JP2001334619A - Resin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin film good in transparency and weatherability and suitable for an agricultural or horticultural film. SOLUTION: The resin film has a layer (C) comprising a resin composition, of which the environmental stress crack resistance is 1,000 hr or more, consisting of 100 pts.wt. of a resin (A) comprising low density polyethylene with a melt flow rate of 0.1-10 g/10 min and a density of 0.92-0.94 g/cm3 and 30-150 pts.wt. of a resin (B) comprising an ethylene/4-12C α-olefin copolymer with a melt flow rate of 0.1-10 g/10 min and a density of 0.91-0.93 g/cm3 as at least one outermost surface layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a resin film which can be suitably used for agricultural and horticultural applications.

[0002]

2. Description of the Related Art In recent years, there has been a strong demand for long-term use of agricultural and horticultural materials due to aging of farmers and strengthening of agricultural competitiveness. Investigations for long-term use of agricultural films, which have been used for a relatively short time, are now underway. As agricultural films, polyvinyl chloride films and polyolefin resin films are mainly used because of their advantages such as light weight, applicability to simple facilities, and low cost. The latter are becoming mainstream due to their small size. However, the polyolefin resin film is inferior in transparency to the polyvinyl chloride film, and when used for a long period of time (for example, 4 years or more), the surface of the film exhibited in a facility such as a house, particularly outside the facility. Dust adheres to the surface facing the, and the illuminance in the facility gradually decreases, and the attached dirt deteriorates the film. Further, when the surface of the film is cleaned with a detergent, the film is likely to be deteriorated or whitened.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a resin film having excellent transparency and weather resistance, which is suitable as an agricultural and horticultural film.

[0004]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a specific low-density polyethylene and a specific ethylene /
The present inventors have found that the above problem can be solved by a resin film having an outermost layer made of a resin composition comprising an α-olefin copolymer and having a resistance to environmental stress cracking of a certain level or more, and solved the present invention.

That is, according to the present invention, as at least one outermost layer, 100 parts by weight of the following resin (A) and 30 to 1
A resin film comprising a layer (C) comprising a resin composition comprising 50 parts by weight of the following resin (B) and having an environmental stress crack resistance of 1000 hours or more. Resin (A): melt flow rate is 0.1 to 10 g / 1
0 minute, low density polyethylene resin having a density of 0.92 to 0.94 g / cm ³ (B): a melt flow rate of 0.1 to 10 g / 1
0 minutes, density exceeds 0.91 g / cm ³ and 0.93 g / c
m ³ resin film less is ethylene / carbon number 4 to 12 α- olefin copolymer above configuration is excellent in transparency and weather resistance, it is suitable as an agricultural or horticultural film. In addition, since the resin film has the layer (C) as the outermost layer, dust hardly adheres to the film surface. Therefore, when the resin film is spread as a covering material for the house, the illuminance in the house due to the contamination of the film due to the film contamination Was also found to be unlikely to decrease. Furthermore, it was also found that the resin film hardly deteriorates or whitens even when washed.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Low density polyethylene (resin (A)) used for layer (C) in the resin film of the present invention
Has a melt flow rate of 0.1 to 10 g / 10 min, preferably 0.1 to 2 g / 10 min. If the melt flow rate is too low, processability during film production is poor, and if it is too high, the film strength may be poor.
In addition, from the viewpoint of film blocking properties, JIS
The density measured in accordance with K7112 (hereinafter the same) is
0.92 to 0.94 g / cm ³ , preferably 0.1 to 0.94 g / cm ³ .
92 to 0.93 g / cm ³ .

The α-olefin of the ethylene / α-olefin copolymer (resin (B)) used for the layer (C) is 4
Has ~ 12 carbon atoms. Examples of such α-olefins are propylene, 1-butene, 1-pentene,
1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-cyclohexene,
Cyclohexylethylene is mentioned. Ethylene / α-
The olefin copolymer may be a copolymer of ethylene and one type of α-olefin, or a copolymer of ethylene and two or more types of α-olefin. The content of the α-olefin monomer unit in the ethylene / α-olefin copolymer (the total amount when two or more α-olefins are used in combination) is usually about 0.5 mol% to about 25 mol%.
Mol%, preferably from about 0.5 mol% to about 10 mol%, more preferably from about 1 mol% to about 7 mol%.

[0008] The melt flow rate of the ethylene / α-olefin copolymer is 0.1 to 10 g / 10 minutes, preferably 0.1 to 4 g / 10 minutes. If the melt flow rate is too low, processability during film production is poor, and if it is too high, the film strength may be poor.
Further, from the viewpoint of the strength of the film, the density of the ethylene / α-olefin copolymer is preferably 0.93 g / cm ³ or less. In the present invention, the density of the ethylene / α-olefin copolymer is more than 0.91 g / cm ³ and 0.93
g / cm ³ or less.

The above-mentioned ethylene / α-olefin copolymer is a so-called single-site catalyst such as a complex catalyst of a transition metal such as palladium or nickel or a metallocene-based catalyst obtained by converting ethylene and an α-olefin having 4 to 12 carbon atoms. In the presence or absence of a solvent in the gas phase /
It can be produced by a method of polymerizing in a solid phase, liquid phase / solid phase or homogeneous liquid phase. The polymerization temperature is usually about 30 ° C.
To about 300 ° C., and the polymerization pressure is usually about atmospheric pressure
It is about 3000 kg / cm ² . For example, JP-A-6-9
724, JP-A-6-136195, JP-A-6-136196, and so-called metallocene-based olefin polymerization catalyst containing a metallocene catalyst component described in JP-A-6-207057. An ethylene / α-olefin copolymer can be produced by copolymerizing ethylene and an α-olefin having 4 to 12 carbon atoms.

The blend ratio of the low-density polyethylene and the ethylene / α-olefin copolymer in the layer (C) is determined based on 100 parts by weight of the low-density polyethylene from the viewpoint of environmental stress cracking resistance, transparency and processability. The ethylene / α-olefin copolymer is 30 to 150 parts by weight, and the specific blend ratio is such that the environmental stress crack resistance of the resin composition is 1000 hours depending on the type of the ethylene / α-olefin copolymer used. It is appropriately selected so as to be as described above. For example,
When the ethylene / α-olefin copolymer is an ethylene / butene copolymer or an ethylene / pentene copolymer, the blending ratio is usually 70 to 150 parts by weight based on 100 parts by weight of the low-density polyethylene. Is preferred,
In the case of an α-olefin copolymer having 6 or more ethylene / carbon atoms, the blending ratio is preferably 30 to 150 parts by weight based on 100 parts by weight of the low-density polyethylene.
When the blend ratio of the ethylene / α-olefin copolymer is less than 30 parts by weight based on 100 parts by weight of the low-density polyethylene, the resin composition constituting the layer (C) generally has an environmental stress crack resistance of 1000 hours. Will fall below
The detergent resistance and stain resistance of the resin film become insufficient.
When the amount of the ethylene / α-olefin copolymer is more than 150 parts by weight, the transparency of the layer (C) and the processability of the film generally deteriorate.

The layer (C) is composed of a fatty acid amide compound or an organic compound from the viewpoints of anti-blocking properties, dust resistance and abrasion resistance of the film, and prevention of wrinkles when another layer is laminated on the layer (C). It is preferable to contain fine particles, inorganic fine particles, and the like.

Examples of the fatty acid amide compound include a saturated fatty acid amide, an unsaturated fatty acid amide, and a bisfatty acid amide having a melting point of about 50 to about 200 ° C. Specific examples include behenic acid amide, stearic acid amide,
Palmitic acid amide, lauryl amide, erucic acid amide, oleic acid amide, methylenebisstearic acid amide, methylenebisbehenic acid amide, methylenebisoleic acid amide, ethylenebisstearic acid amide, ethylenebisbehenic acid amide, Examples include ethylenebisoleic acid amide, hexamethylenebisstearic acid amide, hexamethylenebisbehenic acid amide, hexamethylenebisoleic acid amide, and octamethylenebiserucic acid amide. When blending such a fatty acid amide,
The compounding amount in the layer (C) is about 0.0 parts by weight based on 100 parts by weight in total of the resin components (low-density polyethylene, ethylene / α-olefin copolymer, etc.) in the layer (C).
It is preferably at least 1 part by weight, more preferably at least about 0.03 part by weight. From the viewpoint of economy, the amount is preferably about 1 part by weight or less, more preferably about 0.5 part by weight or less.

Examples of the organic fine particles that can be contained in the layer (C) include a crosslinked polymer having a particle size of about 0.5 μm to about 20 μm. A closer one is preferred. For example, crosslinked beads such as polyethylene and polymethyl methacrylate are preferably used. When such organic fine particles are blended, the blending amount thereof in the layer (C) is preferably about 0.1 part by weight or more based on 100 parts by weight of the total of the resin components in the layer (C), and about 0.3 part by weight.
The amount is more preferably at least part by weight. Also, from an economic perspective,
It is preferably about 20 parts by weight or less, more preferably about 10 parts by weight or less, and particularly preferably about 5 parts by weight or less.

Examples of the inorganic fine particles that can be contained in the layer (C) include an infrared absorber described below. The amount of the inorganic fine particles in the layer (C) is 100 parts by weight of the total amount of the resin component in the layer (C). It is preferably at least about 0.1 part by weight, more preferably at least about 0.3 part by weight. Also, it is preferably about 20 parts by weight or less, more preferably about 10 parts by weight or less, and particularly preferably about 5 parts by weight or less.

The laminated film of the present invention can contain one or more infrared absorbers. What is an infrared absorber?
There is no particular limitation as long as it has better infrared absorbing ability than the resin material of the layer (C) and other layers. Examples of inorganic infrared absorbers include lithium aluminum composite hydroxides, composite hydroxides such as hydrotalcite compounds, oxides of metals such as magnesium oxide, calcium oxide, aluminum oxide, silicon oxide, and titanium oxide, and lithium hydroxide. , Magnesium hydroxide, calcium hydroxide, hydroxides such as aluminum hydroxide, magnesium carbonate, calcium carbonate, basic aluminum carbonate (for example,
Carbonates such as basic aluminum carbonate double salt described in JP-A-279131), sulfates such as potassium sulfate, magnesium sulfate, calcium sulfate, zinc sulfate and aluminum sulfate, lithium phosphate, sodium phosphate, potassium phosphate, calcium phosphate, and phosphoric acid Zirconium (for example, H-type zirconium phosphate described in JP-A-8-67774)
Such as phosphates, magnesium silicate, calcium silicate,
Silicates such as aluminum silicate and titanium silicate, aluminates such as sodium aluminate, potassium aluminate and calcium aluminate, aluminosilicates such as sodium aluminosilicate, potassium aluminosilicate and calcium aluminosilicate, kaolin, clay and talc Clay minerals, composite oxides and the like. Examples of the organic infrared absorber include polyacetal, polyvinyl alcohol and derivatives thereof, and ethylene / vinyl alcohol copolymer. Among these infrared absorbers, those having a density of about 3 g / cm ³ or less, particularly about 2.4 g / cm ³ or less are preferred from the viewpoint of the efficiency of recycling the resin film, and inorganic infrared rays are preferred from the viewpoint of infrared absorption ability. Absorbers are more preferred.

When the infrared absorbing agent is an inorganic infrared absorbing agent, its refractive index is closer to the refractive index of the resin material used from the viewpoint of light transmittance, and it is broader from the viewpoint of heat insulation. It is preferable to have absorption performance in the wavelength range. From these viewpoints, hydrotalcite compounds,
Lithium-aluminum composite hydroxides, aluminosilicates, basic aluminum carbonate double salts and the like are preferred.

The hydrotalcite compound is represented by the following formula:
(I): M²⁺ _1-xAl³⁺ _x(OH^-)_Two(A₁ ^n-)_{x / n}・ MH_TwoO (I) (where M²⁺Is a divalent metal ion;₁ ^n-Is n-valent
X, m and n are 0 <x <0.5,
The condition 0 ≦ m ≦ 2, 1 ≦ n is satisfied. )
Compound. M²⁺As Mg²⁺, Ca²⁺, Zn²⁺
And the like. The n-valent anion is not particularly limited,
For example, Cl^-, Br^-, I^-, NO_Three ^-, ClO _Four ^-, S
O_Four ^2-, CO_Three ^2-, SiO_Three ^2-, HPO_Four ^3-, HBO_Four ^3-,
PO_Four ^3-, Fe (CN)₆ ^3-, Fe (CN)₆ ^Four-, CH_ThreeC
OO^-, C₆H_Four(OH) COO^-, (COO)_Two ^2-, Tele
Shadow of phthalate ion, naphthalene sulfonate ion
Ion or polysilicon described in JP-A-8-217912.
Acid ions and polyphosphate ions are exemplified. In particular,
For example, natural hydrotalcite and alkamiser D
A synthetic resin such as HT-4A (trade name, manufactured by Kyowa Chemical Industry)
A hydrotalcite can be used.

Also, calcium hydroxide or a general formula:
A calcium / aluminum composite hydroxide represented by CaAl _x (OH) _{2 + 3x} may be used in combination with a hydrotalcite compound.

Examples of the lithium aluminum complex hydroxide, for example, the following formula disclosed in ^{JP-A-5-179052 (II): Li + (} Al 3+) 2 (OH -) 6 · (A 2 n- _{1 / n} · mH ₂ O (II) (wherein A ₂ ⁿ⁻ is an n-valent anion, m and n
Satisfies the condition of 0 ≦ m ≦ 3, 1 ≦ n). The n-valent anion is not particularly limited, and examples thereof include the same anions as A ₁ ^n- in the compound of the formula (I).

Other than the above two types of composite hydroxides,
For example, alkaline earth metals, transition metals, Zn and Si
At least one element selected from the group consisting of
A composite hydroxide containing Li and Al and having a hydroxyl group is exemplified. Of the alkaline earth metals, magnesium and calcium are preferred. Further, among the transition metals, divalent or trivalent iron, cobalt, nickel, and manganese are preferable, and among them, iron is particularly preferable. The molar ratio of Al to Li (Al / Li) is usually 1.5 / 1 to 2.5 / 1.
And preferably from 1.8 / 1 to 2.5 / 1.

Further, alkaline earth metals, transition metals, Zn
The molar ratio (a) of an element selected from the group consisting of Si and Si to 1 mol of Li element is usually 0 <a <1.5, preferably 0.1 ≦ a ≦ 1.4, more preferably 0.1 ≦ a ≦ 1.4. Is 0.2 ≦ a ≦ 1.2. The anion portion other than the hydroxyl group of such a composite hydroxide is, for example, pyrosilicate ion,
Polysilicate ion such as cyclosilicate ion, isosilicate ion, phyllosilicate ion, tectosilicate ion, carbonate ion, halide ion, sulfate ion, sulfite ion, nitrate ion, nitrite ion, phosphate ion, phosphite ion, hypophosphite ion, polyphosphate ion, aluminate ion, silicate ion, perchlorate ion, inorganic acid ions such as borate ^{_{ions, Fe (CN) 6 3-,}} Fe
Anionic transition metal complexes such as (CN) ₆ ^4- , and organic acid ions such as acetate ion, benzoate ion, formate ion, terephthalate ion and alkyl sulfonate ion. Among these, carbonate ion, halide ion, sulfate ion, phosphate ion, polyphosphate ion, silicate ion, polysilicate ion, and perchlorate ion are preferable, and carbonate ion, polyphosphate ion, silicate ion, and polysilicate are preferred. Ions are particularly preferred. Specific examples of such a composite hydroxide include Al, Li, and Mg, and Al / Li / Mg = about 2.3 / 1 / 0.28.
(Molar ratio) complex hydroxide (trade name: LMA, manufactured by Fuji Chemical Industry), Al, Li, Si, and Al /
A composite hydroxide having a Li / Si ratio of about 2/1 / 1.2 (molar ratio) (trade name: Fujilein LS, manufactured by Fuji Chemical Co., Ltd.) may be used.

[0022] WO97 / 00,828 disclosed the following formula ^{(III): [(Li +} (1-x) M 2+ x) (Al 3+) 2 (OH -) 6] 2 (Si y O (2y + ₁₎ ^2- ) _{(1 + x)} · mH ₂ O (III) (where M ²⁺ is a divalent metal ion, and m, x and y are 0 ≦ m <5, 0 ≦ x < 1, 2 ≦ y ≦ 4) and JP-A-8-21
No. 7912, the following formula (IV): [(Li ⁺ _(1-x) M ²⁺ _x ) (Al ³⁺ ) ₂ (OH ⁻ ) ₆ ] ₂ (A ⁿ⁻ ) _{2 (1 + x ) / n} · mH ₂ O (IV) (where M ²⁺ is a divalent metal ion, A ⁿ⁻ is an n-valent anion, and m, x and n are 0 ≦ m <5 , 0.
The compound represented by the following formula (01 ≦ x <1, 1 ≦ n) is a preferable example of the above-mentioned composite hydroxide. As M ²⁺ in the formulas (III) and (IV), Mg ²⁺ ,
Ca ²⁺ and Zn ²⁺ are exemplified.

Further, the following formula (V): mAl ₂ O _3. (N / p) M _{2 / p} O.X.kH ₂ O (V) (where X is a carbonate group and M is an alkali metal Or an alkaline earth metal, p is equal to the valence of the metal M, and m, n and k are 0.3 ≦ m ≦ 1, 0.3 ≦ n ≦ 2, 0.5 ≦
The basic aluminum carbonate double salt represented by the formula (1) which satisfies the condition of k ≦ 4) is also one of preferred infrared absorbers. In the above formula (V), X represents sulfur oxyacid (sulfuric acid, sulfurous acid), nitrogen oxyacid (nitric acid, nitrous acid), hydrochloric acid,
Inorganic anions derived from oxyacids of chlorine (eg, perchloric acid), oxyacids of phosphorus (phosphoric acid, phosphorous acid, metaphosphoric acid), acetic acid, propionic acid, adipic acid, benzoic acid, phthalic acid, terephthalic acid Acid, maleic acid, fumaric acid,
A double salt containing an organic anion derived from succinic acid, p-oxybenzoic acid, salicylic acid, picric acid, toluenesulfonic acid or the like may be used in combination with the basic aluminum carbonate double salt. These double salts can be produced by the method disclosed in JP-A-9-279131.

When the above-mentioned composite hydroxide or basic aluminum carbonate double salt is used as an infrared absorbent, the average particle size is preferably about 5 μm or less, more preferably about 0.05 to about 3 μm, and more preferably about 0.1 to about 3 μm. More preferred is 1 to about 1 μm. The specific surface area measured by the BET method is 1 to 3.
0 m < ² > / g is preferred, and about 2 to about 20 m < ² > / g is more preferred.

When the resin film of the present invention is used for applications requiring a high degree of transparency, the refractive index of the infrared absorber is preferably close to the refractive index of the resin material of the layer containing it. The refractive index measured by the method described in JIS K0062 is preferably 1.47 to 1.55,
1.48 to 1.54 is more preferable, and 1.49 to 1.5
3 is particularly preferred.

In order to improve the dispersibility of the infrared absorber in the resin film, the infrared absorber may be subjected to a surface treatment with a higher fatty acid or an alkali metal salt of a higher fatty acid. The amount of the infrared absorber in the resin film of the present invention, the desired radiation transmission index of the film at 23 ℃,
It is appropriately set in consideration of the type of the infrared absorber used, the layer configuration of the film, and the like. For example, when the above-mentioned composite hydroxide is used as an infrared absorbing agent, its compounding amount is preferably about 6% by weight to about 13% by weight based on the total weight of the resin film.

The radiation transmission index at 23 ° C. of a resin film is a measure of the heat retention when the film is used as a covering material for agricultural houses and the like, and has an effect on the growth of crops. It is determined by the measurement method used. The smaller the value of the radiation transmission index, the better the heat retention of the film. The radiation transmission index at 23 ° C. of the resin film of the present invention is preferably 25 or less. When the resin film has a radiation transmission index of 25 or less, the heat retention is equal to or better than that of the conventional polyvinyl chloride film, and when used in a heated house, the heating cost can be reduced and the economic efficiency can be reduced. Contribute to the improvement of The radiation transmission index is preferably as close to zero as possible, more preferably 20 or less, and even more preferably 15 or less.

The radiation transmission index at 23 ° C. of the resin film is measured by the following method. The infrared absorption spectrum (transmission method) of the resin film was measured at a temperature of 23 ° C. using an infrared spectrophotometer (Perkin Elmer 1640 type FT-IR) in a wave number range of 4000 to 400 cm ⁻¹ , and the wave number ν was measured. The value of the transmittance T (ν)% is obtained. On the other hand, according to the equation (1) obtained from Planck's law, the blackbody radiation spectrum intensity e (ν) at the wave number ν at 23 ° C. is calculated. Here, the transmittance of the blackbody radiation spectrum intensity e (ν)
The value obtained by multiplying (ν) becomes the radiation transmission intensity f (ν) (Equation (2)). The radiation transmission intensity f (ν) is set to a wave number of 4000 to 40.
The radiation integrated energy F and the blackbody radiation spectrum intensity e (ν) integrated in the range of 0 cm ⁻¹ are represented by the wave numbers 4000 to 4.
The value integrated in the range of 00 cm ^-1 is defined as a black body radiation energy E, which is defined as a radiation transmission index G = 100 × F / E. In the actual integration, the interval is divided into intervals of 2 cm ^-1 at the wave number interval, and each interval is calculated and integrated by trapezoidal approximation. e (ν) = (A / λ ⁵ ) / ｛exp (B / (λ × T)) ^-1 } (1) A = 2πhC ² = 3.74 × 10 ^-16 (W · m ² ) B = hC /K=0.01439 (mK) T (K) is an absolute temperature. λ (cm) is the wavelength. (The wave number ν is the reciprocal of the wavelength.) (H is Planck's constant, C is the speed of light, k is Boltzmann's constant.) F (ν) = e (ν) × T (ν) / 100 (2)

The resin film of the present invention can contain at least one kind of light stabilizer. As the light stabilizer, a nickel complex light stabilizer can be used, but a hindered amine compound is preferable, and in particular, a molecular weight of about 1500
The above hindered amine compounds are preferred. Examples of the hindered amine compound include those having a structural formula described in JP-A-8-73667, and specific examples thereof include Tinuvin 622-LD (trade name) and Chimasorb 9
44-LD, Tinuvin 123 (all manufactured by Ciba Specialty Chemicals), Hostabin N30, VP Sand
uvor PR-31 (all manufactured by Clariant) and Syasorb UV3529 (a product of Cytec). Hindered amine compound-containing stabilizers are disclosed in
Composition described in 3-286448 (trade name: Tinuvin 492, Tinuvin 494, manufactured by Ciba Geigy)
Is exemplified. When using a light stabilizer, the amount thereof is about 0.0 with respect to the total weight of the resin film from the viewpoint of the balance between the weather resistance improving effect and the suppression of blooming of the light stabilizer.
A range of 2 to about 5% by weight is preferred, about 0.1 to about 2% by weight is more preferred, and about 0.5 to about 2% by weight is even more preferred. From the viewpoint of the weather resistance improving effect, it is more preferable that the light stabilizer is used in combination with the following ultraviolet absorber.

The resin film of the present invention can contain at least one kind of ultraviolet absorber. The ultraviolet absorber may be an organic compound or an inorganic compound.
Examples of organic UV absorbers that can be used include benzophenone UV absorbers, benzotriazole UV absorbers,
Benzoate UV absorbers, cyanoacrylate UV absorbers, and the like. The inorganic ultraviolet absorber may contain a metal oxide such as cerium oxide or titanium oxide. For example, an ultraviolet absorber commercially available from Nippon Inorganic Chemical Industry Co., Ltd. under the trade name: Serigard can be used. . When an ultraviolet absorber is used, the amount thereof is in the range of about 0.01 to about 3% by weight based on the total weight of the resin film, from the viewpoint of the balance between the effect of improving weather resistance and suppressing blooming of the ultraviolet absorber. Preferably, about 0.05 to
About 1% by weight is more preferred.

The resin film of the present invention may contain an antifogging agent for the purpose of imparting antifogging properties. When blending an antifogging agent, the blending amount is 0.1 to 4 with respect to the film weight.
% By weight, more preferably 0.5 to 3% by weight,
1.5 to 3% by weight is more preferable, and 2.2 to 2.8% by weight is particularly preferable. In the case of a multilayer film, the antifogging agent may be blended in any of the layers, and when blended in two or more layers, the amount of each layer may be the same or different.

As the anti-fogging agent, there are a solid type and a liquid type at normal temperature (23 ° C.). Examples of the solid anti-fogging agent include nonionic surfactants such as sorbitan monostearate. Sorbitan fatty acid ester surfactants such as sorbitan monopalmitate, sorbitan monobehenate, sorbitan monomontanate, glycerin monolaurate, glycerin monopalmitate, glycerin monostearate, diglycerin distearate, triglycerin monostearate Fatty acid ester surfactants such as glycerin and tetraglycerin monomontanate, polyethylene glycol surfactants such as polyethylene glycol monopalmitate and polyethylene glycol monostearate, and alkylphenol oxide addition of alkylphenol Of carboxylic acid, sorbitan / glycerin condensate and organic acid; polyoxyethylene alkylamine compounds such as polyoxyethylene (2 mol) stearylamine, polyoxyethylene (2 mol) laurylamine, polyoxyethylene (4 mol) stearylamine Polyoxyethylene (2 mol) stearylamine monostearate, polyoxyethylene (2 mol) stearylamine distearate, polyoxyethylene (4 mol) stearylamine monostearate, polyoxyethylene (4 mol) stearylamine distearate Polyoxyethylenes such as stearate, polyoxyethylene (8 mol) stearylamine monostearate, polyoxyethylene (2 mol) stearylamine monobehenate, polyoxyethylene (2 mol) laurylamine stearate Fatty acid esters of Chi alkylene alkyl amine compounds, polyoxyethylene (2
Mol) amine surfactants such as fatty acid amides of polyoxyethylene alkylamine compounds such as stearic acid amide;

Further, if a film-like anti-fog agent is added to the film at room temperature, it is possible to avoid deterioration of the light transmittance at the time of storage and expansion. Mixing is effective. Examples of the liquid antifogging agent at room temperature include glycerin monooleate,
Glycerin series such as diglycerin monooleate, diglycerin sesquioleate, tetraglycerin monooleate, hexaglycerin monooleate, tetraglycerin trioleate, hexaglycerin pentaoleate, tetraglycerin monolaurate, hexaglycerin monolaurate, etc. Fatty acid esters also include sorbitan fatty acid esters such as sorbitan monooleate, sorbitan dioleate and sorbitan monolaurate. When the liquid antifogging agent is blended in the film, the amount is preferably in the range of 0.2 to 3% by weight, more preferably 0.5 to 2% by weight, based on the weight of the film.

The resin film of the present invention can contain an antifog agent. Examples of usable antifog agents include fluorine compounds having perfluoroalkyl groups and ω-hydrofluoroalkyl groups (especially fluorine-based surfactants), silicon compounds having alkylsiloxane groups (especially silicon-based surfactants), and the like. Is mentioned. When an antifog is contained, its amount is preferably in the range of about 0.01 to about 3% by weight, more preferably about 0.02 to about 1% by weight, based on the weight of the film.

The resin film of the present invention may be used, if necessary,
It can contain additives such as commonly used stabilizers (eg, antioxidants, heat stabilizers), antiblocking agents, lubricants, antistatic agents, pigments, and the like.

The resin film of the present invention may contain a near-infrared blocking agent. When a resin film containing a near-infrared ray blocking agent is used as a covering material for an agricultural house, it is possible to suppress a temperature drop inside the house during a hot day. As a near-infrared ray blocking agent, for example,
Organic compounds disclosed in JP-A-193522 (e.g., nitroso compounds and metal complexes thereof, cyanine compounds, squarylium compounds, thiol nickel complex compounds, phthalocyanine compounds, triallylmethane compounds, immonium compounds, diimonium Compounds, naphthoquinone compounds, anthraquinone compounds,
Amino compounds, aminium salt compounds) and inorganic compounds (eg, carbon black, antimony oxide, tin oxide doped with indium oxide, 4A and 5A in the periodic table)
Oxides or carbides of metals belonging to Group A or 6A,
Boron compound). A film containing a near-infrared ray blocking agent may be formed on the surface of the resin film of the present invention.
As a method of forming the coating, for example, a method of applying a coating liquid containing a near-infrared ray blocking agent and a water-soluble resin binder to a resin film and drying the coating liquid may be mentioned.

The thickness of the resin film of the present invention is preferably in the range of about 0.02 mm to about 0.3 mm in view of film strength, film splicing workability and coating workability, and is preferably about 0.05 mm.
More preferably, from mm to about 0.25 mm. When the resin film of the present invention is a laminated film comprising the layer (C) and one or more other layers, the thickness of the layer (C) is preferably about 10% or more of the thickness of the film. Is preferably about 20% or more from the viewpoint of moldability, and more preferably about 30% or more from the viewpoint of transparency, film strength and the like.

When the resin film of the present invention is a multilayer resin film, examples of the resin layer other than the layer (C) include an olefin resin layer. As olefin resins,
For example, polyethylene, homopolymer of α-olefin such as polypropylene, ethylene / propylene copolymer,
Ethylene / α-olefin copolymers such as ethylene / butene-1 copolymer, ethylene / 4-methyl-1-pentene copolymer, ethylene / 1-hexene copolymer and ethylene / 1-octene copolymer Ethylene / α-olefin copolymer containing α-olefin as a main component, furthermore, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / methyl methacrylate copolymer, ethylene / vinyl acetate / methyl Methacrylate copolymer,
Examples thereof include an ethylene / polar vinyl monomer copolymer such as an ionomer resin.

Among these olefin resins, low-density polyethylene, ethylene / α-olefin copolymer,
Ethylene represented by ethylene / vinyl acetate copolymer
Polar vinyl monomer copolymers and the like are preferred because they are excellent in transparency and flexibility and provide a laminated film at low cost. Among ethylene / polar vinyl monomer copolymers,
Ethylene having a vinyl acetate unit content of 30% by weight or less /
The vinyl acetate copolymer is preferable from the viewpoint of excellent flexibility, suppressing generation of wrinkles when the laminated film is spread, and excellent heat retention. In addition, ethylene / α-
Olefin copolymers, particularly those having a narrow distribution in composition and molecular weight polymerized using a metallocene catalyst or the like, are preferable because of excellent mechanical strength and transparency.

The method for producing the resin film of the present invention is not particularly limited. The resin film of the present invention can be produced, for example, by the following method. The additives selected as necessary are added to the resin material for the layer (C), and these are mixed by a mixer such as a ribbon blender, a super mixer, a Banbury mixer, a single-screw or twin-screw extruder, and a resin composition is obtained. Get things. Using the resin composition thus obtained, a resin film can be produced by a molding method such as a T-die film molding method or an inflation film molding method. The multilayer film can be manufactured by a co-extrusion T-die film forming method.

As described above, the resin film of the present invention comprises:
Since it is excellent in transparency and weather resistance, it can be suitably used as an agricultural and horticultural film. For example, the agricultural and horticultural film comprising the resin film of the present invention can be used as a covering material for agricultural houses and the like. In a house in which the film is stretched so that the layer (C) is located on the outside, dust hardly adheres to the film surface, so that the illuminance in the house is hardly reduced. In addition, the resin film of the present invention hardly deteriorates or whitens even when washed with a detergent.

[0042]

Since the resin film of the present invention has excellent transparency and weather resistance, it is suitable as an agricultural film used in agricultural and horticultural facilities.

[0043]

EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited to these examples.
In addition, the test method in an Example and a comparative example is as follows.

(1) Environmental stress cracking resistance The components contained in the outer layer shown in Table 1 were kneaded at 150 ° C. for 5 minutes using a Banbury mixer, and then granulated by a granulator to form a resin composition constituting the outer layer. The product was obtained in the form of a pellet. This was press-molded to obtain a sheet having a thickness of 3 mm.
Environmental stress crack resistance was measured in accordance with JIS K6760-1981 (constant strain environmental stress crack measurement method). The reagent used was a 10% aqueous solution of Igepearl CO-630 (alkyl allyl polyethylene glycol manufactured by GAF).
If the environmental stress crack resistance is 1000 hours or more, the detergent resistance and the stain resistance are excellent.

(2) Transparency Haze (%), which is a measure of transparency, was evaluated using a digital haze meter (manufactured by Suga Test Instruments).

(3) Weather Resistance Test A test piece punched out with a JIS No. 1 dumbbell was exposed to a black panel temperature of 63 ° C. over time using a sunshine weather meter (manufactured by Suga Test Instruments). A tensile test was performed using (manufactured by Shimadzu Corporation), the elongation percentage (%) was measured, and the weather resistance test time when the elongation was reduced to half of the original test piece was determined. The greater the value of this time, the better the weather resistance. 1000 hours was set as the pass level of this test.

Examples 1 and 2 and Comparative Example 1 [Preparation of base material] A three-layer tube comprising a first layer, a third layer, and a second layer sandwiched between the first and third layers in the following manner. (Substrate) was produced. The first layer was the inner layer of the tube, the second layer was the middle layer of the tube, and the third layer was the outer layer of the tube. The composition of each layer is as shown in Table 1. The numerical value in parentheses after the symbol indicating the component in Table 1 is a percentage of the amount of the component with respect to the total amount of all components of the layer containing the component. First, the components contained in each layer were kneaded at 150 ° C. for 5 minutes using a Banbury mixer, and then granulated by a granulator to obtain a resin composition constituting each layer in the form of pellets. Using a resin composition pellet for each layer or a resin pellet, a three-layer tube was formed by a three-layer blown film forming machine such that each layer had the thickness shown in Table 1.

[Formation of antifogging layer] Alumina sol (trade name: alumina sol 520, solid content: 20%, manufactured by Nissan Chemical Co., Ltd.), colloidal silica (trade name: Snowtex 2 manufactured by Nissan Chemical Co., Ltd.)
0; solid content 20%), sodium dodecylbenzenesulfonate (manufactured by Kao, trade name Neoperex F25), and sodium decanoate (manufactured by Nacalai Tesque) at a solid content of 1.6%, 0.4%, 0.08% and 0.
Water was added and mixed so as to be 08% to prepare a coating liquid. A coating liquid is applied to the surface of the third layer of the base material that has been subjected to corona treatment in advance so that the solid content thickness is about 0.2 g / m ^2, and the coating solution is dried at room temperature to prevent defogging on the third layer. A layer was formed.

Table 1 shows the evaluation results of the film thus obtained. The films of Examples 1 and 2 were superior to the film of Comparative Example 1 in transparency and weather resistance. Further, the films of the examples were also excellent in heat retention, transparency, toughness, dustproofness and antiblocking properties.

[0050]

[Table 1]

The abbreviations described in Table 1 are as follows. A1: Low density polyethylene (trade name: Sumikasen F20)
8-1; MFR: 1.4 g / 10 min; Density: 0.923
g / cm ³ ; Sumitomo Chemical Co., Ltd.) A2: Ethylene / hexene copolymer (trade name: Sumikacene EFV203; MFR: 2.2 g / 10 minutes; density:
0.913 g / cm ^3; manufactured by Sumitomo Chemical Co., Ltd.) A3: Ethylene / hexene copolymer (trade name: SUMIKATHENE E FV401; MFR: 4.1g / 10 min; density 0.904 g / cm ^3; manufactured by Sumitomo Chemical Co., Ltd.) A4: Ethylene / vinyl acetate copolymer (trade name: Evatate H2031; vinyl acetate unit content: 19% by weight;
MFR: 1.5 g / 10 min; density: 0.940 g / cm
^3, manufactured by Sumitomo Chemical Co.) A5: Ethylene / vinyl acetate copolymer (trade name: Ebateto H2021; vinyl acetate unit content: 15 wt%;
MFR: 1.4 g / 10 min; Density: 0.935 g / cm
^3, manufactured by Sumitomo Chemical Co.) A6: Ethylene / vinyl acetate copolymer (trade name: Ebateto D2011; vinyl acetate unit content: 5 wt%; M
FR: 1.8 g / 10 min; Density: 0.922 g / c
m ^3; manufactured by Sumitomo Chemical Co., Ltd.) E1: Trade name: Irganox HP2225; Ciba Geigy E2: trade name: Irganox 1010; Ciba Geigy F1: hindered amine compound (trade name: Tinuvin 7
83; Ciba-Geigy) F2: Hindered amine compound (trade name: Tinuvin 4)
62; Ciba-Geigy) F3: Hindered amine compound (trade name: Hostabine N30; Clariant) G1: Trade name: Sumisorb 130; Sumitomo Chemical J1: Lithium-aluminum composite hydroxide (trade name: Misuzu Karak; Mizusawa Chemical Co., Ltd.) K1: fatty acid amide compound oleic acid amide K2: fatty acid amide compound ethylenebisstearic acid amide

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hitoshi Nanbu 2-10-1 Tsukahara, Takatsuki-shi, Osaka Sumitomo Plastics Co., Ltd. F-term (reference) 2B024 DB01 DB07 2B029 EB03 EC06 EC19 EC20 4F100 AK01B AK06A AK06B AK08A AK08C AK68B AK68C AL05A BA02 BA03 BA07 BA10A BA10B BA15 BA16 GB01 JA06A JA13A JB02B JJ02 JK01 JL06 JL09 JN01 YY00A 4J002 BB03W BB05X GA01

Claims (3)

[Claims] 1. A resin composition comprising, as at least one outermost layer, 100 parts by weight of the following resin (A) and 30 to 150 parts by weight of the following resin (B), and having an environmental stress crack resistance of 1,000 hours or more. A resin film having a layer (C) comprising: Resin (A): melt flow rate is 0.1 to 10 g / 1
0 minute, low density polyethylene resin having a density of 0.92 to 0.94 g / cm ³ (B): a melt flow rate of 0.1 to 10 g / 1
0 minutes, density exceeds 0.91 g / cm ³ and 0.93 g / c
m ³ or less is ethylene / carbon number 4 to 12 α- olefin copolymer 2. A resin (A) having a melt flow rate of 0.1
2. The resin (B) has a melt flow rate of 0.1 to 4 g / 10 minutes.
The resin film of the above. 3. An agricultural and horticultural film comprising the resin film according to claim 1.