JP5117301B2 - Laminate film and agricultural and horticultural facilities - Google Patents

Description

The present invention relates to a laminated film and an agricultural and horticultural facility.

In recent years, the demand for resins used outdoors, such as automobile materials, building materials, and agricultural materials, has increased dramatically. For example, as an agricultural material, the film for agriculture used for covering of facilities, such as a house and a tunnel, is mentioned. Conventionally, films made of polyolefin resins such as polyvinyl chloride films, polyethylene, and ethylene / vinyl acetate copolymers have been widely used as agricultural films. Recently, polyolefin resin films, which are lightweight and hardly generate toxic gases during incineration, have been widely used for gardening. One of the important performances required for these agricultural films is to prevent dew condensation on the inside of the horticultural facility caused by temperature differences between the inside and outside of the horticultural facility and to prevent the formation of water droplets. Function, i.e. anti-fogging properties.

As a method for imparting an antifogging property to a film, a method of kneading an antifogging agent in the film or a method of applying a coating liquid containing an antifogging agent to the film surface is general. As an example of an agricultural film kneaded with an antifogging agent, as disclosed in Patent Document 1, an outer layer made of an ethylene / vinyl acetate copolymer, an ultra-low density ethylene / α-olefin copolymer, and And a laminated film composed of an intermediate layer containing an antifoggant and / or an antifoggant, an ethylene / vinyl acetate copolymer, and an inner layer containing an antifoggant and / or an antifoggant. Patent Document 2 discloses a three-layer antifogging olefin agricultural film.

JP-A-6-126911 JP 2000-188966 A

The type of agricultural film in which the above-described film is kneaded with an antifogging agent is kneaded with a certain surfactant into a polyethylene-based resin mainly composed of an ethylene-vinyl acetate copolymer. Bleed out to give antifogging performance, but wide range of addition amount of disclosed ethylene-vinyl acetate copolymer, concentration of constituent unit derived from vinyl acetate, addition concentration of surfactant, etc. In some cases, the combination within the range does not exhibit antifogging performance.

The present invention relates to the surfactant content in the film and the concentration of the structural unit derived from vinyl acetate for each layer, by specifying the range more specifically than before, a laminated film having excellent antifogging performance, and The present invention provides an agricultural and horticultural facility having excellent anti-fogging performance obtained by spreading the laminated film.
That is, the first of the present invention is a laminated film having at least three layers, and all layers are formed of an ethylene-based resin, one surface layer being an A layer, the other surface layer being a B layer, and an A layer. When the other layer located between the B layer is the C layer, the laminated film is characterized by satisfying all the following conditions.
(1) The thickness of the C layer is 50% or more and 70% or less of the thickness of the laminated film. (2) _CVA is 0% or more and 8% or less. However, C _VA = {(ethylene-vinyl acetate copolymer weight contained in the C layer Total weight of structural units derived from vinyl acetate in coalescence) / (weight of layer C)} × 100
(3) A _VA is 0% or more and 5% or less, provided that A _VA = {(total weight of structural units derived from vinyl acetate in the ethylene / vinyl acetate copolymer contained in layer A) / (weight of layer A) )} × 100
(4) B _VA is 0% or more and 1% or less. However, B _VA = {(total weight of structural units derived from vinyl acetate in ethylene / vinyl acetate copolymer contained in B layer) / (weight of B layer) )} × 100
(5) A _VA ≧ B _VA
(6) The nonionic surfactant concentration (% by weight) having a melting point of 40 ° C. or higher in the laminated film is in the following range.
When 0 ≦ C _VA ≦ 3% 1.3% or more and 2% or less 3 <C _VA ≦ 5% When 1.3% or more and 2.4% or less 5 <C _VA ≦ 8% When 1.6% or more 4% or less A second aspect of the present invention is the laminated film, which is an agricultural film.
A third aspect of the present invention is an agricultural and horticultural facility, wherein the agricultural and horticultural facility frame is spread so that the layer A of the agricultural film is on the inside of the facility.

The laminated film of the present invention is excellent in anti-fogging performance, in which water droplets hardly adhere to the film surface. The agricultural and horticultural facilities of the present invention in which the laminated film is stretched are excellent in anti-fogging performance.

Laminated film with anti-fogging agent is kneaded when the anti-fogging agent in the film is exposed to the film surface, but the resin that constitutes the film simply because of the requirements of mechanical strength and optical characteristics Simply selecting a seed and kneading an antifogging agent does not necessarily reveal the antifogging performance. In order to efficiently develop the antifogging performance, it is necessary to determine the antifogging agent addition concentration from the saturation solubility of the antifogging agent in the resin, and further to select the layer structure of the film so that the addition amount is minimized. It is. When an excessive antifogging agent is added, not only the productivity is deteriorated, but also transparency required particularly when used as an agricultural film is deteriorated.
In order to optimize the flowability of the laminated film, an appropriate layer structure and antifogging agent concentration exist, and the present invention has found these. The present invention is described in detail below.

The laminated film of the present invention is a laminated film having at least three layers and all layers are formed of an ethylene-based resin, wherein one surface layer is an A layer, the other surface layer is a B layer, and the A layer and the B layer. When the other layer positioned between the layers is a C layer, the laminated film satisfies all of the following conditions.
(1) The thickness of the C layer is 50% or more and 70% or less of the thickness of the laminated film. (2) _CVA is 0% or more and 8% or less. However, C _VA = {(ethylene-vinyl acetate copolymer weight contained in the C layer Total weight of structural units derived from vinyl acetate in coalescence) / (weight of layer C)} × 100
(3) A _VA is 0% or more and 5% or less, provided that A _VA = {(total weight of structural units derived from vinyl acetate in the ethylene / vinyl acetate copolymer contained in layer A) / (weight of layer A) )} × 100
(4) B _VA is 0% or more and 1% or less. However, B _VA = {(total weight of structural units derived from vinyl acetate in ethylene / vinyl acetate copolymer contained in B layer) / (weight of B layer) )} × 100
(5) A _VA ≧ B _VA
(6) The nonionic surfactant concentration (% by weight) having a melting point of 40 ° C. or higher in the laminated film is in the following range.
When 0 ≦ C _VA ≦ 3% 1.3% or more and 2% or less 3 <C _VA ≦ 5% When 1.3% or more and 2.4% or less 5 <C _VA ≦ 8% When 1.6% or more 4% or less

Hereinafter, each condition will be described in detail.
The C layer may be a single layer or a multilayer, but in any case, the thickness is 50% or more and 70% or less, preferably 55% or more and 65% or less of the total thickness of the laminated film. It is. The C layer is usually 1 to 3 layers.

When the {/ (weight of layer C) (the total weight of structural units derived from vinyl acetate in an ethylene-vinyl acetate copolymer contained in the C layer)} × 100 and C _VA, C _VA is 0% or more and 8 % Or less.

When the {/ (weight of layer A) (total weight of structural units derived from vinyl acetate in an ethylene-vinyl acetate copolymer contained in the A layer)} × 100 and A _VA, film strength and the film overlapped From the viewpoint of preventing blocking between films when stored together, _AVA is 0% or more and 5% or less.

When the {/ (weight of layer B) (total weight of structural units derived from vinyl acetate in an ethylene-vinyl acetate copolymer contained in the B layer)} × 100 The B _VA, film strength and the film overlapped From the viewpoint of preventing blocking between the films when stored together, _BVA is 0% or more and 1% or less.

The A layer and the B layer satisfy the relationship of A _VA ≧ B _VA .

The present invention, in the above laminated film, a non-ionic surfactant concentration of melting point 40 ° C. or more laminate films in (wt%) affects the anti-fog properties of the film, the melting point of 40 ° C. or more by C _VA It is found that the preferable range of the nonionic surfactant concentration is different, and the range is defined. Hereinafter, the term “nonionic surfactant” in the present specification means a nonionic surfactant having a melting point of 40 ° C. or higher.

In the above laminated film, laminated film nonionic surfactant concentration of melting point 40 ° C. or more in (wt%) is different in preferable range by C _VA, the following conditions are suitable.
When 0 ≦ C _VA ≦ 3%, the nonionic surfactant concentration in the laminated film is 1.3% or more and 2% or less from the viewpoint of the balance between the antifogging performance and transparency of the film, and 1.4 % To 1.8% is particularly preferable.
When 3 <C _VA ≦ 5%, the nonionic surfactant concentration in the laminated film is 1.3% or more and 2.4% or less from the viewpoint of the balance between the antifogging performance and the transparency of the film. It is particularly preferably 5% or more and 2.2% or less.
When 5 <C _VA ≦ 8%, the concentration of the nonionic surfactant in the laminated film is 1.6% or more and 4% or less from the viewpoint of the balance between the antifogging performance and transparency of the film. In particular, A _VA is 5% or less than 4%, preferably C _VA is not more than 2.6% to 1.6% is possible C _VA is not more than 2.0% or more 1.7% Particularly preferred.

The concentration of the nonionic surfactant in the laminated film can be calculated by the following calculation formula.
The layer thickness of the A layer is T _A , the layer thickness of the B layer is T _B , the layer thickness of the C layer is T _C , the concentration of the nonionic surfactant in the A layer is X _A , and the nonionic surfactant of the B layer the X _B concentration of agent, when the X _C, the concentration of the nonionic surfactant of the C layer, the concentration of the nonionic surfactant in the film _{(X a × T a + X} B × T B + X _C × T _C) a _{/ (T a + T B +} T C).

The ethylene / vinyl acetate copolymer in the present invention is an ethylene / vinyl acetate copolymer containing a structural unit derived from ethylene and a structural unit derived from vinyl acetate.
In order to adjust the A _VA , B _VA and C _VA , the ethylene / vinyl acetate copolymer can be diluted with an ethylene-based resin for each layer. Moreover, each layer should just be comprised from the ethylene-type resin, and does not need to contain the ethylene-vinyl acetate copolymer.

As the ethylene-based resin, a known ethylene-based resin can be used. For example, a low-density polyethylene, a linear low-density polyethylene, a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, However, it is not limited to these.

Examples of the α-olefin having 3 to 20 carbon atoms include propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene and 1-decene. More preferable examples include 4-methyl-1-pentene and 1-hexene. The α-olefin having 3 to 20 carbon atoms may be a combination of two or more. For example, 1-butene and 4-methyl-1-pentene, 1-butene and 1-hexene, 1-butene and 1 -Octene, 1-butene, 1-decene and the like. More preferably, 1-butene and 4-methyl-1-pentene, 1-butene and 1-hexene are mentioned.

The ethylene / α-olefin copolymer in the present invention is preferably a copolymer of ethylene and an α-olefin having 5 to 10 carbon atoms, or ethylene, 1-butene and an α-olefin having 5 to 10 carbon atoms. More preferably, it is a copolymer of ethylene and an α-olefin having 6 to 10 carbon atoms, or a copolymer of ethylene, 1-butene and an α-olefin having 6 to 10 carbon atoms. It is a polymer.

The laminated film of the present invention contains a nonionic surfactant having a melting point of 40 ° C. or higher as an antifogging agent. Specific examples of such anti-fogging agents include sorbitan fatty acid esters such as sorbitan monopalmitate, sorbitan monostearate, sorbitan monopalmitate, sorbitan monomontanate, sorbitan monooleate, sorbitan dioleate and alkylene thereof. Sorbitan surfactants such as oxide adducts, glycerol monopalmitate, glycerol monostearate, diglycerol distearate, triglycerol monostearate, tetraglycerol dimontanate, glycerol monooleate, diglycerol monooleate, Diglycerin sesquioleate, tetraglycerin monooleate, hexaglycerin monooleate, hexaglycerin trioleate, tetraglycerin trioleate, tetraglycerin mono Glycerin surfactants such as glycerol fatty acid esters and alkylene oxide adducts thereof such as urate and hexaglycerol monolaurate, polyethylene glycol surfactants such as polyethylene glycol monopalmitate and polyethylene glycol monostearate, alkylene oxides of alkylphenols Adduct, ester of sorbitan / glycerin condensate and organic acid, polyoxyethylene (2 mol) stearylamine, polyoxyethylene (4 mol) stearylamine, polyoxyethylene (2 mol) stearylamine monostearate, polyoxy And polyoxyethylene alkylamines such as ethylene (4 mol) laurylamine monostearate and fatty acid esters thereof. These may be used alone or in combination of two or more.

In addition to the nonionic surfactant having a melting point of 40 ° C. or higher, the laminated film of the present invention may contain a surfactant that is liquid at room temperature represented by glycerin oleate and diglycerin oleate. The addition ratio of the above liquid surfactant having a melting point of less than 40 ° C. is 3% from the viewpoint of the balance between the antifogging performance and transparency of the film when the total surfactant contained in the film is 100% by weight. It is preferable that it is 30% or less.

The laminated film of the present invention may contain a known additive in addition to the antifogging agent, if necessary. Examples of the additive include an antioxidant, a light stabilizer, an ultraviolet absorber, an antifoggant, a lubricant, an antiblocking agent, an antistatic agent, a pigment, and an inorganic filler.

Examples of the antioxidant include phosphorus-based compounds containing trivalent phosphorus atoms such as so-called hindered phenol compounds such as 2,6-dialkylphenol derivatives and 2-alkylphenol derivatives, phosphite compounds, and phosphonite compounds. An ester compound is mentioned. These antioxidants may be used alone or in combination of two or more. In particular, from the viewpoint of stabilizing the hue, it is preferable to use a hindered phenol compound and a phosphorus ester compound in combination. Moreover, when the weight of each layer is 100%, the antioxidant is preferably contained in each layer in an amount of 0.01 to 1% by weight, and more preferably 0.03 to 0.5% by weight.

Examples of the light stabilizer include a hindered amine compound having a structure described in JP-A-8-73667, and specific examples thereof include trade names of tinuvin 622-LD, chimasorb 944-LD (hereinafter referred to as Ciba Specialty). Chemicals), Hostabin N30, VP Sanduvor PR-31 (manufactured by Clariant, Inc.), Saiyasorb UV3529, Saiyasorb UV3346 (manufactured by Cytec). Furthermore, a sterically hindered amine ether compound having a structure described in JP-A-11-315067 can be mentioned, and specifically, trade name Tinuvin NOR371 (manufactured by Ciba Specialty Chemicals) can be mentioned. The amount of the light stabilizer contained in each layer is preferably 0.01 to 3% by weight, more preferably 0.05 to 2% by weight, and particularly preferably 0.1 to 1% by weight.

Examples of UV absorbers include benzophenone UV absorbers, benzotriazole UV absorbers, benzoate UV absorbers, and cyanoacrylate UV absorbers. These can be used alone or in combination of two or more. You may use together. The amount of the ultraviolet absorber contained in each layer is preferably 0.01 to 3% by weight, more preferably 0.03 to 2% by weight, from the viewpoint of weather resistance imparting effect and suppression of bleeding on the film surface.

Examples of the antifogging agent include fluorine compounds having a perfluoroalkyl group, ω-hydrofluoroalkyl group, etc. (especially fluorine surfactants), and silicon compounds having an alkylsiloxane group, particularly silicon surfactants. ) And the like. Specific examples of the fluorosurfactant include Unidyne DS-403, DS-406, DS-401 (trade name) manufactured by Daikin Industries, Ltd., and Surflon KC-40 (trade name) manufactured by Seimi Chemical Co., Ltd. Examples of the silicon-based surfactant include SH-3746 (trade name) manufactured by Toray Dow Corning Silicon Co., Ltd. These may be used alone or in combination of two or more. The content of the antifogging agent is preferably 0.01 to 3% by weight, more preferably 0.02 to 2% by weight, and particularly preferably 0.05 to 1% by weight. From the viewpoint of antifogging performance, the antifogging agent is preferably added to the A layer.

Examples of the inorganic filler include composite hydroxides such as hydrotalcite compounds and lithium aluminum composite hydroxide. Specific examples of the hydrotalcite compound include natural hydrotalcite and synthetic hydrotalcite such as trade name: DHT-4A (manufactured by Kyowa Chemical Industry) and magcrista (manufactured by Kyowa Chemical Industry). Specific examples of the lithium aluminum composite hydroxide include Mizukarak (manufactured by Mizusawa Chemical Industry), Fujirain (manufactured by Fuji Chemical Industry), and the like. Furthermore, metal oxides such as magnesium oxide, calcium oxide, aluminum oxide, silicon oxide, and titanium oxide; hydroxides such as lithium hydroxide, magnesium hydroxide, calcium hydroxide, and aluminum hydroxide; magnesium carbonate, calcium carbonate, etc. Carbonates of: sulfates such as potassium sulfate, magnesium sulfate, calcium sulfate, zinc sulfate, aluminum sulfate; lithium phosphate, sodium phosphate, potassium phosphate, calcium phosphate phosphate (for example, JP-A-8-67774) Disclosed phosphates such as H-type zirconium phosphate); silicates such as magnesium silicate, calcium silicate, aluminum silicate, titanium silicate; aluminates such as sodium aluminate, potassium aluminate, calcium aluminate; aluminum Sodium silicate, potassium aluminosilicate, aluminosilicates such as calcium aluminosilicate; kaolin, clay, clay minerals such as talc, and other composite oxides thereof.

The thickness of the laminated film of the present invention is preferably 0.01 mm or more from the viewpoint of film strength. Moreover, when using this laminated | multilayer film as a coating film of an agricultural and horticultural facility, from viewpoints of covering workability etc., 0.3 mm or less is preferable and the range of 0.03-0.25 mm is more preferable.

The method for producing the laminated film of the present invention is not particularly limited. When a resin composition containing a resin or additive is used as a material for forming each layer, the resin and the desired additive are mixed using a mixer to produce a resin composition, and the resin It can manufacture with a well-known film forming method using a composition. As the mixer, for example, a conventional apparatus such as a ribbon blender, a super mixer, a Banbury mixer, a single screw extruder, or a twin screw extruder can be used.

Examples of the method for producing the laminated film include a coextrusion inflation molding method, a coextrusion T-die casting molding method, an extrusion lamination molding method, and a dry lamination molding method. It is preferable to manufacture by a coextrusion inflation molding method. When the agricultural film of the present invention is produced by the coextrusion inflation molding method, it is preferable that the A layer is located outside the inflation tube. When a film is produced by inflation molding, a film is usually wound around a portion of the film extruded from an inflation die so as to be opened at the time of stretching. In the wound state, the inner layers of the tubular film are in contact with each other. When the film is spread on an agricultural and horticultural facility frame to be used as an agricultural or horticultural facility, the film is pulled out from the wound state, opened from the cut line, and spread on the agricultural and horticultural facility frame. Considering the workability at that time, it is preferable that the A layer is located outside the tube as described above.

  The laminated film of the present invention is suitable as an agricultural film, that is, a covering film for agricultural and horticultural facilities such as greenhouses and tunnels for plant cultivation. In particular, it is preferable that the layer A of the laminated film of the present invention is spread on an agricultural and horticultural facility frame so that the layer A is inside the agricultural and horticultural facility, thereby forming an agricultural and horticultural facility. Such agricultural and horticultural facilities are excellent in anti-fogging properties and are suitable for growing crops.

  Furthermore, the laminated film of the present invention can also be used for applications such as food packaging films that prevent adhesion of water droplets due to condensation caused by temperature differences inside and outside the film.

Examples of the present invention will be described below, but the present invention is not limited thereto. In addition, the test method in an Example and a comparative example is as follows.
<Drip performance evaluation method>
The film was affixed to a 34 × 5 cm acrylic frame with double-sided tape, the B layer surface was exposed to the outside air, the A layer surface was exposed to the water in the water tank, and the periphery was bonded with aluminum tape. The acrylic frame with the film fixed is placed on a thermostatic water bath placed in an environmental test chamber at 0 ° C. with an inclination of 15 degrees with respect to the horizontal plane, the water temperature is set to 40 ° C., and one week later The film droplet performance was determined according to the following criteria.
○: The film surface is uniformly wet.
Δ: Some water droplets are attached.
X: Water droplets adhere to the entire surface and are white and cloudy.

<Preparation of additive masterbatch>
Each resin and additive is weighed with the formulation shown in (1) and (2) below, kneaded at 150 ° C. for 5 minutes using a 5 L Banbury mixer, then granulated with a granulator, and then an additive master batch. Pellets MB1 to MB3 were obtained.
MB1 A3 / D1 = 75/25
MB2 A3 / C1 / F1 = 49/48/3
MB3 A3 / F1 / H1 = 95.6 / 4 / 0.4
The meanings of the abbreviations are as follows.
A3: Sumikasen F200-0 manufactured by Sumitomo Chemical Co., Ltd. (low density polyethylene)
C1: Lithium aluminum composite hydroxide (trade name: Mizukarak Mizusawa Chemical Co., Ltd.)
D1: Nonionic surfactant Product name Riquemar STR100 Made by Riken Vitamin (mixture with a melting point of 40-70 ° C: 95%, mixture with a melting point of less than 40 ° C: 5%)
F1: Hindered amine compound (trade name: Tinuvin 111FDL, manufactured by Ciba Specialty Chemicals)
H1: Fluorosurfactant (trade name: Yunidyne DS403, manufactured by Daikin Industries)

<Creation of pellet blend for film production>
According to the formulation shown in Table 1, each resin and MB1 to MB3 were dry blended.

<Production of agricultural film>
A three-layer inflation molding machine equipped with a 40 mm extruder for each layer, using a 100 mmφ die, 1.2 mm lip, and at a processing temperature of 180 ° C., the A layer is 20 μm, the C layer is 60 μm, and the B layer is 20 μm. A three-layer tube-shaped film was formed by adjusting the discharge amount from the die, and was cut open to obtain a three-layer laminated film. The inner layer of the tubular film was a B layer and the outer layer was an A layer.

[Evaluation]
The drop performance evaluation of each film was performed by the method described above. The results are shown in the table.

The abbreviations listed in the table are as follows.
A1: A1 pellet (ethylene / 1-hexene copolymer) described in Examples of JP2007-289147A
A2: A2 pellets (ethylene / 1-hexene copolymer) described in Examples of JP2007-289147A
A4: Sumikasen E FV203 manufactured by Sumitomo Chemical Co., Ltd. (ethylene / 1-hexene copolymer)
B1: Evertate H2020 (ethylene-vinyl acetate copolymer, MFR = 1, content of structural unit derived from vinyl acetate 15% by weight) Sumitomo Chemical Co., Ltd.

Claims (3)

A laminated film having at least three layers, all layers formed of an ethylene-based resin, one surface layer being an A layer, the other surface layer being a B layer, and the other being located between the A layer and the B layer When the layer of C is a C layer, the laminated film is characterized by satisfying all of the following conditions.
(1) The thickness of the C layer is 50% or more and 70% or less of the thickness of the laminated film.
(2) _CVA is greater than 5% and less than 8%
However, C _VA = {(total weight of structural units derived from vinyl acetate in ethylene / vinyl acetate copolymer contained in C layer) / (weight of C layer)} × 100
(3) A _VA is 4 % or more and 5% or less
However, A _VA = {(total weight of structural units derived from vinyl acetate in the ethylene / vinyl acetate copolymer contained in layer A) / (weight of layer A)} × 100
(4) B _VA is 0.3 % to 1%
However, B _VA = {(total weight of structural units derived from vinyl acetate in ethylene / vinyl acetate copolymer contained in B layer) / (weight of B layer)} × 100
(5) A _VA ≧ B _VA
(6) The nonionic surfactant concentration (wt%) having a melting point of 40 ° C. or higher in the laminated film is 1.6% or higher and 2.6% or lower. The laminated film according to claim 1 , which is an agricultural film. An agricultural and horticultural facility, wherein the agricultural and horticultural facility frame is spread so that the layer A of the agricultural film according to claim 2 is located inside the facility.