate is pressed against the core material to cover it.
18. Interior materials for vehicles, exterior materials for vehicles, exterior covers for straddle-type vehicles, housings for household appliances, decorative steel plates, decorative panels, housing equipment, or information communication, which are produced using the molded article according to 12. equipment housing.

ADVANTAGE OF THE INVENTION According to this invention, the resin sheet which has a deep appearance with high saturation can be provided.

Hereinafter, the resin sheet, laminate, molded article, and method for producing the molded article according to the present invention will be described. In this specification, "x to y" represents a numerical range of "x or more and y or less". If there are multiple lower limits such as "x or more" or multiple upper limits such as "y or less" for one technical matter, arbitrarily select and combine the upper and lower limits shall be possible.

1. Resin Sheet A resin sheet according to an aspect of the present invention contains polypropylene containing smectic crystals and an interference pearlescent pigment.
Smetic crystals are intermediate phases in a metastable state, and since each domain size is small, polypropylene having smectic crystals has high transparency. By mixing an interference pearl pigment with such a polypropylene-based resin sheet, the color and brightness of the interference pearl pigment can be fully exhibited, and a bright appearance without cloudiness can be realized. In addition, the high transparency of polypropylene produces a sense of depth (three-dimensional effect), and the flip-flop property (shadow effect) of the interference pearl pigment is also combined, so that a resin sheet with depth and high design property can be obtained. Moreover, by adopting such a resin sheet for the surface of the molded article, it is possible to obtain a molded article having excellent designability as described above.
Each material used for the resin sheet will be described below.

(polypropylene)
Polypropylene is a polymer containing at least propylene. Specific examples include homopolypropylene, copolymers of propylene and olefins, and the like. In particular, homopolypropylene is preferred because of its heat resistance and hardness.

The polypropylene used in the resin sheet according to one aspect of the present invention contains smectic crystals. As described above, smectic crystals are intermediate phases in a metastable state, and are excellent in transparency due to the small size of each domain. Since the α-crystals contained in the polypropylene sheet obtained by the conventional method have a large crystal size, the molded article usually has an opaque and cloudy appearance. Even if a pearl pigment is added to such polypropylene, the color development of the pearl pigment is poor due to the effect of white turbidity, the chroma becomes low, and the design lacks depth. Since transparency can be obtained, such problems can be eliminated and an excellent appearance can be realized.
In addition, since smectica crystals are in a metastable state, the sheet is softened with a lower amount of heat than α-crystals, which are highly crystallized.

The crystal structure of polypropylene may include other crystal forms such as α-crystal, β-crystal, γ-crystal, and amorphous part, in addition to smectica crystal.
For example, 10% by mass or more, 20% by mass or more, 30% by mass or more, 50% by mass or more, 70% by mass or more, or 90% by mass or more of the polypropylene in the resin sheet may be smectic crystals.
A specific method for confirming the crystal structure is as described in Examples described later.

In one aspect of the present invention, the polypropylene preferably has an isotactic pentad fraction of 80 mol % or more.
If the isotactic pentad fraction is 80 mol % or more, sufficient rigidity can be obtained when made into a resin sheet.
The isotactic pentad fraction of polypropylene is preferably 85 mol% or more, more preferably 90 mol% or more, further preferably 95 mol% or more, and 99 mol% or less. preferably 98.5 mol % or less.
When the isotactic pentad fraction is 80 mol % or more and 99 mol % or less, a resin sheet having excellent rigidity and sufficient transparency can be obtained.
The isotactic pentad fraction is preferably 80 mol% or more and 99 mol% or less, more preferably 85 mol% or more and 99 mol% or less, and 90 mol% or more and 98.5 mol% or less. is more preferable.

The isotactic pentad fraction is the isotactic fraction of a pentad unit (five consecutive isotactic bonds of propylene monomers) in the molecular chain of the resin composition. This fraction can be measured by, for example, the method described in Macromolecules, Vol. 8 (1975), p. 687, and can be measured by ¹³ C-NMR.
A specific method for measuring the isotactic pentad fraction is as described in Examples below.

A copolymer of propylene and an olefin may be a block copolymer or a random copolymer as long as the isotactic pentad fraction is 80 mol % or more (preferably 80 to 99 mol %). or a mixture thereof.
Olefins include ethylene, butylene, cycloolefins, and the like.

In one aspect of the present invention, the melt flow rate (hereinafter sometimes referred to as "MFR") of polypropylene is preferably 0.5 g/10 min or more, more preferably 1 g/10 min or more. , 2 g/10 minutes or more. Further, it is preferably 10 g/10 minutes or less, more preferably 8 g/10 minutes or less, and even more preferably 6 g/10 minutes or less. Within this range, the formability into a film shape or a sheet shape is excellent. The MFR of polypropylene is measured at a temperature of 230° C. and a load of 2.16 kg according to JIS-K7210.

In one aspect of the present invention, the crystallization rate of polypropylene at 130° C. is preferably 2.5 min ⁻¹ or less, more preferably 2.0 min ⁻¹ or less, from the viewpoint of moldability.
When the crystallization speed is 2.5 min ⁻¹ or less, it is possible to prevent deterioration of the design.
Although the lower limit is not particularly limited, it is usually 0.01 min ^-1 or more, preferably 0.05 min ^-1 or more.
A specific method for measuring the crystallization rate is as described in Examples.

In one aspect of the present invention, the resin sheet does not substantially contain a nucleating agent, or preferably does not contain a nucleating agent.
Even when the nucleating agent is included, it is preferably in a small amount, for example, 1.0% by mass or less, 0.5% by mass or less, 0.1% by mass or less, or 0.01% by mass of the resin composition. or less, or 0.001% by mass or less. Moreover, it is 1.0 mass % or less, 0.5 mass % or less, 0.1 mass % or less, 0.01 mass % or less, or 0.001 mass % or less with respect to the amount of polypropylene.
Nucleating agents include, for example, sorbitol-based crystal nucleating agents, and commercially available products include Gelol MD (Shin Nihon Rikagaku Co., Ltd.) and Rikemaster FC-1 (Riken Vitamin Co., Ltd.).

In one embodiment, the crystallization rate of polypropylene is set to 2.5 min ⁻¹ or less without adding a nucleating agent, and the above-described smectic crystals are formed by cooling at 80 ° C./sec or more to achieve excellent transparency. It is possible to obtain a resin sheet having

In order to obtain a resin sheet having an isotactic pentad fraction of 80 mol % or more and 99 mol % or less and a polypropylene crystallization rate of 2.5 min ^-1 or less and having excellent transparency and gloss, smectica crystals are usually used. It is necessary to form
By heating the resin sheet, the polypropylene in the resin sheet transitions to α crystals while maintaining the fine structure derived from smectica crystals, but the polypropylene in the molded product has an isotactic pentad fraction of 85 mol% or more. If it is 99 mol % or less and the crystallization rate of polypropylene is 2.5 min ⁻¹ or less, it can be said that it is derived from smectic crystals.

By calculating the scattering intensity distribution and the long period by the small-angle X-ray scattering analysis method, it is possible to judge whether the resin sheet is obtained by cooling at 80° C./sec or more or not. That is, it is possible to judge whether or not the resin sheet has a fine structure derived from smectic crystals by the above analysis. Measurement is performed under the following conditions.
・An ultraX 18HF (manufactured by Rigaku Corporation) is used as an X-ray generator, and an imaging plate is used to detect scattering.
・Light source wavelength: 0.154 nm
・Voltage/current: 50kV/250mA
・Irradiation time: 60 minutes ・Camera length: 1.085m
・Sample thickness: Sheets are stacked so that the thickness is 1.5 to 2.0 mm. The sheets are stacked so that the film-forming (MD) direction is aligned.
In order to shorten the measurement time, the sheets are overlapped so as to have a thickness of 1.5 to 2.0 mm.

In one aspect of the present invention, the polypropylene is preferably 1 J / g or more, preferably 1.5 J / g or more on the low temperature side of the maximum endothermic peak in a curve (DSC curve) obtained by differential scanning calorimetry (DSC) measurement. It has an exothermic peak (also referred to as a “low temperature side exothermic peak”). Although the upper limit is not particularly limited, it is usually 10 J/g or less.

In one aspect of the present invention, the content of polypropylene in the resin sheet is usually 50% by mass or more, 60% by mass or more, or 70% by mass or more, preferably 80% by mass or more or 90% by mass or more. .
In addition, it is usually 99.99% by mass or less, preferably 99.97% by mass or less or 99.95% by mass or less, and may be 99.7% by mass or less or 99.5% by mass or less.

(interference pearl pigment)
An interference pearl pigment is a pigment in which the surface of a flaky substrate (scale-like fine particles) is coated with a metal oxide made of a colorless material with a high refractive index such as titanium oxide, and generally has translucency. By arranging such scaly microparticles in layers, light is reflected multiple times, and a metallic or pearl-like luster can be produced.
In addition, since the coating layer has a constant thickness, reflected light and transmitted light change to produce various interference colors, and the color changes depending on the viewing direction (angle) (flip-flop property). Interference pearl pigments are sometimes called iridescent pearl pigments or polarizing pearl pigments.
Examples of flaky substrates include mica (mica), alumina, glass (glass flakes), silica and the like.

Interference pearlescent pigments include, but are not limited to, titanium oxide-coated mica, titanium oxide-coated glass, and titanium oxide-coated alumina.
As the interference pearl pigment, one type may be used alone, or two or more types may be used in combination.

干渉パール顔料の市販品（商品名）としては、例えば、Ｌｕｍｉｎａ Ｒｏｙａｌ Ｒｕｓｓｅｔ、Ｌｕｍｉｎａ Ｅｘｔｅｒｉｏｒ Ｒｕｓｓｅｔ Ｓ５９０３Ｄ、Ｌｕｍｉｎａ Ｒｏｙａｌ Ｃｏｐｐｅｒ、Ｌｕｍｉｎａ Ｒｏｙａｌ Ｅｘｔｅｒｉｏｒ Ｂｌｕｅ ６８０３Ｈ、Ｌｕｍｉｎａ Ｅｘｔｅｒｉｏｒ Ｇｏｌｄ ２３０３Ｄ、Ｌｕｍｉｎａ Ｅｘｔｅｒｉｏｒ Ｂｒａｓｓ ２３２３Ｄ、Ｍｅａｒｌｉｎ Ｅｘｔｅｒｉｏｒ ＣＦＳ Ｍｉｃｒｏ Ｒｕｓｓｅｔ ４５０３Ｍ 、Ｍｅａｒｌｉｎ Ｅｘｔｅｒｉｏｒ ＣＦＳ Ｂｒｉｇｈｔ Ｓｉｌｖｅｒ １３０３Ｚ、Ｇｌａｃｉｅｒ Ｅｘｔｅｒｉｏｒ Ｆｒｏｓｔ Ｗｈｉｔｅ Ｓ１３０３Ｄ（以上、ＢＡＳＦカラー＆エフェクトジャパン株式会社製）、Ｉｒｉｏｄｉｎ ７２２５ Ｕｌｔｒａ Ｒｕｔｉｌｅ Ｂｌｕｅ Ｐｅａｒｌ、Ｉｒｉｏｄｉｎ ７２１９ Ｕｌｔｒａ Ｒｕｔｉｌｅ Ｌｉｌａｃ Ｐｅａｒｌ、Ｘｉｒａｌｌｉｃ Ｇａｌａｘｙ Ｂｌｕｅ、Ｃｏｌｏｒｓｔｒｅａｍ Ｔ１０－０４ Ｌａｐｉｓ Ｓｕｎｌｉｇｈｔ , Miraval 5426 Magic Green, Miraval 5421 Magic Copper (manufactured by Merck Performance Materials LLC), TWINCLE PEARL SXA, and TWINCLE PEARL YXB (manufactured by Nihon Koken Kogyo Co., Ltd.).

In one aspect of the present invention, the particle size of the interference pearlescent pigment is usually 1-200 μm, preferably 5-100 μm.
The particle size of the interference pearl pigment is measured using a particle size distribution meter. Specifically, according to JIS Z 8828 (2013), using a dynamic light scattering particle size distribution analyzer, a measurement sample in which particles are dispersed in a dispersion medium is placed in a sample cell. A measurement sample is irradiated with laser light, and the particle size distribution is obtained based on the frequency intensity distribution of the light scattered by the particles.
It is preferable that at least 70% by number, at least 80% by number, or at least 90% by number of all the particles fall within the above particle size range. In the present specification, the phrase “pigment mainly composed of particles having a particle size of AA to BB μm” means that the particle size of 90% or more of the particles contained in the pigment is within the range of AA to BB μm. .

In one aspect of the present invention, the content of the interference pearl pigment in the resin sheet is usually 0.01% by mass or more, preferably 0.03% by mass or more, and more preferably 0.05% by mass or more. For example, it may be 0.3% by mass or more, or 0.5% by mass or more. Moreover, it is usually 20% by mass or less, preferably 10% by mass or less.

In one aspect of the present invention, the thickness of the resin sheet may be 5 μm or more, 10 μm or more, or 20 μm or more, and may be 3000 μm or less, 2000 μm or less, or 500 μm or less.

2. Laminate The resin sheet according to one aspect of the present invention may be formed into a laminate by laminating layers for imparting various functions and design properties. Examples of such layers include transparent layers and colored layers, as described below.

(transparent layer, colored layer)
A laminate according to an aspect of the present invention includes a first layer (transparent layer) containing polypropylene containing smectic crystals, and a second layer (interference pearl pigment-containing layer) made of the above resin sheet.

As described for the resin sheet, polypropylene containing smectica crystals has high transparency. A further sense of depth (three-dimensional effect) is produced over the entire body, making it possible to achieve an appearance with greater depth and design.

The polypropylene used for the first layer (transparent layer) is the same as the polypropylene used for the resin sheet according to one aspect of the present invention.
The thickness of the first layer (transparent layer) may be 5 μm or more, 7 μm or more, or 10 μm or more, and may be 300 μm or less, 250 μm or less, or 200 μm or less.

Further, a layer (colored layer) containing a thermoplastic resin and a colorant may be laminated on the resin sheet (interference pearl pigment-containing layer) according to one aspect of the present invention. By providing the colored layer, it is possible to prevent the transmission of light and improve the reflectance, so when viewed from the side of the interference pearl pigment-containing layer, the colored layer can be used as a background to achieve better color development of the interference pearl pigment. .

In one aspect of the present invention, both the transparent layer and the colored layer may be provided to form a laminate of (colored layer/interference pearl pigment-containing layer/transparent layer), and the effects described above can be achieved at the same time. Become.

Known dyes, inorganic pigments, organic pigments, and the like can be used as the coloring agent used in the colored layer. Considering that the pigment may be blended with the thermoplastic resin in advance, it is preferable to use a pigment such as an inorganic pigment or an organic pigment.
Dyes include iso dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, indigoid dyes, and the like.

Inorganic pigments include titanium oxide, zinc ferrite, yellow iron oxide, iron black, zinc sulfide, zinc oxide, carbon black, titanium yellow, ultramarine blue, cobalt blue, cobalt green, chromium oxide, iron oxide red, and composite oxide pigments. etc.

Organic pigments include benzimidazolone yellow, quinophthalone yellow, isoindolinone yellow, disazo yellow, monoazo yellow, condensed azo yellow, perinone orange, benzimidazolone orange, perylene red quinacridone red, quinacridone magenta, diketopyrrolopyrrole, quinacridone violet, phthalocyanine blue, phthalocyanine green and the like.

The method of coloring the colored layer is not particularly limited, and for example, a method of preliminarily blending a coloring agent with a raw material resin, melting and kneading the mixture, and then molding it into a sheet can be employed. Alternatively, a method may be employed in which a coloring agent is blended in advance with a raw resin or another resin, melt-kneaded, extruded to form a masterbatch, blended with the raw resin, and formed into a sheet.

In this way, by adding a colorant to the raw material resin in advance to produce the colored layer, there is no need to apply a special treatment to the sheet surface as in the case of producing the colored layer by printing, which simplifies the production process. This can lead to cost reduction.

The coloring color is not particularly limited, and examples thereof include black, white, red, yellow, green, and blue. According to the laminate according to one aspect of the present invention, it is possible to enhance the designability according to the color regardless of the color.

The content of the coloring agent in the colored layer is usually 0.1% by mass or more, preferably 1% by mass or more, and more preferably 1.5% by mass or more. Moreover, it is usually 10% by mass or less, preferably 7% by mass or less.

The thermoplastic resin is not particularly limited, and examples thereof include polypropylene, polyethylene and the like, preferably polypropylene.
When polypropylene is used as the resin component of the colored layer, it may be the same as or different from the polypropylene used in the first layer. Identical means that the various physical properties of the polypropylene described above are identical.

The content of the thermoplastic resin in the colored layer is usually 90% by mass or more, preferably 93% by mass or more. Moreover, it is usually 99.9% by mass or less, preferably 99% by mass or less, and more preferably 98.5% by mass or less.
The thickness of the colored layer may be 20 μm or more, 40 μm or more, or 50 μm or more, and may be 900 μm or less, 700 μm or less, or 500 μm or less.

Moreover, the resin sheet according to one aspect of the present invention can be laminated with layers for imparting various functions in addition to the layers described above. Such layers include an easy-adhesion layer, an undercoat layer, a metal layer, a printing layer, and the like. These layers are described below.

(Easy adhesion layer)
The easy-adhesion layer preferably contains one or more resins selected from the group consisting of urethane-based resins, acrylic-based resins, polyolefin-based resins and polyester-based resins.
By providing such an easy-adhesion layer, the easy-adhesion layer can follow the resin sheet to form a good layer structure even when the molded body described later is molded in a complicated non-planar shape, and cracks can be formed. and peeling can be prevented.

As the urethane-based resin, a urethane-based resin obtained by reacting a diisocyanate, a high molecular weight polyol and a chain extender is preferable. High molecular weight polyols may be polyether polyols or polycarbonate polyols. Commercially available urethane resins include Hydran WLS-202 (manufactured by DIC Corporation).
Acrylic resins include ACRYT 8UA-366 (manufactured by Taisei Fine Chemicals Co., Ltd.).
Examples of polyolefin resins include Arrowbase DA-1010 (manufactured by Unitika Ltd.).
Polyester-based resins include polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate.

The easy-adhesion layer may use the materials described above singly or in combination of two or more.

Of the urethane-based resins, acrylic resins, polyolefin-based resins and polyester-based resins contained in the easy-adhesion layer, urethane-based resins are preferred in consideration of the adhesion and moldability to the metal layer and printed layer described below.

When the easy-adhesion layer contains a polypropylene-based resin, the polypropylene-based resin contained in the easy-adhesion layer is usually different from the polypropylene that may be contained in the resin sheet or the main body of the molded body.

The easy-adhesion layer may be a single layer, or may have a laminated structure of two or more layers.

The thickness of the easy adhesion layer may be 35 nm or more and 3000 nm or less, 50 nm or more and 2000 nm or less, or 50 nm or more and 1000 nm or less.
Also, the thickness of the easy adhesion layer may be 35 nm or more, or 50 nm or more, and may be 3000 nm or less, 2000 nm or less, or 1000 nm or less.

The easy-adhesion layer can be formed, for example, by coating the above-described resin with a gravure coater, kiss coater, bar coater, or the like, and drying at 40 to 100° C. for 10 seconds to 10 minutes.

Various coatings such as ink, hard coat, antireflection coat, and heat shield coat can be laminated on the easy adhesion layer.
Further, in the resin sheet, another easy-adhesion layer (second easy-adhesion layer) may be provided on the surface opposite to the easy-adhesion layer (first easy-adhesion layer). By doing so, it is possible to impart functionality such as surface treatment and hard coating to the polyolefin resin layer that forms the surface of the molded body.

(undercoat layer)
The undercoat layer is a layer that allows the easy-adhesion layer and the metal layer to adhere to each other. By providing the undercoat layer, even when stress is applied during thermoforming, it is possible to generate numerous extremely fine cracks in the metal layer, thereby eliminating or reducing the occurrence of the rainbow phenomenon.
Materials for forming the undercoat layer include urethane resins, acrylic resins, polyolefins, polyesters, and the like.

Acrylic resin is preferable as a material for forming the undercoat layer from the viewpoint of whitening resistance (hardness of occurrence of whitening phenomenon) during molding and adhesion with the metal layer. 105" can be used.

You may use the said material individually by 1 type or in combination of 2 or more types.

In the undercoat layer, a curing agent may be used in combination with the resin component (main agent) described above. Examples of curing agents include aziridine compounds, blocked isocyanate compounds, epoxy compounds, oxazoline compounds, carbodiimide compounds, and the like. For example, "CL102H" manufactured by Arakawa Chemical Industries, Ltd. can be used.

When a curing agent is used, the content ratio of the main agent and the curing agent in the undercoat layer is, for example, 35:4 to 35:40, preferably 35:4 to 35:32, in terms of mass ratio of the solid content. It is preferably 35:12 to 35:32. Also, it may be 35:12 to 35:20.
When the amount of the curing agent is 4 or more with respect to the main agent 35, the curing reaction proceeds without problems, and whitening resistance can be maintained. When it is 40 or less, the elongation of the undercoat layer is good, and cracks during molding can be suppressed.

As a method for forming the undercoat layer, for example, the above-mentioned material is applied with a gravure coater, a kiss coater, a bar coater, or the like, dried at 50 to 100 ° C. for 10 seconds to 10 minutes, and dried at 40 to 100 ° C. for 10 to 200 It can be formed by time aging.

The thickness of the undercoat layer may be 0.05 μm to 50 μm, 0.1 μm to 10 μm, or 0.5 μm to 5 μm.
The thickness of the undercoat layer may be 0.05 μm or more, 0.1 μm or more, or 0.5 μm or more, and may be 50 μm or less, 10 μm or less, or 5 μm or less.

(metal layer)
A metal layer is a layer containing a metal or a metal oxide.
The metal that forms the metal layer is not particularly limited as long as it can impart a metallic design to the laminate. Examples include tin, indium, chromium, aluminum, nickel, copper, silver, gold, platinum and zinc. and an alloy containing at least one of these may be used.
Among the above, indium and aluminum are preferable because they are particularly excellent in extensibility and color tone. When the metal layer has excellent extensibility, cracks are less likely to occur when the laminate is three-dimensionally molded.

The method of forming the metal layer is not particularly limited, but from the viewpoint of imparting a metallic design with a high texture and a high-class feeling to the laminate, for example, a vacuum deposition method, a sputtering method, and an ion plating method using the above metals. A vapor deposition method such as a method can be used. In particular, the vacuum deposition method is low cost and can reduce damage to the object to be deposited. The conditions for the vacuum deposition method may be appropriately set according to the melting temperature or evaporation temperature of the metal used.

In addition to the above method, a method of applying a paste containing the above metal or metal oxide, a plating method using the above metal, and the like can also be used.

The thickness of the metal layer may be 5 nm or more and 80 nm or less. When it is 5 nm or more, the desired metallic luster can be obtained without any problem, and when it is 80 nm or less, cracks are less likely to occur.

(Print layer)
The shape of the printed layer is not particularly limited, and includes various shapes such as solid, carbon tone, and wood grain tone.
Usable printing methods include screen printing, offset printing, gravure printing, roll coating, and spray coating. In particular, since the screen printing method can thicken the film thickness of the ink, it is difficult for the ink to crack when formed into a complicated shape.
For example, in the case of screen printing, an ink with excellent elongation during molding is preferable, and examples include "FM3107 High Density White" and "SIM3207 High Density White" manufactured by Jujo Chemical Co., Ltd., but the ink is not limited to this.

3. Method for Producing Resin Sheet (or Laminate) The method for producing the resin sheet (or laminate) according to one aspect of the present invention is not particularly limited, and examples thereof include an extrusion method (co-extrusion method). The extrusion method includes cooling the melt of the resin sheet described above (hereinafter referred to as the molten resin), and the cooling is preferably performed at a cooling rate of 80 ° C./sec or more, so that the internal temperature of the resin sheet reaches the crystallization temperature. Repeat until: As a result, the crystal structure of the polypropylene contained in the resin sheet can be the smectic crystal described above. The cooling rate is more preferably 90° C./second or higher, more preferably 150° C./second or higher.
A specific manufacturing method will be described in detail in Examples.

4. Molded Body The resin sheet or laminate according to one aspect of the present invention can be used to form a molded body. A molded article is manufactured by molding a resin sheet or laminate by a method such as thermoforming. In one embodiment, the molded body is given a shape including a three-dimensional curved surface.

5. Molded Body Manufacturing Method A molded body manufacturing method according to an aspect of the present invention includes molding a resin sheet or laminate. Examples of the molding method include in-mold molding, insert molding, in-mold insert molding, cover molding, and the like.

In-mold molding is a method in which a laminate is placed in a mold and molded into a desired shape by the pressure of a molding resin supplied into the mold to obtain a molded product.
In-mold molding is preferably performed by mounting the laminate in a mold and supplying molding resin to integrate the laminate.

Insert molding is a method of obtaining a molded body by preliminarily shaping a shaped body to be placed in a mold and filling the shape with a molding resin. More complex shapes can be formed.
Insert molding can be carried out by shaping a laminate to match a mold, mounting the shaped laminate on the mold, and supplying a molding resin to integrate the laminate.
Shaping (pre-shaping) so as to match the mold can be performed by vacuum forming, pressure forming, vacuum pressure forming, press forming, plug-assist forming, or the like.

A moldable thermoplastic resin can be used as the molding resin. Specific examples include polypropylene, polyethylene, polycarbonate, acetylene-styrene-butadiene copolymer, and acrylic polymer, but are not limited to these. Inorganic fillers such as fibers and talc may be added to the thermoplastic resin.
The supply is preferably performed by injection, preferably at a pressure of 5 MPa or more and 120 MPa or less. The mold temperature is preferably 20°C or higher and 90°C or lower.

Also, as one type of insert molding, there is a method in which a resin sheet is preliminarily shaped in a mold for injection molding.
Specifically, the resin sheet is heated and placed on the cavity surface of the mold, and the resin sheet is shaped so as to match the shape of the mold, and the resin sheet shaped with the molding resin. Integrating the molding resin and the shaped resin sheet by feeding toward.
As a method of preforming the resin sheet, for example, the resin sheet is preheated with a heater or the like, the heated resin sheet is placed on the cavity surface of the mold for injection molding, and the inside of the cavity is sucked. , the resin sheet can be shaped to match the internal shape of the mold. Thereafter, while the shaped resin sheet is placed in the cavity, the cavity is filled with a molding resin to obtain a molded body.
According to this method, a compact having a more complicated shape can be formed by a simpler method.

In covering molding, a core material is arranged in a chamber box, a laminate is placed above the core material, the pressure inside the chamber box is reduced, the laminate is heated and softened, and the laminate is placed on the upper surface of the core material. The laminated body that has been brought into contact and softened by heating can be pressed onto the core material to cover it.
After heat softening, the laminate may be brought into contact with the upper surface of the core material. Pressing can be performed by pressurizing the opposite side of the laminate to the core material while decompressing the side of the laminate in contact with the core material in the chamber box.

The core material may be convex or concave, and examples thereof include resins, metals, and ceramics having three-dimensional curved surfaces. The resin is not particularly limited, and examples thereof include those similar to the thermoplastic resins used for the molding described above.

For covering molding, for example, a chamber box composed of upper and lower molding chambers separable from each other can be used.
First, the core material is placed and set on the table in the lower molding chamber. A laminate, which is an object to be molded, is clamped to the upper surface of the lower molding chamber. At this time, the pressure inside the upper and lower molding chambers is atmospheric pressure.
Next, the upper molding chamber is lowered to join the upper and lower molding chambers to close the inside of the chamber box. Both the upper and lower molding chambers are evacuated from the atmospheric pressure state by the vacuum tank.
After evacuating the upper and lower molding chambers, the heater is turned on to heat the laminate. Next, the table in the lower molding chamber is raised while the upper and lower molding chambers are kept in a vacuum state.
The laminate is then pressed against the core and overlaid (molded) by releasing the vacuum in the upper molding chamber and introducing atmospheric pressure. By supplying compressed air into the upper molding chamber, it is possible to adhere the laminate to the core material with a greater force.
After the overlay is completed, the heater is turned off, the vacuum in the lower molding chamber is released to return to atmospheric pressure, the upper molding chamber is raised, and the product covered with the laminate as the skin material is taken out.

6. Use of Molded Article The use of the molded article described above is not particularly limited, and the molded article can be used for various purposes. In one embodiment, the molded body can be used for an exterior part of a straddle-type vehicle or an exterior part of a four-wheeled vehicle. In addition, the molded article can be used for interior materials and exterior materials for vehicles, housings for home electric appliances, decorative steel plates, veneers, housing equipment, housings for information communication equipment, and the like.

Examples of the present invention are described below, but the present invention is not limited to these examples.

Example 1
The following materials were prepared for the production of the resin sheet.
- Polypropylene resin: homopolypropylene (“Prime Polypro F-133A” manufactured by Prime Polymer Co., Ltd., MFR: 2.8 g / 10 minutes, hereinafter referred to as “PP1”)
Luster pigment: interference pearl pigment (titanium oxide-coated mica, BASF Color & Effect Japan Co., Ltd. "Lumina Exterior Russet S5903D", red interference color, pigment mainly composed of particles with a particle size of 6 to 43 μm, hereinafter referred to as "interference pearl 1”)

[Production and Evaluation of Resin Sheet]
PP1 and interference pearl 1 were melt-kneaded in the blending amounts shown in Table 1 to obtain a pellet-like melt-kneaded product. The resulting melt-kneaded product is extruded at a molding temperature of 230° C. using a cast molding machine with an extruder diameter of 20 mm ("TEACH-LINE extruder E20T" manufactured by Dr. COLLIN) to form a resin sheet having a thickness of 40 μm. manufactured. After that, the obtained resin sheet is sandwiched between stainless steel plates, heated to 200 ° C. using a press (“TJ-S5030SM” manufactured by Tokyo Jitsugyo Co., Ltd.), and then immersed in water at 10 ° C. (cooling rate: 95 ° C. / sec) to obtain a resin sheet (the above manufacturing method is hereinafter referred to as “manufacturing method 1”).

The obtained resin sheets were evaluated as follows. Table 1 shows the results.
(Isotactic pendulum fraction)
The isotactic pendatt fraction was determined by evaluating the ¹³ C-NMR spectrum for PP1. Specifically, the isotactic pendulum fraction is measured according to the peak assignments proposed in "Macromolecules, 8, 687 (1975)" by A. Zambelli et al. and a calculation formula.
Apparatus/conditions Apparatus: JNM-EX400 type ¹³ C-NMR apparatus manufactured by JEOL Ltd. Method: Proton complete decoupling method Concentration: 220 mg/ml
Solvent: 90:10 (volume ratio) mixed solvent of 1,2,4-trichlorobenzene and deuterated benzene Temperature: 130°C
Pulse width: 45°
Pulse repetition time: 4 seconds Accumulation: 10000 times ・Calculation formula isotactic pendulum fraction [mmmm] = m/S x 100
S: signal intensity of side chain methyl carbon atoms of all propylene units m: mesopentad chain: 21.7 to 22.5 ppm

(Crystallization speed)
The crystallization rate of PP1 was measured using a differential scanning calorimeter (DSC) (product name: "Diamond DSC", manufactured by PerkinElmer). Specifically, PP1 was heated from 50°C to 230°C at 10°C/min, held at 230°C for 5 minutes, cooled from 230°C to 130°C at 80°C/min, and then cooled to 130°C. Crystallization was performed while holding. When the temperature reached 130° C., the change in heat quantity was started to obtain a DSC curve. From the obtained DSC curve, the crystallization speed was determined by the following procedures (i) to (iv).
(i) A baseline was obtained by linearly approximating the change in the amount of heat from 10 times to 20 times the time from the start of measurement to the peak top.
(ii) The intersection of the tangent line with a slope at the inflection point of the peak and the baseline was determined, and the crystallization start and end times were determined.
(iii) The time from the obtained crystallization start time to the peak top was measured as the crystallization time.
(iv) The crystallization rate was determined from the reciprocal of the obtained crystallization time.

(crystal form)
Crystal forms of polypropylene-based resins are described in T.W. Confirmed by wide-angle X-ray diffraction (WAXD) with reference to the method used by Konishi et al. (Macromolecules, 38, 8749, 2005). For the analysis, peak separation was performed for each of the amorphous phase, the intermediate phase, and the crystalline phase for the X-ray diffraction profile, and the abundance ratio was obtained from the peak area attributed to each phase.

(saturation)
Using a spectrophotometer ("CM-M6" manufactured by Konica Minolta Japan Co., Ltd.), L ^* a ^* b ^* table under the conditions of D65 light source, 10 degree field of view, illumination angle of 45 °, light receiving angle of 15 ° The color system was measured and the value of chroma C ^* was measured.
Saturation C ^* was calculated as {(a ^* ) ² +(b ^* ) ² } ^1/2 .

(depth of design)
The depth of the design of the resin sheet was visually evaluated according to the following criteria.
A: The design has depth and can be observed three-dimensionally.
B: The design lacks depth and is observed planarly.
C: The sheet is cloudy and the design lacks depth.

(Flip-flop property)
The flip-flop property of the resin sheet was visually evaluated according to the following criteria.
A: It has a flip-flop property and gives a sense of shade.
B: There is no flip-flop property, and it feels planar.

Example 2
The luster pigment is an interference pearl pigment (titanium oxide coated mica, "Iriodin 7225" manufactured by Merck Performance Materials LLC, a blue interference color, a pigment mainly composed of particles with a particle diameter of 10 to 60 μm, hereinafter referred to as "interference pearl 2". ), a resin sheet was produced and evaluated in the same manner as in Example 1, except that it was changed to . Table 1 shows the results.

Example 3
The luster pigment is an interference pearl pigment (titanium oxide coated mica, BASF Color & Effect Japan Co., Ltd. "Lumina Royal Exterior Copper 3903H", a pigment mainly composed of particles with a particle size of 6 to 43 μm, a red copper interference color, hereinafter referred to as " A resin sheet was produced and evaluated in the same manner as in Example 1, except that it was changed to "interference pearl 3"). Table 1 shows the results.

Example 4
A resin sheet was produced and evaluated in the same manner as in Example 3, except that the amount of luster pigment was changed to 1.0% by mass. Table 1 shows the results.

Example 5
The lustrous pigment is an interference pearl pigment (titanium oxide coated alumina, "Xirallic T60-23 SW Galaxy Blue" manufactured by Merck Performance Materials LLC, a pigment mainly composed of particles with a particle size of 5 to 30 μm, a blue interference color, hereinafter referred to as " A resin sheet was produced and evaluated in the same manner as in Example 1, except that it was changed to "Interference Pearl 4"). Table 1 shows the results.

Comparative example 1
In the production of the resin sheet of Example 1, a resin sheet obtained by a cast molding machine ("TEACH-LINE extruder E20T" manufactured by Dr. COLLIN) without heating with a press and immersion in water at 10 ° C. A resin sheet was produced and evaluated in the same manner as in Example 1 except that the was used as it was (cooling rate: 45° C./sec; this resin sheet production method is hereinafter referred to as “production method 2”). Table 1 shows the results.

Comparative example 2
A resin sheet was produced and evaluated in the same manner as in Example 2, except that the resin sheet was produced by production method 2. Table 1 shows the results.

Comparative example 3
A resin sheet was produced and evaluated in the same manner as in Example 3, except that the resin sheet was produced by production method 2. Table 1 shows the results.

Comparative example 4
A resin sheet was produced and evaluated in the same manner as in Example 4, except that the resin sheet was produced by production method 2. Table 1 shows the results.

Comparative example 5
A resin sheet was produced and evaluated in the same manner as in Example 5 except that the resin sheet was produced by production method 2. Table 1 shows the results.

Comparative example 6
The lustrous pigment is an aluminum pigment ("Silveeds M100-BP" manufactured by Asahi Kasei Co., Ltd., a pigment mainly composed of particles with a particle diameter of 3 to 30 μm, a metallic pigment containing 90% by weight of aluminum and 10% by weight of polyethylene glycol, hereinafter referred to as " A resin sheet was produced and evaluated in the same manner as in Example 1, except that it was changed to "aluminum 1"). Table 1 shows the results.
In Comparative Example 6, a resin sheet was produced by manufacturing method 1, but since the aluminum 1 was opaque, the transparency of the entire resin sheet was lowered, and a sense of depth and three-dimensionality could not be obtained, resulting in a poor design.

Comparative example 7
A resin sheet was produced and evaluated in the same manner as in Comparative Example 6 except that the resin sheet was produced by Production Method 2. Table 1 shows the results.

The molded article obtained from the laminate of the present invention can be used in a wide variety of applications. It can be used as a decorative sheet to replace painting on the body.

Claims (18)

A resin sheet containing polypropylene containing smectic crystals and an interference pearl pigment. 2. The resin sheet according to claim 1, wherein the polypropylene has an isotactic pendant fraction of 85 mol % to 99 mol %. 3. The resin sheet according to claim 1, wherein the polypropylene has a crystallization speed at 130° C. of 2.5 min ⁻¹ or less. The resin sheet according to any one of claims 1 to 3, wherein the polypropylene has an exothermic peak of 1 J/g or more on the low temperature side of the maximum endothermic peak in a curve obtained by differential scanning calorimetry. The resin sheet according to any one of claims 1 to 4, wherein the interference pearl pigment is one or more selected from the group consisting of titanium oxide-coated mica, titanium oxide-coated glass, and titanium oxide-coated alumina. The resin sheet according to any one of claims 1 to 5, wherein the content of the interference pearl pigment is 0.01% by mass or more and 20% by mass or less. A laminate comprising a first layer comprising polypropylene containing smectic crystals, and a second layer comprising the resin sheet according to any one of claims 1 to 6. 8. The laminate of claim 7, comprising a third layer comprising a thermoplastic resin and a colorant on the side of said second layer opposite said first layer. A laminate comprising the resin sheet according to any one of claims 1 to 6 and an easy-adhesion layer. The laminate according to claim 9, wherein the easy-adhesion layer contains one or more resins selected from the group consisting of urethane, acrylic, polyolefin and polyester. The layered product according to claim 9 or 10 which has a printing layer in the field on the side opposite to said resin sheet in said easy adhesion layer. A molded article produced using the resin sheet according to any one of claims 1 to 6 or the laminate according to any one of claims 7 to 11. A method for producing a molded article by molding the resin sheet according to any one of claims 1 to 6 or the laminate according to any one of claims 7 to 11. placing the resin sheet or laminate on a mold; and feeding molding resin toward the resin sheet or laminate to conform the resin sheet or laminate to the mold. 14. The method for producing a molded article according to claim 13, comprising integrating the molding resin and the resin sheet or the laminate while shaping the molded article in such a manner. shaping the resin sheet or the laminate so as to match a mold; and supplying a molding resin toward the shaped resin sheet or the shaped laminate. 14. The method of manufacturing a molded article according to claim 13, comprising integrating the resin with the shaped resin sheet or the shaped laminate. heating the resin sheet or the laminate and placing it on the cavity surface of a mold to shape the resin sheet or the laminate so as to match the shape of the mold; Integrating the molding resin with the shaped resin sheet or the shaped laminate by supplying it toward the shaped resin sheet or the shaped laminate. The method for producing a molded article according to claim 13, comprising A core material is arranged in a chamber box, the resin sheet or the laminate is arranged above the core material, the resin sheet or the laminate is heated and softened, and the pressure in the chamber box is reduced to perform the heating. 14. The method for producing a molded article according to claim 13, wherein the softened resin sheet or the heat-softened laminate is pressed against the core material to cover it. Interior materials for vehicles, exterior materials for vehicles, exterior covers for straddle-type vehicles, housings for home appliances, decorative steel plates, decorative panels, housing equipment, or information and communication, which are produced using the molded article according to claim 12. equipment housing.