JP7338987B2 - Polyvinyl chloride resin composition for light diffusion film - Google Patents

Description

The present invention relates to a polyvinyl chloride resin composition. More specifically, the present invention relates to a polyvinyl chloride resin composition that can be suitably used as a material for light diffusion films.

A surface light source device that functions as a backlight for illuminating a display panel is used in a transmissive image display device such as a liquid crystal image display device. Surface light source devices are used for the purpose of diffusing the light from the light source to hide the image of the light source (concealing and making it inconspicuous), and even when the image is enlarged and projected, the brightness of the edge and the center of the screen is reduced. For the purpose of displaying a good image without any difference in color, a film having light diffusing properties (light diffusing film) is incorporated. The light diffusing film is required to have high light diffusing properties, exhibit sufficient light source hiding properties, and to have high light transmittance and sufficiently high utilization efficiency of light from the light source.

In recent years, due to the demand for energy saving, LEDs (light-emitting diodes) have become popular as light sources, and light-diffusing films are now required to have a higher degree of light-source shielding properties. Therefore, many proposals have been made to improve the performance of the light diffusion film (for example, Patent Document 1). In this technique, it is proposed to use a spherical body containing a crosslinked melamine resin as a light diffusing agent.

However, since last year, the environmental problem of microplastics has increased rapidly, and on January 30, 2019, the European Chemical Agency proposed a regulation proposal (hereinafter referred to as "ECHA (Sometimes abbreviated as “Draft Regulations”) was published and submitted for general consultation. Unlike microplastics added to detergents, which are known to be released into the environment, light diffusing agents are fixed in the film. However, there is an urgent need for business operators to take countermeasures on the assumption that the use of microplastics as light diffusion agents will also be prohibited.

JP 2011-175227 A

An object of the present invention is to provide a polyvinyl chloride-based resin composition capable of obtaining a light diffusing film having good light diffusing properties (light source hiding properties) and light transmittance. Another object of the present invention is to provide a polyvinyl chloride-based resin composition and a light diffusing film thereof, in which the risk of prohibiting the use of microplastics as a diffusing agent is eliminated in accordance with the principle of the draft ECHA regulations. It is in. A further object of the present invention is to provide a polyvinyl chloride resin composition that is less discolored even when calendar roll rolling film formation or T-die extrusion film formation is applied, and light diffusion (light source hiding property) and light To provide a light diffusing film having excellent transparency and good weather resistance.

As a result of intensive research, the present inventors have found that the above-mentioned objects can be achieved with a specific polyvinyl chloride-based resin composition.

That is, aspects of the present invention are as follows.
[1].
(A) 100 parts by mass of polyvinyl chloride resin; and
(C) 10 to 150 parts by mass of barium sulfate having an average particle size of 0.1 to 20 μm;
A resin composition comprising:
[2].
(A) polyvinyl chloride resin 60 to 99.9% by mass; and
(B) 40 to 0.1% by mass of core-shell rubber;
Per 100 parts by mass of the resin mixture consisting of
(C) 10 to 150 parts by mass of barium sulfate having an average particle size of 0.1 to 20 μm;
wherein the sum of the component (A) polyvinyl chloride resin and the component (B) core-shell rubber is 100% by mass; resin composition.
[3].
The resin composition according to item [1] or [2], which does not contain resin fine particles.
[4].
The resin composition according to any one of [1] to [3], further comprising (D) 0.01 to 1 part by mass of titanium oxide.
[5].
The resin composition according to any one of [1] to [4], further comprising (E) 1 to 60 parts by mass of a plasticizer.
[6].
The resin composition according to item [5], wherein the component (E) plasticizer contains a polyester plasticizer, wherein the polyester plasticizer has a polystyrene-equivalent weight average molecular weight of 1,000 or more.
[7].
The resin composition according to any one of [1] to [6], further comprising (F) an ultraviolet absorber.
[8].
The resin composition according to item [7], wherein the (F) UV absorber comprises a benzophenone UV absorber and the anilide oxalate UV absorber.
[9].
The resin composition according to any one of [1] to [8], which is used for a light diffusion film.
[10].
An article comprising the resin composition according to any one of [1] to [9].
[11].
A light diffusing film comprising the resin composition according to any one of [1] to [9].
[12].
The light diffusing film according to item [11], which has a total light transmittance of 80% or more and a light diffusion rate of 20% or more.
[13].
An article comprising the light-diffusing film according to item [11] or [12].
[14].
A method for producing a light diffusing film, comprising a step of forming a film using a calendar roll rolling film forming apparatus using the resin composition according to any one of [1] to [9]. .

A light diffusing film formed using the polyvinyl chloride resin composition of the present invention has good light diffusing properties (light source hiding properties) and light transmittance. In addition, since the polyvinyl chloride resin composition of the present invention uses barium sulfate as a light diffusing agent, the risk of prohibiting the use of microplastics as a light diffusing agent in accordance with the principle of the ECHA regulation draft is eliminated. there is Furthermore, the polyvinyl chloride-based resin composition of the present invention has little discoloration even when calender roll rolling film formation or T-die extrusion film formation is applied, has excellent light diffusion properties (light source hiding properties) and light transparency, and has excellent weather resistance. can obtain a good light diffusing film. Therefore, the light-diffusing film formed using the polyvinyl chloride-based resin composition of the present invention can be suitably used for transmissive image display devices such as liquid crystal image display devices.

In this specification, the term "resin" is used as a term including resin mixtures containing two or more resins and resin compositions containing components other than resins. The term "film" is used herein interchangeably or interchangeably with "sheet." As used herein, the terms "film" and "sheet" are used for those that can be industrially wound into rolls. The term "plate" is used for those that cannot be industrially wound into rolls. Further, in this specification, laminating a certain layer and another layer in order means directly laminating those layers, and interposing one or more layers such as an anchor coat between those layers. lamination.

In this specification, the term "greater than or equal to" regarding a numerical range is used to mean a certain numerical value or more than a certain numerical value. For example, 20% or more means 20% or more than 20%. The term “up to” regarding a numerical range is used to mean a certain numerical value or less than a certain numerical value. For example, 20% or less means 20% or less than 20%. The symbol “~” for numerical ranges is used to mean a certain numerical value, greater than a certain numerical value and less than another numerical value, or some other numerical value. Here, another certain numerical value is assumed to be a larger numerical value than the certain numerical value. For example, 10-90% means 10%, greater than 10% and less than 90%, or 90%. Furthermore, the upper limit and the lower limit of the numerical range can be arbitrarily combined, and embodiments in which they are arbitrarily combined can be read. For example, regarding the numerical range of a certain characteristic, "usually 10% or more, preferably 20% or more. On the other hand, it is usually 40% or less, preferably 30% or less." ~30%." should read that a property is 10-40%, 20-30%, 10-30%, or 20-40% in one embodiment.

Except in the examples or unless otherwise specified, all numerical values used in the specification and claims are to be understood as being modified by the term "about." Without trying to limit the application of the doctrine of equivalents to the claims, each numerical value should be interpreted in the light of significant digits and by applying conventional rounding techniques.

The polyvinyl chloride resin composition of the present invention contains (A) polyvinyl chloride resin; and (C) barium sulfate. In one embodiment, the polyvinyl chloride-based resin composition of the present invention contains (A) polyvinyl chloride-based resin; (B) core-shell rubber; and (C) barium sulfate. In another embodiment, the polyvinyl chloride resin composition of the present invention may further contain (D) titanium oxide. In another embodiment, the polyvinyl chloride resin composition of the present invention may further contain (E) a plasticizer. Each component will be described below.

(A) Polyvinyl chloride resin:
The polyvinyl chloride resin composition of the present invention contains the component (A) polyvinyl chloride resin. Examples of polyvinyl chloride resins that can be used as the component (A) include polyvinyl chloride (vinyl chloride homopolymer); vinyl chloride/vinyl acetate copolymer, vinyl chloride/(meth)acrylic acid copolymer, Vinyl chloride/methyl (meth)acrylate copolymer, vinyl chloride/ethyl (meth)acrylate copolymer, vinyl chloride/maleic acid ester copolymer, vinyl chloride/ethylene copolymer, vinyl chloride/propylene copolymer Copolymer, vinyl chloride/styrene copolymer, vinyl chloride/isobutylene copolymer, vinyl chloride/vinylidene chloride copolymer, vinyl chloride/styrene/maleic anhydride terpolymer, vinyl chloride/styrene/acrylonitrile terpolymer Polymer, vinyl chloride-butadiene copolymer, vinyl chloride-isoprene copolymer, vinyl chloride-chlorinated propylene copolymer, vinyl chloride-vinylidene chloride-vinyl acetate terpolymer, vinyl chloride-acrylonitrile copolymer , Vinyl chloride-based copolymers of vinyl chloride and other monomers copolymerizable with vinyl chloride, such as vinyl chloride and various vinyl ether copolymers; modified (chlorinated, etc.) polymers; and the like. Furthermore, chlorinated polyolefins similar in chemical structure to polyvinyl chloride, such as chlorinated polyethylene, may be used. Among these, polyvinyl chloride (vinyl chloride homopolymer) is preferable from the viewpoint of yellowing resistance. One or a mixture of two or more thereof can be used as the component (A).

(B) Core-shell rubber:
In one embodiment, the polyvinyl chloride-based resin composition of the present invention contains the component (B) core-shell rubber. The above component (B) functions to improve film formability by calender roll rolling. It also works to improve weather resistance and discoloration resistance.

Examples of the component (B) include a methacrylate/styrene/butadiene rubber graft copolymer, a methacrylate/styrene/styrene/butadiene rubber graft copolymer, an acrylonitrile/styrene/butadiene rubber graft copolymer, and acrylonitrile.・Styrene/styrene/butadiene rubber graft copolymer, acrylonitrile/styrene/ethylene/propylene rubber graft copolymer, acrylonitrile/styrene/acrylate rubber graft copolymer, methacrylate/acrylate rubber graft copolymer , a methacrylate/styrene/acrylate rubber graft copolymer, and a methacrylate/acrylonitrile/acrylate rubber graft copolymer. Among them, acrylonitrile/styrene/acrylate rubber graft copolymer, methacrylate/acrylate rubber graft copolymer, methacrylate/styrene/acrylate ester rubber graft copolymer, and methacrylate/styrene/acrylate ester rubber graft copolymer Rubber graft copolymers, acrylic ester rubber graft copolymers such as methacrylic acid ester/acrylonitrile/acrylic acid ester rubber graft copolymers, etc., in which (meth)acrylic acid, acrylonitrile, styrene, etc. are graft copolymerized. Core-shell rubber is preferred. As used herein, "(meth)acrylic acid" means acrylic acid or methacrylic acid. One or a mixture of two or more thereof can be used as the component (B).

In the embodiment containing the component (B), the compounding ratio of the component (B) is such that the sum of the component (A) and the component (B) is 100% by mass, and the calendar roll rolling film formability is improved. from the viewpoint of reliably obtaining the 5% by mass or less), more preferably 1% by mass or more (the above component (A) is 99% by mass or less), still more preferably 4% by mass or more (the above component (A) is 96% by mass or less), still more preferably 7% by mass % or more (93 mass % or less of component (A)), most preferably 10 mass % or more (90 mass % or less of component (A)). On the other hand, from the viewpoint of light transmittance, usually 40% by mass or less (60% by mass or more of component (A)), preferably 30% by mass or less (70% by mass or more of component (A)), more preferably 25% by mass or less (75 mass % or more of component (A)), more preferably 20 mass % or less (80 mass % or more of component (A)).

(C) barium sulfate with an average particle size of 0.1 to 20 μm:
The polyvinyl chloride resin composition of the present invention contains the component (C) barium sulfate having an average particle size of 0.1 to 20 μm. The above component (C) functions to improve the light diffusibility.

The average particle size of the component (C) is usually 0.1 µm or more, preferably 0.5 µm or more, more preferably 1 µm or more, from the viewpoint of reliably obtaining light diffusing properties. On the other hand, from the viewpoint of maintaining a high total light transmittance, the thickness is usually 20 μm or less, preferably 15 μm or less, more preferably 10 μm or less, and even more preferably 7 μm or less.

In this specification, the average particle size of barium sulfate is measured by a laser diffraction/scattering method using a laser diffraction/scattering particle size analyzer. It is the particle diameter that becomes the mass %. As the laser diffraction/scattering particle size analyzer, for example, a laser diffraction/scattering particle size analyzer “MT3200II (trade name)” manufactured by Nikkiso Co., Ltd. can be used.

Examples of the above-mentioned component (C) barium sulfate having an average particle size of 0.1 to 20 μm include pulverized natural minerals (for example, barite) (hereinafter referred to as “elutriated barium sulfate”). precipitated barium sulfate produced by metathesis (typically, the metathesis of barium sulfide and sodium sulfate); Among these, precipitated barium sulfate is preferred from the viewpoint of the appearance (surface smoothness, color tone, etc.) of the light diffusing film.

The above component (C) may contain impurities such as iron, manganese, strontium, calcium, and sulfides as long as they do not contradict the purpose of the present invention. From the viewpoint of the appearance (especially color tone) and weather resistance of the light diffusing film, the above component (C) preferably contains few impurities/high purity.

One or a mixture of two or more thereof can be used as the component (C).

The blending amount of the component (C) is 100 parts by mass of the component (A) (in an embodiment using the component (B), the total of the component (A) and the component (B) is 100 parts by mass). ), from the viewpoint of improving the light diffusibility, it is usually 10 parts by mass or more, preferably 20 parts by mass or more, more preferably 30 parts by mass or more, still more preferably 40 parts by mass or more, most preferably 45 parts by mass Department or above. On the other hand, from the viewpoint of calendar roll rolling film formability and the viewpoint of maintaining a high total light transmittance, the It is below.

(D) Titanium oxide:
The polyvinyl chloride-based resin composition of the present invention may further contain the component (D) titanium oxide, if desired, as long as the object of the present invention is not compromised. The above component (D) functions to develop sufficient light source hiding properties. In recent years, due to the demand for energy saving, LEDs (light emitting diodes) have been widely used as light sources, and light diffusion films are required to have higher light source hiding properties. It is preferable to use the component (D) when a high degree of light source hiding property is to be imparted. The above component (D) also functions as an ultraviolet absorber to improve weather resistance.

The average particle size of component (D) is not particularly limited, but from the viewpoint of dispersibility, it may be usually 2 μm or less, preferably 1 μm or less, more preferably 0.5 μm or less. On the other hand, from the viewpoint of light source concealability, the thickness is usually 0.1 μm or more, preferably 0.2 μm or more.

In the present specification, the average particle size of titanium oxide is defined as a particle size distribution curve measured by a laser diffraction/scattering method using a laser diffraction/scattering particle size analyzer. It is the particle diameter that becomes the mass %. As the laser diffraction/scattering particle size analyzer, for example, a laser diffraction/scattering particle size analyzer “MT3200II (trade name)” manufactured by Nikkiso Co., Ltd. can be used.

The titanium oxide used as the component (D) may be of rutile type or anatase type without any limitation.

One or a mixture of two or more thereof can be used as the component (D).

The amount of component (D) is not particularly limited because it is an optional component. In the embodiment containing the component (D), the amount of the component (D) is 100 parts by mass of the component (A) (in the embodiment containing the component (B), the component (A) and For a total of 100 parts by mass with the component (B)), from the viewpoint of reliably obtaining the effect of improving the light source hiding property, usually 0.01 parts by mass or more, preferably 0.05 parts by mass or more, more preferably 0 .1 parts by mass or more. On the other hand, from the viewpoint of maintaining a high total light transmittance, the good.

(E) plasticizer:
If desired, the polyvinyl chloride resin composition of the present invention may further contain the component (E) plasticizer as long as the object of the present invention is not compromised. The component (E) plasticizer is not particularly limited as long as it is a plasticizer commonly used in polyvinyl chloride resin compositions.

Examples of the plasticizers include phthalate plasticizers, trimellitate plasticizers, pyromellitic ester plasticizers, adipate plasticizers, itaconate plasticizers, and citric ester plasticizers. cyclohexanedicarboxylate-based plasticizers, epoxy-based plasticizers, and the like.

Examples of the plasticizer include polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butanediol, Using 1,5-hexanediol, 1,6-hexanediol, neopentyl glycol, etc., and polyvalent carboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, trimellitic acid, and pimelic acid. , suberic acid, maleic acid, azelaic acid, sebacic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, etc., and if necessary, a monohydric alcohol or monocarboxylic acid as a stopper. be able to.

Examples of the phthalate plasticizer include dibutyl phthalate, butylhexyl phthalate, diheptyl phthalate, di(2-ethylhexyl) phthalate, diisononyl phthalate, diisodecyl phthalate, diundecyl phthalate, ditridecyl phthalate, Examples include dilauryl phthalate, dicyclohexyl phthalate, and dioctyl terephthalate.

Examples of the trimellitate plasticizer include tri(2-ethylhexyl) trimellitate, tri(n-octyl) trimellitate, and tri(isononyl) trimellitate.

Examples of the adipate plasticizer include bis(2-ethylhexyl) adipate, dioctyl adipate, diisononyl adipate, and diisodecyl adipate.

Examples of the epoxy plasticizer include epoxidized soybean oil, epoxidized linseed oil, epoxidized fatty acid octyl ester, and epoxidized fatty acid alkyl ester.

Examples of the above plasticizers include trimellitic acid plasticizers, tetrahydrophthalate diester plasticizers, glycerol ester plasticizers, epoxy hexahydrophthalate diester plasticizers, isosorbide diester plasticizers, and phosphate plasticizers. agent, azelaic acid plasticizer, sebacic acid plasticizer, stearic acid plasticizer, citric acid plasticizer, pyromellitic acid plasticizer, biphenyltetracarboxylic acid ester plasticizer, chlorine plasticizer, etc. I can give

Among these, the polyester plasticizer is preferable as the component (E) from the viewpoint of weather resistance. It is also preferable to use the polyester plasticizer and the epoxy plasticizer in combination.

Polystyrene conversion obtained from a differential molecular weight distribution curve (hereinafter sometimes abbreviated as "GPC curve") measured by gel permeation chromatography (hereinafter sometimes abbreviated as "GPC") of the polyester plasticizer The weight average molecular weight (Mw) is usually 1,000 or more, preferably 2,500 or more, more preferably 3,100 or more, still more preferably 3,500 or more, and even more preferably 4,000 or more, from the viewpoint of weather resistance and suppression of bleeding of the plasticizer. Even more preferably 4500 or more, most preferably 5000 or more. On the other hand, from the viewpoint of the plasticization efficiency of the plasticizer, the mass average molecular weight may be usually 100,000 or less, preferably 50,000 or less, more preferably 10,000 or less.

GPC measurement was performed using a high-performance liquid chromatography system "HLC-8320 (trade name)" manufactured by Tosoh Corporation (a system including a degasser, a liquid feed pump, an autosampler, a column oven and an RI (differential refractive index) detector). ) as GPC columns; Shodex's GPC column "KF-806L (trade name)" two, "KF-802 (trade name)" and "KF-801 (trade name)" each one A total of four tubes are connected in order of KF-806L, KF-806L, KF-802, and KF-801 from the upstream side and used; ) as a mobile phase; the flow rate is 1.0 ml/min, the column temperature is 40° C., the sample concentration is 1 mg/ml, and the sample injection amount is 100 microliters. The amount of elution in each retention volume can be obtained from the amount detected by the RI detector assuming that the refractive index of the sample to be measured does not depend on the molecular weight. In addition, the calibration curve from the retention volume to the polystyrene equivalent molecular weight was obtained using standard polystyrene "EasiCal PS-1 (trade name)" (Plain A molecular weight 6375000, 573000, 117000, 31500, 3480; Plain B with molecular weights of 2517000, 270600, 71800, 10750, 705). As an analysis program, Tosoh Corporation's "TOSOH HLC-8320GPC EcoSEC (trade name)" can be used. For the theory and actual measurement of GPC, refer to reference books such as "Size Exclusion Chromatography, High Performance Liquid Chromatography of Polymers, Author: Sadao Mori, First Edition, First Edition, December 10, 1991" by Kyoritsu Shuppan Co., Ltd. You can refer to it.

FIG. 1 shows the differential molecular weight distribution curve of the following component (E-1) used in Examples. It has oligomer component peak tops at molecular weights of 650, 860, 1100 and 1400, and major component peak tops at molecular weight 5500, and the overall weight average molecular weight is 5200 and the number average molecular weight is 2300.

One or a mixture of two or more thereof can be used as the component (E).

The amount of component (E) is not particularly limited because it is an optional component. In the embodiment containing the component (E), the amount of the component (E) is 100 parts by mass of the component (A) (in the embodiment containing the component (B), the component (A) and With respect to a total of 100 parts by mass with the above component (B)), from the viewpoint of blocking resistance and preventing troubles due to migration of the plasticizer, usually 60 parts by mass or less, preferably 45 parts by mass or less, more preferably It may be 35 parts by mass or less. On the other hand, the lower limit of the amount of component (E) is not particularly specified because it is an optional component, but from the viewpoint of calendar roll rolling film formability, it is usually 1 part by mass or more, preferably 5 parts by mass or more, more preferably 10 parts by mass. It may be at least parts by mass.

(F) UV absorber:
If desired, the polyvinyl chloride resin composition of the present invention may further contain the component (F) ultraviolet absorber as long as the object of the present invention is not compromised. The component (F) functions to improve the weather resistance of the polyvinyl chloride resin composition of the present invention.

As the component (F), an organic compound ultraviolet absorber; zinc oxide, titanium oxide, calcium carbonate, cerium oxide, silica, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, carbon black, white carbon, zeolite, and Inorganic ultraviolet absorbers such as graphite; From the viewpoint of maintaining a high total light transmittance, the component (F) is preferably an organic compound-based ultraviolet absorber.

Examples of the organic compound-based ultraviolet absorbers include benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, triazine-based ultraviolet absorbers, cyanoacrylate-based ultraviolet absorbers, aromatic benzoate-based ultraviolet absorbers, and oxalic acid anilide-based ultraviolet absorbers. Absorbents, malonic acid ester-based UV absorbers, and the like can be mentioned.

Examples of the benzophenone-based ultraviolet absorbers include [2-hydroxy-4-(octyloxy)phenyl](phenyl)methanone, 2,2′,4,4′-tetrahydroxybenzophenone, and 2,2′-dihydroxy -4,4'-dimethoxybenzophenone and the like can be mentioned.

Examples of the benzotriazole-based ultraviolet absorbers include 2-(5-chloro-2H-benzotriazol-2-yl)-4-methyl-6-tert-butylphenol, 2-(2H-benzotriazol-2-yl )-4,6-bis(1-methyl-1-phenylethyl)phenol, 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol, 2 , 2′-methylenebis[6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol], and 2-(2H-benzotriazol-2-yl) -p-cresol and the like.

Examples of the triazine-based ultraviolet absorber include 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[2-(2-ethylhexanoyloxy)ethoxy]phenol, and 2,4,6-tris(2-hydroxy-4-hexyloxy-3-methylphenyl)-1,3,5-triazine.

Examples of the cyanoacrylate ultraviolet absorbers include ethyl-2-cyano-3,3-diphenyl acrylate, 2-ethylhexyl-2-cyano-3,3-diphenyl acrylate, and pentaerythritol tetrakis(3,3-diphenyl -2-cyanoacrylate).

Examples of the aromatic benzoate ultraviolet absorbers include 4-tert-butylphenyl salicylate, 4-octylphenyl salicylate, resorcinol monobenzoate, 2,4-di-tert-butylphenyl-3,5-di-tert-butyl- 4-hydroxybenzoate, hexadecyl-3,5-di-tert-butyl-4-hydroxybenzoate, and the like.

Examples of the oxalic acid anilide-based ultraviolet absorber include 2-ethyl-2'-ethoxyoxanylide and 2-ethoxy-4'-dodecyloxanylide.

Examples of the malonic ester-based ultraviolet absorber include dimethyl [(4-methoxyphenyl)-methylene]propanedioate and tetraethyl-2,2-(1,4-phenylene-dimethylidene)-bismalonate. can be done.

Among these, as the component (F), from the viewpoint of film color tone (little yellowness), the benzophenone-based ultraviolet absorber, the oxalic acid anilide-based ultraviolet absorber, and the malonic acid ester-based ultraviolet absorber. is preferable, and the above oxalic acid anilide-based ultraviolet absorbers and the above-described malonate ester-based ultraviolet absorbers are more preferable.

As the component (F), it is preferable to use the benzophenone ultraviolet absorber and the anilide oxalic acid ultraviolet absorber or/and the malonic ester ultraviolet absorber in combination. The synergistic effect of both can greatly improve the weather resistance. When the benzophenone-based ultraviolet absorber and the oxalic acid anilide-based ultraviolet absorber or/and the malonic acid ester-based ultraviolet absorber are used in combination, the mixing ratio of the two (the amount of the benzophenone-based ultraviolet absorber (parts by mass) / the above The sum of the amount of the oxalic acid anilide-based ultraviolet absorber and the amount of the malonic acid ester-based ultraviolet absorber (parts by mass)) is usually 20/1 to 1/20, preferably 10/1 to 1/10, more preferably may be from 5/1 to 1/5, more preferably from 3/1 to 1/3, most preferably from 2/1 to 1/2.

One or a mixture of two or more thereof can be used as the component (F).

The amount of component (F) is not particularly limited because it is an optional component. In the embodiment containing the component (F), the amount of the component (F) is 100 parts by mass of the component (A) (in the embodiment containing the component (B), the component (A) and From the viewpoint of weather resistance, usually 0.01 parts by mass or more, preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, based on a total of 100 parts by mass with the above component (B). More preferably, it may be 1 part by mass or more. On the other hand, from the viewpoint of suppressing the trouble that the component (F) bleeds out on the film surface, it is usually 10 parts by mass or less, preferably 7 parts by mass or less, more preferably 5 parts by mass or less, and still more preferably 4 parts by mass or less. It can be.

If desired, the polyvinyl chloride resin composition of the present invention may further contain substances commonly used in polyvinyl chloride resin compositions, as long as the objects of the present invention are not compromised. Optional ingredients that may be included include lubricants, antioxidants, weather stabilizers, heat stabilizers, processing aids, nucleating agents, release agents, antistatic agents, urea-formaldehyde wax, and surfactants. agents; inorganic fillers such as calcium carbonate, talc, mica, and clay; The amount of these optional ingredients is not particularly limited since they are optional ingredients. The blending amount of these optional components is 100 parts by mass of component (A) (in an embodiment containing component (B), the total of component (A) and component (B) is 100 parts by mass). ), it may be usually 50 parts by mass or less, preferably 20 parts by mass or less, or usually about 0.01 to 10 parts by mass.

In one preferred embodiment, the polyvinyl chloride-based resin composition of the present invention does not contain fine resin particles. Resin fine particles (typically, a cured resin of an amino compound such as melamine resin and formaldehyde; crosslinked acrylic resin; It is useful from the viewpoint of improving diffusibility. On the other hand, there is a risk that fine resin particles will be banned in the future in accordance with the principle of the proposed ECHA regulations. Therefore, in one preferred embodiment of the present invention, this risk is eliminated by using barium sulfate as a light diffusion agent.

It should be noted here that the "resin fine particles" retain their particle shape even after being melt-kneaded or film-formed at the normal processing temperature of polyvinyl chloride-based resin compositions. That is, like powders such as polyvinyl chloride resins, core-shell rubbers, and acrylic processing aids, polyvinyl chloride resin compositions are melted and integrated into particles by melt-kneading at ordinary processing temperatures. Those that lose their shape are removed from the resin microparticles. Moreover, "not including resin fine particles" means that resin fine particles are not intentionally added. When resin fine particles are used as a light diffusing agent, they are usually added in an amount of 1 part by mass or more per 100 parts by mass of the base resin. It can also be said that the content is usually less than 1 part by mass, preferably 0.1 part by mass or less, and more preferably 0.01 part by mass or less.

The polyvinyl chloride-based resin composition of the present invention is prepared by melt-kneading the components (A), (C), and optional components as desired, simultaneously or in any order, using any melt-kneader. It can be obtained by putting it into a machine and melt-kneading it.

Examples of the melt-kneader include batch kneaders such as pressure kneaders and mixers; extrusion kneaders such as a single-screw extruder, a co-rotating twin-screw extruder, and a counter-rotating twin-screw extruder; calendar roll kneaders; can give Any combination of these may be used.

The resulting composition can be pelletized by any method and then formed into any article by any method. The pelletization can be carried out by methods such as hot cutting, strand cutting, and underwater cutting.

The light-diffusing film of the present invention can be obtained by using the polyvinyl chloride-based resin composition of the present invention and forming a film using any film forming apparatus. Examples of the film forming apparatus include a calendar roll rolling machine and a calendar roll rolling film forming apparatus comprising a take-up device; a T-die film forming apparatus comprising an extruder, a T die, and a take-up device; can give

The light-diffusing film of the present invention can be obtained by using the polyvinyl chloride-based resin composition of the present invention and preferably using a calender roll rolling film forming apparatus. More preferably, it can be obtained by using a calender roll rolling film forming apparatus and forming a film at a roll temperature of 160°C to 200°C.

Examples of the calender roll mill include upright 3-rolls, upright 4-rolls, L-4 rolls, reverse L-4 rolls, and Z-rolls. Examples of the extruder include a single-screw extruder, a co-rotating twin-screw extruder, and a counter-rotating twin-screw extruder. Examples of the T-die include a manifold die, a fishtail die, and a coat hanger die.

The thickness of the light-diffusing film of the present invention is not particularly limited, but may be usually 20 μm or more, preferably 30 μm or more, from the viewpoint of facilitating the expression of light source hiding properties. On the other hand, from the viewpoint of light transmittance, the thickness is usually 200 μm or less, preferably 100 μm or less.

The light diffusing film of the present invention has a total light transmittance of usually 80% or more, preferably 85% or more, more preferably 90% or more, and still more preferably 92% or more, from the viewpoint of utilization efficiency of light from a light source. good. A higher total light transmittance is preferable from the viewpoint of utilization efficiency of light from the light source. Here, the total light transmittance is a value measured according to JIS K 7105:2011, 5.5.2 Measurement method A.

The light diffusion film of the present invention has a light diffusion rate of usually 20% or more, preferably 25% or more, more preferably 30% or more, still more preferably 35% or more, and most preferably 40%, from the viewpoint of light source hiding property. or more. A higher light diffusivity is preferable from the viewpoint of light source concealability. Here, the light diffusivity is a value measured according to the test (b) of the following examples.

FIG. 2 shows the relationship between the light receiving angle and the transmitted light intensity (relative value) in Examples 1 and 13 of the following examples measured using a goniophotometer “GC5000L (trade name)” manufactured by Nippon Denshoku Industries Co., Ltd. Show relationship. Example 1 is an example of a good light source hiding property, but the transmitted light is diffused over a wide light receiving angle and the intensity of the transmitted light is very low near the light receiving angle of 0 degrees. On the other hand, Example 13 is an example of an insufficient light source hiding property, but the transmitted light is concentrated near the light receiving angle of 0 degrees, and the transmitted light intensity near the light receiving angle of 0 degrees is extremely high. It can be seen that the light source hiding property can also be evaluated by comparing the transmitted light intensity near the light receiving angle of 0 degree.

EXAMPLES The present invention will be described below with reference to Examples, but the present invention is not limited to these Examples.

Measurement method (a) Total light transmittance, parallel light transmittance, diffuse transmittance, and haze:
According to JIS K 7105: 2011 5.5.2 Measurement method A, using a spectrophotometer "single beam system haze computer HZ-1 (trade name)" of Suga Test Instruments Co., Ltd., total light transmittance, parallel light Transmittance, diffuse transmittance, and haze were measured. In the table of the results, the values output from the spectrophotometer are listed as they are.

(b) Light diffusivity:
Using Nippon Denshoku Industries Co., Ltd.'s goniophotometer "GC5000L (trade name)", light is incident at a projection angle of 0°, and the transmittance is calculated at intervals of 1° from -85° to 85°. After the reflectance was measured, the light diffusivity was calculated using the program built into the goniophotometer (calculation formula below).
Light diffusivity=( _L20 + _L70 )/(2· _L5 )=( _T20 /cos20°+ _T70 /cos70°)/(2· _T5 /cos5°)
Here, _L20 is the reflectance when the light receiving angle is 20°, _L70 is the reflectance when the light receiving angle is 20°, _L5 is the reflectance when the light receiving angle is 5°, and _T20 is when the light receiving angle is 20°. , _T70 is the transmittance at the light receiving angle of 70°, and _T5 is the transmittance at the light receiving angle of 5°.

(c) Light source hiding property:
Panasonic Corporation's Hf fluorescent lamp (32 watts, three-wavelength neutral white) "FHF32EX-N-H (model)" is turned on, and a light diffusion film is held at a position 5 cm away from the fluorescent lamp. From a position 50 cm away from the fluorescent lamp (the illuminance at this position was 500 lux), the fluorescent lamp was visually observed (both eyes) through the light diffusing film, and evaluated according to the following criteria. The naked eye visual acuity of the examiner was 1.2 for both eyes.
◯: The outline of the fluorescent lamp could not be recognized.
△: The outline of the fluorescent lamp was obscure but could be recognized ×: The outline of the fluorescent lamp was clearly recognized

(d) Weather resistance:
In accordance with JIS Z8722: 2009, using a spectrophotometer "CM600d" of Konita Minolta Japan Co., Ltd., XYZ coordinates are measured under geometric conditions c and conditions including specular reflection components, and L * a * b * By converting to coordinates, the b* value before treatment was determined. Subsequently, using a sunshine carbon arc lamp type weather resistance tester (SWOM) “Sunshine Weather Meter S300 (trade name)” of Suga Test Instruments Co., Ltd. specified in JIS B7753: 2007, the irradiance was measured at 225 W / m ² ( The specifications of the glass filter are type A in the above standard table 2, the irradiance classification is the normal type in the above standard table 3), water spray for 18 minutes every 120 minutes, ambient temperature 43 ° C, black panel temperature 63 ° C, and After processing for 2000 hours under conditions of relative humidity of 50±5%, the b* value after processing was determined according to the method described above. The absolute value (Δb*) of the difference between the b* values before and after the treatment was evaluated according to the following criteria. For the L*a*b* coordinates, the website of Konita Minolta Japan Co., Ltd. (address below) can be referred to.
http://www.konicaminolta.jp/instruments/knowledge/color/part1/07.html
○: Δb * was 10 or less △: Δb * was more than 10 and 20 or less ×: Δb * was more than 20

(e) Heat discoloration resistance:
In accordance with JIS Z8722: 2009, using a spectrophotometer "CM600d" of Konita Minolta Japan Co., Ltd., XYZ coordinates are measured under geometric conditions c and conditions including specular reflection components, and L * a * b * Color coordinates before treatment were obtained by converting to coordinates. Next, after processing for 14 days in a gear oven at 80° C. (humidity was not controlled), the color coordinates after processing were determined in the same manner. From the color coordinates before processing and the color coordinates after processing, the CIELAB color difference was calculated according to JIS Z8781-4:2013, 4.3 color difference, and evaluated according to the following criteria.
O: The color difference is 1 or less.
Δ: The color difference is more than 1 and less than 2.
x: The color difference is 2 or more.

(f) Film formability:
Using an inverted L-type four calendar roll rolling film production device of Nippon Roll Manufacturing Co., Ltd., the first roll temperature is 180 ° C., the second roll temperature is 180 ° C., the third roll is 185 ° C., the fourth roll is 180 ° C., and the winding is performed. The film formability when a film having a thickness of 80 μm was formed at a take-up speed of 60 m/min was evaluated according to the following criteria.
○: Roll peelability, plate-out resistance, and color tone stability were all good △: Roll peelability, plate-out resistance, and color tone stability were at least one of the problems x: Roll peeling There was a big problem with at least one of durability, plate-out resistance, and color tone stability.

(g) Color tone stability:
After melt-kneading for 5 minutes at a temperature of 180° C. and a roll rotation speed of 18 rpm using two 8-inch test rolls, a separate sheet (0.3 mm thick) is taken and further 10 minutes (total After melt-kneading for 15 minutes, a separate sheet (0.3 mm thick) was collected again. In accordance with JIS Z8722: 2009, the color coordinates of the separated sheet obtained in this way are measured using a spectrophotometer "CM600d" manufactured by Konita Minolta Japan Co., Ltd., and the XYZ coordinates are calculated under geometric conditions c and conditions including specular reflection components. was measured and converted to L*a*b* coordinates. Next, the CIELAB color difference between the color coordinates of the separated sheet sampled after melt-kneading for 5 minutes and the color coordinate of the separated sheet sampled after melt-kneading for 15 minutes was determined in accordance with JIS Z8781-4:2013 4.3 color difference. and evaluated according to the following criteria. It can be expected that a film with good color tone can be obtained because the color tone stability of the resin composition is good.
O: The color difference is 1 or less.
Δ: The color difference is more than 1 and less than 2.
x: The color difference is 2 or more.

Raw materials used (A) polyvinyl chloride resin:
(A-1) A polyvinyl chloride homopolymer having a degree of polymerization of 800.

(B) Core-shell rubber:
(B-1) Acrylic core-shell rubber (methacrylate/styrene/acrylate rubber graft copolymer) “METABLEN W-300A (trade name)” manufactured by Mitsubishi Rayon Co., Ltd.

(C) barium sulfate with an average particle size of 0.5 to 10 μm:
(C-1) Precipitated barium sulfate “BMH-40 (trade name)” manufactured by Sakai Chemical Industry Co., Ltd., average particle size 5.0 μm.

(C') resin fine particles:
(C'-1) Nippon Shokubai Co., Ltd.'s microparticles of crosslinked acrylic resin "Eposter MA1002 (trade name)", average particle size 2 μm.

(D) Titanium oxide:
(D-1) Rutile-type titanium oxide “CR-90 (trade name)” manufactured by Ishihara Sangyo Co., Ltd., average particle size 0.25 μm.

(E) plasticizer:
(E-1) Polyester-based plasticizer "ADEKA CIZER PN-280 (trade name)" manufactured by ADEKA Corporation, weight average molecular weight (Mw) 5,200.
(E-2) Epoxyhexahydrophthalate di(2-ethylhexyl) “Sanso Cizer E-PS (trade name)” from Shin Nippon Rika Co., Ltd.;
(E-3) Di(2-ethylhexyl) phthalate.

(F) UV absorber:
(F-1) Benzophenone-based UV absorber ([2-hydroxy-4-(octyloxy)phenyl](phenyl)methanone) “ADEKA STAB 1413 (trade name)” from ADEKA Corporation.
(F-2) Sabo S. p. a. oxalic acid anilide-based UV absorber (2-ethyl-2′-ethoxyoxanylide) “SABOSTAB UV312 (trade name)” from the company.

(G) Other ingredients:
(G-1) Mitsubishi Chemical Corporation's acrylic processing aid "P-530A (trade name)".
(G-2) Barium zinc complex salt stabilizer.
(G-3) Lubricant "ADEKA STAB LS-16 (trade name)" manufactured by ADEKA Corporation.

Examples 1-14
A resin composition having a formulation (parts by mass) shown in Table 1 or 2 was melt-kneaded using a mixer kneader at a discharge resin temperature of 140° C. to obtain a polyvinyl chloride resin composition. Next, using a film forming apparatus equipped with an inverted L-shaped four calendar roll rolling machine and a take-up device manufactured by Nippon Roll Manufacturing Co., Ltd., the first roll temperature was 180 ° C., the second roll temperature was 180 ° C., and the third roll was 185. A film having a thickness of 80 μm was formed under the conditions of 180° C. for the fourth roll, and 60 m/min for take-up speed. The above tests (a) to (g) were performed. The results are shown in Table 1 or 2.

A good film could be formed from the polyvinyl chloride resin composition of the present invention using a calender roll rolling film forming apparatus. The obtained film exhibited good properties as a light diffusing film.

Also, since the light diffusing agent is fixed in the film, it is possible that the use of microplastics as a light diffusing agent will not be prohibited at this time. In this case, the combined use of barium sulfate (density: 4.5 kg/m ³ ) and fine resin particles (the density of the crosslinked acrylic resin used in Example 14 is 1.2 kg/m ³ ) as a light diffusing agent is effective for improving the quality of the article. Example 14 confirmed that it is useful from the viewpoint of weight reduction.

4 is a differential molecular weight distribution curve of the component (E-1) used in Examples. It is the relationship between the light receiving angle and the transmitted light intensity in Examples 1 and 13 of the embodiment.

Claims (13)

(A) 100 parts by mass of polyvinyl chloride resin; and
(C) more than 40 parts by mass and 150 parts by mass or less of barium sulfate having an average particle size of 0.1 to 20 μm;
A resin composition for a light diffusing film comprising:
(A) polyvinyl chloride resin 60 to 99.9% by mass; and
(B) 40 to 0.1% by mass of core-shell rubber;
Per 100 parts by mass of the resin mixture consisting of
(C) more than 40 parts by mass and 150 parts by mass or less of barium sulfate having an average particle size of 0.1 to 20 μm;
including
Here, the sum of the component (A) polyvinyl chloride resin and the component (B) core-shell rubber is 100% by mass;
A resin composition for a light diffusion film .
3. The resin composition according to claim 1 , wherein the content of said component (C) barium sulfate having an average particle size of 0.1 to 20 μm is 45 to 150 parts by mass.
4. The resin composition according to any one of claims 1 to 3 , which does not contain resin fine particles.
5. The resin composition according to any one of claims 1 to 4, further comprising (D) 0.01 to 1 part by mass of titanium oxide.
6. The resin composition according to any one of claims 1 to 5 , further comprising (E) a plasticizer of 1 to 60 parts by mass.
7. The resin composition according to claim 6 , wherein the component (E) plasticizer contains a polyester plasticizer, wherein the polyester plasticizer has a polystyrene-equivalent weight average molecular weight of 1,000 or more.
8. The resin composition according to any one of claims 1 to 7 , further comprising (F) an ultraviolet absorber.
9. The resin composition according to claim 8 , wherein the (F) UV absorber comprises a benzophenone UV absorber and an oxalic acid anilide UV absorber.
A light diffusing film comprising the resin composition according to any one of claims 1 to 9 .
11. The light diffusion film according to claim 10 , which has a total light transmittance of 80% or more and a light diffusion rate of 20% or more.
An article comprising the light-diffusing film according to claim 10 or 11 .
A method for producing a light diffusing film, comprising the step of forming a film using the resin composition according to any one of claims 1 to 9 using a calender roll rolling film forming apparatus.