JP2630186B2 - Agricultural vinyl chloride resin film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vinyl chloride resin film for agricultural use. More specifically, the present invention relates to an agricultural vinyl chloride resin film having improved durability against undesired deterioration phenomena such as discoloration, embrittlement, and reduced dust resistance caused by stretching outdoors.

[0002]

2. Description of the Related Art A vinyl chloride resin film conventionally used as an agricultural covering material has been affected by sunlight, especially ultraviolet rays, etc., and its appearance has been degraded after one year of use. Changes over time, such as a decrease in the flexibility of Furthermore, recently improved agricultural techniques, especially those aimed at economy and labor saving, require the covering materials to have properties that can withstand more severe conditions than ever before. Therefore, a technique of forming a film by adding and mixing an organic phosphate or a metal organic phosphate to a vinyl chloride resin as a base material for the purpose of improving weather resistance has been widely adopted.

On the other hand, according to the conventional experience, a flexible vinyl chloride resin film used for agriculture varies in extent depending on the region and place where it is used, but it has been used for two years since the start of use. As time passes, the dust resistance of the surface located outside the house or tunnel is significantly reduced, making it unusable for use. As methods for eliminating the above-mentioned disadvantages, Japanese Patent Publication No. 47-28740 and Japanese Patent Publication No. 50-31195 are known.
Gazette, JP-A-56-99237, and JP-B-56-99237.
As described in Japanese Patent No. 99665 and the like, there is a method of forming a coating of a specific acrylic resin on one surface or both surfaces of a vinyl chloride resin film as a substrate.

Further, Japanese Patent Application Laid-Open No. Sho 51-70282 describes a method for forming a coating of an acrylic resin having a specific composition containing an ultraviolet absorber on a film surface of a substrate. However, the acrylic resin of the composition using these methods, especially in the summer when the outside air temperature is high, the additives that are blended in the base film migrate to the surface through the coating, are washed away and disappear, It is difficult to completely suppress it, and there is still a problem in extending and using the film outdoors for a long time. Also, JP-A-61-2156
No. 30, JP-B-63-9987, etc., pay attention to the molecular weight and molecular weight distribution of the acrylic resin, but when extended for a long time, various performances are reduced,
It was not yet satisfactory enough, such as poor crack resistance.

[0005]

SUMMARY OF THE INVENTION The present invention is directed to an agricultural vinyl chloride having improved durability, in which undesirable degradation phenomena such as discoloration, embrittlement, and reduced dust resistance caused by stretching outdoors are greatly improved. It is intended to provide a base resin film.

[0006]

Means for Solving the Problems The present inventors have solved the above-mentioned problems by the conventional method by using an acrylic resin containing a phosphate group as a coating component of a vinyl chloride resin film. The present invention was found to be obtained. That is, the gist of the present invention is to provide an acrylic acid or methacrylic acid alkyl ester and an acrylic acid containing a phosphate ester group on one or both surfaces of a vinyl chloride resin film containing an organic phosphate or an organic metal phosphate. 99.9 to 70 in weight ratio with the system monomer
The glass transition temperature obtained by copolymerizing a mixture of the latter 0.1 to 30 (the total amount of both is 100) is 30 to 30.
It exists in a vinyl chloride resin film for agricultural use in which an acrylic resin film having a temperature of 90 ° C. is formed. Less than,
The present invention will be described in detail.

[0007] 1. Vinyl Chloride Resin In the present invention, the vinyl chloride resin refers to not only polyvinyl chloride but also a copolymer containing vinyl chloride as a main component.
Examples of monomer compounds copolymerizable with vinyl chloride include vinylidene chloride, ethylene, propylene, acrylonitrile, maleic acid, itaconic acid, acrylic acid, methacrylic acid, and vinyl acetate. These vinyl chloride resins may be produced by any of conventionally known production methods such as an emulsion polymerization method, a suspension polymerization method, a solution polymerization method, and a bulk polymerization method.

[0008] In order to impart flexibility, the vinyl chloride resin serving as the substrate is blended with 20 to 60 parts by weight of a plasticizer with respect to 100 parts by weight of the resin. By setting the blending amount of the plasticizer in the above range, the desired soft vinyl chloride molded article can be imparted with excellent flexibility and mechanical properties. Examples of the plasticizer include di-n-octyl phthalate, di-2-ethylhexyl phthalate, dibenzyl phthalate, diisodecyl phthalate,
Phthalic acid derivatives such as didodecyl phthalate and diundecyl phthalate; isophthalic acid derivatives such as dioctyl phthalate; adipic acid derivatives such as di-n-butyl adipate and dioctyl adipate; maleic acid derivatives such as di-n-butyl malate; tri-n Citric acid derivatives such as butyl citrate; itaconic acid derivatives such as monobutyl itaconate; oleic acid derivatives such as butyl oleate; ricinoleic acid derivatives such as glycerin monoricinoleate; Agents and the like.

In the vinyl chloride resin film for agricultural use of the present invention, an organic phosphate or a metal organic phosphate is blended with the vinyl chloride resin. Examples of the organic phosphate include triisopropylphenyl phosphate, isodecyldiphenylphosphate, tricresylphosphate, tris (isopropylphenyl) phosphate, tributylphosphate, triethylphosphate, trioctylphosphate, tributoxyethylphosphate, triphenylphosphate, octyldiphenyl Among them, there are phosphate, trixylenyl phosphate and the like. Among them, tricresyl phosphate and trixylenyl phosphate are particularly preferable.

The above organic phosphates can be used alone or in the form of a composite. Specifically, a composite of an organic phosphite and an organic phosphite is exemplified, and the organic phosphite includes, for example, a phosphonate-based compound such as diphenylphosphonate. Examples of the organophosphate metal salt include those represented by the general formula [I] or [II].

[0011]

Embedded image

(Wherein M represents zinc, calcium, barium, magnesium, cobalt or strontium, and R ¹ , R ² and R ³ are each an alkyl,
An alkyl group having an aryl, arylalkyl, alkylaryl or ether bond is meant. Examples of the alkyl group represented by R ¹ , R ² and R ³ include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, amyl, neopentyl, isoamyl, hexyl, isohexyl and heptyl. Octyl, isooctyl, 2-ethylhexyl, decyl, isodecyl, lauryl, tridecyl, C ₁₂
-C ₁₃ mixed alkyl, stearyl, cyclopentyl, cyclohexyl, cyclooctyl, cyclododecyl, 4-
And a methylcyclohexyl group.

Examples of the aryl group include phenyl and naphthyl groups. Examples of the arylalkyl group include a benzyl, β-phenylethyl, α-phenylpropyl, β-phenylpropyl group and the like. Examples of alkylaryl groups include tolyl,
Xylyl, ethylphenyl, butylphenyl, tertiary butylphenyl, octylphenyl, isooctylphenyl, tertiary octylphenyl, nonylphenyl, 2,4-
And di-tert-butylphenyl group.

Examples of the alkyl group having an ether bond include furfuryl, tetrahydrofurfuryl, 5-methylfurfuryl and α-methylfurfuryl, or methyl-, ethyl-, isopropyl-, butyl-, isobutyl-, and hexyl-. , Cyclohexyl-, phenyl cellosolve residue; methyl-, ethyl-, isopropyl-, butyl-, isobutyl carbitol residue; triethylene glycol monomethyl ether, -monoethyl ether, -monobutyl ether residue; glycerin 1,2- Dimethyl ether, -monoethyl ether, -monobutyl ether residue; glycerin 1,2-dimethyl ether, -1,3
-Diethyl ether, 1-ethyl-2-propyl ether residue; nonylphenoxypolyethoxyethyl, lauroxypolyethoxyethyl residue and the like.

The metal represented by M is particularly preferably zinc, calcium and barium. These organic phosphates or metal organic phosphates may be used alone or in combination of two or more. In the agricultural film of the present invention, it is preferable to use an organic phosphoric acid ester and a metal organic phosphate in combination from the viewpoints of coatability and outdoor expandability. The compounding amount of the organic phosphoric acid ester or the organic phosphoric acid metal salt is in the range of 0.1 to 15 parts by weight, preferably in the range of 0.2 to 10 parts by weight based on 100 parts by weight of the vinyl chloride resin. To be elected. If the amount is less than 0.1 part by weight, the weather resistance and dust resistance of the soft vinyl chloride resin film are not improved.
If the amount is more than 15 parts by weight, the transparency of the film becomes extremely poor, which is not preferable. Within the above range, 0.
Particularly preferred is a range of 2 to 8 parts by weight.

In addition to the above-mentioned plasticizer, organic phosphoric acid ester or metal organic phosphate, a known resin which is usually added to a synthetic resin for molding may be added to the vinyl chloride resin, if necessary. Substances, for example, lubricants, heat stabilizers, ultraviolet absorbers, light stabilizers, antioxidants, stabilizing aids, antistatic agents, antifoggants, antifungal agents, antialgal agents, inorganic fillers, coloring agents, etc. Can be blended.

A lubricant which can be added to the film according to the present invention,
Examples of the heat stabilizer or antioxidant include polyethylene wax, bisamide-based compounds, liquid paraffin, organic phosphite compounds, β-diketone compounds, and the like. Each of the above various resin additives can be used alone or in combination of several types. The addition amount of the above various resin additives can be selected within a range that does not deteriorate the properties of the film, usually within a range of 10 parts by weight or less based on 100 parts by weight of the vinyl chloride resin as the substrate.

In order to mix the plasticizer, the organic phosphate or the metal organic phosphate, and other resin additives with the vinyl chloride resin serving as the base material of the film, the necessary amounts are weighed, and a ribbon blender is used. Banbury mixers, super mixers and other conventionally known blending machines and mixers may be used. The resin composition thus obtained can be formed into a film by a method known per se, for example, a melt extrusion molding method (including a T-die method and an inflation method), a calendar molding method, a solution casting method, and the like. I'll do it.

2. Coating component 2-1. Alkyl esters of acrylic acid or methacrylic acid Alkyl esters of acrylic acid or methacrylic acid (hereinafter simply referred to as "acrylic monomers") include methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n C ₁ -C ₂₂ alkyl esters of acrylic acid such as -butyl acrylate, iso-butyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, dodecyl acrylate, tridecyl acrylate, stearyl acrylate, etc .: methyl methacrylate, ethyl Methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, cyclohexane Hexyl methacrylate, 2-ethylhexyl methacrylate, decyl methacrylate, dodecyl methacrylate, tridecyl methacrylate, C ₁ ~ methacrylic acid such as stearyl methacrylate
Alkyl esters of C ₂₂ and the like. These monomers may be used in combination of several kinds.

2-2. Acrylic Monomer Containing Phosphate Ester Group The acrylic monomer containing a phosphate ester group refers to one in which the ester portion of an alkyl ester of acrylic acid or methacrylic acid is substituted with a phosphate ester.
Phosphoric acid esters include trialkyl esters, dialkyl esters, and monoalkyl esters, and are mono-, di-, and tri-substituted depending on the type.

Specifically, for example, mono (2-hydroxyethyl acrylate) acid phosphate, mono (2-hydroxyethyl acrylate)
(Hydroxyethyl methacrylate) azidophosphate, mono (2-hydroxypropyl acrylate) acid phosphate, mono (2-hydroxypropyl methacrylate) acid phosphate, mono (3-hydroxypropyl acrylate) acid phosphate, mono (3
-Hydroxypropyl methacrylate) acid phosphate, mono (3-chloro-2-hydroxypropyl methacrylate) acid phosphate, acid phosphooxypolyoxyethylene glycol monomethacrylate, di (2,3-dihydroxypropyl acrylate) acid phosphate, di (2 3-dihydroxypropyl methacrylate) acid phosphate and the like.

3. Coating 3-1. Mixing ratio of coating composition The mixing ratio of the acrylic monomer and the acrylic monomer containing a phosphate group is 99.9 to 7 by weight.
0 to the latter 0.1 to 30 (the total amount of both is 100)
And particularly preferred is 99.5 to 80 to 0.
5-20. If the compounding ratio of the latter is larger than this, the adhesion between the vinyl chloride resin film and the formed film is deteriorated, which is not preferable. Conversely, if the latter compounding ratio is less than this, it is not preferable because the dust resistance and weather resistance of the formed film cannot be sufficiently improved.

The monomer mixture may further contain other monomers copolymerizable with the monomer. Examples of other monomers include α, β-ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid, and itaconic acid; , 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 Acrylamides; glycidyl esters of acrylic acid or methacrylic acid; These monomers may be used alone or in combination of two or more.

3-2. Polymerization of coating A mixture of acrylic monomer and acrylic monomer containing a phosphate group in a prescribed ratio and another monomer copolymerizable with other monomer together with an organic solvent or water , And a polymerization initiator and, if necessary, a molecular weight regulator are added, and the mixture is heated and polymerized with stirring. The polymerization is
Generally known methods such as a suspension polymerization method, a solution polymerization method and a soap-free polymerization method are employed.

The organic solvent used for the polymerization includes methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol.
Alcohols such as butanol, n-amyl alcohol, isoamyl alcohol, tert-amyl alcohol, n-hexyl alcohol, and cyclohexanol; aromatic hydrocarbons such as benzene, toluene, and xylene; and acetates such as ethyl acetate and butyl acetate. Acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl isobutyl ketone, diethyl ketone, 2-hexanone,
Ketones such as 3-hexanone, di-n-propyl ketone, diisopropyl ketone, di-n-amyl ketone, and cyclohexanone; tetrahydrofuran and the like can be used singly or as a mixture of two or more.
Examples of the polymerization initiator that can be used include radical generation catalysts such as α, α-azobisisobutyronitrile, benzoyl peroxide, and cumene hydroperoxide. Examples of the molecular weight regulator include butyl mercaptan, n-dodecyl mercaptan, tert-dodecyl mercaptan, β-mercaptoethanol and the like.

In addition to the above-mentioned acrylic resin, in addition to these components, auxiliary components such as an antioxidant, a neutralizing agent, an ultraviolet absorber, a light stabilizer, an antistatic agent, a pigment, a dye, and a fungicide Agents, anti-algal agents, foaming agents, lubricants, etc.
It can be used after being dispersed and / or dissolved in water or an organic solvent.

Examples of the organic solvent include heptane and cyclohexane as aliphatic hydrocarbons; benzene, toluene, xylene and the like as aromatic hydrocarbons; methanol, ethanol, isopropyl alcohol, polyoxyethylene glycol and the like as alcohols; Hydrogen such as chloroform, tetrachloride hydrocarbon, chlorobenzene, etc .; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, etc .; esters, such as methyl acetate, allyl acetate, ethyl stearate, etc .; amines, such as trimethylamine, diphenylamine, hexamethylenediamine, etc. ; Other dimethylformamide, dimethylacetamide, dioxane, diethyl ether, diethylenedithioglycol, diacetone alcohol, benzonit Le, there are dimethyl sulfoxide and the like, can be used in these alone or in combination of two or more thereof.

The glass transition temperature (Tg) of the acrylic resin obtained by copolymerization is in the range of 30 to 90 ° C. Such Tg can be obtained by selecting the type of the monomer to be used and the amount to be used (blended amount). If the Tg of the acrylic resin used exceeds 90 ° C., the coating formed from the coating composition containing such a resin has insufficient flexibility, which is not preferable. On the other hand, when Tg is lower than 30 ° C., it is not preferable from the viewpoint of tackiness, easy adhesion of dirt, and dustproofness.

3-2. Film formation To form a film on the surface of the vinyl chloride resin film,
Various known methods are applied depending on the shape of the molded article. For example, when forming a film in a solution state, such as doctor blade coating method, gravure roll coating method, air knife coating method, reverse roll coating method, dib coating method, curtain roll coating method, spray coating method, rod coating method and the like An application method is used.

The method for drying the solvent includes, for example, a natural drying method, a hot air drying method, an infrared drying method, a far infrared drying method and the like. The hot air drying method is advantageous in consideration of the drying speed and safety. In this case, the temperature condition is in the range of 50 to 150 ° C., and the time is preferably selected from 10 seconds to 15 minutes. Also,
When the coating resin is formed as a single coating without being in a solution state, a coextrusion method, an extrusion coating method, an extrusion lamination method, and a lamination method are used.

In the present invention, the thickness of the film formed on the surface of the base film is 1/10 of the thickness of the base film.
It is preferred that: If the thickness of the coating is more than 1/10 of the thickness of the base film, there is a difference in flexibility between the base film and the coating, so that the coating is liable to peel off from the base film and the like. Occurs, and a phenomenon that the strength of the base film is reduced occurs, which is not preferable.

Before applying the above coating composition, the surface of the vinyl chloride resin film is previously washed with alcohol or water, subjected to plasma discharge treatment or corona discharge treatment, or coated with another paint or primer. A pretreatment such as undercoating may be performed. When actually using the agricultural polyvinyl chloride resin film according to the present invention for agriculture, when the coating is formed on only one side, the surface provided with the coating is outside the house or tunnel. Use it as

[0033]

Industrial Applicability The vinyl chloride resin film for agricultural use of the present invention has high adhesion between a base film and a film derived from a specific acrylic resin coating composition formed on its surface, so that the film is peeled off. It is suitable as an agricultural film to be spread and used outdoors because it is difficult to perform and a decrease in physical properties and dust resistance is small for a long time.

[0034]

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 to 5, Comparative Examples 1 to 3

I. Preparation of base film 100 parts by weight of polyvinyl chloride (average degree of polymerization 1400),
50 parts by weight of dioctyl phthalate, epoxidized soybean oil 3
Parts by weight, barium-zinc composite liquid stabilizer 1.5 parts by weight, barium stearate 0.2 parts by weight, zinc stearate 0.4 parts by weight, sorbitan laurate 1.5 parts by weight, 2,4-dihydroxybenzophenone A resin composition consisting of 0.5 parts by weight was prepared, and the kinds and amounts of organic phosphates or metal organic phosphates shown in Table 2 were blended. After mixing and blending each composition with a super mixer for 10 minutes, kneading on a mill roll heated to 180 ° C,
A substrate film having a thickness of 0.15 mm was prepared.

II. Preparation of coating resin Acrylic monomer and phosphoric acid ester group-containing acrylic monomer were added to a reactor equipped with a thermometer, a stirrer, a reflux condenser and a charging nozzle in the types and amounts shown in Table 1, Further, 1 part by weight of benzoyl peroxide, 1 part of isopropyl alcohol
Add 50 parts by weight, stir in a nitrogen gas stream, and add 8 parts by weight.
The reaction was continued for about 3 hours at 0 ° C. for 3 hours and further 0.5 parts by weight of benzoyl peroxide was added at the same temperature to obtain a to g acrylic resins. The Tg of the obtained resin is shown in Table 1.

III. Formation of Coating One side of the base film prepared by the method described in I was coated with the coating resin prepared in II using a # 5 bar coater. The applied film was kept in an oven at 130 ° C. for 1 minute to evaporate the solvent. The amount of the coating on each of the obtained films was about 3 g / m ² .

IV. Evaluation of Film Each performance of the eight films was evaluated by the following method,
Table 3 shows the results. (I) Initial appearance The film appearance was visually observed. The evaluation criteria are as follows. ◎ ・ Colorless and excellent in transparency. ○ ・ ・ Somewhat white but transparent. Δ: White and translucent. ×: Cloudy and devitrified.

(Ii) Flexibility of Coating Each film was cut into a width of 5 cm and a length of 15 cm, and alternately folded at a distance of 2 cm in a direction perpendicular to the length direction. In this state, a load of 2 kg was applied from above and left for 24 hours in a thermostat kept at 15 ° C. Then, the load was removed, the fold of the film was extended, and the appearance of the coating was visually observed. ◎: No change in the film at the fold is observed. Δ: Cracks are observed in the fold film. ×: Cracks are remarkably observed in the film at the fold.

(Iii) Outdoor extension test A surface in which each film was coated on a roof-type house (width 3 m, depth 5 m, ridge height 1.5 m, roof slope 30 °) installed in a test field in Isshi-gun, Mie Prefecture. Was covered outside the house, and a two-year expansion test was conducted from June 1990 to June 1994. For the stretched film, the appearance test of the film and the elongation retention of the film were measured by the following methods, and the dust resistance of the film during the stretching test was evaluated. -Film appearance: Appearance observed with the naked eye. The evaluation criteria are as follows. ◎: No change in appearance such as discoloration is observed.・: Some change in appearance such as slight discoloration is observed. Δ: A change in appearance such as discoloration is recognized. ×: Discoloration is recognized on the entire surface.

Film retention of elongation: means a value calculated by the following equation. (Elongation of film after stretching) ÷ (Elongation of film before stretching) × 100 (%) Dustproofness: Evaluated from the value calculated by the following equation. (Light transmittance of the film collected over time after stretching)
(Light transmittance of the film before stretching *) × 100 (%) * Direct light transmittance at a wavelength of 555 μm (using EPS-2U type, manufactured by Hitachi, Ltd.) The display of the measurement results was as follows. ◎ · The light transmittance after expansion is 90% or more before expansion.・: The light transmittance after expansion is in the range of 70 to 89% before expansion. Δ: The light transmittance after expansion is in the range of 50 to 69% before expansion. X: The light transmittance after expansion is less than 50% before expansion.

[0042]

[Table 1]

[0043]

[Table 2]

[0044]

[Table 3]

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Atsushi Obayashi 2 Oike, Iwazuka-cho, Nakamura-ku, Nagoya-shi, Aichi Prefecture Mitsubishi Kasei Vinyl Co., Ltd. Nagoya Plant (56) References 1988-137933 (JP, A)

Claims (1)

(57) [Claims] An acrylic acid or methacrylic acid alkyl ester is formed on one or both sides of a vinyl chloride resin film containing an organic phosphate or a metal organic phosphate.
The former is 99.9-70 by weight and the latter is 0.1-3 by weight ratio of stels and acrylic monomer containing phosphate group.
Agricultural vinyl chloride resin film formed by coating an acrylic resin having a glass transition temperature in the range of 30 to 90 ° C. obtained by copolymerizing a mixture of 0 (the total amount of both is 100). .