JP2617678B2 - Agricultural vinyl chloride resin film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an agricultural vinyl chloride resin film. More specifically, the present invention relates to a vinyl chloride resin film for agricultural use having excellent durability of ultraviolet shielding ability.

[0002]

2. Description of the Related Art Hitherto, there has been a close relationship between the growth of a plant and irradiation light, particularly light in the ultraviolet region, and various studies have been made on the cultivation of plants using light quality. There are many known agricultural films used in. More recently, the propagation of certain plant pathogenic fungi, such as fungus pathogens, sesame leaf blight fungus, sclerotium fungus, botrytis fungus, anthracnose fungus, vine wilt fungus, black mold fungus, spot fungus, etc. It has also been found that there is a close relationship with the wavelength of the region.

For example, JP-A-52-98125, JP-A-52-117738, JP-B-55-12208,
JP-B-53-47383, JP-A-53-27539
JP-A-53-136050, JP-A-53-138
844, JP-A-53-138845, JP-A-54-
No. 54843, JP-A-54-54844, JP-A-54
-97233 and JP-A-55-23920.

Further, effects such as promotion of plant growth, improvement of quality, improvement of harvest and yield, and control of pests and birds have been found. For example, JP-A-52-43637, JP-A-5-43637
3-75039, JP-A-53-98238, JP-A-53-98242, JP-A-53-107938, JP-B-55-10203, and JP-A-53-127126.
JP-A-53-124556, JP-A-53-127
129, JP-A-53-127130, JP-A-53-
138842, JP-A-53-138843, JP-A-53-138846, JP-A-54-66295, JP-A-54-85963, JP-A-54-97273,
JP-A-54-160630, JP-A-55-23919
JP-A-55-23921, JP-A-55-6173
No. 6, JP-A-55-96039, and the like.

On the other hand, as agricultural films for cultivating general useful plants, vinyl chloride resin films having excellent heat retention and durability are widely used. The vinyl chloride resin film has much higher durability than polyethylene film and ethylene-vinyl acetate copolymer film, and can be used for about two years. Recently, with the advance of the technology of selectively combining the compounding aids, even a vinyl chloride resin film can exhibit durability for up to 3 to 5 years.

However, from the point of view of the ability of the film to block light rays in the ultraviolet region, at present it is still insufficient in terms of sustainability. In other words, the ultraviolet absorber compounded in the base vinyl chloride resin film has an ultraviolet absorbing ability (absorption effect) because it is washed away, volatilized or deteriorates while the film is used as a house or tunnel covering material. The fact is that it cannot be sustained for a long time.

[0007] There is a method of maintaining the ultraviolet shielding effect of the film by selecting the type and amount of the ultraviolet absorber to be incorporated into the basic vinyl chloride film, but the effect is still insufficient. When the blending amount of the ultraviolet absorber is increased, the ultraviolet shielding ability of the film is improved, but at the same time, since the ultraviolet absorber oozes out on the film surface, the transparency is greatly reduced during use. Also, if you want to maintain the UV absorption of the film at a specific value, according to the value to be maintained,
Since the amount of the ultraviolet absorber is determined, it cannot be increased without limit. Some types of UV absorbers have excellent durability of UV absorbing ability, but are still insufficient for practical use.

[0008]

SUMMARY OF THE INVENTION In view of such circumstances, the present inventors have conducted intensive studies with the aim of providing a vinyl chloride resin film for agricultural use having excellent durability of ultraviolet shielding ability. The invention has been completed.

[0009]

Means for Solving the Problems The gist of the present invention is that (A) a benzophenone-based ultraviolet absorber 0.4 expressed by the following general formula (I) per 100 parts by weight of a vinyl chloride-based resin. ~ 5 parts by weight,

[0010]

Embedded image

[In the formula (I), R ₁ has 1 to 1 carbon atoms.
2 represents an alkoxy group. (B) As a raw material, a mixed alcohol containing xylenol, cresol and ethylphenol as main components,
The composition ratio between xylenol and cresol is 2/1 to 20 /
0.5 to 10 parts by weight of an organic phosphate ester produced by using a mixed alcohol having a composition ratio of P-ethylphenol in the mixed alcohol of 1 to 30% by weight or less, (C) General formula

[0012]

Embedded image

[In the formula (II), R _{2 to} R ₅ represent an alkyl group having 1 to 4 carbon atoms, and R ₆ represents hydrogen or an alkyl group having 1 to 4 carbon atoms. ] The hindered amine type compound which contains one or more structural units shown by these in 0.2-1.
0 parts by weight each, the thickness is 0.075-0.3
mm. The present invention is an agricultural vinyl chloride resin film characterized in that an acrylic resin film having a thickness of 0.5 to 10 μm is formed on one or both surfaces of the film.

Hereinafter, the present invention will be described in detail. In the present invention, the vinyl chloride resin, in addition to polyvinyl chloride,
It is meant to include a copolymer containing vinyl chloride as a main component.
Examples of monomers that can be copolymerized with vinyl chloride include vinylidene chloride, ethylene, propylene, acrylonitrile, vinyl acetate, maleic acid, itaconic acid, acrylic acid, and methacrylic acid, but are not limited to those exemplified. Not something.

The vinyl chloride resin may be produced by any conventionally known production method such as suspension polymerization method, emulsion polymerization method, emulsion-suspension polymerization method, solution polymerization method and bulk polymerization method. . In the vinyl chloride resin film according to the present invention, a benzophenone ultraviolet absorber represented by the following general formula (I) is blended as the component (A) with the vinyl chloride resin.

[0016]

Embedded image

[In the formula (I), R ₁ has 1 to 1 carbon atoms.
2 represents an alkoxy group. ] Specific examples of the compound represented by the above general formula (I) include 2-hydroxy-4-methoxybenzophenone and 2
-Hydroxy-4-n-octoxybenzophenone, 4
-Dodecyloxy-2-hydroxybenzophenone and the like.

The ultraviolet absorber represented by the above formula (I) may be used alone or in combination of two or more. The blending amount of the component (A) into the vinyl chloride resin varies depending on the type of the ultraviolet absorber, but the resin 100
It is preferable to select in the range of 0.4 to 5 parts by weight with respect to parts by weight. Agricultural vinyl chloride resin film according to the present invention,
As the component (B), an organic phosphate ester having a specific composition is blended. Organophosphate ester of this characteristic composition,
In addition to the function of plasticizing the vinyl chloride resin, the function of improving the weather resistance of the film, and the function of maintaining the ultraviolet absorbing ability (absorbing effect) of the ultraviolet absorber incorporated in the film.

According to the experiments conducted by the present inventors, the organic phosphoric acid ester is a mixed alcohol containing xylenol, cresol and ethylphenol as the main components, and the composition ratio of xylenol and cresol is 2/1. ~ 2
It has been found that an organic phosphate ester produced by using a mixed alcohol having a composition ratio of P-ethylphenol in the mixed alcohol of 0/1 and 30% by weight or less is suitable. That is, it has been found that when the composition of the organic phosphate ester satisfies the above requirements, the effect of sustaining the ultraviolet absorbing ability of the ultraviolet absorber (ultraviolet shielding ability of the film) becomes remarkable.

The above-mentioned organic phosphate ester can be produced by a general method for synthesizing a normal phosphate ester. For example, to a total of 3 moles of a mixed alcohol satisfying the above requirements, an aluminum chloride catalyst was added at 2% by weight based on the amount of the mixed alcohol, and 1 mole of phosphorus oxychloride was added dropwise to this mixture at 30 ° C. with stirring, and gradually added. The reaction is completed by heating at 120 ° C. for 2 hours while removing generated hydrogen chloride by passing it through an external alkali absorption tube. After the reaction, the mixture is cooled, water is added to decompose the aluminum chloride catalyst, and the oil layer is separated and collected.

Next, the rare earth aqueous solution of soda is added to the oil layer and shaken to separate the oil layer. For further purification, the oil layer is distilled and the main fraction at 200 to 270 ° C. is reduced under a reduced pressure of 4 mmHg. obtain. The main fraction is further decolorized through an activated carbon packed tower.
Deodorization can be performed to obtain the desired organic phosphate ester. According to the experiments of the present inventors, if the amount of the organic phosphate ester (B) to be added to the vinyl chloride resin is too small, the ultraviolet absorbing ability of the ultraviolet absorbent cannot be maintained, and On the contrary, it was found that the effect was reduced when it was too much. The preferred amount is 0.5 to 10 parts by weight based on 100 parts by weight of the vinyl chloride resin, and it is found that the preferable range is 1 to 5 parts by weight. This (B)
It is preferable that the amount of the component is proportional to the amount of the component (A) within the above range. The vinyl chloride resin film for agriculture according to the present invention comprises the following general formula (II) as component (C):

[0022]

[Chemical 6]

[In the formula (II), R _{2 to} R ₅ represent an alkyl group having 1 to 4 carbon atoms, and R ₆ represents hydrogen or an alkyl group having 1 to 4 carbon atoms. ] A hindered amine compound containing one or more structural units represented by The hindered amine compound functions to improve the weather resistance of the vinyl chloride resin film. The following can be illustrated as specific examples of the hindered amine compound containing one or more structural units represented by the above formula (II) in one molecule.

[0024]

Embedded image

[0025]

Embedded image

[0026]

[Chemical 9]

[0027]

[Chemical 10]

[0028]

[Chemical 11]

[0029]

[Chemical 12]

[0030]

Embedded image

[0031]

Embedded image

[0032]

Embedded image

[0033]

Embedded image

[0034]

Embedded image

[0035]

Embedded image

[0036]

[Chemical 19]

[0037]

[Chemical 20]

[0038]

Embedded image

If the amount of the hindered amine compound as the component (C) to be blended in the vinyl chloride resin film is too small, the weather resistance of the film will not be sufficiently excellent, which is not preferable, and even if it is too large. The weather resistance of the film does not improve in proportion to the amount added, and a problem of spouting from the film surface occurs. The preferred amount is
0.2 to 1.0 per 100 parts by weight of vinyl chloride resin
It is in the range of parts by weight.

The film according to the present invention is as described above.
A film obtained by adding a UV absorber as a component (A), an organic phosphoric acid ester as a component (B), and a hindered amine compound as a component (C) to a vinyl chloride resin as a substrate. Before addition, if necessary, other resin additives such as plasticizers, lubricants, heat stabilizers,
Antioxidants, antifogging agents, pigments, dyes and the like can be added.

Examples of plasticizers that can be used include di-n.
-Phthalic acid derivatives such as octyl phthalate, di-2-ethylhexyl phthalate, dibenzyl phthalate, diisodecyl phthalate, didodecyl phthalate, diundecyl phthalate; isophthalic acid derivatives such as diisooctyl isophthalate; di-n-butyl adipate, dioctyl Adipic acid derivatives such as adipate; Maleic acid derivatives such as di-n-butyl maleate; Citric acid derivatives such as tri-n-butyl citrate; Itaconic acid derivatives such as monobutyl itaconate; Oleic acid derivatives such as butyl oleate; Glycerin Ricinoleic acid derivatives such as monoricinoleate; tricresyl phosphate, epoxidized soybean oil, epoxy resin-based plasticizer and the like.

The lubricants or heat stabilizers that can be used include:
Examples include polyethylene wax, liquid paraffin, stearic acid, zinc stearate, fatty alcohol, calcium stearate, barium stearate, barium ricinoleate, dibutyltin dilaurate, dibutyltin malate and the like. The antistatic agent or antifogging agent that can be used is mainly a nonionic surfactant, for example, sorbitan monostearate, sorbitan monopalmitate, sorbitan monobenzoate and other sorbitan surfactants; glycerin monolaurate, Glycerin-based surfactants such as diglycerin monopalmitate and glycerin monostearate; polyethylene glycol-based surfactants such as polyethylene glycol monostearate and polyethylene glycol monopalmitate; alkylphenol oxide adducts of alkylphenols;
Esters of a sorbitan / glycerin condensate with an organic acid; and the like. These surfactants can be used alone or in combination of two or more.

These various resin additives are added in the usual amounts,
For example, the plasticizer is up to 80 parts by weight with respect to 100 parts by weight of the vinyl chloride resin, in the range of 30 to 80 parts by weight in the case of soft blending, the additives excluding the plasticizer are in the range of 5 parts by weight or less, You can choose each one. In order to add the components (A) to (C) and, if necessary, other resin additives to the vinyl chloride-based resin as the base material, the usual mixing and mixing techniques such as ribbon blender, Banbury mixer and super mixer are used. The method of using other compounding machines and mixing machines can be adopted.

In order to produce the film according to the present invention, the vinyl chloride resin as the base is added with the components (A) to (C).
The composition obtained by blending the components and, if necessary, various resin additives is formed into a film by a film forming technique known per se. Known film forming techniques include a calender molding method, a T-die extrusion method, an inflation molding method, and a solution casting method. The film may be any of a transparent film, a matte film, a semi-matte film, and the like.

The thickness of the film according to the present invention is 0.07.
The range is 5 to 0.2 mm. The agricultural vinyl chloride resin film according to the present invention has an acrylic resin film formed on one or both surfaces of the base film. In the present invention, the acrylic resin means 5 to 40% by weight of a hydroxyalkyl (meth) acrylate, 0 to 20% by weight of an α, β-unsaturated carboxylic acid compound containing one or more carboxyl groups in a molecule, and A polymer obtained by copolymerizing these compounds with another copolymerizable vinyl compound.

Examples of hydroxyalkyl (meth) acrylates are hydroxymethyl acrylate, hydroxymethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate and 3-hydroxypropyl acrylate. , 3-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl acrylate, 4-
Examples thereof include hydroxybutyl methacrylate, 2-hydroxypentyl acrylate, 2-hydroxypentyl methacrylate, 6-hydroxyhexyl acrylate, and 6-hydroxyhexyl methacrylate.

These hydroxyalkyl (meth) acrylate compounds improve the adhesion between the acrylic resin and the base vinyl chloride resin film because the resulting acrylic resin is easily dissolved in an organic solvent, and further, the film surface has a stain. It is a component that greatly contributes to the action of suppressing the migration of the plasticizer that comes out. When the proportion of the hydroxyalkyl (meth) acrylate in the acrylic resin is less than 5% by weight, the solubility in an organic solvent, the adhesion to a base film, and the effect of suppressing migration of a plasticizer are sufficiently exhibited. It is not preferable because it cannot be obtained. On the other hand, if the content is more than 40% by weight, the cost is high and the effect obtained is not so large as compared with the cost increase, which is not preferable.

The α, β-unsaturated carboxylic acid compound containing one or more carboxyl groups in the molecule includes acrylic acid, methacrylic acid, itaconic acid, maleic acid, aconitic acid, crotonic acid and the like. . When these compounds are used in combination with the hydroxyalkyl (meth) acrylates, the effect of improving the adhesiveness between the acrylic resin and the vinyl chloride resin film and suppressing the property of the films sticking to each other (blocking) is exerted. Demonstrate. The amount of these compounds used is up to 20% by weight.
If it is more than this, the property that the films adhere to each other when the film is moistened with moisture (the blocking property when wet) is undesirably enhanced.

Other vinyl compounds copolymerizable with the above compounds include methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate and the like. These compounds play a role of improving the flexibility of the coating film and the adhesion to the base vinyl chloride resin. Acrylic resin for forming a film on one surface or both surfaces of a vinyl chloride resin film is prepared by combining the above monomers in a predetermined amount and charging the mixture with an organic solvent in a polymerization vessel, a polymerization initiator and, if necessary, a molecular weight regulator. Can be added and heated with stirring to polymerize.

The acrylic resin film formed on one or both sides of the vinyl chloride resin film is preferably applied by dissolving the acrylic resin in an organic solvent. The organic solvent for dissolving the acrylic resin may be the same as the solvent used when producing the acrylic resin. Specifically, alcohols are preferable, for example, methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol,
n-amyl alcohol, isoamyl alcohol, ter
t-amyl alcohol, n-hexyl alcohol, cyclohexanol and the like. In addition to the above alcohols, ethyl acetate, methyl ethyl ketone, tetrahydrofuran, hexane, toluene, xylene, chloroform and the like can be used. These may be one kind or a mixture of two or more kinds.

To form a coating film of the acrylic resin on one side or both sides of the vinyl chloride resin film, the acrylic resin is dissolved in the above organic solvent, and the spray coating method, roll coating method, gravure coating method, reverse coating method is used. Law,
In addition to the dip coating method and the like, it is preferable to apply and dry by various known coating methods such as a screen printing method and a flexographic printing method. Available drying methods include, for example, a hot air drying method, an infrared drying method, and a far infrared drying method.
The drying temperature is preferably a temperature at which the organic solvent is scattered, that is, a boiling point of the organic solvent in which the acrylic resin is dissolved or higher. The shorter the drying time, the better. Therefore,
It is preferable to dry at a temperature equal to or higher than the boiling point of the organic solvent in as short a time as possible.

The thickness of the acrylic resin film formed on the surface of the base film depends on the thickness of the base film.
Select from the range of 0.5 to 10 microns. When the thickness is more than 10 microns, there is a difference in flexibility between the base film and the coating, so that a phenomenon such as peeling of the coating from the base film is likely to occur, and the coating is cracked to lower the strength of the base film. This phenomenon is not preferable. When the thickness is less than 0.5 μm, the effect of improving the weather resistance of the base film is not exhibited, which is not preferable. The thickness of the coating is preferably proportional to the thickness of the base film within the above range.

In practical use of the agricultural vinyl chloride resin film according to the present invention, when the coating is formed on only one side, the side provided with this coating is the outside of the house or tunnel. It is good to expand in this way.

[0054]

The vinyl chloride resin film for agriculture according to the present invention is as described above, has the following particularly remarkable effects, and its industrial utility value is extremely large. (1) The vinyl chloride resin film for agriculture according to the present invention comprises a base film, an ultraviolet absorber as the component (A),
Since the organic phosphate ester (B) and the hindered amine compound (C) are blended, the ultraviolet absorbing ability of the ultraviolet absorber (the ultraviolet shielding ability of the film)
For a long time.

(2) In the vinyl chloride resin film for agriculture according to the present invention, the base film is blended with the components (A), (B) and (C), and the surface itself has weather resistance. Since the excellent acrylic resin film is formed, it can be used for a long time. (3) The agricultural vinyl chloride resin film according to the present invention suppresses bleeding of the component (A), the component (B), the component (C), the plasticizer and other resin additives blended in the base film. be able to. Therefore, since the surface is not stained for a long period of time, the film transmits a wavelength higher than the visible region at a high rate for a long period of time, and is suitable for agricultural house coating.

[0056]

EXAMPLES The present invention will be described in detail below based on examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. Examples 1 to 3, Comparative Examples 1 to 8

[0057]

Table 1 (1) Preparation of base film Polyvinyl chloride (average degree of polymerization: 1400) 100 parts by weight Dioctyl phthalate 45 〃 Epoxy resin (trade name "EP-828") 1 〃 Barium-zinc composite stabilizer 1.5バ Barium stearate 0.2 亜 鉛 Zinc stearate 0.4 〃 Sorbitan monostearate 1.5 エ チ レ ン Ethylene bis stearamide 0.1 〃

The basic composition is shown in Table 1. Further, the composition of the ultraviolet absorbent [(A) component], the organic phosphate ester [(B) component] (the mixed alcohol composition of the raw materials) shown in Table 1 is shown in Table 1. ) And a hindered amine compound [component (C)] were blended in the blending ratio shown in the table. Using a calender molding machine, the composition was prepared in a thickness of 0.1 m by a conventional method.
m film.

(2) Formation of Coating Film 150 parts by weight of isopropyl alcohol and 2 parts
-20 parts by weight of hydroxyethyl methacrylate, 10 parts by weight of acrylic acid, 40 parts by weight of methyl methacrylate and 30 parts by weight of ethyl methacrylate, 0.5 part by weight of benzoyl peroxide, and 8 parts by weight under a nitrogen gas stream.
The polymerization reaction was performed at 0 ° C. for 10 hours. Isopropyl alcohol was added to the obtained copolymer solution to reduce the solid content to 2%.
The coating material was adjusted to 0% by weight. The coating material was applied to one surface of the base film by the gravure coating method, and then the coating material was placed in a warm air drying oven whose temperature was adjusted to 150 ° C.
The solution was allowed to stay for 2 seconds to disperse the solvent, and a film having a thickness of about 2 microns was formed.

For each film, according to the following method
The durability of the UV shielding ability was evaluated. The results are shown in Table 1. Test method: A plurality of films were exposed on a window frame-shaped exposure test table facing south, set at a 45-degree angle to the plane (location: Kaifu-gun, Aichi Prefecture). A part of the film was removed from the exposure test table, and the light transmittance at a wavelength of 350 nanometers was measured (using a spectrophotometer 323 manufactured by Hitachi, Ltd.).

From Table 1, the following becomes clear. (1) The vinyl chloride resin film for agricultural use according to the present invention does not change its ultraviolet shielding ability even when used outdoors for a long period of time, and is excellent in persistence of the shielding ability. (2) As the ultraviolet absorber, the use of the compound represented by the above formula (I) has a higher ultraviolet shielding ability than the case of using other compounds (Comparative Examples 1, 2, 3). Sustainability will be excellent. (3) If the composition ratio (the amount of xylenol / cresol and P-ethylphenol component) of the mixed alcohol used for the production of the organic phosphate ester is outside the scope of the claims (Comparative Example 4), the ultraviolet light of the film is used. The persistence of the shielding ability is inferior. (4) Even if the three components of the ultraviolet absorber, the organic phosphoric acid ester, and the hindered amine are within the scope of the claims, if there is no acrylic resin film on the surface (Comparative Example 5),
The UV shielding ability of the film is not long-lasting.

[0062]

[Table 2]

[0063]

[Table 3]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-58-187121 (JP, A) JP-A-57-168933 (JP, A) JP-A-58-206652 (JP, A) JP-A-58- 168643 (JP, A)

Claims (2)

(57) [Claims] 1. A benzophenone-based ultraviolet absorber represented by the following general formula (I): 0.4 to 5 parts by weight per 100 parts by weight of a vinyl chloride resin; [In the formula (1), R ₁ represents an alkoxy group having 1 to 12 carbon atoms. (B) As a raw material, a mixed alcohol containing xylenol, cresol and ethylphenol as main components,
The composition ratio between xylenol and cresol is 2/1 to 20 /
1, and 0.5 to 10 parts by weight of an organic phosphoric acid ester produced by using a mixed alcohol having a composition ratio of P-ethylphenol in the mixed alcohol of 30% by weight or less; General formula: [In the formula (II), R _{2 to} R ₅ represent an alkyl group having 1 to 4 carbon atoms, and R ₆ represents hydrogen or an alkyl group having 1 to 4 carbon atoms. A hindered amine-based compound containing at least one structural unit in one molecule in an amount of 0.2 to 1.0 parts by weight, to form a film having a thickness of 0.075 to 0.3 mm. A vinyl chloride resin film for agricultural use, characterized in that an acrylic resin film having a thickness of 0.5 to 10 microns is formed on one or both surfaces of the film. 2. The method according to claim 1, wherein the acrylic resin film formed on the surface of the vinyl chloride resin film contains 5 to 40% by weight of a hydroxyalkyl (meth) acrylate compound and / or contains one or more carboxyl groups. 2. Agricultural vinyl chloride according to claim 1, comprising 0 to 20% by weight of an unsaturated carboxylic acid compound and a polymer obtained by copolymerizing these compounds with another vinyl compound. Resin film.