JPS60192189A - Flexible hose - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a flexible hose that has improved flexibility and low and high temperature properties without impairing gas barrier properties.

Typical examples of the flexible hose of the present invention include hoses used for transporting gas, particularly hoses used for transporting 7 Leon gas for automobile coolers.

[Prior Art] It is desirable to use a nylon-based resin hose for the hose used for transporting 7 Leon gas in an automobile cooler, considering its light weight and low cost. Therefore, in the automobile industry, as shown in Fig. 1, the inner tube 1 is made of a nylon resin layer with a thickness of about 1 mm, and the outer tube 2 is made of a reinforcing yarn layer 3 and a single layer of elastomer 4, which makes it lightweight. A hose with high performance and low cost has been developed4.Although nylon resin hoses are sufficiently lightweight and low cost, if the gas barrier properties of the inner tube 1 made of nylon resin are improved, There is a problem in that the flexibility of the inner tube 1 is reduced and the flexibility of the hose is insufficient.

However, increasing the flexibility of the inner tube 1 reduces the gas barrier properties of the inner tube 1. Furthermore, when a plasticizer is added to nylon resin to make it softer, there are problems when using it under severe conditions such as low or high temperatures. For example, when the temperature is extremely low, the inner tube 1 becomes stiff due to crystallization of the plasticizer and its strength decreases, and when the temperature is extremely high, the plasticizer scatters from the inner tube 1 and the inner tube i becomes hard.

Due to the above-mentioned circumstances, it has been difficult to ensure gas barrier properties, flexibility, low-temperature and high-temperature properties with a hose whose inner tube is made of nylon resin.

By the way, the present applicant has recently developed a flexible hose that uses a saponified olefin-vinyl acetate copolymer for the inner tube and has excellent gas barrier properties, flexibility, and low- and high-temperature properties. Since the olefin-vinyl acetate copolymer is hard, the layer of the saponified olefin-vinyl acetate copolymer is extremely thin, about 10 to 50 microns, thereby ensuring the flexibility of the hose. However, during extrusion molding of a hose, it is extremely difficult to form the saponified material into a very thin film of about 10 to 50 microns, which poses a manufacturing problem. Furthermore, the above silicide has the disadvantage that it is a brittle material with low physical elongation and is very easily hydrolyzed, and there are concerns about its environmental resistance in view of the usage conditions of the hose.

[Object of the Invention] The present invention was developed in view of the problems of the nylon resin hose and the problem of the saponified olefin-vinyl acetate copolymer hose described above. Therefore, the present invention ensures a well-balanced gas barrier property, flexibility, low-temperature and high-temperature properties, and unlike hoses made of saponified olefin-vinyl acetate copolymer, there are no manufacturing problems, and furthermore, the hose has excellent durability considering the usage conditions of the hose. To provide a flexible hose with improved environmental friendliness.

[Summary of the structure of the invention] The flexible hose of the present invention includes a plastic inner tube and an outer tube surrounding the inner tube, and includes:
The inner tube is characterized by being composed of a hard nylon resin layer thinned into a film shape and a single layer of elastomer that covers and integrally holds the hard nylon resin layer. The flexible hose of the present invention integrates a hard nylon resin and a single layer of elastomer. Note that the hard nylon resin layer may be located inside or outside the inner tube.

[Detailed explanation of the structure of the invention]

The inner tube, which characterizes the flexible hose of the present invention, is composed of a hard nylon resin layer thinned into a film shape and a single layer of elastomer that covers and integrally holds the hard nylon resin layer.

The hard nylon resin layer has good gas barrier properties.

This is because resin materials such as nylon resin generally tend to have lower sandy 1-7F barrier properties, but as they become harder, gas barrier properties tend to improve.

For example, in the case of nylon 6 containing no plasticizer, plasticized nylon containing plasticizer, for example 11 nylon containing plasticizer,
3 compared to nylon, 12 nylon, and 6.66 nylon.
It has an excellent gas burr V- property of 0 to 50 times. Freon gas permeation is therefore mainly blocked by the hard nylon resin layer.

The thickness of the hard nylon resin layer thinned into a film is
Usually, it is extremely thin, less than 100μ. When the flexible hose is a hose used for transporting Freon gas in an automobile cooler, the thickness of the hard nylon resin layer is typically in the range of 50 to less than 100 microns. 50-1
The purpose of making the hard nylon resin layer extremely thin, less than 00μ, is to ensure the required flexibility of the inner tube. That is, if the thickness of the hard nylon resin layer is increased, the hardness of the inner tube becomes excessive, but if the thickness of the hard nylon resin layer is decreased, the amount of deflection as a flexible boce can be ensured.

It is said that the thickness of the hard nylon resin layer is preferably 50 to 100 μm, but this value is not suitable for the flexible Bose gas barrier.
In particular, the material was determined with consideration to ensuring the same degree of Freon gas barrier properties as conventional flexible hoses. Therefore, if the gas barrier target, particularly the Freon gas barrier target, changes, the thickness of the hard nylon resin layer will change accordingly.

As mentioned above, the harder the hard nylon resin layer is, the better the gas barrier properties can be, so it is desirable that the hard nylon resin layer does not contain a plasticizer. However, although it is not preferable, it may be included as necessary.

If the hard nylon resin layer is made from a nylon resin that does not contain a plasticizer as described above, it is possible to suppress cancerous formation of the nylon resin due to crystallization of the plasticizer at low temperatures. Furthermore, it is possible to suppress the hardening of the nylon resin due to the scattering of the plasticizer at high temperatures.

The hard nylon resin layer is made of 6 nylon, 66 nylon, 1
It can be made from 1 nylon, 6.1o nylon, and 6.12 nylon. Alternatively, it can be made from a mixture of nylon 6 and nylon 6.10, a mixture of nylon 6 and an ionomer, and the like.

The extomer layer, which is a component of the present invention, refers to a layer made of a material that has rubber elasticity at room temperature and has the ability to quickly return to its original shape when stress is removed. This single layer of elastomer covers the hard nylon resin layer, which is usually thinned to less than 100 microns, and holds the hard nylon resin layer integrally. By covering the hard nylon resin layer thinned into a film shape with a single layer of elastomer, the hard nylon resin layer can be protected. For example, when the end of a flexible hose is caulked, the hard resin layer thinned into a film may be damaged and torn by the external force applied during caulking. The elastomer layer protects the hard nylon resin and prevents the above damage. As the elastomer layer, a nylon elastomer or a polyester elastomer can be used. The thickness of one layer of elastomer is usually preferably 0.3 to 1.5 mm1jlf. When the flexible hose is a hose used for transporting 7 Leon gas in an automobile cooler, the thickness of the extomer layer is usually desirably about imm. Preferably, the elastomer layer does not contain a plasticizer.

When integrating the hard nylon resin layer and the elastomer layer, it is desirable to form an adhesive layer between them. By forming the adhesive layer in this manner, the degree of integration between the elastomer layer and the hard nylon resin layer can be increased. Furthermore, even if one layer of the elastomer contains an adhesive, the degree of integration can be increased. As the adhesive, a thermoplastic resin type, a thermosetting resin type, or a vulcanized rubber type can be used. As the thermoplastic resin type, various types such as olefin type, polyvinyl chloride type, polyamide type, polycarbonate type, etc. can be selected and used. Thermosetting resins include phenolic resins, amino resins, unsaturated polyesters,
Various epoxy resins can be selected and used.

In addition, as vulcanized rubber type, C8M type, fluororubber type, N
Various types such as OR system, EPDM system, IIR system, etc. can be selected and used.

The outer tube, which is a component of the present invention, has the outer shape of a hose, and its configuration can be similar to that of a conventional hose. For example, it can be formed from a reinforcing thread layer and a cover layer surrounding the reinforcing thread layer. In short, the outer tube only needs to be able to maintain the shape of the hose and protect the inner tube. However, when considering a Freon hose, it is desirable that water permeation into the interior of the hose is small, so it is desirable to select a material with low water permeability for the cover layer, which is one of the constituent elements of the outer tube.

The hard nylon resin layer described above may be formed by curing the nylon resin to a depth of less than 100 μm by a UV method, that is, by irradiating the surface of the nylon resin with ultraviolet rays.

[Effects of the Invention] “The flexible hose of the present invention can improve flexibility and low- and high-temperature properties without impairing gas barrier properties.The reasons are as follows.Firstly, , a hard nylon resin layer with good gas barrier properties is provided.Secondly, if only a hard and inflexible hard nylon resin layer is used, the inner tube will have poor flexibility; The thinner wall is usually less than 100μ, and the thinner wall provides the hose with the necessary flexibility.Thirdly, it is not only possible to use a hard nylon resin layer thinned in the form of a film. However, by covering this with a single layer of elastomer and integrating it, this damage can be suppressed while protecting the hard nylon resin.

The flexible hose of the present invention can be manufactured satisfactorily even when the hard nylon resin layer is thinned into a film, for example, to a thickness of less than 100 μm. In this respect, it differs from conventional flexible hoses that use olefin-vinyl acetate copolymer chloride. This is because nylon-based resins have good processability, unlike olefin-vinyl acetate copolymer compounds.

(Examples) Hereinafter, the present invention will be explained in more detail according to each example.The details of each example are shown in Table 1.

[First Embodiment] FIG. 2 shows cross-sectional views of flexible hoses according to the first embodiment.

In the flexible hose of the first embodiment, the inner tube 10 is composed of a hard nylon resin layer 11 made of nylon 6 with a wall thickness of 75μ, and an elastomer layer 12 made of nylon elastomer with a wall thickness of 500 to iooooμ. has been done.

On the other hand, the outer tube 15 is composed of a reinforcing layer 16 with a wall thickness of 0.6 mm made of 6.6 nylon fiber, and a cover layer 17 with a wall thickness of 1 mm made of an olefin-based lastomer. The method for manufacturing the flexible hose of the first embodiment is as follows. That is, first, the inner tube 10 composed of a hard nylon layer 11 and a single layer of elastomer 12 is molded in one step by co-extrusion molding of the two layers. Thereafter, a reinforcing yarn layer 16 is formed on the outside of the inner tube 10 using a plating machine, and in the final step, a cover layer 17 is extruded to form a 14i layer on the outside of the reinforcing yarn layer 16. The hose is manufactured through the above three steps.

Various properties of the flexible hose of this first example, such as 7 Leon gas barrier properties and flexibility, were tested and compared with the properties of a conventional nylon resin hose shown in FIG. Here, as a conventional nylon resin hose, the inner tube 1 has a wall thickness of 1 m.
The outer tube has exactly the same structure as the Bose outer tube 15 of the first embodiment. That is, all conditions were the same except for the constituent material of the inner tube 10.

The test conditions and results are as follows.

(1> Freon gas barrier test (test conditions) Both ends of a 1 m long flexible hose are closed with metal fittings, Freon gas is fed in liquid form from a valve into the flexible hose, and the hose is sealed. The feeding amount was 5 of the internal volume of the bose.
It is about 0%. Next, the flexible hose is placed in a heat-retaining tank kept at 100°C, and at this time, the inside of the hose reaches the vapor pressure of Freon gas (approximately 34 atmospheres in the case of R-12).
It is kept constant at the exam center. After being kept in the heat insulating tank for 100 hours, the weight of the hose was measured. Then, compare the weight of the flexible hose before putting it in the heat insulating tank and the weight of the flexible hose after being kept in the heat insulating tank for a predetermined time, and define the difference as the amount of gas permeation. Freon gas barrier properties were tested.

(Test results) Freon gas permeation rate of the flexible hose of the first example was 0.
．． 0I Q/m-hr and ivy. On the other hand, the Freon gas permeation rate of the conventional flexible hose shown in Figure 1 is 0.03.
g/m-hr, and the flexibility was higher than that of the first example.

(2) Initial flexibility test (test conditions) A disk-shaped jig with a radius of 75 mm is prepared, and a flexible boce with a length of 400 mm is bent along the outer circumference of the jig, and the magnitude of the load required at that time is The flexibility was tested by

(Test results) In the case of the flexible hose shown in the first example, 1.1k
On the other hand, in the case of the conventional flexible hose shown in Fig. 1, 1.5 JI was required. Therefore, in the case of the flexible hose shown in the first embodiment, the The load was reduced by 20 to 30%.

This is because the flexural modulus of nylon 6 constituting the hard nylon resin layer 11 is 26,000 k (1/Cm2), which is about 6 times higher than the 4,000 kg/cnu of plasticized nylon. Since the wall thickness of the layer 11 is extremely thin, less than 50 to 100 microns, the flexibility of the inner tube is rather higher than that of conventional hoses.

<3) Flexibility after holding at high temperature (test conditions) After holding the flexible Bose at 120°C for 200 hours,
A flexible hose was bent along a disk-shaped jig similar to that used in step 2), and its flexibility after being held at high temperatures was tested depending on the magnitude of the load required at that time.

(Test results) In the case of the flexible hose shown in the first example, 1.2k
(] required. This is almost the same as the load when examining the initial flexibility mentioned in (1).

Therefore, the flexible hose of the first embodiment hardly loses its flexibility even after being held at high temperatures. On the other hand, in the case of the conventional flexible hose shown in FIG. 1, 6.5 ka was required, which was about four times the load when the initial flexibility was examined in (1). Therefore, the flexibility of conventional flexible borses is significantly reduced when held at high temperatures.

(4) Low-temperature embrittlement In the conventional flexible bore shown in FIG. 1, the plastic material contained in the constituent material of the inner tube 1 crystallizes at low temperatures, causing the inner tube 1 to become extremely brittle. However, in the flexible boce of the first embodiment, the hard nylon resin layer 11 and the elastomer layer 12 are made of materials to which no plasticizer is added, so the above-mentioned embrittlement phenomenon is eliminated.

[Second Example] As shown in Table 1, the elastomer layer 12 is thermoplastic,
Made from nylon elastomer blended with resin adhesive. Other details were the same as in the first embodiment. In this second embodiment, since the elastomer layer 12 contains the adhesive described above, the adhesiveness between the hard nylon resin layer 11 and the elastomer layer 12 is improved compared to the first embodiment.

[Third Example] As shown in Table 1, an adhesive layer made of a thermoplastic resin adhesive is provided as an intermediate layer between the hard nylon resin layer 11 and the elastomer layer 12. . The rest is the same as in the first embodiment. In this example, the adhesion between the hard nylon resin layer 11 and the elastomer layer 12 is improved, as in the second example.

[Fourth Example] As shown in Table 1, the elastomer layer 12 is made of a polyester elastomer.

The rest is the same as in the first embodiment.

[Fifth Example] As shown in Table 1, Extomer 1! ! 12 is made from a polyester elastomer blended with a thermoplastic resin adhesive. The rest is the same as in the first embodiment. In this example, since the elastomer layer 12 contains the adhesive described above, the adhesiveness between the hard nylon resin layer 11 and the elastomer layer 12 is improved, similar to the second embodiment.

[Sixth Example] ,,,, -/ -// As shown in the first example, an adhesive made of a new thermoplastic resin adhesive is provided between the elastomer single layer 12 and the hard nylon resin layer 11. The layers are provided as intermediate layers. The rest is the same as in the fourth embodiment. In this example, the above connection 1
Since the 4J layer is provided, the adhesion between the hard nylon resin layer 11 and the elastomer layer 12 is improved, similar to Example 5.

[Seventh Example] As shown in Table 1, the reinforcing layer 16 is made of polyester fiber. The rest is the same as in the sixth embodiment.

[Eighth Example] As shown in Table 1, an adhesive layer made of a thermosetting resin adhesive is provided as an intermediate layer between the hard nylon resin layer 11 and the elastomer layer 12. . Furthermore, the cover layer 17 is made from inbutylene-isoprene rubber (IIR).

The rest is the same as the seventh embodiment. In the eighth embodiment, the initial flexibility is improved by 50% compared to the conventional nylon resin hose, and the water permeability can also be reduced to 1/3 to 115 times. The reason is that the IIR used in the cover layer
However, compared to the olefin elastomer used for the single layer of the cover in Examples 1 to 7, it is a softer material (with an elastic modulus of about 115) and has a water permeability as low as 1/3. Furthermore, the adhesiveness between the hard nylon resin layer 11 and the elastomer layer 12 is as follows.
The structure is even stronger than that of the seventh embodiment.

[Ninth Example] As shown in Table 1, the cover layer 17 is made of a 1-ethylene-propylene-diene terpolymer (EPDM rubber). The rest is the same as in the eighth embodiment.

In this example, the initial flexibility is improved and the moisture permeability is also reduced, almost the same as in the eighth example. Further, the adhesiveness between the hard nylon resin layer 11 and the elastomer layer 12 is strong.

[Tenth Example] As shown in Table 1, in the eighth example, isobutylene-
An intermediate layer composed of isoprene rubber (IIR) is provided. In this example, the adhesion between the venilastomer single layer 12 and the reinforcing yarn layer 16 is improved compared to the eighth example, and the initial flexibility is not further increased.

[Eleventh Example 1 As shown in Table 1, one layer of elastomer 12 and a layer of reinforcing yarn 1
During 6, the ethylene-propylene-diene terpolymer (
An intermediate layer made of EPDM rubber) is provided.

In this example, almost the same as the tenth example, one layer of elastomer 12
The bondability between the reinforcing yarn layer 16 and the reinforcing yarn layer 16 is improved, and the initial flexibility is also increased.

[Twelfth Example As shown in Table 1, an adhesive layer is provided between the hard nylon resin layer 11 and the elastomer layer 12. The contact material layer is made of a vulcanized rubber adhesive. In this example, as in the eleventh example, the adhesiveness between the elastomer layer 12 and the hard nylon resin layer 11 is improved, and the initial flexibility is also increased.

[Example 13] In the cross section of the flexible hose, the inner tube has a single layer of polyester elastomer on the inner side, a hard nylon resin layer made of nylon 6 on the outside, and a layer of polyester elastomer and hard nylon resin. It consists of a vulcanized rubber joint IUffl installed between the The rest is the same as the twelfth embodiment. This example has substantially the same effect as the twelfth example, and in addition, the environmental resistance is improved as described below. That is, refrigeration oil, refrigerant, and even metal salts (for example, ZnC1z, Δ1c13, FeCl3, KC
:l)? 7 impurities pass through the hose. In particular, nylon 6, which constitutes the hard nylon resin layer, has poor resistance to metal salts, and may cause environmental stress cracking due to the metal salts if used for a long period of time.

Therefore, in this example, the innermost layer of the hose is made of a single layer of polyester elastomer to prevent environmental stress cracking of the above-mentioned nylon 6.

[Fourteenth Example] As shown in Table 1, the basic structure of the flexible hose of this example is the same as that of the thirteenth example. However, the adhesive layer is made of a thermosetting resin adhesive. In this example, substantially the same effects as in the thirteenth example can be obtained.

[Fifteenth Example] As shown in Table 1, the basic structure of the flexible hose of this example is the same as that of the fourteenth example. However, in the cross section of the flexible hose, the negative inner side was made of a single layer of nylon elastomer. In this example, substantially the same effects as in the fourteenth example can be obtained.

[Sixteenth Embodiment] As shown in Table 1, the basic structure of the flexible hose of this embodiment is the same as that of the 11th embodiment. However, the hard nylon resin layer 11 is made of 11 nylon. here,
Since nylon 11 has excellent resistance to metal salts, in this example, substantially the same effects as in the 13th example can be obtained.

[Seventeenth Example As shown in Table 1, the basic structure of the flexible hose of this example is the same as that of the eleventh example. However, the hard nylon resin layer 11 is made of 6.10 nylon. Here, since nylon 6.10 has excellent resistance to metal salts, in this example, substantially the same effect as in the thirteenth example can be obtained.

[As shown in Table 1 of the 18th embodiment, the hard nylon resin layer 11 was made of 6.
Made from 12 nylon. The rest is the same as the eleventh embodiment. Here, since 6.12 nylon has excellent resistance to metal salts, in this example, substantially the same effect as in the thirteenth example can be obtained.

[Nineteenth Example] As shown in Table 1, the hard nylon resin layer 11 is made of a blend of nylon 6 and nylon 6.10. The rest is the same as the eleventh embodiment.

In this example, substantially the same effects as in the thirteenth example can be obtained.

[Twentieth Example] As shown in Table 1, the hard nylon resin layer 11 is made of a blend of nylon 6 and nylon 6.12. The rest is the same as the eleventh embodiment.

In this example, substantially the same effects as in the thirteenth example can be obtained.

[21st Example] As shown in Table 1, the hard nylon resin layer 11 is made of a blend of nylon 6 and ionomer resin. The rest is the same as the eleventh embodiment.

In this example, substantially the same effects as in the thirteenth example can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional flexible hose, and FIG. 2 is a sectional view of a first embodiment of the present invention. In the figure, 10 is an inner tube, 15 is an outer tube, 11 is a hard nylon resin layer, 12 is a single layer of elastomer, 16 is a reinforcing yarn layer, and 17 is a single layer of cover. Patent Applicant: Nippondenso Co., Ltd. Agent Patent Attorney: Madoka Okawa Patent Attorney: Shudo Fujitani Patent Attorney: Akio Maruyama Figure 1 Figure 2

Claims (4)

[Claims] (1) In a hose consisting of an inner tube made of plastic and an outer tube surrounding the inner tube, the inner tube has a hard nylon resin layer thinned into a film-like shape and a hard nylon resin layer that covers the hard nylon resin layer and is integral with the hose. 1. A flexible hose comprising a single layer of elastomer that holds the hose in place. (2) The flexible hose according to claim 1, wherein an adhesive layer is formed between the hard nylon resin layer and the elastomer layer. (3) The flexible hose according to claim 1, wherein the elastomer layer contains an adhesive for bonding the hard nylon resin layer. (4) The flexible hose according to claim 1, wherein the hard nylon resin layer has a thickness of less than 100 μm. The flexible hose according to claim 1, which is a hard nylon layer.