Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
1999-09-14
2004-02-10
Hoke, Veronica P. (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C523S136000, C524S120000, C524S151000, C524S153000, C524S291000, C525S902000
Reexamination Certificate
active
06689827
ABSTRACT:
The present invention relates to transparent, impact-modified thermoplastic molding compositions comprising
A) a matrix of at least two different blend components,
B) impact-modifier,
C) an additive consisting essentially of
c
1
) at least one 2,6-disubstituted phenol and
c
21
) at least one organic phosphite of the formula (I)
P(OR
l
)
n
(OAr)
3−n
(I),
where:
R
1
is C
6
-C
30
-alkyl in straight-chain and/or branched form or C
6
-C
20
-cycloalkyl, in each case substituted or unsubstituted,
Ar is C
6
-C
20
-aryl or heteroaryl, in each case substituted or unsubstituted,
n is 1, 2 or 3, where a number of radicals R
1
or Ar in (I) are identical or different, or
c
22
) at least one organic phosphite of the formula (IIa) and/or (IIb)
where:
R
2
is C
6
-C
30
-alkyl in straight-chain and/or branched form or C
6
-C
20
-cycloalkyl, in each case substituted or unsubstituted,
X
1
and X
2
are C
1
-C
20
-alkyl or C
1
-C
20
-alkoxy, C
3
-C
20
-cycloalkyl, C
6
-C
20
-aryl or -aryloxy, C
7
-C
30
-aralkyl, the radicals named being substituted or unsubstituted,
or hydrogen, hydroxyl, NR′R″, where R′ and R″ are hydrogen, C
1
-C
6
-alkyl, C
6
-C
20
-aryl, C
7
-C
30
-aralkyl or C
3
-C
6
-cycloalkyl;
or, together with carbon, are a C
3
-C
10
-carbocycle or a C
2
-C
10
-heterocycle containing one or more heteroatoms selected from groups VA or VIA of the Periodic Table of the Elements, the cyclic structures named being substituted or unsubstituted;
or carbonyl or thiocarbonyl;
Z is unsubstituted or substituted C
1
-C
10
-alkylene or C
6
-C
20
-arylene, —Si(R
3
)(R
4
)— or —R
5
—Si(R
3
)(R
4
)—R
6
—, where
R
3
and R
4
are C
1
-C
10
-alkyl, C
6
-C
14
-aryl or aralkyl having a C
1
-C
10
-alkyl unit and a C
6
-C
10
-aryl unit, in each case substituted or unsubstituted,
R
5
and R
6
are C
1
-C
5
-alkylene, C
6
-arylene, the radicals Z in (IIa) or (IIb) being identical or different; or
c
23
) a mixture of compounds defined under c
21
) and c
22
).
The invention also relates to a process for preparing transparent, impact-modified thermoplastics and to their use for producing shaped articles, fibers and films. The invention relates, furthermore, to these films, fibers and shaped articles, and also to the use of these for producing packaging material or for producing equipment for medical engineering or for medical diagnostics. The invention also relates to transparent packaging material and transparent equipment for medical engineering or for medical diagnostics.
Thermoplastic materials are frequently not completely inert to light, high-energy radiation (eg. &ggr; radiation), moisture, oxygen or heat or various combinations of these agents, with the result that, during processing or storage, they tend to discolor or suffer impairment in other characteristics. In order to bring such disadvantages under control, suitable stabilizers and/or stabilizer systems are usually added to thermoplastic molding compositions. Stabilizing additives for thermoplastic molding compositions are known. However, although a wide variety of different stabilizers are available to the person skilled in the art, it has hitherto not been possible to find a satisfactory method for color-stabilization of transparent, impact-modified molding compositions whose matrix is built up from at least two different blend components. This stems, inter alia, from the fact that the suitability of stabilizer systems cannot be reliably predicted, even within thermoplastic formulations which are related. In the case of thermoplastics which comprise several blend components, it is often possible only to find a stabilizer which gives satisfactory results for one of the blend components, but not for the other materials of the blend or for the entire system. In transparent thermoplastic molding compositions, moreover, discoloration is particularly easy to detect, so that particularly high requirements have to be placed upon the stabilizer system.
Stabilizing additives for methacrylate-butadiene-styrene (MBS) core-shell graft copolymers are known, for example, from U.S. Pat. No. 5,451,624. These are combinations of at least one sterically hindered phenol, an organic phosphite, an organic sulfide and a buffer system, with the use of which, however, it is not possible to avoid cloudiness in transparent thermoplastic molding compositions. In addition, the scope of application of these stabilized molding compositions is considerably limited by the sulfur compounds used, the intrinsic characteristic odor of which can never be completely suppressed.
EP-A 426 499 describes stabilizing formulations for MBS modifiers made from a sterically hindered phenol, a less hindered phenol and a phosphite. These systems, however, give problems, especially with respect to the discoloration of transparent polymers.
It is an object of the present invention to provide effective stabilizers and/or stabilizer systems, in particular for impact-modified, transparent molding compositions.
We have found that this object is achieved by means of the transparent, impact-modified thermoplastic molding compositions described at the outset.
The invention also provides a process for preparing transparent, impact-modified thermoplastics, and their use for producing shaped articles, fibers and films.
The invention furthermore provides films, fibers and shaped articles, and also the use of these for producing packaging material or for producing equipment for medical engineering or for medical diagnostics. The invention also provides transparent packaging material and transparent equipment for medical engineering or for medical diagnostics.
Preference is given to transparent, impact-modified thermoplastic molding compositions comprising
A) a matrix of at least two different blend components,
B) impact-modifier,
C) an additive consisting essentially of
c
1
) at least one 2,6-disubstituted phenol and
c
21
) at least one compound of the formula (I)
P(OR
1
)
n
(OAr)
3−n
(I),
where:
R
1
is C
6
-C
20
-alkyl, C
6
-C
10
-cycloalkyl, in each case substituted or unsubstituted, eg. n-hexyl, n-heptyl, n-octyl, i-octyl, n-dodecyl, cyclohexyl, cycloheptyl or 1-methylcyclohexyl,
Ar is unsubstituted or substituted C
6
-C
10
-aryl, eg. phenyl, naphthyl or tolyl,
n is 1, 2, 3, or
c
22
) at least one compound of the formula (IIb)
where:
R
2
is unsubstituted or substituted C
6
-C
20
-alkyl, eg. n-hexyl, n-heptyl, n-octyl, i-octyl, n-dodecyl, cyclohexyl, cycloheptyl or 1-methylcyclohexyl,
Z is C
1
-C
3
-alkylene, such as methylene, 1,2-ethylene or 1,3-propylene, or o-, m- or p-phenylene, in each case unsubstituted or substituted, where the radicals Z or R
2
in (IIb) are identical or different; or
c
23
) a mixture of compounds as defined under c
21
) and c
22
)
Suitable blend components for the matrix A) of the novel thermoplastic molding compositions are, for example, polyalkyl, such as polymethyl methacrylate, polyethyl methacrylate and poly-2-ethylhexyl methacrylate, styrene-acrylonitrile copolymers, such as the SAN Component Luran® (BASF AG), styrene-acrylonitrile-methyl methacrylate copolymers, styrene-maleic anhydride copolymers, styrene-methyl methacrylate copolymers, styrene-butadiene block copolymers, such as Styrolux® (BASF AG), acrylonitrile-butadiene-styrene copolymers, such as the ABS component Terluran® (BASF AG), or acrylonitrile-styrene-acrylate copolymers, such as the ASA component Luran® S (BASF AG), or the corresponding impact-modified polymers. In principle, the formulation of the blend components in the matrix can be as desired.
Preference is given to a matrix based on an impact-modified polymethyl methacrylate-styrene-acrylonitrile copolymer blend.
Instead of the polymethyl methacrylate component here, it is also possible to use a copolymer of methyl methacrylate and alkyl acrylates, preferably methyl acrylate or butyl acrylate, the proportion derived from methyl methacrylate making up at least 60% by weight, preferably more than 80% by weight and in particular more than 90% by weight. The copolymer advantageously has a mean
Benker Klaus
Kurps Armin
Messinger Claudia
Neumann Rainer
Schade Christian
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