JP2015008648A - Fiber for plant growth and fiber sheet comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fiber for plant growth with high water absorption in which a biodegradable fiber is chemically bound to a water-absorbing component and a plant nutrient.SOLUTION: A fiber for plant growth has biodegradability and water absorption, and is bound to a compound containing at least one element, which is a fertilizer component essential to plant growth, selected from nitrogen, phosphorus and potassium. The fiber can be used as a sheet. The fiber can hold water essential to plant growth and gradually provide the fertilizer component to a plant with biodegradation of the fiber. Consequently, the present invention provides a fiber for plant growth which is free of a problem of environmental pollution and a fiber sheet comprising the same.

Description

  The present invention relates to a fiber for plant growth in which a chemical bond of a water-absorbing component and a plant nutrient are chemically bonded to a biodegradable fiber, and a fiber sheet including the same.

  The three elements of plant nutrients are N (nitrogen), P (phosphorus), and K (potash). These are usually applied with fertilizers. Among these, N (nitrogen) flows out with rainwater or easily escapes in place of gas, so it is preferable to apply fertilization separately. However, depending on the vegetation state of the plant, there may be a problem that it is difficult to apply fertilizer by additional fertilization or cost is increased. For example, in afforestation in the mountains, greening of deserts, greening of large areas, lawn management of golf courses, fertilizing methods that do not require human intervention are desired.

  As a prior art, at least one element selected from phosphorus and nitrogen is provided on at least one surface of a biodegradable fiber sheet, and there is a proposal to provide a flame-retardant resin coating layer that does not contain a halogen and to be used as a fertilizer for plant cultivation ( Patent Document 1). There is also a proposal of dispersing fertilizer and activated carbon in a cellulose fiber sheet and using it as a vegetation mat (Patent Documents 2 to 3).

Japanese Patent Laid-Open No. 2003-211592 JP 2002-125450 A JP 2006-517414 A

   However, the prior art fibers have a problem of insufficient water absorption.

  In order to solve the above-described conventional technique, the present invention provides a fiber for growing plants and a fiber sheet containing the same, wherein the biodegradable fiber is chemically bonded to a chemical bond of a water-absorbing component and a plant nutrient, and has high water absorption. .

  The plant-growing fiber of the present invention is biodegradable plant-growing fiber, and the plant-growing fiber has water absorption and is composed of nitrogen, phosphorus and potassium which are fertilizer components essential for plant growth. It is a fiber in which a compound containing at least one selected element is bonded.

  The fiber sheet of this invention is a sheet | seat containing the said fiber for plant cultivation.

  The present invention provides water necessary for plant growth by combining a biodegradable fiber with a compound containing at least one element selected from nitrogen, phosphorus and potassium, which are essential fertilizer components for water absorption and plant growth. The fertilizer component can be gradually imparted to the plant as the fiber biodegrades. In addition, the fiber for plant cultivation which does not have a problem of environmental pollution, and the fiber sheet containing this can be provided.

FIG. 1 is a graph showing the measurement results of potassium content in one example of the present invention. FIG. 2 is a graph showing the measurement results of phosphorus content in one example of the present invention.

  The present invention is a fiber obtained by binding a biodegradable fiber to a compound containing at least one element selected from nitrogen, phosphorus and potassium, which are fertilizer components essential for water absorption and plant growth. Preferably, the plant-degrading fiber having biodegradability is obtained by binding a water-absorbing compound to biodegradable fiber, and the combined compound contains nitrogen as a fertilizer component essential for plant growth. And at least one element selected from phosphorus and potassium.

A water-absorbing compound is bound to a biodegradable fiber, and the bound compound is used for producing a fiber having at least one element selected from nitrogen, phosphorus and potassium, which are fertilizer components essential for plant growth. Examples of the method include the following.
(1) A method in which a water-absorbing compound is bonded to the biodegradable fiber in advance, and at least one element selected from nitrogen, phosphorus and potassium is bonded to the bonded water-absorbing compound.
(2) A method in which a compound having at least one element selected from nitrogen, phosphorus and potassium is bonded to the biodegradable fiber in advance, and a water-absorbing compound is bonded to the bonded compound.
(3) A water-absorbing compound and at least one element selected from nitrogen, phosphorus and potassium are combined in advance to produce a compound having the water-absorbing property and at least one element selected from nitrogen, phosphorus and potassium. Bonding to degradable fiber.

  As a preferred example, a compound is grafted to form a superabsorbent fiber, and at least one element selected from nitrogen, phosphorus and potassium, which are fertilizer components essential for plant growth, is bound to the grafted compound. It is set as the fiber for plant growth and the fiber sheet containing this. Alternatively, at least one compound selected from an organic group containing phosphoric acid, an organic group containing carboxylic acid, and a ketone group-containing compound is brought into contact with the biodegradable fiber for graft bonding, and plant growth is performed on the grafted compound. At least one element selected from nitrogen, phosphorus and potassium, which are essential fertilizer components, may be combined.

  Various biodegradable fibers are known, for example, cellulose fibers, fibers containing cellulose and protein, animal hair fibers, silk, polylactic acid or polyvinyl alcohol. Among these, it is preferable in terms of cost to use cellulose fibers. Cellulose fibers include natural cellulose such as cotton and regenerated cellulose fibers such as rayon. There is also a fiber containing rayon and protein (Japanese Patent Laid-Open No. 2010-24595, trade name “Lunacel” sold by the applicant). Natural cellulose fibers are natural fibers such as cotton, hemp (including flax, ramie, jute, kenaf, cannabis, manila hemp, sisal hemp, New Zealand hemp), kapok, banana, and palm. The fiber is used in cotton or sheet form. In the case of natural cellulose fibers, such as cotton, the water absorption is synergistically improved by chemically bonding at least one component selected from phosphates, carboxylates and ketone group-containing compounds. Furthermore, water absorption can be further improved by performing mercerization.

  In an example of the present invention, at least one component selected from at least a phosphate, a carboxylate, and a ketone group-containing compound is fixed to the fiber by a chemical bond. As the phosphate, a phosphate ester salt is preferable. As the carboxylate, acrylate and iminodiacetate are preferable. The ketone group-containing compound is not particularly limited, but for example, acetylacetones, bainzoylacetones and diacetones are preferably used, and one or more selected from the group consisting of ethylene glycol monoacetoacetate monomethacrylate and diacetone acrylamide It is more preferable that The rate of weight increase due to chemical bonding is preferably 0.1 to 50% by weight. Within this range, the hydrophilicity can be kept high.

  In a specific method, the step of irradiating the fiber with an electron beam, and bringing the fiber into contact with at least one compound selected from an organic group containing phosphoric acid, an organic group containing carboxylic acid, and a ketone group-containing compound is chemically bonded, Preferably, a step of graft bonding is included. The electron beam irradiation step may be before and / or after the step of contacting at least one compound selected from an organic group containing phosphoric acid, an organic group containing carboxylic acid, and a ketone group-containing compound. Graft bonding can be performed in any order.

  When an organic base material containing phosphoric acid, for example, mono (2-methacryloyloxyethyl) phosphate (also known as 2- (methacryloyloxy) ethyl phosphate, hereinafter referred to as “P1M”) is applied to cellulose fibers by electron beam irradiation. As shown in the following (Chemical Formula 2) and / or (Chemical Formula 3), P1M is graft-bonded to the cellulose, and then neutralized with potassium phosphate salt as shown in the following (Chemical Formula 4) and / or (Chemical Formula 5). Become.

  When, for example, acrylic acid is used as the organic group substance containing carboxylic acid, acrylic acid is grafted to the cellulose shown in the following (Chemical Formula 7) and / or (Chemical Formula 8) by electron beam irradiation, and then neutralized to perform the following process. It becomes a carboxylic acid potassium salt as in (Chemical Formula 9) and / or (Chemical Formula 10).

  As an organic group substance containing a carboxylic acid, for example, when glycidyl methacrylate is graft-bonded to cellulose fiber and iminodiacetic acid (chelate group) is introduced and neutralized, the following chemical formula (12) and / or Glycidyl methacrylate is grafted to cellulose as in (Chemical Formula 13), and then iminodiacetic acid (chelate group) is introduced as in (Chemical Formula 14) and / or (Chemical Formula 15) below. It becomes a carboxylic acid potassium salt as in (Chemical Formula 16) and / or (Chemical Formula 17).

  In another method of the present invention, an aqueous solution containing phosphoric acid and urea is brought into contact with a dough containing cellulose fibers, and a phosphate ester is chemically bonded, preferably covalently bonded, to the cellulose fibers. More preferably, it is then neutralized with an alkali. For example, a cellulose fiber fabric is padded with an aqueous solution containing phosphoric acid and urea (hereinafter also simply referred to as a phosphating solution), and a phosphate ester is covalently bonded to the cellulose fiber. For example, when the phosphoric acid treatment liquid is 100% by weight, 85% by weight phosphoric acid is 10% by weight, urea is 30% by weight, and the rest is water. At this time, the pH is preferably about 2.1. As another example of the phosphoric acid treatment liquid, when the phosphoric acid treatment liquid is 100% by weight, 85% by weight phosphoric acid is 10% by weight, urea is 30% by weight, 28% by weight ammonia water is 8% by weight, The rest is water. At this time, the pH is preferably about 6.5. The pH can be adjusted using an arbitrary amount of aqueous ammonia. The treatment conditions are preferably a temperature of 100 to 180 ° C. and a treatment time of 0.5 to 5 minutes. For example, by this treatment, the phosphate ester can be covalently bonded to the cellulose fiber in an amount of 0.1% by weight or more, preferably 2 to 8% by weight, particularly preferably 5 to 8% by weight.

The cellulose molecule is represented by the following (Chemical Formula 18) (where n is an integer of 1 or more), and has a hydroxyl group rich in reactivity at the C-2, C-3, and C-6 positions of the glucose residue. It is presumed that phosphoric acid is an ester bond. For example, an example in which phosphoric acid is ester-bonded at the C-2 position of the glucose residue is shown below (Chemical Formula 20). In the following (Chemical Formula 20), the —CH ₂ — group to which phosphoric acid is ester-bonded is a hydrocarbon group in the cellulose chain. Next, neutralization treatment results in a potassium phosphate salt as shown below (Chemical Formula 21).

  The chemical formulas 19 to 20 are considered to be the following chemical formulas 22 to 24. Chemical formula 22 is the case where the molar ratio of phosphorus to nitrogen is 1: 1, chemical formulas 23 to 24 are esterified products having a high phosphorus content, and chemical formula 24 has a crosslinked structure.

  As described above, fibers containing N (nitrogen) have chemical formulas 14 to 17 and chemical formulas 22 to 24, and fibers containing P (phosphorus) have chemical formulas 1 to 5 and chemical formulas 19 to 24, and K ( The fiber containing potassium) has chemical formula 4 to chemical formula 5, chemical formula 9 to chemical formula 10, chemical formula 16 to chemical formula 17, and chemical formula 21. If these fibers are mixed, the three elements of fertilizer can be satisfied.

  In the case of irradiation with an electron beam, an irradiation dose of 1 to 200 kGy, preferably 5 to 100 kGy, more preferably 10 to 50 kGy may be achieved. Irradiation is preferably performed under a nitrogen atmosphere as the atmospheric condition, and since there is a permeability, it is only necessary to irradiate one side of the material. A commercially available electron beam irradiation apparatus can be used. For example, as an area beam type electron beam irradiation apparatus, EC250 / 15 / 180L (manufactured by Eye Electron Beam), EC300 / 165/800 (eye electron beam company) And EPS300 (manufactured by NHV Corporation) are used. After irradiation with an electron beam, unreacted components are usually removed by washing with water and drying is performed. Drying is achieved, for example, by holding the material at 20-85 ° C. for 0.5-24 hours.

  In the present invention, it is preferable to apply the processing agent as described above after previously irradiating the fiber material with radiation, and it is particularly preferable to irradiate the radiation again after applying the processing agent. As a result, chemical bonding by graft bonding of the radical polymerizable compound to the fiber material is promoted, and water absorption exothermicity is more effectively expressed. For chemical bonding by graft bonding, the presence of a specific element contained in the grafted product is confirmed by a device employing a fluorescent X-ray analysis method, for example, a wavelength dispersive X-ray fluorescence analyzer ZSX 100e (manufactured by Rigaku Corporation). Can be detected. The specific element is, for example, potassium.

  The fiber sheet of the present invention may be a sheet containing 100% by weight of the fiber for plant growth, but is a fiber sheet containing 10 to 100% by weight of the fiber for plant growth of the present invention, and a ratio of 90% by weight or less to this. In addition, at least one biodegradable fiber selected from cellulose fiber, animal hair fiber, silk, polylactic acid and polyvinyl alcohol may be added. The fiber sheet may be a card web as an example, and the nonwoven fabric sheet may be formed by integrating fibers by needle punching, hydroentanglement, chemical bonding, or the like.

  Hereinafter, the present invention will be described more specifically with reference to examples. The present invention is not limited to the following examples.

Example 1
<Preparation of acrylic acid graft cotton>
15 g of rayon cotton was irradiated with an electrocurtain type electron beam irradiation apparatus EC250 / 15 / 180L (manufactured by I Electron Beam Co., Ltd.) at an acceleration voltage of 250 kV and 40 kGy in a nitrogen atmosphere. Cotton irradiated with an electron beam is 16% by weight of acrylic acid (manufactured by Nacalai Tesque), INVADINE 650 (penetrant) (manufactured by Huntsman Japan Co., Ltd.), 0.5% by weight, HT-150D (manufactured by Osaka Chemical Industry Co., Ltd.) ( Antifoaming agent) 200 mL of a 0.1% by weight aqueous solution was applied, and the mangle was squeezed so that the pickup rate was about 100% by weight relative to the sliver mass. Then, in order to remove unreacted acrylic acid, it was washed with water and dried to obtain rayon cotton having an acrylic acid graft ratio of 11% by weight. The graft ratio was calculated from the mass difference before and after processing as shown in the following formula. The EB process is a process in which a compound is covalently bonded to cellulose fibers by electron beam irradiation. Owf is an abbreviation for on the weight of fiber.
Graft ratio (owf%) = [(Dough weight after EB processing−Dough weight before EB processing) / (Dough weight before EB processing)] × 100

(Example 2)
Rayon cotton with an acrylic acid graft ratio of 40% by weight is treated in the same manner as in Example 1 except that after irradiation with an electron beam, the acrylic acid chemical solution is applied and left for 30 seconds, and the sliver is squeezed with a mangle. Obtained.

Example 3
Cotton cotton having an acrylic acid graft ratio of 10% by weight was obtained by carrying out the same treatment as in Example 1 except that the sliver was squeezed with mangles immediately after application of the acrylic acid chemical solution after irradiation with the electron beam.

Example 4
Cotton with an acrylic acid graft ratio of 50% by weight is treated in the same manner as in Example 1 except that after irradiation with an electron beam, the acrylic acid chemical solution is applied and left for 50 seconds, and the sliver is squeezed with a mangle. Was obtained.

  The acrylic acid graft rayon cotton obtained in Examples 1 and 2 and the acrylic acid graft cotton cotton obtained in Examples 3 to 4 were each immersed in 400 mL of a 1% by weight aqueous solution of potassium hydroxide (manufactured by Nacalai Tesque). The mixture was stirred for 5 minutes, then washed with water several times to completely remove the remaining potassium hydroxide, and dried to fix potassium to the carboxyl group portion.

  Each cotton obtained as described above is washed by sprinkling 100 ml of ion-exchanged water 10 times with a shower, and the potassium content before and after the wavelength dispersive X-ray fluorescence spectrometer ZSX 100e (manufactured by Rigaku Corporation). It was measured by. The potassium content measurement results before and after the shower are shown in Table 1 and FIG. In FIG. 1, the number after the material indicates the example number (the same applies to FIG. 2). As is clear from Table 1 and FIG. 1, no significant loss of potassium was observed by the shower.

(Example 5)
<Production of phosphate neutralized graft cotton>
120 g of mono (2-methacryloyloxyethyl) phosphate (manufactured by Kyoeisha Chemical Co., Ltd .; trade name Light Ester P-1M; hereinafter abbreviated as “P1M”) is dissolved in 179 g of ion-exchanged water so that the temperature becomes 40 ° C. or less. While cooling the beaker, 5 g of ethylenediamine was dropped. Further, 30 g of 25% aqueous ammonia was added dropwise. Further, aqueous ammonia was added dropwise while confirming that the pH was about 5.5 to 5.8 to obtain a neutralized 35 wt% solution of P1M.

  15 g of rayon cotton was irradiated with an electrocurtain type electron beam irradiation apparatus EC250 / 15 / 180L (manufactured by I Electron Beam Co., Ltd.) at an acceleration voltage of 250 kV and 40 kGy in a nitrogen atmosphere. P1M neutralized product adjusted to 20% by weight of rayon cotton irradiated with electron beam, INVADINE650 (penetrant) (manufactured by Huntsman Japan Co., Ltd.) 0.5% by weight, HT-150D (manufactured by Osaka Chemical Industry Co., Ltd.) (antifoaming) Agent) After applying 200 mL of 0.1 wt% aqueous solution, the mixture was allowed to stand for 2 minutes. Next, the mangle was squeezed so that the pickup rate was about 100% by weight with respect to the sliver mass. Thereafter, in order to remove the unreacted P1M neutralized product, it was washed with water and dried to obtain 18% by weight of P1M neutralized product.

(Example 6)
Rayon cotton of 32% by weight of P1M neutralized product should be treated in the same manner as in Example 5 except that after irradiation with an electron beam, it was allowed to stand for 5 minutes after applying an acrylic acid chemical solution and the sliver was squeezed with a mangle. Obtained.

(Example 7)
The P1M neutralized product was processed into cotton cotton in the same manner as the rayon cotton of Example 5 to obtain 12% by weight of P1M neutralized cotton cotton.

(Example 8)
The P1M neutralized product was processed into cotton cotton in the same manner as the rayon cotton of Example 5 to obtain 30% by weight P1M neutralized cotton cotton.

  Each cotton obtained as described above is washed by sprinkling 100 ml of ion-exchanged water 10 times with a shower, and the phosphorus content before and after the wavelength dispersive X-ray fluorescence analyzer ZSX 100e (manufactured by Rigaku Corporation). It was measured by. The phosphorus content measurement results before and after the shower are shown in Table 2 and FIG. As is clear from Table 2 and FIG. 2, no significant loss of phosphorus was observed by the shower. From this, it is estimated that nitrogen can also be fixed.

  Plant growth experiments were conducted using the nutrient rayon cotton obtained in Examples 1-8. In a seedling pod having a height of 90 mm and a size of 105 mm, no. No. 1 potassium-immobilized rayon, No. 1 5 g of phosphorus and nitrogen-fixed rayon were mixed to grow spinach. Due to the water absorption effect of cotton, seedlings were sufficiently grown by watering about 2 to 3 times a week. The mixed cotton began to biodegrade little by little after one month, and the fiber shape almost disappeared after six months. Spinach growth was good.

(Comparative Example 1)
As a comparison, spinach was grown under the same fertilization condition except that cotton was not mixed. Watering was necessary almost every day, and the state of breeding was inferior to that of the example product.

  The fiber for plant cultivation of the present invention can be applied to afforestation, desert greening, urban greening, golf course lawn management, plant pots, agriculture and the like.

Claims (8)

A fiber for plant growth having biodegradability,
The plant-growing fiber is a fiber having a water absorption property and combined with a compound containing at least one element selected from nitrogen, phosphorus and potassium, which are fertilizer components essential for plant growth. Growing fiber.   The plant growth fiber having biodegradability is obtained by binding a water-absorbing compound to biodegradable fiber, and the combined compound includes nitrogen, phosphorus, and fertilizer components essential for plant growth. The fiber for plant cultivation of Claim 1 containing the at least 1 element chosen from potassium.   The biodegradable plant-growing fiber is composed of a biodegradable fiber grafted with a water-absorbing compound to form a water-absorbing fiber, and the grafted compound has nitrogen and phosphorus as essential fertilizer components for plant growth. The fiber for plant cultivation of Claim 1 or 2 containing the at least 1 element chosen from potassium and potassium. The plant-growing fiber according to any one of claims 1 to 3, wherein the water-absorbing compound is at least one selected from a phosphate, a carboxylate, and a ketone group-containing compound.
Adult fiber.   The plant growing fiber according to claim 4, wherein the phosphate is a potassium phosphate ester salt.   The plant growing fiber according to claim 4 or 5, wherein the carboxylate is at least one selected from potassium (meth) acrylate and potassium iminodiacetic acid.   The fiber for plant growth according to any one of claims 4 to 6, wherein the ketone group-containing compound is at least one selected from the group consisting of ethylene glycol monoacetoacetate monomethacrylate and diacetone acrylamide.   The fiber sheet containing the fiber for plant cultivation of any one of Claims 1-7.

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