JPH03294536A - Cord for reinforcing resin hose - Google Patents

Abstract

PURPOSE:To obtain the title cord for reinforcing resin hose consisting of a core-sheath type conjugate fiber mainly each containing specific naphthalate as the core component and a polyamide as the sheath component, having improved dimensional stability and having modulus higher than that of a conventional polyester. CONSTITUTION:The aimed cord being a core-sheath type conjugate fiber composed of a core component consisting of polyethylene-2,6-naphthalate containing ethylene naphthalene-2,6-dicarboxylate as a main component and sheath component containing a polyamide as a main component around the core component and being 30-90wt.% in ratio of the core component forming the conjugate fiber, being >=7.0g/d in strength of the conjugate fiber, <=20% in elongation, >=90g/d in initial tensile resistance and <=5% in dry heat shrinkage and obtained by twisting the conjugate fiber.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a cord for reinforcing a resin hose.
More specifically, the present invention relates to a resin hose reinforcing cord made of a core-sheath type composite fiber whose core component is polyethylene-2.6-naphthalate (hereinafter referred to as 2.6-PEN) and whose sheath component is polyamide.

[Prior Art] A hose using a reinforcing cord made of polyester fiber containing polyethylene terephthalate as a main repeating unit as a reinforcing material is disclosed in, for example, Japanese Patent Application Laid-Open No. 165087/1987.
It is stated in the No.

The resin hose described in JP-A No. 62-16587 has aluminum wire, polyvinyl chloride, or polypropylene wrapped spirally at regular intervals and embedded as a reinforcing body between the resin, The buried portion protrudes outward from the other outer circumferential surface, and a recess is formed in a spiral shape between the pitches of the reinforcing body. A sheathing member is provided between the surface and the surface.

[Problems to be Solved by the Invention] In the case of the resin hose described in the above-mentioned Japanese Patent Application Laid-Open No. 62-165087, when the reinforcing body is wound spirally with a gap formed therein, the reinforcing body is formed with a constant gap. , it is necessary to form recesses with a constant gap, and if the gap is not constant, the winding of the tightening material cannot be constant, and the quality of the resulting resin hose in the length direction cannot be made uniform. is difficult.

In addition, the tightening material is wound around a recess formed at a certain gap, but in this case, the tightening material needs to be thick enough to be inserted into the recess in close contact with the recess. There is a problem that a gap is created between the resin hoses, the pressure resistance of the gap portion is reduced, and the durability of the resin hose as a whole is reduced.

The purpose of the present invention is to solve the above-mentioned problems with conventional hoses, and to provide more desirable properties as a reinforcing material for resin hoses, namely, high modulus, dimensional stability, fatigue resistance, interfacial peeling durability with resin, and heat resistance in resin. An object of the present invention is to provide a cord for reinforcing a resin hose that has properties.

[Means and effects for solving the problems] The present invention has the following features: (1) In a resin hose reinforcing cord, the fibers forming the cord are made of polyethylene whose main component is ethylenenaphthalene-2,6-dicarboxylate. - A core-sheath type composite fiber having a core component of 2,6-naphthalate and a sheath component mainly composed of polyamide surrounding the core component, wherein the proportion of the core component consisting of polyethylene-2,6-naphthalate is 30 to 90% by weight, and the strength of the composite fiber is 7.
．． A resin hose reinforcing cord characterized by being made by twisting composite fibers having an elongation of 0 g/d or more, an elongation of 20% or less, an initial tensile resistance of 90 g/d or more, and a dry heat shrinkage rate of 5% or less.

(2) In (1) above, the intrinsic viscosity [η
] is 0.5 or more, birefringence is 230X10-3 to 350X
10-" density is 1.340 g/cm3 or more, and the relative viscosity of sulfuric acid (77r) of the polyamide forming the sheath component is 2.
．． 8 or more, birefringence is 45 x 104 or more, density is 1.13
5 g/Cm'' or more, and wherein both the core component and the sheath component have a highly oriented and highly crystalline fiber structure.

It is in.

The resin hose reinforcing cord according to the present invention has a core component or 2.
6-PEN is a composite fiber whose sheath component is polyamide, which could not be obtained by conventional technology, and has a high modulus higher than that of polyester, heat resistance in resin, heat resistant adhesion, and a core-sheath composite interface. These properties can be indicated by parameters consisting of a combination of 2) the specified birefringence, density of the 6-PEN and polyamide fiber sections forming the core and sheath, respectively;

2) 6-PEN, which is the core component of the composite fiber, has an intrinsic viscosity [η] of 0.5 or more, preferably 0.6 or more, so that the strength of the composite fiber is 7.0 g/d or more. obtain.

2.6-Like the PEN core component, the polyamide sheath component polymer also requires a high degree of polymerization in order to obtain a high-strength conjugate fiber, and the relative viscosity of sulfuric acid is 2.8 or more, preferably 3.0 or more. The polyamide sheath component contains copper salt as a thermal oxidative deterioration inhibitor.
and other organic and inorganic compounds are added. In particular, copper salts such as iodized steel, copper acetate, copper chloride, and copper stearate are used in an amount of 30 to 500 ppm as copper, and alkali metal halides such as potassium iodide, sodium iodide, and potassium bromide are added in an amount of 0.
It is preferable to contain 0.01 to 0.5% by weight and/or 0.01 to 0.1% by weight of an organic or inorganic phosphorus compound.

The ratio of the 2.6-PEN core component of the composite fiber is 30 to 9.
It is 0% by weight. If the 2.6-PEN component is less than 30% by weight, it is impossible to obtain a composite fiber that can effectively utilize the modulus and dimensional stability of the 2.6-PEN component, so that a preferable resin hose reinforcing cord can be obtained. I can't. On the other hand, when the 2.6-PEN core component accounts for 90% by weight or more, the composite fiber is used as a resin hose reinforcing cord,
When the cord is used as a reinforcing material for a resin hose, it has poor adhesion to the resin, making it impossible to improve the heat resistance of the resin hose reinforcing cord in the resin.

In the composite fiber, both the 2.6-PEN core component and the polyamide sheath component are highly oriented and crystallized, and the 2.6-PEN core component and polyamide sheath component are highly oriented and crystallized.
Birefringence of PEN core component is 230×10-3 to 350×1
It is desirable to keep it within the range of 0-s, and 230
If it is less than 350 x 10-", the strength of the composite fiber may not be 7.0 g/d or more and the initial tensile resistance may not be 90 g/d or more. If it exceeds 350 x 10-", the fatigue resistance may not be improved. It may not be done.

On the other hand, the birefringence of the polyamide sheath component is 45 x 10-3 or more, usually 50 x 10-'' or more, which is highly oriented.If the birefringence is less than 45 x 10-'', a composite fiber with high strength and high initial tensile resistance can be obtained. It is difficult to

The birefringence of the core-sheath composite fiber can be measured as follows. That is, the sheath portion is directly measured using a transmission interference microscope, and the core portion is measured using a transmission interference microscope after dissolving the polyamide sheath component in formic acid, sulfuric acid, fluorinated alcohol, or the like.

The density is 2.6-PEN core component is 1.340g/cTrI
3 or more, the polyamide sheath component is 1,135 g/cms or more and is preferably highly crystallized, and by having a density of each of the above specific values or more, the composite fiber has excellent dimensional stability and fatigue resistance. When the cord is used as a reinforcing material for a resin hose, the heat resistance of the reinforcing material in the resin is significantly improved.

2.6-The density of the PEN core component is determined by dissolving and removing the polyamide sheath component with formic acid, sulfuric acid, fluorinated alcohol, etc., and the density of the polyamide sheath component is 2.6 times the density of the composite fiber.
- It can be calculated from the density of the PEN core.

The composite fiber characterized by the above has a high strength of 7°0 g/d or more, an initial tensile resistance of 90 g/d or more, and an elongation of 20% or less.

More preferable properties of composite fibers are strength of 7.3 g/d or more;
Initial tensile resistance 100g/d or more, elongation 8-16%
This can be achieved by appropriately combining the above conditions.

The composite fiber is manufactured by the novel method shown below.

In order to obtain the above-mentioned 2) polymer physical properties of the 6-PEN core component, a polymer consisting essentially of 2.6-PEN with an intrinsic viscosity [η] of 0.5 or more, usually 0.6 or more is used.

The polyamide sheath component polymer has a sulfuric acid relative viscosity of 2°8 or more,
Usually, a polymer with a high polymerization degree of 3.0 or more is used.

It is preferable to use two extruder type spinning machines for melt spinning the polymer. 2) 6-PEN and polyamide polymer melted in each extruder are introduced into a composite spinning pack, passed through a composite spinning nozzle, and spun into a composite fiber with 2.6-PEN in the core and polyamide in the sheath, Spun yarn and eggplant.

The spinning speed is 300 m/min or more. Immediately below the spinneret, a heated atmosphere of 200° C. or higher, preferably 260° C. or higher is created over a distance of 10 cm or more and within 1 m by providing a heat insulating cylinder, a heating cylinder, etc. After passing through the heating atmosphere, the spun yarn is quenched and solidified with cold air, and after being applied with an oil agent, it is taken off by a take-off roll that controls the spinning speed. Control of the heating atmosphere directly under the spinneret is important in order to maintain stringiness. The undrawn yarn taken off is usually -
Stretch continuously without winding up.

Next, the undrawn yarn is continuously heated to 180°C or higher, preferably 2°C.
It is hot stretched at a temperature of 00°C or higher.

The stretching is carried out in two or more stages, usually three or more stages, and the stretching ratio is in the range of 2.0 to 6.5 times. Adoption of such high-temperature hot stretching according to the present invention contributes to improving the durability of the composite interface. The stretching temperature in the third stage of the stretching is low, for example 160
At temperatures below 180°C, interfacial delamination between the 2.6-PEN core component and the polyamide sheath component often occurs during stretching, and when stretching at temperatures below 180°C, during resin hose processing and when the resin hose is repeatedly used at high pressure. Sometimes. Furthermore, if the stretching ratio is 6.5 times or more, deformation during stretching may be large and interfacial peeling may occur, and fatigue resistance may be lowered, which is not preferable.

As a method for obtaining a resin hose using the composite fiber forming the resin hose reinforcing cord according to the present invention, for example, the obtained drawn yarn is heated to form an untreated cord.

In addition, when forming a hose using the composite fiber specified in the present invention, a cord made of the composite fiber, a fabric woven from the cord, or a cord having interfacial peeling durability with the resin used for the hose at the braid stage, for example, Epoxy resin,
A composition containing phenolic resin, resorcinol, formalin, latex, etc. as a main component may be applied.

When obtaining a hose using the resin reinforcing cord according to the present invention, for example, J I 5-D2606 (1980),
JIS-6335 (1984), JIS-6339 (1982), and JIS-6342
(1982), it can be easily manufactured according to the structure and processing method.

[Example 1 and 2] Comparative Examples 1 to 3 Polyethylene-2°6-naphthalate (2,6-PEN) with intrinsic viscosity [η) of 0.80 and iodized steel 0.02% by weight
and hexamethylene adipamide (N66: sulfuric acid relative viscosity ηr 3.3) containing 0.1% by weight of potassium iodide were each melted in a 40φ engineering spinner, guided into a composite spinning bag, and then passed through a core-sheath composite spinneret. 2.6PEN in the core
The sheath part was spun as a composite yarn of polyamide to obtain a spun yarn. The proportions of the core component and sheath component of the spun yarn were varied as shown in Table 1. The cap used had a hole diameter of 0.4 mmφ and 120 holes.

The polymer temperature was 2.6-PEN was melted at 300°C and polyamide was melted at 290°C, and the spinning pack temperature was set at 300°C.
Spun as ℃. A 30 cm heating cylinder was attached directly below the mouthpiece, and the atmosphere inside the cylinder was heated to 290°C.

The atmospheric temperature is the atmospheric temperature measured at a position 10 cm below the spinneret surface and 1 co+ away from the single yarn running on the outermost circumference of the spun yarn.

An annular chimney with a length of 400 mm was installed under the heating cylinder, and cold air was blown at a rate of 40 m/min at 25° C. from around the yarn at a right angle to the yarn to cool the yarn.

After applying an oil agent, the yarn speed was controlled with a take-up roll rotating at the speed shown in Table 1, and then the yarn was drawn continuously without being wound up. The film was stretched in three stages using five pairs of Nelson type rolls, then subjected to a relaxation heat treatment with 3% relaxation, and then wound up. The stretching conditions were as follows: take-up roll temperature at 60°C, first stretching roll temperature at 120°C, second stretching roll temperature at 190°C, third stretching roll temperature at 225°C.
The tension adjustment roll after stretching was not heated, and the first stage stretching ratio was 70% of the total stretching ratio, and the remainder was divided into two stages for stretching. The yarn was produced by varying the spinning speed, total draw ratio, etc., and the discharge amount was changed in accordance with the spinning speed and draw ratio so that the fineness of the drawn yarn was approximately 500 denier (Example 1)
, 2) Comparative Example 1). Three of the obtained drawn yarns were combined into 15
What happened to 00 denier?

The spinning conditions, the obtained drawn yarn properties, and the fiber structure parameters were determined using polyethylene terephthalate (PET) fiber (1
500-288-702G) (Comparative Example 2) and Nylon 66 fiber (1260-204-1781) (Comparative Example 3)
A comparative test was conducted on the following. Each condition and fiber properties are as shown in Table 1.

(The following is a blank space) Using each of the fibers shown in Table 1 above, these fibers were twisted and twisted in opposite directions at a rate of 40T/10cm to form a 1500/2 raw cord. However, N66 of Comparative Example 3 had a twist number of 39T/10cm and was made into a raw cord of 1260/2. This raw cord was applied with an adhesive and heat-treated in a conventional manner using a dipping machine manufactured by Ritzler to obtain a dip cord.

The dip liquid contained an adhesive component consisting of 20% resorcinol, formalin, and latex, and was adjusted so that about 4% of the adhesive component adhered to the cord. Heat treatment is 225℃ and 80℃
The process was performed while stretching the dip cord so that its intermediate elongation was approximately 5%. Nylon 66 was stretched under the same heat treatment conditions so that the intermediate elongation was approximately 9%. In addition, PET was subjected to two-bath adhesion treatment using a conventional method, and heat treatment was performed at 240°C for 120 seconds, resulting in an intermediate elongation of approximately 5.
%.

Regarding the thus obtained dip cord, a test piece was made embedded in resin in the same manner as when used as a reinforcing material for a resin hose, and the heat resistance, adhesion, fatigue resistance, etc. in the resin were evaluated. The results were as shown in Table 2.

(The following is a blank space) The resin hose reinforcing cord according to the present invention has a modulus and dimensional stability higher than that of a conventional polyester fiber cord, and also has a higher modulus and dimensional stability than a conventional polyester fiber cord.
This shows that it is a high-strength cord with significantly improved heat resistance, heat-resistant adhesion, and fatigue resistance in the resin.

Furthermore, the resin hose reinforcing cord according to the present invention has significantly improved modulus and dimensional stability compared to conventional nylon fiber cords.

[Effects of the Invention] The resin hose reinforcing cord according to the present invention has a modulus higher than that of conventional polyester, improved dimensional stability, and has a higher modulus than that of conventional polyester, and has a reinforcing cord made of conventional polyester. The heat resistance and adhesion in the resin of the cord embedded in the resin hose according to the present invention, especially the heat resistance adhesion and fatigue resistance after being subjected to high temperature history, are significantly improved, and therefore The durability against repeated fatigue is extremely good.

Claims (2)

[Claims] (1) In a resin hose reinforcing cord, the fibers forming the cord have a core component of polyethylene-2,6-naphthalate whose main component is ethylene-naphthalene-2,6-dicarboxylate; It is a core-sheath type composite fiber with a sheath component mainly composed of polyamide, the proportion of the core component forming the composite fiber is 30 to 90% by weight, and the strength of the composite fiber is 7.0 g / d or more, elongation is 20% or less, initial tensile resistance is 90 g/d or more,
A cord for reinforcing a resin hose, which has a dry heat shrinkage rate of 5% or less and is made by twisting the composite fibers described above. (2) In claim (1), polyethylene-2,6-naphthalate forming the core component of the composite fiber has an intrinsic viscosity [η] of 0.5 or more and a birefringence of 230×10
^-^3~350x10^-^3, density 1.340g
/cm^3 or more, the sulfuric acid relative viscosity (ηr) of the polyamide forming the sheath component is 2.8 or more, and the birefringence is 45×1
0^-^3 or more, a density of 1.135 g/cm^3 or more, and both the core component and sheath component have a highly oriented and highly crystalline fiber structure.