USRE24691E

USRE24691E - Process for forming films and filaments

Info

Publication number: USRE24691E
Authority: US
Priority date: 1955-02-21
Publication date: 1959-08-25
Also published as: US2813775A

Description

Aug. 25, 1959 w. STEUBER Re. 24,691v

PROCESS FOR FORMI FILMS AND FILAMENTS DIRECTLY FROM P MER I RMEDIATES Original Filed Feb. 1955 INVENTOR WALTER STEUBER BY 7% I ATTORNEY United States Patent fi ice Re. 24,691 Reissuetl Aug. 25, 1959 PROCESS FOR FORMING FILMS AND FILAMENTS DIRECTLY FROM POLYMER INTERMEDIATES Walter Steuber, Springfield, Pa., assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware Original No. 2,813,7 75, dated November 19, 1957, Serial No. 489,583, February 21, 1955. Application for reissue November 25, 1958, Serial No. 776,666

20 Claims. (Cl. 18-54) Matter enclosed in heavy brackets appears in the original patent but forms no part of this reissue specifi cation; matter printed in italics indicates the additions made by reissue.

This invention relates to a process. More particularly it concerns a process for forming a shaped body having a continuous cross section, by combination of two liquid complementary reactive polymer intermediates, the said combination being accomplished by extruding one of the said intermediates into the other.

It is an object of the present invention to provide -a process for the production of a shaped body of continuous cross section by combination of two liquid complementary reactive polymer intermediates.

Another object is to provide a process for the production of an elastic shaped body of continuous cross section by combination of two liquid complementary reactive polymer intermediates.

These and other objects will become apparent in the course of the following specification and claims.

In accordance with the present invention a process is provided which comprises forming a solid shaped structure of continuous cross section by combining at least two liquid complementary reactive polymer intermediates, one of which contains at least two active hydrogens more reactive than alcoholic hydrogen, whereas its complement contains at least two reactive groups capable of reacting with alcohol at room temperature to form an ester, and at least one of the said complementary reactive polymer intermediates being a multi-functional organic macromolecule possessing recurring amide type linkages and having a molecular weight within the range of from about 400 to about 7000, and at least one of the other of the said complementary reactive polymer intermediates being a poly functional, essentially monomeric, organic molecule, the proportionate molecular weights of macromolecular intermediate to the essentially monomeric molecular intermediate being such that at least about 30% by Weight of the final shaped structure is contributed by the macromolecular intermediate [while at least about by weight of the final shaped structure is contributed by the essentially monomeric molecular intermediate], the combination of the said complementary intermediates being accomplished by extrusion through an orifice of one said complementary polymer intermediate into the other.

The liquid complementary reactive polymer intermediates correspond to the formulae:

wherein n is a small integer greater than 1, X is hydrogen more active than alcoholic hydrogen, Y is a group capable of reacting with alcohol at room temperature to form an ester, R and R are members of the class consisting of the radical of a polyfunctional essentially monomeric organic polymer intermediate and the radical of a polyfunctional macromolecular polymer intermediate containing recurring amide-type linkages and having a molecular weight range of from about 400 to about 7000. The complementary reactive polymer intermediates are so chosen that at least 30% and preferably 60% of the weight of the final shaped article is contributed by the polyfunctional organic macromolecule {whereas at least 10% of the weight of the final shaped article is contributed by the polyfunctional, organic, essentially monomeric molecule].

'By the expression a shaped body of continuous cross section is meant a solid structure in the nature of a filament or film whose cross section is uniform and unbroken as opposed to structures which have soft or hollow centers. The terms monomeric and essentially monomeric are used interchangeably to signify a monomer or a polymer having a low degree of polymerization, i.e., dimer, trimer, etc. The term polyfunctional indicates the presence upon the molecule of at least two reactive groups capable of reaction with a complementary functionally substituted molecule to form a polymer under conditions of the present invention. The expression polymer intermediate denotes a molecule polyfunctionally substituted and capable of reacting with a complementary polyfunctionally substituted molecule to form a polymer under reaction conditions of the present invention. By the expression amide-type linkages is meant that the molecule contains between recurring units, linkages represented by the formula it 1i wherein X II A is a member of the class consisting of o s II N g and 0 g H o and R is hydrogen, lower alkyl, and lower alkylene when the diamine has a ring structure.

Figure 2 is a diagramamtic sketch of the typical spinning set-up of the present invention.

Figure l is an illustration of a cross-sectional element of a filament prepared in accordance with the present invention.

In Figure 2 one of the reactive intermediates is supplied through the supply tube 2 and extruded through the orifice 3 into the other complementary reactive polymer intermediate 1. The filament 4 which is formed by the reaction of the two intermediates is then led around the rollers 5 and 6 to be wound in the conventional manner.

The following examples are cited to illustrate the invention. They are not intended to limit it in any manner. Among the physical properties reported for the products in the examples, polymer melt temperature is the minimum temperature at which a sample of the polymer leaves a wet, molten trail as it is stroked with moderate pressure across a smooth surface of a heated brass block. Fiber stick temperature is the temperature at which the fiber will just stick to a heated brass block when held against the surface of the block for 5 seconds with a 2.00 grams weight. Zero strength temperature is the average temperature at which the two ends of the fiber break if heating is continued with the 3 weight left on after the fiber stick temperature has been determined. Initial modulus is determined by measuring the initial slope of the stress strain curve. The .i sm q has particula alu n the .ptepara e 'of ai t-t sl s .1axiss hi a... Y this p op y st uct es a n l d d wh x it el sti reeqygeriesabove90% and stress decays below 20%. :Elastic recovery is vthe percentage return to original length W .1 9. m nute after the tension has beensreleased .ir in-a sample which has elongated 50% .at the rate of ,;1-00% per minute andlheld at 50% elongation for .onetninute. fStress decay is the percent lossjn stress in a yarn one minute after it has been, elongated to 50% s il ratev .Q 7 m nute- EXAMPLE I A low mo ecula w is i poly m d e prepare y r 113-5 ste (.0 0 mo o a aquenus solu ion son 5%.he am fltvl n diamin wi h 1-.5-0 ams 08 mol) of azelaicacid a la ge polymer-tube. The eua ilfl ed f hed wit rog n, an h i on n ,melted at 245 .Wnter is removed for 20 hours at t at te pe a u e at atmo ph c p e u e a und vvacuum for V3 hoursuntil a tinal pressure of O. 2 mm. of mer-curyis obtained. A 95% yield of calibQXYl-free polymer with an average molecular weight of 16.7.8isobtained.

ma r m l c lar me m. iat p em s d, is ex rude th ou h a n lehol spinn t into a 2 C- .ba co p s n 2 hi wei h of -m thvl mip eny n is eya ate in a silicon oil Q- F u m-mi d w -.DOW lC r i-ns Corpof id nd, .M his Th filaments obtained vare drawabletwotimestheir extruded length in hot air. They have a polymer melt temperature of about 200 C.

EXAMPLE II A polyamide with a molecular weight of 1500 is prepared by heating N,N'-diisobutylhexamethylenediamine with azelaic acid overnight. This liquid, macromolecular intermediate with ends is extruded through a one-hole spinners t into liquid ,hexamethylenediisocyanate (a monomeric intermediate) at room temperature to produce a rubbery filament.

EXAMPLE HI The low molecular weight polyamide of the preceding example is mixed with 2 mols of triethylamine (an acid acceptor) for each mol of polymer. This mixture is extruded through a one-hole spinneret into liquid sebacyl chloride at room temperature. A rubbery filamentis obtained.

' EXAMPLE IV A Ftrimer with hydroxyl ends isprepared by heating and stirring 3 mols of poly(tetrarnethylene oxide) glycol having a molecular weight of 1000 with 2 mols of 4- methyl-m-phenylenediisocyanate and continuing the heating for Shoursover a steam bath. This product is provideflwifl reactive isocyanate. ends byreacting-it for one hour under similar. conditionswith 2 mols ofp ,p-methylenediphenylisocyanate :for each mol of trimer. The P1 dUQI fromthe second reactionismixed withsuflicient N,N-dimethylfonnamide to make a spin dope containing 7 lids The sp d pe e u a 3 4. po per square inchthroughan 8 mil one=hole spinneretinto aliquid ethylenediantlinebath. The filaments formed are removed atfla rate of 56 feetperminute. They are thereaft rtransfe r d hmu ai om th tal lP to a se ond I011. w ic c lle s th fi m a a'r of 80 .feetper minute. They are then wound up one bobbin immersed in water at 67 feetper minute. The as-spun filaments are heat-set in ,water and boiled-0E to yield fi am nt w th. the ,i llowing p op rti nac ty= 19-1 elcna tione319%, initial m du u =0l en s den e 45. st es deay;8.1%. a d nsil reco ery 8%. Thepolymer in hesefila e has n in eren v1scos-ity in hexamethylphosphoramide of 1.03, as com- EXAMPLE V A portion of the spin dope of the preceding example .is extruded intoabath comprising 50% ethylene .diarnine and 50% triethylcnetetraminc. The filament obtained isremoved from the bath at a rate of 44 feet per minute and is woundup at a r-ate of 57 feet perminute on abobbin immersed in water. After relaxing in boiling-water, the as-spun filaments have the following properties: Tenacity=0;25 g.-p.-d., elogation:332%, initialmodulus =0.24 g.p .d.,,,denier=l87, stress decay=15 percent, .and tensile recovery='96%.

As will be apparent from the examples above, the polymer comprising the final shaped article may be of the linear, cross-linked or a combination of-the two varieties. Furthermore, the polymeric product, regardless of its variety of linkage, may be of a coupled type, i.e. only one of each of two complementary intermediates is used in its production, or segmented, i.e. a mixture of at least two 'homofunctional species of one intermediate is reacted with one ormorespecies of complementary homofunctional intermediates. vIn the 'fonnation-of the segmented products the speed of reaction between the-various complementary intermediates is preferably substantially equal. It is preferable thatthespeed of reaction of the fastest reacting complementaryintermediates be close to the speed ofreaction of theslowestreacting complementary intermediates in any particular system.

The invention is particularly useful inthe preparation of shaped articles possessingelasticity. The degree of elasticity will vary somewhat the identity of the complementary polymer intermediates.

The effect of the macromolecularpolymer intermediates is particularly pronounced in-this regard. In general highly elastic products maybe: formed with macromolecularintermediates having a molecular weight in the lower endof the'range specified, i.e., around 400, provided the product iscross-linkedor segmented with units of polymer derived from essentially monomeric polymer intermediates. Arnacromolecular intermediate of somewhat highenmolcular weight, around 800, is preferable,

when the product formedi-s a linear coupled polymer.

The use of a macromolecular intermediate having a meltingpointnohigher-than about 50C. is particularly advantageousinimparting elasticity to'the final product.

The elastic properties of the structures obtained is varied to a lesser extentby the ssentially monomolecular intermediates. This appliesparticularly to the structures ing together toform a polymerwith a-polymer melt temperature above 200 C. in the fiber-forming -molecular weight'range. The higher the melting point of this segment, the closer the molecular weight of the macromolecularintermediate can approach therninimumyalue and still retain excellent elasticity. If the reactive macromolecular intermediate is extruded into a liquid comp-rising only one complementary, essentially monomeric fast-reacting intermediate, then-it is preferred that this essentially. monomeric intermediatebe capable of reactionwithithe endgroups of the macromolecular intermediate to form a polymer which melts above 250 C. in the fiber-forming molecular .weight range. The variation of elasticity caused by the character. of the essentially monomolecular intermediate, as mentioned above, is .much less pronounced When cross-linked structures are prepared. However, generally it is preferred that the final structure con tain only a small number of cross-links per molecule. This can be accomplished by using a relatively high molecular Weight macromolecular intermediate (one having a a molecular weight in the range of about 3000 to about 5000) or by using at least two complementary essentially monomeric intermediates, one of which is difunctional and one of which is multifunctional, the latter representing a small percentage of the mixture.

The use of a macromolecular intermediate having a molecular Weight above the indicated minimum values has an advantage due to the fact that a high molecular weight fiber-forming polymer is obtained by combination of a relatively small number of molecules. As a result, little by-product is formed, particularly where polymerization proceeds by condensation. This simplifies tllreadline formation and attendant purification processes. Furthermore, high solids spinning dopes (i.e. the material extruded) can be used, which reduces solvent removal and recovery problems. An important end result is the ready formation of solid structures, such as filaments and films, rather than collapsed tubular filaments or laminated films. For these reasons the use of at least one macromolecular intermediate having a molecular Weight of about 1000 to about 5000 is preferred.

The liquid complementary reactive polymer intermediates are combined in accordance with the present invention, by extruding at least one such intermediate through an orifice into its complement and the shaped article formed is led away from the orifice as it forms to a reel or other suitable conventional wet-processing collecting means. Generally it is preferred to extrude the phase containing the macromolecular intermediate. For spinning fibers extrusion may be through a conventional wetspinning spinneret. A spinneret providing an orifice of about 3 to about mils is preferred although orifices of larger diameter may be employed. Furthermore, orifices of shapes other than round are suitable. A slotted orifice may be used to produce films and ribbons. The shaped article may be Washed, stretched, lubricated or otherwise after-treated.

Preferably each complementary reactive inter-mediate is a liquid under the conditions of the reaction or is dissolved in a liquid diluent. However, one of the said intermediates may be a finely divided solid dispersed in a liquid in which it is at least partially soluble. When diluents are employed it is preferred that the total concentration of the extruded intermediate be at least about 35% by weight of extruded material. Use of higher concentrations promotes compactness of the polymeric structure and reduces the problems associated with handling large volumes of solvents, particularly the organic solvents, which tend to be toxic, expensive, inflammable, etc. Satisfactory solid products can be obtained by using lower concentrations for some sets of complementary intermediates.

The speed at which the formed solid shaped products can be collected will depend upon the specific reactants and reaction conditions, such as the diluents used and the concentration of the reactants in these diluents. Much of the influence exerted by the diluents appears to lie in their eifect upon the base strength of the intermediate reactant which is to act as a proton donor in the reaction. For example, the effect is quite marked when water is used as a. diluent, but inert diluents for diamines, such as benzene and dioxan, appear to exert little noticeable effect on the course of the reactions involved in this process. Additional functions of the diluents are to control the viscosity of the phases and the interfacial tension between the extruded phase and the bath. For example, it has been noted that the addition of low percentages of N,N-dimethylformamide to viscous spin dopes permits better penetration by the bath and results in higher tenacities.

Useful inert diluents for diamines include dioxan, benzene, tetrahydrofuran, and the like. Suitable inert materials for diluting acid halides, such as acid chlorides and chloroformates, include benzene, toluene, xylene, cyclohexane, trichloroethylene, chlorobenzene, nitrobenzene, heptane, isooctane, diethyl ether, ethyl acetate, methyl amyl ketone, ethylene dichloride, carbon tetrachloride, chloroform, etc. It is essential that the diluents be materials which do not react as readily'with either polymer-forming intermediate as does its complementary intermediate, and thus reduce the probability of polymer formation.

While it is sometimes desirable to add an acid acceptor to a system which involves a reaction between a diacid halide and a coreactant, it is not necessary to do so. The particular advantage in using about an equivalent of alkali per equivalent of diamine in the bath is that it regenerates the diamine from any amine hydrohalide that forms, and minimizes the recovery of diamine from bath liquors. The process is ordinarily operated at room temperature, although temperatures ranging from 10 C. to C. have been used successfully.

As previously defined, one of the complementary polymer intermediates contains at least two active hydrogens more reactive than alcoholic hydrogen, i.e. the hydrogen of an alkanol. Among end groups providing such a hydrogen may be mentioned SH, phenolic-OH, amino- NHR (in which R is H or alkyl) and amidino. The other complementary polymer intermediate contains at least two reactive groups capable of reacting with alcohol to form an ester. Among such groups may be mentioned the acid chloride group, the chloroformate group and the isocyanate group. The use of complementary polymer intermediates which form a self-supporting polymeric structure within 10 seconds after combination at room temperature is preferred. A large variety of suitable such combinations is illustrated in copending U.S. application No. 226,066, filed May 12, 1951, now Patent No. 2,708,617.

As previously disclosed the multifunctional organic macromolecular intermediate is a compound having a molecular weight within the range of from about 400 to about 7000 and containing recurring amide-type linkages. Suitable materials include polyamides, polyureas, polysulfonamides, polyurethanes combinations of these and the like. The polymer chains may be interrupted by oxygen or sulfur. They may he substituted with halogen or the like.

Polyurethanes suitable for use as macrointermediates can be prepared by reacting the bischloroformates of glycols, such as ethylene glycol, cyclohexanediol, or the polyether glycols, with a primary or secondary diamine, such as hexamethylenediamine, 1,4-diaminocyclohexane, pphenylenediamine, and piperazine. For elastomers, these are preferably the aliphatic diamines, such as ethylene diamine, propylene-diamine, butylenediamine, pentamethylenediamine, hexamethylenediamine, and N,N-diisobutylhexarnethylenediamine. As shown by the examples, this can also be accomplished by reacting low molecular weight polyether glycols, such as the poly(alkylene oxide) glycols, with diisocyanates.

Polyureas may be obtained by (1) reacting diamines With phosgene, (2) reacting phosgene with a diamine to [form a biscarbamyl chloride, which is reacted subsequently with another diamine: or more of the same diamine to form a polyure-a, or (3) by reacting a diamine with a diisocyanate. Any diamine, such as ethylenediamine, propylenediamine, butylenediamine, pentamethylenediamine, hexamethylenediamine, p-phenylenediamine, 4- methyl-m-phenylenediamine, bis(p aminomethyl)methane, 1,4-diaminocyclohexane, piperazine, and trans-2,5- dimethylpiperazine, may be used. The corresponding diisocyanates, such as hexamethylene diisocyanate and 4-rnethyl-m-phenylene diisocyanate, may be used as core- -actants whenever available. When low melting low molecular weight polymers are desired, it is preferable to prepare copolymers from aliphatic diamines or diisocyanates, with long chain or branched chain aliphatic diamines producing lower melting polymers more readily.

Polyamides are prepared by reacting acids or their amide-fanning derivatives, particularly the acid halides, such as those derived :from oxalic, sucoinic, adipic, suberic, azelaic, sebacic, isophthalic, terephthalic, hexahydroterephthalic, 1,5-naphthalene disulfonic, .1,2-ethanedisulfonic, and 1,6-hexanedisulfonic acids, with the diamines listed in the two preceding paragraphs. Once again, if it is desired that the low molecular weight macrointerrnediate be low melting, it is preferred that all of the intermediates used to prepare the polyamides be aliphatic. Disecondary diamines, such as N,N-diisobutylhexamethylenediamine, are particularly useful for this purpose.

The polyfunctional essentially monomericorganic polymer intermediate may be any polymer-forming molecule corresponding to the formulae wherein n is a small integer greater than 1, X is hydrogen more active than alcoholic hydrogen, Y is a group capable of reacting with alcohol at room temperature to to form an ester, Z is an organic radical and m is. a small number at least 1. Among such materials may be mentioned alkylene diamines such as ethylene diamine, propylene diamine, ,hexamethylene diarnine, as well as phenylene diamine, diaminocyclohexane, diethylene triamine, adipyl chloride, sebacyl chloride, terephthaloyl chloride, phenols such as resorcinol, the his chloroformates of the alkylene glycols and the like.

The shaped bodies of the present invention are of continuous and uniform cross-section, i.e. they are solid without soft or open centers. In general, these structures are relatively stable to hydrolysis under the conditions .used for commercial laundering. This is an important attribute for filaments which are to be utilized in fabrics subject to washing. Most are more resistant to oxidation than are the conventional elastic filaments. If desired, their stability can be improved by incorporating commercially available antioxidantsand ultra-violet light stabilizers.

The high tenacity, high initial modulus, excellent abrasion resistance, and easily controlled elongation of the elastic structures prepared by the process of this invention 'fit them for many applications, particularly in film and filament form, for which rubber is undesirable. A particular advantage is that uncovered low denier multifilaments can be used to prep-are sheer elastic fabrics. An important additional advantage, particularly for filaments, is that solid structures are obtained by a simple process. A large percentage of the rubber threads used and are prepared by slitting rubber sheets. This produces relatively large denier filaments, which cannot be converted readily into mnltifil-amentsand are not acceptable for many uses, particularly in certain fabrics.

In general, the process of this invention provides a very useful tool for preparing films and fibers comprising high molecular weight condensation polymers. The process circumvents many of the normal steps required for converting polymeric materials into useful shaped articles. -It provides. the only method for the preparation of shaped articles from certain polymeric materials, for example, those prepared from intermediates that are unstable at the high temperatures normally required in the condensation reaction. --It provides a method for preparing elastic polymers of sufliciently high molecular weight at room temperatures that the shaped articles are useful. Also, intermediates which would normally be too impure-forconventional meltpolymerization can be used. In addition, there is. no needto maintain a delicate balance of-materials in. orderto obtainhigh molecular weight polymer, is required by melt polymerization. Flhere 8 is also provided a new method for preparing films and filaments comprising certain cross-linked polymers.

Many equivalent modifications will be apparent to those skilled in the ;art "from a reading of the above description without a. departure from the inventive ,con-

,cept.

wherein and and R is a member of the class consisting ,of hydrogen, lower alkyl, and the lower alkylene chainof a heterocyclic diamine and having a molecular weight within the range of from about 400 to about 7000, and at least one of the other of the said complementary reactive polymer intermediates being a polyfunctional, monomeric, organic molecule, the proportionate molecular weights of .macromolecular intermediate to the monomeric molecular intermediate being such that at least about 30% by weight of the final shaped structure is contributed by the macromolecular intermediate [while at least about 10% by weightof the final shaped structure is contributed by the monomeric molecular intermediate], the combination of the said complementary intermediates being accomplished by extruding through an orifice on said complementary polymer intermediate into the other.

2. The process of claim 1 wherein the macromolecular intermediate comprises at least about 60% by weight of the final shaped article.

3. The process of claim 1 wherein the extruded liquid contains a macromolecular intermediate.

4. The process of claim 1 wherein the macromolecular intermediate is essentially a polyamide.

5. The process of claim 1 wherein the macromolecular intermediate is essentially a polyurethane.

6. The process of claim 1 wherein the macromolecular intermediate is essentially a polyurea.

7. The process of claim 1 wherein the active hydrogens more active than alcoholic hydrogen are supplied by a mercaptan radical.

8. The process of claim 1 wherein the active :hydrogens more active than alcoholic hydrogen are supplied by a phenolic hydroxyl radical.

9. The process of claim 1 wherein the active hydrogens more active than alcoholic hydrogen are supplied by an amino-Nl-IR radical wherein R is a member ,0f the class consisting of hydrogen and alkyl.

10. The process of claim 1 wherein the active hydrogens more active than alcoholic hydrogen are supplied by an amidino radical.

11. The process of claim 1 wherein the reactive groups capable of reacting with alcohol at room temperature to form an ester are acid halide.

12. The process of claim 1 wherein the reactive groups capable of reacting with alcohol at room temperature to form an ester are carbonyl halide.

13. The process of claim 1 wherein the reactive groups capable of reacting with alcohol at room temperature to form an ester are haloformate.

-14. The process of claim 1 wherein the reactive groups capable of reacting with alcohol at room temperature to form an ester are isocyanate.

15. The process of claim 1 wherein the complementary reactive intermediates combine to form an amide.

References Cited in the file of this patent or the original patent UNITED STATES PATENTS Magat May 17, 1955