JPH0523186B2 - - Google Patents

Description

[Detailed description of the invention]

"Industrial Application Field" The present invention relates to an agricultural laminated film with excellent weather resistance, which is suitably used as a covering material or mulching material for agricultural greenhouses. "Prior Art" Conventionally, polyvinyl chloride films, polyolefin resin films such as polyethylene films and ethylene-vinyl acetate copolymer films have been used as covering materials for agricultural greenhouses, tunnel houses, etc. ``Problems to be solved by the invention'' Polyolefin resin films are chemically relatively stable, and their light transmittance does not change much even after long-term use, and harmful gases are generated when incinerated even when disposed of as scrap products. However, compared to vinyl chloride films, this film has the disadvantage that it is more susceptible to deterioration and tearing in the heat storage areas on or near the aggregate due to sunlight etc. when used outdoors as a covering. It was hot. "Means for Solving the Problems" The present inventors have discovered that polyolefin resin films are prone to breakage due to deterioration in heat storage areas on or near aggregates due to exposure to sunlight, etc. when used outdoors as a covering. In order to improve this drawback, as a result of extensive studies, we have discovered that this problem can be solved by using an ionomer resin with a zinc ion crosslinked structure, and have arrived at the present invention. That is, the gist of the present invention resides in an agricultural laminated film in which an ionomer resin layer having a zinc ion crosslinked structure is laminated on at least one side of a polyolefin resin layer. The present invention will be explained in detail below. The polyolefin resin layer in the present invention is α
-Constructed from a homopolymer of olefin or a copolymer containing α-olefin as a main component with other monomers. For example, low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, polypropylene, ethylene-
Vinyl acetate copolymer, ethylene-propylene copolymer, ethylene-butylene copolymer, ethylene-
Ethyl methacrylic acid copolymer, ethylene-acrylic acid copolymer, etc. can be used. Further, the polyolefin resin layer in the present invention may be a single polyolefin resin layer or may be composed of two or more types of resin layers. In addition, if necessary, antifogging agents, heat insulating agents, ultraviolet absorbers, light immersion stabilizers, antioxidants, colorants, antistatic agents, antifungal agents, and algae inhibitors can be blended, applied, or included. . The amount of these additives used is preferably 5 parts by weight or less per 100 parts by weight of the polyolefin resin. The ionomer resin in the present invention is preferably a copolymer of ethylene and methacrylic acid in which the proportion of methacrylic acid is 1 to 5 mol %. Further, the ionomer resin used in the present invention must have a zinc ion crosslinked structure. Density is 0.935g/ ^cm3 or more, 0.975g/ ^cm3 or less, melt index is 0.5g/15g/10 minutes or more
It is preferable that the time is 10 minutes or less. Furthermore, the ionomer resin layer used in the present invention contains 0.05 to 5 parts by weight of an ultraviolet absorber and/or 0.05 to 5 parts by weight of a hindered amine light stabilizer based on 100 parts by weight of the resin, so that it can be used outdoors. , it is possible to more effectively prevent tearing due to deterioration of the heat storage section. Further, if necessary, an antifogging agent, a heat insulating agent, an antioxidant, a coloring agent, an antistatic agent, an antifungal agent, an antialgae agent, and the like can be blended, applied, or impregnated. The amount of these additives used is preferably 5 parts by weight or less per 100 parts by weight of the ionomer resin. Examples of compounds that can be used as ultraviolet absorbers for the ionomer resin layer having a zinc ion crosslinked structure include the following. As a benzotriazole ultraviolet absorber,
2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, 2
-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole,
2-(2'-hydroxy-3'-tert-amyl-5'-isobutylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3'-isobutyl-
5'-methylphenyl)-5'-chlorobenzotriazole, 2-(2'-hydroxy-3'-isobutyl-5'-propylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy3', 5'-G-
tert-butylphenyl)benzotriazole, 2
-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-5'(1,
Examples include 1,3,3-tetramethylbutyl)phenyl)benzotriazole. As a benzophenone ultraviolet absorber, 2,
2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2'4,4'-tetrahydroxybenzophenone, 2-hydroxy-4- Examples include methoxybenzophenone, 2,4-dihydroxybenzophenone, and 2-hydroxy-4-octoxybenzophenone. Examples of salicylic acid-based ultraviolet absorbers include phenyl salicylate and paraoctylphenyl salicylate. The above ultraviolet absorbers can be used alone or in combination of two or more. Among those exemplified above, benzotriazole-based ultraviolet absorbers and benzophenone-based ultraviolet absorbers are particularly preferred, and the blending amount is preferably 0.1 to 3 parts by weight per 100 parts by weight of the ionomer resin. As a light stabilizer, 4-acetoxy-2,2,
6,6-tetramethylpiperidine, 4-stearoyloxy-2,2,6,6-tetramethylpiperidine, 4-acryloyloxy-2,2,6,
6-tetramethylpiperidine, 4-(phenylacetoxy)-2,2,6,6-tetramethylpiperidine, 4-(phenylacetoxy)-2,
2,6,6-tetramethylpiperidine, 4-cyclohexanoyloxy-2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,
2,6,6-tetramethylpiperidine, 4-(o
-chlorobenzoyloxy)-2,2,6,6-
Tetramethylpiperidine, 4-(m-chlorobenzoyloxy)-2,2,6,6-tetramethylpiperidine, 4-(p-chlorobenzoyloxy)
-2,2,6,6-tetramethylpiperidine, 4
-(o-toluyloxy)-2,2,6,6-tetramethylpiperidine, 4-isonicotinoyloxy-2,2,6,6-tetramethylpiperidine,
4-(2-furoyloxy)-2,2,6,6-tetramethylpiperidine, 4-(β-naphthoyloxy)-2,2,6,6-tetramethylpiperidine, bis(2,2,6, 6-tetramethyl-4-
piperidyl) oxalate, bis(2,2,6,
6-tetramethyl-4-piperidyl)malonate, bis(2,2,6,6-tetramethyl-4-
piperidyl) adipate, bis(2,2,6,6
-tetramethyl-4-piperidyl) sebacate,
Bis(2,2,6,6-tetramethyl-4-piperidyl) fumarate, bis(2,2,6,6-tetramethyl-4-piperidyl)hexahydrophthalate, bis(2,2,6,6- Tetramethyl-
4-piperidyl) terephthalate, tris(2,
2,6,6-tetramethyl-4-piperidyl)benzene 1,3,5-tetricarboxylate, tris(2,2,6,6-tetramethyl-4-piperidyl)triazine-2,4,6-tri carboxylate, tris(2,2,6,6-tetramethyl-4-piperidine)nitrilotriacetate,
tris(2,2,6,6-tetramethyl-4-piperidyl)butane-1,2,3-tricarboxylate, tetrakis(2,2,6,6-tetramethyl-4-piperidyl)propane-1, 1, 2,
3-tracarboxylate, tetrakis(2,
2,6,6-tetramethyl-4-piperidyl)butane-1,2,3,4-tetracarboxylate, tetrakis(2,2,6,6-tetramethyl-4-piperidyl)propane-1,1, 3,3-
Tetracarboxylate, tetrakis (2,2,
6,6-tetramethyl-4-piperidyl)ethene-1,1,2,2-tetracarboxylate, tris(2,2,6,6-tetramethyl-4-piperidyl)-2-acetoxypropane-1, 2,3
-tricarboxylate, tris(2,2,6,
Examples include 6-tetramethyl-4-piperidyl)-2-hydroxypropane-1,2,3-tricarboxylate. The blending amount of these light stabilizers is preferably 0.05 to 3 parts by weight per 100 parts by weight of the ionomer resin. The agricultural laminated film of the present invention can be manufactured according to a conventional method. For example, using inflation molding or T-die molding, each resin is fed from separate extruders into a single die, and then laminated and integrated inside or outside the die, a so-called co-extrusion method. Alternatively, a method in which an isocyanate resin or the like is applied, the solvent is evaporated through a drying oven, the film to be laminated is layered on top of the film, and the film is laminated by pressure bonding under heat.
Polyolefin resin is extruded into a film using the T-die method, and while the film is still in a molten state,
Examples include a method in which the resin film is laminated by flowing it down onto another resin film coated with an adhesive, if necessary, and immediately passing it between rolls. In the present invention, it is particularly preferable to mold by coextrusion because it is easy to mold and provides a film with excellent adhesive strength, transparency, etc. "Examples" Hereinafter, the present invention will be described in detail based on Examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof. Examples 1 to 4, Comparative Examples 1 to 5 Pellet A: Low density polyethylene composition Low density polyethylene (Mitsubishi Chemical Industries, Ltd., trade name Novatek-LF-161) 100 parts by weight surfactant (pentaerythritol monostearate) 2 parts by weight The above composition A was mixed with a Henschel mixer, cooled, kneaded using a co-kneader manufactured by Buss, and extruded at a temperature of 170°C.
Made into pellets. Pellet B: Ionomer resin with Zn ion cross-linked structure (Mitsui Polychemical Co., Ltd. trade name: Himilan)
1706) Commercial product pellet C; ethylene-vinyl acetate copolymer (hereinafter abbreviated as EVA) composition EVA (Mitsubishi Yuka Co., Ltd. trade name Yucalon Eva V-
403E) 100 parts by weight Silicon dioxide (Nippon Aerosil Co., Ltd. trade name Aerosil OX-50) 20 parts by weight The composition of C above was mixed in a Henschel mixer, cooled, and then kneaded using a co-kneader manufactured by Buss. It was extruded and pelletized at a temperature of 170°C. Pellet D: Ionomer resin composition with Zn ion crosslinked structure Ionomer resin with Zn ion crosslinked structure (same as pellet B) 100 parts by weight Surfactant 4 (pentaerythritol monopalmitate) 2 parts by weight UV absorber (2-hydroxy- 4-methoxybenzophenone) 0.2 parts by weight Light stabilizer (bis-(2,2,6,6-tetramethyl-4-piperidyl) sebacate) 0.5 parts by weight The composition of D above was mixed in a Henschel mixer, After cooling, the mixture was kneaded using a co-kneader manufactured by Busu Co., Ltd., and extruded into pellets at a temperature of 170°C. Pellet E: Ionomer resin composition with Na ion cross-linked structure Instead of the ionomer resin with Zn ion cross-linked structure used in Pellet D, an ionomer resin with Na ion cross-linked structure (Mitsui Polychemical Co., Ltd. trade name Himilan 1555) was used. Pellets were made with the same composition and under the same processing conditions. Example 1 Pellet A was extruded using a 50 mmφ extruder, and pellet B was extruded using a 40 mmφ extruder at 200 to 210°C, and fed to a composite inflation die for two-layer coextrusion to form a 0.1 m/m thick extruder. A two-layer film with a width of 100 cm was obtained. The ratio of pellet A layer to pellet B layer was approximately 4:1. Comparative Example 1 Pellet E was used instead of pellet B in Example 1, and the same processing method was used to produce a pellet with a thickness of 0.1 m/m (width 100 cm).
A two-layer film was obtained. The ratio of pellet A layer to pellet E layer was approximately 4:1. Example 2 Pellet A was made using a 40mmφ extruder, pellet C was made using a 50mmφ extruder, and pellet B was made into 30mmφ extruder.
Using an extruder, extrude each layer at 200 to 210℃, and feed it to a composite inflation die for three-layer coextrusion so that the 50mmφ extruder becomes the middle layer to a thickness of 0.1m/m (width
A three-layer film of 100 cm) was obtained. The thickness ratio of the pellet A layer, the pellet C layer, and the pellet B layer was 1:4:1. Example 3 Pellet D was used instead of pellet B in Example 2, and a thickness of 0.1 m/m (width 100 cm) was made using the same processing method.
A three-layer film was obtained. The thickness ratio of the pellet A layer, pellet C layer, and pellet D layer is 1:4:1
And so. Comparative Example 2 Pellet E was used instead of Pellet B in Example 2, and a thickness of 0.1 m/m (width 100 cm) was made using the same processing method.
A three-layer film was obtained. The thickness ratio of the pellet A layer, the pellet C layer, and the pellet E layer is 1:4:
It was set as 1. Example 4 Two types of three-layer films were obtained using pellets D in place of pellets A and B in Example 2 and using the same processing method. The ratio of the pellet D layer to the pellet C layer to the pellet D layer was 1:4:1. Comparative Example 3 Commercially available 0.1 m/m polyethylene film (Sekisui Chemical Co., Ltd. Noh Poly) Comparative Example 4 Commercially available 0.1 m/m EVA film (Mitsubishi Yuka Co., Ltd. Noh Sakubi) Comparative Example 5 Commercially available 0.1 m/m polyolefin Multilayer film (Sekisui Chemical Co., Ltd., trade name: Vegitalon) The following characteristics of the above-mentioned multilayer film and single-layer film were investigated and are shown in Table 1. <Weather resistance> The test film was spread out in each pipe house (3.6 m wide, 9 m long) installed in a field in Isshibe, Mie Prefecture. It was deployed for 12 months from March 1959 to March 1960, and weather resistance (breakage due to deterioration on or near the pipe) was visually observed every three months. The evaluation results of "weather resistance" each have the following meanings. ○…No change ○×…Hardening phenomenon is observed on the pipe, but no tear △…Small tear on or near the pipe ×…Large tear on or near the pipe

[Table] "Operations and Effects" As is clear from the Examples and Comparative Examples, the agricultural laminated film of the present invention, which is formed by laminating an ionomer resin layer with a zinc ion crosslinked structure on at least one side of a polyolefin resin film, is similar to ordinary polyolefin resin films. Compared to agricultural films made of resin films, this product greatly reduces and improves tearing caused by deterioration of heat storage areas on or near aggregates when used outdoors, making it highly conducive to agriculture.

Claims (1)

[Claims] 1. An agricultural laminated film comprising a polyolefin resin layer and an ionomer resin layer having a zinc ion crosslinked structure laminated on at least one side of the polyolefin resin layer. 2. Claim 1, characterized in that the ionomer resin layer contains 0.05 to 3 parts by weight of an ultraviolet absorber and/or 0.05 to 3 parts by weight of a hindered amine light stabilizer based on 100 parts by weight of the resin. Agricultural laminated film.