JP2000272068A - Multilayered film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayered film excellent in anti-fogging properties. SOLUTION: A multilayered film has a base material having at least one layer (A-layer) containing an ethylene/α-olefin copolymer of which the compsn. distribution fluctuation coefficient defined by formula Cx=λ/SCBave. (wherein λis the standard deviation of the compsn. distribution of the ethylene/α-olefin copolymer calculated from the elution quantities of an elution component at respective temps. and the branch degrees thereof by a temp. rising column fractionation method and SCBave. is an average value of the number of short chain branches per 1,000 carbon atoms in the ethylene/α-olefin copolymer) is 0.5 or less and the anti-fogging layer provided on the base material to form at least one outermost layer of the multilayered film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer film having excellent antifogging properties.

[0002]

2. Description of the Related Art Agricultural films and food packaging films are often required to have antifogging properties. Conventionally, polyvinyl chloride films have been used as these films with anti-fog properties, but this causes environmental pollution due to the generation of toxic chlorine-containing gas during incineration. Therefore, replacement of a polyvinyl chloride film with a polyolefin-based film is being promoted today. As a polyolefin film having antifogging properties, a multilayer film having a surface layer made of an ethylene / vinyl acetate copolymer containing an antifogging agent is on the market. However,
Such a film in which an antifogging agent is present in the resin cannot maintain the antifogging property for a long period of time. As a technique for maintaining the antifogging property of the antifogging film for a long period of time, a polyolefin-based film having an antifogging layer formed by applying inorganic colloid particles to the surface of a base film has been proposed. However, in such a conventional film, the adhesion of the inorganic colloid particles to the substrate film was not sufficient. For example, when a conventional antifogging film in which a base film is coated with inorganic colloid particles is used as a coating film for a greenhouse for facility horticulture, the antifogging layer is used when the film is displayed or after the display. Often it was peeled off from. Therefore, the durability of the antifogging property of such an antifogging film has not been sufficient. In addition, there was room for improvement in the antifogging property itself. Furthermore, when a conventional anti-fog film is used for a long time as a coating film for a greenhouse, sand or dust adheres to the surface of the film, especially the surface facing the outside of the greenhouse, and algae and moss are generated. As a result, there is also a problem that the illuminance in the greenhouse is reduced. Also, contamination of the film surface
The film itself may be deteriorated, or the film may be deteriorated or whitened by cleaning the stain with a detergent. In addition, conventional ethylene / vinyl acetate copolymers have poor mechanical properties such as tensile strength, and therefore, antifogging films containing the same are used as agricultural films or as food products using automatic packaging machines. In packaging
Easy to tear.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a multilayer film having excellent antifogging properties.

[0004]

According to the present invention, a layer (A) containing an ethylene / α-olefin copolymer having a composition distribution variation coefficient defined by the following formula (1) of 0.5 or less is used.
The present invention provides a multilayer film having a substrate having at least one layer) and an antifogging layer provided on the substrate and serving as at least one outermost layer of the multilayer film. Cx = σ / SCBave. (1) (where, σ is the composition distribution of the ethylene / α-olefin copolymer obtained from the elution amount of the eluting component at each temperature and the degree of branching at each temperature by the temperature rising column fractionation method) And SCBave. Represents the average value of the number of short-chain branches per 1000 carbon atoms in the ethylene / α-olefin copolymer). The multilayer film of the present invention achieves excellent antifogging property and antifogging property retention when at least one layer A is adjacent to the antifogging layer. Further, in the multilayer film of the present invention, when one A layer is the outermost layer of the multilayer film on the side opposite to the anti-fog layer, excellent film strength and excellent film strength are achieved. Further, when the multilayer film of the present invention comprises only at least one layer A and an antifogging layer, excellent antifogging properties, antifogging retention properties and film strength are achieved. Moreover, when the outermost layer is not the layer A, the multilayer film of the present invention achieves excellent antifogging properties, antifogging retention properties, surface smoothness and film strength.
In the present invention, the anti-fogging property is a property of preventing water adhering to the film from collecting into visible water droplets. An antifogging agent is a substance that exhibits antifogging properties. The anti-fog property is a property of preventing generation of fog in a greenhouse. Antifog is a substance that exhibits antifog properties.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION

[0006] The multilayer film of the present invention comprises ethylene / α-
It includes a substrate having at least one layer (A layer) containing an olefin copolymer, and an antifogging layer provided on the substrate. The monomer constituting the ethylene / α-olefin copolymer, α-olefin, usually has 3 to 18, preferably 4 to 12 carbon atoms. Examples of such α-olefins include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-
Octene, 1-decene, 1-dodecene, 1-cyclohexene, cyclohexylethylene are exemplified. Ethylene / α-olefin copolymer is composed of ethylene and one kind of α-olefin.
It may be a copolymer of olefin or a copolymer of ethylene and two or more α-olefins. 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
It is about 25 mol%, preferably about 0.5 mol% to about 10 mol%, more preferably about 1 mol% to about 7 mol%. One A layer may contain two or more types of ethylene / α-olefin copolymers.

[0007] The amount of the ethylene / α-olefin copolymer in the layer A is selected according to the layer constitution of the multilayer film.
In the A layer constituting the outermost layer of the multilayer film and the A layer adjacent to the anti-fog layer, the amount of the ethylene / α-olefin copolymer is usually about about the total weight of the A layer. 50
% Or more, preferably about 60 to 99% by weight. In layer A, which does not constitute the outermost layer of the multilayer film and is not adjacent to the anti-fog layer, the amount of ethylene / α-olefin copolymer is usually about 30% based on the total weight of layer A. weight%
As described above, the content is preferably about 40 to 99% by weight.

The ethylene / α-olefin copolymer has a composition distribution variation coefficient Cx defined by the following general formula of about 0 in order to achieve excellent antifogging property and antifogging property retention of the multilayer film. .5 or less. Cx is preferably from about 0.1 to about 0.4 to achieve particularly good antifogging and antifogging retention properties of the multilayer film, and excellent antiblocking and dustproof properties.

(1) In the formula, σ is an ethylene / α-olefin copolymer obtained from the elution amount of the elution component at each temperature and the degree of branching by the temperature-increasing column fractionation method. Represents the standard deviation of the composition distribution. SCBave. Represents the average value of the number of short-chain branches per 1000 carbon atoms in the ethylene / α-olefin copolymer.

Σ and SCBave. Are respectively obtained as follows. SCBave., As is commonly performed in the measurement of short-chain branching of polyethylene, etc.,
It can be determined from the FT-IR spectrum of the α-olefin copolymer. Here, the short-chain branch is generally a branch having about 1 to 4 carbon atoms (typically, a branch having 1 to 4 carbon atoms).
~ 4 branches). Further, σ is obtained by a standard method of the temperature rise column fractionation method. That is, the ethylene / α-olefin copolymer is dissolved in a solvent heated to a predetermined temperature, put into a column in a column oven, and
The temperature of the oven is lowered, then raised to a predetermined temperature, and the relative concentration and branching degree of the components eluted at that temperature are measured by FT-IR connected to the column. Subsequently, the temperature is increased stepwise to the final temperature (the temperature at which all the copolymers subjected to the test elute). Statistical processing is performed on the obtained relative concentration and branching degree of each eluted component, and the standard deviation σ of the composition distribution is obtained.

The ethylene / α-olefin copolymer has a melt flow rate (MFR) of about 0.1 to about 50 g / 1.
0 minutes is preferred, and about 0.3 to about 20 g / 10 minutes is more preferred. The MFR is ASTM D 1238-65T
And a value measured under the conditions of 190 ° C. and a load of 2.16 kg. If the MFR is too low, the processability during the production of the multilayer film may be poor. If the MFR is too high, the strength of the obtained multilayer film may be poor. The density measured by the method of JIS K7112 is 0.1.
89 to 0.94 g / cm ³ is preferable, and 0.90 to 0.94 g / cm ³ is preferable.
93 g / cm ³ is more preferred. Gel Permea
The molecular weight distribution (Mw / Mn) obtained by the Tion Chromatography (GPC) is preferably from about 1.5 to about 4 and more preferably from about 2 to about 3.5 from the viewpoint of processability and strength.

The environmental stress crack index of the ethylene / α-olefin copolymer is preferably about 1000 hours or more, and more preferably about 2000 hours or more. The environmental stress crack index is determined by a constant strain environmental stress crack measurement method specified in JIS K6760. Environmental stress crack index is about 1
At 000 hours or more, the multilayer film is excellent in detergent resistance and stain resistance.

As the ethylene / α-olefin copolymer having an environmental stress crack index of about 1000 hours or more, those in the category of so-called linear low-density polyethylene having a small number of long-chain branches are preferable, and α having a large number of carbon atoms is preferred. Those containing olefin units are more preferred. However, when the number of carbon atoms is 6 or more, the influence of the number of carbon atoms of the α-olefin on the environmental stress crack index often does not greatly differ.
-The olefin preferably has 3 to 8 carbon atoms, and particularly preferably 6 carbon atoms. When the molecular weight of the ethylene / α-olefin copolymer is substantially the same, the density is preferably low, and when the density of the ethylene / α-olefin copolymer is substantially the same, the higher the molecular weight, the better. .

More specifically, the density is 0.925 g / c.
m ³ of ethylene / 1-butene copolymer, its MF
R is preferably about 2 g / 10 minutes or less, and the density is 0.930.
In the case of a g / cm ³ ethylene / 1-butene copolymer, the MFR is preferably about 1 g / 10 minutes or less. For example, in the case of an ethylene / 1-hexene copolymer having a density of 0.925 g / cm ³ , its MFR is preferably about 10 g / 10 min or less, and ethylene / 1 having a density of 0.930 g / cm ^3.
-Hexene copolymer has an MFR of about 2 g / 10
Minutes or less is preferred.

The melting peak temperature of the ethylene / α-olefin copolymer is preferably 110 ° C. or higher,
It is particularly preferred that the temperature is 115 ° C. or higher.

[0015] The ethylene / α-olefin copolymer used in the multilayer film of the present invention is, for example, ethylene and an α-olefin having 3 to 18 carbon atoms, a complex catalyst of a transition metal such as palladium or nickel. It can be produced by a method of polymerizing in a gas phase / solid phase, liquid phase / solid phase or homogeneous liquid phase in the presence or absence of a solvent using a so-called single site catalyst such as a metallocene catalyst. The polymerization temperature is usually from about 30C to about 300C, and the polymerization pressure is usually from about atmospheric pressure to about 3000 kg /
cm ² . For example, JP-A-6-9724, JP-A-6-136195, JP-A-6-136196
In the presence of a so-called metallocene-based olefin polymerization catalyst containing a metallocene catalyst component described in JP-A No. 6-207057, ethylene is copolymerized with an α-olefin having 3 to 18 carbon atoms. Thereby, an ethylene / α-olefin copolymer can be produced.

Further, according to the method described in JP-A-8-276542, the average value of the number of branches on the high molecular weight side is equal to or more than the average value on the low molecular weight side based on the peak position of the GPC elution curve. Ethylene-α-
An olefin copolymer can be produced and can be suitably used in the present invention. When such a copolymer is used, a multilayer film having particularly excellent antifogging property and antifogging property retention can be obtained.

[0017] In the present invention, for the purpose of improving the transparency of the multilayer film, A layer has a density of 0.94 g / cm ³ or more, a high-density polyethylene is preferably 0.945~0.955g / cm ³ May be contained. When high-density polyethylene is blended, high-density polyethylene having an MFR that is too low is difficult to mix with the ethylene / α-olefin copolymer, so that a so-called fish eye is generated, which not only impairs the appearance of the multilayer film but also causes a pin on the film. Holes may occur. On the other hand, if the MFR is excessive, the strength of the multilayer film is reduced. Therefore, the MFR of the high-density polyethylene to be blended is usually about 0.1 g /
10 minutes to about 20 g / 10 minutes, preferably about 0.3 g / 1
0 minutes to about 10 g / 10 minutes. The weight ratio of high density polyethylene to ethylene / α-olefin copolymer in one layer A is usually about 20/80 or less, preferably in the range of about 1/99 to about 10/90.

The above high-density polyethylene has a value of [g] * defined by the following formula (2) of about 0.2 to about 0.8.
Is more preferable from the viewpoint of improving transparency, and about 0.3
~ 0.6 is more preferred.

[G] * = [η] / [η] l (2) [η] represents the intrinsic viscosity of the high-density polyethylene measured with a tetralin solution at 135 ° C. [Η] _l is the limiting viscosity of the linear high-density polyethylene having the same weight average molecular weight as the high-density polyethylene.
Here, the weight average molecular weight is determined by the GPC-LALLS method (Ge
l Permeation Chromatography-Low Angle Lase
r Light Scatterring method).
[Η] _l is given by the following equation (3) (H. Rachapudy, GGSmith,
VRRaju and WWGlassley, J. Polym. Sci., Pol
ym.Phys.Ed., 17, 1211 (1979)).

[Η] _l = 4.86 × 10 ⁻⁴ [Mw] 0.705 (3)

For the purpose of improving the moldability of the multilayer film of the present invention, the layer A is made of a high-pressure low-density polyethylene, which is an ethylene homopolymer obtained by a high-pressure polymerization, or an ethylene / polar vinyl monomer copolymer (ethylene / vinyl acetate). Copolymer). When compounding high pressure low density polyethylene or ethylene / polar vinyl monomer copolymers, these MFRs are typically from about 0.1 to about 10
0 g / 10 min, preferably about 0.2 to about 10 g / 10
Minutes, more preferably about 0.5 to about 5 g / 10 minutes,
The density is usually 0.915 to 0.935 g / cm ³ , preferably 0.920 to 0.930 g / cm ³ , more preferably 0.922 to 0.928 g / cm ³ .

Further, the swell ratio of the high pressure method low density polyethylene or ethylene / polar vinyl monomer copolymer is 6
It is preferably 0% or less, more preferably 50% or less, and 45% or less.
% Is particularly preferred. The swell ratio is calculated by the following equation (4).

Swell ratio (%) = [(L1 / L0) −1] × 100 (4) In the formula, L1 is a diameter (mm) at a position 5 mm from the tip of the strand obtained at the time of MFR measurement; It is measured with a micrometer. L0 is the diameter of the orifice,
2.0955 mm.

When the high-pressure low-density polyethylene or the ethylene / polar vinyl monomer copolymer is used in the layer A, the weight of the high-pressure low-density polyethylene or the ethylene / polar vinyl monomer copolymer relative to the ethylene / α-olefin copolymer is used. The ratio is about 40/60 or less, preferably about 5 / 95-30 / 70, preferably about 10 / 90-2.
0/80.

As the ethylene / polar vinyl monomer copolymer, an ethylene / vinyl acetate copolymer having a vinyl acetate monomer unit content of 2 to 30 mol% is preferred.
The content of the vinyl acetate monomer unit is more preferably 2 to 20 mol%, and further preferably 2 to 10 mol%. As the high-pressure low-density polyethylene, for example, 1,000 to 2,000
Those produced by radical polymerization at 00 atm and 200 to 300 ° C can be used.

The layer A is composed of a fatty acid amide compound, organic fine particles, and / or an infrared ray as described below, from the viewpoints of anti-blocking properties, dust resistance and abrasion resistance of the multilayer film, and prevention of wrinkling of the anti-fog layer. It preferably contains inorganic fine particles used as an absorbent. In particular, when the A layer is a layer composed of an ethylene / α-olefin copolymer having a Cx of 0.2 to 0.4, it is more preferable to use the fatty acid amide together with the inorganic fine particles.

Examples of the fatty acid amide compound include a saturated fatty acid amide having a melting point of about 50 to about 200 ° C., an unsaturated fatty acid amide, a bisfatty acid amide, and the like. 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 such a fatty acid amide is blended, the amount of the fatty acid amide blended in the layer A depends on the resin components in the layer A (ethylene / α-olefin copolymer, high-density polyethylene, high-pressure low-density polyethylene, ethylene / Polar vinyl monomer copolymer) to about 0.0
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 A include crosslinked polymers having a particle size of about 0.5 μm to about 20 μm, and those having a refractive index close to the refractive index of the resin component contained in the layer A are preferable. . For example, crosslinked beads such as polyethylene and polymethyl methacrylate are preferably used. When compounding such organic fine particles, the compounding amount in the layer A depends on the resin components in the layer A (the above-mentioned ethylene / α-olefin copolymer, high-density polyethylene, high-pressure low-density polyethylene, ethylene / polar vinyl). Monomer copolymer)
Is preferably at least about 0.1 part by weight, more preferably at least about 0.3 part by weight, based on 100 parts by weight of the total. From the viewpoint of economy, the amount 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 may be contained in the layer A include an infrared absorber described below. The amount of the inorganic fine particles in the layer A depends on the resin component in the layer A (the ethylene / α-olefin copolymer described above, High-density polyethylene, high-pressure low-density polyethylene, ethylene / polar vinyl monomer copolymer, etc.)
Is preferably at least about 0.1 part by weight, more preferably at least about 0.3 part by weight, based on 100 parts by weight of the total. Also, about 2
0 parts by weight or less is preferable, about 10 parts by weight or less is more preferable, and about 5 parts by weight or less is particularly preferable.

The layer A can contain an anti-algal agent.
The anti-algal agent is not particularly limited as long as it has the function of suppressing the generation of algae and moss. Nonionic surfactants are preferably used as antialgal agents. When the A layer contains an anti-algal agent, the compounding amount is about 0.01 to about the A layer containing it.
5% by weight. The multilayer film containing the anti-algal agent can prevent a decrease in illuminance in a facility for a long period of time, for example, when used as a covering material for an agricultural facility such as a house or a tunnel.

Examples of the nonionic surfactant used as an antialgal agent include sorbitan monostearate,
Sorbitan fatty acid ester surfactants such as sorbitan monopalmitate, sorbitan monobehenate, sorbitan monomontanate, sorbitan monooleate, glycerin monolaurate, glycerin monopalmitate, glycerin monostearate, glycerin monobehenate, glycerin mono Glycerin fatty acid ester surfactants such as montanate, glycerin monooleate, diglycerin distearate, triglycerin monostearate, tetraglycerin tristearate, tetraglycerin monomontanate, polyethylene glycol monopalmitate, polyethylene glycol monostearate Polyethylene glycol monobehenate, polyethylene glycol monomontanate, etc. Active agents, alkylene oxide adducts of alkylphenols, such as esters of sorbitan / glycerin condensates and organic acids.

In the multilayer film of the present invention, the substrate has at least one A layer. The substrate may be composed of at least one A layer. Alternatively, the substrate may be constituted by at least one A layer and at least one layer other than the A layer. In this case, the layers other than the layer A are:
It is usually based on a resin, typically a polyolefin-based resin. Examples of the polyolefin resin include, for example, α-olefin homopolymers such as polyethylene and polypropylene, ethylene / propylene copolymer, ethylene / butene-1 copolymer, ethylene / 4-methyl-1-pentene copolymer, Ethylene / α-olefin copolymers such as ethylene / 1-hexene copolymer and ethylene / 1-octene copolymer having an α-olefin unit as a main component, ethylene / vinyl acetate copolymer, ethylene / Acrylic acid copolymer, ethylene / methyl methacrylate copolymer, ethylene / vinyl acetate / methyl methacrylate copolymer, copolymer of ethylene and a polar vinyl monomer such as an ionomer resin, and the like.

Among these polyolefin resins,
Ethylene / α-olefin copolymer, low-density polyethylene, copolymer of ethylene and a polar vinyl monomer represented by ethylene / vinyl acetate copolymer, and the like,
It is preferable because a multilayer film having excellent transparency and flexibility can be provided at low cost. Among the copolymers of ethylene and polar vinyl monomer, the vinyl acetate unit content is 3
An ethylene / vinyl acetate copolymer of 0% by weight or less is excellent in flexibility and heat retention, and can provide a multilayer film in which wrinkles are hardly generated during exhibition.

The anti-fog layer, which is an essential element of the multilayer film of the present invention, imparts anti-fog properties to the multilayer film. Examples of the antifogging layer include a layer containing an inorganic oxide represented by colloidal silica or colloidal alumina as an active ingredient, a layer containing a surfactant as an active ingredient, and a layer made of a hydrophilic resin. Here, examples of the hydrophilic resin include polyvinyl alcohol, polysaccharides, and polyacrylic acid.

From the viewpoint of the durability of the antifogging property, the antifogging layer preferably contains inorganic colloid particles as an antifogging agent.
Inorganic colloid particles are particulate inorganic compounds that can be colloidally dispersed in a dispersion medium such as water. Such inorganic colloid particles include metal colloid particles, oxide colloid particles, hydroxide colloid particles, carbonate colloid particles,
Sulfate colloid particles and the like. Examples of the metal colloid particles include colloid particles of gold, palladium, platinum, silver, sulfur and the like. Oxide colloid particles, hydroxide colloid particles, carbonate colloid particles, sulfate colloid particles include silicon, aluminum, zinc,
Magnesium, calcium, barium, titanium, zirconium, manganese, iron, cerium, nickel, tin and other metal oxide colloid particles, hydroxide colloid particles,
Examples thereof include carbonate colloid particles and sulfate colloid particles. Of these oxide colloid particles, hydroxide colloid particles, carbonate colloid particles and sulfate colloid particles, oxide colloid particles and hydroxide colloid particles are preferred. Two or more types of inorganic colloid particles may be used in combination. In particular, aluminum oxide colloid particles and hydroxide colloid particles, and silicon oxide colloid particles and hydroxide colloid particles are preferable. It is preferable to use aluminum oxide colloid particles or hydroxide colloid particles in combination with silicon oxide colloid particles or hydroxide colloid particles.

The size of the inorganic colloid particles is usually about 3
nm to about 200 nm. From the viewpoint of transparency of the multilayer film, colloid particles having a particle diameter smaller than the wavelength of visible light are preferable, and colloid particles having a particle diameter in a range of about 5 nm to about 200 nm are more preferable. Such inorganic colloid particles are described, for example, in Gypsum & Lime (No. 21).
1, P46 (1987)).

The weight of the antifogging layer per unit area of the multilayer film is about 0.01 g from the viewpoint of antifogging property and transparency.
/ M < ² > to about 10 g / m < ² >. When the weight of the anti-fogging layer is within this range, a multilayer film having excellent adhesion strength between the anti-fogging layer and an adjacent layer, and having excellent anti-fogging property and transparency is obtained. The weight of the anti-fog layer is from about 0.02 g / m ² to about 2 g /
m ² is more preferable, and about 0.05 g / m ² to about 0.5 g / m ²
m ² is particularly preferred.

The antifogging layer is used together with the inorganic colloid particles for the purpose of strengthening the interaction between the inorganic colloid particles.
For example, it may contain a surfactant, an organic electrolyte, a binder and the like. The antifogging layer may contain a clay mineral or the like added to the dispersion of inorganic colloid particles for the purpose of imparting thixotropic properties to the dispersion of inorganic colloid particles during the formation thereof.

Among the surfactants used together with the inorganic colloid particles, examples of the anionic surfactant include sodium caprylate, potassium caprylate, sodium decanoate, sodium caproate, sodium myristate, potassium oleate, and stearin. Or ammonium salts of carboxylic acids having an alkyl chain having 6 to 24 carbon atoms, such as tetramethylammonium acid, sodium stearate, potassium behenate, sodium octylsulfonate, sodium dodecylsulfonate, sodium dodecylbenzenesulfonate Having 6 to 24 carbon atoms, such as ammonium dodecylbenzenesulfonate.
Metal or ammonium salts of sulfonic acids having an alkyl chain of: metal salts or ammonium salts of phosphoric acid esters having an alkyl chain of 6 to 24 carbon atoms, boric acid having an alkyl chain of 6 to 24 carbon atoms Hydrocarbon-based anionic surfactants such as ester metal salts or ammonium salts, fluorine-based anionic surfactants such as sodium perfluorodecanoate and sodium perfluorooctylsulfonate, polydimethylsiloxane groups and metal carboxylate bases Examples include a silicon-based anionic surfactant having an anionic group. Particularly, an alkali metal salt of a carboxylic acid having an alkyl chain having 6 to 10 carbon atoms is preferable.

Examples of usable cationic surfactants include cetyltrimethylammonium chloride, dioctadecyldimethylammonium chloride, -N-octadecylpyridinium bromide, and cetyltriethylphosphonium bromide.

Examples of usable nonionic surfactants include sorbitan monostearate, sorbitan monopalmitate, sorbitan fatty acid ester surfactants such as sorbitan monobehenate, glycerin monolaurate, and glycerin monopalmitate. Glycerin fatty acid ester surfactants such as glycerin monostearate, diglycerin distearate, and triglycerin monostearate; polyethylene glycol surfactants such as polyethylene glycol monopalmitate and polyethylene glycol monostearate; alkyl phenol alkylene Fluorinated nonionic surfactants such as oxide adducts, esters of sorbitan / glycerin condensates with organic acids, diglycerin esters of perfluorodecanoic acid, poly Silicon-based non-ionic surfactant or the like, such as condensate of methyl siloxane groups and the alkylene oxide adducts. In addition, an amphoteric surfactant can be used.

When the surfactant is used together with the inorganic colloid particles, the amount of the surfactant used is about 0.5 part by weight or less, preferably about 0.1 part by weight or less based on 100 parts by weight of the inorganic colloid particles. If the amount is too small, the desired effect may be too small. Therefore, the amount is usually about 0.001 part by weight or more, and preferably about 0.01 part by weight or more.

Examples of the organic electrolyte include sodium p-toluenesulfonate, sodium benzenesulfonate, potassium butylsulfonate, sodium phenylphosphinate and sodium diethylphosphate. Particularly, a benzenesulfonic acid derivative is preferable. . When the organic electrolyte is used together with the inorganic colloid particles, the amount of use is usually about 0.1 part by weight or less, preferably about 0.05 part by weight or less based on 100 parts by weight of the inorganic colloid particles. If the amount is too small, the desired effect may be too small. Therefore, the amount is usually about 0.0001 part by weight or more, and preferably about 0.001 part by weight or more.

Examples of the binder used together with the inorganic colloid particles include a thermoplastic resin. Examples of such a thermoplastic resin include an acrylic resin, an ethylene / vinyl acetate resin, a polyethylene resin, a polyurethane resin, a polycarbonate resin, a styrene resin, a vinyl acetate resin, and an unsaturated polyester resin. Acrylic resins are preferred. These thermoplastic resins may be crosslinked, and may contain additives as described below. Further, for example, a binder that forms an emulsion dispersed in a particle form in a medium such as water or that dissolves in the medium easily interacts with the inorganic colloid particles, and thus can be suitably used. Preferred examples of the binder emulsion include an aqueous emulsion of an acrylic resin and an aqueous emulsion of a polyurethane resin. Examples of preferred binder solutions include:
A poly-2-hydroxyethyl methacrylate aqueous solution and the like can be mentioned.

The clay minerals that can be contained in the anti-fog layer are of a two-layer structure in which an octahedral layer having aluminum or magnesium as a central metal is disposed on a tetrahedral layer of silica, aluminum or magnesium. Etc. are classified into a type having a three-layer structure in which an octahedral layer having a central metal as the center is sandwiched between tetrahedral layers of silica from both sides. As an example of the former,
Kaolinite group and antigolite group can be mentioned, and examples of the latter group include smectite group, vermiculite group and mica group. Among such clay-based minerals, an inorganic layered compound that swells in a layered manner in a dispersion medium and exhibits thixotropy is preferable, particularly, a smectite group or a vermiculite group in which an aqueous dispersion exhibits thixotropy, as described later. Is preferred.

When the active ingredient of the antifogging layer is an inorganic colloid, a hydrophilic resin film may be provided on the surface of the antifogging layer. The thickness of the hydrophilic coating is about 0.01 μm to about 10 μm.
m. The hydrophilic coating can serve to prevent damage to the anti-fog layer when spreading the multilayer film on the house aggregate. The hydrophilic resin is not particularly limited as long as it has a strongly hydrophilic polar group in the molecule, but a resin having a polar group fraction of 25 to 70% is preferably used.
Examples of hydrophilic resins that can be used include vinyl resins, acrylic resins, polyester resins, epoxy resins,
Urethane resin, melamine resin, phenol resin,
Polysaccharides and modified polysaccharides can be mentioned, and particularly, water-soluble polysaccharides and polyvinyl alcohol are preferably used. The hydrophilic resin film may contain the above-mentioned inorganic colloid particles.

The multilayer film of the present invention may contain one or more infrared absorbers. What is an infrared absorber?
There is no particular limitation as long as it has better infrared absorption ability than the resin material of the A layer 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. ,
Hydroxides such as magnesium hydroxide, calcium hydroxide, and aluminum hydroxide, magnesium carbonate, calcium carbonate, and basic aluminum carbonate (for example, see JP-A-9-27)
Basic aluminum carbonate double salt described in JP 9131)
Carbonates such as potassium sulfate, magnesium sulfate, calcium sulfate, zinc sulfate, sulfates such as aluminum sulfate, lithium phosphate, sodium phosphate, potassium phosphate,
Calcium phosphate and zirconium phosphate (for example, see JP-A-8-
Phosphates such as H-type zirconium phosphate described in JP-A-67774, silicates such as magnesium silicate, calcium silicate, aluminum silicate and titanium silicate; aluminates such as sodium aluminate, potassium aluminate and calcium aluminate; aluminosilicate Aluminosilicates such as sodium, potassium aluminosilicate and calcium aluminosilicate; clay minerals such as kaolin, clay and talc; and composite oxides. Examples of the organic infrared absorber include polyacetal, polyvinyl alcohol and derivatives thereof, and ethylene / vinyl alcohol copolymer.

Among these infrared absorbers, the density is about 3 g / cm from the viewpoint of the recycling efficiency of the multilayer film.
³ or less, particularly preferably about 2.4 g / cm ³ or less,
Further, from the viewpoint of infrared absorbing ability, an inorganic infrared absorbing agent is more preferable. When the infrared absorbent is an inorganic infrared absorbent, its refractive index is closer to the refractive index of the resin material used from the viewpoint of light transmittance, and from the viewpoint of heat retention, it can be applied to a wide wavelength range. It is preferable to have absorption performance. 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
Shadows such as phthalate ion and 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.

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

[0049] 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).

The composite hydroxides other than the above two types include:
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. The molar ratio (a) of an element selected from the group consisting of alkaline earth metals, transition metals, Zn and Si to 1 mol of Li element is usually 0 <a <1.5, preferably 0 <a <1.5. .1 ≦ a ≦ 1.4, more preferably 0.2 ≦ a ≦
1.2. The anion portion other than the hydroxyl group of the composite hydroxide is, for example, pyrosilicate ion, cyclosilicate ion, isosilicate ion, phyllosilicate ion, polysilicate ion such as 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 (CN) 6 4- , etc. anion And organic acid ions such as an ionic transition metal complex, an acetate ion, a benzoate ion, a formate ion, a terephthalate ion and an alkyl sulfonate ion. Among them, carbonate ion, halide ion, sulfate ion, phosphate ion, polyphosphate ion, silicate ion,
Polysilicate ions and perchlorate ions are preferred, and carbonate ions, polyphosphate ions, silicate ions and polysilicate ions are particularly preferred. Specific examples of such a composite hydroxide include Al, Li, Mg, and Al / Li
/ Mg = approximately 2.3 / 1 / 0.28 (molar ratio) complex hydroxide (trade name: LMA, manufactured by Fuji Chemical Co., Ltd.)
Complex hydroxide (trade name: Fujilein LS, manufactured by Fuji Chemical Co., Ltd.) containing l, Li and Si and having Al / Li / Si = about 2/1 / 1.2 (molar ratio).

The following formula (III) disclosed in WO 97/00828: [(Li ⁺ _(1-x) M ²⁺ _x ) (Al ³⁺ ) ₂ (OH ⁻ ) ₆ ] ₂ (Si _y O _{(2y + 1)} ^2- ) _{(1 + x)} · mH ₂ O (II) (wherein, 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+
2+ , Ca ²⁺ , Zn ^{2+ and the} like.

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 the valence of the metal M, and m, n and k are 0.3 ≦ m ≦ 1, 0.3 ≦ n ≦ 2, 0.5 ≦ k
(Satisfies the condition of ≦ 4) is also one of the 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, its average particle size is usually about 5 μm or less, preferably about 0.02 μm or less.
It is 5 to about 3 μm, more preferably about 0.1 to about 1 μm. The specific surface area measured by the BET method is 1 to 30.
m ² / g, preferably from about 2 to about 20 m ² / g.

When the multilayer 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 used, and is described in JIS K0062. The refractive index measured by the method is preferably from 1.47 to 1.55, and preferably from 1.48 to 1.48.
1.54 is more preferable, and 1.49 to 1.53 is particularly preferable.

In order to improve the dispersibility of the infrared absorber in the multilayer film, the infrared absorber may be subjected to a surface treatment with a higher fatty acid or an alkali metal salt of the higher fatty acid.

The amount of the infrared absorbing agent in the multilayer film is appropriately set in consideration of the desired radiation transmission index of the multilayer film at 23 ° C., the type of the infrared absorbing agent to be used, the layer structure of the multilayer film, and the like. . For example, when the above-mentioned composite hydroxide is used as an infrared absorbent, the compounding amount is about 6% by weight to about 13% by weight based on the total weight of the multilayer film.

The radiation transmission index at 23 ° C. of the multilayer 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 crop growth. It is determined by the measurement method used. The smaller the value of the radiation transmission index, the better the heat retention of the multilayer film. In the present invention, the multilayer film preferably has a radiation transmission index at 23 ° C. of 25 or less. When the multilayer 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.
The following is more preferable, and 15 or less is still more preferable.

The radiation transmission index at 23 ° C. is measured by the following method. Using an infrared spectrophotometer (Perkin Elmer 1640 type FT-IR), a wave number of 40
An infrared absorption spectrum (transmission method) of the multilayer film is measured at a temperature of 23 ° C. in the range of 00 to 400 cm ⁻¹ to obtain a value of transmittance T (ν)% at a wave number ν. On the other hand, according to the equation (4) obtained from Planck's law, the blackbody radiation spectrum intensity e (ν) at the wave number ν at 23 ° C. is calculated. Here, a value obtained by multiplying the blackbody radiation spectrum intensity e (ν) by the transmittance T (ν) becomes a radiation transmission intensity f (ν) (Equation (5)). Radiation transmission intensity f (ν) integrated over a wave number range of 4000 to 400 cm ⁻¹ , radiation transmission energy F, black body radiation spectrum intensity e (ν) integrated over a wave number range of 4000 to 400 cm ^−1. Is defined as black body radiation energy E, and a radiation transmission index G = 100 × F / E is defined. 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} (4) A = 2πhC ² = 3.74 × 10 ⁻¹⁶ (W · m ² ) B = hC / k = 0.01439 (m · K) 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, and k is Boltzmann's constant.)

F (ν) = e (ν) × T (ν) / 100 (5)

From the viewpoint of recycling efficiency, the density of the multilayer film is preferably less than 1.0 g / cm ³ at a temperature of 23 ° C. in accordance with the method of JIS K7112-1980, more preferably 0.99 g / cm ^3. The following is more preferable,
0.98 g / cm ³ or less is more preferable, and 0.97 g / cm ³ or less is preferable.
cm ³ or less is particularly preferred. The term “recycling efficiency” means the ease with which the multilayer film of the present invention can be separated from a vinyl chloride film which has been widely used in agricultural applications.

The multilayer 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 a light stabilizer is used, it is usually used in an amount of about 0.02 to about 5 based on the total weight of the multilayer film from the viewpoint of the balance between the effect of improving the weather resistance and the suppression of blooming of the light stabilizer. %, Preferably from about 0.1 to about 2% by weight, more preferably from about 0.5 to about 2% by weight. From the viewpoint of the weather resistance improving effect, the light stabilizer is more preferably used in combination with the following ultraviolet absorber.

The multilayer 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, its amount is
From the viewpoint of the balance between the effect of improving the weather resistance and the suppression of blooming of the ultraviolet absorber, it is usually about 0.01 to about 3% by weight, preferably about 0.05 to about 3% by weight based on the total weight of the multilayer film.
It is in the range of about 1% by weight.

The substrate in the multilayer film of the present invention may contain an antifogging agent. When compounding an anti-fogging agent, the compounding amount is usually 0.1 to 4% by weight, preferably 0.5 to 3% by weight, more preferably 1.5 to 3% by weight in the whole film.
3% by weight, particularly preferably 2.2 to 2.8% by weight, and may be blended in any layer in the case of a laminated film;
When compounded in two or more layers, the amount of each layer may be the same or different.

Such anti-fogging agents include solid and liquid ones at normal temperature (23 ° C.). Solid anti-fogging agents include nonionic surfactants such as sorbitan monostearate. Rate, sorbitan monopalmitate, sorbitan monobehenate, sorbitan fatty acid ester surfactants such as sorbitan monomontanate, glycerin monolaurate, glycerin monopalmitate, glycerin monostearate, diglycerin distearate, triglycerin mono Glycerin fatty acid ester-based surfactants such as stearate and tetraglycerin monomontanate; polyethylene glycol-based surfactants such as polyethylene glycol monopalmitate and polyethylene glycol monostearate; alkylphenoloxy of alkylphenol Adducts, esters of sorbitan / glycerin condensates and organic acids;

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, polyoxyethylene (8 mol) Fatty acid esters of polyoxyethylene alkylamine compounds such as stearylamine monostearate, polyoxyethylene (2 mol) stearylamine monobehenate, polyoxyethylene (2 mol) laurylamine stearate , Polyoxyethylene (2 mol)
Examples include amine surfactants such as fatty acid amides of polyoxyethylene alkylamine compounds such as stearic acid amide.

The multilayer film of the present invention can contain an antifog. 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 included, the amount is usually about 0.01 to about 3 in the whole film.
%, Preferably in the range of about 0.02 to about 1% by weight.

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

[0069] The multilayer film of the present invention can contain a near-infrared ray blocking agent. When a multilayer film containing a near-infrared blocking agent is used as a covering material for a green house,
It is possible to suppress a decrease in the temperature inside the house during a hot day. As a near-infrared ray blocking agent, for example,
Organic compounds disclosed in JP-A-193522 (for example, nitroso compounds and metal complex salts thereof, cyanine compounds, squarylium compounds, thiol nickel complex salt compounds, phthalocyanine compounds, triallylmethane compounds, immonium compounds, Diimonium compounds, naphthoquinone compounds, anthraquinone compounds, amino compounds, aminium salt compounds) and inorganic compounds (for example, carbon black, antimony oxide,
Tin oxide doped with indium oxide, 4 in the periodic table
Oxides or carbides of metals belonging to Group A, 5A or 6A, boron compounds). A film containing a near-infrared ray blocking agent may be formed on the surface of the multilayer 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 multilayer film and drying the coating liquid may be mentioned.

The layer structure of the multilayer film of the present invention has at least one layer A and at least one antifogging layer, and at least one of the antifogging layers forms at least one outermost layer of the multilayer film. There is no particular limitation. When the multilayer film includes a plurality of A layers, it is not necessary that all the A layers have the same composition and thickness. When a multilayer film includes a plurality of antifogging layers, it is not necessary that all the antifogging layers have the same composition and thickness. Among the multilayer films of the present invention, those in which one of the layers A is adjacent to the outermost antifogging layer of the multilayer film are excellent in the antifogging property and the antifogging property retention property of the multilayer film. In this case, the adhesion strength between the antifogging layer and the substrate is also excellent. A multilayer film in which one of the anti-fog layers constitutes one outermost layer of the multilayer film and one of the A layers constitutes the other outermost layer of the multilayer film has excellent strength (in particular, abrasion resistance on the outermost A layer side). Further, when one of the anti-fog layers forms one outermost layer of the multilayer film, and the A layer is not the other outermost layer of the multilayer film, the surface smoothness and the surface smoothness are lower than when the A layer is the outermost layer of the multilayer film. Excellent strength.

The multilayer film of the present invention having the simplest layer constitution is composed of only one A layer and one antifogging layer, which is excellent in antifogging property, durability of antifogging property and strength.
The multilayer film of the present invention often contains about 3 to 5 layers. When a multilayer film having three or more layers is exhibited to build an agricultural facility such as a house, the layer facing the outside of the facility is called the outer layer, and the layer facing the inside is called the inner layer. Is generally referred to as an intermediate layer (which may have a multilayer structure). Usually, the anti-fog layer is used as the inner layer. However, by laminating the A layer on the anti-fog layer, breakage due to contact between the film and the aggregate of the facility is well prevented. In the multilayer film of the present invention used for agricultural use, the outer layer may be subjected to dustproofing treatment, and the inner layer may be subjected to antifogging treatment and fogproofing treatment.

The thickness of the multilayer film of the present invention is usually in the range of about 0.02 mm to about 0.3 mm in view of film strength, film splicing workability and coating workability.
More preferably, from 5 mm to about 0.25 mm. The thickness of the layer A is usually about 10% or more of the thickness of the multilayer film.
About 20% or more is preferable in terms of moldability of the multilayer film, and about 30% or more is more preferable in terms of transparency, film strength and the like.

The method for producing the multilayer film of the present invention is not particularly limited. The multilayer film of the present invention can be manufactured by the following method. Add the additives selected as needed to the resin material for the base material, and mix and knead them with a mixing and kneading machine such as a ribbon blender, super mixer, Banbury mixer, single screw or twin screw extruder. Obtain a resin composition. Using the resin composition thus obtained, a base film is manufactured by a T-die film forming method, an inflation film forming method, or the like. The multilayer substrate film can be manufactured by a co-extrusion T-die film molding method using two or more types of resin compositions. The anti-fog layer can be provided on the base film by a laminating method or a coating method. In the laminating method, a previously prepared antifogging layer is laminated on a base film, or the antifogging layer is laminated on the base film by coextrusion.

Prior to lamination of the anti-fog layer, the base film may be subjected to anchor coating, corona treatment, flame treatment, or the like. By these treatments, the adhesion strength and wettability between the base film and the anti-fog layer can be improved.
The coating method is to apply a dispersion or a solution of the active ingredient in which the active ingredient of the antifogging layer is dispersed in a dispersion medium to a base film, and then dry the applied dispersion or solution to remove the dispersion medium or the solvent. This is a method of forming an anti-fogging layer. The coating method can be performed by various methods such as a gravure method, a dipping method, and a spray method. In the coating method, it is preferable to use a tubular base film from the viewpoint of production efficiency. When inorganic colloid particles are used as the active ingredient (antifogging agent) of the antifogging layer, water, methanol,
Examples include isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, ethylene glycol, xylene, and mixtures thereof. Polar solvents such as water and alcohol are preferred, and water is particularly preferred. Further, a multilayer film of the present invention can also be manufactured by forming a film to be an anti-fog layer in advance, and overlapping and integrating the film with a base film.

The multilayer film of the present invention is excellent in antifogging property, antifogging property retention property, adhesion between antifogging layer and substrate, mechanical strength, etc. Also, it is suitably used as a lining curtain used in the facility. House made of the multilayer film of the present invention,
Since water droplets attached to the inner surface begin to flow quickly, sunlight penetrates well into the house early in the morning and is suitable for growing crops. The multilayer film of the present invention can be suitably used as a substitute for a vinyl chloride film which has been widely used in conventional agricultural applications.

[0076]

According to the present invention, a multilayer film having excellent antifogging property and antifogging property retention property is provided. Further, according to the present invention, a multilayer film having excellent strength as well as excellent antifogging properties is provided. Further, according to the present invention,
A multilayer film having excellent antifogging property, antifogging property retention and strength is provided. Still further, according to the present invention, there is provided a multilayer film having excellent anti-fogging properties and anti-fogging properties, surface smoothness and strength.

[0077]

EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited to these examples. Test methods in Examples and Comparative Examples are as follows.

The MFR of the melt flow rate resin material is ASTM D 1238-65T
It is measured at 190 ° C. under a load of 2.16 kg. Molecular weight distribution (Mw / Mn) GPC: GPC apparatus manufactured by Nippon Waters Co., Ltd., Model 150C, column: TSK GMH-6 manufactured by Tosoh, solvent: ortho-dichlorobenzene (ODCB), temperature: 135 ° C., flow rate: 1 ml / mi
n, concentration: 10 mg / 10 ml, sample injection volume: 500 μl. Determine the weight average molecular weight Mw and number average molecular weight Mn converted from the calibration curve using standard polystyrene,
Calculate Mw / Mn.

The composition distribution variation coefficient Cx is measured using a multifunctional LC manufactured by Tosoh Corporation. Ethylene-α
-Dissolve the olefin copolymer in the ODCB solvent heated to 140 ° C, put it in a column oven filled with sea sand, and lower the oven temperature to -14 ° C. continue,
The temperature is raised to a predetermined temperature set in advance, and the relative concentration and the degree of branching of the copolymer flowing out during that time are measured by FT-IR connected to the column. The temperature is sequentially raised to the set temperature, and the final temperature is raised while obtaining the relative concentration and branching degree of the copolymer flowing out at each set temperature. A composition distribution curve is obtained from the obtained relative concentration and the degree of branching, and statistical processing is performed. The standard deviation σ of the composition distribution is determined. Further, a composition distribution variation coefficient Cx is obtained from this σ and SCBave. Obtained from the FT-IR measurement.

An anti-fog test film was stuck on an acrylic frame measuring 50 × 60 cm with a double-sided tape, and the test surface was placed on a 40 ° C. water bath placed in a 23 ° C. constant temperature room with the test surface facing down. Installed in After the test surface is sufficiently moistened, the amount of fog generated when ice water is brought into contact with the outside of the film and the time until the film disappears are visually observed, and are determined according to the following criteria. ：: The amount of fog generated is small and disappears immediately. Δ: The amount of fog generated is somewhat large, and it takes time to disappear. X: The amount of fog generated is very large, and it takes time to disappear.

Antifogging test (1) A film was stuck on an acrylic frame measuring 34 cm in length and 5 cm in width with a double-sided tape, and the test surface was placed on a constant temperature water bath placed in an environment test room with a constant temperature. Install at an angle of 15 degrees to the horizontal plane. The temperature conditions (environmental test room / constant water bath) at this time were: low temperature test: 3 ° C / 20 ° C, high temperature test: 20 ° C / 40 ° C. Then, the state of water droplets on the film surface is observed, and the determination is made based on the following criteria. ：: The film surface is uniformly wet. Δ: Water droplets are partially adhered. ×: Water droplets adhered to the entire surface and are cloudy white.

Weather Resistance Test A test piece punched out with a JIS No. 1 dumbbell is exposed with the passage of time at a black panel temperature of 63 ° C. using a sunshine weather meter (manufactured by Suga Test Instruments). The test specimen exposed to the passage of time was subjected to a tensile test using an Autograph DSS100 (manufactured by Shimadzu Corporation) to measure the elongation (%), and the elongation became half that of the original test specimen. Calculate the weather resistance test time when The greater the value of this time, the better the weather resistance, and 1000 hours is regarded as a pass level of this test.

Environmental stress cracking test is carried out in accordance with JIS K6760-1981 (constant strain environmental stress cracking measuring method). The reagent is Igepearl CO-6
A 10% aqueous solution of 30 (alkyl allyl polyethylene glycol manufactured by GAF) was used.

The melting peak temperature is determined in accordance with JIS K7121-1987. Fifteen
After preheating at 0 ° C. for 5 minutes, the temperature is lowered to 40 ° C. at 5 ° C./min, and the temperature is raised again to 150 ° C. at 5 ° C./min.

Antifogging Layer Adhesion Strength Test The outer layer of the sample was fixed on an acrylic plate having a thickness of 3 mm, a cellophane tape was attached to the surface of the antifogging layer, and a 90 ° peel test was performed at a tensile speed of 300 mm / min using a tensile tester. Do.
The test results are indicated by x when the antifogging layer adheres to the tape and peeled off, and by o when the antifogging layer does not peel off.

Antifogging test (2) A sample film was attached to an agricultural pipe house (width 5.7 m / height 3.3 m / depth 25 m) with a pipe span of 50 cm (early July), and green manure (crop: chloratalia) ) Under the cultivation, about one month later in the early morning of early August (weather:
On a sunny day), the flow startability after dew condensation is visually evaluated, and is determined according to the following criteria. ：: Five or more dew flows (per 50 cm span width), and the inside of the house is visible. Δ: Dew condensation flow was less than 5 lines (per 50 cm span), and the inside of the house was slightly visible. X: No dew condensation flow was observed, water droplets adhered to the whole, and became white and cloudy, and the inside of the house was invisible.

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 described in Table 1. Table-
The number in parentheses after the symbol indicating a component in 1 is the percentage of the amount of that component relative to the total amount of all components in the layer in which the component is included. 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 the resin composition pellets or resin pellets for each layer, a three-layer tube was formed by a three-layer blown film forming machine so that each layer had the thickness shown in Table 1. [Formation of antifogging layer] Alumina sol (trade name, alumina 520, solid content 20%, manufactured by Nissan Chemical Co., Ltd.), colloidal silica (trade name, Snowtex 20, solid name, manufactured by Nissan Chemical Co., Ltd. 20)
%), Sodium dodecylbenzenesulfonate (manufactured by Kao, trade name Neoperex F25), and sodium decanoate (manufactured by Nacalai Tesque) at 1.6%, 0.4%, 0.08% and 1.6%, respectively. Water was added so as to be 0.08% and mixed 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 antifogging property was evaluated by the antifogging test (1). The films of Examples 1 and 2 are the same as those of Comparative Example 1.
The film was superior in antifogging property, antifog property and weather resistance as compared with the film of No. In addition, the film of the example is heat insulating,
It was also excellent in transparency, toughness, dust resistance and anti-blocking properties.

Examples 3 and 4 and Comparative Example 2 Example 1 except that the composition of each layer was as shown in Table 2.
A three-layer tube (substrate) was produced in the same manner as described above. The surface of the third layer of the obtained substrate was subjected to a corona treatment, and an antifogging layer was formed on the third layer in the same manner as in Example 1. Table 2 shows the evaluation results of the films thus obtained. The antifogging property was evaluated by the antifogging test (1). The films of Examples 3 and 4 were superior to the film of Comparative Example 2 in antifogging property, fog resistance and weather resistance. Further, the films of the examples were also excellent in heat retention, transparency, toughness, dust resistance, anti-blocking properties, anti-algal properties and detergent resistance. Examples 5 and 6 and Comparative Example 3 Example 1 except that the composition of each layer was as described in Table-3.
A three-layer tube (substrate) was produced in the same manner as described above. The surface of the third layer of the obtained substrate was subjected to a corona treatment, and an antifogging layer was formed on the third layer in the same manner as in Example 1. Further, a 1% aqueous solution of polyvinyl alcohol is applied on the anti-fog layer so that the solid content thickness is about 0.1 g / m ² ,
The film was dried to form a film. Table 3 shows the evaluation results of the films thus obtained. The antifogging property was evaluated by the antifogging test (2). The films of Examples 5 and 6 were superior to the film of Comparative Example 3 in the antifogging property and the adhesive strength between the antifogging layer and the substrate.

Example 7 Example 1 except that the composition of each layer was as shown in Table 4.
A three-layer tube (substrate) was produced in the same manner as described above. The surface of the third layer of the obtained substrate was subjected to a corona treatment, and an antifogging layer was formed on the third layer in the same manner as in Example 1. Further, a 1% aqueous solution of polyvinyl alcohol is applied on the anti-fog layer so that the solid content thickness is about 0.1 g / m ² ,
The film was dried to form a film. Table 4 shows the evaluation results of the films thus obtained. The antifogging property was evaluated by the antifogging test (2). A film excellent in anti-fog properties and anti-fog properties was obtained. In addition, the films of the examples are heat insulating, transparent, tough, dustproof, antiblocking,
It was also excellent in anti-algal properties and detergent resistance.

[0090]

[Table 1]

[0091]

[Table 2]

[0092]

[Table 3]

[0093]

[Table 4] The meanings of the abbreviations described in Tables 1, 2 and 3 are as follows. A1: Ethylene / hexene copolymer (trade name: Sumikacene E FV402-0; hexene content: 11.1% by weight; manufactured by Sumitomo Chemical Co., Ltd.) A2: Ethylene / hexene copolymer (trade name: Sumikacene E FV403- 0; Hexene content: 8.6% by weight; manufactured by Sumitomo Chemical Co., Ltd.) A3: Ethylene / vinyl acetate copolymer (trade name: Evatate D2011; vinyl acetate unit content: 5% by weight; manufactured by Sumitomo Chemical Co., Ltd.) A4: Low density polyethylene (trade name: Sumikasen F20)
0; density: 0.923 g / cm ³ ; manufactured by Sumitomo Chemical Co., Ltd. A5: ethylene / vinyl acetate copolymer (trade name: Evatate H2021; vinyl acetate unit content: 15% by weight);
A6: Ethylene-hexene copolymer (trade name: Sumikacene E FV202 Density: 0.925 g / cm ³ ; Melt index: 1.5 g / 10 minutes; Sumitomo Chemical) A7: Ethylene- A xene copolymer (trade name: Sumikacene E FV401; density: 0.902 g / cm ³ ; melt index: 4 g / 10 minutes; manufactured by Sumitomo Chemical Co., Ltd.) A8: Low-density polyethylene (trade name: Sumikasen F20)
8-1; density: 0.922 g / cm ³ ; melt index: 1.5 g / 10 minutes; manufactured by Sumitomo Chemical Co., Ltd. A9: ethylene-hexene copolymer (trade name: Sumikacene E FV201; density: 0.919 g / cm ³ ; Melt index: 1.5 g / 10 min; manufactured by Sumitomo Chemical Co., Ltd. A10: Ethylene / vinyl acetate copolymer (vinyl acetate unit content: 5% by weight; Melt index: 0.5 g / 1)
0 minutes A11: ethylene / vinyl acetate copolymer (trade name: Evatate H203; vinyl acetate unit content: 19% by weight;
Melt index 1.5 g / 10 min; manufactured by Sumitomo Chemical Co., Ltd. E1: Trade name: Irganox HP2225 manufactured by Ciba Geigy E2: Trade name: Irganox 1010 manufactured by 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, manufactured by Clariant) G1: Trade name: Sumisorb 130, manufactured by Sumitomo Chemical Co., Ltd. H1: Diglycerin sesquioleate H2: Tetraglycerin distearate J1: Lithium aluminum complex hydroxide K1: fatty acid amide compound oleic acid amide K2: fatty acid amide compound ethylenebisstearic acid amide A1, A2, A6, A7 and A9 are ethylene polymerized using a metallocene catalyst -Hexene copolymer, the characteristics of which are shown in Table-5.

[Table 5]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B65D 81/24 B65D 81/24 D 4J002 C08K 3/00 C08K 3/00 5/00 5/00 C08L 23 / 08 C08L 23/08 (72) Inventor Tsutomu Fujita 1-1, Oecho, Niihama-shi, Ehime F-term (reference) 2B024 DB01 DB07 EA01 2B029 EB03 EC02 EC09 EC20 3E067 AB01 AB96 AB99 BA17A BB14A BB15A BB25A CA11 CA30 3E086 BA04 BA15 BA35 BB90 CA40 4F100 AA01C AA17H AA19H AA20H AK06 AK62A AK68 AR00C AT00B BA02 BA03 BA05 BA10A BA10B BA10C CA05 CA10B CA10C CA18 CA23 CA30A DE01C EH462 EJ551 GB07J01 GB07J01 GB01J20 GB01 DE087 DE097 DE107 DE117 DE137 DE147 DE217 DE237 DG037 DG057 DJ017 EH056 FD200 FD2 07 FD310 FD312 FD316 GA01

Claims (16)

[Claims] A substrate having at least one layer (A layer) containing an ethylene / α-olefin copolymer having a composition distribution variation coefficient defined by the following formula (1) of 0.5 or less: A multilayer film having at least one outermost layer of the multilayer film provided on the substrate. Cx = σ / SCB _ave. (1) (where, σ is the composition of the ethylene / α-olefin copolymer obtained from the elution amount of the eluted component at each temperature and the degree of branching at each temperature by the temperature rising column fractionation method) Represents the standard deviation of the distribution, and SCB _ave. Represents the average value of the number of short-chain branches per 1000 carbon atoms in the ethylene / α-olefin copolymer _. ) 2. The multilayer film according to claim 1, wherein at least one layer A is adjacent to the anti-fog layer. 3. The multilayer film according to claim 1, wherein one A layer is the outermost layer of the multilayer film opposite to the antifogging layer. 4. The multilayer film according to claim 1, wherein the outermost layer of the multilayer film is not the A layer. 5. The multilayer film according to claim 1, comprising only at least one layer A and an antifogging layer. 6. A composition distribution variation coefficient Cx of about 0.2 to about 0.5.
The multilayer film according to claim 1, wherein the range is 4. 7. The multilayer film according to claim 1, which has a radiation transmission index at 23 ° C. of about 25 or less. 8. The multilayer film according to claim 1, wherein the antifogging layer contains an antifogging agent. 9. The anti-fogging agent is an inorganic colloid particle.
2. The multilayer film according to item 1. 10. The multilayer film according to claim 1, further comprising at least one selected from the group consisting of a light stabilizer, an ultraviolet absorber, a near-infrared absorber, an antifog, and an inorganic compound. 11. The multilayer film according to claim 3, wherein the ethylene / α-olefin copolymer in the outermost layer A of the multilayer film has an environmental stress crack resistance of 1000 hours or more. 12. The multilayer film according to claim 3, wherein the outermost layer A of the multilayer film further contains an anti-algae. 13. The multilayer film according to claim 12, wherein the anti-algal agent is a nonionic surfactant. 14. The multilayer film according to claim 1, wherein the substrate further contains an antifogging agent. 15. The multilayer film according to claim 1, which is used in greenhouse horticulture. 16. The multilayer film according to claim 1, which is used as a covering film for an agricultural house or a tunnel.