DE2420359A1 - Dyeable polyester fibres - contg. sulphonic acid or sulphonate groups - Google Patents

Abstract

High molecular, linear polyesters contg. sulphonic acid or sulphonates gps., contain the repeating unit: (where Ar is a divalent aromatic gp. and X is (a) 99-70mol. % of a straight or branched chain alkylene gp. with 2-20C, a cycloalkylene gp. or a gp. -where R is a straight or branched chain alkylene gp. with 1-10C, and (b) 1-30-mol. % of sulphonic acid or sulphonate-contg. gp. -where R1 is H or a 1-3C alkyl; m and n are 0-10; M is H, an alkali metal or an alkaline earth metal equivalent). The polyester has a relative viscosity (i.e., 1 g. polymer in 100 ml. cresol at 25 degrees C) of 1.2-3.0. Used as fibres, the polyesters show better physical characteristics than other sulphonic acid or sulphonate contg. polyesters and are easily dyed with basic dyes.

Description

Acid Modified Polyesters The invention relates to sulfonate groups modified polyesters that can be dyed with basic dyes, produced by melt condensation from aromatic dicarboxylic acids or their derivatives, a glycol and a one Sulfonic acid or a sulfonate group-containing diol can be obtained.

It is known that by cocondensation of sodium 3,5-di- (carbomethoxy) -benzenesulfonate, Polyethylene terephthalate containing dimethyl terephthalate and ethylene glycol sulfonate groups (see for example FR-PS 1 154 336 of June 29, 1956). A disadvantage of the comonomer used is its technically difficult accessibility (the Sulfonation of isophthalic acid is carried out with the help of fuming sulfuric acid above 2000C).

Furthermore, polyesters are known in which aliphatic diols or Dicarboxylic acids with sulfonate groups are condensed in (BE-PS 562 460, NE patent application 66.14907).

However, these comonomers are compounds that were obtained by reaction with the highly toxic propane sultone. Because of the danger the split back these are the highly toxic starting components Compounds unsuitable for use in textiles.

Modified polyesters into which diols of structure I or II have been condensed are also known (Japanese patent announcements 20315/68 and 26000/68).

m = 0 or 1, R = alkylene group with 2 - 20 carbon atoms or the group CH2 CH2- (0-CH2-CH2) n- with n = 1 - 3 M = alkali metal.

However, compounds of structure I and II contain the sulfonate group in a very voluminous side group. By including such connections in the polyester, the tendency to crystallize is greatly reduced, which has disadvantages in the physical properties of the products, e.g. lower strength of threads made from it.

It has now been found that the disadvantages cited can be avoided if diols of the formula containing sulfonic acid or sulfonate groups are used in the preparation of polyesters which contain sulfonate groups and can be easily colored with basic dyes in which m and n independently of one another can be integers from 0 - Io, R a hydrogen atom or a lower alkyl group with 1-3 carbon atoms and M hydrogen, an alkali metal or an alkaline earth metal equivalent, or a polyester-forming derivative of such a diol in small amounts with condensed.

The invention accordingly relates to high molecular weight, linear polyesters containing sulfonic acid or sulfonate groups, consisting of recurring structural elements of the general formula wherein Ar is a divalent aromatic radical, preferably the p-phenylene radical, and X is 99-70 mol% a straight-chain or branched alkylene radical having 2-20 carbon atoms, a cycloalkylene radical or the rest in which R denotes a straight-chain or branched alkylene radical having 1 to 10 carbon atoms, and 1 to 30 mol% is a radical of the formula containing sulfonic acid or sulfonate groups in which R, m, n and M are as defined above, the polyesters being relative solution viscosities rel (measured on a solution of 1 g of substance in 100 ml of cresol at 25 ° C) in the range of 1.2-3.0.

The production of such polyesters modified by sulfonate groups can be carried out according to the usual polycondensation processes. For example be the aromatic dimethyl dicarboxylate, the diol and the sulfonic acid or sulfonate groups containing diol at temperatures between 100 and 180 ° C in the presence of transesterification catalysts interesterified and then subsequently at temperatures between 180 and 3000C in the presence of condensation catalysts under an inert gas atmosphere at reduced pressure polycondensed. However, the polyesters according to the invention can also be produced be carried out in such a way that first the dimethyl dicarboxylate and the sulfonate group-free Transesterified diol, then the sulfonic acid or sulfonate-containing diol in the desired amount is added and then the polycondensation is carried out as indicated. Preferred dicarboxylic acids or dicarboxylic acid derivatives are terephthalic acid or Dimethyl terephthalate is used, but other aromatic dicarboxylic acids can also be used or dicarboxylic acid ester, for example dimethyl naphthalene-2,6-dicarboxylate or 1,2-bis (p-methoxycarbonylphenyl) ethane, alone or in combination with dimethyl terephthalate be used.

Preferred sulfonate-free diols are ethylene glycol or 1,4-DihydroxymethylcycGohexane used.

The following compounds are preferred as diols containing sulfonic acid or sulfonate groups: m = 0-2; n = 0-2; m + n = 1 - 4 m = 0-2; n = 0-2; m + n = 1 - 4 As transesterification or condensation catalysts, alkali or alkaline earth metals, zinc, cadmium, manganese, iron, nickel, cobalt, tin, lead, bismuth or combinations of such metals, salts of these metals such as acetates or succinates, alcoholates these metals or oxides of lead, antimony, germanium, silicon or combinations of the listed compounds can be used. The amount of catalyst used is 0.02-156, preferably 0.02-0.556, based on the monomers.

The polycondensation is preferably carried out in the following way: A mixture of dimethyl terephthalate, an excess of ethylene glycol and the desired amount of sulfonate group-containing diol are in the presence of a transesterification catalyst (e.g. Zn acetate) under inert gas (e.g. N2) for 1 - 4 hours at 130 - 2 ob ( interesterified.

After adding a polycondensation catalyst, the temperature is increased to 225 - 28o0C heated. As the temperature rises, the pressure is gradually reduced to less than 1 Torr.

The condensation time is 1 - 18 hours, depending on the viscosity the melt should reach. The modified polyethylene terephthalates obtained in this way can be transformed from the melt into shaped structures, for example threads, fibers and process foils.

The polyester melts can contain additives such as pigments, matting agents, Contain discoloration stabilizers, optical brighteners or antioxidants.

The new products are characterized by good colorability with basic Dyes, good mechanical and thermal properties and good processability the end.

The sulfonate group-containing diols used according to the invention can be prepared from butene-2-diol-1,4 or the corresponding alkoxylation products can be produced by the addition of sodium bisulfite. For the alkoxylation of butene-2-diol-1,4 ethylene oxide, propylene oxide or mixtures of these two epoxides are preferably used. The free sulfonic acids can be obtained from these sulfonates with acidic ion exchangers getting produced.

In the following examples, the preparation of the invention Polyester described in more detail.

Example 1 a) Preparation of the sodium salt of butanediol-1,4-sulfonic acid-2: .880 g (10 mol) of 2-butenediol-1,4 were dissolved in 2 l of water.

Then in the presence of finely divided air in the reaction medium 3120 g (120 mol) of a 40% strength aqueous bisulfite solution were added dropwise. was doing it the pH was kept at 7.1 by adding dropwise dilute sulfuric acid. When the bisulfite addition was complete, the mixture was continued for 1 hour at pH 2 and one temperature between 80 and 100OC, then cooled and neutralized. After narrowing the aqueous solution to dryness became the desired compound with the above methanol extracted.

Yield: 123o g (64 3/0 of theory). Mp .: 178-181 ° C.

b) Polyester production: 194 g of dimethyl terephthalate, 248 g of ethylene glycol and 9.6 g of the sulfonate prepared according to 1 a) are under 3 hours at 150 ° C Nitrogen transesterified in the presence of 1.2 g of Zn acetate. After adding 200 mg of Sb203 the temperature is slowly increased to 270 ° C and the pressure is gradually reduced, so that on reaching 270 ° C a pressure of 0.2 Torr is reached. At 270 ° C is condensed for one hour. The almost colorless polyester obtained can be Spin threads. The relative solution viscosity T rel measured at 25 C on a 1% own solution in cresol, is 1.57.

c) Staining test: 3 g fibers obtained from an analog 1 b) Polyesters are made in a dye liquor that is made from loo ml of water, 2.5 ml of a carrier based on methyl o-cresotinate and 100 ml O, liquid dye solution of a red basic azo dye consists of one hour heated to 1000C. The dye solution is almost completely discolored after this time. The fibers are colored deep red.

When boiling with water, the coloring is only very slightly extracted from the fibers.

Polyester fibers that do not contain sulfonate groups are under the same staining conditions only weakly stained. The dye is in this Case strongly extracted when boiled with water.

Similar results are obtained when using a blue basic Azo dye is stained under the same conditions.

Example 2 a) Propoxylated 1,4-dihydroxy-butene-2 of the formula 445 g (5 mol) of 1,4-dihydroxy-butene-2 were reacted in an autoclave after the addition of 4.5 g of sodium as a catalyst at 90-70 ° C. with 1160 g (20 mol) of propylene oxide. It is advisable to design the metered addition of propylene oxide in such a way that an internal pressure of at most 3 atmospheres is maintained during the reaction time. After the end of the propylene oxide addition, stirring was continued until the excess pressure had dropped.

The OH number determination showed CH-56 in, 97, which is a molecular weight of 310 and a total propylene oxide content of 2 n = 3.8.

b) Propoxylated butanediol sulfonate of the formula 620 g (2 mol) of propoxylated 1,4-dihydroxybutene-2 (prepared according to Example 2a) were dissolved in 1.5 l of water.

Then was in the presence of finely divided air in the reaction medium 520 g (2 mol) of 40% bisulfite solution were added dropwise. The pH was thereby adjusted by dropping constantly kept at 7-7.1 by dilute sulfuric acid. After narrowing the aqueous solution to dryness became the desired compound with methylene chloride extracted.

Yield: 662 g (80.1 56 of theory).

c) Polyester production: 194 g of dimethyl terephthalate, 248 g of ethylene glycol and 16.3 g of the diol with sulfonate groups prepared according to 2 b) were as in 1 b) described converted to polyester.

The pale yellow polyester obtained had a relative Solution viscosity Srel (measured as described in 1 b)) of 1.48.

d) Staining experiments: As described in 1 c), threads were made from a polyester obtained after 2 c) with a red and a blue basic azo dye stained. The dye solutions are completely decolorized. The threads are in stained deep colors. After washing with cold water can be used when cooking Water from the threads no dye can be extracted.

Claims (3)

Claims 1. High molecular weight, linear polyesters containing sulfonic acid or sulfonate groups, consisting of recurring structural elements of the general formula wherein Ar is a divalent aromatic radical, and X to 99-70 mol-56 is a straight-chain or branched alkylene radical having 2 to 20 carbon atoms, a cycloalkylene radical or the radical in which R denotes a straight-chain or branched alkylene radical having 1 to 10 carbon atoms, and for 1 to 30 mol-56 a radical of the formula containing sulfonic acid or sulfonate groups where R is a hydrogen atom or an alkyl group with 1-3 carbon atoms, m and n independently of one another can be integers from 0-10 and M a hydrogen atom, an alkali metal or an alkaline earth metal equivalent, the polyesters being relative solution viscosities Vrel (measured on a solution of 1 g of substance in 100 ml of cresol at 25 ° C) in the range of 1.2-3.0. 2. High molecular weight, linear polyester according to claim 1, characterized in that 1 to 30 mol% of X is a radical of the general formula represents in which R is a hydrogen atom or an alkyl group with 1-3 carbon atoms, and m and n independently represent integers from 0-4, the sum of m and n should be 0-8. 3. Process for the preparation of high molecular weight, linear polyesters containing sulfonic acid or sulfonate groups by reacting dicarboxylic acid derivatives of the general formula wherein Ar is a bivalent aromatic radical and R "is a hydrogen atom or a straight-chain or branched alkyl radical having 1-10 C atoms, with a diol derivative of the general formula R"'- OXOR "' wherein R"'is a hydrogen atom or an acyl radical and X is a straight-chain or branched alkylene radical with 2 - 20 carbon atoms, a cycloalkylene radical or the radical where R is a straight-chain or branched alkylene radical with 1 - Io C atoms, under polyester-forming conditions with exclusion of moisture and oxygen at pressures between normal pressure and o, ol Torr in the presence of known catalysts, characterized in that a further diol derivative general formula where RV is a hydrogen atom or an alkyl radical having 1-3 carbon atoms, M is a hydrogen atom, an alkali metal or an alkaline earth metal equivalent, m and n are independently integers of O-10 and R "'are a hydrogen atom or an acyl radical, in such an amount it is also used that the condensed amount of the diol containing sulfonic acid or sulfonate groups, based on the amount of condensed glycols, is 1-30 mol.