WO1998007921A1 - Process for preparing aqueous, concentrated solutions of n-methylolethers suitable for finishing cellulosic textile materials - Google Patents

Abstract

Aqueous solutions of N-methylolethers of carboxylic acid amides, urethanes, ureas and aminotriazines suitable for finishing cellulosic textile materials are prepared by reacting the corresponding N-methylol compounds with an alcohol in the presence of an acid in the aqueous phase at a pH value from 0 to 3, then by adjusting the pH value of the solution to a value between 4 and 10. One or several alkanolamines or a mixture of alkanolamines with other bases are used to adjust the pH value of the solution to a value between 4 and 10 when an acid is used which forms hardly soluble salts in the obtained solutions together with the mineral bases used to adjust the pH value of the solution to a value between 4 and 10, or one or several C1-C4-alkylsulphonic acids which can be substituted in the alkyl group are used as acids.

Description

Process for the preparation of aqueous concentrated solutions of N-methylol ethers suitable for the finishing of cellulose-containing textile materials

description

The present invention relates to an improved process for the preparation of aqueous solutions of N methylol ethers of carboxylic acid amides, urethanes, ureas and amide triazines suitable for the finishing of cellulose-containing textile materials by reacting the corresponding N-methylol compounds with an alcohol in the presence of an acid in an aqueous phase pH from 0 to 3 and subsequent adjustment of the pH of the solution to 4 to 10. Furthermore, the invention relates to the use of these aqueous solutions as textile finishing agents for cellulose-containing materials.

The N-methylol ether solutions mainly used as finishing agents for cellulose-containing textile materials are usually produced by etherification of the corresponding N-methylol compounds in the presence of a mineral acid, for example hydrochloric acid, sulfuric acid or nitric acid. Petersen shows in the Handbook of Fiber Science and Technology: Vol. II, Chemical Processing of Fibers and Fabrics, Functional Fmishes, Part A, Marcel Dekker, Inc., 1983, in particular on pages 200 to 205, that this is a System deals with equilibrium reactions that require catalysis by acids.

EP-A 392 349 discloses a process for the preparation of aqueous solutions of N-methylol ethers of carboxamides, urethanes, ureas and ammotriazines suitable for the finishing of cellulose-containing textile materials, in which the etherification with boron fluoride, boron fluoride addition compounds or tetrafluoroboric acid is catalyzed.

However, the proton or Lewis acids recommended in the prior art for the stated purpose have disadvantages. The boron-fluorine compounds described in EP-A-392 349 can adversely affect the reactivity of the solution used in the finishing and it can lead to fiber damage or insufficient strength of the finished textile material. When using nitric acid, the lightfastness of dyes and optical brighteners on the textiles is usually greatly reduced. When using hydrochloric acid, toxic bischloromethyl ethers can be formed in the presence of formaldehyde. You sit down Sulfuric acid, which is still the most favorable in terms of toxicology and environmental aspects and on the application-technical requirements, the serious disadvantage arises that ms, especially in the preparation of concentrated N methylol ether solutions, are formed by neutralization with conventional mineral bases, which are difficult to filter off and then must also be disposed of, since such salts are normally not recoverable. Even if these salts do not precipitate out, they represent an undesirable salt load for the solutions produced.

It was therefore an object of the present invention to provide aqueous N-methylol ether solutions which are suitable for rustproofing textiles and which no longer have the disadvantages described.

Accordingly, the initially defined process for the preparation of such solutions was found, which is characterized in that

(a) when using an acid which, with mineral bases used to adjust the pH of the solution from 4 to 10, forms poorly soluble salts in the solutions obtained, to adjust the pH of the solution from 4 to 10 one or more alkanolamines or em Mixture of alkanolamm with other bases or

(b) one or more C 1 -C ₄ alkyl sulfonic acids which may be substituted for the alkyl group are used as the acid.

Carrying out the method according to the invention from embodiment (a) is particularly advantageous if sulfuric acid is used as the acid, since this avoids the problem of salt deposits.

In principle, all water-soluble monoalkanols, dialkanols and trialkanolams can be used as alkanolamines. Trialkanolammes of the general formula I are particularly suitable

T ² -OH

HO T ¹ N (I)

T ³ -OH where T ¹ to T ³ denote the same or different linear or branched alkylene groups each with 2 DIS 4 C atoms. Typical examples of trialkanolammes I are tri-n-propanolamm, tri isopropanolamine, tri n-butanolamm and especially triethanolamine. 5

The alkanolamines or trialkanolammes I mentioned can be used to neutralize the acid after etherification as sole bases or in a mixture with other bases, in particular mineral bases. The mineral bases here are in particular 10 sodium hydroxide and potassium hydroxide or their aqueous solutions.

In a preferred embodiment, a mixture is exposed to adjust the pH of the solution from 4 to 10

15 alkanolamines or trialkanolamines I and other bases, in particular mineral bases, in the ratio of the base equivalents from 20:80 to 80:20, in particular 35:65 to 65:35, especially 45:55 to 55:45. When using a very large excess of alkanolamine or trialkanolamm I compared to the other

20 their base or of alkanolamine or trialkanolamm I alone, the easy-care effect achieved with the equipment can be worsened compared to the use of the mixture of alkanolamine or trialkanolamm I and other base defined above.

In embodiment (b), the optionally substituted Cχ-bs C ₄ - alkylsulfonic acid is, for example, ethanesulfonic acid, trifluoromethanesulfonic acid or, above all, methanesulfonic acid. Mixtures of such alkyl sulfonic acids can also be used. The neutralization of the alkyl sulfonic acids after

Etherification can be carried out using conventional mineral bases, e.g. NaOH or KOH, or also with the alkanolamms mentioned.

The etherification process according to the invention is carried out in a strongly acidic solution, for example at pH 0 to 3, in particular at pH 0.5 to 2.35. Above pH 3, the process according to the invention provides significantly poorer etherification results.

In the ..egel are employed aqueous solutions of N-meth _J lolverbin- compounds having a solids content of usually

40 40 to 85% by weight and a pH of normally 4 to 10, which is reduced to the above range, with 0.5 to 1.5 mol, in particular 0.9 to 1.35 mol, of an alcohol per N-methylol group at temperatures of 20 to 80 ° C, especially 30 to 60 ° C, around each other. The response time to

45 The desired degree of etherification is normally between 0.5 and 8 hours, preferably 1 to 5 Hours. The pH is then adjusted again to 4 to 10, in particular pH 4 to 7.

The solutions of the N-methylol ethers thus obtained are generally adjusted to a water content of 20 to 80% by weight, in particular 30 to 60% by weight, by dilution with water. The degree of etherification of the N-methylol groups in the process according to the invention is normally 50 to 95%.

With the method according to the invention, it is thus possible in particular to produce stable, highly concentrated N-methylol ether solutions, e.g. with solids contents of up to 80% by weight or even up to 85% by weight.

In addition to the alcohols used for etherification, which are specified in more detail below, the aqueous solutions of the N-methylol compounds obtained for etherification may also contain further alcohols in the form of glycols or polyethers, which are important for the finishing process which takes place later. Diethylene glycol should be mentioned in particular as a representative of such glycols or polyethers. The hydroxyl groups of these glycols or polyethers can also partially participate in the etherification of the N-methylol compounds.

The method according to the invention relates in particular to the preparation of aqueous solutions of the N-methylol ethers of the general formula II

R ² 0

R ¹ 0 CH ₂ NCR ³ (II)

R ^{1 represents} a Ci-Cio alkyl group which may be interrupted by oxygen atoms,

R ² denotes hydrogen, the group CH ₂ OR ¹ or a Ci-Cβ-alkyl radical, which additionally contains hydroxyl groups and / or

Ci -C ₄ alkoxy groups as substituents and can be interrupted by oxygen atoms and / or -CC ₄ alkyl groups - nitrogen atoms, and R ^{3 is} hydrogen, a Ci _. Cio-alkyl radical, a Ci -Cχo - alkoxy radical, which can be interrupted by oxygen atoms, or the group (-NR ² -CH ₂ OR ¹ ),

where the radicals R ² and R ^{3 are} joined to form a five or six-membered Rmg and, in the case of R ³ = (-NR ² CH ₂ OR ¹ ), also two such rings via the C atoms of the radicals R ^{2 which are} α-amide nitrogen condensed to a bicyclic system, by reacting the corresponding N-methylol compounds of the general formula III

R ² 0

H 0 CH ₂ NI CII R ³ ( ⁽ T ^U TT ⁱ .

with alcohols of the general formula IV

Ri — OH (IV)

The radical R ¹ stands for a C 1 -C 4 -alkyl group which may be interrupted by oxygen atoms. 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 especially methyl.

The radical R ² denotes hydrogen, the group CH ₂ OR ¹ and s - 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 oxygen atoms and / or by C ₁ -C ₄ -alkyl-bearing nitrogen atoms can be interrupted.

The radical R ³ is hydrogen, a C 1 -C ₁₀ -alkyl radical, a C 1 -C ₁₀ -alkoxy radical which can be interrupted by oxygen atoms, and in particular the group (-NR ² -CH ₂ OR).

The process according to the invention is of particular importance for those N-methylol ethers II in which the radicals R ² and R ³ are linked to form a five- or six-membered R g. 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-position to the amide nitrogen. Examples of N-methylol ether II which can be prepared in aqueous solution by the process according to the invention are:

A ide of Ci -Cχι -carboxylic acids, for example formic acid, acetic acid, propionic acid, butyric acid or valeric acid, which carry one or two CH ₂ OR ¹ groups on nitrogen,

Carbamates with Cχ-Cχo alkyl groups in the ester radical, which can be interrupted by oxygen atoms, for example

Methyl, ethyl, n-propyl, iso-propyl, 2-methoxyethyl or n-butyl, which carry two CH ₂ OR ¹ groups on the nitrogen,

Urea with 1 to 4 CH ₂ OR ¹ groups on the nitrogen atoms,

cyclic ethylene ureas of the general formula Ha,

0

II C

Rl 0 CH ₂ N "" N CH ₂ 0 R ¹ (Ha)

X

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

cyclic propyleneureas of the general formula Hb,

R ¹ - 0 - CH ₂ N " ^C ^ - CH ₂ 0 R ¹ (Hb)

in the Y for CH ₂ . CHOH, C (CH ₃ ) ₂ . represents an O atom or a N atom bearing a Cχ-C ₄ alkyl group and Z denotes hydrogen or a Cχ-C ₄ ~ alkoxy group, for example methoxy or ethoxy, bicyclic glyoxal diureas of the general formula Hc

O

R ¹ 0 CH ₂ N ^" N - CH ₂ 0 - R ¹

(Ilc)

R ^l - 0- -CH; N-. • N-CH ₂ 0 R ^{1 ~} C

0

bicyclic malondialdehyde diureas of the general formula Hd

R ¹ - 0- CH ₂ - ^' N- CH ₂ 0 R ¹

(Hd) R ^l 0 CH ₂ N ^ N CH ₂ OR ¹

II o

Furthermore, the method according to the invention relates to the preparation of aqueous solutions of melamine derivatives of the general formula V.

A ₂ N ^N NA ₂

m 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 C 1 OR ¹ , by reacting the corresponding N-methylol melamine of the general formula VI

NB ₂

N ^^ (VI)

B ₂ N ^N NB ₂ in which the radicals B analogous to A denote hydrogen or the group CH ₂ OH, with alcohols of the general formula IV.

Examples of Melammdeπvate V, which can be prepared by the inventive method in aqueous solution, are methoxymethyl melamine, bis (methoxymethyl) melamm, tris (meth oxymethyl) melamm, tetrakis (methoxymethyl) melamm, pentakis (meth oxymethyl) melamm and Hexakis (methoxymethyl) melamine and the analogous ethoxymethyl and isopropyloxymethyl compounds.

The aqueous solutions of N-methylol ethers produced by the process according to the invention are mainly used for the low-formaldehyde finishing of cellulose-containing textile materials. In this way, excellent finishing properties can be achieved with low levels of formaldehyde that can be split off from the finished textiles.

Examples

example 1

(Etherification with sulfuric acid, pH adjustment with triethanolamm)

931 g of a 75 wt. -% ιgen aqueous N, N '-dimethylol - 4, 5 -dihy- droxyethylene urea solution with a pH of 5.2 were 96 wt with 250 g of methanol and 8.6 ml. -% ιger sulfuric acid stirred at 50 ° C for 2 hours, the reaction solution had a pH of 0.9. After cooling to 30 ° C., a pH of 5.1 was set by adding 41.3 g of triethanolamm. The solution was mixed with 211 g of diethylene glycol. After cooling to 5 ° C. for two hours, the mixture (solids content: 75% by weight, pH value: 5.4) was still clear and no salt precipitations were detectable.

Example 2

(Etherification with sulfuric acid, pH adjustment with triethanolamm / NaOH in equiv. Ratio 48:52)

931 g of a 75 wt. - ιgen aqueous N, N '-dimethylol -4, 5 -dihydroxy ethylene urea solution with a pH of 5.2 were stirred with 250 g of methanol and 8.6 ml of 96% by weight sulfuric acid at 50 ° C. for 2 hours , the reaction solution had a pH of 0.9. After cooling to 30 ° C., a pH of 2.1 was added by adding 20.0 g of triethanolamm and then by adding 22.9 g 25 wt. -% ιger aqueous sodium hydroxide adjusted a pH of 5.1. The solution was mixed with 211 g of diethylene glycol. After cooling to 5 ° C. for two hours, the mixture was still clear, and no salt precipitations were detectable. A solution with a solids content of 72% by weight and a pH of 5.2 was produced by adding a further 34 g of water.

Example 3 for comparison

(Etherification with sulfuric acid, pH adjustment with NaOH)

931 g of a 75 wt. -% ιgen aqueous N, N 'dimethylol - 4, 5 dihydroxy ethylene urea solution with a pH of 5.2 were 96 wt with 250 g of methanol and 8.6 ml. -% ιger sulfuric acid stirred at 50 ° C for 2 hours, the reaction solution had a pH of 0.9. After cooling to 30 ° C .-% was ιger aqueous sodium hydroxide solution em pH of 5.2 is introduced ^¬ by adding 45.7 g of 25 wt. The solution was mixed with 211 g of diethylene glycol. The first salt precipitations occurred after just 10 minutes of stirring at room temperature; after stirring for an hour at 5 ° C., a total of 10 g of salt (essentially a ₂ SO) were filtered off. A solution with a solids content of 72% by weight and a pH of 5.2 was produced by adding a further 13 g of water.

Example 4

(Etherification with methanesulfonic acid)

931 g of a 75 wt. -% ιgen aqueous N, N '-Dιmethylol-4, 5 -dihydroxy- ethylene urea solution with a pH of 5.2 were with 70 g of methanol and 15.5 ml of 70 wt. -% ιger methanesulfonic acid stirred at 50 ° C for 2 hours, the reaction solution had a pH of 0.9. After cooling to 30 ° C by adding 20.8 g 25 wt. -% ιger aqueous sodium hydroxide solution adjusted to pH 5.2. The solution was mixed with 211 g of diethylene glycol. After cooling to 5 ° C. for two hours, the mixture was still clear, and no salt precipitations were detectable. A solution with a solids content of 72% by weight and a pH of 5.3 was produced by adding a further 29 g of water.

Application properties in textile finishing

Shirt poplar made of 100% cotton with a basis weight of 140 g / m ² was impregnated with the aqueous solutions from Examples ¹ , 2 and 4 and from Comparative Example 3 and magnesium chloride hexahydrate as a condensation catalyst using a padder. The liquor absorption was approx. 70% by weight. There was a residual moisture of approx. 8% by weight at 110 ° C. Condensation was then carried out under the conditions given in the table below.

The Monsanto smoothing note was determined on laundry ejected at 60 ° C. for 20 min. Formaldehyde that can be split off on the finished fabric was determined according to the specified standard measuring method.

Claims

claims

1. A process for the preparation of suitable for the finishing of cellulose-containing textile materials aqueous solutions of N methylol ethers of carboxylic acid amides, urethanes, ureas and ammotriazmas by reacting the corresponding N-methylol compounds with an alcohol in the presence of an acid in an aqueous phase at a pH from 0 to 3 and then adjusting the pH of the solution to 4 to 10, characterized in that

(a) When using an acid which, with the mineral bases used to adjust the pH of the solution from 4 to 10, is sparingly soluble in the solutions obtained

Salts forms one or more alkanolamines or a mixture of alkanolamines with other bases to adjust the pH of the solution from 4 to 10 or

(b) one or more 0χ to C ₄ alkyl sulfonic acids, which can be substituted in the alkyl group, are used as the acid.

2. The method according to claim 1, characterized in that one carries out the embodiment (a) when using sulfuric acid.

3. The method according to claim 1 or 2, characterized in that em in embodiment (a) as alkanolamines em or more trialkanolammes of the general formula I.

T ² -OH

HO T ¹ N ^(I> _{T 3-0H}

in which T ¹ to T ³ denote the same or different linear or branched alkylene groups each having 2 to 4 carbon atoms, or a mixture of such trialkanolammers I with other bases.

4. The method according to claims 1 to 3, characterized in that in embodiment (a) to adjust the pH of the solution from 4 to 10 em mixture of alkanol nurse and other bases in the ratio of base equivalents from 20:80 to 80:20.

5. The method according to claim 1, characterized in that one uses methanesulfonic acid in embodiment (b).

6. Process according to claims 1 to 5, characterized in that it is based on the preparation of aqueous solutions of N-methylol ethers of the general formula II

R ² O

R ¹ 0 CH ₂ N C- R ³ (II)

in the

R ^{1 represents} a Cχ-Cχo alkyl group which may be interrupted by oxygen atoms,

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

R ^{3 is} hydrogen, a C -Cχo alkyl radical, a Cχ-Cχo alkoxy radical which can be interrupted by oxygen atoms, or the group (- R ^ C ^ OR ¹ ),

where the radicals R ² and R ^{3 are combined} to form a five- or six-membered R g and, in the case of R ³ = (-NR ² -CH ₂ OR ^x ), two such further groups via the α-position C- to the amide nitrogen Atoms of the radicals R ² can be condensed to form a bicyclic system by reacting the corresponding N-methylol compounds of the general formula III

R ² 0 _H O CH ₂ —NCR ^{3 {III)} with alcohols of the general formula IV

Ri — OH (IV)

applies.

7. The method according to claim 6, characterized in that it is applied to the preparation of such N-methylol ether II, at

10 where the radical R ^{3 is} the group (-NR ² -CH ₂ OR ¹ ).

8. The method according to claim 6 or 7, characterized in that it is applied to the preparation of those N-methylol ethers II in which the radical R ² denotes a 0 - CQ alkyl radical,

15 of which additionally carry hydroxyl groups and / or Cχ-C ₄ alkoxy groups as substituents and can be interrupted by oxygen atoms and / or by nitrogen atoms bearing C -C ₄ alkyl groups.

20 9. The method according to claims 6 to 8, characterized in that it is applied to the preparation of those N-methylol ethers II in which the radical R ^{1 is} a Cχ-C ₃ alkyl group.

25 10. The method according to claims 6 to 9, characterized in that it is applied to the preparation of such N-methylol ether II, in which the radicals R ² and R ^{3 are connected} to a five- or six-membered Rmg.

11. The method according to claims 1 to 5, characterized in that it is based on the production of aqueous solutions of melamine derivatives of the general formula V.

NA ₂ 5

N ': N (V)

A ₂ N ^N NA ₂

0

5 in which the radicals A are identical or different and stand for hydrogen or the group CH ₂ OR ¹ , where at least one of the radicals A must have the meaning CH ₂ OR ^x , by reacting the corresponding N-methylolmelamines of the general formula VI

NB ₂

N ^ N (VI)

B ₂ NN NB2

in which the radicals B analogous to A denote hydrogen or the group CH ₂ 0H, with alcohols of the general formula IV

Ri— OH (IV)

applies.

12. Use of the aqueous solutions of N-methylol ethers according to claims 1 to 11 as textile finishing agents for cellulose-containing materials.