EP0040335B1 - Sizing agent and process for its manufacture - Google Patents

Abstract

A sizing agent for yarns made of cotton, regenerated cellulose and synthetic fibers and their mixture. The sizing agent substantially comprises a hydroxyalkylated polysaccharide from the seed of Cassia occidentalis. The polysaccharide has a viscosity of from 40 to 10,000 mPas (10% aqueous solution, 80 DEG C., Brookfield RVT) and a substitution degree of from 0.05 to 1.0.

Description

Before weaving, warp yarns are provided with solutions, melts, dispersions or emulsions of sizing agents which impart smoothness, consistency, suppleness and strength to the yarn, so that processing on the loom is improved. After weaving, the sizing agent is removed in most cases.

It is known to use native or modified starches, cellulose ethers such as carboxymethyl celluloses, protein products, polyvinyl alcohols, polyacrylates and others as sizing bases. Cotton and rayon wool are mainly treated with sizes based on natural materials, in the case of mixed spun fabrics and synthetic yarns, sizes are predominantly finished with semi-synthetic or fully synthetic products, also in combination with the natural products mentioned.

• a) Schlichten, die sich nur nach Einwirkung von Enzymen oder Chemikalien durch anschließendes Auswaschen mit Wasser entfernen lassen,
• b) Schlichten, die durch einfaches Auswaschen mit Wasser entfernbar sind.

According to their removability from the fiber, a distinction is made between two groups of sizing agents:

• a) Sizes that can only be removed after exposure to enzymes or chemicals by subsequent washing with water,
• b) Finishes that can be removed by simply washing them out with water.

With increasing rationalization, the last group of water-washable sizing agents is becoming increasingly important. Substituted starches, carboxymethyl cellulose, polyvinyl alcohol and polyacrylates are used in particular. From the point of view of easy removability from the tissue, these products are used with advantage. Almost without exception, however, these semi-synthetic or fully synthetic sizing agents show only very poor biodegradability, which manifests itself in a low biological oxygen requirement, but in a correspondingly high chemical oxygen requirement.

Sizing agents based on naturally occurring polysaccharides, e.g. Starch sizing is characterized by good biodegradability, but it is not or only insufficiently suitable for sizing semi-or. fully synthetic fibers. They are therefore preferably used in mixtures with the agents mentioned.

Attempts have also been made to switch to other natural product sizing agents by varying the polysaccharide component. The flour of Tamarindus Indica, the so-called tamarind seed flour, was also described as a sizing agent (Whistler Industrial Gums, 461 ff, Melliand, 1956, 588 ff). However, the use of such sizing agents is almost exclusively limited to the Indian subcontinent, since the disadvantages of the tamarind core sizing agents prevent further spread.

The invention now relates to a readily biodegradable, water-washable sizing agent, which is distinguished by excellent adhesive strength and smoothness.

According to the invention, it was found that the polysaccharide from the seeds of Cassia Occidentalis, after monohydroxyalkylation and partial depolymerization, gives an excellent sizing agent for yarns made of cotton, regenerated cellulose and synthetic fibers, and mixtures thereof.

Dihydroxypropyl ethers of polysaccharides, including Cassia occidentalis, are in principle already known from US-A-2496 670.

The invention relates to a sizing agent for yarns made of cotton, regenerated cellulose and synthetic fibers, and mixtures thereof, which essentially consists of a monohydroxyalkylated polysaccharide from the seeds of Cassia Occidentalis, which has a viscosity of 40-10,000 mPas (10% aqueous solution, 80 ° C, Brookfield RVT) and has a degree of substitution of 0.05 - 1.0.

The sizing agents according to the invention have a viscosity range of 40-10,000 mPas, preferably 200-9,000 mPas, in aqueous solution with a dry substance content of 10%. The viscosity is measured at 80 ° C. on a Brookfield viscometer, model RVT, at 20 rpm.

The monohydroxyalkylated polysaccharides used according to the invention as sizing agents have a degree of substitution of 0.05-1.0, preferably 0.1-0.9.

Monohydroxyethylated and monohydroxypropylated polysaccharide is preferred, although in principle monohydroxy-C _2-4 -alkylated polysaccharide can be used.

The polysaccharide from Cassia Occidentalis used according to the invention is predominantly a galactomannan.

The sizing agents according to the invention are prepared by hydroxyalkylating polysaccharide from the endosperms of Cassia Occidentalis with an alkylene oxide or haloalkanol in a manner known per se and depolymerizing before, during or after the hydroxyalkylation in order to achieve the desired viscosity in a manner known per se. The depolymerization can be carried out, for example, with hydrogen peroxide or with inorganic peroxides, or by hydrolysis or by means of enzymes.

In a preferred method, the polysaccharide from endosperms of Cassia Occidentalis is first kneaded briefly with aqueous NaOH solution in a kneader mixer, then the mixture is mixed with an alkylene oxide, such as preferably ethylene oxide. or propylene oxide, added and worked well at a temperature of 40 - 80 ° C for several hours with the mixer closed. After the reaction has ended, the depolymerization is carried out using an aqueous hydrogen peroxide solution elevated temperature, for example 50 - 90 ° C, carried out. This depolymerization can also be carried out before the hydroxyalkylation. The resultant, almost homogeneous paste can then be dried on a drum dryer, for example. A cold and hot water soluble product is obtained.

The sizing agent according to the invention is practically salt-free and, even in its molecular structure, is not a salt, e.g. the carboxymethylates or polyacrylates. As is well known, salt-free sizing agents protect the weaving tableware and cause no corrosion.

The products according to the invention have the advantage of significantly better sizing effects compared to the set-free starch sizing. Compared to the batch-free sizes based on CMC, PVA or acrylate, the size according to the invention is readily biodegradable and can be easily removed from the waste water in a biological sewage treatment plant. In contrast to polyvinyl alcohol, it is also readily soluble in an alkaline medium.

It therefore combines all the good properties of known sizing agents without having their disadvantages.

By using sizing agents according to the invention it is achieved that, because of the excellent elasticity and the good film-forming ability, the yarns sized with this have a good surface smoothness and thus have sufficient resistance to the heavy demands of the weaving process. This applies in particular to very dense fabric qualities.

Because the sizing can be easily removed from the fabric simply by washing with water, there are additional advantages for further processing. For example, time and costly enzymatic desizing.

The sizing agent according to the invention is readily biodegradable. The chemical oxygen requirement of such a size solution drops to less than 20% of the initial value after 5 days of incubation with activated sludge. Comparisons with the commonly used water-washable sizing agents show that polyvinyl alcohol, polyacrylates and carboxymethyl cellulose are practically not subject to degradation under these conditions.

The following examples illustrate the invention. All parts are parts by weight.

example 1

100 parts of polysaccharide from endosperms from Cassia Occidentalis are placed in a kneading mixer and, with the mixer running, a solution of 1 part of hydrochloric acid (approx. 32%) in 80 parts of water is added within 5 minutes. With thorough mixing, it is left to degrade for a further 60 minutes at approx. 60-80 ° C. Then a solution of 6.5 parts of sodium hydroxide in 50 parts of water is added within 30 minutes and mixed for a further 30 minutes at this temperature (60-80 ° C.). The mixture is then mixed with 15 parts of propylene oxide and the mixer is then sealed. After 3 hours of kneading at 60 ° C (product temperature), the reaction time has ended. Now the excess propylene oxide is removed by vacuum and the reaction mixture is mixed with 5 parts of hydrogen peroxide (approx. 32%) in 500 parts of water and kneaded at 60-90 ° C. for about 90 minutes. The paste is then homogeneous and is dried in a thin layer using a drum dryer.

The scale-like sizing agent is cold and hot water soluble, the 10% aqueous solution shows a viscosity of approx. 7000 - 8500 mPas at 80 ° C. The sizing agent has a degree of substitution of 0.27.

Example 2

100 parts of polysaccharide from endosperms from Cassia Occidentalis are placed in a kneader mixer and mixed with a solution of 40 parts of hydrogen peroxide (32%) in 60 parts of water within about 5 minutes while the mixer is running. With thorough mixing, it is left to mature for a further 30 minutes. A solution of 8 parts of sodium hydroxide in 50 parts of water is then added over the course of about 30 minutes and the mixture is stirred at 80 ° C. for a further 90 minutes. The excess hydrogen peroxide is destroyed with a solution of 8-12 parts of sodium sulfite in 60 parts of water within 30 minutes at 80 ° C. until H ₂ 0 _{2 is} detected negatively.

15 parts of propylene oxide are then added to the mixture, and the mixer is then tightly sealed. After kneading for 3 hours at 60 ° C. (product temperature), the reaction is complete. Now the excess propylene oxide is removed with vacuum. The heavily swollen splits are mixed with 400 parts of water and kneaded at 60-90 ° C for 60 minutes. The light, almost homogeneous paste is dried in a thin layer on a drum dryer.

The scale-shaped sizing agent is cold and hot water soluble, its 10% aqueous solution shows a viscosity of approx. 1000 mPas at 80 ° C. The degree of substitution was determined with 0.25 (iodine-hydrogen method).

Example 3

100 parts of Cassia Occidentalis endosperms are placed in a kneading mixer and a solution of 5 parts of sodium hydroxide in 100 parts of water is added with the mixer running for about 5 minutes. After kneading for 30 minutes, 45 parts of propylene oxide are added to the mixture and the mixer is sealed. With thorough mixing, the reaction mixture is allowed to react at 60 ° C. (product temperature) for a further 3 hours. The excess propylene oxide is then removed in vacuo and 50 parts of hydrogen peroxide (32% strength) in 500 parts of water are added to the reaction mixture, and the mixture is kneaded at 60-90 ° C. for about 90 minutes. The almost homogeneous paste is dried in a thin layer on a drum dryer.

The scale-like sizing agent is soluble in cold and hot water, its 10% aqueous solution shows a viscosity of approx. 700 mPas at 80 ° C. The degree of substitution was determined to be 0.7 (iodine-hydrogen method).

Example 4

100 parts of flour from the endosperms of Cassia Occidentalis are placed in a kneading mixer and mixed with a solution of 5 parts of sodium hydroxide in 30 parts of absolute methanol within about 5 minutes while the mixer is running. After kneading for 30 minutes, the mixture is mixed with 10 parts of propylene oxide and the mixer sealed. With thorough mixing, the reaction mixture is allowed to react at 60 ° C. (product temperature) for a further 3 hours. Now the methanol and the excess propylene oxide are removed and the reaction mixture is mixed with 50 parts of hydrogen peroxide (32%) in 500 parts of water and kneaded at 60-90'C for about 30 minutes. The homogeneous paste is dried in a thin layer on a drum dryer. The scale-like sizing agent is soluble in cold and hot water. The 10% aqueous solution shows a viscosity of approx. 500 mPas at 80 ° C. The degree of substitution was determined to be 0.15.

Example 5

100 parts of polysaccharide from endosperms from Cassia Occidentalis are placed in a kneading mixer and a solution of 5 parts of sodium hydroxide in 100 parts of water is added to the kneading mixer over a period of about 5 minutes. After kneading for 30 minutes, the mixture is mixed with 15 parts of ethylene oxide and the mixer sealed. With thorough mixing, the reaction mixture is left to react at 60 ° C. (product temperature) for a further 3 hours. Now the excess ethylene oxide is removed in vacuo and 50 parts of hydrogen peroxide (32%) in 500 parts of water are added to the reaction mixture and the mixture is kneaded at 60-90 ° C. for about 90 minutes. The homogeneous paste is brought to dryness on a drum dryer.

The scale-like sizing agent is soluble in cold and hot water. Its 10% aqueous solution shows a viscosity of approx. 800 mPas at 80 ° C. The degree of substitution was determined to be 0.3 (iodine-hydrogen method).

Example 6

100 parts of flour from the endosperms of Cassia Occidentalis are placed in a kneading mixer and mixed with a solution of 5 parts of sodium hydroxide in 30 parts of absolute methanol within about 5 minutes while the mixer is running. After kneading for 30 minutes, the mixture is mixed with 15 parts of ethylene oxide and the mixer sealed. With thorough mixing, the reaction mixture is left to react at 60 ° C. (product temperature) for a further 3 hours. Now the excess ethylene oxide is removed (vacuum) and 50 parts of hydrogen peroxide (32% strength) in 50 parts of absolute methanol are added to the reaction mixture and the mixture is kneaded at 60-90 ° C. for about 90 minutes. After drying in vacuo, a cold and hot water-soluble powdered sizing agent is obtained. The 10% aqueous solution of the sizing agent shows a viscosity of approx. 1200 mPas at 80 ° C. The degree of substitution was determined using 0.25 (iodine-hydrogen method).

Example 7

100 parts of endosperms from Cassia Occidentalis are placed in a kneading mixer and mixed with a solution of 10 parts of hydrochloric acid (32%) in 80 parts of water within 5 minutes while the mixer is running. With thorough mixing, it is left to degrade for a further 60 minutes at approx. 60-80 ° C. A solution of 10 parts of sodium hydroxide in 50 parts of water is then added over the course of about 30 minutes and the mixture is stirred at this temperature (60-80 ° C.) for a further 30 minutes. The strongly swollen but still free-flowing endosperms from Cassia Occidentalis are then mixed with 8 parts of propylene oxide and the mixer is then sealed. After kneading for 3 hours at 60 ° C., the reaction is complete. Now the excess propylene oxide is removed with vacuum and the reaction material with 35 parts of hydrogen peroxide (32%) in 35 parts of water and kneaded for approx. 90 minutes at approx. 50 ° C. The strongly swollen, but still free-flowing sizing agent is ground in a mill with simultaneous drying. The 10% aqueous solution of the product shows a viscosity of approx. 200 mPas at 80 ° C. The degree of substitution was determined to be 0.1 (iodine-hydrogen method).

Example 8

100 parts of Cassia Occidentalis endosperms are placed in a kneading mixer and a solution of 5 parts of sodium hydroxide in 100 parts of water is added with the mixer running for about 5 minutes. After kneading for 30 minutes, the mixture is mixed with 15 parts of ethylene oxide and the mixer sealed. With thorough mixing, the reaction mixture is allowed to react at 60 ° C. for a further 3 hours. Now the excess ethylene oxide is removed (vacuum) and 50 parts of hydrogen peroxide (32%) in 50 parts of water are added to the reaction mixture and the mixture is kneaded at 60-90 ° C. for about 90 minutes. The strongly swollen, but still free-flowing product is ground in a mill with simultaneous drying. The 10% aqueous solution of the sizing agent shows a viscosity of 600 mPas at 80 ° C. The degree of substitution was determined using 0.85 (iodine-hydrogen method).

Example 9

40 kg of a sizing agent according to Example 7 were prepared in a turbo cooker with 450 cold water and boiled. The following material was finished on a drum sizing machine.

Nm 30/1 polyester / cotton in the mixing ratio 50%: 50% raw white, 4 456 threads, intended for cord fabrics with the fabric setting 27/54 - 30/20.

The temperature in the sizing trough was constant at 85 ° C. The chain was immersed once in the liquor and squeezed twice, a squeezing effect of 115% being achieved. The warp yarn was processed on Sulzer weaving machines, the weaving efficiency being 98.0%. 0.005 warp thread breaks were calculated for 1000 warp and 10,000 weft threads.

The comparison test with a size product made from soluble starch and CMC with a size approach of 60 kg to a 500 l finished fleet produced a weaving efficiency of 95.6%.

Example 10

• Nm 40/1 Zellwolle, 2 096 Fäden

With 8 kg of sizing agent according to Example 1 and 0.5 kg of sizing grease, 3501 finished liquors were produced in a pressure cooker and the following warp material was thus sized.

• Nm 40/1 cellulose, 2 096 threads

The fabric setting consisted of warp and weft each Nm 40/1 and 20 threads per cm.

The warp yarn was sized on a drum sizing machine, the yarn being immersed twice in the sizing trough and squeezed twice. The temperature of the wash liquor was 90 ° C. A squeezing effect of 124% was determined. The useful output in the weaving mill was 97.8% for the chains thus sized, which corresponded to 0.015 warp thread breaks calculated on 1000 warp and 10,000 weft threads.

A counter-test with a combination size consisting of carboxymethylated starch and polyacrylate and a size concentration of 9 kg on a 350 l finished fleet produced a weaving efficiency of 96.2%.

Example 11

In a pressure cooker, 450 l of finished liquor were produced using 35 kg of sizing agent according to Example 2 and 1.5 kg of sizing grease.

• Nm 64/1 Polyester/Baumwolle im Mischungsverhältnis 50 %:50 %
• mit 5 024 Fäden in der Gewebeeinstellung 34/25 -64/64.

The following warp material was finished:

• Nm 64/1 polyester / cotton in the mixing ratio 50%: 50%
• with 5 024 threads in the fabric setting 34/25 -64/64.

A drum sizing machine with 9 drying cylinders was available as the sizing machine. The liquor temperature was 80 ° C. The warp yarn was immersed twice in the liquor and squeezed twice with a squeezing effect of 129%. A useful output of 97.1% was achieved in the weaving mill. The amount of dust in the dry subfield of the sizing machine as well as in the weaving mill was extremely low.

In the counter-test with 45 kg of low-salt CMC on 450 I of finished liquor, a efficiency of 96.6% was determined in the weaving mill.

Example 12

With 25 kg of sizing agent according to Example 3 and 1.0 kg of sizing wax, 5001 finished liquors were prepared in the turbo cooker. The following warp material was finished on a drum finishing machine.

• Gewebeeinstellung Fäden pro cm 17/17
• Garnnummer Nm Kette und Nm Schuß je 10/1

Nm 10/1 polyacrylonitrile yarn 100% with 2400 threads and the

• Fabric adjustment threads per cm 17/17
• Yarn number Nm warp and Nm weft each 10/1

The liquor temperature in the size trough was 80 ° C. The warp yarn was immersed twice and squeezed twice. The fleet take-up was 124%. The chain was woven into curtain fabrics on Jacquard weaving machines. The useful effect was 0.0 warp thread breaks calculated on 1000 warp and 10,000 weft threads.

In a counter-experiment, 25 kg of polyvinyl alcohol were used on 5001 finished liquors, a weaving use effect of 0.024 warp thread breaks calculated on 1000 warp and 10,000 weft threads being determined.

Example 13

• Nm 16/1 Zellwolle 100 % mit 2 060 Fäden,
• Gewebeeinstellung 17/14 Fäden pro cm,
• Garnnummer Kette Nm 16/1, Schuß Nm 16/1

wurde mit einer Schlichteflotte von 6 kg Schlichtemittel gemäß Beispiel 6 und 0.5 kg Schlichtefett auf 5001 fertiger Flotte auf einer Trommelschlichtmaschine geschlichtet. Die Flottentemperatur betrug im Schlichtetrog konstant 85°C. Das Kettgarn wurde einmal in der Flotte getaucht und zweimal abgequetscht mit einem Abquetscheffekt von 131 %. Das Kettgarn wurde auf 6.5 % Restfeuchte getrocknet. Die Maschinengeschwindigkeit betrug 65 m/min.A warp material

• Nm 16/1 cellulose 100% with 2 060 threads,
• Fabric setting 17/14 threads per cm,
• Yarn number chain Nm 16/1, weft Nm 16/1

was finished with a size liquor of 6 kg size according to Example 6 and 0.5 kg size grease on 5001 finished liquors on a drum size machine. The liquor temperature was a constant 85 ° C in the size trough. The warp yarn was dipped once in the liquor and squeezed twice with a squeezing effect of 131%. The warp yarn was dried to 6.5% residual moisture. The machine speed was 65 m / min.

In the weaving mill, with the chain sized in this way, an efficiency of 95.2% was achieved with extremely little dust, corresponding to 0.018 warp thread breaks on 1000 warp and 10,000 weft threads.

The counter-test was carried out with 25 kg of medium-viscosity polyvinyl alcohol on a 500 l finished liquor, a weaving efficiency of 95.3% being achieved.

Example 14

• Nm 70/1 Baumwolle, vorgesehen für Inlettgewebe,
• mit 6580 Fäden in der Gewebeeinstellung 47/42-70/70

In a turbo cooker, 450 l of finished liquor were prepared with 35 kg of sizing agent according to Example 5 and 0.5 kg of sizing grease. The following warp material was finished:

• Nm 70/1 cotton, intended for ticking fabrics,
• with 6580 threads in the fabric setting 47 / 42-70 / 70

A drum sizing machine with 9 drying cylinders and 2 sizing troughs was available as the sizing machine. The liquor temperature during sizing was 80-85 ° C. The warp yarn was immersed twice in the liquor and squeezed twice with a squeezing effect of 134%. A useful output of 97.8% was achieved in the weaving mill, corresponding to 0.01 warp thread breaks on 1000 warp and 10,000 weft threads.

In the counter-test with 35 kg of low-salt CMC on 450 l of finished liquor, 96.2% efficiency was determined in the weaving mill.

Claims (12)

1. Process for the production of a sizing agent for yarns of cotton, regenerated cellulose and synthetic fibers as well as their mixtures, characterized in that polysaccharide is monohydroxyalkylated from the endosperms of Cassia Occidentalis with an alkylene oxide and depolymerized prior to, during or after the hydroxyalkylation for the purpose of obtaining a substitution degree of 0.05 - -1.0 and a viscosity of 40 -10,000 mPas (10% aqueous solution, 80° C, Brookfield RVT).

2. Process according to claim 1, characterized in that the polysaccharide is monohydroxyethylated or monohydroxypropylated.

3. Process according to claim 1 or 2, characterized in that the sizing agent has a viscosity of 200 - 9,000 mPas (10% aqueous solution, 80°C, Brookfield RVT).

4. Process according to one of the previous claims, characterized in that the monohydroxyalkylated polysaccharide has a substitution degree of 0.1-0.9.

5. Process according to cl aim 1, characterized in that the depolymerization is carried out with hydrogen peroxide.

6. Process according to claim 1, characterized in that the depolymerization is carried out with inorganic peroxides.

7. Process according to claim 1, characterized in that the depolymerization is caused by means of hydrolysis.

8. Process according to claim 1, characterized in that the depolymerization is carried out with enzymes.

9. Use of a monohydroxyalkylated polysaccharide from the seeds of Cassia Occidentalis, which has a viscosity of 40 -10,000 mPas (in 10% aqueous solution at 80° C, Brookfield RVT) and a substitution degree of 0.05 to 1.0 for the sizing of yarns of cotton, regenerated cellulose and synthetic fibers as well as their mixtures.

10. Use of a polysaccharide according to claim 9 in combination with common sizing agents and common sizing additives for sizing yarns of cotton, regenerated cellulose and synthetic fibers as well as their mixtures.

11. Use according to claim 10, the common sizing agents being starch and their derivatives, PVA, CMC and/or acrylate and the common sizing additives being fats, glues and/or waxes.