JPS58160146A - Agricultural film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an agricultural film with good droplet flow properties. More specifically, agricultural linear low density polyethylene (Line
ar Low Density Polyethylene
ne,) hereinafter referred to as L-LDPE) film.

Traditionally, polyvinyl chloride film, polyethylene film, and ethylene film were used for greenhouse cultivation such as agricultural greenhouses and tunnels.
Vinyl acetate film or the like is used as a covering material.

In recent years, L-LDPE, a type of polyethylene, has been used as a covering material, and this L-LDPE film has begun to be used in the field of agricultural covering materials due to its excellent tear strength, impact strength, and stiffness. When the L-LDPE film is used as a covering material, water in the soil condenses and forms water droplets on the film surface, which impairs the transmission of light into the greenhouse tunnel and has a negative impact on crop growth. Problems have arisen due to the poor droplet properties of so-called non-films, such as condensed water droplets falling off and becoming a source of pests that damage crops. Methods for improving the droplet flow properties of L-LDPE films include (1) copolymerizing a vinyl compound such as vinyl acetate or acrylic acid to impart droplet properties, or (2) adding a surfactant to the L-LDPE film. or (3) mixing L-tDPE with a surfactant to form a film. However, although the method (1) of forming a copolymer improves the droplet flow properties slightly, it is still insufficient, and some improvement in the droplet flow properties is required.

In addition, in the method (2) of applying a surfactant, the droplet flow property is good at the beginning of application, but the droplet flow property disappears after a few days due to the surfactant being washed away or diffused. It is necessary to reapply the surfactant each time it disappears. Furthermore, the method (3) of mixing a surfactant to form a film has problems such as poor compatibility between L-LDPE and the surfactant and droplet flow lasting only for a short period of time.

An object of the present invention is to obtain an agricultural L-LDPE film that has good droplet flow properties and maintains the droplet flow properties for a long period of time.

As a result of intensive studies on agricultural L-LDPE lyme with good droplet flow, the inventors found that by providing a resin layer containing a surfactant on one side of the L-LDPE film, the droplet flow was substantially improved. The present inventors have surprisingly found that the droplet flow properties are maintained for a long period of time, and have completed the present invention.

That is, according to the present invention, a base material layer mainly composed of L-LDPE, a material having compatibility with the base material layer and a Bo
An agricultural film is obtained, which is characterized in that layers made of resin containing oi to 8 parts by weight of a surfactant are formed in a multilayered manner (i.e., laminated).

Although it is necessary that the agricultural film of the present invention has a base layer mainly composed of L-LDPE, it is of course possible that the base layer is composed of L-LDPE alone.

L-LDPE, which is used as the main material of the base material layer, is a type of low-density polyethylene), which is composed of ethylene, 1-butene, 1
-It is a copolymer with α-olefin such as octene. L
- In LDPE, the main chains are connected almost linearly, and because side chains of alkyl groups based on copolymerized α = niolefin are attached here and there, L-LDPE has higher tear strength than conventional low-density polyethylene. Excellent impact strength, waist strength, etc.

Although any L-LDPE can be used in the present invention, those having a density of 0.900 to 0.9358/cm' and a melt index of 0.1 to 15 f/10 minutes are preferred. In addition, the density and melt index of L-LDPH are JI
Measured according to SK-6760 (polyethylene test method) (density: JISK-7112, melt index: Bs K-7210 applied mutatis mutandis).

In addition, resins blended with L-LDPE used as the main material of the base material layer include polyethylenes such as low density polyethylene, medium density polyethylene, and high density polyethylene, ethylene-vinyl acetate copolymer, ethylene-a-
Examples include olefin copolymers and polypropylene, which may be used alone or in combination of two or more. L-L
By blending these resins with DPE, 9L-
When using LDPE alone, it is possible to suppress the buildup of additives normally added to polyolefin resins, such as antioxidants such as phenol derivatives and ultraviolet absorbers such as benzotriazole derivatives, and to suppress the build-up of additives that are usually added to polyolefin resins, such as antioxidants such as phenol derivatives, and ultraviolet absorbers such as benzotriazole derivatives. Favorable results such as improved compatibility may be obtained.

In cases where there is a problem when using L-LDPE alone as a base material layer, it is preferable to blend these resins with L-LDPH.

The amount of resin blended into L-LDPE is preferably equal to or less than the amount of L-LDPE. When a resin such as polyethylene is blended in an amount exceeding the amount of L-LDPR, the excellent properties of L-LDPE will rapidly weaken and the properties of the base layer will become close to those of the blended resin. I end up.

The thickness of the base material layer is preferably 5 to 200 microns.

In addition, when making a sheet-like film, the base material layer has a thickness of 200 μm.
Of course, there may be more than one. Note that the base material layer is 5μ
If it is less than that, the strength will be substantially insufficient and it will not function as a base material.

The resin containing the surfactant is preferably a resin that is compatible with the L-LDPE layer. Particularly preferred resins include polyethylenes such as low-density polyethylene, high-density polyethylene, and medium-density polyethylene, ethylene-vinyl acetate copolymers, ethylene-α-olefin copolymers, and ionomer resins. "Compatible" here means that when the L-LDPE layer and the resin layer containing a surfactant are laminated, they have adhesive properties to the extent that they do not peel off from each other, and the resin of both layers There is no requirement for such solubility that the substances are uniformly mixed together.

The thickness of the resin layer containing the surfactant is suitably 5 to 200 microns, preferably 5 to 100 microns.

The thicker the surfactant-containing resin layer, the better the persistence of droplet properties, but if it is too thick, problems arise, such as impairing the properties of the base layer. It is better if it is approximately the same thickness or thinner than the base material layer.

The surfactant used in the present invention may be an anionic, cationic, nonionic or amphoteric surfactant as long as it can provide droplet properties. Examples include (a) anionic surfactant sodium nilauryl phosphate;
V such as polyoxyethylene-sodium lauryl phosphate
sulfonic acid esters, sodium lauryl sulfate, sulfuric acid esters such as sodium salt of sulfated oleic acid, sulfonic acid salts such as sodium stearyl sulfonate, triethanolamine salt of dodecylbenzenesulfonate, sodium salt of dioctyl sulfosuccinate, etc. etc.) Quaternary ammonium salts such as cationic foreign activator nilauryltrimethylammonium chloride, N,N-dimethyl-N-(hydroxyethyl)-3-(stearoami)'')-7''ropylammonium nitrate, 2-
Imidacillin derivatives such as octadecyl-1-(hydroxyethyl)-2-imidacilline, N,N-diethyl-(
79 Nonionic surfactants: ethers of polyethylene glycol such as polyethylene glycol nonyl fer ether and polyethylene glycol stearyl ether,
Carboxylic acid esters of polyethylene glycol such as polyethylene glycol stearate and polyethylene glycol dilaurate, partial carboxylic acid esters of polyhydric alcohols such as glycerin monostearate, sorbitan monopalmitate, and sorbitan tristearate, and polyesters of sorbitan monostearate. oxyethylene derivatives, polyoxyethylene derivatives of partial carboxylic acid esters of polyhydric alcohols such as polyoxyethylene derivatives of sorbitan monolaurate, N,N-di(hydroxyethyl)-laurylamide), N-(2-hydroxy Amide derivatives such as propyl)-stearoamide, block copolymers of polyethylene oxide and polypropylene oxide, etc. → Ampholytic surfactants 2N-lauryl-3-iminodipropionic acid and its sodium salt, N-carboxymethyl-N,N -dimethyl=i≠≠m -'pJ -Betaine compounds such as dodecylammonium hydroxide, 2-; rphtadecyl-1-(hydroxyethyl)-2
Examples include imidacillin sulfate ester, 2-dodecyl-1-carboxymethyl-1-(hydroxyethyl)-2-imidazolinium hydroxide, and imidacillin derivatives of the same metal salts such as sodium and calcium. . These can be used alone or in combination of two or more.

The amount of surfactant to be used is suitably 0.01 to 8 parts by weight, preferably 0.1 to 5 parts by weight, per 100 parts by weight of the resin containing the surfactant. If the amount used is less than 0.01 part by weight, droplet flowability may not be obtained, or even if it is obtained, the droplet flowability is insufficient, and the droplet flowability may be lost within a few days. Moreover, if the amount used exceeds 8 parts by weight, problems such as devitrification of the film and peeling of the two laminated layers occur.

Conveniently, the surfactant is added during the compounding process. Further, any method for adding the surfactant can be used as long as it can be uniformly dispersed. The agricultural film of the present invention requires a base material layer and a resin layer containing a surfactant to be formed in a multilayer manner, and the method for manufacturing this agricultural film involves inflation processing each resin, T. - A method of laminating a film formed by a normal processing method such as goo processing using dry lamination or heat lamination, a method of extrusion laminating a resin layer containing a surfactant on an L-LDPE film,
By double layer extrusion method! +, There are already known methods such as a method of simultaneously extruding a L-LDPE layer and a resin layer containing a surfactant to form a film, and any of these methods can be used.

When a resin layer containing a surfactant is provided on one side of the base film as in the present invention, droplet flow properties can be obtained only on the required surface, and surprisingly, the droplet flow properties can be maintained for a long period of time, which is advantageous.

Furthermore, the agricultural film of the present invention has the advantage of having excellent properties such as tear strength, impact strength, and stiffness that L-LDPE films have.

The following examples illustrate the usefulness of the present invention.

These examples are illustrative and do not limit the scope of the invention.

Examples of production of the agricultural film of the present invention are shown in Examples, and the first
Tables 5 to 5 show the test results of droplet flow properties of the obtained films.

Table 1 shows droplet flow test results for films with different surfactant-containing resins↓, Table 2 shows L-LDPE
Table 3 shows the droplet flow test results for films in which the resin of the base material layer, which is mainly composed of 2) Table 4 shows the test results of the droplet properties of films with different amounts of surfactant added, and Table 4 shows the test results of the droplet properties of films with different types of surfactants used.

Furthermore, for comparison, Table 5 shows a film containing no surfactant at all (Comparative Example 1), a film in which a surfactant is simply kneaded into L-LDPE (Comparative Example 2), and a commercially available agricultural film. The test results of droplet properties of films sold as droplet type films (Reference Examples 1 to 3) are shown.

The droplet properties shown in Tables 1 to 5 were determined by the following test method.

■ Low-temperature sustained droplet flow (5°C method) Put 200 mt of 5°C water in a 300 mt beaker,
Cover with a sample film with the surface of the resin containing the surfactant facing inside. Place this beaker in a water reservoir maintained at 5°C and submerge it to the level of the water surface of the beaker. The beaker and water reservoir are placed in a thermostatic chamber kept at 0° C., and the droplet flow properties of the film are observed after a predetermined period of time.

■ Continuous droplet flow of hot water (50℃ method) 300mt Heater K Pour 200m of hot water at 50℃ and cover with a sample film with the surface of the resin containing surfactant inside. This beaker is immersed in a hot water bath maintained at 50'C up to approximately the level of the hot water in the beaker. The beaker and hot water reservoir are placed in a thermostatic chamber maintained at 15° C., and the droplet flow properties of the film are observed after a predetermined period of time has elapsed.

[Example-1] A commercially available L-LDPE film (thickness 25 μm) was used as the base layer.
, product name Lineace, manufactured by Sunwell Industries Co., Ltd. Melt index 2.0 f 710 minutes, density 0, 92 t/c
On this film, 1.0 parts by weight of the nonionic surfactant sorbitan monopalmitate (trade name Span 40, manufactured by Kao Atlas Co., Ltd.) and low density polyethylene (trade name Mirason 45, manufactured by Kao Atlas Co., Ltd.) were added. Manufactured by Mitsui Polychemical Co., Ltd., melt index 1.5f710
100 parts by weight of the mixture was used as a resin containing a surfactant and extrusion laminated to obtain a film having a thickness of 50 μm.

[Example-2] In Example-1, ethylene-vinyl acetate copolymer (trade name Evaflex P14) was used instead of low-density polyethylene.
03. The same procedure as in Example 1 was used except that a resin containing vinyl acetate (manufactured by Mitsui Polychemical Co., Ltd., melt index 1.4 f/10 min, density 0.939/cm - vinyl acetate 14%) was used, and the thickness was 50 μm. obtained the film.

[Example-3] In Example-1, ionomer resin (trade name Himilan 1706, E-i, l-') was used instead of low-density polyethylene.
Manufactured by IJ Chemical Co., Ltd., melt index 0.7F
/10 minutes, density 0.97 t/cm'', 50 μm thick film was obtained in the same manner as in Example 1 except that ethylene-methacrylic acid copolymer (zinc salt type) was used as the surfactant-containing resin. .

[Example-4] In Example-1, instead of low-density polyethylene, an ionomer resin (trade name Himilan 170.7, manufactured by Mitsui Polychemical Co., Ltd., melt index 0. (1/10
A film with a thickness of 50 μm was prepared in the same manner as in Example 1, except that ethylene-methacrylic acid copolymer (sodium salt type) with a density of 0-95 f/cm” was used as the resin layer containing a surfactant. Obtained.

[Example-5] In Example-1, instead of low-density polyethylene, high-density polyethylene (trade name HIZEX 5000S, manufactured by Mitsui Petrochemical Industries, Ltd., melt index 0.8F/
A film with a thickness of 50 μm was obtained in the same manner as in Example 1, except that the resin containing a surfactant was used as the surfactant-containing resin.

[Example-6] In Example-1, instead of the commercially available L-LDPE film (trade name Lineace), L-LDPE (trade name Ultzex 3021F manufactured by Mitsui Petrochemical Co., Ltd., Melt Index 2-1F/1) was used. (1, density 0, 92 f/
cmF) by the inflation extrusion method to a thickness of 2
A film with a thickness of 50μ was obtained in the same manner as in Example 1, except that a film with a thickness of 5μ was created and the film was used as the base layer.

[Example-7] In Example-1, 70 parts by weight of L-LDPE (trade name Ultsex 3021F) and low density polyethylene (trade name) were used instead of the commercially available L-LDPE film (trade name Lineace).
Product name: Mirason 45) Blend 30 parts of I part and use the resin to extrude by inflation extrusion to a thickness of 25 μm.
A film with a thickness of 50 μm was obtained in the same manner as in Example-1 except that the film was used as the base layer.

[Example-8] 'In Example-1, instead of the commercially available L-LDPE film (product name Lineace), 80 parts by weight of L-LDPE (product name Ultzex 3021F) and 20 parts by weight of high-density polyethylene (product name Hizex 50005) were used. A film with a thickness of 25 μm was prepared using the resin by inflation extrusion method, and a film with a thickness of 50 μm was prepared in the same manner as in Example 1 except that the film was used as the base layer. Obtained.

[Example-9] In Example-1, 70 parts by weight of L-LDPE (trade name Ultzex 3021F) and ethylene-vinyl acetate copolymer (trade name Evaflex P 1403) #0
A film with a thickness of 25 μm was prepared using the resin layer by the inflation extrusion method, and a film with a thickness of 50 μm was prepared in the same manner as in Example 1 except that the film was used as the base layer. I got it.

[Example-10] In Example-1, 80 parts by weight of L-LDPE (trade name Ultzex 3021F) and polypropylene were substituted for the commercially available L-LDPE film (trade name Lineace).
Product name: Mikata Noblen FL-Zoo.

Manufactured by Mitsui Toatsu Chemical Co., Ltd., melt index 8 f/
10 minutes, density 0.91 t/cm'') was blended with 20 parts by weight, and using the resin, a film with a thickness of 25μ was created by inflation extrusion method, and the film was used as a base layer. A film with a thickness of 50 μm was obtained in the same manner as in Example-1.

[Example-11] In Example-1, a film with a thickness of 50 μm was created by the inflation extrusion method using L-LDPE (trade name Ultzex 3021F) instead of the commercially available L-LDPE film (trade name Lineace). , a thickness of 75 mm was obtained in the same manner as in Example-1 except that the film was used as a base material layer.
Get a film of μ.

[Example-12] In Example-1, L-LDPE (trade name: Ultzex 3021F) was used instead of the commercially available L-LDPE film (trade name: Lineace), and a film with a thickness of 50 μm was made by extrusion using an inflator. A film with a thickness of 10 was prepared in the same manner as in Example-1 except that the film was used as a base material layer.
A 0μ film was obtained.

[Example-13] A film with a thickness of 50 μm was obtained in the same manner as in Example-1 except that the amount of sorbitan monopalmitate used in Example-1 was changed to 0.1 part by weight.

[Example-14] A film with a thickness of 50 μm was obtained in the same manner as in Example-1 except that the amount of sorbitan monopalmitate used in Example-1 was changed to 0.2 parts by weight.

[Example-15] The thickness was 5 in the same manner as in Example-1 except that the amount of sorbitan monopalmitate used in Example-1 was changed to 3 parts by weight.
A 0μ film was obtained.

[Example-16] A product with a thickness of 5% was prepared in the same manner as in Example-1 except that the amount of sorbitan monopalmitate used in Example-1 was changed to 5 parts by weight.
A 0μ film was obtained.

[Example-17] In Example-1, the nonionic surfactant polyethylene glycol nonylphenyl ether (trade name: Neuken EA120, No. 1
A film with a thickness of 50 μm was obtained in the same manner as in Example 1, except that a film (manufactured by Kogyo Seiyaku Co., Ltd.) was used.

[Example-18] Same as Example-1 except that in Example-1, an anionic surfactant alkyl phosphate ester (trade name: Leftol φ100, manufactured by NOF Corporation) was used instead of sorbitan monopalmitate. A film with a thickness of 50 μm was obtained.

[Example-19] The same procedure as in Example-1 was used except that sorbitan monono (imidacillin derivative amphoteric surfactant (trade name: Rheostat 53, manufactured by Lion Yushi Co., Ltd.) was used instead of lumitate. A film with a thickness of 50 μm was obtained.

[Example-20] In Example-1, the cationic surfactant NNN-limethyl-5 was used instead of sorbitan monopalmitate.
A film with a thickness of 50 μm was obtained in the same manner as in Example 1, except that -(laurylamide)-propion ammonium and methyl sulfate (trade name Niregan R-115, manufactured by NOF Corporation) were used.

[Comparative Example-1] A commercially available L-LDPE film (trade name: Lineace, thickness: 25 μm) that does not contain a surfactant shows no droplet flow properties.

[Comparative example-2] L-LDPE (trade name Urtozex 3021F) 10
A mixture of 0 parts by weight and 1.0 parts by weight of sorbitan monopalmitate (trade name Span 40) was subjected to inflation processing to obtain a film having a thickness of 50 μm.

The resulting film did not have sufficient droplet flow properties and disappeared within a few days. (Refer to Tables 1 and 5) [Reference Example-1] Commercially available agricultural polyethylene film (trade name: Layer polyethylene thickness 50 μm droplet type, manufactured by Toyo Polylon Co., Ltd.) exhibits a droplet function, but its durability does not last. The properties of the film are inferior to those of the agricultural film of the present invention. (See Table 5) [Reference Example-2] A commercially available agricultural ethylene-vinyl acetate copolymer film (trade name Layer Saku, thickness 50μ, droplet type, manufactured by Toyo Polylon Co., Ltd.) exhibits droplet properties. However, its durability is slightly inferior to that of the agricultural film of the present invention. (See Table 5) [Reference Example-3] Commercially available agricultural vinyl chloride film (trade name: Mikata Vinyl, thickness 50μ, droplet type, manufactured by Mitsui Toatsu Chemical Co., Ltd.)
The test results are shown in Table 5.

Notes for Tables 1 to 5 Note 1) The amount of surfactant added (phr) is parts by weight based on 100 parts by weight of resin.

Note 2) The symbol written on the resin base indicates the following resin.

L-LDPE: Lini-T low density polyethylene L
DPE: Low density polyethylene HDPE: High density polyethylene EVA: Ethylene-vinyl acetate copolymer PP:
Poly, propylene PE: Polyethylene PVC: Polyvinyl chloride Note 3) In terms of droplet properties, IH is at the 1st hour, IW is at the 1st week,
3W indicates 3 weeks, and 5W indicates 5 weeks.

In addition, the degree of droplet flow is indicated by X, from ◎% to 0%.

6; Water droplets do not adhere to the film and 1. It flows out and maintains transparency.

6; Water drops flow out without adhering to the filter, but
The way it leaked out, it was a little sharp.

Δ: Water droplets partially adhere to the film and flow out in a long pattern.

×: Water droplets adhere to the entire surface of the film and do not flow out.

As seen in Comparative Example 2, simply adding a surfactant to L-LDPH may result in the resulting film having poor initial droplet flow properties compared to the agricultural film of the present invention.
The duration of droplet properties is also short and problematic. But L-LD
The agricultural film of the present invention, which has a layer made of a resin containing a surfactant on one side of a PE-based film, has a higher droplet flow rate than commercially available agricultural polyvinyl chloride resin films with good droplet flow properties. There was no difference in the droplet properties, and there was almost no difference in the duration of the droplet properties.

Furthermore, as a result of subjecting the films obtained in these Examples to a one-year outdoor extension test, the droplet flow properties were good during the test period, and the droplet flow properties were good compared to commercially available agricultural polyvinyl chloride films (commercial products) with good droplet flow properties. Name: Mikata Vinyl, manufactured by Mitsui Toatsu Chemical Co., Ltd.
It was found that there was no inferiority in comparison to the commercially available droplet type agricultural polyethylene film and agricultural ethylene-vinyl acetate film.

As described above, the agricultural film of the present invention has good droplet flow properties and maintains droplet flow properties for a long period of time, which is unimaginable when surfactants are kneaded into conventional L-LDPE films. It is something that

patent applicant Mitsui Toatsu Chemical Co., Ltd. 255

Claims (1)

[Claims] 1. Linear low density polyethylene (Line
ar Low Density Polyethylene
ne) and a layer consisting of a resin that is compatible with the base layer and contains 0.01 to 8 parts by weight of a surfactant per 100 parts by weight of the resin are formed in a multilayered manner. An agricultural film with good droplet properties. 2. Resins containing surfactants include polyethylenes such as low-density polyethylene, medium-density polyethylene, and high-density polyethylene, ethylene-vinyl acetate copolymers, ethylene-α-olefin copolymers, ionomer resins, etc. The agricultural film according to claim 1, which is one kind or a mixture of two or more kinds.