JP2000014255A - Coating material for plant growth control - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating material for plant growth control excellent in effect for stimulating or controlling the growth of a plant and having excellent durability. SOLUTION: This coating material comprising a polyolefin film laminate having a multilayered structure of at least three or more layers has the following features: at least the outer layer is an ultraviolet absorber-containing layer; at least one layer is a layer mainly composed of an ethylene-α-olefin copolymer which contains a pigment having the maximum-absorbing wave length in 600-700 nm or 700-900 nm; the transmittance of effective photon flux for photosynthesis of the laminate is 50% or more; the ratio of the photon flux of far red light of 600-700 nm to that of 700-800 nm is 0.9 or less, or 1.3 or more; and the mean value of the spectral transmittance of 290-400 nm is 30% or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating material for promoting or suppressing plant growth. More specifically, the present invention relates to a coating material for controlling plant growth, which is capable of controlling photomorphogenesis of plants by a simple method using natural light and is extremely useful in facility horticulture, home gardening, and the like.

[0002]

2. Description of the Related Art A coating material for controlling plant growth according to the present invention focuses on the photomorphogenetic reaction of a plant, and is used to control the photon flux of 700 to 800 nm of far-red light of 700 to 800 nm transmitted through natural light. The ratio of the photon flux of red light is set to 0.
By controlling to 9 or less or 1.3 or more, the growth of plants is promoted or suppressed. The effect of such photomorphogenesis control has been demonstrated by research using artificial light sources (Murakami et al.,
Vol. 30, No. 4, 135-141, 1992
Year). However, in practice, a method using an artificial light source requires a large amount of equipment cost and an operating cost such as an electric power cost. Therefore, a cheaper method using natural light has been devised.

As an example utilizing natural light, see Japanese Patent Application Laid-Open No. 7-7 / 1995.
No. 9649 and the like. The coating material for controlling plant growth according to the present invention is preferably 600 to 700 to adjust the ratio of the photon flux of red light of 600 to 700 nm to the photon flux of far red light of 700 to 800 nm to 0.9 or less.
A dye having an absorption maximum at nm is used, and a dye having an absorption maximum at 700 to 900 nm is used to adjust to 1.3 or more, and these dyes are dispersed and dissolved in a polymer resin to form a film. The coating material is used as a coating material, and exhibits an excellent plant growth control effect. In the examples of the above publication, a coating material for plant growth control using a polymethyl methacrylate resin or the like is described. However, these plant growth controlling coating materials are not practical because they are hard and easily broken. For example, there is no major problem when producing a small-scale cultivation facility such as a growth cabinet, but it is not used for greenhouse cultivation for facility horticulture. Further, only the initial optical properties of the coating material immediately after production are mentioned, but the persistence of the optical properties is not mentioned.

Generally, polyolefin resin films such as polyethylene and ethylene-vinyl acetate copolymer, and polyvinyl chloride films are used as agricultural films. When a dye is added to these resin films, the optical characteristics of the dye deteriorate more quickly than when a dye is added to the chill methacrylate resin. As a method for solving this problem, for example, Japanese Patent Application Laid-Open No. 9-172882 discloses a photon of far-red light having a transmittance of at least 50% of a photosynthetically effective photon flux when natural light is transmitted and of 700 to 800 nm. An acrylic resin containing an ultraviolet absorber having a maximum absorption wavelength at 250 to 400 nm is provided on a base material having a ratio of the photon flux of red light of 600 to 700 nm to the flux of 0 to 0.9 or 1.3 to 3. A laminated plant elongation control coating material is described.

However, in this method, although the function of the dye in polyethylene or polyvinyl chloride is maintained for a long period of time, cracks occur in the acrylic layer during use over a long period of time, and light is transmitted due to adhesion of dust. However, there is a problem in that the coating rate is reduced, and the coating material is not always satisfactory. If the thickness of the acrylic layer is reduced to avoid this phenomenon, the transmittance of ultraviolet rays may not be sufficiently suppressed, which is still insufficient. Further, since a step of laminating an acrylic layer is added, it is disadvantageous in that the manufacturing method is complicated. There is a demand for a coating material that can be obtained by a simpler method and that can control plant growth well over a long period.

[0006] Polyolefin films for agricultural use are excellent in terms of cold resistance, spreading workability, dust resistance, lightness, etc. as coating materials for house cultivation, tunnel cultivation, and multi-cultivation.
Heat retention, transparency, toughness (mechanical strength), anti-fog, etc.
This is an excellent point of the polyvinyl chloride film, and the polyolefin film also requires these properties. Further, the surface that becomes outside when it is spread on a house or the like needs to have heat resistance, weather resistance, and dust resistance. The surface on the inside needs to have anti-fog properties and heat resistance at the part that comes into contact with the pipe of the house.

Here, the heat retention refers to the temperature inside the house, tunnel, etc. (air temperature and ground temperature) by absorbing and reflecting the radiation emitted at night from the ground where the temperature has risen by absorbing the solar heat during the day. ) Is the ability to maintain Further, the dustproof property refers to a performance of suppressing a decrease in the transparency of the film due to dust adhesion or the like after use for a certain period. Further, the stretching workability indicates whether the film is easy to handle due to stickiness.

In order to obtain a film having the above-mentioned various properties, a method of combining resins having different physical properties to form a multilayer film is employed. Generally, a three-layer film mainly composed of an ethylene-vinyl acetate copolymer is mainly used as an agricultural polyolefin film. As a material resin for an agricultural polyolefin film, an ethylene-vinyl acetate copolymer is superior to polyethylene in terms of heat retention, transparency, compatibility with an antifogging agent and the like, and is widely used. Some of them are used for the outer layer by utilizing the toughness of linear low-density polyethylene. In this case, too, an ethylene-vinyl acetate copolymer is often used for the intermediate layer and the inner layer.

[0009]

Since the coating material for controlling plant growth is required to have excellent heat retention and transparency and to have good compatibility with antifogging agents and the like, ethylene-vinyl acetate is required. It is important to form a layer whose main component is a copolymer. However, according to the findings of the present inventors,
When a dye is added to the ethylene-vinyl acetate copolymer layer, the wavelength selectivity of the dye tends to deteriorate. The purpose of the present invention is
In view of the above problems, an object of the present invention is to provide a coating material for controlling plant growth, which has an effect of promoting or suppressing the growth of plants and has excellent sustainability.

[0010]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that at least one layer of a polyolefin-based plant growth control coating material having a multilayer structure contains an ethylene-α-olefin copolymer as a main component. Formed with resin, the layer contains a dye having the ability to absorb light of a specific wavelength, at least the outer layer contains an ultraviolet absorber, and,
The inventors have found that the above problems can be solved by limiting optical characteristics such as light transmittance of a specific wavelength in a visible region and an ultraviolet region to a specific range, and have completed the present invention.

That is, the coating material for controlling plant growth according to the present invention is a coating material for controlling plant growth formed of a polyolefin-based film having a multilayer structure comprising at least three layers of an outer layer, an intermediate layer and an inner layer, At least the outer layer is a layer containing an ultraviolet absorber, and at least one layer is a layer mainly composed of an ethylene-α-olefin copolymer containing a dye having a maximum absorption wavelength at 600 to 700 nm, or 700 to 900 nm. The coating material has a transmittance of the photosynthetic effective photon flux (hereinafter referred to as PPF transmittance) of 50% or more and a photon flux of the red light of 600 to 700 nm with respect to a photon flux of far-red light of 700 to 800 nm. The ratio (hereinafter referred to as A value) is 0.9 or less, or 1.3 or more, and the average value of the spectral transmittance from 290 to 400 nm is 30% or less. It is a plant growth regulator for coating material characterized.

A feature of the present invention is that, among the above constitutions, in particular, at least one layer of a polyolefin-based plant growth control coating material having a multilayer structure is formed of a resin containing an ethylene-α-olefin copolymer as a main component. The point that the layer contains a dye having a performance of absorbing light of a specific wavelength, and that at least the outer layer contains an ultraviolet absorber to limit the ultraviolet transmittance of the laminate to a specific value or less. . By employing such a configuration, a coating material for controlling plant growth which is excellent in sustaining action of promoting or suppressing plant growth can be obtained.

The A value and the PPF transmittance in the present invention mean values measured by the method described in Examples described later. In the coating material for controlling plant growth of the present invention, the outer layer of the laminate having a multilayer structure is a layer that comes into contact with the outside air when spread on a house or the like. The inner layer is a layer facing the inside of a house or the like. The intermediate layer is a layer sandwiched between the outer layer and the inner layer. When there are four or more layers, the intermediate layer becomes a plurality of layers.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The coating material for controlling plant growth of the present invention is formed of a polyolefin-based film having a multilayer structure of three or more layers of an outer layer, an intermediate layer, and an inner layer. To each polyolefin resin forming each layer, a dye, an ultraviolet absorber, and if necessary, other additives are added to form a resin composition, and the obtained resin composition is subjected to a co-extrusion T-die method, It can be manufactured by laminating an outer layer, an intermediate layer and an inner layer by a known molding method such as an extrusion inflation method.

In the coating material for controlling plant growth of the present invention, at least one layer of the multilayer film is formed of a resin containing an ethylene-α-olefin copolymer as a main component, and the layer is used for adjusting the A value. To which a dye is added. 600 to 70 added to adjust the A value to 0.9 or less
Examples of the plant growth promoting dye having a maximum absorption wavelength at 0 nm include, for example, a compound represented by the following chemical formula (1):

[0016]

Embedded image And a dye group represented by It is not limited to these.

The plant growth inhibiting dye having a maximum absorption wavelength at 700 to 900 nm added to adjust the A value to 1.3 or more includes, for example, a compound represented by the following chemical formula (2).

[0018]

Embedded image And a dye group represented by It is not limited to these.

It is preferable that the coating material for controlling plant growth of the present invention has as high a transmittance as possible for light other than the control wavelength in both cases of promoting growth and suppressing growth.
It is preferable that the amount of the dye added and the thickness of the layer to which the dye is added be adjusted so that the PPF transmittance at 400 to 700 nm is 50% or more. More preferably, the PPF transmittance is 65% or more. If it is less than 50%, photosynthesis of the plant is inhibited, resulting in a prolonged and unhealthy plant. The amount of the dye to be added varies depending on the optical characteristics such as the molar extinction coefficient and the maximum absorption wavelength of the dye and the base resin, but is preferably 0.001 to 2% by weight based on the dye-added layer. The layer to which the dye is added may be any of an outer layer, an intermediate layer, and an inner layer.
However, in view of the continuity of the plant growth controlling action, it is preferable to add it to the middle layer or the inner layer.

In the present invention, the resin serving as the base material of the layer to which the dye is added is a polyolefin resin containing an ethylene-α-olefin copolymer as a main component. The α-olefin forming the copolymer is preferably an α-olefin having 4 to 12 carbon atoms. Specifically, 1-butene,
Examples thereof include 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, and 1-dodecene. Of these, α-olefins having 4 to 10 carbon atoms are preferred. More preferably, it has 4 to 6 carbon atoms.
Α-olefin.

In the present invention, the above ethylene-α-olefin copolymers can be used alone or in combination of two or more. The ethylene-α-olefin copolymer used in the present invention has a constitutional unit derived from ethylene of 50% by weight or more and less than 100%. Preferably it is 60 to 99% by weight. 4 carbon atoms
The content of the structural unit derived from the α-olefin of ~ 12 is 50% by weight or less, preferably 1 to 40% by weight. The ethylene-α-olefin copolymer has a density of 0.880 to 0.9.
40 g / cm ³ , melt flow rate (MFR; AST)
MD-1238-65T, 190 ° C, load 2.16k
g) Those having a concentration of 0.1 to 10 g / 10 minutes are preferably used.

These ethylene-α-olefin copolymers can be produced by a conventionally known method, for example, using a Ziegler catalyst or a metallocene catalyst in a gas phase or a slurry or solution liquid phase. , Ethylene and an α-olefin having 4 to 12 carbon atoms. Either method can be used, but in consideration of excellent properties such as transparency and strength of the resin and weather resistance of the added dye, a resin produced using a metallocene catalyst is preferable.

The above-mentioned ethylene-α-olefin copolymer may be blended with a high-pressure low-density polyethylene, if necessary, for the purpose of improving the formability of the film. However, this high-pressure low-density polyethylene is an ethylene homopolymer and does not include an ethylene-vinyl acetate copolymer. Ethylene-vinyl acetate copolymer is not preferred because it reduces the weather resistance of the pigment and decreases the sustainability of the plant growth control action. As the high-pressure low-density polyethylene, those having a density of 0.915 to 0.935 g / cm ³ and a melt flow rate of 0.1 to 10 g / 10 minutes are preferably used. When the high pressure method low density polyethylene is mixed with the ethylene-α-olefin copolymer, the weight ratio of the former / the latter is about 99/1 to 60/40. Preferably 90/1
It is in the range of 0 to 80/20.

For the other layer to which no pigment is added, any resin may be used as long as it is a resin used for a general agricultural polyolefin film. For example, low density polyethylene, medium density polyethylene, high density polyethylene,
Linear low-density polyethylene, ethylene-vinyl acetate copolymer, or the like can be used. These can be used alone or in combination of two or more. Of course, it may be the same as the resin used for the dye-added layer.

In the present invention, an ultraviolet absorber is contained in at least the outer layer of the multilayer film in order to exhibit a long-lasting growth control effect. It may be contained in other layers. The ultraviolet absorber is not particularly limited as long as it is a compound having a small absorption in the visible region of 400 to 700 nm and a large absorption in the range of 250 to 400 nm. For example, a benzophenone ultraviolet absorber, a benzotriazole ultraviolet absorber, a phenyl salicylate ultraviolet absorber, a cyanoacrylate ultraviolet absorber, and the like can be given.

Specifically, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, 2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2-hydroxy-4-methoxy-5
-Sulfobenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3'-tert-butyl −
5′-methylphenyl) benzotriazole, 2-
(2′-hydroxy-3 ′, 5′-dimethylphenyl)
Benzotriazole, 2- (2′-hydroxy-3 ′,
5'-dimethylphenyl) -5-methoxybenzotriazole, phenyl salicylate, P-octylphenyl salicylate, P-tert-butylphenyl salicylate, resorcinol monobenzoate, 2-ethylhexyl-2-cyano-3,3-diphenyl acrylate and the like Is exemplified.

These can be used alone or in combination of two or more. The ultraviolet absorber is added so that the transmittance of ultraviolet light at 290 to 400 nm is 30% or less, more preferably 20% or less when a multilayer film is formed. Here, the ultraviolet transmittance refers to an average value of spectral transmittance from 290 to 400 nm measured by a spectrophotometer.

The UV absorber is added to at least the outer layer, and has a UV transmittance of 30% or less, more preferably 20% or less, transmitting through the outer layer. By adding an ultraviolet absorber to the outer layer, the function of the plant growth control action of the pigment can be maintained for a long time. 30% UV transmittance
The amount of the ultraviolet absorber to be added is 0.05 to
It is preferably adjusted to be 3 g / m ² . The concentration of the ultraviolet absorber is adjusted by the thickness of the layer to which the ultraviolet absorber is added. The area of the film indicating the amount of the ultraviolet absorber added means the area as a multilayer laminate.

A light stabilizer can be added to the plant growth controlling coating material of the present invention. The light stabilizer may be added to any of the layers, but it is preferable to use the light stabilizer at least in the layer to which the pigment is added, since the sustainability of the plant growth control action is improved. As the light stabilizer, a conventionally known light stabilizer can be used, and among them, a hindered amine light stabilizer is preferably used. As the hindered amine-based light stabilizer, specifically, the following compounds are used.

Bis (2,2,6,6-tetramethyl-4
-Piperidyl) sebacate, dimethyl succinate-1-
(2-hydroxyethyl) -4-hydroxy-2,2,
6,6-tetramethylpiperidine polycondensate, tetrakis (2,2,6,6-tetramethyl-4-piperidyl)-
1,2,3,4-butanetetracarboxylate, 2,
2,6,6-tetramethyl-4-piperidinyl benzoate, bis (1,2,6,6-tetramethyl-4-piperidinyl) -2- (3,5-di-t-butyl-4-hydroxy Benzyl) -2-n-butylmalonate and the like.

The present invention is not limited to these. These light stabilizers can be used alone or in combination of two or more. Such light stabilizers include ethylene-α
-It is preferable to use 0.005 to 5 parts by weight based on 100 parts by weight of the total of the olefin copolymer and the high-pressure low-density polyethylene. More preferably, it is 0.01 to 2 parts by weight. It is also preferable to use 0.005 to 5 parts by weight of the layer to which no dye is added, based on 100 parts by weight of the base resin. More preferably, the ratio is 0.01 to 2 parts by weight.

The coating material for controlling plant growth of the present invention may be prepared by adding the above-mentioned polyethylene resin to the above-mentioned antifogging agent, antifog agent, inorganic compound,
Additives such as heat stabilizers may be added within a range that does not impair the purpose of the present invention.

The method for producing a laminated film is not particularly limited, but it can be produced by laminating an outer layer, an intermediate layer and an inner layer by a co-extrusion T-die method, a co-extrusion inflation method or the like.

The coating material for controlling plant growth of the present invention usually has a layer to which a pigment is added having a thickness of 10 to 150 μm. Preferably it is 20 to 120 μm. The thickness of the other layer to which no dye is added is usually 10 to 150 μm.
Preferably it is 20 to 100 μm. The thickness of the entire multilayer film is 30 to 200 μm. Preferably 60-1
80 μm.

The coating material for controlling plant growth of the present invention obtained by the above method does not lose wavelength selectivity even after long-term use, and has good retention of plant growth controllability.

[0036]

The present invention will be described below in further detail with reference to examples. The weathering acceleration test, ultraviolet transmittance, PPF transmittance, A value at the initial stage, after 2 years and after the acceleration test, and the plant growth control effect at the initial stage and 2 years after were measured by the following methods. Or rated. The resins, light stabilizers, ultraviolet absorbers and dyes used in the examples are described below. However, it is not limited to these.

(1) Weathering Acceleration Test <Testing machine> Sunshine carbon arc lamp type weathering testing machine, model: Weatherometer manufactured by Atlas, Model: CX
W type, <number of lamps> 1, <arc discharge> average voltage; 50V ±
2%, average current; 60A ± 2%, <spectral transmittance of filter (before use)> 255 nm; 1% or less, 302 nm;
68% or more, 375 nm or more; 90% or more, <temperature indicated by black panel thermometer> 63 ± 3 ° C., <irradiation> 400
Time continuous irradiation (interruption for carbon exchange etc. is considered continuous) <water spray condition>cycle; water spray 18 minutes,
No spraying 102 minutes, nozzle diameter: about 1 mm, surface; same as irradiation surface>, <water pressure> 100 ± 20 kPa, water volume: 2.1 ±
0.1 liter / min, <Other conditions> JIS B
According to -7753.

(2) Ultraviolet transmittance (%) spectrophotometer [manufactured by Hitachi, Ltd., model: U-350
0], the light transmittance at a wavelength of 290 to 400 nm is determined.

(3) PPF transmittance (%) spectrophotometer [Model: U-350, manufactured by Hitachi, Ltd.]
0], the transmittance for each wavelength at a wavelength of 400 to 700 nm is measured to obtain (Tλ), and D _{65 is used} as standard light.
The spectral distribution (Dλ) of the photon flux based on (JIS Z-8720) is obtained, and the equation (1) [Equation 1] is obtained.

[0040]

(Equation 1) To determine the PPF transmittance.

(4) The ratio of the photon flux of red light of 600 to 700 nm to the photon flux of far-red light of 700 to 800 nm spectrophotometer [manufactured by Hitachi, Ltd., type: U-350
0], a wavelength of 600 to 700 nm and a wavelength of 7
The transmittance for each wavelength from 00 to 800 nm was measured (T
λ) is determined and D ₆₅ (JIS Z-872) is used as standard light.
0), the spectral distribution (Dλ) of the photon flux is determined, and the expression (2) [Equation 2] is obtained.

[0042]

(Equation 2) A value is obtained from

(5) Evaluation of Plant Growth Control Action The coating material for plant growth control obtained in Examples or Comparative Examples was spread on a pipe house having a height of 2.5 m, a width of 3.6 m and a depth of 8 m. In test cultivation, a pot in which 7 samples of sunflower seedlings having a height of about 8 cm were planted in a house was cultivated in May 1996 for 10 days. The height of the plant is measured and the average value is determined. As a comparative test, a film containing no pigment was covered with a cold gauze and the PPF transmittance was adjusted to be approximately equivalent to the plant growth control coating material obtained in the examples or comparative examples (A value was 1. 08), the same plant growth control coating material as that obtained in each Example or each Comparative Example was produced and subjected to the same test. The ratio of the average height of the plants cultivated in the example or the comparative example to the average height of the plants cultivated in the comparative test was determined to evaluate the growth control effect. Heisei 10
In May, the same cultivation test was repeated. <Evaluation Criteria for Growth Control> If the ratio is 1.2 or more (promoting effect) or 0.8 or less (suppressing effect), the effect is evaluated as "significant". The ratio is 1.1 or more and less than 1.2 (promoting effect), or 0.8
Those with a super value of 0.9 or less (suppression effect) are evaluated as "effect is recognized". The above ratio is less than 1.1 times (acceleration effect),
Alternatively, those having a value of more than 0.9 (suppression effect) are evaluated as "slight effect".

(6) Raw materials used 1) Ethylene-α-olefin copolymer (referred to as resin A) Ethylene and 1-hexene were copolymerized in the presence of a metallocene catalyst to produce an ethylene-hexene copolymer. . (1-hexene content: 7.5% by weight, density: 0.
928 g / cm ³ , melt flow rate (MFR; AS
TM D-1238-65T, 190 ° C, load 2.16
kg): 1.63 g / 10 min] 2) High pressure method low density polyethylene (referred to as resin B) manufactured by Mitsui Chemicals, Inc., trade name: Mirason 104 (density:
0.922 g / cm ³ , melt flow rate: 0.61
g / 10 minutes) 3) Ethylene-vinyl acetate copolymer (referred to as resin C), manufactured by Mitsui-DuPont Polychemical Co., Ltd., trade name: EVA
FLEX P-1403 (vinyl acetate content: 14% by weight, density: 0.930 g / cm ³ , melt flow rate: 1.31 g / 10 minutes) 4) Light stabilizer: Cimasorb 944 (hindered amine-based) Light stabilizer) 5) UV absorber Kyodo Yakuhin Co., Ltd., trade name: Biosorb550 (benzotriazole-based UV absorber) 6) Dye ・ Dye for promoting growth (referred to as Dye D): manufactured by Sando Co., Ltd.
(Product name: SavinylBlue GLS, maximum absorption wavelength: 673 nm) ・ Dye for growth suppression (referred to as dye E): Chemical formula (3)

[0045]

Embedded image (Maximum absorption wavelength: 736 nm).

Example 1 <Resin composition for forming each layer><Outerlayer>: 85 parts by weight of resin A, 15 parts by weight of resin B, 0.2 parts by weight of light stabilizer, 0.6 parts by weight of ultraviolet absorber, <intermediate layer >: 85 parts by weight of resin A, 15 parts by weight of resin B, 0.2 parts by weight of light stabilizer, 0.6 parts by weight of ultraviolet absorber, dye D0.
32 parts by weight, <inner layer>: resin A 85 parts by weight, resin B15
Parts by weight, 0.1 parts by weight of light stabilizer. Using the above resin composition, co-extrusion inflation molding is performed at a molding temperature of 200 ° C., and a thickness of 150 μm (outer layer 60 μm, middle layer 60 μm,
A coating material for controlling plant growth comprising a three-layered film laminate having an inner layer of 30 μm) was produced. When the PPF transmittance and the A value of the obtained plant growth control coating material were determined by the above method, the PPF transmittance was 74% and the A value was 2.21. Further, the coating material for controlling plant growth was subjected to a 400-hour weathering acceleration test by the above method. After the test, when the transmittance was measured in the same manner,
The PPF transmittance was 77% and the A value was 2.01. Wavelength selectivity as a coating material for plant growth control is maintained,
The weather resistance was good. When the plant growth controlling coating material was spread on a pipe house, both workability and strength were good.

The coating material for controlling plant growth obtained in Example 1 was spread on a pipe house, and the effect of controlling plant growth was evaluated by the above method. As a result, the average height of sunflower seedlings (7 samples) cultivated for 10 days was 11.5 ±
0.4 cm, the stem length was 9.0 ± 0.4 cm, and the first internode length was 5.8 ± 0.4 cm. For comparison, a film containing no pigment was covered with cold gauze and the PPF transmittance was 72%.
(A value was 1.08), except that the cultivation was carried out under exactly the same conditions except that the average height was 17.6 ± 0.
7m, stem length 14.5 ± 0.7cm, first internode length 1
0.8 ± 0.6 cm.

From these results, it was confirmed that the growth control effect when the coating material having the A value of 2.21 was used was about 0.7 times that in the case of the comparative film having substantially the same PPF transmittance. did it. Two years later, sunflower seedlings were cultivated in the same pipe house. The average plant height is 1
2.2 ± 0.4 cm, stem length was 8.4 ± 0.3 cm, and first internode length was 5.3 ± 0.4 cm. As for the control effect, the above ratio was about 0.7, and it was confirmed that the growth control effect was maintained. The A value of the coating material for controlling plant growth after two years after being spread on a pipe house is 1.85, P
The PF transmittance was 77%. It was confirmed that the wavelength selectivity was maintained.

Examples 2 to 4 and Comparative Examples 1 to 4 A three-layer structure for controlling plant growth was prepared in the same manner as in Example 1 except that the resin composition shown in Table 1 or 2 was used. The material was manufactured. In the same manner as in Example 1, the obtained coating material was evaluated. The results are shown in [Table 1] or [Table 2].

Comparative Example 5 Methyl methacrylate 59 parts by weight, n-butyl methacrylate 33 parts by weight, hydroxyethyl methacrylate 6
Parts by weight, 100 parts by weight of an acrylic resin obtained by polymerizing a mixed monomer containing 2 parts by weight of methacrylic acid, and 15 parts of the ultraviolet absorbent are dissolved in methyl ethyl ketone,
A coating solution having a resin concentration of 10% by weight was prepared. This coating solution was applied on the outer layer surface of the plant growth controlling coating material obtained in Comparative Example 2 and dried to form an acrylic resin layer having a thickness of 2 μm. The film was evaluated in the same manner as in Example 1. The results are shown in [Table 2].

[0051]

[Table 1]

[0052]

[Table 2]

[0053]

Industrial Applicability The coating material for controlling plant growth according to the present invention is excellent in the action of promoting or suppressing the growth of plants and in its sustainability. Therefore, it is a coating material that is extremely useful in practice in the field of greenhouse horticulture and the like.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Ryu Oi 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Pref. (72) Inventor Osamu 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Chemical Co., Ltd. F-term (reference) 2B024 DA05 DB07 2B029 EB03 EC02 EC14 4F100 AH07H AH10H AK03A AK05A AK06A AK06B AK06C AK62B AK62C AK66B AK66C AK68A AL05B AL05C BA03 BA06 BA07 BA10A BA10C BA13 CA07A CA13B CA13C EJ20 GB01 JA20A JA20B JA20C JN08 JN08A JN30 JN30B JN30C YY00 YY00A YY00B YY00C 4J002 BB032 BB051 EE037 EE056 EJ067 EN066 EN076 ET006 ET007 EU026 EU177 EV046 EV306 EV346 FD040 FD057 FD096 FD206 GA00 GF00

Claims (9)

[Claims] 1. A plant growth controlling coating material formed of a polyolefin film having a multilayer structure comprising at least three layers of an outer layer, an intermediate layer, and an inner layer, wherein at least the outer layer contains a UV absorber. , At least one
The layer is a layer mainly composed of an ethylene-α-olefin copolymer containing a dye having a maximum absorption wavelength at 600 to 700 nm or 700 to 900 nm, and the transmittance of the photosynthetically effective photon flux of the coating material. Is 50% or more, 7
For the photon flux of far-red light of 00 to 800 nm, 60
The ratio of the photon flux of red light of 0 to 700 nm is 0.9 or less,
Or a coating material for controlling plant growth, wherein the average value of the spectral transmittance from 1.3 to 290 to 400 nm is 30% or less. 2. The coating material for controlling plant growth according to claim 1, wherein the content of the pigment is 0.001 to 2% by weight of the layer forming resin. 3. The dye-containing layer has a mixing weight ratio of 99/1 to 60/4 with an ethylene-α-olefin copolymer having 4 to 12 carbon atoms and a high-pressure low-density polyethylene.
The coating material for controlling plant growth according to claim 1, which is a mixed resin layer of 0. 4. The coating material for controlling plant growth according to claim 1, wherein the pigment-containing layer is an intermediate layer or an inner layer. 5. The content of the ultraviolet absorbent is 0.05 to 3 g / m ² in the whole multilayer film.
The coating material for controlling plant growth according to the above. 6. The coating material for controlling plant growth according to claim 1, wherein the average value of the spectral transmittance at 290 to 400 nm transmitted through the outer layer is 30% or less. 7. The non-dye-containing layer is a low-density polyethylene, a medium-density polyethylene, a high-density polyethylene,
2. The coating material for controlling plant growth according to claim 1, which is a film containing at least one polyolefin resin selected from linear low-density polyethylene and ethylene-vinyl acetate copolymer. 8. The ratio of the photon flux of the red light of 600 to 700 nm to the photon flux of the far red light of 700 to 800 nm with a transmittance of the photosynthetic effective photon flux of 50% or more after being spread outdoors for two years is 0%. The coating material for controlling plant growth according to claim 1, wherein the coating material is not more than 0.9 or not less than 1.3. 9. The dye-containing layer has a thickness of 10 to 150.
μm, the thickness of the other layer containing no dye is 10 to 150 μm
m, and the total thickness of the laminated film is 30 to 20.
The coating material for controlling plant growth according to any one of claims 1 to 8, which has a thickness of 0 µm.