EP0779942A1

EP0779942A1 - Process for manufacturing cellulose fibres

Info

Publication number: EP0779942A1
Application number: EP95931179A
Authority: EP
Inventors: Wolfgang Schrott; Wolfram Badura
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 1994-09-06
Filing date: 1995-08-22
Publication date: 1997-06-25
Anticipated expiration: 2015-08-22
Also published as: US5776394A; ES2190169T3; EP0985747A2; EP0985747A3; WO1996007780A1; ATE230447T1; ATE194018T1; EP0985747B1; JPH10505389A; EP0984084A2; EP0984084B1; DE4431635A1; ATE226985T1; ES2148552T3; DE59510523D1; DK0779942T3; DE59508498D1; DE59510440D1; EP0779942B1; EP0984084A3

Abstract

Prodn. of soln. of spun cellulose fibre with reduced fibrillation tendency is by treatment of the fibres with (A) a N-methylol ether of a carboxamide, urethane, urea or aminotriazine; (B) a cyclic hydroxy or alkoxy ethylene urea N-substd. by 1 or more alkyl gps.; (C) a hydrophilic modified polyisocyanate; and/or (D) a polyurethane/isocyanate mixt..

Description

Process for the production of cellulose fibers

description

The present invention relates to a new process for the production of cellulose fibers spun from solvents with a reduced tendency to fibrillate by treating the fibers with certain reactive compounds.

GB-A-2 043 525 describes the production of cellulose fibers by spinning a cellulose solution in a suitable solvent, e.g. an N-oxide of a tertiary amine, such as N-methylmorpholine-N-oxide, is known. In such a spinning process, the cellulose solution is extruded through a suitable nozzle and the resulting fiber precursor is washed in water and then dried. Such fibers are referred to as "solvent spun fibers".

Such cellulose fibers spun from solvents offer many technical advantages, but tend to fibrillate. These are the splicing off of the finest fiber fibrils, which can lead to problems when processing the cellulose fibers in textile production.

To solve this problem, WO-A-92/07124 recommends treating the cellulose fibers with an aqueous solution or dispersion of a polymer which has a large number of cationically ionizable groups, e.g. a polyvinylimidazoline.

Furthermore, EP-A-538 977 teaches the use of compounds which have 2 to 6 functional groups which can react with cellulose, e.g. Products based on dichlorotriazine, for this purpose.

The object of the present invention was to provide a new process for the production of cellulose fibers spun from solvents with a reduced tendency to fibrillate, which is based on other chemical defibrillation reagents.

It has now been found that the production of cellulose fibers spun from solvents with a reduced tendency to fibrillate succeeds advantageously if the fibers are combined with one or more compounds from the group of (A) N-methylol ethers of carboxamides, urethanes, ureas and aminotriazines,

(B) by one or more alkyl groups N-substituted cyclic hydroxy or alkoxyethylene ureas,

(C) hydrophilically modified polyisocyanates and

(D) Mixtures of polyurethanes with isocyanates

treated.

In a preferred embodiment, the compounds (A) used are N-methylol ethers of the general formula I.

in the

R ^{1 represents} a C 1 -C 8 -alkyl group which may be interrupted by non-adjacent oxygen atoms,

R ² denotes hydrogen, the group CH - OR ¹ or a Ci-Cβ-alkyl radical, which additionally carries hydroxyl groups and / or C 1 -C ₄ -alkoxy groups as substituents and is replaced by non-adjacent oxygen atoms and / or Cχ-C - Nitrogen atoms carrying alkyl groups can be interrupted, and

R ^{3 is} hydrogen, a -C-Cιo-alkyl radical, a Cχ-Cιo-alkoxy radical which can be interrupted by non-adjacent oxygen atoms, or the group (-NR ² -CH ₂ OR ¹ ) means

where the radicals R ² and R ^{3 are connected} to form a five- or six-membered ring and, in the case of R ³ - (-NR ² -CH ₂ OR ¹ ), two such rings are also connected via the C atoms which are α to the amide nitrogen the radicals R ² can be condensed to form a bicyclic system.

The N-methylol ethers I are by customary reaction, usually in aqueous solution, of the corresponding N-methylol compounds of the general formula II R ² 0

H 0 CH ₂ N - CR ³ (II) with alcohols of the general formula III

R ¹ —OH (III)

easily available.

The radical R ¹ represents an optionally interrupted by non-adjacent oxygen atoms C gegebenenfalls-Cιo-alkyl group such as -CH ₂ CH ₂ OCH ₃ , -CH ₂ CH ₂ OCH ₂ CH ₃ or -CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ . Examples of R ¹ include: n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, 2-ethylhexyl and 2-methoxyethyl; of particular interest are the C ₁ -C ₃ -alkyl groups ethyl, n-propyl, isopropyl and in particular methyl.

The radical R ² denotes hydrogen, the group CH ₂ OR ¹ and in particular a C ¹ -C 6 -alkyl radical which also carry additional hydroxyl groups and / or C 1 -C ₄ alkoxy groups as substituents and by non-adjacent oxygen atoms and / or can be interrupted by Cι ~ C ₄ alkyl groups bearing nitrogen atoms.

The radical R ³ is hydrogen, a -CC-alkyl radical, a -C-alkoxy radical, which can be interrupted by non-adjacent oxygen atoms, and in particular the group (-NR ² -CH ₂ OR ¹ ).

Those N-methylol ethers I in which the radicals R ² and R ³ are linked to form a five- or six-membered ring are particularly suitable for the process according to the invention. In the case of R ³ = (-NR ² -CH ₂ OR ¹ ), two such rings can also be condensed to form a bicyclic system via the C atoms of the radicals R ² which are α-amide nitrogen.

Examples of N-methylol ether I which can be used in the process according to the invention are:

Amides of Ci-Cn-carboxylic acids, for example formic acid, acetic acid, propionic acid, butyric acid or valeric acid, which carry one or two CH- ^ OR ¹ groups on nitrogen,

- Carbamates with -CC-* alkyl groups in the ester residue, which can be interrupted by non-adjacent oxygen atoms, for example methyl, ethyl, n-propyl, isopropyl, 2-meth oxyethyl or n-butyl, which carry two CH ₂ OR ¹ groups on the nitrogen,

Urea with 1 to 4 CH ₂ -0R ¹ groups on the nitrogen atoms,

cyclic ethylene ureas of the general formula Ia

0 R ¹ -0 CH ₂ - NC - N CH ₂ -0 R ^{1 (Ia)}

in which the radicals X are different or preferably the same and represent hydrogen, hydroxyl groups or -CC ₄ alkoxy groups, for example methoxy or ethoxy,

cyclic propyleneureas of the general formula Ib

R ⁱ - * CH ₂ - N -'C'-N CH ₂ -0 R ¹ (Ib)

in which Y represents CH ₂ , CHOH, C (CH ₃ ) ₂ , a 0 atom or a N atom bearing a C 1 -C 4 alkyl group and Z denotes hydrogen or a C 1 -C 4 alkoxy group, for example methoxy or ethoxy ,

bicyclic glyoxal diureas of the general formula Ic

0

II

R ¹ —0 CH ₂ —N- * ^* C ^** - CH ₂ —0 R ¹ de)

Rl-0 CH ₂ -N ^ C ^ N CH ₂ -0 R ¹

II

0

bicyclic malondialdehyde diureas of the general formula Id

In a further preferred embodiment, melamine derivatives of the general formula IV are used as compounds (A)

in which the radicals A are the same or different and represent hydrogen or the group CH ₂ OR ¹ , where at least one of the radicals A must have the meaning CH OR ¹ and R ^{1 has} the meaning given above.

The melamine derivatives IV are, by customary reaction, usually in aqueous solution, the corresponding N-methylolmelamines of the general formula V

in which the radicals B analogous to A denote hydrogen or the group CH ₂ OH, readily available with alcohols of the general formula III.

Examples of melamine derivatives IV which can be used in the process according to the invention are methoxymethylmelamine, bis (methoxymethyl) melamine, tris (methoxymethyl) melamine, tetrakis (methoxymethyl) melamine, pentakis (methoxymethyl) melamine and hexakis (methoxymethyl) melamine and to call analog ethoxymethyl and isopropyloxymethyl compounds. The compounds (A) are known in the textile field as crosslinking agents in the low-formaldehyde finishing (high finishing) of cellulose-containing textile materials.

In a further preferred embodiment, one sets as

Compounds (B) cyclic hydroxy or alkoxyethylene ureas of the general formula VI

_R - _' C ^ 5 (VI)

R 0 y-OR ⁶

in which R ⁴ and R ^{5 are} hydrogen or Cχ-C ₃ alkyl with the proviso that at least one of the radicals R ⁴ and R ^{5 is} a C ₁ -C ₃ alkyl group, and R ⁶ and R ^{7 are} Are hydrogen or -CC ₄ alkyl, a.

The compounds (B) are known in the textile field as crosslinking agents in the formaldehyde-free finishing (high finishing) of cellulose-containing textile materials.

The hydrophilically modified polyisocyanates (C) are generally used in the process according to the invention in the form of aqueous dispersions which are essentially free from organic solvents and other emulsifiers.

The basis for the hydrophilically modified polyisocyanates used according to the invention are customary diisocyanates and / or customary higher-functionality polyisocyanates with an average NCO functionality of 2.0 to 4.5. These components can be present alone or in a mixture.

Examples of customary diisocyanates are aliphatic diisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate (1,6-diisocyanate hexane), octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, trimethylhexane diisocyanate or tetramethylhexane diisocyanate or 1,4-tetramethylhexane such as cyclodiisocyanate or 1,4-diisocyanate or tetramethylhexane diisocyanate or 1,4-diisocyanate or tetramethylhexane such as aliphatic diisocyanate or tetramethylhexane 1,2-diisocyanatocyclohexane, 4,4'-di (isocyanatocyclohexyl) methane, 1-isocyanato-3,3,5-trimethyl-5- (isocyanatomethyl) cyclohexane (isophorone diisocyanate) or 2,4- or 2, 6-diisocyanato-l-methylcyclohexane and aromatic diisocyanates such as 2,4- or 2,6-tolylene diisocyanate, tetramethylxylylene diisocyanate, p-xylylene diisocyanate, 2,4'- or 4,4'-diisocyanatodiphenylmethane, 1,3- or 1,4- Phenylene diiso- cyanate, l-chloro-2, 4-phenylene diisocyanate, 1, 5-naphthylene diisocyanate, diphenylene-4, 4'-diisocyanate, 4, 4'-diisocyanato-3, 3'-dimethyldiphenyl, 3-methyldiphenylmethane-4 , 4'-diisocyanate or diphenyl ether-4, 4 'diisocyanate. Mixtures of the diisocyanates mentioned can also be present. Of these, aliphatic diisocyanates, in particular hexamethylene diisocyanate and isophorone diisocyanate, are preferred.

Triisocyanates such as 2, 4, 6-triisocyanatotoluene or 2, 4, 4'-triisocyanatodiphenyl ether or the mixtures of di-, tri- and higher polyisocyanates, which are obtained by phosgenation of corresponding aniline / formaldehyde, are suitable as customary higher functional polyisocyanates. Condensates are obtained and represent polyphenyl polyisocyanates having methylene bridges.

Common aliphatic, higher functional polyisocyanates of the following groups are of particular interest:

(a) Isocyanurate group-containing polyisocyanates of aliphatic and / or cycloaliphatic diisocyanates. The corresponding isocyanato-isocyanates based on hexamethylene diisocyanate and isophorone diisocyanate are particularly preferred. The present isocyanurates are, in particular, simple tris-isocyanatoalkyl or triisocyanatocycloalkyl isocyanurates, which are cyclic trimers of the diisocyanates, or mixtures with their higher homologues having more than one isocyanurate ring. The isocyanato isocyanurates generally have an NCO content of 10 to 30% by weight, in particular 15 to 25% by weight, and an average NCO functionality of 2.6 to 4.5.

(b) uretdione diisocyanates with aliphatic and / or cycloaliphatic bound isocyanate groups, preferably derived from hexamethylene diisocyanate or isophorone diisocyanate. Uretdione diisocyanates are cyclic dimers of diisocyanates.

(c) Polyisocyanates containing biuret groups with aliphatically bound isocyanate groups, in particular tris (6-isocyanato-hexyl) biuret, or mixtures thereof with its higher homogenes. These polyisocyanates containing biuret groups generally have an NCO content of 18 to 25% by weight and an average NCO functionality of 3 to 4.5.

(d) Polyisocyanates containing urethane and / or allophanate groups with aliphatic or cycloaliphatic isocyanate groups, such as those obtained by reacting Excess amounts of hexamethylene diisocyanate or isophorone diisocyanate can be obtained with simple polyhydric alcohols such as trimethylolpropane, glycerol, 1,2-dihydroxypropane or mixtures thereof. These polyisocyanates containing urethane and / or allophanate groups generally have an NCO content of 12 to 20% by weight and an average NCO functionality of 2.5 to 3.

(e) Polyisocyanates containing oxadiazinetrione groups, preferably derived from hexamethylene diisocyanate or isophorone diisocyanate. Such polyisocyanates containing oxadiazinetrione groups can be prepared from diisocyanate and carbon dioxide.

(f) Uretonimine-modified polyisocyanates.

For the use according to the invention, aliphatic diisocyanates and aliphatic higher-functional polyisocyanates are particularly preferred.

The described diisocyanates and / or higher functionalized polyisocyanates are converted to NCO-reactive compounds for conversion into non-ionically hydrophilically modified polyisocyanates, which are particularly preferred for the use according to the invention, and the hydrophilic structural elements with non-ionic groups or with polar Contain groups that cannot be converted into ion groups. The diisocyanate or polyisocyanate is present in a stoichiometric excess so that the resulting hydrophilically modified polyisocyanate still has free NCO groups.

Hydroxyl group-terminated polyethers of the general formula VII in particular come as such NCO-reactive compounds with hydrophilicizing structural elements

R ⁸ -E- (D0) _n -H (VII)

in the

R ⁸ represents C ₁ -C ₂ -alkyl, in particular C 1 -C ₄ -alkyl, or C ₂ - to C ₂ o-alkenyl, cyclopentyl, cyclohexyl, glycidyl, oxethyl, phenyl, tolyl, benzyl, furfuryl or tetrahydrofurfuryl .

Denotes sulfur or especially oxygen, D means propylene or, above all, ethylene, where in particular mixed ethoxylated and propoxylated compounds can also occur in blocks, and

n stands for a number from 5 to 120, in particular 10 to 25,

into consideration.

The use of non-ionically hydrophilically modified polyisocyanates which contain the polyethers VII incorporated is therefore also a preferred embodiment.

These are particularly preferably ethylene oxide or propylene oxide polyethers started on C 1-4 alkanol with average molecular weights of 250 to 7000, in particular 450 to 1500.

From the described diisocyanates and / or more functionalized polyisocyanates, it is also possible first of all by reaction with a deficit of hydroxyl-terminated polyesters, on other hydroxyl-terminated polyethers or on polyols, e.g. Generate ethylene glycol, trimethylolpropane or butanediol, prepolymers and then or subsequently, or simultaneously with the polyethers VII in deficit, convert these prepolymers to the hydrophilically modified polyisocyanates with free NCO groups.

It is also possible to prepare nonionically hydrophilically modified polyisocyanates from diisocyanate or polyisocyanate and polyalkylene glycols of the formula HO— (DO) _n —H, in which D and n have the meanings given above. Both terminal OH groups of the polyalkylene glycol react with isocyanate.

The enumerated types of non-ionically hydrophilically modified polyisocyanates are in the documents DE-A 24 47 135,

DE-A 26 10 552, DE-A 29 08 844, EP-A 0 13 112, EP-A 019 844, DE-A 40 36 927, DE-A 41 36 618, EP-B 206 059, EP-A 464 781 and EP-A 516 361.

The described diisocyanates and / or more highly functionalized polyisocyanates are converted into NCO-reactive compounds for conversion into anionically hydrophilically modified polyisocyanates which contain hydrophilic anionic groups, in particular acid groups such as carboxyl groups, sulfonic acid groups or phosphonic acid groups. The diisocyanate or polyisocyanate is present in a stoichiometric excess, so that the resulting hydrophilically modified polyisocyanate still has free NCO groups.

As such NCO-reactive compounds with anionic groups come especially hydroxycarboxylic acids such as 2-hydroxyacetic acid, 3-hydroxypropionic acid, 4-hydroxybutyric acid or hydroxylpivalic acid as well as 2,2-bis- and 2,2,2-tris (hydroxymethyl) alkanoic acids, e.g. 2,2-bis (hydroxymethyl) acetic acid, 2,2-bis (hydroxymethyl) propionic acid, 2,2-bis (hydroxymethyl) butyric acid or 2,2,2-tris (hydroxymethyl) acetic acid, into consideration. The carboxyl groups can be partially or completely neutralized by a base in order to be in a water-soluble or water-dispersible form. The base used here is preferably a tertiary amine, which is known to be inert to isocyanate.

The described diisocyanates and / or more highly functionalized polyisocyanates can also be reacted with a mixture of nonionically hydrophilically modifying and anionically hydrophobically modifying compounds which are added in succession or simultaneously, for example with a deficit of polyethers VII and the described hydroxycarboxylic acids .

The enumerated types of anionically hydrophilically modified polyisocyanates are described in more detail in documents DE-A 40 01 783, DE-A 41 13 160 and DE-A 41 42 275.

The described diisocyanates and / or higher functionalized polyisocyanates are converted into cationically hydrophilically modified polyisocyanates with NCO-reactive compounds which contain chemically incorporated alkylatable or protonatable functions with formation of a cationic center. In particular, such functions are tertiary nitrogen atoms, which are known to be inert to isocyanate and are easily quaternized or protonated. When diisocyanate or polyisocyanate is reacted with these NCO-reactive compounds, the former are in excess so that the resulting hydrophilically modified polyisocyanate still has free NCO groups.

Preferred such NCO-reactive compounds with tertiary nitrogen atoms are amino alcohols of the general formula VIII R ^Q

^ N-RU-OH (VI I I)

_R 10 ^

in the

R ⁹ and R ^{10 are} linear or branched C -.- to C ₂ o-alkyl, in particular Ci- to Cs-alkyl, or together with the N atom form a five- or six-membered ring which is also an O atom or can contain a tertiary N atom, in particular a piperidine, morpholine, piperazine, pyrrolidine, oxazoline or dihydrooxazine ring, where the radicals R ² and R ³ can additionally carry hydroxyl groups, in particular in each case one hydroxyl group, and

R ¹¹ is a C ₂ - to Cio-alkylene group, in particular a C ₂ - to C _δ alkylene group which may be linear or branched, designated

into consideration.

Particularly suitable amino alcohols VIII are N-methyldiethanolamine, N-methyldi (iso) propanolamine, N-butyldiethanolamine, N-butyldi (iso) propanolamine, N-stearyldiethanolamine, N-stearyldi (iso) propanolamine, N, N-dimethylethanolamine , N, N-dimethyl (iso) propanolamine, N, N-diethylethanolamine, N, N-diethyl (iso) propanolamine, N, N-dibutylethanolamine, N, N-dibutyl (iso) propanolamine, triethanolamine, tri (iso) propanol - amine, N- (2-hydroxyethyl) morpholine, N- (2-hydroxypropyl) morpholine, N- (2-hydroxyethyl) piperidine, N- (2-hydroxypropyl) piperidine, N-methyl-N '- (2-hydroxyethyl ) piperazine, N-methyl-N '- (2-hydroxypropyl) piperazine, N-methyl-N' - (4-hydroxybutyl) piperazine, 2-hydroxyethyl oxazoline, 2-hydroxypropyl oxazoline, 3-hydroxypropyl -oxazoline, 2-hydroxyethyl-dihydrooxazine, 2-hydroxypropyl-dihydrooxazine or 3-hydroxypropyl-dihydrooxazine.

Furthermore, such NCO-reactive compounds with tertiary nitrogen atoms are preferably diamines of the general formula IXa or IXb

R ^Q ^R9 \

NR ^ll _NH ₂ d ^χa) NR ^Ü -NH-R ¹² (IXb) RIO- ^ ^' »lO - ^ in which R ⁹ to R ^{11 have} the meanings mentioned above and R ¹² denotes C ₁ -C 4 -alkyl or forms a five- or six-membered ring, in particular a piperazine ring, with R ⁹ .

Particularly suitable diamines IXa are N, N-dimethylethylene diamine, N, N-diethylethylene diamine, N, N-dimethyl-1, 3-diamino-2, 2-dimethylpropane, N, N-diethyl-1 , 3-propylenediamine, N- (3-aminopropyl) morpholine, N- (2-aminopropyl) morpholine, N- (3-aminopropyl) piperidine, N- (2-aminopropyl) piperidine, 4-amino-1 - (N, N-diethylamino) pentane, 2-amino-l- (N, N-dimethylamino) propane, 2-amino-l- (N, N-diethylamino) propane or 2-amino-l- (N, N -diethylamino) -2-methylpropane.

Particularly suitable diamines IXb are N, N, N'-trimethylethylene diamine, N, N, N'-triethylethylene diamine, N-methylpiperazine or N-ethylpiperazine.

Furthermore, polyether (poly) ols with built-in tertiary nitrogen atoms, which can be prepared by propoxylation and / or ethoxylation of starter molecules containing amine nitrogen, can also be used as NCO-reactive compounds. Such polyether (poly) oles are, for example, the propoxylation and ethoxylation products of ammonia, ethanolamine, diethanolamine, ethylenediamine or N-methylaniline.

Other NCO-reactive compounds which can be used are polyester and polyamide resins having tertiary nitrogen atoms, polyols containing urethane groups and tertiary nitrogen atoms, and polyhydroxy polyacrylates having tertiary nitrogen atoms.

The described diisocyanates and / or higher functionalized polyisocyanates can also be reacted with a mixture of nonionically hydrophilically modifying and cationically hydrophilically modifying compounds which are added in succession or simultaneously, for example with a deficit of polyethers VII and amino alcohols VIII or the diamines IXa or IXb. Mixtures of nonionically hydrophilically modifying and anionically hydrophilically modifying compounds are also possible.

The listed types of cationically hydrophilically modified polyisocyanates are described in more detail in the documents DE-A 42 03 510 and EP-A 531 820. Since the hydrophilically modified polyisocyanates (C) mentioned are generally used in aqueous media, the polyisocyanates must be sufficiently dispersible. Within the group of the hydrophilically modified polyisocyanates described, certain reaction products of di- or polyisocyanates and hydroxyl-terminated polyethers (polyether alcohols), such as the compounds VII, act as emulsifiers for this purpose.

The good results achieved with the hydrophilically modified polyisocyanates (C) in aqueous media are all the more surprising since it was to be expected that isocyanates would decompose rapidly in an aqueous medium. Nevertheless, the polyisocyanates used according to the invention have a pot life of several hours in the aqueous liquor, i.e. the present polyisocyanate dispersions are stable within the usual processing time. A dispersion is said to be stable if its components remain dispersed within one another without separating into discrete layers. The term "pot life" means the time during which the dispersions remain processable before they gel and set. Aqueous isocyanate dispersions gel and set because a reaction takes place between the water and the isocyanate, a polyurea being formed.

The mixtures of polyurethanes and isocyanates (D), like the compounds (C), are generally used in the process according to the invention in the form of aqueous dispersions which are essentially free of organic solvents and in most cases free of emulsifiers.

Polyurethanes are understood to be systems composed of polyisocyanates (hereinafter also referred to as monomers I) and compounds which are reactive towards polyisocyanates and have at least one hydroxyl group and, if appropriate, compounds having at least one primary or secondary amino group. As a rule, the polyurethanes no longer have any free isocyanate groups.

The polyisocyanates used to prepare the polyurethanes contained in the mixtures (D) are customary diisocyanates and / or customary higher-functionality polyisocyanates as described for the hydrophilically modified polyisocyanates (C). Here too, aliphatic diisocyanates and aliphatic higher-functional polyisocyanates are preferred. The other structural components of the polyurethane are initially polyols with a molecular weight of 400 to 6000 g / mol, preferably 600 to 4000 g / mol (monomers II).

Polyether polyols or polyester polyols are particularly suitable.

The polyester diols are in particular the known reaction products of dihydric alcohols with dihydric carboxylic acids. Instead of the free polycarboxylic acids, the corresponding polycarboxylic anhydrides or corresponding polycarboxylic acid esters of lower alcohols or their mixtures can also be used to prepare the polyester polyols. The polycarboxylic acids can be aliphatic, cycloaliphatic, aromatic or heterocyclic and optionally, e.g. by halogen atoms, substituted and / or unsaturated. Examples include: succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexa-hydrophthalic anhydride, tetrachlorophthalic anhydride,

Endomethylene tetrahydrophthalic anhydride, glutaric anhydride, maleic acid, maleic anhydride, fumaric acid, dimeric fatty acids. As polyhydric alcohols are e.g. Ethylene glycol, propylene glycol (1,2) and - (1,3), butanediol- (1,4), - (1,3), butenediol- (1,4), butynediol- (1,4), Pentanediol- (1,5), hexanediol- (1,6), octanediol- (1,8), neopentylglycol, cyclohexanedimethanol (1,4-bis-hydroxymethylcyclohexane), 2-methyl-1,3-propanediol , Pentanediol- (1, 5), also diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, dibutylene glycol and polybutylene glycol in question.

Lactone-based polyester diols are also suitable, these being homopolymers or copolymers of lactones, preferably addition products of lactones or lactone mixtures having terminal hydroxyl groups, such as, for example, ε-caprolactone, β-propiolactone, υ- Butyrolactone and / or methyl-ε-caprolactone to suitable difunctional starter molecules, for example the low molecular weight, dihydric alcohols mentioned above as buildup components for the polyester polyols. The corresponding polymers of ε-caprolactone are particularly preferred. Lower polyester diols or polyether diols can also be used as starters for the preparation of the lactone polymers. Instead of the polymers of lactones, the corresponding, chemically equivalent polycondensates of the hydroxycarboxylic acids corresponding to the lactones can also be used. The polyether diols which can optionally be used in a mixture with polyester diols are in particular by polymerization of ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide or epichlorohydrin with themselves, for example in the presence of BF ₃ or by addition of these compounds, if appropriate in a mixture or in succession available on starting components with reactive hydrogen atoms, such as alcohols or amines, for example water, ethylene glycol, propylene glycol (1,3) or - (1,2), 4,4'-dihydroxydiphenylpropane, aniline.

The proportion of the monomer II described above is generally 0.1 to 0.8 gram equivalent, preferably 0.2 to 0.7 gram equivalent of the hydroxyl group of the monomer II based on 1 gram equivalent of isocyanate of the polyisocyanate.

Further structural components of the polyurethane are chain extenders or crosslinkers with at least two groups that are reactive toward isocyanate, selected from hydroxyl groups, primary or secondary amino groups.

Polyols, in particular diols and triols, with a molecular weight below 400 g / mol to 62 g / mol (monomers III) may be mentioned.

In particular, the diols and triols listed above which are suitable for the production of the polyester polyols and also higher than trifunctional alcohols such as pentaerythritol or sorbitol are suitable.

The proportion of the monomers III is generally 0 to 0.8, in particular 0 to 0.7 gram equivalent, based on 1 gram equivalent of isocyanate.

The optionally used monomers IV are at least difunctional amine chain extenders or crosslinkers in the molecular weight range from 32 to 500 g / mol, preferably from 60 to 300 g / mol, which have at least two primary, two secondary or one primary and contain a secondary amino group.

Examples include diamines such as diaminoethane, diaminopropane, diaminobutane, diaminohexane, piperazine, 2,5-dimethylpiperazine, amino-3-aminomethyl-3, 5, 5-trimethyl-cyclohexane (isophorondia in, IPDA), 4,4'-diaminodicyclohexylmethane , 1,4-diaminocyclohexane, aminoethylethanolamine, hydrazine, hydrazine hydrate or triamines such as diethylenetriamine or 1, 8-diamino-4-aminomethyloctane. The chain extenders containing amino groups can also be in blocked form, for example in the form of the corresponding ketimines (see, for example CA-1 129 128), ketazines (see, for example, US Pat. No. 4,269,748) or amine salts (see US Pat. No. 4,292,226). Oxazolidines, as used, for example, in US Pat. No. 4,192,937, also represent blocked polyamines which can be used for the production of the polyurethanes according to the invention for chain extension of the prepolymers. When such capped polyamines are used, they are generally mixed with the prepolymers in the absence of water and this mixture is then mixed with the dispersion water or part of the dispersion water, so that the corresponding polyamines are released as an intermediate hydrolysis.

Mixtures of di- and triamines are preferably used, particularly preferably mixtures of isophoronediamine and diethylenetriamine.

The monomers V, which may also be used as chain extenders, are amino alcohols with a hydroxyl and a primary or secondary amino group, such as ethanolamine, isopropanolamine, methylethanolamine or aminoethoxyethanol.

The proportion of the monomers IV or V is in each case preferably 0 to 0.4, particularly preferably 0 to 0.2 gram equivalent, based on 1 gram equivalent of isocyanate of the polyisocyanate.

Compounds which contain at least one, preferably two, groups which are reactive toward isocyanate groups, that is to say hydroxyl, primary or secondary amino groups, and also, in contrast to the monomers described above, ionic groups or by a simple neutralization or quaternization reaction can be used as a further structural component have ionic groups that can be converted, potentially ionic groups. (Monomers VI). By introducing the monomers VI, the polyurethanes themselves become dispersible, i.e. When dispersing in water, no dispersing aids such as protective colloids or emulsifiers are required in this case.

The cationic or anionic groups can be introduced by using (potential) cationic or (potential) anionic group-containing compounds with isocyanate-reactive hydrogen atoms. These groups of compounds include, for example, polyethers having tertiary nitrogen atoms and preferably having two terminal hydroxyl groups, such as those obtained by alkoxylation of two amines having hydrogen atoms bonded to amine nitrogen, for example methylamine, aniline, or N, N'-dimethylhydrazine, are accessible in a conventional manner. Such polyethers have generally a molecular weight between 500 and 6000 g / mol.

However, the ionic groups are preferably introduced by using comparatively low molecular weight compounds with (potential) ionic groups and groups which are reactive toward isocyanate groups. Examples of this are listed in US Pat. Nos. 3,479,310 and 4,056,564 and GB-1,455,554. Dihydroxyphosphonates, such as the sodium salt of the 2,3-dihydroxypropanephosphonic acid ethyl ester or the corresponding sodium salt of the non-esterified phosphonic acid, can also be used as an ionic structural component.

Preferred (potential) ionic monomers VI are N-alkyl dialkanolamines, e.g. N-methyldiethanolamine, N-ethyldiethanolamine, diaminosulfonates such as the Na salt of N- (2-aminoethyl) -2-aminoethanesulfonic acid, dihydroxysulfonates, dihydroxycarboxylic acids such as dimethylolpropionic acid, diaminocarboxylic acids or carboxylates such as lysine or the Na Salt of N- (2-aminoethyl) -2-aminoethane carboxylic acid and diamines with at least one additional tertiary amine nitrogen atom, for example N-methyl-bis (3-aminopropyl) amine.

Diamino- and dihydroxycarboxylic acids are particularly preferred, in particular the adduct of ethylenediamine with sodium acrylate or dimethylolpropionic acid.

The conversion of the potential ionic groups, which may have been initially incorporated into the polyaddition product, at least partially into ionic groups, takes place in a conventional manner by neutralization of the potential anionic or cationic groups or by quaternization of tertiary amine nitrogen atoms.

For the neutralization of potential anionic groups, e.g. Carboxyl groups, inorganic and / or organic bases are used such as alkali metal hydroxides, carbonates or hydrogen carbonates, ammonia or primary, secondary and particularly preferably tertiary amines such as triethylamine or dimethylaminopropanol.

To convert the potential cationic groups, for example the tertiary amine groups, into the corresponding cations, for example ammonium groups, inorganic or organic acids, for example salt, phosphorus, ants, vinegar, fumaric, maleic, milk, wine, are used as neutralizing agents - or oxalic acid or as quaternizing agent, for example methyl chloride, methyl bromide, methyl iodide, dimethyl sulfate, benzyl chloride, chloroacetic acid ester or bromine suitable for acetamide. Further neutralizing or quaternizing agents are described, for example, in US Pat. No. 3,479,310, column 6.

This neutralization or quaternization of the potential ion groups can take place before, during, but preferably after the isocanate polyaddition reaction.

The amounts of the monomers VI, in the case of potential components containing ion groups, taking into account the degree of neutralization or quaternization, should suitably be chosen so that the polyurethanes have a content of 0.05 to 2 meq / g polyurethane, preferably 0.07 to 1, 0 and particularly preferably from 0.1 to 0.7 meq / g of polyurethane on ionic groups.

If necessary, monofunctional amine or hydroxyl compounds are also used as structural components (monomers VII). They are preferably monohydric polyether alcohols with a molecular weight in the range from 500 to 10,000 g / mol, preferably from 800 to 5,000 g / mol. Monohydric polyether alcohols are e.g. by alkoxylation of monovalent starter molecules, e.g. Methanol, ethanol or n-butanol are available, ethylene oxide or mixtures of ethylene oxide with other alkylene oxides, especially propylene oxide, being used as alkoxylating agents. If alkylene oxide mixtures are used, however, they preferably contain at least 40, particularly preferably at least 65 mol% of ethylene oxide.

Monomers VII can thus, if appropriate, incorporate polyethylene oxide segments present in the terminally arranged polyether chains, which, in addition to the ionic groups, influence the hydrophilic character in the polyurethane and ensure or improve dispersibility in water.

The compounds of the type mentioned are preferred, if use is made of them, in such amounts that from 0 to 10, preferably from 0 to 5,% by weight of polyethylene oxide units are introduced into the polyurethane.

Further examples of compounds which can be used as monomers I to VII in the preparation of the polyurethanes described are, for example, in High Polymers, Vol. XVI, "Polyurethanes, Chemistry and Technology", from Saunders-Frisch, Interscience Publishers, New York, London, volume I, 1962, pages 32 to 42 and pages 44 to 54 and volume II, pages 5 to 6 and 198 to 199. Suitable monomers VIII, which, in contrast to the above monomers, contain ethylenically unsaturated groups, are, for example, esters of acrylic or methacrylic acid with polyols, with at least one OH group of the polyol remaining unesterified. Hydroxyalkyl (meth) acrylates of the formula HO (CH ₂ ) _m OOC (R ¹² ) C = CH ₂ (m - 2 to 8; R ¹² - H, CH ₃ ) and their positional isomers, mono (meth) are particularly suitable acrylic acid esters of polyether diols, such as those listed for the monomers II, trimethylolpropane mono- and di (meth) acrylate, pentaerythritol di- and tri (meth) acrylate or reaction products of epoxy compounds with (meth) acrylic acid, as described, for example, in US Pat. No. 357 221 are mentioned. The adducts of (meth) acrylic acid with bisglycidyl ether of diols such as, for example, bisphenol A or butanediol are particularly suitable.

Adducts of (meth) acrylic acid with epoxidized diolefins such as e.g. 3, -Epoxycyclohexylmethyl-3 ',. '-epoxycyclohexane carboxylate.

By incorporating the monomers VIII, the polyurethane can, if desired, be cured subsequently thermally or photochemically, if appropriate in the presence of an initiator.

In general, the proportion of ethylenically unsaturated groups is less than 0.2 mol per 100 g of polyurethane.

Overall, the proportion of the structural components is preferably chosen such that the sum of the hydroxyl groups reactive toward isocyanate and primary or secondary amino groups is 0.9 to 1.2, particularly preferably 0.95 to 1.1, based on 1 isocyanate group.

The polyurethanes described, in particular as dispersions, can be prepared by the customary methods, such as are described in the above-mentioned documents.

In an inert, water-miscible solvent, such as acetone, tetrahydrofuran, methyl ethyl ketone or N-methylpyrrolidone from the monomers I and II and optionally III, V, VI, VII and VIII, if VI contains no amino groups, the polyurethane or If a further reaction with amino-functional monomers IV or VI is intended, a polyurethane prepolymer with terminal isocyanate groups is prepared.

The reaction temperature is generally between 20 and 160 ° C, preferably between 50 and 100 ° C. To accelerate the reaction of the diisocyanates, the customary catalysts, such as dibutyltin dilaurate, stannous octoate or diazabicyclo (2,2,2) octane, can also be used.

The polyurethane prepolymer obtained can, if appropriate after (further) dilution with solvents of the type mentioned above, preferably with solvents having a boiling point below 100 ° C., at a temperature between 20 and 80 ° C. be reacted further with amino-functional compounds of the monomers VI and optionally IV become.

The transfer of potential salt groups, e.g. Carboxyl groups, or tertiary amino groups, which were introduced into the polyurethane via the monomers VI, are carried out in the corresponding ions by neutralization with bases or acids or by quaternization of the tertiary amino groups before or during the dispersion of the polyurethane in water.

After the dispersion, the organic solvent, if its boiling point is below that of the water, can be distilled off. Any solvents with a higher boiling point that are used can remain in the dispersion.

The content of the polyurethane in the dispersions can in particular be between 5 and 70 percent by weight, preferably between 20 and 50 percent by weight, based on the dispersions.

Customary auxiliaries, e.g. Thickeners, thixotropic agents, oxidation and UV stabilizers or release agents can be added.

Hydrophobic auxiliaries, which can be difficult to distribute homogeneously in the finished dispersion, can also be added to the polyurethane or the prepolymer before the dispersion by the method described in US Pat. No. 4,306,998.

In principle, all compounds having at least one free isocyanate group are suitable as isocyanates, the second component in the mixtures (D). Of particular importance here are the customary diisocyanates, the customary higher-functionality polyisocyanates, as described for the hydrophilically modified polyisocyanates (C), and the hydrophilically modified polyisocyanates themselves described under (C), but also monoisocyanates such as phenyl isocyanate or tolyl isocyanates are suitable. The polyurethanes and isocyanates mentioned are generally present as mixtures in a weight ratio of 10:90 to 90:10, in particular 25:75 to 75:25, especially 40:60 to 60:40.

In a preferred embodiment, one sets as

Compounds (D) mixtures of polyester urethanes and aliphatic diisocyanates, aliphatic higher functional polyisocyanates or hydrophilically modified polyisocyanates in a weight ratio of 10:90 to 90:10.

In the process according to the invention for the production of cellulose fibers, the compounds (A) to (D) can generally be used in an aqueous system, preferably in aqueous solution or emulsion, the aqueous system generally based on the Weight of the aqueous system, 0.1 to 20% by weight, preferably 0.5 to 10% by weight, of the compounds (A) to (D).

The manufacturing processes for cellulose fibers spun from solvents generally run in four stages.

Step 1: Dissolve the cellulose in a water-miscible solvent

Step 2: Extrude the solution through a die to form the fiber precursor

Stage 3: treatment of the fiber precursor with water in order to remove solvents and to form the cellulose fiber

Stage 4: drying the fiber

N-methylmorpholine-N-oxide is preferably used as the solvent in stage 1.

The moist fiber which is obtained in stage 3 is referred to as undried fiber and generally has, based on the dry weight of the fiber, from 120 to 150% by weight of water.

The water content of the dried fiber is generally 60 to 80% by weight, based on the dry weight of the fiber.

The treatment according to the invention with the compounds (A) to (D) can be carried out either on the moist fiber (during or after stage 3) or on the dried fiber (after stage 4). It is but treatment at the stage of fiber production (stage 2), for example in a precipitation bath, is also possible.

If the treatment is carried out on the moist fiber, this can be done, for example, by adding the aqueous system of the compounds (A) to (D) to a circulating bath which contains the fiber precursor. The fiber precursor can e.g. are present as a staple fiber.

10 If the treatment is carried out on the dried fiber, this can e.g. as staple fiber, fleece, yarn, knitwear or fabric. The treatment of the fibers in this case can e.g. done in aqueous liquor.

In contrast to the method described in EP-A-538 977, the presence of alkali can be dispensed with in the process according to the invention.

The treatment is usually carried out at a temperature of 20 to 20 200 ° C, preferably 40 to 180 ° C. A chemical reaction of the compounds (A) to (D) takes place with the hydroxyl groups of the cellulose, it also being possible to chemically link the hydroxyl groups of different cellulose fibrils. This increases the stability of the fiber. 25

The duration of the treatment is usually 1 second to 20 minutes, preferably 5 to 60 seconds and in particular 5 to 30 seconds.

In the impregnation process, the treatment can take place both at room temperature (20 ° C.) with subsequent drying to 100 ° C. and also when condensation is carried out at temperatures up to 200 ° C., in particular at 150 to 180 ° C.

35 The treatment of the moist or dried fiber can be 0.1 to 10% by weight, preferably 0.2 to 5% by weight, in particular 0.2 to 2% by weight, in each case based on the dry weight of the fiber, of compounds (A) to (D). In some cases, however, it may also be advantageous to increase the quantities mentioned.

40 hen, e.g. up to approx. 20% by weight.

In the treatment, other auxiliaries that are customary here can also be used in the amounts customary for this. Antimigration agents, for example based on oxethylation products, are particularly worth mentioning here. When using the compounds (A) and / or (B) according to the invention, the reactivity of these agents can be increased by adding catalytic amounts of Lewis acids such as MgCl, ZnCl ₂ , A1C1 ₃ , BF ₃ or systems such as MgCl ₂ / NaBF ₄ or MgS0 / NaBF ₄ / LiCl or of inorganic or organic acids or corresponding acidic salts, for example HC1, H ₂ S0, H ₃ PO.}, P-toluenesulfonic acid, methanesulfonic acid, NaHS0 ₄ , NaH ₂ P0, (NH) ₄ HS0 or trialkylamine hydrochloride, or of other crosslinking inorganic salts, for example nitrates or teraalkylammonium salts, adapted to the process requirements, ie generally increased.

As already stated, the compounds (A) to (D) can be fixed purely thermally (without alkali) compared with the compounds described in EP-A-538 977, as a result of which they can be optimally integrated into the fiber production process. As a rule, the fibers treated in this way can be dyed with all customary cellulose fiber dyes, including reactive dyes.

Using the test methods described in EP-A-538 977, to which express reference is made here, advantageous results can be achieved.

Claims

claims

1. A process for the production of cellulose fibers spun from solvents with a reduced tendency to fibrillate, characterized in that the fibers with one or more compounds from the group of

(A) N-methylol ethers of carboxamides, urethanes, ureas and aminotriazines,

(C) hydrophilically modified polyisocyanates and

(D) Mixtures of polyurethanes with isocyanates

treated.

2. The method according to claim 1, characterized in that as compounds (A) N-methylol ether of the general formula I.

R ² O

I II

Rl 0 CH ₂ N-CR ^{3 (} I ⁾ in the

R ² denotes hydrogen, the group CH - 0R ¹ or a Ci-Cβ-alkyl radical, which additionally carry hydroxyl groups and / or Cχ-C ₄ alkoxy groups as substituents and by non-adjacent oxygen atoms and / or C -.- C ₄ -Alkyl- nitrogen atoms can be interrupted, and

R ^{3 is} hydrogen, a C 1 -C 8 -alkyl radical, a C 1 -C 8 -alkoxy radical which can be interrupted by non-adjacent oxygen atoms, or the group (-NR ² -CH ₂ OR ¹ ) means,

where the radicals R ² and R ^{3 are connected} to form a five- or six-membered ring and, in the case of R ³ - (-NR ² -CH ₂ 0R ¹ ), two such rings are also connected via the α-position to the amide nitrogen gene C atoms of the radicals R ² can be condensed into a bicyclic system.

3. The method according to claim 1, characterized in that the compounds (A) melamine derivative of the general formula IV

in which the radicals A are the same or different and represent hydrogen or the group CH ₂ OR ¹ , where at least one of the radicals A must have the meaning CH - 0R ¹ and R ^{1 has} the meaning mentioned above .

4. The method according to claim 1, characterized in that as compounds (B) cyclic hydroxy or alkoxyethylene ureas of the general formula VI

R ⁴ NC - N R5 (VI)

R ⁷ 0 - OR ⁶

in which R ⁴ and R ^{5 are} hydrogen or C ₁ -C ₃ -alkyl with the proviso that at least one of the radicals R ⁴ and R ^{5 is} a C ₁ -C ₃ -alkyl group, and R ⁶ and R ^{7 are} hydrogen or Cι- C alkyl are used.

5. The method according to claim 1, characterized in that the compounds (C) modified non-ionically hydrophilic

Polyisocyanates, which are hydroxyl-terminated polyethers of the general formula VII

R8_ _E _ (D0) _n -H (VII)

in the

R ^{8 represents} Ci to C ₂ o-alkyl or C ₂ to C ₂ o-alkenyl, cyclopentyl, cyclohexyl, glycidyl, oxethyl, phenyl, tolyl, benzyl, furfuryl or tetrahydrofurfuryl, E denotes sulfur or oxygen,

D means propylene or ethylene and

n stands for a number from 5 to 120,

built in included, deploys.

6. The method according to claim 1, characterized in that the compounds (D) used are mixtures of polyester urethanes and aliphatic diisocyanates, aliphatic higher-functionality polyisocyanates or hydrophilically modified polyisocyanates in a weight ratio of 10:90 to 90:10 .

7. The method according to claims 1 to 6, characterized gekennzeich¬ net that the fibers with 0.1 to 10 wt .-%, based on the dry weight of the fibers, of the compounds (A) to (D) treated.

8. The method according to claims 1 to 7, characterized gekennzeich¬ net that one carries out the treatment at a temperature of 20 to 200 ° C.