DE2441538A1 - HARD-COMBUSTIBLE TEREPHTHALIC ACID COPOLYESTER - Google Patents

Description

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509 Leverkusen, Bayerwerk Sdt / Zl

2 AUG. \ 97k

Flame-resistant terephthalic acid copolyester

The invention relates to flame-retardant polyesters which can be used for the production of textile fibers.

It is known that synthetic fibers can be produced by adding phosphorus, halogen or antimony-containing compounds for the polyester melt or by applying such substances to the to make spun fiber flame retardant. However, such low molecular weight compounds have the disadvantage of being toxic and - if they are incorporated - to migrate from the polymer over time to the surface or during Wash or dry clean the surface to be removed. So it therefore signified an advance, condensable to use bifunctional bromine compounds, which solidify in the macromolecule with the formation of copolyesters can be installed. For example, in DT-OS 2,313,298 bisoxethylated tetrabromobisphenol A is described as a flame retardant. Although compared to such connections low molecular weight, not capable of condensation additives already have advantages, however, is the influence on the polymer properties are still disadvantageous, e.g. the softening point, melt viscosity and remission of the obtained Copolyester significantly deteriorated compared to the unmodified polymer. The melt viscosity and the remission

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sion properties are for the production of synthetic fibers of great importance. There was therefore a need to produce fiber-forming polyesters with condensable flame retardants are modified, which these negative effects on the polymer properties and thus do not show the fiber quality or only to a lesser extent.

It has now been found that condensable bis (hydroxyalkoxy) benzenes containing bromine in the aromatic nucleus and bis (acyloxyalkoxy) benzenes lead to these desired properties when incorporated into the polyester chain.

The invention relates to flame-retardant, high molecular weight linear terephthalic acid copolyesters, consisting of recurring structural elements of the general formula

-fC-XCOR-oT-Lii il -i
0 0

wherein X is a phenylene radical and
R to 92 to 99 mol #

a straight-chain or branched alkylene radical with 2 to 20 carbon atoms, a cycloalkylene radical or a radical of the general formula

is where R ^ is a straight or branched chain Denotes an alkylene radical having 1 to 10 carbon atoms

and from 1 to 8

a remainder of the general formula

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0-R ₂ -

- (Br) _n

0-R ₂ -

represents where η is a number from 1 to 4 and

R _{0 is} a radical of the formula / CH ₀ -CH-O / CH ₀ -CH-, 2 2, m- 2 ι ■

- ^H 6 6

m zero or a number from 1 to 9, and Rg hydrogen or is a methyl group,

The terephthalic acid copolyesters have relative solution viscosities ''-'j rel in the range from 1.1 to 4.0 (measured on a solution of 1 g of substance in 100 ml of o-chlorophenol at 25 ° C). -

Preference is given to copolyesters made of terephthalic acid, which are composed of recurring structural elements of the general formula

--C - // Μ-C-O-R-O-

o - ο

consist, in which R has the meaning given above.

Dicarboxylic acid derivatives are used to produce these terephthalic acid copolyesters the general formula,.

R ^ -OCXCOR
3

0 0

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wherein X is a phenylene radical, preferably a p-phenylene radical is and Ft, hydrogen or a straight chain or denotes branched alkyl radical with 1 to 10 carbon atoms,

with a mixture of a diol of the general formula

HO-R ₄ -OH,

wherein R ^ is a straight-chain or branched alkylene radical having 2 to 20 carbon atoms, a cycloalkylene radical or a radical of the general formula

is in which R _{1 is} a straight-chain or branched alkylene radical having 1 to 10 carbon atoms

and a bis (hydroxy-alkoxy) -benzene derivative containing bromine in the aromatic nucleus the general formula

(0 R ₅

(Br)

wherein Rc- is a group of the general formula

- <CH ₂ -CH-0) - _m CH ₂ -CH-OR R ^ R. £

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m is zero or a number from 1 to 9, η is a number from 1 to 4, Rg is hydrogen or a methyl group and R _{7 is} hydrogen or an aliphatic acyl radical with 1 to 5 carbon atoms,

in such proportions with each other in the melt at temperatures below 350 ° C at pressures between Normal pressure and 0.001 Torr using known catalysts so polycondensed that the content of the modified Polyester on condensed brominated bis (hydroxyalkoxy) benzene derivative in the range between 1 and 8 mol ^ is based on the amount of condensed dicarboxylic acids.

The copolyesters obtained in this way, preferably of terephthalic acid, can be molded very easily from the melt Forms, especially to process threads, fibers and foils.

The ones used to modify the flame retardant polyesters bis (hydroxyalkoxy) benzene derivatives capable of condensation and containing bromine in the aromatic nucleus are known Process prepared compounds which can be obtained in good yields.

The production takes place by brominated dihydric phenols with suitable alkoxylating agents, e.g. ethylene oxide, propylene oxide, Ethylene carbonate, ethylene chlorohydrin or 1-chloro-2-propanol, implemented or alkoxylated dihydric phenols, their aliphatic hydroxyl groups by esterification with a Monocarboxylic acid protected, can be brominated in suitable solvents.

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Suitable phenols are catechol, resorcinol and hydroquinone, with hydroquinone being used for condensation reactions too linear polymers particularly favorable 1,4-substitution preferred will. The phenols are first brominated or oxalkylated, and then oxalkylated or oxyalkylated in a second step. to be brominated. A suitable starting material is also tetrabromoquinone, which is produced by reduction, e.g. with sulfur dioxide, can be easily converted into the tetrabromohydroquinone.

Ethylene glycols are used as further diols for polycondensation with 2 to 20 carbon atoms, quinite or glycols of the general formula

used, where R _{1 is} a straight-chain or branched alkylene radical having 1 to 10 carbon atoms. Ethylene glycol and bis (1,4-hydroxymethyl) cyclohexane are particularly preferred.

As dicarboxylic acid components, in addition to free terephthalic acid also their esters, e.g. dimethyl terephthalate or bis-ß-hydroxyethyl terephthalate and partly Isophthalic acid and its esters are used.

For the production of the terephthalic acid copolyester, customary Transesterification or condensation catalysts, e.g. salts such as calcium, manganese, cobalt, zinc acetate, as well Titanium tetrabutylate and titanium tetraisopropylate, antimony trioxide, germanium dioxide and combinations of antimony oxide and manganese acetate or antimony trioxide and titanium dioxide are used. The amount of catalyst, based on the monomers, is 0.002 to 0.2 Wt .-? 6.

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To carry out the polycondensation, in a preferred embodiment of the process according to the invention, the Reaction mixture consisting of, for example, a dialkyl terephthalate such as dimethyl terephthalate, ethylene glycol, a bis (hydroxyalkoxy) benzene derivative brominated in the aromatic nucleus and a catalyst or catalyst mixture, the ethylene glycol being used in excess for transesterification, 1-4 hours in the presence of an inert gas, such as Nitrogen, hydrogen or helium, with stirring to 130 to 200 ° C and then 1 to 3 hours to 225 to 280 ° C heated. The pressure is then reduced, generally below 15 torr, preferably below 1 torr, the "temperature im Range of 250 to 290 ° C is maintained. Under these conditions condensation is carried out for 1 to 18 hours until the desired viscosity of the melt is reached. After completion After the reaction, the resulting polyester can immediately be melted into shaped articles such as threads, foils and others Moldings are processed.

Additives such as pigments, Matting agents, discoloration stabilizers, optical brighteners or modifiers to improve the colorability can be added without impairing the properties.

The new products are characterized by a comparatively excellent raw clay as well as good mechanical and thermal properties Properties.

The relative solutions given in the following examples viscosities' £? rel were at 25 ° C on solutions of 1 g Substance measured in 100 ml of o-chlorophenol.

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The copolyester melt was used to assess the burning behavior Filament yarns (dtex 180/50) are spun and processed into a knitted tube. With this material was the oxygen index test was carried out, whereby the samples were placed between fiberglass cloth to avoid an uncontrolled Prevent melting.

The oxygen index test is in "Modem Plastics", (I9? O), Page 124, and gives the minimum volume percentage Oxygen in an oxygen-nitrogen atmosphere, which keeps the tissue burning.

The remission of the Pasern was on an "Elrepho" device of the Measured by the Zeiss company, the measurement method is described in "Color measurement, colorimetry and their application in the textile industry", H. Lapp Verlag, Mönchengladbach I967.

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example 1

In a reaction vessel equipped with an anchor blade stirrer, gas inlet tube, distillation attachment, condenser, vacuum inlet and template are 182 parts by weight of dimethyl terephthalate, 130 parts by weight of ethylene glycol and 10 parts by weight 1.4 bis (ß-hydroxyethoxy) -2,3,5,6-tetrabromopenzene in a mixture 'with 0.016 part by weight of zinc acetate, 0.07 part by weight of antimony acetate and 0.14 part by weight of titanium tetrabutoxide. Under Passing nitrogen over it is melted at 160 ° C. and the stirrer is switched on. The temperature is then 2 Held at 195 ° C. for hours and then increased to 280 ° C. over a further 2 hours. The nitrogen supply is then interrupted and the pressure slowly reduced to 0.05 torr over one hour. After another 2 hours the polycondensation has ended. The almost colorless, homogeneous melt can be processed very easily into molded articles such as threads. The copolyester has a melting range of 245 - 249 C, a remission compared to unmodified Polyethylene terephthalate of 79%, an oxygen index of 32.5 measured on the knitted piece and a relative solution viscosity of 2.1. The copolyester contains 2.1 moles of the brominated compound, based on terephthalic acid units.

In contrast, the oxygen index of an unmodified polyethylene terephthalate is 24.6. The remission of one with 10% by weight of bis-oxethylated tetrabromobisphenol A modified Compared to unmodified material, polyethylene terephthalate is only 48%, the oxygen index

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Production of 1,4-bis (ß-hydroxyethoxy) -2,3,5,6-tetrabromo benzene

100 parts by weight of hydroquinone are suspended in 600 parts by weight of acetic acid and at 20 ° C. with 582 parts by weight of bromine offset. The mixture is then stirred for 16 hours at 30 ° C, the precipitate formed is filtered off with suction, washed neutral with water and suspended in 500 parts by weight of water. That The mixture is heated to 70 ° C., 55 parts by weight of sodium hydroxide are added and, at the same time, the solution of 55 parts by weight Sodium hydroxide in 110 parts by weight of water and 220 parts by weight of ethylene chlorohydrin are metered in separately. Afterward is stirred for 8 hours at 70 ° C and after cooling vacuumed, washed and dried. There are 210 parts by weight of the desired compound with a melting point of 202-205 ° C obtain.

Example 2

In an apparatus according to Example 1, 182 parts by weight Dimethyl terephthalate, 130 parts by weight of ethylene glycol and 10 parts by weight of 1,4-bis (β-acetoxyethoxy) -2,5-dibromobenzene transesterified in a mixture with 0.3 parts by weight of zinc acetate and 0.6 parts by weight of antimony trioxide at 195 ° C. for 2 hours. Then it will be the temperature increased to 285 ° C within a further 2 hours, the pressure slowly reduced to 0.05 Torr and polycondensed for 2 hours at this pressure. homogeneous melt becomes a filament yarn (dtex 180/50) spun and processed into a knitted piece. The copolyester has a melting range of 248 - 251 C, a remission to unmodified polyethylene terephthalate of 81%, an oxygen index of 30.5 and a relative solution viscosity of 2.3. The copolyester contains

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2.4 moles of the brominated compound, based on terephthalic acid units. . Preparation of 1 ^ -Bis-Cß-acetoxyäthoxyj ^^ - dibromobenzene 198 parts by weight of 1,4-bis- (ß-hydroxyethoxy) -benzene are mixed in 500 parts by weight of acetic acid at 20 ° C with 320 parts by weight of bromine. The mixture is stirred for 5 hours at room temperature, then most of the acetic acid is removed in a water jet vacuum at 50 ° C. and the residue is recrystallized from isopropanol / acetone in a ratio of 3: 1; the melting point is 136-139 ° C

Example 3

182 parts by weight of dimethyl terephthalate, 130 parts by weight of ethylene glycol and 5 parts by weight of 1,2-bis (β-hydroxyethoxy) -3,4,5,6-tetrabromobenzene are mixed with 0.016 parts by weight of zinc acetate, 0.07 Part by weight of antimony acetate and 0.14 part by weight of titanium tetraisopropoxide are transesterified and polycondensed in the apparatus described in Example 1. The filament yarn (dtex 180/50) spun from the melt shows an oxygen index of 29.7 on the knitted piece. The melting range of the copolyester is 253-257 ° C., the remission to unmodified polyethylene terephthalate is 77 % and the relative solution viscosity is 2.15. The copolyester contains 1 mole of the brominated compound, based on terephthalic acid units. "" .- ■.

Production of 1,2-bis (ß-hydroxyethoxy) -3,4,5,6-tetrabromo benzene - -

This compound is similar to that described in Example 1 Preparation of the 1,4-derivative. from catechol obtain.

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2U1538 ft

Example 4

182 parts by weight of dimethyl terephthalate, 130 parts by weight of ethylene glycol and 30 parts by weight of 1,4-bis (β-acetoxyethoxy) -2,5-dibromobenzene are mixed with 0.3 parts by weight of zinc acetate and 0 , 6 parts by weight of antimony trioxide transesterified at 195 ° C. for 2 hours. The temperature is then ^{increased to 285 °} C. over the course of 1.5 hours, the supply of nitrogen is removed, evacuated to 0.05 Torr over the course of one hour and polycondensation under these conditions for 2 hours. The copolyester has a melting range of 239-243 ° C., a remission to unmodified polyethylene terephthalate of $ 68, a relative solution viscosity of 2.2 and an oxygen index, measured on the knitted piece, of 31.5. The copolyester contains 7 * 3 mol ^ of the brominated compound, based on terephthalic acid units.

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Claims (4)

Claims 1. Flame-resistant, high molecular weight linear terephthalic acid copolyester, consisting of recurring structural elements of the general formula V - '■ · .- ■ C-X-C-O-R-Ot- Il Ii ^J 0 0 where X is a phenylene radical and '" R from 92 to 99'Mo 196 '* ^: a straight-chain or branched alkylene radical with 2 to 20 carbon atoms, a cycloalkylene radical or a radical of the general formula is where R ^ is a straight or branched chain Denotes an alkylene radical having 1 to 10 carbon atoms and from 1 to 8 MoI ^ a remainder of the general formula LeA 15 937 - 13 - 609811/0794 2 4415 3 represents where η is a number from 1 to 4 and R _{2 is} a radical of the formula - ^ CH ₂ -CH-Oj CH ₂ -CH-, • 6 ¹ H m. zero or a number from 1 to 9, and Rg Is hydrogen or a methyl group, where the terephthalic acid copolyesters have relative solution viscosity '0 rel in the range from 1.1 to 4.0 (measured on a solution of 1 g of substance in 100 ml of o-chlorophenol at 25 ° C). 2. flame-retardant, high molecular weight linear terephthalic acid copolyester, consisting of recurring structural elements of the general formula where R has the meaning given in Example 1, the terephthalic acid copolyester having relative solution viscosities ^{in the} range from 1.1 to 4.0 (measured on a solution of 1 g of substance in 100 ml of o-chlorophenol at 25 ° C.). 3. Process for the production of flame-retardant, high molecular weight linear terephthalic acid copolyester by polycondensation of dicarboxylic acid derivatives with diols, characterized in that dicarboxylic acid derivatives of the general formula R 0-CXCOR _x ³ Il Il ³ 0 0 LeA 15 957 - 14 - 60981 1/0794 wherein X is a l'henylene radical and R. denotes hydrogen or a straight-chain or branched alkyl radical with 1 to 10 carbon atoms, with a mixture of a diol of the general formula HO-R ₄ -OH- wherein R. is a straight-chain or branched alkylene radical with 2 to 20 carbon atoms, a cycloalkylene radical or a radical of the general formula stands, wherein R ^ is a straight-chain or branched alkylene radical having 1 to 10 carbon atoms and a bis (hydroxy alkoxy) benzene derivative containing bromine in the aromatic nucleus the general formula (0R ₅ ) ₂ (Br) _n wherein R ₁ - a radical of the general formula ^ € H _o -CH-0 ^ _{--- CH 0} -CH-OR ₇ _ 2, Jm 2 ι ι ^R 6 ^R 6 LeA 15 957 - 15 - 609811 / Π7 9 away η is a number from 1 to 4, m zero or a number from 1 to 9, Rg is hydrogen or a methyl group and R ^ is hydrogen or mean an aliphatic acyl radical with 1 to 5 carbon atoms, in such proportions with each other in the melt at temperatures below 350 ° C and pressures between normal pressure and 0.001 Torr using known catalysts polycondensed so that the content of condensed brominated bis (hydroxy-alkoxy) -benzene derivative of the
Copolyesters in the range between 1 and 8 mol, based on the amount of condensed dicarboxylic acids. 4. Fibers and threads, consisting of high molecular weight linear terephthalic acid copolyesters according to claim 1. LeA 15 937 - 16 - 60981 1/0794