New grafted polyester sulfones, their preparation process and their use for sizing yarns and textile fibres.

The present invention relates to sulfonated polyesters grafted with units derived from vinyl monomers, their preparation process and their application to the sizing of textile threads and fibers.

It is known to use sizing products in the textile industry in order to improve the abrasion resistance of threads and fibers during weaving, said sizing products being removed with water after weaving.

For this purpose, aqueous dispersions or solutions of acrylic or more generally vinyl copolymers have been proposed; it has been found that such products, in particular those based on vinyl acetate, are not suitable for sizing all textile yarns: for example their adhesion to yarns based on polyesters is insufficient.

Interesting products have been obtained by copolymerization of (meth) acrylic esters and (meth) acrylic acid in the presence of a water-dispersible sulfonated polyester (Japanese applications published under the numbers: 34153/1975 and 201079/1986), by example from 30 to 60% of a water-dispersible sulfonated polyester and from 70 to 40% of a (meth) acrylic ester / (meth) acrylic acid copolymer. However, these products have the disadvantage of being particularly expensive.

The Applicant has found that, surprisingly, an effective sizing agent can be obtained by decreasing on the one hand notably the rate of water-dispersible sulfonated polyester and by replacing on the other hand most of the (meth) acrylic esters with vinyl acetate for example, which is significantly less expensive.

According to the invention, the new sulfonated polyesters grafted with units derived from vinyl monomers are characterized in that they contain: - from 3 to 30 parts by weight, preferably from 3 to 15 and very particularly from 5 to 8 parts by weight, of a backbone polymer consisting of a water-dispersible sulfonated polyester - and 100 parts by weight of grafts derived from a monomer composition comprising: . from 5 to 13 parts by weight, preferably from 6 to 9 parts by weight, of at least one ethylenically unsaturated carboxylic acid; . from 12 to 25 parts by weight, preferably from 17 to 22 parts by weight of butyl acrylate or from 25 to 40 parts by weight, preferably from 30 to 35 parts by weight of a mixture of ethylenically unsaturated monomers other than ethylenically unsaturated carboxylic acids and monoethylenically unsaturated esters of carboxylic acids, said mixture containing from 60 to 70% by weight of butyl acrylate; . and the complement to 100 parts by weight of at least one monoethylenically unsaturated ester of a carboxylic acid.

According to a variant of the product which is the subject of the invention, up to approximately 10% of the weight of butyl acrylate can be replaced by butyl methacrylate.

A preferred product according to the invention consists of a trunk of water-dispersible sulfonated polyester carrying grafts derived from at least one ethylenically unsaturated carboxylic acid, butyl acrylate (approximately 10% by weight of said acrylate which can be replaced by methacrylate butyl) and at least one monoethylenically unsaturated ester of a carboxylic acid, with a weight ratio of butyl acrylate / water-dispersible sulfonated polyester of the order of 0.8 to 8.5 and preferably of the order of 2.5 to 4.

The basic water-dispersible sulfonated polyesters constituting the trunk are well-known products in the field of sizing of textile threads. They can be prepared by co-condensation of an organic diacid (such as a saturated or unsaturated aliphatic diacid, an aromatic diacid, a diacid having several aromatic rings, an arylaliphatic diacid), one of its diesters or its anhydride and of a sulfonated organic diacid or one of its diesters with a diol, in the presence of a usual polyesterification catalyst such as tetraisopropyl orthotitanate.

As starting monomers commonly used for the preparation of the trunk of sulfonated, water-dispersible polyester, there may be mentioned as: - organic diacids: saturated or unsaturated aliphatic diacids, aromatic diacids, such as succinic, adipic, suberic, sebacic acids, maleic, fumaric, itaconic acids, orthophthalic, isophthalic, terephthalic acids, the anhydrides of these acids and their diesters such as diesters methyl, ethyl, propyl, butyl. The preferred compounds are adipic acid, orthophthalic, isophthalic, terephthalic acids; - sulfonated organic diacids: sodium diacid sulfonates or their diesters such as dialkoylisophthalates and dialkoyl sulfosuccinates such as sodium dimethylisophthalate-5 sulfonate or sodium dimethyl sulfosuccinate; - diols: aliphatic glycols such as ethylene glycol, diethylene glycol, dipropylene glycol and higher homologs, butanediol - 1,4, hexanediol-1,6, neopentylglycol and cyclanic glycols such as cyclohexanediol, dicyclohexanediolpropane . The diols preferably chosen are ethylene glycol and diethylene glycol.

The preferred water-dispersible sulfonated polyesters for constituting the trunk are those which have a number average molecular weight of between 10,000 and 35,000, an acid number of less than 5 mg KOH / g, a sulfur content of between 0.8 and 2 % by weight, preferably between 1.2 and 1.8%.

As monomers from which the grafts are derived, there may be mentioned as: - ethylenically unsaturated carboxylic acid: acrylic acid, methacrylic acid ... - monoethylenically unsaturated carboxylic acid ester: vinyl acetate, vinyl propionate, vinyl butyrate, vinyl stearate, vinyl benzoate ... - copolymerizable comonomer (s) with monoethylenically unsaturated carboxylic acids, monoethylenically unsaturated carboxylic acid esters and butyl acrylate: C₁-C₂₀ alkyl acrylates or methacrylates such as methyl, ethyl, propyl, heptadecanyl ...; acrylonitrile; acrylamide; styrene ...

The products which are the subject of the invention can be obtained by copolymerization in aqueous medium of 100 parts by weight, of a monomer composition consisting of: . from 5 to 13 parts by weight, preferably from 6 to 9 parts by weight, of at least one ethylenically unsaturated carboxylic acid; . from 12 to 25 parts by weight, preferably from 17 to 22 parts by weight of butyl acrylate or from 25 to 40 parts by weight, preferably from 30 to 35 parts by weight of a mixture of ethylenically unsaturated monomers other than ethylenically unsaturated carboxylic acids and monoethylenically unsaturated esters of carboxylic acids, said mixture containing from 60 to 70% by weight of butyl acrylate; . and the complement to 100 parts by weight of at least one monoethylenically unsaturated ester of a carboxylic acid in the presence of 3 to 30 parts by weight, preferably from 3 to 15 and very particularly from 5 to 8 parts by weight, a water-dispersible sulfonated polyester.

According to a variant of the process which is the subject of the invention, up to approximately 10% of the weight of butyl acrylate can be replaced by methyl methacrylate.

A preferred embodiment consists in using a mixture consisting of at least one ethylenically unsaturated carboxylic acid, butyl acrylate (approximately 10% by weight of said acrylate which can be replaced by butyl methacrylate) and at least a monoethylenically unsaturated ester of a carboxylic acid, in the presence of a water-dispersible sulfonated polyester, with a weight ratio of butyl acrylate / water-dispersible sulfonated polyester of the order of 0.8 to 8.5 and preferably of the order of 2.5 to 4.

The polymerization operation can be carried out in aqueous emulsion in a conventional manner, in the presence of a water-soluble polymerization initiator, an emulsifier and optionally a chain limiting agent.

Examples of sulfonated water-dispersible polyesters and of monomers used have been given above. The nature and the quantity of ethylenically unsaturated monomer (s) possibly present next to butyl acrylate can be easily determined by a person skilled in the art according to the conditions of future use of the grafted polyester; indeed these conditions of use fix the properties of said product such as for example its glass transition temperature, its hardness, its hydrophilicity, its mechanical properties such as elongation and resistance to breakage; it is known that the addition of styrene or methyl methacrylate for example leads to a harder polymer while the addition of hexyl acrylate will have the opposite effect.

The water-soluble initiator can be represented more particularly by hydroperoxides such as hydrogen peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, diisopropylbenzene hydroperoxide, and by persulfates such as sodium persulfate, persulfate potassium, ammonium persulfate.

It can be used in amounts of between 0.05 and 2% by weight relative to the weight of the monomer composition. These initiators are optionally combined with a reducing agent, such as bisulfite or sodium formaldehyde sulfoxylate, polyethyleneamines, sugars: dextrose, sucrose, metal salts. The amounts of reducing agent used vary from 0 to 3% by weight relative to the weight of the monomer composition.

As an emulsifying agent, it is possible to use the conventional anionic agents represented in particular by fatty acid salts, alkylsulfates, alkylsulfonates, alkylarylsulfonates, sulfosuccinates, alkali metal alkylphosphates, acid salts abietic hydrogenated or not, nonionic agents such as polyethoxylated fatty alcohols, polyethoxylated alkylphenols, sulfated polyethyoxylated alkylphenols, polyethoxylated fatty acids ...

They are used in an amount of 0.01 to 5% by weight relative to the weight of the monomer composition.

The chain limiting agent can optionally be used in proportions ranging from 0 to 3% by weight relative to the monomer composition. It is generally chosen from mercaptans such as N-dodecylmercaptan, tertiododecyl mercaptan; cyclohexene; halogenated hydrocarbons such as chloroform, bromoform, carbon tetrachloride, carbon tetrabromide; the dimers of α methylstyrene.

The polymerization operation can be carried out at a temperature of the order of 60 to 80 ° C, preferably of the order of 70 ° C.

This operation lasts on the order of 6 to 12 hours and generally on the order of 10 hours.

If desired, the latex obtained, which generally contains around 10 to 60% by weight of grafted sulfonated polyester, can be atomized to be stored and transported more easily.

The product in the latex state or in the dry state can be dissolved in water using an alkaline substance, preferably volatile (volatile amines, ammonia). The solution thus obtained generally contains around 5 to 30% of its weight of grafted sulfonated polyester. The latex or preferably its solution is particularly well suited to the sizing of threads or fibers, in particular on a water jet loom or on dry looms in a humid atmosphere.

The present invention also relates to a process for sizing chains of textile yarns (yarns), which consists in applying the above-described water-dispersible grafted sulfonated polyesters in an aqueous medium, according to a conventional technique, the principle of which is to immerse the yarns in a aqueous bath containing the sizing product at the desired concentration and temperature, then wringing said threads by passing between rollers and finally drying the glued threads on heating cylinders, possibly by prior passage in hot chambers: the warp is then ready to be woven.

Among the conventional gluing methods for continuous yarn (filament yarn or continuous filament yarn) we can cite for example gluing in sectional (European system), conventional gluing (classic system or english system) and gluing in tablecloth primary (single end sizing or japan system).

The sizing products of the invention are particularly useful for preparing synthetic yarns (filament yarns) of polyethylene terephthalate which are among the most difficult textile yarns (yarns) but can also be used for fibers (spun yarns). ) polyethylene terephthalate mixed with natural fibers for glass fibers or for other yarns such as: synthetic threads such as acrylics, polyimides, chlorofiber, polyethylene, polypropylene or artificial threads such as acetates, triacetates, viscose ...

In addition, they make it possible to glue any type of thread, whether textured or not, twisted or not, and according to any gluing technique, whether it is sectional, conventional, sheet gluing. primary or other.

A very important advantage of these products is that they resist the performance constraints of new looms. They allow gluing and weaving at high speed. In addition, they are easily removable with water.

The following examples are given for information only and cannot be considered as limiting the scope and spirit of the invention.

EXAMPLE 1

In a 6 liter reactor fitted with an anchor stirrer, the following are introduced: - 2100 g of water - 9.4 g of sodium acetate - 9.4 g of partially sulfated ethoxylated nonylphenol containing 25 ethylene oxide units - 502 g of GEROL PS 20 (sulfonated polyester marketed by RHONE-POULENC) in 26.1% aqueous solution (which corresponds to 131 g of dry product).

The mixture is brought to 70 ° C. with stirring at 150 rpm.

9.4 g of ammonium persulfate dissolved in 65 g of water are added.

We continuously introduce: - on the one hand for 6 hours a mixture of: - 1370 g of vinyl acetate (VA) - 375 g of butyl acrylate (BuA) - 131 g of acrylic acid (AA) - 7.5 g of tertiododecylmercaptan - on the other hand for 8 hours, 7.5 g of tert-butyl hydroperoxide dissolved in 46 g of water - as well as for 8 hours - 12.75 g of sodium formaldehyde sulfoxylate - 4.7 g of sodium bicarbonate dissolved in 300 g of water.

The three continuous introductions start simultaneously.

At the end of the introductions, the medium is left at 70 ° C. for 1 hour and then cooled.

A latex of 40.8% dry extract is obtained.

EXAMPLE 2

The operation described in Example 1 is repeated from the following quantities of products: - 2024 g of water - 9.4 g of sodium acetate - 9.4 g of partially sulfated ethoxylated nonylphenol - 103 g of GEROL PS 20, expressed as dry product (392 g of 26.3% aqueous solution) - 9.4 g of ammonium persulfate in 65 g of water - 1294 g of vinyl acetate - 169 g of acrylic acid - 375 g of butyl acrylate - 37.5 butyl methacrylate - 0 g of tertiododecylmercaptan - 7.5 g of tert-butyl hydroperoxide<img file="EP0333547A2_D0001.tif" />

A latex of 40% dry extract is obtained.

EXAMPLE 3

The operation described in Example 1 is repeated from the following quantities of products: - 1005 g of water - 7.5 g sodium acetate - 7.5 g of partially sulfated ethoxylated nonylphenol - 450 g of GEROL PS 20, expressed as dry product (1711 g of 26.3% aqueous solution) - 7.5 g of ammonium persulfate in 75 g of water - 1095 g of vinyl acetate - 105 g of acrylic acid - 300 g of butyl acrylate - 0 g of tertiododecylmercaptan - 8.57 g of tert-butyl hydroperoxide<img file="EP0333547A2_D0002.tif" />

A latex of 40.5% dry extract is obtained.

EXAMPLE 4

The operation described in Example 1 is repeated from the following quantities of products: - 909 g of water - 6.25 g of sodium acetate - 6.25 g of partially sulfated ethoxylated nonylphenol - 375 g of GEROL PS 20, expressed as dry product (1431 g of 26.2% aqueous solution) - 6.25 g of ammonium persulfate in 30 g of water - 1012.5 g of vinyl acetate - 87.5 g of acrylic acid - 150 g of butyl acrylate - 7.5 g of tertiododecylmercaptan - 7.14 g of tert-butyl hydroperoxide<img file="EP0333547A2_D0003.tif" /> - 2.5 g of mercaptoethanol

A latex of 40.5% dry extract is obtained.

EXAMPLE 5

The operation described in Example 1 is repeated from the following quantities of products: - 2084 g of water - 9.36 g of sodium acetate - 9.37 g of partially sulfated ethoxylated nonylphenol - 150 g of GEROL PS 20, expressed as dry product (569 g of 26.4% aqueous solution) - 9.37 g of ammonium persulfate in 65 g of water - 1406 g of vinyl acetate - 337.5 g of butyl acrylate - 7.5 g of tertiododecylmercaptan - 131.2 g of acrylic acid - 7.5 g of tert-butyl hydroperoxide<img file="EP0333547A2_D0004.tif" />

A latex of 41% dry extract is obtained.

EXAMPLE 6 (comparative)

The operation described in Example 1 is repeated from the following quantities of products: - 1385 g of water - 7.5 g sodium acetate - 7.5 g of partially sulfated ethoxylated nonylphenol - 180 g of GEROL PS 20, expressed as dry product (679 g of 26.5% aqueous solution) - 7.5 g of ammonium persulfate in 75 g of water - 945 g of vinyl acetate - 105 g of acrylic acid - 450 g of butyl acrylate - 0 g of tertiododecylmercaptan - 8.57 g of tert-butyl hydroperoxide<img file="EP0333547A2_D0005.tif" />

A latex of 40.6% dry extract is obtained.

EXAMPLE 7 (comparative)

The operation described in Example 1 is repeated from the following quantities of products: - 1005 g of water - 7.5 g sodium acetate - 7.5 g of partially sulfated ethoxylated nonylphenol - 450 g of GEROL PS 20, expressed as dry product (1711 g of 26.3% aqueous solution) - 7.5 g of ammonium persulfate in 75 g of water - 945 g of vinyl acetate - 105 g of acrylic acid - 450 g of butyl acrylate - 0 g of tertiododecylmercaptan - 8.57 g of tert-butyl hydroperoxide<img file="EP0333547A2_D0006.tif" />

A latex of 40.4% dry extract is obtained.

EXAMPLE 8 (comparative)

In a 6 liter reactor fitted with an anchor stirrer: - 2156 g of water - 1.5 g of NANZA SB 62 based on sodium dodecylbenzenesulfonate, marketed by ALBRIGHT &amp; WILSON - 450 g of GEROL PS 20 sec.

The mixture is brought to 80 ° C. with stirring at 150 rpm. 1.875 g of ammonium persulfate dissolved in 20 g of water are added.

We continuously introduce: - firstly for 5 hours a mixture of: . 75 g acrylic acid (AA) . 75 g methacrylic acid (MAA) . 300 g of ethyl acrylate (EA) . 600 g of butyl acrylate (BuA) . 450 g methyl methacrylate (MeMA) . 5.62 g tertiododecylmercaptan - on the other hand for 5 hours a mixture of:<img file="EP0333547A2_D0007.tif" />

The two introductions start simultaneously.

At the end of the introductions, the medium is left at 80 ° C. for 1 hour and cooled.

A latex with 43% dry extract is obtained.

EXAMPLE 9 (comparative)

The operation described in Example 8 is repeated, using 150 g (instead of 450 g) of dry GEROL PS 20 and 1700 g (instead of 2156 g) of water.

Gluing test

Gluing tests were carried out using aqueous solutions of the products of Examples 1 to 9, solutions constituting the glue baths.

These solutions were prepared as follows: after dilution with demineralized water until a dry extract of 20% is obtained, these products are brought to 60 ° C. and then added in half an hour with an aqueous solution at 20% d ammonia until a pH of about 7.5 is obtained.

The gluing operation is carried out using a SUCKER laboratory machine (marketed by SUCKER) adapted to operate in a "primary ply" system, on a 100 decitex polyester warp, 88 strands, not twisted, speed of passage on the gluing machine being 100 m / min; the settings are optimized in order to deposit on the wire 10% by weight of dry polymer relative to the mass of the wire.

The principle of the operation is as follows: the polyester chain is immersed in the glue bath and then dried by passage through chambers heated to 145 ° C and then on cylinders heated to decreasing temperatures from 125 to 100 ° C; a lubricant (wax melted at 90 ° C) is applied to the wire at a rate of 0.3% relative to the mass of the wire, at the outlet of the drying cylinders. After cooling in a cooling chamber, the wires are wound on the primary beams; these are then brought together to make a beam for the loom.

The effectiveness of the tested products is evaluated before assembling the primary beams, using the "SHIRLEY FILAMENT COUNTER" device from the SHIRLEY INSTITUT of Manchester according to the method published at the 7th Symposium of Textile Bonding in Mulhouse on 15, 16 and October 17, 1986.

This test consists in measuring the ability of a polymer to stick together the individual strands forming the wire.

During the measurement the device records and counts the vibrations emitted during the sectioning of the individualized elements made up of a unitary strand or of several glued strands.

The cohesion index C is expressed by the relation C = 100 (n - x) / (n - 1) or <u style="single">not</u> represents the number of unit strands making up the wire<u style="single">x</u> the number of individual elements counted.

In the absence of glue, all the individual strands are independent; x is then equal to n and C = 0.

Cohesion is maximum when all the unit strands are linked; x is then equal to 1 and C = 100.

The cohesion index is measured before and after work on a WEBTESTER usometer from the Textile Institute of Reutligen (measurement after 50, 150 and 300 cycles).

(This device simulates the work undergone by the thread during the weaving operation).

A curve is then plotted reflecting the loss of cohesion of the bonded wire as a function of the work undergone (abrasion).

The reference of the curves corresponding to the products tested is given below. <tables id="tabl0001" num="0001"><table frame="all"><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><thead valign="top"><row><entry namest="col1" nameend="col1" align="center">Example product</entry><entry namest="col2" nameend="col2" align="center">Reference</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="right">1</entry><entry namest="col2" nameend="col2" align="left">D</entry></row><row><entry namest="col1" nameend="col1" align="right">2</entry><entry namest="col2" nameend="col2" align="left">F</entry></row><row><entry namest="col1" nameend="col1" align="right">3</entry><entry namest="col2" nameend="col2" align="left">G</entry></row><row><entry namest="col1" nameend="col1" align="right">4</entry><entry namest="col2" nameend="col2" align="left">I</entry></row><row><entry namest="col1" nameend="col1" align="right">5</entry><entry namest="col2" nameend="col2" align="left">E</entry></row><row><entry namest="col1" nameend="col1" align="right">6</entry><entry namest="col2" nameend="col2" align="left">-</entry></row><row><entry namest="col1" nameend="col1" align="right">7</entry><entry namest="col2" nameend="col2" align="left">J</entry></row><row><entry namest="col1" nameend="col1" align="right">8</entry><entry namest="col2" nameend="col2" align="left">H</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="right">9</entry><entry namest="col2" nameend="col2" align="left">K</entry></row></tbody></tgroup></table></tables>

Examples 1 to 5 are also compared: - a solution of GEROL AS 10 marketed by RHONE-POULENC ("all acrylic" copolymer based on butyl acrylate, that is to say not derived from monomers other than acrylic or methacrylic esters or acids and devoid of of sulfonated polyester patterns). - to a solution of GEROL VS 30 marketed by RHONE-POULENC (copolymer derived from vinyl acetate in high proportion, butyl acrylate and unsaturated carboxylic acid and devoid of sulfonated polyester units) - And to a solution of GEROL PS 20 marketed by RHONE-POULENC (water-dispersible sulfonated polyester);

The reference of the curves corresponding to these products is as follows: <tables id="tabl0002" num="0002"><table frame="all"><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><thead valign="top"><row><entry namest="col1" nameend="col1" align="center">Product</entry><entry namest="col2" nameend="col2" align="center">Reference</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">GEROL AS 10</entry><entry namest="col2" nameend="col2" align="left">VS</entry></row><row><entry namest="col1" nameend="col1" align="left">GEROL VS 30</entry><entry namest="col2" nameend="col2" align="left">B</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">GEROL PS 20</entry><entry namest="col2" nameend="col2" align="left">AT.</entry></row></tbody></tgroup></table></tables>

The set of curves corresponding to the products of the invention or to the comparative products are the subject of Figures 1 and 2.

Analysis of these curves shows that: - GEROL AS 10 ("all acrylic" copolymer) performs significantly better than GEROL VS 30 (copolymer based on vinyl acetate) on the other hand, surprisingly, the product of Example 1 and that of Example 9, the compositions of which are respectively as follows:<tables id="tabl0003" num="0003"><img file="EP0333547A2_D0008.tif" /></tables> show similar results, whereas we should have expected much better performance from the product of Example 9. The price of acrylic esters being approximately 3 times that of vinyl acetate, we can immediately understand the advantage of the product of Example 1 compared to that of Example 9 - Admittedly, the product of Example 8 is a little more efficient than that of Example 1, but its level of butyl acrylate and of GEROL PS 20 make its price prohibitive for the corresponding performance. The price of GEROL PS 20 is at least 10 times that of vinyl acetate; - There is interest from Example 4, to respect a certain preferential relationship between the rate of GEROL PS 20 and that of butyl acrylate.

The product of example 7 presents good results of cohesion test, but is however not usable industrially because it generates blocking ("blocking on beams" - bonding on beams) during the reunification of the primary beams or the course of the beam of the beam on the loom.

The method of Example 6 could not undergo the cohesion test because numerous breaks in the individual strands of the bonded wire due to blocking were observed during the unwinding of the coils to carry out the test.