DE2060604B2 - Process for the production of modified polyesters - Google Patents

Description

mel HO— (CH ₂ ) ,, - OH, in which η are a whole io tung in the textile field and the property

A number between 2 and 10 denotes, and c) 0.5 to 10 mol of carboxylic acid salts with functional Residues per 100 mol of terephthalic acid or low molecular weight dialkyl ester thereof,

characterized in that the carboxylic acid salts with functional radicals are compounds of the general formulas

CO ₇ Me

X ₁ -CX,

R ₁ O ₂ C

CO ₂ R ₂

CO, Me

F - C - F

R ₁ O ₂ C

CO ₁ R,

C0, Me

CO ₂ CH ₃

C0, Me

CH ₃ O ₂ C

CO ₂ CH ₃

in which X ₁ , X ₂ and X _{3 are} chlorine or fluorine atoms, R ₁ and R _{2 are} alkyl radicals having 1 to 5 carbon atoms and Me is an alkali or alkaline earth metal atom.

have to be dyeable with basic dyes, by producing that an aromatic dicarboxylic acid or a derivative thereof, which forms the ester, with aliphatic glycols in the presence of particular, the basic dyes is converted to affinity compounds, which compounds the obtained polyester give the dyeing properties mentioned.

In the process described in US Pat. No. 3,068,207, these additives are used with which the Polyester is modified by mixing in the molten state, a dianhydride of a dicarboxylic acid and a chelating metal salt. The polyesters modified in this way are with special basic dyes that form chelates, can be dyed.

The in JA-AS 16 794 (reported in the Zentralblatt,

1966, No. 36, No. 2799) described ethylene terephthalate polyester can also by alkali salts

modified by carboxylic acids to achieve certain properties to improve. The additives mentioned there increase the softening point of the polyester, however, they do not give them an increased affinity for basic dyes, since they do not have this effect evoking groups included.

The known modifiers are broken down on the basis of the special functional ones present in them Groups into the polymer chain of the polyester, but give the modified polyester does not have those excellent properties of dyeability with basic dyes, which are particularly important in the fibers which are to be colored very brilliantly and heavily, like this, would be extremely desirable is currently provided with the latest techniques.

The invention relates to a process for the production of modified polyesters by reacting

a) Terephthalic acid or its low molecular weight dialkyl esters, with

b) Polymethylene glycols of the general formula HO— (CH ₂ ) "—OH, in which η is an integer between 2 and 10, and

c) 0.5 to 10 mol of carboxylic acid salts with functional radicals per 100 mol of terephthalic acid or low molecular weight dialkyl ester of the same,

characterized in that the carboxylic acid salts with functional radicals are compounds of the general formulas

CO, Me

X ₁ -C

CH,

// ■

R ₁ O ₂ CV Jl-CO ₂ R ₂

RO, C- \, / -CO ₁ R,

CO ₁ Me

Y
CO ₁ CH,

C O, Me

CH, 0, C

CO ₂ CH ₃

in which X ₁ , X ₂ and X _{3 are} chlorine or fluorine atoms, R ₁ and R _{2 are} alkyl radicals having 1 to 5 carbon atoms and Me is an alkali or alkaline earth metal atom.

In a preferred embodiment, the carboxylic acid salts c) in an amount of 1 to 5 mol each 100 mol of terephthalic acid or its low molecular weight dialkyl ester are used.

The additives according to the claims added at the beginning or during the esterification reactions react with the other monomers and consequently go into the poly-methylene-terephthalic chains, especially in the polyethylene terephthalate chains of the polyester produced.

The additives according to the claims, which thus act as monomers, are metal salts of carboxylic acids, which can be seen from the formulas have electroaffine elements or atomic groups that are in are able to increase the acidity of said carboxyl group and improve it and to give greater affinity to the basic dyes.

example 1

The following are introduced into a test polycondensation vessel made of stainless steel, which is equipped with a stirrer and distillation column: dimethyl terephthalate (DMT) 194 parts, monoethylcnglycol 124 parts, sodium - n, n - difluoro - (3,5 - dimethoxycarbonylphenyl) acetate 6, 2 parts (corresponding to 2 mol percent, based on DMT), zinc acetate dihydrate 0.0388 parts (corresponding to 0.02 percent by weight, based on DMT), antimony trioxide 0.0776 parts (corresponding to 0.04 percent by weight, based on DMT).

The reaction mass is gradually ^{brought to 220 °} C. in 5 hours, during which time all of the methyl alcohol formed in the ester exchange reaction between DMT and monoethylene glycol is distilled off from the reaction vessel.

An increasing vacuum is then in the reaction system is applied which reaches in about 90 minutes values of 0.5 mm Hg residual pressure, while the temperature of 22O ⁰ C to 280 "C is increased. The polycondensation is completed by the reaction mass at 280 ⁰ C. for 3 hours under a vacuum of 0.5 mm Hg. The polyester formed is then pressed into cold water under nitrogen pressure.

The polyester converted into granules and dried has an excellent degree of whiteness. It also has the following characteristics: ίο [/,] = 0.663 (basic viscosity, measured with a phenol tetrachloroethane mixture 60/40 parts by weight; Ig of the polyester in 100 ml of the solution; the viscosity is ^{measured at 20 °} C.).

Melting point: 257 ° C (measured according to the system DTA thermal differential analysis).

Carboxyl end groups ([COOH] / 10 ⁶ g polymer): 31.3.

The dislycol ether radicals (DEG): 1.65 (based on 100 glycol radicals).

This polyester is made into a roving with 31 filaments using the usual spinning and drawing processes and a total of 150 den transformed with which a tubular knitted fabric is produced.

A product sample is boiled for 1 hour with a 3% aqueous solution (due to the weight of the dry product) of a red basic dye (color index: CI basic red 29) in the presence of 2% of a commercially available dispersant and 1 ml / 1 35% CH ₃ COOH treated. The goods are dyed with a medium red tint and are washable.

For comparison, a sample of polyethylene terephthalate is prepared by adding all of the above Process conditions described are observed, only that the DMT no further monomer is admitted. A polyester is obtained which has the following properties:

[//] = 0.671.
Melting point: 26O ⁰ C.
(COOH) / IO ⁶ : 30.1.
DEG: 1.58 mole percent.

A yarn and a tubular knitted fabric are obtained from this polyester, which is dyed under the same conditions as the modified polyester. This comparison yarn absorbs only traces of the dye, which are easily removed when washing.

Example 2

A mixed polyester sample is prepared under the same process conditions as in Example 1, however, the following is used as an additional monomer:

Potassium - «,« - dichloro - / i - (3,5 - dimethoxycarbonylphenyl) propionate in an amount of 9.83 parts (corresponding to 2.5 moles per 100 moles of DMT). The received c Polyester has the following properties:

[,,] = 0.655.

Melting point: 255 ^° C. (DTA).
[COOH] / 10 ⁶ : 35.5.
DEG:!, 88 mole percent.

This polyester is spun and, as in Example 1, converted into a knitted fabric. A sample of the goods is for 2 hours at 120 ⁰ C with a

3% aqueous solution (based on the weight of the dry goods) of a blue dye (color index = basic blue 1) colored. A good blue tint with excellent wash resistance is obtained. Goods made from unmodified polyethylene terephthalate in contrast, takes the dye when it is colored under analogous conditions not to any significant extent.

Examples 3 and 4

Under the process conditions described in Example 1, mixed polyesters with the following Monomers produced:

Example 3: 5.42 parts of the sodium salt of p-methoxycarbonyl-2,6-chloro-benzoic acid, corresponding to 2 moles per 100 moles of DMT;

Example 4: 7.27 parts of sodium dimethyl- (2,4,6-trichloro) -trimesai. corresponding to 2 moles per 100 moles of DMT.

The properties of the polyesters obtained are summarized in the table below.

example

[COOH] Mr. DEG

Melting point

(Mol- (DTAi

prozenll

0.631
0.620

29
30.5

1.80 1.88

253 C

253.5 C

Samples of goods obtained from these polyesters by the usual methods are classified under the In the conditions described in Example 1, dyeing tests were carried out.

All samples had satisfactory dye uptake. whereby the coloring in quite a few Washing treatments is resistant.

Claims (1)

Claim: Process for the preparation of modified polyesters by reacting a) Terephthalic acid or its low molecular weight dialkyl esters, with b) Polymethylene glycols of the general formula The invention relates to the production of linear modified polyester, which is made of fibers or door other utensils such as films, compacts and castings are suitable. In particular, the invention relates to the production of linear modified polyesters that have high affinity to have basic dyes. It is known that linear polyesters, which are particularly important in the form of fibers and yarns