FR2515664A1 - COMPOSITIONS CONTAINING POLYETHYLENE TEREPHTHALATE AND ANTIMONY OXIDE AND THEIR PREPARATION - Google Patents

Abstract

THE INVENTION RELATES TO COMPOSITIONS CONTAINING POLYETHYLENE TEREPHTHALATE AND ANTIMONY OXIDE, AND TO THEIR PREPARATION. MOLDING COMPOSITIONS BASED ON POLYETHYLENE TEREPHTHALATE, CHARACTERIZED BY RAPID CRYSTALLIZATION, ARE PREPARED BY COMBINING POLYETHYLENE TEREPHTHALATE AND A FILLER OR A REINFORCING AGENT, WITH A PROMOTER OR ACTIVATOR OF SPEED CRYSTALLIZATION, WITH A SPEED CRISTALLIZER OR CONSISTENT, ANTIMONY OXIDE.

Description

"Compositions containing polyethylene terephthalate and oxide

of antimony, and their preparation "

  The present invention relates to

  positions containing rapidly crystallizing polyethylene terephthalate and antimony oxide, and

  it also relates to the preparation of these

positions.

  Homopolymers and copolymers of terephthalate

  They are characterized by excellent physical properties which make them materials of great interest for films, fibers and molding applications.

  reinforcement, such as fiberglass, in order to improve

  improve the mechanical properties of the final products

  prepared from polyethylene terephthalate.

  It has been found, however, that the relative speed

  slowly crystallizing the terephthalate

  lyethylene and its copolymers greatly limit the use

  the use of these polyester compositions in

  In this way, many attempts have been made to discover promoters

  or activators that would accelerate the crystallization rate

  polyethylene terephthalate and its copolymers

  lymers Among the various patents that have been issued

  for accelerations of crystallization speed

  polyethylene terephthalate and which develop the efforts made according to the prior art

  to overcome the disadvantages of crystal speed

  These polyesters include US Pat. Nos. 3,673,130, 4,098,845, 4,107,149, and 4,136,089. Further, British Patent No. 1,505,599 and German patents may be mentioned. Nos. 2,545,720, 2,653,120, 2,706,123,

  2,706,124 and 2,706,128. As these letters show.

  previous vests, attempts made following the

  prior art were focused on the devel-

  development of specific additives or promoters

  the crystallization rates of homopoly-

  mothers and copolymers of polyethylene terephthalate.

  However, the stringent requirements of

  injection age and the economic factors involved

  in this field of technology are such that

  courage in predicting other ways to improve

  crystallization rates of these polyesters.

  It has been found, according to the present invention, that the crystallization rate of homopolymers and copolymers of polyethylene terephthalate per se and

  in molding compositions containing these polyes-

  ters, can be improved by the addition of

  polyethylene terephthalate monk and the composites

  containing the latter and its homopolymers or

  lymers The incorporation of antimony oxide into the

  Polyethylene terephthalate

  obtaining a polyethylene terephthalate with crys-

  rapid solution, particularly suitable for

  injection molding processes.

  The compositions containing the antimony oxide,

  fiberglass and the terephthalic-based material

  Polyethylene can be prepared according to

  ceded known to specialists in this field Any-

  It has been found that it is particularly

  to dry mix the basic materials and ex-

  trow the resulting mixture to ensure mixing

  and the tabletting of the metal composition

  It has furthermore been found that it is advantageous to

  to achieve the combination of the ingredients of the composition

  molding process in two or more

  instead of doing it in one phase.

  According to the present invention, it has therefore been

  that antimony oxide is an effective promoter or promoter of the crystallization rate of polyethylene terephthalate and its homopolymers or copolymers,

  to the point of making polyethylene terephthalate

  Readable on a wider range of conditions and applications This antimony oxide can be added to polyethylene terephthalate

  from about 0.1 to about 40.0% by weight of the terephthalene

  It is preferred, however, to add the oxide of

  monk in amounts of about 2 to about 10%.

  We can add antimony oxide as it is

  to a composition based on polyethylene terephthalate.

  However, to obtain the best results, it has been found that it is advantageous to prepare a concentrate

  5% antimony oxide and polyethylene terephthalate

  and add this concentrate to the terephrine

  polyethylene phthalate in an amount calculated to

  give the desired concentration in the final mixture.

  In the general implementation of the pre-

  In this invention, the combination of the ingredients is made by extrusion. However, other means of combination will be obvious to the specialists in this field and will therefore remain within the scope of the present invention.

this invention.

  The following Examples are intended only to illustrate the invention without any limitation of the scope

of it.

  EXAMPLE 1 5 parts of antimony oxide and 95 parts of polyethylene terephthalate are dry blended and

  extrude the resulting mixture at a temperature of

  270-3000 C to combine the mixing and

form into pellets.

  Portions of the resulting concentrate are

  dried with additional quantities of tere-

  polyethylene phthalate and the mixture is extruded at a

  melting temperature of 270-3000 C to give the

  concentration of antimony oxide, compared with the composition

  as shown in the following Table.

  These specimens are identified in this table under the

  heading "Concentrated addition method".

  Other mixtures of

  monk with polyethylene terephthalate, in pre-

  seeing the concentrations, relative to the total composition, as presented in the following Table, this preparation being done by dry mixing followed

  extrusion at a melting temperature of 270-300 ° C.

  These specimens are identified in the following Table

  under the heading "Direct-channel addition method".

BOARD

BOARD

Echantil-

lon% No PET, q Sb 2 o 3, cq Sb 2 g 3

1 1400

  % Addition Method Concentrated Direct Way X

1900

1600

6 1800

7999

8,998

9,997

995

11,992

% 1 t O%

5 O%

400 20%

10 t O% 1 01 l%

2,012%

3 Y y 3%

O 05%

8 o t 8% In the slow DSC test

(calorimetry to explo-

  differential ration), which is mentioned in

  Table above, slices of

  then at least two molding cubes up to a sample weight of 5 mg The samples are loaded into an aluminum dish and closed in a press.

  bowl is heated under nitrogen since the temperature

  biante up to 285-290 C at a rate of 40 C / minute.

  temperature is maintained at 290 C for 5 minutes and DSC T C X X X X X X X X X X

  the aluminum bowl is pressurized to

  good contact with the subjects It is then necessary to

  cold at a rate of 20 C / minute up to 50 C or less.

  The sample is then heated under nitrogen from room temperature, at a rate of 20 C / minute, to the melting point. As soon as we have reached the baseline, cooling is started at 20 C / minute The curves of the melting point and the

freezing point.

  The value t T is the difference between the

  melting point and the freezing point of the thermo-

  DSC value A low AT value indicates a speed

  Rapid crystallization value A T value less than 60 is generally considered an indication of good molding properties More comprehensive considerations regarding the use of "Differential scanning colorimetry" in determining the crystallization properties of polyethylene terephthalate can be found in the article:

  Einfluss verzweigter Codiole auf das Kristallizersver-

  Halten von aromatischen Polyester "P Bier and Col; Die Angewandte Makromolekulare Chemie 65; No. 1005; 1977;

  pages 1-21, especially pages 5-12.

Example 2

  A molding composition is prepared comprising

  60% polyethylene terephthalate, 30% glass fiber and 10% antimony oxide, by dry blending these ingredients and extruding the resulting blends

  at a melting temperature of 270-300 C.

  The resulting composition is molded

  jection into test bars 12.7 cm x 1.27 cm x 0.31 cm.

  The resulting test bars are characterized by smooth and flat surfaces, in contrast with control bars from compositions not containing

  of antimony oxide, these bars having

rough and warped faces.

REVEPDICATIONS

  Compositions, characterized in that they comprise polyethylene terephthalate and

antimony oxide.

  Compositions according to Claim 1, characterized in that they furthermore comprise

glass fibers.

  3 Compositions according to one or the other

  preceding claims, characterized in that the

  ratio of antimony oxide to tere-

  polyethylene phthalate is from about 0.05 to about%. Compositions according to Claim 3,

  characterized in that the proportion of

  monk relative to polyethylene terephthalate is

from about 2.0 to about 10%.

  Process for the preparation of compositions comprising polyethylene terephthalate and oxide

  antimony, characterized in that it comprises the combination

  part of the polyethylene terephthalate with the antimony oxide during an initial operating phase, and the combination, during a second phase, of the rest of the polyethylene terephthalate with the

  combination obtained from the first phase.

  6 Process for the preparation of compositions

  taking polyethylene terephthalate and oxide

  antimony, characterized in that it comprises the combination

  part of polyethylene terephthalate with

  antimony oxide during an initial operational phase

  tial, and the combination of the rest of the polyterephthalate

  ethylene with the combination resulting from the first phase, in two or more additional additions, during

subsequent phases.