JPH09164642A - Agricultural polyethylene terephthalate film - Google Patents

Abstract

(57) [Abstract] [Problem] Excellent anti-adhesion performance of algae and its durability,
Also, provide polyethylene terephthalate film for agriculture that maintains transparency. SOLUTION: An ultraviolet absorber, one or more kinds of phenylurea compounds represented by the following general formula (I), and zinc dimethyldithiocarbamate are provided on one surface of a biaxially stretched polyethylene terephthalate film. Forming an acrylic resin-containing coating (A) on the other surface, (a) an aqueous dispersion of a hydrophobic acrylic resin having a glass transition temperature in the range of 35 to 80 ° C., and (b) an inorganic substance. Colloidal sol and solid content 100 of component (c) (b)
A polyethylene terephthalate film for agriculture, comprising a coating (B) derived from a composition containing 0.01 to 30 parts by weight of a water-soluble inorganic chlorine compound, based on parts by weight. Embedded image

Description

Detailed Description of the Invention

[0001]

The present invention relates to an agricultural polyethylene terephthalate film. More specifically, the present invention relates to a polyethylene terephthalate film for agriculture which is excellent in algae adhesion prevention (algae prevention performance) and its sustainability and maintains transparency.

[0002]

2. Description of the Related Art In recent years, the area of facilities has increased with the expansion of facility horticulture, and the polyethylene terephthalate film for agriculture has been often used in various regions.
At the same time, since the environment used has become diversified, the environmental conditions inside and outside the house have become relatively hot and humid, so that algae grow on the outside or inside of the house where the polyethylene terephthalate film is spread, and the sun's rays penetrate. In addition to inhibiting the above, the number of cases of lowering the mechanical strength of the film has increased. In general, algae are microorganisms that exist in surface water, have photosynthetic ability because they have chlorophyll, and the surface is often covered with an adhesive substance, so the generation of algae on the film is physically, It is difficult to prevent mechanically or remove the generated one.

Conventionally, in order to remove algae from a film in which algae have been generated, there is only a method of physically rubbing it off or waiting for it to be dried and naturally peeled off. The method is also difficult, and it is possible to kill algae by using an aqueous solution of sodium hypochlorite in an attempt to kill algae with chemicals, but it is not necessary to remove dead algae from the film. Yes, and the sustainability of the algicidal effect cannot be expected for so long.

In order to improve these, it has been proposed to incorporate various germicides into the polymer for forming a film (Japanese Patent Publication No. 7-55553, Japanese Patent Publication No. 6-8041).
JP-A-5-179028), it is difficult to maintain the anti-algae property and the transparency for a long time because the coating film containing the bactericide is easily peeled off.

[0005]

It is considered that such peeling of the coating film is influenced by the blocking phenomenon that occurs when the film is wound and stored, and the present inventors have
The present invention has been completed as a result of extensive studies aimed at providing an agricultural polyethylene terephthalate film capable of preventing film peeling due to blocking, and further improving algae resistance and maintaining transparency. It is a thing.

[0006]

SUMMARY OF THE INVENTION However, the gist of the present invention is that a biaxially stretched polyethylene terephthalate film is provided on one side with an ultraviolet absorber and a phenylurea represented by the general formula (I). 1 or 2 of the system compounds
Hydrophobic acrylic resin having a glass transition temperature in the range of 35 to 80 ° C., on the other surface of which a coating film (A) made of an acrylic resin containing at least one species and zinc dimethyldithiocarbamate is formed. To a composition containing 0.01 to 30 parts by weight of a water-soluble inorganic chlorine compound with respect to 100 parts by weight of the solid content of the component (b), and (b) an inorganic colloid glue. It exists in the polyethylene terephthalate film for agriculture which is formed with the coating (B) derived from it.

Hereinafter, the present invention will be described in detail. 1. Polyethylene terephthalate film In the present invention, polyethylene terephthalate means not only polyethylene terephthalate / homopolymer but also copolymerized polyethylene terephthalate and ethylene terephthalate in which the repeating unit of ethylene terephthalate is 85% or more and the rest is other component It is 85% by weight or more and the remaining 15% by weight or less includes a polymer blend which is another polymer. Other polymers that can be blended include polyamides, polyolefins, and other types of polyesters. This polyethylene terephthalate, if necessary, usually,
Additives such as lubricants, colorants, stabilizers, and antioxidants that are added to polyethylene terephthalate can be added.

The polyethylene terephthalate film according to the present invention is stretched biaxially, but the magnification is
The width is preferably 2.0 to 5.0 times. If the stretching ratio is less than 2.0 times, the strength of the product will not be sufficient, which is not preferable. If the stretching ratio exceeds 5.0 times, the strength of the product will be sufficient, but the manufacturing work will be difficult. Therefore, it is not preferable. The stretching ratio is 2.5 to 4.0 in both biaxial directions.
A double range is particularly preferred. The method for producing the biaxially stretched film is not particularly limited and may be any conventionally known method such as sequential or simultaneous biaxial stretching. The polyethylene terephthalate film according to the present invention has a thickness of 0.01 to 0.3.
mm is preferred. If the thickness is less than 0.01 mm, the strength of the product is not sufficient, which is not preferable, and if it exceeds 0.3 mm, the film becomes hard and difficult to handle, which is not preferable.

[0009] 2. Coating (A) The agricultural polyethylene terephthalate film according to the present invention is a coating made of an acrylic resin containing, on one surface thereof, an ultraviolet absorber, one or more kinds of phenylurea compounds, and zinc dimethyldithiocarbamate. (A) is formed.

In the present invention, the acrylic resin is mainly composed of a methacrylic acid alkyl ester monomer or a methacrylic acid alkyl ester monomer in the presence of a crosslinked acrylic acid ester elastic material and can be copolymerized therewith. It is a graft copolymer obtained by polymerizing a mixture with another vinyl-based monomer, wherein the cross-linked acrylic acid ester-based elastic material is from 5 to 8%.
Those containing 0% by weight are preferred.

The crosslinked acrylic ester type monomer is obtained by polymerizing a crosslinkable monomer and a (meth) acrylic acid alkyl ester monomer or a vinyl type monomer copolymerizable therewith. It is a polymer. The crosslinkable monomer may be one that is usually used as a polyfunctional compound, and specific examples include ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate,
1,4-butylene glycol dimethacrylate, propylene glycol dimethacrylate, trimethylolpropane trimethacrylate, tetramethylolmethane tetramethacrylate, dipropylene glycol dimethacrylate, divinylbenzene, divinyl adipate, diallyl phthalate, diallyl malate, allyl acrylate, allyl methacrylate , Triallyl cyanurate and the like, and two or more of them may be used in combination.

The (meth) acrylic acid alkyl ester monomer is an alkyl ester of acrylic acid or methacrylic acid, and specifically, for example, methyl acrylate, ethyl acrylate, -n-propyl acrylate, Isopropyl acrylate, -n-butyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, methyl methacrylate, ethyl methacrylate, methacrylic acid-
n-propyl, isopropyl methacrylate, -n-butyl methacrylate, 2-ethylhexyl methacrylate,
Examples thereof include decyl methacrylate and the like, and generally, an alkyl acrylate having an alkyl group having 1 to 20 carbon atoms and / or an methacrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms are used. You may mix and use.

Vinyl-based monomers copolymerizable with these (meth) acrylic acid alkyl ester monomers include methacrylic acid and alkyl esters of methacrylic acid (having 1 to 12 carbon atoms in the alkyl group) and dialkyl of itaconic acid. Examples thereof include esters (alkyl groups having 1 to 10 carbon atoms), acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, styrene, nuclear alkyl-substituted styrene, and α-methylstyrene. These monomers are used in an amount of 40% by weight or less, preferably 25% by weight or less.

The crosslinked acrylic ester type elastic body is preferably produced by an emulsion polymerization method. The polymerization initiator that can be used at this time is a usual free radical generation initiator. Specific examples include inorganic peroxides such as potassium persulfate and ammonium persulfate; organic hydroperoxides such as cumene hydroperoxide, p-menthane hydroperoxide, ditertiary butyl hydroperoxide; benzoyl peroxide and lauroyl peroxide. Examples thereof include organic peroxides such as oxide and cumene peroxide, and azo initiators such as azobisisobutyronitrile.

Further, an ordinary redox initiator obtained by combining these with a reducing agent such as sodium sulfite, sodium acid sulfite, sodium thiosulfate, sodium formaldehyde sulfoxylate, glucose, polyamine, hydroxyacetone ascorbate is also used. sell.
Usable emulsifiers include ordinary surfactants for emulsion polymerization. For example, anionic surfactants such as sodium, potassium and ammonium salts of alkyl sulfates having 8 to 20 carbon atoms and sodium and potassium salts of aliphatic carboxylic acids such as lauric acid, stearic acid and palmitic acid, and alkylphenols And non-ionic surfactants such as aliphatic alcohols and reaction products of polypropylene oxides and ethylene oxide. In some cases, two or more of these surfactants can be used in combination. Further, a surfactant such as naphthaleneformaldecht condensed sulfonate may be added. If necessary, a cationic surfactant such as an alkylamine hydrochloride can be used.

The method for producing a crosslinked acrylic ester type elastomer by the emulsion polymerization method includes the following. (1) An emulsion polymerization method in which a small amount of a crosslinkable monomer is added to an acrylic acid alkyl ester monomer or a mixture of an acrylic acid alkyl ester monomer and a vinyl monomer copolymerizable therewith. How to manufacture by.

(2) An acrylic acid alkyl ester monomer or an acrylic acid alkyl ester monomer and a vinyl monomer copolymerizable therewith are added to the polymer emulsion obtained by the method (1). A method in which a mixture is added and the mixture is produced by an emulsion polymerization method. (3) The method of (2), wherein a small amount of a crosslinking agent is added to the monomer or the monomer mixture, and the mixture is produced by an emulsion polymerization method.

(4) First, an uncrosslinked polymer is prepared from an acrylic acid alkyl ester monomer or a mixture of an acrylic acid alkyl ester monomer and a vinyl monomer copolymerizable therewith by an emulsion polymerization method. To manufacture. Then, an acrylic acid alkyl ester monomer, or a mixture of an acrylic acid alkyl ester monomer and a vinyl-based monomer copolymerizable therewith, and a small amount of a crosslinkable monomer are added to the polymer. , A method for producing by an emulsion polymerization method.

(5) To one of the polymer emulsions obtained by the methods (1) to (4), an acrylic acid alkyl ester monomer or a vinyl-based monomer copolymerizable therewith is added and crosslinked. A method of producing by an emulsion polymerization method, in which the polymerizable monomer is not added or a small amount thereof is added. The cross-linked acrylic ester-based elastic body adjusts the average particle diameter of the cross-linked elastic emulsion particles by adjusting the amount of the surfactant used and the amount of the aqueous medium to be used, and is 0.05 to 0.30 μm. It is preferable to set it as the range. When the thickness is less than 0.05 μm, the mechanical strength of the acrylic resin used as a coating is lowered, and when it exceeds 0.30 μm, stress whitening becomes remarkable, which is not preferable.

Further, the crosslinked acrylic ester type elastic body is
It is preferable that the gel content measured by the following method is 80% or more and the swelling degree is 15 or less. A predetermined amount W _{0 of the} crosslinked elastic body was sampled, and the swollen weight W ₁ after being immersed in methyl ethyl ketone for 48 hours at room temperature and the weight W ₂ after drying this sample with a vacuum dryer were measured, and calculated by the following formula. To do.

[0021]

## EQU1 ## Gel content = (W ₂ / W ₀ ) × 100 (%) Swelling degree = (W ₁ -W ₂ ) / W ₀

The gel content and the degree of swelling are not limited to the above-mentioned adjustment of the type and amount of the cross-linkable monomer, but also the temperature at which the elastic body is polymerized, the type of the initiator and its amount used, and the unit constituting the elastic body. Since it is influenced by various polymerization conditions such as a method of adding a monomer and the presence / absence of a molecular weight modifier, it is preferable to appropriately adjust. When the gel content is less than 80%, the film-forming acrylic resin obtained from the elastic body is completely dissolved or excessively swelled in the organic solvent described below, and the elastic body particles are deformed, It is not preferable because it loses the function of improving mechanical strength, particularly impact resistance. Regarding the degree of swelling, if it exceeds 15, stress whitening tends to occur, which is not preferable.

The monomer to be grafted on the crosslinked acrylic ester type elastomer is mainly composed of methacrylic acid alkyl ester or methacrylic acid alkyl ester,
It is a mixture with this and a vinyl-based monomer copolymerizable therewith.
The alkyl methacrylate ester as a component to be grafted may be selected from the above-mentioned ones used in the production of an elastic body, and a vinyl monomer copolymerizable therewith is also used in the production of an elastic body. May be selected from those exemplified above.

In this case, the glass transition temperature (T) of the polymer or copolymer itself obtained from the monomer component to be grafted
It is preferable to select the type and combination of monomers so that g) is 50 ° C. or higher. When Tg is less than 50 ° C,
This is not preferable because the polyethylene terephthalate film on which a coating film of an acrylic resin containing this graft polymer is formed has poor blocking resistance (is easily blocked).

The graft polymerization reaction is preferably carried out by an emulsion polymerization method, but may also be carried out by a solution polymerization method. When the emulsion polymerization method is used, for example, a monomer to be grafted is added to the emulsion of the crosslinked acrylate-based elastic material, and if necessary, an emulsifier, a polymerization initiator, a molecular weight regulator,
Water and the like can be added to select and carry out ordinary emulsion polymerization conditions.

The ratio of the crosslinked elastomer to the grafted monomer in carrying out the graft polymerization reaction is 10 to 90 parts by weight of the crosslinked elastic emulsion as a polymer solid content, and the grafted monomer is 90 to 10 parts by weight. It is better to choose from the range of parts by weight. The graft polymer can be used as an acrylic resin for forming a film as it is, or by blending a transparent hard thermoplastic resin having a compatibility with the graft polymer and a Tg of 50 ° C. or higher. In the latter case, when blending, the proportion of the crosslinked elastic body contained in the acrylic resin is 5 to 80% by weight, preferably 10 to 50% by weight.
It is better to set the range. When the proportion of the crosslinked elastic body is less than 5% by weight, the mechanical strength is inferior, and when it exceeds 80% by weight, the film having this as a coating film has poor blocking resistance, which is not preferable.

An ultraviolet absorber, a phenylurea compound and zinc dimethyldithiocarbamate are mixed with these acrylic resins to form a coating on one side of the base film. Examples of the type of the ultraviolet absorber include conventionally known ultraviolet absorbers such as salicylic acid compounds, cyanoacrylate compounds, benzophenone compounds, and benzotriazole compounds. Among these, a benzophenone compound and / or a benzotriazole compound are preferable when evaluated from the viewpoints of solubility in an acrylic resin, weather resistance when applied to a polyethylene terephthalate film and used for agriculture.

The benzophenone compounds include 2-hydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone. 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-
Hydroxy-4-benzoyloxybenzophenone,
2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfonebenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4' -Dimethoxybenzophenone, 2-hydroxy-5-chlorobenzophenone, bis- (2-methoxy-4-hydroxy-5-benzoylphenyl) methane and the like.

The benzotriazole-based compound is 2
-(2'-hydroxyphenyl) benzotriazole,
2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-5-methylphenyl) -5-carboxylic acid butyl ester benzotriazole, 2- (2'-hydroxy-5 ' -Methylphenyl) -5,6-dichlorobenzotriazole, 2-
(2'-Hydroxy-5'-methylphenyl) -5-ethylsulfone benzotriazole, 2- (2'-hydroxy-5'-t-butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy) -5'-t-butylphenyl) benzotriazole, 2- (2'-hydroxy-5'-aminophenyl) benzotriazole,
2- (2'-hydroxy-3 ', 5'-dimethylphenyl) benzotriazole, 2- (2'-hydroxy-
3 ', 5'-Dimethylphenyl) -5-methoxybenzotriazole, 2- (2'-methyl-4'-hydroxyphenyl) benzotriazole, 2- (2'-stearyloxy-3', 5'-dimethylphenyl ) -5-Methylbenzotriazole, 2- (2'-hydroxy-5-
Carboxylic acid phenyl) benzotriazole ethyl ester, 2- (2'-hydroxy-3'-methyl-5'-t
-Butylphenyl) benzotriazole, 2- (2'-
Hydroxy-3 ', 5'-di-t-butylphenyl)-
5-chlorobenzotriazole, 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl) -5-
Chlorobenzotriazole, 2- (2'-hydroxy-
5'-methoxyphenyl) benzotriazole, 2-
(2'-Hydroxy-3 ', 5'-di-t-butylphenyl) -5-chlorobenzotriazole, 2- (2'-
Hydroxy-5'-cyclohexylphenyl) benzotriazole, 2- (2'-hydroxy-4 ', 5'-dimethylphenyl) -5-carboxylic acid benzotriazole butyl ester, 2- (2'-hydroxy-3', 5 ′
-Dichlorophenyl) benzotriazole, 2- (2 '
-Hydroxy-4 ', 5'-dichlorophenyl) benzotriazole, 2- (2'-hydroxy-3', 5'-
Dimethylphenyl) -5-ethylsulfone benzotriazole, 2- (2'-hydroxy-4'-octoxyphenyl) benzotriazole, 2- (2'-hydroxy-5'-methoxyphenyl) -5-methylbenzotriazole, 2- (2'-hydroxy-5'-methylphenyl) -5-carboxylic acid ester benzotriazole, 2
Examples include-(2'-acetoxy-5'-methylphenyl) benzotriazole and the like.

Furthermore, the benzophenone compounds and the benzotriazole compounds, polymers and polymers are also included. The amount of the ultraviolet absorber blended in the acrylic resin is too small, the object of the present invention is not achieved,
Too much can cause bleed-out problems. The preferred amount is 1 part by weight per 100 parts by weight of the acrylic resin.
The range of -40 parts by weight, especially 5-30 parts by weight is preferred.

In the phenylurea compound represented by the general formula (I), R ¹ represents a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, a p-chlorophenoxy group or a p-methoxyphenoxy group. Examples of the halogen atom include a bromine atom and a chlorine atom, and examples of the lower alkyl group include an alkyl group having 5 or less carbon atoms such as a methyl group, an ethylmer group, a propyl group, a butyl group and a pentyl group. Examples of the lower alkoxy group include an alkoxy group having 5 or less carbon atoms corresponding to the above alkyl group. In R ¹ , preferred alkyl groups and alkoxy groups are methyl group and methoxy group.

R ² represents a hydrogen atom, a halogen atom, a trifluoromethyl group or a t-butylaminocarbonyloxy group (-OCONHC (CH ₃ ) ₃ ). And as a halogen atom, a bromine atom, a chlorine atom, etc. are mentioned. In R ² , a preferable halogen atom is a chlorine atom. R ³ and R ⁴ represent a hydrogen atom or a lower alkyl group. As the lower alkyl group, the same alkyl group having 5 or less carbon atoms as in R ¹ can be mentioned. R
^{In 3} and R ⁴ , a preferred alkyl group is a methyl group.

R ⁵ is a hydrogen atom, a lower alkyl group, a lower alkoxy group, an o-methylcyclohexyl group, α, α-
Dimethylbenzyl group _{(-C (CH 3) 2 -C} 6 H 6),
1-methyl-2-propynyl group (-CH (CH ₃₎ CC
H) is represented. Examples of the lower alkyl group and the lower alkoxy group include the same alkyl groups and alkoxy groups having 5 or less carbon atoms as in R ¹ . Preferred alkyl and alkoxy groups for R ⁵ are methyl group, butyl group and methoxy group.

Specific examples of the above phenylurea compounds include the following. (A) Dichlorophenyldimethylurea (b) Chlorophenoxyphenyldimethylurea (c) Dichlorophenylmethylbutylurea

(D) Dichlorophenylmethoxymethylurea (e) Dimethylbenzylmethylphenylurea (f) Chlorophenyldimethylurea (g) Dimethylbenzyl p-tolylurea (h) Dimethylureidophenyl t-butylcarbamate

(I) Chlorophenylmethylpropynylurea (j) Fluoromethylphenyldimethylurea (k) Bromophenylmethoxymethylurea (l) Methylcyclohexylphenylurea The amount of the phenylurea-based compound used is the acrylic resin 10
0 to 30 parts by weight, especially 0.5 to 2 parts by weight
A range of 0 parts by weight is preferred. If the amount used is less than 0.5 parts by weight, the object of the present invention may not be sufficiently achieved, and if it is more than 30 parts by weight, the transparency when formed into a film may deteriorate and the algae-proof property may be reduced. Is not sufficient and is not preferable.

On the other hand, the amount of zinc dimethyldithiocarbamate used was 0.
The range of 01 to 10 times by weight, particularly 0.1 to 2 times by weight is preferable. When the amount used is less than the above range, the combined effect of zinc dimethyldithiocarbamate is not sufficient, and when it is more than the above range, the combined effect is saturated and the weather resistance and transparency of the coating film deteriorate. There is.

Zinc dimethyldithiocarbamate does not exert an antialgal effect by itself, but when it is used together with a phenylurea compound, an extremely strong antialgal effect is exerted over a long period of time. The reason for this and the plant physiological action have not been sufficiently investigated at the present time, but it is considered that the two act together to exhibit a synergistic toxic action. Other herbicides, fungicides, fungicides, insecticides, pest repellents and the like can be used in combination with the composition of the coating film (A) for the purpose of enhancing efficacy or expanding application. Further, if necessary, auxiliary components such as a film-forming aid, a surfactant, an antioxidant, a colorant, a stabilizer, a thickener, a defoaming agent and the like can be added.

The thickness of the coating film (A) made of these compositions is not preferable because the object of the present invention cannot be achieved if it is too thin. If it is too thick, the coating film tends to peel off. The range of 10 μm is preferable. To form the coating film (A), first, biaxially stretched polyethylene terephthalate is produced. Then, on one side of the biaxially stretched polyethylene terephthalate film, one kind of ketones such as methyl ethyl ketone, aromatic hydrocarbons such as benzene, toluene and xylene, acetic acid esters such as methyl acetate and ethyl acetate, etc. Alternatively, an acrylic resin in an organic solvent obtained by mixing two or more kinds,
A solution in which an ultraviolet absorber, a phenylurea-based compound, zinc dimethyldithiocarbamate, and the like are dissolved is applied, and the organic solvent is volatilized by a method such as heating to form an acrylic resin film. As a coating method, a commonly used gravure coating method, a reverse coating method, a spray method, or the like is suitable.

3. Coating (B) In the agricultural polyethylene terephthalate film according to the present invention, a coating (B) made of a composition containing components (a) to (c) is formed on the surface opposite to the surface on which the coating (A) is formed. Has been done. The hydrophobic acrylic resin which is the component (a) of the composition used in the present invention may be any one as long as it has a glass transition temperature in the range of 35 to 80 ° C.
(Meth) acrylic acid alkyl esters or (meth)
100 to 60% by weight of a mixture of acrylic acid alkyl esters and alkenylbenzenes, and 0 to 40% by weight of α, β-ethylenically unsaturated monomer copolymerizable therewith
A homopolymer or a copolymer obtained by polymerizing is preferred.

The (meth) acrylic acid alkyl ester may be selected from those exemplified in 2 above. Examples of the alkenylbenzenes include styrene, α-methylstyrene, vinyltoluene and the like. When a mixture of alkenylbenzenes and (meth) acrylic acid alkyl esters is used, it is usually (meth) acrylic acid alkyl esters, although it varies depending on the amount of the α, β-ethylenically unsaturated monomer used. It is preferable to use 10% by weight or more, and it is preferable that the content of alkenylbenzenes in the hydrophobic acrylic resin is 70% by weight or less.

The hydrophobic acrylic resin used in the present invention is
It contains at least 60% by weight of a (meth) acrylic acid alkyl ester or a mixture thereof with an alkenylbenzene. If the amount is less than 60% by weight, the water resistance of the formed coating film is not sufficient, which is preferable. Absent. Α, β copolymerizable with the above-mentioned (meth) acrylic acid alkyl esters or a mixture thereof with alkenylbenzenes
-As the ethylenically unsaturated monomer, for example, α, β-ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid, and itaconic acid; Like α,
β-ethylenically unsaturated sulfonic acids; 2-acrylamido-2-methylpropanoic acid; α, β-ethylenically unsaturated phosphonic acids; hydroxyl-containing vinyl monomers such as hydroxyethyl of acrylic acid or methacrylic acid; acrylonitriles; Acrylic amides include glycidyl esters of acrylic acid or methacrylic acid. These monomers are
These may be used alone or in combination of two or more.
It can be used in the range of 0% by weight.

As a method of polymerizing the hydrophobic acrylic resin from these monomers, various conventionally known emulsifiers such as anionic surfactants, cationic surfactants and nonionic surfactants are used. Method in the presence of one or more selected from agents, a method of emulsion polymerization in an aqueous medium, a method of polymerization using a reactive emulsifier, and a method of polymerization based on oligosoap theory without containing an emulsifier. Etc. In the case of the polymerization method in the presence of an emulsifier, these emulsifiers are added in an amount of 0.
It is used in the range of 1 to 10% by weight. Outside this range, it is difficult to control the polymerization rate, and the dispersion stability of the synthesized resin is poor.

Examples of the polymerization initiator used in the production of the hydrophobic acrylic resin include persulfates such as ammonium persulfate and potassium persulfate, organic peroxides such as acetyl peroxide and benzoyl peroxide. To be These are 0.1 to the total amount of the charged monomers.
Used in the range of 10% by weight. The hydrophobic acrylic resin in the present invention has a glass transition temperature (Tg) of 35.
It must be in the range of -80 ° C. Such Tg can be obtained by selecting the type of monomer used and the amount (blending amount) used. If the Tg of the acrylic resin used exceeds 80 ° C., it is difficult to obtain a transparent and uniform coating film. When the Tg is less than 35 ° C., the inorganic colloidal particles are likely to aggregate several times to form a non-uniform dispersion state, and the inorganic colloidal particles are not sufficiently fixed to the coating substrate, so that the inorganic colloidal particles may not be adhered to with time. Colloidal particles fall off from the surface of the base material and flow away, impairing the algae preventive performance.

Component (a) of the composition of the coating (B) of the present invention
The aqueous dispersion of the hydrophobic acrylic resin is a product obtained by adding a liquid dispersion medium to this, even if the aqueous emulsion obtained by polymerizing each monomer in an aqueous medium is used as it is. Alternatively, the polymer produced by the above polymerization may be separately collected and redispersed in a liquid dispersion medium to obtain an aqueous dispersion.

The inorganic colloid sol which is the component (b) is
When applied to the surface of a polyethylene terephthalate film having excellent surface smoothness, it fulfills the function of giving unevenness to the film surface. As the inorganic colloid sol, for example, silica, alumina, water-insoluble lithium silicate, iron hydroxide, tin hydroxide, titanium oxide, inorganic aqueous colloid particles such as barium sulfate, by various methods,
Examples thereof include an aqueous sol dispersed in water or a hydrophilic medium. Among them, silica sol and alumina sol are preferable. These may be used alone or in combination. The inorganic colloid sol to be used preferably has a solid average particle diameter in the range of 5 to 100 μm. Within this range, two or more types of colloid sols having different average particle sizes may be used in combination. When the average particle diameter exceeds 100 mμ, the coating film is white and devitrified, and the transparency is lowered, which is not preferable. If it is less than 5 μm, the stability of the inorganic colloid sol may be lacking.

The inorganic colloid sol is preferably blended in a solid content weight ratio of 0.5 to 4 with respect to the acrylic resin. When it is less than 0.5, the ability to prevent sufficient blocking cannot be exhibited, and when it exceeds 4, when the film is transparent, the coating film formed after coating becomes cloudy and has a light transmittance. It is not preferable because the coating film is lowered and the coating film tends to be rough and weak.

Examples of the water-soluble inorganic chlorine compound as the component (c) include hydrogen chloride, ammonium chloride, sodium chloride, potassium chloride, calcium chloride, magnesium chloride, barium chloride, zinc chloride, lithium chloride, aluminum chloride, first chloride. Examples thereof include iron, ferric chloride, stannic chloride, mercuric chloride, sodium hypochlorite, potassium hypochlorite, calcium hypochlorite and the like.

Among these water-soluble inorganic chlorine compounds, monovalent chlorine compounds are particularly preferable. Also, these may be used in combination of two or more. The amount of the water-soluble inorganic chlorine compound added is 0.01 to 30 parts by weight, particularly 0.01 to 20 parts by weight, and particularly preferably 0.01 to 10 parts by weight, based on 100 parts by weight of the solid content of the inorganic colloid sol.

When the chlorine compound is a liquid, it means 100% by weight of the active ingredient. When the addition amount is less than 0.01 part by weight, uniform unevenness is difficult to be formed on the surface, so that the anti-blocking performance is not exhibited and the effect of improving the algae protection persistence is insufficient. If the amount is more than 30 parts by weight, the inorganic colloid sol in the coating liquid aggregates, the transparency of the coating film is reduced, and the algae-preserving effect is impaired.

It is preferable to add a crosslinking agent to the composition of the film (B). The acrylic resin is cross-linked by the cross-linking agent, and the strength of the coating film can be improved. Examples of the crosslinking agent include phenolic resins, amino resins, amine compounds, aziridine compounds, azo compounds, isocyanate compounds, epoxy compounds, silane compounds, etc. And epoxy compounds.

As the amine compounds, aliphatic polyamines such as diethylenetriamine, triethylenepentamine and hexamethylenediamine; 3,3'-dimethyl-4,
Alicyclic amines such as 4'-diaminodicyclohexylmethane and isophoronediamine; and aromatic amines such as 4,4'-diaminodiphenylmethane and m-phenylenediamine are used.

As the aziridine compound, tris 2,
4,6- (1-Aziridinyl) -1,3,5triazine, trimethylolpropane-tri-β-aziridinylpropionate, tris [1- (2-methyl) aziridinyl] phosphine oxide, hexa [1- (2-Methyl) -aziridinyl] triphosphatriazine and the like are used.

Examples of the epoxy compounds include a reaction product of bisphenol A or phenol F and epichlorohydrin, an epoxidized novolak resin formed by reaction of a resin reaction product of phenol (or a substituted phenol) with formaldehyde, and epichlorohydrin, and epichlorohydrin. And an aliphatic polyhydric alcohol such as glycerol, 1,4-butanediol, poly (oxypropylene) glycol or a resinous reaction product produced from a similar polyhydric alcohol component, and a resin obtained by epoxidation using peracetic acid, etc. Is used. In the case of epoxy compounds, it is preferable to use a tertiary amine or a quaternary ammonium salt in combination as a catalyst.

These crosslinking agents can be used in an amount of 0.1 to 30% by weight based on the acrylic resin solid content. In particular, the range of 0.5 to 10% by weight is preferable. Thus, the composition of the coating (B) is usually used in liquid form. The liquid dispersion medium includes an affinity or water-miscible solvent containing water, and water: monohydric alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol:
Polyhydric alcohols such as ethylene glycol, diethylene glycol and glycerin: cyclic alcohols such as benzyl alcohol: cellosolve acetates: ketones and the like.

These may be used alone or in combination, but they are determined in consideration of the dispersion stability of the composition to be used, the leakage property after coating on the film surface, the difficulty of removing the liquid dispersion medium, and the economical efficiency. Is preferred. The composition of the coating (B) is generally prepared at a concentration of 0.5 to 50% by weight as a solid content of the hydrophobic acrylic resin and the inorganic colloid, and usually 1 to 20.
It is often prepared at a concentration of% by weight, and this is often used after dilution.

If necessary, the composition of the coating film (B) prepared in the present invention may further contain conventional additives such as antifoaming agents, plasticizers, film-forming aids, thickeners, pigments and pigment dispersants. The agents can be mixed. The coating film (B) is formed by applying the composition to the surface of the film, forcibly drying or natural drying, and volatilizing the liquid dispersion medium.

As the method for forced drying, a hot air drying method,
An infrared radiation method or the like can be adopted. The heating temperature for forced drying is determined depending on the composition of the coating film (B) applied, but is in the range of 50 to 250 ° C, preferably 70 to 200 ° C. The coating method may be any known method, and specifically, it may be selected from those exemplified in 2 above.

The coating amount of the solid matter after the composition (B) composition is applied on the surface of the film and the liquid dispersion medium is dried and volatilized is usually 0.01 to 10 g / m ² , preferably 0.1. ~
It is in the range of 5 g / m ² . When the adhesiveness between the film surface and the coating film derived from the coating (B) composition used in the present invention is not sufficient, the film surface may be subjected to plasma treatment or corona discharge before applying the composition. The surface of the film may be modified by a method such as treatment.
When the agricultural polyethylene terephthalate film of the present invention is spread and used as an agricultural coating material, a coating (A) is used.
Use with the side provided with the outside of a house or tunnel.

[0060]

The agricultural polyethylene terephthalate film according to the present invention exerts a blocking phenomenon preventive property, and the synergistic effect of the coating film (A) and the coating film (B) dramatically improves the anti-algae sustaining effect. Since it is improved and maintains high transparency for a long period of time, its utility value as an agricultural film is extremely large.

[0061]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments, but the present invention is not limited to the following examples unless it exceeds the gist. Examples 1-8, Comparative Examples 1-9 1. Base polyethylene terephthalate film Stretched 3.5 times in both length and width, and has a density of 1.392
g / cm ² and thickness of 150 μm.

[0062] 2. Coating (A) 2-1. Preparation of acrylic resin 2-1-1. Preparation of acrylic resin solution (i) Production of crosslinked elastic body 300 parts by weight of deionized water (hereinafter, simply referred to as "part" means "part by weight") and potassium persulfate in a polymerization can. 3 parts, 0.5 part of disodium phosphate dodecahydrate,
After charging 0.3 parts of sodium hydrogen phosphate dihydrate and sufficiently purging with nitrogen, the internal temperature was raised to 70 ° C. The internal temperature was maintained at this temperature, and 19.8 g of styrene was added with stirring.
Part, butyl acrylate 69.3 parts, allyl methacrylate 0.9 parts, and dioctyl sodium sulfosuccinate (emulsifier) 2.5 parts were continuously added over 2 hours.

Immediately after the completion of the addition, 1.0 part of t-butylperoxy-2-ethylhexanoate and 2.2 of styrene were used.
Parts, butyl acrylate 7.7 parts, allyl acrylate 0.
One part mixture was added. Thirty minutes after the addition was completed, the internal temperature was raised to 90 ° C., and the reaction was continued at this temperature for 3 hours to obtain a crosslinked elastic emulsion. The average particle size of this crosslinked elastic body was 0.20 μm, the gel content was 97.1%, and the swelling degree was 7.2.

Production of Graft Copolymer A crosslinked elastomer emulsion 400 obtained above was placed in a polymerization vessel.
The mixture was purged with nitrogen while stirring, and then the internal temperature was raised to 80 ° C. While maintaining the internal temperature at this temperature, a solution of 0.15 parts of sodium formaldehyde sulfoxylate dissolved in 3.0 parts of deionized water was added with stirring, and then 30.0 parts of methyl methacrylate and n-octyl mercaptan were added. A mixture of 0.03 part and 0.15 part of paramenthane hydroperoxide (50% solution) was continuously added over 30 minutes.

After the addition was completed, the polymerization reaction was continued for another 30 minutes to obtain a graft copolymer emulsion. The glass transition temperature (Tg) of the copolymer itself obtained from the grafted monomer component was 108 ° C. The obtained graft copolymer emulsion was salted out according to a conventional method, and the polymer was separated by filtration, washed with water, and dried to obtain a graft copolymer powder.

Preparation of Resin Solution 6.5 parts of the graft copolymer obtained above was mixed with methacrylic resin (methyl methacrylate / ethyl methacrylate: 96 parts).
13.5 parts of (4/4 copolymer) beads are mixed,
This mixture was mixed with 64 parts of methyl ethyl ketone and 16 parts of toluene.
Put in a mixed solvent consisting of parts and dissolve with stirring,
An acrylic resin solution B having a solid content of 20% by weight was prepared.

2-1-2. Preparation of Acrylic Resin (B) Production of Crosslinked Elastic Body A polymerization vessel was charged with 250 parts of deionized water, 2.0 parts of sodium dioctylsulfosuccinate and 0.05 parts of sodium formaldehyde sulfoxylate and sufficiently replaced with nitrogen.

While stirring the contents of the polymerization vessel, 1.6 parts of methyl methacrylate, 8 parts of butyl acrylate, 1,3
-Butylene dimethacrylate 0.4 parts, allyl methacrylate 0.1 parts, cumene hydroperoxide 0.0
A mixture of 4 parts was charged. The temperature inside the polymerization vessel was raised to 70 ° C., and the reaction was continued at this temperature for 60 minutes. continue,
1.5 parts of methyl methacrylate, 22.5 parts of butyl acrylate, 1.0 part of 1,3-butylene dimethacrylate, 0.25 parts of allyl methacrylate and 0. A mixture of cumene hydroperoxide in an amount of 05% by weight was added over 60 minutes. The obtained crosslinked elastic body has an average particle size of 0.1.
The gel content was 2 μm, the gel content was 90%, and the swelling degree was 10.

Preparation of Graft Copolymer A solution of 0.01 part of sodium formaldehyde sulfoxylate in 3 parts of deionized water was added to a polymerization vessel containing the above crosslinked elastic emulsion, and then 5 parts of methyl methacrylate was added. , Butyl acrylate 5 parts, allyl acrylate 0.1 parts and 0.03% by weight relative to these monomers
A mixture containing an amount of cumene hydroperoxide was added continuously over 30 minutes. After completion of the addition, the polymerization reaction was continued for another 30 minutes.

A solution prepared by dissolving 0.05 part of sodium formaldehyde sulfoxylate in 3 parts of deionized water was added to the polymerization vessel, and the temperature was raised to 80 ° C. to obtain 52.25 parts of methyl methacrylate and 2 parts of butyl acrylate. 0.75 parts, paramenthane hydroperoxide (50% solution) 0.13
A mixture of parts was added over 30 minutes. After completion of this addition, the polymerization reaction was continued at 80 ° C. for 30 minutes to obtain a graft copolymer emulsion. The glass transition temperature (Tg) of the copolymer itself obtained from the monomer component grafted on the outermost layer was 103 ° C. The obtained graft copolymer emulsion was salted out according to a conventional method, and the polymer was separated by filtration, washed with water, and dried to obtain a graft copolymer powder.

Preparation of Resin Solution 20 parts of the graft copolymer obtained above was placed in a mixed solvent of 64 parts of methyl ethyl ketone and 16 parts of toluene and stirred to obtain an acrylic resin solution having a solid content of 20% by weight. Was prepared. 2-2. Preparation and formation of coating film (A) composition An acrylic resin solution prepared according to the method described in 2-1 above was added with an ultraviolet absorber of the type and amount shown in Table 1.
A phenylurea compound and zinc dimethyldithiocarbamate were added. The solution after addition was applied to one surface of the polyethylene terephthalate film obtained in 1 by a gravure coating method, the applied surface was heated and the solvent was volatilized to form a film (A).

3. Coating (B) 3-1. Preparation of Acrylic Resins (A to I) A four-necked flask was charged with 2 parts by weight of polyoxyethylene lauryl ether and 80 parts by weight of water and heated to 60 ° C. under a nitrogen gas stream, and 0.5 parts by weight of ammonium persulfate was added thereto. Parts, and further, mixture 1 of each monomer shown in Table 2
00 parts by weight were added dropwise over 3 hours. At this time, the reaction temperature was maintained in the range of 60 to 70 ° C., and after the completion of the dropwise addition, the temperature was maintained for 2 hours, followed by cooling to obtain an acrylic resin emulsion. The glass transition temperature of each resin is as shown in Table 2, and is a value calculated by the following formula.

[0073]

## EQU2 ## (1 / Tg) = (W ₁ / Tg ₁ ) + (W ₂ / Tg ₂ ) + ... + (W _n / Tg _n ).

(Where Tg is the glass transition temperature (k) of the hydrophobic acrylic resin, Tg ₁ , Tg ₂ ... Tg _{n is} the glass transition temperature (k) W ₁ of the homopolymer of each component 1, 2 ... W ₂ ... W _n : The weight fraction of each component 1, 2 ... N is shown.)

3-2. Preparation and formation of coating film (B) composition Table 3 shows the acrylic resin emulsion obtained in 3-1.
An inorganic colloid sol, a water-soluble inorganic chlorine compound, and the like in the types and amounts shown in (3) were blended to prepare a coating (B) composition. On the surface of the polyethylene terephthalate film obtained in No. 2 opposite to the surface on which the coating (A) was formed, the composition of the coating (B) was coated by a bar coating method so that the coating amount after drying was 0.5 g / m ² as solid content. So that it becomes 8
The mixture was kept in hot air at 0 ° C. for 1 minute to disperse the solvent.

4. Evaluation of Polyethylene Terephthalate Film Various properties of each polyethylene terephthalate film obtained in 3 were evaluated by the methods described below, and the results are shown in Table 4. Adhesiveness Cellophane tape was adhered to the surface of each film on which the coating (B) was formed, and when the cellophane tape was peeled off, the peeling state of the coating was observed with the naked eye.

The evaluation criteria are as follows. ◯: The film did not peel at all and remained completely. ◯ _X : 2/3 or more of the film remained without peeling. Δ: Two-thirds or more of the coating film peeled off. X: The coating is completely peeled off.

Transparency The appearance of the film was visually observed. The evaluation criteria are as follows. ◯: Transparency is almost equal to that of a film not coated with the coating composition. ○ _X : Some deterioration in transparency is recognized. B: Significant decrease in transparency is recognized. X: The transparency is extremely deteriorated and cannot be put to practical use.

A film (A) was applied to a roof type house (frontage: 3 m, depth: 5 m, ridge height: 1.5 m, roof slope: 30 °) in which an algae-proof film was set up in a test field in Isshi-gun, Mie prefecture. Covered on the outside of the house, from March 1993 to September 1995 2.
An extension test was conducted for 5 years.

With respect to the spread film, the anti-algal property of the film was visually observed. The evaluation criteria are as follows. ⊚: Algae are not observed on the surface. Good: Algae are slightly generated on the surface. Δ: Algae are considerably generated on the surface. X: Algae are generated on the entire surface and are growing.

Blocking resistance The surface on which the coating (A) was formed and the surface on which the coating (B) was formed were overlapped and allowed to stand in a gear oven at 50 ° C. under a load of 2 kg for 1 week. The peeled state of the combined portion was visually observed. The evaluation criteria are as follows. ◯: It can be peeled off with almost no resistance, and the film is not broken. ○ _X : There is some resistance to peeling, and the film is slightly broken. Δ: There is resistance to peeling, and about 1/10 of the film is broken. X: Remarkably resistant to peeling, and more than half of the film is broken.

[0082]

[Table 1]

[0083]

[Table 2]

[0084]

[Table 3]

[0085]

[Table 4]

Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location C08J 7/04 C08J 7/04 Z (72) Inventor Atsushi Obayashi 2 Oike, Oike, Iwazuka-cho, Nakamura-ku, Aichi Prefecture Mitsubishi (72) Inventor Shunichi Onishi 2 Oike, Oike, Iwatsuka-cho, Nakamura-ku, Nagoya, Aichi Mitsubishi Chemical M-C-V Co., Ltd. Nagoya-site

Claims (5)

[Claims] 1. Polyethylene tere biaxially stretched
On one side of the phthalate film, UV absorber, the following general
One of the phenylurea compounds represented by formula (I) or
Contains two or more kinds and zinc dimethyldithiocarbamate
To form a coating (A) made of acrylic resin
(A) glass transition temperature is in the range of 35 to 80 ° C.
Aqueous dispersion of hydrophobic acrylic resin in (b) Inorganic
Colloidal sol and solid content 100 of component (c) (b)
0.01 to 30 parts by weight of water-soluble inorganic chlorine based on parts by weight
A film (B) derived from a composition containing a compound is formed.
Agricultural polyethylene terephthalate fill
M Embedded image(In the general formula (I), R¹Is a hydrogen atom, a halogen atom,
Lower alkyl group, lower alkoxy group, p-chloropheno
An oxy group or a p-methoxyphenoxy group, R ^TwoIs the water
Elementary atom, halogen atom, trifluoromethyl group, t-bu
Cylaminocarbonyloxy group (-OCONHC (CH
_Three)_Three) And R^ThreeAnd R^FourIs a hydrogen atom or a lower atom
Represents a alkyl group;^FiveIs a hydrogen atom, a lower alkyl group,
Lower alkoxy group, o-methylcyclohexyl group, α,
α-dimethylbenzyl group (-C (CH_Three)_Two-C
₆H₆), 1-methyl-2-propynyl group (-CH (C
H_Three) Represents CCH)) 2. The agricultural polyethylene terephthalate film according to claim 1, wherein the ultraviolet absorber which is the composition of the coating film (A) is a benzophenone compound and / or a benzotriazole compound. 3. The ultraviolet absorber which is the composition of the coating film (A) is blended in an amount of 1 to 100 parts by weight of the acrylic resin.
40 parts by weight of the agricultural polyethylene terephthalate film according to claim 1 or 2. 4. The hydrophobic acrylic resin as the component (a) which is the composition of the coating (B) is a mixture of (meth) acrylic acid alkyl esters or (meth) acrylic acid alkyl esters and alkenylbenzenes. Is a homopolymer or a copolymer obtained by polymerizing 100 to 60% by weight and 0 to 40% by weight of an α, β-ethylenically unsaturated monomer copolymerizable therewith. The polyethylene terephthalate film for agriculture according to any one of 1 to 3. 5. The solid average particle diameter of the inorganic colloid sol of the component (b) which is the composition of the coating film (B) is 5 to 100 m.
The polyethylene terephthalate film for agriculture according to any one of claims 1 to 4, which has a thickness of μ.