GB2251633A - Finishing non-woven fabrics - Google Patents

Description

f 223163-S NONVOVENIS FINISH It has been found that certain amphoteric

compounds, as defined below, are eminently suitable as high-affinity finishing agents for optionally bonded non-woven fibre webs comprising hydrophobic thermoplastic fibres, so that their liquid absorbency is improved.

The invention thus provides a process for the production of a finished, optionally bonded non-woven web of thermoplastic fibres, wherein the web material is finished with an amphoteric compound (A), which corresponds in the form of the inner salt to formula R, 1 R-CO---NH-Y--N + Z-X - 1 R2 (I) in which R-Co- signifies the acyl radical of a branched and/or unsaturated fatty acid with 14 to 22 carbon atoms, signifies an alkylene bridge with 2 to 6 carbon atoms, R, and R2 independently from each other signify C1-4-alkyl or C2-4-hydroxyalkyl, Z signifies Cl-4-alkylene or hydrOXY-C3-4-alkylene 9- signifies -COO_ or - S03-.

Y and Further the invention provides the optionally bonded non-woven webs which have been finished with the amphoteric compounds (A).

Unsaturated acids R-COOH which are worth mention, and from which the radical R-CO- may be derived, include the monoethylenically unsaturated acids, e.g. palmitoleic acid, oleic acid, petroselinic acid, elaidic acid, erucic acid, ricinoleic acid and isanolic acid, and the polyunsaturated fatty acids, e.g. linoleic acid, linolenic acid, parinaric acid, arachidonic acid, eleostearic acid, licanic acid and clupanodonic acid; as branched fatty acids R-COOH, from which the corresponding branched radical R-CO- may Case 150-5475 be derived, there may be mentioned in particular 12-methyl-tetradecanoic acid, isopalmitic acid and isostearic acid. Of the said fatty acid radicals, preference is given to those with 16 to 18 carbon atoms, especially the branched ones. R is advantageously an unsubstituted aliphatic hydrocarbon radical.

As Y come principally into consideration ethylene, propylene-1,2, propylene-1,3, tetramethylene, pentamethylene and hexamethylene, of which propylene-1,3 is particularly preferred.

The C3- and C4-alkyl groups in the significance of R, or R2 may be linear or branched, namely n-propyl, isopropyl or n-, sec-, iso- or tert.-butyl. Of the Cl-4-alkyl groups in the significances of R, and R29 preference is given to the lower representatives, namely ethyl and especially methyl. The C2-4-hydroxyalkyl may be in particular 0-hydroxyethyl, Phydroxypropyl, 0--hydroxy-n-butyl and 8-hydroxy-n-butyl, of which 0hydroxyethyl is preferred. R, and R2 most preferably signify methyl.

If X- is the carboxy anion, then Z preferably signifies Cl-4-alkylene, advantageously methylene, ethylene or isopropylene, of which ethylene and in particular methylene are preferred; if f- is the sulphonic acid anion, Z preferably signifies C2-3-alkylene or 0-hydrOXY-C3-4-alkylene, of which ethylene and 0-hydroxy-propylene-1,3 are preferred.

The compounds (A) may be produced in known manner, in particular by quaternization of a compound of formula R-CO---.NE-Y--NR1R2 (II) with a quaternization agent which yields the radical of formula -Z-k-.

The compounds of formula (II) are either known or may be produced analogously to known methods, for example by acylation of an amine of formula H2N-Y---MIR2 (III) with an acylation agent which yields the radical-R-CO-, e.g. the corresponding free acid, the anhydride or an acid halide, e.g. the acid chloride, Case 150-5475 under conventional acylation conditions. Preferably the free acid is reacted under dehydrating conditions with a diamine of formula (III), advantageously in the absence of solvents, preferably at a temperature in the range of 110 to 220C, especially 120 to 190C, advantageously with exclusion of oxygen (e.g. under a nitrogen blanket). The reaction time is especially in the range of 2 to 10 hours. The quaternization of the compounds of formula (II) to introduce the radical -Z-9- advantageously takes place using corresponding halogen-substituted acids Hal-Z-XH (whereby halogen advantageously signifies chlorine or bromine) in an aqueous, aqueous/organic or organic medium, whereby as the organic media come mainly into consideration alcohols (e.g. isopropanol). The reaction is advantageously carried out at a temperature in the range of 60 to 1300C. It is preferable to add an acid-binding base, e.g. an alkali metal hydroxide, or the halogen acids may be used in the form of the salt of a corresponding base, especially as an alkali metal salt (sodium, lithium and/or potassium salt).

The compounds of formula (III) are known or may be produced analogously to known methods, e.g. by the addition of an unsaturated acid nitrile to an amine RjR2NH and hydrogenation of the -CN-group to -CH2NH2 or by one- side alkylation of a diamine in which one amino-group is optionally protected.

If desired, the products (A) thus produced can be purified in conventional way, e.g. separated from solvent (e.g. by distillation) and/or separated from any formed inorganic salt (e.g. by filtration, especially filtering off - optionally under pressure or with vacuum - or by ultra-filtering, or by dialysis), so that depending on the purification method there may be obtained products that are poor in Na- ions or even are practically free from Na-ions. They can be dissolved or dispersed for usage in an appropriate polar solvent or solvent system, in particular in water and/or an aliphatic alcohol, especially an alkanol, a mono- or oligoalkyleneglycol, a lower alkyl monoether of a mono- or oligoalkyleneglycol or a lower aliphatic polyol. The following organic solvents are especially worth mention: isopropanol, butanol, glycerol, mono- or diethylene- or -propyleneglycol, a C1-4-alkyl monoether of monoor diethylene glycol (e.g. methyl, ethyl, isopropyl or butyl monoether) or oligoalkyleneglycols of the average formula HO+Alkylene-O-)- (IV) I - 4 in which Alkylene signifies ethylene or propylene and n signifies 3 to 10, preferably 5 to 9.

Case 150-5475 Particularly worth mention are alcoholic and aqueous/alcoholic solvent systems, especially those containing a simple mono- or polyfunctional alcohol, preferably isopropanol or glycerol, an oligoalkyleneglycol of the average formula (IV) or a mono- or diethyleneglycolmono-(CI-4-alkyl)- ether or a mixture of such alcohols, preferably a mixture of a simple mono- or polyfunctional alcohol with at least one oligoalkyleneglycol of the average formula (IV). If there is employed a mixture of a simple mono- or polyfunctional alcohol with at least one oligoalkyleneglycol and/or mono- or diethyleneglycolmono-(CI-4-alkyl)-ether, the weight ratio of simple monoor polyfunctional alcohol to the other alcohols, in particular oligoalkyleneglycol and/or mono- or diethyleneglycolmono-(CI-4-alkyl)ether, is advantageously in the range of 10/90 to 60/40, preferably 20/80 to 40/60.

The concentration of compound (A) in the solvent or solvent mixture is advantageously in the range of 0.1 to 70 % by weight, preferably 0.5 to 60 % by weight (for concentrated compositions advantageously 10 to 70, preferably 12 to 60 % by weight, for treatment-liquors e.g. 0.1 to 10 % by weight, for aqueous treatment-liquors preferably 0.1 to 2 % by weight). The weight ratio water/alcoholic solvent in concentrated aqueouslalcoholic compositions is advantageously in the range of 10/90 to 70/30, preferably 25/75 to 55/45.

The non-woven webs may be formed from conventional thermoplastic fibres, preferably from hydrophobic synthetic materials [e.g. polyamides, polyurethanes, polyesters or polyalkylenes (especially polyethylene, polybutadiene, polystyrene and/or polypropylene, of which polypropylene is particularly preferred)]. The fibres may be used in a strength and length conventional per se, e.g. as short fibres, staple fibres or continuous fibres (filaments). Optionally the thermoplastic fibres may be blended with other appropriate fibres, e.g. with natural fibrous materials (e.g. with cellulosic fibres, especially of cotton, hemp, linen, sisal or degraded cellulose, or with wool fibres), e.g. to a proportion of 0 to 20 % by weight of the total fibrous material. The thermoplastic fibres may have been produced in conventional manner, e.g. by forming filaments from a melt or solution of Case 150-5475 the thermoplastic material with subsequent stretching or by melt-blowing; micro-fibres are especially worth mention (micro-fibres are understood to be in particular those fibres having a diameter of < 10 pm, preferably in the range of I to 8 pm), particularly those of polypropylene. An especially noteworthy method of producing the non-woven webs is the processing of melt-blown micro-fibres. The fibre webs can be produced in any conventional manner, e.g. mechanically, aerodynamically, hydrodynamically or electrostatically, or by spun web formation, and may be bonded in any conventional manner, i.e. self-bonded e.g. mechanically (for example for needled web), by shrinking, by swelling and/or by adhesion, especially by (part) melting or reactivating the thermoplastic fibres, and/or optionally externally bonded with the assistance of binders, to give the corresponding bonded non-woven fabric-like materials. Especially notable are non-woven webs that are free from (other) binders, especially also spun webs, spunlaced webs and reinforced webs.

The nonwovens are preferably such in which the fibres of which the web material consists, are essentially micro-fibres, in particular polypropylene micro-fibres. Such non-woven webs and their preparation, as well as the preparation of the corresponding micro-fibres, are known per se and are described e.g. in USA Patent Nos. 3 795 571, 3 959 421, 3 978 185, 4 041 203, 4 100 324 and 4 340 563, the content of which USA patents is incorporated herein by reference.

The above-described amphoteric compounds (A) may be applied to the web material before, during and/or after web formation. They have a high affinity for the said substrates and can be applied by any method conventional per Ee, particularly by impregnation with a solution or dispersion of a compound (A) and, advantageously, fixation of the impregnated and optionally dried goods, preferably at temperatures of above 100C. Any usual impregnation method is suitable, e.g. padding, application by-means of a doctor rod or blade, foam application or spraying onto the non-woven web, or dipping the non-woven web into the liquor or spraying the liquor onto the (micro)fibres before and/or during web formation, e.g. analogously to the manner described in USA Patents 4 328 279 and 4 436 780 (the content of these US patents is incorporated herein by reference). To fix the finish, the impregnated goods advantageously are subject-ed to thermal treatment. If an already formed non-woven web is impregnated with the said liquor, the Case 150-5475 thermal treatment is effected, optionally after drying, e.g. at a temperature in the range of 105 to 150'C; if the solution or dispersion is sprayed onto the (micro)fibres before formation of the non-woven web, then fixation may be effected under the thermal conditions for producing the web (for example at a temperature in the range of 120 to 320C for melt-blown fibres and non-woven webs produced therefrom) as corresponds to the apparatus and method used for the non-woven web production (e.g. as described in USA Patent 3 959 421). If the web is produced in hydrodynamic manner, the above-described compound (A) may be added directly to the aqueous liquor; fixation may be effected after drying, analogously as described above.

The basis weight of the non-woven webs may be of any amount conventional in the art; it is advantageously in the range 8 to 250 g/M2, preferably 12 to 120 g/m2. Any required strengthening (in particular self-bonding) of the web can be carried out before, simultaneously with or after the finishing_ treatment according to the invention.

The concentration of the compounds (A), referred to the substrate, is advantageously in the range of 0.1 to 10 % by weight, preferably 0.5 to 5 % by weight, referred to the weight of dry substrate, whereby at concentrations of below 2 % by weight, especially in the range of 0.6 to 1.8 % by weight, referred to the weight of dry substrate, excellent results can already be obtained.

After fixing, the finished goods are ready for use and, depending on their constitution, can be used directly or e.g. be further melted and/or joined to laminates of several layers (e.g. analogously to the manner described in USA Patents Nos 3 795 571 and 4 436 780).

The finished non-woven webs (in particular non-woven fabric-like materials) obtained according to the invention excel by their very high liquid absorption capacity, especially oil and water absorbency, whereas undesired properties such as fluff formation and formation of stripes and flecks upon wiping, are eliminated to a great extent, while inherent properties of the substrate, such as tear-resistance, tensile strength, elasticity to compression and pliability, are substantially not impaired. The finish according to the invention also reduces the soilabili-ty and electrostatic charge of the substrate. The properties of the treated substrate are also main- -- 7 - Case 150-5475 tained even after several washes. The non-woven webs (in particular non- woven fabric-like materials) which are finished according to the invention can be used in many ways (e.g. as described in the above- mentioned USA patents); they are especially suitable for the production of all-round wiping cloths.

In the following examples, the percentages are by weight; the temperatures are given in degrees Celsius.

EXAMPLE 1

Preparation of N-(3-isostearoylamidopropyl)-N,N-dimethylammonioacetate 284 g (1 mol) of isostearic acid are heated to 130-1401C over 4 hours with 112 g (1.1 mols) of 3-dimethylaminopropylamine under a nitrogen blanket, whereby the reaction water is distilled off, and heating is then continued for 10 hours at 1800C. After cooling to 800C, the remaining water and the excess 3-dimethylaminopropylamine are distilled off under vacuum. After further cooling to ca. 60% 600 ml of isopropanol and 298 g (1 mol) of the sodium chloroacetate, dissolved in 400 ml of water, are added and allowed to boil for 12 hours. Filtering off from the sodium chloride and distillation of the isopropanol and water produce an amber- coloured soft mass in a good yield. The compound obtained corresponds to formula C113 1 NI-CH-2COO- Ro --CO--NH--CH-2--CH-2--CH-2 1 C113 (1) wherein R.-COsignifies the acyl radical of isostearic acid.

EXAMPLE 2 Preparation of 2-[N-(31-isostearoylamidopropyl)-N,Ndimethylammoniol-ethanesulphonate The process described in example 1 is repeated, with the difference that instead of sodium chloroacetate, the equivalent quantity of sodium 2- chloroethanesulphonate is used, whereby 2-[N-(31-isostearoylamidopropyl)N, N-dimethylammoniol-ethanesulphonate of formula--- Case 150-5475 CH3 1 RO ---C0-4M-CH2,-CH,2-CH-2--N:-H,- 1 ' CHY-S03 U113 (2) is obtained.

EXAMPLE 3 Preparation of 3-[N-(31-isostearoylamidopropyl)-N,Ndimethylammoniol-2 -hydroxypropane-l-sulphonate The process described in example 1 is repeated, whereby instead of the sodium chloroacetate the equivalent quantity of sodium 2-hydroxy-3- chloropropanesulphonate is used. 3-[N(31isostearoylamidopropyl)-N,Ndimethylammoniol2-hydroxypropane-l-sulphonate of formula CH3 --NH---CH-2--CH-2--CH-2 + RO --CO --N 1 -:__CH2--CHOH-CHT-SO3 CH3 (3) is obtained.

EXAMPLE 4 Preparation of N-(3-oleoylamidopropyl)-N,Ndimethylammonioacetate The process described in example 1 is repeated, with the difference that instead of isostearic acid the equivalent quantity of oleic acid is used, whereupon N-(3-oleylamidopropyl)-N,N-dimethylammonioacetate of formula CH3 CH-3H+27 -CH==CH--H2.,0---NH---CH2"-CH2'--.CH2:--CH-2--Coo 7 1 CH3 (4) is obtained.

EMPLE 5 Preparation of 3-[N-(31-oleoylamidopropyl)-N,N-dimethylammonio]2hydroxypropane-l-sulphonate The process described in example 3 is repeated, with the difference that Case 150-5475 instead of isostearic acid, the equivalent quantity of oleic acid is used, whereupon 3-[N-(31-oleoylamidopropyl)-N,N-dimethylammoniol2hydroxypropanel-sulphonate of formula CH3 1 CH3--H24-CH=CH-H24--CO--NH--CH2-CH,2-CH"2--N:I-CH2'-CHOH--CHy-SO3 7 7 CH is obtained.

APPLICATION EXAMPLE A (5) a) A melt blown polypropylene micro-fibre web of 80 g/M2 is impregnated on a padder with a 1 % isopropanolic solution of the product according to Example 1 up to pick-up of 100 %, then dried in the air for 30 minutes and subsequently fixed for 10 minutes at 1200C. Then, 3 times in succession, the goods thus treated are left to stand in distilled water for 10 minutes and then dried.

The dried goods have very high hydrophilicity, while the starting material was hydrophobic.

A drop of demineralized water which is dropped onto the treated substrate from a height of 5 mm is immediately totally absorbed without forming a specular water surface; the wrong and the right side of the treated substrate are moistened evenly.

The process described in Application Example Am) is repeated, with the difference that instead of the 1 % isopropanolic solution of the product according to Example 1, the same quantity of a 1 % aqueous solution of the product according to Example 1 is used.

y) The process described in Application Example Aa), with the difference that instead of the 1 % isopropanolic solution of the product according to Example 1, the same quantity of a 1 % aqueous/isopropanolic (l/1, vol/vol) solution of the product according to Example 1 is used.

8) The process described in Application Example AP) is repeated, with the - Case 150-5475 difference that the product according to Example I in the form of a concentrated preparation of the following composition: 35 % of the product according to Example 1, 13 % of glycerol, 11.4 % of polypropylene 400, 16.3 % of polyethylene 300, 4.7 % of NaCl and 19.6 % of water, is diluted with water to 1 % of product concentration and is employed in this form.

APPLICATION EXAMPLE B The process described in Application Example A is repeated, whereby instead of the product of Example 1, that of Example 2 is used.

APPLICATION EXAMPLE c The process described in Application Example A is repeated, whereby instead of the product of Example 1, that of Example 3 is used.

APPLICATION EXAMPLE D The process described in Application Example A is repeated, whereby instead of the product of Example 1, that of Example 4 is used.

APPLICATION EXAMPLE E The process described in Application Example A is repeated, whereby instead of the product of Example 1, that of Example 5 is used.

Claims (11)

1. PATENT CLAIMS

   Case 150-5475 1. A process for the production of a finished, optionally bonded non- woven web of thermoplastic fibres, wherein the web material is finished with an amphoteric compound (A), which corresponds in the form of the inner salt to formula R, 1+ - R-CO---NH-Y-N-'Z-X 1 R2 (1) 1 in which R-CO- signifies the acyl radical of a branched and/or unsaturated fatty acid with 14 to 22 carbon atoms, Y signifies an alkylene bridge with 2 to 6 carbon atoms, R, and R2 independently from each other signify CI-4-alkyl or C2-4- hydroxyalkyl, Z signifies C1-4-alkylene or hydroxy-C3-4-alkylene and k- signifies -COO_ or -S03-.
2. 2. A process according to Claim 1, wherein R-CO- signifies the acyl radical of an unsaturated fatty acid with 16 to 18 carbon atoms, Y signifies propylene-1,3, R, and R2 respectively signify methyl and -Z-Xsignifies -CH2-COO-, -CH2- CH2-SO3- or -CH2-CHOH-CH2-SO3-
3. 3. A process according to Claim 1, wherein R-CO- signifies the acyl radical of a branched fatty acid with 16 to 18 carbon atoms, Y signifies propylene-1,3, R, and R2 signify each methyl and -Z-f- signifies -CH2-COO-, -CH2-CH2-SO3or -CH2-CHOH-CH2-SO3
4. 4. A process according to any of Claims 1 to 3, wherein the non-woven web material consists of thermoplastic, hydrophobic micro-fibres.
5. 5. A process according to Claim 4, wherein the thermoplastic, hydrophobic Case 150-5475 micro-fibres are melt-blown polypropylene micro-fibres.
6. 6. A process according to any of Claims 1 to 5, wherein before and/or after finishing the non-woven webs are joined to form fabric-like laminates.
7. 7. A process according to any of Claims 1 to 6, wherein the compounds (A) are used in the form of a solution or dispersion in a polar solvent or solvent mixture.
8. 8. A concentrated preparation of a compound (A) as defined in Claim 1 or of a mixture thereof, which is a solution-or dispersion in a polar solvent or solvent system comprising at least one aliphatic alcohol.
9. 9. A concentrated preparation according to Claim 8, wherein the solvent system is an aqueous/alcoholic system in which the alcoholic solvent is a mixture of glycerol with at least one oligoalkyleneglycol in which alkylene signifies ethylene or propylene.
10. 10. A process according to Claim 7, wherein the compounds (A) are employed in the form of concentrated preparations according to Claim 8 or 9.
11. 11. A finished, optionally bonded non-woven web obtainable by a process according to any of Claims 1 to Tor 10.