JP3267838B2 - Composite flexible hose - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a composite flexible hose. More specifically, the hose can be suitably used for transporting a refrigerant.

[0002]

2. Description of the Related Art Conventionally, a composite flexible hose used for transporting a refrigerant gas for a car air conditioner or a refrigerant gas for a contact freezer is disclosed in, for example, Japanese Patent Application Laid-Open No. 1-111.
No. 0143, etc., and FIG. 2 shows a schematic diagram thereof.

In FIG. 2, 1 is a composite flexible hose, 2a is an innermost layer, 3 is a fiber reinforced layer, 4 is an outer rubber layer,
Reference numeral 5 denotes an intermediate rubber layer, and reference numeral 6 denotes an adhesive layer.

[0004] The properties required of the composite flexible hose include, for example, flexibility and flexibility, and gas barrier properties against a refrigerant gas.
For example, a composite flexible hose having a four-layer structure (a five-layer structure including an adhesive layer) as shown in FIG. 2 is intended to have these properties.

[0005] Further, since the inside of the composite flexible hose may be under negative pressure, in the above-described four-layer structure, the interlayer adhesive force between the respective layers, especially between the innermost layer and the intermediate rubber layer, is particularly increased. It is also required that the refrigerant gas does not leak.

As the material for forming the innermost layer, for example, polyamide 6, polyamide 66 and polyamide 612 are used because of their excellent gas barrier properties against refrigerant gas.
And modified polyamides such as acid-modified polyamides are mainly used.

As the material for forming the intermediate rubber layer, for example, butyl rubber such as isoprene-isobutylene rubber and halogenated isoprene-isobutylene rubber is used because of its excellent flexibility and gas barrier properties. .

However, it is generally difficult to bond the innermost layer made of polyamide or modified polyamide and the intermediate rubber layer made of butyl rubber, and it is necessary to add an adhesive coating step to increase the adhesive force. The process becomes complicated.

Further, since the composite flexible hose is subjected to vibration or bending generated when the refrigerant system is used, if the four-layer structure (laminated body) is cracked, that is, the innermost layer of the hose is cracked. Occurs and the refrigerant gas leaks.

Further, even if the innermost layer and the intermediate rubber layer are integrated into one layer, there is a problem that the polyamide resin and the butyl rubber are poor in compatibility, and phase separation occurs even when blended. .

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to have flexibility, flexibility, gas barrier properties against refrigerant gas,
In particular, it is an object of the present invention to provide a composite flexible hose which does not cause cracking and does not require complicated manufacturing steps.

[0012]

SUMMARY OF THE INVENTION The present invention is a composite flexible hose having a three-layer structure in which an inner layer, a fiber reinforcing layer and an outer rubber layer are laminated, and obtained by being laminated and then vulcanized. And a composite flexible hose characterized in that the inner layer is formed of a polymer alloy comprising butyl rubber, high molecular weight polyamide and a compatibilizer.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the inner side of a fiber reinforced layer of a composite flexible hose is bonded to an innermost layer of a conventional polyamide or a modified polyamide and an intermediate rubber layer of a butyl rubber and these layers. The three-layer structure with the adhesive layer is integrated with the above-mentioned polymer alloy to form a one-layer structure, so that cracking does not occur and a complicated manufacturing process is not required. Can be provided.

Although it is not clear why such an effect is obtained in the present invention, for example, high molecular weight polyamide and butyl rubber have poor compatibility, and problems such as phase separation occur even when blended. There was a point,
The use of a compatibilizer having the structure of both a high molecular weight polyamide and a butyl rubber makes it possible to alloy the high molecular weight polyamide and the butyl rubber. By using this polymer alloy, fiber reinforcement of a composite flexible hose can be achieved. It is probable that the inside of the layer could have a single layer structure.

The high molecular weight polyamide used in the present invention has an average molecular weight of, for example, 15,000 to 5,000,000, preferably 100,000 to 1,000,000 from the viewpoint of good heat resistance and processability. In general, a polyamide having a molecular weight of 10,000 or more is called a high-molecular-weight polyamide, but in the present specification, a polyamide having a molecular weight of 15,000 is used.
The above is called a high molecular weight polyamide.

Specific examples of the high molecular weight polyamide include polyamide 6, polyamide 66, polyamide 1
1, polyamide 12, polyamide 46, polyamide 61
2. Copolymers composed of at least two kinds of these monomer components or polymer blends composed of at least two kinds of these polymers, and the like. Polyamide 6 and polyamide 6 are preferred from the viewpoint of processability and gas barrier properties against refrigerant gas. 66, polyamide 11, polyamide 12
Are preferable, and polyamide 6 and polyamide 11 are more preferable.

As the butyl rubber used in the present invention, for example, isoprene-isobutylene rubber (II)
R), chlorinated butyl rubber (CIIR), halogenated butyl rubber such as brominated butyl rubber or a blend thereof, and the like.
Isoprene-isobutylene rubber is preferred, and chlorinated butyl rubber is more preferred.

The polymer alloy used in the present invention is:
For example, the butyl-based rubber and the high-molecular-weight polyamide include those highly compatibilized by a function of a compatibilizer, which cannot be obtained by a simple polymer blend.

As the compatibilizer, it is necessary to use, for example, one having a chemical structure similar to that of both the high-molecular-weight polyamide and the butyl-based rubber from the viewpoint of high compatibility. The basic skeleton of the chemical structure is, for example, phenol formaldehyde resin in view of good compatibility with polyamide, compatibility with butyl rubber, thermal stability, reactivity with polyamide, and reactivity with butyl rubber. And a brominated alkylphenol formaldehyde resin, but a phenol formaldehyde resin is preferable, and for example, tacky roll 201 manufactured by Taoka Chemical Co., Ltd. is exemplified.

As the compatibilizer, for example, 100 parts (parts by weight, hereinafter the same) of a low-molecular-weight polyamide are added to a mixer.
5 to 200 parts, preferably 30 to 100 parts of a phenol formaldehyde resin are added and kneaded at a temperature higher than the melting point of the low molecular weight polyamide, for example, at 120 to 140 ° C. for 10 to 30 minutes. 50 to 300 parts, preferably 100 to 150 parts, and 1 to 20 parts, preferably 2 parts, of a catalyst such as tin chloride or zinc white
And a mixture obtained by kneading the mixture with 5 to 5 parts with a roll and reacting uniformly.

The low-molecular-weight polyamide has, for example, an average molecular weight of 3,000 from the viewpoint of processability in producing the compatibilizer and good compatibility with the high-molecular-weight polyamide.
It may be 0 or more and less than 15,000, and 6,000 to 1
Preferably it is 000.

As specific examples of the low-molecular-weight polyamide, those having the same chemical structure as those mentioned as specific examples of the high-molecular-weight polyamide may be used. Polyamide 6-Polyamide 66-Polyamide 12 from the viewpoint of solubility and processability
Is preferred.

The butyl rubber, which is one of the raw materials of the compatibilizer, may be one having the same chemical structure as that of the butyl rubber, which is a component of the polymer alloy. Things.

The fibers forming the fiber reinforcing layer in the present invention include, for example, natural fibers such as cotton, hemp, silk and wool, regenerated fibers such as viscose rayon, and semi-synthetic fibers such as diacetate rayon and triacetate rayon. ,
Polyvinyl alcohol, polyamide, aramid,
Synthetic fibers such as polyester-based and acrylic-based fibers and fibers composed of at least two of these are mentioned. Polyamide-based or polyester-based polyesters have good adhesion to the inner layer and the outer rubber layer, and have good workability. Based fibers are preferred.

It is to be noted that those fibers treated with a resorcin-formaldehyde latex adhesive (RFL) can also be used.

The rubber forming the outer rubber layer in the present invention includes, for example, ethylene-propylene-diene terpolymer (EPDM), chloroprene rubber (C
R), chlorosulfonated polyethylene rubber (CSM),
Synthetic rubbers having excellent weather resistance, such as isoprene-isobutylene rubber (IIR) and halogenated isoprene-isobutylene rubber (X-IIR), may be mentioned. Among them, further excellent weather resistance, good extrudability, etc. Ethylene-propylene-diene terpolymer (EP
DM) is preferred.

The composition ratio of the butyl rubber and the high molecular weight polyamide in the above polymer alloy is 95% by weight.
/ 5 to 50/50, and preferably 80/20 to 65/35.

With such a composition ratio, the fluorocarbon permeation resistance of the high molecular weight polyamide, the kink resistance and the rubber elasticity of the butyl rubber can be sufficiently exhibited.

The composition ratio of the compatibilizer is 2 to 30 parts, and 7 to 15 parts with respect to 100 parts in total of the butyl rubber and the high molecular weight polyamide. Preferably, there is.

By adopting such a composition ratio, the butyl rubber and the high-molecular-weight polyamide are highly compatible with each other, and the high-molecular-weight polyamide has a high permeation resistance to fluorocarbon, a high kink resistance and a high elasticity of the butyl-based rubber. Can be demonstrated.

In order to obtain the polymer alloy of the present invention, a conventional method may be used. For example, a high-temperature kneader may be used so that the butyl rubber, the high-molecular-weight polyamide and the compatibilizer have the above-mentioned composition ratio. 180-250 ° C
For 5 to 20 minutes, and finely disperse, for example, a high molecular weight polyamide.

In the kneading for vulcanizing the butyl rubber in the obtained polymer alloy, 5 to 15 parts of phenol formaldehyde resin is added to 100 parts of rubber in the polymer alloy in order to vulcanize the resin. Preferably 7 to
10 parts can be added.

As the phenol formaldehyde resin, for example, Tacchiroll 250 manufactured by Taoka Chemical Co., Ltd.
-I, 250-III, and 201 are commercially available, and tacky roll 250-I is particularly preferable because a catalyst is unnecessary.

It is used as a vulcanizing agent for butyl rubber, but also has a role as a compatibilizer since the polarity of the phenol formaldehyde resin itself is close to that of polyamide.

During the kneading for vulcanizing the butyl rubber in the polymer alloy, various additives such as carbon black, zinc white, stearic acid, a plasticizer, an antioxidant, and a processing aid, in addition to the vulcanizing agent. Can also be added.

In the present invention, not only the resin vulcanization but also ordinary sulfur vulcanization or peroxide vulcanization can be used.

FIG. 1 is a schematic view showing an example of the composite flexible hose of the present invention.

In FIG. 1, 1 is a composite flexible hose, 2 is an inner layer made of a polymer alloy, 3 is a fiber reinforcing layer, and 4 is an outer rubber layer.

In order to obtain such a composite flexible hose, for example, the following method can be used.

A polymer alloy containing a vulcanizing agent for vulcanizing the butyl rubber is supplied to a conventional extruder, and a thickness of 1.0 to 3 is applied under the same conditions as in the case of normal synthetic rubber extrusion. 2.0 mm, preferably 2.0 to 2.5 mm, which is used as the inner layer.

Next, a fiber reinforcing layer (having a thickness of about 1.0 to 2.0 mm) is formed on the surface of the inner layer by braiding or spiral winding using the fibers.

Next, on this layer, the above-mentioned synthetic rubber having excellent weather resistance is extruded by an ordinary extruder to form an outer rubber layer (having a thickness of about 1.0 to 2.0 mm). To obtain a laminate comprising three layers.

Further, the laminate comprising the three layers is placed in a steam vulcanizer at 150 to 160 ° C., 4 to 5, 5 kgf /
vulcanizing for 30 to 60 minutes under a steam pressure of ² cm ² ,
The composite flexible hose of the present invention is obtained.

The composite flexible hose obtained in this manner is excellent in flexibility, flexibility and gas barrier property against refrigerant gas, does not cause cracking, and does not require complicated manufacturing steps. It can be suitably used, for example, for transporting refrigerant gas.

In the present invention, for example, a composite flexible hose having the following structure is preferably used.

(1) Inner layer Butyl rubber / high molecular weight polyamide (thickness 1.0 to 4.0 mm) 95/5 to 50/50 parts Compatibilizer 5 to 30 parts Fiber reinforcing layer Synthetic fiber (thickness (1.0 to 2.0 mm) Outer rubber layer Synthetic rubber (1.0 to 2.0 mm in thickness) This composite flexible hose is advantageous in terms of simplification of the manufacturing process as compared with a conventional hose.

More preferably, inner layer butyl rubber / high molecular weight polyamide (thickness: 2.0 to 2.5 mm) 80/20 to 65/35 parts Compatibilizer 5 to 15 parts Fiber reinforcing layer Synthetic fiber (thickness (1.0 to 2.0 mm) Outer rubber layer Synthetic rubber (1.0 to 2.0 mm in thickness) This composite flexible hose is excellent in gas barrier properties against refrigerant gas.

(2) Inner layer Butyl rubber / polyamide 6 (2.0 to 2.5 mm thick) 80/20 to 70/30 parts Compatibilizer 5 to 15 parts Fiber reinforcing layer Polyester fiber (Thickness 1 0.0 to 2.0 mm) Outer rubber layer EPDM rubber (thickness: 1.0 to 2.0 mm) This composite flexible hose is advantageous in terms of flexibility, flexibility, and gas barrier properties against refrigerant gas. is there.

More preferably, the inner layer is chlorinated butyl rubber / polyamide 6 (thickness: 2.0 to 2.5 mm) 70/30 to 65/35 parts Compatibilizer 5 to 15 parts Fiber reinforcing layer Polyester fiber (thickness: 1 0.0 to 2.0 mm) Outer rubber layer EPDM rubber (1.0 to 2.0 mm in thickness) This composite flexible hose is excellent in heat resistance and gas barrier properties against refrigerant gas.

Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

[0051]

【Example】

Example 1 A butyl rubber, a high molecular weight polyamide 6, and a compatibilizer (reaction product of a low molecular weight polyamide, a phenol formaldehyde resin, and a butyl rubber) at a blending amount shown in Table 1 at 220 ° C. using a high-temperature kneader. And kneading for 5 minutes to form a polymer alloy. Carbon black, a filler, a vulcanizing agent and an antioxidant are added to the polymer alloy,
After kneading at 10 ° C. for 10 minutes, the mixture was extruded to a thickness of 2.5 mm by an extruder to form an inner layer.

Next, the surface of the inner layer is braided with a braiding machine using a polyester fiber by a braiding machine to form a fiber reinforcing layer (thickness 1.
0 mm).

Next, the EPDM rubber was extruded by an extruder to form an outer rubber layer (thickness: 1.5 mm) to obtain a three-layer laminate.

Further, the three-layered laminate was vulcanized in a steam vulcanizer at 160 ° C. for 40 minutes.
With the composite flexible hose of the present invention, the performance of the obtained hose (flexibility, gas barrier property against refrigerant gas)
The following test was carried out to examine.

Gas permeability test: SAE J 51 MA
Y85 (AUTOMOTIVE AIR CONDIT
The amount of permeation of R134a gas was measured according to (IONING HOSE).

Flexibility test: One end of the hose is fixed, wound around a 190 mm-diameter drum in a 180 ° U-shape, and the force required to maintain the state is measured by a push-pull gauge (AE-30, Aiko Engineering ( ○, when the tensile force (bending force) indicated by the spring meter is less than 1.5 kgf,
When it was less than kgf, it was evaluated as Δ, and when it was 2.0 kgf or more, it was evaluated as x.

Table 1 shows the results.

Examples 2 to 4 A composite flexible hose of the present invention was obtained in the same manner as in Example 1 except that the components and amounts of the inner layer shown in Table 1 were used. went. Table 1 shows the results.

Comparative Example 1 100 parts of isoprene-isobutylene rubber, 5 parts of zinc white,
After kneading 50 parts of carbon black, 1 part of stearic acid and 7 parts of tacky roll 250-I as a resin crosslinking agent at 60 to 80 ° C. for 10 minutes using a kneader,
It is extruded to a thickness of 2.5 mm by an extruder to form an inner layer, and the fiber reinforcing layer and the outer rubber layer are coated in the same manner as in Example 1 to form a three-layer laminate, which is a steam vulcanizer In the same manner, vulcanization was performed at 160 ° C. for 40 minutes to obtain a total rubber hose, and the same test as in Example 1 was performed. Table 1 shows the results.

Comparative Examples 2-3 A hose was obtained in the same manner as in Example 1 except that the components and amounts of the inner layer shown in Table 1 were used, and the same test as in Example 1 was performed. Table 1 shows the results.

[0061]

[Table 1]

In Table 1, abbreviations as types of butyl rubber indicate the following.

IIR: isoprene-isobutylene rubber (IIR # 365 manufactured by Nippon Synthetic Rubber Co., Ltd.) CIIR: chlorinated butyl rubber (manufactured by Nippon Synthetic Rubber Co., Ltd.)
CIIR # 1066)

[0064]

As is clear from the above results, the composite flexible hose of the present invention has no gas leakage due to cracking, has flexibility, flexibility, and gas barrier properties against refrigerant gas. It can be obtained without complicated manufacturing processes.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a composite flexible hose of the present invention.

FIG. 2 is a schematic view showing a conventional composite flexible hose.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 composite flexible hose 2 inner layer made of polymer alloy 2 a innermost layer 3 fiber reinforcement layer 4 outer rubber layer 5 intermediate rubber layer 6 adhesive layer

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-1-135846 (JP, A) JP-A-1-110143 (JP, A) JP-A-7-304946 (JP, A) JP-A-63- 309555 (JP, A) JP 6-15915 (JP, B2) JP 53-28474 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16L 11/08

Claims (5)

(57) [Claims] 1. A composite flexible hose having a three-layer structure in which an inner layer, a fiber reinforcing layer and an outer rubber layer are laminated, and obtained by being laminated and then vulcanized, wherein the inner layer is made of a butyl rubber. It is formed of a polymer alloy comprising a high molecular weight polyamide having a molecular weight of 15,000 to 5,000,000 and a compatibilizer, and the compatibilizer has a molecular weight of 3,000 to 1,
Less than 5,000 low molecular weight polyamide and phenolphor
Composite flexible hose, wherein the reaction product der Rukoto of formaldehyde resin and butyl rubber. 2. The composition ratio of the polymer alloy is 95/5 to 5 parts by weight of butyl rubber and high molecular weight polyamide.
The composite flexible hose according to claim 1, wherein the composite flexible hose is 0/50, and 2 to 30 parts by weight of the compatibilizer based on 100 parts by weight of the total amount. 3. The low molecular weight polyamide in the compatibilizer has a molecular weight of 6,000 to 10,000.
Or the composite flexible hose according to 2. 4. The high molecular weight polyamide or the low molecular weight polyamide is polyamide 6, polyamide 66, polyamide 11, polyamide 12, polyamide 46, polyamide 612, a copolymer composed of at least two of these monomer components, or at least one of these polymers. 2
The composite flexible hose according to any one of claims 1 to 3, which is a polymer blend comprising a seed. 5. The composite flexible hose according to claim 1, wherein the inner layer is obtained by vulcanizing a resin.