EP0476371A1 - Sizing agent for staple fiber yarns and filament yarns - Google Patents

Abstract

The use of water-soluble or water-dispersible proteins grafted with monoethylenically unsaturated monomers as sizing agents for staple fibre yarns and filament yarns.

Description

The invention relates to the use of water-soluble or water-dispersible grafted proteins which can be obtained by free-radically initiated polymerization of monoethylenically unsaturated monomers in the presence of proteins as sizing agents for staple fiber and filament yarns.

It is common practice in the textile industry to treat staple fiber and filament yarns with aqueous liquors of natural or synthetic products before they are further processed on the loom. This yarn pretreatment, which is referred to in technical jargon as sizing, is carried out in order to increase the mechanical resistance of the webs, so that they can withstand the high stresses in the weaving process better than in the raw and untreated state. Natural products such as starch or starch derivatives, but also synthetic polymers such as polyvinyl alcohol or polyacrylates are particularly suitable as sizing agents. Proteins have also been used as sizing agents, e.g. as filament sizing for viscose, acetate silk and wool. However, the protein sizes have also been replaced in many of these fields of application by synthetic polymers, carboxymethyl cellulose and starch derivatives. Protein sizing based on animal proteins such as casein or bone or skin glue must be mixed with softening additives such as glycerin, castor oil and its soaps or with surface-active substances in order to be used as a sizing agent at all. For example, a mixture of casein and paraffins serves as an emulsion size for nylon filaments.

DE-AS 15 94 905 discloses the use of water-soluble sodium or ammonium salts of copolymers of acrylonitrile and acrylic acid for the sizing of staple fiber yarns. According to the teaching of DE-PS 29 26 230, water-soluble alkaline earth metal salts of copolymers of (meth) acrylic acid and (meth) acrylonitrile in a mixture with starch or starch derivatives are used as sizing agents.

Other synthetic sizing agents are, for example, polyester sizing, which are described in U.S. Patents 3,546,008, 3,548,026 and 4,268,645.

From US Pat. No. 4,812,550 a process for the production of grafted proteins is known, in which ethylenically unsaturated monomers with no more than 14 carbon atoms in the molecule are radically polymerized in the presence of solubilized proteins in an aqueous medium. The latices obtainable in this way are used as binders for pigmented paper coating slips. Furthermore, it is known from US Pat. No. 3,651,210 that special emulsion copolymers can be reacted with solubilized proteins and the proteins modified in this way can be used as coating agents for the production of leather-like coatings or films. The coatings or films obtainable in this way are biodegradable.

After the weaving process, the sized warp threads are freed from the size. The sizing agents get into the wastewater of the textile companies. Biodegradable or non-eliminable sizing agents pollute the wastewater.

The object of the present invention is to provide sizing agents which are largely biodegradable or can be eliminated from the wastewater and which have improved application properties compared to the known natural material sizing agents.

• (a) monoethylenisch ungesättigten Monomeren
  in Gegenwart von
• (b) Proteinen
  im Gewichtsverhältnis (a):(b) von (0,5 bis 90):(99,5 bis 10) als Schlichtemittel für Stapelfaser- und Filamentgarne.

The object is achieved according to the invention with the use of water-soluble or water-dispersible grafted proteins which can be obtained by free-radically initiated polymerization of

• (a) monoethylenically unsaturated monomers
  in the presence of
• (b) proteins
  in the weight ratio (a) :( b) from (0.5 to 90) :( 99.5 to 10) as a sizing agent for staple fiber and filament yarns.

Monoethylenically unsaturated monomers of group (a) for the preparation of the grafted proteins are, for example, C₃- to C₈-monoethylenically unsaturated carboxylic acids, for example acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, aconitic acid and vinyl acetic acid. In addition, as far as technically accessible, the associated anhydrides of the monomers mentioned can be used, for example maleic anhydride and itaconic anhydride. Of the above compounds, acrylic acid, methacrylic acid or mixtures thereof are preferably used Production of the grafted proteins. The carboxylic acids can be used in the graft copolymerization as free carboxylic acids or in the form of the salts with inorganic or organic bases. For example, sodium hydroxide solution, potassium hydroxide solution, alkaline earth metal oxides and hydroxides, ammonia, trimethylamine, triethylamine, tributylamine, triethanolamine, diethanolamine, morpholine, methylamine or dimethylamine are suitable for neutralizing the monoethylenically unsaturated carboxylic acids. Mixtures of different bases can also be used for neutralization, for example sodium hydroxide solution and ethanolamine.

The compounds of group (a) are also the esters of the above-mentioned carboxylic acids with monohydric or polyhydric C₁ to C₂₂ alcohols. Suitable alcohols which are used for the esterification of the monoethylenically unsaturated carboxylic acids described above are, for example, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, 2-ethylhexyl alcohol, stearyl alcohol, palmityl alcohol, Decyl alcohol, dodecyl alcohol, tallow fatty alcohol, sorbitol, mannitol, glycerin, ethylene glycol, propylene glycol, butanediol. The esters of acrylic acid and methacrylic acid with methanol, ethanol, n-propanol, n-butanol, tert-butanol, 2-ethylhexyl alcohol, stearyl alcohol, ethylene glycol and propylene glycol are preferably used. Of the esters mentioned, n-butyl acrylate, methyl methacrylate, ethylhexyl acrylate and ethyl acrylate in a mixture with acrylic acid and / or methacrylic acid are particularly preferably subjected to the graft copolymerization in the presence of proteins.

Also suitable as monomers of group (a) are the amides of C₃- to C₈-carboxylic acids, which are derived from ammonia, C₁- to C₂₂-alkylamines or dialkylamines. Suitable amines for the preparation of the acid amides are, for example, methylamine, dimethylamine, stearylamine, tallow fatty amine and palmitylamine. In addition, the N-methylol derivatives of the amides can be used in the graft copolymerization, e.g. N-methylol acrylamide or N-methylol methacrylamide. The N-methylol derivatives of the amides mentioned can also be etherified, e.g. with C₁ to C₂₂ alcohols, preferred monomers are N- (butoxymethyl) acrylamide and N- (isobutoxymethyl) acrylamide.

Other suitable monomers (a) are the nitriles of the carboxylic acids, such as acrylonitrile or methacrylonitrile, vinyl ethers of alcohols containing 1 to 18 carbon atoms, for example vinyl methyl ether, vinyl isobutyl ether, vinyl n-butyl ether, vinyl ethyl ether and vinyl esters of saturated C₁ to C Carb carboxylic acids, in particular vinyl acetate, Vinyl propionate and vinyl butyrate. Other suitable monomers are styrene and alkyl styrenes. The graft copolymers contain the monomers (a) in amounts of 0.5 to 90, preferably 10 to 85,% by weight in copolymerized form.

Proteins are used as a further essential component in the graft copolymerization. All proteins are suitable for this, of which a proportion of at least 20% by weight dissolves in the polymerization medium under the polymerization conditions. Suitable proteins are described, for example, in US Pat. No. 4,812,550 cited above. A further overview of suitable proteins can be found in Ullmann's Encyclopedia of Industrial Chemistry, 4th edition, Weinheim 1980 Volume 19, 491 to 557. The proteins are renewable raw materials. For example, they come from hides, supporting and connective tissue, bones and cartilage: collagen, elastin, gelatin, ossein and skin glue. Proteins from milk are whey proteins, casein and lactalbumin. Keratin comes from wool, bristles, feathers and hair. Proteins from fish and eggs and from blood are also suitable as slaughterhouse waste, e.g. Blood proteins, albumin, globulin, globin, fibrinogen and hemoglobin. Other suitable proteins come from plants such as corn, wheat, barley and oats: glutelin, prolamine, zein and gluten. Proteins can also be obtained from seeds, e.g. from soybeans, calico seeds, peanuts, sunflowers, rapeseed, coconut, linseed, sesame, safflower, peas, beans and lentils. The protein components of clover, alfalfa, grass, potatoes, cassava and yam can also be used. Other protein suppliers are bacteria, fungi, algae and yeast, e.g. Pseudomonas, lactobacillus, penicillium, blue-green algae, green algae, chlorella, spirulina and excess yeast. Proteins which are preferably used as component (b) for the production of the graft copolymers are casein, gelatin, bone glue, proteins from soybeans, cereals, in particular wheat, corn and peas. The proteins are obtained from the natural raw materials, for example, by dissolving, grinding, sifting and classifying. In order to convert them into a soluble form, digestion by physical, chemical or enzymatic treatment is necessary in many cases, e.g. Hydrolysis with acid or alkalis, fermentation with yeast, bacteria or enzymes, extraction methods to remove secondary components, coagulation from extracts by heat, addition of electrolyte, pH change or addition of precipitants. To produce pure products, for example, fractional dissolving and precipitating as well as dialysis are possible.

In the copolymerization, (a) the monoethylenically unsaturated monomers in the presence of (b) the proteins in the weight ratio (a) :( b) of (0.5 to 90) :( 99.5 to 10), preferably (10 to 85 ) :( 90 to 15) used.

The monomers (a) are radically polymerized in the presence of proteins. All known compounds can be used as a radical donor. These initiators can be soluble or insoluble in water. Water-soluble initiators are, for example, inorganic peroxides, such as potassium, sodium and ammonium peroxodisulfate and hydrogen peroxide. Also suitable as initiators are organic peroxides, hydroperoxides, peracids, ketone peroxides, perketals and peresters, for example methyl ethyl ketone hydroperoxide, cumene hydroperoxide, tert-butyl hydroperoxide, 1,1-di (tert-butyl peroxy) cyclohexane, di (tert-butyl) peroxide, tert-butyloxy perpivalate, tert-butyl monoperoxy maleate, dicyclohexyl peroxydicarbonate, dibenzoyl peroxide, diacetyl peroxide, didecanoyl peroxide and mixtures of peroxides. Redox systems that contain a reducing component in addition to a peroxy compound are also suitable. Suitable reducing components are, for example, cerium III and iron II salts, sodium sulfite, sodium bisulfite, sodium dithionite, ascorbic acid and sodium formaldehyde sulfoxylate. Suitable initiators are preferably selected by using compounds which form free radicals and which have a half-life of less than 3 hours at the polymerization temperature chosen in each case. If the polymerization is first started at a lower temperature and ends at a higher temperature, it is advisable to work with at least two initiators which disintegrate at different temperatures, namely first an initiator which already disintegrates at a lower temperature and then the initiator Complete the main polymerization with an initiator that decomposes at a higher temperature. The decomposition temperature can be reduced by adding heavy metal salts, for example copper, cobalt, manganese, iron, nickel and chromium salts to peroxidic catalysts. Suitable initiators are also azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-amidinopropane) dihydrochloride, 2,2'-azobis (2-methylpropionamidine) dihydrochloride, 2,2'-azobis- (2, 4-dimethylvaleronitrile) and dimethyl 2,2'-azobisisobutyrate. Hydrogen peroxide, potassium, ammonium and sodium peroxodisulfate and tert-butyl perpivalate are particularly preferably used as initiators in the graft polymerization. Based on the monomers to be polymerized, 0.5 to 10, preferably 1 to 8,% by weight of an initiator or a mixture of polymerization initiators is used. The amount of initiator used can have a considerable influence on the graft polymer formed.

If water-insoluble monomers are used in the graft polymerization, graft polymers with particularly advantageous properties can be obtained by first adding a water-soluble initiator for the main reaction and then for post-polymerizing and removing residual monomers from the latex. However, it may also be advantageous to present a fraction of the total amount of initiator required at the start of the polymerization and the remaining part of the amount of initiator over a period of 10 minutes to Add 10 hours, preferably 1 to 3 hours, continuously or batchwise. This procedure is particularly advantageous for slowly polymerizing monomers and for lowering the residual monomer content of the graft polymer. If the monomers and the initiator are metered into a polymerizing mixture at the same time, it is advantageous to choose a feed time for the initiator of 10 minutes to 2 hours longer than the monomer feed time. For example, the time for the monomer feed can be 2 hours and for the initiator feed 3 hours.

The graft polymerization can optionally be carried out in the presence of regulators. Suitable regulators are, for example, mercapto compounds, such as mercaptoethanol, mercaptopropanol, mercaptobutanol, mercaptoacetic acid, mercaptopropionic acid, butyl mercaptan and dodecyl mercaptan. Also suitable as regulators are allyl compounds, such as allyl alcohol, aldehydes such as formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde and isobutyraldehyde, formic acid, ammonium formate, propionic acid, hydroxylamine sulfate and butenols. If the graft copolymerization is carried out in the presence of regulators, 0.05 to 20% by weight, based on the monomers used in the polymerization, can be used.

The polymerization can be carried out in an aqueous medium or in an organic solvent in which the proteins are at least 20% by weight soluble. Suitable organic solvents are, for example, acetic acid, formic acid, alcohols, such as methanol, n-propanol, isopropanol, n-butanol, tert-butanol, isobutanol, ethers, such as tetrahydrofuran and dioxane. In addition, ketones such as acetone and methyl ethyl ketone can be used as an inert diluent in graft polymerization. The use of methanol, ethanol, isopropanol, acetone, tetrahydrofuran and dioxane is particularly preferred. The graft polymerization can be carried out in mixtures of organic solvents and in mixtures of water and organic solvents which dissolve in water. The concentration of monomer and protein in the solvent used in each case is 10 to 70, preferably 15 to 60% by weight.

The graft polymerization is carried out in conventional devices which are provided with mixing elements, for example pistons, kettles, autoclaves and cylindrical reactors equipped with stirrers. The graft polymerization can also be carried out in cascade cascades or in other polymerization devices connected to one another. The polymerization can be carried out batchwise or continuously. Kneaders are also suitable as the polymerization device. If water-soluble monomers (a) are used in the graft polymerization, the polymerization can also be carried out by the reverse suspension polymerization method or by the water-in-oil emulsion polymerization method. The graft polymerization is preferably carried out as solution polymerization and emulsion polymerization. When carried out as an emulsion polymerization, emulsifiers and protective colloids can also be added in amounts of up to 5% by weight. However, it is preferred to work in the absence of surface-active additives. Precipitation polymerization may be of interest for special applications. In addition to initiation by compounds which form radicals under polymerization conditions, the polymerization can also be initiated by the action of UV radiation or the action of high-energy rays, for example α, β or γ rays. The graft polymerization is carried out in the temperature range from 20 to 160, preferably 30 to 100 ° C. At temperatures that are above the boiling point of the solvent used in each case, the graft polymerization is usually carried out in apparatus designed to be pressure-tight. Polymerization is preferably carried out in the absence of atmospheric oxygen in an inert gas atmosphere, for example nitrogen, argon, helium or carbon dioxide are used as the inert gases. The reaction temperature and the amount of initiator influence the properties of the graft polymers formed.

In the case of smaller polymerization batches in which the heat of polymerization can be dissipated sufficiently quickly, the monomers to be polymerized and the protein can be introduced together with at least one polymerization initiator and polymerized by heating to the polymerization temperature required in each case. However, it is more advantageous if the protein (b) and initially only some of the monomers (a) and the initiator are initially introduced into the polymerization device and the remaining monomers (a) and the initiator are added continuously or batchwise in accordance with the progress of the polymerization. The order in which the reactants are metered into the polymerization reactor can be varied as desired. For example, it is possible to put a protein solution or a dispersion of a protein in a reactor, to heat it to the required polymerization temperature and to add the monomers and initiators continuously or batchwise. If several monomers are used in the graft polymerization, the individual monomers can be metered into the polymerization zone simultaneously, as a mixture or from separate metering devices. For larger polymerization batches and preferably for water-insoluble monomers (a), it may be advantageous to prepare a mixture of water, solvents, regulators, bases and the total amounts of monomers (a) and proteins (b) and this mixture continuously or batchwise at the same time the initiator, according to the progress of the polymerization dosed into the polymerization vessel. However, these process variants can have considerable effects on the effectiveness of the graft polymers as sizing agents.

The pH of the reaction medium can also have an influence on the properties of the graft polymer. The solubility of the proteins below and above the isoelectric point can be used in the graft polymerization. Acidic or basic monomers can be used in the form of the corresponding salts. For example, acrylic acid is used as the free acid or as the ammonium, alkali or alkaline earth salt. The graft polymerization can be carried out in the pH range from 1 to 14, preferably 6 to 12. The graft polymers can be precipitated from solutions, for example, by changes in pH. This can be used in the processing, cleaning and isolation of the graft copolymers. It may be advantageous to use 2 or more proteins in the graft polymerization. The order of the proteins used can have favorable effects on the properties of the graft copolymers formed. In some cases, it is advantageous to take advantage of the emulsifying ability of a protein by first emulsifying a water-insoluble monomer with a protein and then adding another protein and subjecting the reaction mixture to graft copolymerization. For water-insoluble monomers, e.g. In a preferred embodiment, n-butyl acrylate, N-butoxymethylacrylamide, N-isobutoxymethyl methacrylamide, 2-ethylhexyl acrylate or methyl methacrylate can first be a three-phase mixture of monomer, water and insoluble protein, e.g. Casein. Then dissolve by adding alkalis, e.g. Sodium hydroxide solution, potassium hydroxide solution, ammonia solution, triethylamine, alkanolamine, morpholine or other alkaline substances, the protein. The emulsifying effect of the dissolving protein is particularly good in this process variant.

If ammonia, triethylamine or other volatile bases are used as neutralization bases for the protein, the films obtained after the graft polymerization can be converted into a form by heating to 50 ° C. to 150 ° C., particularly well in vacuo, which is only in water then redisperse when the pH is above 7. The films of the graft copolymers prepared and treated in this way are only slightly swellable or insoluble in pure water. However, spontaneous redispersion is achieved by adding a base. This can be used to provide the yarns with a water-resistant protective cover that can only be easily removed again in an alkaline environment. For example, a casein grafted with n-butyl acrylate, which is neutralized with ammonia solution and then isolated as a film by removing the solvents in vacuo and in the drying cabinet at 80 ° C. for 10 minutes was stored, just redispersed in water while the film is water-insoluble after a 1-hour dwell time at 80 ° C. The film can then be stored under water for at least 1 week without losing its shape. After adding a few drops of caustic soda, it dissolves into a fine-particle emulsion that is indistinguishable from the original emulsion.

The proteins used in the graft polymerization can be chemically modified in various ways before or after the graft polymerization. For example, it may be advantageous to partially decompose the protein hydrolytically or enzymatically before the polymerization. Depending on the reaction conditions, a partial hydrolytic degradation of the proteins can take place during the graft polymerization. The graft polymers can be modified in various ways after the graft polymerization, e.g. graft polymers of alkyl acrylates can be saponified onto proteins with the elimination of alcohol.

Before or after the radical grafting, functional groups of the proteins can also be reacted with reactive carboxylic acid derivatives, e.g. Carboxylic anhydrides are implemented. Examples of carboxylic anhydrides are acetic anhydride, succinic anhydride, maleic anhydride.

The proteins obtainable in this way, grafted with monoethylenically unsaturated monomers, which are either in dissolved or dispersed form, have K values of 10 to 200, preferably 15 to 180 (determined according to H. Fikentscher in 1% strength in water at 25 ° C. and pH 7). In the closed bottle test, the graft copolymers show a biodegradation corresponding to the protein content, in the elimination test according to Zahn-Wellens they can be very easily eliminated. A commercial preservative is added for storage in the presence of water. In the air-dried state, the graft polymers can be stored stably even without preservatives.

The graft polymers described are used as sizing agents for staple fiber and filament yarns. These yarns are made of cellulose fibers such as cotton, viscose, linen, jute, ramie; and polyester / cellulose fiber blends, polyester, polyacrylonitrile, rayon rayon, wool, polyester / wool blends, acetate, triacetate and polyamide. The amount of sizing agent on the yarns is usually 0.5 to 30% by weight, based on the yarns. The graft polymers can be used both alone and together with other components. They can also be mixed in any ratio to create specific properties. For example, a relatively soft graft polymer from 60% ethylhexyl acrylate and 40% casein in the form of the aqueous emulsion in any ratio with an aqueous emulsion of a relatively brittle graft polymer of 60% methyl methacrylate and 40% casein. The desired hardness of the resulting films of these mixtures can be set by the mixing ratio of the hard and soft components. In this way it is possible to set specific film properties by deliberately mixing two or more graft copolymers.

The graft polymers to be used according to the invention are notable for their good sizing effect, at the same time having a high film hardness and thus a low tendency to stick the sized warp threads. Furthermore, they show high adhesive strength values as well as mixture stability, storage stability and do not tend to gel under processing conditions. They are also characterized by being easy to wash out before further processing of the fabrics which have been produced using the sizing agents. A particular advantage is the environmentally friendly disposal of the graft polymers contained in the wastewater after washing, because the natural components of the graft polymers are biodegradable and the synthetic components can be easily eliminated.

A graft polymer of, for example, 40% casein and 60% n-butyl acrylate was already 93% eliminated in the Zahn-Wellens test after 2 days from the aqueous supernatant of the test solution.

The K values were determined according to H. Fikentscher, Cellulosechemie, Vol. 13, 58-64 and 71-74 (1932). K = k · 10³. The measurements were carried out on 1% strength by weight aqueous solutions of the graft polymers at 25 ° C. and a pH of 7. The data in% mean% by weight. Proxel XL 2 in the form of a 10% strength aqueous solution was used as a preservative for the aqueous solutions and dispersions of the graft polymers.

Examples Production of the graft polymers Graft polymer 1

A solution of 150 g of bone glue in 100 g of water is placed in a 2 l glass apparatus which is equipped with an anchor stirrer, feed devices for monomers, initiator solutions and sodium hydroxide solution, reflux condenser and nitrogen inlet and outlet and is brought to 80 ° C. under a nitrogen atmosphere warmed up. Once the specified temperature is reached, 30 g of solid casein and 22 g of a 5% aqueous sodium hydroxide solution are added. A viscous, homogeneous solution is obtained, to which 120 g of n-butyl acrylate are added dropwise from 2 feed vessels within 2 hours and 100 g of a 4% strength aqueous sodium peroxodisulfate solution are added dropwise over the course of 3 hours. After the initiator addition has ended, the reaction mixture is stirred for a further 3 hours at 80 ° C. and then diluted by adding 300 g of water. Then 1 g of the usual preservative for casein is added and the reaction mixture is filtered. A milky emulsion with a solids content of 32% is obtained. The K value of the graft polymer is 16.6. The graft polymer contains 0.12% unpolymerized n-butyl acrylate.

Graft polymer 2

In the apparatus described above, 225 g of bone glue are dissolved in 160 g of water by heating to a temperature of 80 ° C under a nitrogen atmosphere. 15 g of n-butyl acrylate are run into this solution within 10 minutes and at the same time 30 g of a 3% strength aqueous sodium peroxodisulfate solution are run in within 15 minutes. After a further 15 minutes, 275 g of a 27% aqueous acrylic acid solution are simultaneously added dropwise within 2 hours and 100 g of a 4% aqueous sodium peroxodisulfate solution are added over 2.5 hours. After the initiator addition has ended, the reaction mixture is stirred for a further 3 hours at 80 ° C. and then neutralized with a solution of 170 g of 25% strength aqueous sodium hydroxide solution and 1 g of the commercially available preservative is added. 370 g of water are added and a cloudy solution with a solids content of 32% is obtained. The K value of the graft polymer is 86 and the residual monomer content is 0.005%.

Graft polymer 3

In the apparatus described in the preparation of the graft polymer 1, 120 g of casein (in the acid form) and 500 g of water are suspended under nitrogen at a temperature of 20.degree. 180 g of n-butyl acrylate are then added in one portion and the mixture is stirred at 20 ° C. for 15 minutes. 32 g of a 12.5% strength aqueous sodium hydroxide solution are then added dropwise over the course of 15 minutes. After the sodium hydroxide solution has been added, the mixture is stirred at 20 ° C. for a further 40 minutes. 100 g of a 3% strength aqueous potassium peroxodisulfate solution are then added in one portion and the temperature of the reaction mixture is raised to 75 ° C. As soon as this temperature has been reached, 70 g of a 3% strength aqueous potassium peroxodisulfate solution are metered in over the course of 2 hours and the reaction mixture is stirred 4 hours at 70 ° C after the end of the Initiator addition. 1 g of the preservative is then added, giving a white latex with a solids content of 29%. The K value of the graft polymer is 20.8. The polymer has a residual monomer content of 0.03% n-butyl acrylate.

Graft polymer 4

In the apparatus described above, 60 g of casein, 500 g of water, 75 g of n-butyl acrylate and 15 g of methyl acrylate are stirred at 20 ° C. in a nitrogen atmosphere and neutralized with 29 g of a 7% aqueous sodium hydroxide solution. The mixture is stirred for a further 30 minutes at 20 ° C. and then mixed with 100 g of a 3% aqueous potassium peroxodisulfate solution. The reaction mixture is heated to a temperature of 75 to 80 ° C. At this temperature, 70 g of a 3% aqueous potassium peroxodisulfate solution are added over the course of 2 hours and the procedure is otherwise as described for the preparation of the graft polymer 3. An emulsion with a solids content of 17.5% is obtained. The graft polymer has a K value of 19.7.

Graft polymer 5 and 6

These graft polymers are prepared with the starting materials specified in the following table in accordance with the instructions given for the preparation of the graft polymer 3.

Graft polymer 7

In the apparatus described for the production of the graft polymer 1, 200 g of bone glue are dissolved in 140 g of water at 80 ° C. under a nitrogen atmosphere. 260 g of a 23% aqueous acrylic acid solution are then added dropwise to the resulting solution over the course of 2 hours, and at the same time 100 g of a 4% aqueous sodium peroxodisulfate solution are added over 3 hours. After the addition of the initiator has ended, the reaction mixture is stirred for a further 1 hour at 80 ° C., cooled and neutralized by adding 170 g of a 20% strength aqueous sodium hydroxide solution. The polymer solution has a solids content of 31%. The graft polymer has a K value of 79.4.

Graft polymer 8

As stated in the preparation of the graft polymer 3, 120 g of casein are slurried in 500 g of water and 30 g of n-butyl acrylate are added. After adding 8 g of 50% aqueous sodium hydroxide solution and intensive emulsification, the polymerization is started by adding 100 g of 3% aqueous potassium peroxodisulfate solution and brought to an end by the continuous addition of 60 g of 3% potassium peroxodisulfate solution. The remaining monomer portions are largely removed by adding 0.5 g of tert-butyl perpivalate. An 18% by weight cloudy solution of the graft polymer having a K value of 26.2 is obtained. The residual n-butyl acrylate content is 0.08%.

Graft polymer 9

In the apparatus used for the production of the graft polymer 1, 150 g of bone glue and 100 g of water are stirred under a nitrogen atmosphere and heated to a temperature of 85.degree. A mixture of 75 g of acrylic acid and 75 g of n-butyl acrylate is allowed to run into the resulting solution within 2 hours and at the same time 100 g of a 4% strength aqueous sodium peroxodisulfate solution are run in within 3 hours. After the initiator addition has ended, the reaction mixture is stirred for a further 2 hours at 80 ° C. and then neutralized by adding 170 g of a 25% strength aqueous sodium hydroxide solution. 500 g of water and 1 g of a commercially available preservative are added, giving a 27% latex. The K value of the polymer is 92. The graft polymer has a residual n-butyl acrylate content of 0.03%.

Graft polymer 10

In the apparatus described in the preparation of the graft polymer 1, 120 g of casein are suspended in 400 g of water and 8 g of 50% strength aqueous sodium hydroxide solution are added. 30 g of acrylic acid are added to the resulting aqueous solution in the course of 10 minutes and then so much 10% strength aqueous sodium hydroxide solution is added dropwise until the precipitate formed has dissolved again. 100 g of a 4% strength aqueous potassium peroxodisulfate solution are then added and the reaction mixture is heated to 70 ° C. under a nitrogen atmosphere. The polymerization time is 3 hours. The reaction mixture is then diluted. An aqueous polymer solution with a solids content of 18% is obtained. The graft polymer has a K value of 28.9.

Graft polymer 11

In the apparatus described in the preparation of the graft polymer 1, 120 g of casein are suspended in 450 g of water at a temperature of 20 ° C. Then 40 g of methyl methacrylate and a solution of 26 g of acrylic acid and 29 g of 50% strength aqueous sodium hydroxide solution in 50 g of water are added in one portion under a nitrogen atmosphere and the resulting mixture is neutralized by adding 32 g of 12.5% strength aqueous sodium hydroxide solution within 10 minutes with vigorous stirring. After adding 100 g of 3% aqueous potassium peroxodisulfate solution, the reaction mixture is heated to a temperature of 75 to 80 ° C. and, when this temperature is reached, 100 g of a 2% aqueous potassium peroxodisulfate solution are added within 2 hours. After the initiator addition has ended, the reaction mixture is stirred at 80 ° C. for a further 4 hours. A latex with a solids content of 19% is obtained. The graft polymer has a K value of 37.7 and contains 0.002% unpolymerized methyl methacrylate.

Graft polymer 12

In the apparatus used for the preparation of the graft polymer 1, 120 g of casein are suspended in 600 g of water at a temperature of 20 ° C. and 80 g of N- (n-butoxymethyl) acrylamide are added at once. After adding 32 g of 12.5% strength aqueous sodium hydroxide solution, a finely divided emulsion is formed after stirring for 40 minutes. 100 g of a 3% aqueous potassium peroxodisulfate solution are added, the mixture is heated to 80 ° C. and 100 g of a 2% aqueous potassium peroxodisulfate solution are added dropwise at this temperature over the course of 2 hours. The emulsion will after the initiator addition has ended, the mixture is stirred at 75 ° C. for 4 hours, diluted with 300 g of water and mixed with 1 g of the preservative. It has a solids content of 20%. The K value of the graft polymer is 45.6.

Graft polymer 13

Example 12 is repeated with the only exception that N- (isobutoxymethyl) acrylamide is now used instead of N- (n-butoxymethyl) acrylamide. In this case, the K value of the graft polymer is 44.8.

Graft polymer 14

140 g of water are placed in the apparatus described in the preparation of the graft polymer 1 and heated to 85.degree. At this temperature, 200 g of gelatin are then added in portions and the mixture is stirred until a clear solution is obtained. Then 50 g of a 4% aqueous sodium peroxodisulfate solution and a solution of 60 g of methacrylic acid in 320 g of water are each added dropwise from 2 metering vessels over the course of 2 hours, and the reaction mixture is then stirred at 85 ° C. for 2 hours. After cooling, the reaction mixture is neutralized by adding 56 g of 50% aqueous sodium hydroxide solution. The polymer solution has a solids content of 31%. The K value of the graft polymer is 96.

Graft polymer 15

• a) Production of the soft component
  In the apparatus described in the preparation of the graft polymer 1, 120 g of casein, 500 g of water and 180 g of ethylhexyl acrylate are intimately mixed under a nitrogen atmosphere at a temperature of 20.degree. After adding 8 g of 50% aqueous sodium hydroxide solution, the casein dissolves. A finely divided, smooth emulsion is obtained which is stirred at 20 ° C. for 40 minutes. 25 g of a 13% strength aqueous sodium peroxodisulfate solution are then added and the reaction mixture is heated to 75.degree. As soon as this temperature is reached, a further 25 g of 13% aqueous sodium peroxodisulfate solution are added dropwise within 2 hours. After the initiator addition has ended, the reaction mixture is stirred for a further 2 hours at 75 ° C., with 1 g of 75% tert-butyl perpivalate, which is added in one portion is added and the mixture is stirred at 75 ° C. for a further 2 hours. The solids content of the emulsion is adjusted to 25% by adding water. The graft polymer has a K value of 21.4. The residual unpolymerized ethylhexyl acrylate content is 0.1%.
• b) Production of the hard component
  The procedure is as given under a), but 180 g of methyl methacrylate is used as the monomer instead of ethylhexyl acrylate. A latex whose solids content is adjusted to 25% is obtained under identical process conditions. The graft polymer has a K value of 18.3. The residual unpolymerized methyl methacrylate content is 0.012%.

The latices obtained according to a) and b) are mixed so that the resulting mixture contains 70% of the latex according to a) and 30% of the latex according to b). The mixture is then mixed with 1 g of the preservative. It is stable for weeks.

Application properties of the graft polymers

The graft polymers 1 to 15 described above are used as sizing agents for staple fiber and filament yarns. To evaluate the application properties of the graft polymers, A) the film properties and B) the pilling values and the pseudo warp thread break values were determined as a measure of the sizing effect.

A) Determination of the film properties using the pendulum hardness

The film hardness of the films was tested to determine the film properties. The test was carried out on the König pendulum device (DIN 53 157).

To produce the films, 1 to 15 2 mm thick films were produced from the graft polymers described above. The films were then dried at 80 ° C. for 3 hours and then kept at 65% or 80% relative humidity and 20 ° C. for 24 hours. Then the pendulum device is tested in accordance with the regulation.

B) Determination of the sizing effect

The sizing effect is tested on the Reutlingen weaving tester, which simulates the load on the warp yarns during the weaving process by repeatedly mechanically stressing sized yarns under a certain tension using metal pins (J. Trauter and R. Vialon, Textil Praxis International 1985, 1201). The number of these stresses (number of turns) at which a certain damage to the yarn can be determined represents a measure of the quality of the sizing agent.

Serve as a criterion for the sizing effect

• a) the pilling values (the pilling value is the number of turns at which the formation of a knot on the sixth yarn is observed) and
• b) the pseudo-warp break values (the pseudo-warp break value is the number of turns at which the sixth yarn slackens).

High pilling and pseudo warp thread break values mean a good sizing effect.

To determine the sizing effect, yarns made from cotton with 8% aqueous liquors and yarns made from polyester / cotton in a weight ratio of 65/35 with 14% aqueous liquors of the graft polymers given below were sized at room temperature.

To determine the sizing effect of the graft polymers in a mixture with starch (hydroxypropyl potato starch), cotton was sized at room temperature with 11% aqueous liquors (67% starch / 33% graft polymer).

The arbitration was carried out on a laboratory sizing machine (DE-PS 2 714 897). The sized yarns were then held at 68% relative humidity and 20 ° C for 24 hours.

The examples show the results of the tests (film properties and sizing effect). The graft polymers 1 to 15 to be used according to the invention are viscoplastic and homogeneous and show good pilling and pseudo warp thread break values with regard to the sizing effect.

Pendulum hardness of graft polymers Examples 1 to 11

Experience has shown that highly effective sizing agents have pendulum hardnesses of 10 to 80 at 65% relative humidity and 5 to 30 at 80% relative humidity. Grafting modifies the brittle and too hard proteins, with pendulum hardness over 80 or 30, in such a way that good films are formed in terms of application technology.

Sizing effect of graft polymers: Examples 12 to 17

Application properties of the graft polymers 1 to 6 on polyester / cotton. The size coating on the yarns was 15%.

Examples 18-21

Application properties of the graft copolymers 1, 2, 5 and 6 on cotton. The size coating on the yarn was 10%.

Examples 22 and 23

Application properties of graft polymers 2 and 7 mixed with starch (67% hydroxypropyl potato starch with 33% graft polymer or as a comparison with 33% bone glue) on cotton. The size coating on the yarns was 15%.

As can be seen from Examples 1 to 23, proteins can be modified by radical grafting with ethylenically unsaturated monomers in such a way that their properties as textile sizes are considerably improved.

Claims (4)

Use of water-soluble or water-dispersible grafted proteins which are obtainable by free-radically initiated polymerization of (a) monoethylenically unsaturated monomers
in the presence of (b) proteins
in the weight ratio (a) :( b) from (0.5 to 90) :( 99.5 to 10) as a sizing agent for staple fiber and filament yarns. Use according to claim 1, characterized in that the grafted proteins are obtainable by radical-initiated polymerization of (A) monomers from the group of monoethylenically unsaturated C₃- to C₅-carboxylic acids, their esters, amides, nitriles, vinyl esters of saturated C₂- to C₄-carboxylic acids, styrene and mixtures of said monomers in the presence of (b) casein, gelatin, bone glue and / or soy, cereal, corn and pea proteins. Use according to claim 1 or 2, characterized in that the grafted proteins are obtainable by radical-initiated polymerization of (A) acrylic acid, methacrylic acid, esters of acrylic acid or methacrylic acid and monohydric C₁ to C₈ alcohols and N- (C₁ to C₄ alkyloxymethyl) acrylamide and N- (C₁ to C₄ alkyloxymethyl) methacrylamide
in water in the presence of (b) casein. Sizing agents for staple fiber and filament yarns are obtained through the free radical polymerization of (a) monoethylenically unsaturated monomers
in the presence of (b) proteins
in the weight ratio (a) :( b) from (0.5 to 90) :( 99.5 to 10).