U.S. patent application number 09/955864 was filed with the patent office on 2003-11-06 for water-soluble, sulfoalkyl-containing, hydrophobically modified cellulose ethers, process for preparing them, and their use in emulsion paints.
Invention is credited to Doenges, Reinhard, Kirchner, Juergen.
Application Number | 20030208063 09/955864 |
Document ID | / |
Family ID | 7885763 |
Filed Date | 2003-11-06 |
United States Patent
Application |
20030208063 |
Kind Code |
A1 |
Doenges, Reinhard ; et
al. |
November 6, 2003 |
Water-soluble, sulfoalkyl-containing, hydrophobically modified
cellulose ethers, process for preparing them, and their use in
emulsion paints
Abstract
Water-soluble sulfoalkyl-containing hydrophobically modified
cellulose ethers, processes for preparing them, and their use in
emulsion paints The present invention relates to water-soluble
ionic cellulose ethers from the group of the hydroxyalkylcelluloses
which are substituted by on average from 0.001 to 1.0 alkyl group
per anhydroglucose unit and which carry from 0.01 to 0.1 sulfoalkyl
group per anhydroglucose unit, to processes for preparing them and
to the use of water-soluble ionic cellulose ethers from the group
of the hydroxyalkylcelluloses which are substituted by on average
from 0.001 to 1.0 alkyl group per anhydroglucose unit and which
carry from 0.01 to 0.4 sulfoalkyl group per anhydroglucose unit in
emulsion paints.
Inventors: |
Doenges, Reinhard; (Bad
Soden, DE) ; Kirchner, Juergen; (Wiesbaden,
DE) |
Correspondence
Address: |
CLARIANT CORPORATION
INTELLECTUAL PROPERTY DEPARTMENT
4000 MONROE ROAD
CHARLOTTE
NC
28205
US
|
Family ID: |
7885763 |
Appl. No.: |
09/955864 |
Filed: |
September 19, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09955864 |
Sep 19, 2001 |
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09427351 |
Oct 26, 1999 |
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6313287 |
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Current U.S.
Class: |
536/84 ;
536/92 |
Current CPC
Class: |
C09D 7/43 20180101; C08L
1/28 20130101; C09D 5/024 20130101 |
Class at
Publication: |
536/84 ;
536/92 |
International
Class: |
C08B 011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 27, 1998 |
DE |
198 49 442.4 |
Claims
What is claimed is:
1. A water-soluble ionic cellulose ether from the group of
hydroxyalkylcelluloses which is substituted by on average from
0.001 to 1.0 alkyl group per anhydroglucose unit and which carries
from 0.01 to 0.1 sulfoalkyl group per anhydroglucose unit.
2. A cellulose ether as claimed in claim 1, wherein the average
number of alkyl groups per anhydroglucose unit is from 0.001 to
0.2.
3. A cellulose ether as claimed in claim 1, of the formula
[C.sub.6H.sub.7O.sub.2(OR.sup.1)(OR.sup.2)(OR.sup.3)].sub.m where
C.sub.6H.sub.7O.sub.2 is an anhydroglucose unit, m is50-3000, and
R.sup.1, R.sup.2, R.sup.3 independently of one another are each a
polyalkylene oxide chain of the formula 2where X.dbd.H,
C.sub.nH.sub.2n+1, C.sub.nH.sub.2+1O, CH.sub.2--CH.sub.2--SO.sub.3Y
or CH.sub.2--CHOH--CH.sub.2SO.sub.3Y, n=4-20 and Y.dbd.H, Na or K,
and in which p, q, and r independently of one another in R.sup.1,
R.sup.2 and R.sup.3 can each independently assume values from 0 to
4, the sum of all (p+q+r) added over R.sup.1, R.sup.2 and R.sup.3
per anhydroglucose unit is on average greater than 1.3 and less
than 4.5, the sequence of the oxyalkylene units in the polyalkylene
oxide chain is arbitrary, and the average number of hydrophobically
modified groups per anhydroglucose unit (DS HM) is from 0.001 to
0.2, and the average number of sulfoalkyl groups per anhydroglucose
unit is from 0.01 to 0.1.
4. A cellulose ether as claimed in claim 1, wherein the average
number of hydrophobically modified groups per anhydroglucose unit
(DS HM) is from 0.01 to 0.04.
5. A cellulose ether as claimed in claim 1, wherein the average
number of sulfoalkyl groups per anhydroglucose unit is from 0.01 to
0,09.
6. A cellulose ether as claimed in claim 1, wherein the sulfoalkyl
groups are sulfoethyl groups.
7. A process for preparing a cellulose ether as claimed in claim 1
by etherifying cellulose with an etherifying agent from the group
of alkylene oxides and etherifying with an alkyl halide or an alkyl
glycidyl ether and a sulfonate, with base catalysis.
8. A process for preparing a cellulose ether as claimed in claim 1
by etherifying cellulose ethers from the group of
hydroxyalkylcelluloses with an alkyl halide or an alkyl glycidyl
ether and a sulfonate, with base catalysis,
9. An emulsion paint comprising one or more water-soluble ionic
cellulose ethers from the group of hydroxyalkylcelluloses which are
substituted by on average from 0.001 to 1.0 alkyl group per
anhydroglucose unit and which carry from 0.01 to 0.4 sulfoalkyl
group per anhydroglucose unit.
10. A method of using a water soluble ionic cellulose ether from
the group of hydroxyalkylcelluloses which is substituted by on
average from 0.001 to 1.0 alkyl group per anhydroglucose unit and
which carries from 0.01 to 0.4 sulfoalkyl group per anhydroglucose
unit in an emulsion paint.
Description
[0001] The present invention is described in the German priority
application No. 19849442.4 filed Oct. 27, 1998 which is hereby
incorporated by reference as is fully disclosed herein.
[0002] The present invention relates to water-soluble,
sulfoalkyl-containing, hydrophobically modified cellulose ethers,
to processes for preparing them and to their use, and to emulsion
paints comprising these compounds.
[0003] Commercially customary emulsion paints possess pronounced
pseudoplasticity. This stands in contrast to the processor's
requirements for paints having more Newtonian rheology, which offer
distinct advantages in terms of brushability, flow and drip. By
using cellulose ethers modified hydrophobically with long-chain
alkyl groups as thickeners, or by using conventional cellulose
ethers in combination with synthetic associative thickeners, a more
Newtonian rheology can be established in emulsion paints.
[0004] A disadvantage of the commercial thickeners comprising
cellulose ethers modified hydrophobically using long-chain alkyl
groups is the undesirably high level of bodying of the emulsion
paint on storage. The consistency of emulsion paint increases
sharply following its preparation and can more than double after
one day of storage. This complicates the deliberate
adjustment/monitoring of paint consistency by the paint
manufacturer. A further disadvantage is the sharp reduction in the
water solubility of the hydrophobically modified cellulose ethers
even at low degrees of substitution.
[0005] In EP-A-0 307 915 the attempt is made to improve the
solubility of hydrophobically modified cellulose ethers by the
additional introduction of a carboxymethyl group. A disadvantage,
however, is the sensitivity of the carboxymethyl group to pH: it is
protonated even in the weakly acidic range and so takes on a
hydrophobic character itself. The carboxymethyl group is also
sensitive to divalent ions, such as calcium ions, for example.
Calcium compounds, however, are frequently used as fillers in
aqueous emulsion paints.
[0006] P. Talaba, I. Srokova, P. Hodul and G. Cik in Chem. Papers
50 (2), 101 (1996) describe hydrophobically modified
sulfoethylcelluloses. High degrees of substitution are necessary in
these compounds, however, because of the absence of other
substituents. They are water-soluble only at low degrees of
polymerization, and possess a strong tendency to form foam, which
is undesirable for use in emulsion paints.
[0007] EP-A-0 781 780 describes sulfoalkylated cellulose ethers
modified hydrophobically using C.sub.10-C.sub.40 alkyl chains,
these ethers likewise possessing a high surfactant action and being
used as thickeners in cosmetic formulations. For these compounds a
degree of sulfoalkylation of from 0.1 to 1 is claimed.
[0008] The object of the present invention is to provide
water-soluble, hydrophobically modified cellulose derivatives which
when used in emulsion paints cause only minimal bodying of the
paints, comparable with that of cellulose ethers not
hydrophobically modified, and which at the same time improve the
non-drip characteristics of the paints when applied with a roller
to an extent similar to that of the commercial cellulose ethers
modified hydrophobically using long-chain alkyl groups. The
invention also intends to provide cellulose derivatives which when
used in emulsion paints bring about a substantial improvement in
their non-drip characteristics even at relatively low paint
viscosities, while at the same time allowing the paint to be easily
spread (by brush or roller, etc.). In addition, the emulsion paint
must attain good abrasion resistance.
[0009] The invention accordingly provides water-soluble ionic
cellulose ethers from the group of hydroxyalkylcelluloses which are
substituted by on average from 0.001 to 1.0, preferably from 0.001
to 0.2, alkyl group per anhydroglucose unit and carry from 0.01 to
0.1 sulfoalkyl group per anhydroglucose unit.
[0010] Preferred cellulose ethers are those of the formula
[C.sub.6H.sub.7O.sub.2(OR.sup.1)(OR.sup.2)(OR.sup.3)].sub.m
[0011] where C.sub.6H.sub.7O.sub.2 is an anhydroglucose unit,
[0012] m is 50-3000, especially 100-1000,
[0013] and R.sup.1, R.sup.2, R.sup.3 independently of one another
are each a polyalkylene oxide chain of the formula 1
[0014] where X.dbd.H, C.sub.nH.sub.2n+1, C.sub.nH.sub.2n-1O,
CH.sub.2--CH.sub.2--SO.sub.3Y or
CH.sub.2--CHOH--CH.sub.2SO.sub.3Y,
[0015] n=4-20
[0016] and Y.dbd.H, Na or K,
[0017] and in which
[0018] p, q, and r independently of one another in R.sup.1, R.sup.2
and R.sup.3 can each independently assume values from 0 to 4, the
sum of all (p+q+r) added over R.sup.1, R.sup.2 and R.sup.3 per
anhydroglucose unit is on average greater than 1.3 and less than
4.5, preferably from 1.5 to 3.0, the sequence of the oxyalkylene
units in the polyalkylene oxide chain is arbitrary, and the average
number of hydrophobically modified groups per anhydroglucose unit
(DS HM) is from 0.001 to 0.2, preferably from 0.01 to 0.04, and the
average number of sulfoalkyl groups per anhydroglucose unit is from
0.01 to 0.1, preferably from 0.01 to 0.09. The sulfoalkyl groups
are preferably sulfoethyl groups.
[0019] The present invention also provides processes for preparing
the cellulose ethers of the invention by etherifying cellulose with
an etherifying agent from the group of the alkylene oxides and
etherifying with an alkyl halide or an alkyl glycidyl ether and a
sulfonate, with base catalysis, or by etherifying ethers from the
group of hydroxyalkylcelluloses with an alkyl halide or an alkyl
glycidyl ether and a sulfonate, with base catalysis, preferably
[0020] A) by etherifying cellulose with ethylene oxide, propylene
oxide and/or glycidyl alcohol and an alkyl halide or an alkylene
oxide or an alkyl glycidyl ether and an alkenylsulfonate or
chloroalkylsulfonate, with base catalysis, preferably in a
suspension medium;
[0021] B) by etherifying hydroxyethylcellulose,
hydroxypropylcellulose, dihydroxypropylcellulose or a cellulose
ether having two or more of said hydroxyalkyl substituents with an
alkyl halide or an alkylene oxide or an alkyl glycidyl ether and an
alkenylsulfonate or chloroalkylsulfonate, with base catalysis,
preferably in a suspension medium.
[0022] Suspension media preferably used are lower alcohols or
ketones, an example being isopropanol, tert-butanol or acetone, in
a weight ratio to the cellulose of from 3:1 to 30:1, preferably
from 8:1 to 15:1. As the base it is usual to use aqueous solutions
of alkali metal hydroxides, especially sodium hydroxide. The molar
ratio of base to anhydroglucose unit is determined by the
carbohydrate (derivative) used. When using cellulose (method A) the
molar ratio is preferably from 1.0 to 1.5; for products which are
already etherified (method B) it is preferably from 0.1 to 1.0 mol
of base per anhydroglucose unit.
[0023] The water content of the reaction mixture is preferably from
5 to 30, in particular from 1 0 to 20, mol of water per
anhydroglucose unit.
[0024] After the suspension medium has been introduced as initial
charge, the cellulose added and the batch rendered alkaline with
the aqueous base, the batch is homogenized thoroughly and stirred
without supply of heat, with cooling if desired, for preferably
from 0.5 to 2 hours. The etherification reagents (epoxyalkanes,
alkyl glycidyl ethers and/or alkyl halides and sulfonic acid
derivatives) are subsequently added in unison or in succession. The
batch is then brought preferably to a temperature in the range from
60 to 120.degree. C., with particular preference from 80 to
100.degree. C., and is heated for preferably from 2 to 6 hours.
After cooling, it is neutralized with an acid, preferably
hydrochloric acid, nitric acid and/or acetic acid, preferably to a
pH of from 6 to 8. The suspension medium is removed by decantation
or filtration. The crude cellulose mixed ether can be freed from
the adhering byproducts, such as polyglycols, glycol ethers and
salts, by extraction with aqueous alcohols or ketones having a
preferred water content of from 10 to 50% by weight, especially
isopropanol, ethanol and acetone. After drying under reduced
pressure or at atmospheric pressure at from 50 to 120.degree. C.,
the desired cellulose mixed ether is obtained as a colorless or
slightly yellowish powder.
[0025] If required, the degree of polymerization desired in
accordance with the invention for the cellulose ether can be
established prior to or during its preparation process by the
addition of a peroxo compound, such as hydrogen peroxide, or a
peroxodisulfate salt or other oxidizing agent, sodium chloride
being one example. These methods of decreasing the molecular
weight, and the respective industrial procedure, are prior art (T.
M. Greenway in "Cellulosic Polymers, Blends and Composites", ed. R.
D. Gilbert, Carl Hanser Verlag, Munich, 1994, p. 178 ff.).
[0026] Suitable reaction apparatus for preparing the cellulose
ether derivatives of the invention comprises, for example, stirred
vessels, mixers and kneading apparatus. In principle it is possible
to use any reaction apparatus which is customary for the
preparation of cellulose derivatives having nonhydrophobic
substituents and which allows sufficiently thorough mixing of the
cellulose or water-soluble cellulose ether with the nonhydrophobic
reagents.
[0027] The present invention additionally provides for the use in
emulsion paints of water-soluble ionic cellulose ethers from the
group of hydroxyalkylcelluloses which are substituted by on average
from 0.001 to 1.0 alkyl group per anhydroglucose unit and carry
from 0.01 to 0.4 sulfoalkyl group per anhydroglucose unit, and
provides an emulsion paint comprising water-soluble ionic cellulose
ethers from the group of hydroxyalkylcelluloses which are
substituted by on average from 0.001 to 1.0 alkyl group per
anhydroglucose unit and carry from 0.01 to 0.4 sulfoalkyl group per
anhydroglucose unit.
[0028] The present invention is described in detail below by
reference to working examples although without being restricted
thereto.
PREPARATION EXAMPLES
Example 1
[0029] The hydrophobic reagent used is a (C.sub.15-C.sub.17)-alkyl
glycidyl ether from EMS-Chemie, Zurich (tradename Grilonit.RTM. RV
1814).
[0030] Finely ground pinewood pulp is suspended in virtually
anhydrous isopropanol in a 2 l glass reactor with anchor stirrer.
Following inertization (evacuation and flooding with nitrogen),
49.5% strength sodium hydroxide solution and water are run in with
stirring at 25.degree. C. The mixture is rendered alkaline at
25.degree. C. for 60 minutes. Ethylene oxide is run in and the
temperature is held at 40.degree. C. for one hour and then at
80.degree. C. for one hour. Then, at about 80.degree. C., the
desired amount of an alkyl glycidyl ether, dissolved in 20 g of
isopropanol, is added and etherificabon is carried out at
80.degree. C. for two hours. 28.3% strength aqueous sodium
vinylsulfonate (NaVSO.sub.3) solution is added and the mixture is
reacted at 80.degree. C. for two to three hours. After cooling to
room temperature, it is neutralized with approximately 20% strength
hydrochloric acid. The product is filtered off with suction, washed
with 80% strength aqueous acetone to a salt content of <0.5%,
and dried at 75.degree. C.
[0031] The quantities used and the degrees of substitution of the
hydrophobically modified hydroxyethylsulfoethylcelluloses obtained
are set out in Table 1.
1 TABLE 1 Degrees of Amounts used (g) Product substitution Example
Isopro- NaOH Grilonit S NaVSO.sub.3 yield MS DS DS 1 Pulp panol
H.sub.2O 49.5% EO RV1814 *) 28.3% g HE HM SE A 75.0 593 103.6 40.0
90.0 -- 20 41.0 121.1 2.46 -- 0.07 B 75.0 593 103.6 40.0 90.0 6.4
20 41.0 123.1 2.49 0.006 0.07 C 75.0 593 103.6 40.0 90.0 12.8 20
41.0 121.2 2.42 0.007 0.07 D 75.0 593 103.6 40.0 90.0 19.2 20 41.0
121.8 2.53 0.011 0.08 E 75.0 593 103.6 40.0 90.0 25.6 20 41.0 119.9
2.49 0.012 0.08 F 85.0 672 117.4 45.3 102.0 -- 22.7 46.5 140.1 2.38
-- 0.07 G 85.0 672 117.4 45.3 102.0 7.3 22.7 46.5 136.5 2.33 0.003
0.07 H 85.0 672 117.4 45.3 102.0 14.5 22.7 46.5 138.8 2.32 0.005
0.07 I 85.0 672 117.4 45.3 102.0 21.8 22.7 46.5 137.3 2.39 0.007
0.07 J 85.0 672 117.4 45.3 102.0 29.0 22.7 46.5 139.4 2.31 0.010
0.08 K 75.0 593 103.6 40.0 90.0 -- 20 62.0 124.3 2.35 -- 0.10 L
75.0 593 103.6 40.0 90.0 6.4 20 62.0 124.5 2.42 0.006 0.10 M 75.0
593 103.6 40.0 90.0 12.8 20 62.0 122.3 2.34 0.007 0.08 N 75.0 593
103.6 40.0 90.0 19.2 20 62.0 119.5 2.36 0.010 0.09 O 75.0 593 103.6
40.0 90.0 25.6 20 62.0 119.6 2.47 0.012 0.09 *) S = solvent for
reagent
Example 2
[0032] The procedure is as in Example 1 except that a larger molar
amount of ethylene oxide is used.
[0033] The amounts used and the degrees of substitution of the
hydrophobically modified hydroxyethylsulfoethylcelluloses obtained
are set out in Table 2.
2 TABLE 2 Degrees of Amounts used (g) Product substitution Example
Isopro- NaOH Grilonit S NaVSO.sub.3 yield MS DS DS 2 Pulp panol
H.sub.2O 49.5% EO RV1814 *) 28.3% g HE HM SE A 75.0 593 103.6 40.0
138.4 -- 20 62.0 142.2 3.59 -- 0.04 B 75.0 593 103.6 40.0 138.4 6.4
20 62.0 142.5 3.61 0.010 0.04 C 75.0 593 103.6 40.0 138.4 12.8 20
62.0 140.8 3.62 0.016 0.06 D 75.0 593 103.6 40.0 138.4 19.2 20 62.0
143.1 3.67 0.021 0.04 E 75.0 593 103.6 40.0 138.4 25.6 20 62.0
149.2 3.59 0.027 0.03 F 75.0 593 103.6 40.0 138.4 38.4 20 62.0
145.7 3.80 0.044 0.03 G 75.0 593 103.6 40.0 138.4 64.0 20 62.0
143.6 3.75 0.055 0.04 *) S = solvent for reagent
Example 3
[0034] The procedure is as in Example 2 except that high molecular
mass linters pulp is used.
[0035] The amounts used and the degrees of substitution of the
hydrophobically modified hydroxyethylsulfoethylcelluloses obtained
are set out in Table 3.
3 TABLE 3 Degrees of Amounts used (g) Product substitution Example
isopro- NaOH Grilonit S NaVSO.sub.3 yield MS DS DS 3 Pulp panol
H.sub.2O 49.5% EO RV1814 *) 28.3% g HE HM SE A 75.0 593 103.6 40.0
138.4 -- 20 62.0 151.9 3.00 -- 0.04 B 75.0 593 103.6 40.0 138.4 --
20 62.0 149.0 3.54 -- 0.09 C 75.0 593 103.6 40.0 138.4 6.4 20 62.0
148.6 3.64 0.009 0.09 D 75.0 593 103.6 40.0 138.4 12.8 20 62.0
149.3 3.56 0.013 0.09 E 75.0 593 103.6 40.0 138.4 19.2 20 62.0
146.0 3.54 0.020 0.08 F 75.0 593 103.6 40.0 138.4 25.6 20 62.0
147.6 3.41 0.022 0.07 G 75.0 593 103.6 40.0 138.4 38.4 20 62.0
147.6 3.31 0.036 0.07 H 75.0 593 103.6 40.0 138.4 64.0 20 62.0
150.6 3.35 0.051 0.07 I 85.0 672 117.4 45.3 156.9 -- 22.7 22.7
160.0 3.18 -- 0.03 J 85.0 672 117.4 45.3 156.9 7.3 22.7 22.7 163.5
3.04 0.011 0.02 K 85.0 672 117.4 45.3 156.9 14.5 22.7 22.7 164.1
3.32 0.016 0.01 L 85.0 672 117.4 45.3 156.9 21.8 22.7 22.7 157.4
3.31 0.020 0.01 M 85.0 672 117.4 45.3 156.9 29.0 22.7 22.7 160.7
3.41 0.027 0.02 N 85.0 672 117.4 45.3 156.9 43.5 22.7 22.7 166.0
3.36 0.037 0.02 O 85.0 672 117.4 45.3 156.9 72.5 22.7 22.7 166.7
3.44 0.063 0.01 *) S = solvent for reagent
Example 4
[0036] The procedure is as in Example 2. For oxidative adjustment
to the molecular weight, etherification with the alkyl glycidyl
ether is followed by addition of a small amount of 3% strength
hydrogen peroxide solution, after which the temperature is held at
80.degree. C. for 15 minutes. After that time, sodium
vinylsulfonate is added.
[0037] The amounts used and the degrees of substitution of the
hydrophobically modified hydroxyethylsulfoethylcelluloses obtained
are set out in Table 4.
4 TABLE 4 Degrees of Amounts used (g) Product substitution Example
isopro- NaOH S H.sub.2O.sub.2 NaVSO.sub.3 yield MS DS DS 4 Pulp
panol H.sub.2O 49.5% EO RV1814 *) 3% 28.3% g HE HM SE A 85.0 672
112.0 45.3 156.9 21.8 22.7 5.5 70.3 156.6 3.21 0.027 0.05 B 85.0
672 114.6 45.3 156.9 21.8 22.7 2.8 70.3 160.2 3.62 0.023 0.07 C
85.0 672 116.0 45.3 156.9 21.8 22.7 1.4 70.3 160.0 3.65 0.021 0.08
D 85.0 672 112.0 45.3 156.9 29.0 22.7 5.5 70.3 156.7 3.54 0.024
0.06 E 85.0 672 114.6 45.3 156.9 29.0 22.7 2.8 70.3 161.0 3.54
0.028 0.08 F 85.0 672 116.0 45.3 156.9 29.0 22.7 1.4 70.3 162.0
3.59 0.025 0.08 *) S = solvent for reagent
Example 5
[0038] The procedure is as in Example 1. The hydrophobicizing
reagent used is the glycidyl ether of a phenyl ethoxylate (5
ethylene oxide units) from Nagase Chemicals Ltd., Osaka (tradename
Denacol.RTM. EX-145).
[0039] The amounts used and the degrees of substitution of the
hydrophobically modified hydroxyethylsulfoethylcelluloses obtained
are set out in Table 5.
5 TABLE 5 Degrees of Amounts used (g) Product substitution Example
Isopro- NaOH Denacol S NaVSO.sub.3 yield MS DS DS 5 Pulp panol
H.sub.2O 49.5% EO EX-145 *) 28.3% g HE HM SE A 85.0 672 117.4 45.3
118.7 -- 22.7 70.3 146.5 2.78 -- 0.09 B 85.0 672 117.4 45.3 118.7
9.4 22.7 70.3 148.6 2.86 0.008 0.10 C 85.0 672 117.4 45.3 118.7
18.9 22.7 70.3 151.7 2.95 0.016 0.10 D 85.0 672 117.4 45.3 118.7
28.3 22.7 70.3 147.5 2.97 0.027 0.09 E 85.0 672 117.4 45.3 118.7
37.8 22.7 70.3 147.2 3.02 0.033 0.09 *) S = solvent for reagent
Example 6
[0040] The procedure is as in Example 1. The hydrophobicizing
reagent used is the glycidyl ether of a lauryl ethoxylate (C.sub.12
alkyl with 15 ethylene oxide units) from Nagase Chemicals Ltd.,
Osaka (tradename Denacol.RTM. EX-171).
[0041] The amounts used and the degrees of substitution of the
hydrophobically modified hydroxyethylsulfoethylcelluloses obtained
are set out in Table 6.
6 TABLE 6 Degrees of Amounts used (g) Product substitution Example
isopro- NaOH Denacol S NaVSO.sub.3 yield MS DS DS 6 Pulp panol
H.sub.2O 49.5% EO EX-171 *) 28.3% g HE HM SE A 85.0 672 117.4 45.3
118.7 -- 22.7 70.3 146.5 2.78 -- 0.09 B 85.0 672 117.4 45.3 118.7
23.0 22.7 70.3 146.5 2.82 0.006 0.09 C 85.0 672 117.4 45.3 118.7
23.0 22.7 70.3 147.2 2.69 0.006 0.10 D 85.0 672 117.4 45.3 118.7
46.1 22.7 70.3 148.1 2.83 0.010 0.11 E 85.0 672 117.4 45.3 118.7
46.1 22.7 70.3 150.3 2.89 0.009 0.10 F 85.0 672 117.4 45.3 118.7
69.1 22.7 70.3 151.9 2.92 0.012 0.10 G 85.0 672 117.4 45.3 118.7
92.1 22.7 70.3 150.7 3.09 0.017 0.11 *) S = solvent for reagent
Example 7
[0042] The procedure is as in Example 1. The suspension medium and
solvent used is a mixture of tert-butanol and isopropanol.
[0043] The amounts used and the degrees of substitution of the
hydrophobically modified hydroxyethylsulfoethylcelluloses obtained
are set out in Table 7.
7 TABLE 7 Degrees of Amounts used (g) Product substitution Example
t-BuOH + NaOH Grilonit S NaVSO.sub.3 yield MS DS DS 7 Pulp IPA
H.sub.2O 49.5% EO RV1814 *) 28.3% g HE HM SE A 85.0 672 117.4 45.3
119.0 21.8 22.7 70.3 146.2 3.24 0.021 0.09 B 85.0 672 117.4 45.3
112.1 21.8 22.7 70.3 177.2 3.28 0.021 0.11 C 85.0 672 117.4 45.3
119.0 21.8 22.7 46.9 169.4 3.50 0.026 0.08 *) S = solvent for
reagent
[0044] The cellulose derivatives prepared in Examples 1 to 7 are
incorporated as thickeners into various emulsion paints and their
action is compared with the prior art thickeners.
[0045] In the formulation of a satin finish paint, the rheology,
stability, gloss and application properties of the paint are
investigated. The composition of the formulation is as follows:
8 Parts by weight Components 207 Water 2 Preservative (.RTM. Mergal
K 9 N), from Riedel de Han GmbH, DE 20 Polyphosphate (10% strength
.RTM. Calgon N) from BK Giulini GmbH, DE 5 Dispersant (.RTM. Lopon
894) from BK Giulini GmbH, DE 4 Defoamer (.RTM. Agitan 295) from
Munzing Chemie GmbH, DE Variable Thickener 225 Titanium dioxide
(.RTM. Hombitan R 611) from Sachtleben, DE 50 Filler (kaolin, .RTM.
China Clay Speshwhite) from ECC International, GB 75 Filler
(CaCO.sub.3, .RTM. Hydrocarb OG) from Omya GmbH, DE 2 Sodium
hydroxide (10% strength) 460 Acrylate dispersion (.RTM. Mowilith
LDM 7712) from Clariant GmbH, DE 10 Film former, butyl diglycol
acetate
[0046] Thickener:
[0047] Sample A: 5 parts by weight of cellulose derivative of
Example 4A
[0048] Sample B: 5 parts by weight of cellulose derivative of
Example 4B
[0049] Sample C: 5 parts by weight of cellulose derivative of
Example 4C
[0050] Sample D: 5 parts by weight of cellulose derivative of
Example 4D
[0051] The following prior art thickeners are used for comparison
with the cellulose derivatives of the present invention. All
thickener viscosities (mPa.s) are measured in 2% strength aqueous
solution at 20.degree. C. in a Happler falling-ball viscometer in
accordance with DIN 53015.
[0052] Sample E: 5 parts by weight of methylhydroxyethylcellulose,
viscosity 6000 mPa.s, 2% strength
[0053] Sample F: 5 parts by weight of hydroxyethylcellulose,
viscosity 6000 mPa.s, 2% strength
[0054] Sample G: 5 parts by weight of hydroxyethylcellulose with
long-chain alkyl radical, viscosity 6000 mPa.s, 2% strength
[0055] Sample H: 5 parts by weight of hydroxyethylcellulose,
viscosity 6000 mPa.s, 2% strength +5 parts by weight of
polyurethane thickener.RTM. Acrysol RM 2020
[0056] Directly following production of the paint, and after
conditioning at 23.degree. C./1 day, the paint viscosities are
measured using the Brookfield rheometer (Spindel 6 at 10 min.sup.-1
and 100 min.sup.-1, 23.degree. C.). The quotient formed from the
viscosity at 100 min.sup.-1 and 10 min.sup.-1 can be used as a
measure of the pseudoplasticity. High values denote lower
pseudoplasticity and closer approximation to the ideally Newtonian
behavior.
[0057] The viscosity values found indicate a lesser degree of
bodying of the products of the invention (Samples A to D) in
comparison to conventional cellulose ethers (Samples E and F) and
the hydrophobically modified cellulose ether (Sample G) and the
thickener combination (Sample H).
[0058] Following an aging period of one day following preparation
of the emulsion paints, the paints are applied using a brush, and
the brushability and appearance of the applied paint films are
assessed in accordance with a scale of ratings (see Remarks on
evaluation).
[0059] For quantitative assessment of the nondrip behavior of an
emulsion paint the following test is carried out, which
reconstructs the application of the paint using a roller:
[0060] A conditioned paint roller is loaded with a defined amount
(35 ml) of emulsion paint and rolled a number of times, using
motor-driven reciprocal motions, over a paint stripper grid
customary in the art. The pressure with which the roller is applied
is kept constant. At the bottom of a dish which serves to support
the rectangular grid there is a black card. The drips of paint
failing on it are compared visually in terms of their number and
areal extent and are assessed in accordance with a fixed scale of
ratings (see Remarks on evaluation).
[0061] The gloss of the dry paint film is measured using a
reflectometer at an angle of 60.degree..
9 Sample Sample Sample Sample Sample Sample Sample Sample Viscosity
Brookfield RVT (mPa s) A B C D E F G H after preparation 10
min.sup.-1 6910 9240 13700 10000 23800 14700 6360 16100 100
min.sup.-1 2550 3310 4000 3490 3840 2420 1580 3020 quotient 100
min.sup.-1/10 min.sup.-1 0.37 0.36 0.29 0.34 0.16 0.16 0.25 0.19
after 1 day 10 min.sup.-1 8800 10300 15900 10900 31700 21300 11200
33500 100 min.sup.-1 3270 3620 5290 4150 5160 3530 2830 6020
quotient 100 min.sup.-1/10 min.sup.-1 0.37 0.35 0.30 0.36 0.16 0.16
0.25 0.18 bodying (%) 10 min.sup.-1 27.4 11.5 16.1 9.0 33.2 44.9
76.1 108.1 100 min.sup.-1 26.3 9.4 32.2 18.9 34.8 45.9 79.1 99.3
syneresis 0 0 0 0 0 3 0 3 60.degree. gloss (%) 18.8 18.1 17.2 15.3
10.9 13.0 14.9 13.7 paint drip test 1+ 1+ 1+ 1 2- 3 1 2
brushability 1 1 1 1 1 1 1 1- flow 1 1 1 1 3 2- 2 2- Remarks on
evaluation: Paint drip test: 1 = slight dripping 2 = dripping 3 =
severe dripping 4 = slight plashing 5 = splashing 6 =severe
splashing Brushability: 1 = very readily brushable 2 = readily
brushable 3 = less readily brushable 4 = hard to brush (viscous) 5
= very hard to brush Flow: 1 = smooth surface 2 = slight
brushstroke marks 3 = distinct brushstroke marks 4 = severe
brushstroke marks 5 = very severe brushstroke marks
[0062] The wash resistance of different thickeners is investigated
in a solvent-free interior paint having the following
formulation.
10 Parts by weight Components 290 Water 1 Preservative (.RTM.
Mergal K 9 N), from Riedel de Han GmbH, DE 10 Polyphosphate (10%
strength .RTM. Calgon N) from BK Giulini GmbH, DE 3 Dispersant
(.RTM. Mowiplus XW 330) from Clariant GmbH, DE 2 Defoamer (.RTM.
Tego Foamex KS 6) from Tego Chemie GmbH, DE 5 Thickener 80 Titanium
dioxide (.RTM. Bayertitan RKB-2) from Bayer AG, DE 200 Filler
(CaCO.sub.3, .RTM. Omyacarb 5 GU) from Omya GmbH, DE 200 Filler
(CaCO.sub.3, .RTM. Omyacarb 2 GU) from Omya GmbH, DE 30 Filler
(mica, .RTM. Plastorit 000) from Luzenac Group, F 50 Filler
(kaolin, .RTM. China Clay Grade B) from ECC International, GB 1
Sodium hydroxide solution (10% strength) 120 Acrylate dispersion
(.RTM. Mowilith LDM 7712) from Clariant GmbH, DE 8 Film former,
butyl diglycol acetate 1000
[0063] Thickeners
[0064] Sample A: Cellulose derivative from Example 2C
[0065] Sample B: Cellulose derivative from Example 2D
[0066] Sample C: Cellulose derivative from Example 2E
[0067] The following prior art thickeners are used for comparison
with the cellulose derivatives of the present invention. All
thickener viscosities (mPa.s) are measured in 2% strength aqueous
solution at 20.degree. C. in a Hoppler falling-ball viscometer in
accordance with DIN 53 015.
[0068] Sample D: Hydroxyethylcellulose, viscosity 30,000 mPa.s/2%
strength
[0069] Sample E: Methylhydroxyethylcellulose, viscosity 30,000
mPa.s/2% strength
[0070] Sample F: Hydroxyethylcellulose with long-chain alkyl
radical, viscosity 6000 mPa.s/2% strength
[0071] In order to assess the wash resistance of the finished
paints, a film drawing apparatus is used to draw down paint films
with a dry film thickness of 100 .mu.m. The wash resistance is
tested in accordance with DIN 53778 Part 2 following conditioning
for 28 days at 23.degree. C./50% relative atmospheric humidity.
11 Sample Number of shear cycles A 974 B 1270 C 1347 D 1347 E 1047
F 1047
[0072] The cellulose derivatives of the invention result in less
bodying of the paints on storage and have a pseudoplasticity
markedly lower than that of cellulose ethers modified
hydrophobically using long-chain alkyl groups. Relative to the
cellulose ethers without hydrophobic modification, the cellulose
derivatives of the invention bring about greatly reduced dripping
of the emulsion paint. Advantages are evident in terms of gloss and
flow. The good washing stability of the finished emulsion paints is
retained despite the introduction of water soluble sulfoethyl
groups. As compared with combinations of conventional cellulose
ethers with synthetic polyurethane thickeners, the possibility
exists of preparing paints with reduced thickener concentrations to
achieved the desired paint consistency.
* * * * *