JP2011073148A - Skin material and compound molding with improved tactile feeling using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a skin material turning a hard tactile feeling of a molding into a soft, moisturized and smooth tactile feeling. <P>SOLUTION: The skin material is formed of a soft polymer layer formed by crosslinking a urethane (meth)acrylate composition on one face of a base material film. The Martens hardness of the soft polymer layer is 0.2-1.3 N/cm<SP>2</SP>, and a surface roughness (Ra) is 0.15-1.0 μm. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a skin material capable of improving the tactile sensation of a molded body, and more specifically, a skin material having a flexible polymer layer formed from urethane (meth) acrylate and a composite molded body having improved tactile sensation using the same. It is about.

  In order to improve the surface properties of the molded body, insert molding is performed in which a liquid silicone rubber composition is injection-molded and cured in a mold in which a pre-molded resin molded body is inserted (for example, Patent Document 1). However, in the method performed in Patent Document 1 and the like, a resin molding process and a liquid silicone rubber injection molding process are required, which leads to complication of the mold and a long molding cycle. There's a problem. Moreover, since the adhesiveness of a silicone rubber and a resin molding is inferior, or when a high decoration is given, since the tactile sensation of the rubber layer is lowered, the design is also inferior. In addition, low molecular weight components contained in silicone rubber bleed out on the surface, which may be a factor that hinders ink adhesion and interlayer adhesion when printing on the rubber layer or laminating other layers. It was.

  On the other hand, film insert molding that can obtain a molded body in which the film and the resin are integrated by placing the film in a mold and then injection-molding the resin has attracted attention (Patent Document 2 and 3 etc.). In film insert molding, the interior of the film can be decorated, so there is an advantage that a molded body with high designability can be obtained at a stretch, and the molding cycle is also short, so a highly designed molded body can be produced with high efficiency. Can be mass produced.

  However, the molded product obtained by the method disclosed in Patent Document 2 has a tactile sensation of a plastic film, and cannot be expected to be soft, moist or smooth. If a polyurethane film is used, softness can be imparted, but a smooth feeling cannot be expected. Furthermore, when a polyurethane film is used, there is a problem of yellowing because the light resistance of the polyurethane film is poor.

  On the other hand, in the method disclosed in Patent Document 3, since the surface layer is leather, the tactile sensation is reasonably good, but since the leather is opaque, a decorative layer is provided on the opposite surface of the skin material. It is not possible to adopt a method such as improving designability.

  In addition, a clear layer that can be cured by irradiating electromagnetic radiation is laminated on the thermoplastic protective film layer, and a colored layer is further laminated on the clear layer. A laminated film for decorating a molded product is known (for example, Patent Document 4). In Patent Document 4, since the surface of the molded product is a thermoplastic protective film layer, it becomes a tactile sensation of a plastic film, and softness, moist feeling, or a smooth feeling cannot be expected.

  Patent Documents 5 and 6 disclose a rubber composite film in which a silicone rubber layer and a plastic film are combined in order to improve the feel of a hard plastic film. In the methods disclosed in Patent Documents 5 and 6, as in the technique disclosed in Patent Document 1, low molecular weight components contained in silicone rubber bleed out on the surface and printed on the rubber layer. When the ink is applied or when other layers are laminated, it becomes a factor that hinders the ink adhesion and interlayer adhesion.

JP 2001-240746 A Japanese Patent Laying-Open No. 2005-305786 JP 2006-175639 A JP 2002-240202 A Japanese Patent Laid-Open No. 10-226022 JP 2002-178478 A

  In light of the above-described conventional technology, the present invention has been aimed at providing a skin material that can make a hard tactile feel of a molded body soft, moist and free of touch.

The skin material of the present invention that has solved the above problems is a skin material in which a flexible polymer layer obtained by crosslinking a urethane (meth) acrylate composition is formed on one surface of a base film, and the Martens hardness of the flexible polymer layer is Is 0.2 to 1.3 N / mm ² , and the surface roughness (Ra) is 0.15 to 1.0 μm.

  The friction resistance of the flexible polymer layer is preferably 18 to 54% of the friction resistance of the biaxially stretched polyester film, and the flexible polymer layer is preferably crosslinked by active energy rays. It is also a preferred embodiment of the present invention that the urethane (meth) acrylate is obtained from a raw material containing a polyisocyanate compound, polycaprolactone polyol and polycaprolactone-modified hydroxyalkyl (meth) acrylate. Furthermore, the base film is preferably a biaxially stretched polyester film.

  In the skin material of this invention, the decorating layer may be formed in the base film side, and the adhesive improvement layer may be formed. It is preferable that a decorative layer is formed on the surface of the base film, and an adhesion improving layer is formed on the surface of the decorative layer.

  In the present invention, the skin material of the present invention is inserted into a mold so that the flexible polymer layer becomes the outermost surface of the molded body, and then the mold is closed and a resin is injected and insert molding is performed. A composite molded body with improved tactile sensation characterized by the above is also included.

  The skin material of the present invention, for example, by sticking this skin material on the surface of the molded body, or by performing film insert molding using this skin material, the hard feel of the molded body is soft and moist. And I was able to make it feel smoother. In the present invention, urethane (meth) acrylate is crosslinked using active energy rays, so that a high-performance skin material can be produced in a short time.

  The skin material of the present invention includes a casing, a protective case, a keypad, etc. of a mobile phone, a mobile personal computer, a portable game machine, a portable audio device, etc .; a casing or member of an OA device or home appliance; The composite molded body of the present invention is useful as a casing for mobile phones, mobile PCs, portable game machines, portable audio devices, etc. Cases, keypads, etc .; housings and members of OA equipment and home appliances; can be used as automotive interior members such as instrument panels and handles.

  In the skin material of the present invention, a flexible polymer layer formed from a crosslinked urethane (meth) acrylate is formed on one surface of a material film. Composite with improved tactile sensation by sticking this skin material to the molded body or placing the skin material in the mold so that the flexible polymer layer contacts the mold, and then integrating the resin by injection molding A molded body can be obtained. In the following description, “molded body” means a cured resin after molding that does not include a skin material, and “composite molded body” is a composite in which the skin material of the present invention and the molded body are integrated. Means the body.

[Base film]
The skin material of the present invention includes a base film as a constituent element. Examples of the base film include polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate and modified products thereof; polycarbonates; acrylic resins such as polymethyl (meth) acrylate; polyolefins such as polystyrene, polymethylpentene, and cyclic polyolefin polymers; Examples thereof include triacetyl cellulose, polyvinyl chloride, and polyvinylidene chloride. Among these, a biaxially stretched polyester film is preferable. Although it does not specifically limit as a manufacturing method of a biaxially stretched polyester film, For example, after drying polyester as needed, it supplies to a well-known melt extruder, it extrudes in a sheet form from a slit-like die, an electrostatic application etc. In this manner, the unstretched sheet may be stretched after being brought into close contact with the casting drum and cooled and solidified to obtain an unstretched sheet. The biaxial stretching method may be either simultaneous biaxial stretching or sequential biaxial stretching.

  As for the thickness of a base film, about 10-300 micrometers is preferable, More preferably, it is 70-260 micrometers. If the film thickness is less than 10 μm, the mechanical strength is insufficient and handling becomes difficult, which is not preferable. On the other hand, when the thickness exceeds 300 μm, the rigidity of the base film becomes too high, and the followability to the shape of the molded body may be deteriorated, which is not preferable.

  The base film may be subjected to known adhesion improving treatment such as corona treatment, flame treatment, plasma treatment and the like. Moreover, you may use the film in which the easy-adhesion process was performed previously as a base film. The easy adhesion treatment is preferably performed on both sides. Furthermore, for the base film, known additives such as antioxidants, heat stabilizers, weather stabilizers, UV absorbers, organic lubricants, pigments, dyes, organic or inorganic fine particles, fillers, antistatic agents An agent, a nucleating agent, etc. may be added.

[Urethane (meth) acrylate composition]
[Urethane (meth) acrylate]
The flexible polymer layer of the skin material of the present invention is formed by crosslinking a composition containing a specific urethane (meth) acrylate. The raw material composition of this urethane (meth) acrylate is not particularly limited as long as the following properties are satisfied. For example, a preferred embodiment is made of a raw material containing a hydroxyalkyl (meth) acrylate containing at least one hydroxyl group in a molecule such as a polyisocyanate compound and 2-hydroxyethyl acrylate and a polyol compound.

  As the hydroxyalkyl (meth) acrylate, polycaprolactone-modified hydroxyalkyl (meth) acrylate is preferably used. In addition, it is preferable to use polycaprolactone polyol as the polyol compound.

  By introducing a polycaprolactone chain, appropriate flexibility and hardness can be imparted to the obtained urethane (meth) acrylate crosslinked product, and the Martens hardness described later can be easily adjusted to an appropriate range. Further, by making the surface roughness within the range described later, it is possible to balance the moist feeling and the smooth feeling.

  In particular, the polycaprolactone polyol / polycaprolactone-modified hydroxyalkyl (meth) acrylate (mass ratio) is preferably in the range of 0.1 / 1.0 to 6.0 / 1.0, preferably 0.2 / 1.0 to 4. 5 / 1.0 is more preferable. By satisfy | filling this range, moderate block property can be provided to a urethane (meth) acrylate crosslinked body, and the below-mentioned preferable characteristic can be obtained stably. For example, if it is less than 0.1 / 1.0, the hardness becomes high and the moist feeling is insufficient. On the other hand, if it exceeds 6.0 / 1.0, the hardness becomes too low and the smooth feeling is lowered, which is not preferable. Hereinafter, the raw material of urethane (meth) acrylate will be described in more detail.

[Polyisocyanate compound]
A polyisocyanate compound is a compound having two or more isocyanate groups in one molecule. Specifically, tolylene diisocyanate, naphthalene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, methyl-2,6-diisocyanate hexano Diisocyanates such as acrylate, norbornane diisocyanate, lysine diisocyanate, tetramethylxylene diisocyanate; these isocyanurate-modified products, adduct-modified products, burette-modified products, 2-isocyanate ethyl-2,6-diisocyanate caproate, triphenylmethanetri Isocyanates, tris (isocyanatophenyl) thiophosphate, rigid Ester triisocyanate, 1,6,11-undecane triisocyanate, 1,3,6-hexamethylene triisocyanate, triisocyanate such as bicycloheptane triisocyanate. These may be used alone or in combination of two or more.

  The blending ratio of the polyisocyanate compound is not particularly limited. What is necessary is just to set suitably in the range with which the below-mentioned characteristic is satisfy | filled. For example, the blending ratio of the polyisocyanate compound is preferably 0.05 to 0.7 in terms of mass ratio with respect to the total amount of polycaprolactone polyol and polycaprolactone-modified hydroxyalkyl (meth) acrylate, and 0.1 to 0.65. Is more preferable.

[Polycaprolactone polyol]
In the present invention, polycaprolactone polyol is used for the synthesis of urethane (meth) acrylate. As the polycaprolactone polyol, polycaprolactone diol, polycaprolactone triol, and polycaprolactone tetraol can be used. The molecular weight is preferably about 500 to about 4000. The polycaprolactone polyol may be used alone or in combination of two or more.

  By using the polycaprolactone polyol to increase the chain length of the polyol, softness and moist feeling can be imparted to the flexible polymer layer.

[Polycaprolactone-modified hydroxyalkyl (meth) acrylate]
In the present invention, it is preferable to use hydroxyalkyl (meth) acrylate modified with caprolactone represented by the following formula (1) for the synthesis of urethane (meth) acrylate.

[Wherein, R ¹ represents hydrogen or a methyl group, R ² represents an alkylene group which may be branched, and n represents an integer of 1 to 25. ]

  In the caprolactone-modified hydroxyalkyl (meth) acrylate, the caprolactone-derived pentylene group is linked between the (meth) acryloyl group and the terminal hydroxy group via the number of moles of caprolactone added via oxygen. The distance between the (meth) acryloyl group and the terminal hydroxyl group is increased. Therefore, for example, when caprolactone-modified hydroxyalkyl (meth) acrylate is reacted at both ends of urethane, the distance between the (meth) acryloyl groups at both ends becomes very long, and the urethane (meth) acrylate is irradiated with an electron beam. When the (meth) acryloyl group is reacted, a cured polymer having a long distance between crosslinking points is formed. Thereby, a soft polymer and a moist feeling can be given to a flexible polymer layer.

R ^{2 in the} above formula (1) is preferably an ethylene group, a propylene group or a butylene group, and n is preferably 2 to 5.

[Other raw materials]
In the synthesis of urethane (meth) acrylate, a hydroxy group-containing (meth) acrylate that is not modified with caprolactone may be used in combination. For example, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2- (meth) acryloyloxyethyl-2-hydroxyethyl- Examples include phthalic acid, 2-hydroxy-3-acryloyloxypropyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, and glycerol mono (meth) acrylate.

  In addition, a long-chain alkyl alcohol having no polycaprolactone moiety may be mentioned as a preferred combination partner. Examples thereof include tridecanol, myristyl alcohol, cetyl alcohol, stearyl alcohol, behenyl alcohol, glycerol monostearate, polyoxyethylene monostearate and the like. Long chain alkyls having 13 to 25 carbon atoms are preferred.

[Synthesis of urethane (meth) acrylate]
Urethane (meth) acrylate is obtained by mixing a polyisocyanate compound and polycaprolactone polyol and reacting both, and then adding polycaprolactone-modified hydroxyalkyl (meth) acrylate and reacting them. The reaction temperature is preferably from room temperature to 100 ° C., and the reaction time is preferably from 1 to 50 hours.

  Both of the above reactions can be carried out in a solvent-free system, but are preferably carried out in the presence of a solvent. Solvents include aromatic hydrocarbon solvents such as toluene and xylene; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester solvents such as ethyl acetate, propyl acetate, isobutyl acetate, and butyl acetate; Used alone or in combination.

  Further, both of the above reactions can also be performed in a dilution monomer such as styrene, isobornyl (meth) acrylate, (meth) acryloylmorpholine, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate and the like. .

  When a long-chain alkyl alcohol having no polycaprolactone moiety is used in combination with a polycaprolactone polyol, the total amount of both hydroxy groups is set within the range of the preferred amount of hydroxy groups of the polycaprolactone polyol. Similarly, when hydroxyalkyl (meth) acrylate not modified with caprolactone is used in combination with polycaprolactone-modified hydroxyalkyl (meth) acrylate, the total amount of both hydroxyl groups is the above-mentioned polycaprolactone-modified hydroxyalkyl (meth) acrylate. Within the preferred range of hydroxy groups.

  In the synthesis of urethane (meth) acrylate, a catalyst such as dibutyltin dilaurate, dibutyltin diethylhexanoate, or dibutyltin sulfite may be used as necessary. The addition amount of the catalyst is preferably 0.01 to 1 part by mass, and more preferably 0.1 to 0.5 part by mass. A polymerization inhibitor such as hydroquinone monomethyl ether may be used. The addition amount of the polymerization inhibitor is preferably 0.01 to 1 part by mass.

[Monomer for dilution]
In applying urethane (meth) acrylate to the base film, the urethane (meth) acrylate solution generated by the synthesis of urethane (meth) acrylate can be applied as it is, but when the viscosity is high, the reaction described above It can be diluted with a solvent. Moreover, you may use the urethane (meth) acrylate composition which added the monomer for dilution to the urethane (meth) acrylate solution produced | generated by the synthesis | combination of urethane (meth) acrylate. Examples of the monomer for dilution include a monofunctional or polyfunctional monomer or oligomer having a (meth) acryloyl group.

  Specifically, monohydroxyethyl (meth) acrylate phthalate, stearyl (meth) acrylate, 2-ethoxyhexyl (meth) acrylate, phenoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-ethoxyethoxy Ethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, polycaprolactone-modified hydroxyethyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, N-vinylpyrrolidone, acryloyl Monofunctional monomers such as morpholine, isobornyl (meth) acrylate, vinyl acetate, styrene; neopentyl glycol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate 1,6-hexanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate , Propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, bisphenol F diglycidyl ether (meth) acrylic acid adduct, bisphenol A diglycidyl ether (meth) acrylic acid adduct, bisphenol F ethylene oxide modified di Bifunctional monomers such as (meth) acrylate and bisphenol A ethylene oxide-modified di (meth) acrylate; trimethylolpropane tri (meth) acrylate, pentaerythritol Tri (meth) acrylate, tri (meth) acrylate of 3 mol propylene oxide adduct of trimethylolpropane, tri (meth) acrylate of 6 mol ethylene oxide adduct of trimethylolpropane, glycerin propoxytri (meth) acrylate, dipenta Multifunctional monomers such as erythritol hexa (meth) acrylate and hexa (meth) acrylate of dipentaerythritol caprolactone adduct; unsaturated polyester, polyester (meth) acrylate, polyether (meth) acrylate, urethane (meth) acrylate And oligomers such as epoxy (meth) acrylate.

  The dilution monomer may be used in the range of 5 to 50 parts by mass with respect to 100 parts by mass of urethane (meth) acrylate.

[Photopolymerization initiator]
In the present invention, it is preferable to add a photopolymerization initiator when the urethane (meth) acrylate is crosslinked by light irradiation. The type of the photopolymerization initiator is not particularly limited, and known ones can be used. Typical examples include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropane- 1-one, benzyl dimethyl ketal, benzoin isopropyl ether, benzophenone and the like can be mentioned. These may be used alone or in combination. In the case of using a photopolymerization initiator, the addition amount thereof is preferably 1 to 10% by mass, more preferably 3 to 5% by mass in 100% by mass of the solid content of the obtained urethane (meth) acrylate composition.

[Urethane (meth) acrylate composition layer]
The method of laminating the urethane (meth) acrylate composition layer on the base film may be arbitrarily selected from conventionally known methods, for example, a method of coating and drying the above composition on the base film; And a method of extruding the above composition under high pressure; a calendar method and the like. In the case of coating, various coating methods such as gravure coating method, rod coating method, bar coating method, Mayer bar coating method, reverse kiss coating method, die coating method, spray coating method and the like can be used.

  The thickness of the urethane (meth) acrylate composition layer is preferably 5 to 200 μm. 10-150 micrometers is more preferable, and 20-100 micrometers is further more preferable. A thickness of less than 5 μm is not preferable because the tactile sensation improving effect is reduced. On the contrary, when it exceeds 200 μm, the tactile sensation improving effect is saturated, which is disadvantageous economically.

[Crosslinking]
In the present invention, the method for crosslinking the urethane (meth) acrylate composition is not particularly limited. For example, thermal crosslinking may be used, and active ray crosslinking may be used. Actinic radiation crosslinking is preferred, and it is preferable to crosslink urethane (meth) acrylate by irradiating with high energy actinic energy rays such as light, electron beam or γ-ray. The method using high-energy active energy rays does not require the addition of an additive for generating radicals such as peroxide. For this reason, it is not necessary to consider the pot life of the urethane (meth) acrylate composition after the addition of a crosslinking catalyst, etc., and contamination of the adherend due to residues of additives such as peroxides and physical properties of the flexible polymer layer The reduction is suppressed, and there are merits such that productivity is increased because crosslinking is completed efficiently in a short time. Among the active energy rays, the electron beam cross-linking method is preferable because of the availability of an irradiation device (EB irradiation device). As an electron beam irradiation amount in an EB irradiation apparatus, the range of 5-50 Mrad is preferable. By setting the electron beam irradiation amount to 5 Mrad or more, the crosslinking reaction of urethane (meth) acrylate can be promoted. On the other hand, by setting the electron beam irradiation amount to 50 Mrad or less, it is possible to suppress a decrease in elasticity due to excessive progress of the crosslinking reaction.

[Surface roughness Ra and basis weight film]
In the skin material of the present invention, the surface roughness (Ra) of the flexible polymer layer must be 0.15 to 1.0 μm. When Ra is smaller than 0.15 μm, the slimy feeling increases and it is difficult to obtain a smooth touch. On the other hand, when Ra exceeds 1.0 μm, the feeling of roughness increases and the tactile sensation improving effect decreases, which is not preferable. Ra is more preferably 0.20 to 0.80 μm.

  In the present invention, the surface roughness Ra is a center line average roughness Ra (JIS B0601: '82), and a surface roughness measuring machine “SE-3C” manufactured by Kosaka Laboratory is used, and the vertical magnification is: The values measured under the conditions of 2000 to 10,000, cut-off: 0.25 mm, measurement length: 8 mm, measurement speed: 0.5 mm / min are employed.

  In order to make the surface roughness of the flexible polymer layer within the above range, it is preferable to employ a weighting method using a weighting film. That is, a weighting material made of a film or fabric having a predetermined surface roughness is stacked on the surface of an uncrosslinked urethane (meth) acrylate composition layer before irradiation with active energy rays, and the surface shape of the weighting material is placed on the surface of the composition layer. It is a method of transcription. Examples of the weighting material include plastic films such as polyethylene film, polyester film, and polyvinyl chloride film subjected to mat processing and emboss processing, and filament fabric such as nylon taffeta and polyester taffeta. The basis material is not limited to these, but it is a preferred embodiment to use a polyester film (hereinafter, sometimes referred to as a basis weight polyester film) that has been subjected to matting or embossing.

  It is preferable to apply the weight after applying an aqueous solution of a surfactant such as an alkali metal salt of an alkyl sulfonate such as sodium dodecylbenzene sulfonate to the matted or embossed surface of the basis weight. Since the peeling force is reduced by the surfactant when peeling the basis weight polyester film after the basis weight processing, smooth peeling becomes possible.

  After applying the massaging material to the urethane (meth) acrylate composition layer, the active energy ray is irradiated to perform crosslinking. In this case, the irradiation may be performed from the base film side to make the peeling smooth. This method is preferable in that the adhesive force between the flexible polymer layer and the base film is also improved.

[Martens hardness]
The flexible polymer layer of the present invention should have a Martens hardness of 0.2 to 1.3 N / mm ² . Martens hardness (ISO 14577) is the hardness measured with a test load applied, and is determined from the value of the load-indentation depth curve when the load increases. In the present invention, Martens hardness was selected as an index representing the softness of the flexible polymer layer. This is because it corresponds well with human touch.

If the Martens hardness of the flexible polymer layer is less than 0.2 N / mm ^2, it is not preferable because it becomes too soft and the smooth feeling is insufficient. When the Martens hardness of the flexible polymer layer exceeds 1.3 N / mm ² , only a hard tactile sensation can be obtained, and a moist feeling is insufficient. The Martens hardness is more preferably 0.2 to 0.8 N / mm ² . The method for adjusting the Martens hardness within these ranges is not particularly limited, but it is preferable to cope with the composition design of the flexible polymer layer, and the composition of the urethane (meth) acrylate composition is within the above-mentioned preferred range, and the crosslinking conditions Is a particularly preferred embodiment.

  In the present invention, the Martens hardness is a value measured under the conditions described later using a dynamic ultra-micro hardness meter “DUH-211” (manufactured by Shimadzu Corporation).

[Friction resistance]
The frictional resistance of the flexible polymer layer of the present invention is preferably 18 to 54% of the frictional resistance of the biaxially stretched polyester film when compared to the biaxially stretched polyester film. This frictional resistance is a value measured by a “portable tactile meter” (manufactured by Shinto Kagaku Co., Ltd.). In the present invention, this frictional resistance was used as an index representing a moist feeling when a soft polymer layer was touched with a finger. . If the frictional resistance of the flexible polymer layer is less than 18% of the frictional resistance of the biaxially stretched polyester film, the moist feeling may be passed and an unsuitable feeling that a finger is likely to attach may be caused. Conversely, if it exceeds 54%, that is, the frictional resistance of the flexible polymer layer approaches the frictional resistance of the biaxially stretched polyester film, the feeling of moistness is insufficient and a slippery sensation is obtained, which is not preferable. The friction resistance of the flexible polymer layer is more preferably 18 to 50% of the friction resistance of the biaxially stretched polyester film.

  The method for adjusting the frictional resistance force to these ranges is not particularly limited, but it is preferable to correspond to the composition design of the flexible polymer layer and the surface roughness design, and the composition of the urethane (meth) acrylate composition is preferable as described above. It is a particularly preferable embodiment that the range is within the range and the crosslinking condition is the above-described preferable condition. In addition, as the biaxially stretched polyester film to be compared, “Cosmo Shine (registered trademark) A4300” (manufactured by Toyobo Co., Ltd .; thickness: 125 μm), which is a highly smooth and highly transparent double-sided easy-adhered polyester film, was used.

[Decoration layer]
In the skin material of the present invention, it is desirable to provide a decorative layer on the surface of the base film (opposite side of the flexible polymer layer forming surface). A composite molded body having a high degree of design can be produced only by a process of sticking the skin material to the molded body or an insert (injection) molding process. Examples of the decorative layer include a printed layer, a metal thin film layer, an inorganic thin film layer, and the like, and it is preferable to form one or more of these layers. A decoration layer is formed in the surface on the opposite side to the flexible polymer layer of a base film.

  For the formation of the printing layer, known printing methods such as gravure printing, flat printing, flexographic printing, dry offset printing, pad printing, and screen printing can be used depending on the product shape and printing application. In particular, offset printing and gravure printing are suitable for multicolor printing and gradation expression. In addition, when the skin material is used for insert molding for molding into a complicated shape, it is preferable to use a printing ink having excellent spreadability, and the binder resin is an ink mainly composed of a flexible resin such as a polyurethane resin. preferable.

  The decorative layer may be not only a printed layer but also a metal or metal oxide thin film layer, or may be a combination of a printed layer and a metal (oxide) thin film layer. When a thin film layer of metal or metal oxide is formed, the permeation of water vapor or oxygen to the resin molded body is suppressed, so that the durability of the resin molded body can be improved. Examples of the method for forming a metal (oxide) thin film layer include vapor deposition, thermal spraying, and plating.

  As the vapor deposition method, either physical vapor deposition or chemical vapor deposition can be used. Examples of physical vapor deposition include vacuum vapor deposition, sputtering, and ion plating. Examples of the chemical vapor deposition (CVD) method include a thermal CVD method, a plasma CVD method, and a photo CVD method. Examples of the thermal spraying method include an atmospheric pressure plasma spraying method and a low pressure plasma spraying method. Examples of the plating method include an electroless plating (chemical plating) method, a hot dipping method, and an electroplating method. In the electroplating method, a laser plating method or the like can also be used. Among these, the vapor deposition method and the plating method are preferable for forming the metal layer, and the vapor deposition method is preferable for forming the metal oxide layer. The vapor deposition method and the plating method can be used in combination.

  As the metal used for vapor deposition, aluminum, chromium, silver, gold, and combinations or alloys thereof are preferable. When the film for skin material is used for insert molding that is molded into a complicated shape, a metal having excellent spreadability is preferable, for example, aluminum in which indium or the like is blended is preferable.

  When a metal (oxide) thin film layer is partially formed on the decorative layer, a solvent-soluble resin layer is formed on a portion that does not require the thin film layer, and then a thin film layer is formed on the entire surface. Then, it is sufficient to remove the unnecessary metal thin film together with the solvent-soluble resin layer by performing solvent cleaning, and the solvent often used in this case is water or a mixed solution of water and a hydrophilic solvent. Another method is to form a metal (oxide) thin film on the entire surface, then form a resist layer on the portion where this thin film is to be left, etch the thin film with acid or alkali, and finally form a resist layer. The method of removing is mentioned.

[Adhesion improvement layer]
If necessary, the skin material used in the present invention may be provided with an adhesion improving layer on the surface of the base film or the surface of the decorative layer to enhance the adhesion with the molded body at the time of insert molding. That is, the adhesion improving layer can be provided on the surface of the base film when the decorative layer is not provided, and on the surface of the decorative layer when the decorative layer is provided.

  The adhesive used for this adhesion improving layer is not particularly limited as long as it has a function of enhancing the adhesion between the skin material film and the molded body. For example, a thermosetting type or a hot melt type can be used.

  As the thermosetting type, laminate adhesives such as polyurethane, polyacrylic, polyester, epoxy, polyvinyl acetate, cellulose, and the like can be used. The crosslinking agent is not particularly limited, and for example, a melamine crosslinking agent, an oxazoline crosslinking agent, an isocyanate crosslinking agent, an aziridine crosslinking agent, and an epoxy crosslinking agent can be used. Although the aging conditions for hardening are not specifically limited, For example, it is preferable that temperature is 45-65 degreeC and time is 20 to 48 hours. If the aging time is too short or the temperature is insufficient, the adhesive layer may be washed away during insert molding, leaving wavy ripples or hindering transparency. On the other hand, if the aging is excessive, the adhesiveness is deteriorated and floating occurs, and even if these disadvantages do not appear at room temperature, the heat resistance may be impaired.

  Hot melt types include natural rubber, acrylic resin, ethylene-vinyl acetate copolymer (EVA), styrene / butadiene / styrene copolymer (SBS), styrene / isoprene / styrene copolymer (SIS), etc. Various thermoplastic resins such as elastomers, polyamides, polyesters, polyolefins, and polyvinyl acetates can be exemplified. Further, a resin modified so as to include various functional groups or polar groups that enhance adhesion, such as a carboxyl group or an acid anhydride group, is more preferable. These modification | denaturation can be performed by a well-known method.

  Although the thickness of the said adhesive improvement layer is not specifically limited, 1-100 micrometers is preferable and 3-50 micrometers is more preferable. If it is less than 1 μm, the effect of improving adhesiveness is lowered, which is not preferable. On the other hand, when it exceeds 100 μm, the effect of improving the adhesiveness is saturated and the heat resistance and the like may be lowered. It is also economically disadvantageous.

  The formation method of the said adhesive improvement layer is not limited, either. For example, it may be formed by applying an adhesive as a solution, or by melting and extruding an adhesive resin. In addition, sheets made of an adhesive may be used in an overlapping manner.

[Composite molding]
By using the skin material of the present invention and composited with a resin molded product, a composite molded product with improved tactile sensation can be obtained. The resin constituting the molded body is appropriately selected depending on market demands, and for example, a thermoplastic resin or a thermosetting resin can be used.

  Examples of the thermoplastic resin include polyolefin resins such as polyethylene and polypropylene; polystyrene resins such as polystyrene, syndiotactic polystyrene, AS resin, and ABS resin; polyethylene terephthalate, polypropylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and the like. Polyester resins; various acrylic resins; polycarbonate resins; polyamides, polyamideimides, polysulfones, polyacetals, polyphenylene ethers, polyphenylene sulfides, polyarylates, polyetherimides, polyethersulfones, polyether ketones, etc., and their blends Articles and alloy compositions can also be used.

  Specific examples of the thermosetting resin include unsaturated polyester resin, vinyl ester resin, epoxy resin, phenol resin and the like. Of these, thermoplastic resins such as polyolefin resins, polystyrene resins, polyester resins, acrylic resins, and polycarbonate resins are preferable. A known reinforcing fiber may be included in the resin.

  There are three methods for compounding with a molded body. (1) a method of insert molding, (2) a method of using an adhesive layer of a skin material, and (3) a method of using a separate double-sided adhesive sheet.

  In the method of (1) insert molding, there is no need to form an adhesive layer on the skin material. It is desirable to provide an adhesion improving layer. Before molding, after the skin material is shaped by vacuum molding, pressure molding under low pressure, press molding, etc., and the skin material is inserted into the mold so that the flexible polymer layer contacts the mold The resin may be integrated by injection molding, or the flat skin material may be placed in a mold and the resin may be injection molded and integrated. The molding conditions and the like may be appropriately selected depending on the resin used.

  In (2), a skin material provided with an adhesive layer is used. What is necessary is just to peel a separate film from the adhesion layer of this skin material, and just stick it on the molded object surface. When providing the adhesive layer, it is preferable to provide it on the outermost surface layer of the skin material on the base film side (opposite side to the surface on which the flexible polymer layer is formed) and cover it with a separate film. The adhesive layer may be any adhesive layer.

  In (3), the molded body and the skin material may be bonded together by using a skin material having a configuration not having an adhesive layer and using a separate double-sided pressure-sensitive adhesive sheet. The separate double-sided PSA sheet may be any double-sided PSA sheet.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited by the following examples, but may be implemented with appropriate modifications within a scope that can meet the gist of the present invention. These are all included in the technical scope of the present invention. In addition, the measurement / evaluation method employ | adopted in the Example is as follows, and these measurement / evaluation performed all by peeling the film for weighting. In the examples, “parts” means “parts by mass”, and “%” means “% by mass” unless otherwise specified.

[Tactile (sensory evaluation)]
As subjects, 5 healthy men and women from 20 to 50 years old, 10 people in total were collected. After having each subject enter an environmental test room conditioned at 23 ° C. and 50% RH and resting for a while, the surface of the flexible polymer layer of the skin material of the example or the comparative example is boiled with a finger. I got it. An interview survey was conducted on the tactile sensation at that time, and the following five levels were evaluated.

The tactile sensation is moist and has a smooth feeling. Therefore, the determination was made based on the degree of lack of moist or smooth feeling.
5: Tactile feeling is excellent 4: Tactile feeling is slightly excellent 3: Normal 2: Tactile feeling is slightly inferior 1: Tactile feeling is inferior

[Surface roughness Ra]
Using a surface roughness measuring machine (model “SE-3C”; manufactured by Kosaka Laboratories), centerline average roughness Ra (JIS B0601: '82), longitudinal magnification: 2000 to 10,000, cut-off: 0.25 mm Measurement length: 8 mm, measurement speed: 0.5 mm / min.

[Martens hardness]
The sample was cut into about 2 cm square, and the opposite surface of the measurement surface was fixed on a glass plate having a thickness of 1 mm or more with a non-carrier type acrylic adhesive (thickness 25 μm) or a cyanoacrylate adhesive. After sticking and fixing, leave it in an environment adjusted to 23 ° C. and 50% RH for 30 minutes or more, and then use a dynamic ultra-micro hardness meter “DUH-211” (manufactured by Shimadzu Corporation) under the following conditions: The Martens hardness (N / mm ² : ISO 14577) was measured.
≪Measurement conditions≫
1) Setting Test mode: Load-unloading test Indenter used: 115 ° ridge angle, triangular pyramid indenter
: Indenter elastic modulus: 1.140 × 10 ⁶ N / mm ²
: Indenter Poisson's ratio: 0.07
Soft sample measurement: Yes Cf-Ap, As correction: Yes 2) Condition Test force: 1.00 mN
Load speed: 0.0150 mN / sec
Load holding time: 5 sec
Unloading holding time: 5 sec

[Friction resistance]
On the sample table of a portable tactile meter (“TYPE: 33”; manufactured by Shinto Kagaku Co., Ltd.), four corners of a 90 mm square sample were attached and fixed with double-sided tape. The frictional resistance was measured by moving the finger about 5 cm while pressing the center of the fixed sample with the finger. Measurement was performed 5 times, and an average value was calculated. As a comparison object, “Cosmo Shine (registered trademark) A4300” (manufactured by Toyobo Co., Ltd .; thickness: 125 μm), which is a polyester film having a highly smooth and highly transparent double-sided easy adhesion treatment, was used.

  The table shows the percentage (%) of the frictional resistance of each sample when the frictional resistance of this polyester film is taken as 100%. Therefore, the larger the percentage value of the frictional resistance, the greater the tactile sensation as the polyester film, and the smaller the value, the different tactile sensation.

Example 1
(1) Preparation of urethane acrylate composition solution 100 parts of toluene, 25 parts of methyl-2,6-diisocyanate hexanoate, 2-hydroxyethyl acrylate ("light acrylate HOA"; manufactured by Kyoeisha Chemical Co., Ltd.); number of repetitions of caprolactone units = 0) 11 parts, polycaprolactone-modified hydroxyethyl acrylate ("Placcel (registered trademark) FA5"; manufactured by Daicel Chemical Industries, Ltd .; repeat number of caprolactone units = 5) 34 parts, hydroquinone monomethyl ether 0.02 part as a polymerization inhibitor Mixed, heated to 40 ° C. and held for 12 hours. Then, 141 parts of polycaprolactone diol (“Placcel (registered trademark) 220; manufactured by Daicel Chemical Industries, Ltd .; molecular weight 2000)” was added and held at 80 ° C. for 30 minutes, and then 0.02 part of dibutyltin laurate was added as an esterification catalyst. The mixture was kept at 80 ° C. for 24 hours, and finally 111 parts of toluene was added to obtain a toluene solution of urethane acrylate having a solid content of 50%, and triethylene glycol diacrylate (“light acrylate”) was added to 74 parts of this urethane acrylate solution. 3EG-A "; manufactured by Kyoeisha Chemical Co., Ltd.) 10 parts, stearyl acrylate (" Blenmer (registered trademark) SA "; manufactured by NOF Corporation) 3 parts, and toluene 13 parts were mixed to prepare a urethane acrylate composition solution.

(2) Preparation of skin material As a base film, a highly transparent biaxially stretched polyester film (“Cosmo Shine (registered trademark) A4300”; manufactured by Toyobo Co., Ltd .; thickness 125 μm; both surfaces easy-adhesion treated) is used, and the above urethane The acrylate composition solution was applied so that the thickness after drying was 50 μm, then introduced into an oven and dried at 80 ° C.

  Separately, a dodecyl benzene sulfonic acid soda so as to have a thickness after drying of about 30 nm on the mat processed surface of a 75 μm thick mat processed polyester film (manufactured by Toyo Cloth; SP3020) as a polyester film for basis weight The solution was applied by a microgravure method and dried.

The surface-treated surface of the basis weight polyester film was overlaid on the surface of the urethane acrylate composition layer, and was continuously laminated while pressing with a pressure roll at a pressure of 30 N / cm ² .

  Next, the above laminate is introduced into an electron beam irradiation device, 200 KV, 10 Mrad electron beam is irradiated from the basis weight polyester film side to crosslink the urethane acrylate composition, and the laminate of the skin material and the basis weight film (Hereinafter simply referred to as a skin material laminate) was obtained and wound into a roll. Table 1 shows the evaluation results of the obtained skin material.

(3) Formation of decorative layer UV curable ink (manufactured by Toka Dye Co., “Best Cure (registered trademark) 161”) is used on the opposite side of the surface of the skin laminate obtained by the above method from the flexible polymer layer. The decorative layer was formed by offset printing.

(4) Formation of Adhesion Improvement Layer “Takelac (registered trademark) A-310” and “Takenate (registered trademark)” as polyurethane adhesives on the decorative layer surface of the decorative layer-containing laminate produced by the above method A-3 "(both manufactured by Mitsui Chemicals) are mixed and applied by an applicator to about 3 g / m ² to form an adhesive layer. For the purpose of curing the adhesive layer, Aging was performed in 24 hours to form an adhesion improving layer. Thereby, the roll-shaped original fabric of the skin material laminated body provided with the decorating layer and the adhesive improvement layer was obtained.

(5) Pre-molding of the skin material From the raw material of the skin material laminate produced as described above, the polyester film for the basis weight is peeled off, and the skin material with the flexible polymer layer as the surface layer is applied to a cutting machine to make a small rise. After that, with a drawing machine, drawing was performed using a drawing die heated at an upper mold of 110 ° C. and a lower mold of 90 ° C., and an insert pre-molded body having a slightly curved periphery was obtained. .

(6) Manufacture of composite molded body Next, the insert pre-molded body is punched into a predetermined shape, and placed in a mold having a film gate having a rectangular cross section so that the flexible polymer layer is in contact with the mold surface. did. The molding conditions were set to mold temperature: 100 ° C., nozzle resin temperature: 300 ° C., injection speed: 2 mm / sec, and insert molding was performed using a polycarbonate resin. A composite molded body in which the skin material was integrated on the surface of the resin molded product was obtained.

  The skin material obtained in this example had a balance between moist and smooth feeling and had excellent tactile sensation. Further, the obtained composite molded article had a high-quality appearance that was excellent in tactile sensation, had a clear printed pattern, and was matted by a flexible polymer layer.

Example 2
A skin material and a composite molded body thereof were obtained in the same manner as in Example 1 except that the urethane acrylate composition solution was changed as described below in the method of Example 1. Table 1 shows the evaluation results of the obtained skin material.

  The skin material and its composite molded body obtained in this example had the same characteristics as the skin material and its composite molded body obtained in Example 1, and were of high quality.

[Urethane acrylate composition]
80 parts of toluene, isocyanurate-modified form of hexamethylene diisocyanate (“Takenate (registered trademark) D-170N”; manufactured by Mitsui Chemicals), polycaprolactone-modified hydroxyethyl acrylate (“Placcel (registered trademark) FA1”; Daicel Chemical) Manufactured by Kogyo Co .; repeat number of caprolactone units = 1) 29 parts, 37 parts of “Placcel (registered trademark) FA5” and 0.02 part of hydroquinone monomethyl ether were mixed, heated to 40 ° C. and held for 6 hours. . Then, 18 parts of polycaprolactone tetraol (“Placcel 410D”; manufactured by Daicel Chemical Industries) was added and held at 80 ° C. for 30 minutes, 0.02 part of dibutyltin laurate was added and held at 80 ° C. for 6 hours, Finally, 54 parts of toluene was added to obtain a urethane acrylate having a solid content of 50%. Then, 78 parts of this urethane acrylate was mixed with 10 parts of monohydroxyethyl acrylate phthalate (“M-5400”; manufactured by Toagosei Co., Ltd.) and 11 parts of toluene to prepare a urethane acrylate composition solution.

Example 3
A skin material and a composite molded body thereof were obtained in the same manner as in Example 1 except that the urethane acrylate composition solution was changed as described below in the method of Example 1. Table 1 shows the evaluation results of the obtained skin material.

  The skin material and its composite molded body obtained in this example had the same characteristics as the skin material and its composite molded body obtained in Example 1, and were of high quality.

[Urethane acrylate composition]
100 parts of toluene, 50 parts of 2-isocyanatoethyl-2,6-diisocyanate caproate, 59 parts of “Placcel® FA1”, 20 parts of “Placcel® FA5” and 0.02 of hydroquinone monomethyl ether The parts were mixed, heated to 40 ° C. and held for 12 hours. Then, 82 parts of polycaprolactone triol (“Placcel 308”; manufactured by Daicel Chemical Industries, Ltd .; molecular weight 850) was added and held at 80 ° C. for 30 minutes, and then 0.02 part of dibutyltin laurate was added and held at 80 ° C. for 24 hours. Finally, 111 parts of toluene was added to obtain a urethane acrylate composition solution having a solid content of 50%.

Example 4
A skin material and a composite molded body thereof were obtained in the same manner as in Example 1 except that the urethane acrylate composition solution was changed as described below in the method of Example 1. Table 1 shows the evaluation results of the obtained skin material.

  The skin material and its composite molded body obtained in this example had the same characteristics as the skin material and its composite molded body obtained in Example 1, and were of high quality.

[Urethane acrylate composition]
100 parts of toluene, 50 parts of methyl-2,6-diisocyanatohexanoate, 56 parts of “Placcel (registered trademark) FA1” and 0.02 part of hydroquinone monomethyl ether were mixed and heated to 40 ° C. for 12 hours. Retained. Then, 82 parts of polycaprolactone triol (“Placcel 312”; manufactured by Daicel Chemical Industries, Ltd .; molecular weight 1250) was added and held at 80 ° C. for 30 minutes, and then 0.02 part of dibutyltin laurate was added and held at 80 ° C. for 24 hours. Finally, 106 parts of toluene was added to obtain a urethane acrylate composition solution having a solid content of 50%.

Example 5
A skin material and a composite molded body thereof were obtained in the same manner as in Example 1 except that the urethane acrylate composition solution was changed as described below in the method of Example 1. Table 1 shows the evaluation results of the obtained skin material.

  The skin material and its composite molded body obtained in this example had the same characteristics as the skin material and its composite molded body obtained in Example 1, and were of high quality.

[Urethane acrylate composition]
82 parts of toluene and 42 parts of stearyl alcohol were charged and heated to 40 ° C. After confirming that the stearyl alcohol was completely dissolved, 25 parts of “Takenate (registered trademark) D-170N” was added, and the temperature was raised to 70 ° C. After reacting at the same temperature for 30 minutes, 0.02 part of dibutyltin laurate was added and kept at the same temperature for 3 hours. Thereafter, 83.3 parts of “Placcel (registered trademark) FA5”, 0.02 part of dibutyltin laurate and 0.02 part of hydroquinone monomethyl ether were added, and the temperature was raised to 40 ° C. and held for 12 hours. Then, 82 parts of polycaprolactone triol (“Placcel 308”; manufactured by Daicel Chemical Industries, Ltd .; molecular weight 850) was added and held at 80 ° C. for 30 minutes, and then 0.02 part of dibutyltin laurate was added and held at 70 ° C. for 3 hours. Finally, 642 parts of toluene was added to obtain a urethane acrylate composition solution having a solid content of 50%.

Comparative Example 1
In the method of Example 1, a skin material and a composite molded body were obtained in the same manner as in Example 1 except that the lamination of the flexible polymer layer was stopped. Table 1 shows the evaluation results of the skin material.

  The skin material and the composite molded body obtained in this comparative example were not laminated with a flexible polymer layer, so both the moist feeling and the smooth feeling were poor, and the touch feeling was inferior.

Comparative Example 2
In Example 1, the skin material and the composite molded body were the same as Example 1 except that the polyester film for weighting was changed to a release polyester film (“E7002”; manufactured by Toyobo Co., Ltd .; thickness 25 μm). Got. Table 1 shows the evaluation results of the skin material.

  The skin material and composite molded body obtained in this comparative example had a low surface roughness on the surface of the flexible polymer layer, so that the smooth feeling was insufficient and the touch feeling was poor.

Comparative Example 3
[Preparation of flexible polymer layer coating solution]
50 parts of toluene and 50 parts of isobutyl acetate were charged, and the temperature was raised to 110 ° C. Separately, 106 parts of ethanol, 270 parts of methyltrimethoxysilane, 23 parts of γ-methacryloxypropylmethyldimethoxysilane, 100 parts of deionized water, 1 part of 1% hydrochloric acid and 0.1 part of hydroquinone monomethyl ether were prepared to synthesize siloxane. . This was adjusted to 50% with methyl isobutyl ketone to obtain siloxane component A.

  1 part of methacrylic acid, 20 parts of methyl methacrylate, 32 parts of caprolactone-modified hydroxyethyl methacrylate ([Placcel (registered trademark) FM5; manufactured by Daicel Chemical Industries, Ltd .; repeat number of caprolactone units = 5), 17 parts of 2-hydroxyethyl methacrylate, the above Mix 10 parts of siloxane component A, 20 parts of methacrylic polydimethylsiloxane (“AK-32”; manufactured by Toagosei Co., Ltd .; molecular weight 2000) and 2 parts of 1,1-azobiscyclohexane-1-carbonitrile as a polymerization initiator. Then, this mixed monomer was added dropwise to the mixed solution of toluene and isobutyl acetate over 2 hours. Thereafter, the mixture was reacted for 8 hours to obtain a polydimethylsiloxane graft copolymer solution having a solid content of 50%.

  36 parts of “Takenate D-170N” was added as a crosslinking agent to 100 parts of the polydimethylsiloxane block copolymer solution to prepare a flexible polymer layer coating solution.

Next, the flexible polymer layer coating solution prepared by the above method was applied to the surface of the “Cosmo Shine (registered trademark) A4300” (thickness 125 μm) so that the thickness after drying was 50 μm. The coated body was put in an oven and dried at 60 ° C. The surface treated surface of the polyester film for weighting used in Example 1 was overlapped on the dried coated surface, and laminated by passing while pressing with a pressure roll at a pressure of 30 N / cm ² .

  The obtained laminated film was put in an oven again, heated at 60 ° C. for 1 hour, and further allowed to stand at room temperature for 1 week to obtain a skin material.

  The skin material obtained in this Comparative Example was inferior to the touch feeling because the Martens hardness of the flexible polymer layer was too large and the moist feeling was insufficient.

Comparative Example 4
In Comparative Example 3, the skin material and the composite molded body were the same as Comparative Example 3 except that the polyester film for weighting was changed to a release polyester film (“E7002”; manufactured by Toyobo Co., Ltd .; thickness 25 μm). Got. Table 1 shows the evaluation results of the skin material.

  The skin material and composite molded body obtained in this comparative example had a low surface roughness on the surface of the flexible polymer layer, so that the smooth feeling was insufficient and the touch feeling was poor.

Comparative Example 5
A skin material and a composite molded body thereof were obtained in the same manner as in Example 1, except that the urethane acrylate composition solution was changed as described below in Example 1. Table 1 shows the evaluation results of the obtained skin material.

  In the skin material obtained in this comparative example, the Martens hardness of the flexible polymer layer was too large, the moist feeling was insufficient, and the touch feeling was inferior.

[Urethane acrylate composition]
95 parts of toluene, 20 parts of “Takenate D-170N”, 75 parts of “Placcel FA5”, 0.02 part of dibutyltin dilaurate and 0.3 part of hydroquinone monomethyl ether were charged and heated to 70 ° C. Thereafter, the same temperature was maintained for 3 hours to obtain a urethane acrylate composition solution having a solid content of 50%.

Comparative Example 6
A skin material and a composite molded body thereof were obtained in the same manner as in Example 1, except that the urethane acrylate composition solution was changed as described below in Example 1. Table 1 shows the evaluation results of the obtained skin material.

  In the skin material obtained in this comparative example, the Martens hardness of the flexible polymer layer was too large, the moist feeling was insufficient, and the touch feeling was inferior.

[Urethane acrylate composition]
29.8 parts of toluene and 4.1 parts of cetyl alcohol were charged, and the temperature was raised to 40 ° C. Thereafter, it was confirmed that cetyl alcohol was completely dissolved, and 50 parts of a trimethylolpropane adduct modified form of isophorone diisocyanate (“Takenate (registered trademark) D-140N”; manufactured by Mitsui Chemicals, Inc.) was charged and heated to 70 ° C. . After reacting at the same temperature for 30 minutes, 0.02 part of dibutyltin dilaurate was added and kept at the same temperature for 3 hours. Thereafter, 57.1 parts of polycaprolactone-modified hydroxyethyl acrylate (“Placcel (registered trademark) FA3”; manufactured by Daicel Chemical Industries, Ltd .; number of repetitions of caprolactone units = 3), 0.02 part of dibutyltin laurate and 0. 02 parts were charged and held at 70 ° C. for 3 hours. A urethane acrylate composition solution having a solid content of 50% was obtained.

Comparative Example 7
In Comparative Example 6, the skin material and the composite molded body were the same as Comparative Example 6 except that the polyester film for weighting was changed to a release polyester film (“E7002”; manufactured by Toyobo Co., Ltd .; thickness 25 μm). Got. Table 1 shows the evaluation results of the skin material.

  In addition to the problem of the skin material obtained in Comparative Example 6, the skin material and composite molded body obtained in this comparative example have a surface roughness that is too small to provide both moist and dry feeling. Was inferior.

Comparative Example 8
A skin material and a composite molded body thereof were obtained in the same manner as in Example 1, except that the urethane acrylate composition solution was changed as described below in Example 1. Table 1 shows the evaluation results of the obtained skin material.

  In the skin material obtained in this comparative example, the Martens hardness of the flexible polymer layer was too large, the moist feeling was insufficient, and the touch feeling was inferior.

[Urethane acrylate composition]
78.3 parts of toluene and 8.5 parts of stearyl alcohol were charged, and the temperature was raised to 40 ° C. Thereafter, it was confirmed that stearyl alcohol was completely dissolved, 50 parts of “Duranate (registered trademark) D-140N” were charged, and the temperature was raised to 70 ° C. After reacting at the same temperature for 30 minutes, 0.02 part of dibutyltin dilaurate was added and kept at the same temperature for 3 hours. Thereafter, 57.1 parts of polycaprolactone-modified hydroxyethyl acrylate ("Placcel (registered trademark) FA4"; manufactured by Daicel Chemical Industries, Ltd .; number of repetitions of caprolactone units = 4), 0.02 part of dibutyltin laurate and 0. 02 parts were charged and held at 70 ° C. for 3 hours. Finally, 111 parts of toluene was added to obtain a urethane acrylate composition solution having a solid content of 50%.

Example 6
The skin material obtained in Example 1 is a polyethylene terephthalate (PET) -based double-sided pressure-sensitive adhesive sheet ("PET") having an adhesive strength of 10 N / 25 mm on one side and 14 N / 25 mm on the other side so that the flexible polymer layer is on the surface side (" 412D50 ": manufactured by Kyodo Giken Chemical Co., Ltd .: substrate thickness 12 μm: total thickness 50 μm), and attached to the surface of the portable game machine. In addition, the skin material was punched out so as not to cover the operation unit and the display unit of the game machine, and pasted so that only other parts were covered. As a result, the feel on the surface of the game machine could be improved. In addition, the double-sided pressure-sensitive adhesive sheet was attached so that the one having a lower adhesive force was placed on the game machine surface side, so that it could be peeled off even when it was stuck, and contamination and damage of the game machine was avoided.

Example 7
The adhesive layer-forming coating solution having the following composition was applied to the surface of the base material film of the skin material obtained in Example 1 so as to have a thickness after drying of 30 μm, dried, and further separated. Were laminated | stacked and the skin material laminated body which has an adhesion layer was obtained. This skin material laminate was punched in the same manner as in Example 6 and attached to the surface of the portable game machine. As a result, the feel on the surface of the game machine could be improved.

  In addition, the initial adhesive strength of the skin material provided with the adhesive layer is 4.8 N / 25 mm, and the adhesive strength after the adhesive strength improving treatment (after pasting and storing for 144 hours at room temperature) is 19.0 N / 25 mm. there were.

  Since the initial adhesive strength was small, the game machine could be peeled off without being contaminated or damaged even if it was stuck. In addition, since the adhesive strength after the adhesive strength improving treatment is large, peeling of the skin material did not occur during use of a game machine or the like.

[Coating liquid for forming adhesive layer]
An acrylic polymer solution was made by mixing 100 parts of a polymer having a weight ratio of butyl acrylate, methyl acrylate and hydroxylethyl acrylate of 60/8/2, 40 parts of ethyl acetate and 60 parts of toluene. To this solution, 2.0 parts of blocked isocyanate ("Duranate (registered trademark) MF-K60X": manufactured by Asahi Kasei) and 3.0 parts of polyisocyanate ("Coronate (registered trademark) L": manufactured by Nippon Polyurethane) were added. It added and mixed uniformly, and the coating liquid for adhesion layer formation was prepared.

Example 8
A skin material and a composite molded body thereof were obtained in the same manner as in Example 1 except that the base film was changed to a polycarbonate sheet having a thickness of 0.3 mm in Example 1.

  As with the skin material obtained in Example 1, the skin material obtained in this example had a balance between moist and smooth feelings and was excellent in tactile sensation. Further, the skin material obtained in this example has a further improved moldability compared to the skin material obtained in Example 1, and a complex molded body having a complicated shape can be obtained by vacuum forming. It has the feature. However, the solvent resistance of the base film was slightly inferior to the skin material of Example 1.

Example 9
In Example 1, a composite molded body in which the skin material was integrated by the same method as in Example 1 was obtained except that the base film was changed to an easily moldable polyester film prepared by the following method.

  The skin material obtained in this example had a good balance between moist and smooth feeling like the skin material obtained in Example 1, and was excellent in tactile sensation. In addition, the skin material obtained in this example has a further improved moldability as compared with that for the skin material obtained in Example 1, and a complex molded body having a complicated shape can be obtained by vacuum forming. It has the feature. Furthermore, the skin material obtained in this example was superior in the solvent resistance of the base material than the skin material obtained in Example 8.

[Preparation method of base film]
A copolymer polyester chip (A) composed of 100 mol% terephthalic acid, 40 mol% ethylene glycol, 60 mol% neopentyl glycol and having an intrinsic viscosity of 0.69 dl / g, and an average viscosity of 0.69 dl / g Each polyethylene terephthalate chip (B) containing 0.04% of amorphous silica having a particle size (SEM method) of 1.5 μm was dried. Chips (A) and (B) were mixed at a mass ratio of 25:75 and melt extruded at 270 ° C. with a T-die of an extruder. An amorphous unstretched polyester film was obtained while rapidly solidifying in the form of a chill roll having a surface temperature of 40 ° C., and simultaneously adhering to the chill roll by an electrostatic application method.

  This unstretched film was stretched 3.3 times at 90 degrees in the longitudinal direction between the heating roll and the cooling roll. Subsequently, a coating solution for an adhesion improving layer prepared by the following method was applied to both surfaces of the film after uniaxial stretching. The coated uniaxially stretched film is guided to a preheating zone while being gripped with a clip, dried at 110 ° C., then guided to a tenter, preheated at 120 ° C. for 10 seconds, the first half of transverse stretching is 110 ° C., and the second half is 100 The film was stretched 3.9 times at ° C.

  Further, the first heat treatment was performed at 220 ° C. and the second heat treatment was performed at 235 ° C. while performing a 7% relaxation treatment in the lateral direction, and heat setting was performed. A biaxially stretched coated polyester film having a thickness of 100 μm in which a 0.15 μm-thick hot water adhesion improving layer was laminated on both sides was obtained. The plane orientation degree of this polyester film was 0.081.

[Method of preparing coating solution for adhesion improving layer]
As an oxazoline-based cross-linking agent ("Epocross (registered trademark) WS-700"; Nippon Shokubai Co., Ltd.) with respect to 100 parts of a solid content of a polyurethane-based aqueous dispersion ("Hydran (registered trademark) AP40"; manufactured by Dainippon Ink and Industry). Product) was added in a solid content of 3 parts to obtain a coating solution for an adhesion improving layer.

  The skin material of the present invention has a good balance between moist and smooth feeling and is excellent in tactile sensation. By decorating the skin material and combining it with a molded body, it has become possible to efficiently mass-produce a composite molded body to which an advanced design has been imparted.

  Therefore, the skin material of the present invention is a casing, a protective case, a keypad, etc. of a mobile phone, a mobile personal computer, a portable game machine, a portable audio device, etc .; an automobile interior such as an instrument panel, a handle, etc. It is useful as a skin material for members, etc., and the composite molded body of the present invention is a case for mobile phones, mobile personal computers, portable game machines, portable audio devices, protective cases, keypads, etc .; It can be used as an automobile interior member such as an instrument panel or a handle.

Claims (9)

A skin material in which a flexible polymer layer obtained by crosslinking a urethane (meth) acrylate composition is formed on one surface of a base film, and the Martens hardness of the flexible polymer layer is 0.2 to 1.3 N / mm ^2. And having a surface roughness (Ra) of 0.15 to 1.0 μm.   The skin material according to claim 1, wherein the friction resistance of the flexible polymer layer is 18 to 54% of the friction resistance of the biaxially stretched polyester film.   The skin material according to claim 1 or 2, wherein the flexible polymer layer is crosslinked by active energy rays.   The skin material according to any one of claims 1 to 3, wherein the urethane (meth) acrylate is obtained from a raw material containing a polyisocyanate compound, a polycaprolactone polyol and a polycaprolactone-modified hydroxyalkyl (meth) acrylate.   The skin material according to any one of claims 1 to 4, wherein the base film is a biaxially stretched polyester film.   The skin material according to any one of claims 1 to 5, wherein a decorative layer is formed on the base film side.   The skin material according to any one of claims 1 to 6, wherein an adhesion improving layer is formed on the base film side.   The skin material according to claim 7, wherein a decorative layer is formed on the surface of the base film, and an adhesion improving layer is formed on the surface of the decorative layer.   The skin material according to any one of claims 1 to 8 is inserted into a mold so that the flexible polymer layer becomes the outermost surface of the molded body, then the mold is closed and a resin is injected, and insert molding is performed. A composite molded body with improved tactile sensation characterized by