JP2015103072A - Touch panel cover - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a protective cover hardly causing whitening, crease, and rainbow when viewing it through polarized sunglasses.SOLUTION: In a touch panel cover, a multilayer film 2 includes a layer (an A layer) containing a polycarbonate resin (A-1 component) and a polyester thermoplastic elastomer (A-2 component), and having a weight ratio of the A-1 component to the A-2 component (A-1 component/A-2 component) of 97/3-50/50, and a layer (a B layer) containing an acrylic resin, where the B layer is laminated on at least one surface of the A layer. The polyester thermoplastic elastomer comprises a hard segment composed of a polybutylene terephthalate unit, and a soft segment composed of a polyester unit in which an aromatic dicarboxylic acid and/or an aliphatic dicarboxylic acid are defined as dicarboxylic acid components and a diol of 5-15 carbons is defined as a diol component. The touch panel cover is formed by laminating the multilayer film 2 on a molding.

Description

  The present invention is a capacitive touch panel applicable to portable information terminals such as mobile phones, portable game machines, PDAs, handy terminals, OA equipment such as copiers and facsimiles, electronic dictionaries, car navigation systems, small PCs, and various home appliances. This relates to the protective cover.

  Conventionally, glass and resin sheets have been used for protective covers of capacitive touch panels. However, in recent years, there has been a demand for a design proposal with a sense of unity with peripheral parts using curved surfaces or stepped shapes that cannot be handled by glass or resin sheets with respect to the protective cover. (Refer nonpatent literature 1) In response to this request | requirement, the method of arrange | positioning a film in a metal mold | die and processing a molded article in an injection molding process is proposed in household appliances and automotive interior parts. Here, as characteristics required for such a base film, transparency, shape following ability to accurately transfer a target shape, surface hardness, rainbow pattern suppression when viewed through polarized sunglasses, etc. Can be mentioned. Conventionally, PET, acrylic, and polycarbonate films have been used as base materials for base films, but there are no base materials that satisfy all of these characteristics, and they have been used with problems depending on the application. Is the current situation.

JP 2012-27622 A JP 2010-79481 A JP 2010-214601 A

Touch panel forefront 2013-2014

  An object of the present invention is to provide a touch panel cover that is less likely to cause rainbow when viewed through whitening, wrinkles, and polarized sunglasses.

  According to the present invention, the above-mentioned problem includes (1) a polycarbonate resin (component A-1) and a polyester-based thermoplastic elastomer (component A-2), and a weight ratio of component A-1 to component A-2 ( A layer (A-1) / A-2 component) is 97/3 to 50/50 (A layer) and a layer containing an acrylic resin (B layer). The B layer is on at least one surface of the A layer. A laminated multilayer film, wherein the polyester-based thermoplastic elastomer comprises a hard segment comprising a polybutylene terephthalate unit and an aromatic dicarboxylic acid and / or aliphatic dicarboxylic acid as a dicarboxylic acid component, and a diol having 5 to 15 carbon atoms. A multi-layer film formed of a soft segment composed of a polyester unit containing diol as a diol component and laminated on a molded product. It is achieved by switch panel cover.

One of the preferred embodiments of the present invention is that (2) the aromatic dicarboxylic acid is terephthalic acid, isophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-diphenylcarboxylic acid It is at least 1 type chosen from the group which consists of bis (4-carboxyphenyl) methane and bis (4-carboxyphenyl) sulfone, It is a touchscreen cover of the said structure (1) characterized by the above-mentioned.
One of the preferred embodiments according to the present invention is the touch panel cover having the above-described configuration (1), wherein (3) the aliphatic dicarboxylic acid is a linear dicarboxylic acid having 4 to 12 carbon atoms.
One of the preferred embodiments according to the present invention is (4) the touch panel cover having the above-described configuration (1), wherein the multilayer film has a haze of 4% or less.
One of the preferred embodiments according to the present invention is (5) the touch panel cover having the above-described configuration (1), wherein the multilayer film has a thickness of 20 μm or more.
One of the preferred embodiments according to the present invention is (6) a method of manufacturing a touch panel cover having the above-described configuration (1), wherein a thermoplastic resin is injected into a mold after the multilayer film is fixed in the mold. It is.

  The touch panel cover of the present invention includes a polycarbonate resin (A-1 component) and a polyester-based thermoplastic elastomer (A-2 component), and a weight ratio between the A-1 component and the A-2 component (A-1 component / A). -Component) is a layer (A layer) having 97/3 to 50/50 and a layer (B layer) containing an acrylic resin, and a multilayer film in which the B layer is laminated on at least one surface of the A layer. It is a touch panel cover that is laminated on a molded product. By using a specific thermoplastic elastomer, the molded product is whitened, wrinkled, and rainbows appear when viewed through polarized sunglasses compared to conventional touch panel covers. It is difficult to use as a touch panel cover.

It is the metal mold | die and multilayer film which were used in the Example. It is the schematic of the touchscreen cover simulation product (thickness 2mm) shape | molded in the Example.

[Multilayer film]
The multilayer film of the present invention contains a polycarbonate resin (A-1 component) and a polyester-based thermoplastic elastomer (A-2 component), and the weight ratio of the A-1 component to the A-2 component (A-1 component / A). -2 component) having a layer (A layer) of 97/3 to 50/50 and a layer containing an acrylic resin (B layer), and a multilayer in which the B layer is laminated on at least one surface of the A layer It is a film.

(Polycarbonate resin)
The polycarbonate resin is a polymer in which a dihydroxy compound is bound by a carbonate ester bond, and is usually obtained by reacting a dihydroxy component and a carbonate precursor by an interfacial polymerization method or a melt polymerization method.

  Representative examples of the dihydroxy component include 2,2-bis (4-hydroxyphenyl) propane (commonly called bisphenol A), 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane, 2,2 -Bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) -3-methylbutane, 2,2-bis (4-hydroxyphenyl) -3,3-dimethylbutane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1- Bis (4-hydroxyphenyl) octane, 1,1-bis (4-hydroxyphenyl) decane, 9,9-bis {(4-hydroxy-3-me L) phenyl} fluorene, 9,9-bis (4-hydroxyphenyl) fluorene, α, α′-bis (4-hydroxyphenyl) -m-diisopropylbenzene, isosorbide, 1,3-propanediol, 1,4- Examples include butanediol and 1,6-hexanediol. A homopolymer using these singly or a copolymer obtained by copolymerizing two or more types may be used. Bisphenol A is preferable from the viewpoint of physical properties and cost. In the present invention, a polycarbonate in which 50 mol% or more of the bisphenol component is bisphenol A is preferable, more preferably 70 mol% or more, and still more preferably 90 mol% or more.

  Specific polycarbonates include a homopolymer of bisphenol A, a binary copolymer of bisphenol A and 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, bisphenol A and 9,9- Examples thereof include binary copolymers with bis {(4-hydroxy-3-methyl) phenyl} fluorene. Most preferred is a homopolymer of bisphenol A.

The glass transition temperature of the polycarbonate resin is preferably in the range of 100 to 200 ° C, more preferably in the range of 120 to 180 ° C. If the glass transition temperature is too high, the resin composition with the polyester-based thermoplastic elastomer is too unfavorable because the melt viscosity becomes too high, making melt film formation difficult, and if the glass transition temperature is too low, the heat resistance of the multilayer film is not preferable. It is not suitable for this use because of lack of properties.
As the carbonate precursor, carbonyl halide, carbonate ester, haloformate or the like is used, and specific examples include phosgene, diphenyl carbonate, dihaloformate of dihydric phenol, and the like.

  In producing a polycarbonate resin by reacting the divalent dihydroxy compound and the carbonate precursor by an interfacial polymerization method or a melt polymerization method, a catalyst, a terminal terminator, a dihydric phenol antioxidant, etc. are added as necessary. May be used. The polycarbonate resin may be a branched polycarbonate resin copolymerized with a trifunctional or higher polyfunctional aromatic compound, or may be a polyester carbonate resin copolymerized with an aromatic or aliphatic difunctional carboxylic acid, Moreover, the mixture which mixed 2 or more types of the obtained polycarbonate resin may be sufficient.

The molecular weight of the polycarbonate resin is preferably in the range of 13,000 to 40,000 in terms of viscosity average molecular weight. When the molecular weight is lower than 13,000, it becomes brittle as a multilayer film, and cracks and burrs are likely to occur during thermoforming, and when it is higher than 40,000, it is not preferable. Since the melt viscosity becomes too high and melt film formation becomes difficult, it is not preferable. The molecular weight is more preferably 15,000 to 35,000, still more preferably 20,000 to 32,000, and particularly preferably 22,000 to 28,000. When the polycarbonate resin is a mixture of two or more, it represents the molecular weight of the entire mixture. Here, the viscosity average molecular weight is obtained by measuring the specific viscosity (ηsp) at 20 ° C. of a solution obtained by dissolving 0.7 g of polycarbonate in 100 mL of methylene chloride, and calculating the viscosity average molecular weight (M) from the following formula.
η _sp /c=[η]+0.45×[η] ^2c
[Η] = 1.23 × 10 ⁻⁴ M ^0.83
(Where c = 0.7 g / dL, [η] is the intrinsic viscosity)

(Polyester thermoplastic elastomer)
The polyester-based thermoplastic elastomer used in the present invention includes a hard segment composed of polybutylene terephthalate units, an aromatic dicarboxylic acid and / or an aliphatic dicarboxylic acid as a dicarboxylic acid component, and a diol having 5 to 15 carbon atoms as a diol component. It is a multi-block copolymer composed of soft segments composed of polyester units. When other than the above-mentioned copolymer is used as the polyester-based thermoplastic elastomer, it is not preferable since the visibility of the touch panel is reduced due to white turbidity of the multilayer film and wrinkles are generated during molding.

  The hard segment used is a hard segment composed of polybutylene terephthalate units. Polybutylene terephthalate is excellent in compatibility with the polycarbonate resin, is preferable from the viewpoint of transparency and thermoformability, and has good characteristics in terms of strength and the like. The polybutylene terephthalate may contain other components as copolymerization components as long as the effects of the present invention are not impaired. The proportion of the copolymer component is preferably 30 mol% or less, more preferably 20 mol% or less, and even more preferably 10 mol% or less, in 100 mol% of all components of both the dicarboxylic acid component and the diol component. The intrinsic viscosity of the polymer serving as the hard segment is preferably in the range of 0.2 to 2.0, more preferably 0.5 to 1.5.

(Soft segment)
The soft segment refers to a segment that has a melting point of a polymer formed from the segment of 100 ° C. or lower, or is liquid and amorphous at 100 ° C. The intrinsic viscosity of the polymer to be a soft segment is preferably in the range of 0.2 to 2.0, more preferably 0.5 to 1.5. The soft segment used is a soft segment composed of a polyester unit having an aromatic dicarboxylic acid and / or an aliphatic carboxylic acid as a dicarboxylic acid component and a diol having 5 to 15 carbon atoms as a diol component. (Hereinafter sometimes referred to as “SS-1”). SS-1 is preferable because extremely good transparency can be obtained.

  The soft segment SS-1 has an aromatic dicarboxylic acid content of 60 to 99 mol% and an aliphatic dicarboxylic acid content of 1 in a total of 100 mol% of the dicarboxylic acid component from the viewpoint of obtaining better transparency. It is preferably ˜40 mol%. More preferably, the aromatic dicarboxylic acid content is 70 to 95 mol% and the aliphatic dicarboxylic acid content is 5 to 30 mol%. More preferably, the aromatic dicarboxylic acid content is 85 to 93 mol% and the aliphatic dicarboxylic acid content is 7 to 15 mol%. It is particularly preferable that the aromatic dicarboxylic acid content is 89 to 92 mol% and the aliphatic dicarboxylic acid content is 8 to 11 mol%.

  SS-1 aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-diphenylcarboxylic acid, and bis (4-carboxyphenyl) methane. And at least one selected from the group consisting of bis (4-carboxyphenyl) sulfone, terephthalic acid and isophthalic acid are more preferable, and isophthalic acid is particularly preferable from the viewpoint of crystallinity reduction. As the aliphatic dicarboxylic acid of SS-1, linear aliphatic dicarboxylic acids having 4 to 12 carbon atoms such as succinic acid, adipic acid, and sebacic acid are preferable, and sebacic acid is particularly preferable.

Examples of the diol component having 5 to 15 carbon atoms of SS-1 include straight chain aliphatic diols having 6 to 12 carbon atoms such as hexamethylene glycol, decamethylene glycol, 3-methylpentanediol, and 2-methyloctamethylenediol. Is more preferable, and hexamethylene glycol is particularly preferable.
SS-1 is particularly preferable from the viewpoint that it has high compatibility with the polycarbonate resin, and therefore can obtain a highly transparent multi-layer film, and also has good surface properties and transparency after thermoforming. More specifically, SS-1 is preferably a polyester composed of isophthalic acid and sebacic acid and hexamethylene glycol.

(Composition etc.)
In the present invention, it is appropriate that the ratio of the hard segment and the soft segment in the polyester thermoplastic elastomer is 20 to 70% by weight for the hard segment and 80 to 30% by weight for the soft segment in 100% by weight of the elastomer. More preferably, the hard segment is 20 to 40% by weight and the soft segment is 80 to 60% by weight. The intrinsic viscosity of the polyester-based thermoplastic elastomer (value measured at 35 ° C. in o-chlorophenol) is preferably 0.6 or more, more preferably in the range of 0.8 to 1.5, and 0.8 to 1 A range of .2 is more preferred. If the intrinsic viscosity is lower than the above range, the strength of the multilayer film may decrease, which is not preferable.

In the present invention, the weight ratio (A-1 component / A-2 component) between the polycarbonate resin (A-1 component) and the polyester-based thermoplastic elastomer (A-2 component) in layer A is 97/3 to 50/50. It is preferably 95/5 to 70/30, and more preferably 92/8 to 75/25. If the weight ratio is less than 97/3, the followability to the mold shape due to the addition of the elastomer is poor, so that wrinkles occur in the film, and if it exceeds 50/50, the thermal deformation temperature of the resin composition becomes too low. The heat resistance of the multilayer film is insufficient.
The layer A of the present invention may contain various additives generally used in each resin. For example, heat stabilizers, antioxidants, ultraviolet absorbers, antistatic agents, dyes and the like can be mentioned. Moreover, in the range which does not impair the effect of this invention, you may contain reinforcement fillers, such as glass fiber.

(Manufacture of polyester-based thermoplastic elastomer)
The polyester-based thermoplastic elastomer can be obtained by reacting the above-described hard segment and soft segment by melt-kneading to form a multi-block copolymer. The reaction is preferably in the range of 200-300 ° C, more preferably 220-260 ° C.

(Acrylic resin)
In the present invention, the acrylic resin used for the B layer is preferably mainly composed of a methacrylic acid ester or an acrylic acid ester polymer. When a resin other than an acrylic resin is used as the B layer, for example, polycarbonate is not preferable because the surface hardness of the multilayer film is low and the molded body is easily damaged. Further, PET resin is not preferred because it tends to cause appearance defects due to thickness unevenness.
Examples of the acrylic resin include a homopolymer of methyl methacrylate or a copolymer containing preferably 50% by weight or more, more preferably 70% by weight or more, and further preferably 80% by weight or more of methyl methacrylate.

Examples of other copolymer components include ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and the like. Moreover, another ethylenically unsaturated monomer is mentioned as another copolymerization component. Specifically, vinyl aromatic compounds such as styrene, α-methylstyrene and vinyltoluene, diene compounds such as 1,3-butadiene and isoprene, alkenyl cyanide compounds such as acrylonitrile and methacrylonitrile, acrylic acid, methacrylic acid, Examples thereof include maleic anhydride and N-substituted maleimide. These may be used alone or in combination of two or more. The content of the copolymer component is preferably 0 to 50% by weight, more preferably 0 to 30% by weight, and still more preferably 0 to 20% by weight.
The acrylic resin production method is generally roughly classified into an emulsion polymerization method, a suspension polymerization method, and a continuous polymerization method. The acrylic resin used in the present invention may be produced by any polymerization method.

  In the present invention, rubber particles may be added to the acrylic resin in order to improve burrs and cracks during thermoforming of the multilayer film, as long as the effects of the invention are not impaired. Toughness improvement by adding rubber particles to an acrylic resin is a well-known technique and widely used, and can also be used in the present invention. In general, when rubber particles are added, the transparency tends to decrease. In the present invention, it is preferable to use rubber particles having the highest transparency. As a preferred rubber particle, a core-shell structure in which a core layer made of an acrylic cross-linked elastic polymer is wrapped with a methacrylic ester resin, a methacrylic ester resin in the center is wrapped with an acrylic cross-linked elastic polymer, and The thing etc. which were made into the 3 layer structure which coat | covered the outer side with the methacrylic ester resin are mentioned. The rubber particles having such a multilayer structure have a good dispersibility with respect to the acrylic resin, and a highly transparent multilayer film can be obtained. In the present invention, considering the transparency comprehensively, the presence / absence of rubber particles and the type, amount, size, and the like of the rubber particles may be determined when the rubber particles are contained. Furthermore, you may add various additives, such as a general heat stabilizer, a coloring agent, a mold release agent, a lubricant, an antistatic agent, and a matting agent, to this acrylic resin layer.

(Layer structure)
The multilayer film of the present invention is a multilayer film in which a B layer is laminated on at least one surface of an A layer. When a film in which the B layer is not laminated is used, the surface hardness of the multilayer film is low, and the molded product is easily damaged and is not preferable. In general, a so-called two-type two-layer laminate is more likely to warp due to a difference in thermal shrinkage between the two resins during film formation by coextrusion molding than a two-type three-layer laminate. Such warping of the film may cause a problem when fixed to a mold during injection molding, and from this point, it is preferable to laminate an acrylic resin (B layer) on both sides.

The total thickness of the multilayer film of the present invention is preferably 20 μm or more, more preferably 50 μm or more, and further preferably 60 μm or more. If the total thickness is too thin, the pencil hardness is low and the scratches are easily scratched, which may make it difficult to use as a touch panel cover. Further, in the step of injecting the thermoplastic resin after fixing the film in the mold, the film is likely to be broken or wrinkled, which is not preferable in production.
Moreover, the thickness of A layer preferable by this invention is 30 to 90% of total thickness. The thickness of the A layer is more preferably 40 to 80% of the total thickness, and further preferably 50 to 70%.

  The thickness of one B layer is preferably 5 μm or more. Here, the thickness of one B layer refers to a thickness focused only on the B layer laminated on one side of the A layer, and accordingly, in the case of a three-layer structure in which the B layer is laminated on both sides of the A layer. The thickness of each B layer is preferably 5 μm or more, and therefore the total of the B layers on both sides is preferably 10 μm or more. If the thickness of one B layer is less than 5 μm, the surface hardness and solvent resistance may be insufficient, which is not preferable. More preferably, the thickness of one B layer is 10 μm or more, and further preferably 20 μm or more. The upper limit of the thickness of one B layer is determined by the total thickness and the thickness of the A layer, but is preferably 70 μm or less, more preferably 50 μm or less.

  As the multilayer film of the present invention, a highly transparent film is preferable. The multilayer film of the present invention preferably has a total light transmittance of 90% or more, more preferably 91% or more. The haze is preferably 4% or less, more preferably 3% or less, and still more preferably 2% or less.

(Manufacture of multilayer films)
The multilayer film of the present invention can be produced by a conventionally known method. For example, each layer is formed separately in advance and laminated, or thermocompression-pressed, or a film of one layer formed in advance is used as a base material and coated on one or both sides to form the other layer. And a method of laminating and forming each resin layer by a coextrusion method. Among these, the production by the coextrusion method is most preferable from the viewpoints of economy and production stability. That is, the multilayer film of the present invention is preferably produced by coextrusion of the molding material A for the A layer and the molding material B for the B layer.

  The molding material A can be prepared by mixing each component, then melt-kneading and pelletizing. As a means for mixing, a known method such as a Nauter mixer, a V-type blender or a Henschel mixer can be used. The multilayer film of the present invention can be produced by supplying the pellets to a film production apparatus. In addition, it is possible to form a film by directly melting and kneading with an extruder and extruding from a die during multi-layer film formation by the coextrusion method without passing through such a pelletizing step. The molding material B can be formed into a film similarly to the component A.

The coextrusion method is a method in which molding materials A and B are melt-extruded using separate extruders and laminated using a feed block or a multi-manifold die to obtain a multilayer film. The total thickness and thickness composition of the resulting multilayer film can be controlled by adjusting the film forming speed, the die slip interval, and the like.
In the case of the coextrusion method, the molten resin from the die is generally cooled with a cooling roll and then wound into a roll to produce a film. In this invention, a protective film is attached to the multilayer film and wound up. May be. In particular, when the acrylic resin does not contain rubber particles, it may be difficult to wind up as it is due to insufficient surface slipperiness. In such a case, it is preferable to wind up with a protective film. In such a case, a known protective film such as polyethylene or polypropylene can be used. If the acrylic resin contains rubber particles and the resulting multilayer film has good surface slipperiness, it can be wound as it is without using a protective film.

(Hard coat)
The multilayer film of the present invention can be applied with a hard coat on one side. The hard coat can be composed of, for example, an acrylic resin, a urethane resin, a melamine resin, an organic silicate compound, a silicone resin, or a metal oxide. In particular, silicone resins and acrylic resins are preferable in terms of hardness and durability, and further, acrylic resins, particularly active ray curable acrylic resins, in terms of curability, flexibility, and productivity. Alternatively, a thermosetting acrylic resin is preferable.

(Molding)
The molded article of the present invention can be obtained by performing various conventionally known moldings of thermoplastic resins. Molding methods include injection molding, injection compression molding that injects molten resin into a mold cavity that has been opened by an extra compression stroke, two-color molding, heat and cool molding that rapidly heats and cools the mold, Examples include an insert mold molding method in which a multilayer film vacuum-formed along an injection mold is set in a mold, a molten resin is injected into the mold, and the film is brought into close contact with the molded article simultaneously with injection molding.

(Touch panel cover)
The touch panel cover of the present invention is composed of the above-described molded product and a multilayer film, and by using the multilayer film, a touch panel cover having a high surface hardness can be obtained by performing various conventionally known moldings.
Examples of the molding method include the above-described insert mold molding method, a roll transfer method in which a film is brought into contact with a molded product, and the film is adhered by hot pressure, and a vacuum molding method in which a heated film is adhered to a molded body in a vacuum state. It is done.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to only these examples. The physical properties measured in Examples and Comparative Examples were measured by the following methods.
(1) Total thickness of multilayer film It is the value of the center part in the film width direction measured with the electronic micro film thickness meter by Anritsu Co., Ltd.
(2) Thickness composition of a multilayer film It is the value of the center part in the film width direction measured by observation of a film cross section using the laser microscope VA-9710 made from Keyence Corporation.
(3) Haze of film It measured using the Nippon Denshoku Industries Co., Ltd. haze meter NDH-5000 type | mold.
(4) Wrinkles and film tears The compact was visually observed and evaluated for wrinkles and film tears.
(5) Rainbow pattern The molded body was laminated on the outermost surface of a liquid crystal monitor (manufactured by Japan HP, ZR2440W) and visually evaluated through polarized sunglasses.
(6) Surface hardness of film Pencil hardness was measured according to JIS K 5600. Preferably it is HB or more, More preferably, it is F or more.

(Manufacture of polyester-based thermoplastic elastomer)
A-2: 175 parts by weight of dimethyl isophthalate, 23 parts by weight of dimethyl sebacate and 140 parts by weight of hexamethylene glycol were subjected to a transesterification reaction with a dibutyltin diacetate catalyst, and then polycondensed to reduce the pressure, whereby an intrinsic viscosity of 1.06 Thus, an amorphous polyester (soft segment) was obtained which does not show an endothermic peak due to crystal melting as measured by the DSC method. The polybutylene terephthalate pellets (hard segment) having an intrinsic viscosity of 0.98 obtained separately by polycondensation with this polyester were dried and added in 107 parts and reacted at 240 ° C. for 45 minutes. One part was added to stop the reaction. The obtained polymer had a melting point of 190 ° C. and an intrinsic viscosity of 0.93.

(Manufacture of molding material for layer A)
C-1: Polycarbonate resin Teijin (manufactured) Panlite L-1250 (A-1) and polyester-based thermoplastic elastomer (A-2) were each pre-dried, and A-1 component / A-2 component = 90/10 After being mixed with a V-type blender so as to be, it was extruded and pelletized at a cylinder temperature of 260 ° C. using a twin-screw extruder to obtain a molding material C-1 for A layer.
C-2: Molding material C-2 for A layer was obtained in the same manner as C-1, except that the mixing ratio of A-1 component / A-2 component was 85/15.
C-3: Molding material C-3 for A layer was obtained in the same manner as C-1, except that the mixing ratio of A-1 component / A-2 component was 80/20.
C-4: Molding material C-4 for A layer was obtained by the same method as C-1, except that the mixing ratio of A-1 component / A-2 component was 60/40.
C-5: Molding material C-5 for layer A was obtained in the same manner as C-1, except that the mixing ratio of A-1 component / A-2 component was 40/60.
C-6: Polycarbonate resin Teijin (manufactured) Panlite L-1250 (A-1 component) and Daicel polycaprolactone Plaxel H1P (A-3 component) were each pre-dried, and A-1 / A-3 = 90 / After mixing with a V-type blender so as to be 10, extrusion was performed at a cylinder temperature of 260 ° C. using a twin-screw extruder, and pelletized to obtain a molding material C-6 for layer A.
C-7: Polycarbonate resin Teijin (manufactured) Panlite L-1250 (component A-1) and polyplastics (manufactured) polybutylene terephthalate resin Juranex 700FP ER201R (component A-4) were each pre-dried, and A- After mixing with a V-type blender so that 1 / A-4 = 90/10, the mixture was extruded and pelletized using a twin screw extruder at a cylinder temperature of 260 ° C. to obtain a molding material C-7 for layer A. .

(Formation of multilayer film)
D-1: Molding material C-1 and Mitsubishi Rayon acrylic resin Acrypet VH001 (B-1) using a single screw extruder with a screw diameter of 40 mm, cylinder temperature 260 ° C. (C-1), 250 ° C. Extruded from a 650 mm wide T-die by the feed block method under the condition (B-1), touched one surface of the molten resin with a cooling roll, cooled, and then edge trimmed to make B layer / A layer / B A multilayer film having a film width of 400 mm and having a three-layer structure was prepared. For winding, a polyethylene-based weakly sticky protective film was used.
The total thickness of the obtained multilayer film was 125 μm, and the thickness composition was B layer / A layer / B layer = 35/57/33 (μm). These are all values at the center in the width direction of the film, but the thickness variation in the width direction is ± 3 μm, and the distribution in the width direction of the thickness composition is within ± 2 μm for each layer, and the film is highly uniform. Met.
D-2: A multilayer film was prepared in the same manner as D-1, except that the material of the A layer was changed to the molding material C-2. The total thickness of the obtained multilayer film was 80 μm, and the thickness composition was B layer / A layer / B layer = 22/36/22 (μm).
D-3: A multilayer film was prepared in the same manner as in D-1, except that the material of the A layer was changed to the molding material C-3. The total thickness of the obtained multilayer film was 105 μm, and the thickness composition was B layer / A layer / B layer = 29/48/28 (μm).
D-4: A multilayer film was prepared in the same manner as in D-1, except that the winding speed and the screw rotation speed were adjusted so that the layer thickness of the multilayer film was 25 μm. The total thickness of the obtained multilayer film was 25 μm, and the thickness composition was B layer / A layer / B layer = 7/11/7 (μm).
D-5: A multilayer film was prepared in the same manner as in D-1, except that the winding speed and the screw rotation speed were adjusted so that the layer thickness of the multilayer film was 180 μm. The total thickness of the obtained multilayer film was 180 μm, and the thickness composition was B layer / A layer / B layer = 50/82/48 (μm).
D-6: A multilayer film was prepared in the same manner as in D-1, except that the material of the A layer was changed to the molding material C-4. The total thickness of the obtained multilayer film was 125 μm, and the thickness composition was B layer / A layer / B layer = 35/57/33 (μm).
D-7: An actinic radiation curable resin prepared in a ratio of 67% by weight of dipentaerythritol hexaacrylate, 29% by weight of N-vinylpyrrolidone, and 4% by weight of 1-hydroxycyclohexyl phenyl ketone on a multilayer film with toluene / ethyl acetate The mixture was diluted to 50% by weight with a 1: 1 mixed solution, applied to a base film by a die coating method, dried in an oven at 70 ° C. for 2 minutes, and then set to an irradiation intensity of 80 W / cm at a height of 9 cm from the coated surface. A multilayer film was prepared in the same manner as in D-1, except that the actinic radiation curable resin was cured by irradiating ultraviolet rays with a high pressure mercury lamp for 15 seconds and a hard coat layer having a thickness of 5 μm was provided. The thickness of the obtained multilayer film was 130 μm, and the thickness composition was B layer / A layer / B layer / HC = 35/57/33/5 (μm).
D-8: A multilayer film was prepared in the same manner as in D-1, except that the material of the A layer was changed to polycarbonate resin Teijin (manufactured) Panlite L-1250. The total thickness of the obtained multilayer film was 125 μm, and the thickness composition was B layer / A layer / B layer = 35/57/33 (μm).
D-9: PET resin and Mitsubishi Rayon acrylic resin Acrypet VH001 (B-2), each using a single screw extruder with a screw diameter of 40 mm, cylinder temperature 280 ° C. (PET resin), 250 ° C. (B-2 ) Under the conditions of) by a feed block method and extruding from a T-die having a width of 650 mm, touching one surface of the molten resin with a cooling roll, cooling, and then edge trimming to obtain B layer / A layer / B layer 3 A multilayer film having a layer structure and a film width of 400 mm was prepared. For winding, a polyethylene-based weakly sticky protective film was used. The total thickness of the obtained multilayer film was 125 μm, and the thickness composition was B layer / A layer / B layer = 35/57/33 (μm).
D-10: A multilayer film was prepared in the same manner as in D-1, except that the material of the A layer was changed to the molding material C-6. The total thickness of the obtained multilayer film was 125 μm, and the thickness composition was B layer / A layer / B layer = 35/57/33 (μm).
D-11: A multilayer film was prepared in the same manner as in D-1, except that the material of the A layer was changed to the molding material C-7. The total thickness of the obtained multilayer film was 125 μm, and the thickness composition was B layer / A layer / B layer = 35/57/33 (μm).
D-12: A multilayer film was prepared in the same manner as in D-1, except that the material of the A layer was changed to the molding material C-5. The total thickness of the obtained multilayer film was 125 μm, and the thickness composition was B layer / A layer / B layer = 35/57/33 (μm).
D-13: A multilayer film was prepared in the same manner as D-1, except that the material of the B layer was changed to polycarbonate resin Teijin (manufactured) Panlite L-1250, and the cylinder temperature of the B layer was changed to 260 ° C. . The total thickness of the obtained multilayer film was 125 μm, and the thickness composition was B layer / A layer / B layer = 35/57/33 (μm).
D-14: Extrude molding material C-1 from a 650 mm wide T-die using a single-screw extruder under a cylinder temperature of 260 ° C. with a feed block method, and touch one side of the molten resin on the cooling roll. After cooling, edge trimming was performed to prepare a single layer film having a film width of 400 mm. For winding, a polyethylene-based weakly sticky protective film was used. The total thickness of the obtained film was 125 μm.

[Example 1]
After drying polycarbonate resin pellets (Teijin (manufactured) Panlite L-1225ZL100) with a hot air dryer at 120 ° C. for 5 hours, FN8000 injection molding made by Nissei Plastic Industry with a cylinder diameter of 50 mmφ and a clamping force of 46,950 kN. A simulated touch panel cover shown in FIG. 2 was formed by injection molding using the multilayer film D-1 using the machine and the mold shown in FIG. Molding was performed at a cylinder temperature of 300 ° C., a hot runner set temperature of 300 ° C., a mold temperature of 100 ° C. on both the fixed side and the movable side, and a cooling time of 10 seconds. The film was sandwiched by a mold frame and then sucked with a vacuum pump and fixed to the mold. The properties of the molded product thus prepared were measured by the method described above.

[Example 2]
Molding and evaluation of properties were performed in the same manner as in Example 1 except that the multilayer film was D-2.

[Example 3]
Molding and evaluation of properties were performed in the same manner as in Example 1 except that the multilayer film was D-3.

[Example 4]
Molding and evaluation of properties were performed in the same manner as in Example 1 except that the multilayer film was D-4.

[Example 5]
Molding and evaluation of properties were performed in the same manner as in Example 1 except that the multilayer film was D-5.

[Example 6]
Molding and evaluation of properties were performed in the same manner as in Example 1 except that the multilayer film was D-6.

[Example 7]
Molding and evaluation of properties were performed in the same manner as in Example 1 except that the multilayer film was D-7.

[Comparative Example 1]
Molding and property evaluation were performed in the same manner as in Example 1 except that the multilayer film was D-8.

[Comparative Example 2]
Molding and evaluation of properties were performed in the same manner as in Example 1 except that the multilayer film was D-9.

[Comparative Example 3]
Molding and property evaluation were performed in the same manner as in Example 1 except that the multilayer film was D-10.

[Comparative Example 4]
Molding and evaluation of properties were performed in the same manner as in Example 1 except that the multilayer film was D-11.

[Comparative Example 5]
Molding and evaluation of properties were performed in the same manner as in Example 1 except that the multilayer film was D-12.

[Comparative Example 6]
Molding and evaluation of properties were performed in the same manner as in Example 1 except that the multilayer film was D-13.

[Comparative Example 7]
Molding and evaluation of properties were performed in the same manner as in Example 1 except that the multilayer film was D-14.
Table 1 shows the results of the characteristic evaluation of each example and comparative example.

1. Mold 2. 2. Multilayer film 3. Film fixing frame Vacuum slot

Claims (7)

  A polycarbonate resin (A-1 component) and a polyester-based thermoplastic elastomer (A-2 component) are included, and the weight ratio of the A-1 component to the A-2 component (A-1 component / A-2 component) is 97 / A multilayer film comprising a layer (A layer) of 3 to 50/50 and a layer (B layer) containing an acrylic resin, wherein the B layer is laminated on at least one surface of the A layer, The plastic elastomer is composed of a hard segment composed of a polybutylene terephthalate unit and a soft segment composed of a polyester unit containing an aromatic dicarboxylic acid and / or an aliphatic dicarboxylic acid as a dicarboxylic acid component and a diol having 5 to 15 carbon atoms. A touch panel cover formed by laminating a multilayer film on a molded product.   Aromatic dicarboxylic acids are terephthalic acid, isophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-diphenylcarboxylic acid, bis (4-carboxyphenyl) methane and bis (4- The touch panel cover according to claim 1, wherein the touch panel cover is at least one selected from the group consisting of (carboxyphenyl) sulfone.   The touch panel cover according to claim 1, wherein the aliphatic dicarboxylic acid is a linear dicarboxylic acid having 4 to 12 carbon atoms.   The touch panel cover according to claim 1, wherein the multilayer film has a haze of 4% or less.   The touch panel cover according to claim 1, wherein the multilayer film has a thickness of 20 μm or more.   The touch panel cover according to claim 1, wherein a hard coat is applied to one surface of the multilayer film.   The method for manufacturing a touch panel cover according to claim 1, wherein after the multilayer film is fixed in the mold, a thermoplastic resin is injected into the mold.