JPS6225100B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention has a coating film of a vinyl chloride resin coating composition on one or both sides of a vinyl chloride resin base film (in the present invention, the term "film" includes a sheet) containing an antifogging agent. The present invention relates to a dustproof film for agricultural and horticultural use and a vinyl chloride resin coating composition thereof. More specifically, the present invention has improved properties such as excellent dust resistance, blocking resistance, adhesion to the base film, and curl resistance, as well as being able to overcome the decline in dust resistance in the summer, while also being able to overcome the decline in dust resistance that tends to occur in the winter. A dustproof film for agriculture and horticulture that can avoid the problem of surface cracks, has excellent crack resistance and heat seal strength improvement effects, and has unique improved properties such as preventing rainwater clouding. and a coating composition thereof. In particular, the present invention provides the following methods: [A] (i) vinyl chloride/vinyl acetate copolymer resin; (ii) vinyl chloride polymer on one or both sides of a vinyl chloride resin film containing at least an antifogging agent; resin and (iii) methyl methacrylate/ethyl methacrylate copolymer resin, [B] The sum of (i) and (ii) above is the sum of (i), (ii) and (ii) above.
i)
occupies 50% by weight or more based on the combined weight of [C] and the weight ratio of (i) and (ii) above is (i):(ii)=1:2
The present invention relates to a dustproof film for agriculture and horticulture, characterized in that it has a coating film of a vinyl chloride resin coating composition having a ratio of ~2:1. The present invention also relates to a coating composition suitable for coating an antifogging agent-containing vinyl chloride resin film to make the film an excellent dustproof film for agriculture and horticulture. For example, synthetic resin film coverings containing antifogging agents are widely used in agricultural and horticultural greenhouses, tunnels, etc., and the plasticizer migrates to the film surface over time, causing dust to accumulate. As a result, the light transmittance is reduced, and furthermore, along with the migration of the plasticizer, the antifogging agent also migrates to the surface and is washed away, causing the antifogging effect to be lost in a relatively short period of time. There are disadvantages such as the inconvenience of In order to avoid such difficulties, there is also a known proposal to apply a resin coating to at least one side of an olefin-based, vinyl chloride-based, or other synthetic resin film containing at least an antifogging agent to overcome the above-mentioned difficulties. There is. For example, Japanese Patent Publication No. 7061/1973 proposes a paint for soft vinyl chloride resin products. This proposal specifically referred to anti-fog films for agriculture and horticulture, but it also addressed the drawbacks of conventional paints, which had the disadvantage that the plasticizer in these products migrated to the surface or the surface was easily contaminated due to static electricity. In order to overcome this problem, antistatic agents such as cationic quaternary ammonium salts, polyethylene polyamines, and nonionic betaine types are added to the copolymer of methyl methacrylate and butyl methacrylate in a specific monomer weight range. Paints for soft PVC products containing 0.1 to 1 part by weight have been proposed. For example, Japanese Patent Publication No. 46-37429 proposes a method for producing a hydrophilic synthetic resin film or sheet by applying a resin coating to the synthetic resin film or sheet in order to impart hydrophilic properties to the film or sheet. Similar to the above proposal, this proposal also makes no mention of antifogging films for agriculture and horticulture, their technical problems, and their solutions. In this proposal, at least one selected from an acrylic acid ester polymer or a copolymer thereof, a vinyl acetal polymer or a copolymer thereof, and a vinyl alcohol fatty acid ester polymer or a copolymer thereof, and a surfactant such as a fatty acid. It has been proposed to coat synthetic resin films and sheets with a mixture of sorbitan ester and sorbitan ester. Furthermore, Japanese Patent Publication No. 47-28740 proposes a vinyl chloride film for agricultural use. In this proposal, a specific acrylic resin, i.e. hydroxyalkyl (meth)acrylates 15-25
A resin obtained by polymerizing a monomer mixture consisting of 0.5 to 5% by weight of α/β-unsaturated acid monomer and other (meth)acrylic monomers is applied to one or both sides of a vinyl chloride film. It has been proposed to form a coating film by coating. Furthermore, as a proposal similar to the above proposal,
No. 50-5733 discloses an acrylic resin obtained by polymerizing the same monomer mixture as the above proposal in a vinyl chloride resin non-solvent, and a vinyl chloride resin non-solvent or the non-solvent and a small amount of a vinyl chloride resin good solvent. Coatings for soft or semi-rigid vinyl chloride resins have been proposed, and the application of these coatings to agricultural films has also been described. In addition, Japanese Patent Publication No. 50-31195 discloses an anti-fog agent that limits the migration of the anti-fog agent to the film surface only to one side of the film, thereby prolonging the persistence of the anti-fog effect on that one side. A film consisting only of polymethacrylate or polyacrylate alone or a copolymer thereof is formed on one side of an antifogging film for agricultural chemicals selected from polyethylene and polyvinyl chloride mixed with an additive, and the antifogging film on the other side is A method of improving the anti-fog persistence of the film has been proposed to extend the persistence. Furthermore, Japanese Patent Publication No. 50-281117 discloses a monomer mixture of a specific composition, namely 70-90 parts by weight of methyl methacrylate, 5-30 parts by weight of methyl acrylate or ethyl acrylate and 0.5-5 parts by weight of acrylic acid or methacrylic acid. An agricultural vinyl chloride film has been proposed in which a semi-rigid or flexible vinyl chloride film is coated with a resin coating film obtained by polymerizing a monomer mixture consisting of parts by weight on one or both sides of the film. Moreover, in JP-A-50-38734, methyl methacrylate/ethyl methacrylate (80 to 90
wt%/20~10wt%) copolymer or 1~5
100 parts by weight of a copolymer further reacted with % by weight of α/β-unsaturated carboxylic acid, 40 to 100 parts by weight of vinyl chloride/vinylidene chloride (50-80% by weight/50-20% by weight) copolymer A coating composition for polysmoked vinyl film has been proposed, which comprises a solvent common to both copolymers. As introduced above, agricultural anti-fog films or similar films are produced by providing a resin coating film on at least one side of a synthetic resin film containing an anti-fog agent to prevent migration of plasticizers and anti-fog agents to the coating side. In the conventional proposals regarding products, attention has been focused on means for preventing the above-mentioned migration by coating films made of acrylic or methacrylic resins, and many proposals as described above have been made. However, the various properties desired for anti-fog films for agriculture and horticulture, such as anti-fog properties, dustproof properties, crack resistance, anti-blocking properties, adhesion to the base film, and even heat sealability,
In practice, it has been extremely difficult to achieve both to a sufficiently satisfactory degree. Furthermore, there are technical issues arising from acrylic or methacrylic resin coatings, such as the occurrence of severe and complex cracks when the dustproof film is exposed under natural conditions to the influence of tensile stresses such as wind pressure and tensile stress. For example, it is difficult to obtain sufficient crack resistance against various factors, for example, cloudy spots of raindrops appear on the coating after rain, and furthermore, there is a reduction in dust resistance in the summer and the surface resistance under natural conditions in the winter. Technical issues such as the difficulty of generating microcracks and the parasitic propagation of mold in such surface microcracks have been overlooked. In addition to solving these technical problems, neither the intention nor the means for achieving the above-mentioned improvements in properties have hitherto been proposed. The present inventors have conducted research to develop a dust-proof film for agriculture and horticulture that can solve the above-mentioned technical problems with an acrylic or methacrylic resin coating and that has the above-mentioned properties desired for a dust-proof film for agriculture and horticulture. I kept coming. As a result, as mentioned above, whereas conventional proposals have focused exclusively on the formation of acrylic or methacrylic resin coatings, it has been found that at least antifogging coatings of vinyl chloride resin compositions have been used. It has been discovered that the above problems can be solved all at once by providing the agent on at least one side of a vinyl chloride synthetic resin film containing the agent. Therefore, an object of the present invention is to provide a dustproof film for agriculture and horticulture, which has a coating film made of a vinyl chloride resin composition and has excellent properties. Another object of the present invention is to provide a vinyl chloride resin composition for coating an agricultural and horticultural film containing an antifogging agent, which is suitable for use in providing such a film. The above objects and many other objects and advantages of the present invention will become more apparent from the following description. The agricultural and horticultural dust-proof film of the present invention has [A] (i) vinyl chloride/vinyl acetate copolymer resin, (ii) vinyl chloride on one or both sides of a vinyl chloride resin film containing at least an antifogging agent. [B] The sum of (i) and (ii) above is the sum of (i), (ii) and (ii) above. (ii
i)
occupies 50% by weight or more based on the total weight of [C] and the weight ratio of (i) and (ii) above is (i):(ii)=1:2
It has a coating film of a vinyl chloride resin coating composition of ~2:1. As the vinyl chloride/vinyl acetate copolymer resin (i) above, a resin in which vinyl chloride is the main component is preferable, particularly a resin in which vinyl chloride:vinyl acetate=70-95:30-5 (weight ratio). Resin is preferred;
More preferably, the resin has a ratio of vinyl chloride to vinyl acetate of 80 to 90:20 to 10 (weight ratio). The copolymer resin is
Small amounts of other comonomers may be included, e.g.
It may contain up to about 10% by weight, preferably up to 5% by weight, based on the sum of vinyl chloride and vinyl acetate, of other comonomers. Examples of such comonomers include ethylene,
Examples include propylene, vinylidene chloride, acrylonitrile, maleic acid, itaconic acid, acrylic acid, and methacrylic acid. The vinyl chloride polymer (ii) is preferably a polyvinyl chloride resin, but may contain a small amount of other comonomers. For example, it may contain up to about 10%, preferably up to about 5%, by weight of the vinyl chloride, of other comonomers. Examples of such comonomers include vinylidene chloride, ethylene, propylene, acrylonitrile, maleic acid, itaconic acid, acrylic acid, and methacrylic acid. Furthermore, the methyl methacrylate/ethyl methacrylate copolymer resin (iii) is preferably a resin in which methyl methacrylate is the main component, particularly methyl methacrylate/ethyl methacrylate = 60 to 95:40. 5 (weight ratio)
A resin having a ratio of methyl methacrylate/ethyl methacrylate of 80 to 90:20 to 10 (weight ratio) is more preferred. The copolymer resin may contain small amounts of other comonomers, such as up to about 10% by weight, preferably about 5% by weight, based on the sum of methyl methacrylate and ethyl methacrylate.
Up to % by weight of other comonomers may be included. Examples of such other comonomers include n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, cyclohexyl (meth)acrylate, C ₃ -C ₂₂ alkyl esters of acrylic acid or methacrylic acid such as acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, stearyl (meth)acrylate α-, β-unsaturated fatty acids such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid and maleic acid; epoxidized alkyl esters of acrylic acid such as glycidyl acrylate and tetrahydrofurfuryl acrylate; such as styrene, Styrenes such as vinyltoluene and any combination of these can be mentioned. In the present invention, the vinyl chloride resin coating composition may further contain up to about 3% by weight of an antifogging agent, based on the total weight of (i), (ii), and (iii) above. can. Examples of such antifogging agents include fatty acids selected from the group consisting of sorbitan monoesters, -diesters and -sesquiesters of preferably _C12 to _C22 , more preferably _C16 to _C22 fatty acids. The use of sorbitan esters alone or in any combination is preferred. Specific examples of such fatty acid sorbitan esters include sorbitan laurate, sorbitan myriritate, sorbitan palmitate, sorbitan stearate,
Fatty acid sorbitan esters such as sorbitan isostearate, sorbitan behenate, sorbitan oleate, sorbitan hydroxystearate, ethylene oxide adduct of sorbitan palmitate, and ethylene oxide adduct of sorbitan stearate can be mentioned. Also preferably _C12 to _C22 , more preferably
Glycerin-monoesters of _C16 - _C22 fatty acids,
- diesters and diglycerin-monoesters,
It is preferable to use fatty acid glycerol esters and fatty acid diglycerol esters selected from the group consisting of -diesters alone or in any combination. Specific examples of such fatty acid (di)glycerin esters include (di)glycerin palmitate, (di)glycerin dipalmitate, (di)glycerin stearate, (di)glycerin distearate, and (di)glycerin oleate. ate, (di)glycerol hydroxystearate, and ethylene oxide adducts of (di)glycerol stearate. Furthermore, it is preferable to use polyether phosphoric acids selected from the group consisting of dipolyoxyethylene alkyl ether phosphoric acid and tripolyoxyethylene alkyl ether phosphoric acid alone or in any combination. Examples of such polyether phosphoric acids include the following. Dipolyoxyethylene (4) lauryl ether phosphoric acid, dipolyoxyethylene (8) oleyl ether phosphoric acid, dipolyoxyethylene (10) oleyl ether phosphoric acid, tripolyoxyethylene (4) stearyl ether phosphoric acid, tripolyoxyethylene (8) Octyl ether phosphoric acid, tripolyoxyethylene (10) Octyl ether phosphoric acid (however, the number in parentheses is the number of moles of polyoxyethylene added). Furthermore, as the antifogging agent used in the base film used in the present invention, that is, the vinyl chloride resin film containing at least an antifogging agent, fatty acid sorbitan esters similar to the above antifogging agents can be preferably used. The antifogging agent used in the base film and the antifogging agent that may be contained in the coating composition may be the same or different. In the present invention, the total of (i) vinyl chloride/vinyl acetate copolymer resin and (ii) vinyl chloride polymer resin in the vinyl chloride resin coating composition is the sum of (i) and (ii) above. and (iii) methyl methacrylate/
It accounts for 50% by weight or more based on the total weight of the ethyl methacrylate copolymer resin. If the total amount of resins (i) and (ii) is less than 50% by weight, surface microcracks may occur under natural conditions in winter, crack resistance during tension may decrease, cloudy spots on raindrops may increase after rain, and This is disadvantageous in terms of reduced sealing performance, etc. In addition, in the present invention, the weight ratio of the above (i) and (ii) is
(i):(ii) is selected so that the ratio range is 1:2 to 2:1. If either (i) or (ii) is too small outside the above ratio range, cloudy spots on raindrops after rain will increase, blocking performance will increase, dustproof performance will decrease, and the rate of improvement in seal strength will decrease. This is inconvenient as it causes problems such as lowering the temperature. Preferably, (i) above:
(ii)=1:2 to 1:1 is more advantageous. The vinyl chloride resin base film in the agricultural and horticultural dustproof film of the present invention includes polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, vinyl chloride-ethylene copolymer, vinyl chloride-vinylidene chloride copolymer, chloride Examples include vinyl-acrylonitrile copolymers alone or any combination thereof. These bases
The resin of the film may optionally contain a minor amount of other resins compatible with the resin, such as up to about 50% by weight, more preferably up to about 30% by weight, based on the weight of the base film resin. It can contain other resins. Examples of such blending resins include polymethyl methacrylate, polybutyl methacrylate, polydodecyl methacrylate, polystearyl methacrylate, polybutyl acrylate, poly 2-ethylhexyl acrylate, and methyl methacrylate-butyl acrylate copolymer. , methyl methacrylate-dodecyl acrylate copolymer, methyl methacrylate-butyl methacrylate copolymer, methyl methacrylate-2-ethylhexyl acrylate copolymer, ethylene-vinyl acetate copolymer, methyl methacrylate-butadiene-styrene copolymer polymer,
Examples include one type or arbitrary combination of resins such as acrylonitrile-butadiene-styrene copolymer. The amount of dustproof agent added to the vinyl chloride resin base film as exemplified above can be selected and determined as appropriate, but based on the weight of the base film resin, for example,
An example usage amount is 0.1 to 3% by weight. The vinyl chloride resin coating composition for agricultural and horticultural films containing an antifogging agent of the present invention may further contain a plasticizer. Examples of such plasticizers include preferably polyester plasticizers, such as polypropylene adipate, polypropylene sebacate, polypropylene azelate, polyethylene adipate, polyethylene sebacate, polyethylene phthalate, and the like. The amount of plasticizer used is resin (i),
An example may be an amount of 0 to about 10% by weight based on the sum of (ii) and (iii). When producing a dustproof film for agriculture and horticulture having a coating film of the vinyl chloride resin coating composition of the present invention, the above (i) , (ii) and (iii) by applying a coating composition consisting of a solvent solution of a vinyl chloride resin composition and drying. The application means itself can be selected appropriately, such as spray coating, roll coating, gravure coating,
Application methods such as screen printing and flexo printing can be used. Appropriate means can be selected for drying, such as hot air drying, infrared drying, and far infrared drying. Solvents used to form such coating solvent solution compositions include toluene, methyl acetate, ethyl acetate, methyl ethyl ketone, acetone, methyl butyl ketone, methanol, ethanol, isopropanol, tetrahydrofuran, methyl cellosolve, dimethyl formamide, and the like. can be exemplified. Furthermore, in the present invention, the base film made of vinyl chloride synthetic resin may contain other additives, such as phthalate esters such as diethyl phthalate, dibutyl phthalate, di-n-octyl phthalate, and di-2-ethylhexyl phthalate; For example, sebacic acid esters such as di-2-ethylhexyl sebacate and dibutyl sebacate; azelaic acid esters such as di-2-ethylhexyl azelate, di-isooctyl azelate, and dibutyl sebacate; −(2
Trimellitic acid esters such as -ethylhexyl) trimellitate and tri-isodecyl trimellitate; adipic acid esters such as di-(2-ethylhexyl) adipate, diisodecyl adipate and dibutyl adipate; tricresyl phosphate, tricresyl phosphate, phosphoric acid esters such as renylphosphate; epoxidized fatty acid esters such as epoxidized soybean oil, epoxidized castor oil, epoxidized linseed oil; e.g. sebacic acid, adipic acid, azelaic acid, phthalic acid Plastics such as polyesters and the like can be included. Furthermore, vinyl chloride resin-based films are
For example, waxes such as polyethylene wax and liquid paraffin; fatty acids such as stearic acid, oleic acid, and palmitic acid; fatty acid amides such as stearic acid amide, oleic acid amide, and palmitic acid amide; such as butyl stearate, methyl Lubricants such as fatty acid esters such as hydroxystearate may be included. Furthermore, organotin stabilizers such as dibutyltin dilaurate, dibutyltin maleate ester, dioctyltin mercaptide; such as calcium stearate, barium stearate, zinc stearate, cadmium stearate, calcium laurate, barium ricinoleate, olein; Stabilizers such as metal soap stabilizers such as calcium oxide and zinc octoate can be included. Also, for example, t-butylhydroxytoluene, 2,2'-methylenebis(6-t-
butyl-4-ethylphenol), antioxidants such as dilaurylthiodipropionate and stabilizing aids such as triphenylphosphite, dioctylphosphite, tris(phenylphenyl)phosphite, trilauryltrithiophosphite, Furthermore, colorants such as phthalocyanine blue, phthalocyanine green, Hansa yellow, alizarin lake, titanium oxide, zinc white, permanent red, carbon black, and quinacridone can be contained. In the present invention, the vinyl chloride resin base film and/or the vinyl chloride resin coating composition may contain an ultraviolet absorber capable of preventing the transmission of ultraviolet light including near ultraviolet light of 380 nm or less. Examples of such ultraviolet absorbers include 2-(2'-hydroxy-3', 5', di-
tert-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3'-tert -Amyl-5'-isobutylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3'-
Isobutyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-
3'-isobutyl-5'-propylphenyl)-5-
2'-hydroxyphenyl-5-chlorobenzotriazole UV absorbers such as chlorobenzotriazole, e.g. 2-(2'-hydroxy-3'.
2'-hydroxyphenylbenzotriazole type ultraviolet absorbers such as 5'-di-tert-butylphenyl)benzotriazole, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, e.g. 2,2'-dihydroxy- 2,2'-dihydroxybenzophenones such as 4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone; UV absorbers such as 2
-hydroxy-4-methoxybenzophenone,
2- such as 2,4-dihydroxybenzophenone
Hydroxybenzophenone UV absorbers, such as 2-ethylhexyl-2-cyano-3.3-
Examples include cyanoacrylate ultraviolet absorbers such as diphenyl acrylate, and salicylic acid ester ultraviolet absorbers such as phenyl salicylate. Among these ultraviolet absorbers, benzophenone-based and benzotriazole-based ones are preferred, and benzophenone-based ones include 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,
2'-dihydroxy-4-methoxybenzophenone and 2,2',4,4'-tetrahydroxybenzophenone are preferred, and in the benzotriazole type, 2-(2'-hydroxy-5'-methylphenyl) Benzotriazole, 2-(2'-hydroxy-5'-methylphenyl)-5,6-dichlorobenzotriazole, 2-(2'-hydroxy-5'-tert-butylphenyl)benzotriazole, 2-
(2'-hydroxy-3'-methyl-5'-tert-butylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chloro-benzotriazole and 2- (2'-hydroxy-5'-phenylphenyl)-5-chlorobenzotriazole, 2(2'-hydroxy-3'・5'-
ditertiarybutylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-5'-octoxyphenyl)benzotriazole, 2-
(2'-Hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-
(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5,6 dichlorobenzotriazole and the like are preferred. Particularly suitable UV absorbers have the formula or In the formula, R ₁ and R ₂ are the same or different and each represents a lower alkyl group or an aryl group (especially a phenyl group), and in particular R ₁ is preferably a branched lower alkyl group or a phenyl group having C ₅ or less. is a benzotriazole derivative represented by the following formula, where R ₃ represents an alkyl group of C ₆ or more, especially C ₈ to C ₁₀ , and X is a hydrogen atom or a halogen atom, especially a chlorine atom. The amount of the ultraviolet absorber as described above can be varied widely depending on the type of ultraviolet absorber, the type of synthetic resin used, the thickness of the film, etc. For example, 0.01 to 5 parts by weight, preferably 0.1 parts by weight per 100 parts by weight of the vinyl chloride resin coating composition.
A range of 4 parts by weight, more preferably 0.1 to 2.5 parts by weight is suitable. Hereinafter, several embodiments of the anti-fog and dust-proof film for agriculture and horticulture of the present invention will be explained in more detail with reference to comparative examples and examples. In addition, in the following examples, the test method and evaluation are as follows. (1) Dustproof test: - (1) A test house with a wooden frame with a width of approximately 3 m, a depth of approximately 4 m, a ridge height of approximately 1.5 m, and a roof slope of approximately 30 degrees is used. The length of the roof in the ridge direction is 1
The test film was constructed so that multiple wooden frames (spans) with a length of 1.2 m in the roof slope direction were formed, and the test film was made with the coating surface facing the outside of the house on the central span. . A test film is spread over the entire surface of the house except the bottom, and an accessible test house is constructed outdoors, and an anti-fog and dust-proof test is conducted under natural outdoor conditions. A temperature controller inside the house
A hot water tank maintained at a temperature of The solar radiation value was actually measured outside, and the other one was used to actually measure the solar radiation value at a position 20 cm directly below the approximate center of the test film stretched over the central span inside the house. It is expressed as a percentage of the actual value inside the house compared to the actual value outside the house. The larger the % value, the better the anti-fog and dust-proof properties. The test period was from September to March of the following year. (Part 2) Dustproof test Attach a 60 x 60 m/m test film to a glass plate with the coating side up using double-sided adhesive tape. Clean the dirt on the coating surface with powdered soap (synthetic detergent for washing). Heat the glass plate in an electric incubator (Kiya Seisakusho model A-) at 50℃.
2) After drying, cool to room temperature. Next, approximately 35 g/m ³ of talc (Wako Pure Chemical Reagent Grade 1) is sprinkled on the coating surface of the test film. This was placed in an electric incubator at 50°C for 3 days, then taken out and allowed to cool to room temperature. Next, the glass plate was tilted at an angle of approximately 30° and the height was approximately 300m/300m.
Sprinkle 20/m ³ of water over approximately 1 minute. Thereafter, the film was placed in an electric incubator at 50° C. for about 1 hour to dry the surface of the film, and then cooled to room temperature. Next, cut the film to 20 x 40 m/m and use an integrating sphere turbidity meter (Japan Seimitsu Optics, model: SEP).
-T), the diffuse transmittance and total transmittance are measured, and the haze (turbidity) is determined by the following formula. Haze (%) = Diffuse transmittance (%) / Total transmittance (%)
×100 The smaller the haze value, the better the anti-fog and dust-proof properties. Similar tests were conducted at 40°C and the results were evaluated. (2) Cracking resistance test: - A test film of 80 x 80 m/m was placed on a Tensilon (manufactured by Toyo Baldwin, model UTM-1-
5000B) with a distance between the gauge lines of 40m/m, and extend it by 100% at 500mm/min (40 → 80m/m).
After stretching it to the maximum, return it to the original position at the same speed. Repeat this operation three times. This film was cut into a size of 20 x 40 m/m and the haze (%) was determined in the same manner as in the anti-fog and dust-proof test (Part 2). The smaller the haze value, the better the crack resistance. Similar test with 200% elongation (40→120m/m)
were also conducted and the results were evaluated. (3) Blocking resistance test: - On a glass test tube (15φ x 150m/m),
A test film of 30 x 300 m/m is placed at one end.
While applying a load of 750g, roll it up with the coating film on the inside. Transfer the rolled material to a beaker, place the beaker in a desiccator filled with water at the bottom, and keep the humidity constant in an electric incubator at 50°C.
After maintaining the condition at 100% for one week, remove it and
Dry in an electric incubator at ℃ and then allow to cool to room temperature. Attach sellotape to the end of the roll and attach the weight to the sellotape. Gently rotate the test tube in the direction in which the film will be rewound. If the weight load does not cause unwinding, replace the test tube with a weight with a heavier load and repeat the test. Measure the load (g/30mm). The smaller the unwinding load, the better the blocking resistance. (4) Adhesion test with base film: - After subjecting the test film to three stretching and restoring operations in the same manner as the crack resistance test above, the film was placed in an electric incubator at 50℃ and humidity.
The sample was kept at 100% for one week, then taken out from the incubator, dried at 50°C, and cooled to room temperature. Apply Cellotape (manufactured by Sekisui, 18m/m width) to the coating side of this film at 50m/m.
Apply it to the length of , press it firmly with your finger, then peel it off vigorously and check the degree to which the coating surface peels off from the base material. 〇: No peeling at all △: Less than 20% peeling ×: 20% or more to 50% peeling × ×: 50% or more peeling (5) Heat sealability test: - Output using a high frequency sewing machine made by Takano Electric. At dial scale 55 and speed scale 2 (film feed speed 3 m/min), seal the coated side and uncoated side overlappingly, cut this sample into 1 cm width x 10 cm length, open the sample, The stress (Kg/cm) required for rupture or peeling was determined using a tensile tester. (6) Curling test: - Grasp one end of a test film cut to 80 x 80 m/m with your fingers and lift it to check the degree of curl. 〇: Not curled at all △: Slightly curled ×: Significantly curled (7) Tack test immediately after production: - Edge of base film fixed to glass plate in advance with coating liquid adjusted to 10% solids concentration After washing, immediately coat with a wire bar (manufactured by Kodaira Seisakusho, wire diameter 0.15 m/m), and dry in a hot air dryer (manufactured by Tabai, model HPS-11) at 140°C.
℃ for 4 minutes to evaporate the solvent. After cooling to room temperature, check the adhesion of the coated surface with your finger. Furthermore, the degree of peeling is observed after the coated surfaces are pressed together with fingers. 〇: No tackiness at all △: Slight tackiness ×: Significant tackiness (8) Transparency test: - Test film (base film thickness 150
μ: Coating film thickness 3μ) 20×40m/m
Measure the diffused transmittance and total transmittance with an integrating sphere turbidity meter to determine the haze (%). ○: Haze 5% or less Δ: Haze 6-10% ×: Haze 11% or more. (9) Surface crack test during winter: - In the outdoor test expansion house for the dustproof test (Part 1), in mid-March after the test, the film was stretched 30 cm Cut into 30cm square pieces. Add another 2cm x 2cm to the center of this film.
Cut into square pieces and observe the coated surface using an optical microscope at 100x magnification. Based on this observation, the degree of cracking in the film coat surface layer is evaluated as follows. Grade 5: No cracks observed at all Grade 4: Slight cracks observed (less than 10 lines in the visual field) Grade 3: Slight cracks observed (no cracks observed in the visual field)
20 or less) Grade 2: Considerable cracks are observed (within the visual field
40 lines or less) Grade 1: Significant cracks are observed (41 or more lines in the visual field) In the following Examples and Comparative Examples, the abbreviations are as follows. Base film: - [Composition] [Parts by weight] Polyvinyl chloride resin (degree of polymerization 1300) 100 Dioctyl phthalate (plasticizer) 45 Tricresyl phosphate (plasticizer) 5 Epoxidized soybean oil (plasticizer) 5 Stearin Cadmium acid (stabilizer) 1 Barium stearate (stabilizer) 0.2 Sorbitan monostearate (antifogging agent) 1.3 Sorbitan monopalmitate (antifogging agent) 0.7 2-(2'-Hydroxy-3', 5'-di tertbutylphenyl)-5-chlorobenzotriazole (ultraviolet absorber) 0.8 The above ingredients are mixed and made into a base film with a thickness of 150 microns at 170°C using a calender. PVC: - Polyvinyl chloride, degree of polymerization 450. VC/VAC (1): - Vinyl chloride-vinyl acetate copolymer (1): - Vinyl chloride/vinyl acetate ratio 90wt%/10w% Degree of polymerization approximately 450. VC/VAC (2): - Vinyl chloride-vinyl acetate copolymer (2): - Vinyl chloride/vinyl acetate ratio 85wt%/15wt% Degree of polymerization approximately 450. VC/VAC (3): - Vinyl chloride-vinyl acetate copolymer (3): - Vinyl chloride/vinyl acetate ratio 80wt%/20wt% Degree of polymerization approximately 800. MMA/EMA: - Methyl methacrylate/ethyl methacrylate copolymer, MMA/EMA ratio 88wt%/12wt%, molecular weight approximately 200,000. VC/VDC: - Vinyl chloride/vinylidene chloride copolymer, VC/VDC ratio 80wt%/20wt%, molecular weight approximately 450. MMA/BMA/2HEMA/AA:- Methyl methacrylate/butyl methacrylate/2-hydroxyethyl methacrylate/acrylic acid copolymer, MMA/BMA/2HEMA/AA
Ratio 45wt%/35wt%/18wt%/2wt%. Examples 1 to 5 and Comparative Examples 1 to 6 A coating film of a coating composition shown in Table 1 below was formed on the base film described above. The coating film was prepared by adding resin and other additives to methyl ethyl ketone/toluene (1:1 weight ratio) in the ratio shown in the ratio (wt%) column of Table 1.
Gradually add and dissolve the coating liquid in the mixed solvent and adjust the solid content to 10% using a wire bar (0.15
m/m wire diameter) in a hot air dryer.
It was formed by drying at the drying temperature and for 4 minutes. The results of testing the performance of the obtained dustproof film are shown in Tables 1 and 2 below. In addition, when preparing the test film for the dustproof test (part 1), a three-roll reverse roll coater with a roll surface length of 1200 m/m width was used, and the coating thickness was adjusted to 1.5 microns after drying. Coated. Table 1 also shows the results of Comparative Examples 1 to 6, which do not satisfy the essential requirements of the present invention, and a control example using only the base film.

【table】

【table】

[Table] M)
Example 6 In Example 3, acrylic acid, butyl acrylate, or 2-hydroxymethacrylate listed in Table 3 was added to the monomer for copolymerizing MMA-EMA (2) as a third component to the total weight of MMA-EMA. Table 3 shows the results of a test conducted in exactly the same manner as in Example 3, except that the terpolymer polymerized by adding 3 parts by weight of each of the MMA-EMA(2) copolymers was substituted for the MMA-EMA(2) copolymer.

【table】

Claims (1)

[Scope of Claims] 1. [A](i) Vinyl chloride/vinyl acetate copolymer resin (ii) Vinyl chloride polymer resin on one or both sides of a vinyl chloride resin film containing at least an antifogging agent. and (iii) contains a methyl methacrylate/ethyl methacrylate polymer resin, and [B] the sum of (i) and (ii) above is the sum of (i), (ii) and (iii) above.
occupies 50% by weight or more based on the total weight of [C], and the weight ratio of (i) and (ii) above is (i):(ii)=1:2
A dustproof film for agriculture and horticulture, characterized in that it has a coating film of a vinyl chloride resin coating composition having a ratio of ~2:1. 2. Claim 1, wherein the vinyl chloride resin coating composition further contains up to about 3% by weight of an antifog agent, based on the total weight of (i), (ii), and (iii). Film mentioned in section. 3 The weight ratio of vinyl chloride to vinyl acetate in the (i) vinyl chloride/vinyl acetate copolymer resin is
The film according to claim 1, wherein the vinyl chloride:vinyl acetate ratio is 70-95:30-5. 4. A patent claim in which the weight ratio of methyl methacrylate to ethyl methacrylate in said (iii) methyl methacrylate/ethyl methacrylate copolymer resin is methyl methacrylate: ethyl methacrylate = 60-95:40-5. A film according to item 1 in the range.