JP2022061503A - Resin composition, resin laminate and molding - Google Patents

Abstract

To provide a resin composition suitable as coating material for imparting weathering resistance while maintaining good product appearance in the case where a cured coating film of UV-curable resin composition is provided on a resin substrate made of polycarbonate-based resin or the like, a resin laminate containing the resin composition, and a molding including the resin laminate.SOLUTION: A resin composition contains a methacrylic-based resin (A), benzotriazole-based UV absorber (B1), and a benzotriazole-based UV absorber (B2). The benzotriazole-based UV absorber (B1) has a molecular weight of 500 or more, and the benzotriazole-based UV absorber (B2) has a molecular weight of 400 or less.SELECTED DRAWING: None

Description

The present invention relates to a resin composition, a resin laminate and a molded product.

Polycarbonate-based resins are used as housings and exterior parts for mobile phones, electrical and electronic devices, and the like. However, since the polycarbonate resin has a low surface hardness, there is a problem that the scratch resistance is insufficient. Further, the polycarbonate-based resin has a problem of insufficient weather resistance because it discolors when exposed to ultraviolet rays such as sunlight.

As a method for improving the scratch resistance of a polycarbonate-based resin, Patent Document 1 proposes a resin laminate in which a cured film made of an ultraviolet curable resin is formed on the surface of a polycarbonate-based resin layer.
As a method for improving the weather resistance of a polycarbonate-based resin, Patent Documents 2 to 6 propose a resin laminate in which an acrylic resin layer containing an ultraviolet absorber is laminated on the surface of the polycarbonate-based resin layer. ..

Japanese Unexamined Patent Publication No. 2014-124786 Japanese Unexamined Patent Publication No. 2013-202815 Japanese Unexamined Patent Publication No. 11-58626 Japanese Unexamined Patent Publication No. 2010-221648 Japanese Unexamined Patent Publication No. 2010-234640 International Publication No. 2014/157149

However, in the resin laminate disclosed in Patent Document 1, the polycarbonate-based resin layer is colored by ultraviolet irradiation when forming a cured film. In the resin laminates disclosed in Patent Documents 2 to 6, cracks are generated in at least one of the acrylic resin layer and the polycarbonate resin layer by irradiating the resin laminate with ultraviolet rays for a long time.

An object of the present invention is to provide a resin composition, a resin laminate, and a molded product containing the resin laminate that solves the above problems.

As a result of repeated studies to solve the above problems, the present inventors have provided a protective film on the resin base material before forming the cured film on the resin base material made of a polycarbonate resin, and then provided the cured film. The present invention was completed by finding that the above-mentioned problems can be solved by forming the above-mentioned problem.
That is, the present invention exists as follows.
[1] A resin composition comprising a methacrylic resin (A), a benzotriazole-based ultraviolet absorber (B1) having a molecular weight of 500 or more, and a benzotriazole-based ultraviolet absorber (B2) having a molecular weight of 400 or less.
[2] The resin composition of [1], wherein the benzotriazole-based ultraviolet absorber (B1) has a molecular weight of 600 or more.
[3] The resin composition of [1] or [2], wherein the benzotriazole-based ultraviolet absorber (B2) has a molecular weight of 270 or less.
[4] The resin composition according to any one of [1] to [3], wherein the benzotriazole-based ultraviolet absorber (B1) is a compound represented by the following general formula (I).

(In formula (I), R ₁ and R ₂ each independently represent a linear or branched alkyl group having 1 to 16 carbon atoms.)
[5] The benzotriazole-based ultraviolet absorber (B1) is 2,2-methylenebis [4- (1,1,3,3-tetramethylenebutyl) -6- (2H-benzotriazole-2-yl) phenol]. The resin composition according to any one of [1] to [4].
[6] The resin composition according to any one of [1] to [5], wherein the benzotriazole-based ultraviolet absorber (B2) is a compound represented by the following general formula (II).

(In formula (II), R represents a linear or branched alkyl group having 1 to 6 carbon atoms.)
[7] The resin composition according to any one of [1] to [6], wherein the benzotriazole-based ultraviolet absorber (B2) is 2- (2'-hydroxy-5'-methylphenyl) benzotriazole.
[8] The content of the benzotriazole-based ultraviolet absorber (B1) is 1.3 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the methacrylic resin (A), [1] to [ 7] Any of the resin compositions.
[9] A resin laminate comprising a protective film provided at least a part of a resin base material, wherein the protective film contains the resin composition according to any one of [1] to [8].
[10] The resin laminate of [9], wherein the resin base material is made of a polycarbonate-based resin composition.
[11] The resin laminate of [9] or [10], wherein at least a part of the protective film is provided with a cured film.
[12] A molded product containing the resin laminate according to any one of the above [9] to [11].

According to the present invention, it is possible to provide a resin composition, a resin laminate and a molded product having an excellent product appearance and improved weather resistance without the polycarbonate-based resin layer being colored or cracking.

Hereinafter, the present invention will be described in detail.
As used herein, "(meth) acrylic acid" means at least one selected from "acrylic acid" and "methacrylic acid".
In the present specification, "monomer" means an unpolymerized compound, and "repeating unit" and "structural unit" mean a unit derived from the monomer formed by polymerizing the monomer. do. The repeating unit and the structural unit may be a unit directly formed by a polymerization reaction, or a part of the unit may be converted into another structure by processing a polymer.
In the present specification, the "obtained resin laminate" is obtained by forming a protective film containing the resin composition of the present invention on at least one surface of a resin base material made of a polycarbonate-based resin composition. A resin laminate.
In the present specification, "% by mass" indicates the content ratio of a predetermined component contained in 100% by mass of the total amount.
Unless otherwise specified, the numerical range represented by "-" in the present specification means a range including the numerical values before and after "-" as the lower limit value and the upper limit value, and "AB". "" Means that it is A or more and B or less.
In the present invention, "transparency" means that the total light transmittance measured according to JIS K7361-1 is 75% or more.

<Resin composition>
The resin composition of the present invention is a resin composition containing a methacrylic resin (A), a benzotriazole-based ultraviolet absorber (B1), and a benzotriazole-based ultraviolet absorber (B2).
In particular, the resin composition of the present invention contains both a benzotriazole-based ultraviolet absorber (B1) and a benzotriazole-based ultraviolet absorber (B2) having a lower molecular weight than the benzotriazole-based ultraviolet absorber (B1). It is a feature.

Since the resin composition of the present invention contains the methacrylic resin (A), a resin laminate having a protective layer made of the resin composition on the surface of the resin base material made of the polycarbonate resin composition (hereinafter referred to as “a resin laminate”). The "obtained resin laminate") has excellent transparency.
Since the resin composition of the present invention contains both a benzotriazole-based ultraviolet absorber (B1) and a benzotriazole-based ultraviolet absorber (B2), the obtained resin laminate is excellent in weather resistance and product appearance.

In the resin composition of the present invention, known additives such as an impact strength modifier, a mold release agent, an ultraviolet absorber, a polymerization inhibitor, an antioxidant, a flame retardant, etc. are added to the resin composition of the present invention, if necessary. It may be contained within a range that does not impair the effect.

<Methyl resin (A)>
The methacrylic resin (A) is one of the constituents constituting the resin composition of the present invention.

The methacrylic resin (A) in the present invention may contain a repeating unit derived from methyl methacrylate (hereinafter referred to as "methyl methacrylate unit") in an amount of 70% by mass or more based on the total mass of the methacrylic resin (A). preferable.
In one embodiment of the methacrylic resin (A) in the present invention, the content of the methyl methacrylate unit in the copolymer of methyl methacrylate or the methacrylic resin (A) is 70% by mass or more and less than 100% by mass. Methyl methacrylate copolymer (hereinafter, also referred to as “polymer (A1)”) can be mentioned.

<Polymer (A1)>
The polymer (A1) is a homopolymer of methyl methacrylate or another simple polymer capable of copolymerizing with a methyl methacrylate unit of 70% by mass or more and less than 100% by mass and a methyl methacrylate of more than 0% by mass and 30% by mass or less. It is a methyl methacrylate copolymer containing a repeating unit derived from a mass (hereinafter referred to as "another monomer unit").

Among these polymers (A1), a copolymer in which the content of the methyl methacrylate unit in the polymer (A1) is 90% by mass or more, or a homopolymer of methyl methacrylate is preferable. A copolymer in which the content of the methyl methacrylate unit in (A1) is 95% by mass or more or a homopolymer of methyl methacrylate is more preferable.

The other monomer is not particularly limited as long as it is a monomer copolymerizable with methyl methacrylate, and for example, methyl acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, and iso. -Propyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) ) Acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, norbornyl (meth) acrylate, adamantyl (meth) acrylate, dicyclopentenyl (Meta) acrylate compounds other than methyl methacrylate such as (meth) acrylate, dicyclopentanyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate; (meth) acrylic acid; Meta) Acrylonitrile; (meth) acrylamide compounds such as (meth) acrylamide and N-dimethyl (meth) acrylamide; aromatic vinyl compounds such as styrene and α-methylstyrene; vinyl methyl ether, vinyl ethyl ether, 2-hydroxyethyl vinyl ether Vinyl ether compounds such as vinyl acetate; vinyl carboxylate compounds such as vinyl acetate and vinyl butyrate; olefin compounds such as ethylene, propylene, butene and isobutene can be mentioned. These other monomers may be used alone or in combination of two or more. Among these other monomers, a (meth) acrylate compound other than methyl methacrylate is preferable because it does not impair the original performance of the acrylic resin, and the obtained resin molded product is excellent in heat-decomposability. Therefore, methyl acrylate , Ethyl acrylate and n-butyl acrylate are more preferable, and methyl acrylate and ethyl acrylate are even more preferable.

When the polymer (A1) contains other monomer units, the content ratio of the other monomer units to 100% by mass of the polymer (A1) is preferably 20% by mass or less, preferably 10% by mass or less. More preferably, 5% by mass or less is further preferable.

Examples of the method for producing the polymer (A1) include a bulk polymerization method, a suspension polymerization method, an emulsion polymerization method, and a solution polymerization method. Among these polymerization methods, the bulk polymerization method and the suspension polymerization method are preferable, and the bulk polymerization method is more preferable, because they are excellent in productivity.

The mass average molecular weight of the polymer (A1) is preferably 20,000 to 200,000, more preferably 50,000 to 150,000. When the mass average molecular weight of the polymer (A1) is 20,000 or more, the mechanical properties of the obtained resin molded product are excellent. Further, when the mass average molecular weight of the polymer (A1) is 200,000 or less, the fluidity at the time of melt molding is excellent.
In the present specification, the mass average molecular weight is a value measured by using standard polystyrene as a standard sample and using gel permeation chromatography.

The lower limit of the content ratio of the methacrylic resin (A) in the total mass (100% by mass) of the resin composition of the present invention is 55 from the viewpoint of transparency, heat resistance, weather resistance, etc. of the obtained resin molded product. Mass% or more is preferable. 70% by mass or more is more preferable, and 90% by mass or more is further preferable. The upper limit of the content ratio of the methacrylic resin (A) is preferably 99% by mass or less from the viewpoint of excellent scratch resistance of the obtained resin molded product. 98% by mass or less is more preferable, and 97% by mass or less is further preferable.
The above preferred upper limit and preferred lower limit can be arbitrarily combined. For example, the content ratio of the methacrylic resin (A) in the total mass (100% by mass) of the resin composition of the present invention is preferably 55% by mass or more and 99% by mass or less, and 70% by mass or more and 98% by mass or less. Is more preferable, and 90% by mass or more and 97% by mass or less are further preferable.

Examples of commercially available methacrylic resins include Acripet (registered trademark) VH, MD, MF, IRK304, VRL40 (trade names, all manufactured by Mitsubishi Chemical Corporation) and the like.

<Benzotriazole UV absorber (B1)>
The benzotriazole-based ultraviolet absorber (B1) (hereinafter referred to as “ultraviolet absorber (B1)”) is one of the constituent components of the resin composition of the present invention.
When the resin composition of the present invention contains an ultraviolet absorber (B1), it is possible to provide a resin laminate having excellent weather resistance and excellent product appearance.

The lower limit of the wavelength showing the maximum value of the absorbance of the ultraviolet absorber (B1) is 340 nm or more, more preferably 343 nm or more, still more preferably 345 nm or more. With such a wavelength, coloring due to ultraviolet irradiation can be suppressed when a cured film is formed on the surface of the resin base material. On the other hand, the upper limit of the wavelength showing the maximum value of the absorbance is 400 nm or less, more preferably 385 nm or less, further preferably 370 nm or less. With such a wavelength, it is possible to efficiently absorb the ultraviolet rays irradiated when forming the cured film on the surface of the resin base material and prevent the resin base material from being colored.
The above preferred upper limit and preferred lower limit can be arbitrarily combined. For example, the wavelength indicating the maximum value of the absorbance of the ultraviolet absorber (B1) is 340 nm or more and 400 nm or less. It is more preferably 343 nm or more and 385 nm or less, and further preferably 345 nm or more and 370 nm or less.

The lower limit of the molecular weight of the ultraviolet absorber (B1) is 500 or more from the viewpoint of particularly excellent weather resistance of the obtained resin laminate. 550 or more is more preferable, and 600 or more is further preferable. On the other hand, the upper limit of the molecular weight is not particularly limited, but is 1300 or less from the viewpoint of excellent solubility in the resin composition. 1000 or less is more preferable, and 750 or less is further preferable.

By setting the lower limit of the molecular weight of the ultraviolet absorber (B1) to 500 or more, the ultraviolet absorber is also present inside the protective layer without bleeding out on the surface of the protective layer or being localized near the surface. Therefore, it is presumed that the weather resistance of the obtained resin laminate will be excellent.

The above preferred upper limit and preferred lower limit can be arbitrarily combined. For example, the molecular weight of the ultraviolet absorber (B1) in the present invention can be 500 or more and 1300 or less. It is more preferably 550 or more and 1000 or less, and further preferably 600 or more and 750 or less.

Examples of the ultraviolet absorber (B1) include 2,2-methylenebis [4- (1,1,3,3-tetramethylenebutyl) -6- (2H-benzotriazole-2-yl) phenol], β. -[3- (2H-benzotriazole-2-yl) -4-hydroxy-5-tert-butylphenyl] -propionic acid poly (ethylene glycol) 300-ester, bis {β- [3- (2H-benzotriazole) -2-yl) -4-hydroxy-5-tert-butylphenyl] -propionic acid} poly (ethylene glycol) 300-ester and the like. Specifically, commercially available products such as ADEKA STAB (registered trademark) LA-31G, LA-31RG, (product name, manufactured by ADEKA), and Tinuvin (registered trademark) 1130 (product name, manufactured by BASF) can be used. .. These ultraviolet absorbers may be used alone or in combination of two or more.

The structure of the ultraviolet absorber (B1) is not particularly limited, but the compound represented by the following general formula (I) is preferable from the viewpoint of excellent weather resistance and product appearance of the obtained resin molded product.

(In formula (I), R ₁ and R ₂ are linear or branched alkyl groups having 1 to 16 carbon atoms independently of each other.)

Specific examples of the compound represented by the general formula (I) include ADEKA STAB (registered trademark) LA-31G and LA-31RG (product name, compound name: 2,2-methylenebis [4- (1,1,1). 3,3-Tetramethylenebutyl) -6- (2H-benzotriazole-2-yl) phenol], manufactured by ADEKA Corporation) and the like are commercially available products.

The lower limit of the content of the ultraviolet absorber (B1) contained in the resin composition is not particularly limited, but the methacrylic resin is excellent from the viewpoint of excellent weather resistance and product appearance of the obtained resin molded product. (A) 0.01 parts by mass or more is preferable with respect to 100 parts by mass. 0.1 part by mass or more is more preferable, 0.3 part by mass or more is further preferable, and 1.3 part by mass or more is particularly preferable. On the other hand, the upper limit of the content of the ultraviolet absorber (B1) is not particularly limited, but coloring by the ultraviolet absorber (B1) itself is suppressed in the obtained resin laminate, and the product appearance is good. From the viewpoint of being able to maintain the above, 10 parts by mass or less is preferable with respect to 100 parts by mass of the methacrylic resin (A). 7.0 parts by mass or less is more preferable, 5.0 parts by mass or less is further preferable, and 3.0 parts by mass or less is particularly preferable.
The above preferred upper limit and preferred lower limit can be arbitrarily combined. That is, the content of the ultraviolet absorber (B1) contained in the resin composition is preferably 0.01 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the methacrylic resin (A). 1 part by mass or more and 8.5 parts by mass or less are more preferable, 0.3 parts by mass or more and 7.0 parts by mass or less are further preferable, and 1.3 parts by mass or more and 5.0 parts by mass or less are particularly preferable.

<Benzotriazole UV absorber (B2)>
The benzotriazole-based ultraviolet absorber (B2) (hereinafter referred to as “ultraviolet absorber (B2)”) is one of the constituent components of the resin composition of the present invention.
When the resin composition of the present invention further contains an ultraviolet absorber (B2) in addition to the ultraviolet absorber (B1), the weather resistance and product appearance of the obtained resin laminate can be further improved. ..

The upper limit of the molecular weight of the ultraviolet absorber (B2) is less than 500 from the viewpoint of better weather resistance of the obtained resin laminate. 400 or less is more preferable, and 270 or less is further preferable. On the other hand, the lower limit of the molecular weight is not particularly limited, but from the viewpoint of heat resistance of the resin laminate and anti-blocking property (surface stickiness), 150 or more is preferable, 180 or more is more preferable, and 200 or more is further preferable. ..

By using the ultraviolet absorber (B2) in combination with the ultraviolet absorber (B1), as described above, the ultraviolet absorber (B1) is present inside the protective layer of the obtained resin laminate. On the other hand, the ultraviolet absorber (B2) having a small molecular weight bleeds out or is localized in the vicinity of the surface of the protective layer made of the resin composition. As a result, it is presumed that the weather resistance of the obtained resin laminate becomes more excellent because the ultraviolet absorber is present on the surface, in the vicinity of the surface, and inside the protective layer.

The above preferred upper limit and preferred lower limit can be arbitrarily combined. For example, the molecular weight of the ultraviolet absorber (B2) in the present invention can be 150 or more and less than 500. 180 or more and 400 or less are more preferable, and 200 or more and 270 or less are further preferable.

The lower limit of the wavelength indicating the maximum value of the absorbance of the ultraviolet absorber (B2) is not particularly limited. From the viewpoint of complementing the ultraviolet absorbing action of the ultraviolet absorber (B1), it is 320 nm or more, more preferably 330 nm or more, still more preferably 335 nm or more.
On the other hand, the upper limit of the wavelength showing the maximum value of the absorbance is 360 nm or less, more preferably 355 nm or less, still more preferably 350 nm or less.
The above preferred upper limit and preferred lower limit can be arbitrarily combined. For example, the wavelength showing the maximum value of the absorbance of the ultraviolet absorber (B2) in the present invention is 320 nm or more and 360 nm or less. It is more preferably 330 nm or more and 355 nm or less, and further preferably 335 nm or more and 350 nm or less.

Examples of the ultraviolet absorber (B2) include 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- (2'-hydroxy-5'-t-octylphenyl) benzotriazole, and 2,2'. -Methylenebis [6- (benzotriazole-2-yl) -4-tert-octylphenol], 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2 -(2-Hydroxy-5-tert-butylphenyl) -2H-benzotriazole, 2- [5-chloro- (2H) -benzotriazole-2-yl] -4-methyl-6- (tert-butyl) phenol , 2- (2'-Hydroxy-5'-methylphenyl) benzotriazole, and the like. Specifically, ADEKA STAB (registered trademark) LA-24, LA-29, LA-32, LA-36 (product name, manufactured by ADEKA), Tinuvin (registered trademark) P, PS, 99-2, 326, 384. -2, 900, 929 (product name, manufactured by BASF) and other commercially available products can be used.

The structure of the ultraviolet absorber (B2) is not particularly limited, but the compound represented by the following general formula (II) is preferable from the viewpoint of excellent weather resistance and product appearance of the obtained resin molded product.

(In formula (II), R represents a linear or branched alkyl group having 1 to 6 carbon atoms.)

<Manufacturing method of resin composition>
The resin composition of the present invention is produced by mixing a mixture containing the methacrylic resin (A), the ultraviolet absorber (B1), and the ultraviolet absorber (B2).
The mixing method is not particularly limited, and for example, a known melt-kneading method, a known solvent kneading method, a known dry blending method, and the like are used, and the melt-kneading method is preferably used from the viewpoint of productivity. .. As the equipment used for mixing, a normal mixer, a kneader, etc. can be used, and specifically, a uniaxial kneading extruder, a twin-screw kneading extruder, a ribbon blender, a Henschel mixer, a Banbury mixer, a drum tumbler, etc. Can be mentioned.
In the resin composition of the present invention, by using a twin-screw kneading extruder, an ultraviolet absorber (B1) and an ultraviolet absorber (B2) (hereinafter, "ultraviolet absorbers (B1, B2)) are contained in the resin composition. ”) Can be uniformly dispersed without agglomeration, so that the obtained resin laminate has excellent weather resistance and product appearance.
Specifically, a mixture containing the methacrylic resin (A) and the ultraviolet absorbers (B1, B2) is mixed with a twin-screw kneading extruder to have a melting point equal to or higher than the melting point of the methacrylic resin (A) and a melting point of + 100 ° C. It can be obtained as a pellet-shaped resin composition by melting and mixing in the following temperature range.
Using a twin-screw kneading extruder, the temperature at which the mixture containing the methacrylic resin (A) and the ultraviolet absorbers (B1, B2) is melted and mixed is set to a temperature equal to or higher than the melting point of the methacrylic resin (A). By setting the temperature in the melting point + 100 ° C. or lower, deterioration and coloring due to heating of the mixture can be suppressed, so that the transparency of the obtained resin laminate becomes excellent.

The resin composition of the present invention contains various additives such as antioxidants, stabilizers, ultraviolet absorbers, lubricants, processing aids, antistatic agents, colorants, impact-resistant aids, and foaming agents, if necessary. Known additives such as agents, fillers and matting agents may be contained within a range that does not impair the effects of the present invention.

The resin composition of the present invention can be suitably used as a coating material for imparting weather resistance to a resin base material made of a polycarbonate-based resin composition without impairing the appearance of the product.
Therefore, the resin composition of the present invention is suitable as a protective layer for coating a resin base material made of a polycarbonate-based resin composition in applications such as a mobile phone housing, a mobile phone front plate, or an electric / electronic device housing. Can be used.

<Resin laminate>
The resin laminate of the present invention is a resin laminate having a protective film on at least one surface of the resin base material.

In the resin laminate of the present invention, the resin base material is made of a polycarbonate-based resin composition.
Since the resin base material is made of a polycarbonate-based resin composition, the transparency of the obtained resin laminate is excellent.

In the resin laminate of the present invention, a cured film described later is further formed on the surface of the protective film, and the pencil hardness of the surface of the cured film in the resin laminate can be 4H or more.

(Polycarbonate resin composition)
The polycarbonate-based resin composition in the present invention is a material for forming a resin base material of the resin laminate of the present invention, and is a resin composition containing a polycarbonate-based resin described later.
When the polycarbonate-based resin composition contains the polycarbonate-based resin, the resin laminate of the present invention has excellent transparency.

The polycarbonate-based resin composition may be composed of 100% by mass of the polycarbonate-based resin. Alternatively, the polycarbonate-based resin composition can contain 80% by mass or more of the polycarbonate-based resin with respect to the total mass of 100% by mass of the polycarbonate-based resin composition. When the content ratio of the polycarbonate resin is 80% by mass or more, the transparency of the obtained resin laminate can be improved.

The polycarbonate-based resin composition may be used as an impact strength modifier, a mold release agent, an ultraviolet absorber, a polymerization inhibitor, an antioxidant, a flame retardant, a lubricant, a plasticizer, an antistatic agent, and a weather resistance, if necessary. Known additives such as a sex stabilizer, a light-resistant stabilizer, a heat stabilizer, a filler, a pigment, a dye, and a fluorescent agent can be contained within a range that does not impair the effects of the present invention.

(Polycarbonate resin)
The polycarbonate-based resin that can be used as the transparent resin in the present invention is obtained by, for example, reacting a known divalent phenol with a known carbonylating agent by an interfacial polycondensation method, a molten ester exchange method, or the like; Those obtained by polymerizing a known carbonate prepolymer by a solid phase ester exchange method or the like; those obtained by polymerizing a known cyclic carbonate compound by a ring-opening polymerization method and the like can be mentioned.

Commercially available polycarbonate-based resins include Panlite series (trade name, manufactured by Teijin Kasei), Iupiron series (trade name, manufactured by Mitsubishi Engineering Plastics), SD Polyca series (trade name, manufactured by Sumitomo Dow), and Caliber (trade name). Product name, Dow Chemical Co., Ltd.), CZ series and PCZ series (trade name, manufactured by Mitsubishi Gas Chemical Co., Ltd.), APEC series (trade name, manufactured by Bayer Co., Ltd.) and the like can be mentioned.

In the resin laminate of the present invention, the protective film contains the resin composition of the present invention.
By including the resin composition of the present invention in the protective film, the weather resistance and the molded appearance of the obtained resin laminate become excellent for the above-mentioned reasons.

The lower limit of the total thickness of the resin laminate of the present invention is not particularly limited, but can be 100 μm or more from the viewpoint of ensuring sufficient mechanical strength. On the other hand, the upper limit of the thickness is not particularly limited, but can be 3000 μm or less from the viewpoint of molding processability of the resin laminate.

In the resin laminate of the present invention, the thickness of the protective film is not particularly limited, but is 1 to 50% of the total thickness from the viewpoint of improving the weather resistance and product appearance of the resin laminate. Can be.

In the resin laminate of the present invention, the lower limit of the thickness of the resin base material is not particularly limited, but can be 100 μm or more from the viewpoint of ensuring sufficient mechanical strength. On the other hand, the upper limit of the thickness is not particularly limited, but can be 3000 μm or less from the viewpoint of molding processability of the resin laminate.

<Manufacturing method of resin laminate>
The method for producing the resin laminate of the present invention is not particularly limited, and examples thereof include the following methods.

Coextrusion molding method: The polycarbonate-based resin composition is preferably at a temperature 100 to 200 ° C. higher than the glass transition temperature (hereinafter Tg) of the polycarbonate-based resin composition, and the resin composition of the present invention is used for the resin. Each is melt-coextruded at a temperature 100 to 200 ° C. higher than the Tg of the composition, and cooled with a cooling roll at 80 to 160 ° C.

Injection molding method: The polycarbonate-based resin composition is 100 to 200 ° C. higher than the Tg of the polycarbonate-based resin composition, and the resin composition of the present invention is 100 to 200 to Tg of the transparent resin composition. Two-color molding is performed at a high temperature. Alternatively, after arranging one of the molded sheets of the polycarbonate-based resin composition and the transparent resin composition of the present invention previously molded by extrusion molding or injection molding in a mold, the other is injection-molded and integrated. ..

Thermocompression bonding method: A molded sheet of a polycarbonate resin composition previously molded by extrusion molding or injection molding and a molded sheet of the resin composition of the present invention are thermocompression bonded with a laminating machine or a pressing machine. Alternatively, one sheet of the polycarbonate-based resin composition immediately after extrusion and the resin composition of the present invention is thermocompression-bonded to the other sheet previously molded. In this case, the temperature of thermocompression bonding is preferably 100 to 200 ° C. higher than the Tg of the polycarbonate resin composition and the resin composition of the present invention, whichever has the higher Tg.

In addition, the resin laminate of the present invention can be obtained by adhering a preformed molded sheet of a polycarbonate-based resin composition and a molded sheet of the transparent resin composition of the present invention using an adhesive or the like.

<Hardened film>
The resin laminate of the present invention can form a cured film formed by further curing the ultraviolet curable resin composition on the surface of the protective film.
By forming a cured film on the surface of the protective film, the scratch resistance of the obtained resin laminate becomes more excellent. Specifically, it is preferable to form the cured film so that the pencil hardness of the surface of the cured film in the resin laminate is 4H or more.

The value of the pencil hardness can be controlled by appropriately selecting the composition of the resin composition used as the protective film, the composition of the ultraviolet curable composition which is the raw material of the cured film, and the film thickness of the cured film. ..

As the cured film, for example, a cured resin composition obtained by curing a known ultraviolet curable resin composition can be used from the viewpoint of excellent productivity and workability.

The type of the ultraviolet curable resin composition is not particularly limited, but is an acrylic curable resin composition, a polyurethane curable resin composition, a urethane acrylate curable resin composition, and a silicone resin curable resin composition. , At least selected from the group consisting of polyether-based curable resin compositions, polyester-based curable resin compositions, phenol-based curable resin compositions, melamine-based curable resin compositions, and epoxy-based curable resin compositions. One type of curable resin composition is mentioned. The cured resin composition obtained by curing these curable resin compositions is excellent in scratch resistance and transparency, and is also excellent in adhesion to the protective layer.

Among the above-mentioned ultraviolet curable resin compositions, the acrylic curable resin composition is particularly advantageous in that it has excellent adhesion to the protective layer.

Examples of the acrylic curable resin composition include a curable composition containing a polyfunctional acrylate-based compound as a main component (hereinafter, referred to as “polyfunctional acrylate-based curable composition”).
The polyfunctional acrylate-based curable composition is a curable composition containing a compound (c1) having at least two (meth) acryloyl groups in the molecule and a polymerization initiator (c2). Specific examples include those disclosed in paragraphs [0006] and [0007] of JP-A-2005-248070. In addition, for details of the acrylic cured film, reference can be made to paragraphs [0014] to [0033] of the same publication.

In the resin laminate of the present invention, the method for forming a cured film on the surface of the protective film is not particularly limited, but for example, first, an ultraviolet curable composition is applied by using a roll coat, a bar coat, a slit die, or the like. It can be applied to the surface of the protective layer of the resin laminate by using a known application method.
Next, the ultraviolet curable composition applied to the surface of the protective layer is irradiated with ultraviolet rays, and the ultraviolet curable composition is cured to obtain a resin cured product. An ultraviolet lamp can be used as a method of irradiating with ultraviolet rays.
Examples of the ultraviolet lamp include a high-pressure mercury lamp, a metal halide lamp, a fluorescent ultraviolet lamp and the like. Curing by ultraviolet irradiation may be performed in one stage, or curing may be performed in two stages, such as curing in the first stage and then irradiating with ultraviolet rays to perform curing in the second stage. May be. A resin laminate having a cured film formed on the surface of the protective layer can be obtained.

The light to be irradiated in the curing treatment is, for example, an electron beam or an ultraviolet ray, and the type of light to be irradiated and the irradiation conditions are appropriately selected according to the type of the component of the curable composition to be used. Generally, by irradiating ultraviolet rays with an irradiation light amount of about 500 to 2000 mJ / cm ² , it is possible to form a high-strength cured film that contributes to improving the scratch resistance of the resin laminate.

In the resin laminate of the present invention, the thickness of the cured film is not particularly limited, but is usually 0.5 to 50 μm from the viewpoint of achieving both improved durability and optical characteristics of the resin laminate. It may have a thickness of 5 to 40 μm or a thickness of 10 to 30 μm.

<Molded body>
The resin laminate of the present invention is excellent in weather resistance and product appearance. Therefore, the molded product containing the resin laminate of the present invention can be suitably used for a mobile phone housing, a mobile phone front plate, or an electrical / electronic device housing.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples.

<Evaluation method>
The evaluation in Examples and Comparative Examples was carried out by the following method.

(1) Surface hardness As an index of scratch resistance, the pencil hardness of the surface of the protective film of the resin laminate obtained in Examples and Comparative Examples was measured according to ISO 2409: 1992, and the surface hardness was evaluated.
In the comparative example in which the resin laminate did not have a protective film and consisted only of the resin base material, the surface of the resin base material was evaluated.
In the example in which the resin laminate provided with a cured film on the surface of the protective film, the surface of the cured film of the resin laminate was evaluated.

(2) Product appearance As an index of product appearance, the resin laminates obtained in Examples and Comparative Examples are mainly irradiated with the light of a desk lamp (fluorescent lamp 27W) as the resin laminate (resin base material). Visual observation was made from a direction parallel to the plane, and the degree of increase in coloring with respect to the resin substrate of Reference Example 1 was observed, and the determination was made using the following criteria. The results are shown in Table 2.
(criterion)
◯: Almost no increase in coloring was observed on the resin substrate.
Δ: A slight increase in coloring was observed on the resin substrate.
X: A significant increase in coloring was observed on the resin substrate.

(3) Weather resistance As an index of weather resistance, the resin laminates obtained in Examples and Comparative Examples and the resin base material of Production Example 1 were subjected to a super-accelerated weather resistance tester (Iwasaki Electric Co., Ltd. "Ai". Using the Super UV Tester SUV-W161 "), an accelerated weathering test was conducted with the following three steps as one cycle.
(1) UV irradiation step (irradiation intensity: 150 mW / cm ² , temperature: 63 ° C, humidity: 50%) 6 hours (2) condensation step (temperature: 60 ° C, humidity: 90%) 4 hours (3) resting step 2 hours

Next, a test piece having a size of 300 mm in length and 300 mm in width was cut out from the resin laminate (reference example 1 is a resin base material) after the test time of 300 hours, and the light of a desk stand (manufactured by Panasonic, fluorescent lamp 27W) was used in a dark room. The area around the visually observed crack was checked with an oil-based pen while irradiating. The above observation was performed on both sides of the resin laminate (reference example 1 is the resin base material), the total number of cracks in the protective film and the resin base material was measured, and the determination was made using the following criteria. It should be noted that what is measured by this method is the total number of cracks observed in the laminate composed of the protective film and the resin base material. The results are shown in Table 2.
(criterion)
◯: No crack was observed.
Δ: The number of cracks was 1 to 9.
X: The number of cracks was 10 or more.

(raw materials)
The abbreviations of the compounds used in Examples and Comparative Examples are as follows.
Acrylic resin (A-1): Acrypet (registered trademark) VH (trade name, manufactured by Mitsubishi Chemical Corporation, acrylic resin containing 95% by mass or more of repeating units derived from methyl methacrylate, mass average molecular weight: 80,000)
PC resin (1): Polycarbonate resin (Product name: Iupiron S-2000, manufactured by Mitsubishi Engineering Plastics)
Benzotriazole-based UV absorber (B1-1): 2,2-methylenebis [4- (1,1,3,3-tetramethylenebutyl) -6- (2H-benzotriazole-2-yl) phenol], molecular weight 659, wavelength 350 m indicating the maximum value of absorbance (trade name: ADEKA STAB (registered trademark) LA-31RG, manufactured by ADEKA)
Benzotriazole-based ultraviolet absorber (B2-1): 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, molecular weight 225, wavelength 341 nm showing maximum absorbance (trade name: Tinuvin P, manufactured by BASF) )

Hereinafter, an example of the resin composition and the resin laminate of the present invention will be disclosed in Examples.

[Manufacturing Example 1]
Acrylic resin (A-1) 100 parts by mass, benzotriazole ultraviolet absorber (B1-1) 1.5 parts by mass as an ultraviolet absorber (B1), and benzotriazole ultraviolet absorber (B2) as an ultraviolet absorber (B2) B2-1) 0.1 part by mass was supplied to a twin-screw extruder (model name "PCM30", manufactured by Ikegai Co., Ltd.) and kneaded at 250 ° C. to obtain a pellet-shaped methacrylic resin composition. Was used as the resin composition (X-1).

[Manufacturing Examples 2 to 8]
Except for the formulations shown in Table 1, the same operations as in Example 1 were carried out to obtain pellet-shaped methacrylic resin compositions, which were used as resin compositions (X-2) to (X-8), respectively. And said.

[Manufacturing Example 9]
The ultraviolet curable composition (1) used as a raw material for the cured film was produced according to the following procedure.
31.5 parts of a urethane compound obtained by reacting 3 mol of 3-acryloyloxy-2-hydroxypropyl methacrylate with 1 mol of a triisocyanate composed of a hexamethylene diisocyanate trimerate, 6 parts of pentaerythritol triacrylate, and 6 parts of pentaerythritol triacrylate. 4 parts of pentaerythritol tetraacrylate, 58.5 parts of 1,6-hexanediol diacrylate, and 1.5 parts of benzoin ethyl ether as a photopolymerization initiator are mixed and dissolved, and this is used as an ultraviolet curable composition (1). And said.

[Example 1]
The PC resin (1) is used in a single-screw extruder [manufactured by Toshiba Machine Co., Ltd.] with a screw diameter of 60 mm, and the resin composition (X-1) obtained in Production Example 1 is used in a single-screw extruder (Toshiba) with a screw diameter of 40 mm. Each is melted by Machine Co., Ltd., laminated and integrated into two layers by the feed block method, and extruded through a T-shaped die with a set temperature of 280 ° C., and the obtained sheet-like material has a smooth surface. Cooled with a metal roll, a protective layer having a thickness of 50 μm made of a transparent resin composition (X-1) was formed on the surface of a resin base material having a thickness of 1000 μm made of PC resin (1), and having a width of 300 mm. A sheet-shaped resin laminate having a two-layer structure was produced.

Next, the ultraviolet curable composition (1) produced in Production Example 8 was prepared on the surface of the protective layer of the obtained two-layer structure resin laminate using a bar coater so that the film thickness was 27 μm. It was coated to provide a layer of pre-curing coating (1-1).
Next, the resin laminate was passed 20 cm below the high-pressure mercury lamp (output 30 W / cm ² ) at a speed of 10 m / min with the layer of the pre-curing coating (1-1) facing up. The pre-curing coating (1-1) was irradiated with ultraviolet rays of a high-pressure mercury lamp, and the pre-curing coating (1-1) was cured to obtain a cured coating. That is, a sheet-like three-layered resin laminate having a thickness of 1075 μm was obtained by further laminating a cured film having a film thickness of 25 μm on the surface of the resin laminate.
Table 2 shows the evaluation results of the obtained three-layer structure resin laminate.

[Examples 2 to 3, Comparative Examples 1 to 5]
The operation was carried out in the same manner as in Example 1 except that the types of the resin composition used for the protective film were as shown in Table 1, to obtain a sheet-shaped resin laminate having a three-layer structure. Table 2 shows the evaluation results of the obtained three-layer structure resin laminate.

[Reference Example 1]
The PC resin (1) is melted with a single-screw extruder [manufactured by Toshiba Machine Co., Ltd.] having a screw diameter of 60 mm and extruded through a T-shaped die having a set temperature of 280 ° C. It was cooled by a smooth metal roll to produce a sheet-shaped resin base material having a thickness of 1000 μm and a width of 300 mm made of PC resin (1).
Table 2 shows the evaluation results of the obtained sheet-shaped resin base material. The pencil hardness was measured on the surface of the resin base material. The weather resistance was evaluated for the above resin base material.

[Comparative Example 6]
A cured film having a film thickness of 25 μm formed by curing the ultraviolet curable composition (1) produced in Production Example 8 by performing the same operation as in Example 1 on the surface of the resin base material obtained in Reference Example 1. A sheet-like two-layer structure laminated body having a thickness of 1025 μm was obtained. Table 2 shows the evaluation results of the obtained two-layer structure laminate.

The resin laminates obtained in Examples 1 to 3 had good weather resistance and product appearance.

The resin laminate obtained in Comparative Example 1 was inferior in product appearance and weather resistance because the protective film did not contain an ultraviolet absorber (B1) and an ultraviolet absorber (B2).
The resin laminate obtained in Comparative Example 2 had insufficient product appearance and weather resistance because the protective film did not contain an ultraviolet absorber (B1).
The resin laminates obtained in Comparative Examples 3 to 5 had insufficient product appearance and weather resistance because the protective film did not contain an ultraviolet absorber (B2).
The resin base material of Reference Example 1 had a poor pencil hardness because it did not have a cured film. In addition, the weather resistance was inferior.
Since the resin laminate obtained in Comparative Example 6 does not have a protective film, the product appearance and weather resistance were inferior.

The resin composition of the present invention provides weather resistance while maintaining good product appearance when a resin base material made of a polycarbonate-based resin composition is provided with a cured film formed by curing an ultraviolet curable resin composition. It is suitable as a covering material to be applied.
The resin laminate of the present invention is provided with a protective film containing the resin composition of the present invention on the surface of a resin base material made of a polycarbonate-based resin composition, and further, a cured film formed by curing the ultraviolet curable resin composition. In addition to scratch resistance, the product appearance and weather resistance are excellent.
The resin laminate of the present invention can be suitably used for a mobile phone housing, a mobile phone front plate, or an electrical / electronic device housing.

Claims (12)

A resin composition comprising a methacrylic resin (A), a benzotriazole-based ultraviolet absorber (B1) having a molecular weight of 500 or more, and a benzotriazole-based ultraviolet absorber (B2) having a molecular weight of 400 or less. The resin composition according to claim 1, wherein the benzotriazole-based ultraviolet absorber (B1) has a molecular weight of 600 or more. The resin composition according to claim 1 or 2, wherein the benzotriazole-based ultraviolet absorber (B2) has a molecular weight of 270 or less. The resin composition according to any one of claims 1 to 3, wherein the benzotriazole-based ultraviolet absorber (B1) is a compound represented by the following general formula (I).

(In formula (I), R ₁ and R ₂ each independently represent a linear or branched alkyl group having 1 to 16 carbon atoms.) The benzotriazole-based ultraviolet absorber (B1) is 2,2-methylenebis [4- (1,1,3,3-tetramethylenebutyl) -6- (2H-benzotriazole-2-yl) phenol]. The resin composition according to any one of claims 1 to 4. The resin composition according to any one of claims 1 to 5, wherein the benzotriazole-based ultraviolet absorber (B2) is a compound represented by the following general formula (II).

(In formula (II), R represents a linear or branched alkyl group having 1 to 6 carbon atoms.) The resin composition according to any one of claims 1 to 6, wherein the benzotriazole-based ultraviolet absorber (B2) is 2- (2'-hydroxy-5'-methylphenyl) benzotriazole. Any of claims 1 to 7, wherein the content of the benzotriazole-based ultraviolet absorber (B1) is 1.3 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the methacrylic resin (A). The resin composition according to. A laminate in which a protective film is provided in at least a part of a resin base material, wherein the protective film contains the resin composition according to any one of claims 1 to 8. The resin laminate according to claim 9, wherein the resin base material is a polycarbonate-based resin composition. The resin laminate according to claim 9 or 10, wherein at least a part of the protective film is provided with a cured film. A molded product containing the resin laminate according to any one of claims 9 to 11.