Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
2002-03-18
2004-09-14
Yoon, Tae H. (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C524S090000, C524S092000, C524S094000, C524S190000, C524S357000
Reexamination Certificate
active
06790884
ABSTRACT:
The invention relates to the use of certain diaryidiketopyrrolo[3,4-c]pyrrole derivatives as additives in the pigmentation of partially crystalline plastics, especially those processed by injection moulding. By using such additives it is possible to avoid warping.
In the plastics processing industry, warping following injection moulding is a familiar and severe problem which in the case of partially crystalline plastics is observed in particular in the presence of organic pigments. It is generally assumed that the principal cause of this warping is a nucleation effect induced by the organic pigment particles.
Numerous attempts have already been made, with usually moderate success, to solve this problem, for example by slowing down the injection moulding process, by altering the pigment structure or pigment morphology, by coating the pigment particles, or by means of additives.
Altering the injection moulding parameters is awkward, uneconomic and heavily dependent on the size and geometry of the article being produced. With any change in pigmentation, moreover, laborious adaptation of the parameters is required.
The morphology of the pigment particles can be altered by known methods, for example by milling acicular pigments (including, in particular, phthalocyanines), or by conversion to a different crystal modification or coarser form. The colouristic properties of the pigments, however, are undesirably altered by the change in their morphology. JP 04/372632, for example, proposes diphenyidiketopyrrolo[3,4-c]pyrroles having a specific surface area of 3-15 m
2
/g, which provide very weak colouring.
EP 498667 describes dyes substituted with polyalkyleneoxy groups, which can be used instead of pigments. The improvement in warping, however, is insufficient, and these dyes have unsatisfactory fastness properties. The same applies to the pentyloxy-substituted phthalocyanines known from JP-53/121845.
U.S. Pat. No. 4,233,206 describes a method of colouring polyolefin articles using methylol-substituted pigments esterified with long-chain acids. However, the pigment properties suffer: for example the migration, especially in the case of classes of pigment whose good properties are based on the presence of primary or secondary amide groups which with this method, however, are substituted by methylol and hence disappear. A further factor is that, in combination with normal pigments, these dyes must be either added in high concentrations or else thoroughly, intimately mixed with the pigment. This method, moreover, yields unsatisfactory results in the case of pigments having a particularly high warping tendency, for example with diketopyrrolo[3,4-c]pyrroles.
As described in Chimia 48/9, 436 [1994], therefore, the best method to date has been to provide the pigment with a polymer coating. However, this method does not permit totally warp-free pigmenting, since in the course of dispersion fracture surfaces, which act as nucleation centres, always form in some of the aggregates.
Finally, it is known that reinforcing agents can be added to the plastic, examples being glass fibres or polyamides as disclosed in JP-57/159831 and WO-98141570. By virtue of such reinforcing agents, however, the material properties are fundamentally—and for the most part undesirably—altered. Depending on the material to be strengthened, compatibility problems arise, and the materials are no longer recyclable to the desired extent
The object was therefore to find a process with which partially crystalline plastics can be pigmented in the injection moulding process even with highly warp-promoting pigments, and especially with Colour Index Pigment Red 254 and its analogues, without a change in their mechanical and chemical properties.
EP-511165 discloses diketopyrrolo[3,4-c]pyrrole compounds which have nitrogen-containing groups attached to alkoxy or polyalkyleneoxy chains and which exhibit outstanding rheological properties in coating systems and printing inks.
EP-133156 discloses diketopyrrolo[3,4-c]pyrroles suitable for colouring high molecular mass organic material including, for example, polyolefins. Included in the disclosure, as one of two examples of compounds monosubstituted on the nitrogen, is 1,4-diketo-2-n-butyl-5-hydro-3,6-diphenylpyrrolo[3,4-c]pyrrole, which is suitable as a polyester dye but whose lightfastness is only borderline.
U.S. Pat. No. 4,579,949 and U.S. Pat. No. 4,490,542 disclose, among many other compounds, alkoxy- or alkylthio-substituted diketopyrrolo[3,4-c]pyrroles, but without concrete examples. In this case too, polyolefins are among the many plastics mentioned.
The abovementioned object has been solved in a surprisingly effective way by the use of the colorant combinations of the invention. The dimensional stability is better by far than when using the pigmentations known to date, and the pigmentary properties of the principal component are essentially retained; in very many cases, indeed, warping has completely disappeared.
The invention provides a composition comprising
a pigment containing at least one each of the groups
which are joined to one another as
or are in conjugation with one another, and
a colorant of the formula
in which
R
1
, R
2
, R
3
and R
4
independently of one another are hydrogen, halogen, R
6
, OR
6
or SR
6
, R
5
is hydrogen or linear or branched C
1
-C
12
alkyl, benzyl or phenethyl, and R
6
is an apolar group which is unsubstituted or substituted one or more times by halogen or by OC
1
-C
6
alkyl, with the proviso that if R
5
is hydrogen, R
1
, R
2
, R
3
or R
4
is R
6
, OR
6
or SR
6
.
If R
5
is hydrogen then preferably at least two of R
1
, R
2
, R
3
and R
4
are R
6
, OR
6
or SR
6
. Preferred colorants of the formula (I) are those in which R
1
and R
2
are OR
6
or SR
6
and R
3
and R
4
are hydrogen, or in which R
1
and R
2
are hydrogen and R
3
and R
4
are OR
6
or SR
6
. Particularly preferred colorants of the formula (I) are those in which R
1
and R
2
are SR
6
and R
3
and R
4
are hydrogen, or in which R
1
and R
2
are hydrogen and R
3
and R
4
are SR
6
. These are particularly suitable in combination with diketopyrrolo[3,4-c]pyrroles, even so when R
5
is hydrogen.
R
5
is preferably C
1
-C
12
alkyl or benzyl and, with particular preference, is linear C
1
-C
12
alkyl.
R
6
is, for example, an apolar saturated, mono- or polyunsaturated or aromatic, substituted or unsubstituted hydrocarbon radical, preferably unsubstituted or halogen- or OC
1
-C
6
alkyl-substituted, linear or branched C
1
-C
30
alkyl, or C
2
-C
30
alkenyl. With particular preference R
6
is unsubstituted linear C
1
-C
30
alkyl.
C
1
-C
30
alkyl is, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-amyl, tert-amyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, tetracosyl or triacontyl. Halogen is for example iodine, fluorine, bromine or, preferably, chlorine.
For optimum results R
1
, R
2
, R
3
and R
4
can be tailored to R
5
(or vice versa). If R
5
is C
5
-C
12
alkyl, benzyl or phenethyl, then R
1
, R
2
, R
3
and R
4
are arbitrary and can, for example, all simultaneously be hydrogen. If R
5
is C
2
-C
4
alkyl, then there are preferably at least 6 carbon atoms in total in R
1
, R
2
, R
3
, R
4
and R
5
. If R
5
is methyl, there is preferably an alkyl or alkylene chain of at least 6 carbon atoms in R
1
, R
2
, R
3
or R
4
. If R
5
is hydrogen, then there are preferably two alkyl or alkylene chains of at least 6 carbon atoms, or one alkyl or alkylene chain of at least 12 carbon atoms, in R
1
, R
2
, R
3
or R
4
. A higher number of carbon atoms, or longer alkyl or alkylene chains, are generally advantageous.
The preferred minimum chain lengths of the substituents on the nitrogen and on the phenyl rings lead to a supposition of a connection with the polarity, which might, for example, have consequences for the solubility and the melting point. At any rate it is surprising that the
Bugnon Philippe
Flandrin Franck Rey
Hao Zhimin
Hu Guo-Hua
Ciba Specialty Chemicals Corporation
Mansfield Kevin T.
Stevenson Tyler A.
Yoon Tae H.
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