WO2013073579A1 - Multilayered resin sheet and molded vessel - Google Patents

Multilayered resin sheet and molded vessel Download PDF

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Publication number
WO2013073579A1
WO2013073579A1 PCT/JP2012/079523 JP2012079523W WO2013073579A1 WO 2013073579 A1 WO2013073579 A1 WO 2013073579A1 JP 2012079523 W JP2012079523 W JP 2012079523W WO 2013073579 A1 WO2013073579 A1 WO 2013073579A1
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Prior art keywords
resin
resin sheet
styrene
ultraviolet absorber
absorber
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PCT/JP2012/079523
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French (fr)
Japanese (ja)
Inventor
洪太 永岡
中里　利勝
小茂田　含
Original Assignee
電気化学工業株式会社
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Application filed by 電気化学工業株式会社 filed Critical 電気化学工業株式会社
Priority to CN201280055646.9A priority Critical patent/CN103930276A/en
Priority to JP2013544297A priority patent/JP6091425B2/en
Publication of WO2013073579A1 publication Critical patent/WO2013073579A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
    • B32B27/302—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising aromatic vinyl (co)polymers, e.g. styrenic (co)polymers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/40—Properties of the layers or laminate having particular optical properties
    • B32B2307/412—Transparent
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/70—Other properties
    • B32B2307/71—Resistive to light or to UV
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2439/00—Containers; Receptacles
    • B32B2439/70—Food packaging
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2439/00—Containers; Receptacles
    • B32B2439/80—Medical packaging

Definitions

  • the present invention generally relates to a multilayer resin sheet, and more particularly to a thermoplastic resin sheet suitable for use in packaging materials in which deterioration of contents due to ultraviolet rays is a problem.
  • the present invention also relates to a molded container formed by molding such a resin sheet.
  • Patent Document 1 proposes a food packaging material containing an unsaturated fatty acid in its contents, to which an inorganic ultraviolet absorbent mainly composed of titanium oxide is added.
  • an inorganic ultraviolet absorbent mainly composed of titanium oxide
  • an organic ultraviolet absorber capable of cutting ultraviolet rays having a wavelength of 380 to 400 nm as the ultraviolet absorber.
  • Patent Document 2 even when an organic ultraviolet absorber is used, there is a problem in health and safety due to precipitation and elution of the ultraviolet absorber into the contents due to migration or the like. Furthermore, when an organic ultraviolet absorber is used, a problem arises in that the mold and the like are contaminated by precipitates of the components during heat molding, and productivity is impaired.
  • the present invention has been made in view of the above circumstances, and a main object of the present invention is to provide a multilayer resin sheet suitable for use as a packaging material in applications where deterioration of contents due to ultraviolet rays is a problem.
  • the present invention uses an organic ultraviolet absorber, it is possible to reliably suppress the alteration, discoloration, deterioration, etc. of the contents, and the transparency is not significantly reduced, and the organic ultraviolet absorber
  • An object of the present invention is to provide a multilayer resin sheet that eliminates the conventional problems caused by the precipitation of slag.
  • Another object of the present invention is to provide a molded container that can be obtained by molding the multilayer resin sheet.
  • an outer layer made of a styrene resin not containing an organic ultraviolet absorber is laminated on both sides of an inner layer made of a styrene resin containing an organic ultraviolet absorber.
  • a multilayer resin sheet is provided.
  • the organic ultraviolet absorbent that can be used for the purpose of the present invention is not limited to a specific one. However, in one embodiment, it can be used for packaging materials such as foods, and ultraviolet light having a wavelength of 380 to 400 nm. Therefore, a benzophenone-based or benzotriazole-based ultraviolet absorber is preferably selected.
  • the addition amount of the organic ultraviolet absorber is preferably 0.1 to 1.0 parts by mass (that is, 0.1 to 1.0 parts by mass with respect to 100 parts by mass of all resin components including the inner layer and the outer layer). To 1.0 PHR), more preferably 0.1 to 0.8 parts by mass (that is, 0.1 to 0.8 PHR).
  • the thickness of the outer layer containing no organic ultraviolet absorber is at least 25 ⁇ m or more, preferably 30 ⁇ m or more, more preferably 35 ⁇ m or more.
  • the multilayer resin sheet has excellent transparency, and its total light transmittance is 60% or more, preferably 70% or more, more preferably 80% or more.
  • a molded container formed by molding the multilayer resin sheet is provided.
  • the molded container is a molded container for packaging contents that may be altered, discolored, deteriorated or the like due to ultraviolet rays, and is preferably required to be transparent so that the contents are visible. is there.
  • the multilayer resin sheet of the present invention contains an organic ultraviolet absorber, it is possible to cut ultraviolet rays having a wavelength of 380 nm to 400 nm, and there is no possibility of poor dispersion or a decrease in transparency.
  • the outer layer does not contain an organic UV absorber, the organic UV absorber does not precipitate and does not contaminate the mold even if a heat molding process is performed using a mold or the like. There is no contamination of the contents due to the precipitation.
  • the multilayer resin sheet includes an inner layer and an outer layer formed on both surfaces of the inner layer.
  • the outer layer is divided into a notch forming side outer layer on which a notch is to be formed and a notch non-forming outer layer on the opposite side, both of which may be formed of the same resin or different resins. May be.
  • the inner layer may be a single layer of a specific resin, but is preferably formed in a plurality of layers using a plurality of different resins. In the case of multiple layers, there are no restrictions on the number of layers, the thickness of each layer, etc., the resin structure is changed between the notch formation side and the notch non-formation side, or one or more types of central layers with different functionality are interposed between them. Can be provided.
  • the resin for the inner layer contains an organic ultraviolet absorber, while the resin for the outer layer does not contain an organic ultraviolet absorber.
  • an organic ultraviolet absorber is contained in at least one of the resins, and preferably, an organic ultraviolet absorber is contained in all the inner layers.
  • the organic ultraviolet absorber is not contained in any outer layer in the resin of the outer layer.
  • a styrene resin is used because of its excellent thermoformability and rigidity.
  • the styrene resin has a normal meaning understood by those skilled in the art, and in addition to the homopolymer of the styrene monomer, a monomer copolymerizable with the styrene monomer is polymerized. Also included are modified resins such as copolymers and rubber-modified styrene resins.
  • styrene monomer examples include styrene, ⁇ -methyl styrene, p-methyl styrene, dimethyl styrene, vinyl toluene, t-butyl styrene, chlorostyrene, and the like, and can be copolymerized with the styrene monomer.
  • Examples of the monomer include acrylic acid, ethyl acrylate, methyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, acrylonitrile, methacrylic acid, ethyl methacrylate, methyl methacrylate, butyl methacrylate, 2-methacrylic acid 2- Examples include ethylhexyl, acrylonitrile, maleic anhydride, N-phenylmaleimide, ethylene, propylene and the like.
  • polystyrene for example, general-purpose polystyrene resin (GPPS), which can be mentioned first as the styrene resin, is the most versatile styrene resin in consideration of transparency and cost.
  • GPPS general-purpose polystyrene resin
  • styrene-based resins include styrene-methyl methacrylate copolymers, styrene-methyl acrylate copolymers, styrene-methacrylic acid copolymers, styrene-acrylic acid copolymers, and styrene-acrylonitrile copolymers.
  • AS resin styrene-N-phenylmaleimide copolymer, and the like.
  • the amount of the styrene monomer in the copolymer is preferably 4 to 95 parts by mass, more preferably 10 to 94 parts by mass, and particularly preferably 20 to 90 parts by mass.
  • the content is high, the bending cracking property when formed into a molded product tends to be inferior, and the splitting property of the molded product due to perforation or the like tends to decrease, and when it is low, the transparency tends to decrease.
  • a rubber-modified styrenic resin can be used as the styrenic resin.
  • This is a polymer in which a rubbery polymer is dispersed in the form of a matrix composed of a normal unmodified styrenic resin.
  • a graft copolymer obtained by polymerizing an aromatic vinyl monomer by a conventional method in the presence of a rubber-like polymer.
  • Examples of the rubbery polymer include diene rubber, polyisoprene, styrene-butadiene copolymer, styrene-isoprene copolymer, butadiene-acrylonitrile copolymer, isobutylene-isoprene copolymer, acrylic rubber, ethylene- ⁇ - Examples include olefin-polyene copolymers, urethane rubber, silicone rubber, butyl rubber, and hydrogenated diene rubber. Such rubber-modified styrenic resins are used to improve impact resistance and buffering properties.
  • styrene resin polystyrene (GPPS), styrene-acrylonitrile copolymer (AS resin), styrene-methyl methacrylate copolymer, acrylonitrile-styrene-methyl methacrylate copolymer, styrene-maleic anhydride Copolymer, high impact polystyrene (HIPS), styrene-acrylonitrile-butadiene copolymer (ABS resin), ⁇ -methylstyrene modified ABS resin, imide modified ABS resin, styrene-methyl methacrylate-butadiene copolymer (MBS) Resin), a resin obtained by graft polymerization of acrylonitrile and styrene on the rubber component, and the like are preferably used.
  • GPPS polystyrene
  • AS resin styrene-acrylonitrile copolymer
  • AS resin styrene-
  • GPPS general-purpose polystyrene resin
  • HIPS impact-resistant polystyrene
  • GPPS General polystyrene resin
  • GPPS is mainly composed of styrene as mentioned above, but o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 1,3-dimethylstyrene as trace components.
  • ⁇ -methylstyrene, vinylnaphthalene, vinylanthracene, 1,1-diphenylethylene and other aromatic vinyl compounds may be used, and commercially available resins may be used.
  • the impact-resistant polystyrene resin specifically refers to a polystyrene resin containing fine-grained graft rubber grafted with a styrenic monomer.
  • rubber components in the graft rubber include 1,3. -Butadiene (butadiene), 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, 2-methylpentadiene, etc.
  • Those using diene rubber as a monomer are preferably used.
  • thermoplastic elastomer of a styrene-conjugated diene block copolymer having a diene component of 50% by mass or more can also be used.
  • polybutadiene and styrene-butadiene block copolymers are preferred.
  • the amount is 96 to 5 parts by mass, preferably 90 to 6 parts by mass, particularly preferably 80 to 10 parts by mass.
  • the average particle diameter of rubber particles of impact-resistant polystyrene (HIPS) is 1.0 ⁇ m or less, preferably 0.8 ⁇ m or less, more preferably 0.5 ⁇ m or less, and the lower limit is 0.01 ⁇ m.
  • HIPS impact-resistant polystyrene
  • the organic ultraviolet absorber used in the present invention is not limited to a specific one as long as it can be used for packaging materials such as food and can cut ultraviolet rays having a wavelength of 380 to 400 nm.
  • a benzophenone-based or benzotriazole-based ultraviolet absorber is preferably selected.
  • a specific thing can also be used for these ultraviolet absorbers individually, and multiple types can also be used together.
  • benzophenone ultraviolet absorber examples include, for example, 2,4-dihydroxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2-hydroxy-4- ( ⁇ -hydroxyethoxy) -benzophenone, bis (5-benzoyl-4-hydroxy-2-methoxyphenyl) methane and the like. Of these, bis (5-benzoyl-4-hydroxy-2-methoxyphenyl) methane is particularly preferable because of its good heat resistance.
  • benzotriazole ultraviolet absorber examples include 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- [3,5-bis (2,2-dimethylpropyl) -2-hydroxyphenyl].
  • Benzotriazole 2- (3-tertiarybutyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-ditertiarybutyl-2-hydroxyphenyl) -5-chlorobenzotriazole 2- [2-hydroxy-3,5-bis ( ⁇ , ⁇ -dimethylbenzyl) phenyl] -2H-benzotriazole, 2,2-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol] and the like.
  • 2- [2-hydroxy-3,5-bis ( ⁇ , ⁇ -dimethylbenzyl) phenyl] -2H-benzotriazole, 2,2-methylenebis [4- (1,1,3,3-tetramethyl) Butyl) -6- (2H-benzotriazol-2-yl) phenol] is particularly preferred because of its good heat resistance.
  • the styrene-based resin includes mineral oil, rosin esters, terpene resins, higher fatty acids, higher fatty acid salts, higher fatty acid amides, antioxidants, antistatic agents, antibacterial agents and the like as long as the effects of the present invention are not impaired. These additives can also be contained.
  • the total thickness of the resin sheet of the present invention is not particularly limited, but may be any thickness that can be used for normal thermoforming such as vacuum forming and vacuum / pressure forming, for example, a thickness of 0.2 to 2.5 mm. it can.
  • the thickness of each outer layer must have a sufficient thickness so that the UV absorber in the inner layer does not precipitate out of the sheet during heat processing, and the notch forming side and the notch forming side In any case, it is at least 25 ⁇ m or more, preferably 30 ⁇ m or more, more preferably 35 ⁇ m or more.
  • the upper limit of the thickness of each outer layer is not particularly limited as long as the total thickness of the resin sheet and the amount of the organic ultraviolet absorber contained are appropriate, and are, for example, 50 ⁇ m or less.
  • the resin sheet of the present invention is formed of a styrene resin as described above, the resin component can be adjusted to have excellent transparency.
  • the total light transmittance of the sheet is 60% or more. , Preferably 70% or more, more preferably 80% or more.
  • the total light transmittance can be measured by a method described in, for example, JIS K-7361-1, K-7105 and the like.
  • the method for producing the multilayer resin sheet of the present invention is not particularly limited, and a general method can be used.
  • the multilayer resin sheet of the present invention is excellent in thermoformability, rigidity, and transparency, so that transparency is required or preferred, and further, for packaging contents that may be altered, discolored, deteriorated, etc. by ultraviolet rays. It is suitably used for forming a molding container.
  • the method of thermoforming the resin sheet of the present invention includes general vacuum forming, pressure forming, and as an application thereof, a plug assist method in which a plug is brought into contact with one side of the sheet, and a pair of both sides of the sheet.
  • a method called so-called match mold molding, which performs molding by bringing the male and female molds forming the contact into contact, is not limited thereto.
  • a known sheet heating method such as radiation heating with an infrared heater or the like which is non-contact heating can be applied.
  • HIPS resin “Toyostyrene H850” (manufactured by Toyo Styrene Co., Ltd., butadiene content: 9.0% by mass)
  • GPPS resin “Toyostyrene G200C” (manufactured by Toyo Styrene Co., Ltd.)
  • Organic ultraviolet absorber A benzotriazole ultraviolet absorber ("Tinuvin P" manufactured by Ciba Specialty Chemicals) was used.
  • Example 1> Using three 40 mm single-screw extruders, the outer layer (organic UV absorber-free styrene resin layer) 35 ⁇ m / inner layer (organic UV absorber-containing styrene resin layer) 680 ⁇ m / A three-layer resin sheet having a thickness of 750 ⁇ m and a layer structure of 35 ⁇ m was manufactured as an outer layer (an organic ultraviolet absorber-free styrene resin layer).
  • HIPS / GPS a mixture of HIPS resin and GPPS resin at a mass ratio of 65/35
  • HIPS / GPS a mass ratio of HIPS resin and GPPS resin
  • the organic ultraviolet absorber was added to the resin mixed with GPPS) so as to have a ratio of 0.3 PHR to 100 parts by mass of all resin components including the inner layer and the outer layer.
  • the ultraviolet transmittance at a wavelength of 380 to 400 mm was measured using a spectrophotometer, and the ultraviolet shielding rate was determined to be 95%.
  • the total light transmittance measured by the method described in JIS K-7105 was 68%.
  • Example 2 Except that the amount of organic ultraviolet absorber added was 0.2 PHR (Example 2), 0.9 PHR (Example 3) and 0.1 PHR (Example 4), the same conditions as in Example 1 were obtained. A three-layer resin sheet was produced, and performance was evaluated for the same characteristics as in Example 1. As for Example 3, although the total light transmittance and film-forming property were slightly inferior, both levels had no practical problems. there were. In Example 4, the ultraviolet shielding rate was inferior, but it was a level with no practical problem.
  • Examples 5 and 6 Three-layer resin sheet under the same conditions as in Example 1 except that the ratio of the two types of styrene resins (HIPS resin and GPPS resin) used for the outer layer and inner layer was changed as described in Table 1. When performance was evaluated for the same characteristics as in Example 1, satisfactory results were obtained.
  • HIPS resin and GPPS resin styrene resins
  • Examples 7 and 8> Except for changing the total thickness as described in Table 1, a three-layer resin sheet was produced under exactly the same conditions as in Example 1, and the performance was evaluated for the same characteristics as in Example 1. Satisfactory results were obtained.
  • Table 1 summarizes the results of Examples 1 to 8 and Comparative Example.
  • surface is as follows.
  • X The occurrence of fumes is observed to some extent in practical use.

Abstract

Disclosed is a multilayered resin sheet which is obtained by laminating a styrene-based resin outer layer not containing an organic UV absorber on both surfaces of a styrene-based resin inner layer containing an organic UV absorber. The organic UV absorber is either a benzophenone or a benzotriazole absorber. If the multilayered resin sheet is used as a packaging material, it is possible to reliably control content denaturation, discoloration, deterioration, and the like, and if the sheet is used as a transparent packaging material in particular, it is possible to obtain a multilayered resin sheet that shows no reduction in transparency. A molded vessel is obtained by molding the multilayered resin sheet.

Description

多層樹脂シート及び成形容器Multilayer resin sheet and molded container
　本発明は、一般に多層樹脂シートに係り、より詳細には、紫外線による内容物の劣化等が問題となる用途の包装材料に用いて好適な熱可塑性樹脂シートに関する。また本発明は、このような樹脂シートを成形してなる成形容器にも関する。 The present invention generally relates to a multilayer resin sheet, and more particularly to a thermoplastic resin sheet suitable for use in packaging materials in which deterioration of contents due to ultraviolet rays is a problem. The present invention also relates to a molded container formed by molding such a resin sheet.
　従来から、食品、化粧品、医薬、医療品などの包装材料においては、包装材料を透過する紫外線によって、内容物が変質、変色、劣化する場合があり、このような不具合を抑制するため、包装材料中に紫外線吸収剤を添加する手段が採られてきた。例えば特許文献１には、内容物に不飽和脂肪酸を含有する食品の包装材として、酸化チタンを主成分とする無機系紫外線吸収剤を添加したものが提案されている。
　しかしながら、無機系紫外線吸収剤を用いた場合、３８０～４００ｎｍの波長の紫外線はカットできない問題や、無機粒子を樹脂中に分散、混合させるので分散不良や透明性が低下するなどの問題があった。 Conventionally, in packaging materials such as foods, cosmetics, pharmaceuticals, and medical products, the contents may be altered, discolored, or deteriorated by ultraviolet rays that pass through the packaging material. Means have been taken to add ultraviolet absorbers therein. For example, Patent Document 1 proposes a food packaging material containing an unsaturated fatty acid in its contents, to which an inorganic ultraviolet absorbent mainly composed of titanium oxide is added.
However, when an inorganic ultraviolet absorber is used, there are problems that ultraviolet rays having a wavelength of 380 to 400 nm cannot be cut, and that inorganic particles are dispersed and mixed in the resin, resulting in poor dispersion and reduced transparency. .
　そこで、紫外線吸収剤として３８０～４００ｎｍの波長の紫外線をカットすることができる有機系紫外線吸収剤を用いることが提案されている。しかしながら、特許文献２に記載されているように、有機系紫外線吸収剤を用いた場合でも、紫外線吸収剤が移行などによって内容物へ析出、溶出することで安全衛生上の問題があった。更に、有機系紫外線吸収剤を用いる場合は、加熱成形時に当該成分の析出物によって金型等が汚染され、生産性が損なわれるという問題も惹起した。 Therefore, it has been proposed to use an organic ultraviolet absorber capable of cutting ultraviolet rays having a wavelength of 380 to 400 nm as the ultraviolet absorber. However, as described in Patent Document 2, even when an organic ultraviolet absorber is used, there is a problem in health and safety due to precipitation and elution of the ultraviolet absorber into the contents due to migration or the like. Furthermore, when an organic ultraviolet absorber is used, a problem arises in that the mold and the like are contaminated by precipitates of the components during heat molding, and productivity is impaired.
特許３６４６１４３号公報Japanese Patent No. 3646143 特開２００７－１６８３５７号公報JP 2007-168357 A
　本発明は、上記事情に鑑みてなされたもので、紫外線による内容物の劣化等が問題となる用途の包装材料に用いて好適な多層樹脂シートを提供することを主たる目的とする。
　また、本発明は、有機系紫外線吸収剤を用いるため、内容物の変質、変色、劣化等を確実に抑制することができる上、透明性を大きく低下させることがなく、しかも有機系紫外線吸収剤の析出等による従来の不具合を解消した多層樹脂シートを提供することを目的とする。
　更に本発明は、上記多層樹脂シートを成形して得ることのできる成形容器を提供することも目的とする。 The present invention has been made in view of the above circumstances, and a main object of the present invention is to provide a multilayer resin sheet suitable for use as a packaging material in applications where deterioration of contents due to ultraviolet rays is a problem.
In addition, since the present invention uses an organic ultraviolet absorber, it is possible to reliably suppress the alteration, discoloration, deterioration, etc. of the contents, and the transparency is not significantly reduced, and the organic ultraviolet absorber An object of the present invention is to provide a multilayer resin sheet that eliminates the conventional problems caused by the precipitation of slag.
Another object of the present invention is to provide a molded container that can be obtained by molding the multilayer resin sheet.
　すなわち、本発明者等は、有機系紫外線吸収剤を添加したスチレン系樹脂シートを製造しようとした場合に、長時間の製膜によりロール汚れが生じてしまうことが分かり、その問題を解消するには、有機系紫外線吸収剤を一定範囲の樹脂表面には配合しないようにすればよいことを知見し、本発明を完成させるに至った。
　よって、本発明の一態様によれば、有機系紫外線吸収剤を含有するスチレン系樹脂製の内部層の両面に、有機系紫外線吸収剤を含有しないスチレン系樹脂製の外部層を積層してなる多層樹脂シートが提供される。 That is, the present inventors have found that when a styrene resin sheet to which an organic ultraviolet absorber is added is manufactured, roll contamination is caused by long-time film formation, and the problem is solved. Has found that the organic ultraviolet absorber should not be added to the resin surface in a certain range, and has completed the present invention.
Therefore, according to one aspect of the present invention, an outer layer made of a styrene resin not containing an organic ultraviolet absorber is laminated on both sides of an inner layer made of a styrene resin containing an organic ultraviolet absorber. A multilayer resin sheet is provided.
　上記態様において、本発明の目的に使用できる有機系紫外線吸収剤は特定のものに限定されるものではないが、一実施態様では、食品等の包装材に使用でき、３８０～４００ｎｍの波長の紫外線をカットすることもできることから、ベンゾフェノン系又はベンゾトリアゾール系の紫外線吸収剤が好適に選択される。また一実施態様では、有機系紫外線吸収剤の添加量は、内部層及び外部層を含む全樹脂成分１００質量部に対して、好ましくは０．１～１．０質量部（すなわち、０．１～１．０ＰＨＲ）の範囲、更に好ましくは０．１～０．８質量部（すなわち、０．１～０．８ＰＨＲ）の範囲とされる。
　他の実施態様では、有機系紫外線吸収剤を含有しない外部層の厚みは、それぞれ、少なくとも２５μｍ以上、好ましくは３０μｍ以上、より好ましくは３５μｍ以上である。
　また更なる実施態様では、多層樹脂シートは優れた透明性を有しており、その全光線透過率は６０％以上、好ましくは７０％以上、より好ましくは８０％以上である。 In the above embodiment, the organic ultraviolet absorbent that can be used for the purpose of the present invention is not limited to a specific one. However, in one embodiment, it can be used for packaging materials such as foods, and ultraviolet light having a wavelength of 380 to 400 nm. Therefore, a benzophenone-based or benzotriazole-based ultraviolet absorber is preferably selected. In one embodiment, the addition amount of the organic ultraviolet absorber is preferably 0.1 to 1.0 parts by mass (that is, 0.1 to 1.0 parts by mass with respect to 100 parts by mass of all resin components including the inner layer and the outer layer). To 1.0 PHR), more preferably 0.1 to 0.8 parts by mass (that is, 0.1 to 0.8 PHR).
In another embodiment, the thickness of the outer layer containing no organic ultraviolet absorber is at least 25 μm or more, preferably 30 μm or more, more preferably 35 μm or more.
In a further embodiment, the multilayer resin sheet has excellent transparency, and its total light transmittance is 60% or more, preferably 70% or more, more preferably 80% or more.
　他の態様によれば、上記多層樹脂シートを成形してなる成形容器が提供される。好ましくは、成形容器は、また紫外線によって変質、変色、劣化等する虞のある内容物を包装するための成形容器であり、好ましくは内容物が視認可能な程度の透明性が要求されるものである。 According to another aspect, a molded container formed by molding the multilayer resin sheet is provided. Preferably, the molded container is a molded container for packaging contents that may be altered, discolored, deteriorated or the like due to ultraviolet rays, and is preferably required to be transparent so that the contents are visible. is there.
　本発明の多層樹脂シートは、有機系紫外線吸収剤を含有しているため、３８０ｎｍ～４００ｎｍの波長の紫外線もカットすることが可能である上、分散不良や透明性の低下の虞はない。また外部層には有機系紫外線吸収剤を含有させていないので、金型等を用いて加熱成形工程を施しても有機系紫外線吸収剤の析出がなく、金型等を汚染することもない上、その析出による内容物の汚染もない。 Since the multilayer resin sheet of the present invention contains an organic ultraviolet absorber, it is possible to cut ultraviolet rays having a wavelength of 380 nm to 400 nm, and there is no possibility of poor dispersion or a decrease in transparency. In addition, since the outer layer does not contain an organic UV absorber, the organic UV absorber does not precipitate and does not contaminate the mold even if a heat molding process is performed using a mold or the like. There is no contamination of the contents due to the precipitation.
　本発明の好適な実施形態では、多層樹脂シートは、内部層と該内部層の両表面に形成される外部層を具備する。外部層は、ノッチが形成されることとなるノッチ形成側外部層と、その反対側のノッチ非形成外部層とに分かれるが、何れも同じ樹脂によって形成してもよいし、異なる樹脂によって形成してもよい。また、内部層は、特定の樹脂の単層であっても構わないが、複数種の異なる樹脂を用いて複層に形成するのが好ましい。複層にする場合、層数や各層の厚み等に制限はなく、ノッチ形成側とノッチ非形成側との間で樹脂構成を変えたり、その間に機能性の異なる一又は複数種の中央層を設けることができる。 In a preferred embodiment of the present invention, the multilayer resin sheet includes an inner layer and an outer layer formed on both surfaces of the inner layer. The outer layer is divided into a notch forming side outer layer on which a notch is to be formed and a notch non-forming outer layer on the opposite side, both of which may be formed of the same resin or different resins. May be. The inner layer may be a single layer of a specific resin, but is preferably formed in a plurality of layers using a plurality of different resins. In the case of multiple layers, there are no restrictions on the number of layers, the thickness of each layer, etc., the resin structure is changed between the notch formation side and the notch non-formation side, or one or more types of central layers with different functionality are interposed between them. Can be provided.
　本発明においては、上記内部層の樹脂には有機系紫外線吸収剤が含有させられる一方、外部層の樹脂には有機系紫外線吸収剤は含有させられない。内部層が複層で構成される場合はその少なくとも一層の樹脂に有機系紫外線吸収剤が含有させられ、好ましくは内部層の全層に有機系紫外線吸収剤が含有させられる。これに対して、外部層の樹脂には、何れの外部層にも有機系紫外線吸収剤は含有させられない。 In the present invention, the resin for the inner layer contains an organic ultraviolet absorber, while the resin for the outer layer does not contain an organic ultraviolet absorber. When the inner layer is composed of a plurality of layers, an organic ultraviolet absorber is contained in at least one of the resins, and preferably, an organic ultraviolet absorber is contained in all the inner layers. On the other hand, the organic ultraviolet absorber is not contained in any outer layer in the resin of the outer layer.
　上記内部層及び上記外部層を構成する樹脂は、その優れた熱成形性及び剛性から、スチレン系樹脂が使用される。ここで、スチレン系樹脂とは、当業者が理解する通常の意味を有し、スチレン系単量体の単独重合体以外に、スチレン系単量体と共重合可能な単量体を重合させた共重合体、ゴム変性スチレン系樹脂等の変性樹脂も包含する。 As the resin constituting the inner layer and the outer layer, a styrene resin is used because of its excellent thermoformability and rigidity. Here, the styrene resin has a normal meaning understood by those skilled in the art, and in addition to the homopolymer of the styrene monomer, a monomer copolymerizable with the styrene monomer is polymerized. Also included are modified resins such as copolymers and rubber-modified styrene resins.
　スチレン系単量体には、例えばスチレン、α－メチルスチレン、ｐ－メチルスチレン、ジメチルスチレン、ビニルトルエン、ｔ－ブチルスチレン、クロロスチレン等が挙げられ、またスチレン系単量体と共重合可能な単量体としては、例えばアクリル酸、アクリル酸エチル、アクリル酸メチル、アクリル酸ブチル、アクリル酸－２－エチルヘキシル、アクリロニトリル、メタクリル酸、メタクリル酸エチル、メタクリル酸メチル、メタクリル酸ブチル、メタクリル酸２－エチルヘキシル、アクリロニトリル、無水マレイン酸、Ｎ－フェニルマレイミド、エチレン、プロプレン等が挙げられる。 Examples of the styrene monomer include styrene, α-methyl styrene, p-methyl styrene, dimethyl styrene, vinyl toluene, t-butyl styrene, chlorostyrene, and the like, and can be copolymerized with the styrene monomer. Examples of the monomer include acrylic acid, ethyl acrylate, methyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, acrylonitrile, methacrylic acid, ethyl methacrylate, methyl methacrylate, butyl methacrylate, 2-methacrylic acid 2- Examples include ethylhexyl, acrylonitrile, maleic anhydride, N-phenylmaleimide, ethylene, propylene and the like.
　よって、スチレン系樹脂として先ず挙げることのできるものは、ポリスチレン、例えば一般用ポリスチレン樹脂（ＧＰＰＳ）であり、これは透明性とコストを加味した最も汎用性の高いスチレン系樹脂である。またスチレン系樹脂として挙げることができるものは、スチレン－メチルメタクリレート共重合体、スチレン－メチルアクリレート共重合体、スチレン－メタクリル酸共重合体、スチレン－アクリル酸共重合体、スチレン－アクリロニトリル共重合体（ＡＳ樹脂）、スチレン－Ｎ－フェニルマレイミド共重合体等である。ここで、共重合体中のスチレン系単量体の量は、好ましくは４～９５質量部、より好ましくは１０～９４質量部、特に好ましくは２０～９０質量部である。含有量が高くなると成形品にしたときの折り曲げ割れ性が劣る傾向やミシン目等による成形品の分割性が低下する傾向が見られ、低くなると透明性が低下する傾向になる。 Therefore, polystyrene, for example, general-purpose polystyrene resin (GPPS), which can be mentioned first as the styrene resin, is the most versatile styrene resin in consideration of transparency and cost. Examples of styrene-based resins include styrene-methyl methacrylate copolymers, styrene-methyl acrylate copolymers, styrene-methacrylic acid copolymers, styrene-acrylic acid copolymers, and styrene-acrylonitrile copolymers. (AS resin), styrene-N-phenylmaleimide copolymer, and the like. Here, the amount of the styrene monomer in the copolymer is preferably 4 to 95 parts by mass, more preferably 10 to 94 parts by mass, and particularly preferably 20 to 90 parts by mass. When the content is high, the bending cracking property when formed into a molded product tends to be inferior, and the splitting property of the molded product due to perforation or the like tends to decrease, and when it is low, the transparency tends to decrease.
　更にスチレン系樹脂として、ゴム変性スチレン系樹脂を使用することができ、これは、通常の未変性のスチレン系樹脂で構成されたマトリックス中にゴム状重合体が粒子状に分散させられた重合体であり、例えばゴム状重合体の存在下、芳香族ビニル単量体を常法によって重合させることによって得られるグラフト共重合体である。ゴム状重合体としては、例えばジエン系ゴム、ポリイソプレン、スチレン－ブタジエン共重合体、スチレン－イソプレン共重合体、ブタジエン－アクリロニトリル共重合体、イソブチレン－イソプレン共重合体、アクリルゴム、エチレン－α－オレフィン－ポリエン共重合体、ウレタンゴム、シリコーンゴム、ブチルゴム、水添ジエン系ゴムが挙げられる。このようなゴム変性スチレン系樹脂は耐衝撃性及び緩衝性を改善するために使用される。 Furthermore, a rubber-modified styrenic resin can be used as the styrenic resin. This is a polymer in which a rubbery polymer is dispersed in the form of a matrix composed of a normal unmodified styrenic resin. For example, a graft copolymer obtained by polymerizing an aromatic vinyl monomer by a conventional method in the presence of a rubber-like polymer. Examples of the rubbery polymer include diene rubber, polyisoprene, styrene-butadiene copolymer, styrene-isoprene copolymer, butadiene-acrylonitrile copolymer, isobutylene-isoprene copolymer, acrylic rubber, ethylene-α- Examples include olefin-polyene copolymers, urethane rubber, silicone rubber, butyl rubber, and hydrogenated diene rubber. Such rubber-modified styrenic resins are used to improve impact resistance and buffering properties.
　上記から、スチレン系樹脂としては、ポリスチレン（ＧＰＰＳ）、スチレン－アクリロニトリル共重合体（ＡＳ樹脂）、スチレン－メタクリル酸メチル共重合体、アクリロニトリル－スチレン－メタクリル酸メチル共重合体、スチレン－無水マレイン酸共重合体、耐衝撃性ポリスチレン（ＨＩＰＳ）、スチレン－アクリロニトリル－ブタジエン共重合体（ＡＢＳ樹脂）、α－メチルスチレン変性ＡＢＳ樹脂、イミド変性ＡＢＳ樹脂、スチレン－メタクリル酸メチル－ブタジエン共重合体（ＭＢＳ樹脂）、ゴム成分にアクリロニトリルとスチレンがグラフト重合した樹脂などが好適に使用される。 From the above, as the styrene resin, polystyrene (GPPS), styrene-acrylonitrile copolymer (AS resin), styrene-methyl methacrylate copolymer, acrylonitrile-styrene-methyl methacrylate copolymer, styrene-maleic anhydride Copolymer, high impact polystyrene (HIPS), styrene-acrylonitrile-butadiene copolymer (ABS resin), α-methylstyrene modified ABS resin, imide modified ABS resin, styrene-methyl methacrylate-butadiene copolymer (MBS) Resin), a resin obtained by graft polymerization of acrylonitrile and styrene on the rubber component, and the like are preferably used.
　これらのスチレン系樹脂のなかでも、一般用ポリスチレン樹脂（ＧＰＰＳ）と耐衝撃性ポリスチレン（ＨＩＰＳ）、及びそれらの混合物が最も好適に使用される。一般用ポリスチレン樹脂（ＧＰＰＳ）は、前述のように単量体としてスチレンが主体であるが、微量成分としてｏ－メチルスチレン、ｐ－メチルスチレン、ｐ－ｔｅｒｔ－ブチルスチレン、１，３－ジメチルスチレン、α－メチルスチレン、ビニルナフタレン、ビニルアントラセン、１，１－ジフェニルエチレン等の芳香族ビニル化合物の１種以上を含有するものであってもよく、市販の樹脂を用いることもできる。また耐衝撃性ポリスチレン樹脂（ＨＩＰＳ）は、詳細には、スチレン系単量体がグラフトした微粒子状のグラフトゴムを含有するポリスチレン樹脂を指すが、グラフトゴム中のゴム成分としては、例えば１，３－ブタジエン（ブタジエン）、２－メチル－１，３－ブタジエン（イソプレン）、２，３－ジメチル－１，３－ブタジエン、１，３－ペンタジエン、１，３－ヘキサジエン、２－メチルペンタジエン等を単量体とするジエン系ゴムが用いられるものが好適に使用される。また、ゴム成分として、ジエン成分が５０質量％以上のスチレン－共役ジエンブロック共重合体の熱可塑性エラストマーを用いることもできる。中でも、ポリブタジエンやスチレン－ブタジエンブロック共重合体が好ましい。 Among these styrene resins, general-purpose polystyrene resin (GPPS), impact-resistant polystyrene (HIPS), and a mixture thereof are most preferably used. General polystyrene resin (GPPS) is mainly composed of styrene as mentioned above, but o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 1,3-dimethylstyrene as trace components. , Α-methylstyrene, vinylnaphthalene, vinylanthracene, 1,1-diphenylethylene and other aromatic vinyl compounds may be used, and commercially available resins may be used. The impact-resistant polystyrene resin (HIPS) specifically refers to a polystyrene resin containing fine-grained graft rubber grafted with a styrenic monomer. Examples of rubber components in the graft rubber include 1,3. -Butadiene (butadiene), 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, 2-methylpentadiene, etc. Those using diene rubber as a monomer are preferably used. As the rubber component, a thermoplastic elastomer of a styrene-conjugated diene block copolymer having a diene component of 50% by mass or more can also be used. Of these, polybutadiene and styrene-butadiene block copolymers are preferred.
　耐衝撃性ポリスチレン（ＨＩＰＳ）を用いる場合、その量は９６～５質量部、好ましくは９０～６質量部、特に好ましくは８０～１０質量部である。含有量が低くなると成形品にしたときの耐衝撃強度が不足する傾向が見られ、高くなると透明性が低下する傾向になる。また、耐衝撃性ポリスチレン（ＨＩＰＳ）のゴム粒子の平均粒子径は１．０μｍ以下、好ましくは０．８μｍ以下、更に好ましくは０．５μｍ以下であり、下限は０．０１μｍである。１．０μｍを越える粒子径の耐衝撃性ポリスチレン（ＨＩＰＳ）を用いた場合、得られたシート及び成形品の透明性の低下（曇りの増大）が大きくなる傾向があり、好ましくない。 When impact-resistant polystyrene (HIPS) is used, the amount is 96 to 5 parts by mass, preferably 90 to 6 parts by mass, particularly preferably 80 to 10 parts by mass. When the content is low, the impact strength when formed into a molded product tends to be insufficient, and when the content is high, the transparency tends to decrease. Moreover, the average particle diameter of rubber particles of impact-resistant polystyrene (HIPS) is 1.0 μm or less, preferably 0.8 μm or less, more preferably 0.5 μm or less, and the lower limit is 0.01 μm. When impact-resistant polystyrene (HIPS) having a particle diameter exceeding 1.0 μm is used, there is a tendency that the decrease in transparency (increase in haze) of the obtained sheet and molded product tends to increase, which is not preferable.
　本発明において用いられる有機系紫外線吸収剤としては、食品等の包装材に使用でき、３８０～４００ｎｍの波長の紫外線をカットすることもできるものであれば、特定のものに限定されるものではないが、ベンゾフェノン系又はベンゾトリアゾール系の紫外線吸収剤が好適に選択される。これら紫外線吸収剤は特定のものを単独で用いることもできるし、複数種を併用することもできる。 The organic ultraviolet absorber used in the present invention is not limited to a specific one as long as it can be used for packaging materials such as food and can cut ultraviolet rays having a wavelength of 380 to 400 nm. However, a benzophenone-based or benzotriazole-based ultraviolet absorber is preferably selected. A specific thing can also be used for these ultraviolet absorbers individually, and multiple types can also be used together.
　ベンゾフェノン系紫外線吸収剤の具体例としては、例えば、２，４－ジヒドロキシベンゾフェノン、２，２’，４，４’－テトラヒドロキシベンゾフェノン、２－ヒドロキシ－４－（β－ヒドロキシエトキシ）－ベンゾフェノン、ビス（５－ベンゾイル－４－ヒドロキシ－２－メトキシフェニル）メタン等が挙げられる。なかでもビス（５－ベンゾイル－４－ヒドロキシ－２－メトキシフェニル）メタンが、耐熱性が良好なため、特に好ましい。 Specific examples of the benzophenone ultraviolet absorber include, for example, 2,4-dihydroxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2-hydroxy-4- (β-hydroxyethoxy) -benzophenone, bis (5-benzoyl-4-hydroxy-2-methoxyphenyl) methane and the like. Of these, bis (5-benzoyl-4-hydroxy-2-methoxyphenyl) methane is particularly preferable because of its good heat resistance.
　またベンゾトリアゾール系紫外線吸収剤の具体例としては、２－（５－メチル－２－ヒドロキシフェニル）ベンゾトリアゾール、２－〔３，５－ビス（２，２－ジメチルプロピル）－２－ヒドロキシフェニル〕ベンゾトリアゾール、２－（３－ターシャリーブチル－５－メチル－２－ヒドロキシフェニル）－５－クロロベンゾトリアゾール、２－（３，５－ジターシャリーブチル－２－ヒドロキシフェニル）－５－クロロベンゾトリアゾール、２－〔２－ヒドロキシ－３，５－ビス（α，α－ジメチルベンジル）フェニル〕－２Ｈ－ベンゾトリアゾール、２，２－メチレンビス〔４－（１，１，３，３－テトラメチルブチル）－６－（２Ｈ－ベンゾトリアゾール－２－イル）フェノール〕等が挙げられる。なかでも、２－〔２－ヒドロキシ－３，５－ビス（α，α－ジメチルベンジル）フェニル〕－２Ｈ－ベンゾトリアゾール、２，２－メチレンビス〔４－（１，１，３，３－テトラメチルブチル）－６－（２Ｈ－ベンゾトリアゾール－２－イル）フェノール〕が、耐熱性が良好なため、特に好ましい。 Specific examples of the benzotriazole ultraviolet absorber include 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- [3,5-bis (2,2-dimethylpropyl) -2-hydroxyphenyl]. Benzotriazole, 2- (3-tertiarybutyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-ditertiarybutyl-2-hydroxyphenyl) -5-chlorobenzotriazole 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2,2-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol] and the like. Among them, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2,2-methylenebis [4- (1,1,3,3-tetramethyl) Butyl) -6- (2H-benzotriazol-2-yl) phenol] is particularly preferred because of its good heat resistance.
　また上記スチレン系樹脂には、本発明の効果を阻害しない範囲において、鉱物油、ロジンエステル類、テルペン樹脂、高級脂肪酸、高級脂肪酸塩、高級脂肪酸アミド、酸化防止剤、帯電防止剤、抗菌剤等の添加剤を含有させることもできる。 In addition, the styrene-based resin includes mineral oil, rosin esters, terpene resins, higher fatty acids, higher fatty acid salts, higher fatty acid amides, antioxidants, antistatic agents, antibacterial agents and the like as long as the effects of the present invention are not impaired. These additives can also be contained.
　本発明の樹脂シートの総厚みは、特に限定されないが、真空成形や真空圧空成形などの通常の熱成形に用いることが可能な厚みであればよく、例えば０．２～２．５ｍｍの厚みとできる。一方、各外部層の厚みは、内部層中の紫外線吸収剤が熱加工時にシート外へ析出することがないように十分な厚みを有していなければならず、ノッチ形成側とノッチ非形成側の何れにおいても、少なくとも２５μｍ以上、好ましくは３０μｍ以上、より好ましくは３５μｍ以上である。各外部層の厚みの上限は、樹脂シートの総厚み、含有される有機系紫外線吸収剤の量が適切ならば、特に制限はなく、例えば５０μｍ以下である。 The total thickness of the resin sheet of the present invention is not particularly limited, but may be any thickness that can be used for normal thermoforming such as vacuum forming and vacuum / pressure forming, for example, a thickness of 0.2 to 2.5 mm. it can. On the other hand, the thickness of each outer layer must have a sufficient thickness so that the UV absorber in the inner layer does not precipitate out of the sheet during heat processing, and the notch forming side and the notch forming side In any case, it is at least 25 μm or more, preferably 30 μm or more, more preferably 35 μm or more. The upper limit of the thickness of each outer layer is not particularly limited as long as the total thickness of the resin sheet and the amount of the organic ultraviolet absorber contained are appropriate, and are, for example, 50 μm or less.
　本発明の樹脂シートは、前述のようにスチレン系樹脂によって形成されるので、優れた透明性を持つように樹脂成分を調整することができ、好ましくは、シートの全光線透過率を６０％以上、好ましくは７０％以上、より好ましくは８０％以上とすることができる。ここで、全光線透過率は、例えばＪＩＳ Ｋ－７３６１－１、Ｋ－７１０５等に記載された方法により測定することができる。 Since the resin sheet of the present invention is formed of a styrene resin as described above, the resin component can be adjusted to have excellent transparency. Preferably, the total light transmittance of the sheet is 60% or more. , Preferably 70% or more, more preferably 80% or more. Here, the total light transmittance can be measured by a method described in, for example, JIS K-7361-1, K-7105 and the like.
　本発明の多層樹脂シートの製造方法は特に限定されず、一般的な方法を用いることができる。例えば複数台の単軸もしくは二軸の押出機で、それぞれの原料樹脂を層状に溶融押出し、フィードブロックとＴダイにより多層樹脂シートを得る方法や、マルチマニホールドダイを使用し多層樹脂シートを得る方法が挙げられる。 The method for producing the multilayer resin sheet of the present invention is not particularly limited, and a general method can be used. For example, a method of obtaining a multilayer resin sheet using a feed block and a T die and a multilayer resin sheet using a multi-manifold die by extruding each raw resin in layers with a plurality of single-screw or twin-screw extruders. Is mentioned.
　本発明の多層樹脂シートは、熱成形性、剛性、透明性に優れるので、透明性が要求されるか又は好まれ、更に紫外線によって変質、変色、劣化等する虞のある内容物を包装するための成形容器の成形に好適に使用される。
　本発明の樹脂シートを熱成形する方法は、一般的な真空成形、圧空成形や、これらの応用として、シートの片面にプラグを接触させて成形を行うプラグアシスト法、また、シートの両面に一対をなす雄雌型を接触させて成形を行う、いわゆるマッチモールド成形と称される方法等が挙げられるが、これらに限定されるものではない。また成形前にシートを加熱軟化させる方法として非接触加熱である赤外線ヒーター等による輻射加熱等、公知のシート加熱方法を適用することができる。 The multilayer resin sheet of the present invention is excellent in thermoformability, rigidity, and transparency, so that transparency is required or preferred, and further, for packaging contents that may be altered, discolored, deteriorated, etc. by ultraviolet rays. It is suitably used for forming a molding container.
The method of thermoforming the resin sheet of the present invention includes general vacuum forming, pressure forming, and as an application thereof, a plug assist method in which a plug is brought into contact with one side of the sheet, and a pair of both sides of the sheet. A method called so-called match mold molding, which performs molding by bringing the male and female molds forming the contact into contact, is not limited thereto. Further, as a method of heating and softening the sheet before molding, a known sheet heating method such as radiation heating with an infrared heater or the like which is non-contact heating can be applied.
　以下、本発明を、実施例を用いてより具体的に説明するが、本発明の範囲がこれら実施例によって限定されるものではない。 Hereinafter, the present invention will be described more specifically using examples, but the scope of the present invention is not limited by these examples.
＜使用原料＞
（１）スチレン系樹脂
　次のＨＩＰＳ樹脂とＧＰＰＳ樹脂を一定の比で混合して用いた。
ＨＩＰＳ樹脂：「トーヨースチロールＨ８５０」（東洋スチレン社製、ブタジエン含量９．０質量％）
ＧＰＰＳ樹脂：「トーヨースチロールＧ２００Ｃ」（東洋スチレン社製）
（２）有機系紫外線吸収剤
　ベンゾトリアゾール系紫外線吸収剤（チバ・スペシャルティ・ケミカルズ社製「チヌビンＰ」）を用いた。 <Raw materials>
(1) Styrenic resin The following HIPS resin and GPPS resin were mixed and used at a certain ratio.
HIPS resin: “Toyostyrene H850” (manufactured by Toyo Styrene Co., Ltd., butadiene content: 9.0% by mass)
GPPS resin: “Toyostyrene G200C” (manufactured by Toyo Styrene Co., Ltd.)
(2) Organic ultraviolet absorber A benzotriazole ultraviolet absorber ("Tinuvin P" manufactured by Ciba Specialty Chemicals) was used.
＜実施例１＞
　３台の４０ｍｍ単軸押出機を使用し、フィードブロック法により、外部層（有機系紫外線吸収剤非含有スチレン系樹脂層）３５μｍ／内部層（有機系紫外線吸収剤含有スチレン系樹脂層）６８０μｍ／外部層（有機系紫外線吸収剤非含有スチレン系樹脂層）３５μｍの層構成を有する厚み７５０μｍの３層樹脂シートを製造した。ここで、外部層には共に、ＨＩＰＳ樹脂とＧＰＰＳ樹脂を質量比６５／３５（ＨＩＰＳ／ＧＰＰＳ）で混合したものを用い、内部層にはＨＩＰＳ樹脂とＧＰＰＳ樹脂を質量比６５／３５（ＨＩＰＳ／ＧＰＰＳ）で混合した樹脂に有機系紫外線吸収剤を、内部層及び外部層を含む全樹脂成分１００質量部に対して０．３ＰＨＲの割合となるように添加した。 <Example 1>
Using three 40 mm single-screw extruders, the outer layer (organic UV absorber-free styrene resin layer) 35 μm / inner layer (organic UV absorber-containing styrene resin layer) 680 μm / A three-layer resin sheet having a thickness of 750 μm and a layer structure of 35 μm was manufactured as an outer layer (an organic ultraviolet absorber-free styrene resin layer). Here, a mixture of HIPS resin and GPPS resin at a mass ratio of 65/35 (HIPS / GPPS) is used for the outer layer, and a mass ratio of HIPS resin and GPPS resin is used for the inner layer of 65/35 (HIPS / GPS). The organic ultraviolet absorber was added to the resin mixed with GPPS) so as to have a ratio of 0.3 PHR to 100 parts by mass of all resin components including the inner layer and the outer layer.
　この３層樹脂シートについて、分光光度計を用いて波長３８０～４００ｍｍの紫外線透過率を測定し、紫外線遮蔽率を求めたところ、９５％であった。一方、ＪＩＳ Ｋ－７１０５に記載された方法により測定した全光線透過率は６８％であった。これらは何れも満足できる結果である。
　また上記３層樹脂シートの製膜性について、溶融押出機を１０時間運転した後の引取ロールの汚れ、ヒューム発生量、目ヤニ発生頻度を調べたところ、何れも満足できる結果が得られた。 With respect to this three-layer resin sheet, the ultraviolet transmittance at a wavelength of 380 to 400 mm was measured using a spectrophotometer, and the ultraviolet shielding rate was determined to be 95%. On the other hand, the total light transmittance measured by the method described in JIS K-7105 was 68%. These are all satisfactory results.
Further, regarding the film formability of the above three-layer resin sheet, the contamination of the take-up roll, the amount of fume generated, and the frequency of generation of eyes after the melt extruder was operated for 10 hours were examined, and satisfactory results were obtained.
＜実施例２～４＞
　有機系紫外線吸収剤の添加量を０．２ＰＨＲ（実施例２）、０．９ＰＨＲ（実施例３）及び０．１ＰＨＲ（実施例４）とした以外は、実施例１と全く同様の条件で、３層樹脂シートを製造し、実施例１と同様の特性について性能を評価したところ、実施例３については、全光線透過率と製膜性が若干劣るものの、何れも実用上問題のないレベルであった。また実施例４は、紫外線遮蔽率が劣るが、実用上問題のないレベルであった。 <Examples 2 to 4>
Except that the amount of organic ultraviolet absorber added was 0.2 PHR (Example 2), 0.9 PHR (Example 3) and 0.1 PHR (Example 4), the same conditions as in Example 1 were obtained. A three-layer resin sheet was produced, and performance was evaluated for the same characteristics as in Example 1. As for Example 3, although the total light transmittance and film-forming property were slightly inferior, both levels had no practical problems. there were. In Example 4, the ultraviolet shielding rate was inferior, but it was a level with no practical problem.
＜実施例５、６＞
　外部層及び内部層に用いた２種類のスチレン系樹脂（ＨＩＰＳ樹脂とＧＰＰＳ樹脂）の比率を表１に記載した通りに変更した以外は、実施例１と全く同様の条件で、３層樹脂シートを製造し、実施例１と同様の特性について性能を評価したところ、いずれも満足できる結果が得られた。 <Examples 5 and 6>
Three-layer resin sheet under the same conditions as in Example 1 except that the ratio of the two types of styrene resins (HIPS resin and GPPS resin) used for the outer layer and inner layer was changed as described in Table 1. When performance was evaluated for the same characteristics as in Example 1, satisfactory results were obtained.
＜実施例７、８＞
　各総厚を表１に記載したとおりに変更した以外は、実施例１と全く同様の条件で、３層樹脂シートを製造し、実施例１と同様の特性について性能を評価したところ、いずれも満足できる結果が得られた。 <Examples 7 and 8>
Except for changing the total thickness as described in Table 1, a three-layer resin sheet was produced under exactly the same conditions as in Example 1, and the performance was evaluated for the same characteristics as in Example 1. Satisfactory results were obtained.
＜比較例＞
　１台の４０ｍｍ単軸押出機を使用し、ＨＩＰＳ樹脂とＧＰＰＳ樹脂を質量比６５／３５（ＨＩＰＳ／ＧＰＰＳ）で混合した樹脂に有機系紫外線吸収剤を０．３ＰＨＲの割合で添加したスチレン系樹脂層（厚み７５０μｍ）の単層樹脂シートを製造した。この樹脂シートについて、実施例１と同様の特性について性能を評価したところ、全光線透過率が実施例１とほぼ同等であり、紫外線遮蔽率が劣るも、実用上問題のないレベルであったが、溶融押出機を１０時間運転した後の引取ロールに汚れが見られ、ヒューム発生量も多く観察され、また目ヤニも発生した。 <Comparative example>
Styrenic resin using one 40mm single-screw extruder and adding organic UV absorber at a ratio of 0.3PHR to a resin in which HIPS resin and GPPS resin are mixed at a mass ratio of 65/35 (HIPS / GPPS) A single-layer resin sheet having a layer (thickness: 750 μm) was produced. When the performance of this resin sheet was evaluated with respect to the same characteristics as in Example 1, the total light transmittance was almost the same as in Example 1, and the ultraviolet shielding rate was inferior, but it was at a level causing no practical problems. After the melt extruder was operated for 10 hours, dirt was observed on the take-up roll, a large amount of fume was observed, and eye cracks were also generated.
　実施例１～８及び比較例の結果をまとめて表１に示す。なお、表中の製膜性に係わる評価の記号は以下のとおりである。
＜ロール汚れ＞
　◎：ロールがほとんど汚れない。
　○：ロールが若干汚れるが実用上問題ない。
　×：ロールが実用上問題がある程度に汚れる。
＜ヒューム発生量＞
　◎：ヒュームの発生がほとんど観察されない。
　○：ヒュームの発生が若干観察されるが実用上問題ない。
　×：ヒュームの発生が実用上問題がある程度に観察される。
<目ヤニ発生頻度＞
　◎：目ヤニがほとんど発生しない。
　○：目ヤニが若干発生するが実用上問題ない。
　×：目ヤニが実用上問題がある程度に発生する。 Table 1 summarizes the results of Examples 1 to 8 and Comparative Example. In addition, the symbol of evaluation regarding the film forming property in a table | surface is as follows.
<Roll dirt>
A: The roll is hardly soiled.
○: The roll is slightly stained but there is no practical problem.
X: The roll is soiled to some extent for practical use.
<Fume generation amount>
A: Fume generation is hardly observed.
○: Fume generation is slightly observed, but there is no practical problem.
X: The occurrence of fumes is observed to some extent in practical use.
<Freaking frequency of eyes>
A: Scars hardly occur.
○: Slight eyes are generated but there is no practical problem.
X: The problem of practical use occurs to some extent.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001

Claims (6)

  1. 　有機系紫外線吸収剤を含有するスチレン系樹脂製の内部層の両面に、有機系紫外線吸収剤を含有しないスチレン系樹脂製の外部層を積層してなる多層樹脂シート。 A multilayer resin sheet in which an outer layer made of a styrene resin not containing an organic ultraviolet absorber is laminated on both sides of an inner layer made of a styrene resin containing an organic ultraviolet absorber.
  2. 　有機系紫外線吸収剤がベンゾフェノン若しくはベンゾトリアゾール系である請求項１に記載の多層樹脂シート。 The multilayer resin sheet according to claim 1, wherein the organic ultraviolet absorber is benzophenone or benzotriazole.
  3. 　有機系紫外線吸収剤の添加量が、内部層及び外部層を含む全樹脂成分１００質量部に対して０．１～１．０質量部である請求項１又は２に記載の多層樹脂シート。 The multilayer resin sheet according to claim 1 or 2, wherein the addition amount of the organic ultraviolet absorber is 0.1 to 1.0 part by mass with respect to 100 parts by mass of all resin components including the inner layer and the outer layer.
  4. 　外部層の厚みが２５μｍ以上である請求項１から３の何れか一項に記載の多層樹脂シート。 The multilayer resin sheet according to any one of claims 1 to 3, wherein the outer layer has a thickness of 25 µm or more.
  5. 　全光線透過率の数値が６０％以上である請求項１から４の何れか一項に記載の多層樹脂シート。 The multilayer resin sheet according to any one of claims 1 to 4, wherein a numerical value of total light transmittance is 60% or more.
  6. 　請求項１から５の何れか一項に記載の多層樹脂シートを成形してなる成形容器。 A molded container formed by molding the multilayer resin sheet according to any one of claims 1 to 5.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015199311A (en) * 2014-04-10 2015-11-12 電気化学工業株式会社 Laminated sheet and container using the same

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000066603A (en) * 1998-08-20 2000-03-03 Fuji Seal Inc Polystyrene-based frost-tone thermal contraction label
JP2002326324A (en) * 2001-05-08 2002-11-12 C I Kasei Co Ltd Ultraviolet absorbing polystyrenic resin heat-shrinkable film
JP2008036849A (en) * 2006-08-02 2008-02-21 Asahi Kasei Chemicals Corp Thermoplastic resin composite sheet

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5530905A (en) * 1978-08-25 1980-03-05 Tokan Kogyo Co Ltd Double layer polysthylene sheet
JP2697097B2 (en) * 1989-03-17 1998-01-14 株式会社生駒化学工業 Multilayer container
JPH11235794A (en) * 1998-02-23 1999-08-31 Daicel Chem Ind Ltd Easily openable container
AU780351B2 (en) * 2000-02-01 2005-03-17 Ciba Specialty Chemicals Holding Inc. Method of content protection with durable UV absorbers
DE10033659A1 (en) * 2000-07-11 2002-01-31 Basell Polyolefine Gmbh Weathering-resistant coextruded multilayer thermoplastic resin film, used for e.g. food packaging, comprises at least one covering layer containing protective pigment
JP2004050460A (en) * 2002-07-17 2004-02-19 Dainippon Printing Co Ltd Inorganic vapor deposited resin film and laminated material using the same
JP4386062B2 (en) * 2006-10-11 2009-12-16 住友化学株式会社 Multi-layer acrylic resin film
JP5237654B2 (en) * 2007-07-06 2013-07-17 出光ユニテック株式会社 Multi-layer sheet, container and package

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000066603A (en) * 1998-08-20 2000-03-03 Fuji Seal Inc Polystyrene-based frost-tone thermal contraction label
JP2002326324A (en) * 2001-05-08 2002-11-12 C I Kasei Co Ltd Ultraviolet absorbing polystyrenic resin heat-shrinkable film
JP2008036849A (en) * 2006-08-02 2008-02-21 Asahi Kasei Chemicals Corp Thermoplastic resin composite sheet

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015199311A (en) * 2014-04-10 2015-11-12 電気化学工業株式会社 Laminated sheet and container using the same

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