U.S. patent application number 10/492468 was filed with the patent office on 2004-12-30 for method for producing a granular formulation of plastic-soluble colorants.
Invention is credited to Balliello, Paolo, Dumler, Walter.
Application Number | 20040266918 10/492468 |
Document ID | / |
Family ID | 4566915 |
Filed Date | 2004-12-30 |
United States Patent
Application |
20040266918 |
Kind Code |
A1 |
Balliello, Paolo ; et
al. |
December 30, 2004 |
Method for producing a granular formulation of plastic-soluble
colorants
Abstract
The present invention relates to a method of producing a
granular formulation of colorants soluble in plastics, which method
comprises suspending in water a filter cake obtained from
preparation of the colorant, adding thereto from 0.1 to 5.0% by
weight, calculated with respect to the weight of colorant, of a
polyvinylpyrrolidone or of a sodium lauryl sulfate and, where
appropriate, further adjuvants, and then drying the aqueous
suspension to form granules, to the granular formulations
obtainable according to that method, and to the use thereof in the
production of colored plastics or colored polymeric particles.
Inventors: |
Balliello, Paolo;
(Rheinfelden, CH) ; Dumler, Walter; (Bad
Bellingen, DE) |
Correspondence
Address: |
CIBA SPECIALTY CHEMICALS CORPORATION
PATENT DEPARTMENT
540 WHITE PLAINS RD
P O BOX 2005
TARRYTOWN
NY
10591-9005
US
|
Family ID: |
4566915 |
Appl. No.: |
10/492468 |
Filed: |
April 13, 2004 |
PCT Filed: |
October 15, 2002 |
PCT NO: |
PCT/EP02/11504 |
Current U.S.
Class: |
524/35 ;
106/499 |
Current CPC
Class: |
C09B 67/0095 20130101;
C09B 67/0004 20130101 |
Class at
Publication: |
524/035 ;
106/499 |
International
Class: |
C08K 005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 24, 2001 |
CH |
2001 1957/01 |
Claims
What is claimed is:
1. A method of producing a granular formulation of a colorant that
is soluble in plastics, which comprises suspending in water a
filter cake obtained from preparation of the colorant, addition
thereto from 0.1 to 5.0% by weight, calculated with respect to the
weight of colorant, of a polyvinylpyrrolidone or of a sodium lauryl
sulfate and, where appropriate, further adjuvants, as then drying
the aqueous suspension to form granules.
2. A method according to claim 1, wherein from 0.1 to 5.0% by
weight, calculated with respect to the weight of colorant, of a
polyvinylpyrrolidone is used.
3. A method according to claim 1, wherein from 0.1 to 5.0% by
weight, calculated with respect to the weight of colorant, of a
sodium lauryl sulfate is used.
4. A method according to any one of claims 1 to 3, wherein there is
used, as a further adjuvant, a viscosity regulator.
5. A method according to claim 4, wherein the viscosity regulator
used is hydroxypropyl methylcellulose, hydroxypropylcellulose or
methylcellulose.
6. A method according to any one of claims 1 to 5, wherein the
granulation is carried out with spray drying.
7. A granular formulation of a colorant soluble in plastics, which
comprises (A) a colorant soluble in plastics, (B) from 0.1 to 5.0%
by weight, calculated with respect to the weight of colorant, of a
polyvinylpyrrolidone or of a sodium lauryl sulfate and, (C) where
appropriate, further adjuvants.
8. A method of producing colored plastics or colored polymeric
particles, which comprises using a granular formulation according
to claim 7.
9. Use of a granular formulation according to claim 7 in the
production of colored plastics of colored polymeric particles.
10. Use of a granular formulation according to claim 7 for coloring
food packaging.
Description
[0001] The present invention relates to a method of producing a
granular formulation of colorants that are soluble in plastics, and
to low-dust granular formulations of such colorants.
[0002] A method of producing colorant granules that are soluble in
plastics, which granules comprise a colorant and up to 5.0% by
weight of a polyglycol, is known, for example, from DE-A-4 038
002.
[0003] Those formulations do not, however, meet all of the
requirements currently made of such colorant granules.
[0004] There is therefore still a need for novel granular
formulations low in dust and stable to rubbing that are suited also
to the use of colorant granules, for example, in the food sector,
are to the mass coloration, accompanied by very high temperatures,
of plastics or polymeric particles.
[0005] It has now, surprisingly, been found that the granular
formulations produced in accordance with the invention
substantially satisfy the criteria set out above.
[0006] The present invention accordingly relates to a method of
producing a granular formulation colorants that are soluble in
plastics, which method comprises suspending in water a filter cake
obtained from preparation of the colorant, adding thereto from 0.1
to 5.0% by weight preferably from 0.3 to 4.0% by weight, and
especially from 0.5 to 3.5% by weight, calculated with respect to
the weight of colorant, of a polyvinylpyrrolidone or of a sodium
lauryl sulfates and, where appropriate, further adjuvants, and then
drying the aqueous suspension to form granules.
[0007] Colorants suitable for the method according to the invention
are, for example, those described under "Solvent Dyes" in the
Colour Index, 3rd Edition (3rd Revision 1987 including Additions
and Amendments to No. 85).
[0008] In the method according to the invention, preference is
given to colorants from the class of the azo, anthraquinone,
styrene, pyrazolone, quinophthalone, naphthazine, perinone,
coumarin, thioxanthene, thioindigo and metal complex colorants that
are soluble in plastics.
[0009] In the method according to the invention, special preference
is given to use of the colorants of formulae 123
[0010] The colorants of formulae (1) to (20) are known and can be
prepared according to general known methods.
[0011] The polyvinylpyrrolidone used in the method according to the
invention [poly(1-vinyl-2-pyrrolidinone), abbreviation PVP] is a
polymeric compound of the general formula 4
[0012] wherein n is an integer, having a molecular weight of
approximately from 2500 to 900 000 g/mol.
[0013] In the method according to the invention, preference is
given to polyvinylpyrrolidones having a molecular weight of from
5000 to 750 000 g/mol, especially from 10 000 to 90 000 g/mol and
more especially from 10 000 to 50 000 g/mol.
[0014] Further adjuvants that come into consideration for use,
where appropriate, in the method according to the invention
include, for example, bridging additives, buffers and, especially,
so-called viscosity regulators. There may be mentioned as examples
of such viscosity regulators hydroxypropyl methylcellulose,
hydroxypropylcellulose and, especially, methylcellulose.
[0015] Prior to granulation, from 0.1 to 3.5% by weight, preferably
from 0.2 to 2.5% by weight, calculated with respect to the weight
of colorant, of a viscosity regulator is preferably added to the
aqueous suspension comprising a colorant soluble in plastics and
from 0.1 to 5.0% by weight, preferably from 0.3 to 4.0% by weight
and especially from 0.5 to 3.5% by weight, calculated with respect
to the weight of colorant, of a polyvinylpyrrolidone of formula
(21) and of a sodium lauryl sulfate.
[0016] The granulation of the aqueous suspension comprising a
colorant soluble in plastics and from 0.1 to 5.0% by weight,
calculated with respect to the weight of colorant, of a
polyvinylpyrrolidone of formula (21) or of a sodium lauryl sulfate
and, where appropriate, further adjuvants, is carried out
preferably with spray-drying or fluidised-bed granulation.
[0017] In a preferred embodiment, the aqueous suspension comprising
a colorant soluble in plastics and from 0.1 to 5.0% by weight,
calculated with respect to the weight of colorant, of a
polyvinylpyrrolidone of formula (21) or of a sodium lauryl sulfate,
is homogenised, for example in a rotor/stator mill and/or bead
mill, to form a dispersion having a particle size of from 1 to 100
.mu.m. The resulting dispersion is then spray-dried in a spray
dryer, preferably a pressurised nozzle tower, to form
microgranules.
[0018] In a further preferred embodiment, the viscosity of the
aqueous suspension comprising a colorant soluble in plastics and
from 0.1 to 5.0% by weight, calculated with respect to the weight
of colorant, of a polyvinylpyrrolidone of formula (21) or of a
sodium lauryl sulfate, is adjusted to a desired value by the
addition of from 0.1 to 3.5% by weight, calculated with respect to
the weight of colorant, of a viscosity regulator, and the
suspension is homogenised, for example in a rotor/stator mill
and/or bead mill, to form a dispersion having a particle size of
from 1 to 100 .mu.m. The resulting dispersion is then spray-dried
in a spray dryer, preferably a pressurised nozzle tower, to form
microgranules.
[0019] The homogeneous suspension is advantageously adjusted to a
pH value >8 prior to drying preferably using a buffer system or
a weak base, for example NH.sub.4OH or Na.sub.2CO.sub.3.
[0020] The particle size of the prepared microgranules can vary
within a wide range and is generally from 5 to 1000 .mu.m,
preferably from 20 to 750 .mu.m, and especially from 50 to 250
.mu.m.
[0021] The present invention relates also to a granular formulation
of colorants soluble in plastics which comprises
[0022] (A) a colorant soluble in plastics,
[0023] (B) from 0.1 to 5.0% by weight, calculated with respect to
the weight of colorant, of a polyvinylpyrrolidone or of a sodium
lauryl sulfate and,
[0024] (C) where appropriate, further adjuvants.
[0025] A preferred granular formulation comprises:
[0026] as component (A), from 95 to 99.9% by weight of a colorant
soluble in plastics and,
[0027] as component (B), from 0.1 to 5.0% by weight, calculated
with respect to the weight of colorant, of a
polyvinylpyrrolidone.
[0028] A further preferred granular formulation comprises:
[0029] as component (A), from 91.5 to 99.8% by weight of a colorant
soluble in plastics,
[0030] as component (B), from 0.1 to 5.0% by weight, calculated
with respect to the weight of colorant, of a polyvinylpyrrolidone
and,
[0031] as component (C), from 0.1 to 3.5% by weight, calculated
with respect to the weight of colorant, of a viscosity
regulator.
[0032] A further preferred granular formulation comprises:
[0033] as component (A), from 95 to 99.9% by weight of a colorant
soluble in plastics and,
[0034] as component (B), from 0.1 to 5.0% by weight, calculated
with respect to the weight of colorant, of a sodium lauryl
sulfate.
[0035] A further preferred granular formulation comprises:
[0036] as component (A), from 91.5 to 99.8% by weight of a colorant
soluble in plastics,
[0037] as component (B), from 0.1 to 5.0% by weight, calculated
with respect to the weight of colorant, of a sodium lauryl sulfate
and,
[0038] as component (C), from 0.1 to 3.5% by weight, calculated
with respect to the weight of col rant, of a viscosity
regulator.
[0039] With respect to the colorants, the polyvinylpyrrolidone and
the sodium lauryl sulfate, the definitions and preferred meanings
given hereinabove for the method of producing a granular
formulation of colorants soluble in plastics apply.
[0040] Likewise, with respect to the further adjuvants used where
appropriate, the definitions and preferred meanings given
hereinabove for the method of producing a granular formulation
colorants soluble in plastics apply.
[0041] The colorant granules according to the invention are used
especially for coloring polymeric particles or thermoplastic
plastics, especially in the form of fibres, granules, films or
mouldings.
[0042] They are also suitable especially for coloring the mouldings
used in optics, for example lenses and headlight lenses, and for
coloring food packaging.
[0043] Preferred polymeric particles or thermoplastic plastics that
can be colored in accordance with the invention are, as high
molecular weight organic materials, very generally polymers have a
dielectric constant .gtoreq.2.5, especially polyester,
polycarbonate (PC), polystyrene (PS), polymethyl methacrylate
(PMMA), polyamide, polyethylene, polypropylene,
styrene/acrylonitrile (SAN) or acrylonitrile/butadiene/styrene
(ABS).
[0044] Polyester, PC and ABS are especially preferred. More
especially preferred are linear aromatic polyesters, which can be
obtained by polycondensation of terephthalic acid or
naphthalene-2,6-dicarboxylic acid and glycols, especially ethylene
glycol, or condensation products of terephthalic acid and
1,4-bis(hydroxymethyl)cyclohexane, for example polyethylene
terephthalate (PET), polyethylenenaphthalene-2,6-dicarboxyla- te
(PEN) or polybutylene terephthalate (PBTP); also polycarbonates,
e.g. those from
.alpha.,.alpha.-dimethyl-4,4-dihydroxy-diphenylmethane and
phosgene, or polymers based on polyvinyl chloride and also on
polyamide, for example polyamide 6 or polyamide 6,6.
[0045] The plastics colored with the colorant granules according to
the invention are suitable also for packaging liquid foods and,
especially, solid foods.
[0046] The coloring of the high molecular weight organic materials
using the colorant granules ac cording to the invention is carried
out, for example, by using rolling mills, mixing apparatus grinding
apparatus to admix the colorant granules with the substrates, the
colorant granules being dissolved or finely distributed in the high
molecular weight material.
[0047] The high molecular weight organic material with the admixed
colorant granules is then processed according to methods known per
se, such as, for example, calendering, compressed moulding,
extrusion, coating, spinning, pouring or injection moulding, as a
result of which the colored material acquires its final shape.
Admixture of the colorant granules according to the invention can
also be effected directly before the actual processing step, for
example by continuously metering, directly into the inlet zone of
an extruder, the colorant granules and a granulated or pulverulent
high molecular weight organic material and, where appropriate, also
other ingredients, such as additives, the constituents being mixed
in just before being processed. Generally, however, preference is
given to mixing the colorant granules according to the invention
into the high molecular weight organic material beforehand, since
more uniformly colored substrates can be obtained.
[0048] The present invention relates also to the above-mentioned
use of the colorant granules according to the invention.
[0049] The following Examples serve to illustrate the invention.
Unless specified otherwise, the parts are parts by weight and the
percentages are percentages by weight. The temperatures are given
in degrees Celsius. The relationship between parts by weight and
parts by volume is the same as between grams and cubic
centimetres.
EXAMPLE 1
[0050] In a laboratory reaction apparatus, 392.0 parts by weight of
an aqueous colorant filter cake containing 147.0 parts by weight of
colorant of formula 5
[0051] are homogeneously mixed at room temperature, with vigorous
stirring, with 1.5 parts by weight of polyvinylpyrrolidone K 30 and
120.5 parts by weight of water, and then ground in Fryma mill.
[0052] The resulting dispersion is subsequently spray-dried in a
laboratory atomizer at an inlet temperature of 150.degree. C. and
an outlet temperature of from 105 to 110.degree. C.
[0053] Low-dust, free-flowing granules having an average particle
size of from 5 to 15 .mu.m and a residual water content of
.ltoreq.1% are obtained.
EXAMPLE 2
[0054] In a laboratory reaction apparatus, 369.5 parts by weight of
an aqueous colorant filter cake containing 295.5 parts by weight of
colorant of formula 6
[0055] are homogeneously mixed, with vigorous stirring, with 3.0
parts by weight of polyvinylpyrrolidone K 30, 3.0 parts by weight
of hydroxypropyl methylcellulose and 290.0 parts by weight of
water.
[0056] The homogeneous suspension is then spray-dried in a
laboratory atomizer at an inlet temperature of 150.degree. C. and
an outlet temperature of from 105 to 110.degree. C.
[0057] Low-dust, free-flowing microgranules having an average
particle size of from 5 to 15 .mu.m a having a residual water
content of .ltoreq.1% are obtained.
EXAMPLE 3
[0058] In an apparatus equipped with a stirrer, 369.5 parts by
weight of an aqueous colorant filter cake containing 295.5 parts by
weight of colorant of formula 7
[0059] are homogeneously mixed at room temperature, with vigorous
stirring, with 4.4 parts by weight of polyvinylpyrrolidone K 30,
3.0 parts by weight of hydroxypropyl methylcellulose and about
290.0 parts by weight of water, in order to adjust the dry matter
content of the suspension to about 20% by weight.
[0060] Using a NIRO pilot plant scale atomizer having a binary
nozzle, the homogeneous suspension is then spray-dried at an inlet
temperature of 150.degree. C., an outlet temperature of from 10 to
110.degree. C. and a water vaporization capacity of 1 kg/h.
[0061] Low-dust, free-flowing colorant granules having an average
particle size of from 30 to 100 .mu.m and a size range of from 10
to 300 .mu.m and having a residual water content of .ltoreq.1% are
obtained.
EXAMPLE 4
[0062] In an apparatus equipped with a stirrer, 369.5 parts by
weight of an aqueous colorant filter cake containing 295.5 parts by
weight of colorant of formula 8
[0063] are homogeneously mixed at room temperature, with vigorous
stirring, with 4.5 parts by weight of a sodium lauryl sulfate, 3.0
parts by weight of hydroxypropyl methylcellulose and 290.0 parts by
weight of water.
[0064] Using a NIRO pilot plant scale atomizer having an atomizer
disc, the homogeneous suspension is then spray-dried at an inlet
temperature of 150.degree. C. and an outlet temperature of from 105
to 1100.degree. C.
[0065] Low-dust, free-flowing colorant granules having an average
particle size of from 20 to 100 .mu.m and a size range of from 10
to 250 .mu.m and having a residual water content of .ltoreq.1% are
obtained.
EXAMPLE 5
[0066] In an apparatus equipped with a stirrer, 295.5 parts by
weight of colorant of formula (3) are made into a slurry, using
water, with 4.4 parts by weight of polyvinylpyrrolidone K 17 and
3.0 parts by weight of methylcellulose and homogeneously mixed with
vigorous stirring. The homogeneous slurry is buffered to a pH value
>9 by the addition of an NH.sub.4OH solution, a the solids
content is adjusted to approximately 25% by weight by the addition
of water.
[0067] Using a NIRO atomizer having a binary nozzle, the
homogeneous suspension is then spray dried at an inlet temperature
of 150.degree. C. and an outlet temperature of from 105 to
110.degree. C.
[0068] Low-dust, free-flowing colorant granules having a particle
size of from 10 to 200 .mu.m and a residual water content of <1%
by weight are obtained.
EXAMPLES 6 to 21
[0069] Analogously to the procedures described in Examples 1 to 5,
the colorants of formulae (5) (20) are spray-dried to form granules
and microgranules.
* * * * *