U.S. patent application number 16/961984 was filed with the patent office on 2021-03-25 for thermoplastic elastomer-silicone composition.
The applicant listed for this patent is Arkema France. Invention is credited to Florent ABGRALL, Philippe BLONDEL, Katherine LOYEN, Sebastien MERZLIC, Sebastien-Jun MOUGNIER, Damien RAULINE.
Application Number | 20210087399 16/961984 |
Document ID | / |
Family ID | 1000005289768 |
Filed Date | 2021-03-25 |
![](/patent/app/20210087399/US20210087399A1-20210325-C00001.TIF)
United States Patent
Application |
20210087399 |
Kind Code |
A1 |
MERZLIC; Sebastien ; et
al. |
March 25, 2021 |
THERMOPLASTIC ELASTOMER-SILICONE COMPOSITION
Abstract
The invention relates to a composition comprising: (A) a
copolymer having rigid blocks and flexible blocks (TPE), (B) a
non-crosslinked polysiloxane silicone, preferably a non-crosslinked
polyorganosiloxane, optionally (C) a compatibilizer, improving the
compatibility between the TPE and the silicone, the compatibilizer
(C) being chosen from a polyolefin or a mixture of several
polyolefins.
Inventors: |
MERZLIC; Sebastien;
(Serquigny, FR) ; BLONDEL; Philippe; (Serquigny,
FR) ; ABGRALL; Florent; (Serquigny, FR) ;
LOYEN; Katherine; (Serquigny, FR) ; RAULINE;
Damien; (Serquigny, FR) ; MOUGNIER;
Sebastien-Jun; (Serquigny, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Arkema France |
Colombes |
|
FR |
|
|
Family ID: |
1000005289768 |
Appl. No.: |
16/961984 |
Filed: |
January 15, 2019 |
PCT Filed: |
January 15, 2019 |
PCT NO: |
PCT/FR2019/050075 |
371 Date: |
July 14, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08L 2205/02 20130101;
C08L 2207/04 20130101; C08L 2203/20 20130101; C08L 2205/03
20130101; C08L 87/005 20130101; C08L 2205/035 20130101; C08J 3/201
20130101; C08L 2205/08 20130101 |
International
Class: |
C08L 87/00 20060101
C08L087/00; C08J 3/20 20060101 C08J003/20 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 15, 2018 |
FR |
1850303 |
Claims
1. A composition comprising: (A) a block copolymer having rigid
blocks and flexible blocks (TPE), and (B) a non-crosslinked
polysiloxane silicone.
2. The composition as claimed in claim 1, wherein the silicone is a
non-crosslinked polyorganosiloxane.
3. The composition as claimed in claim 1, additionally comprising:
(C) a compatibilizer, improving the compatibility between the TPE
and the silicone, chosen from a polyolefin or a mixture of several
polyolefins.
4. The composition as claimed in claim 1, wherein said rigid blocks
comprise at least one block chosen from: polyamide, polyurethane,
polyester and their copolymers.
5. The composition as claimed in claim 1, wherein said flexible
blocks comprise at least one block chosen from: polyether,
polyester, polysiloxane, polyolefin, polycarbonate and their
copolymers.
6. The composition as claimed in claim 1, wherein the block
copolymer is chosen from copolymers having polyester blocks and
polyether blocks, copolymers having polyurethane blocks and
polyether blocks and copolymers having polyamide blocks and
polyether blocks.
7. The composition as claimed in claim 1, wherein the flexible
blocks in the copolymer (A) are polyether blocks chosen from PTMG,
PPG, PO3G and/or PEG.
8. The composition as claimed in claim 4, wherein the polyamide
blocks in the block copolymer (A) are PA 11 and/or PA 12
blocks.
9. The composition as claimed in claim 1, wherein the ratio by
weight of TPE (A) with respect to the silicone (B) is from 10:90 to
95:5.
10. The composition as claimed in claim 1, comprising, by weight:
from 55% to 95% of copolymer (A), from 5% to 45% of silicone (B),
optionally from 0% to 45% of compatibilizer (C), from 0% to 15% of
additives (D), with regard to the total weight of the composition,
this being 100%.
11. The composition as claimed in claim 1, wherein the
number-average molar mass Mn of the flexible blocks, is greater
than 800 g/mol.
12. The composition as claimed in claim 1, wherein the ratio by
weight of the rigid blocks, to the flexible blocks, in the
copolymer (A) is less than or equal to 1.2.
13. The composition as claimed in claim 3, wherein the polyolefin
or the mixture of polyolefins of the compatibilizer (C) carries a
functional group chosen from maleic anhydride, carboxylic acid,
carboxylic anhydride and epoxide functional groups.
14. The composition as claimed in claim 1, additionally comprising
at least one additive (D) selected from the group consisting of:
organic or inorganic fillers, reinforcing agents, plasticizers,
stabilizers, antioxidants, UV stabilizers, flame retardants, carbon
black, carbon nanotubes, pigments, dyes, mold-release agents,
lubricants, foaming agents, impact-resistant agents, flame
retardants, nucleating agents, surface-modifying agents and their
mixtures.
15. A process for the manufacture of the composition as claimed in
claim 1, comprising the step of mixing of block copolymer (A) and
of non-crosslinked silicone (B), and of the optional components (C)
and/or (D).
16. The process as claimed in claim 15, wherein the mixing is
carried out in a device for mixing in the molten state, at a
temperature of 150.degree. C. to 250.degree. C.
17. An article comprising at least one part comprising the
composition as claimed in claim 1.
18. The article as claimed in claim 17, wherein said article is
manufactured by a process involving at least one of the following
stages: injection molding, overmolding, extrusion or
co-extrusion.
19. The article as claimed in claim 17, wherein said article is
selected from the group consisting of a footwear sole, a sports
footwear sole, an insole, midsole or outer sole, a ski boot liner,
a sock, a racket, an inflatable ball, a solid ball, a floater,
gloves, personal protection equipment, a helmet, a rail foot, a
motor vehicle part, a pushchair part, a tire, a wheel, a
smooth-riding wheel, a tire, a handle, a seat element, a child car
seat part, a construction part, an electrical and/or electronic
equipment part, an electronic protection part, an audio equipment,
acoustic insulation and/or heat insulation part, a part targeted at
dampening impacts and/or vibrations, an article of transport, a
padding element, a toy, a medical object, a splint, an orthosis, a
cervical collar, a dressing, an antimicrobial foam dressing, an art
or handicraft object, a life jacket, a backpack, a membrane, a
carpet, a sports mat, a sports floor covering, a carpet underlay,
and any article comprising a mixture of these articles.
20. The article as claimed in claim 17, the article being selected
from the group consisting of: an article or article element of
footwear; an optical article or article element: components of
spectacle frames, nose pads or nosepieces, protective elements on
frames; an automotive article or article element: interior
decorative element; an article or article element of manufacturing
industry: transmission or conveyor belt, silent gear; a medical
article or article element: patch, drug delivery system, sensor; an
electronic article or article element: headset, earphone,
Bluetooth.RTM. jewelry or watch, display screen, connected watch,
connected glasses, interactive game component or device, GPS,
connected footwear, bioactivity monitor or sensor, interactive belt
or bracelet, child or pet tracker, pocket scanner or palmtop,
location sensors, and tracker or vision assist device.
21. The article as claimed in claim 17, the article being an
electrical or electronic article comprising a casing or protective
casing, a portable computer, a portable telephone or a tablet.
Description
TECHNICAL FIELD
[0001] The present invention relates to thermoplastic elastomer
polymer-silicone compositions and to articles manufactured from
these compositions.
TECHNICAL BACKGROUND
[0002] Thermoplastic elastomer polymers (TPEs), such as
thermoplastic polyurethanes (TPUs) or copolymers having polyamide
blocks and polyether blocks (PEBAs), are used in various
applications, such as sports, electronics, optics, motor vehicles
and household electrical appliances. Their typical hardness is from
25 to 80 Shore D. Their main advantages are their processability
(that is to say, ease of use in injection molding and extrusion),
their elastomeric mechanical properties, their high resilience,
their good impact strength and their low density.
[0003] However, existing TPEs have certain limitations: [0004] it
is not possible to target a hardness (in Shore D) less than 25
Shore D, that is (in Shore A) a hardness of less than 80 Shore A,
while retaining good processability, especially in injection
molding; [0005] the exudation of low molecular weight components is
observed, in particular for the flexible grades, with a high
content of flexible polyether blocks, in particular due to the
limited compatibility between the hard polyamide blocks and the
flexible polyether blocks; [0006] they exhibit a limited abrasion
resistance; [0007] they exhibit a low chemical resistance to oily
components, such as sebum; [0008] they exhibit a limited resistance
to soiling, that is to say to the transfer of color resulting from
an external product; [0009] they have limited thermomechanical
resistance; [0010] their haptic properties are not entirely
satisfactory.
[0011] In contrast, silicone-based materials are generally used in
mass consumption applications due to a number of advantages: [0012]
low hardness (<80 Shore A); [0013] good haptic properties;
[0014] good chemical resistance, in particular to sebum; [0015]
good thermomechanical properties.
[0016] Their processability is their main disadvantage, because of
the long cycle times required. Their mechanical properties (tear
strength, abrasion resistance) are limited. In addition, their
bonding or their compatibility with other thermoplastics is
generally weak or requires the use of a primer or a
compatibilizer.
[0017] There thus exists a need for polymer systems without the
various disadvantages mentioned above, for the manufacture of a
material exhibiting a good compromise between:
[0018] the flexibility and durability of the TPE material: abrasion
resistance and tear strength, chemical resistance and mechanical
strength which are sufficient for repeated everyday use, and
[0019] the attractiveness and the soft and silky feel (in
particular "peachskin"), expected by the users. The present
invention is targeted at at least some, indeed even most, of the
following properties, the measurement standards for which are
specified below in table 2 of this description:
TABLE-US-00001 Hardness, instantaneous (Shore A) <80 Hardness,
15 s (Shore A) <75 Tensile tests, stress at 25% strain (MPa)
<2.0 Tensile test, stress at 100% strain (MPa) <4.0 Tensile
test, breaking stress (MPa) >10 Tensile test, elongation at
break (%) >500 Flexural modulus (MPa) < or =12 Tear strength
(kN/m) >40 Taber abrasion resistance - H18 grinding wheel <50
(weight loss in mg/1000 revolutions) Taber abrasion resistance -
CS10 grinding wheel (weight loss in mg/1000 revolutions)
Compressive residual strain at 23.degree. C. (%) <20 Ease of
processing, and of removal from the mold. Recyclability Density
<1.00 Resistance to exudation Chemical resistance (including
sebum) Resistance to stains and soiling.
SUMMARY OF THE INVENTION
[0020] A subject matter of the present invention is thus a
composition comprising: [0021] (A) a copolymer having rigid blocks
and flexible blocks (TPE), [0022] (B) a non-crosslinked silicone,
that is to say polysiloxane, such as linear polydimethylsiloxane,
preferably a polyorganosiloxane, [0023] optionally (C) a
compatibilizer, improving the compatibility between the TPE and the
silicone, and advantageously chosen from a polyolefin or a mixture
of several polyolefins.
[0024] Advantageously, said rigid blocks comprise at least one
block chosen from: polyamide, polyurethane, polyester and their
copolymers. Advantageously, said flexible blocks comprise at least
one block chosen from: polyether, polyester, polysiloxane,
polyolefin, polycarbonate and their copolymers.
[0025] Preferably, the block copolymer is chosen from copolymers
having polyester blocks and polyether blocks, copolymers having
polyurethane blocks and polyether blocks and copolymers having
polyamide blocks and polyether blocks, and preferably it is a
copolymer having polyamide blocks and polyether blocks.
[0026] According to one embodiment, the ratio by weight of TPE (A)
with respect to the silicone (B) is from 10:90 to 95:5, preferably
50:50 to 90:10, indeed even better still from 60:40 to 85:15.
[0027] Preferably, the composition of the invention comprises, by
weight: [0028] from 55% to 95% of copolymer (A), preferably from
60% to 80%, [0029] from 5% to 45% of silicone (B), preferably from
10% to 40%, optionally [0030] from 0% to 45% of compatibilizer (C),
preferably from 5% to 30%, [0031] from 0% to 15% of additives (D),
preferably from 0.1% to 10%, with regard to the total weight of the
composition, this being 100%.
[0032] The percentage by weight of silicone is thus fixed in order
to improve the abrasion resistance, feel and soiling resistance
properties of the product. This solution also makes it possible to
eliminate the phenomena of exudation observed with regard to the
most flexible TPEs and to facilitate the use of the product, the
silicone limiting the adhesion of the mixture to metal walls.
[0033] According to one embodiment, the flexible blocks are
polyether blocks in the copolymer (A), and are preferably
polytetramethylene glycol blocks.
[0034] According to one embodiment, the rigid blocks are polyamide
blocks in the copolymer (A), and are preferably PA 11 or PA 12
blocks.
[0035] According to one embodiment, the number-average molar mass
Mn of the flexible blocks, in particular polyether blocks, is
greater than 800 g/mol, preferably greater than 1000 g/mol,
preferably greater than 1200 g/mol, preferably greater than 1400
g/mol, preferably greater than 1600 g/mol, preferably greater than
1800 g/mol and preferably greater than or equal to 2000 g/mol.
[0036] Advantageously, the ratio by weight of the rigid blocks, in
particular polyamide blocks, to the flexible blocks, in particular
polyether blocks, in the copolymer (A) is less than or equal to
1.2, preferably less than or equal to 1, preferably less than or
equal to 0.8 and preferably less than or equal to 0.5.
[0037] According to one embodiment, the composition of the
invention additionally comprises one or more additives (D).
[0038] The invention also relates to a process for the manufacture
of the above composition, comprising the production of the mixture
of at least one block copolymer (A) and of a non-crosslinked
silicone. According to one embodiment, the process is carried out
in a device for mixing in the molten state, preferably in a
twin-screw extruder, preferably at a temperature of the order of
150.degree. C. to 250.degree. C., preferably 160.degree. C. to
220.degree. C.
[0039] The invention also relates to an article comprising at least
one part having a composition in accordance with the present
invention.
[0040] According to one embodiment, the article is manufactured by
a manufacturing process involving a stage of injection molding,
overmolding, extrusion or co-extrusion of the composition according
to the invention.
[0041] The applications of the composition according to the
invention advantageously comprise fast-moving consumer products
containing a flexible part exposed to daily wear and tear
(footwear, interior decorative parts in motor cars), a part in
regular contact with the skin (glasses, medical, electronics) or
industry (conveyor belts).
[0042] According to one embodiment, the article is an electrical or
electronic article comprising a casing or protective casing
manufactured from the composition according to the invention, said
article preferably being a portable computer, a portable telephone
or a tablet.
[0043] The present invention makes it possible to overcome the
disadvantages of the prior art. In particular, the invention
provides compositions combining the advantageous properties of TPEs
and silicones and in particular: [0044] good formability (in
injection molding and extrusion), [0045] elastomeric mechanical
properties, [0046] high resilience, [0047] low density, [0048] low
hardness, [0049] good abrasion resistance, [0050] good compressive
properties, [0051] good haptic and esthetic properties; [0052] good
chemical resistance, in particular to sebum; [0053] high
thermomechanical properties; [0054] good properties of adhesion to
other materials, such as polyamides, including polyamides mixed
with fillers, such as glass fibers, polyether-block-amides (PEBAs),
copolyetheresters (COPEs), thermoplastic polyurethanes (TPUs),
polycarbonate (PC), ABS and PC/ABS.
[0055] This is achieved by providing a thermoplastic elastomer in
the form of a composition according to the invention, based on TPE,
preferably based on PEBA, and on non-crosslinked silicone.
[0056] It has proven particularly advantageous to use a copolymer
(A) in which the flexible blocks, preferably polyether blocks, have
a relatively high molar mass. Without wishing to be bound by
theory, it is assumed that the polyether blocks aid compatibility
with the non-crosslinked silicones of the composition according to
the invention.
DESCRIPTION OF EMBODIMENTS
[0057] The invention is now described in greater detail and in a
nonlimiting way in the description which follows.
[0058] In the present description, it is specified that, when
reference is made to intervals, the expressions of the type
"ranging from . . . to", "extending from . . . to" or "comprising
from . . . to" include the limits of the interval. Conversely, the
expressions of the type "between . . . and . . . " exclude the
limits of the interval.
[0059] Unless otherwise mentioned, the percentages expressed are
percentages by weight. Unless otherwise mentioned, the parameters
to which reference is made are measured at atmospheric pressure and
ambient temperature (20-25.degree. C., generally 23.degree.
C.).
[0060] The composition of the present invention is a thermoplastic
elastomer, obtained by mixing a TPE (A) and a non-crosslinked
silicone (B), and optionally a compatibilizing polymer (C),
improving the compatibility between the TPE and the silicone.
[0061] The composition according to the invention is an intimate
mixture or alloy of polymers, that is to say a macroscopically
homogeneous mixture of at least two polymers (A) and (B), indeed
even polymers (A), (B) and (C).
[0062] Additional components, such as various additives (D), can
also be added to the composition according to the invention.
Copolymer (A):
[0063] Block copolymer according to the invention is understood to
mean thermoplastic elastomer polymers (TPEs), which alternately
comprise "hard" or "rigid" blocks or segments (with a rather
thermoplastic behavior) and "flexible" or "supple" blocks or
segments (with a rather elastomeric behavior). For example,
polyamide blocks are known to be "rigid" segments with a melting
point (M.p.) or glass transition temperature (Tg) which are higher
than the working temperature of the polymer, whereas polyether
blocks are "flexible" segments with an M.p. or Tg which are lower
than the working temperature of said polymer.
[0064] More specifically, a block is said to be "flexible" if it
exhibits a low glass transition temperature (Tg). Low glass
transition temperature is understood to mean a glass transition
temperature Tg of less than 15.degree. C., preferably of less than
0.degree. C., advantageously of less than -15.degree. C., more
advantageously still of less than -30.degree. C., optionally of
less than -50.degree. C.
[0065] Flexible or soft blocks which can be envisaged in the
copolymer according to the invention is understood to mean in
particular those chosen from polyether blocks, polyester blocks,
polysiloxane blocks, such as polydimethylsiloxane or PDMS blocks,
polyolefin blocks, polycarbonate blocks and their mixtures. The
flexible blocks which can be envisaged are described, for example,
in French patent application No. 0 950 637, page 32, line 3, to
page 38, line 23. By way of example, the polyether blocks are
chosen from poly(ethylene glycol) (PEG), poly(1,2-propylene glycol)
(PPG), poly(1,3-propylene glycol) (PO3G), poly(tetramethylene
glycol) (PTMG) and their copolymers or mixtures.
[0066] The rigid blocks can be based on polyamide, on polyurethane,
on polyester or on a mixture of these polymers. These blocks are
described in particular in French patent application No. 0 856 752.
The rigid blocks are preferably polyamide-based. The polyamide
(abbreviated to PA) blocks can comprise homopolyamides or
copolyamides. The polyamide blocks which can be envisaged in the
composition of the invention are in particular those defined in
application FR 0 950 637 from page 27, line 18, to page 31, line
14.
[0067] Advantageously, said at least one block copolymer comprises
at least one block chosen from: polyether blocks, polyester blocks,
polyamide blocks, polyurethane blocks and their mixtures. Mention
may be made, as examples of copolymers having rigid blocks and
flexible blocks, respectively of (a) copolymers having polyester
blocks and polyether blocks (also known as COPEs or
copolyetheresters), (b) copolymers having polyurethane blocks and
polyether blocks (also known as TPUs, the abbreviation for
thermoplastic polyurethanes) and (c) copolymers having polyamide
blocks and polyether blocks (also known as PEBAs according to the
IUPAC, or also polyether-block-amide).
[0068] Preferably, said at least one block copolymer (A) comprises
a copolymer having polyamide blocks and polyether blocks
(PEBAs).
[0069] PEBAs result from the polycondensation of polyamide blocks
having reactive ends with polyether blocks having reactive ends,
such as, inter alia, the polycondensation:
1) of polyamide blocks having diamine chain ends with
polyoxyalkylene blocks having dicarboxyl chain ends; 2) of
polyamide blocks having dicarboxyl chain ends with polyoxyalkylene
blocks having diamine chain ends, obtained, for example, by
cyanoethylation and hydrogenation of .alpha.,.omega.-dihydroxylated
aliphatic polyoxyalkylene blocks, known as polyetherdiols; 3) of
polyamide blocks having dicarboxyl chain ends with polyetherdiols,
the products obtained being, in this specific case,
polyetheresteramides.
[0070] The polyamide blocks having dicarboxyl chain ends originate,
for example, from the condensation of polyamide precursors in the
presence of a chain-limiting dicarboxylic acid.
[0071] The polyamide blocks having diamine chain ends originate,
for example, from the condensation of polyamide precursors in the
presence of a chain-limiting diamine.
[0072] Three types of polyamide blocks can advantageously be
used.
[0073] According to a first type, the polyamide blocks originate
from the condensation of a dicarboxylic acid, in particular those
having from 4 to 20 carbon atoms, preferably those having from 6 to
18 carbon atoms, and of an aliphatic or aromatic diamine, in
particular those having from 2 to 20 carbon atoms, preferably those
having from 6 to 14 carbon atoms.
[0074] Mention may be made, as examples of dicarboxylic acids, of
1,4-cyclohexanedicarboxylic acid, butanedioic acid, adipic acid,
azelaic acid, suberic acid, sebacic acid, dodecanedicarboxylic
acid, octadecanedicarboxylic acid and terephthalic and isophthalic
acids, but also dimerized fatty acids.
[0075] Mention may be made, as examples of diamines, of
tetramethylenediamine, hexamethylenediamine,
1,10-decamethylenediamine, dodecamethylenediamine,
trimethylhexamethylenediamine, the isomers of
bis(4-aminocyclohexyl)methane (BACM),
bis(3-methyl-4-aminocyclohexyl)methane (BMACM) and
2,2-bis(3-methyl-4-aminocyclohexyl)propane (BMACP),
para-aminodicyclohexylmethane (PACM), isophoronediamine (IPDA),
2,6-bis(aminomethyl)norbornane (BAMN) and piperazine (Pip).
Advantageously, polyamide blocks PA 4.12, PA 4.14, PA 4.18, PA
6.10, PA 6.12, PA 6.14, PA 6.18, PA 9.12, PA 10.10, PA 10.12, PA
10.14 and PA 10.18 are used. In the PA X.Y notation, X represents
the number of carbon atoms resulting from the diamine residues and
Y represents the number of carbon atoms resulting from the diacid
residues, in a conventional way.
[0076] According to a second type, the polyamide blocks result from
the condensation of one or more .alpha.,.omega.-aminocarboxylic
acids and/or of one or more lactams having from 6 to 12 carbon
atoms in the presence of a dicarboxylic acid having from 4 to 12
carbon atoms or of a diamine. Mention may be made, as examples of
lactams, of caprolactam, oenantholactam and lauryllactam. Mention
may be made, as examples of .alpha.,.omega.-aminocarboxylic acids,
of aminocaproic acid, 7-aminoheptanoic acid, 11-aminoundecanoic
acid and 12-aminododecanoic acid.
[0077] Advantageously, the polyamide blocks of the second type are
PA 11 (polyundecanamide), PA 12 (polydodecanamide) or PA 6
(polycaprolactam) blocks. In the PA X notation, X represents the
number of carbon atoms resulting from the amino acid residues.
[0078] According to a third type, the polyamide blocks result from
the condensation of at least one .alpha.,.omega.-aminocarboxylic
acid (or one lactam), at least one diamine and at least one
dicarboxylic acid.
[0079] In this case, the polyamide PA blocks are prepared by
polycondensation: [0080] of the linear aliphatic or aromatic
diamine(s) having X carbon atoms;
[0081] of the dicarboxylic acid(s) having Y carbon atoms; and
[0082] of the comonomer(s) {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);
[0083] said comonomer(s) {Z} being introduced in a proportion by
weight advantageously ranging up to 50%, preferably up to 20%, more
advantageously still up to 10%, with respect to the combined
polyamide precursor monomers;
[0084] in the presence of a chain stopper chosen from dicarboxylic
acids.
[0085] Advantageously, the dicarboxylic acid having Y carbon atoms
is used as chain stopper, which acid is introduced in excess with
respect to the stoichiometry of the diamine(s).
[0086] According to an alternative form of this third type, the
polyamide blocks result from the condensation of at least two
.alpha.,.omega.-aminocarboxylic acids or of at least two lactams
having from 6 to 12 carbon atoms or of a lactam and of an
aminocarboxylic acid not having the same number of carbon atoms, in
the optional presence of a chain stopper. Mention may be made, as
examples of aliphatic .alpha.,.omega.-aminocarboxylic acids, of
aminocaproic acid, 7-aminoheptanoic acid, 11-aminoundecanoic acid
and 12-aminododecanoic acid. Mention may be made, as examples of
lactams, of caprolactam, oenantholactam and lauryllactam. Mention
may be made, as examples of aliphatic diamines, of
hexamethylenediamine, dodecamethylenediamine and
trimethylhexamethylenediamine. Mention may be made, as examples of
cycloaliphatic diacids, of 1,4-cyclohexanedicarboxylic acid.
Mention may be made, as examples of aliphatic diacids, of
butanedioic acid, adipic acid, azelaic acid, suberic acid, sebacic
acid, dodecanedicarboxylic acid or dimerized fatty acids. These
dimerized fatty acids preferably have a dimer content of at least
98%; preferably, they are hydrogenated; they are, for example, the
products marketed under the Pripol brand by Croda or under the
Empol brand by BASF or under the Radiacid brand by Oleon, and
polyoxyalkylene-.alpha.,.omega.-diacids. Mention may be made, as
examples of aromatic diacids, of terephthalic acid (T) and
isophthalic acid (I). Mention may be made, as examples of
cycloaliphatic diamines, of the isomers of
bis(4-aminocyclohexyl)methane (BACM),
bis(3-methyl-4-aminocyclohexyl)methane (BMACM) and
2,2-bis(3-methyl-4-aminocyclohexyl)propane (BMACP), and
para-aminodicyclohexylmethane (PACM). The other diamines commonly
used can be isophoronediamine (IPDA),
2,6-bis(aminomethyl)norbornane (BAMN) and piperazine.
[0087] Mention may be made, as examples of polyamide blocks of the
third type, of the following:
[0088] PA 6.6/6, where 6.6 denotes hexamethylenediamine units
condensed with adipic acid and 6 denotes units resulting from the
condensation of caprolactam;
[0089] PA 6.6/6.10/11/12, where 6.6 denotes hexamethylenediamine
condensed with adipic acid, 6.10 denotes hexamethylenediamine
condensed with sebacic acid, 11 denotes units resulting from the
condensation of aminoundecanoic acid and 12 denotes units resulting
from the condensation of lauryllactam.
[0090] The notations PA X/Y, PA X/Y/Z, and the like, relate to
copolyamides in which X, Y, Z, and the like, represent
homopolyamide units as described above.
[0091] Advantageously, the polyamide blocks of the copolymer used
in the invention comprise blocks of polyamide PA 6, PA 11, PA 12,
PA 5.4, PA 5.9, PA 5.10, PA 5.12, PA 5.13, PA 5.14, PA 5.16, PA
5.18, PA 5.36, PA 6.4, PA 6.9, PA 6.10, PA 6.12, PA 6.13, PA 6.14,
PA 6.16, PA 6.18, PA 6.36, PA 10.4, PA 10.9, PA 10.10, PA 10.12, PA
10.13, PA 10.14, PA 10.16, PA 10.18, PA 10.36, PA 10.T, PA 12.4, PA
12.9, PA 12.10, PA 12.12, PA 12.13, PA 12.14, PA 12.16, PA 12.18,
PA 12.36, PA 12.T, or mixtures or copolymers of these; and
preferably comprise blocks of polyamide PA 6, PA 11, PA 12, PA
6.10, PA 10.10, PA 10.12, or mixtures or copolymers of these.
[0092] The polyether blocks consist of alkylene oxide units. The
polyether blocks can in particular be PEG (polyethylene glycol)
blocks, that is to say consisting of ethylene oxide units, and/or
PPG (propylene glycol) blocks, that is to say consisting of
propylene oxide units, and/or PO3G (polytrimethylene glycol)
blocks, that is to say consisting of polytrimethylene ether glycol
units, and/or PTMG blocks, that is to say consisting of
tetramethylene glycol units, also called polytetrahydrofuran. The
PEBA copolymers can comprise several types of polyethers in their
chain, it being possible for the copolyethers to be block or
random.
[0093] Use may also be made of blocks obtained by oxyethylation of
bisphenols, such as, for example, bisphenol A. The latter products
are described in particular in the document EP 613 919.
[0094] The polyether blocks can also consist of ethoxylated primary
amines. Mention may be made, as examples of ethoxylated primary
amines, of the products of formula:
##STR00001##
in which m and n are integers between 1 and 20 and x is an integer
between 8 and 18. These products are, for example, commercially
available under the Noramox.RTM. brand from CECA and under the
Genamin.RTM. brand from Clariant.
[0095] The flexible polyether blocks can comprise polyoxyalkylene
blocks having NH.sub.2 chain ends, it being possible for such
blocks to be obtained by cyanoacetylation of aliphatic
.alpha.,.omega.-dihydroxylated polyoxyalkylene blocks called
polyetherdiols. More particularly, the Jeffamine or Elastamine
commercial products can be used (for example Jeffamine.RTM. D400,
D2000, ED 2003, XTJ 542, commercial products from Huntsman, also
described in the documents JP 2004346274, JP 2004352794 and EP 1
482 011).
[0096] The polyetherdiol blocks are either used as is and
copolycondensed with polyamide blocks having carboxyl end groups,
or aminated in order to be converted into polyetherdiamines and
condensed with polyamide blocks having carboxyl end groups. The
general method for the two-stage preparation of the PEBA copolymers
having ester bonds between the PA blocks and the PE blocks is known
and is described, for example, in the document 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 is described, for example, in the document EP 1
482 011. The polyether blocks can also be mixed with polyamide
precursors and a diacid chain stopper in order to prepare polymers
having polyamide blocks and polyether blocks possessing randomly
distributed units (one-stage process).
[0097] Of course, the designation PEBA in the present description
of the invention relates just as well to the PEBAX.RTM. products
sold by Arkema, to the Vestamid.RTM. products sold by Evonik.RTM.,
to the Grilamid.RTM. products, to the Griflex products sold by EMS,
as to the PEBA-type Pelestat.RTM. products sold by Sanyo or to any
other PEBA from other suppliers.
[0098] While the block copolymers described above generally
comprise at least one polyamide block and at least one polyether
block, the present invention also covers all the copolymer alloys
comprising two, three, four (indeed even more) different blocks
chosen from those described in this description.
[0099] For example, the copolymer according to the invention can be
a segmented block copolymer comprising three different types of
blocks (or "triblock"), which results from the condensation of
several of the blocks described above. Said triblock is preferably
chosen from copolyetheresteramides and
copolyetheramideurethanes.
[0100] PEBA copolymers which are particularly preferred in the
context of the invention are: PA12-PEG, PA6-PEG, PA6/12-PEG,
PA11-PEG, PA12-PTMG, PA6-PTMG, PA6/12-PTMG, PA11-PTMG,
PA12-PEG/PPG, PA6-PEG/PPG, PA6/12-PEG/PPG, PA11-PEG/PPG, PA11/PO3G,
PA6.10/PO3G and/or PA10.10/PO3G.
[0101] Preferably, the PA blocks comprise at least 30%, preferably
at least 50%, preferably at least 75%, preferably 100%, by weight
of PA 11 and/or PA 12, as regards the total weight of the PA
blocks.
[0102] The polyether blocks preferably represent from 50% to 80% of
the total weight of the block copolymer (A) used in the composition
according to the invention.
[0103] Advantageously, the number-average molar mass of the
polyamide blocks in the PEBA copolymer has a value from 200 to 2000
g/mol; the number-average molar mass of the polyether blocks has a
value from 800 to 2500 g/mol; and the ratio by weight of the
polyamide blocks with respect to the polyether blocks of the
copolymer is from 0.1 to 1.2.
[0104] The number-average molar mass is fixed by the content of
chain stopper. It can be calculated according to the
relationship:
Mn=(nmonomer/nstopper)*Mrepeat unit+Mstopper
[0105] nmonomer=number of moles of monomer
[0106] nstopper=number of moles of diacid in excess
[0107] Mrepeat unit=molar mass of the repeat unit
[0108] Mstopper=molar mass of the diacid in excess
[0109] According to specific embodiments, the copolymers are
defined by the following ranges of number-average molar masses
M.sub.n:
TABLE-US-00002 M.sub.n of block polyamides M.sub.n of polyether
blocks No. 1 200 to 300 g/mol 800 to 1000 g/mol No. 2 300 to 400
g/mol 800 to 1000 g/mol No. 3 400 to 500 g/mol 800 to 1000 g/mol
No. 4 500 to 600 g/mol 800 to 1000 g/mol No. 5 600 to 700 g/mol 800
to 1000 g/mol No. 6 700 to 800 g/mol 800 to 1000 g/mol No. 7 800 to
900 g/mol 800 to 1000 g/mol No. 8 900 to 1000 g/mol 800 to 1000
g/mol No. 9 200 to 300 g/mol 1000 to 1200 g/mol No. 10 300 to 400
g/mol 1000 to 1200 g/mol No. 11 400 to 500 g/mol 1000 to 1200 g/mol
No. 12 500 to 600 g/mol 1000 to 1200 g/mol No. 13 600 to 700 g/mol
1000 to 1200 g/mol No. 14 700 to 800 g/mol 1000 to 1200 g/mol No.
15 800 to 900 g/mol 1000 to 1200 g/mol No. 16 900 to 1000 g/mol
1000 to 1200 g/mol No. 17 1000 to 1100 g/mol 1000 to 1200 g/mol No.
18 200 to 300 g/mol 1200 to 1400 g/mol No. 19 300 to 400 g/mol 1200
to 1400 g/mol No. 20 400 to 500 g/mol 1200 to 1400 g/mol No. 21 500
to 600 g/mol 1200 to 1400 g/mol No. 22 600 to 700 g/mol 1200 to
1400 g/mol No. 23 700 to 800 g/mol 1200 to 1400 g/mol No. 24 800 to
900 g/mol 1200 to 1400 g/mol No. 25 900 to 1000 g/mol 1200 to 1400
g/mol No. 26 1000 to 1100 g/mol 1200 to 1400 g/mol No. 27 1100 to
1200 g/mol 1200 to 1400 g/mol No. 28 1200 to 1300 g/mol 1200 to
1400 g/mol No. 29 200 to 300 g/mol 1400 to 1600 g/mol No. 30 300 to
400 g/mol 1400 to 1600 g/mol No. 31 400 to 500 g/mol 1400 to 1600
g/mol No. 32 500 to 600 g/mol 1400 to 1600 g/mol No. 33 600 to 700
g/mol 1400 to 1600 g/mol No. 34 700 to 800 g/mol 1400 to 1600 g/mol
No. 35 800 to 900 g/mol 1400 to 1600 g/mol No. 36 900 to 1000 g/mol
1400 to 1600 g/mol No. 37 1000 to 1100 g/mol 1400 to 1600 g/mol No.
38 1100 to 1200 g/mol 1400 to 1600 g/mol No. 39 1200 to 1300 g/mol
1400 to 1600 g/mol No. 40 1300 to 1400 g/mol 1400 to 1600 g/mol No.
41 1400 to 1500 g/mol 1400 to 1600 g/mol No. 42 200 to 300 g/mol
1600 to 1800 g/mol No. 43 300 to 400 g/mol 1600 to 1800 g/mol No.
44 400 to 500 g/mol 1600 to 1800 g/mol No. 45 500 to 600 g/mol 1600
to 1800 g/mol No. 46 600 to 700 g/mol 1600 to 1800 g/mol No. 47 700
to 800 g/mol 1600 to 1800 g/mol No. 48 800 to 900 g/mol 1600 to
1800 g/mol No. 49 900 to 1000 g/mol 1600 to 1800 g/mol No. 50 1000
to 1100 g/mol 1600 to 1800 g/mol No. 51 1100 to 1200 g/mol 1600 to
1800 g/mol No. 52 1200 to 1300 g/mol 1600 to 1800 g/mol No. 53 1300
to 1400 g/mol 1600 to 1800 g/mol No. 54 1400 to 1500 g/mol 1600 to
1800 g/mol No. 55 200 to 300 g/mol 1800 to 2000 g/mol No. 56 300 to
400 g/mol 1800 to 2000 g/mol No. 57 400 to 500 g/mol 1800 to 2000
g/mol No. 58 500 to 600 g/mol 1800 to 2000 g/mol No. 59 600 to 700
g/mol 1800 to 2000 g/mol No. 60 700 to 800 g/mol 1800 to 2000 g/mol
No. 61 800 to 900 g/mol 1800 to 2000 g/mol No. 62 900 to 1000 g/mol
1800 to 2000 g/mol No. 63 1000 to 1100 g/mol 1800 to 2000 g/mol No.
64 1100 to 1200 g/mol 1800 to 2000 g/mol No. 65 1200 to 1300 g/mol
1800 to 2000 g/mol No. 66 1300 to 1400 g/mol 1800 to 2000 g/mol No.
67 1400 to 1500 g/mol 1800 to 2000 g/mol No. 68 200 to 300 g/mol
2000 to 2200 g/mol No. 69 300 to 400 g/mol 2000 to 2200 g/mol No.
70 400 to 500 g/mol 2000 to 2200 g/mol No. 71 500 to 600 g/mol 2000
to 2200 g/mol No. 72 600 to 700 g/mol 2000 to 2200 g/mol No. 73 700
to 800 g/mol 2000 to 2200 g/mol No. 74 800 to 900 g/mol 2000 to
2200 g/mol No. 75 900 to 1000 g/mol 2000 to 2200 g/mol No. 76 1000
to 1100 g/mol 2000 to 2200 g/mol No. 77 1100 to 1200 g/mol 2000 to
2200 g/mol No. 78 1200 to 1300 g/mol 2000 to 2200 g/mol No. 79 1300
to 1400 g/mol 2000 to 2200 g/mol No. 80 1400 to 1500 g/mol 2000 to
2200 g/mol No. 81 200 to 300 g/mol 2200 to 2500 g/mol No. 82 300 to
400 g/mol 2200 to 2500 g/mol No. 83 400 to 500 g/mol 2200 to 2500
g/mol No. 84 500 to 600 g/mol 2200 to 2500 g/mol No. 85 600 to 700
g/mol 2200 to 2500 g/mol No. 86 700 to 800 g/mol 2200 to 2500 g/mol
No. 87 800 to 900 g/mol 2200 to 2500 g/mol No. 88 900 to 1000 g/mol
2200 to 2500 g/mol No. 89 1000 to 1100 g/mol 2200 to 2500 g/mol No.
90 1100 to 1200 g/mol 2200 to 2500 g/mol No. 91 1200 to 1300 g/mol
2200 to 2500 g/mol No. 92 1300 to 1400 g/mol 2200 to 2500 g/mol No.
93 1400 to 1500 g/mol 2200 to 2500 g/mol
[0110] Preferably, the ratio by weight of the polyamide blocks with
respect to the polyether blocks of the copolymer is from 0.1 to
1.2; preferably 0.1 to 1; preferably from 0.2 to 0.5. This ratio by
weight can be calculated by dividing the number-average molar mass
of the polyamide blocks by the number-average molar mass of the
polyether blocks.
[0111] According to specific embodiments, this ratio has a value
from 0.1 to 0.2; or from 0.2 to 0.3; or from 0.3 to 0.4; or from
0.4 to 0.5; or from 0.5 to 0.6; or from 0.6 to 0.7; or from 0.7 to
0.8; or from 0.8 to 0.9.
[0112] Preferably, the copolymer used in the invention exhibits an
instantaneous hardness of less than or equal to 45 Shore D, more
preferably of less than or equal to 35 Shore D, more preferably of
less than or equal to 25 Shore D. The hardness measurements can be
carried out according to the standard ISO 868.
[0113] Advantageously, the copolymer has an inherent viscosity of 2
or less; preferably of 1.5 or less; preferably of 1.4 or less;
preferably of 1.3 or less; preferably of 1.2 or less. In the
present description, the inherent viscosity is determined according
to the standard ISO 307:2007 in m-cresol at a temperature of
20.degree. C., at a polymer concentration of 0.5% by weight in
solution in meta-cresol with respect to the total weight of the
solution, using an Ubbelohde viscometer.
The Silicone (B)
[0114] The silicone or "polysiloxane" used in the composition of
the present invention is non-crosslinked and non-crosslinkable. It
can advantageously be polyorganosiloxane by comprising one or more
organic chains, indeed even comprise groups, preferably polar
functional groups, which promote its compatibility or its mixing
with the other components, in particular the TPE, of the present
composition.
[0115] Within the meaning the present invention:
[0116] "non-crosslinked silicone" is understood to mean a silicone
which is neither crosslinked nor crosslinkable, even in situ, in
the composition according to the invention or during its use in
order to obtain the final product. In particular,
non-crosslinked/non-crosslinkable silicone is understood to mean a
silicone not containing alkenyl groups having from 2 to 20 carbon
atoms in the molecule, in particular a silicone not containing a
vinyl, allyl, butenyl, pentenyl, hexenyl or decenyl group capable
of causing the silicone to crosslink.
[0117] This requirement for the silicone of the present composition
not only ensures the ability for transformation (processability),
the ease of use, but also the recyclability of the composition
according to the invention.
[0118] "polysiloxane" is understood to mean a polymer comprising a
polymeric backbone composed of siloxy --(Si(R.sub.2)--O--)-- repeat
units which can be cyclic, linear or branched units, for example
lower dialkylsiloxy units, such as in particular dimethylsiloxy
units, and optionally organic side groups.
[0119] The organic groups (that is to say, non-alkenyl groups)
bonded by the silicon are preferably independently drawn from
hydrocarbons or from halogenated hydrocarbon groups which contain
no aliphatic unsaturation. These can be specifically illustrated by
alkyl groups having from 1 to 20 carbon atoms, such as methyl,
ethyl, propyl, butyl, pentyl and hexyl; cycloalkyl groups such as
cyclohexyl and cycloheptyl; aryl groups of 6 to 12 carbon atoms,
such as phenyl, tolyl and xylyl; aralkyl groups of 7 to 20 carbon
atoms, such as benzyl and phenethyl; and halogenated alkyl groups
having from 1 to 20 carbon atoms, such as 3,3,3-trifluoropropyl and
chloromethyl.
[0120] Mention may in particular very simply be made of linear
polydimethylsiloxane (PDMS).
[0121] "polyorganosiloxane" is understood to mean a polymer which
combines siloxy --(Si(R.sub.2)--O--)-- repeat units of silicones
with hydrocarbons or repeat units having a hydrocarbon main chain.
It can then concern copolymers. One advantageous example is
polysiloxane-co-urethane (for example in the Carbosil.RTM. range
from DSM). It can also concern a branched copolymer. An example is
the CoatOSil.RTM. range from Momentive, which carries a pendent
polyether group on a silicone backbone. Conversely, a hydrocarbon
backbone branched with silicone chain can also be envisaged and
included in the definition of the polyorganosiloxane which can be
used in the composition according to the invention.
[0122] "poly(organo)siloxane having a polar functional group" is
understood to mean a poly(organo)siloxane having at least one polar
radical, the polar radical being present at one of the ends of the
poly(organo)siloxane backbone or on the poly(organo)siloxane
backbone.
[0123] "polar radical" is understood to mean a radical which
confers polar properties on the organopolysiloxane. Examples of
polar radicals according to the present invention are: hydroxy,
hydroxyl, urea, amine, amide, carboxylate, ester, ether, acrylate,
thiol, sulfonate, sulfate and phosphate. Mention may be made, by
way of example, of the Baysilone.RTM. range from Momentive, which
in particular comprises an amine-functionalized
polyorganosiloxane.
The Compatibilizer (C):
[0124] The compatibilizer advantageously consists of a polymer
exhibiting a flexural modulus of less than 100 MPa, measured
according to the standard ISO 178, and a Tg of less than 0.degree.
C. (measured according to the standard 11357-2 at the inflection
point of the DSC thermogram), in particular a polyolefin.
[0125] The polyolefin of the compatibilizer can be functionalized
or nonfunctionalized or be a mixture of at least one functionalized
and/or of at least one nonfunctionalized. To simplify, the
polyolefin has been denoted by (C), and functionalized polyolefins
(C1) and nonfunctionalized polyolefins (C2) have been described
below.
[0126] A nonfunctionalized polyolefin (C2) is conventionally a
homopolymer or copolymer of .alpha.-olefins or of diolefins, such
as, for example, ethylene, propylene, 1-butene, 1-octene or
butadiene. Mention may be made, by way of example, of: [0127]
polyethylene homopolymers and copolymers, in particular LDPE, HDPE,
LLDPE (linear low density polyethylene), VLDPE (very low density
polyethylene) and metallocene polyethylene, [0128] propylene
homopolymers or copolymers, [0129] ethylene/.alpha.-olefin
copolymers, such as ethylene/propylene, EPRs (abbreviation of
ethylene/propylene rubbers) and ethylene/propylene/dienes (EPDMs),
[0130] styrene/ethylene-butene/styrene (SEBS),
styrene/butadiene/styrene (SBS), styrene/isoprene/styrene (SIS) or
styrene/ethylene-propylene/styrene (SEPS) block copolymers, [0131]
copolymers of ethylene with at least one product chosen from salts
or esters of unsaturated carboxylic acids, such as alkyl
(meth)acrylate (for example methyl acrylate), or vinyl esters of
saturated carboxylic acids, such as vinyl acetate (EVA), it being
possible for the proportion of comonomer to reach 40% by
weight.
[0132] The functionalized polyolefin (C1) can be a polymer of
.alpha.-olefins having reactive units (the functionalities); such
reactive units are acid, anhydride or epoxy functional groups.
Mention may be made, by way of example, of the preceding
polyolefins (C2) grafted or copolymerized or terpolymerized by
unsaturated epoxides, such as glycidyl (meth)acrylate, or by
carboxylic acids or the corresponding salts or esters, such as
(meth)acrylic acid (it being possible for the latter to be
completely or partially neutralized by metals such as Zn, and the
like), or else by carboxylic acid anhydrides, such as maleic
anhydride. A functionalized polyolefin is, for example, a PE/EPR
mixture, the ratio by weight of which can vary within broad limits,
for example between 40/60 and 90/10, said mixture being cografted
with an anhydride, in particular maleic anhydride, according to a
degree of grafting, for example, from 0.01% to 5% by weight.
[0133] The functionalized polyolefin (C1) can be chosen from the
following (co)polymers, grafted with maleic anhydride or glycidyl
methacrylate, in which the degree of grafting is, for example, from
0.01% to 5% by weight:
[0134] PE, PP, copolymers of ethylene with propylene, butene,
hexene or octene containing, for example, from 35% to 80% by weight
of ethylene;
[0135] ethylene/.alpha.-olefin copolymers, such as
ethylene/propylene, EPRs (abbreviation of ethylene/propylene
rubbers) and ethylene/propylene/dienes (EPDMs),
[0136] styrene/ethylene-butene/styrene (SEBS),
styrene/butadiene/styrene (SBS), styrene/isoprene/styrene (SIS) or
styrene/ethylene-propylene/styrene (SEPS) block copolymers,
[0137] copolymers of ethylene and vinyl acetate (EVA), containing
up to 40% by weight of vinyl acetate;
[0138] copolymers of ethylene and alkyl (meth)acrylate, containing
up to 40% by weight of alkyl (meth)acrylate;
[0139] copolymers of ethylene and vinyl acetate (EVA) and alkyl
(meth)acrylate, containing up to 40% by weight of comonomers.
[0140] The functionalized polyolefin (C1) can also be chosen from
ethylene/propylene copolymers, predominant in propylene, grafted by
maleic anhydride and then condensed with monoaminated polyamide (or
a polyamide oligomer) (products described in EP-A-0 342 066).
[0141] The functionalized polyolefin (C1) can also be a copolymer
or terpolymer of at least the following units: (1) ethylene, (2)
alkyl (meth)acrylate or saturated carboxylic acid vinyl ester and
(3) anhydride, such as maleic or (meth)acrylic acid anhydride, or
epoxy, such as glycidyl (meth)acrylate.
[0142] Mention may be made, as examples of functionalized
polyolefins of the latter type, of the following copolymers, where
ethylene preferably represents at least 60% by weight and where the
termonomer (the functional group) represents, for example, from
0.1% to 10% by weight of the copolymer: [0143] ethylene/alkyl
(meth)acrylate/(meth)acrylic acid or maleic anhydride or glycidyl
methacrylate copolymers; [0144] ethylene/vinyl acetate/maleic
anhydride or glycidyl methacrylate copolymers; [0145]
ethylene/vinyl acetate or alkyl (meth)acrylate/(meth)acrylic acid
or maleic anhydride or glycidyl methacrylate copolymers.
[0146] In the preceding copolymers, the (meth)acrylic acid can be
salified with Zn or Li.
[0147] The term "alkyl (meth)acrylate" in (C1) or (C2) denotes
C.sub.1 to C.sub.8 alkyl methacrylates and acrylates and can be
chosen from methyl acrylate, ethyl acrylate, n-butyl acrylate,
isobutyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate,
methyl methacrylate and ethyl methacrylate.
[0148] The abovementioned copolymers, (C1) and (C2), can be
copolymerized in random or block fashion and can exhibit a linear
or branched structure.
[0149] The molecular weight, the MFI index and the density of these
polyolefins can also vary within a broad range, which will be
perceived by a person skilled in the art. MFI is the abbreviation
for Melt Flow Index. It is measured according to the standard ISO
1133.
[0150] The nonfunctionalized polyolefins (C2) are advantageously
chosen from polypropylene homopolymers or copolymers, and any
ethylene homopolymer, or copolymer of ethylene and of a comonomer
of higher .alpha.-olefin type, such as butene, hexene, octene or
4-methyl-1-pentene. Mention may be made, for example, of PPs, high
density PEs, medium density PEs, linear low density PEs, low
density PEs or ultra low density PEs. These polyethylenes are known
by a person skilled in the art as being produced according to a
"radical" process, according to a "Ziegler" type catalysis or, more
recently, according to a "metallocene" catalysis.
[0151] The functionalized polyolefins (C1) are advantageously
chosen from any polymer comprising .alpha.-olefin units and units
carrying reactive polar functional groups, such as epoxy,
carboxylic acid or carboxylic acid anhydride functional groups.
Mention may be made, by way of example of such polymers, of
terpolymers of ethylene, of alkyl acrylate and of maleic anhydride
or of glycidyl methacrylate, such as the Lotader.RTM. products of
the applicant company, or polyolefins grafted by maleic anhydride,
such as the Orevac.RTM. products of the applicant company, and also
terpolymers of ethylene, of alkyl acrylate and of (meth)acrylic
acid. Mention may also be made of homopolymers or copolymers of
polypropylene grafted by a carboxylic acid anhydride and then
condensed with polyamides or oligomers, which are monoaminated, of
polyamide.
[0152] The MFI of the copolymer (A) and the MFI of the
compatibilizer (C) can be chosen within a wide range. However, to
facilitate the dispersion of (C), it is recommended that the MFI of
the copolymer (A) be greater than that of (C).
Additives
[0153] Advantageously, the composition of the invention comprises
at least one additive selected from organic or inorganic fillers,
reinforcing agents, plasticizers, stabilizers, antioxidants, UV
stabilizers, flame retardants, carbon black, carbon nanotubes,
pigments, dyes, mold-release agents, lubricants, foaming agents,
impact-resistant agents, nucleating agents, surface-modifying
agents and their mixtures.
Manufacturing Process
[0154] The process for the manufacture of the composition according
to the invention comprises carrying out the mixing of block
copolymer (A) and of non-crosslinked silicone (B), and of the
optional other components (C) and/or (D).
[0155] The mixing is preferably carried out in a device for mixing
in the molten state, such as a twin-screw or single-screw extruder,
or else in a device using Buss co-kneaders.
[0156] Preferably, said mixing is carried out in a twin-screw
extruder.
[0157] It is preferably carried out at a temperature of the order
of 150.degree. C. to 250.degree. C., preferably of 160.degree. C.
to 220.degree. C.
[0158] The thermoplastic elastomer composition according to the
invention can then be processed by conventional techniques, such as
extrusion, vacuum forming, injection molding, blow molding,
overmolding or compression molding. In addition, the compositions
according to the invention can be retransformed (recycled) with
little or no deterioration in the mechanical properties.
Applications
[0159] The novel thermoplastic elastomers with a composition in
accordance with the present invention can be used to manufacture
insulators of wires and cables; sound and vibration dampening
components; electrical connectors; automotive components and
appliances, such as belts, hoses, air lines, bellows, gaskets and
fuel line components; furniture components; soft-feel handles for
portable devices (for example, tool handles); seals for
architecture; bottle closures; medical devices; sports equipment;
and other parts of components generally of rubber appearance which
can be replaced by components with a composition according to the
invention.
[0160] A subject-matter of the present invention is in particular
an article or an article part chosen from a footwear sole, in
particular a sports footwear sole, such as an insole, midsole or
outer sole, a ski boot liner, a sock, a racket, an inflatable ball,
a solid ball, a floater, gloves, personal protection equipment, a
helmet, a rail foot, a motor vehicle part, a pushchair part, a
tire, a wheel, a smooth-riding wheel, such as a tire, a handle, a
seat element, a child car seat part, a construction part, an
electrical and/or electronic equipment part, an electronic
protection part, an audio equipment, acoustic insulation and/or
heat insulation part, a part targeted at dampening impacts and/or
vibrations, such as those generated by a means of transport, a
padding element, a toy, a medical object, such as a splint, an
orthosis, a cervical collar, a dressing, in particular an
antimicrobial foam dressing, an art or handicraft object, a life
jacket, a backpack, a membrane, a carpet, a sports mat, a sports
floor covering, a carpet underlay, and any article comprising a
mixture of these articles.
[0161] The thermoplastic elastomers of the present invention are
particularly useful for manufacturing the following articles:
[0162] footwear and especially sports footwear, in particular the
soles, outer soles, insoles or midsoles; this is because the
compositions of the invention have properties of good adhesion to
PEBA and to polyamide, in particular by overmolding, good abrasion
resistance and they can be easily transformed into footwear
components; [0163] in the optical industry: components of spectacle
frames, nose pads or nosepieces, protective elements on frames;
this is because the compositions of the invention have a soft-silky
feel, adhere well to polyamide and more specifically to transparent
polyamide by overmolding, and resistant to sebum; [0164] in the
automotive industry: interior decorative elements; this is because
the compositions of the invention have a soft feel, good haptic
properties, adhere perfectly by overmolding, are resistant to sebum
and resistant to abrasion; [0165] in manufacturing industry:
transmission or conveyor belts, silent gears; this is because the
compositions of the invention are resistant to heat, resistant to
abrasion, and easy to process by overmolding; [0166] in the medical
sector: patches, biofeedback patches, drug delivery systems,
sensors; [0167] in the electronics industry: headsets, earphones,
Bluetooth.RTM. jewelry and watches, display screens, connected
watches, connected glasses, interactive game components and
devices, GPS, connected footwear, bioactivity monitors and sensors,
interactive belts and bracelets, child or pet tracker, pocket
scanner or palmtop, location sensors, trackers or vision
assist.
[0168] In a preferred embodiment, the compositions of the invention
are used for the manufacture of a casing or protective casing in
items of electrical or electronic equipment, such as in particular
a portable computer, a portable telephone or a tablet.
Examples
[0169] The following examples illustrate the invention without
limiting it.
Materials Used in the Examples:
Compositions According to the Invention
A:
[0170] PEBA 2+30% of polyorganosiloxane polycarbonate polyurethane
copolymer (Carbosil.RTM. 20 80A silicone from DSM).
B:
[0171] PEBA 2+15% of polyorganosiloxane polycarbonate polyurethane
copolymer (Carbosil.RTM. 20 80A from DSM)+15% of
styrene/ethylene-butylene/styrene block copolymer grafted by maleic
anhydride (Kraton.RTM. FG-1924).
C
[0172] PEBA 3+15% of polyorganosiloxane polycarbonate polyurethane
copolymer (Carbosil.RTM. 20 80A from DSM)+15% of
styrene/ethylene-butylene/styrene block copolymer grafted by maleic
anhydride (Kraton.RTM. FG-1924).
D:
[0173] PEBA 4 (PA12-PTMG (Mn: 2000-1000), copolymer having PA 12
blocks and PTMG blocks with respective number-average molecular
weights (Mn) 2000-1000. The ratio by weight: PA blocks/PE
blocks=2)+15% of polyorganosiloxane polycarbonate polyurethane
copolymer (Carbosil.RTM. 20 80A from DSM)+15% of
styrene/ethylene-butylene/styrene block copolymer grafted by maleic
anhydride (Kraton.RTM. FG-1924).
Comparative Examples
E:
[0174] PEBA 1: PA 12-PTMG (Mn: 600-2000)
[0175] PEBA 1 is a copolymer having PA 12 blocks and PTMG blocks
with respective number-average molecular weights (Mn) 600-2000.
[0176] The ratio by weight: PA blocks/PE blocks=0.3
F:
[0177] PEBA 2: PA 12-PTMG (Mn: 850-2000)
[0178] PEBA 2 is a copolymer according to the invention having PA
12 blocks and PTMG blocks with respective number-average molecular
weights (Mn) 850-2000.
[0179] The ratio by weight: PA blocks/PE blocks=0.4
G:
[0180] PEBA 3: PA 12-PTMG (Mn: 2000-2000)
[0181] PEBA 3 is a copolymer according to the invention having PA
12 blocks and PTMG blocks with respective number-average molecular
weights (Mn) 2000-2000.
[0182] The ratio by weight: PA blocks/PE blocks=1
H:
[0183] TPU-based thermoplastic crosslinked silicone (TPSiV.RTM.
4000-75A SR, Multibase)
I:
[0184] TPU (Desmopan.RTM. 9370AU, Covestro)
[0185] Formulations A to I are prepared (by mixing in the case of
A, B, C and D) in a twin-screw extruder at a temperature of
210.degree. C.
[0186] Tensile testing plaques and bars are produced by injection
molding at 200.degree. C. in a mold at 30.degree. C. The results of
measurement of the properties of these plaques and bars, with
respective compositions A to I, are shown in the following table
1.
TABLE-US-00003 TABLE 1 Target values sought by the invention and
results of measurement of the properties measured on dumbbells
(plaques or bars) with compositions A to I Target A B C D
Physicochemical properties Density <1.0 0.96 0.98 1.00 1.00
Resistance to exudation .largecircle. .largecircle. .largecircle.
.largecircle. .largecircle. Chemical resistance (++) ++ ++ ++ ++
(including sebum) Resistance to (++) ++ ++ ++ + stains/to soiling
"Peachskin" feel 5 5 5 5 4 Mechanical properties Hardness,
instantaneous <80 75 75 83 91 (Shore A) Hardness, 15 s <75 70
70 82 90 (Shore A) Tensile test, stress at 25% strain <2.0 1.7
1.8 5.9 8.7 (MPa) Tensile test, stress at 100% strain <4.0 2.9
3.1 7.4 10.9 (MPa) Tensile test, breaking stress >10 >10
>11 (MPa) Tensile test, elongation at break >500 >500
>500 (%) Flexural modulus (MPa) < or = 12 10 10 Tear strength
(kN/m) >40 35 45 47 Taber abrasion resistance - H18 <50 70 40
80 106 grinding wheel (weight loss in mg/1000 revolutions) Taber
abrasion resistance - CS10 <50 50 19 grinding wheel (weight loss
in mg/1000 revolutions) Compressive residual strain (%) <20 20
20 34 at 23.degree. C. Compressive residual strain (%) 73 72 22 13
at 70.degree. C. Ease of processing Melt Flow Index at 235.degree.
C., >10 1 kg (g/10 min) Ease of injection .largecircle.
.largecircle. .largecircle. .largecircle. .largecircle. Ease of
removal from the mold .largecircle. .largecircle. .largecircle.
.largecircle. .largecircle. Recyclability .largecircle.
.largecircle. .largecircle. .largecircle. .largecircle. Target E F
G H: I Physicochemical properties Density <1.0 1.00 1.00 1.00
1.1 1.06 Resistance to exudation .largecircle. X: X: X:
.largecircle. .largecircle. Chemical resistance (++) -- - + ++ -
(including sebum) Resistance to (++) - - - ++ - stains/to soiling
"Peachskin" feel 5 1 1 1 4 3 Mechanical properties Hardness,
instantaneous <80 77 85 90 80 75 (Shore A) Hardness, 15 s <75
74 80 89 79 72 (Shore A) Tensile test, stress at <2.0 2.6 1.7
25% strain (MPa) Tensile test, stress at <4.0 4.2 3.0 100%
strain (MPa) Tensile test, breaking stress >10 32 39 40 >10
>10 (MPa) Tensile test, elongation >500 >750 >600
>450 >500 >500 at break (%) Flexural modulus < or = 12
12 21 77 23 9 (MPa) Tear strength >40 66 78 116 47 45 (kN/m)
Taber abrasion resistance - <50 99 77 62 33 7 H18 grinding wheel
(weight loss in mg/1000 revolutions) Taber abrasion resistance -
<50 CS10 grinding wheel (weight loss in mg/1000 revolutions)
Compressive residual strain at <20 19 22 32 19 18 23.degree. C.
(%) Compressive residual strain at 62 54 21 70 69 70.degree. C. (%)
Ease of processing Melt Flow Index at 235.degree. C., >10 10 8 5
1 kg (g/10 min) Ease of injection .largecircle. .largecircle.
.largecircle. .largecircle. X .largecircle. Ease of removal from
the mold .largecircle. X X .largecircle. .largecircle.
.largecircle. Recyclability .largecircle. .largecircle.
.largecircle. .largecircle. X .largecircle.
[0187] The protocols for measuring the properties characterized
according to the present invention and measured according to the
examples are described in Table 2 below:
TABLE-US-00004 TABLE 2 Methods and standards for measurement of the
properties Property measured Standard/method Specifications Density
ISO 1183-3 Measured at 23.degree. C. Resistance to Internal method
Measured after conditioning in a Blinder exudation container at
70.degree. C. and 62% relative humidity (RH) for 7 days. The
samples were 100 .times. 100 .times. 2 mm plaques. Classification
by visual observation: .largecircle. = No exudation X = Exudation
at the surface Resistance to Internal method Measured after
conditioning in an oven at stains/to soiling 23.degree. C. and 50%
RH for 7 days. The change in color is evaluated by measurement of
the chromatic aberration before and after exposure to chemicals and
everyday products, generating a Delta E value. The samples are 100
.times. 100 .times. 2 mm plaques. Classification by visual
observation .largecircle. = No change in color at the surface 2 =
Slight change in color at the surface 5 = Significant coloration at
the surface Chemical resistance Internal method Measured after
conditioning in an oven at to sebum 23.degree. C. and 50% RH for 7
days. A given weight of sebum is spread at the surface of the
samples and then removed after conditioning. The samples thus
exposed are weighed after cleaning and the uptake in weight (%) of
the sample during the test is calculated. The possible visual
changes are also recorded. The samples are 50 .times. 50 .times. 2
mm plaques. Classification scale: (++) = low uptake in weight, no
visual changes (+) = low uptake in weight, slight visual changes
(-) = high uptake in weight, slight visual changes "Peachskin" feel
Internal method The feel was evaluated by a trained sensory panel
made up of 10 people, on a scale ranging from 1 to 5. On this
scale, "1" represents inferior properties of feel (no "peachskin"
sensation), while "5" represents superior properties of "peachskin
feel". Soft-silky feel or "peachskin" feel: Definition:
Characterizes a velvety effect to the touch, such as the velvety
skin of the peach. Protocol: Take a sample and make small movements
at the surface of the sample with the fingers without pressure.
Evaluation: Note the velvety sensation or "peachskin" feel.
Hardness ISO 868 23.degree. C. Tensile test ISO527 50 mm/min at
23.degree. C. Flexural modulus ISO 178 23.degree. C. Tear strength
ISO 34-B 500 mm/min, unnotched samples Taber abrasion ISO 9352 1000
g load, CS10 abrasive grinding wheel, resistance 1000 revolutions
per cycle. The samples are 100 .times. 100 .times. 2 mm plaques.
Compressive ISO 815 Constant strain of 25% applied for 72 hours at
residual strain 23.degree. C. or for 22 hours at 70.degree. C.
Measurement of the residual strain after 24 h of relaxation. The
samples are type B cylinders. Melt Flow Index ISO 1133 235.degree.
C., 1 kg (MFI) Ease of injection Internal method Classification
according to: .largecircle. = high-speed thin part injection
molding without deformation of the final object X = high-speed thin
part injection molding which exhibits deformations or defects in
surface appearance Ease of removal Internal method Classification
according to: from the mold .largecircle. = easy removal from the
mold, no sticking X = difficult removal from the mold, sticky
material Recyclability Internal method The recyclability is defined
as the possibility of reprocessing an already molded component, by
melting and again molding the material, without impacting the
quality of the reprocessed component. Classification according to:
X = nonrecyclable .largecircle. = recyclable
[0188] The characterizations are carried out on samples conditioned
at 23.degree. C., 50% relative humidity, for 2 weeks.
[0189] The compositions of the invention exhibit a low Shore A
hardness, especially formulations A and B, exhibiting a Shore A
hardness of less than or equal to 70 after 15 s, while retaining
good transformability in injection molding, and no exudation. These
formulations show the haptic properties required by mass
consumption applications, such as sports devices, portable devices,
for example in items of electronic equipment, or optical
accessories, such as glasses.
[0190] The compositions of the invention also combine a low
flexural modulus while retaining very good transformability in
injection molding and no exudation, as well as good resistance to
high temperatures.
[0191] The compositions of the invention, in the composition B
comprising a maleated SEBS compatibilizer, exhibit a better
abrasion resistance than the PEBA materials and than the TPSiV.RTM.
products resulting from TPU. The surface characteristics after
abrasion are improved: the surface remains smooth and homogeneous
without deep scratches. The visual appearance is retained after
abrasion, and there is no risk of injury on contact with the skin,
which is necessary for the materials used in footwear components,
such as footwear heels, for example, or for sports equipment.
[0192] The formulations of the invention are a solution for
avoiding the bonding stage necessary today to adhesively bond the
thermosetting rubber outer sole to the thermoplastic components of
the ski boot. This bonding stage takes time, requires the use of
primer and adhesive which may contain solvents, and requires a
crosslinking stage at high temperature.
[0193] On the contrary, the formulations of the invention can be
combined directly with the thermoplastics used in ski boots, such
as PEBA or TPU.
[0194] The compositions of the invention have a more mat surface
and a softer feel than the PEBA reference materials.
[0195] The compositions of the invention do not exhibit visible
exudation, unlike PEBAs.
[0196] The compositions of the invention have a lower absorption of
moisture than the PEBA reference materials. This contributes to
giving a greater resistance to stains, especially toward
hydrophilic stains (coffee, tea, wine, and the like).
[0197] The compositions of the invention have a lower compressive
residual strain compared with PEBAs (comparative examples E, F and
G) and with TPSiV.RTM. (H) resulting from TPUs, especially at
70.degree. C. This contributes to obtaining better performance
qualities under stress, for example in sports equipment or
industrial applications, such as sealants.
[0198] It has been observed that soft PEBA materials (typical
materials with a hardness of less than 35 Shore D) are difficult to
injection mold because they tend to stick to the mold and to deform
during removal from the mold. The composition (comprising silicone)
of the invention is a solution for solving this injection-molding
problem while retaining the various advantageous properties of
PEBAs, this being the case for materials which are even more
flexible.
[0199] In addition, when the design of the mold becomes complex,
the standard PEBA cannot be injected (because of its stiffness),
while there is no problem in injecting the composition
(PEBA-silicone) according to the invention.
* * * * *