Resin sheet having trichomes and molded article thereof

Abstract

The purpose of the present invention is to provide a resin sheet that can be secondarily molded while maintaining excellent tactile properties, and a molded article of the resin sheet.　A thermoplastic resin sheet having hair-like bodies arranged regularly on at least one surface of an underlayer and forming a continuous phase without structural boundary between the underlayer and the hair-like bodies, wherein the temperature at which the average height of the hair-like bodies decreases, due to heating for five minutes, by 5% from the average height before heating is adjusted to 130-200°C.

Description

Technical Field

[0001] The present invention relates to a resin sheet having hair-like bodies and a molded article thereof.

Background Art

[0002] Conventionally, sheets of paper materials and polymer materials have been used for interior materials of automobiles, housings of accessory parts, housings of electronic devices and household appliances, building materials such as wallpapers, housings of toys and game machines, and members of daily necessities. Further, as a method for imparting good tactile properties to the sheet surface, for example, Patent Document 1 proposes a resin sheet having hair-like bodies regularly arranged on the surface. On the other hand, when using such a resin sheet as an interior product such as a dashboard or a seat of an automobile, it is necessary to attach it to the surface of an object by, for example, insert molding.

[0003]

Patent Document 1

Summary of the Invention

[0004] However, in secondary molding such as insert molding, when molding on the surface of an object, it comes into contact with the molten raw material resin of the object, and it has been found that in the resin sheet as described above, the hair-like bodies may be greatly deformed or disappear, and there is a risk that good tactile properties cannot be maintained. The problem to be solved by the present invention is to provide a resin sheet and a molded article thereof that can be secondarily molded while maintaining good tactile properties.

[0005] That is, as a result of examining various means, the present inventor has found that in a thermoplastic resin sheet having hair-like bodies regularly arranged on at least one surface of a base layer and forming a continuous phase without a structural boundary between the base layer and the hair-like bodies, by adjusting the temperature at which the average height of the hair-like bodies decreases by 5% from the average height before heating to 130°C or higher and 200°C or lower by heating for 5 minutes, it is possible to perform secondary molding while maintaining good tactile properties, and the present invention has been completed.

[0006] The present invention for solving the above problems is composed of the following. (1) A thermoplastic resin sheet having hair-like bodies regularly arranged on at least one surface of a base layer, and having no structural boundary between the base layer and the hair-like bodies to form a continuous phase, wherein the temperature at which the average height of the hair-like bodies decreases by 5% from the average height before heating after heating for 5 minutes is 130°C or higher and 200°C or lower. (2) The resin sheet according to (1), wherein the average height of the hair-like bodies is 30 μm or more and 500 μm or less, the average diameter of the hair-like bodies is 1 μm or more and 50 μm or less, and the average interval between the hair-like bodies is 20 μm or more and 200 μm or less. (3) The resin sheet according to (1) or (2), wherein the thermoplastic resin contains a urethane-based elastomer. (4) The resin sheet according to any one of (1) to (3), having a base material layer on the surface of the base layer opposite to the hair-like bodies. (5) A molded article of the resin sheet according to any one of (1) to (4). (6) The molded article according to (5), which is an insert molded article or a vacuum molded article. (7) The molded article according to (5) or (6), which is provided on the surface of an automotive interior material, an exterior material of an electronic device, or a cosmetic container.

[0007] According to the present invention, it is possible to provide a resin sheet and a molded article thereof that enable secondary molding while maintaining good tactile properties.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0009] Hereinafter, various embodiments of the resin sheet will be described, and then the manufacturing method of the resin sheet will be described. When the specific description given for one embodiment also applies to other embodiments, the description will be omitted for other embodiments.

[0010] [First Embodiment] The resin sheet according to the first embodiment of the present invention is a thermoplastic resin sheet having hair-like bodies regularly arranged on at least one surface of the base layer, and forming a continuous phase without a structural boundary between the base layer and the hair-like bodies, and the temperature at which the average height of the hair-like bodies decreases by 5% from the average height before heating after heating for 5 minutes is 130°C or higher and 200°C or lower.

[0011] [Base Layer] The base layer (1a) is a layer that serves as the base for the hair-like bodies, and among the reference numeral 1, it refers to the portion other than the hair-like bodies 1b on the surface. The thickness of the base layer refers to the thickness from the root of the hair-like bodies to the surface on the opposite side of the base layer. The average thickness of the base layer is preferably 15 μm to 500 μm, more preferably 30 μm to 300 μm, and even more preferably 50 μm to 150 μm. By setting it to 15 μm or more, the height of the hair-like bodies can be sufficiently expressed. Also, by setting it to 500 μm or less, the hair-like bodies can be efficiently formed. There may be no structural boundary between the base layer and the hair-like bodies, and a continuous phase may be formed. Having no structural boundary means that the base layer and the hair-like bodies are integrally formed and there is no structurally distinct boundary portion between them. Also, forming a continuous phase means that there is no seam between the base layer and the hair-like bodies and it is in a non-discontinuous (continuous phase) state. In this regard, it is different from the structure in which the hair-like bodies are implanted in the base layer. The base layer and the hair-like bodies may have the same composition, and the bond between the base layer and the hair-like bodies may include a covalent bond. A covalent bond refers to a chemical bond formed by sharing an electron pair between two atoms. In a thermoplastic resin that is a chain molecule formed by monomers linked together, individual polymers are bonded by covalent bonds and are bonded more strongly than van der Waals bonds or hydrogen bonds acting between polymer molecules. Further, the base layer and the hair-like bodies may be derived from the same solid thermoplastic resin sheet. Derived from the same solid thermoplastic resin sheet means, for example, that the hair-like bodies and the base layer are directly or indirectly obtained based on the same resin sheet. Also, the base layer and the hair-like bodies may be formed from the same solid thermoplastic resin sheet. Formed from the same solid thermoplastic resin sheet means that the hair-like bodies and the base layer are directly formed by processing a single resin sheet. There is no structural boundary between the base layer and the hair-like bodies, and they form a continuous phase, thereby suppressing the separation of the hair-like bodies from the base layer by external stimuli and resulting in a sheet with good tactile sensitivity. Also, it can be manufactured in fewer steps than when implanting the hair-like bodies.

[0012] The base layer and the hair-like bodies are made of the same thermoplastic resin composition mainly composed of a thermoplastic resin. Here, mainly composed means containing 50% by mass or more. Preferably, it contains 60% by mass or more, 70% by mass or more, 80% by mass or more, or 90% by mass or more. In one embodiment of the present invention, a resin containing at least one of urethane-based elastomers (TPU), styrene-based resins, polyolefin-based resins, polyvinyl chloride resins, thermoplastic elastomers, and fluorine-based resins can be used.

[0013] The urethane-based elastomer is a resin using diisocyanate and polyol as reaction raw materials. As the combination, any combination of diisocyanate being diphenylmethane diisocyanate (MDI)-based, H 12 MDI-based, hexamethylene diisocyanate (HDI)-based, and polyol being polyether-based, polyester-based, or polycarbonate-based can be selected, or a plurality can be combined. In one embodiment of the present invention, a combination of an MDI-based or HDI-based diisocyanate and a carbonate-based polyol can be preferably used.

[0014] As the styrene resin, a homopolymer or copolymer of styrene monomers such as styrene, α-methylstyrene, p-methylstyrene, dimethylstyrene, p-t-butylstyrene, chlorostyrene, etc., a copolymer of these styrene monomers and other monomers, for example, styrene-acrylonitrile copolymer (AS resin), or a graft polymer graft-polymerized in the presence of the styrene monomer and still other polymers such as polybutadiene, styrene-butadiene copolymer, polyisoprene, polychloroprene and other diene rubbery polymers, for example, high impact polystyrene (HIPS resin), styrene-acrylonitrile graft polymer (ABS resin) and other polystyrenes can be used. Also, styrene-based thermoplastic elastomers can be used.

[0015] The polyolefin resin means a resin composed of a polymer containing an α-olefin as a monomer, and includes polyethylene resins and polypropylene resins. As the polyethylene resin, high density polyethylene, low density polyethylene, linear low density polyethylene, linear medium density polyethylene, etc. can be used, and not only the single substance but also copolymers, grafts, and blends having their structures can be used. Examples of the latter resins include those obtained by copolymerizing and blending resins having a polar group in the polyethylene chain, such as blends of ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, ethylene-methacrylic acid ester copolymer, ethylene-vinyl acetate-vinyl chloride copolymer, and further ternary copolymers with acid anhydrides.

[0016] In addition, as the polypropylene resin, homopolypropylene, random polypropylene, block polypropylene, etc. can be used. When using homopolypropylene, the structure of the homopolypropylene may be any of isotactic, atactic, and syndiotactic. When using random polypropylene, as the α-olefin copolymerized with propylene, those having preferably 2 to 20 carbon atoms, more preferably 4 to 12 carbon atoms, such as ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene can be used. When using block polypropylene, block copolymers (block polypropylene), block copolymers containing a rubber component, graft copolymers, etc. can be used. In addition to using these olefin resins alone, other olefin-based resins can also be used in combination.

[0017] As the polyvinyl chloride resin, a vinyl chloride homopolymer or a copolymer of vinyl chloride and other comonomers can be used. When polyvinyl chloride is a copolymer, it may be a random copolymer or a graft copolymer. As an example of the graft copolymer, for example, an ethylene-vinyl acetate copolymer or a thermoplastic urethane polymer as a main polymer with vinyl chloride graft-polymerized thereto can be mentioned. The polyvinyl chloride of the present embodiment represents a soft polyvinyl chloride capable of extrusion molding and is a composition containing additives such as a high molecular weight plasticizer. As the high molecular weight plasticizer, known high molecular weight plasticizers can be used, and for example, ethylene copolymer high molecular weight plasticizers such as ethylene-vinyl acetate-carbon monoxide copolymer, ethylene-(meth)acrylate-carbon monoxide copolymer, and ethylene-vinyl acetate copolymer with a high vinyl acetate content can be mentioned as preferred examples.

[0018] Thermoplastic elastomers include those having a structure combining a soft polymer substance and a hard polymer substance. Specifically, styrenic elastomers, olefinic elastomers, vinyl chloride elastomers, polyester elastomers, and polyamide elastomers can be mentioned. These elastomers can generally be selected and used from commercially available ones.

[0019] As the fluororesin, a homopolymer of vinylidene fluoride and a vinylidene fluoride copolymer mainly composed of vinylidene fluoride can be used. Polyvinylidene fluoride (PVDF) resin is a crystalline resin showing various crystal structures such as α-type, β-type, γ-type, and αp-type. As the vinylidene fluoride copolymer, for example, vinylidene fluoride - hexafluoropropylene copolymer, vinylidene fluoride - tetrafluoroethylene copolymer, vinylidene fluoride - chlorotrifluoroethylene copolymer, vinylidene fluoride - trifluoroethylene copolymer, vinylidene fluoride - tetrafluoroethylene - hexafluoropropylene terpolymer, vinylidene fluoride - chlorotrifluoroethylene - hexafluoropropylene terpolymer, and mixtures of two or more of these can be mentioned.

[0020] The melt mass flow rate of the thermoplastic resin composition at 190°C to 300°C is preferably 4 g / 10 min or more. By setting it to 4 g / 10 min or more, the transferability of the shape of the hair-like body can be improved. The melt mass flow rate is a value measured under the conditions of a load (2.16 Kg to 10.0 Kg) in the temperature range of the test temperature from 190°C to 300°C in accordance with JIS K 7210.

[0021] The thermoplastic resin composition may be an alloy of each of the above thermoplastic resins in an arbitrary ratio as long as the effects of the present invention are not inhibited. Further, it may contain other additives. As other additives, within the range where the effects of the present invention are not inhibited, water / oil repellents, colorants such as pigments and dyes, lubricants / release agents such as silicone oil and alkyl esters, fibrous reinforcing agents such as glass fibers, and as fillers, granular fine particles such as talc, clay, silica, and flaky fine particles such as mica, low molecular weight antistatic agents such as salt compounds of sulfonic acid and alkali metals, and polymer type antistatic agents such as polyether ester amide, flame retardants, antibacterial agents, antiviral agents, heat stabilizers and other additives can be added. Also, the scrap resin generated in the resin sheet manufacturing process can be mixed and used.

[0022] Examples of the water / oil repellent include silicone-based water repellents, carnauba wax, and fluorine-based water / oil repellents. Examples of silicone include organopolysiloxane, dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, etc. Among them, dimethylpolysiloxane is preferably used. Commercially available products include, for example, "Clinbell CB50-PP", "Clinbell CB-30PE", "Clinbell CB-1", "Clinbell CB-50AB" (manufactured by Fuji Chemical Co., Ltd.) in which silicone is alloyed with resin. Examples of commercially available carnauba wax include "Carnauba No. 1" (manufactured by Nikko Rica Co., Ltd.). Examples of the fluorine-based water / oil repellent include surfactants having a perfluoroalkyl group. Commercially available products include "Surflon KT-PA" (manufactured by AGC Seimi Chemical Co., Ltd.). The addition amount of the water / oil repellent is preferably from 0.5% by mass to 25% by mass. If it is less than 0.5% by mass, there is a risk that a sufficient water / oil repellent effect cannot be obtained, and if it exceeds 25% by mass, there is a risk that the moldability deteriorates.

[0023] Examples of the antistatic agent include polyether ester amide-based polymer antistatic agents and ionomer-based polymer antistatic agents. Examples of the polyether ester amide-based polymer antistatic agents include commercially available products such as "Pelestat 230", "Pelestat 6500", "Perektron AS", and "Perektron HS" (manufactured by Sanyo Chemical Industries, Ltd.). Examples of the ionomer-based polymer antistatic agents include commercially available products such as "Entira SD100" and "Entira MK400" (manufactured by Mitsui DuPont Polychemicals Co., Ltd.). The addition amount of the antistatic agent is preferably 5% by mass to 30% by mass. If it is less than 5% by mass, there is a risk that sufficient antistatic properties cannot be obtained, and if it exceeds 30% by mass, the production cost increases.

[0024] As the antibacterial agent, either an inorganic or an organic agent may be added. Considering dispersibility, an inorganic agent is preferred. Specifically, examples include inorganic antibacterial agents of metal ions (Ag, Zn, Cu) and antibacterial agents of calcined shell calcium. Commercially available products of the inorganic antibacterial agent of metal ions include "Bacter Killer BM102VT" (manufactured by Fuji Chemical Industry Co., Ltd.), "Novaron VZF200", "Novaron (AG300)" (manufactured by Toagosei Co., Ltd.), "KM-10D-G", and "IM-10D-L" (manufactured by Sinanenzymeomic Co., Ltd.). Examples of the antibacterial agent of calcined shell calcium include "Scaro" (manufactured by FID Co., Ltd.). The addition amount of the antibacterial agent is preferably 0.5% by mass to 5% by mass. If it is less than 0.5% by mass, there is a risk that sufficient antibacterial properties cannot be obtained, and if it exceeds 5% by mass, the production cost increases.

[0025] As the lubricant and mold release agent, alkyl-based lubricants and mold release agents such as aliphatic hydrocarbon-based compounds, higher fatty acid-based compounds, higher aliphatic alcohol-based compounds, and fatty acid amide-based compounds, silicone-based lubricants and mold release agents, and fluorine-based lubricants and mold release agents can be used. When using the lubricant and mold release agent, the addition amount is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, and even more preferably 0.1 to 2 parts by mass out of a total of 100 parts by mass with the resin composition. By setting the addition amount to 0.01 part by mass or more, the risk of a low mold release effect is reduced, and by setting it to 5 parts by mass or less, the risk of bleeding out on the sheet surface is reduced.

[0026] In addition, a masterbatch in which a lubricant or a mold release agent is alloyed with a thermoplastic resin in advance can also be used. For example, a commercially available masterbatch based on a urethane-based thermoplastic elastomer, "Wax Master V" (manufactured by BASF), can be mentioned. Considering production efficiency, it is preferable to use a masterbatch. The addition amount of the masterbatch is preferably 1 to 8 parts by mass, more preferably 2 to 7 parts by mass, and even more preferably 3 to 6 parts by mass out of a total of 100 parts by mass with the resin composition.

[0027] <Trichome> The trichome (1b) refers to a portion that extends in a hair-like manner from the surface of the base layer (1a) as shown in FIG. 1. The trichomes are regularly arranged on the surface of the base layer. Here, being regularly arranged means a non-random arrangement state of the trichomes, that is, an orderly arrangement state (for example, at a certain interval) in one direction or two directions. The arrangement of the trichomes is determined by the arrangement state of the roots of the trichomes. In an embodiment, the trichomes are located on the base layer at a predetermined interval, and the positions of the bottom surfaces of the trichomes are orderly arranged in the longitudinal direction and the transverse direction of the base layer. In addition, the arrangement form of the trichomes is not particularly limited, and a checkerboard arrangement or a staggered arrangement arranged vertically and horizontally can be selected. Since the trichomes are regularly arranged on the surface of the base layer, it becomes easy to exhibit uniform and non-uniform good tactile properties. The trichomes can form fingerprint marks that are different in gloss and color tone from the surrounding parts due to being pressed, for example, by tracing with a finger, causing the trichomes to fall over. In addition, the trichomes can provide a tactile sensation similar to that of a napped fabric with a suede finish.

[0028] The average height (h) of the trichomes is preferably 30 μm to 500 μm, more preferably 60 μm to 250 μm, even more preferably 80 μm to 200 μm, and even more preferably 90 μm to 180 μm. By setting the average height to 30 μm or more, sufficient good tactile properties can be ensured, and by setting the average height to 500 μm or less, good tactile properties such as a moist feeling, a soft feeling, and a fluffy feeling can be obtained. When the trichomes are almost upright with respect to the underlying layer, the length from the base to the tip of the trichomes represents the height of the trichomes. On the other hand, when the trichomes are inclined with respect to the underlying layer or when the trichomes have a coiled portion, the distance from the surface of the underlying layer at the location where the trichomes are most separated from the surface of the underlying layer is defined as the height h of the trichomes. Also, the total value of the intervals obtained by subdividing the distance from the tip to the central part of the base of the trichomes by multi-point measurement is defined as the length L of the trichomes. The average height and the average length of the trichomes can be measured at any number of locations on the resin sheet using an electron microscope and image processing software, and the arithmetic mean value of the measured values can be used.

[0029] The average diameter (d) of the trichomes is preferably from 1 μm to 50 μm, more preferably from 5 μm to 50 μm, and even more preferably from 5 μm to 40 μm. By setting the average diameter of the trichomes to 1 μm or more, good tactile sensitivity can be ensured, and by setting the average diameter of the trichomes to 50 μm or less, good tactile sensitivities such as a moist feeling, a soft feeling, and a fluffy feeling can be obtained. The average diameter of the trichomes is a value obtained by measuring the diameter at the intermediate height (h / 2) of the trichomes from several locations on the resin sheet using an electron microscope and image processing software and using the arithmetic mean value of the measured values. Also, the aspect ratio of the trichomes can be expressed as (average height of the trichomes / average diameter of the trichomes). The aspect ratio of the trichomes is preferably from 2 to 20, more preferably from 2 to 10, and even more preferably from 2 to 5. By setting the aspect ratio to 2 or more, good tactile sensitivity can be ensured, and by setting the aspect ratio to 20 or less, not only can good tactile sensitivities such as a moist feeling, a soft feeling, and a fluffy feeling be obtained, but also the risk that the ratio of the height to the length of the trichomes becomes below a certain level can be reduced. On the other hand, the aspect ratio can also be based on the average bottom diameter of the trichomes. The average bottom diameter of the trichomes is preferably 10 μm to 150 μm, more preferably 20 μm to 120 μm, and even more preferably 30 μm to 100 μm. The average bottom diameter of the trichomes is a value obtained by measuring the intervals between adjacent trichomes at several locations on the resin sheet and using the arithmetic mean value of the measured values. When based on the bottom diameter of the trichomes, the aspect ratio is preferably 1.0 to 10, more preferably 1.0 to 5, and even more preferably 1.0 to 2.5. By setting the aspect ratio to 1.0 or more, good touch feeling can be ensured. By setting the aspect ratio to 10 or less, not only good touch feelings such as moist feeling, soft feeling, and fluffy feeling can be obtained, but also the possibility that the ratio of the height to the length of the trichomes becomes a certain value or less can be reduced.

[0030] The average interval (t) between the trichomes is preferably 20 μm to 200 μm, more preferably 40 μm to 150 μm, and even more preferably 40 μm to 100 μm. The interval between the trichomes means, for example, the distance between the center of the root of one trichome and the center of the root of an adjacent trichome as shown in FIG. 2. By setting the average interval to 20 μm or more, good touch feeling is ensured. By setting it to 200 μm or less, good touch feelings such as moist feeling, soft feeling, and fluffy feeling can be obtained. The average interval between the trichomes is a value obtained by measuring the intervals between adjacent trichomes at several locations on the resin sheet and using the arithmetic mean value of the measured values.

[0031] The shape of the trichome is not particularly limited, but it may be hairy and extend in a direction away from the underlying layer, gradually becoming thinner as it approaches the tip, or may have a configuration with a bulge formed at its tip. That is, it may have a shape in which the cross-sectional area gradually decreases and then once increases and then terminates as it moves away from the underlying layer. Also, the shape of the tip of the trichome may be bud-shaped or mushroom-shaped. Further, the trichome may have a portion located at the base extending in a direction away from the underlying layer, a portion extending from the portion located at this base and bent with a certain curvature or gradually changing curvature, and further a portion wound in a spiral or spiral shape. In this case, the tip of the trichome may have a shape in which it is folded inward. Such a shape results in a good tactile sensation. Also, when the bud-shaped or mushroom-shaped portion is hollow, a better tactile sensation is exhibited. When forming a bud-shaped or mushroom-shaped shape at the hairy tip, the ratio of the average diameter of the width of the bud-shaped or mushroom-shaped shape to the average diameter of the trichome is preferably 1.1 times or more. The height of the bud-shaped or mushroom-shaped shape is preferably 7 μm or more. The average diameter of the trichome, the average diameter of the width of the bud-shaped or mushroom-shaped shape, and the height are values measured from an electron scanning microscope photograph and using the arithmetic mean value. The trichome is made of a thermoplastic resin. As the thermoplastic resin, the same resin as the resin that can be used in the above-mentioned underlying layer can be used.

[0032] The thermoplastic resin contained in the underlying layer and the hair-like bodies may at least partially form a three-dimensional crosslinked structure (e.g., a three-dimensional network structure). For example, in certain embodiments, at least a part of the hair-like bodies is a crosslinked body, in another embodiment, the entire surface of the hair-like bodies is a crosslinked body, and in yet another embodiment, the entire hair-like bodies (from the boundary with the underlying layer to the tip) may be crosslinked bodies. Examples of methods for forming crosslinked bodies include, for example, irradiating an electron beam onto the surface having the hair-like bodies after molding a resin sheet, adding an organic peroxide, and forming by heating and humidifying during or after molding the resin sheet. As commercially available resins added with an organic peroxide, there are "Linkron" manufactured by Mitsubishi Chemical Corporation, etc. In the present embodiment, it is preferable to form a crosslinked body (electron beam crosslinked body) by irradiating an electron beam.

[0033] <Resin sheet> In the present embodiment, "tactility" means the texture and feel of the surface of the resin sheet. It is judged whether a pleasant feeling is felt when touching the surface of the resin sheet, and if so, those with good specific tactile feelings such as moist, soft, and fluffy are regarded as having good tactile properties.

[0034] In one embodiment of the present invention, the thickness of the resin sheet refers to the sheet thickness obtained by combining the average height of the hair-like bodies and the average thickness of the underlying layer. The sheet thickness is preferably 65 μm to 1600 μm, more preferably 115 μm to 1050 μm, and still more preferably 165 μm to 550 μm. By setting the thickness to 65 μm or more, good tactile properties can be sufficiently ensured, and by setting it to 1600 μm or less, the manufacturing cost can be suppressed.

[0035] In the resin sheet of the present embodiment, the temperature at which the average height of the hair-like bodies decreases by 5% from the average height before heating after 5 minutes of heating is 130°C or higher and 200°C or lower. The difference between the average height before heating and the average height after heating was defined as the reduction rate of the trichomes at that temperature with respect to the average height before heating. Also, the temperature at which the reduction rate of the trichomes becomes 5% was defined as the 5% reduction temperature of the trichome height of the resin sheet. The 5% reduction temperature of the trichome height can be measured by examining the temperature at which the reduction rate of the trichomes becomes 5% while changing the temperature of the gear oven by 1°C for each resin sheet and measuring the reduction rate of the trichomes at each temperature. It is more preferable that the 5% reduction temperature of the trichome height is 135°C or higher and 190°C or lower, and further preferably 138°C or higher and 185°C or lower. By setting the 5% reduction temperature of the trichome height to 130°C or higher, it becomes possible to maintain good touch sensitivity even after insert molding, and by setting it to 200°C or lower, the trichomes are not too hard and good touch sensitivity can be achieved. Also, by setting it to 130°C or higher and 155°C or lower, a moist touch can be obtained, and by exceeding 155°C and setting it to 200°C, a crispy touch can be obtained. By adjusting the blending ratio and molecular weight of the raw materials when synthesizing the thermoplastic resin composition, it is possible to achieve a 5% reduction temperature of the trichome height of 130°C or higher and 200°C or lower.

[0036] [Second Embodiment] As an example of the resin sheet according to the second embodiment of the present invention, as shown in FIG. 3, it is a resin sheet in which a base material layer is formed on the surface opposite to the trichomes of the base layer. That is, the layer structure of the resin sheet according to the second embodiment is, from top to bottom, the trichomes and the base layer (1), and the base material layer (2). Here, since the trichomes are the same as those described in the first embodiment, the description is omitted. However, the thickness of the trichomes and the base layer represented by the sum of the average height of the trichomes and the average thickness of the base layer is preferably 150 μm to 1500 μm, more preferably 150 μm to 1050 μm, and even more preferably 150 μm to 500 μm. By setting it to 150 μm or higher, good touch sensitivity can be ensured, and by setting it to 1500 μm or lower, production costs can be suppressed. The average thickness of the base material layer is preferably 50 μm to 1500 μm, more preferably 100 μm to 1000 μm, and even more preferably 150 μm to 500 μm. By setting it to 50 μm or more, the film forming process becomes easier, and by setting it to 1500 μm or less, the production cost can be suppressed. As the base material layer in the resin sheet according to the second embodiment, it is preferable to use a thermoplastic resin having excellent adhesiveness to the underlayer, and polycarbonate resins, polyester resins, and polymer alloy resins thereof can be preferably used. The mass ratio of the polycarbonate resin to the polyester resin is preferably 50:50 to 90:10, more preferably 60:40 to 80:20, and even more preferably 65:35 to 75:25. Here, the polymer alloy resin is a polymer multi-component system, and may be a polymer blend having a certain compatibility by mixing or the like, or may be a block copolymer or a graft copolymer by copolymerization, or may be a mixture of incompatible resins.

[0037] Examples of the polycarbonate resin include those derived from aliphatic dihydroxy compounds and those derived from aromatic dihydroxy compounds. For example, those derived from aromatic dihydroxy compounds can be preferably used, and in particular, those derived from aromatic dihydroxy compounds (bisphenols) in which two aromatic dihydroxy compounds are bonded via a certain bonding group are preferable. These can be produced by a known production method by polycondensation of a dihydroxy compound and phosgene or a carbonic acid ester, and are not limited to the production method, and commercially available resins can also be used.

[0038] As the polyester resin, polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, polymethylene terephthalate, and as copolymerization components, for example, diol components such as diethylene glycol, neopentyl glycol, polyalkylene glycol, and dicarboxylic acid components such as adipic acid, sebacic acid, phthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, etc. A polyester resin copolymerized with such can be used.

[0039] The base material layer may contain other additives as necessary. As other additives, within the range that does not inhibit the effects of the present invention, water repellents, oil repellents, colorants such as pigments and dyes, lubricants and mold release agents such as silicone oil and alkyl esters, fibrous reinforcing agents such as glass fibers, and as fillers, granular fine particles such as talc, clay, silica, and flaky fine particles such as mica, low molecular weight antistatic agents such as salt compounds of sulfonic acid and alkali metals, and polymer antistatic agents such as polyether ester amide, flame retardants, antibacterial agents, antiviral agents, additives such as heat stabilizers can be added. Also, the scrap resin generated in the resin sheet manufacturing process can be mixed and used. Further, within the range that does not inhibit the effects of the present invention, the base material layer may partially have a crosslinked structure.

[0040] [Manufacture of Resin Sheet] The manufacturing method of the resin sheet according to the present invention is not limited and can be any method, but typically includes a step of melt-extruding a raw material resin and imparting hair-like bodies regularly arranged on at least one surface of the obtained extruded resin sheet.

[0041] When producing a multilayer resin sheet, any resin sheet forming method can be used. For example, a feed block or a multi-manifold die can be used. In addition, although the layer configuration of each embodiment of the resin sheet of the present invention is basically as described above, for example, scrap raw materials generated in the manufacturing process of the resin sheet and the forming container of the present invention can be added to the base material layer as long as no deterioration in physical properties is observed, or laminated as an additional layer.

[0042] The method for imparting the trichomes is not particularly limited, and any method known to those skilled in the art can be used. For example, a method of manufacturing using an extrusion molding method, a method of manufacturing using a roll-to-roll method, a method of manufacturing using a photolithography method, a method of manufacturing using a hot press method, a method of manufacturing using a pattern roll and a UV curable resin, a method of manufacturing using a 3D printer, a method of covalently bonding by a polymerization reaction after embedding the trichomes in a resin layer, and the like.

[0043] For example, when using the extrusion molding method, the resin sheet can be extruded by the T-die method, and the resin sheet according to the present invention can be manufactured by casting with a transfer roll having concavo-convex processing and a touch roll so as to impart a trichome shape to the surface of the resin sheet. As the transfer roll having concavo-convex processing, a roll having fine concavo-convexities with a size of several μm to several hundred μm regularly formed on the surface of the roll by a laser engraving method, an electroforming method, an etching method, a milling engraving method, or the like can be used. Here, "regular" means an arrangement state in which the concavo-convexities are not random, that is, an orderly arrangement in one direction or two directions. As the arrangement of the concavo-convexities in an embodiment, a checkerboard arrangement or a staggered arrangement arranged vertically and horizontally can be selected. Examples of the shape of the concave portion include a conical shape (circular cone, square pyramid, triangular pyramid, hexagonal pyramid, etc.), a semi-circular shape, a rectangular shape (square prism), and the like. As the size, the opening diameter of the concave portion, the depth of the concave portion, and the interval of the concave portion shape are several μm to several hundred μm. As the material of the transfer roll, for example, metal, ceramic, or the like can be used. By adjusting the interval of the concave portions of the transfer roll, the interval of the trichomes can be adjusted, and by adjusting the depth of the concave portions of the transfer roll, the height of the trichomes can be adjusted, and thereby the touch feeling can also be adjusted. In addition, it is preferable to perform concavo-convex processing with a high aspect ratio on the surface of the transfer roll. For example, when processing the concave shape on the surface of the transfer roll, the aspect ratio (concave depth / concave opening diameter) is preferably 1.0 to 9.0 or 1.0 to 2.0. To perform concavo-convex processing with a high aspect ratio on the surface of the transfer roll, the laser engraving method or the electroforming method is particularly preferably used because it is suitable for precision processing in the depth direction compared to the etching method, the blasting method, the milling engraving method, etc. As the material of the transfer roll, for example, metal, ceramic, etc. can be used. On the other hand, as the touch roll, various materials can be used. For example, rolls made of silicone rubber, NBR rubber, EPT rubber, butyl rubber, chloroprene rubber, and fluororubber can be used. In an embodiment, a touch roll with a rubber hardness (JIS K 6253) of 40 to 100 can be used. Also, a Teflon (registered trademark) layer may be formed on the surface of the touch roll. As the touch roll, various materials can be used. For example, rolls made of silicone rubber, NBR rubber, EPT rubber, butyl rubber, chloroprene rubber, and fluororubber can be used. In an embodiment, a touch roll with a rubber hardness (JIS K 6253) of 40 to 100 can be used. Also, a Teflon (registered trademark) layer may be formed on the surface of the touch roll. By using the roll set of the above transfer roll and touch roll, the resin sheet of the present embodiment can be manufactured. In an embodiment, the temperature of the transfer roll is adjusted to a temperature near the crystal melting temperature, glass transition point, or melting point of the thermoplastic resin (for example, 100 to 150 °C when using random polypropylene), and the pinch pressure between the transfer roll and the touch roll is 30 to 120 Kg / cm 2 By casting as, the resin sheet of the present embodiment can be manufactured. The cast resin sheet is taken up at a line speed of 0.5 to 30 m / min using a pinch roll or the like. Moreover, although the above embodiments are specifically shown, they are not limited thereto.

[0044] [Molded article] The molded article of the present invention is a molded article using the resin sheet of the present invention. The resin sheet of the present invention can be used for general molding. As molding methods, in addition to insert molding and in-mold molding, general vacuum molding, pressure-air molding, and as applications thereof, methods such as heating and softening the resin sheet in a vacuum state and then overlaying (molding) it on the surface of an existing molded article by releasing it under atmospheric pressure can be mentioned, but it is not limited thereto. Also, as a method of heating and softening the sheet before molding, known sheet heating methods such as radiant heating by an infrared heater or the like, which is non-contact heating, can be applied. In the vacuum-pressure-air molding of an embodiment, for example, the resin sheet has a surface temperature of 60°C to 220°C, is heated for 20 seconds to 480 seconds, and then molded onto the surface of an existing molded article, and can be stretched 1.05 to 2.50 times depending on the shape of the surface.

[0045] [Article] The resin sheet having the hair-like bodies imparted to its surface according to the present invention can be applied to uses that require the above-described good touch feeling. For example, the resin sheet of the present invention can be applied as a surface material for automobile interior materials, exterior materials for electronic devices, or cosmetic containers.

[0046] Examples of automobile interior materials include handles, dashboards, levers, switches, etc., which are parts that can be touched by hand inside an automobile company. For example, an interior material obtained by molding and bonding the above-described resin sheet to the surface of a known instrument panel, pillar (for example, Japanese Patent Application Laid-Open No. 2009-184421) can be mentioned. By bonding the resin sheet, an interior material with good touch feeling can be obtained. As the material of the resin sheet to be bonded, an olefin-based resin, a PVC-based resin, or a urethane-based elastomer is preferable in consideration of light resistance and chemical resistance. The method of bonding the resin sheet and the interior material is not particularly limited.

[0047] Examples of the exterior materials for electronic devices include the transmitter housing of a keyless entry system, smartphone housing, smartphone case, music player case, game console housing, digital camera housing, electronic organizer housing, calculator housing, tablet housing, mobile personal computer housing, keyboard, mouse, etc. For example, a portable transmitter for a keyless entry system in which the resin sheet of the present invention is molded and laminated on the surface of a known portable transmitter housing (for example, Japanese Patent Application Laid-Open No. 2005-228911) can be mentioned. By laminating the resin sheet, a portable transmitter with good touch sensitivity can be obtained. As the material of the resin sheet to be laminated, olefin-based resin and urethane-based elastomer are preferable. The method of laminating the resin sheet and the housing is not particularly limited.

[0048] Examples of cosmetic containers include face cream containers, pack cream containers, foundation containers, and eyeshadow containers. For example, a cosmetic container in which the resin sheet of the present invention is molded and laminated on the surface of a lid member of a known foundation container (Japanese Patent Application Laid-Open No. 2017-29608) can be mentioned. By laminating the resin sheet, a cosmetic container with good touch sensitivity can be obtained. As the material of the resin sheet to be laminated, olefin-based resin and urethane-based elastomer are preferable. The method of laminating the resin sheet is not particularly limited.

[0049] Furthermore, a hair-like sheet printed with characters and patterns by a general printing method (offset printing method, gravure printing method, flexographic printing method, screen printing method, foil stamping, etc.) can be produced on the surface of the hair-like body and applied to the above uses. The material of the resin sheet to be printed is not particularly limited, but it is preferable to consider the printability with the ink agent used for printing.

[0050] In addition, a laminate can be produced by laminating and molding the resin sheet of the present invention with a printed matter (such as paper or metal thin film) printed with characters, patterns, etc., or a non-woven fabric (dry lamination molding, extrusion lamination molding). For example, it can be laminated and molded on the printed surface of a business card to produce a business card with a tactile sensation. The material of the resin sheet to be laminated is not particularly limited.

Example

[0051] Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. However, the present invention is not limited to the contents of the Examples and the like. In addition, "parts" in the present Examples are based on weight.

[0052] The various raw materials used in the Examples and the like and their production methods are as follows. ·(Polyol A-1) Into a reaction apparatus equipped with a stirrer, a thermometer, a heating device, and a distillation column, 926 g of 1,6-hexanediol (hereinafter referred to as 1,6HD) and 671 g of diethyl carbonate (hereinafter referred to as DEC) were charged so that the molar ratio of 1,6-HD to DEC was 1.38:1. Further, 0.05 g of tetrabutyl titanate (hereinafter referred to as TBT) was charged as a reaction catalyst, and the temperature was gradually raised to 190 °C under a nitrogen stream. When the distillation of ethanol became slow and the temperature at the top of the distillation column became 50 °C or lower, the reaction temperature was kept at 190 °C, and the pressure was gradually reduced to 1.3 kPa. The reaction was further carried out at a pressure of 1.3 kPa for 7 hours. Further, under a reduced pressure of 1.3 kPa or lower at a reaction temperature of 190 °C, the reaction was continued until the hydroxyl value of the reaction product reached 222 - 226 (mgKOH / g), and Polyol A-1 was obtained. The hydroxyl value of Polyol A-1 was 224.4 (mgKOH / g), and the number average molecular weight was calculated to be 500. ·(Polyol A-2) Polyol A-2 was obtained in the same manner as the production of Polyol B-1, except that 913 g of 1,6-HD and 686 g of DEC were charged so that the molar ratio of 1,6-HD to DEC was 1.33:1. The hydroxyl value of Polyol A-2 was 172.6 (mgKOH / g), and the number average molecular weight was calculated to be 650. ·(Polyol A-3) Polyol A-3 was obtained in the same manner as the production of Polyol B-1, except that 898 g of 1,6-HD and 700 g of DEC were charged so that the molar ratio of 1,6-HD to DEC was 1.28:1. The hydroxyl value of Polyol A-3 was 149.6 (mgKOH / g), and the number average molecular weight was calculated to be 750. ·(Polyol A-4) Except that 878 g of 1,6-HD and 720 g of DEC were charged so that the molar ratio of 1,6-HD to DEC was 1.22:1, it was synthesized in the same manner as the production of Polyol B-1 to obtain Polyol A-4. The hydroxyl value of Polyol A-4 was 132.0 (mgKOH / g), and the number average molecular weight was calculated to be 850. ·(Polyol A-5) Except that 938 g of 1,6-HD and 660 g of DEC were charged so that the molar ratio of 1,6-HD to DEC was 1.42:1, it was synthesized in the same manner as the production of Polyol B-1 to obtain Polyol A-5. The hydroxyl value of Polyol A-5 was 280.5 (mgKOH / g), and the number average molecular weight was calculated to be 400. ·(Polyol A-6) Except that 872 g of 1,6-HD and 726 g of DEC were charged so that the molar ratio of 1,6-HD to DEC was 1.20:1, it was synthesized in the same manner as the production of Polyol B-1 to obtain Polyol A-6. The hydroxyl value of Polyol A-6 was 118.1 (mgKOH / g), and the number average molecular weight was calculated to be 950. The number average molecular weight was calculated based on the following formula. Number average molecular weight = (56100×2) / hydroxyl value (The hydroxyl value of the polycarbonate diol was determined by titration according to JIS K 1557. Here, the unit of the hydroxyl value is mgKOH / g. The acid value of the polycarbonate diol was determined by titration according to JIS K 1557. Here, the unit of the acid value is mgKOH / g.) ·(B) Aliphatic diol: 1,4-butanediol ·(C-1) Diisocyanate: Hexamethylene diisocyanate (HDI) ·(C-2) Diisocyanate: 4,4'-Diphenylmethane diisocyanate (MDI) ·(D) Release agent masterbatch "Wax Master V" (manufactured by BASF) ·(E) PC / polyester resin "PCX-6694" (manufactured by Sumika Polycarbonate)

[0053] (Manufacture of Trichomes and Underlying TPU) To obtain the composition described in Table 1, polyol (A) and aliphatic diol (B) were charged into a reaction vessel equipped with a stirrer and a thermometer and uniformly mixed. After heating the resulting mixture to 100°C, diisocyanate (C) was added and vigorously stirred with a hand mixer. When the reaction temperature reached 130°C, the mixture was poured onto a release paper and solidified. The obtained solid was aged in an electric furnace at 120°C for 1 hour, cooled to room temperature, and then pulverized to obtain flaky TPU. The obtained flaky TPU was compounded with a release agent masterbatch (D) in a weight ratio of 95:5 using a twin-screw extruder, and the resulting strands were pelletized to obtain TPU pellets (G) that serve as the raw material for the trichomes and the underlying layer.

[0054] (Manufacture of Resin Sheet with Trichomes) [Examples 1 to 6, Comparative Examples 1 to 3] The above TPU (G) serving as the trichomes and the underlying layer was extruded from a 40-mm single-screw extruder, and PC / polyester resin (E) serving as the base layer was extruded from a 65-mm single-screw extruder. The resin sheet extruded by the T-die method was subjected to uneven processing by chromic oxide spraying and laser engraving, and casting was performed using a transfer roll adjusted to 60°C to 150°C with uneven processing and a touch roll made of silicon rubber with a rubber hardness of 70 adjusted to 10°C to 90°C, and then taken up at a line speed of 1 m / min to 15 m / min using a pinch roll. As a result, a resin sheet having the composition, thickness, and surface shape shown in Table 1 was obtained.

[0055] The evaluation methods for various properties of the resin sheets produced in the examples and comparative examples and the molded products obtained by vacuum pressure molding of the resin sheets are as follows.

[0056] (1) Average height of trichomes, average length of trichomes, average diameter of trichomes, average interval of trichomes, average thickness of underlying layer The height (h) of the hair-like structures on the resin sheet, the diameter (d) of the hair-like structures, the spacing (t) between the hair-like structures, the thickness of the underlying layer, and the thickness of the base material layer were measured using a laser microscope (VK-X100, manufactured by Keyence Corporation). For the measured samples, cross-sectional slices were cut out from three arbitrary locations of the resin sheet using a microtome. For the average height of the hair-like structures, the height of 10 hair-like structures was measured for each sample, and the arithmetic mean value of the 30 measurement values was used. For the average diameter of the hair-like structures, the diameter at the mid-height (h / 2) of 10 hair-like structures was measured for each sample, and the arithmetic mean value of the 30 measurement values was used. For the average spacing between the hair-like structures, the distance between the center of the base of one hair-like structure and the center of the base of the adjacent hair-like structure was measured at 10 locations for each sample, and the arithmetic mean value of the 30 measurement values was used. For the average thickness of the underlying layer, the thickness from the base of the hair-like structures to the other layer interface was measured at 10 locations for each sample, and the arithmetic mean value of the 30 measurement values was used. For the average thickness of the base material layer, the thickness from the boundary with the underlying layer to the interface opposite the surface with the hair-like structures was measured at 10 locations for each sample, and the arithmetic mean value of the 30 measurement values was used.

[0057] (3) Measurement of the reduction rate of the hair-like structures For the obtained resin sheet, test pieces were cut out from three arbitrary locations to a size of 100 mm × 100 mm. The test pieces were placed in a gear oven at a predetermined temperature for 5 minutes, and after removal, the average height of the hair-like structures was measured using a laser microscope in the same manner as above. The difference between the average height before heating and the average height after heating was defined as the reduction rate of the hair-like structures at that temperature. The temperature at which the reduction rate of the hair-like structures becomes 5% was defined as the 5% reduction temperature of the hair-like structure height of the resin sheet. While changing the temperature of the gear oven by 1°C each time, the reduction rate of the hair-like structures at each temperature was measured each time, and the 5% reduction temperature of the hair-like structure height was measured.

[0058] (2) Tactile evaluation after insert molding Insert molding was performed on the obtained resin sheet. A mold for an injection insert molding machine that can obtain a resin plate with a width of 250 mm, a length of 140 mm, and a thickness of 3 mm was prepared. The resin sheet was trimmed so that it would fit snugly on the surface formed by the width of 250 mm and the length of 140 mm without any gaps. The trimmed resin sheet was placed such that the surface having the hair-like bodies was in contact with the mold surface and the base material layer faced the resin flow side of the cavity. Note that the mold had a single-point gate on the surface formed by the width of 250 mm and the thickness of 3 mm, and was structured such that the injected resin flowed in parallel with the resin sheet. For the mold with such a resin sheet placed therein, PC resin heated to 280 °C and melted was injected using an injection molding machine to obtain an insert molded product of the resin sheet having hair-like bodies. For the good touch feeling, a sensory evaluation was conducted in which a total of 10 external panelists, 5 men and 5 women, were asked to touch the resin sheet. Each of the specific touch feelings (smooth, crispy, moist, rough, scratchy, etc.) when touching the surface of the resin sheet was evaluated on a scale of 0 to 10 points, and the touch feeling with the highest score was taken as the touch feeling of the surface of the resin sheet. In Table 1, "〇" indicates that the scores for smooth, crispy, or moist were high, and a good touch feeling like that of a suede-like raised sheet was obtained even after secondary molding. "×" indicates that the scores for rough or scratchy were high, and a good touch feeling was not obtained after secondary molding.

[0059] Table 1 shows the results of evaluation tests on various properties using the resin sheets obtained in each of the examples and comparative examples.

[0060]

Table 1

[0061] The following was revealed from the results shown in Table 1. All of the resin sheets of Examples 1 to 6 had good touch feeling, and the temperature at which the height of the hair-like bodies decreased by 5% was higher than 130 °C, which is generally the temperature at which the resin melted in insert molding is heated, and it was found that the good touch feeling was maintained even after insert molding. On the one hand, the resin sheet of Comparative Example 1 is a resin sheet with a 5% reduction temperature of the hair height of 125°C. However, the hair-like structures were greatly deformed by insert molding, and their tactile properties became rough, and it was not possible to perform insert molding while maintaining good tactile properties. The resin sheet of Comparative Example 2 is a resin sheet with a 5% reduction temperature of the hair height of 118°C. However, the hair-like structures were greatly deformed by insert molding, and their tactile properties became rough, and it was not possible to perform insert molding while maintaining good tactile properties. The resin sheet of Comparative Example 3 is a resin sheet with a 5% reduction temperature of the hair height of 207°C. Although it was possible to perform insert molding while maintaining the tactile properties before insert molding, the hardness of the thermoplastic resin composition constituting the base layer and the hair-like structures was high, and the tactile properties were rough both before and after insert molding, and it did not have good tactile properties.

[0062] As described above, the present invention has been described using various embodiments. Needless to say, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is obvious to those skilled in the art that various changes or improvements can be made to the above embodiments. Also, it is obvious from the description of the claims that forms with such changes or improvements can also be included in the technical scope of the present invention.

Industrial Applicability

[0063] Since the resin sheet of the present embodiment can maintain good tactile properties even after secondary molding, it has industrial applicability as a resin sheet capable of secondary molding and its molded product.

Explanation of Reference Numerals

[0064] 1 Hair-like structures and base layer 1a Base layer 1b Hair-like structures d Diameter of hair-like structures h Height of hair-like structures t Spacing between hair-like structures 2 Base material layer

Claims

1. A thermoplastic resin sheet having trichomes regularly arranged on at least one surface of a base layer, and forming a continuous phase without a structural boundary between the base layer and the trichomes, wherein the temperature at which the average height of the trichomes decreases by 5% from the average height before heating after heating for 5 minutes is 130°C or higher and 200°C or lower.

2. The resin sheet according to claim 1, wherein the average height of the trichomes is 30 μm or more and 500 μm or less, the average diameter of the trichomes is 1 μm or more and 50 μm or less, and the average interval between the trichomes is 20 μm or more and 200 μm or less.

3. The resin sheet according to claim 1 or 2, wherein the thermoplastic resin contains a urethane-based elastomer.

4. The resin sheet according to claim 1 or 2, having a base material layer on the surface of the base layer opposite to the trichomes.

5. A molded article of the resin sheet according to claim 1 or 2.

6. The molded article according to claim 5, which is an insert molded article or a vacuum molded article.

7. The molded article according to claim 5, which is provided on the surface of an automotive interior material, an exterior material for an electronic device, or a cosmetic container.

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