CA1047689A - Polyester production - Google Patents
Polyester productionInfo
- Publication number
- CA1047689A CA1047689A CA218,502A CA218502A CA1047689A CA 1047689 A CA1047689 A CA 1047689A CA 218502 A CA218502 A CA 218502A CA 1047689 A CA1047689 A CA 1047689A
- Authority
- CA
- Canada
- Prior art keywords
- parts
- weight
- amount
- terephthalic acid
- per million
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/78—Preparation processes
- C08G63/82—Preparation processes characterised by the catalyst used
- C08G63/85—Germanium, tin, lead, arsenic, antimony, bismuth, titanium, zirconium, hafnium, vanadium, niobium, tantalum, or compounds thereof
- C08G63/86—Germanium, antimony, or compounds thereof
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/78—Preparation processes
- C08G63/82—Preparation processes characterised by the catalyst used
- C08G63/83—Alkali metals, alkaline earth metals, beryllium, magnesium, copper, silver, gold, zinc, cadmium, mercury, manganese, or compounds thereof
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Polyesters Or Polycarbonates (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE:
Polyesters, eg polyethylene terephthalate, are produced by a direct esterification process.
The esterification is performed in the presence of a germanium dioxide polycondensation catalyst dissolved in an alkaline glycol solution. The alkali in the catalyst solution acts as the softening point stabilizer. An antimony polycondensation catalyst is also employed.
Polyesters, eg polyethylene terephthalate, are produced by a direct esterification process.
The esterification is performed in the presence of a germanium dioxide polycondensation catalyst dissolved in an alkaline glycol solution. The alkali in the catalyst solution acts as the softening point stabilizer. An antimony polycondensation catalyst is also employed.
Description
- P~ 26752 .
~his in~ention rel~te~ to polyester production and in particular to the production o~ linear aromatic polyesters.
Such polyesters are normally produced by first forming ~ monomeric ester b~ esterification of an aromatic carboxylic acid, e~g. terep~thalic acid, with a gl~col (so called direct esterification) or an ester ` interch nge reaction by reacting a glycol with a dialkyl ester o~ ~he acid, e.g. dimethyl te~ephthalate. ~he "mo~omer",e.g. bis(~-hydrox~ alkyl) terephthalate,is then polyconde~ed. ~he prese~t inventio~ is concer~ed with the direct esterificatio~ process.
The pol~condensatio~ reaction is normally conducted in the prese~ce o~ a catalyst such as a germanium or an `1 15 antimon~ compou~d.
Germanium compounds~are particularly useful as ~; they generally give polyester6 of improved colour compared with the use of antimon~ compounds but it has , :
been foun~ that the use of a combination of germa~ium a~d ant~mo~ compounds give p~rticularly good polyesters.
.1 , .
Ger~a~ium dioxide i8 the most commonl~ used germanium catalyst but the most readil~ obtainable .
form thereo~, viz hexagonal crystalline~germanium , : ~
dioxide,is only poorly soluble in the reaction medium.
Various methods have been proposed ~or improving its
~his in~ention rel~te~ to polyester production and in particular to the production o~ linear aromatic polyesters.
Such polyesters are normally produced by first forming ~ monomeric ester b~ esterification of an aromatic carboxylic acid, e~g. terep~thalic acid, with a gl~col (so called direct esterification) or an ester ` interch nge reaction by reacting a glycol with a dialkyl ester o~ ~he acid, e.g. dimethyl te~ephthalate. ~he "mo~omer",e.g. bis(~-hydrox~ alkyl) terephthalate,is then polyconde~ed. ~he prese~t inventio~ is concer~ed with the direct esterificatio~ process.
The pol~condensatio~ reaction is normally conducted in the prese~ce o~ a catalyst such as a germanium or an `1 15 antimon~ compou~d.
Germanium compounds~are particularly useful as ~; they generally give polyester6 of improved colour compared with the use of antimon~ compounds but it has , :
been foun~ that the use of a combination of germa~ium a~d ant~mo~ compounds give p~rticularly good polyesters.
.1 , .
Ger~a~ium dioxide i8 the most commonl~ used germanium catalyst but the most readil~ obtainable .
form thereo~, viz hexagonal crystalline~germanium , : ~
dioxide,is only poorly soluble in the reaction medium.
Various methods have been proposed ~or improving its
2 ~
: .
: . . - . " . : ~ . , . . ~ -~047G8~
solubility and, in particular, it has been proposed, in British Patent 1,197, 004, to make an alkaline solution of the crystalline germanium dioxide in a glycol. :
In the direct esterification process it is conventional practice to utilise a base, such as sodium hydroxide, as a softening point stabiliser :
(see British Patent 782,036).
We have found that if the alkaline germanium dioxide/glycol solution :
is present during the esterification process, polyesters of enhanced softening ;; point and improved colour are obtained compared with processes wherein simply 10 a base is used as a softening point stabiliser and the germanium dioxide solu- :.
tion is added after the esterification process has taken place. ;;
. Accordi.ngly we provide a process for the production of polyethylene ` terephthalate which comp~ises: ta) esterifying terephthalic acid with ethy- ~ .
- lene glycol at an elevated temperature; and ~b) polycondenslng the product of :
. ~a}, without isolation, under reduced pressure and ln the presence of antimony trioxide in amount 100 to 1000 parts per million by weight of the terephthalic .
. acid originally present; step ~a) being carried out in the presence of a ~:
~ solution of germanium dioxide in alkal~i metal hydroxide and ethylene glycol~
,; , ~ the amount of germanium dioxide being 10 to 200 parts per~million by welght based on the amount of terephthalic acid present at the start of the reaction and the amount of the~alkali metal hydroxide being: ~i) greater than the equi-' ~ ~:: valent per mole of germanium dioxide; (ii) greater~than 0.5 gram equivalents .:`, per million grams of the dicarboxylic acid~ and (iii) less than the greater -~ .
,' ;.~ ':'.:' . 1 o twice the equivalent per mole of germanlum dioxide and 2,5 gram equivalents : -~
,", ~ . . , : per million grams of~the dicarboxylic:acid. : ~
In a preferred~embodiment~ there lS provided a process for the produc- .:
: tlon of~polyethylene~terephthalate which comprlses: ~a~ esterifying terephtha- ..
lic acid:~with ethylene glycol at an~elevated temperature; ~b) polycondensing ~ ; :
the product of ~a), without lsolation, under reduced pressure and in the pre~
30~ sence of~antimony trloxide in :amount~100 to 1000 parts per million by weight of the terephthallc acid originally present; step ~a) being carried out in the .. :
pre:sence of a solutlon o~ germanium dioxide in sodium hydroxide and ethylene ~ :. l :
~ 76~
glycol, the amount of germanium dioxide being 10 to 200 parts per million by weight based on the amount of terephthalic acid present at the start of the - reaction and the amount of the sodium hydroxide be:ing: (i) greater than 38.2 parts by weight per 100 parts by weight of germanium dioxide; ~ii) greater than 20 parts by weight per million parts by weight of the terephthalic acid; ~iii) less than the greater of 76.4 parts by weight per ]L00 parts by weight of ger-manium dioxide and 100 parts by weight per million parts by weight of terephth-alic acid.
It is important that at least one equivalent of the alka:li metal hydroxide is used for each mole of germanium dioxide in order to ensure that the latter is dissolved. Thus, when using sodium hydroxide, for each :L00 parts by weight of germanium dioxide, at least 38.2 parts of sodium hydroxide should be ~; used. In place of sodium hydroxide, hydroxides of other alkali metals, e.g.
lithium, potassium, rubidium and caesium may be employed. However~ for econo-mic reasons, sodium hydroxide is preferred.
We have found that the addition of too much of the alkali metal hy-droxide adversely affects the colour of the product and so we prefer to use less than 2, particularly less than 1.5, equivalents per mole of germanium di~
oxide.
The amount of germanium dioxide used is 10 to 200 parts per million parts by weight of the terephthalic acid. However, where small amounts, i.e.
at the lower end of this range, of germanium dioxide are used~ more than 2 equivalents of alkali metal hydroxide may be used for each mole of germanium dioxide. Thus, the amount of alkali metal hydroxide is preferably within the ange 0.5-2.5, preferably 0.75-2.0, gram equivalents per million grams of the :
dicarboxylic acid, i.e. for sodium hydroxide 20-100, preferably 30-80, parts per million parts by weight of dicarboxylic acid.
The amount of ethylene glycol used to form the germanium catalyst solution should be sufficient to ensure dissolution of the germanium dioxide and alkali metal hydroxide.
The amount of antimony trioxide used as additional polycondensation catalyst should be sufficient to ensure an acceptable polycondensation rate is _4_ ;-,.
768~
obtained The amount used ;s in the range 100-1000, preferably 200-750, parts per million parts by weight of terephthalic acid orlginally present. The antimony trioxide is generally added after completion of the esterification reaction and then, while maintaining the reaction medium at an elevated temp-erature, the prevailing pressure reduced to effect polycondensation.
. ~.
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, . .
.
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.. . . . . . .
Pf 26752 ~ 4~6~
Other additives commonly employed in polyester manufacture may be added at a suitable stage in the process, generally before or during the polgcondensation reaction. Examples of such additives are phosphorus compounds, such as o~yacids of phosphorus, e.g.
phosphoric or phosphorous acids, or salts or esters thereof, dyeing assistants, delus1tra~ts, fillers, optical whiteners, dyes, pigments and chain ex~enders.
The esterification reaction is conducted at an ele~ated temperature, generally in the range 200~280C, ~- generally under ele~ated pressure, with removal of water by distillation.
The polycondensation reaction is generally conducted at a temperature in the range of 250-300C under a reduced pressure, generally less than 30 mm of mercur~, with removal of the evolred glycol.
The invention is particularly suited to the ~; production of polyesters for ~ibre or film manufacture.
~he inventio~ is illustrated by the ~ollowing e~amples wherein all parts and percentages are , expressed by weight~
(Examples I, II and IV are comparative).
Example I ~ -60.5 part~of terephthalic acid and 38 8 parts ; 2~5~ ethylene~glycol were esterified under a pre~Burs of .
,::
P~ 26152 768~
40 psi at a temperature of 240C i.n the presence of 0.0035 parts sodium hydroxide. 0.07 parts triphenyl phosphate stabiliser were then added after esterification, followed by 0.0035 parts of : 5 amorphous germanium dioxide and 0.021 ~arts antimony : trioxide were added as polycondensation catalyst.
Polycondensa~ion was completed by raisi~g the . temperature to 290C and applying a vacuum of 0.1 mm .
of mercury~ ~he resultant polymer had an intrinsic : .
~ 10 viscosity (IY) - as measured on a 1% solution in -~
: o-chlorophenol at 25C - of 0.658, a yellowness of 30 units and softening point of 255.4C. ~he yellowness figure quoted is a measurement uf the colour of the sample obtained on a "colormaster" dif~erential .1 15 colorimeter. ~he higher the yellowness figure, the poorer the colour of the polymer.
: : Exam~e II : :
-~ Polymer was made as described in Example I but .. ~ instead of amorphous germanium dioxide, 0.0035 parts hexagonal germanium dioxlde dissolved in an ethylene glycol solution containing 0.0014 parts sodium hydroxide were added after esterification together ~wlth the:antimon;~ trioxide as polycondensation catalyst.
he resultant~polymer~had~an IV Or 00694~, a yellowness :: of~40 units `and a softening point of 255.1C. . ;
. .
P~ 26752 ~47~3 ; Example III
60.5 parts terephthalic acid and 38.8 part~
; .
ethylene glycol were esterified under the conditions deQcribed in Example I but i~ the presence o~ 0.00~5 5 parts hexagonal germanium dioxide dissolved in ~n ethylene gl~col solution containillg the 0.0035 part~
sodium hydroxide. 0.07 parts triphenyl phosphate :
~tabiliser and 0.021 parts antimony trioxide catalyst were added a~ter esterification and polycondensation . ~, completed as in ~xamplea I and II. ~he polymer .. ..
of IV 90682 ga~e a yellowne~s o~ 27 unit~ and a sortanin~ point of 256~7Co ~, Example IV
86.5 parts terephthalic acid and 42 p~rts ethylene glycol we~e esterified at a temp~erature o~ 241C and ~: J ~ a~ pre~ure o~ 2~8 atmospheres in~the presence of 0.005 part~ sodium hydroxide.; 0.21 part~ triphenyl ~ : :
phosphate as ~tabiliser and 0.005 parts he~agona1 germani~m dioxide, dis~oIved~in an~eth~lene glycol ~ ~olution containing 0.002 parts sodium h~droxide, and 0.03 part3 antimo~y trioxide as po1ycondensation ~,~ catalyst were then added. Polycondensation was completed~by~rai~ing~the tomperature to 290a and~
decreasing the pr~sQure to 0.1 mm mercur~ pressure.
Pf 26752 6~
~he polymer had a~ IV of 0~658, a yellowness of 32 units and softening point of 25B.8C.
., ~Z
86.5 parts terephthalic acid and 42 part~i ethylene glycol were esterified at a temperature of 241C
and pressure of 2.8 atmospheres in the presence o~ :
0.005 parts hexago~al germanium di~Dxide di~solved in an ethylene gl~col solution containing 0.005 parts sodium hydroxide. 0.21 parts triphenylphosphate and 0.03 parts a~timony trioxide were added a~ter esterification and the polycondensation was co~pleted ~ as in Example IV. ~he polymer had a~ IV of 0.645, :1 yellow~ess of 25 units and softening point 259~2C --~, ;,~ . :' . .
~:
'~
.
.
. ~ ~
.. : . ;. . ;.. - :. - . , ~ ., ,: " ..... ., . - . . , ~ : . ... . .
, . , ~ ~ . , : :. ... .. ... .. . . . .... ... .. .
: .
: . . - . " . : ~ . , . . ~ -~047G8~
solubility and, in particular, it has been proposed, in British Patent 1,197, 004, to make an alkaline solution of the crystalline germanium dioxide in a glycol. :
In the direct esterification process it is conventional practice to utilise a base, such as sodium hydroxide, as a softening point stabiliser :
(see British Patent 782,036).
We have found that if the alkaline germanium dioxide/glycol solution :
is present during the esterification process, polyesters of enhanced softening ;; point and improved colour are obtained compared with processes wherein simply 10 a base is used as a softening point stabiliser and the germanium dioxide solu- :.
tion is added after the esterification process has taken place. ;;
. Accordi.ngly we provide a process for the production of polyethylene ` terephthalate which comp~ises: ta) esterifying terephthalic acid with ethy- ~ .
- lene glycol at an elevated temperature; and ~b) polycondenslng the product of :
. ~a}, without isolation, under reduced pressure and ln the presence of antimony trioxide in amount 100 to 1000 parts per million by weight of the terephthalic .
. acid originally present; step ~a) being carried out in the presence of a ~:
~ solution of germanium dioxide in alkal~i metal hydroxide and ethylene glycol~
,; , ~ the amount of germanium dioxide being 10 to 200 parts per~million by welght based on the amount of terephthalic acid present at the start of the reaction and the amount of the~alkali metal hydroxide being: ~i) greater than the equi-' ~ ~:: valent per mole of germanium dioxide; (ii) greater~than 0.5 gram equivalents .:`, per million grams of the dicarboxylic acid~ and (iii) less than the greater -~ .
,' ;.~ ':'.:' . 1 o twice the equivalent per mole of germanlum dioxide and 2,5 gram equivalents : -~
,", ~ . . , : per million grams of~the dicarboxylic:acid. : ~
In a preferred~embodiment~ there lS provided a process for the produc- .:
: tlon of~polyethylene~terephthalate which comprlses: ~a~ esterifying terephtha- ..
lic acid:~with ethylene glycol at an~elevated temperature; ~b) polycondensing ~ ; :
the product of ~a), without lsolation, under reduced pressure and in the pre~
30~ sence of~antimony trloxide in :amount~100 to 1000 parts per million by weight of the terephthallc acid originally present; step ~a) being carried out in the .. :
pre:sence of a solutlon o~ germanium dioxide in sodium hydroxide and ethylene ~ :. l :
~ 76~
glycol, the amount of germanium dioxide being 10 to 200 parts per million by weight based on the amount of terephthalic acid present at the start of the - reaction and the amount of the sodium hydroxide be:ing: (i) greater than 38.2 parts by weight per 100 parts by weight of germanium dioxide; ~ii) greater than 20 parts by weight per million parts by weight of the terephthalic acid; ~iii) less than the greater of 76.4 parts by weight per ]L00 parts by weight of ger-manium dioxide and 100 parts by weight per million parts by weight of terephth-alic acid.
It is important that at least one equivalent of the alka:li metal hydroxide is used for each mole of germanium dioxide in order to ensure that the latter is dissolved. Thus, when using sodium hydroxide, for each :L00 parts by weight of germanium dioxide, at least 38.2 parts of sodium hydroxide should be ~; used. In place of sodium hydroxide, hydroxides of other alkali metals, e.g.
lithium, potassium, rubidium and caesium may be employed. However~ for econo-mic reasons, sodium hydroxide is preferred.
We have found that the addition of too much of the alkali metal hy-droxide adversely affects the colour of the product and so we prefer to use less than 2, particularly less than 1.5, equivalents per mole of germanium di~
oxide.
The amount of germanium dioxide used is 10 to 200 parts per million parts by weight of the terephthalic acid. However, where small amounts, i.e.
at the lower end of this range, of germanium dioxide are used~ more than 2 equivalents of alkali metal hydroxide may be used for each mole of germanium dioxide. Thus, the amount of alkali metal hydroxide is preferably within the ange 0.5-2.5, preferably 0.75-2.0, gram equivalents per million grams of the :
dicarboxylic acid, i.e. for sodium hydroxide 20-100, preferably 30-80, parts per million parts by weight of dicarboxylic acid.
The amount of ethylene glycol used to form the germanium catalyst solution should be sufficient to ensure dissolution of the germanium dioxide and alkali metal hydroxide.
The amount of antimony trioxide used as additional polycondensation catalyst should be sufficient to ensure an acceptable polycondensation rate is _4_ ;-,.
768~
obtained The amount used ;s in the range 100-1000, preferably 200-750, parts per million parts by weight of terephthalic acid orlginally present. The antimony trioxide is generally added after completion of the esterification reaction and then, while maintaining the reaction medium at an elevated temp-erature, the prevailing pressure reduced to effect polycondensation.
. ~.
.~ ; ~'.
'"',:
~; .
, . .
.
. ' ''. ';
,~ ' .
.. . . . . . .
Pf 26752 ~ 4~6~
Other additives commonly employed in polyester manufacture may be added at a suitable stage in the process, generally before or during the polgcondensation reaction. Examples of such additives are phosphorus compounds, such as o~yacids of phosphorus, e.g.
phosphoric or phosphorous acids, or salts or esters thereof, dyeing assistants, delus1tra~ts, fillers, optical whiteners, dyes, pigments and chain ex~enders.
The esterification reaction is conducted at an ele~ated temperature, generally in the range 200~280C, ~- generally under ele~ated pressure, with removal of water by distillation.
The polycondensation reaction is generally conducted at a temperature in the range of 250-300C under a reduced pressure, generally less than 30 mm of mercur~, with removal of the evolred glycol.
The invention is particularly suited to the ~; production of polyesters for ~ibre or film manufacture.
~he inventio~ is illustrated by the ~ollowing e~amples wherein all parts and percentages are , expressed by weight~
(Examples I, II and IV are comparative).
Example I ~ -60.5 part~of terephthalic acid and 38 8 parts ; 2~5~ ethylene~glycol were esterified under a pre~Burs of .
,::
P~ 26152 768~
40 psi at a temperature of 240C i.n the presence of 0.0035 parts sodium hydroxide. 0.07 parts triphenyl phosphate stabiliser were then added after esterification, followed by 0.0035 parts of : 5 amorphous germanium dioxide and 0.021 ~arts antimony : trioxide were added as polycondensation catalyst.
Polycondensa~ion was completed by raisi~g the . temperature to 290C and applying a vacuum of 0.1 mm .
of mercury~ ~he resultant polymer had an intrinsic : .
~ 10 viscosity (IY) - as measured on a 1% solution in -~
: o-chlorophenol at 25C - of 0.658, a yellowness of 30 units and softening point of 255.4C. ~he yellowness figure quoted is a measurement uf the colour of the sample obtained on a "colormaster" dif~erential .1 15 colorimeter. ~he higher the yellowness figure, the poorer the colour of the polymer.
: : Exam~e II : :
-~ Polymer was made as described in Example I but .. ~ instead of amorphous germanium dioxide, 0.0035 parts hexagonal germanium dioxlde dissolved in an ethylene glycol solution containing 0.0014 parts sodium hydroxide were added after esterification together ~wlth the:antimon;~ trioxide as polycondensation catalyst.
he resultant~polymer~had~an IV Or 00694~, a yellowness :: of~40 units `and a softening point of 255.1C. . ;
. .
P~ 26752 ~47~3 ; Example III
60.5 parts terephthalic acid and 38.8 part~
; .
ethylene glycol were esterified under the conditions deQcribed in Example I but i~ the presence o~ 0.00~5 5 parts hexagonal germanium dioxide dissolved in ~n ethylene gl~col solution containillg the 0.0035 part~
sodium hydroxide. 0.07 parts triphenyl phosphate :
~tabiliser and 0.021 parts antimony trioxide catalyst were added a~ter esterification and polycondensation . ~, completed as in ~xamplea I and II. ~he polymer .. ..
of IV 90682 ga~e a yellowne~s o~ 27 unit~ and a sortanin~ point of 256~7Co ~, Example IV
86.5 parts terephthalic acid and 42 p~rts ethylene glycol we~e esterified at a temp~erature o~ 241C and ~: J ~ a~ pre~ure o~ 2~8 atmospheres in~the presence of 0.005 part~ sodium hydroxide.; 0.21 part~ triphenyl ~ : :
phosphate as ~tabiliser and 0.005 parts he~agona1 germani~m dioxide, dis~oIved~in an~eth~lene glycol ~ ~olution containing 0.002 parts sodium h~droxide, and 0.03 part3 antimo~y trioxide as po1ycondensation ~,~ catalyst were then added. Polycondensation was completed~by~rai~ing~the tomperature to 290a and~
decreasing the pr~sQure to 0.1 mm mercur~ pressure.
Pf 26752 6~
~he polymer had a~ IV of 0~658, a yellowness of 32 units and softening point of 25B.8C.
., ~Z
86.5 parts terephthalic acid and 42 part~i ethylene glycol were esterified at a temperature of 241C
and pressure of 2.8 atmospheres in the presence o~ :
0.005 parts hexago~al germanium di~Dxide di~solved in an ethylene gl~col solution containing 0.005 parts sodium hydroxide. 0.21 parts triphenylphosphate and 0.03 parts a~timony trioxide were added a~ter esterification and the polycondensation was co~pleted ~ as in Example IV. ~he polymer had a~ IV of 0.645, :1 yellow~ess of 25 units and softening point 259~2C --~, ;,~ . :' . .
~:
'~
.
.
. ~ ~
.. : . ;. . ;.. - :. - . , ~ ., ,: " ..... ., . - . . , ~ : . ... . .
, . , ~ ~ . , : :. ... .. ... .. . . . .... ... .. .
Claims (3)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for the production of polyethylene terephthalate which comprises: (a) esterifying terephthalic acid with ethylene glycol at an ele-vated temperature; and (b) polycondensing the product of (a), without isolation, under reduced pressure and in the presence of antimony trioxide in amount 100 to 1000 parts per million by weight of the terephthalic acid originally present, step (a) being carried out in the presence of a solution of germanium dioxide in alkali metal hydroxide and ethylene glycol, the amount of germanium dioxide being 10 to 200 parts per million by weight based on the amount of terephthalic acid present at the start of the reaction and the amount of the alkali metal hydroxide being: (i) greater than the equivalent per mole of germanium dioxide;
(ii) greater than 0.5 gram equivalents per million grams of the dicarboxylic acid; and (iii) less than the greater of twice the equivalent per mole of ger-manium dioxide and 2.5 gram equivalents per million grams of the dicarboxylic acid.
(ii) greater than 0.5 gram equivalents per million grams of the dicarboxylic acid; and (iii) less than the greater of twice the equivalent per mole of ger-manium dioxide and 2.5 gram equivalents per million grams of the dicarboxylic acid.
2. A process for the production of polyethylene terephthalate which comprises: (a) esterifying terephthalic acid with ethylene glycol at an ele-vated temperature; (b) polycondensing the product of (a), without isolation, under reduced pressure and in the presence of antimony trioxide in amount 100 to 1000 parts per million by weight of the terephthalic acid originally present;
step (a) being carried out in the presence of a solution of germanium dioxide in sodium hydroxide and ethylene glycol, the amount of germanium dioxide being 10 to 200 parts per million by weight based on the amount of terephthalic acid present at the start of the reaction and the amount of the sodium hydroxide being: (i) greater than 38.2 parts by weight per 100 parts by weight of ger-manium dioxide; (ii) greater than 20 parts by weight per million parts by weight of the terephthalic acid; (iii) less than the greater of 76.4 parts by weight per 100 parts by weight of germanium dioxide and 100 parts by weight per million parts by weight of terephthalic acid.
step (a) being carried out in the presence of a solution of germanium dioxide in sodium hydroxide and ethylene glycol, the amount of germanium dioxide being 10 to 200 parts per million by weight based on the amount of terephthalic acid present at the start of the reaction and the amount of the sodium hydroxide being: (i) greater than 38.2 parts by weight per 100 parts by weight of ger-manium dioxide; (ii) greater than 20 parts by weight per million parts by weight of the terephthalic acid; (iii) less than the greater of 76.4 parts by weight per 100 parts by weight of germanium dioxide and 100 parts by weight per million parts by weight of terephthalic acid.
3. A method according to claim 1 or 2, in which the solution of german-ium dioxide employed in step (a) is a solution of the hexagonal, crystalline form of germanium dioxide.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB383174A GB1458585A (en) | 1974-01-28 | 1974-01-28 | Polyester production |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1047689A true CA1047689A (en) | 1979-01-30 |
Family
ID=9765769
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA218,502A Expired CA1047689A (en) | 1974-01-28 | 1975-01-23 | Polyester production |
Country Status (10)
| Country | Link |
|---|---|
| JP (1) | JPS50108393A (en) |
| AU (1) | AU7737975A (en) |
| BE (1) | BE824886A (en) |
| CA (1) | CA1047689A (en) |
| DE (1) | DE2503392A1 (en) |
| FR (1) | FR2259121B1 (en) |
| GB (1) | GB1458585A (en) |
| IT (1) | IT1030994B (en) |
| LU (1) | LU71731A1 (en) |
| NL (1) | NL7500751A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5242645A (en) * | 1989-11-15 | 1993-09-07 | Toray Industries, Inc. | Rubber-reinforcing polyester fiber and process for preparation thereof |
-
1974
- 1974-01-28 GB GB383174A patent/GB1458585A/en not_active Expired
-
1975
- 1975-01-16 AU AU77379/75A patent/AU7737975A/en not_active Expired
- 1975-01-20 IT IT1941575A patent/IT1030994B/en active
- 1975-01-22 NL NL7500751A patent/NL7500751A/en not_active Application Discontinuation
- 1975-01-23 CA CA218,502A patent/CA1047689A/en not_active Expired
- 1975-01-24 FR FR7502230A patent/FR2259121B1/fr not_active Expired
- 1975-01-27 LU LU71731A patent/LU71731A1/xx unknown
- 1975-01-28 JP JP1183975A patent/JPS50108393A/ja active Pending
- 1975-01-28 BE BE152801A patent/BE824886A/en unknown
- 1975-01-28 DE DE19752503392 patent/DE2503392A1/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| NL7500751A (en) | 1975-07-30 |
| JPS50108393A (en) | 1975-08-26 |
| BE824886A (en) | 1975-07-28 |
| FR2259121A1 (en) | 1975-08-22 |
| GB1458585A (en) | 1976-12-15 |
| FR2259121B1 (en) | 1979-09-28 |
| AU7737975A (en) | 1976-07-22 |
| IT1030994B (en) | 1979-04-10 |
| DE2503392A1 (en) | 1975-07-31 |
| LU71731A1 (en) | 1976-08-19 |
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