JPH03213520A - High-elastic modulus polyether imide fiber and its production - Google Patents

Abstract

PURPOSE:To obtain the subject fiber suitable as a substrate for printed boards, etc., by respectively and separately melting a thermoplastic polyether imide and a main chain type liquid crystal resin, joining both so that the main chain type liquid crystal resin may be present in a fibrous form in the polyether imide and discharging both the joined components from a spinneret. CONSTITUTION:The objective fiber, obtained by respectively and separately melting a thermoplastic polyether imide (preferably having a structural formula expressed by formula I) and a main chain type liquid crystal resin [preferably having a structural formula expressed by formula II (n1>=70), etc.], joining both so that the main chain type liquid crystal resin may be present in a continuous fibrous form (preferably >=10 fibrous substances having <=10mu diameter are present in the cross section) and discharging both the joined components from a spinneret and having at least the surface layer composed of the polyether imide at (10/90) to (80/20) weight ratio of the polyester imide/main chain type liquid crystal resin.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a polyetherimide fiber with a high elastic modulus and a method for producing the same, and more specifically to a polyetherimide fiber made of thermoplastic polyetherimide and a main chain type liquid crystal resin. The present invention relates to a high modulus composite polyetherimide fiber and a method for producing the same.

[Prior Art] Thermoplastic polyetherimide has extremely high heat resistance even though it can be thermoformed, and also has advantages such as high flame retardancy and UV resistance, and excellent dielectric properties. It is something. However, due to its low elastic modulus and low strength, it currently has little use as a fiber.

In order to eliminate such drawbacks of thermoplastic polyetherimide fibers, methods for producing polyetherimide fibers are described in JP-A-6.3-75712 and JP-A-1-132824. . However, the elastic modulus of such fibers is at most about 60 g/d, and
Its strength is also on the order of 4 g/d, and its use has been extremely limited, especially when used for materials, except in special cases.

[Problems to be Solved by the Invention] In view of the above-mentioned points, the object of the present invention is to provide a thermoplastic polyetherimide fiber with a high elastic modulus that can be widely used in various materials fields, and a method for producing the fiber. The goal is to provide the following.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present inventors have made extensive studies and have arrived at the present invention.

The present invention has the following configuration in order to solve the above problems.

That is, the polyetherimide fiber of the present invention is a polyetherimide fiber in which a thermoplastic polyetherimide component forms at least a surface layer portion, and a main chain type liquid crystal resin exists continuously in the fiber. It is a high elastic modulus polyetherimide fiber characterized by

Further, in the high elastic modulus polyetherimide fiber of the present invention, preferably, the polyetherimide is represented by the following formula, or alternatively, preferably, the polyetherimide and It is also characterized in that the weight ratio of the main chain type liquid crystal resin is (polyetherimide)/(main chain type liquid crystal resin) = 10/90 to 80/20.

Alternatively, preferably, in the polyetherimide fiber of the present invention, a main chain type liquid crystal resin exists continuously in a fibrous form in the fibrous polyetherimide component, and the main chain type liquid crystal resin The diameter of the fibrous material is 10μ
It is characterized by the following.

Alternatively, preferably, in the above-mentioned high elastic modulus polyetherimide fibers of the present invention, the main chain type liquid crystal resin is preferably liquid crystal polyester or liquid crystal polyester amide, or alternatively, the main chain type liquid crystal resin is preferably is a high elastic modulus polyetherimide fiber characterized by being one of those represented by the following formula, or alternatively, the main chain type liquid crystal resin has a number average molecular weight of 4.
It is more than 10,000.

However, nl〉(n2+n3) nl　≧70 n, +n2 + n3 = io.

In addition, the method for producing polyetherimide fibers of the present invention involves melt-molding polyetherimide and a main chain type liquid crystal resin independently, and then molding them so that the main chain type liquid crystal resin is an island component and the polyetherimide is the main chain component. The method is characterized in that the main chain type liquid crystal resin is merged into a sea component surrounding the type liquid crystal resin to form a composite flow in which the main chain type liquid crystal resin exists in the form of fibers in the polyetherimide, and then it is discharged from the spinneret for spinning. This is a method for producing high-strength polyetherimide fiber.

Alternatively, the polyetherimide and the main chain type liquid crystal resin are melt-molded independently, and then both are melt-molded so that the main chain type liquid crystal resin is the island component and the polyetherimide is the sea component surrounding the main chain type liquid crystal resin. to form a composite flow in which the main chain type liquid crystal resin exists in the form of fibers in polyetherimide,
This is a method for producing a high elastic modulus polyetherimide fiber, which is characterized in that the fiber is spun by being discharged from a spinneret, and then heat treated at a temperature of (melting point -70)C or higher of the main chain type liquid crystal resin.

Preferably, the method for producing high modulus polyetherimide fibers of the present invention is characterized in that the atmosphere for the heat treatment is an inert gas or a vacuum.

[Action Co. The present invention will be explained in more detail below.

According to the present invention, it is possible to easily produce polyetherimide fibers with a high elastic modulus that can be widely used for various materials such as tension members or base materials for printed circuit boards. is surprising.

The polyetherimide fiber of the present invention is made of thermoplastic polyetherimide and a main chain type liquid crystal resin.

First, polyetherimide will be described.

The polyetherimide resin that can be applied to the present invention is not particularly limited, and thermoplastic resins can be widely used. For example, polyetherimide described in JP-A-63-275712 and the like can be effectively used.

Such a polyetherimide component forms at least the surface layer of the polyetherimide fiber of the present invention, and if the component does not form the surface layer, the polyetherimide's major characteristic of durability is improved. It is unable to exhibit its characteristics such as chemical resistance, UV resistance, and easy adhesion.

In other words, when a main chain type liquid crystal resin constitutes the surface layer of polyetherimide fibers, the disadvantages of the main chain type liquid crystal resin, such as low resistance to ultraviolet rays, arise, and the characteristics of polyetherimide are lost. It is not preferable because it cannot be performed well.

Among such polyetherimides, those represented by the following formula are particularly preferred.

That is, such resins have great advantages such as excellent melt moldability, high heat resistance, and excellent electrical properties, and it is desirable to better bring these characteristics to the polyetherimide fiber of the present invention. It is something that can be done. The method for producing such a resin is not particularly limited, and any method can be widely applied.

The main chain type liquid crystal resin is not particularly limited and can be widely applied as long as it is a thermoplastic main chain type liquid crystal resin. That is, liquid crystal polyester, liquid crystal polyester amide,
Those made of liquid crystal polycarbonate, liquid crystal polyazomethine, etc. are widely applicable, and those shown in the following structural formula can be used.

2 4 15 to 1 Here.

X is hydrogen.

halogen.

carbon number 4 or less Represents an alkyl group.

7 8 19 Here, Σn,=100 in each structural formula. Particularly preferred are those in which n in each structural formula is 4 or more. Moreover, various substituents including halogen etc. may be added to each formula.

Particularly preferred are liquid crystal polyester and liquid crystal polyester amide.

Liquid crystalline polyester is particularly preferred because it is inexpensive and has high melt moldability, yet has high heat resistance, high strength and high modulus, and high chemical resistance.

Among these, those shown in the following formula are:
It is particularly preferred because it has high strength and high elasticity.

0 However, nl> (n2+n3) nl ≧70 n□ +n2 +n3 = 100 These materials have high melt formability and high strength, and also have high melting points and glass transition points, so they are particularly preferred. be.

Although such a main chain type liquid crystal resin is originally thermoplastic, it may be infusible after becoming a component of the polyetherimide fiber.

Next, when the polyetherimide fiber of the present invention is particularly required to have high strength and high elastic modulus, it is preferable that the number average molecular weight of the main chain type liquid crystal resin component is high to some extent. More preferably, the number average molecular weight is 18,000 or more. Particularly preferred is 40,000 or more. When the number average molecular weight of the main chain type liquid crystal resin reaches such a value, the strength, elastic modulus, and elongation will all be high. Therefore, the elastic modulus and strength of the polyetherimide fibers are also increased, which is preferable.

Although the polyetherimide fiber of the present invention includes these two types of polymers as essential constituent components, there is no problem in using other polymers as constituent polymers.

The polyetherimide fiber of the present invention is made of a combination of such polymers, and its form can be various, and is not particularly limited. Preferred are those that are substantially covered with polyetherimide, i.e., for example, the core
Preferably, the fiber is of a so-called polymer array type, in which a large number of islands are dispersed in a sheath or matrix polymer.

The main chain type liquid crystal resin is continuous within the polyetherimide. The continuous form is not particularly limited, but a particularly preferred form is a continuous fiber with a uniform shape in the longitudinal direction. If the main chain type liquid crystal resin has a continuous morphology and a uniform diameter,
Both the strength and elastic modulus of polyetherimide fibers become extremely high.

Further, the thickness of the main chain type liquid crystal resin component in the polyetherimide is not particularly limited. However, especially when polyetherimide fibers are to be made into fibers with stable strength, it is preferable that the fibrous material made of the main chain type liquid crystal resin component has a thickness (thinness) of 20 μm or less in diameter. More preferred is one with a diameter of 10μ or less. That is, if the diameter of the fibrous material made of the main chain type liquid crystal resin component dispersed in the polyetherimide fiber is small, the polyetherimide fiber can have high strength and high elastic modulus. In addition, the impact strength is particularly high. Moreover, the physical properties become stable.

In addition, the large number of continuous fibrous bodies made of main chain type liquid crystal resin dispersed in polyetherimide fibers means that
Since external force can be dispersed, physical properties more stable than those in 3 can be obtained, which is preferable.

Specifically, 3 per cross section of polyetherimide fiber
at least 5, particularly preferably at least 5, even more preferably at least 1
It is preferable that fibrous materials consisting of zero or more main chain type liquid crystal resins are dispersed. Further, it is preferable that the main chain type liquid crystal resin is highly oriented. Further, it is preferable that the elastic modulus is as high as possible.

The form of the polyetherimide fiber of the present invention is not particularly limited, and may have any shape, for example, a cross-section of a circle or a cross-section of a triangle. Further, the fineness is not particularly limited either.

Next, regarding the ratio of polyetherimide to main chain type liquid crystal resin, this value should also be selected appropriately depending on the purpose and use.

More preferably, the weight ratio of polyetherimide and main chain liquid crystal resin is (polyetherimide)/(
main chain type liquid crystal resin) = within the range of 10/90 to 80/20. If the amount of polyetherimide is less than the range 4, the properties of polyetherimide cannot be exhibited well, while if it is more than that, the elastic modulus tends to be low, and in either case, it is difficult to apply it to a wide range of fields. Become.

By adopting the above structure, the elastic modulus of the polyetherimide fiber obtained by the present invention can easily show a value of, for example, 90 g/d or more, and the polyetherimide fiber with such a high elastic modulus value can be easily obtained. The uses of etherimide fibers are greatly expanded. A more preferable elastic modulus is 100 g/d or more, and an even more preferable elastic modulus is 200 g/d or more, and according to the present invention, such a high-level elastic modulus can also be achieved satisfactorily. When a fiber exhibits such an elastic modulus value, its uses can be successfully expanded to include reinforcing materials that require light resistance, as well as base materials for printed circuit boards.

In addition, as an unexpected effect of the present invention, the fiber according to the present invention has the secondary effect of improving dimensional stability and achieving particularly good dimensional stability. For example, even if the temperature of the fiber of the present invention is increased or it is immersed in water, the dimensional change is extremely small.

Note that the polyetherimide fiber of the present invention may be made of only polyetherimide and a main chain type liquid crystal resin, but may also be made of other polymers, plasticizers, light stabilizers, antistatic agents, terminal stoppers, and fluorescent whitening agents. A flame retardant, an antiaging agent, etc. may be contained. Further, inorganic substances such as titanium oxide, iron oxide, carbon black, etc. may be contained as appropriate.

Furthermore, in order to improve the compatibility between the polyetherimide and the main chain type liquid crystal resin, it is particularly preferable to add a compatibilizer or to modify the polyetherimide and the main chain type liquid crystal resin.

Next, a method for producing the polyetherimide fiber of the present invention will be described.

That is, the polyetherimide and the main chain type liquid crystal resin are first melted independently, and then the polyetherimide surrounds the main chain type liquid crystal resin and are merged to form a sea component, whereby the main chain type liquid crystal resin is melted. A composite flow exists in the form of fibers in polyetherimide, which is then discharged from a spinneret, spun and wound.

Here, the specific method for combining the polyetherimide and the main chain type liquid crystal resin is not particularly limited, and any suitable method can be applied. Typical examples thereof include a core-sheath melt molding method, a so-called polymer array method, and a micro-division method using a static mixer. Particularly preferred are the so-called polymer array method and core-sheath melt molding method.

By using such a method, the main chain type liquid crystal resin component can be easily made to have a high elastic modulus, so that a polyetherimide fiber having a high elastic modulus can be obtained. Furthermore, since the ratio of polyetherimide and main chain liquid crystal resin is always constant down to the microstructure, highly reliable fibers can be produced.

When the fibers of the present invention are produced by melt spinning, they are preferably drawn at a speed of 50 m/min or more. This gives the fiber a higher modulus. Furthermore, applying an electric field or a magnetic field during melt spinning is also a particularly preferred method.

Composite melting of polyetherimide and main chain type liquid crystal resin 7. Melt spinning is based on the polymer species, die, surrounding atmosphere under the die, melting time,
Since it is subtly affected by the discharge speed, etc., it is important to set the conditions appropriately. That is, it is particularly effective to use a heating cylinder, a heat retaining cylinder, etc.

Further, according to the present invention, especially when a core-sheath melting method or a polymer array method is applied, since the melt spinning speed is increased, a polyetherimide fiber having a particularly high modulus of elasticity can be produced.

Note that the polyetherimide fibers may be subjected to dry cleaning treatment or various chemical treatments as necessary.

In addition, especially when a polyetherimide fiber with high elastic modulus and high strength is desired, the fiber thus obtained can be
The heat treatment is preferably performed for 0 minutes or more at a temperature of (melting point -70)C or higher of the main chain type liquid crystal resin. More preferably, the heat treatment is performed under a flow of an inert gas such as nitrogen or under vacuum at a temperature equal to or higher than the melting point of the main chain liquid crystal resin (-70°C). Further, by carrying out such treatment, the number average molecular weight of the main chain type liquid crystal resin is set to 40,000 or more. According to the findings of the present inventors, by doing so, both the strength and elastic modulus of the polyetherimide fiber can be dramatically improved.

The polyetherimide fiber of the present invention has characteristics such as high elastic modulus and high strength that conventional polyetherimide fibers do not have, so it can be used in a wide range of applications, such as for example.

That is, for example, high-strength reinforcing materials, reinforcing materials, reinforcing materials for optical fibers, window frame base materials, blind base materials, chemical-resistant materials, materials for parabolic antennas, weather-resistant reinforcing materials, fishing nets, binding materials, and concrete reinforcing materials. , marine concrete reinforcement,
Marine materials, helmet base materials, molding chips, high-strength molding chips, FRP, base materials for FRP, base materials for electrical insulation, base materials for printed circuit boards, ropes, protective materials, screen gauze, filters for chemicals, filters, Reinforcing materials for filters, base materials for mixed yarns with carbon fiber, etc., fire prevention materials, car materials, roofing materials, tents, temporary roofing materials, wall materials, desks, plywood facing materials, high-strength cloth, various Frames, bicycle base materials, etc., superconducting materials, cleaning brushes, gaskets, backing materials, filters for cartridges, paper making, shear fabrics for printing, etc., Demister-1 sliding members, skits,
It can be used for various purposes such as ski base materials.

[Example] Hereinafter, it will be explained in more detail with reference to Examples.

It goes without saying that the present invention is not limited to these Examples.

Example 1 A core-sheath composite polyetherimide fiber having a main chain type liquid crystal resin as an island component and polyetherimide as a sea component was produced as shown below.

A. Silk spinning conditions Sea component (polyetherimide): Polyetherimide (Ultem D, General Electret Company, USA)
5001) ■ Island component (main chain type liquid crystal resin): JP-A-62-3962
A main chain type liquid crystal polyester resin was produced according to the method described in Publication No. 2, particularly the method described in Example 2. The resin has a melting point of 291°C and a number average molecular weight of 1°60,000.

■ Island/sea (weight ratio) = 50150 ■ Number of islands - 1 ■ Spinning temperature = 355°C ■ Spinning speed = 550 m/min ■ Stretching ratio = None The oils used for spinning were silicone oil and alkyl phosphoric acid. It's potash.

B8 Characteristics of the obtained polyetherimide fiber ■ Fineness of polyetherimide fiber - 15 denier (hereinafter referred to as d) ■ Thickness (diameter) of high fiber = 27 μ ■ Elastic modulus = 310 g/d ■ Strength = 6 .1 g/d ■ Elongation -1.8% That is, as can be seen from these characteristic values, a polyether 1 imide fiber with an unprecedentedly high modulus of elasticity and high strength was obtained.

When this polyetherimide fiber was used as a tension member for optical fiber, it was very good.

Example 2 The fibers of Example 1 were washed with a trichloride solution to remove only the silicone oil, and then heated at 220°C at 4°C/hour for 2 hours.
When the temperature was raised to 70°C and heat treatment was performed at 270°C for 2 hours in a nitrogen stream, the elastic modulus was 470 g/d and the strength was 12 g.
/d, elongation of 2.4%, and a shrinkage rate of 0.1% or less even after free heat treatment in air at 250°C for 10 hours, which is an extremely high modulus and high strength polyether. We were able to obtain imide fiber.

The number average molecular weight of the main chain type liquid crystal resin of this fiber is 5.
It was 10,000.

Example 3 Polyetherimide fibers made of polymer array fibers were produced by spinning in the same manner as in Example 1 and heat-treating in the same manner as in Example 2.

2 A. Silk spinning conditions ■ Sea component: Same as Example 1 ■ Island component: Same as Example 1 ■ Island/sea (weight ratio) = 70/30 ■ Number of islands - 36 ■ Spinning temperature - 355°C ■ Spinning speed = 750 m/min ■ Stretching ratio = None The oil agent used was the same as in Example 1 - B. Characteristics of the obtained fiber ■ Fineness of polyetherimide fiber = 20 d ■ Thickness (diameter) of high fiber - 6 μ ■ Elastic modulus -640 g/d ■ Strength = 17 g/d ■ Elongation = 2.5% That is, as can be seen from these characteristic values, a polyetherimide fiber with a high elastic modulus and high strength, which has never been seen before, was obtained.

[Effects of the Invention] By adopting the structure of the present invention, the following great effects are brought about. According to the present invention, the polyetherimide fiber has high elastic modulus characteristics and can also maintain high strength. , polyetherimide fibers with very good mechanical performance can be obtained.

■According to the present invention, polyetherimide fibers having a high elastic modulus characteristic with an elastic modulus of generally 90 g/d or more can be obtained.
It can be expanded significantly compared to the conventional method, and is ideal for various industrial materials such as tension members and printed circuit board base materials.

(2) According to the present invention, polyetherimide fibers having various characteristics such as high weather resistance, high chemical resistance, high heat resistance, high electrical properties, and low water absorption can be obtained.

■According to the present invention, since the main chain type liquid crystal resin is continuous in the fiber, polyetherimide has extremely high dimensional stability against temperature and water absorption. Fiber can be obtained.

Claims (10)

[Claims] (1) A polyetherimide fiber in which a thermoplastic polyetherimide component forms at least a surface layer portion,
A high elastic modulus polyetherimide fiber characterized in that a main chain type liquid crystal resin exists continuously within the fiber. (2) The high elastic modulus polyetherimide fiber according to claim (1), wherein the polyetherimide is represented by the following formula. ▲Contains mathematical formulas, chemical formulas, tables, etc.▼ (3) The weight ratio of polyetherimide and main chain type liquid crystal resin is (polyetherimide)/(main chain type liquid crystal resin) = 1
A claim characterized in that the ratio is 0/90 to 80/20 (
The high elastic modulus polyetherimide fiber described in 1) or (2). (4) The main chain liquid crystal resin exists continuously in the form of fibers in the fibrous polyetherimide component, and the diameter of the fibrous main chain liquid crystal resin is 10μ or less. The high elastic modulus polyetherimide fiber according to claim (1), (2) or (3). (5) Claim (1) characterized in that the main chain type liquid crystal resin is liquid crystal polyester or liquid crystal polyester amide.
), (2), (3) or (4) the high elastic modulus polyetherimide fiber. (6) Claims (1) and (2) characterized in that the main chain type liquid crystal resin is one of those represented by the following formula.
), (3), (4) or (5) high elastic modulus polyetherimide fiber. ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ However, n_1>(n_2+n_3) n_1≧70 n_1+n_2+n_3=100 (7) Claims (1), (2), (3), (
4), the high elastic modulus polyetherimide fiber according to (5) or (6). (8) Polyetherimide and main chain type liquid crystal resin are melt-molded independently, and then both are formed so that the main chain type liquid crystal resin becomes an island component and the polyetherimide becomes a sea component surrounding the main chain type liquid crystal resin. A method for producing high-strength polyetherimide fiber, which comprises merging the two to form a composite flow in which a main chain liquid crystal resin exists in the form of fibers in polyetherimide, and then spun by discharging from a spinneret. (9) Polyetherimide and main chain type liquid crystal resin are melt-molded independently, and then both are formed so that the main chain type liquid crystal resin is an island component and the polyetherimide is a sea component surrounding the main chain type liquid crystal resin. The main chain type liquid crystal resin is merged to form a composite flow in which the main chain type liquid crystal resin exists in the form of fibers in polyetherimide, and then the main chain type liquid crystal resin is spun by being discharged from the spinneret.
A method for producing a high elastic modulus polyetherimide fiber, characterized by heat treatment at a temperature of melting point -70)°C or higher. (10) The method for producing a high elastic modulus polyetherimide fiber according to claim (9), wherein the heat treatment atmosphere is an inert gas or a vacuum.