JPH0247013Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a dustproof agricultural film, and more specifically, a matte agricultural vinyl chloride resin film with good dustproofness and weather resistance that can replace the conventional embossed satin film. Regarding.

Embossed soft vinyl chloride resin films (hereinafter referred to as satin films) have been widely used for drying soft vegetables, crops such as grapes that are sensitive to leaf burn, and tobacco leaves. When used for a long period of time, there are drawbacks such as a significant decrease in light transmittance due to dust adhesion due to the bleeding of the plasticizer and unevenness of the surface due to embossing, as well as a significant decrease in weather resistance.

On the other hand, it has been known to apply an acrylic resin to the surface of a general agricultural soft vinyl chloride resin film for dust prevention.

Therefore, in order to eliminate the drawbacks of the satin film, the inventors of the present invention attempted to apply dustproofing to the satin film using acrylic resin. It returned and disappeared due to the wind, making it impossible to produce a satin film with the desired light transmittance.

The object of the present invention is to provide a dust-proof agricultural vinyl chloride resin film that can be used for a long period of time and whose light transmittance is suitably suppressed by matting, which can replace the conventional satin film.

According to the present invention, the above purpose is to achieve a gel fraction of 10~10.
Containing 1 to 50 parts by weight of 60% crosslinked vinyl chloride polymer particles per 100 parts by weight of vinyl chloride resin;
The transmittance of straight light with a wavelength of 550 nm is 20 to 70%, and
A dust-proof agricultural vinyl chloride resin comprising a matte soft vinyl chloride resin film having a total transmittance of at least 80% for light at a wavelength of 550 nm and an acrylic resin coating covering one side of the film. Achieved by film.

Hereinafter, the film of the present invention will be described in more detail with reference to the accompanying drawings.

In FIG. 1, the film 1 of the present invention consists of a matte soft vinyl chloride resin film 2 and an acrylic resin coating 3 coated on one side of the film.

Matte soft vinyl chloride resin film 2
In this method, crosslinked vinyl chloride polymer particles having a gel fraction of 10 to 60%, preferably 20 to 50%, are added in an ordinary soft vinyl chloride resin matrix in an amount of 1 to 50 parts by weight per 100 parts by weight of the resin matrix. , preferably 3
It is made matte by blending it in a proportion of ~20 parts by weight, and the degree of matteness is determined by appropriately adjusting the type of crosslinked vinyl chloride polymer, its particle size, and the amount blended. Therefore, the transmittance of film 1 of the present invention for straight light with a wavelength of 550 nm is 20 to 70.
%, preferably 30 to 60%, and the total transmittance of light with a wavelength of 550 nm is at least 80%, preferably 85% or more.

Here, the "straight light transmittance" and "total transmittance" of light are values recorded and measured using a 330 type self-recording spectrophotometer with an integrating sphere (manufactured by Hitachi, Ltd.).

The cross-linked vinyl chloride polymer used for this matte finish is known per se, for example, as described in JP-A-54-117550 and JP-A-56-92024, etc. A compound having two or more active double bonds in the molecule and copolymerizable with the above monomer or comonomer is added to a vinyl chloride monomer or a mixture of a vinyl chloride monomer and a comonomer copolymerizable with it, and polymerized. This is a vinyl chloride polymer containing a gel component that is insoluble in tetrahydrofuran. Here, "gel fraction" refers to cross-linked vinyl chloride polymer particles.
Accurately weigh ₁ g of W, extract it with hot tetrahydrofuran for 22 hours using a Soxhlet extractor, and then
Remove insoluble matter with a 350 mesh filter,
The weight after drying, W ₂ g, is accurately weighed, and the value is calculated using the following formula.

Gel fraction (%) = W ₂ /W ₁ ×100 In the present invention, in particular, the average degree of polymerization of the tetrahydrofuran soluble portion is 400 to 10,000, preferably
600 to 3000 and a gel fraction in the range of 20% to 50%, such as XEL-C manufactured by Kanekabuchi Chemical Co., Ltd.
(Product name) is particularly suitable.

Such a crosslinked vinyl chloride polymer is usually blended into a soft (plasticized) vinyl chloride resin in powder form.
In this case, it is convenient that the average particle size of the crosslinked vinyl chloride polymer is generally in the range of 100 to 150 microns.

The above-mentioned crosslinked vinyl chloride polymer powder is mixed and dispersed in the soft vinyl chloride resin in the above amount in order to suppress the light transmittance of the soft vinyl chloride resin film (make it matte).

The soft vinyl chloride resin used in the present invention can have the same composition as that conventionally used in the field of agricultural coating materials, and its basic composition has a number average degree of polymerization. Approximately 800 to approx.
2000, preferably from about 1000 to about 1500, or a vinyl chloride-based copolymer (e.g.
(ethylene-vinyl chloride copolymer, vinyl acetate-vinyl chloride copolymer, vinyl chloride-halogenated olefin copolymer), or other compatible resins mainly composed of these polyvinyl chloride-based or vinyl chloride copolymers (Example: polyester resin, epoxy resin, acrylic resin, vinyl acetate resin, urethane resin, acrylonitrile-styrene-butadiene copolymer resin, partially saponified polyvinyl alcohol, etc.) [hereinafter referred to as these polyvinyl chloride, copolymer The combined and blended products are collectively referred to as vinyl chloride resins], per 100 parts by weight of these vinyl chloride resins,
30-70 parts by weight, preferably 40-60 parts by weight of plasticizer; 0.05-7 parts by weight, preferably 1.0-5.0 parts by weight of lubricants and/or heat stabilizers; 0-5.0 parts by weight, preferably 1.0-4.0 parts by weight. Parts by weight of antifog agent (or surfactant); 0 to 3.0 parts by weight, preferably 0.1 to 0.5 parts by weight of ultraviolet absorber; 0 to 5.0 parts by weight, preferably 0.1
It can be composed of ~1.0 parts by weight of an anti-blocking agent, etc., and may also contain other usual resin additives such as an antioxidant, an antistatic agent, a coloring agent, etc. as necessary. can.

Examples of plasticizers that can be blended include G-n-
Phthalic acid derivatives such as octyl phthalate, di-2-ethylhexyl phthalate, and diisodecyl phthalate; Isophthalic acid derivatives such as diisooctyl isophthalate; Adipic acid derivatives such as dioctyl adipate; Other tricresyl phosphate, tricylenyl phthalate Included are osphates, epoxidized soybean oil, and the like, among which dioctyl phthalate, tricresyl phosphate, dioctyl adipate, and epoxidized soybean oil are suitable.

Examples of lubricants or heat stabilizers that can be included in the vinyl chloride resin include polyethylene wax, stearic acid, zinc stearate, barium stearate, calcium stearate, barium ricinoleate, chelators such as organic phosphites, Examples of antifogging agents (or surfactants) include sorbitan surfactants such as sorbitan monostearate, sorbitan monopalmitate, and sorbitan monobehenate; glycerin monolaurate and diglycerin monolaurate; Glycerin surfactants such as palmitate and glycerin monostearate; polyethylene glycol surfactants such as polyethylene glycol monostearate and polyethylene glycol monopalmitate; alkylene oxide adducts of alkylphenols; sorbitan/glycerin condensates; Examples include esters with organic acids, and examples of ultraviolet absorbers include 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone,
2-hydroxy-4-n-dodecyloxybenzophenone, 2-hydroxy-4-n-octadecyloxybenzophenone, 2-hydroxy-4-
Benzyloxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, 2-hydroxy-5-chlorobenzophenone, 2, 4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-di-methoxybenzophenone, 2,2'-dihydroxy-4,4 Benzophenone ultraviolet absorbers such as '-di-methoxy-5-sulfobenzophenone and 2,2'4,4'-tetrahydroxybenzophenone; 2
-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-5'-tert
-butylphenyl)benzotriazole, 2-
(2'-hydroxy-3',5'-dimethylphenyl)benzotriazole, 2-(2'-methyl-4'-hydroxyphenyl)benzotriazole, 2-
(2'-hydroxy-3'-methyl-5'-tert-butylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-amylphenyl)benzotriazole, 2-(2'- hydroxy-3′,
5'-di-tert-butylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-dimethylphenyl)-5-methoxybenzotriazole, 2
-(2'-n-octadecyloxy-3',5'-dimethylphenyl)-5-methylbenzotriazole,
2-(2'-hydroxy-5'-methoxyphenyl)
Benzotriazole, 2-(2'-hydroxy-
4′-octoxyphenyl)benzotriazole,
2-(2'-hydroxy-5'-methoxyphenyl)-
5-Methylbenzotriazole, 2-(2'-hydroxy-5'-methylphenyl)-5,6-dichlorobenzotriazole, 2-(2'-hydroxy-
5'-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-
tert-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-5'-phenylphenyl)-5-chlorobenzotriazole, 2
-(2'-hydroxy-5'-dichlorohexylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-dichlorophenyl)benzotriazole, 2-(2'-hydroxy-4', 5'-dichlorophenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-
Chlorobenzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5
-chlorobenzotriazole, 2-(2'-hydroxy-5'-methylphenyl)-5-butoxycarbonylbenzotriazole, n-dodecyl-phosphite, tris-n-nonylphenyl)phosphite, tri-n-dodecyl-trithiophosphite, phenyl-di-n-decyl phosphite,
Examples of antistatic agents include quaternary ammonium salts, amines, imidazolines, amine oxidized ethylene adducts, polyethylene glycols, sorbitan esters, etc. Can be mentioned. Examples of coloring agents include titanium oxide, ultramarine blue, phthalocyanine blue, and quinacridone red.

Furthermore, the coating material of the present invention may contain an inorganic filler for the purpose of improving blocking resistance, infrared absorption and/or reflection, and the like. Examples of inorganic fillers that can be blended for this purpose include silica, talc, and calcium carbonate, which can be used alone or in combination of two or more. The amount of the inorganic filler is generally determined by the amount of vinyl chloride resin.
It can be up to 5.0 parts by weight, preferably up to 3.0 parts by weight per 100 parts by weight.

Furthermore, examples of antioxidants that may be added as necessary include phenolic antioxidants, such as 2,6-di-t-butyl-p-cresol, 4,
4'-thiobis-(3-methyl-6-t-butylphenol), 2,2-di(4-hydroxyphenyl)propane, 1,1,3-tris-(2-methyl-4-hydroxy-5 -t-butylphenyl)
Butane, octadecyl-3-(3,5-di-t-
Butyl-4-hydroxyphenyl) propionate, pentaerythritol-tetra-(3,5-
di-t-butyl-4-hydroxyphenyl)-propionate, 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate, tris-(3,5- G
t-Butyl-4-hydroxybenzyl) isocyanurate: thiodipropionic acid ester, e.g. di-n-dodecyl-thiodipropionate,
di-n-octadecyl-thiodipropionate,
Aliphatic sulfides and disulfides such as di-n-dodecyl sulfide, di-n-octadecyl sulfide, di-n-octadecyl disulfide; aliphatic, aromatic or aliphatic-aromatic phosphites and thiophosphites such as tri-2 -(2'-hydroxy-4',5'-dimethylphenyl)-5-butoxycarbonylbenzotriazole, 2-(2'-hydroxy)-5-ethoxycarbonylbenzotriazole, 2-(2'-acetoxy-5 '-methylphenyl)benzotriazole,
2-(2'-hydroxy-5'-methylphenyl)-5
-ethylsulfonebenzotriazole, 2-
(2'-hydroxy-3',5'-dimethylphenyl)-
5-ethylsulfonebenzotriazole, 2-
Benzotriazole UV absorbers such as (2'-hydroxy-5'-phenyl phenyl) benzotriazole, 2-(2'-hydroxy-5'-aminophenyl) benzotriazole; phenyl salicylate, p-tert-butyl phenyl salicylate, p-
Examples include salicylic acid ester ultraviolet absorbers such as methyl phenyl salicylate and p-octylphenyl salicylate.

In addition, anti-blocking agents include, for example, fatty acid amides such as methylene bis stearylamide; higher fatty acids and their derivatives such as butyl stearate; higher alcohols such as stearyl alcohol; and metal soaps such as calcium stearate. be done.

The matte soft vinyl chloride resin film 2 of the present invention is produced by combining the basic ingredients of the soft vinyl chloride resin composition described above, the crosslinked vinyl chloride polymer powder, etc. It can be manufactured by thoroughly mixing or kneading with a mixer such as a mold or an extruder, and then molding it into a film according to a normal molding method such as a calendar method, T-die method, or inflation method. . The thickness of the film at that time is generally 50~
200 microns, preferably within the range of 50 to 150 microns. The film thus formed is then subjected to dustproofing treatment.

The acrylic resins that can be used for this dustproofing treatment are mainly acrylic resins that have been used for the dustproofing of agricultural soft vinyl chloride resin films, that is, esters of acrylic acid or methacrylic acid. For example, Japanese Patent Publication No. 46-28194, Japanese Patent Publication No. 52-
Publication No. 6214, Japanese Patent Publication No. 15608/1983, Japanese Patent Publication No. 1987-15608
-1392, etc., but in particular, a combination of 4 to 13% by weight of N-methylolacrylamide and acrylic acid or methacrylic acid described in Japanese Patent Publication No. 57-15608, Acrylic resins obtained through copolymerization with 87 to 96% by weight of at least one C ₁ to _{C 12} alkyl ester have excellent dust resistance and blocking resistance, as well as flexibility. It is suitable because it has high frequency weldability. Among them, methyl methacrylate 35-55% by weight, ethyl methacrylate 10-30% by weight, methyl acrylate 10-55% by weight.
Particularly preferred is a resin based on an acrylic resin obtained by copolymerizing 25% by weight, 0 to 10% by weight of butyl acrylate, and 4 to 13% by weight of N-methylol acrylamide, and furthermore, a resin based on the above five copolymerized monomers. It is also effective to copolymerize with a small amount (0.01 to 2% by weight) of at least one monomer selected from , butyl methacrylate, ethyl acrylate, acrylic acid, methacrylic acid, etc.

In order to provide a dustproof coating layer made of such an acrylic resin on the surface of the vinyl chloride resin film, the acrylic resin as described above is dissolved in an appropriate organic solvent and coated, in the same manner as in the usual dustproofing method. A composition is prepared and coated on the surface of a vinyl chloride resin film. In addition to the acrylic resin, the coating composition optionally contains:
For example, cellulose acetate butyrate, polyvinyl chloride, polyvinylidene chloride, polystyrene,
Other compatible resins such as polyurethane, ethylene-vinyl acetate copolymer, etc. can be added to the acrylic resin.
It may be contained in a proportion of 40 parts by weight or less, preferably 30 parts by weight or less, more preferably 25 parts by weight or less per 100 parts by weight, and if necessary, a light stabilizer such as an ultraviolet absorber and an antistatic agent. Appropriate amounts of additives, colorants, anti-blocking agents, plasticizers, etc. can also be added.

Coating with the above-mentioned coating composition can be carried out according to conventional methods, such as roll coating, knife coating, spray coating, dip coating, curtain flow coating, etc. The thickness of the coating film (after drying) must be strictly controlled. Although not limited, it is generally advantageous to have a range of 1 to 20 microns, preferably 1 to 5 microns.

The film of the present invention described above does not undergo matting by mechanical methods such as embossing, so it does not require processing with an embossing roll, and the manufacturing process is simple. Since it does not return and is dustproofed with acrylic resin, it has excellent stain resistance, weather resistance, durability, etc., and has the advantage of being able to be used for two or more seasons.

Therefore, the film of the present invention can be applied to, for example, crops that suffer from leaf burn or sprout burn due to moderate irradiation with sunlight.
For example, it can be widely used in soft vegetables such as celery, salad greens, Japanese chrysanthemum, spinach, and honeydew; fruits such as grapes and mandarin oranges; greenhouse cultivation of paddy rice seedlings, tunnel cultivation, or drying of leaf tobacco.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the film of the present invention. In the figure, 1...the film of the present invention, 2...the matte soft vinyl chloride resin film, and 3...the acrylic resin coating film.

Claims (1)

[Scope of utility model registration request] Contains 1 to 50 parts by weight of crosslinked vinyl chloride polymer particles with a gel fraction of 10 to 60% per 100 parts by weight of vinyl chloride resin, and has a transmittance of straight light with a wavelength of 550 nm.
Dust-proofing consisting of a matte soft vinyl chloride resin film having a total transmittance of 20 to 70% and at least 80% for light with a wavelength of 550 nm, and an acrylic resin coating covering one side of the film. Agricultural vinyl chloride resin film.