JPH0741665A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition consisting of a specific crystalline copolyamide and a liquid crystal fiber, having low specific gravity and small coefficient of liner expansion as well as high heat distortion temperature, excellent in heat resistance and stiffness and useful for electrical and electronic parts, etc. CONSTITUTION:This composition is obtained by blending (A) 100 pts.wt. crystalline copolyamide consisting of (i) hexamethylene terephthalic amide unit of formula I and either one unit selected from the formula III to the formula IV, (ii) hexamethylene isophthalic amide unit and (iii) hexamethylene adipamide unit of formula III and (iv) a caproamide unit of formula IV and being in the range of a copolymerization wt. ratio of the component (i)/the component (ii) of (55/45) to (80/20) or the component (i)/the component (iii) of (20/80) to (80/20) or the component (i)/the component (iv) of (55/45) to (90/10) with (B) preferably 10-100 pts.wt. of liquid crystal fiber such as an aromatic polyamide, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyamide resin reinforced with liquid crystal fibers, and particularly to electric
The present invention relates to a thermoplastic resin composition suitable for electronic parts and automobile parts.

[0002]

2. Description of the Related Art Polyamides are widely used in the fields of automobiles, electric and electronic fields, etc. by utilizing their excellent properties as engineering plastics.

Conventionally, nylon 6 and nylon 66 reinforced with glass fibers have been used for these molded articles (Japanese Patent Laid-Open No. 59-161461), but the temperature rise in the engine room of automobiles due to recent technological innovations and With the progress of microelectronics, there has been a demand for materials for ultra-thin molded products that can withstand use in a higher temperature atmosphere. However, the melting points (Tm) of nylon 6 and nylon 66 are 220 ° C. and 260 ° C., respectively, and even when reinforced with glass fiber, the limits of the heat distortion temperature are only the melting points.

Recently, many copolyamide resin compositions containing terephthalic acid and isophthalic acid, or glass fiber reinforced products thereof have been proposed as copolyamide resin compositions that can withstand use under these high temperature atmospheres (special features). JP-A-59-161428 and JP-A-59-1554.
26, JP-A-59-53536, JP-A-6.
2-156130).

[0005]

However, these compositions have problems such as insufficient dimensional stability in a high temperature atmosphere and glass fiber reinforced products having a poor surface appearance and a large specific gravity. It was In particular, a composition having a small linear expansion coefficient and a low specific gravity is desired in order to solve these problems in a portion that comes into contact with metal or ceramics. Therefore,
An object of the present invention is to provide a polyamide composition having a low linear expansion coefficient, a high rigidity and a low specific gravity that can sufficiently withstand use in a high temperature atmosphere.

[0006]

In view of the above circumstances, the inventors of the present invention have made earnest studies on a method for solving the above-mentioned problems, and as a result, have found that a high-melting point polyamide is reinforced with a liquid crystal fiber having a low linear expansion coefficient so as to obtain a high temperature. The inventors have found that a polyamide composition having a low linear expansion coefficient, a high rigidity, and a low specific gravity, which can sufficiently withstand use in an atmosphere, can be obtained, and arrived at the present invention. That is, the present invention provides (1) a repeating unit (I) a hexamethylene terephthalamide unit represented by the following structural unit,

[Chemical 5] And any unit selected from the following repeating units (II) to (IV), (II) a hexamethylene isophthalamide unit represented by the following structure,

[Chemical 6] (III) a hexamethylene adipamide unit represented by the following structural unit,

[Chemical 7] (IV) a caproamide unit represented by the following structural unit,

[Chemical 8] And the copolymerization ratio is (I) / (II) = 55 by weight.
/ 45-80 / 20 or (I) / (III) = 20/8
0-80 / 20 or (I) / (IV) = 55 / 45-9
A thermoplastic resin composition comprising a crystalline copolyamide in the range of 0/10 and liquid crystal fibers.

The crystalline copolyamide of the present invention is any one selected from (I) hexamethylene terephthalamide unit, (II) hexamethylene isophthalamide unit, (III) hexamethylene adipamide unit and (IV) caproamide unit. And a copolymerization ratio of (I) / (II) is 55/4 by weight.
The copolymerization ratio of 5 to 80/20 (hereinafter referred to as 6T / 6I copolyamide) or (I) / (III) is 2 by weight.
0/80 to 80/20 (hereinafter referred to as 6T / 66 copolyamide). Alternatively, the copolymerization ratio of (I) / (IV) is in the range of 55/45 to 90/10 (hereinafter referred to as 6T / 6 copolyamide) in weight ratio.

According to the present invention, the copolymerization ratio of 6T / 6I is 55 / 45-80 / 20, preferably 60 / 40-8.
It should be 0/20, more preferably 60/40 to 75/25. Further, the copolymerization ratio of 6T / 66 is 20/80 to 80/20, preferably 30/70.
~ 70/30, more preferably 30/70 to 60/40
Must be within the range. The copolymerization ratio of 6T / 6 is 55/45 to 90/10, preferably 60/4.
0-85 / 15, more preferably 60 / 40-80 / 2
It must be in the 0 range. 6T / 6 here
The copolymerization ratios of I, 6T / 66 and 6T / 6 copolyamide relate to crystalline copolyamides having a polymer melting point in the range of approximately 270 ° C to 340 ° C. 6T /
When the copolymerization ratios of 6I, 6T / 66 and 6T / 6 are less than 55/45, 20/80 and 55/45, respectively, the polymer melting point is lowered, so that heat resistance such as heat distortion temperature is lowered, which is preferable. Absent. Also, 6T / 6I, 6T
The copolymerization ratios of / 66 and 6T / 6 are 80/2, respectively.
When it is more than 0, 80/20, 90/10, the melting point of the polymer becomes high and the heat resistance is improved, but the processing temperature becomes high and the polymer is thermally decomposed, which is not preferable. The degree of polymerization of the crystalline copolyamide is not particularly limited, and the relative viscosity (ηr) of a 1% sulfuric acid solution at 25 ° C. is usually 1.8 to 5.
Those at 0 can be used arbitrarily.

Any method may be used to polymerize the crystalline copolyamide of the present invention. For example, a method of producing the crystalline copolyamide in a single stage in a polymerization reaction tank and a method of forming a primary condensate in the polymerization reaction tank and then obtaining a high degree of polymerization There is a method of manufacturing in two steps. From the thermal stability of the crystalline copolyamide, the two-stage production method is preferable.

In the one-stage production method of the present invention, an aqueous solution of the above-mentioned monomer or salt is charged into a pressure polymerization kettle usually used for polymerization of nylon 66 and the like, and the mixture is stirred under a stirring condition of 150.
Heat to ℃ ~ 350 ℃. The reaction temperature is 150 ° C to 350
℃ is preferred, more preferably 180 ℃ ~ 340 ℃,
More preferably, it is 190 ° C to 330 ° C. When the reaction temperature is lower than 150 ° C., the reaction time becomes long, which is not preferable, and when the reaction temperature is higher than 350 ° C., foaming due to thermal decomposition of the crystalline copolyamide is not preferable. The pressure during polymerization is usually 0 to 100 kg / cm ² -G
To be operated.

In the two-stage production method of the present invention, a primary condensate which can be formed at the initial stage of the above polymerization conditions can be used. The pressure during polymerization is usually 0 to 100 kg / cm.
^2- G, preferably ^{2 to} 70 kg / cm ² -G, more preferably 5 to 60 kg / cm ² -G. Discharging is preferably performed under steam pressurization. The water vapor pressure is not particularly limited, but preferably exceeds 0 to 7
0 kg / cm ² -G range, more preferably 2-60 k
g / cm ² -G, more preferably 5 to 60 kg / cm
Operated to keep at ^2- G. The steam pressure is preferably maintained during discharge, and it is preferable to supply water or steam into the polymerization tank and maintain a constant steam pressure during discharge, or discharge while increasing the pressure. From outside the system
When supplying water, preferably ion-exchanged water, into the polymerization tank with a metering pump, it is preferable to preheat and supply water via a heat exchanger. The heating temperature is preferably 100 ° C or higher, more preferably 150 ° C or higher. The heating temperature is
The saturated steam temperature of the pressure in the polymerization tank is more preferable for maintaining the stability of the polymerization state. Further, when steam is supplied from outside the system into the polymerization tank, the boiler for steam generation needs to be higher than the pressure in the polymerization tank. The relative viscosity (ηr) of the primary condensate is preferably 1.04 to 2.5, more preferably 1.08 to 2.3, and further preferably 1.08 to 2.1. preferable. When the relative viscosity (ηr) is less than 1.04, the polymerization time for increasing the degree of melt polymerization is unfavorably long. The apparatus for producing the primary condensate is not particularly limited, and a known apparatus such as a batch reaction kettle or a 1- to 3-tank continuous reaction apparatus can be used.

As a method for increasing the degree of polymerization of the primary condensate, a method using a melter, a method of solid phase polymerization, a melter,
A method of using a solid phase polymerization machine in combination can be used.
When using a melting machine, the melting temperature is preferably in the range of 10 to 70 ° C. higher than the melting point of the primary condensate. When using a primary condensate having a high 6T content and a high melting point, it is necessary to set the upper limit temperature to 370 ° C. or lower in order to prevent thermal decomposition and thermal deterioration of the polymer. As the melt extruder, an extruder and a kneader can be used, but a twin screw extruder and a twin screw kneader are preferable. The residence time in the melting machine is not specified,
It is preferably 20 seconds or longer, particularly preferably 30 seconds or longer. If the residence time is short, the degree of polymerization cannot be effectively increased, which is not preferable. It is also effective to connect two or more melters in series in order to increase the residence time and increase the degree of polymerization. The phosphorus-based catalyst is effective for increasing the degree of polymerization, and may be added if necessary. If necessary, the polymer having a high degree of polymerization can be solid-phase polymerized to further increase the degree of polymerization.

As a method for solid-phase polymerization of the primary condensate of the present invention, a method of applying pressure or normal pressure in the presence of an inert gas,
Alternatively, a method under reduced pressure, or a combination thereof may be used. The solid-state polymerization temperature is required to be 150 ° C to the melting point or lower, preferably 200 ° C to
Melting point -10 ° C, more preferably 220 ° C to melting point -15
℃. If the solid phase polymerization temperature is lower than 150 ° C., the reaction rate becomes slow, which is not preferable. The solid-phase polymerization time can be arbitrarily selected until the relative viscosity of the copolyamide used for ordinary molded articles is reached. The solid-state polymerization apparatus of the present invention is not particularly limited, and any known method can be used. Specific examples of the solid-state polymerization apparatus include a kneader, a twin-screw paddle type, a tower type, a rotating drum type, and a double-cone type solid-state polymerization apparatus.

In ordinary polyamide polymerization, the total amount of COOH groups and total NH ₂ contained in the monomer and salt are
It is common to charge the raw material so that the amount of the base is equal, but in the present invention, the dicarboxylic acid component or the diamine component is excessive during the charge of the raw material, and the crystallinity of the amount of the terminal carboxyl group or the amount of the terminal amino group is large. Copolyamides can also be made. The amount of excess dicarboxylic acid or diamine added is 0 to 10 mol%, preferably 0.3 to 10 mol%,
It should be more preferably 0.3 to 8 mol%, and even more preferably 0.5 to 7 mol%. Addition amount is 1
If it exceeds 0 mol%, it becomes difficult to increase the degree of polymerization, which is not preferable. Further, in the polymerization reaction of the present invention, it is effective to add a polymerization degree modifier in order to facilitate the control of the degree of polymerization of the crystalline copolyamide and the degree of polymerization at a high degree of polymerization. As the polymerization degree regulator, monoamine compounds and monocarboxylic acid compounds are usually used, but acetic acid, benzoic acid and stearic acid are preferable, and acetic acid and benzoic acid are particularly preferable. The degree of polymerization modifier is 0 to 0.1 times, preferably 0.00 times the total number of moles of the constituent monomer and the dicarboxylic acid component unit and the diamine component unit of the salt.
It is used in an amount of 01 to 0.05 times.

The liquid crystal fibers of the present invention may be solution liquid crystal fibers or molten liquid crystal fibers. Solution liquid crystal fibers include aromatic polyamide, aromatic polyazomethine, aromatic polyimide, and the like, and are fibers produced from a polymer that exhibits liquid crystal in a constant concentration region of a solution. On the other hand, as the fused liquid crystal fiber, there is an aromatic polyester, which is a fiber produced from a polymer in which the melt exhibits liquid crystal at a certain temperature or higher. The composition (weight ratio) is, for example, polyethylene terephthalate / p-hydroxybenzoic acid (HBA) =
60/40 to 10/90, Hydroquinone carboxybenzene propionate / HBA = 10/90 to 50 /
50, HBA / 6-hydroxy-2-naphthoic acid = 85
/ 15 to 60/40, phenylhydroquinone-terephthalic acid / HBA = 100/0 to 60/40, and the like.

The liquid crystal fiber of the present invention may be used as it is or may be surface-treated before use. As the surface treatment agent, a commonly used known surface treatment agent can be used. For example, compounds such as epoxy compounds, isocyanate compounds, silane compounds and titanate compounds can be used. As a method of surface treatment, a surface treatment agent may be applied to the liquid crystal fibers in advance or added at the time of kneading.

There is no particular limitation on the method for blending the crystalline copolyamide with the liquid crystal fiber in the present invention, and any known method can be used. A specific example of the compounding method is a method in which liquid crystal fibers are dry blended with crystalline copolyamide pellets and melt-kneaded with a single-screw or twin-screw extruder.
When the polymerization degree is increased in the melting machine, the method of adding the liquid crystal fibers from the middle of the melting machine is preferable because of high production efficiency. The diameter of the liquid crystal fiber is not particularly limited, but it is preferably about 0.1 to 20 μm, and the fiber length may be in the range in which it can be blended.
It is preferably about 0.1 to 20 mm. The mixing ratio of the liquid crystal fibers is more than 0 and 200 parts by weight, preferably 10 to 100 parts by weight, based on 100 parts by weight of the crystalline copolyamide. Furthermore, from the viewpoint of the morphology of the composition, the temperature during compounding is preferably higher than the melting point of the crystalline copolyamide and lower than the melting point of the liquid crystal fiber.

A filler can be further added to the polyamide resin composition obtained in the present invention. What is a filler?
Fiber or beads made of glass, talc, kaolin, wollastonite, mica, silica, alumina, diatomaceous earth, clay, gypsum, red iron oxide, graphite, titanium dioxide, zinc oxide, copper, stainless powder, etc. It is a compound, other polymer fiber (carbon fiber), etc., and preferably glass fiber. Particularly preferred as glass fibers are glass rovings, glass chopped strands, glass yarns and the like made from strands of continuous long fibers having a diameter of about 3 to 20 μm. The blending ratio of such a filler is usually in the range of 0 to 200 parts by weight, preferably more than 0 and 150 parts by weight, particularly preferably 10 to 100 parts by weight based on 100 parts by weight of the polyamide.
Parts by weight. When the blending ratio of the filler exceeds 200 parts by weight, the fluidity at the time of melting is deteriorated, it is difficult to injection-mold a thin-walled molded product, and the appearance of the molded product is deteriorated, which is not preferable.

There is no particular limitation on the method of adding the filler to the crystalline copolyamide of the present invention, and any known method can be used. Specific examples of the compounding method include a method in which a crystalline copolyamide pellet is dry-blended with a filler at the same time as liquid crystal fibers, and this is melt-kneaded with a single-screw or twin-screw extruder. Further, when the polymerization degree is increased by the melting machine, the method of adding the filler from the middle of the melting machine is preferable because of high production efficiency.

In the present invention, a catalyst, a heat resistance stabilizer, a weather resistance stabilizer, a plasticizer, a release agent, a lubricant, a crystal nucleating agent, etc. may be used in the melt polymerization, the high degree of polymerization of the melt, the compound or the molding step, etc. Pigments, dyes, other polymers and the like can be added. These additives include heat-resistant stabilizers (hydadephenol-based, hydroquinone-based, phosphite-based and substitution products thereof, copper iodide, potassium iodide, etc.), weather-resistant stabilizers (resorcinol-based, salicylate-based, benzoic acid-based Triazole-based, benzophenone-based, hindered amine-based, etc., mold release agents and lubricants (montanic acid and its salts, its esters, its half esters, stearyl alcohol, stearamide, various bisamides,
Bisurea and polyethylene wax), pigments (cadmium sulfide, phthalocyanine, carbon black, etc.), and dyes (such as nigrosine), other polymers (other polyamides, polyesters, polycarbonates, polyphenylene ethers, polyphenylene sulfides, liquid crystal polymers, poly Ether sulfone, ABS resin, SA
N resin, polystyrene, acrylic resin, polyethylene,
Polypropylene, ethylene / α-olefin copolymer,
Ionomer resin, SBS, SEBS, etc.) can be mentioned.

From the viewpoint of productivity, it is more preferable that the compounding of the additive is carried out simultaneously or continuously with the increase in the degree of polymerization in the melting machine.

Addition of an antioxidant is effective for improving the color tone of the polyamide resin, and addition of sodium hypophosphite and a hindered phenol type antioxidant is particularly preferable. Sodium hypophosphite is also effective in promoting a high degree of polymerization of the primary condensate.

The thermoplastic resin composition of the present invention is used in switches, micro slide switches, DIP switches, switch housings, lamp sockets, binding bands, connectors, connector housings, connector shells, IC sockets, coil bobbins, Bobbin cover, relay, relay box, condenser case, motor internal parts, small motor case, gear cam, dancing pulley, spacer, insulator, fastener, buckle, wire clip, bicycle wheel, caster, helmet, terminal block, electric Tool housing, starter insulation, spoiler, canister, radiator tank, chamber tank, reservoir tank,
Fuse box, air cleaner case, air conditioner fan, terminal housing, wheel cover, intake / exhaust pipe, bearing retainer, cylinder head cover, intake manifold, water pipe impeller, engine roll damper, clutch release, speaker diaphragm, heat resistant container, microwave oven Parts, rice cooker parts, printer ribbon guides, double-sided adhesive tape between IC chips, electric / electronic-related parts such as double-sided adhesive tape between IC and leads, automobile / vehicle related parts, household /
It is effective for office electrical product parts, computer related parts, facsimile / copier related parts, machine related parts, and other various applications.

[0024]

The present invention will be described in more detail with reference to the following examples. The properties in the examples and comparative examples were measured by the following methods.

1) Melting point (Tm) Samples 8 to 10 using DSC (PERKIN-ELMER7 type)
Let (T) be the temperature at which the maximum value of the melting curve obtained by measuring mg at a heating rate of 20 ° C./min. Sample 8-
10 mg is heated at a temperature rising rate of 20 ° C / min to T + 20 ° C.
For 5 minutes, then at a temperature decrease rate of 20 ° C / min for 3 minutes.
After cooling to 0 ° C and holding at 30 ° C for 5 minutes, 20
Heat up to T + 20 ° C. at a heating rate of ° C./min. The maximum value of the melting curve at this time was defined as the melting point (Tm).

2) Relative Viscosity (ηr) According to JIS K6810, 1 g of the sample was dissolved in 100 ml of 98% concentrated sulfuric acid, and the relative viscosity at 25 ° C. was measured.

Example 1 Hexamethylene ammonium adipate (66 salt) 9.
00 kg, 6.72 kg of terephthalic acid, 7.02 kg of a 64.5 wt% aqueous solution of hexamethylenediamine and 6.40 kg of ion-exchanged water were charged into a 0.10 m ³ batch type pressure polymerization kettle (diamine component unit and dicarboxylic acid component unit). (1 mol% terephthalic acid was added to the total number of moles of the above), nitrogen replacement was sufficiently performed, and then heating was continued. The temperature was raised to 255 ° C. over 3.5 hours with stirring, and the polymerization pressure was 40 kg / cm ² -G. The reaction was completed by maintaining the temperature at 255 ° C to 260 ° C for 30 minutes. The discharge was performed over 1 hour while supplying ion-exchanged water by a metering pump at a rate of 3 l / h and maintaining the water vapor pressure at 40 kg / cm ² -G. The viscosity of this primary condensate is ηr
= 1.3, melting point was 287 ° C. primary condensation product. After vacuum drying the obtained primary condensate at 100 ° C. for 24 hours,
A 30 mmφ bent type twin-screw extruder has a residence time of 200 seconds,
The maximum degree of resin temperature was 325 ° C, and the degree of polymerization was increased by melting. White pellets having a polymer viscosity ηr = 2.5 and a polymer melting point of 298 ° C. were obtained. The discharge of the primary condensate was stable, and finally a high molecular weight (ηr), high melting point polyamide (polyamide 1) could be obtained. The results are shown in Table 1.

Polyamide 1 and Kevlar 29 (Type 97
0, chopped fiber, 13 mm cut) (fiber a) and then mixed with a 30 mmφ bent type twin screw extruder for a residence time of 1
The mixture was kneaded for 00 seconds at a maximum resin temperature of 315 ° C. Table 2 for physical properties
Shown in.

Example 2 8.76 kg of terephthalic acid, 8.93 kg of a 64.5 wt% aqueous solution of hexamethylenediamine, 6.00 kg of ε-caprolactam and 6.66 kg of deionized water were added.
The mixture was charged into a 10 m ³ batch-type pressure polymerization kettle (2 mol% terephthalic acid was excessively charged relative to the total number of moles of the monomer, dicarboxylic acid component and diamine component), nitrogen substitution was sufficiently performed, and heating was continued. 2 for 5 hours under stirring
After the temperature was raised to 70 ° C. and the polymerization pressure was 40 kg / cm ² -G, the reaction was further completed at 270 ° C. to 275 ° C. for 30 minutes. The ion pumped water is discharged by a metering pump for 2
It is supplied at a rate of 1 / h and the steam pressure is 45 kg / cm ² −.
It was carried out for 1 hour while being kept at G. The melting point of the obtained primary condensate was 300 ° C., and ηr was 1.5. This primary condensate was melt-polymerized to a high degree of polymerization by the method of Example 1 except for the conditions shown in Table 1. The discharge of the primary condensate was stable, and finally a high molecular weight (ηr), high melting point polyamide (polyamide 2) could be obtained. The results are shown in Table 1.

Polyamide 2 and Kevlar 29 (Type 97
0, chopped fiber, 13 mm cut) (fiber a) and then mixed with a 30 mmφ bent type twin screw extruder for a residence time of 1
The mixture was kneaded for 00 seconds at a maximum resin temperature of 315 ° C. Table 2 for physical properties
Shown in.

Examples 3-6 Polyamides 1, 3-5 were polymerized according to the method of Example 1. The results are shown in Table 1.

Polyamides 1, 3 to 5 and fiber a or Vectran (1500d / 300f, 6 mm cut) (fiber b) were kneaded according to the method of Example 1. The physical properties are shown in Table 2.

In each of the methods of Examples 1 to 6, a high melting point polyamide resin composition having low specific gravity, high rigidity and low linear expansion coefficient was obtained.

Comparative Example 1 Nylon 66 (CM3001N, Toray Industries, Inc.) and Kevlar 29 (Type 970, chopped fiber, 13 mm cut) (fiber a) were mixed and then retained in a vented twin-screw extruder having a diameter of 30 mm. Kneading was performed for 100 seconds at a maximum resin temperature of 285 ° C. The physical properties are shown in Table 2. The composition obtained had low heat distortion temperature and tensile strength.

Comparative Example 2 Polyamide 1 polymerized according to the method of Example 1 and glass fiber (diameter 13 μm, length 3 mm) were mixed, and then 30 mm
The mixture was kneaded with a φ-vent type twin-screw extruder at a residence time of 100 seconds and a maximum resin temperature of 315 ° C. The physical properties are shown in Table 2. The obtained composition had a high heat distortion temperature, but had a large specific gravity,
It had a large linear expansion coefficient in the direction perpendicular to the machine.

[0036]

[Table 1]

[0037]

[Table 2]

[0038]

EFFECTS OF THE INVENTION The thermoplastic resin composition obtained by the present invention has not only high rigidity and high heat distortion temperature, but also low specific gravity and small linear expansion coefficient.
Suitable for automobile parts.

Claims (1)

[Claims] 1. (1) Repeating unit (I) Hexamethylene terephthalamide unit represented by the following structural unit: embedded image And any unit selected from the following repeating units (II) to (IV), (II) a hexamethylene isophthalamide unit represented by the following structural unit, and (III) a hexamethylene adipamide unit represented by the following structural unit: (IV) a caproamide unit represented by the following structural unit: And the copolymerization ratio is (I) / (II) = 55 by weight.
/ 45-80 / 20 or (I) / (III) = 20/8
0-80 / 20 or (I) / (IV) = 55 / 45-9
A thermoplastic resin composition comprising a crystalline copolyamide in the range of 0/10 and liquid crystal fibers.