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Publication numberUS3437641 A
Publication typeGrant
Publication dateApr 8, 1969
Filing dateFeb 28, 1966
Priority dateMar 3, 1965
Also published asDE1232735B
Publication numberUS 3437641 A, US 3437641A, US-A-3437641, US3437641 A, US3437641A
InventorsJurgen Lenz, Ernst Meyer
Original AssigneeGlanzstoff Ag
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Process for improving the acid dye receptivity of polylactams and polylactam products so produced
US 3437641 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)

United States Patent US. Cl. 26078 Claims ABSTRACT OF THE DTSCLOSURE Process of improving the acid dye receptivity of polycaprolactam and the resulting product wherein there is homogeneously incorporated in the polycaprolactam a small amount of (a) a phosphoric acid ester or an alkyl or aryl phosphonic acid or an ester thereof, and (b) an alkylene polyamine. The product exhibits improved receptivity for acid dyes with a minimum reduction of its solution viscosity.

This invention relates to a process for improving the dye receptivity of polylactams for acid dyes, and more particularly, the invention is directed to a process of incorporating a combination of certain organic phosphorous compounds and amines into a fiber-forming polylactam, especially polycaprolactam, so as to obtain a product which is easily spun into textile fibers and which can be dyed in an improved manner with acid dyes.

It is known that the dye receptivity of fiber-forming polyamides for acid dyes can be improved if the polyamide is initially treated so as to contain an increased number of amino end groups. One method of achieving this result has been to add free amines to the polyamide-forming initial materials prior to polycondensation. Suitable amines which have been suggested for this purpose include aliphatic monoamines or diamines and heterocyclic amines. Where the polyamide is obtained by polycondensation of dicarboxylic acids and diamines, e.g., in the preparation of polyhexamethylene adipamide, only a small excess of the above-noted free amines is necessary. On the other hand, a considerably greater amount of the free amines must be added when using lactams as the monomers in the formation of a fiber-forming polyamide. The polyamides which are produced according to this known process and which show a higher number of amino groups are not fully satisfactory because they are more difficult to spin into filaments or fibers. For example, if one wishes to obtain an appreciable improvement in dyeability and correspondingly adds larger amounts of the amine, the resulting polyamide has a substantially lower viscosity and the molten polyamide tends to drip during spinning, so that a spinning of the polyamide melt into filaments is no longer practical.

According to another known process, this defect in the polyamide caused by the addition of the amine is supposed to be avoided by adding phosphorous compounds to the polyamide prior to spinning. Suitable phosphorous compounds suggested for this purpose are hypophosphites of alkali and alkaline earth metals as well as those of zinc, cadmium, manganese, aluminum and tin, and also salts of phosphinic acid. According to still another known process, the dye receptivity of polyamides is supposed to be improved by the addition of alkylor aryl-phosphinic acids or their amine salts. It has become apparent that the addition of such compounds, particularly the amine salts of phosphinic acids, results in an appreciable improvement of the dye receptivity whereas the metal salts of phosphinic acid do not have any efiect. In any case, the known processes are restricted to polyamides prepared from dicarboxylic acids and diamines. If one attempts to apply these additives to polyamides formed from lactams, then it has been found that only a slight and unimportant improvement in dye receptivity is possible.

One object of the present invention is to provide a process whereby a substantially improved acid dye receptivity can be imparted to a fiber-forming polylactam without impairing the subsequent spinning of the polymer into filaments.

Another object of the invention is to provide a process for improving the receptivity of a fiber-forming polylactam for acid dyes by using a novel combination of additives which can be easily incorporated into the polylactam either before or during polycondensation of the lactam monomer or subsequently to the polylactam before it is spun into textile fibers.

These and other objects and advantages of the invention will become more apparent upon consideration of the following detailed specification.

It has now been found, in accordance with the invention, that the foregoing objects can be achieved by homogeneously incorporating into a fiber-forming polylactam: (a) about 0.05 to 3 0 by weight, preferably about 0.1 to 2% by weight, of an organic phosphorous compound selected from the group consisting of phosphoric acid esters and alkyl and aryl phosphonic acids and their esters; and (b) about 0.01 to 1% by weight, preferably 0.02 to 0.5% by weight, of a polyamine of the formula wherein m represents an integer of O to 3, n represents an 1nteger of 2 to 6 and the sum of m and n is not more than 6 The term dye receptivity is employed herein with reference to the ability of the polymer fiber to absorb or take up an acid dye during any conventional method of dyeing. The polylactams which are improved by the proc ess of this invention are well known fiber-forming polymers containing recurring NHCO groups connected by an alkylene group in the polymer chain. Polycaprolactam, sometimes referred to as nylon 6, is most often used for commercial textiles, and the production of the polyamide fromthe monomeric lactam, such as epsiloncaprolactam is quite well known and requires no further explanation.

The two essential additives of the invention, i.e., the organic phosphorous compound and the polyamine can be introduced and incorporated into the polycaprolactam at any point prior to spinning filaments or fibers therefrom, under conditions which ensure an homogeneous mixture of the polymer and the additives, e.g., by thorough mixing during polycondensation or by kneading and homogenizing the additives with the molten polymer in an extruder or similar mixing device. Thus, the additives may be introduced before the polycondensation of the lactam monomer or at any suitable time during the polycondensation reaction. Moreover, it is possible to admix the two essential components of the invention with the polylactam product, which is in the form of cuttings, granules or small pellets at a point prior to spinning, e.g., by panniering the cuttings or otherwise surface coating the polymer particles. Thereafter, the organic phosphorous compound and the polyamine are homogeneously mixed with the polylactam by any conventional method, e.g., by reextruding the treated material in a screw extruder or even in a mixing section just preceding the melt spinning operation.

As the organic phosphorous compound employed as component (a) in the process of the invention, it is particularly desirable to employ those compounds of the formula in which X stands for aryl or alkyl, preferably phenyl and lower alkyl such as methyl, ethyl, propyl or butyl, X stands for aryl such as phenyl, aralkyl such as benzyl or lower alkyl, i.e., alkyl of 1 to 4 carbon atoms, and Y stands for hydrogen, aryl such as phenyl, or lower alkyl of 1 to 4 carbon atoms. Specific organic phosphorous compounds suitable for the purposes of the invention can be listed as follows:

Tributyl phosphate Methanephosphonic acid dimethyl ester Ethanephosphonic acid diethyl ester Phenyl-methancphosphonic acid diethyl ester Tripropylphosphate Triethylphosphate Trimethylphosphate Triphenylphosphate Phenyl-methanephosphonic acid dibutyl ester Phenyl-methanephosphonic acid diphenyl ester Benzenephosphonio acid Benzenephosphonic acid dibutyl ester Benzenephosphonic acid diphenyl ester Ethanephosphonic acid As to the amine component (b), the best results are achieved in accordance with the invention by using a compound of the formula in which p stands for an integer of 2 to 4, i.e., diethylene triamine, triethylene tetramine and tetraethylene pentamine. In addition, the following specific polyamines are also suitable:

Hexamethylene diamine Pentamethylene diarnine Tetramethylene diamine Trimethylene diarnine Ethylene diamine Dipropylene diamine Tripropylene tetramine Tetrapropylene pentamine Dibutylene triarnine Tributylene tetramine Dipentylene triamine If a phosphoric or phosphonic acid ester of the invention is added alone for increasing the .acid dye receptivity of the polylactam, then some increase in dyeability does take place-although it is proportionately less than that achieved by the process of the invention. Even this effect cannot be achieved with the known phosphinic acids or phosphinic acid derivatives when they .are used with a polylactam.

On the other hand, even when using the organic phosphorous compounds of the present invention, the acid dye receptivity cannot be further increased simply by the addition of larger amounts of this component because the viscosity of the polylactam is then simultaneously reduced. However, if one introduces a mixture of the phosphoric or phosphonic acid ester together with a small amount of the polya-mine as the second component, within the proportions defined by the invention, then the acid dye receptivity of the polylactam increases quite sharply in a very surprising manner. Although the amines just as the organic phosphorous compounds cause a lowering of the viscosity, it has been found that a definite synergistic effect takes place with the dye receptivity increasing much more rapidly than any accompanying decrease in viscosity. Thus, one can obtain an optimum improvement of dye aflinity or receptivity with the least possible reduction of viscosity by the suitable selection of the phosphorous compounds and amines as well as by choosing appropriate amounts of these compounds within the prescribed limits of the invention. In this respect, the preferred polyethylene polyamines as noted above offer the greatest advantage because they yield a very substantial increase in dye absorption even when using quite small amounts, and these small amounts of the polyamine have only a slight influence on the viscosity.

Especially favorable results are achieved according to the invention if the organic phosphorous compounds and amines are added to the completely condensed polylactam prior to spinning into filaments. When the process of the invention is carried out in this manner, there is practically no influence on the viscosity of the polymer. Surprisingly, however, the improvement in the acid dye receptivity is considerable. This result was not at all expected because it had been previously assumed that in order to increase the number of amino end groups, it would be absolutely essential to introduce any additives especially aminesinto the initial monomeric materials.

The invention is further illustrated by without being limited to the following examples. In these examples as well as in the appended claims and elsewhere in this specification, the percentages of the phosphorous and amine compounds are by weight with reference to the particular lactam or polylactam which is being treated. The solution viscosity is measured in each instance by measuring the flew rate of a 1% solution of the polylactam in formic acid. Extinction values are obtained by conventional measurement of the dye solutions.

EXAMPLE I While caprolactam is being polycondensed in a conventional manner, there is added to the fluid monomer 1% by weight of ethanephosphonic acid diethyl ester and 0.3% by weight of diethylene triamine. The resulting polyamide has a solution viscosity of 2.05 and has good spinning qualities. In order to ascertain the dyeing improvement which has been achieved, filaments of the polyamide containing the above named additives are dyed together with polyamide filaments which contain no additives in the same bath with the acid dye Anthralan Blue B. The dye absorbed from the bath by the two filament samples is thereafter completely extracted with a pyridinewater mixture. The extinction of both dye solutions is measured, and amounted to a proportion of 1:3.8 (polyamide without additiveszpolyamide+phosphorous compound +amine) As described in the above example, further tests were carried out while changing the additive compounds or their proportions as summarized in the following table:

the solution viscosity of the additive-containing cuttings compared to the normal polyamide is somewhat lower,

TABLE I Percent Solution Extinction Additives by viscosity proportion weigh Test Number:

1 Ethanephosphonic diethyl ester 1.0 2 05 1 3 8O "i g g h i 3 anep osp euro 2101 re y "{Diethylene triamine 0.4 i 1 3 {Ethanephosphonic acid diethyl es 0.1 2 14 1 2 34 gtefiametlhylefie diamigeafilnfuy 0.3

anep osp onic aci 1e y es en iHexamethylene diamjne 5 15 1 27 {Ethanephosphonic acid diethyl ester: 0.7 2 14 1 3 05 Hexamethyleue diamine 0.3

Ethanephosphonie acid diethyl ester 1.0 l 2 06 1 2 93 Hexamethylene diamine 0.3 J

Ethanephosphonic acid diethyl este 1 5 1 90 1 2 83 Hexamethylene diamine Ethanephosphonic acid diethyl ester- 2.0 1 90 1 2 95 '"ilgekilrametllliylege diamigeanfi; 1 .i 0.3

t anep osp onic aci ie y es en 9 "illgielilrametlhylege diamigeaifilflfuiuu 5 05 1 30 t anep osp onic aci e y es er 10 "{lgagametliliylefie diamireaufii 1 E s 0 99 1 35 anep osp onic aci ie y es er 1.5 n '{gerlamethlylenlei diaminefa flt fi i t $5 89 1 80 l e anep osp onic aci ime y es er 12 "{DiethyIene triamine 0. 3 05 1 31 13 1 Phenyl-methanephosphonic acid dimethyl ester- 2. 5 2.01 1 1. 65 14 1Etf. "t'"t "ha em? "'i'6" t anep osp omc aci 1e y es er 15 irifthyltlilne titramineafii EH1? I 0O 1 56 t anep osp onic aci e y es er 16 "{Tetraethylene pentarm'ne 0.5 i 1 05 1 Comparative tests.

EXAMPLE II Dried polycaprolactam cuttings ready for spinning with a solution viscosity of 2.55 are mixed in a tumbler drier successively with 0.3% by weight of hexamethylene diamine and 1% by weight of tributyl phosphate. Thereafter, these cuttings are regranulated in an extruder. After the regranulation, the modified polycaprolactam exhibits a solution viscosity of 2.53. The cuttings are then spun and the resulting filaments dyed as described in EX- ample I. By measuring the extinction proportion of the dyestuff extracted from each of the filament samples, the dyeing improvement of the modified polyamide by comparison with the unmodified polyamide is ascertained. The extinction proportion in this case amounts to 1:2.63 (polyamide without additive:polyamide-i-phosphorous compound-i-amine) As described in Example II above, further tests are carried out with changes in the compounds or additive amounts as summarized in the following table:

an increase of the viscosity occurs in the spinning process. In this manner, therefore, a very high viscosity of the finished filaments is assured. The addition of the amine, on the other hand, acts as a viscosity stabilizer and reduces the filament viscosity during the spinning process, thereby preventing an undesirably large increase in the solution viscosity. Also, this eifect has proven to be certain as shown in the following tests.

EXAMPLE III TABLE II Percent Solution Extinction j Addltives by weight viscosity of proportion cuttings Test Number: T b t 1 h h t 1 riuypospae 2.0 2 "{Hexamethylene diamine.-- 0. 3} 47 91 3 Tributyl phosphate 1.0 2. 62 1:2. 13 4 Hexarnethylene diamine.. 0.3 2. 42 112.02

1 Comparative tests.

A further advantage of the process according to the invention is to be seen in the fact that during the spinning of 'the polyamide the added phosphorous compounds cause a considerable after-condensation, so that even if in Example I. Through the high increase of the solution viscosity during the spinning, the effect of the phosphonic acid ester and amine added during the polymerization in lowering the solution viscosity in substantially reduced.

The invention is hereby claimed as follows:

1. A process for improving the receptivity of a fiberforming polycaprolactam for acid dyes which comprises: homogeneously incorporating into said polycaprolactam:

(a) about 0.05 to 3% by weight, with reference to the polycaprolactam, of an organic phosphorous compound selected from the group consisting of phosphorie acid esters and alkyl and aryl phosphonic acids and their esters, and

(b) about 0.01 to 1% by weight, with reference to the polycaprolactam, of a polyamine of the formula wherein m represents an integer of to 3, n represents an integer of 2 to 6 and the sum of m and n. is not more than 6.

2. A process as claimed in claim 1 wherein (a) is used in an amount of about 0.1 to 2% by weight and (b) is used in an amount of about 0.02 to 0.5% by weight.

3. A process as claimed in claim 1 wherein component (a) is a phosphoric acid ester of the formula X0 OX wherein X represents a substituent selected from the group consisting of lower alkyl and phenyl.

4. A process as claimed in claim 1 wherein component (a) is a compound of the formula YO OY wherein X' represents a substituent selected from the 8 group consisting of lower alkyl, phenyl and benzyl and Y represents a suhstituent selected from the group consisting of hydrogen, lower alkyl and phenyl.

5. A process as claimed in claim 1 wherein component (b) is a compound of the formula wherein p represents an integer of 2 to 4.

6. A process as claimed in claim 1 wherein component (b) is hexamethylene diamine.

7. A process as claimed in claim 1 wherein component (a) is ethanephosphonic acid diethyl ester.

8. A process as claimed in claim 1 wherein component (a) is methanephosphonic acid dimethyl ester.

8. A process as claimed in claim 1 wherein component (a) is tributyl phosphate.

'10. The polylactam product obtained by the process of claim 1.

References Cited UNITED STATES PATENTS 2,241,322 5/194'1 Hanford 260-7-8 2,510,777 6/1950 Gray 260-78 2,557,808 6/1951 Walker 260-78 2,904,536 9/1959 Reith 260-78 3,296,215 1/1967 Crovatt 260-78 3,296,216 1/ 1967 Snooks 260-78 3,300,448 '1/ 1967 Gauthier et al. 260-78 WILLIAM H. SHORT, Primary Examiner.

H. D. ANDERSON, Assistant Examiner.

US. Cl. X.R. 260-78; 8-55 U.S. DEPARTMENT OF COMMERCE PATENT OFFICE Washington, D.C. 20231 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,437,641 April 8, 1969 Jiirgen Lenz et a1.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

In the heading to the printed specification, line 10, "U 27,948" should read V 27,948

Signed and sealed this 21st day of April 1970.

(SEAL) Attest:


Commissioner of Patents Edward M. Fletcher, Jr.

Attesting Officer

Patent Citations
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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3687904 *Dec 4, 1970Aug 29, 1972Ici LtdPolyamides
US3846532 *Mar 1, 1971Nov 5, 1974Bayer AgContinuous spinning and stretching process of the production of polyamide-6 filaments
US4258142 *Aug 30, 1978Mar 24, 1981Argus Chemical Corp.Clarified olefin polymer composition
US4390667 *Jul 6, 1981Jun 28, 1983Allied CorporationProcess for increasing the melt viscosity of polyamide with aryl phosphate compound
US5216054 *Feb 27, 1992Jun 1, 1993Tonen Sekiyukagaku Kabushiki KaishaPolymer composition
US5487856 *Oct 11, 1994Jan 30, 1996Basf CorporationProcess for the manufacture of a post-heat set dyed fabric of polyamide fibers having improved dye washfastness and heat stability
US6867266Jun 4, 2002Mar 15, 2005Basf CorporationLight-stabilized polymeric articles and methods of making the same
EP0382559A2 *Feb 9, 1990Aug 16, 1990Tonen Chemical CorporationPolymer composition
WO2002102885A1 *May 22, 2002Dec 27, 2002Basf AgLight-stabilized polymers comprising light-stabilizing moieties, articles therefrom and a method of making the same
U.S. Classification528/487, 528/492, 524/132, 524/130, 524/602, 8/584, 525/420, 528/323
International ClassificationC08K5/524, C08K5/5333, C08G69/02, C08K5/17
Cooperative ClassificationC08K5/5333, C08G69/02, C08K5/524, C08K5/17
European ClassificationC08K5/524, C08K5/5333, C08K5/17, C08G69/02