EP1005584A1

EP1005584A1 - Wool with a non-felting finish and self-dispersing isocyanates therefor

Info

Publication number: EP1005584A1
Application number: EP98946313A
Authority: EP
Inventors: Bernhard Jansen; Ferdinand Kümmeler; Helga Thomas
Original assignee: Bayer AG
Current assignee: Bayer Chemicals AG
Priority date: 1997-08-22
Filing date: 1998-08-11
Publication date: 2000-06-07
Also published as: JP2001514341A; AU730514B2; WO1999010590A1; DE19736542A1; AU9341098A

Abstract

Wool with a non-felting finish is disclosed, as well as a process for producing the same by (a) prior treatment with a low pressure plasma; and (b) subsequent treatment with aqueous dispersions of self-dispersing isocyanates. Also disclosed are water-dispersible isocyanates useful for that purpose with improved storage stability.

Description

Felt-free finished wool and self-dispersing isocyanates therefor

The invention relates to wool finished with a felt-free finish, a process for its production by a) a pretreatment with a low-pressure plasma b) a post-treatment with aqueous dispersions of self-dispersing isocyanates and water-dispersible isocyanates which can be used for this purpose.

Isocyanates for imparting felt to textiles have long been known and can be used, for example, as described in DE-OS 1.904.802, in organic solvents or, as described in DE-OS 1.769.121, in aqueous dispersion with the aid of emulsifiers. Both organic solvents and, if applicable, wastewater-polluting emulsifiers are no longer appropriate today for ecological and industrial hygiene reasons. In the following, therefore, we will either speak of self-dispersing isocyanates or of formulations which use as little as possible solvents and emulsifiers as auxiliaries and additives.

FR 1,542,831 describes the treatment of textile materials with baths, the polymers or copolymers of vinyl or divinyl compounds, an aqueous

Contain dispersion of isocyanates, ammonium salts or metal salts and surfactants. Auxiliary solvents are used here. DE-OS 1,794,221 describes the treatment of fiber materials with isocyanate prepolymers which still contain free isocyanate groups; this finishing can be done in solvents (perchlorethylene) or in aqueous emulsion using auxiliary emulsifiers. US Pat. No. 3,847,543 discloses a process for the non-felting of wool, in which the following are present in aqueous dispersion: aliphatic isocyanates, OH-functional crosslinking agents and organometallic catalysts. Although this process takes place in the aqueous phase, auxiliary solvents and emulsifiers are still required. DE-OS 4.415.451 (WO 95/30045) describes a process in which water-dispersible isocyanates are used for the finishing of wool without felt. Here you can work without solvents and without an emulator, because the isocyanates used are water-dispersible. The examples describe that there However, the process described is such that the wool is first subjected to a pretreatment by oxidizing agents, followed by a reduction treatment, before the water-dispersible isocyanates are used. Of course, this pretreatment causes wastewater which must be neutralized and clarified in accordance with the regulations. These isocyanates also have a only limited storage stability

In contrast to this, the present invention does not cause any wastewater due to the pretreatment by low-pressure plasma and is ecologically positive. Surprisingly, it was found that oxidative and / or reducing pretreatment agents are not required and a very good felt-free finish on wool can be achieved if a low-pressure plasma treatment is carried out before the treatment with aqueous dispersed isocyanates

The present invention relates to felt-free finished wool, which is characterized in that colored or undyed wool sliver

(a) exposed to low pressure plasma in a pretreatment and

b) aftertreated with aqueous dispersions of self-dispersing isocyanates

Another object of the present invention is a method for felt-free removal of wool, which is characterized in that dyed or undyed WoUkammzug

(a) exposed to low pressure plasma in a pretreatment and

b) aftertreated with aqueous dispersions of self-dispersing isocyanates

The self-dispersing isocyanates are also an object of the invention, they have an isocyanate content of 1 to 25% by weight. calculated as NCO (molecular weight 42) and based on the total weight of the isocyanates, and can be obtained by reaction in any order from:

I) with organic polyisocyanates with an average NCO functionality of 1.8 to 4.2

II) Polyalkylene oxide alcohols, amines and / or thiols of the formula

R ¹ N N- (CHX-CHY-0) _n -CHX-CHY-ZH (I),

_ /

R

in the

n represents a number from 3 to 70,

X and Y are hydrogen or methyl with the proviso that in the case of methyl only one of the radicals X and Y is methyl and the other is hydrogen,

R ¹ and R ² independently of one another are straight-chain or branched Ci-Cg-alkyl or C _j -C ₆ -acyl, where R ^{1 can be} acyl, R ^{2 can} also be hydrogen and R ¹ and R ² together can represent tetramethylene, pentamethylene or hexamethylene, in which one or two methylene groups can be replaced by O and / or NH and / or one or two methylene groups can be substituted by methyl, and

Z represents O, S or NH,

and if necessary with III) further NCO-reactive compounds which contain anionic or cationic or potentially anionic or cationic groups

The term "self-dispersing" in the present context means that the mixtures in a concentration of up to 70% by weight, preferably up to 50

% By weight in water of finely divided dispersions with particle sizes of <500 nm (measured using an ultracentrifuge)

Examples of suitable starting materials for the self-dispersing isocyanates are

I) Non-modified, ahphatic, cycloaliphatic, arahphatic or aromatic isocyanates of the NCO functionality from 1.8 to 4.2. Preferably used are ahphatic and cycloaliphatic polyisocyanates which contain uretdione and / or isocyanurate and / or allophanate and / or biuret - and / or oxadiazine structures and which can be prepared in a manner known per se from ahphatic, cycloahphatic, araliphatic or aromatic diisocyanates. For example, 1,4-dnsocyanate butane, 1,6-dusocyanatohexane, 15-dnsocyanato are suitable. 2,2-dimethylpentane, 2,2,4- or 2,4,4-trimethyl-l, 6-dnsocyanatohexane, 1,3- and 1,4-dnsocyanatocylohexane, 1-isocyanato-3 3,5-tπmethyl -5-isocyanatomethylcyclohexane, l-isocyanato-l-methyl-4-isocyanatomethylcyclohexane and 4,4-dnsocyanatodicyclohexylmethane or any mixture of such dnsocyanates

The preferred uretdione, isocyanurate, allophanate, oxadiazine groups reaction products of these dnsocyanates are essentially from tπmerem 1,6-dusocyanatohexane or l-isocyanato-3,3,5-tπmethyl-5-ιsocyanatomethyl-cyclohexane and from the corresponding higher homologues, isocyanurate groups and optionally containing uretdione groups containing polvisocyanate mixtures with an NCO content of 19 to 24% by weight. The corresponding, largely uretdione group-free, isocyanate group-containing polyisocyanates of the stated NCO content are used, as described by known, catalyzed trimerization of 1,6-diisocyanatohexane or l-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane with isocyanurate formation and which preferably have an (average) NCO functionality of 3.2 to 4 , 2 have. Preference is also given to the trimeric polyisocyanates obtained by reaction of 1,6-diisocyanato-hexane with a deficit of water in a known manner and having essentially biuret groups and having an NCO content of 19 to 24% by weight.

Other suitable polyisocyanates are aliphatic or aromatic diisocyanates such as hexamethylene diisocyanate, tolylene diisocyanate, 1,5-diisocyanatonaphthalene, diphenylmethane diisocyanate and their higher homologues with uretdione, isocyanurate, allophanate and biuret groups.

Among the polyalkylene oxide ether alcohols, ether amines and / or ether thiols of the formula (I), the polyalkylene oxide ether alcohols are preferred.

The polyalkylene oxide ether alcohols are mono- or polyvalent polyalkylene oxide ether alcohols containing on average 3 to 70, preferably 6 to 60 alkylene oxide units per molecule, as are known in a manner known per se by alkylation of suitable starter molecules. Any secondary amines or acid amides can be reacted as starter molecules to produce these polyalkylene oxide ether alcohols. Heterocyclic nitrogen compounds such as morpholine are also suitable for the alkoxylation reaction. Identical compounds can also be obtained by using morpholinoethanol as a starter for the

Ethoxylation reaction used. Acylation products of ethanolamine, such as acetylethanolamine, can also be used as starters. Alkylene oxides suitable for the alkoxylation reaction are ethylene oxide and propylene oxide, which can be used individually or in any order or in a mixture in the alkoxylation reaction. The polyalkylene oxide ether alcohols are either pure polyethylene oxide polyethers, pure polypropylene polyethers or mixed polyalkylene oxide polyethers which have at least one polyether sequence which have at least 3, generally 3 to 70, preferably 6 to 60 and particularly preferably 7 to 20 alkylene oxide units, and their

At least 60 mol%, preferably at least 70 mol%, of alkylene oxide units consist of ethylene oxide units. Preferred such polyalkylene oxide polyether alcohols are monofunctional polyalkylene oxide polyethers started on an aliphatic, nitrogen-containing starter according to structure (I) and having a statistical average of 6 to 60 Contain ethylene oxide units

The ether alcohols can be obtained by reaction with H ₂ S ether thiols (Z = S) and with NH ₃ ether amines (Z = NH)

The other NCO-reactive compounds which contain anionic or cationic and / or potential anionic or cationic groups are

I) hydroxyl-functional or amino-functional compounds with tertiary amino groups, as have been described in detail in DE-OS-4 319 571,

n) hydroxyl-functional or amino-functional compounds with carboxy or sulfonic acid groups, as have been described in detail in DE-19 520 092,

in) hydroxyl-functional or amino-functional compounds with carboxylate or sulfonate groups whose counterions are metal cations from the alkali or alkaline earth group or ammonium, as have been described in detail in DE 19 520 092,

IV) hydroxyl-functional or amino-functional compounds with ammonium ions, which in a manner known per se by alkylation or pro- toning, as described in EP-A 0 582 166, can be obtained from the tertiary amino groups of the compounds i).

Of course, any mixtures of NCO-reactive groups, if chemically useful, for example from groups i) and iv), for example obtainable by partial alkylation of tertiary amino groups, or for example from groups ii) and iv), can also be used according to the invention.

The unmodified polyisocyanates to be used according to the invention can also be used in combination with external ionic or nonionic emulsifiers. Such emulsifiers are described, for example, in Methods of Organic Chemistry, Houben-Weyl, Vol. XIV / 1, Part 1, pages 190-208 Thieme-Verlag, Stuttgart (1961), in US Pat. No. 3,428,592 and EP-A 0 013 112. The emulsifiers are used in an amount which ensures dispersibility. If polyisocyanates I are first reacted with polyalkylene oxide polyether alcohols, this reaction can be carried out in a manner known per se, while maintaining an NCO / OH equivalent ratio of at least 2: 1, generally from 4: 1 to about 1000: 1, where Polyether-modified polyisocyanates with an average NCO functionality of 1.8 to 4.2, preferably from 2.0 to 4.0, and a content of aliphatically or cycloaliphatically bound isocyanate groups of 12.0 to 21.5% by weight and a content of ethylene oxide units arranged within polyether chains (calculated as C2H O, molecular weight = 44 g / mol) of 2 to 20% by weight, the polyether chains having a static average of 3 to 70 ethylene oxide units.

The starting components can be reacted in any order with the exclusion of moisture, preferably without a solvent. With increasing amount of component (II), a higher viscosity of the end product is achieved, so that in certain cases (if the viscosity rises sharply) a solvent can be added, which is preferably miscible with water, but is inert towards the polyisocyanate. Suitable solvents of this type are: alkyl ether acetates, glycol diesters, toluene, carboxylic acid esters, acetone, methyl ethyl ketone, tetrahydrofuran and dimethylformamide. By using known catalysts such as dibutyltin dilaurate, tin (II) octoate or 1,4-diazabicyclo [2,2,2] octane in amounts of 10 to 1000 ppm, based on the reaction components, the reaction can be accelerated Reaction is in the temperature range up to 130 ° C, preferably in the range between

10 ° C and 100 ° C, particularly preferably between 20 ° C and 80 ° C, The reaction is carried out by titration of the NCO content or by measuring the IR spectra and evaluating the NCO band at 2260-2275 cm ^~ l is tracked and ended when the isocyanate content is not more than 0.1% by weight above the value which is achieved for a given stochimetry with complete conversion. As a rule, reaction times of less than 24 hours are sufficient. The solvent-free synthesis of the invention is preferred polyisocyanates to be used

In a further embodiment, it is also possible to mix the polyisocyanate mixtures according to the invention by mixing

1) unmodified polyisocyanates I)

2) Polyisocyanates obtained by reacting polyisocyanates I) with the NCO-reactive compounds mentioned under III), the equivalent ratio of the isocyanate-reactive groups from III) to the NCO groups of component II) used being 1 1 to 1 1000 be, and

3) polyisocyanates obtained by reacting polyisocyanates I) with polyalkylene oxide polyether alcohols, amines and / or thiols II), the ratio of equivalents of the isocyanate-reactive groups of component II to the NCO groups of component I) 1 1 to Amounts to 1 1000,

The number of NCO-reactive equivalents, the polyether content, the NCO content and the NCO functionality should be adjusted by the person skilled in the art by appropriate weighing in such a way that the mixture obtained is suitable for the water dispersions. has the required composition, in particular the preferred ranges already mentioned apply.

The self-dispersible polyisocyanate mixtures are technically easy to handle and can be stored for many months if moisture is excluded. This stability is one

Advantage over prior art materials.

According to the invention, the self-dispersible polyisocyanate mixtures are preferably used without organic solvents. They are very easy to emulsify in water at temperatures up to 100 ° C. The active substance content of the emulsion can be up to 70

% By weight. However, it is more advantageous to prepare emulsions with an active substance content of 1 to 50% by weight, which can then optionally be further diluted before the metering point. Mixing units customary in technology (stirrers, mixers with a rotor-stator principle and e.g. high-pressure emulsifying machines) are suitable for emulsification.

The preferred self-dispersible polyisocyanates are self-emulsifying, ie they can be easily emulsified after being added to the water phase without the action of high shear forces. A static mixer is usually sufficient. The emulsions obtained have a processing time of up to 24 hours, which depends on the structure of the polyisocyanates to be used according to the invention, in particular on their content of basic N atoms.

Examples

A) Self-dispersing isocyanates

Self-dispersing isocyanate 1 (for comparison):

85 parts by weight of an isocyanate with an NCO content of 22.5%, consisting essentially of trimeric hexamethylene diisocyanate, were reacted at 60 ° C. with 15 parts by weight of a polyethylene glycol monomethyl ether with an average molecular weight of 350. The resulting product had an NCO content of

17% and a viscosity of 1500 mPas at 25 ° C. The product was very easy to disperse in a beaker with water by simply stirring with a glass rod. Computational NCO functionality: F = 2.70.

Self-dispersing isocyanate 2 (according to the invention):

85 parts by weight of an isocyanate with an NCO content of 22.5%, consisting essentially of trimeric hexamethylene diisocyanate, were reacted at 60 ° C. with 15 parts by weight of an ethylene oxide polyether started on morpholine and having an average molecular weight of 420 . The resulting product had an NCO

Content of 16.5% and a viscosity of 2550 mPas at 25 ° C. Computational NCO functionality: F = 2.76.

Self-dispersing isocyanate 3 (according to the invention):

65 parts by weight of an isocyanate with an isocyanate content of 22.5%, consisting essentially of trimeric hexamethylene diisocyanate, were reacted at 60 ° C. with 35 parts by weight of an ethylene oxide polyether started on morpholine and described above. The product had an NCO content of 10.9% and a viscosity of 4400 mPas at 25 ° C. Computational NCO functionality: F = 2.52. 0590

1 1

Self-dispersing mean of the felt ball Remarks

Isocyanate No. diameter

1 2,621 comparison

2 2,483 according to the invention

3 2,767

4 2,578

C) Experiments on storage stability

To investigate the storage stability, the self-dispersing isocyanates 2 (according to the invention) and 5 (for comparison) were each produced in kg and filled into 11 small bottles with a volume of 100 ml. After determining an initial value, these bottles were made for both the isocyanate content and the

Viscosity stored in a drying cabinet heated to 60 ° C. The storage stability was checked by measuring the isocyanate content and the viscosity on a weekly basis (the last two measurements were carried out every two weeks); falling NCO content and increasing viscosity are indications of side reactions in the stored samples. Fresh bottles were always opened, so that the test could not be influenced by the penetration of atmospheric humidity when the bottle was opened and closed again. Samples that had already been tested were then discarded. The following table gives an overview of the values found:

Week self-dispersing isocyanate 2 (according to the invention) 5 (for comparison)

Viscosity NCO content Viscosity NCO content

[mPas] [mPas] [%]

(Zero value) 2620 17.3 9116 15.1

1 2700 17.3 10230 14.5

2 2760 17.2 13520 13.9

3 2760 17.0 18245 13.8

4 2880 16.9 29200 13.0

5 2790 16.9 70612 1 1.6

6 2910 17.0 177510 1 1.2

7 3000 17.0 no more values measured

8 3050 17.0 "

10 3000 17.0

12 3000 17.0 ,,

This extremely sensitive test convincingly showed the much better storage stability of the self-dispersing isocyanate 2 according to the invention. This is surprising for the person skilled in the art, because the content of tertiary nitrogen in the self-dispersing isocyanate 2 according to the invention is significantly higher than that of the self-dispersing isocyanate 5 used comparatively

Claims

claims

1. Felt-free finished wool, characterized in that dyed or undyed wool sliver

(a) exposed to low pressure plasma in a pretreatment and

b) aftertreated with aqueous dispersions of self-dispersing isocyanates.

2. Felt-free finished wool according to claim 1, characterized in that the self-dispersing isocyanates used for the after-treatment have an isocyanate content of 1 to 25%, calculated as NCO with the molecular weight 42 and based on the total weight of the isocyanates, and by reaction in any order

I) with organic polyisocyanates with an average NCO functionality of 1.8 to 4.2

II) Polyalkylene oxide alcohols, amines and / or thiols of the formula

N- (CHX-CHY-0) _n -CHX-CHY-ZH

R 4

(I),

in the

n represents a number from 3 to 70, X and Y are hydrogen or methyl with the proviso that in the case of methyl only one of the radicals X and Y is methyl and the other is hydrogen,

R ¹ and R ² independently of one another straight-chain or branched

Cj-Cg-alkyl or Ci-C ^ -acyl mean, where in the case that R ^{1 is} acyl, R ^{2 can} also be hydrogen and where R ¹ and R ² together can represent tetramethylene, pentamethylene or hexamethylene, wherein one or two methylene groups can be replaced by O and / or NH and / or one or two methylene groups can be substituted by methyl, and

Z represents O, S or NH,

and if necessary with

III) further NCO-reactive compounds which contain anionic or cationic or potentially anionic or cationic groups,

are available.

3. Self-dispersing isocyanates with an isocyanate content of 1 to 25%, calculated as NCO with a molecular weight of 42 and based on the total weight of the isocyanates, obtainable by reaction in any order from

I) with organic polyisocyanates with an average NCO functionality of 1.8 to 4.2

II) Polyalkylene oxide alcohols, amines and / or thiols of the formula 15

^R '\

N- (CHX-CHY-0) _n -CHX-CHY-ZH (I),

R s

in the

n represents a number from 3 to 70,

R ¹ and R ² independently of one another straight-chain or branched C _j -

C ₆ alkyl or C ^ -Cg acyl mean, in the event that

R ¹ means acyl, R ^{2 can} also be hydrogen and where R ¹ and R ² together can represent tetramethylene, pentamethylene or hexamethylene, in which one or two

Methylene groups can be replaced by O and / or NH and / or one or two methylene groups can be substituted by methyl, and

Z represents O, S or NH,

and if necessary with

III) further NCO-reactive compounds which contain anionic or cationic or potentially anionic or cationic groups.

4. Felt-free finished wool according to claim 2, characterized in that the organic polyisocyanates I) are ahphatic, cycloaliphatic, araliphatic or aromatic isocyanates. 0590

16

5. Felt-free finished wool according to claim 2, characterized in that the polyalkylene oxide alcohols, amines and / or thiols II) have polyether chains of an average molecular weight of up to 3500 (number average) and these are composed of alkylene oxide units.

6. Felt-free finished wool according to claim 2, characterized in that the NCO-reactive compounds III) have hydroxyl, amino and / or Mer- capto groups and additionally tertiary amino groups or their protonated or alkylated variants or carboxyl groups and / or sulfone may contain acid groups or carboxylate or sulfonate groups obtained by salt formation.

7. A method for felt-free finishing of wool, characterized in that colored or uncolored wool sliver

(a) exposed to low pressure plasma in a pretreatment and

b) aftertreated with aqueous dispersions of self-dispersing isocyanates.

8. A process for the felt-free finishing of wool according to claim 7, characterized in that the aftertreatment b) of the colored or uncolored woolen pretreated in process step a) is carried out discontinuously in the pull-out process or continuously by dipping, roller application, padding, spraying or spraying.