US3468850A - Polyamide containing recurring saturated fluorene rings - Google Patents

Description

United States Patent 3,468,850 POLYAMIDE CONTAINING RECURRING SATURATED FLUORENE RINGS Peter William Foster, Geneva, Switzerland, assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware N0 Drawing. Filed May 20, 1965, Ser. No. 457,504

Int. Cl. C08g 20/00 US. Cl. 260-78 1 Claim ABSTRACT OF THE DISCLOSURE A synthetic linear fiber-forming polymer consisting essentially of recurring units of the formula wherein the geometric figure containing the letters S denotes a saturated fluorene ring for the hydrogen of which R, representing alkyl containing no more than 3 carbon atoms, may be substituted, and wherein n is a whole number from 0 to 12, inclusive, preferably a number from 4 to inclusive. The polymer may contain up to 10 weight percent of polyamide copolymeric units.

This invention concerns a novel and useful polymer. More specifically, it relates to a synthetic, linear, fiberforming polyamide containing polyalicyclic groups as an integral part of the polymer chain.

An object of this invention is to provide a novel and useful fiber-forming polymer. Another object is to provide a novel and useful fiber-forming polymer having good resilience. Still another object is to provide a synthetic linear fiber-forming polycarbonamide containing fused alicyclic groups as an integral part of the polymer molecule. These and other objects will become apparent in the following specification and claims.

In accordance with the present invention a synthetic linear, fiber-forming polymer is provided consisting essentially of recurring units of the Formula I wherein the geometric figure containing the letters S denotes a saturated fluorene ring for the hydrogen of which R, representing alkyl containing no more than 3 carbon atoms, may be substituted, n equals a whole number from 0 to 12 inclusive but preferably 4 to 10 inclusive, and X is copolymeric units whenever present constituting no more than about 10 mol percentage of the said polymer and being a member of the class consisting of polyamides, polyesters, polyurethane, polysulfonamide and polyureas.

The radical may be linked to any of the 4 carbon atoms of the 6 membered rings which are not involved in the fused ring linkages, provided they are not on the same ring. Preferably the two X radicals are attached to the perhydrofiuorene nucleus in a symmetrical manner.

A preferred embodiment of the invention is a synthetic, linear, fiber-forming polycarbonamide wherein the recurring carbonamide linkage is an integral part of the Patented Sept. 23, 1969 polymer chain consisting essentially of recurring units of the Formula II OH H! By fiber-forming is meant that the product of this invention is capable of being formed into useful filaments and fibers. The fiber-forming stage can be tested for in the conventional manner by touching the molten polymer with a rod and drawing the rod away. A continuous filament of considerable strength and pliability is readily formed if a fiber-forming stage has been reached. Normally a sufficiently high molecular weight to provide an inherent viscosity of at least 0.4 is required to reach the fiber-forming stage. Inherent viscosity as discussed herein is determined in a conventional manner on a solution containing .25 gram of polymer in 50 milliliters of m-cresol.

The polymers of this invention can be prepared in a conventional manner from the diamines or their amide forming derivatives and the dicarboxylic acids or their amide forming derivatives. The alicyclic diamines used as starting materials can be prepared using conventional organic synthetic procedures by nitrating fluorene to form the dinitro compound, followed by hydrogenation of both the nitro groups and the aromatic rings to produce the diaminoperhydrofiuorene compound. Conventional techniques can be used to separate the resulting isomers as desired. Perhydrofluorene dicarboxylic acid compounds may be prepared using conventional organic synthesis techniques by reduction of the corresponding dinitrofluorene compound to the aromatic diamine. The diamine is then converted to the aromatic dinitrile, by a Sandmeyer reaction for example, and hydrolyzed to the aromatic diacid. The fluorene dicarboxylic acid is then hydrogenated to give the corresponding dicarboxylic perhydrofluorene.

The following examples are cited for description purposes only and are not intended to limit the scope of the invention. Tensile strain recovery as reported herein is useful for predicting wash-wear performance. It is conducted by mounting a 10 in. specimen in the yarn clamps of an Instron Tensile Tester, immersing the specimen in 40 C. water for 2 minutes and then extending to a given elongation (0.5, 1.0, 1.5, 2.0, 3.0%). The clamp separation is maintained for a 2 minute period. The immersion tank is removed from the specimen and the stress reduced to 0.042 g.p.d., and maintained for a 2 minute period. The Instron clamps are then returned to the original separation and the resulting increase in yarn slack measured. The dilference between the amount of elongation imparted to the yarn and the amount of slack remaining after recovery is an indication of the recovery obtained at specific elongations. The test is repeated with a fresh sample at each elongation. The tensile strain recovery value is plotted vs. elongation and the area under the curve integrated; this indicates the average value at 0.042 g.p.d. stress. The final value recorded is the average of the determinations at the five different elongations. The stress level of 0.042 g.p.d. is chosen to simulate the effect of fiber friction in a fabric. A tensile strain recovery value of 40 or above is considered to give acceptable wash-wear performance.

EXAMPLE I 2,7-diaminofluorene grams) is hydrogenated in 100 ml. dioxane using 10 grams 5% ruthenium on aluminum oxide as catalyst in the presence of 25 grams ammonia at 200-215 C., and 5,000 p.s.i. hydrogen pressure. The resulting 2,7-diaminoperhydrofiuorene has a boiling point 161 C./ mm. mercury and a neutralization equivalent of 113. Vapor phase chromatography of the N,N'-diethyl derivatives shows the presence of 4 geometrical isomers (17, 18, 60 and 5% composition).

Thirty-three grams 2,7-diaminoperhydrofluorene are added to 23.2 grams adipic acid heated in 84 ml. water. A nylon salt is formed in solution and the pH is adjusted to 7.7 by addition of 2,7-diaminoperhydrofiuorene. On evaporation 45 grams of the ammonium salt are obtained.

The salt is charged in a glass polymer tube, the tube purged with nitrogen, evacuated and sealed off and thereafter heated for 2 hours at 235 C. After this, the tube is opened and heated under nitrogen for 2 hours at 300 C. The resulting polymer has an inherent viscosity of 0.64 and a polymer softening temperature, as determined on a heated metal block, of 260-265 C.

Filaments are prepared by press Spinning molten polymer at 3l0-330 C. with a windup speed of 150-300 ft. per minute using a plunger pressure of 400 p.s.i. The quench filaments are drawn 2.75 X over an 80 C., heated pin. The drawn fibers are heated in water at 70 C., and, after air drying, physical properties as shown in the following table are found:

Tenacity1 .3 grams per denier Elongation3 8 Initial modulus-28 Work recovery, 3 S %--74/ 61 Tensile recovery, 3 5 %-90/ 89 Tensile strain recovery-46 Work recovery and tensile recovery values are shown at both 3 and 5% elongations.

EXAMPLE II A diammoniurn salt is prepared by adding 10.7 grams 2,7-diaminoperhydrofiuorene in 25 ml. isopropanol to 9.4 grams azelaic acid in 80 ml. isopropanol. The salt separates as an oil and solidifies upon standing. Yield is 8 grams. The pH of the 1% solution is 5.7 and a pH of 7.75 is found at the isoelectric point. Using the procedure of Example I, the salt is heated in a sealed tube at 235 C. for two hours, then under nitrogen for 2 hours at the same temperature. The resulting polymer has an inherent viscosity of 0.73 and a polymer softening temperature of 175-180 C.

EXAMPLE III A solution of 42.5 g. of 2,7-diaminoperhydrofluorene in 100 cc. of ethanol is added to 46 g. of dodecanedioic acid dissolved in 300 cc. of ethanol. The salt crystallizes after cooling on standing. The yield is 75 g. The pH of a 0.5% solution in water is 7.2 and the pH at the isoelectric point is found to be 7.75. Using the procedure of Example I, the salt is heated in a sealed tube at 235 C. The resulting polymer has an inherent viscosity of 0.76 and a polymer softening temperature of 170-175 C.

This invention includes polycarbonamides which can be prepared from any perhydrofiuorene diamine or any dicarboxylic acid in which the two reactive groups are not attached to the same 6 membered ring. Referring to Formula III,

the functional groups may be attached to the perhydrofiuorene nucleus in any of the positions 1 through 8 inclusive. Preferred constituents are those substituted in a symmetrical manner such as 1,8-diamino-; 2,7-diamino-; 3,6-diamino-; and 4,idiaminoperhydrofluorene and the corresponding dicarboxylic acids. Unsymmetrically substituted compounds such as 1,5-diamino-; 2,6-diamino-; 3,8-dicarboxy-perhydrofiuorene and the like are also suitable.

The polymers of this invention contain in addition to perhydrofiuorene nuclei, straight chain alkylene groups. When the polymer is based on diaminoperhydrofluorene units, the aliphatic units are derived from alpha,ornegaaliphatic dicarboxylic acids. Examples of such acids are oxalic, adipic, azelaic, sebacic, and the like. When the polymer is derived from a perhydrofiuorene dicarboxylic acid, the aliphatic straight chain hydrocarbon units are derived from aliphatic diamines such as ethylene diamine, hexamethylene diamine, nonamethylene diamine, decamethylene diamine and the like.

The polymers of this invention may also contain copolymeric units as previously recited. Examples of such copolymeric polyamide units are hexamethylene adipamide, hexamethylene sebacamide, metaphenylene isophthalamide, hexamethylene terephethalamide, caproamide, and the like.

The di-substituted perhydrofluorene compounds of this invention exist in various geometrical isomer forms. The' geometrical isomer composition can be regulated by known isomer purification techniques and by the experimental conditions employed for hydrogenation of the aromatic rings. The geometrical isomer composition determines somewhat the properties of the polymers and fibers prepared therefrom.

The polymers, filaments, and fibers of this invention are useful in textiles, knitted and nonwoven fabric applications and other well-known uses for synthetic polymers, filaments and fibers.

The polymer may be used as a homopolymer, or blended or cospun with other polymers by procedures well known in the art. They may contain conventional additives such as stabilizers, antioxidants, delusterants, pigments, dyes, antistatic agents and the like.

Other aspects of the invention will be obvious to those skilled in the art. The invention is limited only as defined by the following claim.

What is claimed is:

1. A synthetic, linear, fiber-forming polycarbonamide consisting essentially of recurring units of the formula wherein the geometric figure containing the letters S denote a perhydrofiuorene ring in which R may be hydrogen or an alkyl radical containing no more than 3 carbon atoms, and n is a whole number from 0 to 12 inclusive.

References Cited UNITED STATES PATENTS 2,585,163 2/1952 Pease et al. 260-78 3,069,468 12/1962 Cox et al. 26078 3,143,530 8/1964 DOIlOfriO 260-78 HAROLD D. ANDERSON, Primary Examiner US. Cl. X.R.