JPH09275822A - Thermoplastic synthetic resin film for agriculture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a thermoplastic synthetic resin film for agriculture with the growing of crops at cold time is promoted, the growing of weak vegetables is not obstructed at high-temperature time and high-temperature faults and high beam irradiation faults can be prevented. SOLUTION: In the thermoplastic synthetic resin film for agriculture composed of an intermediate layer and two outer layers, both the outer layers contain an ultraviolet absorber from 0.1 to 3 pts.wt. based on 100 pts.wt. of the thermoplastic synthetic resin, one of outer layers additionally contains violet pigments or dyes from 0.005 to 0.1 pts.wt. for selectively absorbing the light beam of wavelength from 500 to 620nm, and the full beam transmissivity of the entire film is from 50% to 89%.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an agricultural thermoplastic resin film.

[0002]

2. Description of the Related Art Recently, cropping patterns of leaf vegetables such as spinach, butterbur, leek, asparagus, garland chrysanthemum, komatsuna and bok choy are more and more differentiated to control light transmittance and sunshine duration or heat ray transmittance. As a result, flower bud differentiation is suppressed, physiological disorders such as leaf scorch due to a decrease in water content of plants are prevented, and these leaf vegetables are supplied year-round.

As a countermeasure against this, conventionally, a light-shielding film for agriculture has been coated with ginseng in the summer (Japanese Patent Laid-Open No. 62-210924, etc.), or added with aluminum powder, white pigment, carbon black, etc. -1113
No. 50, etc.), a light-shielding film for agriculture (Publication No. 6-46686) for the same purpose to which pigments such as aniline black, hematite, and perylene black are added have been used.

[0004] However, the ginseng cannot be used in forcing crops such as the cultivation of butterbur and other early spring and late fall seasons that require high temperature and humidity, and the shade is generally large, and the crops can be used. There is.

Further, all of the agricultural light-shielding films to which aluminum powder, white pigment, carbon black, etc. are added have a large degree of light-shielding, and have wavelengths of 380 to 500 nm and 650 to 780 nm which are regions required for plant growth. Due to the significant decrease in the light transmittance, the leafy vegetables grow longer,
Or, it may cause physiological disorders.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above facts, and an object of the present invention is to solve the above problems, to promote the growth of crops in cold weather, and to , Without inhibiting the growth of soft vegetables,
Moreover, it is intended to provide an agricultural thermoplastic synthetic resin film capable of preventing high temperature damage and high light irradiation damage.

[0007]

[Means for Solving the Problems]

The present invention is a thermoplastic thermoplastic resin film for agriculture comprising an intermediate layer and two outer layers, both outer layers containing an ultraviolet absorber of 0.1 part by weight per 100 parts by weight of the thermoplastic synthetic resin.
In addition to 1 to 3 parts by weight, at least one outer layer further contains 0.005 to 0.005 of a violet pigment or dye that selectively absorbs light having a wavelength of 500 to 620 nm.
A gist of the thermoplastic thermoplastic resin film for agriculture is that it contains 0.1 part by weight and the total light transmittance of the whole film is 50 to 89%.

The wavelength of 50 used for the outer layer in the present invention
The violet pigment or dye that selectively absorbs the light of 0 to 620 nm is not particularly limited as long as it efficiently absorbs the light of the above wavelength range, but, for example, it is generally a purple dioxazine. And organic pigments such as perylene and inorganic pigments such as manganese and cobalt. In addition, a red azo-based, quinacridone-based, anthraquinone-based, perylene-based, thioindigo-based organic pigment and a blue-based phthalocyanine-based, anthraquinone-based, ultramarine blue and other organic and inorganic pigments are combined to produce a purple pigment or dye. May be used.

The amount of the purple pigment or dye that selectively absorbs light having a wavelength of 500 to 620 nm is 0.005 to 0.1 part by weight, preferably 0.01 to 100 parts by weight of the thermoplastic synthetic resin. ~ 0.05 parts by weight. When the blending amount exceeds 0.1 parts by weight, the total light transmittance of the resulting thermoplastic synthetic resin film becomes 50% or less, and the spinach, leek, asparagus, celery, wipes,
When the growing condition of cultivated plants such as Japanese mustard spinach becomes poor, the foliage is lengthened, the commercial value is lost, and when the blending amount is less than 0.005 parts by weight, the total light transmittance of the obtained thermoplastic synthetic resin film is 89% or more. Therefore, the above-mentioned cultivated plants suffer high temperature damage such as leaf burning, and soft vegetables are greened, and all lose their commercial value.

The reason why the total light transmittance of the thermoplastic synthetic resin film of the present invention is limited to 50 to 89% is based on the above reason.

The ultraviolet absorber used in the present invention includes, for example, benzophenone-based, benzotriazole-based, hydroquinone-based, benzoate-based, cyanoacrylate-based ultraviolet absorbers, and specifically, Sumisorp 250, 350. (Brand name: all manufactured by Sumitomo Chemical Co., Ltd.), UV531 (Brand name: manufactured by Cyanamid Co., Ltd.), Tinuvin 326, 327 (Brand name: all manufactured by Ciba Geigy), etc., and the type of thermoplastic synthetic resin used. It is selected and used as appropriate. In addition, a hindered amine-based light stabilizer, which is abbreviated as HALS, is expected to have the same effect, and is therefore included in the ultraviolet absorber of the present invention.
Specific examples of this include tinuvin 622 and Kima soap 94.
4 (trade name: all manufactured by Ciba-Geigy) and the like.

The amount of the ultraviolet absorber blended is 0.1 to 3 parts by weight, preferably 0.02 to 0.5 part by weight, based on 100 parts by weight of the thermoplastic synthetic resin. If the blending amount is less than 0.1 part by weight, the blended effect cannot be sufficiently obtained, and the number of pests coming into the facility such as a house or a tunnel increases, so that the above-mentioned cultivated crops have a sclerotia or wilt disease. , Spore formation of pathogenic bacteria such as mold disease increases, causing serious growth disorders such as diseases. Further, when the blending amount exceeds 3 parts by weight, the effect of the ultraviolet absorber is saturated, and further blending does not substantially increase the effect, but also causes bleedout and a decrease in total light transmittance. In addition, since the ultraviolet absorber itself is an expensive drug, it causes a high cost of the thermoplastic synthetic resin film obtained,
Not preferred.

The thermoplastic synthetic resin film used in the present invention is mainly composed of polyvinyl chloride or vinyl chloride having a degree of polymerization of about 800 to 2,000 and vinyl acetate, ethylene, propylene, alkyl vinyl ether,
Acrylic ester, methacrylic acid ester, copolymer with copolymerizable monomers such as acrylonitrile, a mixture of the above vinyl chloride homopolymers or copolymers, or a mixture of these polymers and chlorine such as chlorinated polyethylene. Vinyl chloride resin composed of polymer blend with polymer or copolymer, low density polyethylene, mainly ethylene, a copolymer of this with a copolymerizable monomer such as vinyl acetate, the ethylene homopolymer or Examples thereof include ethylene-based resins, ester-based resins and the like, which are composed of a mixture of copolymers, a polymer having compatibility with these, or a polymer blend with the copolymer.

The above-mentioned thermoplastic synthetic resin is a stabilizer, a stabilizing aid, an antioxidant, a plasticizer, an antifogging agent, an antifog agent, a filler, a lubricant, and a coloring agent without departing from the spirit of the present invention. Additives such as agents may be added.

As the filler, for example, silicon oxide, silicates, phosphates, glass fine powder, etc. are added in an amount of 2 to 20 parts by weight, preferably 4 to 10 parts by weight, based on 100 parts by weight of the thermoplastic synthetic resin. Then, it acts as an appropriate heat retaining agent, and it is possible to mitigate abrupt changes in the outside temperature such as a temperature difference between day and night and a low temperature which is out of time.

The amount of the filler having the above heat retaining effect added is
When it exceeds 20 parts by weight with respect to 100 parts by weight of the above-mentioned thermoplastic synthetic resin, the visible light transmittance of the obtained thermoplastic synthetic resin film is lowered and its mechanical strength is also lowered. Further, the function of suppressing flower bud differentiation and preventing overgrowth intended by the present invention may be diminished.

The method for producing the thermoplastic synthetic resin film of the present invention is not particularly limited, but a thermoplastic synthetic resin composition comprising the above-mentioned constituents may be used, for example, in an inflation molding method, a T-die molding method, Calender molding method,
It can be molded by a method such as a solution casting method.

The thickness of the thermoplastic synthetic resin film of the present invention is not particularly limited as long as the total light transmittance satisfies 50 to 89%, but if it is too thin, the mechanical strength will be insufficient and the film will break. On the contrary, if it is too thick, it becomes difficult to form a film during the production of the thermoplastic synthetic resin film, and the subsequent handling becomes troublesome, so generally,
The range of 0.03 to 0.3 mm is preferably used.

The composition of the intermediate layer and the outer layer of the thermoplastic synthetic resin film is preferably such that the intermediate layer is less than 95% of the total thickness of the thermoplastic synthetic resin film, and two layers are provided on both sides of the intermediate layer. Outer layer (one side constitutes the outer wall of a facility such as a house or a tunnel, and the other side constitutes the inner wall)
It is preferably 1: 3 to 3: 1.

The layer ratio of the intermediate layer to the outer layer or the layer ratio of the two outer layers in the thermoplastic synthetic resin film is set within the above range because the outer layer forming the outer wall of a facility such as a house or a tunnel is extremely large. When it is thin, the concentration of the ultraviolet absorbent contained in the outer layer may be required to be more than 3 parts by weight with respect to 100 parts by weight of the thermoplastic synthetic resin, and bleeding out from the resulting thermoplastic synthetic resin film may occur. ,
This is because not only the effect of protecting the pigment or dye from ultraviolet rays may be lowered, but also the total light transmittance of the thermoplastic synthetic resin film may be lowered.

Since the thermoplastic synthetic resin film of the present invention is constructed as described above, the purple pigment or dye contained in the outer layer should be deteriorated and deteriorated mainly by the ultraviolet rays radiated from the inner and outer surfaces of the house or tunnel. Less, long-term spinach or soft vegetables that do not function in the growth of wavelengths of 500 ~ 620nm can be cut for a long time, because the total light transmittance can be maintained at 50 ~ 89% suitable for the growth of these cultivated plants. , Suppresses flower bud differentiation of long-day plants such as spinach, asparagus, greening and hardening of soft vegetables such as honeybee, and further prevents high temperature damage such as leaf burning, and because sufficient growth is possible, The long-day plants and soft vegetables can be effectively used as covering materials for greenhouses and tunnels that can be forcibly cultivated and suppressed cultivated throughout the year.

Further, the thermoplastic synthetic resin film of the present invention comprises an ultraviolet absorber incorporated in a predetermined amount in the outer layer,
Spore formation such as sclerotium disease, wilt disease, and mold disease is suppressed by pest repellent action and pathogenic bacteria growth inhibition action, and there is little pest damage in facilities such as greenhouses and tunnels that easily become hot and humid, and high quality products. Can be produced efficiently.

[0024]

Embodiments of the present invention will be described below.

Example 1 Ethylene-vinyl acetate copolymer (vinyl acetate content 10% by weight, specific gravity 0.96, MI
= 1.2) 100 parts by weight, dioxazine violet (maximum absorption 520 to 620 nm) 0.02 parts by weight, and a benzotriazole-based ultraviolet absorber (manufactured by Ciba-Geigy, trade name: Tinuvin 326) 1.0 parts by weight. 25 μm thick two outer layers and ethylene-vinyl acetate copolymer (vinyl acetate content 15% by weight, specific gravity 0.96, MI
= 1.4) 100 parts by weight, silicates (manufactured by Kyowa Chemical Co., Ltd., trade name: BHT-4A) 8 parts by weight 50 μm thick
The intermediate layer of m was subjected to a multilayer inflation molding method to obtain an agricultural ethylene-vinyl acetate copolymer film having a total thickness of 100 μm. The obtained ethylene-vinyl acetate copolymer film for agriculture was spread on a house, and spinach (cultivar: varieties: in a field in the suburbs of Nagoya city for three months from June to August 1994).
Orion) was cultivated.

Example 2 The same as Example 1 except that 0.02 parts by weight of a mixed pigment of a phthalocyanine blue pigment and a quinacridone red pigment was used in place of the outer layer of dioxazine violet in Example 1. And the total thickness is 100
An ethylene-vinyl acetate copolymer film for agriculture having a thickness of μm was obtained. Spinach (variety: Orion) was cultivated in the same manner as in Example 1 using the obtained ethylene-vinyl acetate copolymer film for agriculture as a covering material.

Comparative Example 1 The outer layer of Example 1 was mixed with 0.02 parts by weight of dioxazine violet in an amount of 0.004 parts by weight and 1.0 parts by weight of tinuvin 326 (trade name) in an amount of 0.1 parts by weight. An agricultural ethylene-vinyl acetate copolymer film having a total thickness of 100 μm was obtained in the same manner as in Example 1 except that the amount was changed to 08 parts by weight. The obtained agricultural ethylene-
Spinach (variety: Orion) was cultivated in the same manner as in Example 1 using the vinyl acetate copolymer film as a covering material.

(Comparative Example 2) Tinuvin 3 in the outer layer of Example 1
A total thickness of 10 was obtained in the same manner as in Example 1 except that the compounding amount of 26 (trade name) was changed from 1.0 part by weight to 0.08 part by weight.
A 0 μm agricultural ethylene-vinyl acetate copolymer film was obtained. Spinach (variety: Orion) was cultivated in the same manner as in Example 1 using the obtained ethylene-vinyl acetate copolymer film for agriculture as a covering material.

Comparative Example 3 A total thickness of 1 was obtained in the same manner as in Example 1 except that the compounding amount of dioxazine violet in the outer layer of Example 1 was changed from 0.02 part by weight to 0.15 part by weight.
A 00 μm ethylene-vinyl acetate copolymer film for agriculture was obtained. Spinach (variety: Orion) was cultivated in the same manner as in Example 1 using the obtained ethylene-vinyl acetate copolymer film for agriculture as a covering material.

(Comparative Example 4) 0.002 parts by weight of dioxazine violet in the intermediate layer of Example 1 was added to 0.002 parts by weight.
An agricultural ethylene-vinyl acetate copolymer film having a total thickness of 100 μm was obtained in the same manner as in Example 1 except that the weight part was changed. Spinach (variety: Orion) was cultivated in the same manner as in Example 1 using the obtained ethylene-vinyl acetate copolymer film for agriculture as a covering material.

The total light transmittance and weather resistance of the thermoplastic thermoplastic resin films for agriculture of the respective examples obtained as described above were measured and evaluated by the following methods. The results of spinach cultivation tests carried out using the thermoplastic thermoplastic resin films for agriculture obtained in the above examples were measured and evaluated by the following methods.

1. Total light transmittance: The total light transmittance was measured using a self-recording spectrophotometer manufactured by Hitachi, Ltd.

2. Weather resistance evaluation: Based on JIS K 6732, visually observe the degree of fading of the thermoplastic thermoplastic resin film for agriculture after irradiation for 500 hours with a sunshine carbon arc weather resistance tester, ○: almost no fading, × : Remarkably discolored, and evaluated in two stages.

3. Cultivation test results: The growing condition of spinach was evaluated from the three points of high temperature damage, growing and leaf color at the time of harvest. Regarding the high temperature damage, the leaf scorch was observed mainly, and it was evaluated in two stages of ◯: almost no leaf scorch and x: leaf scorch. Regarding the growth, the size and thickness of roots and foliage and the degree of overgrowth were mainly observed, and the presence or absence thereof was evaluated. For leaf color, chlorophyll meter (SP manufactured by Minolta, SPA
D-502), and the amount of chlorophyll formed (the larger the number, the more chlorophyll is formed and the better the growing condition).
Was measured.

The above measurement and evaluation results are shown in Table 1.

[0036]

[Table 1]

[0037]

EFFECT OF THE INVENTION Since the agricultural thermoplastic resin film of the present invention has the above-mentioned constitution, it has excellent weather resistance, flower bud differentiation of long-day plants such as spinach and softness of asparagus, honeybee and the like. Since high temperature damage such as vegetable greening, hardening and even leaf burning can be avoided and sufficient cultivation can be carried out, forcible cultivation of these long-day plants and soft vegetables throughout the year, for greenhouses and tunnels for suppression cultivation It can be effectively used as a covering material.

Further, the thermoplastic synthetic resin film of the present invention has a sclerotia, wilt, mold, etc. due to the pest repellent action and the pathogenic bacterium growth inhibitory action of the ultraviolet absorber blended in a predetermined amount in the outer layer. Spore formation due to diseases and the like is suppressed, and there is little pest damage in the facilities such as greenhouses and tunnels that tend to be hot and humid, and high-quality products can be efficiently produced.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C08K 5/07 C08K 5/07 5/132 KAU 5/132 KAU 5/17 KAY 5/17 KAY 5 / 315 KAX 5/315 KAX 5/3475 KBM 5/3475 KBM C08L 101/00 KAQ C08L 101/00 KAQ

Claims (1)

[Claims] 1. A thermoplastic thermoplastic resin film for agriculture comprising an intermediate layer and two outer layers, both outer layers containing 0.1 to 3 parts by weight of an ultraviolet absorber with respect to 100 parts by weight of the thermoplastic synthetic resin. In addition, at least one outer layer further contains 0.005 to 0.1 parts by weight of a violet pigment or dye that selectively absorbs a light ray having a wavelength of 500 to 620 nm, and the total amount of the entire film is Light transmittance is 50
A thermoplastic thermoplastic resin film for agriculture, characterized in that it is ˜89%.