JPH0953767A - Composite flexible hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve gas barrier performance and cracking resistance by forming an inner layer of polymer alloy composed of butyl rubber, high molecular weight polyamide and a campatibilizer in a composite fiexible hose by layering the inner layer, a fiber reinforced layer and an outside surface rubber layer. SOLUTION: This flexible hose 1 suitable for transport of a refrigerant or the like has a three-layer structure by layering an inner layer 2, a fiber reinforced layer 3 and an outside surface rubber layer 4, and is manufactured by vulcanizing them after they are layered. In this case, the inner layer 2 is formed of polymer alloy composed of butyl rubber, high molecular weight polyamide and a compatibilizer, and the composition ratio of the polymer alloy is set in 95/5 to 50/50 in pts.wt. of the butyl rubber and the high molecular weight polyamide, and is set in the compatibilizer 20 to 30 pts.wt. to these total quantity 100 pts.wt. A reaction product of low molecular weight polyamide, phenol formaldehyde resin and butyl type rubber is used as the compatibilizer.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD 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, as a composite flexible hose used for transporting a refrigerant gas for a car air conditioner or a refrigerant gas for a contact freezer, for example, Japanese Unexamined Patent Publication No. 1-11 has
It is described in Japanese Patent Publication No. 0143, etc., and its schematic diagram is shown in FIG.

In FIG. 2, 1 is a composite flexible hose, 2a is the innermost layer, 3 is a fiber reinforcing layer, 4 is an outer rubber layer,
5 is an intermediate rubber layer, and 6 is an adhesive layer.

Properties required of the composite flexible hose include, for example, flexibility, flexibility, and gas barrier property against 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 provided so as to have these properties.

Further, since a negative pressure may be generated inside the composite flexible hose, in the above-mentioned four-layer structure, the interlayer adhesive force between the layers, among them, the layer between the innermost layer and the intermediate rubber layer, is particularly strong, It is also required to prevent the refrigerant gas from leaking.

As a material for forming the innermost layer, for example, polyamide 6, polyamide 66, and polyamide 612 are excellent in gas barrier property against refrigerant gas.
Polyamides such as or modified polyamides such as acid-modified polyamides are mainly used.

Further, as a 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 property. .

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

Further, since the composite flexible hose is subjected to vibration or bending when a refrigerant system is used, if it has a four-layer structure (laminate) as described above, it 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, the polyamide resin and the butyl rubber have poor compatibility and there is a problem that they are phase-separated even when blended. .

[0011]

The object of the present invention is to have flexibility, flexibility, and gas barrier property against refrigerant gas,
In particular, it is to provide a composite flexible hose that does not cause cracking and can be obtained without a complicated manufacturing process.

[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 reinforced layer and an outer rubber layer are laminated and laminated and then vulcanized. The present invention relates to a composite flexible hose, wherein the inner layer is formed of a polymer alloy composed of butyl rubber, high molecular weight polyamide and a compatibilizer.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the inside of the fiber reinforced layer of a composite flexible hose is bonded to the innermost layer of a conventional polyamide or modified polyamide, the intermediate rubber layer of butyl rubber, and these layers. What has been a three-layer structure with an adhesive layer is integrated with these layers using the polymer alloy to form a one-layer structure, so that cracking does not particularly occur and complicated manufacturing steps can be avoided. Can provide a composite flexible hose.

In the present invention, it is not clear why such an effect can be obtained. However, for example, high molecular weight polyamide and butyl rubber have poor compatibility, and phase separation occurs even when blended. There was a point,
By using a compatibilizer having both the structure of high molecular weight polyamide and butyl rubber, alloying of high molecular weight polyamide and butyl rubber becomes possible. By using this polymer alloy, the fiber reinforcement of the 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 15,000 or more and 5,000,000 or less, preferably 100,000 to 1,000,000, from the viewpoint of good heat resistance and processability. It should be noted that generally, those having a molecular weight of 10,000 or more are referred to as high molecular weight polyamides, but in the present specification, the molecular weight is 15,000.
The above is called high molecular weight polyamide.

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

The butyl rubber used in the present invention is, for example, isoprene-isobutylene rubber (II
R), chlorinated butyl rubber (CIIR), brominated butyl rubber, and other halogenated butyl rubbers, or blends thereof. Examples include chlorinated butyl rubbers because of their good heat resistance and processability as polymer alloys.
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 highly compatibilized substances due to the function of a compatibilizing agent, which cannot be obtained by a simple polymer blend.

As the compatibilizing agent, it is necessary to use, for example, one having a chemical structure similar to both the high molecular weight polyamide and the butyl rubber from the viewpoint of high compatibilization. The basic skeleton of the chemical structure is, for example, a phenol formaldehyde resin in view of its compatibility with polyamide, compatibility with butyl rubber, thermal stability, reactivity with polyamide, and reactivity with butyl rubber. Examples thereof include brominated alkylphenol formaldehyde resin, and phenol formaldehyde resin is preferable, and examples thereof include Tacky Roll 201 manufactured by Taoka Chemical Co., Ltd.

As the compatibilizer, for example, 100 parts of low molecular weight polyamide (part by weight, the same applies hereinafter) in a mixer,
After adding 5 to 200 parts, preferably 30 to 100 parts of a phenol formaldehyde resin and kneading at a temperature above the melting point of the low molecular weight polyamide, for example, 120 to 140 ° C. for 10 to 30 minutes, this kneaded product and a butyl rubber as described below 50 to 300 parts, preferably 100 to 150 parts and 1 to 20 parts, preferably 2 catalysts such as tin chloride and zinc white.
Examples include those obtained by kneading ~ 5 parts with a roll and uniformly reacting.

The low-molecular weight polyamide has, for example, an average molecular weight of 3,000 in terms of processability in producing a 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.

Specific examples of the low molecular weight polyamide may be those having the same chemical structure as the specific examples of the high molecular weight polyamide, and these are different only in the average molecular weight, Polyamide 6-polyamide 66-polyamide 12 from the viewpoint of compatibility and processability
Is preferable.

As the butyl rubber which is one of the raw materials of the compatibilizer, any butyl rubber having the same chemical structure as the butyl rubber which is one component of the polymer alloy may be used, and specific examples thereof are described above. Something is included.

The fibers forming the fiber reinforcing layer in the present invention include natural fibers such as cotton, hemp, silk and wool, regenerated fibers such as viscose rayon, semi-synthetic fibers such as diacetate rayon and triacetate rayon. ,
Polyvinyl alcohol type, polyamide type, aramid type,
Examples thereof include synthetic fibers such as polyester-based and acrylic-based fibers or fibers composed of at least two of these, but polyamide-based or polyester-based fibers have good adhesiveness to inner and outer rubber layers and good processability. Fibers of the system are preferred.

As these fibers, those treated with 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) and chloroprene rubber (C).
R), chlorosulfonated polyethylene rubber (CSM),
Examples thereof include synthetic rubbers having excellent weather resistance such as isoprene-isobutylene rubber (IIR) and halogenated isoprene-isobutylene rubber (X-IIR). Among these, weather resistance is good, extrusion processability is good, etc. From the viewpoint of ethylene-propylene-diene terpolymer (EP
DM) is preferred.

The composition ratio of butyl rubber and high molecular weight polyamide in the 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 of the butyl rubber, and the rubber elasticity can be sufficiently exhibited.

The composition ratio of the compatibilizing agent is 2 to 30 parts and 7 to 15 parts based on 100 parts of the total amount of the butyl rubber and the high molecular weight polyamide. Preferably there is.

With such a composition ratio, the butyl rubber and the high molecular weight polyamide are highly compatible with each other, and the fluorocarbon resistance of the high molecular weight polyamide, the kink resistance and the rubber elasticity of the butyl rubber are improved. Can be demonstrated.

The polymer alloy in the present invention can be obtained by a usual method, but for example, a high temperature kneader is used so that the butyl rubber, the high molecular weight polyamide and the compatibilizer have the above composition ratio. 180 ~ 250 ℃
The mixture may be kneaded for 5 to 20 minutes to finely disperse the high molecular weight polyamide.

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

As the phenol formaldehyde resin, for example, Takki Roll 250 manufactured by Taoka Chemical Co., Ltd.
-I, 250-III, 201, and the like, which are commercially available, and Tackyroll 250-I is particularly preferable because no catalyst is required.

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

At the time of kneading for vulcanizing the butyl rubber in the polymer alloy, various additives such as carbon black, zinc white, stearic acid, plasticizer, anti-aging agent and processing aid other than 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.

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-based rubber is supplied to an ordinary extrusion molding machine, and a thickness of 1.0 to 3 is obtained under the same conditions as in the extrusion of ordinary synthetic rubber. It is extruded to 0.0 mm, preferably 2.0 to 2.5 mm to form an inner layer.

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

Next, the above-mentioned synthetic rubber having excellent weather resistance is extruded on this layer by an ordinary extrusion molding machine to form an outer rubber layer (thickness is about 1.0 to 2.0 mm). A laminate consisting of three layers is obtained.

Further, the laminated body consisting of these three layers was placed in a steam vulcanizer at 150 to 160 ° C., 4 to 5 and 5 kgf /.
Vulcanization is performed for 30 to 60 minutes under a vapor pressure of cm ² ,
The composite flexible hose of the present invention can be obtained.

The composite flexible hose thus obtained is excellent in flexibility, flexibility, and gas barrier property against refrigerant gas, does not cause cracking, and does not require complicated manufacturing steps. And can be suitably used, for example, for transporting a 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 reinforced layer Synthetic fiber (thickness 1.0 to 2.0 mm) Outer rubber layer Synthetic rubber (thickness 1.0 to 2.0 mm) This composite flexible hose is advantageous in that the manufacturing process is simplified as compared with the 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 1.0-2.0 mm) Outer rubber layer Synthetic rubber (thickness 1.0-2.0 mm) This composite flexible hose is excellent in gas barrier property against refrigerant gas.

(2) Inner Layer Butyl Rubber / Polyamide 6 (Thickness 2.0 to 2.5 mm) 80/20 to 70/30 Parts Compatibilizer 5 to 15 Parts Fiber Reinforcing Layer Polyester Fiber (Thickness 1 External 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 property against refrigerant gas. is there.

More preferably, inner layer 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 External rubber layer EPDM rubber (thickness 1.0 to 2.0 mm) This composite flexible hose is excellent in heat resistance and gas barrier property against refrigerant gas.

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

[0051]

【Example】

Example 1 220 ° C. of 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 220 ° C. in a blending amount shown in Table 1. Knead for 5 minutes to form a polymer alloy, add carbon black, a filler, a vulcanizing agent, and an antioxidant to the polymer alloy,
After kneading at 10 ° C. for 10 minutes, it was extruded with an extruder to a thickness of 2.5 mm to form an inner layer.

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

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

Further, the laminate consisting of these three layers was vulcanized in a steam vulcanizer at 160 ° C. for 40 minutes,
The composite flexible hose of the present invention is obtained, and the performance of the obtained hose (flexibility, gas barrier property against refrigerant gas)
The following tests were conducted to investigate

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

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

Table 1 shows the results.

Examples 2 to 4 The composite flexible hose of the present invention was obtained in the same manner as in Example 1 except that the inner layer compounding ingredients and compounding amounts shown in Table 1 were used, and the same tests as in Example 1 were carried out. went. The results are shown in Table 1.

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 Takkyroll 250-I as a resin crosslinking agent at 60 to 80 ° C. for 10 minutes,
The extruding machine extruded it to a thickness of 2.5 mm to form an inner layer, and in the same manner as in Example 1, the fiber reinforced layer and the outer rubber layer were coated to form a three-layer laminate, which was then steam vulcanized. The same test as in Example 1 was carried out by vulcanizing at 160 ° C. for 40 minutes to obtain a total rubber hose. The results are shown in Table 1.

Comparative Examples 2 to 3 A hose was prepared in the same manner as in Example 1 except that the inner layer compounding ingredients and compounding amounts shown in Table 1 were used, and the same test as in Example 1 was conducted. The results are shown in Table 1.

[0061]

[Table 1]

In Table 1, the abbreviations for the types of butyl rubbers are as follows.

IIR: isoprene-isobutylene rubber (IIR # 365 manufactured by Japan Synthetic Rubber Co., Ltd.) CIIR: chlorinated butyl rubber (manufactured by Japan 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 property against refrigerant gas, and It can be obtained without complicated manufacturing process.

[Brief description of 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]

 1 Composite Flexible Hose 2 Inner Layer 2a Inner Layer Made of Polymer Alloy 3 Fiber Reinforcement Layer 4 Outer Rubber Layer 5 Intermediate Rubber Layer 6 Adhesive Layer

Claims (5)

[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 laminating and then vulcanizing, wherein the inner layer is butyl rubber. A composite flexible hose formed by a polymer alloy comprising a high molecular weight polyamide and a compatibilizer. 2. The composition ratio of the polymer alloy is 95/5 to 5 in parts by weight of butyl rubber and high molecular weight polyamide.
The composite flexible hose according to claim 1, wherein the amount is 0/50, and the compatibilizing agent is 2 to 30 parts by weight with respect to the total amount of 100 parts by weight. 3. The composite flexible hose according to claim 1, wherein the compatibilizing agent is a reaction product of a low molecular weight polyamide, a phenol formaldehyde resin and a butyl rubber. 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 comprising at least two of these monomer components, or at least one of these polymers. Two
The composite flexible hose according to any one of claims 1 to 3, which is a polymer blend consisting of seeds. 5. The composite flexible hose according to claim 1, wherein the inner layer is obtained by resin vulcanization.