JP2020176263A - Film and agricultural and horticultural facilities - Google Patents

Abstract

To provide a film capable of maintaining high mechanical strength at high temperature while having a light control performance based on an atmospheric temperature change, and a technique related thereto.SOLUTION: A film includes at least one layer composed of a resin composition including: a polyethylene-based resin (A-1); a polypropylene resin (A-2); and a particle (B) with a volume median diameter of 1-20 μm. A density of the polypropylene resin (A-2) is 850-905 kg/m3. A refractive index of the particle (B) is 1.50-1.53.SELECTED DRAWING: None

Description

The present invention relates to films and agricultural and horticultural facilities.

Patent Document 1 describes an ethylene-vinyl acetate copolymer having a vinyl acetate-based monomer unit content of 15 to 30% by weight in the intermediate layer and methyl methacrylate-styrene methacrylate having an average particle size of 3 to 15 μm. Agricultural films with layers containing copolymer particles have been described.

Further, in Patent Document 2, the inner layer and the outer layer contain at least one selected from linear low-density polyethylene, low-density polyethylene, and ethylene-vinyl acetate copolymer having a vinyl acetate content of 1 to 10% by weight. A multilayer film is described in which the intermediate layer contains an ethylene-vinyl acetate copolymer (A) having a vinyl acetate content of 1 to 20% by weight, and at least the intermediate layer contains crosslinked acrylic particles.

Further, Patent Document 3 has at least one layer made of a resin composition containing an ethylene-α-olefin copolymer and copolymer particles of (meth) acrylic acid ester and styrene. Is described.

Japanese Unexamined Patent Publication No. 2014-209903 Japanese Unexamined Patent Publication No. 2015-112746 JP-A-2018-172680

The film spreading work as described in Patent Documents 1 to 3 is a work performed regardless of the season, and is performed even in a period of severe residual heat from summer to autumn. When the heat is harsh, the pipes used as the framework of agricultural and horticultural facilities often get hot due to strong sunlight. If the film is stretched in such a case, there is a problem that the film is torn by the heat of the pipe at the contact portion between the film and the hot pipe. For this reason, the film has dimming performance based on changes in temperature (that is, the performance that the light scattering property in summer is high, the light scattering property in winter is low, and the difference in light scattering property between summer and winter is large). On the other hand, it is required to maintain high mechanical strength not only in the period from low temperature to mild temperature such as winter to spring but also in the period when the temperature is high from summer to autumn.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a film capable of maintaining high mechanical strength even at high temperatures while having dimming performance based on changes in air temperature and related techniques thereof. There is.

In order to solve the above problems, the film according to one embodiment of the present invention includes a polyethylene resin (A-1), a polypropylene resin (A-2), and particles having a volume median diameter of 1 μm or more and 20 μm or less (B). ) having at least one layer comprising a resin composition containing a density of the polypropylene-based resin (a-2) is at 850 kg / ^{m 3} or more 905 kg / ^{m 3} or less, the refractive index of the particles (B) is It is 1.50 or more and 1.53 or less.

In addition, another preferred embodiment of the present invention is an agricultural and horticultural facility in which the film is spread on an agricultural and horticultural facility frame.

According to one embodiment of the present invention, it is possible to provide a film capable of maintaining high mechanical strength even at a high temperature while having dimming performance based on a change in air temperature, and related techniques thereof.

<Agricultural film>
The agricultural film according to one embodiment of the present invention includes a polyethylene resin (A-1), a polypropylene resin (A-2), and particles (B) having a volume median diameter of 1 μm or more and 20 μm or less (hereinafter, particles (B). ) and it is referred) having at least one layer comprising a resin composition containing a density of the polypropylene-based resin (a-2) is equal to or less than 850 kg / ^{m 3} or more 905 kg / ^{m 3,} the particles ( The refractive index of B) is 1.50 or more and 1.53 or less.

According to the above configuration, the film is provided with the performance of high light scattering in summer, low light scattering in winter, and a large difference in light scattering between summer and winter, and at a higher temperature of 40 ° C. In, high tensile breaking strength can be imparted.

The layer composed of the resin composition containing the polyethylene-based resin (A-1), the polypropylene-based resin (A-2), and the particles (B) is a main layer constituting the agricultural film according to one form. In the specification, it is simply described as "layer", and unless otherwise specified, the "layer" refers to polyethylene resin (A-1), polypropylene resin (A-2) and particles (B). It indicates a layer composed of a resin composition containing.

(Haze value)
In this specification, the haze value is measured using a temperature control haze meter (THM-150TL) manufactured by Murakami Color Technology Research Institute Co., Ltd. in accordance with JIS K 7136: 2000 for measurement conditions other than temperature. Value. In the present specification, the light scattering property of the film can be evaluated by the haze value.

The agricultural film according to one embodiment of the present invention has a haze value at 40 ° C. of preferably 45% or more, more preferably 55% or more, and even more preferably 65% or more. When the haze value at 40 ° C. is 45% or more, the light irradiated to the film can be suitably scattered in the summer when the amount of solar radiation is large.

Further, in the agricultural film according to one embodiment of the present invention, the difference between the haze value at 0 ° C. and the haze value at 40 ° C. is, for example, 30% or more, more preferably 35% or more, and 40 ° C. The haze value at 0 ° C. is higher than the haze value at 0 ° C. Therefore, it is possible to prevent the light irradiating the film from being scattered in the winter when the amount of solar radiation is small.

In the agricultural film according to one embodiment of the present invention, the thickness of one layer is preferably 1 μm or more, more preferably 30 μm or more, from the viewpoint of enhancing light scattering in the summer when the temperature reaches around 40 ° C. From the viewpoint of lowering the light scattering property and reducing the weight of the film to improve the handleability in winter when the temperature reaches around 0 ° C., it is preferably 500 μm or less, more preferably 300 μm or less.

(Tensile breaking strength)
The agricultural film according to one embodiment of the present invention has an advantage of high tensile breaking strength at a high temperature of 40 ° C. The tensile breaking strength of an agricultural film is measured under the condition of a tensile speed of 500 mm / min in an atmosphere of 40 ° C.

The resin composition constituting at least one layer of the agricultural film according to one form contains a polyethylene-based resin (A-1) and a polypropylene-based resin (A-2). The polyethylene-based resin (A-1) is a polyolefin-based resin containing a monomer unit derived from ethylene as a main monomer unit, and the polypropylene-based resin (A-2) is a monomer derived from propylene. It is a polyolefin resin containing a unit as a main monomer unit.

[Polyethylene resin (A-1)]
The polyethylene-based resin (A-1) is selected from the group consisting of an ethylene-α-olefin copolymer (A-1-1) and an ethylene-polar group-containing monomer copolymer (A-1-2). One or more polyethylene resins are preferred.

As the polyethylene-based resin (A-1), only the ethylene-α-olefin copolymer (A-1-1) may be used, or only the ethylene-polar group-containing monomer copolymer (A-1-2). May be used, or these may be used in combination. When the ethylene-α-olefin copolymer (A-1-1) and the ethylene-polar group-containing monomer copolymer (A-1-2) are used in combination, the polyethylene-based resin (A-) contained in the resin composition is used in combination. Assuming that the total of 1) is 100% by mass, the proportion of the ethylene-α-olefin copolymer (A-1-1) is preferably 20% by mass or more and less than 100% by mass, and the ethylene-polar group-containing monomer is also included. The proportion of the copolymer (A-1-2) is preferably 80% by mass or less. The proportion of the ethylene-α-olefin copolymer (A-1-1) in the polyethylene resin (A-1) is more preferably 25% by mass or more from the viewpoint of increasing the strength at high temperatures, and further. It is preferably 30% by mass or more, more preferably 75% by mass or less, still more preferably 65% by mass or less (however, it is contained in the resin composition) from the viewpoint of enhancing the light scattering property at 40 ° C. The total of the polyethylene-based resin (A-1) is 100% by mass).

The proportion of the ethylene-polar group-containing monomer copolymer (A-1-2) in the polyethylene resin (A-1) is preferably 25% by mass or more from the viewpoint of enhancing the light scattering property at 40 ° C. It is more preferably 35% by mass or more, and from the viewpoint of increasing the strength at high temperature, it is preferably 75% by mass or less, and more preferably 70% by mass or less. (However, the total of the polyethylene-based resin (A-1) contained in the resin composition is 100% by mass).

[Ethylene-α-olefin copolymer (A-1-1)]
The ethylene-α-olefin copolymer (A-1-1) is a monomer unit derived from ethylene (hereinafter, may be referred to as an ethylene-derived monomer unit) and a monomer derived from α-olefin. It is an ethylene-α-olefin copolymer having a unit (hereinafter, sometimes referred to as an α-olefin-derived monomer unit) as a main monomer unit. The ethylene-α-olefin copolymer (A-1-1) may be a random copolymer of an ethylene monomer and an α-olefin monomer.

The content of the ethylene-derived monomer unit in the ethylene-α-olefin copolymer (A-1-1) is preferably 50% by mass or more and 90% by mass or less, and more preferably 55% by mass or more and 85% by mass. It is the following, more preferably 60% by mass or more and 80% by mass or less (however, the mass of the ethylene-α-olefin copolymer (A-1-1) is 100% by mass).

The α-olefin monomer preferably has 3 to 20 carbon atoms, and examples of the ethylene-α-olefin copolymer (A-1-1) include an ethylene-1-butene copolymer. Examples thereof include an ethylene-1-pentene copolymer, an ethylene-1-hexene copolymer, an ethylene-1-heptene copolymer, and an ethylene-1-octene copolymer. Of these, ethylene-1-butene copolymers, ethylene-1-hexene copolymers, and ethylene-1-octene copolymers are particularly preferable. Further, an ethylene-propylene copolymer may be used as long as the content of the ethylene-derived monomer unit is 50% by mass or more. As the ethylene-α-olefin copolymer (A-1-1), one obtained by copolymerizing an ethylene monomer and two or more kinds of α-olefin monomers may be used.

The ethylene-α-olefin copolymer (A-1-1) contributes to the provision of a film having excellent strength. From the viewpoint of obtaining a high-strength film, the ethylene-α-olefin copolymer (A-1-1) is preferably polymerized with an ethylene monomer and an α-olefin monomer using a metallocene catalyst. It was done.

Examples of commercially available products that can be used as the ethylene-α-olefin copolymer (A-1-1) include the following. Excellen (registered trademark) FX (manufactured by Sumitomo Chemical Co., Ltd.), Toughmer (registered trademark) A (manufactured by Mitsui Chemicals Co., Ltd.), Toughmer (registered trademark) DF (manufactured by Mitsui Chemicals Co., Ltd.), ENGAGE (registered trademark) (Dow Chemical) , AFFINITY (registered trademark) (Dow Chemical), EXACT (registered trademark) (ExxonMobile), Kernel (registered trademark) (manufactured by Nippon Polyethylene Co., Ltd.).

As the ethylene-α-olefin copolymer (A-1-1), a single ethylene-α-olefin copolymer may be used, or two or more kinds of ethylene-α-olefin copolymers may be used in combination. May be good.

The density of the ethylene-α-olefin copolymer (A-1-1) is preferably 860 kg / m ³ or more and 900 kg / m ³ or less from the viewpoint of enhancing light scattering in the summer when the temperature reaches around 40 ° C. More preferably, it is 865 kg / m ³ or more and 890 kg / m ³ or less. The density in the present invention is a value measured according to the method specified in JIS K7112: 1999.

When two or more types of ethylene-α-olefin copolymers are used in combination as the ethylene-α-olefin copolymer (A-1-1), the ethylene-α-olefin copolymer (A-1-1) can be used in combination. The density d may be estimated by the following formula (1).
d (kg / m ³ ) =
_{(D 1 · W 1 + d} 2 · W 2 + ... + d m · W m) / (W 1 + W 2 + ... Wm) (1)
(However, ethylene-α-olefin copolymer 1, ethylene-α-olefin copolymer 2, ... Ethylene-α-olefin copolymer m-type ethylene-α-olefin copolymer m is used in combination (m). Is an integer of 2 or more), the density of the ethylene-α-olefin copolymer k (unit: kg / m ³ ) is d _k , and the content of the ethylene-α-olefin copolymer k (unit: kg) is W. and _k (integer k from 1 to m).)

The melt flow rate (MFR) of the ethylene-α-olefin copolymer (A-1-1) is preferably 0.05 g / 10 minutes or more and 20 g / 10 minutes or less, and more preferably 0.1 g / 10 minutes. Minutes or more and 15 g / 10 minutes or less. The MFR is measured by the A method under the conditions of a temperature of 190 ° C. and a load of 21.18 N according to JIS K 7210: 1995.

[Ethylene-Polar Group-Containing Monomer Copolymer (A-1-2)]
The ethylene-polar group-containing monomer copolymer (A-1-2) is a copolymer containing an ethylene-derived monomer unit and a monomer unit derived from a polar group-containing monomer. The monomer having a polar group is a compound containing a polar group and an ethylenically unsaturated bond, and examples of the polar group include a carbonyl group, a carboxyl group, a carboxylate group, an oxyacyl group and a cyano group. be able to. Specific examples of the monomer containing a polar group include vinyl ester, unsaturated carboxylic acid and its derivative.

Preferred examples of the ethylene-polar group-containing monomer copolymer (A-1-2) include an ethylene-vinyl ester copolymer and an ethylene-unsaturated carboxylic acid (derivative) copolymer. In addition, either one of the ethylene-vinyl ester copolymer and the ethylene-unsaturated carboxylic acid (derivative) copolymer may be contained, or both may be contained.

Ethylene - density of the polar group-containing monomer copolymer (A-1-2), from the viewpoint of enhancing the light scattering in summer reaching around 40 ° C., not more than 930 kg / ^{m 3} or more 960 kg / ^{m 3} preferable. The density of the ethylene-polar group-containing monomer copolymer (A-1-2) in the present invention is a value measured according to the method specified in JIS K7112: 1999. Density or less than 930 kg / ^{m 3,} and greater than 960 kg / ^{m 3,} is not preferred since it is difficult to obtain light scattering (haze) is near 40 ° C.. From the viewpoint of enhancing the light scattering property at around 40 ° C., the density of the ethylene-polar group-containing monomer copolymer (A-1-2) is more preferably 940 kg / m ³ or more, still more preferably 945 kg / m ^3. That is all. Further, more preferred from the viewpoint of increasing the strength at high temperatures and at 958kg / ^{m 3} or less, more preferably 955 kg / ^{m 3} or less.

When two or more types of ethylene-polar group-containing monomer copolymers are used in combination, the density d'of the ethylene-polar group-containing monomer copolymer (A-1-2) can be roughly estimated by the following formula (2). Good.
d'(kg / m ³ ) =
(D' ₁ · W ₁ + d' ₂ · W ₂ + ... + d' _m · W _m ) / (W ₁ + W ₂ + ... W _m ) (2)
(However, ethylene-polar group-containing monomer copolymer 1, ethylene-polar group-containing monomer copolymer 2, ... Ethylene-polar group-containing monomer copolymer m of m-type ethylene-unsaturated carboxylic acid (derivative) ) A copolymer is used in combination (m is an integer of 2 or more), the density of the ethylene-polar group-containing monomer copolymer k (unit: kg / m ³ ) is d' _k , and the ethylene-polar group-containing monomer co-weight. the content of polymer k (unit: kg) is referred to as _{W k} (integer k from 1 to m)).

The melt flow rate (MFR) of the ethylene-polar group-containing monomer copolymer (A-1-2) is preferably 0.1 g / 10 minutes or more and 10 g / 10 minutes or less from the viewpoint of processing into a film. The MFR is measured by the A method under the conditions of a temperature of 190 ° C. and a load of 21.18 N according to JIS K7210: 1999.

(Ethylene-vinyl ester copolymer)
The ethylene-polar group-containing monomer copolymer (A-1-2) is preferably an ethylene-vinyl ester copolymer, and the ethylene-vinyl ester copolymer is an ethylene-derived monomer unit and a vinyl ester. Refers to an ethylene-vinyl ester copolymer having a monomer unit derived from (hereinafter, may be referred to as a vinyl ester-derived monomer unit) as a main monomer unit. The ethylene-vinyl ester copolymer may be a random copolymer of an ethylene monomer and a vinyl ester monomer.

The vinyl ester used as a constituent material of the ethylene-vinyl ester copolymer is, for example, a vinyl ester of a fatty acid, and the fatty acid has 2 to 4 carbon atoms. More specifically, acetic acid. Examples thereof include vinyl and vinyl propionate. In one embodiment of the present invention, the ethylene-vinyl ester copolymer may contain two or more kinds of vinyl ester-derived monomer units. Above all, the vinyl ester is preferably vinyl acetate.

Specific examples of the ethylene-vinyl ester copolymer having an ethylene-derived monomer unit and a vinyl ester-derived monomer unit include an ethylene-vinyl acetate copolymer and an ethylene-vinyl acetate copolymer. In particular, ethylene-vinyl acetate copolymer (EVA) is preferably used. Further, the ethylene-vinyl ester copolymer may be used alone, or two or more kinds of ethylene-vinyl ester copolymers may be used in combination.

Further, the ethylene-vinyl ester copolymer may contain a monomer unit derived from a monomer other than ethylene and vinyl ester.

Commercially available products that can be used as ethylene-vinyl ester copolymers include, for example, Evertate (registered trademark) (manufactured by Sumitomo Chemical Co., Ltd.), Sumitate (registered trademark) (manufactured by Sumitomo Chemical Co., Ltd.), Novatec (registered trademark). ) EVA (manufactured by Nippon Polyethylene Co., Ltd.), Ultrasen (registered trademark) (manufactured by Tosoh Co., Ltd.), Suntech (registered trademark) EVA (manufactured by Asahi Kasei Co., Ltd.), Evaflex (registered trademark) (Mitsui DuPont Polychemical Co., Ltd.) (Made) and so on.

In the ethylene-vinyl ester copolymer, the content of the vinyl ester-derived monomer unit is preferably 7% by mass or more and 30% by mass or less, more preferably 10% by mass or more and 28% by mass or less, and further preferably. Is 12% by mass or more and 25% by mass or less.

Further, in the ethylene-vinyl ester copolymer, the content of the ethylene-derived monomer unit is preferably 70% by mass or more and 93% by mass or less, more preferably 72% by mass or more and 90% by mass or less, and further. It is preferably 75% by mass or more and 88% by mass or less.

When two or more types of ethylene-vinyl ester copolymers are used in combination as the ethylene-vinyl ester copolymer, the content E of the ethylene-derived monomer unit in the copolymer is calculated by the following formula (3).
E (mass%) =
(E ₁・ W ₁ + E ₂・ W ₂ +… + _Em・ W _m ) / (W ₁ + W ₂ +… W _m ) (3)
(However, ethylene-vinyl ester copolymer 1, ethylene-vinyl ester copolymer 2, ... Ethylene-vinyl ester copolymer m of m-type ethylene-vinyl ester copolymers are used in combination (m is 3 or more). Let the content (mass%) of the ethylene-derived monomer unit in the ethylene-vinyl ester copolymer k be E _k , and the content of the ethylene-vinyl ester copolymer k be W _k (k is 1). Integer from to m).)

Similarly, when two or more types of ethylene-vinyl ester copolymers are used in combination as the ethylene-vinyl ester copolymer, the content E'of the vinyl ester-derived monomer unit in the copolymer is expressed by the following formula (4). ) Is calculated.
E'(mass%) =
_{(E '1 · W' 1} + E '2 · W' 2 + ... + E 'm · W' m) / (W '1 + W' 2 + ... W 'm)
(4)
(However, copolymer 1, copolymer 2, ... m-type copolymer of copolymer m is used in combination (m is an integer of 3 or more), and the vinyl ester-derived monomer unit in the copolymer k is used. The content (% by mass) of is E'k, and the content of the copolymer _{k in} the resin composition is _W'k (k is an integer from 1 to m).

The content of the ethylene-derived monomer unit and the content of the vinyl ester-derived monomer unit in the ethylene-vinyl ester copolymer can be quantified by the saponification method, and more specifically, polyethylene. When the system resin is an ethylene-vinyl acetate copolymer, it can be quantified according to JIS K 7192: 1999.

(Ethylene-unsaturated carboxylic acid (derivative) copolymer)
Examples of the ethylene-polar group-containing monomer copolymer (A-1-2) include an ethylene-unsaturated carboxylic acid (derivative) copolymer and an ethylene-unsaturated carboxylic acid (derivative) copolymer. Is mainly composed of an ethylene-derived monomer unit and a monomer unit derived from an unsaturated carboxylic acid and / or a derivative thereof (hereinafter, may be referred to as an unsaturated carboxylic acid (derivative) -derived monomer unit). It is a copolymer having as a monomer unit, and is also hereinafter also referred to as an ethylene-unsaturated carboxylic acid (derivative) copolymer. The ethylene-unsaturated carboxylic acid (derivative) copolymer may be a random copolymer of an ethylene monomer and an unsaturated carboxylic acid monomer and / or an unsaturated carboxylic acid derivative monomer.

Unsaturated carboxylic acids that are constituent materials of ethylene-unsaturated carboxylic acid (derivative) copolymers include unsaturated monocarboxylic acids such as (meth) acrylic acid, crotonic acid, isocrotonic acid, and 3-butenoic acid; maleic acid. , Unsaturated dicarboxylic acids such as fumaric acid, and the like, but are not limited thereto. Among them, unsaturated monocarboxylic acid is preferable, and for example, (meth) acrylic acid is preferable. In addition, in this specification, acrylic acid and methacrylic acid are generically referred to as (meth) acrylic acid.

Examples of the unsaturated carboxylic acid derivative used as the constituent material of the ethylene-unsaturated carboxylic acid (derivative) copolymer include the above-mentioned unsaturated carboxylic acid salt, unsaturated carboxylic acid ester, acid anhydride, and unsaturated carboxylic acid amide. Examples thereof include unsaturated carboxylic acid imides, preferably salts of unsaturated carboxylic acids and unsaturated carboxylic acid esters. Examples of the unsaturated carboxylic acid salt include sodium salt, potassium salt, calcium salt, and zinc salt of unsaturated carboxylic acid. Examples of the unsaturated carboxylic acid ester include unsaturated carboxylic acid alkyl esters such as unsaturated carboxylic acid methyl ester, unsaturated carboxylic acid ethyl ester, and unsaturated carboxylic acid butyl ester; and unsaturated carboxylic acid aryl such as unsaturated carboxylic acid phenyl ester. Esters; unsaturated carboxylic acid glycidyl esters and the like can be mentioned.

A specific example of the ethylene-unsaturated carboxylic acid (derivative) copolymer having an ethylene-derived monomer unit and an unsaturated carboxylic acid (derivative) -derived monomer unit in the present invention is ethylene- (meth). Ethylene-unsaturated carboxylic acid copolymers such as acrylic acid copolymers; some or all of the carboxyl groups of ethylene-unsaturated carboxylic acid copolymers such as ethylene- (meth) acrylic acid copolymers are sodium and potassium. , Ionomer neutralized with metal ions such as calcium and zinc; ethylene- (meth) methyl acrylate copolymer, ethylene- (meth) ethyl acrylate copolymer, ethylene- (meth) butyl acrylate copolymer, etc. Ethylene-unsaturated carboxylic acid ester copolymers of, in particular, ethylene- (meth) acrylate copolymer, ethylene- (meth) methyl acrylate copolymer, ethyl ethylene- (meth) acrylate copolymer. Copolymers and the like are preferably used. Further, in one embodiment of the present invention, the ethylene-unsaturated carboxylic acid (derivative) copolymer may contain two or more kinds of unsaturated carboxylic acid (derivative) -derived monomer units.

Specific examples of the ethylene-unsaturated carboxylic acid (derivative) copolymer include the following.
(I) Ethylene-unsaturated carboxylic acid copolymer Nuclel (registered trademark) (ethylene-methacrylic acid copolymer, manufactured by Mitsui-Dupont Polychemical Co., Ltd.)
(Ii) Ionomer Hymilan® (registered trademark) in which some or all of the carboxyl groups of the ethylene-unsaturated carboxylic acid copolymer are neutralized with metal ions. Some of the carboxyl groups of the ethylene-methacrylic acid copolymer are zinc ions. Or ionomer neutralized with sodium ions, manufactured by Mitsui / Dupont Polychemical Co., Ltd.)
(Iii) Ethylene-unsaturated carboxylic acid ester copolymer Aklift (registered trademark) (ethylene-methyl methacrylate copolymer, manufactured by Sumitomo Chemical Co., Ltd.), Lexpearl (registered trademark) EMA (ethylene-methyl acrylate copolymer) Combined, Lexpearl (registered trademark) EEA (ethylene-ethyl acrylate copolymer, manufactured by Nippon Polyethylene Co., Ltd.), Rotril (registered trademark) (ethylene-methyl acrylate copolymer or ethylene-) Butyl acrylate copolymer (manufactured by Alchema), Elvalois (registered trademark) AC (ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, Dupont) Made by the company)

The ethylene-unsaturated carboxylic acid (derivative) copolymer may be used alone, or two or more kinds of ethylene-unsaturated carboxylic acid (derivative) copolymers may be used in combination.

The content of the unsaturated carboxylic acid (derivative) -derived monomer unit in the ethylene-unsaturated carboxylic acid (derivative) copolymer is preferable from the viewpoint of the balance between the rigidity of the film and the light scattering property (haze value) at 40 ° C. Is 10% by mass or more and 40% by mass or less, more preferably 15% by mass or more and 35% by mass or less, and further preferably 20% by mass or more and 30% by mass or less (however, ethylene-unsaturated carboxylic acid (derivative). ) The mass of the copolymer is 100% by mass).

The content of the unsaturated carboxylic acid (derivative) -derived monomer unit in the ethylene-unsaturated carboxylic acid (derivative) copolymer can be measured by an infrared absorption spectrum analysis method.

The content of the ethylene-derived monomer unit in the ethylene-unsaturated carboxylic acid (derivative) copolymer is preferably 60% by mass or more and 90 in consideration of the balance between the rigidity of the film and the light scattering property (haze value) at 40 ° C. It is mass% or less, more preferably 65% by mass or more and 85% by mass or less, and further preferably 70% by mass or more and 80% by mass or less (however, the mass of the ethylene-unsaturated carboxylic acid (derivative) copolymer). Is 100% by mass).

The content of the ethylene-derived monomer unit in the ethylene-unsaturated carboxylic acid (derivative) copolymer is 100% by mass of the content of the unsaturated carboxylic acid (derivative) -derived monomer unit measured by the infrared absorption spectrum analysis method. It can be calculated by subtracting from%.

When two or more types of ethylene-unsaturated carboxylic acid (derivative) copolymers are used in combination as the ethylene-unsaturated carboxylic acid (derivative) copolymer, the content E "of the ethylene-derived monomer unit in the copolymer is , Calculated by the following formula (5).
E "(mass%) =
(E " ₁・ W ₁ + E" ₂・ W ₂ + ... + E " _m・ W _m ) / (W ₁ + W ₂ + ... W m) (5)
(However, ethylene-unsaturated carboxylic acid (derivative) copolymer 1, ethylene-unsaturated carboxylic acid (derivative) copolymer 2, ... Ethylene-unsaturated carboxylic acid (derivative) copolymer m-type ethylene -The content of the ethylene-derived monomer unit in the ethylene-unsaturated carboxylic acid (derivative) copolymer k is E ", assuming that an unsaturated carboxylic acid (derivative) copolymer is used in combination (m is an integer of 2 or more). Let the content of _k and the ethylene-unsaturated carboxylic acid (derivative) copolymer k be W _k (k is an integer from 1 to m).

[Polypropylene resin (A-2)]
Examples of the polypropylene-based resin (A-2) include a propylene homopolymer, a copolymer of a propylene monomer and an ethylene monomer, and / or an α-olefin monomer having 4 or more carbon atoms. Of these, a copolymer of a propylene monomer and an ethylene monomer and / or an α-olefin monomer having 4 or more carbon atoms is preferable.

A propylene-derived monomer unit in a copolymer of the propylene monomer and an ethylene monomer and / or an α-olefin monomer having 4 or more carbon atoms (hereinafter, referred to as a propylene-derived monomer unit). The content (which may be) is preferably 70% by mass or more and 99.5% by mass or less (however, a propylene monomer and an ethylene monomer and / or an α-olefin monomer having 4 or more carbon atoms). The mass of the copolymer of is 100% by mass).

When the polypropylene-based resin (A-2) is a copolymer of a propylene monomer and an ethylene monomer and / or an α-olefin monomer having 4 or more carbon atoms, the ethylene-derived monomer unit and / Or The content of the α-olefin-derived monomer unit having 4 or more carbon atoms is preferably 0.5% by mass or more and 30% by mass or less (however, the propylene monomer, the ethylene monomer, and / or the carbon number of carbon atoms). The mass of the copolymer with 4 or more α-olefin monomers is 100% by mass).

When two or more kinds of polypropylene-based resins are used in combination, the density d "of the polypropylene-based resin (A-2) may be estimated by the following formula (6).
d "(kg / m ³ ) =
(D " ₁・ W ₁ + d" ₂・ W ₂ + ... + d " _m・ W _m ) / (W ₁ + W ₂ + ... W _m ) (6)
(However, polypropylene-based resin 1, polypropylene-based resin 2, ... m-type polypropylene-based resin of polypropylene-based resin m is used in combination (m is an integer of 2 or more), and the density of polypropylene-based resin k (unit: kg). / M ³ ) is d " _k , and the content of polypropylene resin k (unit: kg) is W _k (k is an integer from 1 to m).

The density of the polypropylene resin (A-2) is 850 kg / ^{m 3} or more 905 kg / ^{m 3} or less. By density using 850 kg / ^{m 3} or more 905 kg / ^{m 3} or less of the polypropylene resin (A-2), without impairing the light scattering in the film, it is possible to particularly improve the strength of the film at high temperatures. Further, the density of the polypropylene resin (A-2) is more preferably 895 kg / m ³ or less from the viewpoint of preventing the occurrence of fish eyes during processing, improving the appearance, and enhancing the light scattering property at high temperature. It is more preferably 890 kg / m ³ or less. Further, from the viewpoint of further improving the strength of the film at high temperature, it is more preferably 860 kg / m ³ or more, and further preferably 865 kg / m ³ or more.

The melt flow rate (MFR) of the polypropylene-based resin (A-2) is preferably 0.05 g / 10 minutes or more and 20 g / 10 minutes or less, and more preferably 0.1 g / 10 minutes or more and 15 g / 10 minutes or less. Is. The MFR is measured by the A method under the conditions of a temperature of 230 ° C. and a load of 21.18 N according to JIS K 7210: 1999.

The content of the polypropylene-based resin (A-2) contained in the resin composition constituting the layer is preferably 100% by mass based on the total of the polyethylene-based resin (A-1) and the polypropylene-based resin (A-2). It is 5 to 50% by mass, more preferably 10 to 35% by mass. On the other hand, the content of the polyethylene-based resin (A-1) contained in the resin composition constituting the layer is 100 mass by mass of the total of the polyethylene-based resin (A-1) and the polypropylene-based resin (A-2). % Is preferably 50 to 95% by mass, and more preferably 65 to 90% by mass. The total content of the polyethylene-based resin (A-1) and the polypropylene-based resin (A-2) contained in the resin composition constituting the layer is preferably 60 to 95% by mass, with the resin composition as 100% by mass. %, More preferably 65 to 90% by mass. The agricultural film according to one form can improve the breaking strength at high temperature by containing the polypropylene resin (A-2) in the resin composition constituting the layer.

Examples of commercially available products that can be used as the polypropylene-based resin (A-2) include the following. Sumitomo Noblen (registered trademark) series (manufactured by Sumitomo Chemicals, Ltd.), Novatec (registered trademark) PP series (manufactured by Nippon Polypro Co., Ltd.), Wintech (registered trademark) series (manufactured by Nippon Polypro Co., Ltd.), Prime Polypro (registered trademark) ) Series (manufactured by Prime Polymer Co., Ltd.), Vistamaxx (registered trademark) series (manufactured by Exxon Mobile), Versify (registered trademark) series (manufactured by Dow Chemicals), Elmodu (registered trademark) series (manufactured by Idemitsu Kosan Co., Ltd.) ), Toughmer (registered trademark) XM series (manufactured by Mitsui Chemicals, Inc.). Of these, polypropylene-based resins having a density within the above range may be used.

[Particle (B)]
Examples of the particles (B) include organic particles and inorganic particles.

The refractive index of the particle (B) is 1.50 or more and 1.53 or less, more preferably higher than 1.50 and lower than 1.53, and further preferably 1.51 or more and 1.52 or less. Most preferably, it is 1.51 or more and lower than 1.52. Since the refractive index of the components contained in the dispersed phase is 1.50 or more and 1.53 or less, the light scattering property of the film is enhanced in the summer when the temperature reaches around 40 ° C, and the light is light in the winter when the temperature reaches around 0 ° C. It is possible to lower the scattering property and increase the difference in light scattering property depending on the height difference of the temperature. The refractive index is a value measured by the particle immersion method at room temperature, and here, the value of the refractive index after the third decimal place is rounded off.

(Organic particles)
The organic particles are preferably resin particles, and examples of the resin particles include crosslinked acrylic particles. Examples of the crosslinked acrylic particles include crosslinked copolymer particles of (meth) acrylic acid ester and styrene (crosslinked MMA-St copolymer particles). Examples of the (meth) acrylate ester include methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate and the like, and methyl acrylate, methyl methacrylate or methacrylic is preferable. It is butyl acid, more preferably methyl methacrylate.

The crosslinked copolymer particles of (meth) acrylic acid ester and styrene are monomer units derived from (meth) acrylic acid ester (hereinafter, may be referred to as (meth) acrylic acid ester-derived monomer units). It may be a crosslinked copolymer particle containing only a monomer unit derived from styrene (hereinafter, may be referred to as a monomer unit derived from styrene) and a monomer unit derived from (meth) acrylic acid ester. It may be a crosslinked copolymer particle containing a monomer unit derived from styrene and a monomer unit other than these. In the crosslinked copolymer particles of the (meth) acrylic acid ester and styrene, the total content ratio of the (meth) acrylic acid ester-derived monomer unit and the styrene-derived monomer unit in all the monomer units. Is preferably 80% by mass or more.

The content of the (meth) acrylic acid ester-derived monomer unit in the crosslinked copolymer particles of the (meth) acrylic acid ester and styrene is preferably 50 to 99% by mass, and more preferably 60 to 90% by mass. %. The content of the styrene-derived monomer unit in the crosslinked copolymer particles of the (meth) acrylic acid ester and styrene is preferably 1 to 50% by mass, more preferably 10 to 40% by mass. .. (However, the total of the (meth) acrylic acid ester-derived monomer unit and the styrene-derived monomer unit is 100% by mass.)

The crosslinked copolymer particles of the (meth) acrylic acid ester and styrene are a single amount containing at least one selected from the (meth) acrylic acid ester, styrene, and if necessary, other monomers. It can be obtained by polymerizing the body component by a known method such as suspension polymerization.

Examples of the method for obtaining crosslinked acrylic particles include a method in which a monomer component is suspended and polymerized together with a crosslinking agent. As the cross-linking agent, it is preferable to use a compound having two or more unsaturated groups, and specific examples thereof include ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and divinylbenzene. ..

The volume median diameter of the organic particles is preferably 1 μm or more, more preferably 2 μm or more, still more preferably 3 μm or more, from the viewpoint of increasing the light scattering property in the summer when the temperature reaches around 40 ° C. The volume median diameter is preferably 20 μm or less, more preferably 15 μm or less, and even more preferably 10 μm or less. The volume median diameter of organic particles is measured by the Coulter counter method.

Examples of commercially available organic particles include Techpolymer (registered trademark) MSX series, Techpolymer (registered trademark) SSX series (all manufactured by Sekisui Plastics Co., Ltd.), Art Pearl (registered trademark) G series, and Art. Examples include Pearl (registered trademark) GS series (above, manufactured by Negami Kogyo Co., Ltd.) and Ganz Pearl (registered trademark) GSM series (above, manufactured by Aika Kogyo Co., Ltd.).

(Inorganic particles)
Examples of the inorganic particles include glass particles, kaolin, aluminosilicate (zeolite) and the like.

Glass particles are particles containing silicon dioxide (SiO ₂ ), and are boron oxide (B ₂ O ₃ ), aluminum oxide (Al ₂ O ₃ ), sodium oxide (Na ₂ O), calcium oxide (CaO), and It may contain at least one inorganic compound selected from the group consisting of zinc oxide (ZnO). The glass particles may further contain additional inorganic compounds and additives, if desired. Specifically, in addition to the above-mentioned inorganic compounds, zirconium oxide, magnesium oxide, strontium oxide, lanthanum oxide, yttrium oxide, gadolinium oxide, bismuth oxide, antimony oxide, tantalum oxide, niobium oxide, tungsten oxide, magnesium carbonate, etc. Conventional inorganic compounds such as silicon nitride, aluminum nitride, aluminum oxynitride, magnesium fluoride, calcium fluoride, sodium fluoride, lithium fluoride, and iron can be appropriately mixed as required.

The shape of each of the inorganic particles is not particularly limited, and spherical (for example, glass beads, etc.) inorganic particles can be used.

The volume median diameter of the inorganic particles is preferably 1 μm or more, more preferably 2 μm or more, still more preferably 3 μm or more, from the viewpoint of increasing the light scattering property in the summer when the temperature reaches around 40 ° C. The volume median diameter is preferably 20 μm or less, more preferably 15 μm or less, and even more preferably 10 μm or less. The volume median diameter of the inorganic particles is measured by laser diffraction.

In addition, the inorganic particles may be surface-treated with a surface treatment agent such as a coupling agent.

The particles (B) are preferably resin particles or glass particles having a volume median diameter of 1 μm or more and 20 μm or less and a refractive index of 1.50 or more and 1.53 or less. Further, the particles (B) are preferably crosslinked acrylic particles or glass particles having a volume median diameter of 1 μm or more and 20 μm or less and a refractive index of 1.50 or more and 1.53 or less.

The content of the particles (B) contained in the resin composition constituting the layer is preferably 5 to 40% by mass, more preferably 10 to 35% by mass, with the resin composition as 100% by mass.

(Additive)
In addition, the resin composition constituting the layer is composed of an infrared absorber, a light stabilizer, an ultraviolet absorber, an antifogging agent, an antioxidant, an antifog agent, a lubricant, etc., as long as the effect of the present invention is not impaired. It may contain at least one additive of choice. When the resin composition constituting the layer contains the additive, the content thereof is preferably 0.1% by mass or more, more preferably 1% by mass or more. Further, 20% by mass or less is preferable, and 15% by mass or less is more preferable. However, the mass of the resin composition is 100% by mass.

Examples of the infrared absorber include hydrotalcite compounds and lithium-aluminum composite hydroxide. Specific examples of hydrotalcite compounds include natural hydrotalsite, trade names: DHT-4A (manufactured by Kyowa Chemical Industry Co., Ltd.), Magclear (manufactured by Toda Kogyo Co., Ltd.), Magcella (registered trademark) 1 (Kyowa Chemical Industry Co., Ltd.). (Manufactured by Co., Ltd.), Staviace (registered trademark) HT-P (manufactured by Sakai Chemical Industry Co., Ltd.) and the like. Specific examples of the lithium-aluminum composite hydroxide include OPTIMA-SS (manufactured by Toda Kogyo Co., Ltd.), Mizukarak (registered trademark) (manufactured by Mizusawa Industrial Chemicals Co., Ltd.) and the like.

In one embodiment of the present invention, the hydrotalcite compound may be used alone, or the lithium aluminum composite hydroxide may be used alone. Alternatively, both may be used in combination.

When the resin composition constituting the layer contains an infrared absorber, the content thereof is preferably 0.05% by mass or more, more preferably 0.5% by mass or more, and particularly preferably 5% by mass or more. Further, 20% by mass or less is preferable, 17% by mass or less is more preferable, and 15% by mass or less is particularly preferable. However, the mass of the resin composition is 100% by mass.

Examples of the light stabilizer include hindered amine compounds having the structure described in JP-A-8-73667. Specifically, trade names: Chinubin (registered trademark) 622, Kimasorb (registered trademark) 944, Kimasorb (registered trademark) 119 (all manufactured by BASF), Hostabin (registered trademark) N30, Hostabin (registered trademark) PR-31 (registered trademark) Examples thereof include Clarianto (registered trademark) UV3529 and Sayasorb (registered trademark) UV3346 (registered trademark).

Further, examples thereof include hindered amine compounds having the structures described in JP-A-11-315067, JP-A-2001-139821, WO2005 / 082852, and JP-A-2009-530428. Specifically, product names: NOR371 (manufactured by BASF), ADEKA STAB (registered trademark) LA-900 (manufactured by ADEKA Corporation), ADEKA STAB (registered trademark) LA-81 (manufactured by ADEKA Corporation), Hostabin (registered trademark) NOW (Made by Clariant Co., Ltd.).

Further, as the light stabilizer, an ethylene-cyclic aminovinyl compound copolymer having a monomer unit derived from ethylene and a monomer unit derived from a cyclic amino vinyl compound can also be mentioned. Examples of such an ethylene-cyclic aminovinyl compound copolymer include those having the structure described in JP-A-2002-265693.

When the resin composition constituting the layer contains a light stabilizer, the content thereof is preferably 0.01 to 3% by mass, more preferably 0.05 to 2% by mass, and particularly 0.1 to 1% by mass. preferable. However, the mass of the resin composition is 100% by mass.

Examples of the ultraviolet absorber include 2-hydroxybenzophenones, 2- (2'-hydroxyphenyl) benzotriazoles, benzoates, substituted oxanilides, cyanoacrylates, triazines and the like.

Examples of 2-hydroxybenzophenones include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, and 5,5'-methylenebis (2-hydroxy-4-methoxy). Benzophenone) and the like.

Examples of 2- (2'-hydroxyphenyl) benzotriazoles include 2- (2'-hydroxy-5'-methylphenyl) benzotriazole and 2- (2'-hydroxy-3', 5'-ditertiary butyl. Phenyl) Benzotriazole, 2- (2'-hydroxy-3', 5'-ditertiary butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-tertiary butyl-5'- Methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-5'-tertiary octylphenyl) benzotriazole, 2- (2'-hydroxy-3', 5'-dicumylphenyl) benzotriazole, 2- (2-Hydroxy-3,5-ditertiary pentylphenyl) benzotriazole, 2,2'-methylenebis (4-third octyl-6-benzotriazolyl) phenol, 2- (2'-hydroxy- 3'-Triary butyl-5-carboxyphenyl) Benzotriazole and the like can be mentioned.

Examples of benzoates include phenylsalicylate, resorcinol monobenzoate, 2,4-ditertiary butylphenyl-3', 5'-ditertiary butyl-4'-hydroxybenzoate, and 2,4-ditertiary amylphenyl-3. '5'-Di-tertiary butyl-4'-hydroxybenzoate, hexadecyl-3,5-di-tertiary butyl-4-hydroxybenzoate and the like can be mentioned.

Examples of the substituted oxanilides include 2-ethyl-2'-ethoxyoxanilide, 2-ethoxy-4'-dodecyloxanilide and the like.

Examples of cyanoacrylates include ethyl-α-cyano-β, β-diphenyl acrylate, methyl-2-cyano-3-methyl-3- (p-methoxyphenyl) acrylate and the like.

Examples of triazines include 2- (4,6-diphenyl-1,3,5-triazine-2-yl) -5-[(hexyl) oxy] -phenol and 2- [4,6-bis (2,4). -Dimethylphenyl) -1,3,5-triazine-2-yl] -5- (octyloxy) phenol, 2- (2-hydroxy-4-octoxyphenyl) -4,6-bis (2,4-di) Tri-butylphenyl) -s-triazine, 2- (2-hydroxy-4-methoxyphenyl) -4,6-diphenyl-s-triazine, 2- (2-hydroxy-4-propoxy-5-methylphenyl)- Examples thereof include 4,6-bis (2,4-ditriary butylphenyl) -s-triazine.

2- (2'-Hydroxyphenyl) benzotriazoles are preferred, and 2- (2'-hydroxy-3'-tertiary butyl-5'-methylphenyl) -5-chlorobenzotriazoles are more preferred. 2- (2-Hydroxy-3,5-dithrench pentylphenyl) benzotriazole can be mentioned.

The UV absorbers are used alone or in combination of two or more. When the resin composition constituting the layer contains an ultraviolet absorber, the content thereof is preferably 0.001 to 3% by mass, more preferably 0.005 to 1% by mass. However, the mass of the resin composition is 100% by mass.

Examples of the antifogging agent include sorbitan fatty acid esters such as sorbitan monopalmitate, sorbitan monostearate, sorbitan monopalmitate, sorbitan monomontanate, sorbitan monooleate, and sorbitan dioleate, and sorbitan such as an alkylene oxide adduct thereof. Surfactants, Glycerin Monopalmitate, Glycerin Monostearate, Diglycerin Distearate, Triglycerin Monostearate, Tetraglycerin Dimontanate, Glycerin Monooleate, Diglycerin Monooleate, Diglycerin Sesquioleate, Glycerin-based surfactants such as tetraglycerin monooleate, hexaglycerin monooleate, hexaglycerin trioleate, tetraglycerin trioleate, tetraglycerin monolaurate, hexaglycerin monolaurate, and glycerin-based surfactants thereof and alkylene oxide adducts thereof. Agents, polyethylene glycol-based surfactants such as polyethylene glycol monopalmitate, polyethylene glycol monostearate, alkylene oxide adducts of alkylphenols, esters of sorbitan / glycerin condensates with organic acids, polyoxyethylene (2 mol) stearylamine , Polyoxyethylene (4 mol) stearylamine, polyoxyethylene (2 mol) stearylamine monostearate, polyoxyethylene (4 mol) laurylamine monostearate and other polyoxyethylene alkylamines and their fatty acid esters and the like. Examples include ionic surfactants. These may be used alone or in combination of two or more.

When the resin composition constituting the layer contains an antifogging agent, the content thereof is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and particularly preferably 1% by mass or more. Further, 5% by mass or less is preferable, 4% by mass or less is more preferable, and 3% by mass or less is particularly preferable. However, the mass of the resin composition is 100% by mass.

Examples of the antioxidant include phosphorus containing a trivalent phosphorus atom such as a so-called hindered phenol compound such as a 2,6-dialkylphenol derivative or a 2-alkylphenol derivative, a phosphite compound or a phosphonite compound. Examples include system ester compounds. These antioxidants may be used alone or in combination of two or more. In particular, from the viewpoint of hue stabilization, it is preferable to use a hindered phenol-based compound and a phosphorus-based ester compound in combination.

When the resin composition constituting the layer contains an antioxidant, the content thereof is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and particularly preferably 0.05% by mass or more. Further, 0.5% by mass or less is preferable, 0.4% by mass or less is more preferable, and 0.3% by mass or less is particularly preferable. However, the mass of the resin composition is 100% by mass.

Examples of the antifogging agent include a fluorine compound having a perfluoroalkyl group, an ω-hydrofluoroalkyl group, etc. (particularly a fluorine-based surfactant), and a silicone-based compound having an alkylsiloxane group (particularly a silicone-based surfactant). ) Etc. can be mentioned. Specific examples of fluorine-based surfactants include Unidyne (registered trademark) DSN-403N, DS-403, DS-406, DS-401 (trade name) manufactured by Daikin Industries, Ltd., and Surflon manufactured by AGC Seimi Chemical Co., Ltd. (Registered Trademarks) KC-40, AF-1000, AF-2000 (trade name) and the like can be mentioned, and SH-3746 (trade name) manufactured by Toray Dow Corning Co., Ltd. can be mentioned as a silicone-based surfactant. These may be used alone or in combination of two or more. The content of the antifog agent contained in the resin composition constituting the layer is preferably 0.01 to 3% by mass, more preferably 0.02 to 2% by mass, and particularly preferably 0.05 to 1% by mass. However, the mass of the resin composition is 100% by mass.

The resin composition constituting the layer may contain calcium carbonate as an additive. When the resin composition constituting the layer contains calcium carbonate, the content thereof is preferably 0.5% by mass or more, more preferably 1% by mass or more. Further, 8% by mass or less is preferable, and 5% by mass or less is more preferable. However, the mass of the resin composition is 100% by mass.

[Other layers]
The agricultural film according to one embodiment of the present invention may be a film having only a layer composed of a resin composition containing a polyethylene resin (A-1), a polypropylene resin (A-2) and particles (B). It may be a film having a layer other than the layer concerned. As one of the preferred forms of the film of the present invention, a layer made of a resin composition containing a polyethylene-based resin (A-1), a polypropylene-based resin (A-2) and particles (B) is an intermediate layer, and the intermediate layer is the intermediate layer. A multilayer film in which a layer exists between two layers can be mentioned. Here, the two layers are preferably layers containing a polyolefin resin, and this layer structure has an advantage that the strength of the film can be improved. These two layers may also be referred to as a polyolefin-based resin layer, and are a layer composed of a resin composition containing a polyethylene-based resin (A-1), a polypropylene-based resin (A-2) and particles (B), and a polyolefin. The based resin layer can be distinguished from the point that the polyolefin resin layer does not contain particles (B).

The two polyolefin resin layers in the multilayer film may be the same or different. More specifically, as the structure of the multilayer film, 2 types 3 layers, 3 types 3 layers, 3 types 4 layers, 4 types 4 layers, 4 types 5 layers, 5 types 5 layers and the like can be exemplified.

When the multilayer film is composed of four or more kinds of layers, both the layer composed of the resin composition containing the polyethylene resin (A-1), the polypropylene resin (A-2) and the particles (B) and the polyolefin resin layer It may have different layers, or may have three or more polyolefin resin layers. Further, there may be two or more layers composed of a resin composition containing a polyethylene-based resin (A-1), a polypropylene-based resin (A-2), and particles (B).

For example, when the polyolefin-based agricultural film is a five-layer film, the polyolefin-based resin layer is composed of a resin composition containing A, a polyethylene-based resin (A-1), a polypropylene-based resin (A-2), and particles (B). When the layer is B, A, and the layer different from B is C, C / A / B / A / C, A / B / A / C / C, A / A / B / A / A, A / A. It may be any of / B / B / A, A / B / A / B / A and the like.

Further, from the viewpoint of the balance between the temperature sensitivity around 0 ° C. to 40 ° C. and the strength of the film, the polyolefin resin layer / polyethylene resin (A-1), polypropylene resin (A-2) and particles (B). The thickness ratio of the layer made of the resin composition containing the above to the polyolefin-based resin layer is preferably 1/2/1 to 1/4/1.

The polyolefin-based resin layer constituting the multilayer film contains a polyolefin-based resin. Examples of the polyolefin resin include high-pressure low-density polyethylene, high-density polyethylene, ethylene-α-olefin copolymers such as ethylene-1-butene copolymers and ethylene-1-hexene copolymers, and ethylene-acrylic acid. Examples thereof include ethylene-unsaturated carboxylic acid ester copolymers such as methyl copolymers and ethylene-methyl methacrylate copolymers. Only one type of these polyolefin resins may be used, or two or more types may be used in combination.

The polyolefin-based resin layer may contain a light stabilizer, an ultraviolet absorber, an antifogging agent, an antioxidant, an antifogging agent, a lubricant, an antiblocking agent, an antistatic agent, a pigment, and the like, if necessary. It is good, but it is distinguished from the layer composed of the resin composition containing the polyethylene resin (A-1), the polypropylene resin (A-2) and the particles (B) in that it does not contain the predetermined particles (B). obtain.

[Anti-fog coating layer]
The film according to one embodiment of the present invention may have an antifogging coating film layer as one surface layer or on both sides. Examples of such an antifogging coating layer include an antifogging layer made of an inorganic colloid and an antifogging coating layer containing an inorganic colloid and a binder resin.

The inorganic colloid imparts hydrophilicity to the surface of a hydrophobic polyolefin resin film, and is usually used in the form of a sol in which the inorganic colloid is dispersed in a liquid dispersion medium such as water. Specific examples thereof include silica sol and alumina sol, and silica sol is preferable.

Examples of the binder resin include polyurethane-based resins, acrylic-based resins, acrylic-modified polyurethane-based resins, polyester-based resins, and epoxy-based resins.

The binder resin is usually used as an aqueous emulsion in which the resin is dispersed in a mixed solvent of water or water and an aqueous solvent such as alcohol.

The antifogging coating film layer is preferably an antifogging layer containing silica and a binder resin. Further, as the binder resin, a polyurethane resin, an acrylic resin, and an acrylic modified polyurethane resin are preferable.

Preferred silica includes those having an average particle diameter of 5 to 100 nm, and the shape of the particles in the silica is not limited, and examples thereof include spherical particles.

When the total of silica and binder resin contained in the antifogging coating layer is 100% by mass, the content of silica is 30 to 70% by mass and the content of binder resin is 30 to 70% by mass. The content of silica is preferably 50 to 65% by mass, and the content of binder resin is more preferably 35 to 50% by mass. If the silica content is too low, a sufficient antifogging effect cannot be obtained, and conversely, if the silica content is too high, the coating film becomes cloudy and the light transmittance at low temperature can be lowered.

The antifogging coating film layer containing silica and a binder resin can be formed, for example, as shown below. An aqueous emulsion containing a binder resin, an aqueous silica sol containing silica, and water as a dispersion medium are mixed and stirred to obtain a coating liquid. Next, the antifogging layer can be formed by applying this coating liquid by a known means and drying it. Specific examples of the coating means include bar coating, gravure coating, reverse coating, brush coating, spray coating, kiss coating, die coating, dipping and the like. Examples of the drying means include hot air drying.

The thickness of the coating film composed of silica and the binder resin is preferably 0.3 to 1.5 μm, more preferably 0.5 to 1.2 μm.

The coating liquid may contain a silicone-based surfactant and a fluorine-based surfactant in order to improve the coatability. Examples of the silicone-based surfactant include polyether-modified silicone oil.

Further, a cross-linking agent, a light stabilizer, an ultraviolet absorber and the like may be added to the coating liquid, if necessary.

The antifogging coating film layer may be formed as one surface layer of the film, or may be formed as both surface layers. Further, the antifogging layer may be a single layer film or a multilayer film having two or more layers.

<Agricultural and horticultural facilities>
In the agricultural and horticultural facilities covered with the agricultural film according to one embodiment of the present invention, since the light scattering property of the film is high in the summer when the temperature reaches around 40 ° C., obstacles such as leaf burning of crops due to excessive direct light are observed. Can be prevented. In addition, since the light scattering property of the film is low in winter when the temperature reaches around 0 ° C., sufficient direct light can be delivered to the crop. It can be used all year round and can deliver a stable amount of light. The agricultural and horticultural facilities are suitably used for cultivating spinach, tomatoes, leeks, cucumbers, strawberries and the like.

Examples of agricultural and horticultural facilities equipped with an agricultural film according to an embodiment of the present invention include greenhouses and tunnels for plant cultivation. In an agricultural and horticultural facility, the agricultural film is spread on, for example, an agricultural and horticultural facility frame.

The agricultural film according to one embodiment of the present invention can maintain high mechanical strength even when the temperature is high from summer to autumn. It is possible to prevent the film from breaking at the contact portion between the frame and the film, which has become hot, for example, during the stretching work when the temperature is high. Therefore, a method of extending to an agricultural and horticultural facility using an agricultural film according to an embodiment of the present invention and an agricultural and horticultural facility extended using an agricultural film are also within the scope of the present invention.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention.

[Summary]
The agricultural film according to the first aspect of the present invention is made of a resin composition containing a polyethylene resin (A-1), a polypropylene resin (A-2), and particles (B) having a volume median diameter of 1 μm or more and 20 μm or less. The polypropylene resin (A-2) has at least one layer, the density of the polypropylene resin (A-2) is 850 kg / m3 or more and 905 kg / m3 or less, and the refractive index of the particles (B) is 1.50 or more and 1.53 or less. is there.

Further, the agricultural and horticultural facility according to the second aspect of the present invention is an agricultural and horticultural facility in which the agricultural film according to the first aspect is spread on the agricultural and horticultural facility frame.

Hereinafter, examples of the present invention will be shown. The test method in the examples is as follows.

<Haze value>
A temperature control haze meter (THM-150TL) manufactured by Murakami Color Technology Laboratory Co., Ltd. was used, and measurements were performed under the respective conditions of 0 ° C. and 40 ° C. Measurement conditions other than temperature are JIS
Compliant with K 7136: 2000.

<Tensile breaking strength>
A test piece was produced by punching a test piece from a film using a super dumbbell cutter SDK-300 (manufactured by Dumbbell Co., Ltd.). The prepared test piece was attached to a tensile tester (AGS-5kNX manufactured by Shimadzu Corporation) with a distance between grippers of 40 mm, the test environment was adjusted to 40 ° C in the attached constant temperature bath, and the tensile speed was 500 mm / min. The test piece is pulled until it breaks under the conditions, and the value (unit: kgf / cm ² ) obtained by dividing the load at break by the cross-sectional area of the initial test piece (that is, the width x thickness of the central constriction of the dumbbell) is the tensile breaking strength. And said. The tensile breaking strength test was carried out for each of MD (Machine Direction) and TD (Transverse Direction).

<Density>
The densities of each of the polyolefin resins were measured as follows. A test piece for density measurement was prepared using a compression molding machine (NF-37, manufactured by Shinto Metal Industry Co., Ltd.). Specifically, for the polyethylene resin (A-1), a predetermined amount of polyethylene resin (A-1) resin pellets is placed in a SUS mold, and the upper and lower parts are sandwiched between aluminum plates (thickness 1 mm) at 150 ° C. It was set in the first compression molding machine set to the above, preheated for 5 minutes without pressurization, and then pressurized to a gauge pressure of 150 kgf / cm ² while maintaining the temperature at the above temperature, and held for 5 minutes. After that, the resin was moved together with the mold to a second compression molding machine set at a temperature of 30 ° C., held at a gauge pressure of 150 kgf / cm ² for 5 minutes to cool, and a test of about 4 cm in length × about 4 cm in width × 1 mm in thickness. I got a piece. Next, the density of the prepared test piece was measured at 23 ° C. according to the method A of JIS K 7112: 1999. For the polypropylene resin (A-2), a test piece was prepared under the same conditions as the polyethylene resin (A-1) except that the set temperature of the first compression molding machine was set to 180 ° C., and the density was measured. Was done. For the polyethylene resin (PE), a test piece was prepared under the same conditions as the polyethylene resin (A-1), and then the prepared test piece was subjected to the annealing treatment described in JIS K 6760-1981, and then the prepared test piece was subjected to the annealing treatment. The density was measured.

[material]
The materials used are shown below.

The MFR described below corresponds to a value measured by the A method under the condition of a load of 21.18 N at a predetermined temperature in accordance with JIS K 7210: 1999.
Polyethylene resin (A-1):
Ethylene-α-olefin copolymer (A-1-1);
(1) Ethylene-1-hexene copolymer (hereinafter referred to as ER-1)
Density 890 kg / m ³
MFR (190 ° C, 21.18N, method A) 3.2 g / 10 minutes
(Excellen (registered trademark) FX307, manufactured by Sumitomo Chemical Co., Ltd.)
(2) Ethylene-1-hexene copolymer (hereinafter referred to as ER-2)
Density 880 kg / m ³
MFR (190 ° C, 21.18N, method A) 8g / 10 minutes
(Excellen (registered trademark) FX402 manufactured by Sumitomo Chemical Co., Ltd.)
(3) Ethylene-1-butene copolymer (hereinafter referred to as ER-3)
Density 885 kg / m ³
MFR (190 ° C, 21.18N, method A) 3.6 g / 10 minutes
(Toughmer (registered trademark) A4085S manufactured by Mitsui Chemicals, Inc.)
(4) Linear low density polyethylene resin (LLDPE) (hereinafter referred to as LLDPE-1)
Ethylene-Polar Group-Containing Monomer Copolymer (A-1-2):
(5) Ethylene-vinyl acetate copolymer (EVA) (hereinafter referred to as EVA-1)
Density 952 kg / m ³
MFR (190 ° C, 21.18N, method A) 7g / 10 minutes
Ethylene-derived monomer unit content 72% by mass, vinyl acetate (VA) -derived monomer unit content 28% by mass (EVA-1 mass is 100% by mass)
(Sumitate (registered trademark) KA-30 manufactured by Sumitomo Chemical Co., Ltd.)
(6) Ethylene-vinyl acetate copolymer (EVA) (hereinafter referred to as EVA-2)
Density 935 kg / m ³
MFR (190 ° C, 21.18N, method A) 1.5g / 10 minutes
Content of ethylene-derived monomer unit 85% by mass, content of ethylene-vinyl acetate (VA) -derived monomer unit 15% by mass (the mass of EVA-2 is 100% by mass)
(Evertate (registered trademark) H2020 manufactured by Sumitomo Chemical Co., Ltd.)
(7) Ethylene-methyl methacrylate copolymer (EMMA) (hereinafter referred to as EMMA-1)
Density 943 kg / m ³
MFR (190 ° C, 21.18N, method A) 7g / 10 minutes
Ethylene-derived monomer unit content 75% by mass, methyl methacrylate (MMA) -derived monomer unit content 25% by mass (EMMA-1 mass is 100% by mass)
(Aklift (registered trademark) WK307 manufactured by Sumitomo Chemical Co., Ltd.)
Polypropylene resin (A-2):
(8) Propylene-ethylene random copolymer (hereinafter referred to as PP-1)
Density 899 kg / m ³
MFR (230 ° C, 21.18N, method A) 2.5 g / 10 minutes
Content of propylene-derived monomer unit 99.4% by mass
(Sumitomo Noblen (registered trademark) FS2011DG3 manufactured by Sumitomo Chemical Co., Ltd.)
(9) Propylene-ethylene random copolymer (hereinafter referred to as PP-2)
Density 895 kg / m ³
Content of propylene-derived monomer unit 96.8% by mass
MFR (230 ° C, 21.18N, method A) 3 g / 10 minutes
(Sumitomo Noblen (registered trademark) FH3315 manufactured by Sumitomo Chemical Co., Ltd.)
(10) Propylene-ethylene random copolymer (hereinafter referred to as PP-3)
Density 870 kg / m ³
MFR (230 ° C, 21.18N, method A) 3 g / 10 minutes
(Vistamaxx® 3020FL ExxonMobil)
(11) Propylene-ethylene random copolymer (hereinafter referred to as PP-4)
Density 856 kg / m ³
MFR (230 ° C, 21.18N, method A) 3 g / 10 minutes
(Vistamaxx® 6102FL ExxonMobil)
(12) Propylene-ethylene-1-butene random copolymer (hereinafter referred to as PP-5)
Density 893 kg / m ³
MFR (230 ° C, 21.18N, method A) 6g / 10 minutes
(Sumitomo Noblen (registered trademark) FL6741G manufactured by Sumitomo Chemical Co., Ltd.)
(13) Propylene-1-butene random copolymer (hereinafter referred to as PP-6)
Density 883 kg / m ³
MFR (230 ° C, 21.18N, method A) 7 g / 10 minutes
(Toughmer (registered trademark) XM7070 manufactured by Mitsui Chemicals, Inc.)
Polyolefin resin:
(14) Polyethylene resin (PE) (hereinafter referred to as PE-1)
Density 912 kg / m ³ (after annealing)
MFR (190 ° C, 21.18N, method A) 0.5 g / 10 minutes
(Excellen (registered trademark) GMH GH030, manufactured by Sumitomo Chemical Co., Ltd.)
(15) Polyethylene resin (PE) (hereinafter referred to as PE-2)
Density 921 kg / m ³ (after annealing)
MFR (190 ° C, 21.18N, method A) 0.4 g / 10 minutes
(Excellen (registered trademark) GMH GH051 manufactured by Sumitomo Chemical Co., Ltd.)
Particle (B):
(1) Crosslinked methyl methacrylate-styrene copolymer particles (MMA-St)
(Hereinafter referred to as particle-1)
Medium volume diameter = 5 μm
Refractive index (23 ° C) = 1.51
(Techpolymer (registered trademark) MSX-5Z Sekisui Plastics Co., Ltd.)
(2) Glass particles (hereinafter referred to as particle-2)
Medium volume diameter = 5 μm
Refractive index (23 ° C) = 1.52
(Omicron (registered trademark) NP5-P0 manufactured by Sovitec)
Additive:
(1) Calcium carbonate (average particle size 2.1 μm) (hereinafter referred to as additive-1)

A film having a layer of the resin composition was prepared by the method described below and evaluated.

[Example 1]
<Masterbatch>
A masterbatch containing 50 parts by mass of EVA-1 and 50 parts by mass of particles-1 was used. Let this masterbatch be MB-1.

<Film molding>
Three-layer inflation equipped with an inner layer extruder (40 mm extruder), an intermediate layer extruder (40 mm extruder), an outer layer extruder (40 mm extruder), and a 100 mmφ die (lip gap 1.2 mm). A three-layer tubular film was molded using a molding machine (manufactured by Placo Co., Ltd.).

Specifically, the material of the polyolefin resin composition for the outer layer is put into the extruder for the outer layer, the material of the resin composition for the intermediate layer is put into the extruder for the middle layer, and the material of the polyolefin resin composition for the inner layer is put into the extruder. Was melt-kneaded in each extruder, and then the discharge amount was adjusted from a 100 mmφ die so that the inner layer was 30 μm, the intermediate layer was 90 μm, and the outer layer was 30 μm (total thickness was 150 μm). The melted resin composition of each layer was extruded and cooled to obtain a three-layer tubular film. At this time, the temperature of the extruder for the inner layer and the extruder for the outer layer was set to 160 ° C, and the temperature for the extruder and the die for the intermediate layer was set to 150 ° C.

In the film of Example 1, the materials of the polyolefin resin composition for the outer layer are PE-1 and PE-2, and the blending amounts are 50% by mass for PE-1 and 50% by mass for PE-2. there were. The materials of the resin composition for the intermediate layer are ER-1, EVA-1, PP-3 and MB-1, and the content of each composition contained in the resin composition is as shown in Table 1 as a part by mass. .. The material of the polyolefin-based resin composition for the inner layer was the same as the material of the polyolefin-based resin composition for the outer layer.

For the film of Example 1, the haze value at 0 ° C. and the haze value at 40 ° C. were measured, and the difference between the haze value at 40 ° C. and the haze value at 0 ° C. was determined. Further, with respect to the film of Example 1, the tensile breaking strength at 40 ° C. was measured, and the level of fish eye was visually evaluated. The evaluation results are shown in Table 1 below.

[Example 2]
The film of Example 2 was formed in the same manner as in Example 1 except that PP-2 was used instead of PP-3 and the temperature of the extruder of the intermediate layer was 160 ° C. Table 1 below shows the haze values at each temperature and the differences between the haze values, the tensile breaking strength at 40 ° C., and the fish eye level in the film of Example 2.

[Example 3]
Using PP-4 instead of PP-3, the film of Example 3 was molded in the same manner as in Example 1. Table 1 below shows the haze values at each temperature and the differences between the haze values, the tensile breaking strength at 40 ° C., and the fish eye level in the film of Example 3.

[Examples 4 to 6]
The films of Examples 4 to 6 are the same as in Example 1 except that ER-1, EVA-1, PP-3, and MB-1 are blended so that each composition has the content shown in Table 1. Was molded respectively. Table 1 below shows the haze values at each temperature and the differences between the haze values, the tensile breaking strength at 40 ° C., and the fish eye level in each of the films of Examples 4 to 6.

[Example 7]
<Masterbatch>
A masterbatch containing 50 parts by mass of ER-1 and 50 parts by mass of particles-1 was used. Let this masterbatch be MB-2.

<Film molding>
The film of Example 7 was molded in the same manner as in Example 1 except that ER-1, ER-2, PP-3, and MB-2 were blended so that each composition had the content shown in Table 1. did. Table 1 below shows the haze values at each temperature and the differences between the haze values, the tensile breaking strength at 40 ° C., and the fish eye level in the film of Example 7.

[Example 8]
Example 8 as in Example 1 except that ER-2, EVA-1, EVA-2, PP-3, and MB-1 were blended so that each composition had the content shown in Table 1. Film was molded. Table 1 below shows the haze values at each temperature and the differences between the haze values, the tensile breaking strength at 40 ° C., and the fish eye level in the film of Example 8.

[Example 9]
The film of Example 9 was molded in the same manner as in Example 1 except that ER-1, EVA-1, PP-3, and MB-1 were blended so that each composition had the content shown in Table 1. did. Table 1 below shows the haze values at each temperature and the differences between the haze values, the tensile breaking strength at 40 ° C., and the fish eye level in the film of Example 9.

[Example 10]
Examples except that ER-1, EVA-1, PP-1, and MB-1 were blended and the temperature of the extruder in the intermediate layer was set to 175 ° C. so that each composition had the content shown in Table 1. The film of Example 10 was molded in the same manner as in 1. Table 1 below shows the haze values at each temperature and the differences between the haze values, the tensile breaking strength at 40 ° C., and the fish eye level in the film of Example 10.

[Example 11]
The film of Example 11 was molded in the same manner as in Example 1 except that EVA-1, PP-3, and MB-1 were blended so that each composition had the content shown in Table 2. Table 2 below shows the haze values at each temperature and the differences between the haze values, the tensile breaking strength at 40 ° C., and the fish eye level in the film of Example 11.

[Example 12]
The film of Example 12 was molded in the same manner as in Example 1 except that PP-5 was used instead of PP-3. Table 2 below shows the haze values at each temperature and the differences between the haze values, the tensile breaking strength at 40 ° C., and the fish eye level in the film of Example 12.

[Example 13]
The film of Example 13 was molded in the same manner as in Example 1 except that PP-6 was used instead of PP-3. Table 2 below shows the haze values at each temperature and the differences between the haze values, the tensile breaking strength at 40 ° C., and the fish eye level in the film of Example 13.

[Example 14]
<Masterbatch>
A masterbatch containing 50 parts by weight of EMMA-1 and 50 parts by weight of particles-1 was used. Let this masterbatch be MB-3.

<Film molding>
The film of Example 14 was molded in the same manner as in Example 1 except that EMMA-1, PP-3, and MB-3 were blended so that each composition had the content shown in Table 2. Table 2 below shows the haze values at each temperature and the differences between the haze values, the tensile breaking strength at 40 ° C., and the fish eye level in the film of Example 14.

[Example 15]
<Masterbatch>
A masterbatch containing 50 parts by weight of ER-3 and 250 parts by weight of particles was used. Let this masterbatch be MB-4.

<Film molding>
The film of Example 15 was molded in the same manner as in Example 1 except that EVA-2, PP-3, and MB-4 were blended so that each composition had the content shown in Table 2. Table 2 below shows the haze values at each temperature and the differences between the haze values, the tensile breaking strength at 40 ° C., and the fish eye level in the film of Example 15.

[Examples 16 to 18]
<Masterbatch>
A masterbatch containing 40 parts by mass of LLDPE-1 and 60 parts by mass of additive-1 is used. Let this masterbatch be MB-5.

The films of Examples 16 to 18 are the same as in Example 1 except that EVA-1, PP-3, MB-1, and MB-5 are blended so that each composition has the content shown in Table 3. Are molded respectively. The haze value at each temperature and the difference between the haze values, the tensile breaking strength at 40 ° C., and the level of fish eye are evaluated in each of the films of Examples 16 to 18.

The agricultural film of the above results, the present invention includes a polypropylene resin density of less 850 kg / ^{m 3} or more 905 kg / ^{m 3,} and a volume median diameter of 1μm or more 20μm or less, a refractive index of 1.50 It was confirmed that by including the particles having a temperature of 1.53 or less, not only the change in the haze value in the temperature range of 0 ° C to 40 ° C can be increased, but also the tensile breaking strength at 40 ° C can be increased. did it.

The film according to the present invention can be suitably used as a covering material or the like in agricultural and horticultural facilities such as greenhouses and tunnels for plant cultivation.

Claims (2)

It has at least one layer made of a resin composition containing a polyethylene resin (A-1), a polypropylene resin (A-2), and particles (B) having a volume median diameter of 1 μm or more and 20 μm or less.
The density of the polypropylene-based resin (A-2) is equal to or less than 850 kg / ^{m 3} or more 905 kg / ^{m 3,}
A film having a refractive index of 1.50 or more and 1.53 or less of the particles (B). The agricultural and horticultural facility in which the film according to claim 1 is spread on the agricultural and horticultural facility frame.