JPH0736724B2 - Seeding and raising seedling sheet using ultraviolet curing adhesive and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seeding and raising sheet used for seeding and raising seedlings in a field, and more particularly to a seeding and raising sheet suitable for seeding and raising small seeds and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, sowing work in a field is generally performed by hand, and in some cases, sowing is also performed by a machine. In addition, by further promoting labor saving of sowing, so-called seed tape in which seeds are enclosed in water-soluble tape, seed paper in which seeds are fixed on water-soluble paper with an adhesive, etc. are put on the field or nursery to germinate and grow seedlings. Some have been done. Further, a seeding and raising seedling sheet suitable for a cultivation method in which seedlings are preliminarily sown at a specific place to grow seedlings has been developed in recent years (Japanese Patent Laid-Open No. 64-20035, Japanese Patent Laid-Open No. 1-296909, etc.).
The seed tape, which was developed for the purpose of labor saving sowing, is a seed that is physically contained in a tape made of a water-soluble film so as not to fall off, and it is difficult to keep the positions between seeds at an appropriate distance. It may also damage the seedlings. Further, the seed paper is a paper in which the seed is fixed with a water-soluble adhesive, which is excellent in setting and fixing the position of the seed, but since the position where the adhesive and the seed are dropped is mechanically determined, It is difficult to make patterns with closely spaced seeds, and it is difficult to apply to very small seeds.
Since the seeding and raising seedling sheet developed in recent years is not intended to firmly fix the seeds, it is not necessarily suitable to arbitrarily perform the work with the seeds mounted on the sheet.

[0003]

In the above-mentioned prior art, in the sowing work, when seeding is carried out by hand sowing or by using a sowing device or a sowing tool, a predetermined number of seeds,
It is extremely difficult to sow at a predetermined interval. Therefore, it is necessary to carry out thinning work after germination and growth, which requires enormous time and labor, and labor saving has been strongly desired. Further, regarding the seeding and raising seedling sheet, it was desired that the seeds be firmly fixed to the tape.

The object of the present invention is to solve the problems of the above-mentioned prior art, and to arrange seeds in an arbitrary pattern and interval.
And a seeding and raising sheet which is firmly fixed so that it can be easily handled without fear of falling off, can flexibly respond to sowing and raising seedlings of various flowers, vegetables, etc. and can contribute to labor saving of seeding and It is to provide the manufacturing method.

[0005]

[Means for Solving the Problems] The above object is to provide a pressure-sensitive adhesive composition obtained by applying a mixed solution comprising the following four components to a predetermined position on a sheet-shaped support on which the roots of young plants can easily penetrate and expand. By seeding and raising seedling sheet using an ultraviolet-curable adhesive characterized by fixing the seed by, (A) alkyl group having 1 to 14 carbon atoms (meth) acrylic acid alkyl ester monomer 80 to 99.9 wt% 100 parts by weight of an acrylic polymer having a weight average molecular weight of 50,000 to 300,000 obtained by polymerizing 0.1 to 20% by weight of a copolymerizable ethylenic monomer containing a functional group, and (B) capable of reacting with a functional group of the acrylic polymer. Cross-linking agent
0.01 to 20 parts by weight, (C) 5 to 100 parts by weight of a polyfunctional oligomer containing two or more unsaturated double bonds in the molecule, (D) 0.1 to 10 parts by weight of a photoinitiator, and the following 4 After applying a pressure-sensitive adhesive composition comprising the components to a predetermined position on a sheet-shaped support where roots of seedlings can easily penetrate and spread, seeds are adhered to the pressure-sensitive adhesive and then irradiated with ultraviolet rays. It can be achieved by a method for producing a seedling-growing sheet using an ultraviolet-curable pressure-sensitive adhesive, which comprises curing the pressure-sensitive adhesive to fix the seed to the support.

(A) 80 to 99.9% by weight of a (meth) acrylic acid alkyl ester monomer having an alkyl group having 1 to 14 carbon atoms and a copolymerizable ethylenic monomer having a functional group of 0.1 to 2
100 parts by weight of an acrylic polymer having a weight average molecular weight of 5 to 300,000, which is obtained by polymerizing 0% by weight, (B) 0.01 to 20 parts by weight of a crosslinking agent capable of reacting with a functional group of the acrylic polymer, (C) 2 in the molecule. 5 to 100 parts by weight of a polyfunctional oligomer containing one or more unsaturated double bonds, and (D) a photoinitiator of 0.1 to 10 parts by weight.

Various kinds of curable pressure-sensitive adhesives for fixing seeds can be used, but when the thermosetting pressure-sensitive adhesives are used, heat of curing may damage the tissues and components of the seeds. Also, high energy ionizing radiation, deep ultraviolet rays, etc. can be used for curing the pressure-sensitive adhesive, but this is also not preferable because there is a high possibility that the radiation will damage the seeds. Adhesives that cure with near UV light are most suitable. However, since there is a problem that it is difficult to apply a fine dot coating when using an ultraviolet curable pressure-sensitive adhesive currently on the market, and it may have an adverse effect on the growth of seedlings even after curing, the present invention Those who maintain the adhesive property sufficient to capture the seeds before the irradiation with ultraviolet rays, after the irradiation with ultraviolet rays develops the adhesiveness that can firmly fix the seeds so that the seeds do not fall off in the normal operation, , A novel pressure-sensitive adhesive composition that retains excellent printing characteristics capable of long-term fine-dot printing coating and does not have a component that inhibits the growth of plant seedlings after UV curing is synthesized. The above problem was solved by applying it to the production of a sowing sheet.

[0008]

[Function] Since the adhesive has sufficient adhesiveness to capture seeds, if it is accurately applied at a predetermined position on a support such as water-soluble paper, the support can be sprinkled with the support to support it. Seeds can be applied at desired locations on the top at desired intervals. By curing this pressure-sensitive adhesive, it is possible to prevent the seeds from falling off during various handlings during the production of the sheet, during transportation, and the like. Further, by using an ultraviolet-curable adhesive as the adhesive, it is possible to firmly fix the seed to the support without causing physiological damage to the seed. When the seeding sheet produced by the above means is applied to a field, seeds can be rapidly seeded at a predetermined position by a predetermined number of grains.

Here, the adhesive used in the seedling raising seedling sheet of the present invention will be described. As a result of extensive and experimental studies, the present inventors have found that an adhesive comprising the following components (A), (B), (C) and (D) can achieve the above object.

The component (A) is an acrylic polymer, which is the base of the adhesive. Among these, as the main monomer, an alkyl group (meth) acrylic acid alkyl ester monomer having 1 to 14 carbon atoms, such as methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, pentyl acrylate, isopentyl acrylate, hexyl acrylate, octyl. Examples thereof include acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, lauryl methacrylate and the like. Main monomer is 80% by weight
It is desirable to contain the above components, and if it is less than 80% by weight, the tackiness will decrease. Further, as the ethylenic monomer having a functional group to be copolymerized with the main monomer, acrylic acid, methacrylic acid, itaconic acid, fumaric acid or the like having a carboxyl group-containing monomer, 2-hydroxyethyl acrylate, 2-hydroxyethyl Monomers containing hydroxyl groups such as methacrylate, monomers containing epoxy groups such as glycidyl methacrylate, acrylic amide,
Methacrylic amide, acrylonitrile, methacrylonitrile, dimethylaminoethyl methacrylate, dimethylaminopropyl acrylate, etc. can be mentioned. These are the crosslinking points of the polymer. If necessary, monomers such as vinyl acetate, styrene, α-methylstyrene may be copolymerized. The weight average molecular weight of the acrylic polymer is preferably from 50,000 to 300,000, and if it is less than 50,000, bleeding into the substrate will occur. On the other hand, when it is 300,000 or more, the screen printing characteristics are deteriorated and the mesh is clogged, stringing and the like are not preferable. In addition, acrylic polymer is solution polymerization,
It may be produced by any polymerization method such as suspension polymerization, emulsion polymerization, bulk polymerization, etc., but it is finally necessary to use a solvent-free type capable of screen printing or a high boiling point solution type.

The component (B) is a cross-linking agent capable of reacting with the functional group of the acrylic polymer, and prevents bleeding, bleeding and flow into the substrate even when a low-molecular-weight polyfunctional oligomer is blended, and it has an adhesive property. It is necessary to maintain sufficient viscoelasticity as an agent. As the cross-linking agent capable of reacting with the functional group,
Bifunctional or higher functional epoxy resin, polyisocyanate, melamine resin, urea resin, metal chelate, etc. can be mentioned. (C) component is a polyfunctional oligomer containing two or more unsaturated double bonds in one molecule, Specifically, dicyclopentenyl acrylate, dicyclopentenyl oxyethyl acrylate, 1,3-butanediol diacrylate, 1,4
-Butanediol diacrylate, 1,6-hexanediol diacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, polyethylene glycol 400 diacrylate, hydroxypivalate neopentyl glycol diacrylate, tripropylene glycol diacrylate, 1,3 -
Bis (3'-acryloxyethoxy-2'-hydroxypropyl) -5,5-dimethylhydantoin, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, dipentaerythritol monohydroxypentaacrylate, dipenta In addition to erythritol hexaacrylate or these methacrylates, various commercially available oligomers and the like can be mentioned, and one or more of these may be used. The addition amount is preferably 5 to 100 parts by weight with respect to 100 parts by weight of the acrylic polymer.If it is 5 parts by weight or less, curing by ultraviolet rays is insufficient, and if it is 100 parts by weight or more, it is overcured, and seeds fall off due to vibration, impact, etc. Is likely to occur. Preferably, 10 to 60 parts by weight are suitable.

Component (D) is a photoreaction initiator, and specific examples thereof include benzophenones, Michler's ketone, chlorothioxanthone, benzylmethyl ketal, and 2-hydroxymethylphenyl propane. These 1 type (s) or 2 or more types are used, and 0.1-10 weight part is added.

Next, the support for holding the above-mentioned adhesive will be briefly described. As the support, water-soluble film, water-soluble paper, etc. are suitable. Specifically, the water-soluble film is made of polyvinyl alcohol, the water-soluble paper is made of a mixture of a woody pulp and a water-soluble resin such as carboxymethyl cellulose, and various other materials. There is a combination of layers. These supports can be appropriately selected and used so as to be compatible with the kind of seeds, the seeding method and the like.

Next, a method of applying the pressure-sensitive adhesive will be briefly described. The pressure-sensitive adhesive is applied on the support in a desired shape and at a desired interval. The shape of the adhesive must be dot-like and small enough to be suitable for mounting seeds one by one. Screen printing is most suitable for this. When the pressure-sensitive adhesive is a solvent-free pressure-sensitive adhesive, it is subjected to the seed mounting step as it is, and when the pressure-sensitive adhesive is a solvent-based pressure-sensitive adhesive, the solvent is removed by heating after coating and then used for seed mounting.

In order to mount the seed on the sheet coated with the adhesive, a simple operation such as sprinkling the seed on the sheet may be carried out. Excess seeds other than those attached to the adhesive can be easily removed by tilting the sheet.

Next, in order to prevent the loaded seeds from falling off,
The adhesive is solidified to firmly fix the seed to the support. That is, since the pressure-sensitive adhesive of the above composition has a property of being crosslinked and cured by ultraviolet rays, ultraviolet rays are irradiated from above the seeds or, in some cases, from the back surface of the support to cure the pressure-sensitive adhesive. If the seed completely covers the pressure-sensitive adhesive layer or if the support is too thick when irradiating ultraviolet rays from the back surface of the support, the pressure-sensitive adhesive may not cure,
According to the experiments conducted by the present inventors, it is possible to realize a curing state sufficient to fix the seeds by the irradiation method as described above. Further, for the purpose of using the sheet of the present invention, it is not always necessary to completely cure the pressure-sensitive adhesive, and if the seeds can be prevented from falling off, the pressure-sensitive adhesive may be semi-cured and flexible.

Ultraviolet rays used for curing the pressure-sensitive adhesive should be those having a too short wavelength in order to prevent seed damage. Since the resistance to ultraviolet rays differs depending on the type of seed, it cannot be said unequivocally, but short-wavelength ultraviolet rays having a wavelength shorter than the wavelength in the ozone generation region are not preferable. That is, wavelength 230n
It is desirable to irradiate ultraviolet rays of m or more. The pressure-sensitive adhesive having the above composition is an ultraviolet-crosslinking pressure-sensitive adhesive having a spectral sensitivity in the ultraviolet region with a wavelength of 290 nm or more, and meets this condition.

Even if the ultraviolet rays used for curing the pressure-sensitive adhesive are in the long wavelength region, the seeds will be damaged if exposed to high temperature heat for a long time during the irradiation of ultraviolet rays. Therefore, heat rays generated from the light source of the ultraviolet irradiation device must be sufficiently removed so that the seeds are not exposed to high temperature. Most seeds will not be damaged even if they are left in that atmosphere for a long time if the temperature is about 50-60 ° C or less, so cool the device so that the temperature of the UV irradiation part does not rise any more. Is desirable.

As described above, materials such as adhesives and supports to be used,
The method of applying the pressure-sensitive adhesive, the method of mounting the seed, the method of curing the pressure-sensitive adhesive with ultraviolet rays, and the like have been described, but these are merely the essential points for explaining the configuration of the present invention.

[0020]

EXAMPLES The constitution of the present invention will be specifically described below with reference to examples.

[0021]

[Example 1] 92 parts by weight of butyl acrylate in a reactor equipped with a thermometer, a stirrer, a nitrogen introducing tube, a reflux cooling tube, and the like.
Acrylic acid 8 parts by weight, azobisisobutyronitrile 0.2
Parts by weight, 40 parts by weight of xylene, 60 parts by weight of cyclohexanone were charged, and after the inside of the reactor was made a nitrogen atmosphere, the mixture was heated to 65 ° C. to carry out a polymerization reaction, and after 12 hours, an acrylic polymer having an average molecular weight of 200,000 was prepared. Obtained. To a reaction liquid containing this polymer, 0.8 part by weight of a tetrafunctional epoxy compound was added as a crosslinking agent to 100 parts by weight of the acrylic polymer, and 15 parts by weight of trimethylolpropane triacrylate as a polyfunctional oligomer and benzophenone as a photopolymerization initiator. 0.5 part by weight was added to obtain an ultraviolet-curable adhesive.

Next, the UV-curable pressure-sensitive adhesive was printed and coated on water-soluble paper in a dot shape having a diameter of 1 mm. Since this dot-coated adhesive has sufficient adhesiveness to fix the seeds, the seeds of Komatsuna were adhered on the adhesive. Then, the seeds were fixed by irradiating them with ultraviolet rays of 400 mJ / cm ² using an ultraviolet irradiator using a high-pressure mercury lamp equipped with a cooling device as a light source. The fixed state of the seeds was sufficient to withstand the subsequent transportation and sowing work.

Further, the above-mentioned seed mounting sheet was transferred to a nursery box on which a urethane mat was placed, and water was applied to conduct a germination test.

Further, stock seeds were mounted in the same manner as Komatsu rape seeds and fixed by irradiation with ultraviolet rays so as not to fall off. This seed mounting fixed sheet was placed on a seed bed whose temperature was adjusted to 25 ° C with the seed mounting surface facing upward, and the seeds were irrigated without soil to perform a germination test.

[0025]

Example 2 As Raw Material for Acrylic Polymer Synthesis 2-
A polymerization reaction was performed in the same manner as in Example 1 except that a mixture of 90 parts by weight of ethylhexyl acrylate and 10 parts by weight of maleic acid was used to synthesize an acrylic polymer having an average molecular weight of 260,000. Next, 0.1 part by weight of a tetrafunctional epoxy compound as a cross-linking agent was added to 100 parts by weight of the acrylic polymer in a reaction liquid containing the acrylic polymer, and 15 parts by weight of dipentaerythritol hexaacrylate as a polyfunctional oligomer and a photoreaction start. 0.5 parts by weight of the agent benzoin methyl ether was added to obtain an ultraviolet-curable adhesive.

The pressure-sensitive adhesive was printed on water-soluble paper in the same manner as in Example 1 and the komatsuna and stock seeds were mounted and fixed for characteristic evaluation.

[0027]

Example 3 55 parts by weight of butyl acrylate, 40 parts by weight of 2-ethylhexyl acrylate and 2-hydroxyethyl methacrylate as raw materials for synthesizing acrylic polymer 5
A polymerization reaction was carried out in the same manner as in Example 1 except that a mixture of parts by weight was used to synthesize an acrylic polymer having an average molecular weight of 225,000. Next, to the reaction liquid containing this acrylic polymer, 2.0 parts by weight of tetrabutyl titanate was added as a cross-linking agent to 100 parts by weight of the acrylic polymer, and 20 parts by weight of 1,6-hexanediol diacrylate as a polyfunctional oligomer and an optical catalyst were added. A reaction initiator 4'-isopropyl-2-hydroxy-2-methylpropiophenone (1.0 part by weight) was added to obtain a UV-curable adhesive.

This pressure-sensitive adhesive was printed on water-soluble paper in the same manner as in Example 1, and then the komatsuna and stock seeds were mounted and fixed, and the characteristics were evaluated.

[0029]

Example 4 Polymerization was carried out in the same manner as in Example 1 except that a mixture of 95 parts by weight of isononyl acrylate and 5 parts by weight of 2-hydroxyethyl acrylate was used as a raw material for synthesizing an acrylic polymer, and the average molecular weight was 18 Many acrylic polymers have been synthesized. Next, 1.0 part by weight of Coronate L as a cross-linking agent was added to the reaction solution containing the acrylic polymer, and 20 parts by weight of pentaerythritol triacrylate as a polyfunctional oligomer and 0.5 part by weight of a photoinitiator benzophenone were added to the ultraviolet curing type. An adhesive was obtained.

The pressure-sensitive adhesive was printed on water-soluble paper in the same manner as in Example 1 and the komatsuna and stock seeds were mounted and fixed for characteristic evaluation.

[0031]

Comparative Example 1 Using the same monomer composition as in Example 1, 40 parts by weight of toluene and 60 parts by weight of ethyl acetate were polymerized to synthesize an acrylic polymer having a weight average molecular weight of 440,000.

Using the reaction liquid containing the acrylic polymer to which the same crosslinking agent and UV-polymerizable polyfunctional oligomer as in Example 1 were added, the same characteristic evaluation as in Example 1 was performed.

[0033]

Comparative Example 2 All of Example 1 except that the UV-polymerizable polyfunctional oligomer of Example 1 and the photoinitiator were not used.
The same characteristic evaluation as in Example 1 was performed using the same material as in.

[0034]

[Comparative Example 3] The same property evaluation as in Example 1 was carried out for the same treatment as in Example 3 except that the crosslinking agent Coronate L of Example 3 was not used.

[0035]

Comparative Example 4 100 parts by weight of butyl acrylate, 0.2 parts by weight of azobisisobutyronitrile, 50 parts by weight of xylene, 50 parts of cyclohexanone as raw materials for synthesizing acrylic polymer
A polymerization reaction was performed in the same manner as in Example 1 except that a mixture of parts by weight was used to synthesize an acrylic polymer having an average molecular weight of 200,000.

Next, using the reaction liquid containing the acrylic polymer to which the same crosslinking agent, polyfunctional oligomer and photoreaction initiator as in Example 1 were added, the same characteristic evaluation as in Example 1 was performed. It was

Table 1 summarizes the evaluation results of the screen printability, UV curability, seed fixability and germination ability of the samples of Examples 1 to 4 and Comparative Examples 1 to 4 above.

[0038]

[Table 1]

[0039]

As described above, the seeding and raising sheet and the method for producing the same are used as the seeding and raising sheet and the method for producing the same according to the present invention. The seeds are firmly fixed in an arbitrary pattern and at intervals so that they can be easily handled without fear of falling off, and it is possible to flexibly respond to seeding and raising seedlings of various flowers, vegetables, etc., contributing to labor saving of sowing It was possible to provide a seedling raising seedling sheet and a method for producing the same. In addition, by doing so, it is possible to provide high-performance seedling raising seedling sheets to farmers, etc., which can contribute to labor saving and efficiency improvement of seeding work, and also to provide high quality flowers and vegetables to the public. Becomes

Front page continuation (72) Inventor Norimasa Kamezawa 3819 Noborito, Tama-ku, Kawasaki City, Kanagawa Prefecture Sliontech Co., Ltd. 72) Inventor Yuji Ikeda 130 Kamihirose Mukaida, Sayama City, Saitama Prefecture Soken Chemical Co., Ltd. Sayama Plant

Claims (3)

[Claims] 1. A seed is fixed with a pressure-sensitive adhesive composition obtained by applying a mixed solution comprising the following four components to a predetermined position on a sheet-shaped support on which seedling roots can easily penetrate and expand. Seedling raising seedling sheet using a UV-curable pressure sensitive adhesive, (A) a copolymerizable ethylene containing 80 to 99.9% by weight of a (meth) acrylic acid alkyl ester monomer having 1 to 14 carbon atoms of an alkyl group and a functional group. 100 parts by weight of an acrylic polymer having a weight average molecular weight of 50,000 to 300,000, which is obtained by polymerizing 0.1 to 20% by weight of a polymerizable monomer, and (B) a crosslinking agent 0.01 capable of reacting with a functional group of the acrylic polymer.
˜20 parts by weight, (C) 5 to 100 parts by weight of a polyfunctional oligomer containing two or more unsaturated double bonds in the molecule, (D) 0.1 to 10 parts by weight of a photoinitiator. 2. A seedling-growing sheet using an ultraviolet-curable pressure-sensitive adhesive according to claim 1, wherein the sheet-shaped support is a support made of water-soluble or water-dispersible paper or polymer film. . 3. A pressure-sensitive adhesive composition comprising the following four components is applied to a predetermined position on a sheet-shaped support where roots of young plants can easily penetrate and grow, and then seeds are adhered to the pressure-sensitive adhesive. , Then, a method for producing a seedling-growing sheet using an ultraviolet-curable adhesive, which comprises irradiating ultraviolet rays to cure the adhesive to fix the seeds to the support, (A) the carbon number of the alkyl group 1 to 14 (meth) acrylic acid alkyl ester monomer 80 to 99.9% by weight and a copolymerizable ethylenic monomer containing a functional group 0.1 to 20% by weight, an acrylic resin having a weight average molecular weight of 50 to 300,000. 100 parts by weight of polymer, (B) 0.01 crosslinker capable of reacting with functional groups of acrylic polymer
˜20 parts by weight, (C) 5 to 100 parts by weight of a polyfunctional oligomer containing two or more unsaturated double bonds in the molecule, (D) 0.1 to 10 parts by weight of a photoinitiator.