JPH08118567A - Agricultural laminated film - Google Patents

Abstract

PURPOSE: To obtain excellent heat insulation, blocking resistance and transparency by an agricultural laminated film in which a front surface layer contains olefin composition which contains specific wt.% of lithium-aluminum composite hydrixide salt represented by the general formula (I) of a laminated film and an olefin polymer and an inner layer contains olefin copolymer. CONSTITUTION: A laminated film comprises a front surface layer formed of olefin composition containing 1 to 25wt.% of lithium-aluminum composite hydroxide salt represented by the general formula (in the formula, X is inorganic or organic anion, n is valence number of anion X and m is 3 or less) and 75 to 99% of olefin polymer A, and an inner layer formed of olefin copolymer B. An agricultural laminated film contains olefin polymer A having ethylene sole polymer having a density of 0.91 to 0.935g/cm<3> , ethylene-α-olefin copolymer having a density of 0.89 to 0.935g/cm<3> and/or ethylene-vinyl acetate copolymer having a density of 0.92 to 0.95g/cm<3> and less than 20wt.% of vinyl acetate content.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to agricultural laminated films. More specifically, it relates to an agricultural laminated film having excellent heat retention, blocking resistance and transparency.

2. Description of the Related Art A large amount of plastic film is used as a covering material for agricultural houses and tunnels,
Typical examples include vinyl chloride polymer film (hereinafter abbreviated as “agricultural vinyl”), ethylene polymer film (hereinafter abbreviated as “agricultural poly”), ethylene vinyl acetate copolymer film (hereinafter abbreviated as “agricultural vinyl acetate”), and the like. Among them, agricultural vines are excellent in heat retention, transparency, toughness, antifogging property, house adhesion, and economical efficiency, and are most often used. However, in agricultural products, the plasticizer contained in the film bleeds out on the surface and stickiness occurs, resulting in workability,
Problems such as dustproofness and generation of harmful gas at the time of disposal by incineration are occurring, and alternatives thereof are desired. Agricultural poly and agricultural vinegar do not contain a plasticizer in the film and the chemical structure is stable, so the transparency does not decrease even during long-term use, and no harmful gas is generated when incinerated. However, it has a problem that it does not have better heat retention than the farm.

Generally, heat retention is a characteristic of an agricultural house covering material for preventing a temperature decrease in a greenhouse at night, and heat absorbed in the ground in the agricultural house during the daytime is grounded at night. As radiation is emitted from the
Keeping the temperature inside the agricultural house high. Therefore, the greater the heat transmission rate of the agricultural house covering material, the more the heat inside the agricultural house is dissipated to the outside of the agricultural house. It becomes impossible to keep the temperature inside the house higher than the outside air. Therefore, the heat-retaining property of the film used for the agricultural house coating material depends on the heat transmittance.
The lower the rate, the better.

[0003] Generally, the blocking resistance of the film is better in agricultural poly and agricultural vinegar than in agricultural plastic, but even in the case of agricultural poly and agricultural vine, thermal fusion occurs under high temperature conditions in summer and peeling is impossible. Therefore, since problems occur in the spreading work and the ventilation work, there has been a demand for agricultural plastics and agricultural vinegar having more excellent blocking resistance.

[0004]

DISCLOSURE OF THE INVENTION The inventors of the present invention have conducted various studies in order to obtain an agricultural laminated film which is excellent in heat retention, blocking resistance, transparency and the like. As a result, a laminated film using an olefin composition containing a specific lithium-aluminum composite hydroxide salt for the surface layer and an olefin polymer for the inner layer had excellent heat retention, blocking resistance and transparency. The present invention was completed based on this finding by finding out that it becomes a film.

[0005]

The present invention has the following constitution. (1) In the laminated film, the surface layer is an olefin composition comprising 1 to 25% by weight of a lithium-aluminum composite hydroxide salt represented by the following general formula (I) and 75 to 99% by weight of an olefin polymer (A). And an agricultural laminated film using an olefin copolymer (B) as an inner layer. [Al ₂ Li (OH) ₆ ] _n X · mH ₂ O (I) In the formula, X is an inorganic or organic anion, n is the valence of the anion X, and m is 3 or less. (2) ethylene homopolymer of the olefin polymer according to Item 1, wherein (A) the density 0.91~0.935g / cm ^3, ethylene density 0.89~0.935g / cm ³ ·
α-olefin copolymer and / or density is 0.92
The laminated film for agriculture according to the above 1, which is an ethylene / vinyl acetate copolymer having a vinyl acetate content of 0.95 g / cm ^{3 and a} vinyl acetate content of less than 20% by weight. (3) ethylene homopolymer of the olefin polymer of item 1, wherein (B) the density 0.91~0.935g / cm ^3, ethylene density 0.89~0.935g / cm ³ ·
α-olefin copolymer and / or density is 0.92
0.95 g / cm ^{3 and} vinyl acetate content 10-2
1 which is 0% by weight of ethylene-vinyl acetate copolymer
The agricultural laminated film according to the item.

Hereinafter, the present invention will be described in detail. The olefin polymer (A) and the olefin polymer (B) include α
An olefin homopolymer or a copolymer containing α-olefin as a main component, such as ethylene homopolymer, propylene homopolymer, ethylene / propylene copolymer, ethylene / butene copolymer, ethylene-4- Examples thereof include methyl-1-pentene copolymer, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, and ionomer. Among the olefin polymers, the olefin polymer (A) has a density of 0.91 to 0.935 g / cm 3.
³ , ethylene homopolymer, density 0.89-0.935g
/ Cm ³ of ethylene-alpha-olefin copolymer and / or density of 0.92～0.95G / cm ³ and a vinyl acetate content is less than 20% by weight of ethylene-vinyl acetate copolymer. The olefin polymer (B) in the ethylene homopolymer having a density 0.91~0.935g / cm ^3, the ethylene density 0.89~0.935g / cm ³ ·
α-olefin copolymer and / or density is 0.92
0.95 g / cm ^{3 and} vinyl acetate content 10-2
0% by weight of ethylene / vinyl acetate copolymer is preferred.

The ethylene homopolymer and ethylene / α-
The method for producing an olefin copolymer is as follows: ethylene or 1-butene and 1
-A method of obtaining at least one α-olefin selected from the group such as hexene by a high pressure method can be exemplified. Melt flow rate of these olefin polymer (A) and olefin polymer (B) [190 ° C; 21.18N] (hereinafter MFR
Abbreviated. ) Is not limited, but when the film molding method is an inflation method, 0.5)
It is preferably about 2 to 10 g / 10 min in the case of the T-die method. The general formula of the lithium-aluminum composite hydroxide salt used in the present invention is [Al ₂ Li (OH) ₆ ] _n X.mH ₂ O where X is an inorganic or organic anion, and n is an anion X. It is desirable that m is a number of 3 or less, and that the lithium-aluminum composite hydroxide salt has an average particle size of 0.1 to 5 μm and a BET specific surface area of 50 m ² / g or less. The lithium-aluminum composite hydroxide salt is produced by a known production method.

The content of the lithium-aluminum composite hydroxide salt in the olefin composition is 1 to 25% by weight, preferably 2 to 20% by weight. For the purpose of improving the heat retaining property, another heat retaining agent such as a hydrotalcide compound, a silicic acid compound, an aluminosilicic acid compound or an aluminic acid compound can be added to the inner layer within a range not impairing the object of the present invention. In addition, a stabilizer, an ultraviolet absorber, a hindered amine weathering agent, a lubricant, an antifogging agent, an antifog agent or other various additives are added to the olefin composition and the olefin polymer (B) within a range not impairing the object of the present invention. It can be blended. The method for obtaining the agricultural laminated film of the present invention,
The inflation method, the T-die method, etc. can be illustrated. The thickness of the agricultural laminated film is 0.05 to 0.2.
It is preferably 0 mm. Further, if necessary, a dustproof coating agent or the like may be applied to the surface of the agricultural laminated film and dried to form a film on the surface.

[0009]

EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. The properties used in the following examples and comparative examples were evaluated by the following methods. (1) The heat retention is determined by the temperature difference in the heat retention test between the standard sample (100 μm thick polyvinyl chloride film for agriculture (trade name: Kumiai vinyl “High hit Kirisaraba”; manufactured by Chisso Corporation)) and the sample. Thermal insulation test: A box in which one surface is opened using a heat insulating material (15 cm thick styrofoam) on five surfaces (outer dimensions:
180 × 90 × 60 cm, opening: 150 × 90 cm)
Then, insert a heating block of 50 ° C. inside, immediately close the box with a sample (film having a thickness of 100 μm) on one side that is open, and leave it at room temperature for 1 hour, and then measure the temperature inside the box. .

(2) The transparency (definition) of the film is JI
The haze value was measured using a haze meter in accordance with SK-7105 and used as the scale. (3) Transparency (brightness) is based on JIS K-71
The total light transmittance was measured using a haze meter in accordance with 05 and used as the scale. (4) Blocking property was obtained by cutting the film into 5 × 10 cm, attaching water to the cut pieces and stacking them, and
Apply a load of cm ² , leave it in a constant temperature bath at 80 ° C for 2 hours,
The film taken out after that was left in a constant temperature room at 23 ° C. for 2 hours, then peeled by a tensile tester, and the load required for it was measured and used as a scale.

Example 1 Two-kind three-layer T-die (lip width 1200 mm) having a 50 mm extruder for the surface layer and a 90 mm extruder for the inner layer
Using an apparatus, ethylene-vinyl acetate copolymer having a vinyl acetate content of 15% by weight (MFR = 2.5 g / 10 mi
n, density = 0.94 g / cm ³ ) 90.5% by weight, lithium-aluminum composite hydroxide salt [compositional formula Al ₂ L
i (OH) ₆ (Co ₃ ) .1.6H ₂ O, average particle size 0.
2 μm, BET specific surface area 25 m ² / g; Mizusawa Chemical Co., Ltd.
8% by weight of trade name "Mizucarac"] and 0.5% by weight of glycerin monostearate as an antifogging agent, 0.5% by weight of polyglycerin monostearate and 0.5% by weight of diglycerin monolaurate. % Of the composition was blended in a 50 mm extruder with an ethylene / vinyl acetate copolymer having a vinyl acetate content of 15% by weight (MFR = 2.5 g / 1
0 min, density = 0.94 g / cm ³ ) 98% by weight,
And polyglycerin monostearate as an antifogging agent 1.
A composition containing 0% by weight, 0.5% by weight of glycerin monostearate, and 0.5% by weight of diglycerin monolaurate was supplied to a 90 mm extruder to form an inner layer of 70 μm and a surface layer of 15 μm with a total thickness of 100 μm. A two-kind three-layer film was obtained. The characteristics of this film are shown in Table 1.

Example 2 In place of the ethylene / vinyl acetate copolymer used in the composition fed to the 50 mm extruder in Example 1, low density polyethylene (density = 0.925 g / cm ³ , MFR =
The same procedure as in Example 1 was carried out except that 2.0 g / 10 min) was used to obtain a two-kind three-layer film. The characteristics of this film are shown in Table 1. Example 3 Instead of the ethylene / vinyl acetate copolymer used in the composition fed to the 90 mm extruder in Example 1, low density polyethylene (density = 0.925 g / cm ³ , MFR =
A two-kind three-layer film was obtained in the same manner as in Example 1 except that 2.4 g / 10 min) was used. The characteristics of this film are shown in Table 1. Example 4 Instead of the ethylene / vinyl acetate copolymer used in the composition fed to the 50 mm extruder in Example 1, low density polyethylene (density = 0.925 g / cm ³ , MFR =
2.0 g / 10 min) instead of the ethylene / vinyl acetate copolymer used in the composition fed to the 90 mm extruder, low-density polyethylene (density = 0.925 g / cm ³ ,
A two-kind three-layer film was obtained in the same manner as in Example 1 except that MFR = 2.4 g / 10 min) was used. The characteristics of this film are shown in Table 1.

Comparative Example 1 Instead of the lithium-aluminum composite hydroxide salt used in the composition fed to the 50 mm extruder in Example 1, a hydrotalcite compound [compositional formula Mg _0.7 Al _0.3
(OH) ₂ (Co ₃ ) _0.15 / 0.55H ₂ O, average particle size 0.3 μm, BET specific surface area 14 m ² / g; Kyowa Chemical Co., Ltd., trade name “DHT-4”] Was performed in the same manner as in Example 1 to obtain a two-kind three-layer film. The characteristics of this film are shown in Table 1. Comparative Example 2 Same as Example 1 except that silicon oxide powder (average particle size 0.6 μm) was used instead of the lithium-aluminum composite hydroxide salt used in the composition fed to the 50 mm extruder in Example 1. Then, a two-kind three-layer film was obtained. The characteristics of this film are shown in Table 1. The characteristics of this film are shown in Table 1.

[0014]

INDUSTRIAL APPLICABILITY The agricultural laminated film of the present invention exhibits excellent effects such as heat retention, blocking resistance and transparency, and is extremely useful as an agricultural coating material for agricultural houses and tunnels.

[0015]

[Table 1]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location B32B 27/28 101 9349-4F C08K 3/10 KAC

Claims (3)

[Claims] 1. A laminated film comprising a lithium-aluminum composite hydroxide salt represented by the following general formula (I) in an amount of 1 to 1: 1.
An agricultural laminated film using an olefin composition comprising 25% by weight and an olefin polymer (A) of 75 to 99% by weight as a surface layer and an olefin copolymer (B) as an inner layer. [Al ₂ Li (OH) ₆ ] _n X · mH ² O (I) In the formula, X is an inorganic or organic anion, n is the valence of the anion X, and m is 3 or less. Wherein the ethylene homopolymer of the olefin polymer of claim 1 wherein (A) the density 0.91~0.935g / cm ^3, the density of 0.89~0.935g / cm ³ ethylene · alpha- Olefin copolymer and / or density is 0.92-
An ethylene / vinyl acetate copolymer having a content of 0.95 g / cm ^{3 and a} vinyl acetate content of less than 20% by weight.
The agricultural laminated film described. Wherein the ethylene homopolymer of the olefin polymer of claim 1 wherein (B) the density 0.91~0.935g / cm ^3, the density of 0.89~0.935g / cm ³ ethylene · alpha- Olefin copolymer and / or density is 0.92-
0.95 g / cm ^{3 and} vinyl acetate content 10-2
The agricultural laminated film according to claim 1, which is 0% by weight of an ethylene / vinyl acetate copolymer.