JP3353157B2 - Superabsorbent tubular body and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to superabsorbent tubular body, such as cold air and refrigerant pipe of the air conditioner, and superabsorbent tube <br/> shaped body that the tubular body is produced by blow molding of thermoplastics And a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, a molded article in which a nonwoven fabric is adhered to the surface of a hollow body of a thermoplastic plastic is disclosed in JP-A-63-963.
No. 2431 is used as a cooling air or refrigerant pipe for an air conditioner of an automobile or a building.

[0003]

Generally, in cold air and refrigerant pipes of air conditioners of automobiles and buildings, water droplets are formed on the surface of the cooling air or refrigerant, and therefore, it is necessary to take measures to absorb and remove the water droplets. Air-conditioning equipment with cold air or refrigerant pipes with a non-woven fabric attached to the surface of a hollow body can absorb a considerable amount of water droplets with the non-woven fabric, but do not have sufficient water-drop absorption capacity. In this type of hollow body, it is a technical problem to further improve the absorbability of water droplets.

An object of the present invention is to solve the above-mentioned technical problem by attaching a surface of a tubular structure and attaching it to the surface.
Granular superabsorbent resin between eyes
By adopting the configuration, it is excellent in water absorption and long
Super absorbent tube that can maintain high water absorption over a period
Only by the process of blow-molding the body and the thermoplastic tubular structure, the nonwoven fabric integrally adhered to the surface is given a high water absorption , and the high water absorption is maintained for a long period of time.
An object of the present invention is to provide a method for manufacturing a superabsorbent tubular body that can be held upright .

[0005]

A superabsorbent tubular body according to the present invention for achieving the above object is as follows.
In other words, on the surface of a thermoplastic tubular structure
A tubular body to which a nonwoven fabric is adhered , the surface of the tubular structure
Between the eyes of the non-woven fabric attached to the surface
Characterized in that it contains an aqueous resin.
You.

[0006] The method for producing the superabsorbent tubular body according to the present invention is as follows. That is, in a method of manufacturing a tubular body in which a nonwoven fabric is adhered to the surface of a thermoplastic tubular structure, a plasticized plastic plastic parison is placed between a blow mold having a cavity for molding the tubular structure. Along with disposing, between the parison and the cavity, a nonwoven fabric coated with a granular high water-absorbing resin is disposed on the parison side surface, and then the blow mold is closed to introduce a pressurized fluid into the parison. By expanding the parison, the parison is formed into a tubular three-dimensional shape along the cavity of the blow mold, and a non-woven fabric is closely bonded to the surface of the formed tubular structure, thereby forming the tubular structure.
Between the surface of the fabric and the eyes of the non-woven fabric attached to the surface
To obtain a tubular body into which the highly water-absorbent resin is introduced .

[0007]

According to the manufacturing method of the tubular body according to the present invention, the tubular structure of the thermoplastic plastic in the process of blow molding, granular superabsorbent polymer coated nonwoven tubular structure on the surface of Parisun side It is stuck on the surface of the body. The non-woven fabric stuck on the surface of the tubular structure got into its eyes
Because it has a granular high water-absorbing resin between the surface of the tubular structure in the state, it is excellent in water absorption , and high
Water absorption is maintained for a long time. For this reason, even if dew is formed on the surface of the tubular body, no water droplet is generated. Since the superabsorbent resin applied to the nonwoven fabric is in a granular form, when applied, it enters into the eyes of the nonwoven fabric and maintains a stable state. Further, since the superabsorbent resin enters between the eyes of the nonwoven fabric and exhibits a stable state with a large or small amount of application, it is easy to control the application amount.

[0008]

An embodiment of the present invention will be described with reference to the drawings. FIG.
1 is a perspective view illustrating a cold air pipe of an air conditioner of an automobile as a tubular body according to the present invention. 1 is a cold air pipe, 2
Is a cool air inlet, 3 is a cool air outlet, and 4 is a mounting stay. Reference numeral 5 denotes a parting line formed on the mating surface of the mold. The cold air pipe 1 is obtained by integrally bonding a nonwoven fabric 7 to the surface of a polypropylene tubular structure 6,
The two nonwoven fabrics 7 are joined with the parting line 5 as a boundary.

FIG. 2 illustrates a method of manufacturing the cold air pipe 1 by blow molding. Reference numerals 8 and 8 denote blow molds, and reference numerals 9 and 9 denote cavities. The cavities 9 and 9 have a three-dimensional shape for forming the tubular structure 6. In the blow molding of the cold air pipe 1, a parison 10 which is made by heating and softening polypropylene and extruded from a head 11 is disposed between the open blow molds 8 and 8, and the parison 10 and the blow molds 8 and 8 are arranged. The two nonwoven fabrics 12 are arranged between the cavities 9 and 9. The nonwoven fabrics 12, 12 are arranged and moved in the horizontal direction at the upper position, and move in the vertical direction via the rollers 13.
Granular superabsorbent resin 15 is applied to nonwoven fabrics 12 and 12 by dripping from dropping tubes 14 and 14 at the upper part moving in the horizontal direction. This superabsorbent resin 15 is 20 to 200
μm granules.
Even if it enters between the eyes and moves vertically, it does not go outside. Also, by dripping the superabsorbent resin 15 on the non-woven fabrics 12 at the portions that move in the horizontal direction, it is possible to freely control even a small application amount. In addition,
The application of the highly water-absorbent resin 15 to the nonwoven fabrics 12, 12 may be performed when the nonwoven fabrics 12, 12 are moved in the vertical direction or by spraying after the disposition. A conductive resin may be added. When the Paris 10 arranged between the blow molds 8 reaches the lower end of the blow molds 8, the hanging of the Paris 10 is stopped and the blow molds 8, 8 are closed. Then Parison 10
A pressurized fluid is introduced from a blowing nozzle (not shown)
While the expanding parison 10 is pressed against the nonwoven fabrics 12, 12, the tubular structure 6 shown in FIG. The parison 10 which expands in this step stretches the nonwoven fabrics 12 and 12 to form the cavities 9 and 9.
, And the non-woven fabrics 12 are integrally adhered to the surface of the tubular structure 6 completely. FIG. 3 shows the details of the mode of attaching the nonwoven fabrics 12 and 12. Next, after the parison 10 is cooled and solidified through the blow molds 8, 8, the blow molds 8, 8 are opened, and the cold air pipe 1 having the nonwoven fabric 7 integrally adhered to the surface shown in FIG. obtain.

As described above, the cold air pipe 1 manufactured by blow molding has a granular structure in which the nonwoven fabric 7 is integrally adhered to the surface of the tubular structure 6 and is inserted between the eyes of the nonwoven fabric 7. Since the highly water-absorbent resin 15 is disposed between the surface of the tubular structure 6 and the nonwoven fabric 7, water droplets generated by condensation on the surface of the cold air pipe are generated between the eyes of the nonwoven fabric 7 and the surface of the tubular structure 6. Is absorbed by the superabsorbent resin 15 and does not drop. Moreover, the highly water-absorbent resin 15 is made of the nonwoven fabric 12
Since the water-absorbent resin 15 is inside the eyes, the water-absorbing performance of the super-water-absorbent resin 15 can be brought out greatly, and dripping of water droplets can be effectively prevented.

[0011] The nonwoven fabric is a cloth-like article formed by stacking fibers in parallel or crossing each other or by randomly dispersing the fibers to form a web and then joining the fibers that have become the web. Raw material fibers for nonwoven fabrics include synthetic fibers such as polyester, polypropylene, polyamide, acrylic, vinylon, and polyurethane; semi-synthetic fibers such as acetate and rayon; regenerated fibers such as viscose rayon and copper ammonia rayon; cotton, hemp, and sheep silk. Such as natural fibers and blended fibers thereof, and as an adhesive for forming a non-woven fabric, acrylic, polyvinyl acetate, ethylene-vinyl acetate copolymer, polyvinyl chloride, butadiene-styrene polymer, polyethylene, Ethylene-acrylic acid copolymers, ethylene-acrylate copolymers, ethylene-methacrylate copolymers, and the like. The nonwoven fabric used in the present invention has a basis weight of 30 to 200 g / m ² , and preferably 50 to 150 g / m ² . When the basis weight is less than 30 g / m ² , the portion far from the mating surface of the non-woven fabric to be stuck to the tubular body is elongated and thinned, so that the base material which is the tubular structure is exposed, the appearance is impaired, and the heat insulating property is reduced. And the ability to absorb water decreases. The basis weight is 200 g / m ²
When it exceeds, the reproducibility of the three-dimensional structure is poor, and distortion occurs particularly when the tubular structure has a circular cross section. The fibers constituting the nonwoven fabric used in the present invention preferably have crimps throughout the fibers. Crimp is a wavy or spiral crimp that natural fibers such as silk fibers and animal hair fibers originally have naturally. In the present invention, not only natural fibers but also synthetic fibers are physically and chemically treated. Accordingly, a fiber with a wavy or spiral crimp can also be used as a crimped fiber. As a means for crimping synthetic fibers, there is a so-called shrinkage difference mixed weave yarn. Taking into account the adhesion of the base material to the polyolefin, a shrinkage difference mixed woven yarn of polypropylene is particularly suitable. This shrinkage difference mixed weave yarn has a different shrinkage rate to heat.
A type of mixed-shrink yarn with a combination of different types of polypropylene fibers.After forming into a non-woven fabric or a fiber, it is subjected to heat treatment, and the difference in shrinkage causes the lower shrinkage to become crimped. is there. As described above, since the fiber has crimps, the elongation is improved as a nonwoven fabric, and as a result, it is possible to cope with the elongation of the polyolefin by blow molding, and the three-dimensional reproducibility is good and the appearance is beautiful. The result is a tubular body which does not hinder the elongation of the parison during the blow molding process and which is not deformed in appearance exactly along the cavity of the blow mold.

The superabsorbent resin refers to a polymer network having a three-dimensional network structure having a hydrophilic group and a water-soluble polymer compound having an ionizable group. A polymer network having a three-dimensional network having a hydrophilic group is a hydrophilic polymer which exhibits a water absorption of 10 to 1500 times its own weight with respect to distilled water, but is substantially insoluble in water. There is a polymer network having a three-dimensional structure formed by chemical means such as cross-linking or by physical means giving the same properties as cross-linked. In particular, a polymer network having an ionizable group, that is, an ionized carboxyl group such as a sodium carboxylate group, a potassium carboxylate group, or an ammonium carboxylate group, or a sulfonic acid group is 50%.
It is preferable because it has a water absorption of twice or more. The polymer network structure as described above includes a synthetic polymer system and a semi-synthetic polymer system. The synthetic polymer has a hydrophilic group such as a carboxyl group, a sulfonic group, an amide group, an ether group, and a hydroxyl group. Vinyl alcohol-unsaturated carboxylic acid copolymer, isobutylene maleic anhydride copolymer, polyvinyl alcohol, polyacrylic acid, polyacrylamide, acrylic acid-acrylamide copolymer, polyethylene oxide and the like can be used as the basic polymer. Examples of the polymer network having a vinyl alcohol-unsaturated carboxylic acid copolymer as a basic polymer include a vinyl alcohol-acrylic acid group copolymer network obtained by hydrolyzing a vinyl acetate-methyl acrylate copolymer or ethylene-vinyl. There is a vinyl alcohol-acrylate copolymer network such as an alcohol-acrylate terpolymer (for example, “Sumikagel S type and SP type” manufactured by Sumitomo Chemical Co., Ltd.). This hydrophilic network structure is excellent in water absorption, gel strength, transparency, compatibility with each resin, and dispersibility.
Examples of the polymer network having isobutylene-maleic anhydride as a basic polymer include an isobutylene-maleic anhydride copolymer-based network (for example, “KI gel” manufactured by Kuraray). In addition, as a polymer network structure having polyvinyl alcohol as a basic polymer, a polymer network structure obtained by crosslinking an aqueous solution of polyvinyl alcohol with radiation, a suspension of polyvinyl alcohol in an aprotic solvent, and a cyclic acid anhydride are used. There is a polymer network structure crosslinked by reacting certain maleic anhydride, phthalic anhydride, or the like (for example, “GP resin” manufactured by Nippon Synthetic Chemical Industry). The polymer network having a polyacrylic acid base polymer as the basic polymer includes a polymer network obtained by copolymerizing acrylic acid and its salts with a small amount of a divinyl compound, and a polymer obtained by ion-crosslinking with a polyvalent metal ion. There are a network structure and a polymer network structure which is self-crosslinked by appropriately selecting polymerization conditions (for example, “Aqua Keep” manufactured by Iron and Steel, “Aqua Lip C” manufactured by Nippon Shokubai Chemical Industry).
A ", Sumitomo Chemical" Sumikagel N Type and NP "
type"). Examples of the polymer network having an acrylic acid-acrylamide copolymer as a basic polymer include an acrylate-acrylamide copolymer network (eg, “Sumika Gel F Type” manufactured by Sumitomo Chemical Co., Ltd.).
Further, as a polymer network structure having a polyoxymethylene-based polymer as a basic polymer, “Sumikagel®” manufactured by Sumitomo Chemical Industries, Ltd.
30 "). In the case of semi-synthetic polymer systems, starch, cross-linked starch, cellulose, cross-linked cellulose, etc. are graft-polymerized with acrylonitrile, acrylamide, etc. and alkali-hydrolyzed, or acrylic acid, methacrylic acid, etc. are graft-polymerized. Polymer network structure obtained by adding carboxymethylated or sodium carboxymethylated starch, cross-linked starch, cellulose, cross-linked cellulose, etc. (for example, acrylic manufactured by Sanyo Chemical Industries, Ltd.) Acid-grafted starch "Sunwet"). Further, the term “water-soluble polymer compound having an ionizable group” refers to a water-soluble polymer compound having an equilibrium moisture content of 20% or more based on the absolute dry weight at a temperature of 20 ° C. and a relative humidity of 65%. Sodium carboxylate, potassium carboxylate, ammonium carboxylate, sodium sulfonic acid, sulfonic acid It is a polymer electrolyte having a group or the like. The water-soluble polymer compound as described above includes a synthetic polymer, a semi-synthetic polymer, and a natural polymer. In the synthetic polymer system, the above-mentioned polyacrylate having an ionizable group, acrylate-acrylamide copolymer, vinyl alcohol-unsaturated carboxylate copolymer, isobutylene-anhydride maleate copolymer, polymeta A water-soluble high molecular polymer such as rilsulfonic acid or a salt thereof can be used.
In addition, acrylic acid derivatives such as acrylonitrile, methyl acrylate, methyl methacrylate, and acrylamide are graft-polymerized to polyvinyl alcohol or ethylene-vinyl alcohol copolymer, and further hydrolyzed with alkali, acrylic acid, methacrylic acid, and the like. A water-soluble polymer obtained by graft polymerization of an acrylate, methacrylate or the like obtained by graft polymerization and neutralization can also be used. Specifically, for example, Nippon Kayaku “Panakayak B”,
Examples include sodium polyacrylate such as "Panakayak Parc NP" and sodium poly-L-glutamate.
In the semi-synthetic polymer system, carboxymethyl cellulose (CMC) obtained by sodium carboxymethylation of cellulose
and so on. In the natural polymer system, sodium alginate (for example, Kimitsu Algin manufactured by Kimitsu Chemical Industry)
and so on.

[0013]

According to the present invention, the surface of the tubular structure is
Granular high water absorption between eyes of non-woven fabric stuck on its surface
By adopting a structure in which resin is inserted, water absorption is achieved.
Detachable and can maintain high water absorption for a long time
A superabsorbent tube can be obtained, and the above superabsorbent tube
The shape can be obtained only by a step of blow-molding a thermoplastic tubular structure.

[Brief description of the drawings]

FIG. 1 is an overall perspective view illustrating a super-absorbent tubular body according to the present invention and illustrating a cold air pipe of an air conditioner of an automobile.

FIG. 2 is a sectional view showing a blow molding mode for manufacturing the cold air pipe shown in FIG.

FIG. 3 is an enlarged sectional view of a part of the one shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cold air piping 6 Tubular structure 7 Attached nonwoven fabric 8,8 Blowing mold 9,9 Cavity 10 Paris 12,12 Nonwoven fabric 14 Drop tube 15 Granular superabsorbent resin

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B32B 1/08 F16L 11/12 B29C 49/00-49/80

Claims (2)

(57) [Claims] 1. Table of thermoplastic tubular structures
A tubular body having a non-woven fabric attached to the surface, the surface of the tubular structure, and the eyes of the non-woven fabric attached to the surface.
It is characterized in that a granular superabsorbent resin
Highly water-absorbing tubular body. 2. A method for producing a tubular body in which a non-woven fabric is adhered to the surface of a thermoplastic tubular structure, wherein the thermoplastic plasticized plastic is placed between a blow mold having a cavity for molding the tubular structure. And a non-woven fabric coated with a granular high water-absorbent resin on the parison side surface between the parison and the cavity, and then closing the blow mold and pressing the pressurized fluid into the parison. By introducing and expanding the parison, the parison is formed into a tubular three-dimensional shape along the cavity of the blow mold, and the nonwoven fabric is closely bonded to the surface of the formed tubular structure, and the surface of the tubular structure and Affixed to its surface
Insert the granular super absorbent resin between the eyes of the non-woven fabric
A method for producing a superabsorbent tubular body, characterized by obtaining a tubular body comprising: