JP3181082B2 - Agricultural vinyl chloride resin film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a novel agricultural chloride having excellent weather resistance, dust resistance and excellent durability which can be used for a long period of time, which is suitable for use in houses and for cultivating tunnels. The present invention relates to a vinyl resin film.

[0002]

2. Description of the Related Art Agricultural films based on a vinyl chloride resin film are coated with an acrylic resin film on the surface in order to prevent dust and the like from adhering to the surface. Recently, a film obtained by adding tetraalkoxysilane to an acrylic resin has been proposed (Japanese Patent Application Laid-Open No. 1-184130). Must be heat-treated, and the operation becomes complicated.

On the other hand, a coating comprising a copolymer of an acrylic monomer and a monomer having a reactive silicon-containing group has also been proposed (JP-A-1-131271), but this polymer is brittle and has poor stability. In order to improve this, a (meth) acrylic ester monomer having an alkyl group having 10 or more carbon atoms is blended to improve the brittleness.

Embedded image (X in the formula is a hydrolyzable group, and R ⁴ is 1 to 18 carbon atoms.
(N is an integer of 1 to 4), and it is necessary to incorporate a hydrolyzable organosilicon compound represented by the following formula: Is complicated, and the cost is unavoidable.

[0004]

SUMMARY OF THE INVENTION The present invention overcomes the drawbacks of the conventional dust-proof agricultural resin film,
The composition of the coating composition is simple, has a coating that can be easily and efficiently formed without requiring complicated operations such as heat treatment in advance, has excellent weather resistance and dust resistance, and can be used for a long time. An object of the present invention is to provide a novel agricultural vinyl chloride resin film having excellent durability.

[0005]

The present inventors have conducted various studies to develop a vinyl chloride resin film for agricultural use having the above-mentioned preferable characteristics, and as a result, a specific trialkoxysilicate monomer and hydroxy By using a (meth) acrylic ester monomer containing an alkyl group in combination, the crosslinking reaction can proceed efficiently at a low temperature even with a small amount of silicate, and a film having excellent stability and weather resistance can be formed. And found that the object could be achieved, and based on this finding, completed the present invention.

That is, according to the present invention, (A) a compound represented by the following general formula (A) is provided on at least one surface of a vinyl chloride resin film.

Embedded image Wherein R ¹ is hydrogen or a methyl group, R ² is a direct bond or a divalent organic residue, and R ³ is an alkyl group.
10% by weight, (B) 0.1-20% by weight of a (meth) acrylic ester monomer containing a hydroxyalkyl group and (C) 70.0-99.8% by weight of another copolymerizable monomer. A vinyl chloride resin film for agricultural use, characterized in that a coating comprising a coating composition containing 100 parts by weight of the obtained copolymer and (5) 90 parts by weight of an alcohol having 12 or less carbon atoms as a main component is provided. Is provided.

The copolymer of the component (a) in the coating composition for the vinyl chloride resin film for agricultural use of the present invention is obtained from the following monomer components (A), (B) and (C). Can be

As the trialkoxysilicate monomer of the formula (I) of the component (A), for example, CH ₂ ＣＨCHSi
(OCH ₃ ) ₃ , CH ₂ ＣＨCHCOOCH ₂ CH ₂ Si
(OCH ₃ ) ₃ , CH ₂ ＣC (CH ₃ ) COOCH ₂ C
H ₂ Si (OCH ₃ ) ₃ , CH ₂ ＣC (CH ₃ ) COO
(CH ₂ ) ₃ Si (OCH ₃ ) ₃ ,

[0009]

Embedded image

[0010]

Embedded image

CH ₂ ＣＨCHCH ₂ S (CH ₂ ) ₃ Si
(OCH ₃ ) ₃ , CH ₂ ＣＨCHCH ₂ NH (CH ₂ ) ₃
Si (OCH ₃ ) ₃ , CH ₂ ＣＨCHSi (OC ₂ H ₅ )
₃ , CH ₂ ＣＨCHSi (OCOCH ₃ ) ₃ , CH ₂ ＣC
HSi (OCH ₂ CH ₂ OCH ₃ ) ₃ , CH ₂ ＣＨCHS
i (OCH (CH ₃ ) ₂ ) _{3 and the} like. These may be used alone or in combination of two or more.

The (meth) acrylic ester containing a hydroxyalkyl group as the component (B) is capable of undergoing a cross-linking reaction with the component (A), and is particularly effective for improving the dustproof effect. As such, for example, hydroxymethyl acrylate, hydroxymethyl methacrylate, 2-hydroxyethyl acrylate,
2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 3-
Hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, 2-hydroxypentyl acrylate, 2-hydroxypentyl methacrylate, 6
-Hydroxyhexyl acrylate, 6-hydroxyhexyl methacrylate and the like. These may be used alone or in combination of two or more.

The copolymerizable monomer of the component (C) is effective for adjusting the hardness of the coating. Examples of such a monomer include an alkyl ester of acrylic acid or methacrylic acid. Such as methyl acrylate, ethyl acrylate,
n- propyl acrylate, isopropyl acrylate, n- butyl acrylate, isobutyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, dodecyl acrylate, tridecyl acrylate, alkyl esters of C ₁ -C ₂₂ acrylic acid, such as stearyl acrylate , Methyl methacrylate, ethyl methacrylate, n
- propyl methacrylate, isopropyl methacrylate, n- butyl methacrylate, isobutyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, decyl methacrylate, dodecyl methacrylate, tridecyl methacrylate, alkyl esters of C ₁ -C ₂₂ methacrylic acid such as stearyl methacrylate, Α, containing one or more carboxyl groups in the molecule of acrylic acid, methacrylic acid, itaconic acid, maleic acid, aconitic acid, crotonic acid, etc.
In addition to β-unsaturated carboxylic acids and the like, a small amount of styrene, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl propionate, acrylamide, methacrylamide, n-butoxyacrylamide,
Those containing n-butoxymethacrylamide and the like are included. These may be used alone or in combination of two or more.

The proportion of the various monomers used is 0.1 to 10% by weight for the component (A), 0.1 to 20% by weight for the component (B), and 70.0 to 99.8 for the component (C). It is selected in the range of weight%. If the proportion of the component (A) is too small, the dust-proofing effect is small, and if it is too large, not only is it economically disadvantageous, but the elongation of the coating film is reduced, and white wrinkles are noticeable. If the proportion of the component (B) is too small, water whitening resistance and dust resistance are poor, and if too large, the water resistance is poor, and the composition is not suitable for outdoor use. If the proportion of the component (C) is too small, elongation and water resistance of the coating film are insufficient, and if it is too large, the dustproof effect is not sufficient, which is not preferable.

The alcohol having 12 or less carbon atoms as the component (b) used in the present invention is effective for maintaining the liquid stability of the coating composition. Examples of such an alcohol include methanol, ethanol, and n. -Propanol, isopropanol, n-butanol, sec-butanol, tert
-Butanol, n-amyl alcohol, isoamyl alcohol, tert-amyl alcohol, n-hexyl alcohol, cyclohexanol, benzyl alcohol,
Furfuryl alcohol and the like can be mentioned. These alcohols are added after polymerization as a diluent, but are advantageously used as organic solvents for polymerization.

The above-mentioned copolymer used in the present invention is prepared by combining one or more of each of these polymerizable monomers in a predetermined amount and charging the mixture with an organic solvent in a polymerizable container. It is manufactured by a method such as polymerization by adding an agent. In this case, when the required amount of the alcohol (b) is used as the organic solvent as described above, the product directly constitutes the coating composition.

As the above-mentioned polymerization initiator, for example, α, α-
Radical generation catalysts such as azobisisobutyronitrile, benzoyl peroxide, cumene hydroperoxide and the like can be mentioned, and are selected according to the reaction temperature and the like. Also,
Examples of the molecular weight regulator include butyl mercaptan, n
-Dodecyl mercaptan, tert-dodecyl mercaptan, β-mercaptoethanol and the like.

Examples of the organic solvent used for the polymerization include aromatic alcohols such as benzene, toluene and xylene, acetates such as ethyl acetate and butyl acetate, acetone, methyl ethyl ketone, methyl -N-propyl ketone, methyl isobutyl ketone, diethyl ketone, 2-hexanone, 3-hexanone, di-n-propyl ketone, diisopropyl ketone,
Examples thereof include ketones such as di-n-amyl ketone and cyclohexanone, and tetrahydrofuran. These can be used alone or in combination of two or more.

The coating composition thus obtained can be obtained by blending 5-90 parts by weight of the alcohol of component (b) per 100 parts by weight of the copolymer thus obtained.
If the amount of the alcohol is too large, the solubility of the resin is reduced and gelation is likely to occur. If the amount is too small, the effect of stability is small and the viscosity increases, which is not preferable.

The coating composition may contain, if necessary, auxiliary components such as an antioxidant, a neutralizing agent, an ultraviolet absorber, a light stabilizer, an antistatic agent, and a pigment within a range not to impair the purpose of the present invention. , A dye, a lubricant, and the like.

The coating composition can be used by dispersing and / or dissolving it in an organic solvent. Examples of the organic solvent include methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol,
alcohols such as tert-butanol, n-amyl alcohol, isoamyl alcohol, tert-amyl alcohol, n-hexyl alcohol, and cyclohexanol; ketones such as acetone, methyl ethyl ketone, cyclohexanone, and diisobutyl ketone; other ethyl acetate, butyl acetate, and tetrahydrofuran , Dimethylformamide, diacetone alcohol, hexane, toluene, xylene and the like.
A mixture of more than one species can be used.

In the present invention, the above coating composition is applied to the surface of a vinyl chloride resin base film to form a coating. Various generally known methods are applied to this film formation. For example, when forming a film in a solution state,
Doctor blade coating method, gravure roll coating method,
Coating methods such as an air knife coating method, a reverse roll coating method, a dave coating method, a curtain roll coating method, a spray coating method, and a rod coating method are used.

When the above coating composition is formed as a single film without being in a solution state, a coextrusion coating method, an extrusion lamination method, or a lamination method is used.

When a coating method is used to form a film, examples of the drying method include a natural drying method, a hot air drying method, an ultraviolet drying method, an infrared drying method and a far infrared drying method. From this point, the hot air drying method is advantageous. The heating temperature at this time is preferably in the range of 50 to 150 ° C., and the heating time is preferably in the range of 10 seconds to 15 minutes.

When the above coating composition is applied to the surface of a vinyl chloride resin base film to form a coating, the amount of the coating depends on the coating method, but is usually 0.1% after drying and solidifying.
10 g / m ² , preferably 0.5-5 g / m ² . If the coating amount is less than 0.1 g / m ^2, the effect of preventing the plasticizer in the film from migrating to the surface is not sufficient, and if it is more than 10 g / m ² , the coating amount is too large to be economical. In addition to the disadvantage, the mechanical strength of the film itself may be reduced.

Before coating with the coating composition, the surface of the film may be washed in advance with alcohol or water, subjected to a plasma discharge treatment or a corona discharge treatment, or be primed with another paint or primer. Pre-processing may be performed.

When the film of the present invention having a film formed on only one side is actually used for agriculture, the film-coated side should be located outside a house or a tunnel. I do.

[0028]

The agricultural resin film of the present invention has excellent weather resistance and dust resistance, and has excellent durability that can be used for a long period of time. Therefore, it is suitably used for house and tunnel cultivation.

The coating composition used for forming the film of the film has a simple composition and can easily and efficiently form a film without requiring a complicated operation such as a heat treatment in advance. Things.

[0030]

Next, the present invention will be described in more detail by way of examples.

Example 1 20 parts by weight of dehydrated ethyl alcohol (hereinafter referred to as EA)
80 parts by weight of ethyl acetate, methyl methacrylate (hereinafter M
MA), 60 parts by weight of n-butyl methacrylate (hereinafter, referred to as nBMA), 2 parts by weight of 2-hydroxyethyl methacrylate (hereinafter, referred to as HEMA),
And 2 parts by weight of γ-methacrylpropyltrimethoxysilane (hereinafter referred to as γMPTMS) were charged into a 3 liter four-necked flask, and 1 part by weight of benzoyl peroxide (hereinafter referred to as BPO) was added thereto and stirred to dissolve.
Next, the mixture was heated to 80 ° C. while stirring, and reacted at 80 ° C. for 8 hours. After completion of the reaction, the mixture was diluted with 150 parts by weight of isopropanol (hereinafter referred to as IPA) and 50 parts by weight of toluene to obtain a coating solution having a solid content of 25% and a viscosity of 105 cp.

Next, this coating solution was applied at a coating amount of ² g / m ^{2 to} a 100 μm thick dust-proof vinyl chloride resin film for agricultural use (C-I Chemical Co., Ltd., C-I-No-Bi Co., Ltd.) using a # 5 bar coater. For 3 minutes to evaporate the solvent to produce a desired agricultural vinyl chloride resin film.

Example 2 5 parts by weight of EA, 95 parts by weight of ethyl acetate, 55 parts by weight of MMA, 30 parts by weight of nBMA, 10 parts by weight of HEMA, and γ
After 5 parts by weight of MPTMS was charged in a 3 liter four-necked flask, 1 part by weight of BPO was added and stirred to dissolve. Then, the temperature is raised to 80 ° C. while stirring.
The reaction was performed at 8 ° C. for 8 hours. After completion of the reaction, the mixture was diluted with 150 parts by weight of IPA and 50 parts by weight of toluene to obtain a coating solution having a solid content of 25% and a viscosity of 205 cp. Next, a desired resin film was prepared in the same manner as in Example 1.

Example 3 10 parts by weight of EA, 90 parts by weight of ethyl acetate, 45 parts by weight of MMA, 25 parts by weight of nBMA, 20 parts by weight of HEMA, and 10 parts by weight of γMPTMS were charged into a 3 liter four-necked flask, and 1 part by weight of BPO was added. And stir to dissolve. Then, raise the temperature to 80 ° C while stirring,
The reaction was performed at 80 ° C. for 8 hours. After the completion of the reaction, the mixture was diluted with 150 parts by weight of IPA and 50 parts by weight of toluene to obtain a solid content of 25 parts.
%, And a coating liquid having a viscosity of 250 cp was obtained. Then, Example 1
A desired resin film was prepared in the same manner as described above.

Comparative Example 1 10 parts by weight of EA, 90 parts by weight of ethyl acetate, 58 parts by weight of MMA, 32 parts by weight of nBMA, and 10 parts by weight of HEMA
After charging into a liter four-necked flask, 1 part by weight of BPO was added and stirred to dissolve. Next, the mixture was heated to 80 ° C. while stirring, and reacted at 80 ° C. for 8 hours.
After completion of the reaction, the mixture was diluted with 150 parts by weight of IPA and 50 parts by weight of toluene to obtain a coating solution having a solid content of 25% and a viscosity of 110 cp. Next, a desired resin film was prepared in the same manner as in Example 1.

Comparative Example 2 10 parts by weight of EA, 90 parts by weight of ethyl acetate, 60 parts by weight of MMA, 35 parts by weight of nBMA and 5 parts by weight of γMPTMS were charged into a 3 liter four-necked flask, and then BPO1
The parts by weight were added and stirred to dissolve. Next, the mixture was heated to 80 ° C. while stirring, and reacted at 80 ° C. for 8 hours. After completion of the reaction, the mixture was diluted with 150 parts by weight of IPA and 50 parts by weight of toluene to obtain a coating solution having a solid content of 25% and a viscosity of 120 cp. Next, a desired resin film was prepared in the same manner as in Comparative Example 1.

Comparative Example 3 100 parts by weight of ethyl acetate, 55 parts by weight of MMA, nBMA
After charging 35 parts by weight, 5 parts by weight of HEMA, and 5 parts by weight of γMPTMS into a 3 liter four-necked flask,
1 part by weight of PO was added and dissolved by stirring. Then, the mixture was heated to 80 ° C. with stirring, and reacted at 80 ° C. for 8 hours. As a result, gelling occurred, and this product did not form a film, and thus a predetermined film could not be formed.

The film samples of each of the above Examples and Comparative Examples 1 and 2 were exposed on an outdoor exposure table at an angle of 20 degrees for 6 to 24 months, and the appearance was determined according to the following evaluation criteria. ：: Not significantly different from the state at the time of exposure. Δ: Dust is slightly adhered. ×: Dust is remarkably adhered. Table 1 shows the results.

[0039]

[Table 1]

From the results, with respect to the film samples of Comparative Examples 1 and 2, a little dust adhered after 12 months of exposure,
It can be seen that all of the films of the present invention are excellent in dustproofness even after exposure for 24 months, while dust adhesion is remarkable for practical use after exposure for 24 months.

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-3-231848 (JP, A) JP-A-1-185336 (JP, A) JP-A-1-131254 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) C08J 7/04

Claims (3)

(57) [Claims] 1. At least one side of a vinyl chloride resin film, (A) (A) general formula Wherein R ¹ is hydrogen or a methyl group, R ² is a direct bond or a divalent organic residue, and R ³ is an alkyl group.
10% by weight, (B) 0.1-20% by weight of a (meth) acrylic ester monomer containing a hydroxyalkyl group and (C) 70.0-99.8% by weight of another copolymerizable monomer. A vinyl chloride resin film for agricultural use, characterized in that a coating comprising a coating composition containing 100 parts by weight of the obtained copolymer and (5) 90 parts by weight of an alcohol having 12 or less carbon atoms as a main component is provided. . 2. The vinyl chloride resin film for agricultural use according to claim 1, wherein the trialkoxysilicate monomer of the component (A) is γ-methacrylpropyltrimethoxysilane. 3. The agricultural vinyl chloride resin film according to claim 1, wherein the (meth) acrylic ester monomer containing a hydroxyalkyl group as the component (B) is 2-hydroxyethyl methacrylate.