JPH10160059A - Resin hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin hose with high oilproofing, heat resistance, and flexibility. SOLUTION: This hose is provided with a tubular inner layer 1, and outer layer 2 laminated on the outer periphery of the tubular inner layer 1. The tubular inner layer 1 is constituted of a double-layer structure of an inmost layer (A) 1a consisting of polyester elastomer and inner layer (B) 1b, consisting of thermoplastic polyurethane, formed at the outer periphery of the inmost layer (A) 1a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin hose used as a hydraulic hose for various machines.

[0002]

2. Description of the Related Art In general, hydraulic hoses used in general industrial machines, construction machines, civil engineering machines and the like have a multilayer structure in which a plurality of layers formed by utilizing characteristics of various resins are combined. As an example of the above-mentioned multi-layered hydraulic hose, for example, as shown in FIG. 3, the inner layer 10 is formed of a polyamide resin such as nylon 11, nylon 12, nylon 6/66, or a polyester elastomer.
A three-layer structure in which a reinforcing yarn layer 11 braided with a polyester-based reinforcing yarn or the like is formed on the outer peripheral surface of the inner layer 10, and a polyurethane outer layer 12 is formed on the outer peripheral surface of the reinforcing yarn layer 11. Hydraulic hose has been awarded.
Above all, a hydraulic hose using a polyester elastomer as a material for forming the inner layer 10 has been awarded as a particularly preferable one because it has both excellent oil resistance and heat resistance.

[0003]

However, conventional hydraulic hoses using a polyester elastomer as the material for forming the inner layer 10 are excellent in oil resistance and heat resistance, but are required as one characteristic of the hydraulic hose together with these characteristics. There is a problem that flexibility is poor. As described above, the fact is that a hydraulic hose satisfying all the properties of oil resistance, heat resistance and flexibility has not yet been obtained.
There is a long-awaited need for a hydraulic hose having all of these characteristics.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a resin hose having excellent oil resistance, heat resistance, and flexibility.

[0005]

In order to achieve the above-mentioned object, a resin hose of the present invention comprises a tubular inner layer and an outer layer laminated on the outer peripheral surface of the tubular inner layer. The tubular inner layer has a two-layer structure of the following innermost layer (A) and the following inner layer (B) formed on the outer peripheral surface of the innermost layer (A). (A) Innermost layer made of polyester elastomer. (B) Inner layer made of thermoplastic polyurethane.

The present inventors have conducted a series of studies to obtain a resin hose having excellent flexibility as well as excellent oil resistance and heat resistance. Focusing on the material for forming the tubular inner layer of the resin hose, and examining a method of imparting flexibility while taking advantage of the excellent oil resistance and heat resistance of the conventionally used polyester elastomer, as a result, the tubular inner layer was simply formed. Instead of a layer structure, a two-layer structure for providing flexibility was recalled. That is, of the two-layer structure serving as the tubular inner layer, the innermost layer (A) is formed of a polyester elastomer (hereinafter referred to as “TPEE”) having excellent oil resistance and heat resistance.
When the inner layer (B) made of thermoplastic polyurethane having excellent flexibility (hereinafter abbreviated as “TPU”) is formed on the outer peripheral surface of the innermost layer (A), The present inventors have found that a resin hose having both excellent oil resistance and heat resistance possessed and excellent flexibility possessed by the inner layer (B) can be obtained, and arrived at the present invention.

[0007]

Next, embodiments of the present invention will be described in detail.

As an example of the resin hose of the present invention, as shown in FIG. 1, a tubular inner layer 1 having a two-layer structure in which an inner layer 1b is formed on the outer peripheral surface of an innermost layer 1a, and a tubular inner layer 1 formed on the outer peripheral surface of the tubular inner layer 1 And a resin hose having a three-layer structure of the outer layer 2 as described above. As described above, in the resin hose of the present invention, the tubular inner layer 1 has a two-layer structure of the innermost layer 1a and the inner layer 1b formed on the outer peripheral surface of the innermost layer 1a. The two layers 1b are each formed of a special material.

As the material for forming the innermost layer 1a constituting the tubular inner layer 1, TPEE is used. The above TPEE
It is preferable that they have excellent oil resistance and heat resistance and have good adhesion to the TPU as the material for forming the inner layer 1b. For example, a block copolymer of polyester and polyether, and a block copolymer of polyester and polyester are preferable. And polymers.

The Shore D hardness of the TPEE is preferably 44 or more, and particularly preferably 44 to 57. That is, when the Shore D hardness of the TPEE is less than 44, the flexibility is improved, but the oil resistance and heat resistance are reduced, and the balance of oil resistance, heat resistance and flexibility tends to be deteriorated. is there.

[0011] The TPEE comprises a combination of a soft segment and a hard segment. As the soft segment, an aliphatic polyether copolymer is particularly preferred, and as the hard segment, an aromatic polyester copolymer is particularly preferred. In addition, the above TPE
The ratio (weight ratio) of the soft segment to the hard segment in E is particularly preferably soft segment / hard segment = 35/65 to 55/45.

As a material for forming the inner layer 1b constituting the tubular inner layer 1, TPU is used. As the TPU, those having excellent flexibility and good adhesion to TPEE as the material for forming the innermost layer 1a are preferable, and for example, TPUs such as ether-based, ester-based, carbonate-based, and caprolactone-based are preferable. .

The Shore D hardness of the TPU is preferably 40 or more, and the TPU based on JIS K 7206
The softening temperature of PU is preferably 100 ° C. or higher.

The material for forming the outer layer 2 formed on the outer peripheral surface of the tubular inner layer 1 is not particularly limited, and a conventionally known material can be used. For example, TPU, polyamide elastomer, TPEE and the like can be mentioned.

The resin hose of the present invention uses the above-mentioned material,
For example, it is manufactured as follows.

First, the tubular inner layer 1 is produced, for example, as follows. That is, the innermost layer 1a of the tubular inner layer 1
TPEE as a forming material and inner layer 1b of tubular inner layer 1
A TPU, which is a forming material, is prepared, and two layers are co-extruded at the same time.
A tube having a layer structure is manufactured. Next, the tubular inner layer 1
The outer layer 2 is extruded using an extruder to form the outer layer 2 on the outer peripheral surface of the inner layer 1b, thereby forming the innermost layer 1a made of TPEE, the inner layer 1b made of TPU, and the outer peripheral surface of the inner layer 1b. A resin hose having a three-layer structure of the formed outer layer 2 is manufactured (see FIG. 1).

The thickness of each layer in the three-layer resin hose is set as follows. Innermost layer 1 of tubular inner layer 1
The thickness of a is preferably in the range of 0.2 to 2.8 mm,
Particularly preferably, it is set in the range of 0.5 to 0.8 mm. Further, the thickness of the inner layer 1b of the tubular inner layer 1 is preferably in the range of 0.2 to 2.8 mm, particularly preferably 0.2 to 2.8 mm.
It is set in the range of 0.5 mm. And the thickness of the outer layer 2 is usually set in the range of 0.3 to 3.0 mm, preferably in the range of 0.3 to 1.5 mm. Above all, the thickness (a) of the innermost layer 1a is equal to the thickness (a) of the innermost layer 1a.
And the total thickness [(a) + (b)] of the thickness (b) of the inner layer 1b
(That is, equivalent to the thickness of the tubular inner layer 1)
It is preferable to set the thickness ratio to be 0.5 to 0.8.

The resin hose of the present invention is not limited to the three-layer structure shown in FIG. 1, but for example, as shown in FIG. 3
May be used as a four-layer structure. In the resin hose shown in FIG. 2 as well, the tubular inner layer 1 has a two-layer structure of an innermost layer 1a and an inner layer 1b, and two layers of the innermost layer 1a and the inner layer 1b constituting the tubular inner layer 1 are respectively the same as those shown in FIG.
As with the three-layer resin hose shown in FIG.

The reinforcing layer 3 formed on the outer peripheral surface of the inner layer 1b constituting the tubular inner layer 1 is, for example, a reinforcing yarn layer formed by braiding using a reinforcing yarn. As the reinforcing yarn, a yarn having good adhesion to the inner layer 1b is preferable, and particularly, a polyester yarn, a polyamide yarn, a vinylon yarn, a rayon yarn, an aromatic polyamide yarn and the like are preferable.
Among these, polyester yarns are mainly used from the viewpoints of strength, versatility, cost and the like.

The resin hose having a four-layer structure in which the reinforcing layer 3 is interposed between the inner tubular layer 1 and the outer layer 2 shown in FIG. 2 can be manufactured, for example, as follows. That is, in the same manner as described above, the tubular inner layer 1 having a two-layer structure is formed.
After forming (the innermost layer 1a + the inner layer 1b), the reinforcing layer 3 is formed on the outer peripheral surface of the inner layer 1b of the tubular inner layer 1, and the outer layer 2 is formed on the outer peripheral surface of the reinforcing layer 3 in the same manner as described above. Thus, a resin hose having a four-layer structure shown in FIG. 2 in which the reinforcing layer 3 is interposed between the tubular inner layer 1 and the outer layer 2 is obtained. When a reinforcing yarn is used as the material for forming the reinforcing layer 3, the reinforcing layer 3 is braided by using a braiding machine.
Can be formed.

Next, examples will be described together with comparative examples.

[0022]

Examples 1 to 4 First, the ratio of the soft segment (aliphatic polyether) to the hard segment (aromatic polyester) and the Shore D hardness as shown in Table 1 below were used as the innermost layer forming material of the tubular inner layer. While preparing each TPEE having (Shore D), a polyether-based TPU (Pandex T-8195N manufactured by Dainippon Ink and Chemicals, Inc.) was prepared as an inner layer forming material, and an extruder was used according to the above-described method. By extruding two layers at the same time, a tube having a two-layer structure to be a tubular inner layer was prepared. Next, a TPU (Pandex T-8195 manufactured by Dainippon Ink and Chemicals, Inc.) was applied to the outer peripheral surface of the tube having the two-layer structure.
To form an outer layer by an extruder. Thus, a three-layer resin hose (inner diameter 9.5 mm × outer diameter 1)
5.3 mm) (see FIG. 1).

[0023]

[Table 1]

Using the resin hoses of the examples thus obtained, oil resistance and flexibility were measured and evaluated according to the following methods. The results are shown in Table 2 below.

[Oil resistance] Only a tubular inner layer of a resin hose is used, sealed with JIS # 3 oil, and heated at 100 ° C for 1 hour.
It was left for 68 hours.

[Flexibility] As shown in FIG. 4, one end of each resin hose 20 is attached and fixed to the flat plate 21, and a force is applied to the fixed resin hose 20 so as to be in a vertical state (broken line).
The resin hose 20 is bent in a substantially L-shape from
mm (length C section). Then, the force in the direction of arrow F when the straight line portion AB on the other end side of the resin hose 20 became parallel to the flat plate 21 was measured and used as an index of flexibility evaluation as a bending repulsion force index. That is, it can be said that the smaller the bending resilience index is, the more excellent the flexibility is. In addition, the bending resilience index indicated the force in the direction of arrow F when the hose of Comparative Example 1 was used as 100.

[0027]

[Table 2]

From the results shown in Table 2, it can be seen that the resin hoses of Examples 1 to 4 are excellent in both oil resistance and flexibility. In particular, the resin hoses of Examples 1 to 3 using TPEE having a Shore D hardness of 44 to 57 have higher oil resistance than the resin hoses of Example 4 using TPEE having a Shore D hardness of 31. It turns out that it is excellent.
This indicates that it is preferable to use TPEE having a Shore D hardness of 44 to 57.

[0029]

Examples 5 to 7 First, TPEE (Perprene P-90BD manufactured by Toyobo Co., Ltd.) was used as the innermost layer forming material of the tubular inner layer.
As well as an ether-based TPU (Pandex T-Made by Dainippon Ink and Chemicals, Inc.)
8195) was prepared, and two layers were simultaneously extruded using an extruder so as to have a thickness shown in Table 3 below to prepare a tube having a two-layer structure as a tubular inner layer according to the method described above. Otherwise, a three-layer resin hose (inner diameter: 9.5 mm × outer diameter: 15.3 mm) was produced in the same manner as in Example 1 (see FIG. 1).

[0030]

Comparative Example 1 The tubular inner layer had a single-layer structure made of TPEE (Perprene P-90BD manufactured by Toyobo) (thickness: 1).
mm). Except for this, a resin hose having a two-layer structure (inner diameter: 9.5 mm × outer diameter: 15.3 mm) was produced in the same manner as in Example 1.

[0031]

Comparative Example 2 The tubular inner layer had a one-layer structure (thickness: 1 mm) composed of an ether-based TPU (Pandex T-8195 manufactured by Dainippon Ink and Chemicals, Inc.). Otherwise, in the same manner as in Example 1, a resin hose having a two-layer structure (inner diameter: 9.5 mm
X outer diameter 15.3 mm).

[0032]

[Table 3]

Using the resin hoses of Examples and Comparative Examples thus obtained, oil resistance and flexibility were measured and evaluated in accordance with the above method. The results are shown in Table 4 below.

[0034]

[Table 4]

From the results shown in Table 4 above, it can be seen that the resin hose of the example product is superior in both oil resistance and flexibility to the resin hose of the comparative example product.

[0036]

Examples 8 to 12 First, as a material for forming the innermost layer of the tubular inner layer, TPEE (Perprene P-90B manufactured by Toyobo Co., Ltd.) was used.
While preparing D), each TPU shown in Table 5 below is prepared as an inner layer forming material, and two layers are simultaneously extruded using an extruder according to the method described above, thereby forming a tube having a two-layer structure as a tubular inner layer. Was prepared. Otherwise, in the same manner as in Example 1, a resin hose having a three-layer structure (inner diameter: 9.5 m
m × 15.3 mm in outer diameter) (see FIG. 1).

[0037]

[Table 5]

Using the resin hoses of the examples thus obtained, oil resistance and flexibility were measured and evaluated according to the above-mentioned method. The results are shown in Table 6 below.

[0039]

[Table 6]

From the results shown in Table 6, it can be seen that the resin hoses of the examples are excellent in both oil resistance and flexibility.

[0041]

As described above, the resin hose of the present invention
The innermost layer made of TPEE and the outer peripheral surface of the innermost layer
It has a two-layer tubular inner layer on which an inner layer made of PU is formed. Therefore, the innermost layer forming material TPE
The excellent oil resistance and heat resistance of E can be utilized, and flexibility can be given by TPU which is an inner layer forming material. Therefore, the resin hose of the present invention can be suitably used, for example, as a hydraulic hose used in general industrial machines, construction machines, civil engineering machines, and the like.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a resin hose of the present invention.

FIG. 2 is a perspective view showing another example of the resin hose of the present invention.

FIG. 3 is a perspective view showing a conventional hydraulic hose.

FIG. 4 is a schematic diagram for explaining a method for measuring flexibility.

[Explanation of symbols]

 Reference Signs List 1 tubular inner layer 1a innermost layer 1b inner layer 2 outer layer

Claims (4)

[Claims] 1. A resin hose comprising: a tubular inner layer; and an outer layer laminated on an outer peripheral surface of the tubular inner layer, wherein the tubular inner layer has the following innermost layer (A) and the innermost layer (A) A resin hose having a two-layer structure of the following inner layer (B) formed on the outer peripheral surface of the resin hose. (A) Innermost layer made of polyester elastomer. (B) Inner layer made of thermoplastic polyurethane. 2. The resin hose according to claim 1, wherein the Shore D hardness of the polyester elastomer is 44 or more. 3. The resin hose according to claim 1, wherein the thermoplastic polyurethane is at least one selected from the group consisting of ether-based, carbonate-based, ester-based, and caprolactone-based thermoplastic polyurethanes. 4. The resin hose according to claim 1, wherein the thickness of the innermost layer (A) made of the polyester elastomer is set so as to satisfy the following inequality (1). 0.5 ≦ (a) / [(a) + (b)] ≦ 0.8 (1) [In the formula (1), (a) represents the innermost layer (A) of the polyester elastomer. (B) represents the thickness of the inner layer (B) made of thermoplastic polyurethane. ]