DE1495625B - Use of linear aromatic poly ester for the production of high-shrinkage, easily dyeable fibers - Google Patents

Description

J 495 625

1 2

Linear polyesters from aromatic dicarboxylic acids can be found in the presence of them at the same time

and bifunctional unbranched hydroxyl compounds to be used unbranched bifunctional hy-

for the production of threads, fibers, hydroxyl compounds, spinnable polyester, aromatic

or films are widely used. The standard table dicarboxylic acids with interesting properties

type of these compounds is polyalkylene terephthalate. 5 can be obtained.

However, since not all of the properties of the monomers are derived from it, there are several

satisfy the products provided in the same way and open avenues that are partly of technical interest

in addition, many special claims for certain purposes. So you can 2,2-dimethyl-1,3-propane

Properties are desired, one has already number diol easily by condensation of isobutyraldehyde

Extensive possibilities examined, instead of poly- io with formaldehyde in alkaline aqueous solution

Ethylene terephthalate other linear aromatic poly- win, at the same time reducing the

to use ester. ' In addition to several aldehyde groups, this also occurred. Isobutyraldehyde for its part

aromatic dicarboxylic acids also already different is in good yields after the oxo synthesis

bifunctional unbranched hydroxyl compounds propylene and water gas accessible. Others in the

suggested. Among the latter are z. B. Homologous 15 2,2-substituted derivatives of propanediol

of ethylene glycol, such as trimethylene glycol, or obtained from fibers of mesoxalic acid

1,4-butanediol, 1,4-dimethylolcyclohexane, diphenols, condensation with e.g. B. Benzene in the presence of

like hydroquinone, or glycols with in the chain aluminum chloride and subsequent reduction of the

built-in heteroatoms, e.g. B. / Jj / J'-dihydroxy di-ester groups with lithium aluminum hydride, while

to name ethyl ether. When choosing such a 20 bifunctional hydroxyl compounds with hetero-

one always has connections from the thought of atoms, z. B. oxygen, in the chain by reaction

let lead that only unbranched glycols or the corresponding glycols with ethylene oxide represent-

Phenols are suitable because it was believed that they are bar.

Substituents which lead to branched products, In addition to these compounds, according to the invention generally valuable properties of the unbranched hydroxyl compounds to be used from the 25 Products obtained from polyesters disadvantageously correspond to the known representatives of this class of substance, to change. which are already known for the construction of linear polyesters. It is therefore surprising that under certain are, for. B. ethylene glycol, 1,3-propanediol, 1,4-butane requirements also from aromatic polyesters diol, / 3, / 9'-dihydroxydiethyl ether, 1,4-dimethylolcyclomite branched bifunctional hydroxyl compounds 30 hexane, p-xylylene glycol or hydroquinone. As usable Fibers with interesting, partly newly suitable aromatic dicarboxylic acids are included like effects can be obtained. It was found among other things: terephthalic acid, isophthalic, that this is possible when one goes to the acidic, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenylme production the polyester based on aromatic thandicarboxylic acid, 4,4'-stilbene dicarboxylic acid, p, p'-Sul-dicarboxylic acids besides bifunctional unbranched fonyldicarboxylic acid. Be in place of acids Hydroxyl compounds proportionally bifunctional usually their functional derivatives, such as esters, branched hydroxyl compounds are used, which are especially dimethyl esters, as well as acid halides for by the general formula used to manufacture the polyester. It is also

possible to use several aromatic dicarbon

Use R 40 acids or their derivatives. The preferred one

I dicarboxylic acid component for the production of the

HO ^ A — C — A — OH linear, thread-forming polyester according to the invention Process is terephthalic acid.

R The polycondensation is carried out in a manner known per se

45 way through by the aromatic dicarboxylic acids

be expressed. R denotes methyl or their functional derivatives with the bifunctional

Methoxyl, ethyl or phenyl radicals and A the hydroxyl compounds at elevated temperature for

Methylene group or another unbranched, two-reaction are brought. It is useful to

Valuable group of no more than 5 chain links, from the branched bifunctional to be used

the, in addition to carbon atoms, also oxygen or hydroxyl compounds of the formula indicated

May contain sulfur atoms; the amount of initially a precondensate with an aromatic

The branched diol component is generally dicarboxylic acid (terephthalic acid) or one of its

1 to 20 percent by weight, based on the polyester. to produce functional derivatives, for example

These linear aromatic polyesters are made by transesterification of the corresponding dimethyl ester

according to the invention for producing high-shrinkage 55 with this hydroxyl compound. The received re-

fenden, easily dyeable fibers are used. Action product is then proportionate to a mixture

As examples of such bifunctional branched diesters of the same and / or the diesters of a

Compounds may be mentioned: 2,2-dimethyl-1,3-pro- or several other aromatic dicarboxylic acids

pandiol, 2,2-diethyl-1,3-propanediol, 2,2-diphenyl and an unbranched bifunctional hydroxyl

1,3-propanediol, 2,2-dimethoxy-1,3-propanediol, 3,3-di-60 compound added, the latter in excess

methyl-l, 5-dihydroxypentane, 2,2-dimethyl-l, 3-bis- is present and expediently a lower Sicdc-

(/? - hydroxyethoxy) -propane, bis (hydroxymethylsup! fo- point possesses as the branched bifunctional ITy-

nyl) dimethyl methane, bis (4,4'-hydroxyphenyl) dimethyl compound. Then as usual

methyl methane. interesterified and polycondensed. The transesterifications

While it is known to use such compounds for 65 are usually carried out at a temperature of 160 to 19O ⁰ C.

Plasticizers and varnish raw materials as well as for distilling off the corresponding lower

position of alkyd resins, polyurethanes or poly-alcohols. like methanol, and with the exclusion of air,

to use carbonates. However, this did not result in additions of small amounts

Substances that have a beneficial effect on catalysts, such as the acetates of zinc, manganese, calcium or cadmium. To the The reaction mass is then polycondensed to higher temperatures, preferably with stirring heated to 250 to 290 ° C, the pressure is reduced and the excess portions of the not substituted unbranched hydroxyl compound distilled off. In this reaction stage, under slowly increasing melt viscosity, the macromolecules of the copolyester are formed. Suitable catalysts are heavy metal oxides, such as those of antimony, lead or bismuth.

The properties of the linear polyester produced in this way are determined, among other things, by the chemical nature and the proportions of the monomers. The symmetrical construction of the invention Polyester with substituted branched hydroxyl compounds affects the macromolecular Structure favorable, so that important properties of polyethylene terephthalate, such as high melting point, good spinnability and stretchability, are retained, while some shortcomings are obtained from those made of polyethylene terephthalate manufactured products such as hand and dyeability can be improved. In addition, can However, the polyesters according to the invention also give rise to novel effects, for example polyester threads or produce fibers with a high shrinkage capacity and self-crimping, as they are used for production of crepe and fleece items are desirable.

The amounts of the substituted branched hydroxyl compounds incorporated are dependent on them Composition, the chemical nature of the other monomers and the desired effect. In general, relatively small amounts are sufficient, corresponding to a content of 1 to 20%> preferably 1 to 12%, based on the spinnable polyester.

The polyesters used according to the invention are colorless, clear masses with a high average Degree of polymerization, which have a very good thread-forming capacity. The melting points are generally between 200 and 250 ° C. Leave the threads made from the polyesters - preferably at 60 to 80 ° C - easily stretch to several times their length and then have high strength with medium elongation. They are dyeable for disperse dyes compared to threads made from the previously known polyesters, so that swelling agents or superatmospheric Pressure at high temperatures in dyeing processes are unnecessary. By increasing the It is an addition to the branched, substituted hydroxyl compounds in the manufacture of the polyester also possible to produce shaped structures with high shrinkage capacity. Curl fibers of this type z. B. spontaneously in a hot aftertreatment and then have a particularly soft, full handle. The shrinkage value can be adjusted by varying the temperature and by optionally using Water, steam or dry heat changed within wide limits and the present needs be adjusted.

B e i s ρ i e 1 1

126 g of dimethyl terephthalate are mixed with 22.5 g of 2,2-dimethyl-1,3-propanediol, 0.22 g of zinc acetate and 0.12 g of triphenyl phosphite are added and the mixture is heated in a descending cooler while passing through a slow stream of nitrogen and removing methanol 4 by distillation hours at 180 ⁰ C. Low, sublimating the starting proportions of the glycol is brought back to the reaction mass from time to time. It is then cooled to room temperature; there are again added 324 g of dimethyl terephthalate and 0.40 g of zinc acetate and 392 g of ethylene glycol and 0.45 g of antimony trioxide and heated to above 6 hours at 18O ⁰ C. Then, the pressure in the apparatus at 10 Torr is reduced and with stirring, the temperature increased to 260 ° C within 3 hours. Only the excess ethylene glycol distills off, the distillate is free from dimethylpropanediol. The cooler is then removed, the pressure is reduced to 1 Torr and heated to 285 ° C. for 90 minutes. The reaction product is a viscous, crystal-clear and colorless mass which is discharged under nitrogen and quenched in cold water. Their average degree of polymerization corresponds to a K value of 53, the melting point is 240 ° C. The polyester is spun from the melt flow at 268 ° C. and the threads are drawn at 80 ° C. in a ratio of 1: 4.5. With an elongation at break of 24%, they have a strength of 4.2 g / den, their dyeability for disperse dyes is twice as high as that of pure polyethylene terephthalate. The threads shrink by 24% at 180.degree. C. in air (1 minute), a flat-arched crimp occurs, the handle is soft and full. The dyeability after heating is 2V ₂ times that of the same treated fiber made of pure polyethylene terephthalate.

Example 2

As described in Example 1, 40 g of 2,2-dimethyl-1,3-propanediol are used transesterified with 232 g of dimethyl terephthalate with the addition of 0.35 g of zinc acetate. To 168 g of dimethyl terephthalate, 360 g of ethylene glycol, 0.26 g of zinc acetate and 0.26 g are added to the cooling Antimony trioxide is added, re-esterified and polycondensed, as described in Example 1. The Outwardly, the reaction product is similar to that of Example 1, the K value is also 53, the melting point 218 ° C.

By spinning the polyester at 256 ° C and drawn the filaments obtained at 7O ⁰ C 1:40. Their strength is 3.9 g / den, the elongation at break 20%. When dyed at boiling temperature with disperse dyes (2% calculated on fiber) for 1.5 hours, almost 4 times the amount of dye on threads spun in the same way from pure Polyethylene terephthalate. They shrink by 48% · By heating it after dyeing and drying (60 to 7O ⁰ C) for 1 minute at 180 ° C, so they shrink again to a total of 65% · The goods will then have a very warm and full grip and a pronounced ripple.

Claims (1)

Claim: Use of linear aromatic polyesters obtained by polycondensation of terephthalic acid or their polyester-forming derivatives and mixtures of unbranched glycols and a quantity, C 6 which corresponds to 1 to 20 percent by weight, one in which R is methyl, methoxy, ethyl or phenyl branched glycol of the formula radicals and A is the methylene group or another unbranched, divalent group of no more ι than 5 chain links, which except carbon atoms ι 5 also contain oxygen or sulfur atoms HO - A - C - A - OH, can mean, have been obtained, for Her make of highly shrinkable, easily dyeable R fibers.