JP2018003926A - Synthetic resin hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase durability of a flexible synthetic resin hose.SOLUTION: A helical reinforcing body 14 made of vinyl chloride resin is integrally formed at a hose wall 11 made of vinyl chloride resin to constitute a synthetic resin hose 1. The helical reinforcing body 14 is formed by vinyl chloride resin that is harder than the hose wall 11. The helical reinforcing body 14 is integrally formed into the hose wall 11 under a state in which it is covered by polyester thermoplastic elastomer. It is preferable that polyester thermoplastic elastomer has mainly block copolymer having a hard segment and a soft segment and the hard segment is polyethylene telephthalate.SELECTED DRAWING: Figure 1

Description

The present invention relates to a flexible synthetic resin hose integrated with a spiral reinforcement. More particularly, the present invention relates to a synthetic resin hose having a vinyl chloride resin hose wall.

Synthetic resin hoses integrated with a spiral reinforcing body are used in various applications such as transfer of liquid, air, powder, and granular materials. In particular, when the hose wall is made of a vinyl chloride resin, the vinyl chloride resin is excellent in moldability, which makes it convenient to manufacture various hoses.

For example, Patent Document 1 discloses a flexible hose composed of a soft vinyl chloride resin hose wall having a laminated structure and a rigid vinyl chloride resin reinforcement body. According to this, the durability and heat resistance of the hose when conveying high temperature pellets can be improved.

JP 2008-82399 A

Since such a flexible hose can be used for various purposes, a higher level of strength and durability has been demanded. For example, when a hose made of a vinyl chloride resin as disclosed in Patent Document 1 is used in a bent state, cracks and cracks occur in the reinforcing body over time, and the hose wall starts from that portion. Was found to break.

In particular, when the temperature of the use environment of the hose is high, the reinforcing body and the hose wall are easily damaged. If the hose is used under reduced pressure at high temperatures, the hose is likely to collapse. Also, damage is likely to occur when pressure is repeatedly applied to the hose.
An object of the present invention is to increase the durability of a flexible hose.

As a result of intensive studies, the inventor has found that the durability of the synthetic resin hose is improved when the resin helical reinforcement is integrated with the hose wall while being covered with another resin. Completed.

The present invention is a synthetic resin hose in which a vinyl chloride resin hose wall is integrated with a vinyl chloride resin hose wall, and the helix wall is formed of a vinyl chloride resin harder than the hose wall. And a synthetic resin hose integrated with the hose wall in a state in which the spiral reinforcing body is covered with a polyester-based thermoplastic elastomer (first invention).
The present invention also relates to a synthetic resin hose in which a helix wall made of polyester thermoplastic elastomer is integrated with a hose wall made of vinyl chloride resin, and the helix wall is harder than the hose wall. This is a synthetic resin hose integrated with the hose wall in a state of being covered with resin (fourth invention).

In the first invention, it is preferable that the polyester-based thermoplastic elastomer is mainly composed of a block copolymer having a hard segment and a soft segment, and the hard segment is polybutylene terephthalate (second invention). In the first invention or the second invention, the hose wall is preferably made of a vinyl chloride resin containing a plasticizer, and the helical reinforcing body is preferably made of a vinyl chloride resin containing no plasticizer ( Third invention). In the fourth invention, it is preferable that the polyester-based thermoplastic elastomer is mainly composed of a block copolymer having a hard segment and a soft segment, and the hard segment is polybutylene terephthalate (fifth invention). In the fourth or fifth invention, it is preferable that the hose wall is formed of a vinyl chloride resin containing a plasticizer, and the resin covering the spiral reinforcing body is a vinyl chloride resin containing no plasticizer ( (Sixth invention).

According to the synthetic resin hose of the present invention (first invention, fourth invention), the durability of the hose is enhanced. Furthermore, if it is made like 2nd invention, 3rd invention, 5th invention, 6th invention, the improvement of durability of a hose will become more remarkable.

It is a partial cross section figure which shows the structure of the synthetic resin hoses of 1st Embodiment. It is a schematic diagram which shows the manufacturing method of the synthetic resin hoses of 1st Embodiment. It is a partial cross section figure which shows the structure of the synthetic resin hoses of 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, taking a synthetic resin hose used for hot water piping as an example. Note that the present invention is not limited to the individual embodiments described below, and the embodiments can be changed and implemented. FIG. 1 is a partially sectional view showing a synthetic resin hose 1 according to a first embodiment of the invention.

The synthetic resin hose 1 is a flexible hose formed of synthetic resin, and has a substantially cylindrical hose wall 11 and a spiral reinforcing body 14. If necessary, another member, for example, a protective cover or the like may be provided outside the hose. The hose wall 11 is made of a vinyl chloride resin. In the present embodiment, the spiral reinforcing body 14 is also made of a vinyl chloride resin. In the present embodiment, the spiral reinforcement body 14 is integrated with the outer periphery of the hose wall 11. The integration of the hose wall 11 and the spiral reinforcement 14 may be a form in which the helix wall 14 is embedded in the hose wall 11, or the spiral reinforcement 14 is integrated on the inner periphery of the hose wall 11. Form may be sufficient.

The specific form of the hose wall 11 is not particularly limited. The hose wall 11 may have a cylindrical shape formed substantially parallel to the central axis, or the hose wall 11 may have a bellows shape having an uneven wave shape. Moreover, the specific form of the spiral reinforcement 14 is not particularly limited as long as it is a reinforcement formed in a spiral shape. The cross-sectional shape of the spiral reinforcing body 14 may be circular as in the present embodiment, or may be other cross-sectional shapes such as a semicircular shape, an elliptical shape, or a rectangular shape. May be provided. Further, the number of spiral reinforcing members is not particularly limited, and may be one as in this embodiment, but the spiral reinforcing members may be provided with two or more strips.

In the present embodiment, the spiral reinforcement body 14 is formed of a vinyl chloride resin that is harder than the hose wall 11. That is, the hose wall 11 is made of a soft vinyl chloride resin that is relatively soft and flexible, while the spiral reinforcing body 14 is made of a harder vinyl chloride resin. The vinyl chloride resin constituting the hose wall 11 may contain a plasticizer. The plasticizer contained in the hose wall 11 is preferably a non-migrating plasticizer. Moreover, it is preferable that the vinyl chloride resin which comprises the spiral reinforcement body 14 does not contain a plasticizer.

In this embodiment, the spiral reinforcement body 14 is integrated with the hose wall 11 in a state of being covered with a polyester-based thermoplastic elastomer. A coating layer 15 is formed on the outer periphery of the spiral reinforcing body 14 by coating with a polyester-based thermoplastic elastomer. The spiral reinforcing body 14 is joined to the hose wall 11 via a coating layer 15 made of a polyester-based thermoplastic elastomer. Bonding of the coating layer 15 and the hose wall 11 is usually by welding, but an adhesive or the like may be used in combination to increase the bonding strength.

The polyester thermoplastic elastomer constituting the coating layer 15 will be described. The polyester thermoplastic elastomer is preferably a thermoplastic resin mainly composed of a block copolymer having a hard segment composed of a polyester component and a soft segment composed of a polyether component. Moreover, it is preferable that the hard segment becomes a crystalline layer and expresses basic properties as a resin, while the soft segment becomes an amorphous phase and expresses properties as an elastomer. Moreover, the said block copolymer contains the thing by which the one part modified | denatured and the thing into which the functional group was introduce | transduced.

Further, in the polyester thermoplastic elastomer constituting the coating layer 15, the hard segment is particularly preferably polybutylene terephthalate (PBT). Such a polyester-based thermoplastic elastomer is commercially available from Toray DuPont Co., Ltd. under the trade name Hytrel (registered trademark).

The hardness of the polyester-based thermoplastic elastomer constituting the coating layer 15 is preferably made lower than the hardness of the vinyl chloride resin constituting the helical reinforcement body 14. Moreover, it is preferable that the hardness of the polyester-based thermoplastic elastomer constituting the coating layer 15 is higher than the hardness of the vinyl chloride resin constituting the hose wall 11.

The manufacturing method of the synthetic resin hose 1 of 1st Embodiment is demonstrated. The synthetic resin hose 1 can be manufactured by a so-called spiral molding method using a known hose molding apparatus M. As shown in FIG. 2, a hose that performs a helical rotational feed operation by supplying a soft polyvinyl chloride resin strip T1 having a parallelogram cross section to a forming shaft SFT of a hose forming apparatus M while extruding it in a semi-molten state. On the forming shaft SFT, the hose wall 11 is formed by winding in a spiral shape so that both side edges of the resin strip T1 overlap each other. Further, a hard vinyl chloride resin to be the spiral reinforcement 14 and a polyester thermoplastic elastomer to be the coating layer 15 are coextruded in a semi-molten state to form a resin strip T2, and a hose forming shaft SFT. It winds around the outer periphery of the hose wall 11 formed above in a spiral shape. Then, the resin strip T2 is welded and integrated with the cylindrical hose wall 11. Then, the said synthetic resin hose 1 is obtained by cooling suitably.

The operation and effect of the synthetic resin hose 1 of the present invention will be described. According to the synthetic resin hose 1, the durability of the hose is enhanced as compared with the conventional hose.

When a hose made of a vinyl chloride resin as disclosed in Patent Document 1 is used in a bent state, cracks and cracks occur in the reinforcing body over time, and the hose wall breaks starting from that portion May end up. In particular, when the hose is used in a high temperature environment, the breakage is likely to occur. The cause of this is not clear, but the reinforcing body is cracked due to a decrease in strength of the reinforcing body due to thermal aging of the resin constituting the reinforcing body, or the occurrence of so-called stress cracks. It is estimated that cracks progress to the hose wall part integrated with the hose wall and the hose wall breaks.

In the synthetic resin hose 1 of the present invention, the spiral reinforcing body 14 is integrated with the hose wall 11 in a state of being covered with the polyester-based thermoplastic elastomer coating layer 15, so that the spiral reinforcing body 14 is cracked. Even so, the coating layer 15 of the polyester-based thermoplastic elastomer is wrapped around the periphery, and crack growth is suppressed. Moreover, even if a crack expands in the reinforcement body 14, the flexible coating layer 15 is provided between the hose wall 11 and the reinforcement body 14, and the crack of the reinforcement body proceeds to the hose wall as it is. Is suppressed. Therefore, the hose wall is prevented from breaking starting from the crack of the reinforcing body, and the durability of the hose is improved.

In particular, when the polyester-based thermoplastic elastomer is mainly composed of a block copolymer having a hard segment and a soft segment, and the hard segment is polybutylene terephthalate, the coating layer 15 has high strength even at a high temperature, and thus the above-mentioned durability. The improvement effect becomes remarkable when the hose is used at a high temperature.

Moreover, when the vinyl chloride resin which comprises the hose wall 11 has a plasticizer, especially a transferable plasticizer, durability of a hose improves also from the following viewpoints.

In a hose made of vinyl chloride resin as disclosed in Patent Document 1, if the plasticizer is contained in the vinyl chloride resin on the hose wall, the plasticizer contained in the hose wall becomes a reinforcing body as the hose is used. Transition. When the use environment of the hose is high, it becomes easy to shift. When the plasticizer is transferred, the reinforcing body is softened, the function of maintaining the cylindrical shape of the hose is weakened, and the hose is easily crushed or kinked. Further, since the plasticizer is released from the hose wall, the hose wall is likely to be rigid, and the flexibility of the hose is impaired and the hose wall is easily broken.

In the synthetic resin hose 1 of the present invention, the helical reinforcing body 14 is integrated with the hose wall in a state of being covered with the polyester thermoplastic elastomer coating layer 15, and therefore, the vinyl chloride resin constituting the hose wall 11. Even if the plasticizer is contained in the polyester thermoplastic elastomer coating layer 15, the polyester-based thermoplastic elastomer coating layer 15 functions as a barrier layer, and the plasticizer is suppressed from moving to the spiral reinforcement 14. Therefore, deterioration of the hose 1 due to migration of the plasticizer can be suppressed, and durability can be enhanced.

In particular, when the polyester-based thermoplastic elastomer is mainly composed of a block copolymer having a hard segment and a soft segment, and the hard segment is polybutylene terephthalate, the effect of suppressing the migration of the plasticizer used for the vinyl chloride resin is obtained. Especially high.

(Example)
A hose corresponding to the synthetic resin hose 1 of the first embodiment was manufactured with a hose inner diameter (diameter) of 25 mm to obtain a hose of the example. As the polyester-based thermoplastic elastomer, an extrusion grade elastomer of Hytrel (registered trademark) manufactured by Toray DuPont Co., Ltd. was used. On the other hand, except for the absence of the coating layer 15, a hose similar in shape and other points was manufactured to obtain a comparative hose.

(Kink resistance test)
Each of the obtained hoses was attached so as to be bent 180 degrees so that the bend R of the hose center line had a radius of 80 mm, and left at an ambient temperature of 80 ° C.
In the comparative hose, kinking of the hose occurred when 3 hours passed. On the other hand, in the hose of the example, no kink was observed even after 24 hours.

(High temperature decompression durability test)
Each of the obtained hoses was reduced in pressure by 760 mmHg (0.1 MPa) at an atmospheric temperature of 80 ° C. As for the hose of the comparative example, the hose wall was blocked by the reduced pressure when 5 minutes passed. On the other hand, the hose of the example did not block the hose wall even after 1 hour.

The invention is not limited to the embodiment described above, and can be implemented with various modifications. Although other embodiments of the invention will be described below, in the following description, portions different from the above-described embodiment will be mainly described, and detailed descriptions of the same portions will be omitted. Moreover, these embodiments can be implemented by combining some of them or replacing some of them.

In FIG. 3, the synthetic resin hose 2 of 2nd Embodiment is shown. In the present embodiment, the helical reinforcing body 24 covered with the covering layer 25 is embedded in the hose wall 21 and the protective layer 22 is provided on the outer periphery of the hose wall 21. Although different from the synthetic resin hose 1 of the first embodiment, the other points are the same. In the present embodiment as well, the durability of the hose, in particular, the durability in a high temperature environment is enhanced. The protective layer 22 need not be made of vinyl chloride, and may be a layer formed of other resins. That is, the hose wall only needs to be made of a vinyl chloride resin at a portion joined to the spiral reinforcement body or the coating layer, and may include another resin at the other portion of the hose wall.

In both the first embodiment and the second embodiment, the spiral reinforcement is made of vinyl chloride resin, and the spiral reinforcement is integrated with the hose wall in a state of being covered with a polyester-based thermoplastic elastomer. Although the embodiment has been described, the invention may be implemented by replacing the resin of the spiral reinforcement (14, 24) and the resin of the coating layer (15, 25). That is, in a synthetic resin hose in which a helix wall made of a polyester-based thermoplastic elastomer is integrated with a hose wall made of vinyl chloride resin, the helical reinforcement body is covered with a vinyl chloride resin harder than the hose wall A synthetic resin hose may be configured so as to be integrated with the hose wall (third embodiment).

Even if it is the structure like 3rd Embodiment, durability of a hose can be improved. The reason for this is that even if a crack occurs in the hard vinyl chloride resin that coats the spiral reinforcement body, the presence of the spiral reinforcement body made of polyester-based thermoplastic elastomer that is integrated inside the coating causes cracks. This is because the growth of the hose does not proceed and the hose wall is prevented from breaking. In addition, when the plasticizer is contained in the vinyl chloride resin that constitutes the hose wall, the problem that the plasticizer migrates and the strength of the hose wall and the like is reduced is the same as in the third embodiment. Since the hard vinyl chloride resin in contact with the wall is a thin coating layer, the absolute amount of the plasticizer to be transferred is reduced, and the strength of the hose wall is not easily lowered. From this point of view, in the present embodiment, it is preferable that the thickness of the layer covering the spiral reinforcement is 1/3 or less of the diameter of the spiral reinforcement.

Also in the third embodiment, the polyester-based thermoplastic elastomer is mainly composed of a block copolymer having a hard segment and a soft segment, and the hard segment is preferably polybutylene terephthalate, and the durability of the hose is further improved. . Also in the third embodiment, the hose wall is formed of a vinyl chloride resin containing a plasticizer, and the resin that covers the spiral reinforcement is preferably a vinyl chloride resin containing no plasticizer. More improved.

The use of the synthetic resin hose of the present invention is not particularly limited. In the description of the above embodiment, a hose through which hot water is passed is illustrated, but it can also be used for other applications, for example, transfer of air, powder, and granular materials.

The synthetic resin hose of the present invention can be used for transferring warm water, for example, and has high industrial utility value.

1, 2 Synthetic resin hoses 11, 21 Hose walls 14, 24 Spiral reinforcements 15, 25 Cover layers made of polyester thermoplastic elastomer

Claims (6)

A synthetic resin hose in which a vinyl chloride resin helix reinforcement is integrated with a vinyl chloride resin hose wall,
The spiral reinforcement is formed of a vinyl chloride resin that is harder than the hose wall,
A synthetic resin hose in which a spiral reinforcing body is integrated with a hose wall in a state of being covered with a polyester-based thermoplastic elastomer. The synthetic resin hose according to claim 1, wherein the polyester-based thermoplastic elastomer is mainly composed of a block copolymer having a hard segment and a soft segment, and the hard segment is polybutylene terephthalate. The synthetic resin hose according to claim 1 or 2, wherein the hose wall is made of a vinyl chloride resin containing a plasticizer, and the helical reinforcement is made of a vinyl chloride resin containing no plasticizer. A synthetic resin hose in which a helix wall made of a polyester-based thermoplastic elastomer is integrated with a hose wall made of a vinyl chloride resin,
A synthetic resin hose integrated with the hose wall in a state in which the helical reinforcement is covered with a vinyl chloride resin harder than the hose wall. The synthetic resin hose according to claim 4, wherein the polyester-based thermoplastic elastomer is mainly composed of a block copolymer having a hard segment and a soft segment, and the hard segment is polybutylene terephthalate. The synthetic resin hose according to claim 4 or 5, wherein the hose wall is formed of a vinyl chloride resin containing a plasticizer, and the resin covering the spiral reinforcement is a vinyl chloride resin containing no plasticizer.

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