JPS59204680A - Water-retentive material - Google Patents

Abstract

PURPOSE:To obtain titled material of high performance, capable of forming adequate air space therein, by making two kinds of fibers into fabric, namely, a high water-absorptive fiber treated with a mixture capable of forming high water-absorptive resin on desolvation and comprising water-soluble polymer, crosslinking agent and solvent, and the other fiber untreated with said mixture. CONSTITUTION:The objective material constituted by a fiber composite obtained by twisting two kinds of fibers each other or making these into fabric, namely, (A) a high water-absorptive fiber (pref., based on cotton, hemp, PVA fiber) treated with a mixture (pref. resulting in a pickup 5-10wt%) capable of forming high water-absorptive resin on desolvation and comprising (i) a water-soluble polymer (pref., having carboxyl or hydroxy group, e.g., alpha-olefin-maleic anhydride copolymer salt, polyacrylic acid salt, PVA), (ii) a crosslinking agent (e.g., polyvalent amine), and (iii) a solvent and (B) a fiber (pref., polyethylene fiber) or strip film untreated with said mixture. USE:For agricultural or horticultural applications.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water-retaining material using fibers having water-absorbing and water-retaining properties, and particularly to a water-retaining material suitable for agriculture and horticulture.

As a water retention material for agriculture and gardening, natural materials such as straw, sawdust or hill stone can be used as ashes, and materials mixed with soil can be used to retain water, retain heat, and prevent soil from falling off. It is used in combination with fibers, paper, etc. on the roots of plants. However, in recent years, natural water drainage has become difficult to collect due to natural destruction, and changes in agricultural and forestry work methods have made it difficult to collect straw or sawdust. For this purpose, super absorbent resins are mixed with soil (for example, Japanese Patent Application Laid-Open No. 57-25586,
6-155286 Publication No. 56-159580
(Japanese Unexamined Patent Publication No. 5), a heat-sealable film is sprayed with a super absorbent resin and dried as a substitute for water drainage (Japanese Patent Laid-Open No. 5
6-84779), 25-1 with high water absorption performance
25■- is molded into a non-woven fabric (Japanese Patent Application Laid-Open No. 5
6-131318), agricultural and horticultural water retaining materials with water retaining properties have been devised. Furthermore, the newest one is a superabsorbent laminate for water retaining material that uses a superabsorbent polymer foam film (Japanese Patent Laid-Open No. 57-208236).

However, when super absorbent resin is mixed with soil,
Because water absorption is extremely high, the amount added to the soil is small, making it difficult to mix uniformly. Also, when water is added, the soil becomes lighter in weight, so it stands out on the surface of the soil and is exposed, causing prolonged rain and sunlight. The partial solubilization of superabsorbent resins caused by exposure to water causes the generation of soluble components, which solidifies the soil surface, causing water to penetrate and rooting in areas where air circulation is difficult. , it is difficult for plants to grow, and the expected effects are not achieved. In addition, water retention materials for water basins made by spraying superabsorbent resin on a heat-sealable film and drying them, and laminates using superabsorbent polymer foam films do not have sufficient water retention capacity, and plants may not germinate. To <<,
Easy to wither. Since the non-woven fabric is molded into a non-woven fabric by thermal bonding, it is difficult to control the water retention during manufacturing, the shape of the molded product is limited, and a sufficient air layer cannot be formed. Plant growth is poor because root growth is hindered.

In view of the current situation, the present inventor has conducted extensive research, and as a result, has discovered a water retaining material, particularly a water retaining material for agriculture and horticulture, that has moderate practical advantages, and has completed the present invention.

The present invention fully demonstrates the water absorption and water retention performance of water retention materials, especially superabsorbent resins, forms a layer containing air necessary for plant growth, and does not hinder root growth. The purpose of the present invention is to provide an artificial water retaining material for agriculture and horticulture that can be easily handled as a strong and stable growing bed.

According to the present invention, the above object is to have water absorption performance obtained by treatment with a mixture of a water-soluble polymer, a crosslinking agent for the polymer, and a solvent, which can form a super absorbent resin by removing the solvent. Fiber (hereinafter referred to as super absorbent A fiber in 11)
(A) and fibers or nutrig-like films (B) which have not been treated with said mixture are combined and still woven into a fiber composite.

Examples of the fibers that serve as the base material of the superabsorbent fibers used in the present invention include natural fibers such as cotton, wool, linen, and silk;
Semi-synthetic fibers such as rayon, polyvinyl alcohol amide fiber T1F (nylon), polyethylene V fiber, polyglopy V fiber, polyester) V fiber, acrylic fiber,
Examples include synthetic fibers such as polyvinyl chloride fibers, and non-IS fibers such as glass fibers, carbon fibers, and asbestos fibers. Among them, cotton, linen, etc., which have water-absorbing properties that are compatible with the water-soluble polymer used in the mixture that can form a superabsorbent resin with a solvent remover and the crosslinking agent of the polymer, are used.
Vinylon is particularly preferred. Note that cotton and hemp are preferably used because they decompose after a long period of time when mixed with soil. These fibers may be used alone or in combination of two or more.

The length of these fibers can be selected depending on the continuous treatment with the mixed liquid of the superabsorbent treatment and the final water retention material, especially the water retention material for agriculture and horticulture. Not only is it difficult to process with the liquid mixture used for water absorption treatment, but when two or more fibers are combined to form a fiber composite, there is no space to form an air layer. The super absorbent resin will fall off.

Therefore, the length of the fiber is more than 20 mm,
The thickness of the fibers is preferably in the range of 1 to 50 deniers, particularly 1 to 50 deniers.

These fibers can be used in the form of single fibers, but they can also be used in the form of two or more twisted yarns, strings, or even narrow woven fabrics.

In the present invention, the water-soluble polymer used in the mixture that can form a superabsorbent resin by removing solvent is preferably a water-soluble polymer containing a carboxyl group, a salt thereof, or a hydroxyl group in the molecule, such as gelatin, cellulose derivatives, etc. A copolymer of natural carboxyluleic acid represented by a natural hydroxyl group-containing polymer or a cellulose derivative, and a vinyl compound or a vinylidene compound, especially an α-olefin (a water-soluble polymer synthesized by anhydrous male synthesis is preferable, especially as described below) Particularly preferred is a water-soluble polymer using a salt of an α-olefin-maleic anhydride copolymer and a basic substance in combination with a crosslinking agent.

Here, α-olefin means a linear or branched unsaturated hydrocarbon having 2 to 12 carbon atoms, preferably 2 to 8 carbon atoms, and examples thereof include ethylene, propylene, butene-1, butene-1, and 2, isobutylene, n-pentene, isoprene, 2-methyl-1-butene, n-hexane 2-
Methyl/1/-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 2-ethy/L/-1-butene, diisobutynone, 1,6-butadiene, 1-,6
-pentadiene, 1,5-hexadiene, 1-3-octadiene, 2-methyV-4-diene, 1-pentene, 2-methyl-4-dimethyl-2-pentene. Among them, isobutylene is preferably used. In addition, inbutylene here also means return BB containing inbutylene.

Vinyl or vinylidene compounds other than α-olefins refer to unsaturated compounds that can be copolymerized with maleic anhydride, such as styrene, vinyl chloride, vinyl acetate, and vinylidene compounds.
Vinyl ropionate, acrylonitrile, metal
Tally mouth Nitrile, Methyl
Vinyl ether, acrylic acid ester, methacrylic acid ester, or vinyl alcohol)V (although it cannot be used industrially as a monomer, it can be obtained, for example, by copolymerizing vinyl acetate and then saponifying it). These monomers may be used alone or in combination of two or more. Of these monomers, α-olefins, methyl vinyl ether and styrene are preferably used, but the use of α-olefins, especially isobutylene, is most suitable for the purpose of the present invention.

Basic substances to be reacted with the carboxyl group-containing polymer or copolymer include ammonia, sodium hydroxide, and potassium hydroxide. It is preferably used in an amount of 0.3 to 2 moles per mole of acid group. Note that ammonia may be in gaseous form or may be dissolved in water.

The crosslinking agent used in conjunction with the water-soluble polymer when treating fibers varies depending on the type of water-soluble polymer, but in the case of a water-soluble polymer with hydroxyl groups, for example, polyvinyl alcohol polyhydric cyanate compounds, borax,
Boron compounds and the like are used. In the case of water-soluble polymers having carboxyl groups, such as salts of copolymers of α-olefin and maleic anhydride, polyacrylic acid, and salts thereof, polyvalent amines or polyvalent epoxy compounds are used. Ru.

The polyvalent amine used as a crosslinking agent includes, for example, tetraethylenepentamine, triethylenetetramine, pentaethylenehexamine, ethylenediamine, linear polyethyleneimine, or branched polyethyleneimine, which is a water-soluble polymer of 100 parts by weight. The polyhydric epoxy compound, which is used in an amount of 0.2 to 60 parts, is a hydrophilic or water-soluble polyhydric diboxyl compound that is well known as an epoxy crosslinking agent. cidyl ether, ethylene glycol diglycidyl ether, po
There are real estate agents, real estate agents, and real estate agents. These polyvalent epoxy compounds are 0 per 100 parts by weight of the water-soluble polymer.
．． 5 to 50 parts are used.

In the present invention, various organic solvents can be used as the solvent for the mixture from which a superabsorbent resin can be formed by removing the solvent, but water is most preferable in terms of ease of handling and cost.

Water-soluble polymer used when treating fibers, crosslinked al-
b t-re ie 811-A, L % Z. a
- A- km ry +- 1. J- y −+−
The concentration of the y+21w+ and e 8 bodies is preferably 2 to 50%, preferably 4 to 3o%. If the concentration is lower than this, it will not be possible to obtain sufficient water retention, and if it is too high, the superabsorbent fiber will lack toughness and will be stiff, making the twisting process difficult.
It is still not possible to prevent the super absorbent resin from falling off because the water absorbency is extremely high.

For example, by wrapping fibers around a drum,
There are methods such as dipping and applying the mixture into a loaf containing the mixture, spreading the mixture onto the fibers, and immersing the fibers in a tank containing the mixture. In this case, the fiber may not be a single simple fiber, but may be a collection of two or more fibers. From the point of view of securing water retention and air space, it is 2.
It's better if it's more than just a book, it's a collection. This is because when the treated superabsorbent fibers are immersed in water, the mixed liquid turns into a gel, and the swelling pressure causes it to return to its original shape, further expanding the air layer.

The amount of the mixed liquid attached to the fiber is 6 with respect to the tL amount of the fiber.
-100%, especially 5-10 fO, preferably in a range such that the water absorption capacity of the attached super absorbent resin is 20 times or more. The water absorption capacity here is the value obtained by subtracting the weight after immersion in distilled water by the weight before immersion (
times).

In addition, when processing fibers, various plant seeds, fertilizers, plant growth promoters, chemicals, sand, clay, etc. can be added to the fibers or mixed solution. If it is molded into a water-retaining material, a completely different agricultural method can be obtained than before, and the way fertilizers, plant growth promoters, and chemicals are applied to the soil can also be improved, contributing to labor savings.

Furthermore, by incorporating sand, clay, etc., it is possible to reliably overcome the drawbacks of conventional superabsorbent resins in that when they become saturated with water, their specific gravity decreases and they tend to be exposed on the soil surface.

Protecting the superabsorbent fiber (A) obtained in this way,
It prevents attached superabsorbent resin from falling off the fibers, provides an appropriate air layer, and when used as a water retention material for agriculture and horticulture, does not hinder the growth of plant roots and is twisted to securely fix the fibers. The fibers used (fibers containing no water-soluble main body, crosslinking agent and solvent, and fibers not treated with a mixed solution capable of forming a superabsorbent resin by desolvation) and the strip-shaped film will be described below. For the former type of fibers, the same or different types of fibers used in producing the superabsorbent fibers in the present invention are used. Among these, hydrophobic synthetic fibers that have toughness even when water is absorbed, such as polyethylene fibers, polypropylene fibers, and polyvinylidene chloride fibers, are often preferred. These may be used alone, in combination of two or more, or even twisted together to form a thread or string. On the other hand, strip-shaped films include cellulose, polyvinyl acetate,
It refers to a strip-shaped film of thermoplastic resin such as polyvinyl alcohol, ethylene-vinyl acetate copolymer or saponified product thereof, polyester, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyester, etc., and such a strip The thickness of the shaped film is 5 to 300 mm to make it easier to twist.
It is preferable that the width is in the range of 50 to 1000μ8, and the width is preferably 20m or more. In order to impart bulkiness, it is preferable to use two or more 711-shaped films. Furthermore, for the same purpose, a strip-like film with slits or punches can also be used.

The fiber composite obtained by twisting super-absorbent fibers and fibers (A) or strip-like films (B) that have not been subjected to super-absorbent treatment has various forms, but typical examples include As shown in Fig. 1, super absorbent fiber 1 and non-super absorbent fiber 2 are twisted into one piece each, and as shown in Fig. 2, super absorbent fiber 1 and fiber 2 are twisted together. Two or more fibers 2 that have not been treated to make them superabsorbent and twisted together, as shown in Figure 3, where two or more fibers that have not been made to make them superabsorbent are centered around superabsorbent fiber 1. 4, where multiple super absorbent fibers 1 are tied together, and the surrounding area is further tied together with 2 fibers that have not been treated to make them highly absorbent. , or a combination of super absorbent fibers 1 and strip-like film 5 as shown in Figures 5 to 7. Among these, super absorbent fibers do not appear on the surface of the composite. is preferable.The ratio of the superabsorbent fiber (A) and the fiber (B1) that has not been treated to make it superabsorbent or the sl-U tubular film (B2) is 1 to 1 of the superabsorbent fiber (A). Fibers or strip-like films that have not been treated to make them superabsorbent 1 to 5 o, and 9 parts 2 to 2
A suitable range is such that the water absorption capacity of the composite is 5 times or more, ie, 9 times or more than 15 times its own weight, at a ratio of 0 (weight ratio, still number side). Moreover, it is preferable that the composite obtained by twisting has a diameter of 1 to 5 mW.

Although it is preferable that the length is substantially infinite, it may be cut to an appropriate length depending on the use, but it is preferably 20 ffIN or more to prevent the composite from losing its integrity.

A conventional manufacturing method is used to manufacture the fiber composite by twisting. In the present invention, the composite is made of a woven fabric woven using super absorbent fibers (A) and a strip-like film (B) that is made of fibers that have not been treated to make them super absorbent. also means

The water retaining material of the present invention comprises super absorbent fiber (A) and fiber a (B1).
It also utilizes the space created by the strip film (B2) and the water retention properties of super absorbent fibers, and is also combined in the form of threads or strings, making it easier to absorb water than when immersed in water or absorbing water. , which can further increase the space and have infinite length instead of short fibers, making it easier to wrap around the roots of plants, and these thread or string-like water retention materials can be further combined. Woven and knitted fabrics can be made by waving and bundling, weaving and braiding processes, and loop carpet-like items can be made by partially fixing pieces sown in a spiral shape. It can also be used in a wide range of agricultural and horticultural applications, such as replacing sphagnum moss and growing seedbeds.

However, potatoes with short fiber length can be used by mixing with soil, and as mentioned earlier, they can be used as seeds, fertilizers, and plant growth promoters.
We believe that a mixture of chemicals, soil, and sand will be useful for the development of new agricultural technology.

In addition, since the water-retaining material has an infinite length, it can be used as a moisture-absorbing material for various electric wires and cables, as a filler in civil engineering applications, and as a water-stopping material. Cut and drill for oil 1. It can also be used to prevent mud slipping during various types of civil engineering work. Also, for special usage,
It has also been found that when the water-retaining material of the present invention is placed in a bag shape and treated with latex, it stops water and does not allow water to penetrate into the material, resulting in a significant improvement in work efficiency.

Next, the present invention will be specifically explained with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Example 1 and Comparative Examples 1 to 5 Isobutylene-maleic anhydride copolymer (ω-1,06
Molar ratio in copolymer, inbutylene: maleic anhydride =
1:1, manufactured by Clarey Isoprene Chemical ■, Isopan-1
0) This ammonia diglycidyl ether/L'1.2 weight was prepared by blowing ammonia gas into 100 parts by weight in a container while stirring to prepare 117 parts by weight of a reaction product of isobutylene-maleic anhydride copolymer and ammonia. After soaking a cotton thread with a thickness of 0.3 and squeezing it at a squeezing rate of 80%, it was wrapped around a drum and subjected to dry heat treatment at 80℃ for 20 minutes to create a super absorbent product with a water absorption capacity of 20 times. Obtained fiber. This super absorbent fiber is mixed with five 0.4m cotton threads,
A water retaining material for agriculture and horticulture was obtained. Two pieces of this water-retaining material were randomly placed in a Petri dish with a diameter of 8 CI 11 and a depth of 2 α, seeds of Tsumamina were sown, 5 cc of water was added, and germination and growth were observed in a room at 25°C. For comparison, K, 2 g of cotton thread with a thickness of 0.4 fin, commercially available sphagnum moss, and a commercially available sphagnum substitute (product name,
We similarly examined germination and growth using New Sphagnum moss). These results are shown in Table 1.

Polyacrylic acid (manufactured by Nippon Tsumugi Co., Ltd.) Jurimer-AC-10
A sodium polyacrylate aqueous solution was prepared by adding 3 parts of sodium hydroxide to 97 parts by weight of a 7% aqueous solution of H). Add 0.5 parts of tetraethylenepentamine to 100 parts by weight of this aqueous solution.
Add part by weight, stir, soak vinylon thread with a thickness of 0.4 m, squeeze it at a squeezing rate of 90, and then heat it to 50°C while opening.
The fibers were heated for 6 hours to obtain super absorbent fibers with a water absorption capacity of 25 times. After weaving these six superabsorbent fibers together, we further weaved the superabsorbent fibers made by twisting vinylon threads of 0.4 ff in thickness to obtain a water retaining material for agriculture and horticulture. The growth performance of snacks was evaluated using the same method as in Example 1. The germination rate was as high as 96% in one day, and the growth performance was excellent at 4.5aR, with a withering point of 7. The maximum plate length was 3 (: 1 g).

Example 6 Polyvinyl alcohol) V (PVA-1 manufactured by Kuraray)
17) 8- Soak a vinylon thread with a thickness of 411s in an aqueous solution, squeeze it at a squeezing rate of 60, then soak it in a 10% borax aqueous solution, squeeze it at a squeezing rate of 90%, and wind it around a drum at 80℃. Drying was performed for 10 minutes. The six superabsorbent fibers obtained,
A water retaining material for agriculture and horticulture was obtained by twisting together eight vinylon films in the shape of 0.01 ff in thickness and 0.2 in width.

Germination was determined in the same manner as in Example 1 using a water retaining material of
When growth was evaluated, the germination rate was 96 in 1 day.
%, the growth rate is excellent at 4.5%, and the withering point is 5%.
It was a long day. The maximum board length was 2.5 mm.

Example 4 and Comparative Example 4 The string-shaped agricultural and horticultural water retaining material obtained in Example 1 was
I placed about 6 meters of coiled material along the inner wall of the flower pot.

Commercially available green pepper seedlings with a height of 20 cIIt were planted in June, surrounded by Kanuma soil, and the growth status was observed outdoors. Green peppers do not require irrigation even in the hot summer, and can be harvested until late November using only rain.

When we removed the peppers from their pots in late November and observed their root development, we found that the roots had grown sufficiently toward the inner wall of the pot and were absorbing rainwater well.

On the other hand, for comparison, without using the above agricultural and horticultural water retaining material,
The diameter is 30mm in the same way as above except that the Kanuma soil is used for that amount.
Green pepper seedlings with a height of 20 tx were planted in a prepared flower pot in May, and their growth status was observed outdoors. The green peppers withered because they were not watered in the hot summer months (late July). Some roots even reached the inner wall of the pot, but the aggregate density was lower than in the above example.

[Brief explanation of the drawing]

1 to 7 are partially enlarged views of the agricultural and horticultural water retaining material of the present invention. FIG. 8 is a partially enlarged view of a woven fabric made of super absorbent fibers and fibers that have not been subjected to super absorbent treatment. In the figure, 1 indicates superabsorbent fibers, 2 indicates fibers that have not been subjected to superabsorbency treatment, and 6 indicates a strip-like film that has not undergone superabsorption treatment. Patent Applicant Wire Company Ri La V Agent Patent Attorney himself Figure 3 Figure 4

Claims (4)

[Claims] (1) A fiber (A
), and a fiber composite obtained by twisting or weaving fibers or strip-like films (B) that have not been treated with the mixture. (2) The water-soluble main body has a force within the molecule! The agricultural and horticultural water retaining material according to claim 1, which is a polymer containing a levoxyl group or a hydroxyl group. (3) The water-retaining material for agriculture and horticulture according to claim 1, wherein the water-soluble polymer is a salt of an α-olefin-maleic anhydride copolymer, a salt of polyacrylic acid, or a polyvinyl alcohol. (4) The water-retaining material according to any one of claims 1, 2, or 3, wherein the water-retaining material is used for agriculture and horticulture.