JP2021146687A - Thermoforming sheet, decorative sheet, and molding using them - Google Patents

Abstract

To provide a thermoforming sheet which achieves both moldability and hardness.SOLUTION: A thermoforming sheet is obtained by laminating at least three layers of a layer (A layer) containing a polycarbonate-based resin, a layer containing an acrylic resin (B layer), and a layer (C layer) formed of an uncured product of an acrylate-based active energy ray-curable resin composition (C composition) in this order. A glass transition temperature (Tg) of the A layer is 100°C or higher and 145°C or lower.SELECTED DRAWING: None

Description

INDUSTRIAL APPLICABILITY The present invention is preferably used in a method of integrating a sheet having a design or a function with a resin molded product by thermoforming in order to impart chemical resistance, scratch resistance and a design to the surface of the resin molded product. The present invention relates to a molding sheet, a decorative sheet, and a molded product using these.

In recent years, the number of resin molded parts used in automobiles has been increasing due to the diversification of automobile designs and the demand for weight reduction of automobiles. These resin molded parts are required to have functions such as wood grain and metal tones, chemical resistance, and scratch resistance, and as a method for imparting designs and functions, specific designs or functions such as decorative sheets are required. A method has been proposed in which a sheet to which the above-mentioned material is applied is integrated with a resin molded product. The following two methods can be exemplified as specific examples. (1) The sheet is preliminarily shaped into a specific shape by thermoforming (vacuum molding, pressure molding, etc.), set in an injection molding mold, and molten resin is injected to form an injection molded product, and at the same time, a preformed sheet and the sheet. A method of integrating, (2) a method of coating a sheet on a prefabricated resin molded product by thermoforming (three-dimensional surface decorative molding). Both of these methods (1) and (2) require thermoforming of the sheet, and the thermoforming sheet used has a hard coat layer in order to have chemical resistance and scratch resistance, and is a base. Since the material sheet is required to be transparent so as not to hinder the appearance of the design layer, an acrylic resin, a polycarbonate resin, and a polyester resin are generally used.

For example, Patent Document 1 discloses an example of a scratch-resistant sheet having an ultraviolet curable hard coat layer on a laminated sheet of a polycarbonate resin layer and an acrylic resin layer containing rubber particles, but the hard coat has been cured. The layer cannot follow the three-dimensional molding, and the hard coat layer is cracked when it is attempted to be molded by the methods (1) and (2) above.

As a countermeasure as described above, in Patent Document 2, in a laminated hard coat film in which an ultraviolet curable hard coat layer is formed on a base film, the hard coat layer is cured with a weak ultraviolet exposure amount before three-dimensional molding, and then tertiary. An example of so-called two-stage curing is disclosed in which both moldability and surface hardness are achieved by performing post-exposure after the original molding. In such two-stage curing, there is a concern that the moldability may vary depending on the state of the first-stage curing, and the product life may be significantly deteriorated.

The thermoforming sheet used in the methods (1) and (2) is mainly required to have the following characteristics. First of all, moldability is required. That is, it is important that it has sufficient extensibility to follow the three-dimensional molding and that appearance defects such as cracks do not occur even if it is stretched. In particular, when high-temperature preheating is performed at the time of molding, even if it has good extensibility before heating, there is a problem that thermosetting of the functional layer progresses due to the preheating and the extensibility is greatly deteriorated. Secondly, surface hardness (pencil hardness, scratch resistance) is required. When the thermoforming sheet is integrated with the resin molded product, the functional layer is arranged on the outermost surface, and the surface function of the resin molded product is required. For that purpose, high surface hardness is required, but in general, there is a trade-off relationship between the hardness of the hard coat layer and the extensibility, and it has been a conventional problem to balance the characteristics of both.

Japanese Patent No. 5176749 Japanese Unexamined Patent Publication No. 2012-210755

An object of the present invention is to provide a thermoforming sheet and a decorative sheet having both moldability and hardness, and a molded product using these. In particular, in order to impart chemical resistance and scratch resistance to the surface of a resin molded product, a thermoforming sheet suitable for use in a method of integrating a sheet having these functions with a resin molded product by thermoforming. And a decorative sheet and a molded product using these.

The above problem was formed from a layer containing a specific polycarbonate resin (layer A), a layer containing an acrylic resin (layer B), and an uncured product of an acrylate-based active energy ray-curable resin composition (composition C). It has been found that the solution is to use a thermoforming sheet in which at least three layers (C layer) are laminated in at least this order.

That is, according to the present invention, the following configurations are provided.

1. 1. A layer (C layer) formed from a layer containing a polycarbonate resin (A layer), a layer containing an acrylic resin (B layer), and an uncured product of an acrylate-based active energy ray-curable resin composition (composition C). A thermoforming sheet obtained by laminating at least three layers in this order, wherein the glass transition temperature (Tg) of the A layer is 100 ° C. or higher and 145 ° C. or lower.

2. The layer A contains a polyester-based thermoplastic elastomer, and the polyester-based thermoplastic elastomer contains a hard segment made of polybutylene terephthalate unit and an aromatic dicarboxylic acid and an aliphatic dicarboxylic acid as a dicarboxylic acid component, and has 5 carbon atoms. The heat-molded sheet according to item 1 above, which is composed of a soft segment composed of a polyester unit containing ~ 15 diols as a diol component.

3. 3. The thermoforming sheet according to item 2 above, wherein the layer A contains 1 to 20 parts by weight of the polyester thermoplastic elastomer according to item 2 above with respect to 100 parts by weight of the polycarbonate resin.

4. The thermoforming sheet according to any one of Items 1 to 3 above, wherein the B layer does not substantially contain rubber particles.

5. The C layer is any of the above items 1 to 4 containing 1 to 5 parts by weight of a hindered amine compound with respect to 100 parts by weight of the uncured product of the acrylate-based active energy ray-curable resin composition (composition C). The thermoforming sheet described.

6. The thermoforming sheet according to any one of the above items 1 to 5, wherein the pencil hardness of the surface of the cured layer obtained by irradiating the C layer with active energy rays and curing the layer C is H or more.

7. The thermoforming sheet according to any one of the above items 1 to 6, wherein a protective film is provided on the C layer, and the protective film can be peeled off from the C layer.

8. The thermoforming sheet according to any one of the above items 1 to 7, wherein the total thickness of the molding sheet is in the range of 0.05 mm or more and 3 mm or less.

9. A decorative sheet in which a decorative layer is formed on the side opposite to the B layer and the C layer side of the A layer of the thermoforming sheet according to any one of the above items 1 to 8.

10. After shaping the thermoforming sheet according to the above items 1 to 8 or the decorative sheet according to the previous item 9 into the shape of the mold cavity in advance, the sheet is placed in the mold and integrated at the same time as the molding of the resin material. A method for producing a molded product, which comprises producing a body, and then performing post-exposure with an active energy ray.

11. The thermoforming sheet according to the preceding items 1 to 8 or the decorative sheet according to the preceding item 9 is attached to the mold cavity side by vacuum pressure to prepare a molded body that is integrated at the same time as molding the resin material. After that, a method for producing a molded product, which comprises performing post-exposure with an active energy ray.

The thermoforming sheet or decorative sheet of the present invention is a thermoforming sheet or decorative sheet that has both moldability and hardness, and particularly imparts chemical resistance and scratch resistance to the surface of a resin molded product. Therefore, it is a thermoforming sheet or a decorative sheet suitable for use in a method of integrating a sheet having these functions with a resin molded product by thermoforming, and a resin molded body using these is an automobile interior material. It can be used for electrical appliances, cosmetic cases, interior and exterior parts of building materials, etc., and its industrial effect is exceptional.

Hereinafter, the present invention will be described in detail.

(Layer containing polycarbonate resin (A layer))
The polycarbonate-based resin used in the present invention is a polymer in which a dihydroxy compound is bound by a carbonic acid ester bond, and is usually obtained by reacting a dihydroxy component with a carbonic acid precursor by an interfacial polymerization method or a melt polymerization method. ..

Typical examples of the dihydroxy component are 2,2-bis (4-hydroxyphenyl) propane (commonly known as bisphenol A) and 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane (bisphenol C). , 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-methyl) phenyl} fluorene, 9,9-bis (4-Hydroxyphenyl) fluorene, α, α'-bis (4-hydroxyphenyl) -m-diisopropylbenzene, isosorbide, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, etc. Can be mentioned. It may be a homopolymer in which these are used alone, or a copolymer in which two or more kinds of copolymers are copolymerized. Bisphenol A is preferable from the viewpoint of physical properties and cost. In the present invention, polycarbonate in which 50 mol% or more of the bisphenol component is bisphenol A and / or bisphenol C is preferable, more preferably 70 mol% or more, still more preferably 90 mol% or more.

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

As the carbonate precursor, carbonyl halide, carbonate ester, haloformate and the like are used, and specific examples thereof include phosgene, diphenyl carbonate, dihaloformate of divalent phenol and the like.

In producing a polycarbonate resin by reacting the above divalent dihydroxy compound with a carbonate precursor by an interfacial polymerization method or a melt polymerization method, a catalyst, a terminal terminator, an antioxidant of dihydric phenol, etc. are added as necessary. You may use it. Further, the polycarbonate resin may be a branched polycarbonate resin obtained by copolymerizing a trifunctional or higher polyfunctional aromatic compound, or a polyester carbonate resin obtained by copolymerizing an aromatic or aliphatic bifunctional carboxylic acid. Further, it may be a mixture of two or more of the obtained polycarbonate resins.

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. If the molecular weight is less than 13,000, the sheet becomes brittle, and cracks and burrs may easily occur during thermoforming. If the molecular weight is more than 40,000, the resin composition with a polyester-based thermoplastic elastomer can be used. The melt viscosity may become too high, making melt film formation difficult. 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 kinds, it represents the molecular weight of the whole mixture. _{Here, the viscosity average molecular weight is obtained by measuring the specific viscosity (η sp} ) of a solution of 0.7 g of polycarbonate in 100 mL of methylene chloride at 20 ° C. and calculating the viscosity average molecular weight (M) from the following formula.
η _sp / c = [η] +0.45 × [ ^{η] 2 c}
[Η] = 1.23 × 10 ^-4 M ^0.83
(However, c = 0.7 g / dL, [η] is the ultimate viscosity)

The glass transition temperature of the layer (layer A) containing the polycarbonate resin of the present invention needs to be in the range of 100 ° C. or higher and 145 ° C. or lower, preferably 110 ° C. or higher and 140 ° C. or lower, more preferably 120 ° C. or higher. It is 130 ° C. or lower. When the glass transition temperature becomes higher than the above range, it is necessary to raise the thermoforming temperature, and it is formed from the uncured product of the acrylate-based active energy ray-curable resin composition (composition C) due to the heat received during thermoforming. Thermal radical polymerization of the layer (C layer) is started, and appearance defects such as cracks occur after molding. When the glass transition temperature becomes lower than the above range, the appropriate molding temperature for thermoforming the A layer is a layer containing an acrylic resin (B layer) or an acrylate-based active energy ray-curable resin composition (composition C). The temperature of the layer (C layer) formed from the uncured product of the above is lower than the glass transition temperature, and thermoforming cannot be performed. Here, the glass transition point means a value measured by the differential scanning calorimetry (DSC) method.

The method for adjusting the glass transition temperature of the A layer is not particularly limited, but a method of blending a polyester-based thermoplastic elastomer with a polycarbonate-based resin is preferable in order to ensure the transparency of the thermoforming sheet. Further, the polyester-based thermoplastic elastomer is composed of a hard segment composed of a polybutylene terephthalate unit and a polyester unit containing an aromatic dicarboxylic acid and an aliphatic dicarboxylic acid as a dicarboxylic acid component and a diol having 5 to 15 carbon atoms as a diol component. It is preferably a multi-block copolymer composed of a soft segment.

The hard segment made of the polybutylene terephthalate unit has excellent compatibility with the polycarbonate resin, is preferable in terms of transparency and thermoformability, and also has good properties in terms of strength and the like. Polybutylene terephthalate may contain other components as a copolymerization component as long as the effects of the present invention are not impaired. The proportion of the copolymerization component is preferably 30 mol% or less, more preferably 20 mol% or less, still more preferably 10 mol% or less, based on 100 mol% of each of the dicarboxylic acid component and the diol component. The intrinsic viscosity of the polymer to be the hard segment is preferably in the range of 0.2 to 2.0, more preferably 0.5 to 1.5.

The soft segment composed of a polyester unit containing the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid as the dicarboxylic acid component and the diol having 5 to 15 carbon atoms as the diol component has a melting point of 100 ° C. or less of the polymer formed from the segment. Alternatively, it indicates a segment that is liquid and shows amorphousness at 100 ° C. The intrinsic viscosity of the polymer to be the 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 containing 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, it may be referred to as "SS-1"). SS-1 is suitable because it provides extremely good transparency.

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 components from the viewpoint of obtaining better transparency. It is preferably ~ 40 mol%. More preferably, the content of the aromatic dicarboxylic acid is 70 to 95 mol% and the content of the aliphatic dicarboxylic acid is 5 to 30 mol%. It is more preferable that the content of the aromatic dicarboxylic acid is 85 to 93 mol% and the content of the aliphatic dicarboxylic acid is 7 to 15 mol%. It is particularly preferable that the content of the aromatic dicarboxylic acid is 89 to 92 mol% and the content of the aliphatic dicarboxylic acid is 8 to 11 mol%.

Examples of the aromatic dicarboxylic acid of SS-1 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 is preferable, terephthalic acid and isophthalic acid are more preferable, and isophthalic acid is particularly preferable from the viewpoint of reducing crystallinity.

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.

As the diol component of SS-1 having 5 to 15 carbon atoms, a linear aliphatic diol 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, high transparency can be obtained, and surface property and transparency after thermoforming are also good. More specifically, as SS-1, a polyester composed of isophthalic acid, sebacic acid, and hexamethylene glycol is preferable.

In the present invention, it is appropriate that the ratio of the hard segment to the soft segment in the polyester-based 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 20-40% by weight and the soft segment is 80-60% 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 0.8 to 1.5, and 0.8 to 1 The range of .2 is more preferred. If the intrinsic viscosity is lower than the above range, the sheet strength may decrease, which is not preferable.

In the present invention, it is preferable that the polyester-based thermoplastic elastomer is contained in an amount of 1 to 20 parts by weight based on 100 parts by weight of the polycarbonate-based resin in the layer A. If the polyester-based thermoplastic elastomer is less than 1 part by weight, the glass transition temperature of the A layer may exceed 145 ° C., and if it exceeds 20 parts by weight, the glass transition temperature of the A layer may be less than 100 ° C. There is.

The thickness of the layer A is preferably in the range of 50 to 3000 μm, more preferably in the range of 100 to 2000 μm, further preferably in the range of 150 to 1500 μm, particularly preferably in the range of 200 to 1000 μm, and most preferably in the range of 250 to 500 μm.

The layer A of the present invention may contain various additives generally used in each resin. Examples thereof include heat stabilizers, antioxidants, ultraviolet absorbers, antistatic agents, dyes and the like. Further, a reinforcing filler such as glass fiber may be contained as long as the effect of the present invention is not impaired.

(Layer containing acrylic resin (B layer))
The acrylic resin used for the B layer in the present invention is preferably mainly composed of a polymer of methacrylic acid ester or acrylic acid ester. When a resin other than an acrylic resin is used as the B layer, for example, a polycarbonate resin has a low surface hardness of the laminated film, and the molded body is easily scratched, which is not preferable. In addition, PET resin is not preferable because it tends to cause poor appearance due to uneven thickness. The acrylic resin is preferably a copolymer containing methyl methacrylate in an amount of preferably 50 mol% or more, more preferably 70 mol% or more, still more preferably 80 mol% or more, and particularly preferably 90 mol% or more.

Examples of other copolymerization components include ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate and the like. Further, as another copolymerization component, other ethylenically unsaturated monomers can be mentioned. Specifically, vinyl aromatic compounds such as styrene, α-methylstyrene and vinyltoluene, diene compounds such as 1,3-butadiene and isoprene, alkenylcyan compounds such as acrylonitrile and methacrylnitrile, acrylic acid and methacrylic acid, Maleic anhydride, N-substituted maleimide and the like can be mentioned. These may be used alone or in combination of two or more. The content of the copolymerization component is preferably 0 to 50% by weight, more preferably 0 to 30% by weight, and further preferably 0 to 20% by weight. The method for producing an acrylic resin is generally roughly classified into an emulsion polymerization method, a suspension polymerization method, and a continuous polymerization method, but the acrylic resin used in the present invention may be produced by any polymerization method. Further, various additives such as general heat stabilizers, colorants, mold release agents, lubricants, antistatic agents, and matting agents may be added to the B layer.

Although rubber particles can be added to the B layer of the present invention, it is preferable that the B layer does not substantially contain rubber particles. Improvement of toughness by adding rubber particles to an acrylic resin is a known technique and is widely used, but it is preferable not to include it from the viewpoint of ensuring transparency and surface hardness.

The thickness of the B layer is preferably in the range of 10 to 300 μm, more preferably in the range of 20 to 250 μm, further preferably in the range of 30 to 200 μm, particularly preferably in the range of 35 to 150 μm, and most preferably in the range of 40 to 100 μm.

(Layer (C layer) formed from the uncured product of the acrylate-based active energy ray-curable resin composition (composition C))
The uncured product of the active energy ray-curable resin composition (composition C) constituting the C layer of the present invention contains an acrylate-based resin such as acrylate or urethane acrylate. Its content is preferably in the range of 70 to 95% by mass based on the total solid content of the C layer. If it is less than 70% by mass, the cohesive force, chemical resistance, scratch resistance, optical characteristics, etc. of the coating film may decrease. If it exceeds 95% by mass, the start of photopolymerization is delayed, so that the productivity may be inferior.

The acrylate-based resin contained in the C layer in the present invention may be either an oligomer or a prepolymer, and is not particularly limited.

The glass transition temperature of the uncured product of the acrylate-based resin composition (composition C) is preferably 30 to 150 ° C, more preferably 35 to 140 ° C, and particularly preferably 40 to 130 ° C. .. When an acrylate-based resin having a glass transition temperature of less than 30 ° C. is used, the coating film after heat-drying in an uncured state has tackiness, and blocking may easily occur during roll winding. If the glass transition point exceeds 150 ° C., sufficient heat is not applied during molding, and cracks may occur.

Further, it is preferable that the pencil hardness of the cured layer after irradiating the uncured product of the acrylate-based resin composition (composition C) with active energy rays such as ultraviolet rays and curing it is H or more. By setting the pencil hardness within this range, there is an advantage that the abrasion resistance is improved. When the pencil hardness is H or more, the scratch resistance becomes sufficient.

Here, the pencil hardness is defined as, as will be described later in Examples, by applying an uncured product of an acrylate-based resin composition (composition C) to a dried sheet by irradiating it with ultraviolet rays at an ^{integrated light amount of 1000 mJ / cm 2.} A value obtained by curing the film to form a test piece and measuring the pencil hardness of the coating film in accordance with JIS K5600-5-4-1999.

In the present invention, the C layer can contain a photopolymerization initiator. By containing the photopolymerization initiator, the polymerization curing reaction of the hard coat layer by light (ultraviolet) irradiation can be performed in a short time. Examples of the photopolymerization initiator include benzophenone, benzyl, Michler's ketone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-diethoxyacetophenone, benzyl dimethyl ketal, 2 , 2-Dimethoxy-1,2-diphenylethane-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenylketone, 2-methyl-1- [4-( Methylthio) phenyl] -2-morpholinopropanol-1, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1-one, bis (cyclopentadienyl) ) -Bis (2,6-difluoro-3- (pill-1-yl) titanium, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, 2,4,6- Examples thereof include trimethylbenzoyldiphenylphosphine oxide. Further, these compounds may be used alone or in combination of two or more.

The photopolymerization initiator contained in the solid content of the C layer is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass, based on the total solid content of the C layer. If the content of the photopolymerization initiator is less than 0.01% by mass, the photocurability may decrease, and if it is blended in excess of 10% by mass, coloring of the C layer may occur. Since the progress of the curing reaction does not change, it may be economically disadvantageous. It is also possible to add various known dyes and sensitizers in order to improve the photocurability.

The thickness of the C layer is preferably in the range of 1 to 50 μm, more preferably in the range of 2 to 30 μm, further preferably in the range of 2.5 to 20 μm, and particularly preferably in the range of 3 to 10 μm.

Depending on the situation, a surfactant such as a leveling agent, a defoaming agent, and an antifouling agent, an additive such as a surface modifier, and a filler such as an organic filler and an inorganic filler can be added to the C layer.

(Hindered amine compound)
The C layer of the present invention preferably contains a hindered amine compound. By containing a hindered amine compound, thermal radicals generated by heat exposure during thermoforming can be captured, and thermal radical polymerization can be suppressed. Further, from the viewpoint of effectively exerting the effect of the present invention, the content of the hindered amine compound is 1 to 1 to 100 parts by weight of the uncured product of the acrylate-based active energy ray-curable resin composition (composition C). It is preferably contained in 5 parts by weight. If the content is less than 1 part by weight, the thermal radical scavenging effect may not be obtained, and if it exceeds 5 parts by weight, curing inhibition of the C layer may be caused.

(Protective film)
In the thermoforming sheet of the present invention, it is preferable to attach a protective film to the surface of the C layer in order to protect the uncrosslinked C layer before curing from contamination and scratches. The protective film is not particularly limited, but a polyethylene film, a polypropylene film, a polyethylene terephthalate film and the like can be preferably used. Considering the heat resistance in the step of forming the decorative layer on the side opposite to the B layer and the C layer side of the A layer of the thermoforming sheet of the present invention by printing or the like after the protective film is attached, heat-resistant polypropylene Films and polyethylene terephthalate films are more preferred.

(Manufacturing method of thermoforming sheet)
The laminated sheet of the A layer and the B layer constituting the thermoforming sheet of the present invention can produce the molding material A for the A layer and the molding material B for the B layer by a coextrusion method. The coextrusion method is a method of obtaining a multilayer sheet by melt-extruding molding material A and molding material B using separate extruders and laminating them using a feed block or a multi-manifold die. By adjusting the extrusion amount, film forming speed, die slip interval, etc., it is possible to control the total thickness and thickness composition of the obtained laminated sheet.

The laminated sheet is formed by bringing the molten resin into close contact with a roll or a belt. Further, since the metal mirror surface can be transferred to the molten resin before it cools and hardens by narrowing the pressure with a metal roll, the surface appearance of the laminated sheet can be improved. The metal elastic roll includes, for example, a shaft roll and a cylindrical metal thin film arranged so as to cover the outer peripheral surface of the shaft roll and in contact with the molten resin. Examples include those in which a temperature-controlled fluid such as water or oil is sealed between the two, and those in which a metal belt is wrapped around the surface of a rubber roll. Among them, the metal elastic roll in which a metal belt is wound around two or more rolls can be cooled by narrowing the pressure of the molten resin on a wider surface on a wider arc so as not to leave stress in the resin as much as possible.

In order to laminate the C layer constituting the thermoforming sheet of the present invention on the laminated sheet of the A layer and the B layer, a coating method is generally used. The coating method is not particularly limited, but coating can be performed by a method that makes it easy to adjust the coating film thickness, such as gravure coating, microgravure coating, fountain bar coating, slide die coating, and slot die coating. Is. In the coating process, an acrylate-based active energy ray-curable resin composition (composition C) and, if necessary, a hindered amine-based compound, an initiator, other additives, etc. are dissolved and dispersed in an appropriate solvent, and a paint is dispersed on the laminated sheet. Is coated and dried to form a C layer. The solvent may be appropriately selected depending on the solubility of the composition C, and may be any solvent that can uniformly dissolve or disperse at least the solid content (resin, polymerization initiator, other additives). Examples of such a solvent include ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), ethers (dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), and alicyclic hydrocarbons (hexane, etc.). Cyclohexane, etc.), aromatic hydrocarbons (toluene, xylene, etc.), carbon halides (dichloromethane, dichloroethane, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), alcohols (methanol, ethanol, isopropanol, etc.) Butanol, cyclohexanol, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, etc.), cellosolve acetates, sulfoxides, amides, etc. can be exemplified. Moreover, the solvent may be used alone or mixed.

The thickness of the thermoforming sheet of the present invention is not particularly limited, but is preferably 0.05 mm or more and 3 mm or less, more preferably 0.1 mm or more and 2.5 mm or less, further preferably 0.15 mm or more and 2 mm or less, and 0.2 mm. More than 1 mm is particularly preferable.

(Manufacturing method of decorative sheet)
The thermoforming sheet of the present invention may be provided with a decorative layer by printing or the like on the side of the A layer opposite to the B layer. Examples of the method for forming the decorative layer include formation of a design layer by printing, formation of a thin film layer of metal or metal oxide, and the like, and these may be used in combination. As a printing method for forming the pattern layer, known printing methods such as gravure printing, flat plate printing, flexo printing, dry offset printing, pad printing, screen printing and the like can be used according to the product shape and printing application. .. Examples of the method for forming a thin film layer of a metal or a metal oxide include a vapor deposition method, a thermal spraying method, and a plating method. Specific examples of the vapor deposition method include vacuum vapor deposition, sputtering, ion plating, thermal CVD, plasma CVD, optical CVD and the like. Examples of the thermal spraying method include atmospheric pressure plasma spraying method and decompression plasma thermal spraying method. Examples of the plating method include an electroless plating method, a hot-dip plating method, and an electroplating method.

Further, in the thermoforming sheet and the decorative sheet, it is preferable that the C layer is the outermost layer because it is excellent in characteristics such as hardness.

(Manufacturing method of molded product)
A molded product can be produced by using the thermoforming sheet or the decorative sheet of the present invention. Molds include automobile interior materials, automobile indicator panels, electrical appliances, cosmetic cases, building material interior and exterior parts, various equipment and products and miscellaneous goods cases, switches, keys, key pads, handles, levers, buttons, home appliances and Examples thereof include housings and exterior parts of personal computers, mobile phones, and mobile devices, which are AV devices.

As the molded body, a molded body can be obtained by performing various conventionally known moldings using a thermoforming sheet or a decorative sheet.

As a molding method of the molded body, a heat molding sheet or a decorative sheet which is preliminarily shaped by vacuum molding, pressure molding, etc. so as to follow the shape of the injection molding mold cavity by the in-mold decoration method in injection molding is used. An insert molding method in which a molten resin is injected into a mold, and at the same time injection molding is performed, a heat molding sheet or a decorative sheet is welded to a resin molded product and integrated to obtain a molded product. ..

Further, as another molding method of a molded product, a thermoforming sheet or a decorative sheet is attached to the mold cavity side by vacuum pressure, and molten resin is injected there to apply heat and pressure. Examples thereof include a molding method in which a thermoforming sheet or a decorative sheet is attached to a resin molded product to obtain a molded product.

Further, a method of laminating by vacuum forming or compressed air forming can be mentioned. As a method for heating the decorative molding film during thermoforming, various methods such as an infrared heater, an electric heater, high frequency induction, a halogen lamp, a microwave, a high temperature derivative (steam, etc.), and a laser can be used.

In the produced molded product, it is preferable that the C layer is located on the outermost surface of the molded product. The compact is cooled or allowed to cool, and the C layer is subsequently cured by irradiation with radiation (ultraviolet, visible, infrared or electron beam). These radiations may be polarized or unpolarized. In particular, ultraviolet rays are preferable from the viewpoints of equipment cost, safety, running cost and the like. When curing by ultraviolet irradiation, it is necessary to add a photopolymerization initiator. As the energy source of ultraviolet rays, for example, a high-pressure mercury lamp, a halogen lamp, a xenon lamp, a metal halide lamp, a nitrogen laser, an electron beam accelerator, a radioactive element, or the like is preferable. The amount of irradiation with the energy radiation source of accumulative exposure at an ultraviolet wavelength of 365 nm, preferably in the range of ^{100~5,000mJ / cm 2, 300~3,000mJ / cm} 2 is more preferable. If the irradiation amount is ^{less than 100 mJ / cm 2} , the curing may be insufficient and the hardness may decrease. If it exceeds 5,000 mJ / cm ² , the C layer may be colored and the transparency may be lowered. The oxygen concentration at the time of irradiation is preferably 5% or less, more preferably 3% or less, and particularly preferably 2% or less. In an oxygen-free or low-concentration atmosphere, the gas contained other than oxygen is preferably an inert gas. Examples of the inert gas include nitrogen, helium, neon, argon and the like.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. The physical properties measured in Examples and Comparative Examples were measured by the following methods.
(Glass-transition temperature)
Using a TA Instruments 2920 type DSC, the temperature was measured at a heating rate of 20 ° C./min, and the falling point was determined.
(Total thickness of thermoforming sheet)
It is a value of the central portion in the sheet width direction measured by an electron micro film thickness meter manufactured by Anritsu Co., Ltd. The sheet width direction represents a direction perpendicular to the sheet flow direction during film formation.
(Pencil hardness)
The prepared thermoforming sheet was irradiated with ultraviolet rays from the C layer side at an integrated light intensity of 1000 mJ / cm ² , and the coating film was cured to form a test piece, and the pencil hardness of the coating film was in accordance with JIS K5600-5-4-1999. Was measured.
(Moldability)
Using a biaxial stretching tester (manufactured by Toyo Seiki Co., Ltd.), the thermoforming sheet was preheated for 1 minute at the temperature of layer A (glass transition temperature +20) ° C, and then at the same temperature, the stretching ratio was 1.3 times. The appearance of the sheet when stretched to the above was evaluated by the following indexes.
〇: No cracks or white turbidity △: Weak cracks or slight white turbidity are observed ×: Cracks or white turbidity are observed

[Preparation Example 1] (Production of Polyester-based Thermoplastic Elastomer)
With respect to 100 parts by weight of dimethyl isophthalate, 13 parts by weight of dimethyl sebacate and 80 parts by weight of hexamethylene glycol were transesterified with a dibutyltin diacetate catalyst and then polycondensed under reduced pressure to obtain an intrinsic viscosity of 1.06. Yes, an amorphous polyester (soft segment) showing no heat absorption peak due to crystal melting was obtained by measurement by the DSC method. To 100 parts by weight of the polyester, 32 parts by weight of polybutylene terephthalate pellets (hard segment) having an intrinsic viscosity of 0.98 were added, and the mixture was further reacted at 240 ° C. for 45 minutes, and then 0.03 weight by weight of phenylphosphonic acid was added. The reaction was stopped by adding a portion. The obtained polymer had a melting point of 190 ° C. and an intrinsic viscosity of 0.93.

[Example 1]
(Molding material A)
Polycarbonate resin pellets (Panlite L1250WP manufactured by Teijin Co., Ltd. (homopolycarbonate resin of bisphenol A (PC-A), viscosity average molecular weight 23,900)) and the thermoplastic elastomer obtained in the above [Preparation Example] are used, respectively. It was pre-dried in advance, mixed with a V-type blender so that 100 parts by weight of the polycarbonate resin pellets became 1 part by weight of the thermoplastic elastomer, and then extruded at a cylinder temperature of 260 ° C. using a twin-screw extruder to pelletize. A molding material A for the A layer was obtained. The glass transition temperature of the molding material A was 145 ° C.

(Molding material B)
As the molding material B for the B layer, an acrylic resin (Acrypet VH-001 manufactured by Mitsubishi Rayon Co., Ltd., an acrylic resin obtained by copolymerizing 95 mol% of methyl methacrylate and 5 mol% of methyl acrylate) was prepared.

(Coextrusion)
Using a single-screw extruder with a screw diameter of 40 mm, the molding material A and the molding material B were subjected to cylinder temperatures of 260 ° C. (molding material A), 250 ° C. (molding material B), and a screw rotation speed of 11 rpm (molding material A). Under the condition of 109 rpm (molding material B), it is extruded from a T-die with a width of 650 mm by a feed block method, the molten resin is narrowly pressed with a metal roll and a metal sleeve roll to cool, then edge trimmed and the winding speed is 10.3 m. It was wound at / min to prepare a laminated sheet having a two-layer structure of A layer / B layer (A layer 440 μm, B layer 60 μm) and a width of 400 mm.

(Paint adjustment)
As the paint forming the C layer, 100 parts by weight of urethane acrylate-based ultraviolet curable resin "Forseed No. 371C (trade name)" (solid content 40%, manufactured by China Paint Co., Ltd.), Irgacure 184 (photopolymerization initiator) , 5 parts by weight of Ciba Speciality Chemical Co., Ltd., 5 parts by weight of hindered amine compound TINUVIN 292 (trade name) "(manufactured by BASF Co., Ltd.) The paint was prepared by diluting to 30% and stirring well.

(Coating)
The paint forming the C layer is applied to the B layer side of the laminated sheet of the A layer and the B layer using a bar coater (# 8), dried with hot air in a drying oven at 80 ° C. for 1 minute, and the coating film is applied. After forming the C layer having a thickness of 5 μm, a polypropylene protective film (manufactured by Oji F-Tex Co., Ltd.) was laminated on the C layer to prepare a thermoforming sheet having a thickness of 0.5 mm. The results of various evaluations are shown in Table 1.

[Example 2]
A thermoforming sheet was prepared in the same manner as in Example 1 except that the content of the polyester-based thermoplastic elastomer, the thickness of the laminated sheet, and the content of the hindered amine compound were changed as shown in Table 1. The results of various evaluations are shown in Table 1.

[Example 3]
A thermoforming sheet was prepared in the same manner as in Example 1 except that the content of the polyester-based thermoplastic elastomer, the thickness of the laminated sheet, and the content of the hindered amine compound were changed as shown in Table 1. The results of various evaluations are shown in Table 1.

[Example 4]
A thermoforming sheet was prepared in the same manner as in Example 1 except that the content of the polyester-based thermoplastic elastomer, the thickness of the laminated sheet, and the content of the hindered amine compound were changed as shown in Table 1. The results of various evaluations are shown in Table 1.

[Example 5]
A thermoforming sheet was prepared in the same manner as in Example 1 except that the content of the polyester-based thermoplastic elastomer and the content of the hindered amine compound were changed as shown in Table 1. The results of various evaluations are shown in Table 1.

[Example 6]
It is a hard polymer obtained by polymerizing a monomer whose innermost layer is 93.8% methyl methacrylate, 6% methyl acrylate and 0.2% allyl methacrylate as rubber particles in the molding material B. The intermediate layer is an elastic polymer obtained by polymerizing a monomer composed of 81% butyl acrylate, 17% styrene and 2% allyl methacrylate, and the outermost layer is 94% methyl methacrylate and 6% methyl acrylate. Rubber particles obtained by the emulsion polymerization method, which is a hard polymer obtained by polymerizing a monomer composed of, were mixed by 5 parts by weight with respect to 100 parts by weight of an acrylic resin. Further, a thermoforming sheet was prepared in the same manner as in Example 1 except that the content of the polyester-based thermoplastic elastomer and the thickness of the laminated sheet were changed as shown in Table 1. The results of various evaluations are shown in Table 1.

[Example 7]
A thermoforming sheet was prepared in the same manner as in Example 1 except that the thickness of the laminated sheet was changed as shown in Table 1. The results of various evaluations are shown in Table 1.

[Example 8]
A thermoforming sheet was prepared in the same manner as in Example 1 except that the content of the polyester-based thermoplastic elastomer, the thickness of the laminated sheet, and the content of the hindered amine compound were changed as shown in Table 1. The results of various evaluations are shown in Table 1.

[Example 9]
A thermoforming sheet was prepared in the same manner as in Example 1 except that the thickness of the laminated sheet and the content of the hindered amine compound were changed as shown in Table 1. The results of various evaluations are shown in Table 1.

[Example 10]
A thermoforming sheet was prepared in the same manner as in Example 1 except that the content of the polyester-based thermoplastic elastomer, the thickness of the laminated sheet, and the content of the hindered amine compound were changed as shown in Table 1. The results of various evaluations are shown in Table 1.

[Example 11]
2,2-Bis {(4-hydroxy-3-methyl) phenyl} propane (commonly known as bisphenol A) instead of 2,2-bis (4-hydroxyphenyl) propane (commonly known as bisphenol A) during the production of polycarbonate resin pellets of molding material A. Bisphenol C; PC-C) was used. Further, a thermoforming sheet was prepared in the same manner as in Example 1 except that the content of the polyester-based thermoplastic elastomer, the thickness of the laminated sheet, and the content of the hindered amine compound were changed as shown in Table 1. The results of various evaluations are shown in Table 1.

[Example 12]
After forming the C layer, the protective film was not attached. Further, a thermoforming sheet was prepared in the same manner as in Example 1 except that the content of the polyester-based thermoplastic elastomer, the thickness of the laminated sheet, and the content of the hindered amine compound were changed as shown in Table 1. The results of various evaluations are shown in Table 1.

[Comparative Example 1]
No polyester-based thermoplastic elastomer was added to the molding material A. Further, a thermoforming sheet was prepared in the same manner as in Example 1 except that the thickness of the laminated sheet was changed as shown in Table 1. The results of various evaluations are shown in Table 2.

[Comparative Example 2]
A thermoforming sheet was prepared in the same manner as in Example 1 except that the content of the polyester-based thermoplastic elastomer, the thickness of the laminated sheet, and the content of the hindered amine compound were changed as shown in Table 1. The results of various evaluations are shown in Table 2.

[Comparative Example 3]
As the resin composition for forming the C layer, isopropanol solution Tossguard 510 containing trifunctional and tetrafunctional alkoxysilane as a main component instead of urethane acrylate-based ultraviolet curable resin "Forseed No. 371C" (Momentive Performance Materials) After applying (manufactured by Materials Co., Ltd.), it was dried with hot air for 1 minute in a drying furnace at 80 ° C. Further, a hard polymer obtained by polymerizing a monomer having the innermost layer of 93.8% methyl methacrylate, 6% methyl acrylate and 0.2% allyl methacrylate as rubber particles in the molding material B. The intermediate layer is an elastic polymer obtained by polymerizing a monomer composed of 81% butyl acrylate, 17% styrene and 2% allyl methacrylate, and the outermost layer is 94% methyl methacrylate and methyl acrylate. Rubber particles obtained by the emulsion polymerization method, which is a hard polymer obtained by polymerizing a monomer consisting of 6%, were mixed in an amount of 5 parts by weight with respect to 100 parts by weight of an acrylic resin. Further, a thermoforming sheet was prepared in the same manner as in Example 1 except that the thickness of the laminated sheet and the content of the hindered amine compound were changed as shown in Table 1. The results of various evaluations are shown in Table 2.

The thermoforming sheet and the decorative sheet of the present invention are excellent in moldability and hardness, and the molded product using the thermoforming sheet and the decorative sheet is an automobile interior material, an automobile indicator panel, an electric appliance, a cosmetic case. , Building materials Interior and exterior parts, cases for various devices and products and miscellaneous goods, switches, keys, key pads, handles, levers, buttons, and useful as housings and exterior parts for personal computers, mobile phones and mobile devices such as home appliances and AV equipment. be.

Claims (11)

A layer (C layer) formed from a layer containing a polycarbonate resin (A layer), a layer containing an acrylic resin (B layer), and an uncured product of an acrylate-based active energy ray-curable resin composition (composition C). A thermoforming sheet obtained by laminating at least three layers in this order, wherein the glass transition temperature (Tg) of the A layer is 100 ° C. or higher and 145 ° C. or lower. The layer A contains a polyester-based thermoplastic elastomer, and the polyester-based thermoplastic elastomer contains a hard segment made of polybutylene terephthalate unit and an aromatic dicarboxylic acid and an aliphatic dicarboxylic acid as a dicarboxylic acid component, and has 5 carbon atoms. The thermoformed sheet according to claim 1, wherein the sheet is composed of a soft segment composed of a polyester unit containing ~ 15 diols as a diol component. The thermoforming sheet according to claim 2, wherein the layer A contains 1 to 20 parts by weight of the polyester-based thermoplastic elastomer according to claim 2 with respect to 100 parts by weight of the polycarbonate resin. The thermoforming sheet according to any one of claims 1 to 3, wherein the B layer does not substantially contain rubber particles. Any of claims 1 to 4, wherein the C layer contains 1 to 5 parts by weight of a hindered amine compound with respect to 100 parts by weight of an uncured product of the acrylate-based active energy ray-curable resin composition (composition C). The thermoforming sheet described in. The thermoforming sheet according to any one of claims 1 to 5, wherein the pencil hardness of the surface of the cured layer obtained by irradiating the C layer with active energy rays and curing the layer C is H or more. The thermoforming sheet according to any one of claims 1 to 6, wherein a protective film is provided on the C layer, and the protective film can be peeled off from the C layer. The thermoforming sheet according to any one of claims 1 to 7, wherein the total thickness of the molding sheet is in the range of 0.05 mm or more and 3 mm or less. A decorative sheet in which a decorative layer is formed on the side opposite to the B layer and the C layer side of the A layer of the thermoforming sheet according to any one of claims 1 to 8. The thermoforming sheet according to claims 1 to 8 or the decorative sheet according to claim 9 is previously shaped into the shape of the mold cavity, placed in the mold, and integrated at the same time as molding the resin material. A method for producing a molded product, which comprises producing a molded product, and then performing post-exposure with an active energy ray. A molded body in which the thermoforming sheet according to claims 1 to 8 or the decorative sheet according to claim 9 is attached to the mold cavity side by vacuum pressure and integrated at the same time as molding the resin material is formed. A method for producing a molded product, which comprises producing, evacuating, and then post-exposing with an active energy ray.