US2795517A

US2795517A - Modification of the properties of fibrous materials

Info

Publication number: US2795517A
Authority: US
Inventors: Lowe Arthur; Williams Gerald
Original assignee: Imperial Chemical Industries Ltd
Current assignee: Imperial Chemical Industries Ltd
Priority date: 1953-12-02
Filing date: 1954-11-30
Publication date: 1957-06-11
Anticipated expiration: 1974-06-11
Also published as: FR1116501A; BE533827A; NL88699C

Description

- June 11, 1957 V A. LOWE E AL MODIFICATION OF THE PROPERTIES OF FIBROUS MATERIALS Filed Nov. 30, 1954 FIBROUS 4 MATERIAL HYDRAZIDE BATH F FORMALDEHYDE BATH L l NITRITE BATH ACID TREATMENT DRYING F I MECHANICAL TREATMENT I L- I r 1 I BAKING I I INVENTOII ARTHUR LOWE GERALD WILL JAMS BYWQMQT ATTORNEY5 Unite MODIFICATION OFTHE PROPERTIES OF FIBROUS MATERIALS Application November 30, 1954, Serial No. 472,208

Claims priority, application GreatBritain November 24, 1954 7 Claims. or. 117-1395 This invention relates to the modification of the properties of fibrous materials and more particularly to the treatment of textiles, leather, paper, etc. with organic hydrazides and nitrous acid, and, preferably, formaldehyde.

According to the present invention we provide a process for the modification of the properties of fibrous materials which comprises treating said materials with an organic hydrazide and with nitrous acid and,.preferably, with formaldehyde and subsequently drying the treated material.

Any organic hydrazide, containing one or more hydrazide groups in the molecule, can be used in the process of this invention. Thus for example there can be used the dihydrazides of succinic, glutaric, adipic and sebacic acids, hexadecane-l:l6-dicarboxylic dihydrazide, benzoic acid hydrazide, isophthalic acid dihydrazide or citric acid trihydrazide. p 1 The treatment of the fibrous material with the'hydrazide and nitrous acid may be accomplished for example by padding through an aqueous-solution or dispersion of an acid salt of the hydrazide, drying and then padding through an aqueous solution of an alkali salt of nitrous acid. Alternatively the hydrazide salt impregnated material may be sprayed with a solution of a nitrite. Y

The application of hydrazide and nitrite may be accomplished simultaneously by padding through a solution or dispersion containing both the hydrazide and the nitrite. The impregnated material is then dried and treat- :ed with an acid in order to liberate the nitrous acid.

In this application of hydrazide and nitrous acid to the material it is essential in order to obtain the best results, that reaction between the two components should occur within the fibre and to this end the components are applied in such forms, as described above, as to ensure that the active agents are liberated only within the fibrous material.

Suitable concentrations of hydrazide or salt thereof and nitrite in the treatment baths are from about 0.5% to about 20% so that with a take-up of about 100%, the proportion of hydrazide and nitrite deposited on the fibre is from about 0.5 to about 20%.

The temperature of the treatment baths may vary between C. and 100 C. It is sometimes convenient to treat the material with the hydrazide salt solution atelevated temperatures such as 50100 C. and then with the alkali nitrite at lower temperaturessuch as 0 to 20. C.

The modification of the properties of thefibrous material is'achieved by drying the material after treatment with hydrazide and nitrous acid. Afterdrying, the treated material is preferably baked at a temperature of from about 50 C. to about 200 C. The time required for the baking step, after drying the material, is usually from about 3 minutes to about half an hour. In some cases, satisfactory results are obtained by conditioning the treated material at room temperature for some hours, with out any. baking stage.

The process of this invention can be applied, with valu- States Patent Ic v materials depends upon the particular material treated.

Thus for example viscose rayon fabrics thathave been treated according to the process of this inventionhave enhanced dimensional stability. Treated paper is found to possess a greatly increased wet strength. -A'substantial degree of water-repellency may also be imparted to cellulosic materials. Softening agents or substances to give a firm handle may be incorporated with the hydrazide in order-to give enhanced effects.

The modification of the properties of the fibrous materials is still further increased by inclusion in the treatment baths of formaldehyde.

The formaldehyde may be added to any of the treatment baths, containing, for example, the hydrazide salt or the nitrite or the mixture of hydrazide and nitrite. The concentration of formaldehyde in the treatment baths is conveniently from about 1% to 15% by weight, so that with a take-up of about the amount of formaldehyde deposited on the fibre is from about -1% to about 15 by weight of the fibre.. 1

The enhancement of effect produced by the use of formaldehyde is most marked when at least some of the hydrazide used is a poly-hydrazide such as a dior trihydrazide. V v 1 Furthermore, the .treatment process of this invention may be combined with other treatments of the fibrous material and these other treatments are thereby modified, improved, enhanced in effect or rendered more permanent;- Such other treatments are for example mechani cal finishes applied to cotton fabrics such as calendering, embossing, beetling, rippling, pressing or schreinering. The effects so obtained vary according to theprocess; thus'for example there may be produced lustre, glaze and finishes known as moire or cite. Normally these processes are very sensitive to moisture, and they may be substantially diminished or even destroyed by water or by aqueous. treatments, for example laundering or steam pressing processes such as. are common in the final stages of garment manufacture. These finishes may be rendered more permanent, especially to the-effect of water, by the simultaneous v or subsequent treatment according to the proces'sof the present invention.

The chemical processes involved in the process of the invention are presumably first the interaction of the hydrazide with nitrous acid to-form the corresponding azide followed by decomposition of the azide on heating to generate the corresponding isocyanate. The valuable etfects achieved by the treatment of fibrous materials with isocyanates are well known but it has not hitherto been possible to effect such treatment in the case of all isocyanates with the use of aqueous solutions or dispersions. Moreover the results obtained by the process of the present invention are superior to those obtainable by any process of the prior art when directed to the I application of the isocyanate corresponding to that which isformed in any specific case accordingto th e foregoing theoretical exposition. The value of the presentinven tion, and the results obtained, does not depend upon the theoretical exposition which is provided merely as a possible explanation of the nature of the processes involved. a

.We are aware that it has already been proposed to treat textiles and other materials with solutions of an azide in benzene or other hydrophobic liquid obtained by interacting a hydrazide and nitrous acid in an aqueous medium, and extracting therefrom with the aforementioned hydrophobic solvents. An essential feature of the present invention; however; resides in the interaction of hydrazide and nitrous acid within the fibre, since thereby full advantage is taken of the swelling power of aqueous solutions. It is'well known that in the case of cellulosic materials, both natural and synthetic, difiiculty is frequently eXperiencedin effecting the desired degree of reaction with reagent-s in organic solvents owing to their reluctance to absorb the majority of organic solvents. It is sometimes necessary to promote the desired additional reactivity by first wetting the materials with water and thenremoving the water by azeotropic distillation. By the process of the invention the liberationof the isocyanate is achieved within the fibre under conditions favouring maximum penetration and the effect of the reagent is accordingly increased over that given by. the application of the corresponding azide or isocyanate in solution in organic solvents.

According to a further feature of the invention an amide, an amidine or an aminotriazine may be applied to the material during the treatment with the hydrazide so as to be present within the material during the subsequent baking treatment. Particularly suitable amides (which include thioamides, carboxylic acid amides and sulphonarnides) are urea, dithiourea and acetamide, benzene sulphonarnide or p-toluene sulphonamide; suitable amidines include cyanamide, guanidine and aminoguanidine; andsuitable aminotriazines include melamine. The improvement which is brought about by these amides, amidines or aminotriazines is demonstrated by the firmer handle of the finished material and the greater resistance of the mechanical eifect to washing.

-The drawing illustrates a flow sheet for the present process. Those steps enclosed by broken lines are not essential to the process but represent additional embodiments as described above. While a separate formaldehyde treatment has been shown, as discussed above, this reagent may be included in the hydrazide bath or the nitrite bath just as the hydrazide bath and nitrite bath may be combined if desired. LlkW1S,'thB Mechanical Treatment is shown in the preferred position. Theinvention is illustrated but not limited by the following examples in which parts and percentages are by weight, unless otherwise indicated.

Example 1 'A cotton fabric is immersed ina solution of parts of sebacic-acid dihydrazide dihydrochloride in 95 parts of water'a't 60 C.'and squeezed between rollers so that the uptake of the solution is 75% of thedry weight of the fabric. The fabric is then dried at 50 'C. and then immersed ina solution'of 5 parts of sodium'nitrite in 95. parts of water and squeezed between rollers so that the uptake of the solution is 75% of the dry weight Example 2 A cotton fabric is immersed in a dispersion containing Sparts of sebacic acid dihydrazide, 3 parts of sodium nitrite, 0.3 part of the disodium salt of methylene dinaphthylene sulphuric acid and 91.7 parts of water and squeezed between rollers so that the uptake of the solution is 75% of the dry weight of the fabric. The fabric is dried at 50 C. and then immersed in a solution of 5 parts of acetic acid in 95 parts of water and squeezed between rollers so that the uptake of the solution is 75% of the dry weight. The fabric isthen dried at 2030 4 C. so that it contains 10-15% of water and is then glazed by treatment in .a known manner on a calender at 200 C. A heat treatment at 150 C. for 3 minutes follows and finally the fabric is washed for 10 minutes in 2% aqueous soap solution at 80 C. followed by washing in water and drying.

The resulting glaze is resistant to boiling soap solutions.

Example 3 A viscose staple fibre plain weave fabric is immersed in a solution containing 3 parts of adipic dihydrazide dihydrochloride and 97 .parts of water and squeezed between rollers so that the uptake of the solution is 80% of the dry weight of the fabric. The fabric is then stretched back to its former dimensions on a pin stenter and sprayed in this state with a solution of 10 parts of sodium nitrite in 90 parts of water so that the whole material is thoroughly wetted out and has increased in weight by 100%. The treated material is then dried and baked by heating in an oven at 125. C. vfor 10 minutes. a

The effect of these treatments is shown in the following table giving the amount of shrinkage obtained by washing the fabric in aqueous solutions of 0.1% soap and 0.1% soda ash at the boil for 1 hour. 7

. Area shrinkage, percent Untreated fabric .a 16.9 Treated fabric 7.4

Exampt'e 4 A viscose staple fibre plain weave fabric is immersed in a solution containing 5 parts of sebacic dihydrazide hydrochloride and 95 parts of water at 60 C. and squeezed between rollers sothat the uptake of the solution is 75% of the dry weight of the fabric. The fabric is then dried at 20,50 C. and then'immersed in a solution of 5 parts of sodium nitrite in 95 parts of water and squeezed between Example 5 'A sheet of absorbent paper is passed through a solution of 1 part of sebacic dihydrazide dihydrochloride in 999 parts of water and then squeezed so that the uptake of the solution is 200% of the dry weight of the paper. The paper is dried at C. and then passed through an aqueous solution'containing 0.1% sodium nitrite. The

material is then dried and baked by heating in an oven at C. for 5 minutes. Theresulting paper has a wet strength many times greater than the untreated material.

Example 6 A viscose staple fibre plain weave fabric is immersed in a. solution containing 2.5 parts of sebacic acid dihydro- :chloride, 2.5 parts ofacetamide and 95 parts of water at 50 C.. and squeezed between rollers so that theuptake of solution is 75% of the-dry weight of thefabric. The

fabric is then 'dried on a pin stenter at 100 C. for 3 minutes and then sprayed on the stenter frame with a solution of 10 parts of sodium nitrite in 90 parts of water so that the whole of the fabric is evenly wetted. The fabric is then dried and baked on the stenter frame by heating in an oven at C. for' 10 minutes. The etfect of these treatments is shown in the following table giving the amount of shrinkage obtained by washing the fabric in Untreated Treated Example 7 A viscose staple fibre plain weave fabric is immersed in a solution containing parts of sebacic dihydrazide dihydrochlon'de and 95 parts of water and squeezed between rollers so that the uptake of the solution is 75% of the dry weight of the fabric. The fabric is stretched back to its original dimensions on a pin stenter and dried in an oven at a temperature of 125 C. for 5 minutes. The dry fabric is then immersed in an aqueous solution containing 1.6% formaldehyde and 3.0% sodium nitrite and squeezed between rollers so that the uptake of the solution is 75% of the dry weight of the fabric. The fabric is stretched to its original dimensions on a pin. stenter and then placed in an oven maintained at a temperature of 125 C. for 15 minutes. y

The effect of these treatments is shown in the following table giving the amount of shrinkage obtained by washing the fabric in aqueous solutions of 0.1% soap and 0.1% soda ash at the boil for 1 hour.

Area shrinkage, percent Untreated fabric 17.3 Treated fabric 5.0

Example 8 A mercerised cotton gaberdine fabric is padded through a solution containing 2.5 parts of sebacic dihydradize dihydrochloride, 3 parts of stearic hydrazide hydrochloride and 94.5 parts of water at 80 C. and squeezed between rollers so that the uptake of the solution is 60% of the dry weight of the fabric. The fabric is then air-dried and padded through a solution containing 1 part of formaldehyde, 3 par-ts of sodium nitrite and 96 parts of water at 20 C., squeezed between rollers so that the uptake of the solution is 60% of the dry weight of the fabric and finally placed in an oven maintained at a temperature of 130 C. for 10 minutes. The fabric is then rinsed in warm water for 5 minutes and dried. The fabric thus obtained has a high degree of water-repellency which is only slightly affected by washing in aqueous solution of 0.1% soap and 0.1% soda ash at the boil for 1 hour, or by dry cleaning in white spirit for /2 hour.

Example 9 A mercerised cotton gaberdine fabric is padded through a solution containing 2.5 parts of sebacicv dihydrazide hydrochloride, 3 parts of stearic hydrazide hydrochloride and 94.5 parts of water at 80 C. and squeezed between rollers so that the uptake of the solution is 65% of the dry weight of the fabric. The fabric is then air dried and padded through a solution containing 3 parts-of sodium nitrite and 97 parts of water at 20 C., squeezed between rollers so that the uptake of the solution is 60% of the dry weight of the fabric and finally placed in an'oven maintained at a temperature of 130 C. for minutes. The fabric is then rinsed in warm water for 5 minutes and dried. The fabric thus obtained has a high degree of water-repellency which is only slightly affected by washing in aqueous 0.1% soap solution at 70 C. for 1 hour.

Example 10 A mercerised cotton gaberdine fabric is padded through a solution containing 2.5 parts of sebacic dihydrazide dihydrochloride, 3 parts of ll-hydroxystearic hydrazide hydrochloride and 94.5 parts of water at 80 C. and squeezed between rollers so that the uptake of the solution is 60% of the dry weight of the fabric. The fabric is then air-dried and padded through a solution containing 1 part of formaldehyde, 3 parts of sodium nitrite and 96 parts of water at C. squeezed between rollers so that the uptake of 6 the solution is 60% of'the dry weight of the fabric and finally "placed'in anoven' maintained'at"atemperature of 130 C. for 10 minutes. The fabricis then rinsedin Warm water for 5 minutes and. dried. The fabric thus obtained has a high degreeof water repellency, which is only slightly affected by washing in an aqueous solution of 0.1% soap and 0.1% sodaash at the boil for 1 hour,

or by dry cleaning in white spirit for /z hour.

l I i Example 11 r v I A mercerised cotton gaberdine fabric is padded through a solution containing 255 parts of sebacic dihydrazide dihydrochloride, 3 parts of stearic hydrazide hydrochloride and-94.5 parts of waterat"- and squeezed between rollers so that the uptake ofthesolution is 60% of the dry weight of the fabric. The;fabric is then padded through a solution containing 3 parts of formaldehyde, 9 parts of sodium nitrite and- 88 parts of water and squeezed between rollers so that the increase in weight of the fabric is now 100% of the dry weight. The wet fabric is then rinsed thoroughly. in water at 015 C., squeezed between rollers to remove as much water as possible and finally placed in an oven maintained at a 7 temperature of 130 C. for 10 minutes. The fabric thus Example 12 I A viscose staple fibre plain 'weave fabric is immersed in a solution containing 2.5 parts 'of isophthalic dihydrazide dihydrochloride and 97.5 parts of water and squeezed between rollers so that the uptake of the solution is 80% of the dry weight of the fabric. The fabric is then stretched back to its former dimensions on a pin stenterand sprayed in this state with a solution of 10 parts of sodium nitrite in 90 parts of water so that the whole material is thoroughly wetted out and has increased in weight by The treated material is then dried and baked by heating in an oven at C. for 10 minutes. The fabric thus obtained shows good resistance to shrinkage by alkaline washing treatments.

Example 13 A viscose staple fibre plain weave fabric isimmersed in a solution containing 4 parts of the hydrochloride of polyacrylic polyhydrazide (obtained by heating ethyl polyacrylate with hydrazide hydrate) and 96 parts of water and squeezed between rollers so that the uptake of the solution is 75 of the dry weight of the fabric. The fabric is then dried at 20-50 C. and then immersed in a solution of 3 parts of sodium nitrite and 1% of formaldehyde in 96 parts of water and squeezed between rollers so that the Y uptake of the solution is 75% of the dry weight. The wet fabric is then stretched to its former dimensions on a pin stenter and then dried and baked by heating in an oven at C. for 10 minutes. The resulting fabric has a firm full handle and shows good dimensional stability when subjected to alkaline washing treatments.

Example :14

A plain weave cotton fabric is immersed in a solutionof 4.5 parts of sebacic dihydrazide dihydrochloride 'in' 95.5 parts of water, squeezed between rollers so that the uptake of the rollers is 7 5% of the dry weight of the fabric. The wet fabric is then immersed in a solution of 4 parts of sodium nitrite in 96 parts of water, squeezed through rollers so that the weight of the fabric is now twice as great as its dry weight. The fabric is then conditioned to contain 10% of its weight of moisture, and embossed according to conventional means. The fabric is then given a heat treatment of 3 minutes at 140 C. The embossed design produced is highly resistant to washing in boiling soap solutions.

If desiredthe heat treatment after embossing may be omitted and the-fabric conditioned at roomtemperature for 24 hfours.- The. resulting embossed design is resistant to washing inboiling soap solutions.

Example 15 A cellulose acetate plain weave fabric is passed through a solution of 4 parts of sebacic dihydrazide dihydrochloride in 96 parts of water at 60 C., squeezed through rollers so that the uptake of the solution is 50% of the dry weight Example 16 A mercerised cotton gaberdine fabric is passed through a solution of" 3 parts of stearic hydrazidehydrochloride and 97 parts of water at 70 C. and squeezed between roller'sso-that'the uptake of the solution is 60% of the dry weight of the fabric. The fabric is then passed through a solution of 2 parts sodium nitrite in 98 parts of water, squeezed between rollers so that the weight of the wet fabric is now twice that of the dry fabric and finally dried and baked in an oven at 140 C. for 10 minutes. The fabric is then rinsed in warm water for minutes and dried. The fabric thus obtained has a high degree of water repellency.

Example 17 25 parts of bleached sulphite pulp are suspended in 1500 parts of water and disintegrated by vigorous stirring. 12.5 parts of a aqueous solution of aluminium sulphate are added followed by 0.6 part of sebacic dihydrazide dihydrochloride. After standing at 20 C. for 30 minutes, 3 parts of sodium nitrite are added and the suspension is stirred for a further 5 minutes. 3500 parts of water are then added and after stirring for a further 5 minutes, the mixture is filtered and the resulting paper dried and baked at 115 C. for 10 minutes. Paper prepared by this method has a markedly higher bursting strength than that prepared when the hydrazide is omitted.

Example 18 A plain weave cloth made up from polyethylene terephthalate yarn is padded through a solution containing 2.5 parts of sebacic-dihydrazide hydrochloride, 3 parts of stearic hydrazide hydrochloride and 94.5 parts of water at 80 C. and squeezed between rollers, the uptake of the solution being 35% of the dry weight of the fabric. The cloth is then dried at 50-60 C. and padded through a solution containing 3 parts of sodium nitrite and 97 parts ofwater at 20 C., squeezed between rollers and placed in an oven maintained at a temperature of 120 C. for minutes. The fabric is then rinsed in warm water and dried. The cloth thus obtained has a high degree of water repellency which is only slightly affected by washing in aqueous 0.1% soap solution at 70 C. for 1 hour.

Example I 9 sebacic dihydrazide' dihydrochloride, 3 parts of ll-li'y droxystearic'hydrazide hydrochloride and 94.5 parts of water at C. and squeezed between rollers so that the uptake of the solution is 45% of the dry weight of the fabric. The cloth is then air dried and padded through a solution containing 1 part of formaldehyde, 3 parts'of sodium nitrite and 96 parts of water at 20 C., squeezed between rollers so that the uptake of the solution is 45% of thedry Weight of the fabric and finally placed in an oven maintained at a temperature of C. for 10 minutes. The fabric is then rinsed in warm water for 5 minutcs'and dried. The fabric thus obtained has a high degree of water repellency.

Example 20 Pelts are immersed in 215% aqueous solution of adipic dihydrazide for 12 hours at a temperature of 1520 C. The pelts are then freed from supernatant liquor by decantation and immersed in a 3% aqueous solutionof nitrous acid containing l;6% formaldehyde for 12 hours at a temperature of 15 C. After thorough rinsing with water and drying at 20 C. a tanned leather having a shrink temperature of 87 C. is obtained.

What we claim is:

l. A process for the modification of the properties of fibrous materials involving in situ formation of an organic isocyanate in said fibrous material which comprises impregnating said material with an organic hydrazide in a substantially aqueous medium and thereafter forming nitrous acid in said hydrazide impregnated material to produce said isocyanate.

2. Fibrous materials p'roduced'by the process of claim 1.

3. The process of claim l'further defined by the additional step of treating said materials with formaldehyde, intermediate said impregnation with an organic hydrazide and said forming of nitrous acid.

4. Process for the modification of the properties of fibrous materials as claimed in claim 1, wherein, after drying, the treated material is baked at a temperature of from about 50 C. to about 200 C.

5. Process for the modification of the properties of fibrous materials as claimed in claim 1, wherein at least some of the hydrazide'used is a polyhydrazide.

6. Process for the modification of the properties of fibrous materials as claimed in claim 1 including the subsequent step consisting of mechanically treating said fibrous materials.

7. Process for the modification of the properties of fibrous materials as claimed in claim 1 wherein'a member of the group consisting of an amide, an amidine and an aminotriazine is applied to the material during the treatment with the hydrazide.

References Cited in the file of this patent UNITED STATES PATENTS Gold June 1, 1954

Claims

1. A PROCESS FOR THE MODIFICATION OF THE PROPERTIES OF FIBROUS MATERIALS INVOLVING IN SITU FORMATION OF AN ORGANIC ISOCYANATE IN SAID FIBROUS MATERIAL WHICH COMPRISES IMPREGNATING SAID MATERIAL WITH AN ORGANIC HYDRAZIDE IN A SUBSTANTIALLY AQUEOUS MEDIUM AND THEREAFTER FORMING NITROUS ACID IN SAID HYDRAZIDE IMPREGNATED MATERIAL TO PRODUCE SAID ISOCYANATE.