U.S. patent application number 12/279575 was filed with the patent office on 2009-01-15 for copolymers comprising polyamide blocks and polyether blocks and having improved optical properties.
This patent application is currently assigned to Arkema France. Invention is credited to Frederic Malet.
Application Number | 20090017246 12/279575 |
Document ID | / |
Family ID | 36952623 |
Filed Date | 2009-01-15 |
United States Patent
Application |
20090017246 |
Kind Code |
A1 |
Malet; Frederic |
January 15, 2009 |
COPOLYMERS COMPRISING POLYAMIDE BLOCKS AND POLYETHER BLOCKS AND
HAVING IMPROVED OPTICAL PROPERTIES
Abstract
Copolymer comprising polyamide PA blocks alternating with
polyether PE blocks, the PA blocks comprising or being composed of
polyamide PA X,Y blocks, optionally PA X,Y/{Z} blocks, obtained by
polycondensation of at least one linear aliphatic diamine having X
carbon atoms; of at least one dicarboxylic acid having Y carbon
atoms; and, if appropriate, of at least one comonomer {Z} chosen
from lactams and .alpha.,.omega.-aminocarboxylic acids having Z
carbon atoms and equimolar mixtures of at least one diamine having
X1 carbon atoms and of at least one dicarboxylic acid having Y1
carbon atoms, (X1, Y1) being different from (X, Y), the said
comonomer or comonomers {Z} having being introduced in a proportion
by weight ranging up to 50%, preferably up to 20%, more
advantageously still up to 10%, with respect to the combined
polyamide precursor monomers; the said copolymer being
characterized in that the said PA blocks comprise carboxyl ends; X
is at least equal to 2; Y is at least equal to 6; the said PE
blocks are either PE blocks comprising hydroxyl ends, otherwise
known as PE diol blocks, so that the bonds between the PA blocks
comprising carboxyl ends and the PE diol blocks are ester bonds;
or, in the case where Y has a number of carbon atoms of greater
than 14, PE blocks comprising NH.sub.2 ends, so that the bonds
between the PA blocks comprising carboxyl ends and the PE blocks
comprising NH.sub.2 ends are amide bonds.
Inventors: |
Malet; Frederic; (Rouen,
FR) |
Correspondence
Address: |
ARKEMA INC.;PATENT DEPARTMENT - 26TH FLOOR
2000 MARKET STREET
PHILADELPHIA
PA
19103-3222
US
|
Assignee: |
Arkema France
Colombes
FR
|
Family ID: |
36952623 |
Appl. No.: |
12/279575 |
Filed: |
February 16, 2007 |
PCT Filed: |
February 16, 2007 |
PCT NO: |
PCT/FR07/50814 |
371 Date: |
August 15, 2008 |
Current U.S.
Class: |
428/36.9 ;
36/25R; 428/221; 525/434 |
Current CPC
Class: |
C08G 69/40 20130101;
Y10T 428/249921 20150401; Y10T 428/139 20150115; C08G 81/00
20130101 |
Class at
Publication: |
428/36.9 ;
525/434; 428/221; 36/25.R |
International
Class: |
B32B 1/08 20060101
B32B001/08; C08L 77/06 20060101 C08L077/06; A43B 13/00 20060101
A43B013/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 16, 2006 |
FR |
06.01355 |
Mar 21, 2006 |
US |
60/784350 |
Claims
1. A copolymer PAX.Y/PE comprising polyamide PA blocks alternating
with polyether PE blocks, the PA blocks being composed of
homopolyamide PAX.Y blocks obtained by polycondensation: of a
linear aliphatic diamine having X carbon atoms; of a dicarboxylic
acid having Y carbon atoms; and said copolymer being wherein: said
PA blocks comprise carboxyl ends; X is at least equal to 4; Y is at
least equal to 10; said PE blocks: (i) are either PE blocks
comprising hydroxyl ends, otherwise known as PE diol blocks, so
that the bonds between the PA blocks comprising carboxyl ends and
the PE diol blocks are ester bonds; (ii) or are PE blocks
comprising NH.sub.2 ends in the case where Y has a number of carbon
atoms of greater than 14, so that the bonds between the PA blocks
comprising carboxyl ends and the PE blocks comprising NH.sub.2 ends
are amide bonds; (iii) comprise from 0 to 39% by weight of
polytrimethylene ether glycol PO3G and/or polyethylene glycol PEG
and from 100 to 61% by weight of polyether other than PO3G or PEG
(% by weight, expressed with respect to the total weight of the
copolymer); wherein the copolymer PAX.Y/PE has improved optical
transmission properties at 460 nm, at 560 nm and at 700 nm in
comparison with a copolymer polyamide 12/polytetramethylene glycol
PA12/PTMG (iv) with the same size of PA block and with the same
size of PE block respectively or (v) with the same stiffness,
defined either by a flexural modulus (in MPa) or by a tensile
modulus (in MPa) or by a Shore D hardness.
2. The copolymer as claimed in claim 1, wherein the 100 to 61% of
polyether in (iii) are chosen from PTMG, polypropylene glycol PPG,
their blends and their copolymers.
3. The copolymer as claimed in claim 1, wherein X+Y.gtoreq.22.
4. The copolymer as claimed in claim 3, wherein X+Y.gtoreq.24.
5. The copolymer as claimed in claim 3, wherein X+Y=22 and the PA
block is a PA10.12 block.
6. The copolymer as claimed in claim 4, wherein X+Y=24 and the PA
block is a PA6.18.
7. The copolymer as claimed in claim 4, wherein the PA block is
PA10.14.
8. The copolymer as claimed in claim 4, wherein X+Y=26 and the PA
block is a PA12.14 block.
9. The copolymer as claimed in claim 4, wherein X+Y=28 and the PA
block is a PA10.18 block.
10. The copolymer as claimed in claim 4, wherein X+Y=30 and the PA
block is a PA12.18 block.
11. The copolymer as claimed in claim 1, wherein the dicarboxylic
acid having Y carbon atoms is chosen from linear aliphatic
diacids.
12. The copolymer as claimed in claim 1, wherein Y is between 12
and 20, limits included.
13. The copolymer as claimed in claim 1, wherein X is between 6 and
20, limits included, preferably between 6 and 14, limits
included.
14. The copolymer as claimed in claim 1, wherein the number-average
molecular weight of its PA blocks is between 500 and 10 000.
15. The copolymer as claimed in claim 1, wherein the number-average
molecular weight of its PE blocks is between 250 and 5000.
16. The copolymer as claimed in claim 1, wherein the number-average
molecular weight of said copolymer is between 5000 and 50 000.
17. The copolymer as claimed in claim 1, wherein the PA blocks
advantageously represent between 5 and 95% by weight, of the sum of
the PA blocks and PE blocks of said copolymer.
18. A process for the preparation of a copolymer as defined in
claim 1, comprising: preparing in a first stage, the polyamide PA
blocks by polycondensation of the linear aliphatic diamine having X
carbon atoms; of the dicarboxylic acids having Y carbon atoms; and
in the presence of a chain-limiting agent chosen from dicarboxylic
acids; then reacting in the second stage, the polyamide PA blocks
obtained with polyether PE blocks in the presence of a
catalyst.
19. The process for the preparation of a copolymer as defined in
claim 1, wherein a single-stage polycondensation is carried out: of
the linear aliphatic diamine having X carbon atoms; in the presence
of a chain-limiting agent chosen from dicarboxylic acids; in the
presence of polyether PE blocks; and in the presence of a catalyst
for the reaction between the PE blocks and the PA blocks.
20. The process as claimed in claim 18, wherein use is made, as
chain-limiting agent, of the dicarboxylic acid having Y carbon
atoms, which is introduced in excess with respect to the
stoichiometry of the diamine.
21. The process as claimed in claim 18, wherein use is made, as
catalyst, of a derivative of a metal chosen from the group formed
by titanium, zirconium and hafnium or a strong acid, such as
phosphoric acid or boric acid.
22. The process as claimed in claim 18, wherein the
polycondensation at carried out at a temperature from 180 to
300.degree. C.
23. A shaped article, comprising the copolymer as defined in claim
1, wherein said article is a fiber, fabric, film, sheet, rod, pipe,
injection-molded component, or a shoe sole,
24. (canceled)
25. The copolymer of claim 1, wherein X is at least 4, and Y is at
least 12.
26. The copolymer as claimed in claim 1, wherein the number-average
molecular weight of its PA blocks is between 1500 and 6000, and the
number-average molecular weight of its PE blocks is between 350 and
1000.
Description
[0001] The present invention relates to novel copolymers comprising
polyamide blocks (abbreviated to PA block) and polyether blocks
(abbreviated to PE block) having improved optical and/or mechanical
properties. Such block copolymers are also known as
polyether-block-amides (abbreviation PEBA).
[0002] The PEBA copolymers of the invention belong to the specific
category of the polyetheresteramides when they result from the
copolycondensation of polyamide blocks comprising reactive carboxyl
ends with polyether blocks comprising reactive ends which are
polyether polyols (polyether diols), the bonds between the
polyamide blocks and the polyether blocks being ester bonds, or
also to the category of the polyetheramides when the polyether
blocks comprise amine ends.
[0003] The document EP 1 500 684 reports antistatic elastomeric
compositions comprising a PEBA copolymer comprising PE blocks
essentially made of PEG and PAX.Y blocks with X an aliphatic
diamine, such as, for example, hexamethylenediamine and C.sub.9 to
C.sub.25 diamines, and Y a C.sub.9 to C.sub.25 aliphatic diacid.
These copolymers possessing antistatic properties do not come
within the scope of our invention and are, of course, excluded as
such.
[0004] The document EP 1 262 527 relates to an antistatic polymer
composition comprising a PEBA of PAX.Y type with, as aliphatic
diamine X: hexamethylenediamine, dodecamethylenediamine and
trimethylhexamethylenediamine, and, as aliphatic diacid Y: butanoic
acid, adipic acid, azelaic acid, suberic acid, sebacic acid,
dodecanedicarboxylic acid, dimerized fatty acids and
polyoxyalkylene-.alpha.,.omega.-diacids. The PE blocks made of PEG,
which confer the antistatic properties on the copolymer and on the
composition, can be used with PPG blocks, indeed even with PTMG
blocks. These copolymers do not come within the scope of our
invention and are, of course, excluded as such.
[0005] The document WO 03/050159 discloses PEBAs with, as hard
segment, a PAX.Y block with X a linear aliphatic diamine comprising
4-14 carbon atoms and Y a linear aliphatic diacid comprising from 4
to 14 carbon atoms and with, as soft segment, PO3G, it being
possible for the latter to comprise up to 60% by weight of another
polyether, such as PEG, PPG and PTMG. These copolymers do not come
within the scope of our invention and are, of course, excluded as
such.
[0006] The document WO 04/037898 has as subject matter a copolymer
comprising PA blocks and PE blocks, the PA blocks of which are
copolyamides which can be of the PAX1.Y1/X2.Y2 or PAX1.Y1/Z type,
X1 and X2 being diamines, Y1 and Y2 being diacids and Z being a
lactam or an amino acid. These copolymers do not come within the
scope of our invention and are, of course, excluded as such.
[0007] The Applicant Company has discovered, surprisingly, a novel
category of PEBAs exhibiting improved optical properties, in
particular a reduction in the opaqueness of the PEBAs, and/or
improved mechanical properties, in particular a very good dynamic
fatigue resistance.
[0008] The subject matter of the present invention is thus, in the
context of improved optical properties, a copolymer PAX.Y/PE
comprising polyamide PA blocks alternating with polyether PE
blocks, the PA blocks being composed of homopolyamide PAX.Y blocks
obtained by polycondensation: [0009] of a linear aliphatic diamine
having X carbon atoms; [0010] of a dicarboxylic acid having Y
carbon atoms; said copolymer being characterized in that: [0011]
said PA blocks comprise carboxyl ends; [0012] X is at least equal
to 4, preferably at least equal to 6; [0013] Y is at least equal to
10, preferably at least equal to 12; [0014] said PE blocks: [0015]
(i) preferably, are either PE blocks comprising hydroxyl ends,
otherwise known as PE diol blocks, so that the bonds between the PA
blocks comprising carboxyl ends and the PE diol blocks are ester
bonds; [0016] (ii) preferably, or are PE blocks comprising NH.sub.2
ends in the case where Y has a number of carbon atoms of greater
than 14, so that the bonds between the PA blocks comprising
carboxyl ends and the PE blocks comprising NH.sub.2 ends are amide
bonds; [0017] (iii) comprise from 0 to 39% by weight of PO3G and/or
PEG and from 100 to 61% by weight of polyether other than PO3G or
PEG (% by weight, expressed with respect to the total weight of the
copolymer); characterized in that the copolymer PAX.Y/PE has
improved optical transmission properties at 460 nm, at 560 nm and
at 700 nm in comparison with a copolymer PA12/PTMG (iv) with the
same size of PA block and with the same size of PE block
respectively and/or (v) with the same stiffness, defined either by
a flexural modulus (in MPa) or by a tensile modulus (in MPa) or by
a Shore D hardness.
[0018] According to one embodiment, the copolymer is characterized
in that the 100 to 61% of polyether in (iii) are chosen from PTMG,
PPG, their blends and their copolymers.
[0019] According to one embodiment, the copolymer is characterized
in that X+Y.gtoreq.22, preferably .gtoreq.24 and is advantageously
equal to 22, 24, 26, 28 or 30.
[0020] According to one embodiment, the copolymer is characterized
in that the PA block is chosen from a PA10.12, PA6.18, PA10.14,
PA12.12, PA12.14, PA10.18 and PA12.18 block.
[0021] The subject matter of the present invention is thus, in the
context of improved mechanical properties, a copolymer PAX.Y/PE
comprising polyamide PA blocks alternating with polyether PE
blocks, the PA blocks being composed of homopolyamide PAX.Y blocks
obtained by polycondensation: [0022] of a linear aliphatic diamine
having X carbon atoms; [0023] of a dicarboxylic acid having Y
carbon atoms; and said copolymer being characterized in that:
[0024] said PA blocks comprise carboxyl ends; [0025] X is at least
equal to 4, preferably at least equal to 6; [0026] Y is at least
equal to 10, preferably at least equal to 12; [0027] said PE
blocks: [0028] (iv) preferably, are either PE blocks comprising
hydroxyl ends, otherwise known as PE diol blocks, so that the bonds
between the PA blocks comprising carboxyl ends and the PE diol
blocks are ester bonds; [0029] (v) preferably, or are PE blocks
comprising NH.sub.2 ends in the case where Y has a number of carbon
atoms of greater than 14, so that the bonds between the PA blocks
comprising carboxyl ends and the PE blocks comprising NH.sub.2 ends
are amide bonds; [0030] (vi) comprise from 0 to 39% by weight of
PO3G and/or PEG and from 100 to 61% by weight of polyether other
than PO3G or PEG (% by weight, expressed with respect to the total
weight of the copolymer); characterized in that (iv) the
crystallinity of the PAX.Y block is > the crystallinity of a
PA12 block of the same size and/or (v) the PA/PE phase separation
of said copolymer PAX.Y/PE is > that of a copolymer PA12/PTMG
composed of PA12 blocks of the same size as the PAX.Y blocks of
said copolymer PAX.Y/PE and of PTMG blocks of the same size as the
PE blocks of the PAX.Y/PE copolymer.
[0031] According to a specific embodiment, the copolymer is
characterized in that X+Y.ltoreq.24, preferably equal to 24 or to
22 or to 20.
[0032] According to one embodiment, the copolymer is characterized
in that the PA block is chosen from a PA10.14, PA12.12, PA6.18,
PA10.12, PA6.14 and PA10.10 block.
[0033] According to one embodiment, the copolymer is characterized,
in the context of the improved mechanical properties and/or
improved optical properties: [0034] in that the dicarboxylic acid
having Y carbon atoms is chosen from linear aliphatic diacids;
[0035] in that Y is between 10 and 20, advantageously between 12
and 20, preferably between 10 and 18, more preferably still between
12 and 18, limits included. Thus, mention may be made, as
dicarboxylic acids having Y carbon atoms, of sebacic acid,
dodecanedicarboxylic acid or octadecanedicarboxylic acid; [0036] in
that X is between 6 and 20, limits included, preferably between 6
and 14, limits included. Thus, mention may be made, as linear
aliphatic diamines having X carbon atoms, of tetramethylenediamine,
hexamethylenediamine and 1,10-decamethylendiamine.
[0037] The polyamide block PAX.Y, depending on its properties, is
advantageously chosen from polyamide 4.12, polyamide 4.14,
polyamide 4.18, polyamide 6.10, polyamide 6.12, polyamide 6.14,
polyamide 6.18, polyamide 9.12, polyamide 10.10, polyamide 10.12,
polyamide 10.14 and polyamide 10.18 blocks. In a more particularly
preferred way, the polyamide block PAX.Y is a PA6.18 or PA10.14
block for the improved optical properties and a PA6.12 or PA6.14
block for the improved mechanical properties.
[0038] PA6.12/PTMG can be excluded from the scope of our
invention.
[0039] The polyamides PAX.Y below result from the condensation of
the diamine X and the diacid Y, such as: [0040] PA4.12:
1,4-tetramethylenediamine and 1,10-decanedicarboxylic acid. [0041]
PA4.14: 1,4-tetramethylenediamine and 1,12-dodecanedicarboxylic
acid. [0042] PA4.18: 1,4-tetramethylenediamine and
1,16-hexadecanedicarboxylic acid. [0043] PA6.10:
hexamethylenediamine and sebacic acid. [0044] PA6.12:
hexamethylenediamine and 1,10-decanedicarboxylic acid. [0045]
PA6.14: hexamethylenediamine and 1,12-dodecanedicarboxylic acid.
[0046] PA6.18: hexamethylenediamine and 1,16-hexadecanedicarboxylic
acid. [0047] PA9.12: 1,9-nonanediamine and 1,10-decanedicarboxylic
acid. [0048] PA10.10: 1,10-decamethylenediamine and sebacic acid.
[0049] PA10.12: 1,10-decamethylenediamine and
1,10-decanedicarboxylic acid. [0050] PA10.14:
1,10-decamethylenediamine and 1,12-dodecanedicarboxylic acid.
[0051] PA10.18: 1,10-decamethylenediamine and
1,16-hexadecanedicarboxylic acid.
[0052] The polyether blocks of the PEBA copolymer of the invention
advantageously result from at least one polyalkylene ether polyol,
in particular a polyalkylene ether diol more particularly chosen
from polypropylene glycol (PPG), polytetramethylene glycol (PTMG),
their blends and their copolymers. Preferably, PTMG will be
chosen.
[0053] For Y>14, the PE blocks can comprise a blend of PE blocks
or be a polyether copolymer. In this case, they comprise 0-39% by
weight of PO3G and/or PEG and 100-61% by weight of polyether(s)
other than PO3G or PEG (weight with respect to the weight of the PE
blocks).
[0054] The PE blocks are never predominantly of PEG and never
comprise more than 39% by weight of PO3G (weight with respect to
the weight of the PE blocks).
[0055] The polyether blocks of the PEBA copolymer according to the
present invention can also be polyoxyalkylene blocks comprising
NH.sub.2 chain ends, it being possible for such blocks to be
obtained by cyanoacetylation of aliphatic
polyoxyalkylene-.alpha.,.omega.-dihydroxyl blocks, also known as
polyether diols. More particularly, use may be made of Jeffamines
(for example Jeffamine.RTM. D400, D2000, ED 2003 and XTJ 542,
products sold by Huntsman. See also patents JP 2004346274, JP
2004352794 and EP 1 482 011).
[0056] The number-average molecular weight of a copolymer according
to the present invention is advantageously between 5000 and 50 000,
preferably between 10 000 and 30 000.
[0057] The number-average molecular weight of the PA blocks is
advantageously between 500 and 10 000, preferably between 600 and
7000, more advantageously still between 1500 and 6000.
[0058] The number-average molecular weight of the PE blocks is
advantageously between 250 and 5000, preferably between 250 and
2000, more advantageously still between 350 and 1000.
[0059] The PA blocks advantageously represent between 5 and 95% by
weight, preferably between 10 and 95% by weight, of the sum of the
PA blocks and PE blocks of the copolymer of the present
invention.
[0060] Another subject matter of the invention is a process for the
preparation of a copolymer as defined above, in several stages,
characterized in that: [0061] in a first stage, the polyamide PA
blocks are prepared by polycondensation [0062] of the linear
aliphatic diamine having X carbon atoms; [0063] of the dicarboxylic
acids having Y carbon atoms; and [0064] in the presence of a
chain-limiting agent chosen from dicarboxylic acids; then [0065] in
the second stage, the polyamide PA blocks obtained are reacted with
polyether PE blocks in the presence of a catalyst.
[0066] The general method for the preparation in two stages of the
PEBA copolymers of the invention having ester bonds between the PA
blocks and the PE blocks is known and is described, for example, in
French patent FR 2 846 332. The general method for the preparation
of the PEBA copolymers of the invention having amide bonds between
the PA blocks and the PE blocks is known and described, for
example, in European patent EP 1 482 011.
[0067] The reaction for the formation of the PA block is usually
carried out between 180 and 300.degree. C., preferably from 200 to
290.degree. C., the pressure in the reactor becomes established
between 5 and 30 bar and is maintained for approximately 2 to 3
hours. The pressure is slowly reduced by placing the reactor at
atmospheric pressure and then the excess water is distilled off,
for example over one or two hours.
[0068] The polyamide comprising carboxylic acid ends having been
prepared, the polyether and a catalyst are subsequently added. The
polyether can be added on one or more occasions, and likewise for
the catalyst. According to an advantageous form, the polyether is
first added and the reaction of the OH ends of the polyether and of
the COOH ends of the polyamide begins with the formation of ester
bonds and elimination of water. As much as possible of the water is
removed from the reaction medium by distillation and then the
catalyst is introduced in order to complete the bonding of the
polyamide blocks and polyether blocks. This second stage is carried
out with stirring, preferably under a vacuum of at least 6 mmHg
(800 Pa), at a temperature such that the reactants and the
copolymers obtained are in the molten state. By way of example,
this temperature can be between 100 and 400.degree. C. and
generally 200 and 300.degree. C. The reaction is monitored by
measuring the torque exhibited by the molten polymer on the stirrer
or by measuring the electric power consumed by the stirrer. The end
of the reaction is determined by the value of the target torque or
of the target power.
[0069] The invention also relates to a process for the preparation
of a copolymer as defined above, characterized in that a
single-stage polycondensation is carried out: [0070] of the linear
aliphatic diamine having X carbon atoms; [0071] in the presence of
a chain-limiting agent chosen from dicarboxylic acids; [0072] in
the presence of polyether PE blocks; and [0073] in the presence of
a catalyst for the reaction between the PE blocks and the PA
blocks.
[0074] Whatever the process for the manufacture of the copolymer,
in a single stage or in several stages: [0075] the process is
characterized in that it is possible to use, as chain-limiting
agent, the dicarboxylic acid having Y carbon atoms, which is
introduced in excess with respect to the stoichiometry of the
diamine; [0076] the process is characterized in that it is possible
to use, as catalyst, a derivative of a metal chosen from the group
formed by titanium, zirconium and hafnium or a strong acid, such as
phosphoric acid or boric acid; [0077] the process is characterized
in that it is possible to carry out the polycondensation at a
temperature from 180 to 300.degree. C.; [0078] the catalyst is
defined as being any product which makes it possible to facilitate
the bonding of the polyamide blocks and the polyether blocks by
esterification or by amidation. The esterification catalyst is
advantageously a derivative of a metal chosen from the group formed
by titanium, zirconium and hafnium or also a strong acid, such as
phosphoric acid or boric acid.
[0079] Examples of catalysts are those described in patents U.S.
Pat. No. 4,331,786, U.S. Pat. No. 4,115,475, U.S. Pat. No.
4,195,015, U.S. Pat. No. 4,839,441, U.S. Pat. No. 4,864,014, U.S.
Pat. No. 4,230,838 and U.S. Pat. No. 4,332,920. [0080] It is also
possible to add, during the synthesis, at the moment judged the
most opportune, one or more molecules used as antioxidant, for
example Irganox.RTM. 1010 or Irganox.RTM. 245.
[0081] Another subject matter of the present invention is a shaped
article which can advantageously be transparent or translucid, such
as, for example, fiber, fabric, film, sheet, rod, pipe or any
injection-molded component (components of shoe soles, and the
like), comprising the copolymers as defined above.
[0082] The invention furthermore relates to the use of a copolymer
PAX.Y/PE mentioned above in manufacturing an item, the optical
properties of which are improved in comparison with the same item
manufactured with a copolymer PA12/PTMG comprising PA blocks made
of PA12 and comprising PE blocks made of PTMG, it being known that:
[0083] the size of the PA blocks of said copolymers PAX.Y/PE and
PA12/PTMG is the same or substantially the same and the size of the
PE blocks of said copolymers PAX.Y/PE and PA12/PTMG is the same or
substantially the same; and/or [0084] the stiffness of said
copolymers PAX.Y/PE and PA12/PTMG is the same or substantially the
same, said stiffness being defined either by a flexural modulus (in
MPa) or by a tensile modulus (in MPa) or by a Shore D hardness.
[0085] "Substantially" means that the value either of the flexural
modulus (in MPa) or of the tensile modulus (in MPa) or of the Shore
D hardness of the copolymer PAX.Y/PE according to the invention is
greater or lower by at most 20%, preferably by at most 10%,
advantageously by at most 5%, than the value either of the flexural
modulus (in MPa) or of the tensile modulus (in MPa) or of the Shore
D hardness respectively of the copolymer PA12/PTMG.
[0086] The invention also relates to the use of a copolymer
PAX.Y/PE mentioned above in manufacturing an item, the mechanical
properties of which are improved in comparison with the same item
manufactured with a copolymer comprising PA blocks made of PA12 and
comprising PE blocks made of PTMG, it being known that: [0087] the
size of the PA blocks of said copolymers PAX.Y/PE and PA12/PTMG is
the same or substantially the same and the size of the PE blocks of
said copolymers PAX.Y/PE and PA12/PTMG is the same or substantially
the same; and/or [0088] the crystallinity of the PAX.Y block is
> the crystallinity of a PA12 block of the same size and/or the
PA/PE phase separation of said copolymer PAX.Y/PE is > that of a
copolymer PA12/PTMG composed of PA12 blocks of the same size as the
PAX.Y blocks of said copolymer PAX.Y/PE and of PTMG blocks of the
same size as the PE blocks of the copolymer PAX.Y/PE.
[0089] The following examples illustrate the present invention
without, however, limiting the scope thereof.
EXAMPLE 1
Preparation of Copolymer Comprising Polyamide 6.18 Blocks and
Comprising Blocks Resulting from Polytetramethylene Ether Glycol:
Abbreviated to PA6.18-PTMG
[0090] A PEBA was prepared from PA6.18 blocks with a molar mass of
2000 g/mol and from PTMG blocks with a molar mass of 1000 g/mol
according to the following procedure:
[0091] The following monomers are introduced into an autoclave
equipped with a stirrer so as to obtain PA6.18 blocks: 5 kg of
hexamethylenediamine and 16.9 kg of octadecanedioic acid. The
mixture thus formed is placed under an inert atmosphere and heated
until the temperature reaches 250.degree. C. and a pressure of 32
bar. After maintaining for 1 h, a pressure-reducing operation
lasting 1 h is subsequently carried out in order to return to
atmospheric pressure.
[0092] Polytetramethylene glycol with a mass of 1000 g/mol (10.22
kg) and Zr(OBu).sub.4 (30 g) are subsequently added to the reactor
in order to complete the polymerization at 240.degree. C. under an
absolute pressure of 8 mbar (i.e., 800 Pa).
[0093] The final product PA6.18-PTMG has an intrinsic viscosity of
1.4 dl/g.
[0094] The injection molding of 100*100*2 mm sheets confirms the
improved optical properties of the product with a transmission at
460 nm of 59%, at 560 nm of 74% and at 700 nm of 82%, an opaqueness
of approximately 20% and a haze of 11, which can be compared with
values obtained for a copolymer with the same block size but based
on PA12 and PE=PTMG, respectively 29, 43, 58, 26 and 30.
EXAMPLE 2
Preparation of Copolymer Comprising Polyamide 10.14 Blocks and
Comprising Blocks Resulting from Polytetramethylene Ether Glycol:
Abbreviated to PA10.14-PTMG
[0095] A PEBA was prepared from PA10.14 blocks with a molar mass of
5000 g/mol and from PTMG blocks with a molar mass of 650 g/mol
according to the proceeding procedure with, however, as diamine,
1,10-decamethylenediamine (11.95 kg), as diacid,
1,12-dodecanedicarboxylic acid (19.4 kg), and polytetramethylene
glycol (3.7 kg).
[0096] The final product PA10.14-PTMG has an intrinsic viscosity of
1.28 dl/g.
[0097] The injection molding of 100*100*2 mm sheets confirms the
improved optical properties of the product with a transmission at
460 nm of 49.5%, at 560 nm of 62.9% and at 700 nm of 71.7%
(measurements carried out according to ASTM D 1003), an opaqueness
of approximately 20% (measurement carried out according to ASTM D
1003) and a haze of 11 (measurement carried out according to ISO
2814), which can be compared with the values obtained for a
copolymer with the same size of PA blocks and with the same size of
PE blocks respectively but based on PA12 and PTMG, the said values
respectively being 14, 23, 35, not measured and 25.
[0098] It has also been observed that the thermal properties, in
particular the melting point of the PA phase, may be higher than in
the case of a PA12/PTMG copolymer, this being the case for the same
molar mass of the PA block and of the PE block. In particular, a
PEBA 6.14/PTMG copolymer with a PA6.14 block with a mass of 5000
g/mol and a PTMG block of 650 g/mol has a melting point of
196-206.degree. C., whereas a PEBA copolymer of PA12/PTMG type with
the same size of blocks has a melting point of 172.degree. C.
EXAMPLE 3
Preparation of Copolymer Comprising Polyamide 6.14 Blocks and
Comprising Blocks Resulting from Polytetramethylene Ether Glycol:
Abbreviated to PA6.14-PTMG
[0099] A PEBA was prepared from PA6.14 blocks with a molar mass of
5000 g/mol and from PTMG blocks with a molar mass of 650 g/mol
according to the proceeding procedure with, however, as diamine,
1,6-hexamethylenediamine (13.2 kg), as diacid,
1,12-dodecanedicarboxylic acid (31.6 kg), and polytetramethylene
glycol (5.3 kg). The final product PA6.14-PTMG has an intrinsic
viscosity of 1.44 dl/g.
[0100] The flexural modulus of the product thus obtained (after
conditioning at 23.degree. C. and 50% relative humidity for 14
days) was measured at 680 MPa, which can be compared with the
flexural modulus at 380 MPa for a copolymer with the same size of
PA blocks and with the same size of PE blocks respectively but
based on PA12 and PTMG. Although much stiffer, the novel product
does not break after 150 000 cycles during a flex fatigue test at
-10.degree. C. (Ross Flex test).
EXAMPLE 4
Preparation of Copolymer Comprising Polyamide 6.12 Blocks and
Comprising Blocks Resulting from Polytetramethylene Ether Glycol:
Abbreviated to PA6.12-PTMG
[0101] A PEBA was prepared from PA6.12 blocks with a molar mass of
4000 g/mol and from PTMG blocks with a molar mass of 650 g/mol
according to the proceeding procedure with, however, as diamine,
1,6-hexamethylenediamine (13.9 kg), as diacid, dodecanedioic acid
(29.8 kg), and polytetramethylene glycol (6.4 kg). The final
product PA6.12-PTMG has an intrinsic viscosity of 1.38 dl/g.
[0102] The flexural modulus of the product thus obtained (after
conditioning at 23.degree. C. and 50% relative humidity for 14
days) was measured at 730 MPa, which can be compared with the
flexural modulus at 380 MPa for a copolymer with a larger size of
PA blocks and with the same size of PE blocks respectively but
based on PA12 and PTMG. Although having a greater percentage of
flexible phase than that of the product based on PA12, the product
PA6.12-PTMG is significantly stiffer and does not break after 150
000 cycles during a flex fatigue test at -10.degree. C. (Ross Flex
test).
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