JPH0530370B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to water and liquid supply hoses, drainage and drainage hoses, and ventilation and exhaust hoses used in fields such as civil engineering, architecture, agriculture, industry, and firefighting. This invention relates to a method for manufacturing a flexible hose suitable for use in commercial hoses, etc. [Prior Art] Flexible hoses made of a cylindrical cloth whose inner surface is coated with various synthetic resins or rubber materials are widely used.
Fibers such as polyester and polyamide are often used as materials for this cylindrical cloth, and the coating layer is made of vulcanized rubber mainly made of natural rubber or styrene-butadiene rubber, soft polyvinyl chloride, polyester Polyurethane-based thermoplastic elastomers and polyurethane-based thermoplastic elastomers are used. [Problems to be solved by the invention] However, when polyester or polyamide fibers are used for the cylindrical cloth and the above-mentioned vulcanized rubber is used for the covering layer, strength, heat resistance, cold resistance, durability, and flexibility are insufficient. Although it has excellent physical properties such as elasticity, it has a complicated processing process, such as requiring various adhesives to bond with fibers, and has problems in terms of quality control and high cost. Furthermore, when soft polyvinyl chloride is used for the coating surface, there is a problem in handling workability because it becomes hard at low temperatures and becomes hard over time due to loss of plasticizer. In addition, when polyester-based or polyurethane-based thermoplastic elastomers are used for the coating layer, there are problems such as poor water resistance and high specific gravity.
Field of use is limited. On the other hand, as materials for the coating layer, there are olefin-based thermoplastic elastomers and styrene-based thermoplastic elastomers as materials that have physical properties on the same level as vulcanized rubber, are lightweight, and can be easily molded into hoses. These have problems such as poor adhesion to fibers such as polyester and polyamide used for tubular cloth, require special adhesives, and are expensive, making it difficult to put them into practical use. An object of the present invention is to provide a flexible hose that has physical properties equivalent to those of a hose using vulcanized rubber for the coating layer and that is easy to mold. [Means for solving the problem] In the present invention, a crystalline propylene polymer is used as part of the fibers used in the tubular cloth, and a soft material made of a specific component is used as the thermoplastic polymer used in the coating layer. By using this, this purpose was achieved. That is, the present invention provides ``a method for making a hose by coating a cylindrical cloth formed by weaving fibers with a thermoplastic polymer, in which (1) the fibers are coated with 50% crystalline propylene polymer;
50% by weight of a flexible hose, and (2) the thermoplastic polymer comprises the following components (a) to (c). (a) Component: General formula A(-B-A) _o (where A is a monovinyl-substituted aromatic hydrocarbon polymer block, B is a conjugated diene elastomeric polymer block, and n is 1 to 5 30 to 70% by weight based on the total amount of components (a) and (b) (b) component: non-aromatic rubber softener , (a) and (b)
70-30% by weight based on the total amount of components (c) Component: crystalline propylene polymer, (a) and (b)
10 to 120 parts by weight based on 100 parts by weight of the total amount of components. [Function] The cylindrical cloth used in the present invention is made by weaving fibers, and such fibers include organic fibers such as polyester, polyamide, polyvinyl alcohol, aromatic polyamide, glass, carbon, alumina, Inorganic fibers such as silicon can be used, and two or more of these can also be combined. Among them,
Polyester fibers are preferred. However, it is essential that the fibers constituting this tubular cloth contain 5 to 50% by weight, preferably 5 to 35% by weight, of a crystalline propylene polymer.
In addition to propylene homopolymers, this crystalline propylene polymer includes other α-based polymers such as ethylene, butene, pentene, hexene, heptene, octene, etc.
A propylene copolymer obtained by copolymerizing -olefin in a proportion by weight is used, but optional components include polyethylene, ethylene-α-olefin (propylene,
butene, hexene, etc.) copolymer resins or other olefin polymers such as rubber, polybutene, ethylenically unsaturated organic acids or derivatives thereof (acrylic acid or its esters and salts, maleic anhydride, etc.) copolymer resins, A thermoplastic polymer such as polyester, polyamide, polyvinyl alcohol, polystyrene, etc. may be mixed in an amount of 30% by weight or less. The method for incorporating the crystalline propylene polymer may be blended spinning by mixing it with raw cotton, mixed twisting by mixing it into a single thread, or mixed weaving by mixing it into separate threads. From the viewpoint of good appearance, mixed spinning or mixed twisting is preferred.
Also, if you classify the method of containing it depending on the type of thread,
There are ways to mix it with both the warp and weft, only with the warp, or only with the weft.
From the viewpoint of physical properties, especially the pressure resistance of the hose, it is preferable to mix it with both yarns or only with the warp yarn. If the content of the crystalline propylene polymer is less than the above range, the adhesion between the cylindrical fabric and the coating layer will be impaired, while if it exceeds the above range, the cylindrical fabric will be susceptible to thermal deformation during molding, resulting in poor appearance. etc. will worsen and this is not desirable. There are various types of fibers used, including spun yarn (spun yarn) and filament yarn (long fiber yarn).
is widely used, and can be easily made into a cylindrical cloth using known methods such as cylindrical fibers. Next, the thermoplastic polymer used in the present invention, which covers the outer surface of the cylindrical cloth, consists of the following components (a) to (c) as essential components. (a) Component: General formula A(-B-A) _o (where A is a monovinyl-substituted aromatic hydrocarbon polymer block, B is a conjugated diene elastomeric polymer block, and n is 1 to 5 30 to 70% by weight based on the total amount of components (a) and (b) (b) component: non-aromatic rubber softener , (a) and (b)
70-30% by weight based on the total amount of components (c) Component: crystalline propylene polymer, (a) and (b)
10 to 120 parts by weight based on 100 parts by weight of the total amount of components Here, as component (a), for example, styrene-
A hydrogenated derivative of a butadiene-styrene block copolymer is commercially available from Shell Chemical Company under the trade name "Krayton-G." Also, as component (b), non-aromatic mineral oil or a liquid or low molecular weight synthetic softener is suitable. This is generally called a process oil or extender oil used for softening, increasing volume, improving processability, etc. of rubber, and paraffin-based oils are preferably used. Further, as the component (c), the crystalline propyrene polymer described above in the fiber section can be used.
Among them, melt flow rate (MFR: ASTM
D-1238, L condition, 230℃, 2.16Kg) is 0.1 to 50
g/10 min, particularly 0.1 to 10 g/10 min, is preferred in terms of coating properties and mechanical strength. Incidentally, it is preferable to incorporate a small amount of other olefin polymer as an optional component in terms of thin-wall moldability. If the amount of component (b) is less than the above amount, the moldability will be poor and it will be difficult to form a thin coating layer, while if it is more than the above amount, mechanical properties such as strength will deteriorate, which is undesirable. . Furthermore, if the blending amount of component (c) is less than the above amount, the adhesion to the tubular cloth will be poor, while if it exceeds the above amount, the flexibility of the hose will be impaired, which is not preferable. A particularly preferable blending amount is
Component (a) is 60 to 40% by weight, component (b) is 40 to 60% by weight, and component (c) is 20 to 100 parts by weight. Here, in addition to the essential components, optional components may be blended within a range that does not significantly impair the effects of the present invention, and it is also possible to partially crosslink using a crosslinking agent such as an unsaturated silane compound. To manufacture a flexible hose, a cylindrical cloth is made from fibers using a conventional method using a cylindrical loom.On the other hand, for the coating, components (a) to (c) above are generally mixed using a conventional kneading machine. This can be easily carried out using equipment widely used in the general thermoplastic resin molding field. That is, usually an extruder with a diameter of 40 to 65 mm is used,
After guiding the cylindrical cloth into the die using a mandrel and continuously coating the inner or outer surface or both sides of the cylindrical cloth with a uniform thickness of about 100 to 2000 microns, cool air or cold water is applied from the die exit. to obtain a flexible hose. Further, after this, the inner and outer surfaces of the hose can be turned inside out using a known method to form a flexible hose. The covering layer may normally be a single layer, but may also be two or more layers of thermoplastic polymers having the same or different compositions. [Effects of the Invention] The manufacturing method of the present invention has good adhesion between the cylindrical cloth and the thermoplastic polymer coating layer, without problems such as peeling, and has good flexibility, and the physical properties of the coating layer and hose A hose with a good appearance can be obtained. [Example] Production of cylindrical cloth Using a cylindrical loom, a cylindrical cloth with an outer diameter of about 40 mm was produced with 400 warp threads. At this time, as shown in Table 1 below, for Examples 1 and 2 and Comparative Examples 2, 3, and 4, threads in which polyester threads and polypropylene threads were mixed and twisted in the ratios shown in the table were used. In Example 3, polyester yarn and polypropylene yarn were mixed and used. For Comparative Example 1, polyester yarn was used. Preparation of thermoplastic polymer for coating layer (a) Component "Krayton-G1650" manufactured by Schiel Chemical Co., Ltd. (Bruckfield viscosity at 77% in 20% by weight toluene solution: 1500 cps), (b) component manufactured by Idemitsu Kosan Co., Ltd. "Diana Process Oil"
"PW90" (paraffinic oil with kinematic viscosity of 95.5cst at 40℃ and average molecular weight of 539) and (c) component "Mitsubishi Polypro FX4" manufactured by Mitsubishi Oil & Chemical Co., Ltd.
(MFR6g/10min propylene-ethylene random copolymer resin) were mixed uniformly in a super mixer using the blending ratios shown in Table 1, and then kneaded at 220℃ using a twin-screw extruder. Made into pellets. Preparation of hose A coating material was continuously extruded and coated on the outer surface of a cylindrical cloth under the following conditions. Extrusion molding machine: diameter 50 mm, full flight screw equipment Set temperature: 220°C Film thickness: 500 microns Take-up speed: 4 m/min The quality of the hose obtained above was evaluated by the following method. (i) Appearance After confirming that the coating had a uniform thickness and a good visual appearance, the hose was turned over inside and outside and the condition of the threads of the cylindrical cloth was visually observed and ranked as follows. ◎: Good with no abnormalities such as thread misalignment or cutting. ○: There are some abnormalities such as misalignment of threads, but there is no problem in practical use. ×: Not suitable for practical use such as cutting threads. (ii) Adhesiveness Expressed as the average stress when the hose is peeled off at a pulling speed of 50 mm/min in the processing direction. It is good if the test piece width is 25mm and the stress is 3.0Kg or more. (iii) Strength, elongation, and hardness of the coating layer The test piece peeled off from the hose was
−K6301 No. 3 dumbbell punched, hardness (JIS
-A) and tensile tests were conducted (tensile speed 500
mm/min). (iv) Flexibility Judged by feeling the hose with your hands. These results are shown in Table 1. 【table】

Claims (1)

[Claims] 1. A method for making a hose by covering a cylindrical cloth formed by weaving fibers with a thermoplastic polymer, in which: (1) the fibers contain 5 to 50% by weight of a crystalline propylene polymer; and (2) the thermoplastic polymer comprises the following components (a) to (c). (a) Component: General formula A(-B-A) _o (where A is a monovinyl-substituted aromatic hydrocarbon polymer block, B is a conjugated diene elastomeric polymer block, and n is 1 to 5 30 to 70% by weight based on the total amount of components (a) and (b) (b) component: non-aromatic rubber softener , (a) and (b)
70-30% by weight based on the total amount of components (c) Component: crystalline propylene polymer, (a) and (b)
10 to 120 parts by weight based on 100 parts by weight of the total amount of ingredients