JPH0461771B2 - - Google Patents

Description

[Detailed description of the invention]

``Object of the Invention'' The present invention relates to an agricultural vinyl chloride resin film. More specifically, the present invention relates to an agricultural vinyl chloride resin film with excellent long-lasting ultraviolet shielding ability. ``Conventional technology'' There has long been a close relationship between plant growth and irradiated light, especially light in the ultraviolet region, and various studies have been conducted on cultivating plants using light quality. There are many known agricultural films used for. In addition, recently, the growth of certain plant pathogenic bacteria, such as Yapophora blight, Sesame leaf blight, Sclerotinia, Botrytis, Anthracnose, Vine blight, Black mold, and Spot bacterium, and the growth of UV rays. It has also been found that there is a close relationship between the wavelength of the region. For example, JP-A-52-98125, JP-A-52-
No. 117738, Special Publication No. 12208, Special Publication No. 53-47383
No., JP-A-53-27539, JP-A-53-136050,
JP-A-53-138844, JP-A-53-138845, JP-A-54-54843, JP-A-54-54844, JP-A-54-
Examples include techniques described in publications such as No. 97233 and Japanese Unexamined Patent Publication No. 55-23920. Furthermore, effects such as promoting plant growth, improving quality, increasing harvest, and yield, and controlling pests and harmful birds have also been found. For example, JP-A-52-43637, JP-A-53
-75039, JP-A-53-98238, JP-A-53-
No. 98242, JP-A-53-107938, JP-A-55-10203
No., JP-A-53-127126, JP-A-53-124556,
JP-A-53-127129, JP-A-53-127130, JP-A-53-138842, JP-A-53-138843, JP-A-53
−138846, JP-A-54-66295, JP-A-54-
No. 85963, JP-A-54-97273, JP-A-54-160630
Examples include techniques described in publications such as JP-A-55-23919, JP-A-55-23921, JP-A-61736, and JP-A-55-96039. On the other hand, vinyl chloride resin films, which are excellent in heat retention, durability, etc., are widely used as agricultural films for cultivating common useful plants. Vinyl chloride resin film has much better durability than polyethylene film or ethylene-vinyl acetate copolymer film, and can be used for about two years. Recently, due to advances in the technology of selecting and combining compounding aids, even vinyl chloride resin films can now exhibit durability for 3 to 5 years. However, from the point of view of the ability of the film to shield light in the ultraviolet region, the reality is that it is still insufficient in terms of sustainability. In other words, the ultraviolet absorber blended into the base vinyl chloride resin film loses its ultraviolet absorption ability (absorption effect) because it evaporates, evaporates, or changes in quality while the film is used as a house or tunnel coating material. The reality is that it cannot be sustained over a long period of time. There is a method of sustaining the ultraviolet shielding effect of the film by selecting the type and amount of the ultraviolet absorber added to the base vinyl chloride film, but this effect is still insufficient. Increasing the amount of ultraviolet absorber added improves the ultraviolet shielding ability of the film, but at the same time, the ultraviolet absorber oozes out onto the film surface, resulting in a significant decrease in transparency during use.
Furthermore, when it is desired to maintain the amount of ultraviolet absorption of the film at a specific value, the amount of ultraviolet absorber to be blended is determined depending on the value to be maintained, so it cannot be increased indefinitely. Depending on the type of ultraviolet absorber, some have excellent sustainability of ultraviolet absorbing ability, but this is still insufficient for practical use. In view of this situation, the present inventors have completed the present invention as a result of intensive studies with the aim of providing an agricultural vinyl chloride resin film with excellent long-lasting ultraviolet shielding ability. be. ``Structure of the Invention'' The gist of the present invention is to add (A) a benzophenone ultraviolet absorber represented by the following general formula () or/and the following general formula () to a vinyl chloride resin.
A benzotriazole ultraviolet absorber represented by [In formulas () and (), R ₁ is an alkyl group having 1 to 18 carbon atoms, R ₂ and R ₃ are hydrogen or an alkyl group having 1 to 18 carbon atoms, and X is hydrogen or a halogen atom. (B) As a raw material, a mixed alcohol containing xylenol, cresol and ethylphenol as main components, in which the composition ratio of xylenol and cresol is in the range of 2/1 to 20/1, and An organic phosphate ester produced using a mixed alcohol containing P-ethylphenol at a composition ratio of 30% by weight or less, (C) the following general formula: [In formula (), R ₄ to R ₇ have 1 to 4 carbon atoms
an alkyl group, R ₈ represents hydrogen or an alkyl group having 1 to 4 carbon atoms. ] A hindered amine compound containing one or more of the structural units shown in each molecule is blended into a film, and an acrylic resin coating with a thickness of 0.5 to 10 microns is formed on one or both sides of the film. An ultraviolet ray shielding agricultural vinyl chloride resin film characterized by: The present invention will be explained in detail below. In the present invention, the vinyl chloride resin includes not only polyvinyl chloride but also copolymers containing vinyl chloride as a main component. Monomers that can be copolymerized with vinyl chloride include vinylidene chloride, ethylene, propylene, acrylonitrile,
Examples include vinyl acetate, maleic acid, itaconic acid, acrylic acid, methacrylic acid, but are not limited to the examples. The vinyl chloride resin may be manufactured by any of the conventionally known manufacturing methods such as suspension polymerization, emulsion polymerization, emulsion-suspension polymerization, solution polymerization, and bulk polymerization. The vinyl chloride resin film according to the present invention includes a benzophenone ultraviolet absorber represented by the following general formula () or/and a benzophenone ultraviolet absorber represented by the following general formula () as component (A) in the above vinyl chloride resin. Contains benzotriazole UV absorbers. [In formulas () and (), R ₁ is carbon number 1
~18 alkyl group, R ₂ and R ₃ are hydrogen or carbon number 1
-18 alkyl group, X represents hydrogen or a halogen atom. ] Specific examples of the compound represented by the above general formula () include 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, and 2-hydroxy-4-benzoyloxybenzophenone. Examples include phenone, 4-dodecyloxy-2-hydroxybenzophenone, and the like. Specific examples of the compound represented by the above general formula () include 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-5min-tert-butylphenyl)-5-chloro Benzotriazole, 2-(2'-hydroxy-5'-tert-butylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-dimethylphenyl)benzotriazole, 2-(2'-hydroxy- 3'-methyl-5'-tert-butylphenyl)benzotriazole, 2-(2'-hydroxy-3',
5'-ditert-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-5'-methoxyphenyl)benzotriazole, 2-(2'-
Hydroxy-5'-phenylphenyl)-5chlorobenzotriazole, 2-(2'-hydroxy-
5'-Phenylphenyl)benzotriazole, 2
-(2'-hydroxy-5'-octoxyphenyl)
Benzotriazole, 2-(2'-hydroxy-
Examples include 3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole. The ultraviolet absorbers represented by the above formula () or () may be blended singly or in combination of two or more. The blending amount of the vinyl chloride resin (A) varies depending on the type of ultraviolet absorber, but it is preferably selected in the range of 0.4 to 5 parts by weight per 100 parts by weight of the resin. The agricultural vinyl chloride resin film according to the present invention contains an organic phosphate ester having a specific composition as the component (B). This organic phosphate ester with a specific composition has the function of plasticizing vinyl chloride resin and improving the weather resistance of the film.
It functions to maintain the ultraviolet absorption ability (absorption effect) of the ultraviolet absorber blended into the film. According to experiments conducted by the present inventors, organic phosphate ester is a mixed alcohol containing xylenol, cresol, and ethylphenol as main components, and has a composition ratio of xylenol and cresol of 2/1 to 20/2. 1, and the composition ratio of P-ethylphenol in the mixed alcohol is 30
Organophosphates prepared using up to % by weight of mixed alcohols have been found to be suitable. That is, it has been found that when the composition of the organic phosphate ester satisfies the above requirements, the effect of sustaining the ultraviolet absorption ability (ultraviolet shielding ability of the film) becomes significant. The above-mentioned organic phosphoric acid ester can be produced by a general method for synthesizing a normal phosphoric acid ester. For example, to a total of 3 moles of mixed alcohol that meets the above requirements, add 2% by weight of aluminum chloride catalyst based on the amount of mixed alcohol, and to this mixture, 1 mole of phosphorus oxychloride is added dropwise at 30°C with stirring, and gradually The hydrogen chloride generated is removed by passing through an external alkali absorption tube.
The reaction was completed by heating at 120°C for 2 hours. After the reaction,
After cooling and adding water to decompose the aluminum chloride catalyst, the oil layer is separated and collected. Next, dilute aqueous soda solution is added to the oil layer and shaken to separate the oil layer.For further purification, the oil layer is distilled to obtain a main fraction at 200-270°C under reduced pressure of 4 mmHg. The main fraction is further passed through an activated carbon packed tower.
The desired organic phosphate ester can be obtained by decolorizing and deodorizing. According to experiments conducted by the present inventors, if the amount of organic phosphoric acid ester (B), which is component (B), is too small, the ultraviolet absorbing ability of the ultraviolet absorber cannot be sustained; It has been found that if it is added too much, the effect will be reduced. The preferred blending amount is 0.5 to 10 parts by weight per 100 parts by weight of vinyl chloride resin.
It has been found that a range of 1 to 5 parts by weight is particularly good. This (B) component is within the above range, (A)
It is preferable to make it proportional to the amount of the ingredients. The agricultural vinyl chloride resin film according to the present invention has the following general formula () as the component (C). [In formula (), R ₄ to _{R 7} represent an alkyl group having 1 to 4 carbon atoms, and R ₈ represents hydrogen or an alkyl group having 1 to 4 carbon atoms. ] A hindered amine compound containing one or more structural units represented by the following in one molecule is blended. This hindered amine compound functions to improve the weather resistance of the vinyl chloride resin film. Specific examples of hindered amine compounds containing one or more structural units represented by the above formula () in one molecule include the following. (1) 4-acetoxy-2,2,6,6-tetramethylpiperidine (2) 4-stearoyloxy-2,2,6,6-
Tetramethylpiperidine (3) 4-acryloyloxy-2,2,6,6-
Tetramethylpiperidine (4) 4-(phenylacetoxy)-2,2,6,6
-tetramethylpiperidine (5) 4-(phenoxyacetoxy)-2,2,6,
6-tetramethylpiperidine (6) 4-cycloheixanoyloxy-2,2,
6,6-tetramethylpiperidine (7) 4-benzoyloxy-2,2,6,6-tetramethylpiperidine (8) 4-(o-chlorobenzoyloxy)-2,
2,6,6-tetramethylpiperidine (9) 4-benzyloxy-2,2,6,6-tetramethylpiperidine (10) 4-(phenylcarbamoyloxy)-2,
2,6,6-tetramethylpiperidine (11) 4-(p-toluenesulfonyloxy)-
2,2,6,6-tetramethylpiperidine (12) 4-(o-toluoyloxy)-2,2,
6,6-tetramethylpiperidine (13) 4-isonicotinoyloxy-2,2,
6,6-tetramethylpiperidine (14) 4-(2-furoyloxy)-2,2,
6,6-tetramethylpiperidine (15) 4-(β-naphthoyloxy)-2,2,
6,6-tetramethylpiperidine (16) Bis(2,2,6,6-tetramethyl-
4-piperidyl) oxalate (17) Bis(2,2,6,6-tetramethyl-
4-Piperidyl) malonate (18) Bis(2,2,6,6-tetramethyl-
4-piperidyl) adipate (19) Bis(2,2,6,6-tetramethyl-
4-Piperidyl) Sebagate (20) Bis(2,2,6,6-tetramethyl-
4-piperidyl) fumarate (21) Bis(2,2,6,6-tetramethyl-
4-Piperidyl)hexahydroterephthalate (22) Bis(2,2,6,6-tetramethyl-
4-piperidyl) terephthalate (23) Tris(2,2,6,6-tetramethyl-4-piperidyl)benzene-1,3,5-tricarboxylate (24) Tris(2,2,6,6-tetramethyl-4-piperidyl)triazine-2,4,6-
tricarboxylate (25) Tris(2,2,6,6-tetramethyl-4-piperidyl)nitrotriacetate (26) Tris(2,2,6,6-tetramethyl-4-piperidyl)butane-1,2,3-tricarboxylate (27) Tetrakis(2,2,6,6-tetramethyl-4-piperidyl)propane-1,1,
2,3-tetracarboxylate (28) Tetrakis(2,2,6,6-tetramethyl-4-piperidyl)butane-1,2,3,
4-tetracarboxylate (29) Tris(2,2,6,6-tetramethyl-4-piperidyl)-2-acetoxypropane-1,2,3-tricarboxylate (30) Tris(2,2,6,6-tetramethyl-4-piperidyl)-2-hydroxypropane-1,2,3-tricarboxylate (31) 1,2,3,4-tetra(4-carbonyloxy-2,2,6,6-tetramethylpiperidine)-butane (32) Tri-(4-acetoxy-2,2,6,
6-tetramethylpiperidine)-amine (33) Tris(2,2,6,6-tetramethyl-4-piperidyl)phosphite (34) 1,3,8-triaza-7,7,9,9
-tetramethyl-2,4-dioxo-spiro[4,5]decane (35) “Tinuvin622” manufactured by Ciba Geigy (36) “Tinuvin144” manufactured by Ciba-Geigy (37) Tetrakis(2,2,6,6-tetramethyl-4-piperidyl)propane-1,1,
3,3-tetracarboxylate (38) “CHIMASSORB944” manufactured by Chisamo Chimica Organica S.B.A. The amount of the hindered amine compound (component (C)) added to the vinyl chloride resin film is not desirable because if it is too small, the weather resistance of the film will not be sufficiently excellent, and if it is too large, the weather resistance of the film will be The properties do not improve in proportion to the amount added, and the problem of spraying out from the film surface occurs. The preferred blending amount is vinyl chloride resin 100%
It ranges from 0.2 to 1.0 parts by weight. As described above, the film according to the present invention includes a vinyl chloride resin as a base, an ultraviolet absorber as a component (A), an organic phosphate as a component (B), and a hindered amine compound as a component (C). However, other resin additives such as plasticizers, lubricants, heat stabilizers, antioxidants, antifogging agents, pigments, dyes, etc. are added as necessary before film formation. can do. Examples of plasticizers that can be used include phthalic acid derivatives such as di-n-octyl phthalate, di-2-ethylhexyl phthalate, dibenzyl phthalate, diisodecyl phthalate, diisodecyl phthalate, didodecyl phthalate, and diundecyl phthalate; Isophthalic acid derivatives such as phthalate; di-n-butyl adipate,
Adipic acid derivatives such as dioctyl adipate; maleic acid derivatives such as di-n-butyl maleate; citric acid derivatives such as tri-n-butyl citrate;
Itaconic acid derivatives such as monobutyl itaconate;
Examples include oleic acid derivatives such as butyl oleate; ricinoleic acid derivatives such as glycerin monoricinoleate; and tricresyl phosphate, epoxidized soybean oil, and epoxy resin plasticizers. Examples of lubricants or heat stabilizers that can be used include polyethylene wax, liquid paraffin, stearic acid, zinc stearate, fatty alkyl, calcium stearate, barium stearate, barium ricinoleate, dibutyltin dilaurate, dibutyltin malate, and the like. It will be done. Antistatic agents or antifogging agents that can be used include:
Nonionic surfactants are mainly preferred; for example, sorbitan surfactants such as sorobitan monostearate, sorbitan monopalmitate, and sorbitan monobenzoate; glycerin monolaurate, diglycerin monopalmitate, and glycerin monostearate. Glycerin surfactant; polyethylene glycol monostearate,
Examples include polyethylene glycol surfactants such as polyethylene glycol monopalmitade; alkylene oxide adducts of alkylphenols; esters of sorbitan/glycerin condensates and organic acids, and the like. These surfactants can be used alone or in combination of two or more. These various resin additives are added in the usual amount, for example, plasticizers are added in amounts up to 80 parts by weight per 100 parts by weight of vinyl chloride resin, and in the range of 30 to 80 parts by weight for soft formulations. The additives to be excluded can be selected within a range of 5 parts by weight or less. Component (A) or
To blend component (C) and, if necessary, other resin additives, use conventional blending and mixing techniques, such as using a ribbon blender, Banbury mixer, super mixer, or other compounding machine or mixer. I can do it. In order to produce the film according to the present invention, components (A) to (C) are added to a vinyl chloride resin as a base.
Furthermore, if necessary, the composition containing various resin additives is formed into a film by a film forming technique known per se. Known film forming techniques include:
Examples include a calendar molding method, a T-die extrusion method, an inflation molding method, and a solution casting method. The film may be a transparent film, a matte film, a semi-matte film, or the like. The thickness of the film according to the present invention is 0.075 to 0.2 mm.
The range shall be . In the agricultural vinyl chloride resin film according to the present invention, an acrylic resin coating is formed on one or both sides of a base film. In the present invention, the acrylic resin refers to 5 to 40% by weight of hydroxyalkyl (meth)acrylate,
A polymer obtained by copolymerizing 0 to 20% by weight of an α,β-unsaturated carboxylic acid compound containing one or more carboxyl groups in the molecule and another vinyl compound that can be copolymerized with these compounds. It means merging. Hydroxyalkyl (meth)acrylates include hydroxymethyl acrylate, hydroxymethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate,
2-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl acrylate, 4-
Examples include hydroxybutyl methacrylate, 2-hydroxypentyl acrylate, 2-hydroxypentyl methacrylate, 6-hydroxyhexyl acrylate, and 6-hydroxyhexyl methacrylate. These hydroxyalkyl (meth)acrylate compounds make the resulting acrylic resin easily soluble in organic solvents, improve the adhesion between the acrylic resin and the base vinyl chloride resin film, and furthermore cause them to ooze out onto the film surface. It is a component that greatly contributes to the effect of suppressing the migration of plasticizers. The proportion of this hydroxyalkyl (meth)acrylate in the acrylic resin is 5% by weight.
If the amount is less, the solubility with the organic solvent, the adhesion with the base film, and the effect of inhibiting plasticizer migration may not be sufficiently exhibited, which is not preferable. On the other hand, if it is more than 40% by weight, the cost will increase and the effect obtained will not be large compared to the increased cost, which is not preferable. Examples of α,β-unsaturated carboxylic acid compounds containing one or more carboxyl groups in the molecule include acrylic acid, methacrylic acid, itaconic acid, maleic acid, aconitic acid, and crotonic acid. When these compounds are used in combination with the above-mentioned hydroxyalkyl (meth)acrylates, they improve the adhesion between the acrylic resin and the vinyl chloride resin film, and have the effect of suppressing the tendency for the films to stick to each other (blocking). Demonstrate. The amount of these compounds used is up to 20% by weight. If it is more than this, the property of the films adhering to each other when the film is moistened with water (blocking property when wet) will be strengthened, which is not preferable. Other vinyl compounds that can be copolymerized with the above formulation include methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, and the like. These compounds play a role in improving the flexibility of the film and the adhesion to the base vinyl chloride resin. The acrylic resin used to form a coating on one or both sides of a vinyl chloride resin film is prepared by combining a predetermined amount of the above monomers together with an organic solvent, and adding a polymerization initiator and, if necessary, a molecular weight regulator. can be added and heated while stirring to polymerize. The acrylic resin coating formed on one or both sides of the vinyl chloride resin film is preferably applied by dissolving the acrylic resin in an organic solvent. The organic solvent for dissolving the acrylic resin may be the same as the solvent used in producing the acrylic resin. Specifically, alcohols are preferred, such as methanol, ethanol, n-
Propanol, isopropanol, n-butanol, sec-butanol, tert-butanol, n-
amyl alcohol, isoamyl alcohol, tert
-amyl alcohol, n-hexyl alcohol,
Examples include cyclohexanol. In addition to the above alcohols, ethyl acetate, methyl ethyl ketone, tetrahydrofuran, hexane, toluene,
Xylene, chloroform, etc. can also be used. These may be used alone or in combination of two or more. In order to form a film of the acrylic resin on one or both sides of a vinyl chloride resin film, the acrylic resin is dissolved in the above organic solvent and then spray coated, roll coated, gravure coated, reverse coated, or dip coated. It is preferable to apply the coating by various coating methods known per se, such as screen printing method, flexographic printing method, etc., and dry it. Available drying methods include, for example, hot air drying method,
These include infrared drying method, far-infrared drying method, etc. The drying temperature is preferably a temperature at which the organic solvent is dispersed, that is, a temperature higher than the boiling point of the organic solvent in which the acrylic resin is dissolved. The shorter the drying time, the better. Therefore, it is preferable to dry at a temperature higher than the boiling point of the organic solvent and in as short a time as possible. The thickness of the acrylic resin coating formed on the surface of the base film depends on the thickness of the base film, but
Choose from a range of 0.5 to 10 microns. When it is thicker than 10 microns, there is a difference in flexibility between the base film and the coating, so phenomena such as the coating peeling off from the base film are likely to occur, and cracks may occur in the coating, reducing the strength of the base film. This is an undesirable phenomenon. If it is thinner than 0.5 micron, it is not preferable because it does not have the effect of improving the weather resistance of the base film. The thickness of the coating is preferably within the above range and proportional to the thickness of the base film. When the agricultural vinyl chloride resin film according to the present invention is actually used, when the coating is formed on only one side, the side on which this coating is provided will be the outside of the house or tunnel. It is best to expand it in this way. "Effects of the Invention" The agricultural vinyl chloride resin film according to the present invention has the above-mentioned effects, and has particularly remarkable effects as described below, and its industrial utility value is extremely large. (1) The agricultural vinyl chloride resin film according to the present invention includes a base film containing an ultraviolet absorber as the component (A), an organic phosphate as the component (B), and a hindered amine compound as the component (C). is added, so the ultraviolet absorption ability of the ultraviolet absorber (ultraviolet shielding ability of the film) is maintained for a long period of time. (2) The agricultural vinyl chloride resin film according to the present invention has component (A), component (B), and component (C) blended into the base film, and the surface of the film is made of acrylic resin which itself has excellent weather resistance. Since it is coated with resin, it can withstand long-term use. (3) The agricultural vinyl chloride resin film according to the present invention suppresses the exudation of component (A), component (B), component (C), plasticizer, and other resin additives blended into the base film. I can do it. Therefore, since the surface does not become dirty for a long period of time, the film transmits wavelengths in the visible range and above at a high rate for a long period of time, and is suitable for covering agricultural greenhouses. "Examples" Hereinafter, the present invention will be described in detail based on Examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof. Examples 1 to 6, Comparative Examples 1 to 10 (1) Preparation of base film Polyvinyl chloride (=1400) 1000 parts by weight Dioctyl phthalate 45 Epoxy resin (trade name "EP-828")
1. Barium-zinc composite stabilizer 1.5. Barium stearate 0.2. Zinc stearate 0.4. Sorbitan monostearate 1.5. Ethylene bisstearamide 0.1. The agent [component (A)], the organic phosphate ester [component (B)] (the composition of the raw material mixed alcohol is shown in the same table), and the hindered amine compound [component (C)] are shown in the same table. They were mixed in the following proportions. This composition was processed using a calendar molding machine to give a thickness of
A 0.1mm film was used. (2) Formation of film In a polymerization can, add 150 parts by weight of isopropyl alcohol, 20 parts by weight of 2-hydroxyethyl methacrylate, 10 parts by weight of acrylic acid, and methyl methacrylate.
Add 40 parts by weight and 30 parts by weight of ethyl methacrylate, add 0.5 parts by weight of benzoyl peroxide,
Polymerization reaction was carried out at 80°C for 10 hours under a nitrogen gas stream. Isopropyl alcohol was added to the obtained copolymer solution to adjust the solid content to 20% by weight to prepare a coating material. After applying the coating material to one side of the base film by gravure coating, it was allowed to stay in a hot air drying oven controlled at 150°C for 10 seconds to scatter the solvent and form a film with a thickness of about 2 microns. A film was formed. The durability of the ultraviolet shielding ability of each film was evaluated according to the following method. The results are shown in Table 1. Test method: Multiple sheets of each film were exposed on a window frame-shaped exposure test stand facing south and tilted at 45 degrees to the plane (location: Ama Gun, Aichi Prefecture), and exposed periodically. Some of the films were removed from the exposure test stand and the light transmittance at a wavelength of 350 nanometers was measured (with a spectrophotometer manufactured by Hitachi, Ltd.).
According to type 323. ).

【table】

[Table] From Table 1, the following becomes clear. (1) Even when the agricultural vinyl chloride resin film according to the present invention is used outdoors for a long period of time, its ultraviolet shielding ability does not change, and the shielding ability has excellent sustainability. (2) As for the ultraviolet absorber, it is better to use the compound represented by the above formula () or () when using a compound other than this (Comparative Examples 1, 2, 3)
Compared to this, the durability of the film's ultraviolet shielding ability is excellent. (3) Organic phosphoric acid ester may be used in cases where the composition ratio of the mixed alcohol used for its production (the amount of xylenol/cresol and P-ethylphenol components) is outside the claimed range (Comparative Example 4,
5,6) The durability of the film's ultraviolet shielding ability is
It becomes inferior. (4) Even if the three components of ultraviolet absorber, organic phosphate ester, and hindered amine are within the claimed range, when there is no acrylic resin coating on the surface (Comparative Example 7), the ultraviolet shielding ability of the film is The sustainability is not excellent. (5) The UV-shielding ability of the film was excellent in cases where no hindered amine compound was added (Comparative Example 8), only a small amount was added (Comparative Example 10), and a large amount was added (Comparative Example 9). do not have.

Claims (1)

[Scope of Claims] 1. Based on 100 parts by weight of vinyl chloride resin, (A) a benzophenone ultraviolet absorber represented by the following general formula () or/and the following general formula ()
0.4 to 5 parts by weight of a benzotriazole ultraviolet absorber (as the total amount of ultraviolet absorbers) [In formulas () and (), R ₁ is an alkyl group having 1 to 18 carbon atoms, R ₂ and R ₃ are hydrogen or an alkyl group having 1 to 18 carbon atoms, and X is hydrogen or a halogen atom. (B) As a raw material, a mixed alcohol containing xylenol, cresol and ethylphenol as main components, in which the composition ratio of xylenol and cresol is in the range of 2/1 to 20/1, and 0.5 to 10 parts by weight of an organic phosphoric acid ester produced using a mixed alcohol with a composition ratio of P-ethylphenol of 30% by weight or less, (C) the following general formula [In formula (), R ₄ to R ₇ have 1 to 4 carbon atoms
an alkyl group, R ₈ represents hydrogen or an alkyl group having 1 to 4 carbon atoms. ] 0.2 to 1.0 parts by weight of a hindered amine compound containing one or more of the structural units shown in each molecule is blended into a film with a thickness of 0.075 to 0.3 mm, and a thick Saga
An agricultural vinyl chloride resin film comprising an acrylic resin film of 0.5 to 10 microns. 2. The acrylic resin film formed on the surface of the vinyl chloride resin film contains 5 to 40% by weight of a hydroxyalkyl (meth)acrylate compound and/or
or 0 to 20% by weight of an α,β unsaturated carboxylic acid compound containing one or more carboxyl groups,
The agricultural vinyl chloride resin film according to claim 1, characterized in that it comprises a polymer obtained by copolymerizing these compounds with other vinyl compounds copolymerizable with them.