JPH0231269B2 - REIBAIGASUYOHOOSUOYOBISONOSEIZOHOHO - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a hose for refrigerant gas, particularly Freon (registered trademark), and a method for manufacturing the same. [Prior Art] Freon hoses generally consist of a rubber core tube with excellent flexibility and Freon resistance, a fiber braid formed around the core tube, and a coating around the fiber braid. However, it had the disadvantage of poor Freon permeation resistance and water permeation resistance. In order to overcome this drawback, various Freon hoses using synthetic resins have been studied, and the core tube is made of thermo-flexible polyamide resin (nylon 6, nylon 66, nylon 11, nylon 12 or their copolymers, etc.). (including compounds based on), the fiber braid is made of high-tensile synthetic fibers such as polyester, polyamide, vinylon, etc., and the sheath is made of polyamide, polyester elastomer, or polyurethane elastomer. A fiber hose was devised. However, this hose has high moisture permeability, so
The use of polyolefin-based polymers with low moisture permeability as sheath materials has been studied, and this has led to improvements in moisture permeation resistance and flexibility. [Problems to be Solved by the Invention] However, in this improved hose, although the core pipe and the fiber braid are bonded to each other, the adhesiveness between the polyolefin polymer and the above-mentioned high-tensile synthetic fiber is low. , the fiber braid and sheath were hardly bonded or not bonded at all. For this reason, when the hose is bent, it tends to kink (bend), and the bending radius becomes large, which poses problems in terms of piping space and installation work. [Means for Solving the Problems] The present invention has been made in order to solve the above problems. In the refrigerant gas hose of the first invention, a fiber braid 2 is formed around a core pipe 1 by a plurality of fibers containing at least polyolefin synthetic fibers, and the fiber braid 2 is bonded to the core pipe 1. An adhesive made of a modified polyolefin polymer is interposed between the fiber blade 2 and the sheath 3 made of a polyolefin elastomer, and the outer surface of the polyolefin synthetic fiber and the adhesive are temporarily melted to bond the fiber braid 2 and the sheath 3. This is what I did. A second invention is an invention of a method for manufacturing the refrigerant gas hose according to the first invention, which first includes a core tube 1.
A fiber braid 2 is formed around the fibers by a plurality of fibers including at least polyolefin synthetic fibers,
This fiber braid 2 is bonded to the core tube 1. Next, an adhesive made of a modified polyolefin polymer is placed on the fiber braid 2, and then the sheath 3 material is extruded in a molten state. In this way, at the same time as the sheath 3 is formed, the outer surface of the polyolefin synthetic fiber and the adhesive are temporarily melted to bond the fiber braid 2 and the sheath 3 together. [Function] Since the polyolefin synthetic fiber, the sheath 3, and the adhesive are all polyolefin-based, their melting points are relatively low and their adhesion to each other is good. Furthermore, the modified polyolefin-based polymer also has good affinity for braided fibers other than polyolefin-based synthetic fibers. Therefore, when the outer surface of the polyolefin synthetic fiber and the adhesive are temporarily melted when forming the sheath 3, they are not only fused together;
The sheath 3 can be firmly adhered to the entire outer surface of the fiber braid 2 due to the excellent adhesive strength of the adhesive. [Example] Hereinafter, an example of the present invention will be described based on the drawings. The figure shows one embodiment of the refrigerant gas hose according to the present invention, in which 1 is a core tube, 2 is a fiber braid woven around the core tube 1, and 3 is a coating around the fiber braid 2. This is the sheath that was used. The core tube 1 is made of plasticized nylon 6/66 copolymer. This nylon 6/66 copolymer has a high resistance to permeation of refrigerant gas such as Freon and is flexible, so it is advantageous for this type of hose. The fiber braid 2 is formed by winding fibers as a blade material around a plurality of carriers and weaving these fibers on the outer peripheral surface of the core tube 1. In this example, polypropylene fibers and polyester fibers are used in combination. are doing. Mix and twist both fibers in an appropriate ratio,
This fiber braid 2 is formed by winding this fiber bundle around each carrier and then weaving it on the outer peripheral surface of the core tube 1. The blending ratio of both fibers varies from 10:90 to 10:90 by weight depending on pressure resistance and adhesive strength with sheath 3.
An appropriate value within the range of 90:10, preferably
It is best to set it within the range of 30:70 to 70:30. In this example, polypropylene fibers and polyester fibers are mixed and twisted and then woven.
The ratio of the number of carriers wound with each fiber may be within the above range, and both fibers may be mixedly woven, or mixed twisting and mixed weaving may be used in combination. Although the core tube 1 and the fiber braid 2 are bonded by plasticization, it goes without saying that they may be bonded using a known adhesive. The sheath 3 is made of an elastomer belonging to the same polyolefin family as the polypropylene fiber that is the material of the fiber blade 2, and is bonded to the fiber blade 2 by an adhesive layer 4 whose main component is modified polypropylene as an adhesive resin. has been done. The process of forming the sheath 3 is as follows.
That is, first, a modified polypropylene adhesive is extruded around the fiber braid 2. Next, the polyolefin elastomer heated in the extruder to a molten state is extruded around the adhesive layer 4 in an annular flow in a die, and is cooled and solidified by a normal cooling method. The temperature of the polyolefin elastomer in the molten state is higher than the melting point of the polypropylene fibers, and when extruded, the heat melts the adhesive layer 4 and the polypropylene fibers on the outer surface of the fiber blade 2. Upon cooling, the fiber braid 2, adhesive layer 4 and sheath 3 will be bonded together. Therefore, the fiber braid 2 and the sheath 3 can be bonded very strongly together with the adhesive strength of the modified polypropylene adhesive. Mixed twisting or mixed weaving of polypropylene fibers and polyester fibers enhances this adhesive effect. Therefore, the refrigerant gas hose configured as described above,
The adhesion between the fiber braid 2 and the sheath 3 improves kink resistance and flexibility, and since high-tensile polyester fibers are also used, the pressure resistance is also very good. Furthermore, since the polypropylene fiber, polyolefin elastomer, and modified polypropylene adhesive are all polyolefin-based, they have very good mutual adhesion and good moisture permeation resistance. In addition, polyethylene fibers can also be used as polyolefin synthetic fibers, and high tensile strength fibers used in combination to supplement the pressure resistance of polyolefin synthetic fibers include nylon 6 fibers, nylon 66 fibers, in addition to polyester fibers. vinylon fiber,
Furthermore, aromatic polyamide-based synthetic fibers (eg, Kevlar) and the like can be used. Moreover, it goes without saying that the fiber braid 2 may be formed by winding it in a spiral around the core tube 1 instead of weaving it.
It is also possible to wrap the modified polypropylene adhesive in the form of a film and wrap it around the fiber braid 2 before extruding the sheath 3 material. If epoxy-treated polyester fibers are used, the kink resistance will be even better due to improved adhesive strength. The following shows the various performances of the refrigerant gas hoses that were actually manufactured. Example 1 Nylon 6/66 copolymer (manufactured by Ube Industries, Ltd.)
5033JU) was extruded at 210℃ to obtain an inner diameter of 8 mm and wall thickness.
Form a 0.8mm core tube. Next, polyester fiber (manufactured by Teijin Ltd., 1000 denier per carrier x 5
Prepare 12 carriers each of polypropylene fiber (manufactured by Ube Nitto Kasei Co., Ltd., 680 denier per carrier x 6 aligned), and plasticize the fiber braid around the core tube using a 24-carrier type blader. Glue and weave. Then, a modified polyolefin resin (manufactured by Mitsubishi Yuka Co., Ltd., Modelix (registered trademark)) is used as an adhesive layer around the fiber blade.
was extruded at 215℃ to a thickness of 0.15 to 0.2mm, and then a polyolefin elastomer (Santoprene, manufactured by Mitsubishi Monsanto Chemical Co., Ltd.) was extruded at 195℃ to form a sheath with a thickness of 1.0mm. . Example 2 A 4360 denier aligned fiber bundle was formed from polyester fibers (1500 denier x 2 aligned) and polypropylene fibers (680 denier x 2 aligned). And, taking this as one carrier,
A fiber braid was plasticized and bonded and woven around the same core tube as in Example 1 using a 24 carrier type braider, and then a sheath was formed around the fiber braid in the same manner as in Example 1. Comparative Example 1 A core tube was formed in the same manner as in Example 1, and around it, polyester fibers (1500 denier x 3 aligned per carrier) were weaved by plasticizing and adhering the fiber blades with a 24 carrier type braider. to be accomplished. Then, a polyolefin elastomer (Mitsubishi Monsanto Chemical Co., Ltd.) is applied directly around the fiber blade.
Santoprene) was extruded and coated in the same manner as in Example 1. Comparative Example 2 A core tube was formed in the same manner as in Example 1, and Example 2
Similarly, a fiber braid is woven by plasticizing and adhering a fiber bundle of polyester fibers and polypropylene fibers around a core tube. Then, a polyolefin elastomer (Santoprene, manufactured by Mitsubishi Monsanto Chemical Co., Ltd.) was extruded and coated directly around the fiber braid in the same manner as in Example 1. The table below compares the various performances of each of the above hoses, and the test method is as follows. Flexibility: When one end of a hose cut to a length of 400 mm was fixed and bent to a bending radius of 45 mm, the bending stress at the other end was measured using a spring scale. In addition, the minimum bending radius that would cause a kink when the hose was bent was also measured. (The goal is for no kink to occur with a bending radius of 20 mm.) Moisture permeability: 18 g of Molecular Sieve Type 4A (manufactured by Union Showa Co., Ltd.) is attached to a 500 mm long hose.
Fill and seal both ends. Thereafter, it is left in saturated steam at 40°C, and the permeated water is absorbed by a molecular sieve. Measure water absorption every 24 hours,
The average value of each measurement value until 240 hours had passed was determined. Freon gas permeability: Fill a 500 mm long hose with 15 g of Freon 12 (manufactured by Mitsui Fluorochemical Co., Ltd.) and seal both ends. After that, it was left in an atmosphere of 100℃, and the weight was measured after 24 hours and 96 hours.
The amount of Freon gas that permeated during 72 hours was calculated from the difference between both measured values.

〔Effect of the invention〕

The present invention has the above-mentioned configuration, and the refrigerant gas hose according to the present invention has excellent kink resistance and flexibility, as well as improved moisture permeation resistance. have.

[Brief explanation of drawings]

The figure shows one embodiment of the refrigerant gas hose according to the present invention, and is a perspective view with its constituent layers sequentially removed. 1... Core tube, 2... Fiber braid, 3... Sheath, 4
...adhesive layer.

Claims (1)

[Scope of Claims] 1 A fiber braid 2 is formed around a core tube 1 by a plurality of fibers containing at least polyolefin synthetic fibers.
At the same time, this fiber braid 2 is bonded to the core tube 1, and an adhesive made of a modified polyolefin polymer is interposed between the fiber braid 2 and a sheath 3 made of a polyolefin elastomer, and an outer layer of the polyolefin synthetic fiber is bonded to the core tube 1. By temporarily melting the surface and adhesive, fiber braid 2 and sheath 3 are attached.
A refrigerant gas hose characterized by adhesively bonding. 2. The refrigerant gas hose according to claim 1, wherein the fiber braid 2 is woven from a fiber bundle formed by mixing and twisting a plurality of fibers. 3. The refrigerant gas hose according to claim 1 or 2, wherein the fiber braid 2 is a mixture of a plurality of fibers. 4. The refrigerant gas hose according to any one of claims 1 to 3, wherein the polyolefin synthetic fiber is a polypropylene fiber. 5. Claim 1, wherein the polyolefin synthetic fiber is polyethylene fiber.
The refrigerant gas hose according to any one of items 1 to 3. 6 A fiber braid 2 is formed around the core tube 1 by a plurality of fibers containing at least polyolefin synthetic fibers.
At the same time, this fiber braid 2 is bonded to the core tube 1, and an adhesive made of a modified polyolefin polymer is placed on the fiber braid 2, and then a sheath 3 material made of a polyolefin elastomer is extruded in a molten state to form a sheath. 3, the outer surface of the polyolefin synthetic fiber and the adhesive are temporarily melted to bond the fiber braid 2 and the sheath 3 together.