JP2000199840A - Aramid fiber reinforced curable resin wire-shaped material, its production and spacer for optical fiber cable consisting of this wire-shaped body as tension member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an A-FRP wire-shaped material which is improved in bending resistance and bending performance, such as reduction of a curl, a process for producing the same and a spacer for an optical fiber cable consisting of such material as a tension member. SOLUTION: The bending performance of the A-FRP wire-shaped material is required to be the minimum bending diameter below 35 times the diameter D of the A-FRP wire-shaped material and to be below 20 times the diameter D in the height of the arc at the chord of the length corresponding to 216 times the diameter D right after opening of the bend after resting for 24 hours in the state of bending the A-FRP wire-shaped material to the diameter of 175 times the diameter D thereof. Aramid fibers as reinforcing fibers of <=15 wt.% and >=60 Å in crystal size which are heat treated just before impregnation of an uncured matrix resin with the aramid fibers are used. A prescribed number of the aramid fibers 11a for reinforcement are drawn out of a creel 20, are converged via a guide plate 21 and are then heat treated to >=300 deg.C in a heat treatment vessel 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for improving the bending performance of an aramid fiber reinforced curable resin linear material, particularly, an aramid fiber reinforced curable resin linear material used for an optical cable or the like.

[0002]

2. Description of the Related Art Since an optical fiber has a small allowable elongation, a tensile strength member for preventing the optical fiber from elongating more than a specified amount is generally used in an optical cable in which the optical fiber is assembled. I have.

[0003] A wire made of an aramid fiber reinforced resin (hereinafter sometimes referred to as A-FRP) is used as the tensile strength member, so that the cable laying work becomes easy due to its light weight, and no induction is required. For this reason, the optical fiber can be used near the power cable without adversely affecting the transmission characteristics of the optical fiber. Therefore, there is a possibility that the total installation cost of the optical cable can be reduced.

[0004]

However, in the case of the A-FRP linear material, the disadvantage that the minimum bending diameter is larger than that of the G-FRP linear material using glass fiber as a reinforcing fiber,
After the A-FRP linear material is wound around the bobbin, when it is unwound for use, it has a curved shape corresponding to the diameter of the bobbin, and has a drawback that the so-called winding habit is large.

[0005] In particular, if the winding habit is large, the assembly speed cannot be increased when an optical fiber is manufactured by storing an optical fiber in a spacer using the A-FRP linear material as a tensile strength wire, and the cable after manufacturing the cable. , There has been a problem that the workability at the time of laying the cable is deteriorated.

[0006] As a cause of the deterioration of the bending performance of the A-FRP linear material, aramid fibers are generally used as process oils and oils for higher-order processing as low molecular weight fatty acid esters having a carbon number of 18 or less, polyethers, and the like. An oil agent such as mineral oil is attached, and the effect of this oil agent may reduce the interfacial adhesion between the aramid fiber as the reinforcing fiber and the curable resin as the matrix resin, and elongation due to creep of the aramid fiber. However, the true cause was uncertain.

In view of the above, an A-FRP linear material having improved bending resistance such as improved bending resistance and reduced curl in an A-FRP linear material, and a spacer for an optical fiber cable using the same as a tensile strength member. The present inventors have made intensive studies with the aim of providing the following and completed the present invention.

[0008]

In order to achieve the above object, the present invention relates to an aramid fiber reinforced curable resin (A-FRP) obtained by impregnating and curing an aramid fiber with a curable resin.
In the linear object, the minimum bending diameter of the linear object is less than 35 times the diameter of the linear object, and the linear object has a minimum bending diameter of 17 times.
Immediately after being bent to a diameter equivalent to 5 times and left for 24 hours, and opened, the arc height for a chord having a length equivalent to 216 times the diameter of the linear object is less than 20 times the diameter of the linear object. A-FR of
It was a P linear object. Further, an A-FRP linear material using the aramid fiber having an amount of oil agent adhesion of 0.15% or less was used. Further, the specific surface area of the aramid fiber is 0.2 m
An A-FRP linear product using ² / g or more was used.
In addition, an A-FRP linear material using a crystalline aramid fiber having a crystal size of a crystal lattice (1,1,0) plane of 60 ° or more was used. The manufacturing method of the present invention prepares a predetermined number of aramid fibers for reinforcement, heat-treats them at 300 ° C. or higher, impregnates with an uncured curable resin, and then shapes them into a predetermined shape with a drawing nozzle, Alternatively, a method for producing an A-FRP linear material in which the impregnated resin is cured while being drawn and formed. Further, the curable resin is a thermosetting resin, impregnated with an uncured thermosetting resin, and then drawn and formed into a predetermined shape, and the outer periphery thereof is seamlessly covered with a molten thermoplastic resin, and immediately. Then, after cooling the thermoplastic resin on the outer periphery, it was led to a heat-curing tank to cure the impregnated resin therein, thereby providing a method for producing an A-FRP linear product. The optical fiber cable spacer of the present invention has a configuration in which the above-described A-FRP linear material of the present invention is used as a tensile strength member and a groove for housing an optical fiber is arranged on the outer periphery.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
It does not limit the invention.

FIG. 1 schematically shows an A-FRP linear material according to the present invention.

An A-FRP linear material 10 shown in FIG. 1 comprises an aramid fiber 11 as a reinforcing fiber, a matrix resin 12
Composed of a curable resin as a thermoplastic resin coating 1
3 may be provided.

The aramid fiber 11 is an aromatic polyamide fiber which is roughly classified into a meta-type, a para-type, and the like, regardless of the kind. The poly-araphenylene terephthalamide sold by the applicant Toray DuPont Co., Ltd. Fiber (trade name “Kevlar”) can be suitably used in the present invention.

The curable resin as the matrix resin 12 is impregnated into aramid fibers as reinforcing fibers and has good wettability.
A resin capable of binding aramid fibers after curing may be selected, but preferred examples include thermosetting resins such as vinyl ester resins and unsaturated polyester resins.

The bending performance of the A-FRP linear object is such that when the linear object having a length of about 6 times or more the minimum bending diameter is gripped at both ends and gradually bent, the A-FRP linear object is bent. It was required that the minimum bending diameter be 35 times or less the diameter D of the object, and after being left for 24 hours in a state of being bent to a diameter of 175 times the diameter D of the A-FRP linear object, the bending was released. Immediately after, the height of the arc in a chord having a length equivalent to 216 times the diameter D is
It must be less than 20 times the diameter D.

The minimum bending diameter is the diameter D of the A-FRP linear object.
As a result, when the A-FRP linear material or the optical fiber cable using the tensile strength material as the tensile strength member is used, the handling of bending is restricted, and the arc height is A-FRP linear material. With a diameter D20 times or more of
Insufficient elastic recovery and large winding habit.

The amount of the oil agent attached to the aramid fiber of the A-FRP linear product is 0.15% by weight (wt) based on the fiber immediately before the aramid fiber as the reinforcing fiber is impregnated into the uncured matrix resin. The following is assumed.

If the adhesion amount exceeds 0.15 wt%, the adhesion between the aramid fiber and the matrix resin after curing becomes insufficient due to the presence of an oil film layer or the like existing at the interface of the aramid fiber, and the minimum bending diameter To increase the winding habit, resulting in a decrease in bending performance.

The use of Aramid fibers having a specific surface area of 0.2 m ² / g or more as the A-FRP linear material efficiently exhibits the reinforcing effect, that is, the strength performance of the used aramid fibers. It is preferred in that it allows

Further, the A-FRP linear material having an aramid fiber having a crystal size of 60 ° or more is used to improve the strength of the A-FRP linear material and improve the strength of the aramid fiber.
It is preferable from the viewpoint of expression of fiber performance.

If the crystal size is less than 60 °, the creep under stress becomes large, the elastic recovery after bending becomes poor, and the winding habit becomes large.

The manufacturing method of the present invention will be described with reference to FIG.

From the creel 20 to the reinforcing aramid fiber 11
a is drawn out by a predetermined number, converged via a guide plate 21, and then heat-treated at 300 ° C. or more in a heat treatment tank 22.

In the heat treatment, the temperature, length, and treatment speed of the heat treatment tank 22 are appropriately set, and the aramid fiber itself is heated for 300 minutes.
What is necessary is just to heat it to the temperature more than ° C.

As a heating method of the heat treatment tank 22, a dry heat heater such as a hot air, an electric heater, or a far infrared heater is suitable.

After the heat-treated aramid fiber 11b is immersed in the impregnating tank 23 and impregnated with the uncured curable resin, the drawn resin is drawn into a predetermined shape by the drawing nozzle 24, and then the resin is cured. In the case of a thermosetting resin, it is inserted into a heated mold having a predetermined inner diameter to be cured (not shown), or the outer periphery of the uncured linear material 9 is placed on a crosshead 25 of a melt extruder. There is a method in which the resin is inserted and covered with a thermoplastic resin, and then guided to the heat curing tank 27 to be cured.

Also, a method of drawing an uncured thermosetting resin by drawing, and extruding a molten thermoplastic resin on the outer periphery thereof to cover it seamlessly is disclosed in Japanese Patent Publication No. 56-20188. Is used.

The optical fiber cable spacer 3 of the present invention
0 will be described with reference to FIG.

The spacer 30 has an A-FR of the present invention at the center.
The P linear object 10 is arranged as a tensile strength member, and if necessary, a preliminary coating layer 31 is provided on the outer periphery thereof, and a spacer body coating layer 33 having a spiral groove 32 for accommodating an optical fiber is provided on the outer periphery thereof.

The pre-coating layer 31 is provided to enhance the groove shape accuracy. The pre-coating layer 31 has a relationship of 0.5 <D1 / D2 <1 between the outer diameter D1 of the pre-coating layer and the outer diameter D2 of the groove bottom. Set to satisfy.

The spiral groove 32 may be either in one direction of Z twist at a predetermined pitch or in the SZ direction in which the spiral grooves are alternately reversed. A- used in the spacer of the present invention
The diameter of the FRP linear object 10 is determined by the tensile strength and the like required as an optical fiber cable.
It is about 7 mm.

In the present invention, the following method was used for measurement. a) Minimum bending diameter: Place a ruler on a nearly horizontal desk,
Then, hold the both ends of the sample, which is about 6 times or more the minimum bending diameter, by hand, bend the sample so that the loop on the center side of the sample becomes smaller, and break it from the outer or inner circumference of the upper end of the loop. The loop interval at the start was read from the scale of the ruler, and was taken as the minimum bending diameter. The sample number n was set to 10, and the average value was used.

B) Winding habit: After being left to stand for 24 hours in a state where it is bent to 175 times the diameter D of the linear object, the diameter D immediately after opening is obtained.
The height Hmm of the arc in a chord having a length equivalent to 216 times of the above was used as a measure of the curl. The number n of samples was set to 5, and the average value was used.

C) Amount of oil applied: pulsed NMR "OXFORD"
It was measured by a nuclear magnetic resonance method using QP20 ″, and the average of three samples was defined as the oil agent adhesion amount.

D) Crystal size: Obtained by using an X-ray apparatus (manufactured by Rigaku Denki Co., Ltd.) and scanning the range of 2θ = 5 to 90 ° in the equator direction by the transmission method with the Bragg angle θ. PPTA (polyparaphenylene terephthalamide)
From the (1,1,0) plane, that is, the apparent half width β _E of the diffraction intensity curve at 2θ = 20.45 °, the Scherrer equation L =
With the average of L values calculated by Kλ / β ₀ cosθ,
The crystal size according to the present invention was used.

Where the constant K = 1.0 and the wavelength λ = 1.54.
18Å, β ₀ = (β _E -β ₁ ) ^1/2 , equipment constant β ₁ = 1.046 × 10 ^-2
Radians.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to preferred examples, but the scope of the present invention is not limited to the following examples.

Embodiment 1 An aramid fiber having a specific surface area of 0.239 m ² / g (“Kevlar” manufactured by Toray Dupont 49: 1414 denier / 1000 filament / type 968) 11a preliminarily dried at 80 ° C. for 24 hours is passed through the guide plate 21. Using an electric burner that blows air into the heated nichrome wire coil as a heat source,
After heat treatment for 20 seconds in the heat treatment tank 22 adjusted to 00 ° C., a vinyl ester resin containing a peroxide-based catalyst (Ester H8100 manufactured by Mitsui Chemicals, Inc.) was impregnated, and this was drawn and formed to form an aramid fiber. As an uncured wire having a content of 56.7 VOL% and an outside diameter of 3.7 mm, the wire was guided to the head 25 of the melt extruder, and LLDPE resin (Neozex 2015M, manufactured by Mitsui Chemicals, Inc.) was applied to the periphery of the wire by a die. It was extruded to form an annular coating, which was immediately cooled to obtain an uncured linear material 15 having a primary coating layer 13, which had a length of 6 mm.
m, guided to a heat-curing tank 27 filled with high-pressure steam at 140 ° C., and cured to form a coating outer diameter of 5.0 mm and an FRP outer diameter of 3.7 mm.
A-FRP linear material 10 having the primary coating layer 13 was obtained.

The oil adhering amount of the aramid fiber 11b obtained after the heat treatment before the resin impregnation was measured by the above-described nuclear magnetic resonance method, and was 0.05 (wt%), and the crystal size was 63 (wt.). Å).

With respect to the obtained A-FRP linear material with a primary coating layer, the primary coating layer was peeled off, and the diameter of the circular arc (minimum bending diameter) at the time when the wire was gradually bent with both ends first and started to be broken. Was measured and found to be 28.4 times the A-FRP diameter at 105 mm.

Next, as the evaluation of the curl, the A-FRP linear material 10 from which the primary coating layer was similarly peeled was bent so as to have a bending diameter φ647.5 mm, which is 175 times the product diameter.
A-FRP immediately after opening after leaving at room temperature for 4 hours
The height of the arc in an 800 mm chord 216 times the diameter was measured to be 66 mm and the A-FRP diameter was 17.
It was eight times.

The obtained A-FRP linear material having the primary coating layer was used as a tensile strength member 15, and the outer periphery thereof was preliminarily coated twice in two times to obtain an outer diameter of 11.0 mm. Into the cross extruder of the melt extruder, and the outer periphery thereof has 15 square grooves having a groove width of 1.4 mm and a groove depth of 2.2 mm, an outer diameter of 15.7 mm, and a Z direction twist pitch of 300 mm. The optical fiber cable spacer was formed of HDPE resin according to a conventional method, and wound around a drum having a drum diameter of 600 mm.

Using the spacer obtained two weeks later,
The optical fiber was assembled to produce a cable, but there was no abnormal trouble in the optical fiber assembling process due to the curl.
-It could be produced more smoothly than in the case of using FRP linear material. Note that the production of the A-FRP linear material and the production of the spacer can be directly performed.

Embodiment 2 FIG . Specific surface area is 0.195m ² / g
Aramid fiber ("Kevlar" 49 manufactured by Dupont Toray,
2840 denier / 1333 filament / type 98
A-FRP in the same manner as in Example 1 except that 9) was used.
A linear product was obtained.

The aramid fiber obtained after the heat treatment had an oil coating amount of 0.05 wt% and a crystal size of 63 °, and the minimum bending diameter and curl of the obtained A-FRP linear product are summarized in Table 1. Shown.

Embodiment 3 FIG . A-A was performed in the same manner as in Example 1 except that the temperature in the bath was 380 ° C. and the heat treatment time was 10 seconds.
An FRP linear product was obtained.

The aramid fiber obtained after the heat treatment had an oil coating amount of 0 wt% and a crystal size of 66 °. The minimum bending diameter and curl of the obtained A-FRP linear product are shown in Table 1. .

Embodiment 4 FIG . The same aramid fiber used in Example 1 ("Kevlar" manufactured by Toray DuPont)
After passing through (49) through the guide plate, an A-FRP linear product was obtained in the same manner as in Example 1 except that a heat treatment was performed at 430 ° C. for 5 seconds by contact heating to the heater plate.

The aramid fiber obtained after the heat treatment had an oil adhering amount of 0 wt% and a crystal size of 69 °, and the minimum bending diameter and curl of the obtained A-FRP linear product are shown in Table 1. .

Comparative Example 1 An A-FRP linear product was obtained in the same manner as in Example 1 except that the heat treatment was performed at a temperature of 250 ° C in the bath for 20 seconds.

The aramid fiber obtained after the heat treatment had an oil adhering amount of 0.2 wt% and a crystal size of 58 °, and the minimum bending diameter and curl of the obtained A-FRP linear product are summarized in Table 1. Shown.

Comparative Example 2 An A-FRP linear product was obtained in the same manner as in Example 1, except that the heat treatment of the aramid fiber before impregnation with the vinyl ester resin was not performed.

Before the resin impregnation, the aramid fiber had an oil adhering amount of 0.3 wt% and a crystal size of 56 °.
Table 1 shows the minimum bending diameter and curl of the FRP linear material.

Comparative Example 3 An attempt was made to produce an A-FRP linear material using an aramid fiber (Kevlar 49: 1412 denier manufactured by Du Pont-Toray Co., Ltd.) without an oil agent.
Single yarn breakage occurred frequently in the process, such as a fiber guide, and an A-FRP linear product could not be obtained.

The contents of the above Examples and Comparative Examples, such as heating conditions, are summarized in the following table.

[0055]

【table】

[0056]

As described above in detail in the examples and comparative examples, in the present invention, a heat treatment tank is provided and heat treatment is performed at a temperature of 300 ° C. or more, so that the oil agent adhering to the aramid fiber can be reduced. Removed, the amount of adhesion is 0.15 wt%
Reduce to below.

As a result, the wettability at the interface between the aramid fiber and the matrix resin is improved, and an A-FRP linear material having improved minimum bending diameter and curl bending performance can be obtained.

Although the production of aramid fibers without the addition of an oil agent was attempted from the beginning, single fibers of fibers frequently break due to rubbing or the like with guides such as creels or guide plates. I cannot get stable.

If the above-described A-FRP linear material having improved bending performance is used as a tensile strength member of an optical fiber cable spacer, a spacer having a small winding habit until used after winding on a drum as a spacer can be obtained. In addition, it is possible to suppress the occurrence of trouble due to deformation of the curl of the spacer or the like in the optical fiber assembly process.

Further, as an optical fiber cable, A
-The winding habit of the cable due to the use of the FRP linear material as the tensile strength member can be reduced, and the problem in the cable laying work can be solved.

In a more preferred embodiment, the use of aramid fibers having a specific surface area of 0.2 m ² / g or more increases the bonding area between the fibers and the matrix resin, thereby improving the reinforcing effect. In addition, an A-FRP linear material having further improved bending characteristics can be obtained, and the same effect as described above can be obtained.

Furthermore, the creep performance of the aramid fiber can be improved by growing the crystal size of the (1,1,0) plane of the realramid fiber to 60 ° or more by the heat treatment. Since the creep elongation of the aramid fiber on the outer side of the linear object, that is, the tensile side generated when bending is reduced, it is possible to obtain an A-FRP with improved bending performance evaluated with a minimum bending diameter and curl, Can be obtained as a tensile strength member.

Further, since the A-FRP linear material according to the present invention has a small minimum bending diameter and a small winding habit due to bobbin winding, it is suitable for a tensile strength member of an optical fiber cable.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an aramid fiber reinforced curable resin linear material of the present invention.

FIG. 2 is an explanatory diagram of a production process of a linear aramid fiber reinforced curable resin product of the present invention.

FIG. 3 is an explanatory view showing an example of a spacer for an optical fiber cable which uses the aramid fiber reinforced curable resin linear material of the present invention as a strength member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 A-FRP linear material 11 Aramid fiber 12 Matrix resin 13 Primary coating layer 15 Tensile body 20 Creel 21 Guide plate 22 Heat treatment tank 23 Impregnation tank 24 Restrictor nozzle 25 Cross head 27 Heat curing tank 28 Pull-off machine 29 Drum 30 For optical cable Spacer 31 Pre-coating layer 32 Spiral groove 33 Spacer body coating

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akira Hidaka 2-1-1, Yabuta Nishi, Gifu City, Gifu Prefecture Ube Nitto Kasei Co., Ltd. Gifu Research Institute (72) Inventor Nori Ishii 2-chome, Yabuta Nishi, Gifu City, Gifu Prefecture No. 1-1 Ube Nitto Kasei Co., Ltd. Gifu Research Laboratories (72) Inventor Shiro Sakamoto 1-5-6 Nihonbashi Honmachi, Chuo-ku, Tokyo Toray DuPont Co., Ltd. F-term (reference) 2H001 BB07 DD04 DD10 DD11 KK08 3B153 AA22 AA30 AA45 AA47 AA50 BB01 CC12 CC13 CC23 CC24 CC31 DD23 DD30 DD34 FF40 GG01 GG05 GG13 GG40

Claims (7)

[Claims] An aramid fiber reinforced curable resin linear product obtained by impregnating and curing an aramid fiber with a curable resin, wherein the minimum bending diameter of the linear material is less than 35 times the diameter of the linear material. And bending the linear object to a diameter equivalent to 175 times the diameter,
For 2 hours, and immediately after opening
An aramid fiber reinforced curable resin linear material, wherein an arc height for a chord having a length equivalent to 16 times is less than 20 times the diameter of the linear material. 2. The oily agent adhering amount of the aramid fiber is 0.1.
The aramid fiber reinforced curable resin linear material according to claim 1, wherein the content is 5% or less. 3. The specific surface area of the aramid fiber is 0.2 m.
The aramid fiber reinforced curable resin linear material according to claim 1 or 2, wherein the linear amount is ² / g or more. 4. The crystal lattice (1,1,0) of the aramid fiber
4. The linear aramid fiber reinforced resin according to claim 1, wherein the crystal size of the plane is 60 [deg.] Or more. 5. A predetermined number of aramid fibers for reinforcement are prepared,
An aramid characterized by impregnating with an uncured curable resin after heat-treating it to 300 ° C. or higher, and then molding the resin impregnated into a predetermined shape with a drawing nozzle or by drawing. A method for producing a fiber-reinforced curable resin linear material. 6. The thermosetting resin is a thermosetting resin,
After impregnating with an uncured thermosetting resin, and then drawing into a predetermined shape, the outer periphery is seamlessly covered with a molten thermoplastic resin, immediately cooling the outer thermoplastic resin, and then heat curing. The method for producing an aramid fiber reinforced curable resin linear material according to claim 5, wherein the impregnated resin is hardened by being guided to a tank. 7. A spacer for an optical fiber cable, comprising using the aramid fiber reinforced curable resin linear material according to claim 1 as a tensile strength member.