U.S. patent application number 11/585807 was filed with the patent office on 2007-12-20 for method for the production of hyperbranched water-soluble polyesters.
This patent application is currently assigned to BASF Aktiengesellschaft. Invention is credited to Bernd Bruchmann, Dietmar Haring, Jean-Francois Stumbe.
Application Number | 20070293634 11/585807 |
Document ID | / |
Family ID | 31502360 |
Filed Date | 2007-12-20 |
United States Patent
Application |
20070293634 |
Kind Code |
A1 |
Stumbe; Jean-Francois ; et
al. |
December 20, 2007 |
Method for the production of hyperbranched water-soluble
polyesters
Abstract
Process for preparing essentially uncrosslinked hyperbranched,
water-soluble or water-dispersible polyesters from dicarboxylic
acids and polyether polyols having at least 3 OH groups.
Water-soluble hyperbranched polyesters which are obtainable by such
a process and their use for producing printing inks, adhesives,
coatings, paints and varnishes.
Inventors: |
Stumbe; Jean-Francois;
(Strasbourg, FR) ; Bruchmann; Bernd; (Freinsheim,
DE) ; Haring; Dietmar; (Schriesheim, DE) |
Correspondence
Address: |
CONNOLLY BOVE LODGE & HUTZ LLP
1875 EYE STREET, N.W.
SUITE 1100
WASHINGTON
DC
20036
US
|
Assignee: |
BASF Aktiengesellschaft
Ludwigshafen
DE
D-67056
|
Family ID: |
31502360 |
Appl. No.: |
11/585807 |
Filed: |
January 16, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10525752 |
Feb 25, 2005 |
7148293 |
|
|
PCT/EP03/08088 |
Jul 24, 2003 |
|
|
|
11585807 |
Jan 16, 2007 |
|
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Current U.S.
Class: |
525/437 ;
528/272 |
Current CPC
Class: |
C08G 83/005 20130101;
C08G 63/668 20130101 |
Class at
Publication: |
525/437 ;
528/272 |
International
Class: |
C08L 67/02 20060101
C08L067/02 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 30, 2002 |
DE |
DE 102 40 817.3 |
Claims
1. A process for preparing essentially uncrosslinked hyperbranched,
water-soluble or water-dispersible polyesters by reacting at least
one dicarboxylic acid or a dicarboxylic acid derivative (A) with at
least one polyether polyol (B) having n OH groups, where n is
.gtoreq.3, at from 40.degree. C. to 160.degree. C. in the presence
of an esterification catalyst, where the components (A) and (B) are
used in such amounts that the molar ratio of OH groups to COOH
groups is from 2:1 to 1:2.
2. A process as claimed in claim 1, wherein n is 3, 4, 5 or 6.
3. A process as claimed in claim 1, wherein n is 3 or 4.
4. A process as claimed in claim 1, wherein the molar ratio of OH
groups to COOH groups is from 1.8:1 to 1:1.8.
5. A process as claimed in claim 1, wherein the molar ratio of OH
groups to COOH groups is from 1.5:1 to 1:1.5.
6. A process as claimed in claim 1, wherein the reaction is carried
out under reduced pressure.
7. A process as claimed in claim 6, wherein the pressure is less
than 500 mbar.
8. A process as claimed in claim 1, wherein the polyether polyol
having at least 30H groups is obtainable by ethoxylation and/or
propoxylation of a molecule having at least 3 acidic H atoms.
9. A process as claimed in claim 8, wherein an ethoxylation is
carried out.
10. A process as claimed in claim 1, wherein a diol is additionally
used as chain extender (V) in an amount of not more than 40 mol %
based on the amount of polyether polyols used.
11. A process as claimed in claim 10, wherein the amount of the
chain extender (V) is not more than 20 mol %.
12. A process as claimed in claim 1, wherein a monofunctional
carboxylic acid or a monofunctional alcohol is additionally used as
chain stopper (S) in an amount of not more than 10 mol % based on
the amount of polyether polyols (B) or dicarboxylic acids (A)
used.
13. A process as claimed in claim 12, wherein the amount of the
chain stopper (S) is not more than 5 mol %.
14. A process as claimed in claim 1, wherein the hyperbranched,
water-soluble or water-dispersible polyester obtained is reacted in
an additional process step with a suitable functionalization
reagent (F) which can react with the OH and/or COOH end groups of
the polyester.
15. A process as claimed in claim 14, wherein the functionalization
reagent (F) comprises one or more compounds selected from the group
consisting of aliphatic and aromatic monocarboxylic acids and their
derivatives, aliphatic and aromatic unsaturated monocarboxylic
acids and their derivatives, aliphatic and aromatic monoalcohols,
aliphatic and aromatic unsaturated monoalcohols, aliphatic and
aromatic monoamines, aliphatic and aromatic unsaturated monoamines,
aromatic and aliphatic monoisocyanates, aliphatic and aromatic
unsaturated monoisocyanates, compounds containing carbodiimide
groups and compounds containing epoxide groups.
16. A process as claimed in claim 1, wherein the esterification
catalyst is an enzyme and the polymerization is carried out at from
40.degree. C. to 120.degree. C. in the presence of a solvent.
17. A process as claimed in claim 16, wherein the polymerization is
carried out at from 50.degree. C. to 80.degree. C.
18. A process as claimed in claim 16, wherein the enzyme is a
lipase or an esterase.
19. A process as claimed in claim 18, wherein the enzyme is Candida
antarctica lipase B.
20. A process as claimed in claim 16, wherein the enzyme is used in
immobilized form.
21. A process as claimed in claim 1, wherein the esterification
catalyst is an acidic inorganic, organometallic or organic
catalyst.
22. A process as claimed in claim 21, wherein the reaction is
carried out at from 60.degree. C. to 160.degree. C.
23. A process as claimed in claim 22, wherein the reaction is
carried out at from 80.degree. C. to 150.degree. C.
24. A process as claimed in claim 21, wherein the reaction is
carried out at a pressure of not more than 100 mbar.
25. A water-soluble or water-dispersible, hyperbranched polyester
obtainable by a process as claimed in claim 1.
26. A water-soluble or water-dispersible, hyperbranched polyester
which has a hydroxyl number of 50-1000 mg KOH/g, an acid number of
0-200 mg KOH/g, a number average molecular weight M.sub.n of 300-15
000 g/mol and a polydispersity M.sub.w/M.sub.n of 1.1-50 and is
obtainable by a process as claimed in claim 1.
27. A water-soluble or water-dispersible, hyperbranched polyester
as claimed in claim 26 which has a hydroxyl number of 100-800 mg
KOH/g, an acid number of 1-100 mg KOH/g, a number average molecular
weight M.sub.n of 500-8000 g/mol and a polydispersity
M.sub.w/M.sub.n of 1.2-20.
28. The use of a water-soluble or water-dispersible hyperbranched
polyester as claimed in claim 25 for preparing polyaddition or
polycondensation polymers.
29. The use of a water-soluble or water-dispersible hyperbranched
polyester as claimed in claim 25 for producing printing inks,
adhesives, coatings, paints and varnishes.
Description
[0001] This application is a Divisional of application Ser. No.
10/525,752 filed on Feb. 25, 2005; which is a National Phase of
PCT/EP2003/008088 filed on Jul. 24, 2003, which claims priority to
Application No. DE 102 40 817.3 filed on Aug. 30, 2002; the entire
contents of all are hereby incorporated by reference.
[0002] The present invention relates to a process for preparing
essentially uncrosslinked hyperbranched, water-soluble or
water-dispersible polyesters from dicarboxylic acids and polyether
polyols having at least 30H groups. It further relates to
water-soluble or water-dispersible hyperbranched polyesters which
are obtainable by such a process, and also to the use of such
water-soluble polyesters for preparing polyaddition or
polycondensation polymers and for producing printing inks,
adhesives, coatings, paints and varnishes.
[0003] Dendrimers, arborols, starburst polymers or hyperbranched
polymers are terms used to refer to polymeric structures which have
a branched structure and a high functionality.
[0004] Dendrimers are molecularly uniform macromolecules having a
highly symmetric structure. Owing to the high functionality and the
highly symmetric structure, they have many interesting properties.
The use of dendrimers has been proposed in a variety of industrial
fields. However, dendrimers have to be synthesized in multistage
syntheses starting from a central starter molecule and are
therefore very expensive. Accordingly, their industrial use is
restricted to special cases in the high-price sector. For wider
use, more economical alternatives to dendrimers are necessary.
[0005] In contrast to dendrimers, hyperbranched polymers are both
molecularly and structurally nonuniform. They have branches which
have both different lengths and different degrees of branching. The
term "hyperbranched polymers" is explained, for example, in Sunder
et al., Chem. Eur. J. 2000, 6, No. 14, pages 2499 to 2506, and in
the references cited therein. The article also gives typical
examples of this class of polymers.
[0006] The term "hyperbranched" does not mean simply a high degree
of branching of the polymer. Rather, hyperbranched polymers have a
particularly regular arrangement of branching points. Monomers
suitable for synthesizing hyperbranched polymers are, in
particular, AB.sub.x monomers. These have two different functional
groups A and B which can react with one another to form a link. The
functional group A is present only once in each molecule and the
functional group B is present two or more times. Reaction of these
AB.sub.x monomers with one another gives uncrosslinked polymers
having a regular arrangement of branching points. The polymers have
virtually exclusively B groups at the ends of the chains.
BRIEF DESCRIPTION OF THE DRAWING
[0007] FIG. 1 shows a typical example of a hyperbranched polymer
which is obtainable by reaction of an AB.sub.2 monomer.
[0008] WO 93/17060 discloses a process for preparing dendritic
polyesters. A polyol as starter molecule, e.g. trimethylolpropane,
is reacted with dimethylolpropionic acid in such an amount that a
dendrimer of the 1st generation is formed. Dendrimers of higher
generations are formed by stepwise addition of dimethylolpropionic
acid. The polyester obtained can subsequently be functionalized
further. Regardless of whether the process is single-stage or
multistage, dimethylolpropionic acid is expensive and the process
allows little flexibility.
[0009] Our own, as yet unpublished patent applications having the
numbers DE 101 631 63.4 and DE 102 195 08.0 disclose processes for
preparing hyperbranched polyesters by means of enzymatic or acid
catalysis. As an alternative to the synthesis from AB.sub.x
molecules, the A.sub.2+B.sub.x strategy is also disclosed. AB.sub.x
molecules are formed in situ from dicarboxylic acids A.sub.2 and
polyols B.sub.x and these form hyperbranched polyesters. However,
the polymers disclosed are not water-soluble and are thus
unsuitable for use in aqueous systems. Polyether polyols as OH
components are not disclosed.
[0010] Polyesters comprising polyether polyols as building block
have been disclosed a number of times.
[0011] U.S. Pat. No. 4,983,712 discloses the preparation of
radiation-curable polyesters from a mixture of terephthalic acid,
adipic acid and, if desired, further dicarboxylic acids and, as
other reactant, a mixture of an ethoxylated triol or polyol and a
nonethoxylated diol in excess. The product obtained is
functionalized further by means of acrylic acid. The reaction is
carried out in the melt at 180.degree. C.-250.degree. C. However,
the high reaction temperature leads to undesirable secondary
reactions such as dehydration, intermolecular crosslinking and to
discoloration of the product.
[0012] EP-A 383 118 discloses the preparation of crosslinkable
polyesters having (meth)acryl groups from unsaturated dicarboxylic
acids, at least one ether alcohol which can have from 1 to 40H
groups and (meth)acrylic acid.
[0013] EP-A 279 303 discloses the preparation of radiation-curable
acrylates by reaction of alkoxylated, 2-6-hydric alcohols,
2-4-basic carboxylic acids and acrylic or methacrylic acid followed
by reaction of the excess carboxyl groups with epoxides.
[0014] GB-A 2 259 514 discloses the preparation of a polyester for
improving the water-wettability of articles from a mixture of a
(poly)ether diol and a (poly)ether polyol, with the proportion of
the diol in the mixture being from 30 to 95% by weight, and, as
other reactant, a mixture of aliphatic and alicyclic dicarboxylic
or polycarboxylic acids.
[0015] The polyesters comprising polyether polyol units disclosed
in the documents mentioned can also have branches. However, none of
the documents indicates the conditions necessary to obtain
essentially uncrosslinked and hyperbranched, i.e. having a regular
branching structure, water-soluble or water-dispersible
polyesters.
[0016] It is an object of the present invention to provide an
economical process for preparing essentially uncrosslinked,
water-soluble or water-dispersible hyperbranched polyesters from
simple monomers. Furthermore, the process should have high
flexibility in order to optimally match the properties of the
water-soluble or water-dispersible hyperbranched polyesters to
particular applications in a simple way. A further object is to
provide novel water-soluble or water-dispersible hyperbranched
polyesters and to provide for their use for preparing polyaddition
or polycondensation polymers and for producing printing inks,
adhesives, paints and varnishes and coatings.
[0017] We have found that this object is achieved by a process for
preparing essentially uncrosslinked hyperbranched, water-soluble or
water-dispersible polyesters, which comprises reacting
[0018] at least one dicarboxylic acid or a dicarboxylic acid
derivative (A) with
[0019] at least one polyether polyol (B) having n OH groups, where
n is .gtoreq.3, at from 60.degree. C. to 160.degree. C. in the
presence of an esterification catalyst, where the components (A)
and (B) are used in such amounts that the molar ratio of OH groups
to COOH groups is from 2:1 to 1:2.
[0020] In a further aspect of the invention, we have found
water-soluble or water-dispersible hyperbranched polyesters which
are obtainable by the process indicated.
[0021] In a third aspect of the invention, we have found the use of
the water-soluble or water-dispersible, hyperbranched polyesters
for producing printing inks, adhesives, coatings, paints and
varnishes.
[0022] The following details may be provided in respect of the
invention.
[0023] The hyperbranched and water-soluble or water-dispersible
polyesters of the present invention are hyperbranched polymers in
the strict sense, i.e. molecularly and structurally nonuniform
polymers. Molecularly and structurally uniform dendrimers as
defined at the outset do not come within the scope of the
invention.
[0024] To carry out the process of the present invention, it is not
necessary to synthesize AB.sub.x molecules, but instead the
corresponding structural units are generated in situ from A.sub.2
and B.sub.x molecules.
[0025] The synthesis is carried out using at least one dicarboxylic
acid (A) or a suitable derivative thereof. Of course, it is also
possible to use mixtures of various dicarboxylic acids or
derivatives. The choice of the derivative is not restricted,
provided that the reaction is not adversely affected thereby.
[0026] Suitable derivatives are, in particular, the relevant
anhydrides in monomeric or polymeric form or monoalkyl or dialkyl
esters, preferably methyl or ethyl esters or mixed methyl ethyl
esters.
[0027] Examples of dicarboxylic acids (A) include saturated
aliphatic dicarboxylic acids such as malonic acid, succinic acid,
glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic
acid, sebacic acid, dodecane-.alpha., .omega.-dicarboxylic acid and
alicyclic carboxylic acids such as 1,2-, 1,3- or
1,4-cyclohexanedicarboxylic acid or cyclopentane-1,2-dicarboxylic
acid. The dicarboxylic acids mentioned may also be substituted, for
example by one or more radicals such as alkyl groups, in particular
C.sub.1-C.sub.10-alkyl groups, cycloalkyl groups, alkylene groups
such as methylene or ethylidene or aryl groups, in particular
C.sub.6-C.sub.14-aryl groups.
[0028] Further examples of dicarboxylic acids (A) include
ethylenically unsaturated acids such as maleic acid and fumaric
acid and also aromatic dicarboxylic acids such as phthalic acid,
isophthalic acid or terephthalic acid.
[0029] Preferred dicarboxylic acids (A) are aliphatic dicarboxylic
acids, in particular succinic acid, glutaric acid and adipic acid,
or their monomethyl or dimethyl esters. Further preference is given
to phthalic acid, isophthalic acid and terephthalic acid and their
monomethyl or dimethyl esters. Very particular preference is given
to adipic acid.
[0030] As second component for the synthesis, use is made of a
polyether polyol (B) having n OH groups, where n is a natural
number greater than or equal to 3. n is preferably 3, 4, 5 or 6 and
particularly preferably 3 or 4.
[0031] Of course, it is also possible to use mixtures of various
polyether polyols.
[0032] Examples of suitable polyether polyols include
oligoglycerols having a degree of polymerization of from 2 to 50,
preferably from 2 to 7 and particularly preferably from 2 to 4.
[0033] Further examples include polyether polyols which are
obtainable by ethoxylation and/or propoxylation of compounds having
at least 3 groups which contain acidic H atoms. Preference is given
to ethoxylation.
[0034] Examples of compounds having at least 3 groups containing
acidic H atoms include alcohols, in particular saturated alcohols,
which have at least 30H groups, e.g. glycerol, trimethylolethane,
trimethylolpropane, ditrimethylolpropane or pentaerythritol.
However, it is also possible to use suitable amines or amino
alcohols, for example diethanolamine, dipropanolamine,
diisopropanolamine, triethanolamine,
tris(hydroxymethyl)aminomethane or diisopropylethanolamine.
[0035] The degree of ethoxylation is usually from 0.1 to 10
ethylene oxide units per OH group or group having an acidic H.
Preference is given to from 1 to 6 and particularly preferably from
2 to 5 units. The number average molecular weight M.sub.n of the
polyether polyols used is usually from 100 to 1000 g/mol.
Preference is given to using ethoxylated trimethylolpropane,
ethoxylated glycerol or ethoxylated pentaerythritol. Star-shaped
molecules having at least 3 arms comprising PPO-PEO blocks are also
suitable.
[0036] According to the present invention, the components (A) and
(B) are reacted in such an amount that the molar ratio of the OH
groups to the COOH groups is from 2:1 to 1:2. If the ratio
mentioned is greater than the upper limit or smaller than the lower
limit, water-soluble or water-dispersible, hyperbranched polymers
of sufficient quality are generally no longer obtained. This does
not rule out the possibility of hyperbranched polymers of
satisfactory quality being able to be obtained in specific cases
when the ratio is slightly below or above the limits specified.
[0037] The molar ratio of OH groups to COOH groups is preferably
from 1.8:1 to 1:1.8, particularly preferably from 1.5: to 1:1.5 and
very particularly preferably from 1.25:1 to 1:1.25.
[0038] In the process of the present invention, use can optionally
also be made of diols as chain extenders (V). Chain extenders make
it possible to lengthen the arms of AB.sub.x units. An example
which may be mentioned is an AVAB.sub.x unit. Chain extenders can
be used to make fine adjustments in the desired properties of the
polymer. For example, the gel point or the density of the
functional groups of the molecule can be influenced thereby.
[0039] The amount of an optionally added chain extender (V) should
in general not exceed 40 mol % of the amount of polyether polyol
used. The amount preferably does not exceed 20 mol %. Furthermore,
the amount is calculated so that the OH/COOH ratio mentioned above
is still adhered to when the OH groups of (V) are taken into
account.
[0040] Examples of diolefins suitable as chain extenders (V)
include ethylene glycol, 1,2-propanediol, 1,3-propanediol,
1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol,
1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol,
2,3-pentanediol, 2,4-pentanediol, 1,2-hexanediol, 1,3-hexanediol,
1,4-hexanediol, 1,5-hexanediol, 1,6-hexanediol, 2,5-hexanediol,
1,2-heptanediol, 1,7-heptanediol, 1,8-octanediol, 1,2-octanediol,
1,9-nonanediol, 1,10-decanediol, 1,2-decanediol, 1,12-dodecanediol,
1,2-dodecanediol, 1,5-hexadiene-3,4-diol, cyclopentanediols,
cyclohexanediols, inositol and derivatives thereof,
(2)-methyl-2,4-pentanediol, 2,4-dimethyl-2,4-pentanediol,
2-ethyl-1,3-hexanediol, 2,5-dimethyl-2,5-hexanediol,
2,2,4-trimethyl-1,3-pentanediol, pinacol, diethylene glycol,
triethylene glycol, dipropylene glycol, tripropylene glycol,
polyethylene glycols HO(CH.sub.2CH.sub.2O).sub.n--H or
polypropylene glycols HO(CH[CH.sub.3]CH.sub.2O).sub.n--H or
mixtures of two or more representatives of the abovementioned
compounds, where n is an integer and n=4. Preference is given to
ethylene glycol, 1,2-propanediol and diethylene glycol, triethylene
glycol, dipropylene glycol and tripropylene glycol.
[0041] To make a fine adjustment in the properties of the
hyperbranched polymer, it is also possible to add a chain stopper
(S). A chain stopper is a monofunctional alcohol or a
monofunctional carboxylic acid. These can react with the reactive
functional end groups of the growing hyperbranched polymer and
serve to make a fine adjustment in the properties, for example to
limit the molecular weight. It is also possible to use mixtures of
various alcohols as chain stoppers or mixtures of various
carboxylic acids as chain stoppers. The use of a mixture of
alcohols and carboxylic acids is generally not advisable, even
though it should not be ruled out absolutely for specific
cases.
[0042] The amount of the optionally added chain stoppers should
generally not exceed 10 mol % of the amount of (A) in the case of
monocarboxylic acids or (B) for the case of monoalcohols.
Preference is given to using not more than 5 mol %. Furthermore,
the amount is calculated so that the OH/COOH ratio mentioned above
is still adhered to when the OH or COOH groups of (S) are taken
into account.
[0043] Examples of monocarboxylic acids which can be used as chain
stoppers (S) include high-boiling straight-chain or branched
saturated monocarboxylic acids, in particular
C.sub.6-C.sub.20-carboxylic acids such as hexanoic acid,
2-ethylhexanoic acid, octanoic acid, decanoic acid, dodecandoic
acid, lauric acid, palmitic acid or stearic acid. The carboxylic
acids can be used as such or in the form of derivatives. The choice
of derivatives is not restricted, provided that the reaction is not
adversely affected thereby. Suitable derivatives are, in
particular, the corresponding anhydrides in monomeric or polymeric
form or alkyl esters, preferably methyl or ethyl esters.
[0044] Examples of suitable monoalcohols include high-boiling
alcohols such as benzyl alcohol, 1-dodecanol, 1-tetradecanol,
1-hexadecanol, glycol monoalkyl ethers such as glycol monoethyl
ether or polyethylene glycol monoalkyl ethers, e.g. polyethylene
glycol monoethyl ether.
[0045] In the process of the present invention, the components (A)
and (B) and, if present, (V) and/or (S) are reacted in the presence
of an esterification catalyst. The reaction temperature is
generally from 40 to 160.degree. C. Outside this temperature range,
it is generally the case that essentially uncrosslinked,
water-soluble or water-dispersible, hyperbranched polyesters of the
quality necessary for the applications according to the invention
are no longer obtained, even when this may be the case in
exceptional circumstances.
[0046] Examples of suitable esterification catalysts include acidic
inorganic, organometallic or organic catalysts.
[0047] Examples of acidic inorganic catalysts include sulfuric
acid, phosphoric acid, phosphonic acid, hypophosphorus acid,
aluminum sulfate hydrate, alum, acidic silica gel (pH=6, in
particular =5) and acidic aluminum oxide. Furthermore, aluminum
compounds of the formula Al(OR).sub.3 and titanates of the formula
Ti(OR).sub.4, for example, can also be used as acidic inorganic
catalysts. Here, the radicals R can be identical or different and
are selected independently from among C.sub.1-C.sub.10-alkyl
radicals. It is preferred that the radicals R in Al(OR).sub.3 or
Ti(OR).sub.4 are in each case identical and are selected from among
isopropyl and 2-ethylhexyl.
[0048] Preference is given to acidic organometallic catalysts
selected, for example, from among dialkyltin oxides R.sub.2SnO,
where R is as defined above. A particularly preferred
representative of acidic organometallic catalysts is di-n-butyltin
oxide, which is commercially available as oxo tin.
[0049] Preferred acidic organic catalysts also include acidic
organic compounds having, for example, phosphate groups, sulfonic
acid groups, sulfate groups or phosphonic acid groups. Particular
preference is given to sulfonic acids such as para-toluenesulfonic
acid. It is also possible to use acidic ion exchangers as acidic
organic catalysts, for example polystyrene resins which are
crosslinked with, for instance, 2 mol % of divinylbenzene and
contain sulfonic acid groups.
[0050] Of course, combinations of two or more of the abovementioned
catalysts can also be used, provided that the combination results
in no undesirable properties. It is also possible to use organic or
organometallic or inorganic catalysts which are present in the form
of discrete molecules in immobilized form. The amount of such
acidic esterification catalysts is usually from 0.1 to 10% by
weight, preferably from 0.2 to 2% by weight, of catalyst based on
the sum of (A) and (B) and, if used, (V) and/or (S).
[0051] The esterification catalyst can also be an enzyme.
Preference is given to using lipases or esterases. Well-suited
lipases and esterases are Candida cylindracea, Candida lipolytica,
Candida rugosa, Candida antarctica, Candida utilis, Chromobacterium
viscosum, Geotrichum viscosum, Geotrichum candidum, Mucorjavanicus,
Mucor mihei, pig pancreas, Pseudomonas spp., Pseudomonas
fluorescens, Pseudomonas cepacia, Rhizopus arrhizus, Rhizopus
delemar, Rhizopus niveus, Rhizopus oryzae, Aspergillus niger,
Penicillium roquefortii, Penicillium camembertii or esterases of
Bacillus spp. and Bacillus thermoglucosidasius. Particular
preference is given to Candida antarctica lipase B. The enzymes
mentioned are commercially available, for example from Novozymes
Biotech Inc., Denmark.
[0052] The enzyme is preferably used in immobilized form, for
example on silica gel or Lewatit.RTM.. Methods of immobilizing
enzymes are known per se, for example from Kurt Faber,
"Biotransformations in Organic Chemistry", 3rd edition 1997,
Springer Verlag, chapter 3.2 "Immobilization", page 345-356.
Immobilized enzymes are commercially available, for example from
Novozymes Biotech Inc., Denmark.
[0053] The amount of immobilized enzyme used is usually from 0.1 to
20% by weight, in particular 10-15% by weight, based on the sum of
(A) and (B) and, if used, (V) and/or (S).
[0054] The process of the present invention can be carried out by
simply heating (A) and (B) and, if desired, (V) and (S) with the
esterification catalyst to the desired temperature. However, the
process can also be carried out in the presence of a solvent.
Suitable solvents include, in particular, hydrocarbons such as
high-boiling paraffins or aromatics. Examples which may be
mentioned are toluene, ethylbenzene and xylene. The amount of
solvent will be determined by a person skilled in the art depending
on the desired reaction conditions.
[0055] The process of the present invention can be carried out in
the presence of a water-withdrawing agent as additive which is
added at the start of the reaction. Examples of suitable additives
of this type are, for example, molecular sieves, in particular 4
.ANG. molecular sieves, MgSO.sub.4 and Na.sub.2SO.sub.4. Further
water-withdrawing agent can also be added during the reaction or
water-withdrawing agent can be replaced by fresh water-withdrawing
agent.
[0056] It is particularly advantageous to distill off water formed
or alcohol formed (when using esters). To avoid solvent losses, it
is also advisable to separate off water from the solvent, for
example by means of a water separator, and to return the solvent
which has been freed of water to the reaction mixture. To remove
water of reaction formed as efficiently as possible, it is
generally advisable to carry out the reaction under reduced
pressure. In a preferred embodiment, the reaction is carried out at
a pressure of less than 500 mbar.
[0057] The most advantageous conditions for the reaction also
depend on the type of catalyst used. If an enzyme is used, it is
generally advisable to use a solvent. An example of a solvent which
has been found to be useful is toluene. Furthermore, the preferred
temperature in this variant is from 40 to 120.degree. C. Particular
preference is given to from 50 to 80.degree. C., very particularly
preferably from 65 to 75.degree. C. Preference is given to a
pressure of from 100 to 500 mbar, particularly preferably from 150
to 350 mbar, for carrying out the reaction.
[0058] If acidic inorganic, organometallic or organic
esterification catalysts are used, the process can be carried out
particularly advantageously without additional solvent. The
preferred temperature in this variant of the reaction is from 60 to
160.degree. C. Particular preference is given to from 80 to
150.degree. C. In this variant, the reaction is preferably carried
out at a pressure of less than 100 mbar, particularly preferably
from 10 to 80 mbar. Intensive mixing of the reaction mixture is
advisable in both variants.
[0059] In many cases, the hyperbranched, water-soluble or
water-dispersible polyesters obtained by means of the process of
the present invention can advantageously be used without further
work-up. Residues of solid catalysts can, if appropriate after
addition of solvent, be removed by filtration and the solvent can
subsequently be taken off again under reduced pressure. If desired,
the polymers can be purified by methods known in principle to a
person skilled in the art of polymers, for example by
reprecipitation.
[0060] Depending on the ratio of components (A) and (B) used, the
water-soluble or water-dispersible, hyperbranched polyesters formed
by the process have terminal OH groups, terminal COOH groups or
both terminal OH groups and terminal COOH groups. In addition, they
also have lateral OH and/or COOH groups (cf. FIG. 1). If carboxylic
esters have been used as starting material, the end groups are of
course not free COOH groups but COOR groups. Entirely or
predominantly OH-terminated polymers are obtained by using 1 mol of
polyether polyol (B) per mole of dicarboxylic acid (A). Entirely or
predominantly COOH-terminated polymers are obtained by using (n-1)
mol of the dicarboxylic acid (A) per mol of (B) having n OH
groups.
[0061] In a further variant of the invention, the hyperbranched
polyesters can be reacted further with a suitable functionalization
reagent (F) which can react either with the terminal OH groups or
the terminal COOH groups or generally with COOH and OH groups. In
this way, end groups which precisely match the intended use of the
hyperbranched polymer can be built into the hyperbranched polymer.
The functionalization is preferably carried out directly after the
polymerization without further work-up of the hyperbranched
polymer. However, it can of course also be carried out only after
isolation and/or work-up of the hyperbranched polymer in an
additional step.
[0062] Functionalization reagents which are particularly suitable
for the functionalization are one or more compounds selected from
the group consisting of aliphatic and aromatic monocarboxylic acids
and their derivatives, aliphatic and aromatic unsaturated
monocarboxylic acids and their derivatives, aliphatic and aromatic
monoalcohols, aliphatic and aromatic unsaturated monoalcohols,
aliphatic and aromatic monoamines, aliphatic and aromatic
unsaturated monoamines, aromatic and aliphatic monoisocyanates,
aliphatic and aromatic unsaturated monoisocyanates, compounds
containing carbodiimide groups and compounds containing epoxide
groups.
[0063] Some possible ways of carrying out a subsequent
functionalization are indicated below by way of example, without
the invention being restricted to the examples mentioned.
[0064] COOH groups still present can be reacted with diols, for
example ethylene glycol, to give products having essentially only
OH groups. It has been found to be useful to use the diols in
excess and to separate off the residual diols after the
reaction.
[0065] Conversely, OH groups still present can be reacted with
dicarboxylic acids such as malonic acid, succinic acid, glutaric
acid or adipic acid, in particular in the form of their anhydrides,
to give polymers having essentially only COOH groups.
[0066] Esterified end groups can be produced in a targeted manner
by means of monoalcohols such as methanol, ethanol, propanol or
long-chain aliphatic monoalcohols, e.g. stearyl alcohol, or,
alternatively, monocarboxylic acids such as acetic acid, propionic
acid or stearic acid.
[0067] It is also possible to use unsaturated monocarboxylic acids
or unsaturated monoalcohols, for example (meth)acrylic acid,
crotonic acid, oleic acid, linoleic acid, linolenic acid, vinyl
alcohol, hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate or
natural oils such as linseed oils or sunflower oils, as (F). This
gives polymers which are used, in particular, in radiation-curing
systems.
[0068] If the functionalization is, as indicated, based on an
esterification reaction, it is particularly advisable not to carry
out a work-up prior to the functionalization or else to reintroduce
the esterification catalysts mentioned at the outset. In the case
of functionalization agents (F) having unsaturated groups, it is
also generally advisable to carry out the functionalization
reaction only under mild reaction conditions. In the case of
enzymes as catalysts, it is advisable to work at from 20 to
80.degree. C., preferably from 40 to 70.degree. C. In the case of
acidic catalysts, the preferred temperature is from 20 to
100.degree. C., particularly preferably from 40 to 80.degree. C. In
both cases, the additional use of an inhibitor to prevent
free-radical polymerization is advisable. In the case of saturated
alcohols or carboxylic acids, the temperatures used in the
polymerization can be maintained.
[0069] Further examples include the introduction of terminal amino
groups, for example by reaction of COOH end groups with diamines or
polyamines such as ethylenediamine or diethylenetriamine, or the
reaction of OH groups with aliphatic or aromatic diisocyanates to
produce isocyanate end groups.
[0070] The water-soluble or water-dispersible hyperbranched
polyesters of the present invention have a molecular weight M.sub.n
of from 300 to 15 000 g/mol, preferably from 500 to 10 000 g/mol,
particularly preferably from 500 to 8000 g/mol.
[0071] The polydispersity M.sub.w/M.sub.n is generally from 1.1 to
50, preferably from 1.2 to 40, particularly preferably from 1.2 to
20.
[0072] The hydroxyl numbers of the polyesters of the present
invention are generally from 50 to 1000 mg KOH/g and preferably
from 100 to 800 mg KOH/g.
[0073] The acid numbers are generally from 0 to 200 mg KOH/g and
preferably from 1 to 100 mg KOH/g.
[0074] The polyesters generally have good to very good solubility
in water, i.e. clear solutions containing up to 50% by weight, in
some cases even as high as 80% by weight, of the polyesters of the
present invention in water can be produced, without gel particles
being visible to the naked eye.
[0075] In a further embodiment, somewhat less hydrophilic
polyesters which are no longer water-soluble but very readily
water-dispersible can be prepared. Here, stable dispersions having
solids contents of up to 50% by weight can be obtained.
[0076] In general, the hyperbranched polyesters of the present
invention are also readily soluble in alcohols or aqueous solvent
mixtures. The degree of hydrophilicity can be regulated by the
choice of the components (A) and (B) and, if appropriate, (V), (S)
and (F).
[0077] The hyperbranched polyesters of the present invention have
essentially no intermolecular crosslinking. They have particularly
low proportions of resinous components and discoloration.
[0078] A further aspect of the present invention is the use of the
hyperbranched, water-soluble polyesters of the present invention
for producing adhesives, printing inks such as flexographic and/or
gravure printing inks, coatings, paints and varnishes. They are
naturally particularly useful for water-based products. Adhesive
layers, printing, coatings or paint/varnish layers comprising the
hyperbranched polyesters of the present invention display excellent
adhesion to a wide variety of substrates.
[0079] For this purpose, the hyperbranched polyesters can be used
as such or else they can advantageously be used for preparing
polyaddition or polycondensation products, for example
polycarbonates, polyesters, polyamides, polyurethanes and
polyethers which can in turn be processed further to give the
abovementioned products. Preference is given to using
hydroxyl-terminated, high-functionality, hyperbranched polyesters
according to the present invention for preparing polyaddition or
polycondensation products, e.g. polycarbonates, polyesters or
polyurethanes.
[0080] The process of the present invention is highly flexible: a
large number of widely differing products can be obtained by means
of the process of the present invention from only few components by
using the building block principle. The process thus allows
particularly good matching of the desired product properties to the
respective desired application.
[0081] The following examples illustrate the invention:
[0082] List of chemicals and abbreviations used: TABLE-US-00001
PG-3 polyglycerol-3 (from Solvay) TMPEO ethoxylated
trishydroxymethylpropane (Lupranol .RTM. VP 9266, BASF) GlyEO
ethoxylated glycerol (Lupranol .RTM. VP 9209, BASF) Novozym .RTM.
435 lipase from Candida antarctica B on a solid support, from
Novozymes Biotech Inc., Denmark Fascat .RTM. di-n-butyltin oxide
(4201 E-Coat, Elf Atochem)
EXAMPLE 1
Adipic Acid/PC-3, Enzymatic Catalysis
[0083] Adipic acid (88 g, 0.60 mol) and PG-3 (120 g, 0.44 mol) were
dissolved at 70.degree. C. while stirring in 80 ml of toluene under
reduced pressure in a three-neck flask equipped for reactions. 14 g
of the enzyme catalyst Novozym.RTM. 435 were added and
polymerization was carried out at 70.degree. C. under reduced
pressure (300 mbar) to remove the water formed during the
polycondensation. The water was separated from the toluene which
likewise distilled off in a distillation apparatus for azeotropic
distillation and the toluene was returned to the reactor.
[0084] After a reaction time of 9 hours, the reaction solution was
filtered to separate off the supported enzyme. The toluene was
subsequently removed on a rotary evaporator and the last traces of
toluene were removed in a high vacuum (<10 mbar) at from 50 to
100.degree. C.
[0085] This gave a honey-like, viscous, colorless to slightly
yellowish hyperbranched polyester. The polyester was very readily
soluble in water. The properties of the polyester obtained are
summarized in table 2.
EXAMPLE 2
Adipic Acid/PG-3, Acid Catalysis
[0086] Adipic acid (1306 g, 8.95 mol) and PG-3 (1774 g, 7.45 mol)
were melted at 130.degree. C. with stirring under reduced pressure
in a three-necked flask equipped for reactions. 2.05 g of the acid
catalyst Fascat.RTM. were added, and polymerization was carried out
at 130.degree. C. under reduced pressure (50 mbar) in order to
remove the water formed during the polycondensation.
[0087] After a reaction time of 9 hours, a honey-like, viscous,
colorless to slightly yellowish hyperbranched polyester had been
obtained. The polyester was very readily soluble in water. The
properties of the polyester obtained are summarized in table 2.
EXAMPLE 3
Adipic Acid/TMPEO, Enzymatic Catalysis
[0088] Adipic acid (22 g, 0.15 mol) and TMPEO (198 g, 0.295 mol)
were reacted while stirring in 25 ml of toluene as described in
example 1.7 g of the enzyme catalyst Novozym.RTM. 435 were used and
the reaction was carried out at a pressure of from 200 to 250
mbar.
[0089] After a reaction time of 16 hours, the hyperbranched
polyester was worked up as described.
[0090] The properties of the polyester obtained are summarized in
table 2.
EXAMPLE 4
Adipic Acid/TMPEO, Acid Catalysis
[0091] Adipic acid (51.9 g, 0.355 mol) and TMPEO (198 g, 0.295 mol)
were reacted as described in example 2. 0.20 g of
Fascat.quadrature. were used and the reaction was carried out at a
pressure of 70 mbar.
[0092] The reaction time was 23 hours. The properties of the
polyester obtained are summarized in table 2.
EXAMPLE 5
Adipic Acid/GlyEO, Enzymatic Catalysis
[0093] Adipic acid (29.3 g, 0.20 mol) and GlyEO (62.3 g, 0.17 mol)
were reacted while stirring in 25 ml of toluene as described in
example 1.7 g of the enzyme catalyst Novozym.RTM. 435 were used and
the reaction was carried out at a pressure of from 200 to 250
mbar.
[0094] After a reaction time of 16 hours, the hyperbranched
polyester was worked up as described.
[0095] The properties of the polyester obtained are summarized in
table 2.
EXAMPLE 6
Adipic Acid/GlyEO, Acid Catalysis
[0096] Adipic acid (80 g, 0.55 mol) and GlyEO (169.6 g, 0.46 mol)
were reacted as described in example 2. 0.60 g of Fascat.RTM. were
used and the reaction was carried out at a pressure of 60 mbar.
[0097] The reaction time was 22 hours. The properties of the
polyester obtained are summarized in table 2.
EXAMPLE 7
Adipic Acid/PG-3/Stearic Acid as Chain Stopper (S), Acid
Catalysis
[0098] Adipic acid (99 g, 0.68 mol), PG-3 (135 g, 0.56 mol) and
stearic acid (15.8 g; 0.056 g corresponding to 8.2 mol % based on
adipic acid) were melted at 100.degree. C. as described in example
2. 0.16 g of Fascat.RTM. were added and polymerization was carried
out at a pressure of 60 mbar and a temperature of 130.degree.
C.
[0099] The reaction time was 8 hours. A wax-like, hyperbranched
polyester was obtained. The properties of the polyester obtained
are summarized in table 2.
EXAMPLE 8
Adipic Acid/PG-3/Glyceryl Monostearate as Chain Extender (V), Acid
Catalysis
[0100] Adipic acid (99 g, 0.55 mol), PG-3 (135 g, 0.56 mol) and
glyceryl monostearate (20.1 g; 0.056 mol corresponding to 10 mol %
based on PG-3) were melted at 130.degree. C. as described in
example 2. 0.16 g of Fascat.RTM. was added and polymerization was
carried out at a pressure of 60 mbar and a temperature of
130.degree. C.
[0101] The reaction time was 15 hours. The properties of the
polyester obtained are summarized in table 2.
EXAMPLE 9
Adipic Acid/PG-3/Ethylene Glycol as Chain Extender (V), Acid
Catalysis
[0102] Adipic acid (102.6 g, 0.70 mol), PG-3 (150 g, 0.625 mol) and
ethylene glycol (2.65 g; 0.043 mol corresponding to 6.9 mol % based
on PG-3) were melted at 130.degree. C. as described in example 2.
0.17 g of Fascat.RTM. was added and polymerization was carried out
at a pressure of 60 mbar and a temperature of 130.degree. C.
[0103] The reaction time was 21 hours. The properties of the
polyester obtained are summarized in table 2.
EXAMPLE 10
Phthalic Anhydride/PG-3, Acid Catalysis
[0104] Phthalic anhydride (99.2 g, 0.67 mol) and PG-3 (150.8 g,
0.625 mol) were melted at 130.degree. C. in the apparatus described
in example 2. 0.20 g of Fascat.RTM. was added and polymerization
was carried out at a pressure of 150 mbar and a temperature of
150.degree. C. After a reaction time of 16 hours, the pressure was
reduced to 50 mbar and polymerization was continued for a further 3
hours at this pressure.
[0105] The properties of the polyester obtained are summarized in
table 2.
EXAMPLE 11
Cyclohexane-1,2-Dicarboxylic Anhydride/PG-3, Acid Catalysis
[0106] Cyclohexane-1,2-dicarboxylic anhydride (101.6 g, 0.695 mol)
and PG-3 (148 g, 0.62 mol) were melted at 130.degree. C. in the
apparatus described in example 2. 0.30 g of Fascat.RTM. was added
and polymerization was carried out at atmospheric pressure and a
temperature of 150.degree. C. After a reaction time of 4.5 hours,
the pressure was reduced to 60 mbar and polymerization was
continued for a further 9 hours at this pressure.
[0107] The properties of the polyester obtained are summarized in
table 2.
COMPARATIVE EXAMPLE 1
[0108] Without Polyether Polyol
[0109] Adipic Acid/Trimethylolpropane/Acid Catalysis
[0110] Adipic acid (702 g, 4.8 mol), trimethylolpropane (537 g, 4
mol), 2.4 g of Fascat.RTM. and 200 g of toluene were heated to
125-130.degree. C. under nitrogen and water formed was separated
off using a water separator. After a reaction time of 11 hours, the
toluene was distilled off under reduced pressure. The viscous,
hyperbranched polyester was soluble in butyl acetate or THF but
insoluble in water.
[0111] The physical and chemical properties of the hyperbranched
polyesters obtained are summarized in table 2. TABLE-US-00002 TABLE
2 Physical and chemical properties of the hyperbranched polyesters
obtained in the examples Acid number [mg of KOH/g of M.sub.n
M.sub.w Solubility in Example Viscosity polyester] [g/mol] [g/mol]
M.sub.w/M.sub.n water 1 4.3 poise (at 75.degree. C.) 37 3400 5300
1.6 Very good 2 2.7 poise (at 75.degree. C.) 117 1450 2220 1.5 Very
good 3 10.0 poise (at 50.degree. C.) 9 8000 24000 3.0 Good 4 3.3
poise (at 25.degree. C.) 50 2340 5860 2.5 Good 5 6.4 poise (at
50.degree. C.) 63 6600 28500 4.3 Good 6 7.2 poise (at 25.degree.
C.) 45 2530 5700 2.3 Good 7 4.0 poise (at 75.degree. C.) 104 2300
3330 1.4 Dispersible 8 2.0 poise (at 75.degree. C.) 66 2500 4080
1.6 Dispersible 9 6.1 poise (at 75.degree. C.) 48 3100 44400 14.3
Very good 10 1.7 poise (at 125.degree. C.) 76 n.d. n.d. n.d.
Dispersible 11 8.2 poise (at 100.degree. C.) 71 n.d. n.d. n.d.
Dispersible C1 n.d. 77 1620 16170 9.9 Insoluble The acid number was
determined in accordance with DIN 53402. M.sub.w and M.sub.n were
determined by gel permeation chromatography in THF or
dimethylacetamide at 35.degree. C. using PMMA as standard. n.d.:
not determined
* * * * *