JPH02503449A - Densified carbon fiber structure - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Densified carbon fiber structure The present invention provides a first plurality of non-combustible non-linear elastic extensible substantially irreversible heat-setting materials. carbonaceous polymer fibers, and combining the fibers with second fibers of carbonaceous polymer precursor material. intertwining together and then heat treating the entire structure to heat set the second m fibers. The present invention therefore relates to a method for manufacturing a fibrous structure.

The fibrous material of the present invention has utility in thermal and/or soundproofing applications and filtration. Two. These structures are preferably f! ＃Reduced and with good shape and shape Structurally stable with multiple compression and load release cycles. be. These structures with relatively high # densification (compared to non-structures) It has an amazingly smooth appearance and fibers with very little breakage.

This large number of carbonaceous fibers can be used as wool-like fimbriae, felts, webs, and blankets. , used to make batting, etc., and these fibers were later referred to as ``fibrous structures''. It is called. When the fibrous structure is densified by the attachment of the second wI fiber, its The structure is here called "Kr11 densified fiber structure" or simply "densified structure". Ru.

The term "planting" as used here generally refers to the tangle and intermixing of fibers. A method of joining or intertwining with each other. Preferably, the fibrous quality of the first fiber The structure is the second WI! , tangle them together by sewing them together.

For many high temperature insulation applications, highly densified fibrous structures (i.e. wool ciliary material or batting) that is exposed to high temperatures over long periods of time. It is desirable to preserve its integrity and its density.

Densified structures are useful at high temperatures above 400°C and have good mechanical and physical properties. maintain the same value.

The non-flammable non-linear elastic carbonaceous fiber suitable for manufacturing the fibrous structure of the present invention is patented in Europe. No. 0199567 (issued on October 29, 1986; name of invention Carbona ceousFibers with Spring-Like Reversi ble Deflection and Method of Manufacture ure; inventor Matsukaran et al.). Before the present invention, the above nonlinear Permanently densifying a fibrous structure of carbonaceous fibers and creating a densified fibrous structure It was not possible to maintain the integrity of the material at temperatures above 400°C.

The above carbonaceous polymer material (non-flammable p-aramid fiber) is Fibers made from (including) decompose and the fibrous structure loses its integrity. .

Therefore, it is permanently dense with polymer fibers that do not lose their physical structure at elevated temperatures. Scales that retain their fibrous structure are quite advantageous.

U.S. Patent No. 4,623,846 (inventor Pyves) describes the method for manufacturing the fibrous structure of the present invention. It describes equipment that can be used to create

The present invention provides a large number of non-combustible, non-linear, substantially irreversibly heat-set and elastic Deflection ratio greater than L2:1 and length and width greater than JO:1 for shape reproducibility and extensibility a first carbonaceous polymer fiber having a ratio of at least one second material attached to form an intertwined fibrous structure; Substantially irreversibly fixed carbonaceous chilimer T#L fiber, yarn or tow The present invention relates to a fibrous structure containing 1# mold.

Preferably, the present invention provides that the first carbonaceous M&fiber has a sinusoidal or coiled form. , a wool-like fluffy material with a non-woven fibrous structure, a batting casing or a small amount of web. in the form of at least one layer, and a second carbon fiber, yarn or tow is linear or or a non-linear morphology and a higher denier than the first carbonaceous fiber. Found in fibrous structures.

Advantageously, the second intertwining carbon fibers are the first carbon fibers of the fibrous structure. chemically similar to or the same as fibers.

The present invention further relates to a dense synthetic fiber ornamental structure having a bulk density of 4.8 to 32 to 97 m''. do.

The present invention also provides a plurality of non-flammable, non-linear, substantially irreversibly heat-set first Relating to a method for manufacturing a fibrous structure from carbonaceous polymer fibers, the method comprises: a second carbonaceous polymer fiber, yarn or The process of planting the tow or tow in an intertwined relationship with the first fiber and then this fiber. The fibrous structure is heated in an inert atmosphere to form the intertwined second fibers, yarns. The method includes a step of heat-setting the tow or tow.

The inventive method also includes incubating the fibrous structure of the first fiber with a needle, for example. a second carbonaceous polymer precursor fiber of large diameter that has high shear resistance to punching operations; allows for blending with fibers. Carbon fibers with a relatively large denier are It can also provide great mechanical strength.

According to a preferable M of the present invention, a heat-set non-linear carbonaceous polymer fiber of Ml Needed by a second fiber, yarn or tow made from a carbonaceous precursor material The bulk, M degree and mechanical strength of the fiber 5i structure are Increase degree. The needle bunch creates loops in the second fiber in the fibrous structure. let

Textile IIF fabrication processing creates hooks in the loop seams.

Also has a felt-like feel and appearance after heat treatment using advanced needle punching. It is possible to create two densified structures.

According to a further aspect of the invention, two or more fibrous structures, e.g. Can be joined together. one batting from the other balatigue It can be used as an Il fiber for interlacing.

The first carbonaceous fiber preferably has a sinusoidal or coiled configuration or It has a complex structural combination. These first fibers are linear heat-set It may also contain carbonaceous polymer fibers.

The carbonaceous fibers used in this invention have a carbon content of at least 65 inches and between 5 and 35 inches. It has a nitrogen content. These fibers are characterized by their degree of carbonization and and/or its electrical conductivity.

The first carbonaceous fiber or fiber matrix is a suitable stabilized carbonaceous polymer precursor. Body vL: for example a stabilized polyacrylonitrile (PAN) based material, or pitch-based substances, i.e. substances derived from petroleum or coal tar pitch; or other polymers that can be converted into non-combustible, heat-stable carbon fibers or fibers. remer materials, produced by heat treating such derived carbonaceous precursor materials. It will be done.

For example, in the case of PAN-based fibers, these fibers are dissolved in a suitable fluid of precursor material. Manufactured by melt or wet spinning, with nominal diameters ranging from 4 to 25 microns. Two.

These cage fibers were collected as an aggregate of many carbon 5i filaments in the form of a tow. , PAN-based thermal fibers are stabilized by conventional methods. stabilized fibers, Tow or stable yarn (made from cut or stretch-broken fiber samples) This warm pheasant, tow, or yarn is then turned into a textile or cloth. Therefore, it can be formed into a coiled and/or sinusoidal shape (other fabric forming methods and It will also be appreciated that coil forming methods may also be used).

The fabric or playback produced in this way is then relaxed or unstressed. In the shape M, heat treatment is performed at a temperature of 525 to 750°C in an inert atmosphere for a period of time. host a thermally induced thermosetting reaction and perform additional cross-linking and/or cross-chain cyclization reactions. occurs between the original polymer chains.

At low temperatures of 150-525°C2, the fibers undergo various degrees of temporary fixation to permanent fixation. Although fixation at a constant temperature is imparted, at high temperatures of 525-750℃, the fiber is provided with a form of substantially permanent or irreversible heat setting.

The term "permanent" or "irreversible heat set" means that the non-linear fibers are Once stretched into a substantially linear shape without exceeding its strength, It means that it has irreversibility to the extent that it returns to its original non-possessed shape when released. the above The heat-treated fibers can be drawn into a substantially linear shape while also being stressed When released, it returns to its original non-stretched, non-linear configuration. Such spreading of fibers Stretching can be done for many cycles without damaging the ia fibers. and the additional tension (without exceeding the tensile strength of the fiber) K11 The same is true even when added to fibers in the l-shaped configuration 11.

The coiled and/or sinusoidal fibers are in a relaxed or unstressed state 'BK and unstressed. If the heat treatment is carried out while under an active non-oxidizing atmosphere, the fibers It should of course be understood that heat treatment at temperatures in the high temperature range may be used. 525 Permanently fixed sinusoids or coils as a result of high temperature treatment in the range ~750℃ The le-shaped form is m! ! ,) attached to one or yarn. Raw material with non-linear structural morphology fibres, tows or yarns (which may be derived by loosening knitted fabrics) is subjected to other processing methods known in Chinese cabbage technology to open the fibers, i.e. to make cloth tows. or the fibers are separated into tangled wool-like fluff*'ti, and the individual fibers are separated into their coils. We have created a method that yields a fairly bulky fibrous structure that retains the shape or sinusoidal morphology. can be done.

For example, after knitting, the temperature is 525℃ or higher without applying relaxed stress. Stabilized fibers permanently fixed in the desired structural form by heating at temperatures Retains properties of elasticity and reversible deflection. Use high temperatures up to approximately 1500℃ However, when carding fibers to create a fluffy material, the most flexible Fiber breakage loss of some fibers and fibers heat treated to a temperature of 525-750℃ It should be understood that it is found in

The second carbon material ll1m used in the present invention is the 11I1. maintenance including fibers that can be intertwined with and can withstand the high temperatures mentioned above. . The second fiber can be derived from another yarn and is a fiber of the adjacent batting. or may be blended with the first fiber to form a wool-like fluff or can be used for densification, even if it can form a pat. Wear.

Preferably, the 21st/lt fiber for entanglement has the same or similar safety as the first fiber. The carbonaceous polymer precursor material can be manufactured from a standardized carbonaceous polymer precursor material. For example, The stabilized precursor material is a PAN or pitch based material (e.g. petroleum or coulter). ) or other high temperature, thermally stable polymeric materials of interest as described above. For example, aramid fiber% and aromatic polyaramid, such as KEYLAE Dupont or Nemours & Co., Inc. ).

The PAN base material is collected as an aggregate of continuous filament tows of a number of base fibers and is It can be stabilized by oxidation in a method. Stabilized second fiber, Touma or staple yarn (cut or stretch-broken fiber staples) to form a fibrous structure or densify the first carbonaceous fiber by the method of the present invention. Can build structures.

When planted in a carbon fiber structure, the second carbon fiber is permanently heat-set. The fibers can be mixed into the structure as linear or non-linear fibers prior to fabrication.

The second non-linear fibers are heated in an inert atmosphere at a temperature range of 150-525°C. The fibers are temporarily heated by heat treatment in a relaxed or unstressed state. By giving a fixation, the 11th! can be manufactured in the same way as . These fibers exhibit varying degrees of temporary stiffness with increasing temperature over a specific temperature range. Fixations ranging from fixed to permanent are granted. These ll! The fibers are then intertwined. After the welding process, permanent Fixed. Preferably, the heat treatment is performed at a temperature of 525° C. or higher to achieve a 1 RaK lifetime. Give it a long-lasting fix.

When the second carbonaceous fiber is permanently heat set, the combination of the first and second carbonaceous fibers Integrity and handling properties are imparted to the fibrous structure formed by the lamination.

As with the first fiber, temperatures up to about 1500°C are used to permanently set the second fiber. However, the most flexible and least fiber breakage loss is 525- It is found in fibers heat treated to temperatures of 750°C.

Intertwined fibrous structures are used for high temperature insulation and sound absorption, and are can be classified into three groups depending on the specific application and environment in which it is incorporated. Wear.

In the first group, the carbon fibers used in the fibrous structure of the present invention are electrically It is essentially non-conductive. Non-conductive means that each has a diameter of 7 to 20 microns. 6. Resistance greater than 4 x 10' ohms 15+ when measured on the fibers of the tow Applies to anti-nine. The specific resistance of each fiber is greater than approximately 102 ohms/cm. Hey.

In the second group, the carbonaceous fibers used in the fibrous structure of the present invention are partially are classified as electrically conductive (i.e. have low electrical conductivity) and are with a carbon content of less than %. The precursor stable fiber is an acrylic fiber, i.e., a pAN-based fiber. When it is fiber, the nitrogen content is between 5 and 35 inches, preferably between 16 and 20 inches. these The partially electrically conductive fibers are used as insulation in aerospace vehicles as well as for public safety. Iil in the area of interest! ! K is excellent for use as a border. child These structures are lightweight, with low moisture absorption and good abrasion strength. It has a good appearance and ease of handling.

The higher the carbon content in the carbonaceous fiber, the higher the electrical conductivity. Such fibers are Especially when formed into a dense structure, most of the fibers are non-linear or coiled. still retains a cool appearance. In addition, the coiled fibers in the structure The larger the value, the greater the elasticity of the structure.

manufactured using these partially conductive fibers as a result of their high carbon content The structure is also thicker in sound absorption (and provides a more effective thermal barrier at high temperatures).

These fibers are 6K) where each fiber has a diameter of 7 to 20 microns. 4x10’ to 4XIO” ohms/cIII voltage when measured on one fiber. Has air resistance.

The third group is carbonaceous fibers with a carbon content of at least 85 inches. this These fibers also have excellent insulation and sound absorption properties as a result of their high carbon content. Two.

The coiled or sinusoidal configuration of the fibers in textile structures provides improved insulation efficiency. Provides insulation with good compressibility and elasticity. using fibers from the third group. The fibrous relics produced in the Have a way.

Preferably, the third group of fibers used is derived from stabilized acrylic fibers. , with a nitrogen content of less than 1O-. As a result of the higher carbon content, this fibrous structure The structure is also electrically conductive. In other words, the electrical resistance of each fiber is 7~ N 4X10 when measured with 6 tow fibers with a diameter of 20 microns 'Ohm/, -less than.

Precursor stabilized acrylic fibers advantageously used in the production of fibrous structures are acryloni Tolyl homopolymer, 7-acrylonitrile copolymer and acrylonitrile ter Poly i-kauereru. The copolymer preferably contains at least about 85 moles of a Crylonitrile units and styrene, methyl acrylate, methyl methacrylate copolymerized with vinyl chloride, vinylidene chloride, vinylpyridine, etc. Contains up to 15 moles of one or more monovinyl units. Also, the activation The ryl filaments preferably contain at least about 85 mole units of acrylonitrile. It can also consist of a terpolymer.

The carbonaceous precursor starting material is fibrous at temperatures above about 1000°C in a non-oxidizing atmosphere. As the structures are heated, they become electrically conductive, on the order of a metal conductor. It should further be understood that the Selected for electrical conductivity Starting materials e.g. pitch (petroleum or coal tar), polyacrylonitrile Polymer (PANOX or GRAFIL-01), polyphenylene, polyvinyl Redene chloride (Saran; MliE from The Dow Chemical Company), etc. can be obtained from.

According to a feature of the invention, antistatic fibers, i.e., those having the ability to dissipate static charges, Fibers can be inserted into fibrous structures for intertwining and! ! @ It is also useful as a fiber substitute.

Preferred precursor fibers include nanofiber or multifilament precursor materials. When melt-spun or wet-spun by known methods to yield a tow of will be built. These fibers, yarns or tows are then used in numerous commercial applications. It can be woven or knitted by any of the techniques. Then this fabric or heating the flattened product to a temperature exceeding about 525°C, preferably above 550°C. , followed by braiding and carding to be used in the fibrous structure of the present invention. A wool-like fluff-like substance is produced.

If desired, the densified fibrous structure can be heat treated to form a carbon or graphite structure. It can also be made into a sculpture. The method of the present invention eliminates the need for complicated knitting operations. Enables the production of structures of Laffite.

It should be understood that all numbers used herein are by weight.

Specific embodiments of the present invention are shown in the following examples.

Example I A. A tow of non-linear carbon fibers that has been heat-treated to 550℃ is opened using a jar-ray opening machine. RK Carbon Fibers, Philadelphia, Pennsylvania, USA Large bone mass large denier 0FF (oxidized PANG fiber) obtained from Incophorated Blend with 25%. The dog bone type OFF was fixed at a temperature of 200℃ before blending. It had temporary crimping. Mix the batting and run through the needle punch machine This precursor fiber f) was densified from a thickness of 7.5 cm to a thickness of L8 tan. .

B. Dense batting generated from the above person, including stitches involving large bone type OFF Alternatively, the felt was heat treated at 700° C. for 60 minutes in a nitrogen atmosphere. Generate! ! Densified batting or felt has good permanent integrity and can withstand temperatures above 400°C. It was stable at temperatures of

Example 2 *A densified batting was prepared according to the method of Example 1. generated batty The material was then heat treated at a temperature of 1500°C for 60 minutes to provide sound and heat insulation. A suitable uniform carbon structure was obtained.

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Claims (21)

[Claims] 1. Multiple non-combustible, non-linear, substantially irreversibly heat-set and elastic shapes Renewable and extensible deflection ratio greater than 1.2:1 and aspect ratio greater than 10:1 a first carbonaceous polymer fiber, and planted in an intertwined relationship with the first fiber; at least one second non-combustible fruit which is intertwined to form an intertwined fibrous structure; Comprising carbonaceous polymer fibers, yarns or tows, which are qualitatively irreversibly heat set. A fibrous structure characterized by comprising: 2. The intertwined fibrous structure is dense and has a bulk of 48 to 32 kg/m3. A structure according to claim 1 having a density. 3. The first and second carbonaceous fibers are stabilized polymers having a diameter of 4 to 25 microns. - A structure according to claim 1, which is derived from precursor fibers or pitch substrate precursor fibers. . 4. The polymer precursor fiber is acrylonitrile homopolymer, acrylonitrile copolymer Acrylic fiber selected from polymer and acrylonitrile terpolymer. and the copolymers and terpolymers contain at least 85 mol% acrylonitrile. one or more polymer units and up to 15 mol% copolymerized with another polymer. 4. A structure according to claim 3, comprising monovinyl units of. 5. The carbonaceous fiber has a carbon content of greater than 65% and an LOI value of greater than 40. A structure according to any one of claims 1 to 4. 6. the carbonaceous fibers are electrically conductive and have a carbon content of at least 85%; When measured on 6K tow fibers where the fibers have a nominal diameter of 7 to 20 microns. 6. The structure of claim 5 having an electrical resistance of less than 4 x 103 ohms/cm. 7. the carbonaceous fibers are electrically non-conductive or do not have static dissipative properties; 6 with a carbon content of less than 6% and each fiber having a nominal diameter of 7 to 20 microns. Electrical resistance greater than 4 x 103 ohms/cm when measured on fibers of K tow 6. The structure according to claim 5. 8. The carbonaceous fiber has low electrical conductivity and low static dissipation, and less than 85% carbon 6K tow fibers with an elementary content and each fiber having a nominal diameter of 7 to 20 microns. having an electrical resistance of 4 x 106 to 4 x 103 ohms/cm when measured on fibers The structure according to claim 5. 9. The first carbonaceous fiber has a sinusoidal or coiled shape, and the fibrous structure in the form of a non-woven wool-like fluff, batting or web; The second carbonaceous fiber has a linear or non-linear morphology and a higher density than the first carbonaceous fiber. 9. A structure according to any one of claims 1 to 8, having a wall. 10. a plurality of non-combustible, non-linear, substantially irreversibly heat-set first carbonaceous polyesters; A method for producing a fibrous structure from mer fibers, the first fiber having at least one type of A second non-heat-set carbonaceous polymer fiber, yarn or tow to the first fiber. and then inert this fibrous structure. heat setting the second fiber, yarn or toe of the entanglement by heat treatment in an atmosphere; A method for producing a fibrous structure, comprising the step of: 11. The second fiber, yarn or tow is irreversibly heat set to the first heat set. Carbon fibers, yarns or tows that are similar or identical in composition to 11. The method of claim 10, wherein the method is made from a precursor carbonaceous polymer material that can be formed. 12. the fibers are acrylic fibers, and the second non-heat-set entanglement A fibrous structure containing roasted fibers is heat treated at a temperature exceeding 525°C in an inert atmosphere. Claim 10, further comprising the step of imparting permanent fixation to the second fiber, yarn or tow. or the method described in 11. 13. The fibrous structure is wool-like, matte, felt or batten. and a second fiber, yarn or fiber is in the form of a 4.8 to 3 It is concentrated to a bulk density of 2 kg/m3 to give the structure integrity and ease of handling. 13. A method according to claim 10, 11 or 12, wherein sea urchin is present in the structure. 14. The attachment of the second fiber to the first fiber is accomplished by needle punching. A method according to any one of claims 10 to 13. 15. Whether the second carbonaceous fiber has the same or different composition as the first carbonaceous fiber 15. The method according to any one of claims 10 to 14. 16. The method according to claims 10 to 15, wherein the planted second fibers are derived from batting. The method described in any one of the above. 17. Any one of claims 10 to 16, wherein the second fiber is a linear or non-linear fiber. The method described in Section 1. 18. Any one of claims 1 to 17, wherein the fibrous structure comprises a plurality of battings. The method described in section. 19. at least one batting has a carbon content of at least 85% 20. The method of claim 18, wherein the method comprises quality fibers. 20. 19. The method of claim 18, wherein at least one butting comprises linear fibers. 21. derived from oxidized polyacrylonitrile, greater than 1.2:1. Reverse deflection ratio, aspect ratio greater than 10:1, and limited oxygen intensities greater than 40 A first non-linear elastic shape reproducible extensible non-flammable thermoset having a dex value providing a first batting of defined carbonaceous fibers; polyacrylonitrile; a second batting of at least one of the fibers above the first batting; Step of layering the polyacrylonitrile fibers from the second batching into the first batching process; The process of intertwining with the heat-set fibers of the twine; and subsequent densification of the whole a step of thoroughly treating the structure and permanently heat fixing the second batting at practical cost; A method of manufacturing a multilayer butting structure comprising: