U.S. patent application number 10/947876 was filed with the patent office on 2005-09-08 for microgels in non-crosslinkable organic media.
Invention is credited to Fruh, Thomas, Galda, Patrick, Obrecht, Werner, Ziser, Torsten.
Application Number | 20050197443 10/947876 |
Document ID | / |
Family ID | 34353138 |
Filed Date | 2005-09-08 |
United States Patent
Application |
20050197443 |
Kind Code |
A1 |
Ziser, Torsten ; et
al. |
September 8, 2005 |
Microgels in non-crosslinkable organic media
Abstract
The present invention relates to a composition containing a
non-crosslinkable medium and at least one microgel, to a process
for its preparation, to uses of the compositions, and to
microgel-containing polymers, rubbers, lubricants, coatings, etc.
produced therefrom.
Inventors: |
Ziser, Torsten; (Birkenau,
DE) ; Fruh, Thomas; (Limburgerhof, DE) ;
Galda, Patrick; (Karlsruhe, DE) ; Obrecht,
Werner; (Moers, DE) |
Correspondence
Address: |
LANXESS CORPORATION
111 RIDC PARK WEST DRIVE
PITTSBURGH
PA
15275-1112
US
|
Family ID: |
34353138 |
Appl. No.: |
10/947876 |
Filed: |
September 23, 2004 |
Current U.S.
Class: |
524/474 |
Current CPC
Class: |
C08L 9/06 20130101; C08K
5/01 20130101; C08L 21/00 20130101; C08L 21/00 20130101; C08L 71/02
20130101; C08L 21/00 20130101; C08L 2666/08 20130101; C08L 9/06
20130101 |
Class at
Publication: |
524/474 |
International
Class: |
C08K 005/01 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 27, 2003 |
DE |
103 44 975.2 |
Claims
What is claimed is:
1. Composition comprising at least one non-crosslinkable organic
medium (A) which has a viscosity of less than 1000 mPas at
120.degree. C., and at least one microgel (B).
2. Composition according to claim 1, the microgel (B) has primary
particles exhibiting approximately spherical geometry.
3. Composition according to claim 2, wherein the microgel (B) has a
variation in diameters of an individual primary particle of the
microgel (B), defined as [(d1-d2)/d1].times.100, wherein d1 and d2
are any two diameters of the primary particle and d1>d2, is less
than 250%.
4. Composition according to claim 2, wherein the primary particles
of the microgel (B) have an average particle size of from 5 to 500
nm.
5. Composition according to claim 1, wherein the microgel (B)
comprise at least about 70 wt. % portions that are insoluble in
toluene at 23.degree. C.
6. Composition according to claim 1, wherein the microgel (B) has a
swelling index in toluene at 23.degree. C. of less than about
80.
7. Composition according to claim 1, wherein the microgel (B) has
glass transition temperatures of from -100.degree. C. to
+100.degree. C.
8. Composition according to claim 1, wherein the microgel (B) is a
crosslinked microgel that has not been crosslinked by means of
high-energy radiation.
9. Composition according to claim 1, wherein the microgel (B) has a
breadth of the glass transition range of greater than about
5.degree. C.
10. Composition according to claim 1, wherein the microgel (B) is
prepared by emulsion polymerization.
11. Composition according to claim 1, wherein the microgel (B) is
based on rubber.
12. Composition according to claim 1, wherein the microgel (B) is
based on homopolymers or random copolymers.
13. Composition according to claim 1, wherein the microgel (B) is
modified by functional groups reactive towards C.dbd.C double
bonds.
14. Composition according to claim 1, wherein the non-crosslinkable
medium (A) is at least one compound selected from the group
consisting of solvents, saturated or aromatic hydrocarbons,
polyether oils, ester oils, polyether ester oils, phosphoric acid
esters, silicon-containing oils and halogenated hydrocarbons.
15. Composition according to claim 1 comprising from 0.5 to 90 wt.
% of the microgel (B), based on the total amount of the
composition.
16. Composition according to claim 1 comprising from 10 to 99.5 wt.
% of the non-crosslinkable organic medium (A).
17. Composition according to claim 1 further comprising fillers and
additives.
18. Composition according to claim 1 prepared a homogenizer, a bead
mill (agitator ball mill) or a three-roller mill.
19. Composition according to claim 1, wherein the composition has a
viscosity at 20.degree. C. of from 2 mPas to 5,000,000 mPas at a
speed of 5 s.sup.-1, determined by means of a cone/plate measuring
system according to DIN 53018.
20. Composition according to claim 19, wherein the microgel (B) has
a swelling index in toluene at 23.degree. C. of from 1 to 15.
21. Composition according to claim 1, wherein the composition is a
thermoplastic plastics, rubbers or thermoplastic elastomers.
22. Microgel-containing polymers comprising compositions according
to claim 1.
23. Use according to claim 22 in the production of
microgel-containing rubbers.
24. Plastics, rubbers, coating compositions or lubricants
comprising the compositions according to claim 1.
25. Process for the preparation of the composition according to
claim 1, comprising subjecting components (A) and (B) .backslash.to
treatment by means of a homogenizer, a bead mill or a three-roller
mill.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a composition containing a
non-crosslinkable medium and at least one microgel, to a process
for its preparation, to uses of the compositions, and to
microgel-containing polymers, rubbers, lubricants, coatings, etc.
produced therefrom.
BACKGROUND OF THE INVENTION
[0002] It is known to use rubber gels, also modified rubber gels,
in blends with a very wide variety of rubbers in order, for
example, to improve the rolling resistance in the production of
motor vehicle tires (see e.g. DE 42 20 563, GB-PS 10 78 400, EP 405
216 and EP 854 171). The rubber gels are always incorporated into
solid matrices.
[0003] It is also known to incorporate printing ink pigments in
finely divided form into liquid media suitable therefore, in order
ultimately to produce printing inks (see e.g. EP 0 953 615 A2, EP 0
953 615 A3). Thereby achieving particle sizes of as little as 100
nm.
[0004] Various dispersing apparatuses such as bead mills,
three-roller mills or homogenizers can be used for the dispersion.
The use of homogenizers and the operation thereof is described in
the Marketing Bulletin of APV Homogenizer Group--"High-pressure
homogenizers processes, product and applications" by William D.
Pandolfe and Peder Baekgaard, principally for the homogenization of
emulsions.
[0005] The above referenced documents do not describe the use of
rubber gels as the solids component in mixtures with liquid organic
media, with the aim of producing very finely divided rubber-gel
dispersions having particle diameters below one .mu.m, and their
homogenization by means of a homogenizer.
[0006] Chinese Journal of Polymer Science, Volume 20, No. 2,
(2002), 93-98 describes microgels fully crosslinked by means of
high-energy radiation and their use for increasing the impact
strength of plastics. In the preparation of specific epoxy resin
compositions, a mixture of a radiation-crosslinked
carboxyl-terminated nitrile-butadiene microgel and the diglycidyl
ether of bisphenol A, a crosslinkable organic medium, is formed as
intermediate. Further liquid microgel-containing compositions are
not described.
[0007] Similarly, US 2003/0,088,036 A1 discloses reinforced
heat-curing resin compositions, the preparation of which likewise
comprises mixing radiation-crosslinked microgel particles with
heat-curing pre-polymers (see also EP 1 262 510 A1).
[0008] Surprisingly it has now found that it is possible to finely
distribute microgels in liquid organic media having a specific
viscosity using a homogenizer, for example. The division of the
microgels in the organic medium to the primary particle range is,
for example, a requirement for utilizing the nano properties of the
microgels in applications of any kind, for example in incorporation
into plastics. The liquid compositions according to the present
invention containing the specific microgels are able to open up a
large number of novel applications for microgels which were not
accessible with the microgels themselves.
SUMMARY OF THE INVENTION
[0009] Compositions according to the present invention, owing to
the fine distributions that are achievable, can be incorporated
into plastics, for example, completely new properties being
obtained as a result. The microgel-containing compositions
according to the present invention can be used in a large number of
fields, such as, for example, in elastomeric PU systems
(cold-casting systems and hot-casting systems), in coating
compositions or as lubricant additives. In the microgel-containing
compositions according to the present invention, materials that are
incompatible per se form a homogeneous distribution which remains
stable even on prolonged storage (6 months).
[0010] P. Potschke et al., Kautschuk Gummi Kunststoffe, 50 (11)
(1997) 787 have shown that, with incompatible materials such as,
for example, p-phenylenediamine derivative as the dispersed phase
and TPU as the surrounding phase, it is not possible to obtain
domains smaller than 1.5 .mu.m. It is surprising that such small
dispersed phases are achieved with the microgels of the present
invention.
[0011] Microgel-containing compositions have been found for which
very different rheological behavior has been demonstrated. In
suitable microgel-containing compositions, a very strong intrinsic
viscosity or thixotropy has surprisingly been found, as well as
flow behavior similar to that of Newtonian fluids. This can be used
to control the flow behavior, as well as other properties, of any
desired liquid compositions in a targeted manner by means of
microgels. Surprisingly, plastics produced from the
microgel-containing compositions according to the present invention
have been found to have improved tear strength.
[0012] The present invention accordingly provides a composition
containing at least one non-crosslinkable organic medium (A) which
has a viscosity of less than 100 mPas at a temperature of
120.degree. C., and at least one microgel (B).
BRIEF DESCRIPTION OF THE DRAWING
[0013] FIG. 1 illustrates the operation of a homogenizing
valve.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The viscosity of the organic medium is preferably less than
200 mPas, more preferably less than 100 mPas, at 120.degree. C. The
viscosity of the crosslinkable organic medium (A) is determined at
120.degree. C. at a speed of 5 s.sup.-1 by means of a cone/plate
measuring system according to DIN 53018.
[0015] Microgels (B)
[0016] The microgel (B) used in the composition according to the
present invention is a crosslinked microgel. Preferably, it is not
a microgel crosslinked by means of high-energy radiation.
High-energy radiation here means electromagnetic radiation having a
wavelength of less than 0.1 .mu.m. The use of microgels crosslinked
by means of high-energy radiation, as described, for example, in
Chinese Journal of Polymer Science, Volume 20, No. 2, (2002),
93-98, is disadvantageous because it is virtually impossible to
produce microgels crosslinked by high-energy radiation on an
industrial scale. In addition, the use of high-energy radiation
from radioactive radiation sources such as radioactive cobalt is
associated with serious safety problems. Furthermore, because the
radiation-crosslinked microgels are generally fully
radiation-crosslinked microgels, the change in modulus, during
incorporation of the composition according to the present invention
into plastics, for example, from the matrix phase to the dispersed
phase is immediate. As a result, sudden stress can cause tearing
effects between the matrix and the dispersed phase, with the result
that the mechanical properties, the swelling behavior and the
stress corrosion cracking, etc. of the microgel-containing plastics
produced using the compositions according to the present invention
are impaired.
[0017] Preferably, the primary particles of the microgel (B)
exhibit approximately spherical geometry. According to DIN
53206:1992-08, primary particles are the microgel particles
dispersed in the coherent phase which can be individually
recognized by means of suitable physical processes (electron
microscope) (see e.g. Rompp Lexikon, Lacke und Druckfarben, Georg
Thieme Verlag, 1998). An "approximately spherical" geometry means
that the dispersed primary particles of the microgels recognizably
have substantially a circular surface when the composition is
viewed, for example, using an electron microscope. Because the form
or morphology of the microgels does not change substantially during
the further processing of the compositions according to the present
invention, the comments made hereinabove and herein below apply in
the same manner also to the microgel-containing compositions, such
as, for example, plastics, coating compositions, lubricants or the
like, obtained using the composition according to the present
invention.
[0018] In the primary particles of the microgel (B) present in the
composition according to the present invention, the variation in
the diameters of an individual primary particle, defined as
[(d1-d2)/d1].times.100,
[0019] wherein d1 and d2 are any two diameters of the primary
particle and d1>d2, is preferably less than 250%, more
preferably less than 100%, most preferably less than 50%.
[0020] Preferably at least 80%, more preferably at least 90%, most
preferably at least 95%, of the primary particles of the microgel
exhibit a variation in the diameters, defined as
[(d1-d2)/d1].times.100,
[0021] wherein d1 and d2 are any two diameters of the primary
particle and d1>d2, of less than 250%, preferably less than
100%, more preferably less than 50%.
[0022] The above-mentioned variation in the diameters of the
individual particles is determined by the following process. A thin
section of the composition according to the present invention is
first prepared as described in the Examples. An image is then
recorded by transmission electron microscopy at a magnification of,
for example, 10,000 times or 200,000 times. In an area of
833.7.times.828.8 nm, the largest and smallest diameters d1 and d2
are determined on 10 microgel primary particles. If the variation
is less than 250%, more preferably less than 100%, most preferably
less than 50%, in all 10 microgel primary particles, then the
microgel primary particles exhibit the above-defined feature of
variation.
[0023] If the concentration of the microgels in the composition is
so high that pronounced overlapping of the visible microgel primary
particles occurs, the evaluatability can be improved by previously
diluting the measuring sample in a suitable manner.
[0024] In the composition according to the present invention, the
primary particles of the microgel (B) preferably have an average
particle diameter of from 5 to 500 nm, more preferably from 20 to
400 nm, most preferably from 30 to 300 nm (diameter data according
to DIN 53206). Because the morphology of the microgels remains
substantially unchanged during the further processing of the
composition according to the present invention, the average
particle diameter of the dispersed primary particles corresponds
substantially to the average particle diameter of the dispersed
primary particles in the products of further processing obtained
using the composition according to the present invention, such as
microgel-containing plastics, lubricants, coatings, etc.. This
constitutes a particular advantage of the composition according to
the present invention. It is possible to provide customers with
liquid, storage-stable microgel formulations which are customized
to a certain degree and exhibit a defined morphology of the
microgels and which the customer can readily process further in the
desired applications. Previous expensive dispersion, homogenization
or even preparation of the microgels is no longer necessary, and it
is therefore to be expected that such microgels will also be used
in fields in which their use hitherto appeared too costly.
[0025] In the composition according to the present invention, the
microgels (B) advantageously contain at least about 70 wt. %, more
preferably at least about 80 wt. %, most preferably at least about
90 wt. %, portions that are insoluble in toluene at 23.degree. C.
(gel content).
[0026] The portion that is insoluble in toluene is determined in
toluene at 23.degree. C. For this purpose, 250 mg of the microgel
are swelled in 20 ml of toluene at 23.degree. C. for 24 hours, with
shaking. After centrifugation at 20,000 rpm, the insoluble portion
is separated off and dried. The gel content is obtained from the
difference between the weighed portion and the dried residue and is
given in percent.
[0027] In the composition according to the present invention, the
microgels (B) advantageously exhibit a swelling index in toluene at
23.degree. C. of less than about 80, more preferably of less than
60, most preferably of less than 40. For example, the swelling
indices of the microgels (Qi) can preferably be between 1-15 and
1-10. The swelling index is calculated from the weight of the
solvent-containing microgel swelled in toluene at 23.degree. C. for
24 hours (after centrifugation at 20,000 rpm) and the weight of the
dry microgel:
Qi=wet weight of the microgel/dry weight of the microgel.
[0028] In order to determine the swelling index, 250 mg of the
microgel are allowed to swell in 25 ml of toluene for 24 hours,
with shaking. The gel is removed by centrifugation and weighed and
then dried at 70.degree. C. until a constant weight is reached and
then weighed again.
[0029] In the composition according to the present invention, the
microgels (B) preferably have glass transition temperatures Tg of
from -100.degree. C. to +100.degree. C., more preferably from
-80.degree. C. to +80.degree. C.
[0030] Furthermore, the microgels (B) used in the composition
according to the present invention preferably have a breadth of
glass transition of greater than 5.degree. C., preferably greater
than 10.degree. C., more preferably greater than 20.degree. C.
Microgels that have such a breadth of glass transition are
generally not completely homogeneously crosslinked--in contrast to
completely homogeneously radiation-crosslinked microgels. This has
the result that the change in modulus from the matrix phase to the
dispersed phase in the microgel-containing plastics compositions,
for example, produced from the compositions according to the
invention is not immediate. As a result, sudden stress on these
compositions does not lead to tearing effects between the matrix
and the dispersed phase, with the result that the mechanical
properties, the swelling behavior and the stress corrosion
cracking, etc. are advantageously affected.
[0031] The glass transition temperatures (Tg) and the breadth of
the glass transition (.DELTA.Tg) of the microgels are determined by
differential scanning calorimetry (DSC) under the following
conditions: For determining Tg and .DELTA.Tg, two cooling/heating
cycles are carried out. Tg and .DELTA.ATg are determined in the
second heating cycle. For the determinations, 10 to 12 mg of the
chosen microgel are placed in a DSC sample container (standard
aluminum ladle) from Perkin-Elmer. The first DSC cycle is carried
out by first cooling the sample to -100.degree. C. with liquid
nitrogen and then heating it to +150.degree. C. at a rate of 20
K/min. The second DSC cycle is begun by immediately cooling the
sample as soon as a sample temperature of +150.degree. C. has been
reached. Cooling is carried out at a rate of about 320 K/min. In
the second heating cycle, the sample is again heated to
+150.degree. C., as in the first cycle. The rate of heating in the
second cycle is again 20 K/min. Tg and .DELTA.Tg are determined
graphically on the DSC curve of the second heating operation. To
that end, three straight lines are plotted on the DSC curve. The
first straight line is plotted on the part of the DSC curve below
Tg, the second straight line is plotted on the branch of the curve
passing through Tg with the point of inflection, and the third
straight line is plotted on the branch of the DSC curve above Tg.
Three straight lines with two points of intersection are thus
obtained. The two points of intersection are each characterized by
a characteristic temperature. The glass transition temperature Tg
is obtained as the mean of these two temperatures, and the breadth
of the glass transition .DELTA.Tg is obtained from the difference
between the two temperatures.
[0032] The microgels present in the composition according to the
present invention, which microgels have preferably not been
crosslinked by high-energy radiation, can be prepared in a manner
known per se (see, for example, EP-A-405 216, EP-A-854 171, DE-A
4220563, GB-PS 1078400, DE 197 01 489.5, DE 197 01 488.7, DE 198 34
804.5, DE 198 34 803.7, DE 198 34 802.9, DE 199 29 347.3, DE 199 39
865.8, DE 199 42 620.1, DE 199 42 614.7, DE 100 21 070.8, DE 100
38488.9, DE 100 39 749.2, DE 100 52 287.4, DE 100 56 311.2 and DE
100 61 174.5). In patent (applications) EP-A 405 216, DE-A 4220563
and in GB-PS 1078400, the use of CR, BR and NBR microgels in
mixtures with double-bond-containing rubbers is claimed. DE 197 01
489.5 describes the use of subsequently modified microgels in
mixtures with double-bond-containing rubbers such as NR, SBR and
BR.
[0033] Microgels are understood as being rubber particles which are
obtained especially by crosslinking the following rubbers:
[0034] BR: polybutadiene
[0035] ABR: butadiene/acrylic acid C1-4 alkyl ester copolymers
[0036] IR: polyisoprene
[0037] SBR: styrene-butadiene copolymerization products having
styrene contents of from 1 to 60 wt. %, preferably from 5 to 50 wt.
%
[0038] X-SBR: carboxylated styrene-butadiene copolymerization
products
[0039] FKM: fluorine rubber
[0040] ACM: acrylate rubber
[0041] NBR: polybutadiene-acrylonitrile copolymerization products
having acrylonitrile contents of from 5 to 60 wt. %, preferably
from 10 to 50 wt. %
[0042] X-NBR: carboxylated nitrile rubbers
[0043] CR: polychloroprene
[0044] IIR: isobutylene/isoprene copolymerization products having
isoprene contents of from 0.5 to 10 wt. %
[0045] BIIR: brominated isobutylene/isoprene copolymerization
products having bromine contents of from 0.1 to 10 wt. %
[0046] CIIR: chlorinated isobutylene/isoprene copolymerization
products having chlorine contents of from 0.1 to 10 wt. %
[0047] HNBR: partially and completely hydrogenated nitrile
rubbers
[0048] EPDM: ethylene-propylene-diene copolymerization products
[0049] EAM: ethylene/acrylate copolymers
[0050] EVM: ethylene/vinyl acetate copolymers
[0051] CO and ECO: epichlorohydrin rubbers
[0052] Q: silicone rubbers
[0053] AU: polyester urethane polymerization products
[0054] EU: polyether urethane polymerization products
[0055] ENR: epoxidized natural rubber or mixtures thereof.
[0056] The preparation of the uncrosslinked microgel starting
products is preferably carried out by the following methods:
[0057] 1. emulsion polymersation
[0058] 2. solution polymerization of rubbers which are not
obtainable by variant 1,
[0059] 3. naturally occurring latices, such as, for example,
natural rubber latex, can additionally be used.
[0060] The microgels (B) used in the composition according to the
preferably invention are preferably those which are obtainable by
emulsion polymerization and crosslinking.
[0061] The following free-radically polymerizable monomers, for
example, are preferably used in the preparation of the microgels
used according to the invention by emulsion polymerization:
butadiene, styrene, acrylonitrile, isoprene, esters of acrylic and
methacrylic acid, tetrafluoroethylene, vinylidene fluoride,
hexafluoropropene, 2-chlorobutadiene, 2,3-dichloro-butadiene, and
also double-bond-containing carboxylic acids, such as, for example,
acrylic acid, methacrylic acid, maleic acid, itaconic acid, etc.,
double-bond-containing hydroxy compounds, such as, for example,
hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxybutyl
methacrylate, amine-functionalized (meth)acrylates, acrolein,
N-vinyl-2-pyrrolidone, N-allyl-urea and N-allyl-thiourea, and also
secondary amino(meth)acrylic acid esters, such as
2-tert.-butylaminoethyl methacrylate and
2-tert.-butylaminoethylmethacrylamide, etc.. Crosslinking of the
rubber gel can be achieved directly during the emulsion
polymerization, such as by copolymerization with multifunctional
compounds having crosslinking action, or by subsequent crosslinking
as described herein below. Preferred multifunctional comonomers are
compounds having at least two, preferably from 2 to 4,
copolymerizable C.dbd.C double bonds, such as diisopropenylbenzene,
divinylbenzene, divinyl ethers, divinylsulfone, diallyl phthalate,
triallyl cyanurate, triallyl isocyanurate, 1,2-polybutadiene,
N,N'-m-phenylenemaleimide, 2,4-toluylenebis(maleimide) and/or
triallyl trimellitate. There come into consideration also the
acrylates and methacrylates of polyhydric, preferably di- to
tetra-hydric, C2 to C10 alcohols, such as ethylene glycol,
1,2-propanediol, butanediol, hexanediol, polyethylene glycol having
from 2 to 20, preferably from 2 to 8, oxyethylene units, neopentyl
glycol, bisphenol A, glycerol, trimethylolpropane, pentaerythritol,
sorbitol, with unsaturated polyesters of aliphatic diols and
polyols, as well as maleic acid, fumaric acid and/or itaconic
acid.
[0062] Crosslinking to form rubber microgels during the emulsion
polymerization can also be effected by continuing the
polymerization to high conversions or by the monomer feed process
by polymerization with high internal conversions. Another
possibility consists in carrying out the emulsion polymerization in
the absence of regulators.
[0063] For the crosslinking of the uncrosslinked or weakly
crosslinked microgel starting products following the emulsion
polymerization there are best used latices which are obtained in
the emulsion polymerization. In principle, this method can also be
used with non-aqueous polymer dispersions which are obtainable by
other means, e.g. by recrystallization. Natural rubber latices can
also be crosslinked in this manner.
[0064] Suitable chemicals having crosslinking action are, for
example, organic peroxides, such as dicumyl peroxide,
tert.-butylcumyl peroxide,
bis-(tert.-butyl-peroxy-isopropyl)benzene, di-tert.-butyl peroxide,
2,5-dimethylhexane 2,5-dihydroperoxide, 2,5-dimethylhexane
3,2,5-dihydroperoxide, dibenzoyl peroxide,
bis-(2,4-dichlorobenzoyl) peroxide, tert.-butyl perbenzoate, and
also organic azo compounds, such as azo-bis-isobutyronitrile and
azo-bis-cyclohexanenitrile, and also di- and poly-mercapto
compounds, such as dimercaptoethane, 1,6-dimercapto-hexane,
1,3,5-trimercaptotriazine and mercapto-terminated polysulfide
rubbers, such as mercapto-terminated reaction products of
bis-chloroethylformal with sodium polysulfide.
[0065] The optimum temperature for carrying out the
post-crosslinking is naturally dependent on the reactivity of the
crosslinker and can be carried out at temperatures from room
temperature to about 180.degree. C., optionally under elevated
pressure (see in this connection Houben-Weyl, Methoden der
organischen Chemie, 4th Edition, Volume 14/2, page 848).
Particularly preferred crosslinkers are peroxides.
[0066] The crosslinking of rubbers containing C.dbd.C double bonds
to form microgels can also be carried out in dispersion or emulsion
with the simultaneous partial, or complete, hydrogenation of the
C.dbd.C double bond by means of hydrazine, as described in U.S.
Pat. No. 5,302,696 or U.S. Pat. No. 5,442,009, or optionally other
hydrogenating agents, for example organometal hydride
complexes.
[0067] Enlargement of the particles by agglomeration can optionally
be carried out before, during or after the post-crosslinking.
[0068] The preparation process that is preferably employed
according to the present invention without the use of high-energy
radiation always yields incompletely homogeneously crosslinked
microgels which can exhibit the above-described advantages.
[0069] Rubbers produced by solution polymerization can also be used
as starting materials for the preparation of the microgels. In such
cases, solutions of the rubbers in suitable organic solvents are
used as starting material.
[0070] The desired sizes of the microgels are produced by mixing
the rubber solution by means of suitable apparatuses in a liquid
medium, preferably in water, optionally with the addition of
suitable surface-active auxiliary substances, such as, for example,
surfactants, so that a dispersion of the rubber in the appropriate
particle size range is obtained. For the crosslinking of the
dispersed solution rubbers, the procedure described above for the
subsequent crosslinking of emulsion polymerization products is
followed. Suitable crosslinkers are the compounds mentioned above,
it being possible for the solvent used for the preparation of the
dispersion optionally to be removed prior to the crosslinking, for
example by distillation.
[0071] As microgels for the preparation of the composition
according to the present invention there may be used both
non-modified microgels, which contain substantially no reactive
groups especially at the surface, and microgels modified by
functional groups, especially microgels modified at the surface.
The latter can be prepared by chemical reaction of the already
crosslinked microgels with chemicals that are reactive towards
C.dbd.C double bonds. These reactive chemicals are especially those
compounds by means of which polar groups, such as, for example,
aldehyde, hydroxyl, carboxyl, nitrile, etc., and also
sulfur-containing groups, such as, for example, mercapto,
dithiocarbamate, polysulfide, xanthogenate, thiobenzthiazole and/or
dithiophosphoric acid groups and/or unsaturated dicarboxylic acid
groups, can be chemically bonded to the microgels. The same is also
true of N,N'-m-phenylenediamine. The purpose of modifying the
microgels is to improve the microgel compatibility when the
composition according to the invention is used to prepare the
subsequent matrix, into which the microgel is incorporated, or the
composition according to the present invention is used for
incorporation into a matrix, in order to achieve a good
distribution capacity during preparation as well as good
coupling.
[0072] Preferred methods of modification are the grafting of the
microgels with functional monomers and reaction with low molecular
weight agents.
[0073] For the grafting of the microgels with functional monomers,
there is preferably used as starting material the aqueous microgel
dispersion, which is reacted under the conditions of a free-radical
emulsion polymerization with polar monomers such as acrylic acid,
methacrylic acid, itaconic acid, hydroxyethyl (meth)acrylate,
hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate,
acrylamide, methacrylamide, acrylonitrile, acrolein,
N-vinyl-2-pyrrolidone, N-allyl-urea and N-allyl-thiourea, and also
secondary amino-(meth)acrylic acid esters such as
2-tert.-butylaminoethyl methacrylate and
2-tert.-butylaminoethylmethac- rylamide. In this manner there are
obtained microgels having a core/shell morphology, wherein the
shell should be highly compatible with the matrix. It is desirable
for the monomer used in the modification step to be grafted onto
the unmodified microgel as quantitatively as possible. The
functional monomers are preferably metered in before crosslinking
of the microgels is complete.
[0074] Grafting of the microgels in non-aqueous systems is also
conceivable in principle, modification with monomers by means of
ionic polymerization methods also being possible in this
manner.
[0075] Suitable reagents for the surface modification of the
microgels with low molecular weight agents include the following:
elemental sulfur, hydrogen sulfide and/or alkylpolymercaptans, such
as 1,2-dimercaptoethane or 1,6-dimercaptohexane, also dialkyl and
dialkylaryl dithiocarbamate, such as the alkali salts of dimethyl
dithiocarbamate and/or dibenzyl dithiocarbamate, also alkyl and
aryl xanthogenates, such as potassium ethylxanthogenate and sodium
isopropylxanthogenate, as well as reaction with the alkali or
alkaline earth salts of dibutyldithiophosphoric acid and
dioctyidithiophosphoric acid as well as dodecyidithiophosphoric
acid. The mentioned reactions can also be carried out in the
presence of sulfur, the sulfur being incorporated with the
formation of polysulfide bonds. For the addition of this compound,
free-radical initiators such as organic and inorganic peroxides
and/or azo initiators can be added.
[0076] There comes into consideration also modification of
double-bond-containing microgels such as, for example, by
ozonolysis as well as by halogenation with chlorine, bromine and
iodine. A further reaction of modified microgels, such as, for
example, the preparation of hydroxyl-group-modified microgels from
epoxidized microgels, is also understood as being the chemical
modification of microgels.
[0077] According to the present invention, the microgels can be
modified by hydroxyl groups, especially also at the surface
thereof. The hydroxyl group content of the microgels is determined
as the hydroxyl number with the dimension mg of KOH/g of polymer by
reaction with acetic anhydride and titration of the acetic acid
liberated thereby with KOH according to DIN 53240. The hydroxyl
number of the microgels is preferably from 0.1 to 100, more
preferably from 0.5 to 50, mg of KOH/g of polymer.
[0078] The amount of modifying agent used is governed by its
effectiveness and the demands made in each individual case and is
in the range from 0.05 to 30 wt. %, based on the total amount of
rubber microgel used, particular preference being given to from 0.5
to 10 wt. %, based on the total amount of rubber gel.
[0079] The modification reactions can be carried out at
temperatures of from 0 to 180.degree. C., preferably from 20 to
95.degree. C., optionally under a pressure of from 1 to 30 bar. The
modifications can be carried out on rubber microgels without a
solvent or in the form of their dispersion, it being possible in
the latter case to use inert organic solvents or alternatively
water as the reaction medium. The modification is preferably
carried out in an aqueous dispersion of the crosslinked rubber.
[0080] The use of unmodified microgels is preferred in the case of
compositions according to the present invention that are used for
incorporation into non-polar rubbers or non-polar thermoplastic
materials, such as, for example, polypropylene, polyethylene and
block copolymers based on styrene, butadiene, isoprene (SBR, SIR)
and hydrogenated isoprene-styrene block copolymers (SEBS), and
conventional TPE-Os and TPE-Vs, etc.
[0081] The use of modified microgels is preferred in the case of
compositions according to the invention that are used for
incorporation into polar rubbers or polar thermoplastic materials
(A), such as, for example, PA, TPE-A, PU, TPE-U, PC, PET, PBT, POM,
PMMA, PVC, ABS, PTFE, PVDF, etc.
[0082] The mean diameter of the prepared microgels can be adjusted
with high accuracy, for example, to 0.1 micrometer (100 nm).+-.0.01
micrometer (10 nm), so that, for example, a particle size
distribution is achieved in which at least 75% of all the microgel
particles are from 0.095 micrometer to 0.105 micrometer in size.
Other mean diameters of the microgels, especially in the range from
5 to 500 nm, can be produced with the same accuracy (at least 75
wt. % of all the particles are located around the maximum of the
integrated particle size distribution curve (determined by light
scattering) in a range of .+-.10% above and below the maximum) and
used. As a result, the morphology of the microgels dispersed in the
composition according to the present invention can be adjusted
virtually "point accurately" and hence the properties of the
composition according to the present invention and of the plastics,
for example, produced therefrom can be adjusted.
[0083] The microgels so prepared can be worked up, for example, by
concentration by evaporation, coagulation, by co-coagulation with a
further latex polymer, by freeze coagulation (see U.S. Pat. No.
2,187,146) or by spray-drying. In the case of working up by
spray-drying, commercially available flow auxiliaries, such as, for
example, CaCO.sub.3 or silica, can also be added.
[0084] In a prferred embodiment of the composition according to the
present invention, the microgel (B) is based on rubber.
[0085] In a preferred embodiment of the composition according to
the present invention, the microgel (B) has been modified by
functional groups reactive towards C.dbd.C double bonds.
[0086] Preferably according to the present invention, the microgel
(B) has a swelling index in toluene at 23.degree. C. of from 1 to
15.
[0087] The composition according to the present invention
preferably has a viscosity at 20.degree. C. of from 2 mPas to
5,000,000 mpas, more preferably from 50 mPas to 3,000,000 mpas, at
a speed of 5 s.sup.-1 in a cone/plate viscometer according to DIN
53018.
[0088] Non-Crosslinkable Organic Medium (A)
[0089] The composition according to the present invention contains
at least one organic medium (A) which has a viscosity at a
temperature of 120.degree. C. of less than 1000 mPas, preferably
200 mPas, more preferably 100 mPas.
[0090] Such a medium is liquid to solid at room temperature
(20.degree. C.).
[0091] Organic medium within the scope of the present invention
means that the medium contains at least one carbon atom.
[0092] Within the scope of the present invention, non-crosslinkable
media are understood as being especially media that do not contain
groups crosslinkable via hetero-atom-containing functional groups
or C.dbd.C groups, such as, especially, conventional monomers or
pre-polymers which are crosslinked or polymerized in the
conventional manner by means of free radicals, by means of UV
radiation, thermally and/or with the addition of crosslinkers (e.g.
polyisocyanates) etc. with the formation of oligomers or polymers.
Non-crosslinkable media are preferably also solvents, more
preferably those according to DIN 55 945.
[0093] The non-crosslinkable medium (A) is preferably a
non-crosslinkable medium that is liquid at room temperature
(20.degree. C.), more preferably a hydrocarbon (straight-chain,
branched, cyclic, saturated, unsaturated and/or aromatic
hydrocarbons having from 1 to 200 carbon atoms, which may
optionally be substituted by one or more substituents selected from
halogens, such as chlorine, fluorine, hydroxy, oxo, amino, carboxy,
carbonyl, aceto, amido), synthetic hydrocarbon, polyether oil,
ester oil, phosphoric acid ester, silicon-containing oil or
halogenated hydrocarbon or carbon halide (see e.g. Ullmanns
Enzyklopdie der technischen Chemie, Verlag Chemie Weinheim, Volume
20, (1981) 457 ff, 504, 507 ff, 517/518, 524). Such
non-crosslinkable media (A) are distinguished especially by
viscosities of from 2 to 1500 mm.sup.2/s (cSt) at 40.degree. C.
[0094] The non-crosslinkable medium (A) is preferably a
non-crosslinkable medium that is liquid at room temperature
(20.degree. C.), preferably a solvent according to DIN 55 495, such
as xylene, solvent naphtha, methyl ethyl ketone, methoxypropyl
acetate, N-methylpyrrolidone, dimethyl sulfoxide.
[0095] Synthetic hydrocarbons are obtained by polymerization of
olefins, condensation of olefins or chloroparaffins with aromatic
compounds, or dechlorinating condensation of chloroparaffins.
Examples of polymer oils are ethylene polymers, propylene polymers,
polybutenes, polymers of higher olefins, alkyl aromatic compounds.
The ethylene polymers have molecular weights of from 400 to 2000
g/mol. The polybutenes have molecular weights of from 300 to 1500
g/mol.
[0096] In the case of the polyether oils, a distinction is made
between aliphatic polyether oils, polyalkylene glycols, especially
polyethylene and polypropylene glycols, their mixed polymers, their
mono- and di-ethers and also ester ethers and diesters,
tetrahydrofuran polymer oils, perfluoropolyalkyl ethers and
polyphenyl ethers. Perfluoropolyalkyl ethers have molar masses of
from 1000 to 10,000 g/mol. The aliphatic polyether oils have
viscosities of from 8 to 19,500 mm.sup.2/s at 38.degree. C.
[0097] Polyphenyl ethers are prepared by condensation of alkali
phenolates with halobenzenes. The diphenyl ether and its alkyl
derivatives are also used.
[0098] Examples of ester oils are the alkyl esters of adipic acid,
bis-(2-ethylhexyl) sebacate and bis-(3,5,5-trimethylhexyl) sebacate
or adipate. A further class is formed by the fluorine-containing
ester oils. In the case of phosphoric acid esters, a distinction is
made between triaryl, trialkyl and alkylaryl phosphates. Examples
are tri-(2-ethylhexyl) phosphate and bis-(2-ethylhexyl)-phenyl
phosphate.
[0099] Silicon-containing oils are the silicone oils (polymers of
the alkyl- and aryl-siloxane group) and the silicic acid
esters.
[0100] The halogenated hydrocarbons or carbon halides include
chlorinated paraffins, such as chlorotrifluoroethylene polymer oils
and hexafluorobenzene.
[0101] (Non-reactive) solvents according to DIN 55 945 are hexane,
special boiling point gasoline, white spirit, xylene, solvent
naphtha, balsam turpentine, methyl ethyl ketone, methyl isobutyl
ketone, methyl amyl ketone, isophorone, butyl acetate,
1-methoxypropyl acetate, butyl glycol acetate, ethyl diglycol
acetate and N-methylpyrrolidone (Brock, Thomas, Groteklaes,
Michael, Mischke, Peter, Lehrbuch der Lacktechnologie, Curt R.
Vincentz Verlag Hannover, (1998) 93 ff).
[0102] Preferred non-crosslinkable media (A) are the large class of
the hydrocarbons, the polyether oils, and the solvents according to
DIN 55 945.
[0103] The composition according to the present invention
preferably contains from 0.5 to 90 wt. %, more preferably from 1 to
40 wt. %, most preferably from 2 to 30 wt. %, of the microgel (B),
based on the total amount of the composition.
[0104] The composition according to the present invention further
contains preferably from 10 to 99.5 wt. %, more preferably from 40
to 97 wt. %, most preferably from 50 to 95 wt. %, even more
preferably from 60 to 95 wt. %, of the organic medium (A).
[0105] The composition according to the present invention
preferably contains the non-crosslinkable organic medium (A) and
the microgel (B) and optionally the further components mentioned
herein below. The presence of water is not preferred, more
preferably the presence of water is excluded.
[0106] Further, the composition according to the present invention
can additionally contain fillers, pigments and additives, such as
dispersing aids, de-aerators, flow agents, auxiliary substances for
the wetting of substrates, adhesion promoters, anti-settling
agents, auxiliary substances for controlling substrate wetting, for
controlling conductivity, auxiliary substances for controlling
color stability, gloss and floating, oxidation inhibitors,
pour-point depressors, high-pressure additives, foam-preventing
agents, demulsifying agents.
[0107] The mentioned additives can preferably be incorporated into
the compositions according to the present invention uniformly,
which in turn leads to an improvement in the polymer compositions
produced therefrom.
[0108] Particularly suitable pigments and fillers for the
preparation of the compositions according to the present invention
containing the non-crosslinkable medium (A), and of
microgel-containing plastics produced therefrom, are, for example:
inorganic and organic pigments, silicate-like fillers such as
kaolin, talcum, carbonates such as calcium carbonate and dolomite,
barium sulfate, metal oxides such as zinc oxide, calcium oxide,
magnesium oxide, aluminum oxide, highly dispersed silicas
(precipitated silicas and silicas produced by thermal means), metal
hydroxides such as aluminum hydroxide and magnesium hydroxide,
glass fibers and glass fiber products (laths, threads or glass
microspheres), carbon fibers, thermoplastic fibers (polyamide,
polyester, aramid), rubber gels based on polychloroprene and/or
polybutadiene, and also any other gel particles described above
having a high degree of crosslinking and a particle size of from 5
to 1000 nm.
[0109] The mentioned fillers can be used alone or in a mixture.
Preferably, from 0.5 to 30 parts by weight of rubber gel (B),
optionally together with from 0.1 to 40 parts by weight of fillers,
and from 30 to 99.5 parts by weight of the non-crosslinkable liquid
medium (A) are used to prepare the compositions present according
to the invention.
[0110] The compositions according to the present invention can
contain further auxiliary substances, such as anti-ageing agents,
heat stabilizers, light stabilizers, anti-ozonants, processing
aids, plasticizers, tackifiers, blowing agents, colorings, waxes,
extenders, organic acids and also filler activators, such as, for
example, trimethoxysilane, polyethylene glycol, or other auxiliary
substances known in the described industries.
[0111] The auxiliary substances are used in the conventional
amounts, which are governed inter alia by the intended use.
Conventional amounts are, for example, amounts of from 0.1 to 50
wt. %, based on the amounts of liquid medium (A) used.
[0112] Preferably, the composition according to the present
invention is prepared by means of a homogenizer, a bead mill or a
three-roller mill. Disadvantages of bead mills are the
comparatively limited viscosity range (tendency towards thin
compositions), the high outlay in terms of cleaning, the expensive
change-over of the compositions that can be used, and wear of the
beads and the grinding apparatus. Homogenization of the
compositions according to the present invention is preferably
carried out by means of a homogenizer or a three-roller mill.
Disadvantages of three-roller mills are the comparatively limited
viscosity range (tendency towards very thick compositions), the low
throughput and the fact that the procedure is not closed (poor
working protection). Homogenization of the compositions according
to the present invention is more preferably carried out by means of
a homogenizer. The homogenizer allows thin and thick compositions
to be processed with a high throughput (high flexibility). Product
change-over is possible relatively quickly and without
difficulty.
[0113] The dispersion of the microgels (B) in the liquid medium (A)
takes place in the homogenizer in the homogenizing valve (The
FIGURE).
[0114] In the process used according to the present invention,
agglomerates are comminuted into aggregates and/or primary
particles. Agglomerates are physically separable units which
undergo no change in primary particle size during dispersion.
[0115] The product to be homogenized enters the homogenizing valve
at low speed and is accelerated to high speeds in the homogenizing
gap. Dispersion takes place downstream of the gap, principally as a
result of turbulence and cavitation (William D. Pandolfe, Peder
Baekgaard, Marketing Bulletin of APV Homogenizer
Group--"High-pressure homogenizers processes, product and
applications").
[0116] The temperature of the composition according to the present
invention on introduction into the homogenizer is advantageously
from -40 to 140.degree. C., preferably from 20 to 80.degree. C.
[0117] The composition according to the present invention to be
homogenized is preferably homogenized in the apparatus at a
pressure of from 200 to 4000 bar, preferably from 500 to 2000 bar,
more preferably from 900 to 2000 bar. The number of passes is
governed by the desired dispersion quality and can vary from 1 to
20, preferably from 1 to 10, passes.
[0118] The compositions prepared according to the present invention
have a fine particle distribution, which is achieved especially
with the homogenizer and is extremely advantageous also in respect
of the flexibility of the process with regard to varying
viscosities of the liquid media and of the resulting compositions
and necessary temperatures as well as the dispersion quality.
[0119] The present invention relates also to the use of the
composition according to the present invention in the production of
microgel-containing polymers or plastics, as discussed above.
[0120] If the compositions according to the present invention are
incorporated into thermoplastic polymers, it is surprisingly found
that microgel-containing polymers that behave like thermoplastic
elastomers are obtained.
[0121] The present invention relates also to the molded bodies and
coatings produced therefrom by conventional processes.
[0122] The invention is further illustrated but is not intended to
be limited by the following examples in which all parts and
percentages are by weight unless otherwise specified.
EXAMPLES
Example 1
[0123] In Example 1 described herein below it is shown that
compositions according to the present invention having specific
rheological characteristics, such as intrinsic viscosity,
thixotropy and approximately Newtonian flow behavior, are obtained
using microgels based on SBR.
[0124] The composition of the microgel phase is given in the table
below:
1 1. T 110 80% 2. Micromorph 5P 20% Total 100%
[0125] T 110 is hydrogenated naphthenic oil from Nynas Naphthenics
AB. Micromorph 5P is an SBR-based crosslinked rubber gel having an
OH number of 4 from RheinChemie Rheinau GmbH. Micromorph 5P
consists of 40 wt. % styrene, 57.5 wt. % butadiene and 2.5 wt. %
dicumyl peroxide. Micromorph 1P is an SBR-based, crosslinked,
surface-modified rubber gel from RheinChemie Rhienau GmbH.
[0126] Micromorph 1P consists of 80 wt. % styrene, 12 wt. %
butadiene, 5 wt. % ethylene glycol dimethacrylate (EGDMA) and 3 wt.
% hydroxyethyl methacrylate (HEMA).
Preparation Example 1 Relating to Micromorph 1P
[0127] Microgel based on hydroxyl-modified SBR, prepared by direct
emulsion polymerization using the crosslinking comonomer ethylene
glycol dimethacrylate (Micromorph 1P).
[0128] 325 g of the Na salt of a long-chain alkylsulfonic acid (330
g of Mersolat K30/95 from Bayer AG) and 235 g of the Na salt of
methylene-bridged naphthalenesulfonic acid (Baykanol PQ from Bayer
AG) were dissolved in 18.71 kg of water and placed in a 40-litre
autoclave. The autoclave is evacuated three times and charged with
nitrogen. Then 8.82 kg of styrene, 1.32 kg of styrene, 503 g of
ethylene glycol dimethacrylate (90%), 314 g of hydroxyethyl
methacrylate (96%) and 0.75 g of hydroquinone monomethyl ether were
added. The reaction mixture was heated to 30.degree. C., with
stirring. An aqueous solution containing 170 g of water, 1.69 g of
ethylenediaminetetraacetic acid (Merck-Schuchardt), 1.35 g of iron
(II) sulfate * 7H2O, 3.47 g of Rongalit C (Merck-Schuchradt) and
5.24 g of trisodium phosphate * 12H2O was then metered in. The
reaction was started by addition of an aqueous solution of 2.89 of
p-menthane hydroperoxide (Trigonox NT 50 from Akzo-Degussa) and
10.53 g of Mersolat K 30/95, dissolved in 250 g of water. After a
reaction time of 5 hours, activation was carried out using an
aqueous solution containing 250 g of water in which 10.53 g of
Mersolat K30/95 and 2.8 g of p-menthane hydroperoxide (Trigonox NT
50) were dissolved. When a polymerization conversion of 95-99% was
reached, the polymerization was stopped by addition of an aqueous
solution of 25.53 g of diethylhydroxylamine dissolved in 500 g of
water. Unconverted monomers were then removed from the latex by
stripping with steam. The latex was filtered and stabilizer was
added as in Example 2 of U.S. Pat. No. 6,399,706, followed by
coagulation and drying.
[0129] For the preparation of the composition according to the
present invention, T110 was placed in the vessel and Micromorph 5P
was added with stirring by means of a dissolver. The composition
was passed through the homogenizer four times at 950 bar.
[0130] The rheological properties of the composition were
determined by means of a rheometer, MCR300, from Physica. A
plate/cone system, CP25-1, was used as the measuring body. The
measurements were carried out at 20.degree. C.
[0131] (For the composition consisting of 80% T110 and 20%
Micromorph 1P or Micromorph 5P, some measuring results are shown in
the following table).
[0132] As a comparison, the greases Li-120H AK33, Fuchs-Lubritech
GmbH, and E301 (15%), laboratory product of RheinChemie Rheinau
GmbH, were measured concomitantly.
[0133] The table shows the viscosities v', which were measured at
shear rates of 5 s.sup.-1, 100 s.sup.-1, 1000 s.sup.-1, 3000
s.sup.-1 and 0.1 s.sup.-1. The quotient v'(0.1 s.sup.-1)/v'(3000
s.sup.-1) was defined as an arbitrary measure of the
viscosity-increasing action of microgel.
[0134] The composition containing 80% T110 and 20% Micromorph 5P,
which was passed through the homogenizer four times at 950 bar,
exhibits Theological behavior comparable to that of Li-120H AK33 or
E301. Micromorph 1P, on the other hand, exhibits no appreciable
thickening in Nynas T110.
2 v' v' v' v' v' (5 s.sup.-1) (100 s.sup.-1) (1000 s.sup.-1) (3000
s.sup.-1) (0.1 s.sup.-1) v' (0.1 s.sup.-1)/ Name Characteristics
[Pas] [Pas] [Pas] [Pas] [Pas] v' (3000 s.sup.-1) Notes Li-120H
0.0935 s.sup.-1 375 23.3 3.93 -- 7950 2023 Example grease, AK33
instead of 0.1 s.sup.-1 intrinsically viscous, not very thixotropic
E301 (15%) 0.15 s.sup.-1 83.3 14.6 6.58 -- 2420 368 Example grease,
instead of intrinsically viscous in 0.1 s.sup.-1 mineral oil
AE25648/6 M. 5 P.sup.1)/ 11.9 5.38 3.82 2.44 2150 563 intrinsically
viscous 1 .times. 950 bar AE25648/6 M. 5 P.sup.1)/ 19.6 5.99 3.58
2.34 1750 489 intrinsically viscous 2 .times. 950 bar AE25648/6 M.
5 P.sup.1)/ 32.5 6.81 3.56 2.36 1580 444 intrinsically viscous 3
.times. 950 bar AE25648/6 M. 5 P.sup.1)/ 56.9 7.65 3.62 2.40 1720
475 intrinsically viscous, not 4 .times. 950 bar very thixotropic
AE25648/5 M. 1 P.sup.2)/ 1.81 1.42 1.24 1.11 5.9 4.8 almost
Newtonian flow 1 .times. 950 bar behavior AE25648/5 M. 1 P.sup.2)/
2.31 1.77 1.34 1.20 1.99 1.5 almost Newtonian flow 2 .times. 950
bar behavior AE25648/5 M. 1 P.sup.2)/ 3.93 2.01 1.42 1.25 1.72 1.2
slightly thixotropic 3 .times. 950 bar AE25648/5 M. 1 P.sup.2)/
9.34 2.80 1.71 1.46 3.27 1.9 thixotropic 4 .times. 950 bar
.sup.1)Micromorph 5 P .sup.2)Micromorph 1 P
[0135] The measured values show a thickening which, with suitable
selection of the microgel/lubricant combination, is suitable for
the production of lubricating greases.
[0136] In addition, it is possible to control rheological
properties in the described liquid media using microgels. The
compositions according to the present invention are valuable as
thickeners, as anti-dripping and anti-settling agents and as a
rheological additive.
[0137] The described compositions can advantageously be used in
lubricants, paints and inks, adhesives, rubber and gel coats.
[0138] The compositions prepared in Example 1 can be used in
lubricating greases. They result in advantageous properties
therein, such as high intrinsic viscosity.
[0139] Although the invention has been described in detail in the
foregoing for the purpose of illustration, it is to be understood
that such detail is solely for that purpose and that variations can
be made therein by those skilled in the art without departing from
the spirit and scope of the invention except as it may be limited
by the claims.
* * * * *