CN104471119A

CN104471119A - Method of producing fine amorphous polymer fibres, fine amorphous polymer|fibres, and spinneret for producing such fibres

Info

Publication number: CN104471119A
Application number: CN201380037820.1A
Authority: CN
Inventors: 理查德·彼得斯; 戴维·沃伦; 迈克尔·林赛
Original assignee: SABIC Innovative Plastics IP BV
Current assignee: SABIC Global Technologies BV
Priority date: 2012-08-06
Filing date: 2013-07-31
Publication date: 2015-03-25
Anticipated expiration: 2033-07-31
Also published as: WO2014025586A1; KR20150039762A; US20140037957A1; KR102049905B1; CN104471119B; EP2880207A1; JP2015528532A; IN2014DN10001A; JP6110491B2

Abstract

A method, including extruding a melt including an amorphous polymer composition through a spinneret under a pressure from 400 to 1500 psi to produce a spun fiber; collecting the spun fiber on a feeding roll without drawing the spun fiber; producing a solidified fiber from the spun fiber. The solidified fiber can have a dpf of from greater than 0 to 2.5 dpf, and a shrinkage less than or equal to 2%. The method can also include collecting the solidified fiber onto a spool without subjecting the solidified fiber to a drawing step. A spinneret for producing fibers of at most 2.5 dpf from a composition comprises an amorphous polyetherimide, the spinneret comprising a die having a plurality of round melt channels but no distribution plates. Fibers produced by the method and from the spinneret are also disclosed.

Description

Method for producing fine amorphous polymer fibers, fine amorphous polymer fibers and spinneret for producing such fibers

Technical Field

The present invention generally relates to fibers and systems, methods, and apparatus for producing fibers. More particularly, the present invention relates to fine denier amorphous polymer fibers (e.g., fine denier polyetherimide fibers), and systems, methods, and apparatus for producing such fibers by melt spinning a polymer without draw-spinning the fiber.

Background

Synthetic fibers have been produced for many years using well established processes and processing equipment that have been optimized for the melt and physical properties of semi-crystalline materials, i.e., low melt viscosity, excellent thermal stability, and crystallinity. Traditionally, synthetic fibers have been produced using semi-crystalline materials that have very low viscosity in the molten state and require processing or die design methods to produce a uniform melt distribution over the spinneret hole pattern. The spinneret (spinneret) is designed to help the uniform distribution of the melt. These designs, however, do not advantageously use amorphous polymers, including thermoplastics such as polyetherimides. Processing amorphous thermoplastics into fibers using melt spinning methods is a new method attempted on traditional melt spinning lines with limited success. Some of these problems may be due to the design of the processing equipment not being suitable for amorphous materials. Although desirable, there is no specially designed melt spinning line (melt spinning line) or spinneret for producing amorphous thermoplastics into fine fibers by melt spinning them to reduce their denier without drawing the synthetic fibers.

Conventionally, synthetic fibers have been produced using semi-crystalline materials that crystallize after being drawn out from a spinneret and are easily melt-spun into fine denier fibers of 2 denier (dpf) and below per thread. Amorphous material does not form crystals after drawing and therefore does not have sufficient elongation and strength during drawing the drawn part of the process to 2dpf and below using conventional melt spinning methods. Conventional processing schemes are not suitable for converting certain amorphous engineering thermoplastic compositions, such as Polyetherimide (PEI) pellets, to fine denier fibers because conventional methods result in limitations on how fine fibers can be achieved. There is a need for polyetherimide fibers having a dpf of 2 or less. There is a need to develop methods and processing techniques that will allow the production of fibers of 2dpf and less from amorphous engineering thermoplastics such as PEI. Attempts are currently made to produce fine denier fibers by conventional methods and are drawn in post-conversion process extension operations, or are not capable of drawing as low as 2dpf and less.

Disclosure of Invention

One embodiment relates to a method comprising the steps of: the process comprises extruding a polymer melt through a spinneret at a pressure of 400 to 1500psi to produce spun fibers, collecting the spun fibers on a forwarding roll (also sometimes referred to as a feed roll), producing solidified fibers from the spun fibers, and collecting the solidified fibers onto a spool (speol) without subjecting the solidified fibers to a drawing step. The melt can comprise an amorphous polymer composition, such as a polyetherimide. The cured fiber may have a dpf in the range of greater than 0 to 2.5dpf, and a shrinkage of less than or equal to 2%.

Further embodiments relate to undrawn amorphous polymer fibers having a denier of less than 2.5 and a shrinkage of greater than 0 to less than or equal to 2%.

Still other embodiments relate to a spinneret for producing amorphous undrawn polyetherimide fibers of up to 2.5dpf from a composition comprising an amorphous polyetherimide, such as a polyetherimide. The spinneret can avoid the use of distribution plates and can operate at a pressure at least 40% lower than the operating pressure of the spinneret including the distribution plates. The spinneret may include a screen pack filter (screen pack filter) in combination with the die to distribute the composition to the die. The die may have a plurality of circular melt channels, wherein each circular melt channel has a length and a diameter, and wherein the ratio of the length of each circular melt channel: the ratio of the diameters is 2:1 to 6: 1.

Drawings

These and other features, aspects, and advantages will become better understood with regard to the following description and appended claims, and accompanying drawings where:

FIG. 1 is a schematic view of a prior art spinneret design including two distribution plates not present in the design of various embodiments of the present invention;

FIG. 2 is a schematic of a 72 hole spinneret design with a central core distribution of three concentric rings of feed capillaries according to various embodiments of the present invention;

FIG. 3 is a schematic of a 144-hole spinneret design for a distributed screen pack filter with six concentric rings of feed capillaries according to various embodiments of the present invention;

fig. 4 is a schematic view of a prior art fiber production process that can be modified to employ spinnerets according to various embodiments of the present invention.

It should be understood that the various embodiments are not limited to the arrangements and instrumentality shown in the drawings.

Detailed Description

In the following detailed description and the appended claims, reference will be made to a number of terms, which are defined to have the following meanings:

"denier" is a measure of the linear mass density of a fiber. In the present application and claims, this is defined as the mass in grams per 9000 meters.

As used in this application and in the claims, a "spinneret" is a multi-hole device through which a plastic polymer melt is extruded to form fibers.

All numerical values herein are assumed to be modified by the term "about," whether or not explicitly indicated. The term "about" generally refers to a range of numbers that one of skill in the art would consider equivalent to the recited value (e.g., having the same function or result). In many instances, the term "about" may include numbers that are rounded to the nearest significant figure.

Embodiments of the present invention relate to methods for producing fine denier fibers from engineering thermoplastics, such as polyetherimides.

In conventional processes for forming fibers by melt extrusion, high pressures (1000 to 2000psi) are critical to maintaining a uniform distribution of melt across the spinneret orifices, and where a quenching device is employed to control the cooling rate, and thus the crystallinity of the material as it is drawn from the spinneret. The various embodiments of the present invention avoid these conditions, which are not desirable for processing amorphous engineering thermoplastics into fine denier fibers. According to embodiments of the present invention, the pressure can be reduced (400 to 2000psi) to reduce the shear on the material in the melt state and thus reduce the negative impact of that drawback, i.e., dripping or breaking of fiber strands. It has been found that the relatively high viscosity of the amorphous thermoplastic in the melt state can provide sufficient back pressure in the system to evenly distribute the melt across the spinneret. The material is not cooled in a quench cabinet (nozzle) after exiting the nozzle, but in fact, surprisingly benefits from the use of heat in this space to slow the rate of temperature reduction of the amorphous material and reduce the quenching effect on the spun material. Using the methods described above, the method according to the present invention can be successfully used to melt spin polyetherimide fibers to 2dpf and below.

One embodiment is directed to a method comprising a series of steps. These steps may be continuous or non-continuous. The method may include the step of extruding the melt through a spinneret to produce spun fibers.

The melt may be extruded through a spinneret at a pressure within a range having a lower limit and/or an upper limit. The range may or may not include a lower limit and/or an upper limit. The lower limit and/or the upper limit may be selected from 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350, 1400, 1450, 1500, 1550, 1600, 1650, 1700, 1750, 1800, 1850, 1900, 1950, and 2000 psi. For example, according to certain preferred embodiments, the melt may be extruded through a spinneret at a pressure of 400 to 1500 psi.

The melt may comprise an amorphous polymer composition. The amorphous polymer composition may have a melt flow rate within a range having a lower limit and/or an upper limit. The range may or may not include a lower limit and/or an upper limit. The lower limit and/or the upper limit may be selected from any one of 1,2, 3,4, 5, 6,7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, and 60g/10 min. For example, according to certain preferred embodiments, the amorphous polymer composition may have a melt flow rate of 4 to 18 grams per 10min (g/10 min).

The melt may include one or more crystalline materials. The amorphous polymer composition may comprise a polyimide. Polyimides include polyetherimides and polyetherimide copolymers. The polyetherimide can be selected from the group consisting of (i) polyetherimide homopolymers, e.g., polyetherimides, (ii) polyetherimide copolymers, e.g., polyetherimide sulfones, and (iii) combinations thereof. Polyetherimides are known polymers and are described inAnd SILTEM (trademark) under the SABICINnovative Plastics IP B.V. sold by SABIC Innovative Plastics.

In one embodiment, the polyetherimide has the formula (1):

wherein a is greater than 1, for example, 10 to 1,000 or more, or more specifically, 10 to 500.

The group V in formula (1) is a tetravalent linker comprising an ether group (as used herein "polyetherimide") or a combination of an ether group and an arylene sulfone group ("polyetherimide sulfone"). Such linkers include, but are not limited to: (a) substituted or unsubstituted, saturated, unsaturated or aromatic monocyclic and polycyclic groups having 5 to 50 carbon atoms, optionally substituted with ether groups, arylene sulfone groups or a combination of ether groups and arylene sulfone groups; (b) a substituted or unsubstituted, linear or branched, saturated or unsaturated alkyl group having 1 to 30 carbon atoms and optionally substituted with an ether group or a combination of an ether group, an arylene sulfone group and an arylene sulfone group; or combinations comprising at least one of the foregoing. Suitable additional substitutions include, but are not limited to, ethers, amides, esters, and combinations comprising at least one of the foregoing.

The R group in formula (1) includes, but is not limited to, a substituted or unsubstituted divalent organic group, such as: (a) aromatic hydrocarbon groups having 6 to 20 carbon atoms and halogenated derivatives thereof; (b) a linear or branched alkylene group having 2 to 20 carbon atoms; (c) a cycloalkylene group having 3 to 20 carbon atoms, or (d) a divalent group of formula (2):

wherein Q is¹Including but not limited to divalent moieties such as-O-, -S-, -C (O) -, -SO₂-，-SO-，-C_yH_2y- (y is an integer from 1 to 5), and halogenated derivatives thereof, comprising a perfluoroalkylene group.

In one embodiment, linker V comprises, but is not limited to, a tetravalent aromatic group of formula (3):

wherein W is a divalent moiety comprising-O-, -SO₂Or a group of formula-O-Z-O-, wherein the divalent bond of the-O-or-O-Z-O-group is in the 3,3 ', 3, 4', 4,3 ', or 4, 4' position, and wherein Z comprises, but is not limited to, a divalent group of formula (4):

wherein,q comprises, but is not limited to, a divalent moiety comprising-O-, -S-, -C (O), -SO₂-，-SO-，-C_yH_2y- (y is an integer from 1 to 5), and halogenated derivatives thereof, comprising a perfluoroalkylene group.

In a specific embodiment, the polyetherimide comprises greater than 1, specifically, 10 to 1000, or, more specifically, 10 to 500 structural units of formula (5):

wherein T is-O-or a group of the formula-O-Z-O-, wherein the divalent bond of the-O-or-O-Z-O-group is in the 3,3 ', 3, 4', 4,3 ', or 4, 4' position; as defined above, Z is a divalent group of formula (3); and as defined above, R is a divalent radical of formula (2).

In another specific embodiment, the polyetherimide sulfone is a polyetherimide comprising an ether group and a sulfone group, wherein at least 50 mole% of linkers V and groups R in formula (1) comprise a divalent arylene sulfone group. For example, all linkers V, but no group R, may comprise an arylene sulfone group; or all groups R, but none of the linkers V, may comprise an arylene sulfone group; or arylene sulfones may be present as some portion of the linker V and R groups provided that the total molar fraction of V and R groups containing aryl sulfone groups is greater than or equal to 50 mole%.

Even more specifically, the polyetherimide sulfone can comprise greater than 1, specifically, 10 to 1000, or, more specifically, 10 to 500 structural units of formula (6):

wherein Y is-O-, -SO₂-, or a group of the formula-O-Z-O-, in which-O-, SO₂Di-of a-or-O-Z-O-groupThe valency is in the 3,3 ', 3, 4', 4,3 ', or 4, 4' position, wherein Z is a divalent radical of formula (3) as defined above, and provided that more than 50 mole% of the sum of the moles of Y + the moles of R in formula (2) comprises-SO₂-a group, R being a divalent group of formula (2) as defined above.

It is to be understood that the polyetherimides and polyetherimide sulfones may optionally comprise a linker V that does not contain ether or ether and sulfone groups, such as a linker of formula (7):

the imide units comprising such linkers are generally present in an amount of from 0 to 10 mol%, specifically, from 0 to 5 mol% of the total number of units. In one embodiment, no additional linkers V are present in the polyetherimide and polyetherimide sulfone.

In another specific embodiment, the polyetherimide comprises from 10 to 500 structural units of formula (5) and the polyetherimide sulfone comprises from 10 to 500 structural units of formula (6).

Polyetherimides and polyetherimide sulfones may be prepared by any suitable method. In one embodiment, the polyetherimides and polyetherimide copolymers include polycondensation polymerization processes and halo-displacement polymerization processes.

The polycondensation process may include a process for preparing a polyetherimide having the structure (1), referred to as a nitro-displacement process (in formula (8), X is a nitro group). In one example of the nitro metathesis process, N-methylphthalimide is nitrated with 99% nitric acid to produce a mixture of N-methyl-4-nitrophthalimide (4-NPI) and N-methyl-3-nitrophthalimide (3-NPI). After purification, a mixture comprising about 95 parts of 4-NPI and 5 parts of 3-NPI in toluene in the presence of a phase transfer catalystWith the disodium salt of bisphenol A (BPA). This reaction produces BPA-bisimides and NaNO in a step known as nitro-displacement₂. After purification, the BPA-bisimide is reacted with phthalic anhydride in an imide exchange reaction to provide BPA dianhydride (BPADA), which in turn is reacted with a diamine (e.g., m-phenylene diamine (MPD) in o-dichlorobenzene in an imidization-polymerization step) to provide the product polyetherimide.

Other diamines are also possible. Examples of suitable diamines include: m-phenylenediamine; p-phenylenediamine; 2, 4-diaminotoluene; 2, 6-diaminotoluene; m-xylylenediamine; p-xylylenediamine; benzidine; 3, 3' -dimethylbenzidine; 3, 3' -dimethoxybenzidine; 1, 5-diaminonaphthalene; bis (4-aminophenyl) methane; bis (4-aminophenyl) propane; bis (4-aminophenyl) sulfide; bis (4-aminophenyl) sulfone; bis (4-aminophenyl) ether; 4, 4' -diaminodiphenylpropane; 4,4 '-aminodiphenylmethane (4, 4' -methylenedianiline); 4, 4' -diaminodiphenyl sulfide; 4, 4' -diaminodiphenyl sulfone; 4,4 '-diaminodiphenyl ether (4, 4' -oxydianiline); 1, 5-diaminonaphthalene; 3, 3' -dimethylbenzidine; 3-methyl heptamethylene diamine; 4, 4-dimethyl heptamethylene diamine; 2,2 ', 3, 3' -tetrahydro-3, 3,3 ', 3' -tetramethyl-1, 1 '-spirobi [ 1H-indene ] -6, 6' -diamine; 3,3 ', 4, 4' -tetrahydro-4, 4,4 ', 4' -tetramethyl-2, 2 '-spirobi [ 2H-1-benzo-pyran ] -7, 7' -diamine; 1, 1' -bis [ 1-amino-2-methyl-4-phenyl ] cyclohexane, and isomers thereof, as well as mixtures and blends comprising at least one of the foregoing. In one embodiment, the diamine is a specific aromatic diamine, particularly meta-phenylenediamine and para-phenylenediamine, and mixtures comprising at least one of the foregoing.

Suitable dianhydrides that may be used with diamines include, but are not limited to, 2-bis [4- (3, 4-dicarboxyphenoxy) phenyl ] propane dianhydride; 4, 4' -bis (3, 4-dicarboxyphenoxy) diphenyl ether dianhydride; 4, 4' -bis (3, 4-dicarboxyphenoxy) diphenyl sulfide dianhydride; 4, 4' -bis (3, 4-dicarboxyphenoxy) benzophenone dianhydride; 4, 4' -bis (3, 4-dicarboxyphenoxy) diphenyl sulfone dianhydride; 2, 2-bis [4- (2, 3-dicarboxyphenoxy) phenyl ] propane dianhydride; 4, 4' -bis (2, 3-dicarboxyphenoxy) diphenyl ether dianhydride; 4, 4' -bis (2, 3-dicarboxyphenoxy) diphenyl sulfide dianhydride; 4, 4' -bis (2, 3-dicarboxyphenoxy) benzophenone dianhydride; 4, 4' -bis (2, 3-dicarboxyphenoxy) diphenyl sulfone dianhydride; 4- (2, 3-dicarboxyphenoxy) -4' - (3, 4-dicarboxyphenoxy) diphenyl-2, 2-propane dianhydride; 4- (2, 3-dicarboxyphenoxy) -4' - (3, 4-dicarboxyphenoxy) diphenyl ether dianhydride; 4- (2, 3-dicarboxyphenoxy) -4' - (3, 4-dicarboxyphenoxy) diphenyl sulfide dianhydride; 4- (2, 3-dicarboxyphenoxy) -4' - (3, 4-dicarboxyphenoxy) benzophenone dianhydride; 4- (2, 3-dicarboxyphenoxy) -4' - (3, 4-dicarboxyphenoxy) diphenylsulfone dianhydride; 1, 3-bis (2, 3-dicarboxyphenoxy) benzene dianhydride; 1, 4-bis (2, 3-dicarboxyphenoxy) benzene dianhydride; 1, 3-bis (3, 4-dicarboxyphenoxy) benzene dianhydride; 1, 4-bis (3, 4-dicarboxyphenoxy) benzene dianhydride; 3,3 ', 4, 4' -biphenyltetracarboxylic dianhydride; 3,3 ', 4, 4' -benzophenone tetracarboxylic dianhydride; naphthalene dicarboxylic acid dianhydride such as 2,3,6, 7-naphthalene dicarboxylic acid dianhydride, etc.; 3,3 ', 4, 4' -diphenylsulfonic acid tetracarboxylic dianhydride; 3,3 ', 4, 4' -diphenyl ether tetracarboxylic dianhydride; 3,3 ', 4, 4' -dimethyldiphenylsilanetetracarboxylic dianhydride; 4, 4' -bis (3,4 dicarboxyphenoxy) diphenyl sulfide dianhydride; 4, 4' -bis (3, 4-dicarboxyphenoxy) diphenyl sulfone dianhydride; 4, 4' -bis (3, 4-dicarboxyphenoxy) diphenylpropane dianhydride; 3,3 ', 4, 4' -biphenyltetracarboxylic dianhydride; bis (phthalic acid) phenylsulfinyloxide dianhydride; p-phenylene-bis (triphenylphthalic acid) dianhydride; m-phenylene-bis (triphenylphthalic acid) dianhydride; bis (triphenylphthalic acid) -4, 4' -diphenyl ether dianhydride; bis (triphenylphthalic acid) -4, 4' -diphenylmethane dianhydride; 2, 2' -bis (3, 4-dicarboxyphenyl) hexafluoropropane dianhydride; 4, 4' -oxydiphthalic dianhydride; pyromellitic dianhydride; 3,3 ', 4, 4' -diphenylsulfone tetracarboxylic dianhydride; 4, 4' -bisphenol a dianhydride; hydroquinone diphthalic dianhydride; 6,6 '-bis (3, 4-dicarboxyphenoxy) -2, 2', 3,3 '-tetrahydro-3, 3', 3,3 '-tetramethyl-1, 1' -spirobi [ 1H-indene ] dianhydride; 7,7 '-bis (3, 4-dicarboxyphenoxy) -3, 3', 4,4 '-tetrahydro-4, 4, 4', 4 '-tetramethyl-2, 2' -spirobi [ 2H-1-benzopyran ] dianhydride; 1, 1' -bis [1- (3, 4-dicarboxyphenoxy) -2-methyl-4-phenyl ] cyclohexane dianhydride; 3,3 ', 4, 4' -diphenylsulfone tetracarboxylic dianhydride; 3,3 ', 4, 4' -diphenylsulfide tetracarboxylic dianhydride; 3,3 ', 4, 4' -diphenylsulfoxide tetracarboxylic dianhydride; 4, 4' -oxydiphthalic dianhydride; 3, 4' -oxydiphthalic dianhydride; 3, 3' -oxydiphthalic dianhydride; 3, 3' -benzophenone tetracarboxylic dianhydride; 4, 4' -carbonyldiphthalic dianhydride; 3,3 ', 4, 4' -diphenylmethane tetracarboxylic dianhydride; 2, 2-bis (4- (3, 3-dicarboxyphenyl) propane dianhydride, 2-bis (4- (3, 3-dicarboxyphenyl) hexafluoropropane dianhydride, (3,3 ', 4,4 ' -diphenyl) phenylphosphinetetracarboxylic dianhydride, (3,3 ', 4,4 ' -diphenyl) phenylphosphine oxide tetracarboxylic dianhydride, 2 ' -dichloro-3, 3 ', 4,4 ' -biphenyltetracarboxylic dianhydride, 2 ' -dimethyl-3, 3 ', 4,4 ' -biphenyltetracarboxylic dianhydride, 2 ' -dicyano-3, 3 ', 4,4 ' -biphenyltetracarboxylic dianhydride, 2 ' -dibromo-3, 3 ', 4,4 ' -biphenyltetracarboxylic dianhydride, 2 ' -diiodo-3, 3 ', 4, 4' -biphenyltetracarboxylic dianhydride; 2,2 ' -bistrifluoromethyl-3, 3 ', 4,4 ' -biphenyltetracarboxylic dianhydride; 2,2 ' -bis (1-methyl-4-phenyl) -3,3 ', 4,4 ' -biphenyltetracarboxylic dianhydride; 2,2 ' -bis (1-trifluoromethyl-2-phenyl) -3,3 ', 4,4 ' -biphenyltetracarboxylic dianhydride; 2,2 ' -bis (1-trifluoromethyl-3-phenyl) -3,3 ', 4,4 ' -biphenyltetracarboxylic dianhydride; 2,2 ' -bis (1-trifluoromethyl-4-phenyl) -3,3 ', 4,4 ' -biphenyltetracarboxylic dianhydride; 2,2 ' -bis (1-phenyl-4-phenyl) -3,3 ', 4,4 ' -biphenyltetracarboxylic dianhydride; 4, 4' -bisphenol a dianhydride; 3, 4' -bisphenol a dianhydride; 3, 3' -bisphenol a dianhydride; 3,3 ', 4, 4' -diphenylsulfoxide tetracarboxylic dianhydride; 4, 4' -carbonyldiphthalic dianhydride; 3,3 ', 4, 4' -diphenylmethane tetracarboxylic dianhydride; 2,2 ' -bis (1, 3-trifluoromethyl-4-phenyl) -3,3 ', 4,4 ' -biphenyltetracarboxylic dianhydride, and all isomers thereof, as well as combinations thereof.

Halogen displacement polymerization processes for the manufacture of polyetherimides and polyetherimide sulfones include, but are not limited to, the reaction of bis (phthalimides) of formula (8):

wherein R is as described above and X is a nitro group or a halogen. For example, bis-phthalimide (8) may be formed by condensation of the corresponding anhydride of formula (9) with an organic diamine of formula (10):

wherein X is a nitro group or a halogen,

H₂N-R-NH₂(10)，

wherein R is as described above.

An illustration of the amine compound of formula (10) comprises: ethylenediamine, propylenediamine, trimethylenediamine, diethylenetriamine, triethylenetetramine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, 1, 12-dodecyldiamine, 1, 18-octadecenediamine, 3-methylheptamethylenediamine, 4-dimethylheptamethylenediamine, 4-methylnonamethylenediamine, 5-methylnonamethylenediamine, 2, 5-dimethylhexamethylenediamine, 2, 5-dimethylheptamethylenediamine, 2-dimethylpropylenediamine, N-methyl-bis (3-aminopropyl) amine, 3-methoxyhexamethylenediamine, 1, 2-bis (3-aminopropoxy) ethane, bis (3-aminopropyl) sulfide, 1, 4-cyclohexanediamine, bis- (4-aminocyclohexyl) methane, m-phenylenediamine, p-phenylenediamine, 2, 4-diaminotoluene, 2, 6-diaminotoluene, m-xylylenediamine, p-xylylenediamine, 2-methyl-4, 6-diethyl-1, 3-phenylenediamine, 5-methyl-4, 6-diethyl-1, 3-phenylenediamine, benzidine, 3 '-dimethylbenzidine, 3' -dimethoxybenzidine, 1, 5-diaminonaphthalene, bis (4-aminophenyl) methane, bis (2-chloro-4-amino-3, 5-diethylphenyl) methane, bis (4-aminophenyl) propane, 2, 4-bis (b-amino-tert-butyl) toluene, p-phenylenediamine, m-xylylenediamine, p-xylylene, Bis (p-b-amino-tert-butylphenyl) ether, bis (p-b-methyl-o-aminophenyl) benzene, bis (p-b-methyl-o-aminopentyl) benzene, 1, 3-diamino-4-isopropylbenzene, bis (4-aminophenyl) ether and 1, 3-bis (3-aminopropyl) tetramethyldisiloxane. Mixtures of these amines may be used. Illustrative of amine compounds of formula (10) containing sulfone groups include, but are not limited to, Diamino Diphenyl Sulfone (DDS) and bis (aminophenoxyphenyl) sulfone (BAPS). Combinations comprising any of the foregoing amines may be used.

Polyetherimides can be synthesized by the reaction of bis (phthalimide) (8) with an alkali metal salt of a dihydroxy-substituted aromatic hydrocarbon of the formula HO-V-OH, wherein V is as described above, in the presence or absence of a phase transfer catalyst. Suitable phase transfer catalysts are disclosed in U.S. Pat. No. 5,229,482. In particular, dihydroxy-substituted aromatic hydrocarbons, bisphenols, such as bisphenol A, or combinations of alkali metal salts of bisphenols and additional alkali metal salts of dihydroxy-substituted aromatic hydrocarbons may be used.

In one embodiment, the polyetherimide comprises structural units of formula (5), wherein each R is independently p-phenylene or m-phenylene or a mixture comprising at least one of the foregoing; and T is a group of formula-O-Z-O-, wherein the divalent bonds of the-O-Z-O-group are in the 3, 3' position, and Z is a 2, 2-diphenylenepropane group (bisphenol A group). Further, the polyetherimide sulfone comprises structural units of formula (6), wherein at least 50 mole% of the R groups have formula (4), wherein Q is-SO₂-and the remaining R groups are independently p-phenylene or m-phenylene or a combination comprising at least one of the foregoing; t is a group of formula-O-Z-O-wherein the divalent bonds of the-O-Z-O-group are in the 3, 3' position and Z is a 2, 2-diphenylenepropane group.

In making the polymeric components described herein, polyetherimides and polyetherimide sulfones may be used alone or in combination with each other or with other disclosed polymeric materials. In one embodiment, only polyetherimide is used. In another embodiment, the polyetherimide: the polyetherimide sulfone can be in a weight ratio of 99:1 to 50: 50.

The polyetherimide can have a weight average molecular weight (Mw) of 5000 to 100,000 grams per mole (g/mole) as measured by Gel Permeation Chromatography (GPC). In some embodiments, the Mw may be 10,000 to 80,000. Molecular weight as used herein refers to the absolute weight average molecular weight (Mw).

The polyetherimide can have an intrinsic viscosity greater than or equal to 0.2 deciliters per gram (dl/g) as measured in m-cresol at 25 ℃. Within this range the intrinsic viscosity may be 0.35 to 1.0dl/g as measured in m-cresol at 25 ℃.

The polyetherimide can have a glass transition temperature greater than 180 ℃, specifically, 200 ℃ to 500 ℃, as measured using Differential Scanning Calorimetry (DSC) according to ASTM test D3418. In some embodiments, the polyetherimides, in particular, polyetherimides, have a glass transition temperature of 240 to 350 ℃.

The polyetherimide can have a melt index of 0.1 to 10 grams per minute (g/min), as measured by American Society for Testing Materials (ASTM) DI 238 at 340 to 370 ℃ using a 6.7 kilogram (kg) weight.

An alternative halogen displacement polymerization process for the manufacture of polyetherimides (e.g., polyetherimides having structure (1)) is the process known as the chloro-displacement process (in formula (8), X is chlorine). The chlorine substitution method is explained below: 4-chlorophthalic anhydride is reacted with m-phenylenediamine in the presence of a catalytic amount of sodium phenylphosphinate catalyst to produce the bischlorophthalimide of m-phenylenediamine (CAS number 148935-94-8). The bischlorophthalimide is then polymerized by chloro-displacement with BPA disodium salt in the presence of a catalyst in a solvent of ortho-dichlorobenzene or anisole. Alternatively, a mixture of 3-chloro-and 4-chlorophthalic anhydrides may be employed to provide a mixture of isomeric bischlorophthalimides, which may be polymerized by chloro-displacement with the disodium salt of BPA as described above.

The siloxane polyetherimide can comprise a polysiloxane/polyetherimide block copolymer having a siloxane content of greater than 0 and less than 40 weight percent (wt%), based on the total weight of the block copolymer. The block copolymer comprises siloxane blocks of formula (I):

wherein, at each occurrence, R^1-6Independently selected from the group consisting of: a substituted or unsubstituted, saturated, unsaturated, or aromatic monocyclic group having 5 to 30 carbon atoms, a substituted or unsubstituted, saturated, unsaturated, or aromatic polycyclic group having 5 to 30 carbon atoms, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, V is a tetravalent linker selected from the group consisting of: substituted or unsubstituted, saturated, unsaturated, or aromatic monocyclic and polycyclic groups having 5 to 50 carbon atoms, substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms, substituted or unsubstituted alkenyl groups having 2 to 30 carbon atoms, and combinations comprising at least one of the foregoing linkers, g is equal to 1 to 30, and d is 2 to 20. Commercially available siloxane polyetherimides are available from SABIC Innovative Plastics under the trade name SILTEM (trade mark of SABIC Innovative Plastics IP b.v.).

The polyetherimide can have a weight average molecular weight (Mw) within a range having a lower limit and/or an upper limit. Ranges may or may not include lower and/or upper limits. The lower and/or upper limit may be selected from 5000, 6000, 7000, 8000, 9000, 10000, 11000, 12000, 13000, 14000, 15000, 16000, 17000, 18000, 19000, 20000, 21000, 22000, 23000, 24000, 25000, 26000, 27000, 28000, 29000, 30000, 31000, 32000, 33000, 34000, 35000, 36000, 37000, 38000, 39000, 40000, 41000, 42000, 43000, 44000, 45000, 4700, 47000, 48000, 49000, 50000, 51000, 52000, 53000, 54000, 55000, 56000, 57000, 58000, 59000, 60000, 61000, 62000, 63000, 64000, 65000, 66000, 67000, 68000, 69000, 70000, 71000, 72000, 73000, 75000, 78000, 77000, 92000, 79000, 250000, 92000, 250000, 92000, 79000, 250000, 79000, 250000, 79000, 250000, 79000, 250000, 79000, 250000, 79000. For example, the polyetherimide can have a weight average molecular weight (Mw) of 5,000 to 10,000 daltons, 5,000 to 80,000 daltons, or 5000 to 70,000 daltons. The primary alkylamine-modified polyetherimide will have a lower molecular weight and higher melt flow than the starting unmodified polyetherimide.

The polyetherimide may be selected from the group consisting of: polyetherimides (e.g., as described in U.S. Pat. Nos. 3,875,116; 6,919,422 and 6,355,723); silicone polyetherimides (e.g., as described in U.S. Pat. nos. 4,690,997 and 4,808,686); polyetherimide sulfones (as described in U.S. patent 7,041,773), and combinations thereof, each of which is incorporated herein in its entirety.

The polyetherimide can have a glass transition temperature within a range having a lower limit and/or an upper limit. Ranges may or may not include lower and/or upper limits. The lower limit and/or the upper limit may be selected from 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, and 310 degrees celsius. For example, the polyetherimide can have a glass transition temperature (Tg) greater than about 200 degrees celsius.

The polyetherimide may be substantially free of benzylic protons (less than 100 ppm). The polyetherimide may be free of benzylic protons. The polyetherimide can have benzylic protons in an amount less than 100 ppm. In one embodiment, the amount of benzylic protons is between greater than 0 and less than 100 ppm. In another embodiment, the amount of benzylic protons is undetectable.

The polyetherimide can be substantially free of halogen atoms (less than 100 ppm). The polyetherimide can be free of halogen atoms. The polyetherimide can have halogen atoms in an amount less than 100 ppm. In one embodiment, the amount of halogen atoms is between greater than 0 and less than 100 ppm. In another embodiment, the amount of halogen atoms is undetectable.

In one embodiment, the polyetherimide comprises a polyetherimide thermoplastic composition comprising: (a) a polyetherimide, (b) a phosphorus-containing stabilizer in an amount effective to increase melt stabilization of the polyetherimide, wherein the phosphorus-containing stabilizer exhibits a lower volatility such that greater than or equal to 10 percent by weight of the initial amount of the sample remains unevaporated after heating the sample from room temperature to 300 ℃ at a heating rate of 20 ℃ per minute under an inert atmosphere as measured by thermogravimetric analysis of the initial amount of the sample comprising the phosphorus-containing stabilizer. In one embodiment, the phosphorus-containing stabilizer has the formula P-Ra, wherein R' is independently H, an alkyl, alkoxy, aryl, aryloxy, or oxy substituent, and a is 3 or 4. Examples of such suitable stabilized polyetherimides can be found in U.S. Pat. No. 6,001,957, which is incorporated herein in its entirety.

The method may include the step of collecting the spun fibers on advancing or feed rollers without drawing the spun fibers. In a typical prior art process as depicted in fig. 4, a converging guide (converging guide)406 collects the spun fibers and applies a pulling force (pull) on the fibers as a series of draw godets (collectively 409) (typically operated at high speed) draw the fibers to reduce their denier. The oiling material may be applied to the solidified fibres 407 by an oiling device (finishapplicator) in the form of a kiss roll 408. In the apparatus according to the invention, the use of the oil feed and dampening rollers 408 is optional, and a series of draw-off godets 409, may be dispensed with entirely in some embodiments. The apparatus according to the invention therefore comprises a spinneret according to fig. 2 or 3, an advancing or feeding roll (forwarding or feeding roll) for collecting the spun fibres and at least one spool (spool) or bobbin (bobbin) on which the fine denier undrawn fibres are collected for further use. The method may include the step of producing a solidified fiber from the melt spun polymer. Embodiments of the method may include the step of collecting the solidified fiber on a spool without subjecting the solidified fiber to a drawing step. Embodiments of the method can produce solidified fibers without a forced air cooling step. The method may include the step of collecting the fibers on a spool without any quenching step. The method may include the step of heating the spun fiber after it exits the spinneret.

The solidified fibers can have a dpf within a range having a lower limit and/or an upper limit. Ranges may or may not include lower and/or upper limits. The lower and/or upper limits may be selected from 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9 and 5 dpf. For example, according to certain preferred embodiments, the solidified fibers may have a dpf in the range of greater than 0 to 2.5 dpf.

The solidified fiber may have a shrinkage within a range having a lower limit and/or an upper limit. Ranges may or may not include lower and/or upper limits. The lower and/or upper limits may be selected from 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9 and 5%. For example, according to certain preferred embodiments, the solidified fiber may have a shrinkage of less than or equal to 2%.

One embodiment also relates to new spinneret designs suitable for using high viscosity amorphous engineering thermoplastics to produce fibers with low denier and low shrinkage. Unlike known processing of polyetherimide fibers that require the use of high pressure conditions (e.g., 1500 to 2000psi) to maintain a uniform distribution of melt across the spinneret orifices, spinnerets according to various embodiments are designed to be capable of uniform distribution at pressures as low as 400psi (e.g., in the range of 400 to 1500psi, preferably in the range of 400 to 1200psi, most preferably in the range of 400 and 1000 psi). The die design and corresponding spinneret allow for melt spinning of amorphous thermoplastics, such as PEI into fine denier fibers. These embodiments can minimize dead space, or pause (hang up) areas where amorphous material will pool or swirl and not flow easily, and pause (hang up) and degrade, within a fully circular melt channel throughout the die, then intermittently release degraded material into the melt stream. The length to diameter ratio of the melt channel can be optimized for amorphous material, and the distribution channel can be designed to reduce shear on the material, as well as to use the higher viscosity of the amorphous material in the melt state to obtain uniform distribution of the melt across the spinneret. Using similar designs on the proposed things, materials that could not previously be spun into fibers at all, regardless of denier, can be spun and wound on spools and the process optimized to achieve fine denier fibers.

One particular embodiment relates to a spinneret and/or a spin pack comprising a spinneret for producing amorphous undrawn polyetherimide fibers of up to 2.5dpf from a composition comprising an amorphous polyetherimide. The spinneret need not have distribution plates.

The spinneret can include a die having a plurality of circular melt channels, wherein each circular melt channel has a length and a diameter. Length of each circular melt channel: the ratio of diameters may be 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, or 12: 1. For example, according to certain preferred embodiments, the length of each circular melt channel: the ratio of the diameters may be 2:1 to 6: 1.

According to one embodiment, the spinneret can be operated at a reduced pressure as compared to the same spinneret including the distribution plates. According to various embodiments, the operating pressure of a spinneret without distribution plates can be reduced by a percentage relative to the same spinneret including distribution plates. The percentage may be within a range having a lower limit and/or an upper limit. Ranges may or may not include lower and/or upper limits. The lower and/or upper limits may be selected from 1,2, 3,4, 5, 6,7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, and 60%. For example, according to certain preferred embodiments, according to various embodiments, the operating pressure of a spinneret without distribution plates can be reduced by a percentage of at least 40% relative to the same spinneret including distribution plates.

The spinneret may further comprise at least one screen pack filter (screen pack filter) associated with the die to distribute the composition to the die. The screen assembly filter may have a screen size in a range having a lower limit and/or an upper limit. Ranges may or may not include lower and/or upper limits. The lower limit and/or the upper limit may be selected from 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, and 500 mesh. For example, according to certain preferred embodiments, the screen pack filter may have a US mesh size of 200 to 400 mesh.

Other embodiments relate to amorphous polymer fibers. The fiber can be drawn out, but even in an undrawn state, the fiber can have excellent properties.

According to various embodiments, the undrawn amorphous polymer fiber can have a denier within a range having a lower limit and/or an upper limit. Ranges may or may not include lower and/or upper limits. The lower and/or upper limit may be selected from 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, and 3. For example, according to certain preferred embodiments, the undrawn amorphous polymer fiber may have a denier of less than 2.5.

According to various embodiments, the undrawn amorphous polymer fiber can have a shrinkage within a range having a lower limit and/or an upper limit. Ranges may or may not include lower and/or upper limits. The lower and/or upper limit may be selected from 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9 and 4%. For example, according to certain preferred embodiments, the undrawn amorphous polymer fiber can have a shrinkage of greater than 0 to less than or equal to 2%.

According to various embodiments, the undrawn amorphous polymer fiber can have a polydispersity (Mw/Mn) within a range having a lower limit and/or an upper limit. Ranges may or may not include lower and/or upper limits. The lower and/or upper limit may be selected from 1, 1.25, 1.5, 1.75, 2, 2.25, 2.5, 2.75, 3, 3.25, 3.5, 3.75, 4, 4.25, 4.5, 4.75, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, and 100. For example, according to certain preferred embodiments, the undrawn amorphous polymer fibers can have a polydispersity (Mw/Mn) greater than or equal to 2.5, according to various embodiments.

According to various embodiments, the undrawn amorphous polymer fiber can have a denier within a range having a lower limit and/or an upper limit. Ranges may or may not include lower and/or upper limits. The lower and/or upper limits may be selected from 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9 and 4. For example, according to certain preferred embodiments, the undrawn amorphous polymer fiber can have a denier of less than 2.2, according to various embodiments.

According to various embodiments, the undrawn amorphous polymer fiber can have a strength within a range having a lower limit and/or an upper limit. Ranges may or may not include lower and/or upper limits. The lower and/or upper limit may be selected from 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5, 10, 15, 20, 25, 30, 35, 40, 45 and 50 cN/dtex. For example, according to certain preferred embodiments, the undrawn amorphous polymer fiber can have a strength of at least 2.6cN/dtex according to various embodiments.

According to various embodiments, undrawn amorphous polymer fibers can have the properties identified above while also being un-quenched (unannneled unannealed).

Additional embodiments relate to articles comprising undrawn amorphous polyetherimide fibers. Articles may include, but are not limited to, yarns made from polyetherimide fibers (including one or more unannealed amorphous polyetherimide fibers, optionally wrapped, woven, knitted, spun, or otherwise combined with different types of fibers), fabrics made from undrawn amorphous fibers and/or yarns, and composites including or based on fabrics made from undrawn amorphous fibers. Examples of suitable compounds include, but are not limited to: paper, for example, electrical paper (electrical paper), honeycomb paper, woven specialty paper (woven specialty paper), nonwoven specialty paper (non-wovens specialty paper); a structural composite; a semi-structural complex.

In summary, a method for making undrawn amorphous polymer fiber includes extruding a melt through a spinneret at a pressure of 400 to 1500psi (e.g., from 400 to 1000psi) to produce a spun fiber, wherein the melt comprises an amorphous polymer composition, e.g., a polyetherimide, optionally, wherein the amorphous polymer composition can have a melt flow rate of 4 to 18g/10 min; collecting the spun fiber on a feed roll without drawing the spun fiber, producing a solidified fiber from the spun fiber, wherein the solidified fiber has a dpf of greater than 0 to 2.5dpf, and the solidified fiber has a shrinkage of less than or equal to 2%; and winding the solidified fiber onto a spool without subjecting the solidified fiber to a drawing step. In any of the above embodiments, one or more of the following conditions may apply: the method may further optionally include collecting the fiber onto a spool without an annealing step; the method may further comprise heating the spun fiber after it exits the spinneret to produce a solidified fiber without a forced air cooling step; the melt comprises one or more crystalline materials (crystalline materials).

Amorphous polymer fibers, such as those made by the above-described method, having a denier of less than 2.5, less than 2.2, or less than 2.0, and a shrinkage of greater than 0 to less than or equal to 2%; the fibers can further be polyetherimide fibers, for example, polyetherimine optionally having a melt flow rate of 4 to 18g/10min, further optionally wherein the fibers have a polydispersity (Mw/Mn) greater than or equal to 2.5, and optionally a strength of at least 2.6 cN/dtex. The fibers may be unannealed. Articles comprising the above-described fibers include yarns, fabrics, and composites.

The spinneret useful in the above-described process for producing amorphous undrawn polyetherimide fiber of up to 2.5dpf (e.g., having a melt flow rate of 4 to 18g/10 min) has no distribution plates; and a die having a plurality of circular melt channels, wherein each circular melt channel has a length and a diameter, and wherein the ratio of the length of each circular melt channel: the ratio of diameters is from 2:1 to 6:1, optionally wherein the spinneret is operated at a pressure at least 40% lower than the operating pressure of the same spinneret comprising distribution plates, further optionally wherein the spinneret further comprises at least one screen pack filter in combination with the die to distribute the composition to the die, for example a filter having a US mesh size of from 200 to 400 mesh.

The invention is further described in the following exemplary embodiments, in which all parts and percentages are by weight unless otherwise indicated.

Examples

Table 1 lists the materials employed in the examples.

Two spinneret designs were used in the examples. First, an alpha spinneret Design (AlphaSpinneret Design) was used (see fig. 1). These types of spinneret designs will now be described in more detail. Next, a Beta pack spinneret Design (Beta pack spinneret Design) according to various embodiments of the present invention was employed (see fig. 2 and 3).

1. Description of alpha spinneret design

As shown in FIG. 1, a spin pack 100 according to the prior art includes a capillary spinneret plate 102, which is a rectangular block fitted into the heater jacket area of the extruder with a gap of approximately 0.25 inches around it. The prior art spin pack assembly 100 requires a series of distribution plates 103 to be installed between the base plate 101 and the capillary spinneret plate 102. The distribution plate 103 is designed to provide both pressure blocks to evenly distribute the melt to a rectangular array of 144 capillaries. The plates may be of different sizes and shapes depending on the extruder used.

The distribution plate 103 is very thin, having a thickness of only about 0.02 inches, and the melt channel of the material is only 0.01 inches in diameter and 3/16 inches in length. The restrictive dimensions of the melt channel create strict flow conditions for the amorphous material and the high internal component pressure. Internal assembly pressure results in a limited machining window of material. It also causes material to leach out or accumulate onto the face of capillary spinneret plate 102 during production. This residue builds up over time and has to be scraped off the surface. This causes an undesirable interruption in the process.

Temperature control of the spin pack assembly 100 is achieved by convective heating of the air gap space around the assembly mounted in the extruder. Systems employing the spin pack assembly 100 respond relatively slowly to changes in operating conditions, such as temperature and pressure. In addition, a significant temperature loss from the set point to the spin pack assembly is typically observed, requiring the operator to adjust the set point temperature to about 20 degrees celsius above the desired temperature.

2. Description of the New spinneret design ("beta Module design")

According to various embodiments, a capillary spinneret for producing melt spun fibers from polyetherimide can be similar to a bath head design in that the capillary spinneret can have an array of capillaries uniformly distributed around the face of the circular assembly.

Fig. 2 is a schematic illustrating a spin pack 200 having a capillary spinneret 201, according to various embodiments. The particular capillary spinneret 201 illustrated in fig. 2 has 72 capillaries 202, however any suitable number of capillaries may be employed. Capillary spinneret 201 may be sandwiched between base plate 204 and end cap 205 along with distribution block 203. The distribution block 203 can have a plurality of distribution holes 206 for distributing the molten material to the capillary spinneret 201. The end cap 205 may have a plurality of through holes 207 alignable with corresponding holes 208 on the base plate 204 to secure and compress the spin pack assembly 200 via bolts or other fastening means.

Fig. 3 is a schematic illustrating a spin pack assembly 300 having a capillary spinneret 301, according to various embodiments. The particular capillary spinneret 301 illustrated in fig. 3 has 144 capillaries 315, however any suitable number of capillaries 315 can be employed. Between the end cap 305 and the base plate(s), a capillary spinneret 301 may be sandwiched along with a screen pack filter 302, a first washer 303 and a second washer 304. As shown in fig. 3, a first base plate 306 and a second base plate 307 may be employed.

The end cap 305 may have a plurality of through holes 308 alignable with corresponding holes 309 on the first base plate 306 to secure and compress a plurality of components of the spin pack assembly 200 via bolts or other fastening means. The first base plate 306 may be fastened to the second base plate 307 via bolts or other fastening devices that are inserted through holes 310 in the first base plate 306 into receiving holes 311 in the second base plate 307.

The second base plate 307 may include an injection port 312 through which molten material may be injected into the spin pack assembly 300, for example, from an extruder to which the spin pack assembly 300 is fastened via bolts or other fastening devices inserted through fastening holes 313 in the second base plate 307. The first base plate 306 may include one or more distribution ports 314 to allow the molten material to continuously flow through the spin pack assembly 300.

The embodiment described below employs a spin pack 300 as shown in fig. 3, since a capillary spinneret 301 with 144 capillaries results in a similar throughput as the old "alpha" pack design.

In this design, the delivery of the melt to the component face has been simplified and improved (streamlined). The distributor plate has been eliminated and the distribution of the melt is accomplished only through the screen assembly filter 302. Distribution port 314 provides a full circular work wheel system to direct the melt stream from the machine outlet to the center of the filter backside of the screen pack filter. Gaskets 303 and 304 may provide sufficient cavity behind filter 302 (i.e., on the side closest to first base plate 306) to allow for uniform flow of material behind the screen. Once sufficient pressure is built up after the screen pack filter, the melt passes through and into the spinneret. It is then extruded through a capillary 315 via a forming pressure and drawn off onto a take-up roll (take up roll) and wound onto one or more bobbins (bobbin)410, as shown in fig. 4.

Fig. 4 is a schematic diagram of a fiber process 400. The melt stream 401 from the extruder can be fed to a metering pump 402, through a filter 403, and through a spinneret 404. After exiting the spinneret 404, the melt stream 401 can be passed through an air anneal 405. A converging guide 406 may guide the fibers 407 to an oil feeder 408 and wound onto one or more bobbins 410 by a series of draw godet rollers 409.

Various spinnerets were designed and constructed to allow different length to diameter (L/D) ratios (1 to 6), and diameters of 0.2mm to 1.0mm to be studied in the capillary bore. In addition, depending on the material viscosity, screen pack filters with mesh sizes ranging from 200 to 400 mesh were used.

This spin pack design was installed on a Hills GHP bicomponent melt spinning extrusion line. It is designed to fit within the same component housing (pack envelope) used in the alpha design. The new design is configured to provide sufficient space around the assembly head to allow direct contact temperature control with a high wattage heater band. The new design provides tighter and faster thermal control over the face of the spin pack (the critical component in the melt spinning process).

Description of the manufacture of PEI with a novel beta spinneret design

The material was dried at 300 degrees fahrenheit for 4 to 8 hours to remove any moisture that would cause polymer degradation in the melt state.

The spin pack assembly was assembled and placed in a preheating oven to bring it to operating temperature before installation into the machine and melt stream.

The machine was turned on and preheated for several hours before any material was introduced into the extruder. Once the temperature was reached, the extruder was charged with pellets using an automatic loader on a hopper above the extruder. The melt pump was turned on and then the extruder was turned on. These are manually controlled until both melt streams come out of the machine and reasonable melt pressures and velocities are achieved. Subsequently, the melt pressure is automatically controlled by pressure throughout the remainder of the process.

When the temperature and pressure reached the desired equilibrium, the pump and extruder were stopped, and the spinneret was removed from the oven and installed into the machine. An external heating band is mounted to the spin pack assembly along with its control thermocouples. This unit is then turned on and set to the desired set point.

Subsequently, the melt pump and extruder were restarted. The extruded fibers were collected in a trash can and the culture spinnerets brought to operating temperature. When this occurs, a sample of the melt is taken as a fiber to determine the melt specific gravity.

Once the temperature and pressure became horizontal, the fibers were then drawn into a suction gun and collected on feed or forwarding rolls under an optional spin finish kiss roll. The speed of the pump and impeller rollers defines the diameter, or denier per filament (dpf), of the resulting fiber. Once the desired dpf is obtained, the fibers are then loaded into a winder. The winder winds the fiber bundle onto at least one spool or a plurality of bobbins for subsequent use in a downstream process.

For 2dpf and lower denier PEI fibers, we run the pump at 4 to 6rpm and the impeller rolls at 1500 to 2500 m/min. No further stretching is required on any draw rolls (draw rolls) or no annealing is required on any relax rolls (relax rolls) with this process configuration.

Description of the manufacture of PEI with an old alpha spinneret design

The steps of the alpha spinneret design are identical in terms of process steps of start-up and run-up. The difference occurs when you want to achieve 2dpf or finer fibers. In this case it is necessary to draw the fiber on a draw roll and try to control the shrinkage on a relax roll.

For 2dpf PEI fibers using this setup, we run the melt pump between 5 and 7rpm and the feed rolls are 1500 to 2500 m/min. A feed roll operating at a temperature of 200 degrees celsius maintained between 1500m/min and 2500m/min, a draw roll (draw roll) maintained at a temperature of 200 degrees celsius maintained between 2250m/min and 3000m/min, and a relax roll also maintained at a temperature of 200 degrees celsius maintained between 2250m/min and 3000 m/min. The annealing of the fiber and the resulting shrinkage can be controlled by increasing the number of windings on the godet (godet) and the temperature of the godet.

Techniques for measuring fiber denier

Fiber denier or linear density is measured according to ASTM D1907-07 test method. For a specified number of revolutions, the fiber is wound on a spool one meter in circumference and then weighed. The mass and length of the sample determine the linear density or denier of the individual fiber filaments.

Technique for measuring fiber shrinkage

Fiber shrinkage testing was performed according to ASTM D2559 dry heat method. A fiber sample 1 meter long was placed in an oven and exposed to a suitable temperature for a predetermined amount of time. The sample was then removed from the oven and the subsequent length was measured. Its deviation from the original 1 meter length determines its percent change or shrinkage.

Example 1

The purpose of this example is to make PEI fibers according to our invention. The fibers were made according to the procedure described above, except that an 11/4 inch extruder and beta block design were used. A0.6 mm capillary spinneret with 4L/D was used, and a 325 mesh screen pack filter was used.

The fibers produced had a dpf of 2 and a shrinkage of less than 2%. Unexpectedly, the fibers exhibit a combination of low denier and low shrinkage when produced directly from a spinneret without the need to stretch or anneal the fibers after initial receipt. It is possible to produce fibers at speeds of 1500 to 2250m/min for at least 2 hours without damage. This example advantageously demonstrates that low denier fibers can be made from polyetherimides having a molecular weight distribution of at least 2.5.

Example 2

The purpose of this example is to repeat the performance of the method of example 1 and to produce polyetherimide fibers according to various embodiments of the invention. The fibers were made according to the procedure described above. A0.6 mm capillary spinneret was used with a 4L/D and 325 mesh screen pack filter. The resulting fiber had 1.8dpf and a shrinkage of less than 2%.

The resulting fibers exhibit a combination of low denier and low shrinkage when produced directly from a spinneret under low shear conditions without the need to stretch (draw) or anneal the fibers. It is possible to produce fibers at speeds of 1500 to 2250m/min for at least 2 hours without damage. This example advantageously demonstrates that low denier fibers can be made from polyetherimides having a molecular weight distribution of at least 2.5.

Example 3

The objective of this example is to produce polyetherimide fibers according to an embodiment of the invention when a lower purpose filter screen assembly filter is included. Fibers were made according to the procedures of example 1 and example 2, except that a 200US mesh screen pack filter was used.

The resulting fibers exhibit a combination of low denier and low shrinkage when produced directly from a spinneret under low shear conditions without the need to stretch or anneal the fibers. It is possible to make 2dpf fibers with 1.9% shrinkage. The fibers are produced at a speed of 1500m/min to 2250m/min for at least 2 hours without damage. This example advantageously demonstrates that low denier fibers can be made from polyetherimides having a molecular weight distribution of at least 2.5.

Example 4

The purpose of this example is to manufacture polyetherimide fibers according to an embodiment of the invention when a lower mesh filter screen assembly filter is included. The fibers were manufactured according to the procedures of example 1 and example 2, except that 400 mesh filter screen pack filters were used.

The resulting fibers exhibit a combination of low denier and low shrinkage when produced directly from a spinneret under low shear conditions without the need to stretch or anneal the fibers. It is possible to make 2dpf fibers with 1.8% shrinkage. The fibers are produced at a speed of 1500m/min to 2250m/min for at least 2 hours without damage. This example advantageously demonstrates that low denier fibers can be made from polyetherimides having a molecular weight distribution of at least 2.5.

Example 5

The purpose of this example is to manufacture polyetherimide fibers according to an embodiment of the invention. Fibers were made according to the procedure described in example 4, except that a 2L/D spinneret was used.

The resulting fibers exhibit a combination of low denier and low shrinkage when produced directly from the spinneret without the need to stretch or anneal the fibers. It is possible to make 2dpf fibers with less than 2% shrinkage. The fibers are produced at a speed of 1500m/min to 2250m/min for at least 2 hours without damage. This example advantageously demonstrates that low denier fibers can be made from polyetherimides having a molecular weight distribution of at least 2.5.

Example 6

The purpose of this example is to repeat the performance of example 5 and to manufacture PEI fibers according to an embodiment of the present invention.

The resulting fibers exhibit a combination of low denier and low shrinkage when produced directly from a spinneret under low shear conditions without the need to stretch or anneal the fibers. It is possible to make 2dpf fibers with less than 2% shrinkage. The fibers are produced at a speed of 1500m/min to 2250m/min for at least 2 hours without damage. This example advantageously demonstrates that low denier fibers can be made from PEI having a molecular weight distribution of at least 2.5.

Example 7

The purpose of this example is to manufacture polyetherimide fibers according to an embodiment of the invention. Fibers were made according to the process described above, except that this example was run on a 1 inch screw with a beta pack design. This setup used a 0.2mm capillary tube with 4L/D and a 200 mesh screen pack filter.

The resulting fibers exhibit a combination of low denier and low shrinkage when produced directly from a spinneret under low shear conditions without the need to stretch or anneal the fibers. It is possible to make 1.7dpf fibers with 1.1% shrinkage. The fibers are produced at a speed of 1500m/min to 2250m/min for at least 2 hours without damage. For this embodiment, the smaller capillary size results in the module pressure rising to 1400 psi. This example advantageously demonstrates that low denier fibers can be made from PEI having a molecular weight distribution of at least 2.5.

Example 8

The purpose of this example is to manufacture polyetherimide fibers according to an embodiment of the invention. Fibers were made according to the process described above, except that the present example was run on a 1 inch extruder using a beta pack design. The spinneret was a 0.4mm capillary diameter with a 4L/D ratio. Also in this scheme, a 200 mesh screen pack filter is employed.

The resulting fibers exhibit a combination of low denier and low shrinkage when produced directly from a spinneret under low shear conditions without the need to stretch or anneal the fibers. It is possible to make 2dpf fibers with 1.5% shrinkage. The fibers are produced at a speed of 1500m/min to 2250m/min for at least 2 hours without damage. This example advantageously demonstrates that low denier fibers can be made from PEI having a molecular weight distribution of at least 2.5.

Example 9 (comparative example)

The purpose of this example was to produce polyetherimide fibers according to the prior art "alpha" spin pack assembly design (shown in FIG. 1 as comprising a distribution plate). Fibers were made according to the above procedure and the following results were obtained. Use of9011 PEI fibers were made. This example was run on a 1 inch extruder. A0.6 mm capillary spinneret with 4L/D and a 325 mesh screen pack filter were used.

The results indicate that when PEI fibers are made under high shear conditions, e.g., at pressures greater than or equal to 1400psi, it is not possible to make undrawn and unannealed PEI fibers that exhibit the low shrinkage exhibited by fibers produced according to various embodiments of the present invention. More particularly, in this example, the fibers were produced at 2.2dpf and 4% shrinkage. Furthermore, in order to obtain fibers using an alpha spin pack, it is necessary to draw out the fibers and then anneal them in an attempt to achieve 2 dpf. This method then results in a higher shrinkage than the method according to various embodiments of the present invention. Additionally, this example employs high assembly pressures in excess of 1500psi, as compared to the pressures of most previous embodiments (400 to 600 psi).

Table 2 provides a summary of the results obtained in examples 1-9.

Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.

The contents of all papers and documents which are filed concurrently with this specification and those which are open to public inspection are incorporated herein by reference.

All the features disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

Claims

1. A method, comprising:

extruding a melt through a spinneret at a pressure of 400 to 1500psi to produce a spun fiber, wherein the melt comprises an amorphous polymer composition;

collecting the spun fibers on a feed roll without drawing the spun fibers,

producing a solidified fiber from the spun fiber,

wherein the cured fibers have a dpf of greater than 0 to 2.5dpf,

wherein the cured fiber has a shrinkage of less than or equal to 2%; and

winding the solidified fiber onto a spool without subjecting the solidified fiber to a drawing step.

2. The method according to claim 1, wherein the amorphous polymer composition has a melt flow rate of 4 to 18g/10 min.

3. The method of any one of claims 1 or 2, wherein the pressure is 400 to 1000 psi.

4. The method of any of claims 1-3, further comprising collecting the fiber onto the spool without an annealing step.

5. The method of any one of claims 1 to 4, wherein the solidified fibers are produced without a forced air cooling step.

6. The process of any one of claims 1 to 5, wherein the process further comprises heating the spun fiber after it exits the spinneret.

7. The method of any one of claims 1 to 6, wherein the melt comprises one or more crystalline materials.

8. The method of any one of claims 1 to 7, wherein the amorphous polymer composition comprises a polyetherimide.

9. An undrawn amorphous polymer fiber having a denier of less than 2.5 and a shrinkage of greater than 0 to less than or equal to 2%.

10. The undrawn amorphous polymer fiber of claim 9, wherein the polymer fiber is a polyetherimide fiber, wherein the fiber has a polydispersity (Mw/Mn) greater than or equal to 2.5.

11. The undrawn amorphous polyetherimide fiber of any one of claims 9 to 10, wherein the fiber has a denier of less than 2.2.

12. The undrawn amorphous polyetherimide fiber of any one of claims 9 to 11, wherein the fiber has a strength of at least 2.6 cN/dtex.

13. The undrawn amorphous polyetherimide fiber of any one of claims 9 to 12.

14. An article comprising the undrawn amorphous polyetherimide fiber of any one of claims 9 to 13.

15. A spinneret for producing an amorphous undrawn polyetherimide fiber of at most 2.5dpf from a composition comprising an amorphous polyetherimide, the spinneret comprising

There is no distribution plate; and

a die having a plurality of circular melt channels, wherein each circular melt channel has a length and a diameter, and wherein each circular melt channel has a length: the ratio of the diameters is 2:1 to 6: 1.

16. The spinneret of claim 15, wherein the spinneret operates at a pressure at least 40% lower than the operating pressure of an identical spinneret comprising distribution plates.

17. The spinneret of any one of claims 15-16, wherein the spinneret further comprises at least one screen pack filter associated with the die to distribute the composition to the die.

18. A spinneret according to claim 17, wherein the filter screen pack filter has a US mesh size of 200 to 400 mesh.