Process for preparing aqueous polyester dispersions and their use.

It is known in the textile industry to treat textile yarns consisting of a large number of individual threads, which are used as warp yarns in the weaving process, with a sizing agent which connects the individual threads of the yarns to one another. Treatment with a sizing agent strengthens and solidifies the warp yarns and makes them more abrasion-resistant for the weaving process. Filament yarns, especially the fine treads made from individual filaments with a titer in the range from 4 to less than 1 dtex, require a very special mechanical protection for processing in the weaving mill so that they can be woven on high-performance weaving machines without destruction. This protection is achieved by sizing the warp yarns with special synthetic polymers. Smooth filament yarn in particular can now only be successfully sized with the highest tack and abrasion resistance.

Most of the sizes, which a few years ago were still state of the art, have to be classified as outdated and not sufficiently resistant to abrasion in this area where high productivity is required.

The following requirements must be met today for good filament sizing:<ul id="ul0001" list-style="none"><li>1. in the arbitration - Applicability on single thread finishing machines at speeds up to 500 m / min; this requires low-viscosity, low-foaming, shear-stable wash liquors - Easy liquor preparation, low viscosity, independent of the shear rate - good filament wetting, easy and quick penetration - good compatibility with the preparation oils of the yarns - The warp threads do not stick under the influence of moisture and / or preparation oils or post-oil products</li><li>2nd in the weaving mill: - Applicability on all weaving machines including water jet weaving machines - Climate-stable, abrasion-resistant sizing film, also stable in humid climates - high thread closure, thread adhesion - high weaving efficiency with low order quantity</li><li>3rd in pretreatment: - easy to wash out - Compatibility even with water hardness - Insensitivity to alkali - Good loss of goods, ie unaffected handle and good absorbency of the fabric after desizing - no wastewater problems, high eliminability and mineralizability.</li></ul>

The fulfillment of these requirements can be checked with objective measurement methods.

According to this, there is currently no filament sizing agent, especially not for smooth filament, that meets all requirements. Compromises often have to be made. Improvements on the one hand lead to deterioration on the other:

For example, extremely climate-insensitive sizing agents are often difficult to wash out due to their good water resistance. Since they consist of hydrophobic building blocks, they usually have a higher sensitivity to the oil components in the yarn preparation; the yarns sized with it tend more to electrostatic charging. The wash liquors are more prone to skin formation.

Sizing agents that are insensitive to preparation oil and post-oil products contain more hydrophilic or polar groups. They point in the

Usually better washability and better antielketrostatic behavior. This advantage has to be bought with the disadvantage of higher climate sensitivity. These sizing agents are often no longer suitable for water jet weaving machines.

Softening of sizing films due to temperature, moisture and / or yarn preparation oil and post-oil product can be compensated for by setting a higher film hardness in the synthesis of sizing agents. However, the hardness and adhesive strength of the sizing films are largely linked. This means that when the size of the sizing agent is approximately the same, the harder film has a lower adhesive strength than the softer one. This means that depending on the influence of moisture (climate), preparation oil, post-oil product, possibly other additives to the size liquor and temperature, the size softens more or less. The adhesive strength of the size fluctuates with different weaving climates and under the influence of the numerous, different, depending on the type of yarn, preparation oils or spinning agents.

Practice has so far shown that it is difficult - for the reasons mentioned above - to make do with a single filament size for the entire filament area, at least for one yarn class (eg only polyester).

Most size manufacturers therefore offer several sizes for filament size. There is an adaptation to the respective yarn type with the corresponding preparation pad, to the climate and weaving room conditions of the countries in which weaving is to take place and to the respective weaving machine type.

Acrylate or methacrylate copolymers and polyester condensation products are particularly suitable for sizing polyester filament. Each product class has its special advantages:

Acrylate or methacrylate copolymers are less sensitive to alkali, salt or polyelectrolyte than polyester resins. They are therefore particularly easy to wash out. Less intolerance reactions are also to be expected when preparing the liquor in the sizing shop. Acrylate or methacrylate copolymers which are suitable for sizing warp threads on water jet looms are less sensitive to moisture than polyester resins according to the prior art. Polyester resins, on the other hand, are more resistant to abrasion if they are not exposed to excessive moisture and usually result in better thread closure. This is particularly evident in the case of smooth polyester filament yarn.

In order to achieve the same weaving effect with a polyester filament (eg PES filament smooth dtex 70 f 24), for example, 3.5% by weight of a polyester size or 5.5% by weight of a poly (meth) acrylate size is required. Ie even when comparing two good products according to the state of the art, this example shows an active ingredient ratio of 1: 1.6.

The softening oil sensitivity of the polyester resins, in which aromatic dicarboxylic acids or their sodium sulfonate derivatives are used as building blocks for synthesis, is less pronounced than in the case of acrylate copolymers. In the field of smooth filament yarns, polyester sizes based on condensation products made from isophthalic acid (esters) and / or terephthalic acid (esters), diols (sometimes also polyols) and dicarboxylic acids containing sulfonate groups or diols or polyols are used in fabric production for unprotected high-performance weaving machines.

Polyester sizes are known for example from US-PS 3 546 008 and US-PS 3 548 026. The production of polyesters with free carboxyl groups by a two-stage process is described in US Pat. No. 4,268,645. In the first stage, aromatic dicarboxylic acids or their esters are condensed with at least one diol to form a prepolymer with an acid number of less than 4 and in the second stage the prepolymer thus obtained with at least one compound which increases the molecular weight, for example trimellitic anhydride, to give polyesters with an acid number of 15 to 55 implemented. The polyester is dissolved in sec-butanol and neutralized with a combination of ammonium hydroxide and sodium hydroxide solution. Further dilution with Waser results in a 30% dispersion which, according to claim 9 of US Pat. No. 4,268,645, is suitable for sizing polyester and polyester / cotton warp yarn, that is to say for staple fiber warp yarn. Dispersions containing sec-butanol are not easy to process. In addition, the polyester sizes neutralized with ammonia and sodium hydroxide are very sensitive to the climate and tend to stick together without the addition of other additives to warp yarn.

The products mentioned are not suitable for sizing filament warp yarn, when used alone they are too sensitive to the climate. The size films are too soft at 65% relative humidity and even sticky at 80% relative humidity. The filament yarn preparation and usual liquor additives and / or post-oil products create a further softening and would severely impair the abrasion resistance when sizing filament yarn.

When assembling the individual trees, increased pulling forces occur, which are accompanied by defibrillation (tearing of the filament composite). After a longer storage period, the warp beams become blocked because the warp threads stick together, so that further processing is impossible. The polyester dispersion described in more detail above is therefore also not suitable as a sizing agent for use on water jet looms.

The object of the invention is to provide a polyester dispersion which is particularly suitable as a sizing agent for filament and can be processed on all weaving machines. The sizing agent should have a high adhesive strength and should result in climate-stable, water-resistant, abrasion-resistant and non-blocking films on the sized threads.

The object is achieved according to the invention by a process for the preparation of aqueous polyester dispersions<ul id="ul0002" list-style="none"><li>a) condensing aromatic dicarboxylic acids or their esters with at least one diol to form prepolymers with an acid number of 2 to 8,</li><li>b) reaction of the prepolymers with at least one molecular weight-increasing compound from the group of tricarboxylic acids, esters of tricarboxylic acids and carboxylic anhydrides with at least one free carboxyl group to form polyesters with acid numbers from 40 to 60 and</li><li>c) dispersing the polyesters in an aqueous medium to form aqueous dispersions,</li></ul> if, to disperse the polyester, aqueous mixtures of ammonia and amines in a molar ratio of 10: 1 to 1:10 are added to a polyester melt which has a temperature in the range from 150 to 230 ° C. The partially or completely neutralized dispersions of polyesters thus obtainable are sizing agents for filament warp threads, in particular for filament warp threads made of polyesters.

The polyesters are produced by a two-stage polycondensation process which is known, for example, from US Pat. No. 4,268,645. In process step a), a prepolymer with an acid number of 2 to 8 is first prepared by condensing aromatic dicarboxylic acids or their esters with at least one diol at temperatures of 180 to 240, preferably 230 to 235 ° C. Examples of suitable aromatic carboxylic acids are terephthalic acid, isophthalic acid and tertiary butyl isophthalic acid. Instead of the dicarboxylic acids, the methyl and ethyl esters of the carboxylic acids, for example dimethyl terephthalate, can also be used. A modification of the prepolymers is also possible by sulfonated aromatic dicarboxylic acids or sulfonated aromatic dicarboxylic acid esters in a mixture with the aromatic dicarboxylic acids or Dicarboxylic acid esters used in the condensation.

The amount of sulfonated aromatic dicarboxylic acids or dicarboxylic acid esters is 0.5 to 4 mol% of the total aromatic carboxylic acids used in the condensation.

Examples of suitable diols are α, ω-alkylene glycols having 2 to 12 carbon atoms, for example ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, neopentyl glycol, 1,4-bis (hydroxymethyl) cyclohexane, polyalkylene glycols, such as diethylene glycol, Triethylene glycol and tetraethylene glycol. Diethylene glycol and mixtures of diethylene glycol and 1,4-bis (hydroxymethyl) cyclohexane in a molar ratio of 0.6 to 0.4 to 0.8 to 0.2 are preferably used.

The aromatic dicarboxylic acids and the diols are condensed at temperatures from 180 to 240 ° C., preferably from 230 to 235 ° C. in an inert gas atmosphere, for example nitrogen. When using the esters, for example methyl terephthalate, a reaction temperature of 180 to 200 ° C is sufficient. A small molar excess of diol is usually used in step a) to prepare the prepolymers. The molar ratio of diol to dicarboxylic acid or Dicarboxylic acid ester is 1.1 to 1 to 1.2 to 1 and is preferably 1.16 to 1. The water formed during the condensation is distilled off from the reaction mixture. However, care must be taken to ensure that the diols are not removed together with the water formed in the reaction. The water is therefore expediently distilled off through a well-separating column, so that components boiling higher than water are retained. The top temperature of the column is preferably kept in the range of 70 to 95 ° C. Temperatures above 100 ° C should be avoided at the top of the column. The polycondensation is carried out using the customary esterification or transesterification catalysts, for example alkali metal hydroxides or alkali metal alcoholates, organic titanium compounds, salts of organic carboxylic acids, but especially organic tin compounds such as dibutyltin oxide, butyltinic acid, tetrabutyltin and butylchlorotin dihydroxide are used for this purpose; organic titanium compounds, especially titanium alcoholates, such as titanium isopropylate. Alkaline earth oxides and alkaline earth alcoholates are also suitable as catalysts for the condensation reaction. You can also use manganese acetate or manganese formate. The amount of catalysts is 0.05 to 1% by weight, based on the total amount of the components.

The condensation in reaction stage a) is carried out to the extent that a prepolymer is obtained which has an acid number of 1.5 to 8, preferably 1.5 to 4. The acid number is determined potentiometrically and the numerical value indicates mg KOH / g condensate.

As soon as the condensation of the aromatic dicarboxylic acids or their esters with at least one diol leads to prepolymers whose acid number is 2 to 8, the temperature of the condensation product thus obtained is reduced to about 160 to 180 ° C. During the condensation and preferably also during the cooling of the prepolymer, thorough mixing of the reactants or the reaction product is ensured.

In process stage b), the prepolymers are then reacted with at least one molecular weight-increasing compound from the group of tricarboxylic acids, esters of tricarboxylic acids and carboxylic anhydrides with at least one free carboxyl group. The polyesters thus obtainable have carboxyl groups as end groups. Trimellitic anhydride is preferably used to introduce these carboxyl groups in stage b) of the condensation. The amount of compounds used according to b) for the preparation of the polyesters containing acid end groups is 10 to 20 mol%, based on the total amount of diol.

The condensation reaction in stage b) is carried out at temperatures of about 180 to 230 ° C., preferably 195 to 205 ° C. The reaction mixture is also stirred here. The condensation has ended when the reaction product formed has an acid number of 40 to 60, preferably 45 to 55.

The average molecular weight of the polyesters modified with acid groups is preferably 150,000 to 350,000 and is in particular in the range from 165,000 to 200,000 (average molecular weight, determined with the aid of light scattering in dimethylformamide as solvent).

According to the invention, the polyesters obtainable according to b) for the production of aqueous polyester dispersions according to process step c) are dispersed by adding aqueous mixtures of ammonia to the still hot melt, which has a temperature in the range from 150 to 210.degree and amines in a molar ratio of 10: 1 to 1:10. Dispersion in process step c) is also carried out by mixing the reactants. The use of a dispersant is not necessary. Water is added in such an amount that 10 to 40% by weight polyester dispersions are formed. The amounts of ammonia and amine are chosen so that partial to complete neutralization of the polyester obtained in b) is achieved. Partial neutralization means, for example, a degree of neutralization of at least 70% of the carboxyl groups in the polyester. An excess of ammonia / amine is possible, but has no advantages in the practical use of the aqueous polyester dispersions obtainable in this way as sizing agents.

The aqueous mixture of ammonia and amines is added to the polyester melt at temperatures of the melt in the range from 150 to 210 ° C., preferably at temperatures from 150 to 200 ° C. However, the temperature should not fall below 150 ° C, because otherwise there is a risk that no finely dispersed distribution of the polyester in water will be obtained. The aqueous polyester dispersion can also be prepared from the melt by first slowly adding up to about half of the required amount of water, then adding the mixture of ammonia and amine and finally adding the remaining amount of water. When water or the aqueous mixture of ammonia and amine is added to the melt, the temperature of the melt drops. The water added to the melt at a temperature of 150 to 200 ° C can optionally be heated to temperatures which are close to the boiling point of the water. Usually, water with a temperature of 10 to 95 ° C. is added to the melt. The aqueous mixture of ammonia and amines added to the hot melt can have temperatures in the range of 10 to 40 ° C. The temperature of the components which are added to the melt is usually from 10 to 25 ° C. After the entry of the ammonia / amine / water mixture has ended, the temperature of the mixture is 70 to 100.degree. The polyester dispersion thus obtained is stirred for a further 2 to 12, preferably 4 to 6, hours at a temperature of 95 to 35 ° C. and then cooled to ambient temperature.

Ammonia is usually used in the form of the concentrated aqueous solution. Although all amines can be used, some are preferred because of their easy handling. These amines include, for example, diethylethanolamine, triethanolamine, methyldiethanolamine, dimethylethanolamine, dibutylethanolamine, butyldiethanolamine, diisopropanolamine and triisopropanolamine. Of the amines mentioned, triethanolamine is preferably used.

The molar ratio of ammonia to amine is 10: 1 to 1:10 and is preferably in the range from 1: 1 to 6.5: 3.5. Aqueous mixtures of ammonia and triethanolamine in a molar ratio of 3: 1 to 1: 2 are particularly preferred.

In stage c), aqueous polyester dispersions with a solids content of 10 to 40% by weight and a size of the dispersed polyester particles of ≦ 1 μm are obtained. The dispersion should be able to be filtered through a cotton filter batiste with almost no residue. The polyester dispersions obtainable in this way are used as sizing agents for sizing filament warp threads, in particular for sizing filament warp threads made of polyester. A weaving of filament yarn, which consists of numerous endless individual filaments, into textile goods is only possible if the warp yarn is treated with a sizing agent before the weaving, which has the task of holding the individual filaments together under the high mechanical stresses of weaving and thus thread breaks and Avoid formation of nodules through filament deferments and thread abrasion.

A measure of the quality of a size with regard to the protection and stabilization of the thread is the thread closure. It can be determined using the Shirley filament counter. The filament thread is cut before and after finishing. The number of free, unglued individual filaments can be calculated from the pulses counted during cutting. The raw yarn value is set to 100, ie 100% of the individual filaments are unglued. After finishing, there is a significantly lower proportion of non-glued filaments. With a good size, this proportion should be between 10 and 25%, depending on the type of yarn.

In the literature, these numbers are found as manra values. Manra value 12 means, for example, that only 12% of the original individual filaments determined with the Shirley filament counter are not glued together at the interface. Until a few years ago, these manra values ​​were still sufficient when comparing the quality of different sizes. In the meantime, the mechanical stresses during weaving have increased enormously due to the modern high-performance weaving machines. The quality of the sizing products has increased to such an extent that it is hardly possible to distinguish between them using the simple manra values. That is why today the sized yarns are mechanically stressed before measurement with the Reutlingen weaving tester. The Reutlingen web tester simulates the weaving process.

The combination of a web tester with a Shirley filament counter gives test results that allow practical predictions about the weaving behavior of a sized warp yarn.

The lower the manra values ​​in the test methods mentioned, with the smallest possible sizing agent application, the better the thread closure and thread adhesion and thus the achievable weaving effect.

In the following text, the designation MO means that this mana value was measured on the weaving tester before the filament warp yarn was loaded. M 200 indicates that the yarn was subjected to 200 stress cycles before the measurement with the filament counter on the weaving tester.

Under these circumstances, a usable sizing agent yields at least a mana value of 50. The smaller the difference between MO and M 200, the better the adhesive strength and the thread closure due to the sizing agent.

A good sizing agent, however, not only has to ensure good thread closure and mechanical stabilization of the warp yarn, but also has numerous other special properties so that its use does not lead to malfunctions.

The size must not result in sticky abrasion on metallic thread guide elements; the size of the thread should have as little metal friction as possible and should not stick to other size threads or parts of the apparatus. You must be sufficiently soluble or dispersible in water and the ready-to-use, aqueous solutions or dispersions must not tend to skin formation, since the skins lead to stubborn dirt and sticking of the threads and thus ultimately to malfunctions. It is particularly important that the size can be completely removed from the textile material by washing after the weaving process. This requirement is a prerequisite for trouble-free further processing, for example for dyeing.

Preliminary tests can be carried out quickly to check whether a sizing agent is mechanically adversely affected by climatic influences and tends to form abrasion:<ul id="ul0003" list-style="none"><li>1. Assessment of the size films after water storage at different temperatures or in climatic chambers at 65 and 80% relative humidity and</li><li>2nd Numerical recording of the mechanical level by determining the pendulum hardness after storing the films for 24 hours at 65 and 80% relative humidity.</li></ul>

As a guideline, in accordance with practical results, the pendulum hardness should not be less than 20 at 65% relative humidity and not less than 10 at 80% relative humidity. Otherwise, the size is not suitable for water-jet, the layers of yarn stick to the warp beams (block) with increasing storage and there is abrasion and mechanical malfunctions during weaving.

Water jet looms suitable sizing should be completely washable by a short-term process under the conditions, 80 ° C, 2 g / l soda, 1 g / l of a good wetting agent with good washing mechanics. When using 2 g / l soda, you can also work with wash water of slightly higher natural hardness when testing the washability of the sizing agent.

The polyester dispersions which are used as sizing agents according to the present invention meet the above-mentioned requirements.

(Literature: Melliand textile reports <u style="single">67</u>, 270 (1987), MS Kellon, C. Pividori, M. Alphonsus, "Desizing the most important size families on polyester filament yarns, especially the water-dispersible polyester sizes").

Example 1:

In a dry 1 liter four-necked flask with stirrer, thermometer. 68.9 g (0.65 mol) of diethylene glycol and 50.5 g (0.35 mol) of cyclohexanedimethanol (= 1,4-bis (hydroxymethyl) cyclohexane) are placed in a gas inlet tube and a Vigreux column with a reflux condenser under a nitrogen atmosphere and set to 80 ° C warmed. At this temperature, 121.2 g (0.73 mol) of isophthalic acid and 21.6 g (0.13 mol) of terephthalic acid are added and the mixture is heated to 135.degree. For this purpose, 0.1% (0.3 g) butyltinic acid is added as a catalyst. It is now slowly heated to 230 ° C. The reaction temperature remains at 230-235 ° C until the resulting polyester has an acid number of 1.5-3 mg KOH / g. After the aforementioned acid number has been reached, the mixture is allowed to cool to 200 ° C. and 28.8 g (0.15 mol) of trimellitic anhydride are added. The reaction mixture is then stirred at 200 ° to 205 ° C. until it has an acid number of 50 mg KOH / g. The mixture of 600 g of water, 10.4 g (0.11 mol) of triethanolamine and 9.1 g (0.134 mol) of ammonia (25% strength) is then stirred very slowly into the hot melt. The temperature drops and is kept at 90 ° C. The mixture is stirred for four hours at 90 ° C., then the approximately 30% polyester dispersion is cooled to room temperature. The average size of the dispersed particles of the dispersion was &lt;1 μm. The degree of neutralization of the dispersed polyester was 100%.

Example 2:

The procedure according to Example 1 was followed with the exceptions that terephthalic acid was replaced by dimethyl terephthalate and the condensation temperature was reduced from 230 ° to 235 ° C. to 200 ° to 205 ° C. With a degree of neutralization of 100%, a polyester dispersion with very similar properties as in Example 1 was obtained. The average particle size of the dispersed particles was &lt;1 μm.

Example 3:

The procedure was as in Example 1, but the polyester dispersion was prepared by first stirring in half the water at 200 ° C., then at 100 ° C., the ammonia / amine mixture and then the remaining water. The average particle size of the dispersed polyester was &lt;1 μm, the degree of neutralization 100%.

Example 4:

Table 1 shows the properties of sized warp threads that were sized with polyester dispersions, for the preparation of which the condensation product described in Example 1 was treated at 200 ° C. with the ammonia / amine mixtures listed in Table 1. The degree of neutralization was 100%.<tables id="tabl0001" num="0001"><table frame="all"><title>Table 1</title><tgroup cols="6" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="26.25mm" /><colspec colnum="2" colname="col2" colwidth="26.25mm" /><colspec colnum="3" colname="col3" colwidth="26.25mm" /><colspec colnum="4" colname="col4" colwidth="26.25mm" /><colspec colnum="5" colname="col5" colwidth="26.25mm" /><colspec colnum="6" colname="col6" colwidth="26.25mm" /><thead valign="top"><row><entry namest="col1" nameend="col1" /><entry namest="col2" nameend="col2" align="center">Ammonia / amine ^a)</entry><entry namest="col3" nameend="col4" align="center">Pendulum hardness ^b)</entry><entry namest="col5" nameend="col6" align="center">Manra values ^c)</entry></row><row><entry namest="col1" nameend="col1" /><entry namest="col2" nameend="col2" /><entry namest="col3" nameend="col3" align="center">65</entry><entry namest="col4" nameend="col4" align="center">80</entry><entry namest="col5" nameend="col5" align="center">MO</entry><entry namest="col6" nameend="col6" align="center">M 200</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" /><entry namest="col2" nameend="col2" /><entry namest="col3" nameend="col4" align="center">% rel. humidity</entry><entry namest="col5" nameend="col5" /><entry namest="col6" nameend="col6" /></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">Polyester dispersion A</entry><entry namest="col2" nameend="col2" align="left">Ammonia / triethanolamine</entry><entry namest="col3" nameend="col3" align="right">41</entry><entry namest="col4" nameend="col4" align="right">20</entry><entry namest="col5" nameend="col5" align="right">13</entry><entry namest="col6" nameend="col6" align="right">18</entry></row><row><entry namest="col1" nameend="col1" align="left">B</entry><entry namest="col2" nameend="col2" align="left">Ammonia / tetramethylethylenediamine</entry><entry namest="col3" nameend="col3" align="right">42</entry><entry namest="col4" nameend="col4" align="right">21</entry><entry namest="col5" nameend="col5" align="right">13</entry><entry namest="col6" nameend="col6" align="right">44</entry></row><row><entry namest="col1" nameend="col1" align="left">C.</entry><entry namest="col2" nameend="col2" align="left">Ammonia / methyldiethanolamine</entry><entry namest="col3" nameend="col3" align="right">26</entry><entry namest="col4" nameend="col4" align="right">17</entry><entry namest="col5" nameend="col5" align="right">14</entry><entry namest="col6" nameend="col6" align="right">24</entry></row><row><entry namest="col1" nameend="col1" align="left">D</entry><entry namest="col2" nameend="col2" align="left">Ammonia / butyldiethanolamine</entry><entry namest="col3" nameend="col3" align="right">20</entry><entry namest="col4" nameend="col4" align="right">12</entry><entry namest="col5" nameend="col5" align="right">15</entry><entry namest="col6" nameend="col6" align="right">32</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">E</entry><entry namest="col2" nameend="col2" align="left">Ammonia / diethylethanolamine</entry><entry namest="col3" nameend="col3" align="right">28</entry><entry namest="col4" nameend="col4" align="right">19</entry><entry namest="col5" nameend="col5" align="right">21</entry><entry namest="col6" nameend="col6" align="right">35</entry></row></tbody></tgroup><tgroup cols="6" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="26.25mm" /><colspec colnum="2" colname="col2" colwidth="26.25mm" /><colspec colnum="3" colname="col3" colwidth="26.25mm" /><colspec colnum="4" colname="col4" colwidth="26.25mm" /><colspec colnum="5" colname="col5" colwidth="26.25mm" /><colspec colnum="6" colname="col6" colwidth="26.25mm" /><tbody valign="top"><row><entry namest="col1" nameend="col6" align="justify">a) Molar ratio ammonia / amine 1: 1</entry></row><row><entry namest="col1" nameend="col6" align="justify">b) Determination of the pendulum hardness according to König</entry></row><row><entry namest="col1" nameend="col6" align="justify">c) Manra values ​​for 6% application on smooth polyester dtex 50f18, calculated by linear regression from at least three different application quantities, between 3 and 8% by weight.</entry></row></tbody></tgroup></table></tables><tables id="tabl0002" num="0002"><img file="EP0332980A2_D0001.tif" /></tables>

Table 2 shows the direct influence of the ammonia / amine mixing ratio with regard to pendulum hardness and mana values.

The tables clearly show that the polyester dispersion can be specifically adjusted to certain desired application properties by appropriate mixing of ammonia / amine.

Example 5:

The procedure of Example 1 was repeated, with the exception that isophthalic acid was replaced by 3 mol% of sulfoisophthalic acid. The solubilizing principle of the polyester dispersions obtained is now based on a mixture of the sulfo group and the carboxyl group in the polyester. The polyester dispersions obtained in this way also have good properties and are suitable for water jet applications.

The close connection between the selection of the building blocks for the polyester condensation polymer, degree of condensation and condensation process, procedure in the preparation of the dispersion, choice of the neutralization component only becomes clear in practice through the application test or when sizing polyester filament yarn, in particular smooth yarn.

US Pat. No. 4,268,645 describes the production of polyester sizes from the same building blocks, but none of the examples mentioned gives a polyester size for filament that is useful in terms of application technology. In addition, there is no desired climate stability.

Comparative Example 1:

According to US Pat. No. 4,268,645, Example 1, a polyester is prepared from isophthalic acid, diethylene glycol (6 + 7 mol) and 1.05 mol trimellitic anhydride with an acid number of 42-45 and with sec-butanol, NH ,OH / NaOH and water transferred a dispersion with a solids content of 29%. The degree of neutralization was 100%.

Comparative Example 2:

According to US Pat. No. 3,546,008, a polyester with an acid number of 43.5 is produced by condensing isophthalic acid, terephthalic acid and diethylene glycol in a molar ratio of 1.02: 0.18: 1.40 and 0.21 mol of trimellitic anhydride. The product was ground and dispersed with triethylamine and water (solids content of the dispersion was 32.5%; the degree of neutralization was 100%).

Comparative Example 3

Isophthalic acid, terephthalic acid, diethylene glycol, 1,4-cyclohexanedimethanol are condensed in a molar ratio of 1.02: 0.18: 0.91: 0.49 with 0.21 mol of trimellitic anhydride to form a polyester with an acid number of 45.9.

The product was ground and brought into a 30% dispersion (degree of neutralization 100%) with triethylamine and water. <tables id="tabl0003" num="0003"><table frame="all"><title>Table 3</title><tgroup cols="3" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="52.50mm" /><colspec colnum="2" colname="col2" colwidth="52.50mm" /><colspec colnum="3" colname="col3" colwidth="52.50mm" /><thead valign="top"><row rowsep="1"><entry namest="col1" nameend="col1" align="left">Polyester dispersion according to the comparative example</entry><entry namest="col2" nameend="col2" align="center">Pendulum hardness at 65/80% rel. humidity</entry><entry namest="col3" nameend="col3" align="center">Film evaluation after water storage at 22 ° C</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="right">1</entry><entry namest="col2" nameend="col2" align="right">11/3</entry><entry namest="col3" nameend="col3" align="left">sticky, smears off</entry></row><row><entry namest="col1" nameend="col1" align="right">2</entry><entry namest="col2" nameend="col2" align="right">2/2</entry><entry namest="col3" nameend="col3" align="left">tarnishes white, extremely stretchy</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="right">3</entry><entry namest="col2" nameend="col2" align="right">13/4</entry><entry namest="col3" nameend="col3" align="left">tarnishes white, sticky after 60 min severe mechanical impairment strength</entry></row></tbody></tgroup></table></tables>

All three size films also have low thermal stability: hot melt adhesive effect, the films begin to flow at temperatures below 80 ° C. This would inevitably cause problems on the drying cylinders of the sizing machine.

A hardness test, namely the water storage of the films at 50 ° C. also shows the water insensitivity of the products according to the invention in comparison to products according to the prior art (see Table 4).<tables id="tabl0004" num="0004"><img file="EP0332980A2_D0002.tif" /></tables>

Only the product obtained according to Comparative Example 1 is suitable as a water loom, at least under climatic conditions in Northern Europe. The products according to Comparative Examples 2 and 3 are too sensitive to water or the climate. The size according to example 1 is superior to all other products.