U.S. patent application number 12/919278 was filed with the patent office on 2011-05-19 for coating composition comprising autoxidisable component.
Invention is credited to Gerardus Cornelis Overbeek, Ronald Tennebroek, Ilse Van Casteren.
Application Number | 20110118407 12/919278 |
Document ID | / |
Family ID | 39671683 |
Filed Date | 2011-05-19 |
United States Patent
Application |
20110118407 |
Kind Code |
A1 |
Van Casteren; Ilse ; et
al. |
May 19, 2011 |
COATING COMPOSITION COMPRISING AUTOXIDISABLE COMPONENT
Abstract
An aqueous emulsion coating composition comprising an
autoxidisable vinyl oligomer having .gtoreq.20 wt % of unsaturated
fatty acid residue; Tg from -50 to +15.degree. C.; Mw from 2,500 to
40,000 g/mol; polydispersity from 2 to 12, said composition having
.ltoreq.15% co-solvent by weight of solids, .ltoreq.13% NMP by
weight of solids .gtoreq.38% solids by weight of composition; said
composition when in the form of a coating having a telegraphing
value defined as the difference in gloss at a 20.degree. angle of
between a film cast on rough PVC and a film cast on smooth PVC of
10 gloss units.
Inventors: |
Van Casteren; Ilse;
(Waalwijk, NL) ; Overbeek; Gerardus Cornelis;
(Waalwijk, NL) ; Tennebroek; Ronald; (Waalwijk,
NL) |
Family ID: |
39671683 |
Appl. No.: |
12/919278 |
Filed: |
March 31, 2009 |
PCT Filed: |
March 31, 2009 |
PCT NO: |
PCT/EP09/53829 |
371 Date: |
December 20, 2010 |
Current U.S.
Class: |
524/548 ;
427/386; 525/327.3; 525/386 |
Current CPC
Class: |
C08F 220/325 20200201;
C08F 8/14 20130101; C08F 8/14 20130101; C08J 5/18 20130101; C08F
220/32 20130101; C09D 139/06 20130101; C08F 120/06 20130101; C08F
220/28 20130101; C08F 212/08 20130101; C09D 137/00 20130101; C08F
120/06 20130101; C08F 8/14 20130101; C08F 220/325 20200201; C08F
8/44 20130101; Y10T 428/31938 20150401; C08F 2810/30 20130101; C08F
8/44 20130101; C08F 2810/50 20130101; C08F 8/14 20130101; C08F
212/08 20130101; C08F 220/325 20200201 |
Class at
Publication: |
524/548 ;
525/327.3; 525/386; 427/386 |
International
Class: |
C08L 63/00 20060101
C08L063/00; C08F 265/04 20060101 C08F265/04; B05D 3/00 20060101
B05D003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 31, 2008 |
EP |
0800627.48 |
Claims
1. An aqueous emulsion, coating composition that comprises an
autoxidisable vinyl oligomer where: I) said autoxidisable vinyl
oligomer has: i) fatty acid residue in an amount greater than or
equal to 20% by weight of the autoxidisable vinyl oligomer; ii) a
glass transition temperature (T.sub.g) from -50.degree. C. to
+15.degree. C.; iii) an acid value less than 40 mg KOH/g; iv) a
weight average molecular weight (M.sub.w) from 2,500 to 40,000
g/mol; v) a polydispersity (PDi) from 2 to 12; II) said composition
has: a) a co-solvent content less that 25% by weight of solids; b)
a N-methylpyrrolidone content less than 13% by weight of solids; c)
a solids content greater than or equal to 38% by the total weight
of said composition; and III) said composition when in the form of
the film has a telegraphing value of less than 10 gloss units,
where the telegraphing value is the difference between an initial
smooth gloss value minus an initial rough gloss value of the film,
where the initial smooth gloss value is the gloss when the film is
cast on smooth PVC (R.sub.z=1 .mu.m [.+-.0.25 .mu.m]); the initial
rough gloss value is the gloss when the film is cast on rough PVC
(R.sub.z=25 microns [.mu.m] [.+-.5 .mu.m]); and where each film has
a dry film thickness of 52 .mu.m [.+-.6 .mu.m]; and each initial
gloss value is measured at a 20.degree. angle, one day (24 hours)
after the film has been cast.
2. An aqueous autoxidisable coating composition according to claim
1 comprising an autoxidisable vinyl oligomer obtained by a process
comprising steps of: I) polymerising ethylenically unsaturated
vinyl monomers comprising: i) 30% to 70% of at least one monomer G
selected from hydroxylalkyl(meth)acrylates and epoxy functional
vinyl monomers; ii) 30% to 70% of at least one other ethylenically
unsaturated vinyl monomer; and iii) <1% of chlorine containing
monomers; where the percentages are by weight of total monomers;
II) reacting the oligomer obtained in step I) with fatty acids
having an average iodine value in the range of 80 to 180
gl.sub.2/100 g fatty acid; where the autoxidisable vinyl oligomer
has i) oligomeric backbone in an amount from 35% to 62% by weight
of the oligomer; ii) fatty acid residue in an amount from 38% to
65% by weight of the oligomer; iii) a Tg from -50 to 15.degree. C.;
iv) a Mw from 6500 to 25000 g/mol; and v) a PDi from 2 to 8; said
composition having a) a co-solvent content <15 wt % by weight of
solids; b) a N-methylpyrrolidone content <13 wt % by weight of
solids; c) heterocyclic amine containing solvent content of 0 wt %
by weight of solids; d) a solids content >38 wt %; e) a pH in
the range of from 4.1 to 8.4; and where said composition when in
the form of a coating has a telegraphing value (as defined in claim
1) of less than 10 gloss units.
3. An aqueous autoxidisable coating composition according to claim
1 where 0% of glycidyl esters of unsaturated fatty acids are used
in the preparation of the autoxidisable vinyl oligomer.
4. An aqueous autoxidisable coating composition according claim 1
where the autoxidisable vinyl oligomer, if carboxylic acid
functional conforms to the following relationship:
ND.times.AV<22 where ND=neutralization degree of the acid groups
on the oligomer; and where AV=acid value.
5. An aqueous autoxidisable coating composition according to claim
1 comprising <5% of N-methylpyrrolidone by weight of solids.
6. An aqueous autoxidisable coating composition according to claim
1 comprising <13% by weight of solids, of nitrogen containing
molecules with an evaporation rate <0.1 which are either
aromatic, heterocyclic or which are aromatic and aliphatic primary
and secondary (di)amines with the proviso that the amount of
nitrogen in such molecules is >5% by weight of the molecule.
7. An aqueous emulsion coating composition according to claim 1
where said composition comprises: i) 38% to 65% of the
autoxidisable vinyl oligomer; ii) 0 to 20% of co-solvent; and iii)
15% to 58% of water; where the percentages are by weight of the
composition and i)+ii)+iii)=100%.
8. An aqueous emulsion coating composition according to claim 1
where said composition comprises: i) 20% to 45% of TiO.sub.2; ii)
20% to 45% of the autoxidisable vinyl oligomer; iii) 0 to 10% of
co-solvent; iv) 0.1% to 3% of thickener; v) 0 to 5% of dispersing
agent; and vi) 25% to 60% water; where the percentages are by
weight of the composition and i)+ii)+iii)+iv)+v)=100%.
9. A method for preparing an autoxidisable vinyl oligomer, where
said autoxidisable vinyl oligomer is capable of forming a coating
composition that when in the form of the film has a telegraphing
value of less than 10 gloss units (as defined in claim 1); the
process comprising the steps of: I) polymerising ethylenically
unsaturated vinyl monomers comprising: i) 30% to 70% of at least
one monomer G selected from hydroxylalkyl(meth)acrylates and epoxy
functional vinyl monomers; ii) 30% to 70% of at least one other
ethylenically unsaturated vinyl monomer; and iii) <1% of
chlorine containing monomers; where the percentages are by weight
of total monomers; II) reacting the oligomer obtained in step I)
with fatty acids having an average iodine value in the range of 80
to 180 gl.sub.2/100 g fatty acid; to obtain an autoxidisable vinyl
oligomer having i) oligomeric backbone in an amount from 35% to 62%
by weight of the oligomer; ii) fatty acid residue in an amount from
38% to 65% by weight of the oligomer; iii) a T.sub.g from -50 to
15.degree. C.; iv) a Mw from 6500 to 25000 g/mol; and v) a PDi from
2 to 8.
10. A method as claimed in claim 9, where said autoxidisable vinyl
oligomer is capable of forming a coating composition that has a) a
co-solvent content .ltoreq.15% by weight of solids; b) a
N-methylpyrrolidone content .ltoreq.13% by weight of solids; c)
heterocyclic amine containing solvent content of 0 wt % by weight
of solids; d) a solids content .gtoreq.38% by weight of the
composition; and e) a pH from 4.1 to 8.4.
11. An autoxidisable vinyl oligomer obtained and/or obtainable by a
process as claimed in either claim 9.
12. A coating composition comprising an autoxidisable vinyl
oligomer as claimed in claim 11.
13. A coating composition as claimed in claim 12 where the
composition comprises: a) a co-solvent content .ltoreq.15% by
weight of solids; b) a N-methylpyrrolidone content .ltoreq.13% by
weight of solids; c) heterocyclic amine containing solvent content
of 0 wt % by weight of solids; d) a solids content .gtoreq.38% by
weight of the composition; and e) a pH from 4.1 to 8.4; and where
said composition is in the form of the film, the film has a
telegraphing value (as defined in claim 1) of less than 10 gloss
units.
14. A coating composition as claimed in claim 1, in which the an
autoxidisable vinyl oligomer is present in an amount from 38 to 65%
by weight of the composition.
15. A coating obtained and/or obtainable by a coating composition
as claimed in claim 1 and having a telegraphing value (as defined
in claim 1) of less than 10 gloss units.
16. A substrate coated with a coating as claimed in claim 15.
17. A method of coating a substrate comprising the steps of i)
applying a coating composition as claimed in claim 1 to a
substrate; ii) drying the substrate to form a coating thereon;
where the coating has a telegraphing value (as defined in claim 1)
of less than 10 gloss units.
18. Use of an autoxidisable vinyl oligomer and/or a coating
composition as claimed in claim 1 for the purpose of obtaining
coatings having a telegraphing value (as defined in claim 1) of
less than 10 gloss units.
19. A method of manufacture of an autoxidisable vinyl oligomer
and/or a coating composition as claimed in claim 1 for the purpose
of obtaining coatings having a telegraphing value (as defined in
claim 1) of less than 10 gloss units.
Description
[0001] The present invention relates to certain coating
compositions that comprise an autoxidisable component and processes
for making such compositions. Coatings of the invention show
reduced telegraphing of surface irregularities after the
composition has been applied to a surface.
[0002] There is a general need when applying a decorative or
protective coating to a substrate to obtain a smooth surface
without visible irregularities. The degree to which an underlying
surface can be visually ascertained through a coating is often
described as telegraphing (i.e. giving a clumsily obvious hint or
premature indication of something to come). It has been found that
irregularities on substrates (such as wood), which contribute to
the roughness, are often telegraphed through conventional dry
coatings.
[0003] Thicker coating materials are often used to reduce
telegraphing because they are sufficiently able to level out any
unevenness in the surface. Thus the underlying surface roughness of
the substrate shows through to a reduced extent into the final
coating which appears visually smooth. However, thicker coatings
are disadvantageous because they may need to be applied in several
layers, increasing the cost. Also slower through-drying, wrinkling
and sagging can occur when using thicker layers.
[0004] Organic solvents have been used to reduce telegraphing.
However with a continuing concern about the use of organic solvents
there has been a long felt need for an aqueous coating composition
with comparable properties to those achievable using compositions
based on organic solvents.
[0005] A coating should also dry sufficiently quickly to avoid the
adherence of dust and to ensure that the coating quickly becomes
water resistant (e.g. in case of outdoor applications), blocking
resistant and tack-free.
[0006] Aqueous compositions such as water dilutable autoxidisable
esters (also known as water dilutable unsaturated alkyds or alkyd
emulsions) have also been used to address the issue of
telegraphing. However these systems have many well known
problems.
[0007] Water dilutable alkyds may also suffer from backbone
hydrolysis. This may lead to changes in the performance over time
which is undesirable. Traditional alkyd emulsions are discussed in
"Water borne and solvent based alkyds and their end user
applications" by N. Tuck, volume VI, Wiley/Sita Series In Surface
Coatings technology; (ISBN 471985910) published in 2000.
[0008] Another common problem of traditional alkyd emulsions is
their tendency to produce cissing (also known as crawling) when
applied as an over-coat. Cissing is when a coating refuses to form
a continuous film, recedes from the surface, collects in beads and
leaves the surface partially exposed thus reducing the appearance
of the painted object.
[0009] Yet another disadvantage of traditional alkyd systems,
especially those containing a relatively high percentage of
unsaturated fatty acid residues, is their pronounced tendency to
yellow (in light or dark) over time.
[0010] Current coatings lack some or all of the above mentioned
performance characteristics, so coatings which exhibit reduced
telegraphing with a combination of: minimal hydrolysis of the
backbone of the alkyd, low yellowing over time and/or reduced
cissing are desired.
[0011] Prior aqueous coatings have not been widely accepted in many
markets as alternatives to solvent based coatings. For example
solvent based alkyds are still preferred in the decorative market,
where very low telegraphing is required as these coatings are often
applied by brush. It is also desired that aqueous compositions are
not milky or opaque but clear or transparent.
[0012] It is also generally known that polyester based alkyds (PE
alkyds) typically have a broad molecular weight distribution and
thus comprise a significant amount of material having a low
molecular weight, which dries more slowly and therefore means the
coating remains tacky for a longer period (i.e. has long tack free
times). The presence of material of lower molecular weight cannot
be avoided for many reasons. For example both glycerol (with three
fatty acids--triglycerides) and pentaerythritol (with four fatty
acids) are common raw materials used to prepare PE alkyds. To
address the issues raised by the presence of the low molecular
weight fraction, PE alkyds may be prepared in a highly branched
form to obtain a high molecular weight fraction that dries more
quickly. However the resultant branched PE alkyds have a
significantly increased viscosity and reduced flow (compared to
less branched equivalents) and thus must be diluted with more
organic solvent before they can be used. This is undesirable as for
example it increases the amount of volatile organic compounds (VOC)
and adversely affects the flow of the composition.
[0013] It is known that autoxidisable vinyl polymers may be
prepared by a radical polymerisation of vinyl monomers in the
presence of a fatty acid derivative. However the resultant polymers
have a broad molecular weight distribution, and these polymers
require higher amounts of solvent to make a coating, which
generally also contains high levels of free monomer. Without
wishing to be bound by theory it is believed that unsaturated fatty
acids retard radical polymerisation and graft onto the vinyl
polymer resulting in more material of higher molecular weight and a
broader molecular weight distribution.
[0014] WO 2002-033012 (=EP 1328594) (Avecia) discloses an aqueous
coating composition based on a cross-linkable water-dispersible
vinyl oligomer and optionally a dispersed polymer. The oligomers
described in this application have a low amount of fatty acid
(<40% by weight). As shown by the comparative data herein these
oligomers are designed for a different purpose (improved open time)
and produce coatings which, within a few days, lack satisfactory
body (in the tests as defined herein), do not produce satisfactory
tack free times. The acid functional acrylates described also
contain high levels of NMP which will reduce the rate of curing and
may contribute to yellowing.
[0015] U.S. Pat. No. 5,089,342, EP 0370299 and EP 0316732 (all
Bayer) disclose an aqueous, air drying coating composition
containing a water-soluble, air-drying polyacrylate with a
molecular weight of more than 1000 g/mole and 5-40wt % of
chemically incorporated fatty acids and 50-100 milli-equivalents
per 100 grams of solid of chemically incorporated quaternary
ammonium moieties. This reference describes systems that are
cationic, teaching away from using anionic systems (e.g. see col.
1, line 53) and teaches use of styrenic monomers as part of the
vinyl monomers which is not ideal as it can cause yellowing in the
final product.
[0016] U.S. Pat. No. 5,096,959 (Valspar) discloses water based
alkyd resins that are modified to provided increased hydrolytic
stability by reacting them with a polybasic acid composition
containing one or more cyclo-aliphatic polybasic acids.
[0017] WO 2007-147559 (DSM) describes air drying fatty acid
functional hyper-branched resins. The resins are water soluble, due
to a relatively high OH content and a low fatty acid level. This is
less desirable due to the effect it has on water resistance and
rate of cure and therefore on final properties.
[0018] US 2004-198903 discloses an ambient curable aqueous
dispersion of polymer particles containing pendant ethylenically
unsaturated side chains.
[0019] U.S. Pat. No. 6,653,381 discloses fatty acid functional
vinyl polymers obtained by copolymerisation of fatty acid
functional vinyl monomers. The low levels of fatty acid used may
lead to insufficient flow during drying and slow cure rates.
[0020] EP 425085 discloses water based autoxidisable coating
compositions comprising a partially esterified carboxylic acid
functional film forming copolymer derived from olefinically
unsaturated monomers. This reference teaches that it is essential
for all or most of the autoxidisable groups to be
3-allyloxy-2-hydroxypropyl groups (or the 3-alkylallyl or butyl
analogues) for the copolymer to retain a high degree of water
solubility. This may result in a low cure rate and the allyl groups
have been reported to release toxic compounds during cure.
[0021] JP 60110765 discloses the reaction of copolymer of an alpha
beta unsaturated acid, such as acrylic acid and other monomers with
a glycidyl ester of unsaturated fatty acid to form a resin which is
combined with a second resin to give a thick aqueous coating.
[0022] We have now found ways to overcome the above mentioned
disadvantages, especially when combinations of more then one of the
problems need to be overcome in one coating system.
[0023] It is an object of the invention to solve some or all or the
problems identified herein. A preferred object of the invention
provides a method of improving the appearance of coated substrates,
the substrates containing visual irregularities. In a more
preferred object of the invention the method can be used with a
wide variety of coating compositions.
[0024] The applicant has found that certain vinyl polymers prepared
by radical polymerisation of certain vinyl/acrylic monomers may
comprise significantly less low molecular weight fraction (like the
aforementioned triglycerides) avoiding the need to use significant
amounts of high molecular weight material, for example to improve
drying. The applicant has also surprisingly found that certain
vinyl polymers (with specific molecular weight, PDi and T.sub.g
values), that are prepared by radical polymerisation of epoxy
functional vinyl monomers with other vinyl monomers, and then
reacted with certain unsaturated fatty acids may overcome some or
all of the above identified problems with prior art vinyl
polymers.
[0025] According to the present invention there is provided an
aqueous emulsion, coating composition that comprises an
autoxidisable vinyl oligomer where:
[0026] I) said autoxidisable vinyl oligomer has: [0027] i) fatty
acid residue in an amount greater than or equal to 20% by weight of
the autoxidisable vinyl oligomer; [0028] ii) a glass transition
temperature (T.sub.g) from -50.degree. C. to +15.degree. C.; [0029]
iii) an acid value less than 40 mg KOH/g; [0030] iv) a weight
average molecular weight (M.sub.w) from 2,500 to 40,000 g/mol;
[0031] v) a polydispersity (PDi) from 2 to 12;
[0032] II) said composition has: [0033] a) a co-solvent content
less than 25% by weight of solids; [0034] b) a N-methylpyrrolidone
content less than 13% by weight of solids; [0035] c) a solids
content greater than or equal to 38% by the total weight of said
composition; and
[0036] III) said composition when in the form of the film has a
telegraphing value of less than 10 gloss units, [0037] where the
telegraphing value is the difference between an initial smooth
gloss value minus an initial rough gloss value of the film, where
[0038] the initial smooth gloss value is the gloss when the film is
cast on smooth PVC (R.sub.z=1 .mu.m [.+-.0.25 .mu.m]); [0039] the
initial rough gloss value is the gloss when the film is cast on
rough PVC (R.sub.z=25 microns [.mu.m] [.+-.5 .mu.m]);and where
[0040] each film has a dry film thickness of 52 .mu.m [.+-.6
.mu.m]; and [0041] each initial gloss value is measured at a
20.degree. angle, one day (24 hours) after the film has been
cast.
[0042] As used herein PVC means a polyvinylchloride substrate used
as described in the test methods herein.
[0043] Dry film thickness is measured herein after 24 hours of
drying, under standard conditions. As used herein, unless the
context indicates otherwise, the terms `standard conditions`
denotes a relative humidity of 50%.+-.5%, ambient temperature and
an air flow less than or equal to 0.1 m/s; and `ambient
temperature` denotes 23.degree. C..+-.2.degree..
[0044] The telegraphing values herein will be positive numbers. In
general the greater the reduction in telegraphing, the smaller will
be the telegraphing value.
[0045] The term "comprising" as used herein means that the list
that immediately follows is non exhaustive and may or may not
include any other additional suitable items, for example one or
more further feature(s), component(s), ingredient(s) and/or
substituent(s) as appropriate. "Substantially comprising" as used
herein means a component or list of component(s) is present in a
given material in an amount greater than or equal to about 90%,
preferably .gtoreq.95%, more preferably .gtoreq.98% by weight of
the total amount of the given material. The term "consisting of" as
used herein mean that the list that follows is exhaustive and does
not include additional items.
[0046] For all upper and lower boundaries of any parameters given
herein, the boundary value is included in each range for each
parameter. All combinations of minimum and maximum values of the
parameters described herein may be used to define the parameter
ranges for various embodiments and preferences of the
invention.
[0047] It will be understood that the total sum of any quantities
expressed herein as percentages cannot (allowing for rounding
errors) exceed 100%. For example the sum of all components of which
the composition of the invention (or part(s) thereof) comprises
may, when expressed as a weight (or other) percentage of the
composition (or the same part(s) thereof), total 100% allowing for
rounding errors. However where a list of components is
non-exhaustive the sum of the percentage for each of such
components may be less than 100% to allow a certain percentage for
additional amount(s) of any additional component(s) that may not be
explicitly described herein.
[0048] As used herein the terms oligomer and polymer both refer to
macromolecules which comprises a plurality of units derived,
actually or conceptually, from molecules of lower molecular mass.
These terms may also be used adjectivally to describe a part or the
whole of a macromolecule. Often the term oligomer may be used more
specifically to refer to macromolecules of intermediate relative
molecular mass, where the oligomer properties vary significantly
with the removal of one or a few units. Polymer may be used both
generally to refer to any macromolecule and also more specifically
to refer to macromolecules of high relative molecular mass where
usually addition or removal of one or a few units has a negligible
effect on the molecular properties (although this may not be always
be the case for example where polymers have certain properties that
are critically dependent on fine details of the molecular
structure). It will be understood that the molecular mass boundary
between an oligomer and a polymer (in its specific rather than
general meaning) may vary according to the specific macromolecule
and/or applications of interest and so they may be significant
overlap where the same macromolecules may be considered both a
oligomer and a polymer. Therefore, unless the context herein
clearly indicates otherwise, the terms oligomer and polymer are
used herein interchangeably.
[0049] Preferably each of the coating compositions of the invention
are non-adhesive compositions. As used herein the term
`non-adhesive composition` denotes any composition that does not
remain substantially tacky after drying under ambient conditions
for a length of time which would be commercially acceptable.
Non-adhesive compositions may be those which have a tack-free time
of less than or equal to 16 hours, preferably .ltoreq.10 hours,
more preferably .ltoreq.6 hours, most preferably .ltoreq.4 hours.
Tack free time may conveniently be measured as described
herein.
[0050] Preferred compositions of the invention produce coatings
that have a telegraphing value (as defined herein) of less than 7
gloss units, more preferably less than 4 gloss units and most
preferably less than 2 gloss units.
[0051] Preferably the initial rough gloss should not deteriorate
significantly over time. This can be measured as a `gloss decay`
defined as the initial rough gloss minus a rough gloss measured at
a later specified time. For example "gloss decay (`n` days)" is
calculated as the initial rough gloss (measured 1 day after film
formation) minus the rough gloss measured `n` days after film
formation (i.e. in this case n is always >1). Preferably the
gloss decay is measured 4 days, more preferably 7 days and most
preferably 14 days after film formation. Preferred values of gloss
decay (for example after each of the periods given above) are less
than 14 gloss units, more preferably less than 10 gloss units, most
preferably less than 7 gloss units and especially less than 4 gloss
units.
[0052] Without wishing to be bound by any theory it is believed
that the vinyl polymers of the invention have a comb like structure
allowing excellent control of molecular weight distribution to give
a relatively narrow distribution resulting in good flow, reduced
telegraphing and fast drying. Conventional vinyl polymers are
typically highly branched and used under conditions which are close
to those which cause the polymer to gel. In contrast the vinyl
polymers of the invention are hydrolytically stable as their
backbone is more resistant to hydrolysis. These properties are
especially important for decorative paints which may stay on the
shelf for a long time.
[0053] Polymers of the invention have a narrow molecular weight
distribution (PDi) and a relatively low weight average molecular
weight (M.sub.w) and therefore an improved balance between M.sub.w
and PDi. As such polymers have less material of low molecular
weight, coating compositions of the invention (comprising such
polymers) can dry fast, for example have short dust and/or tack
free times. Aqueous compositions of the invention have other
advantages. They may be prepared with lower viscosity due to the
reduced amount of high molecular weight material and lower
viscosity can reduce telegraphing. Compositions of the invention
can also be prepared with a high solids content.
[0054] Preferably the autoxidisable vinyl polymer will cross-link
at ambient temperature. Cross-linking by autoxidation means the
cross-linking results from an oxidation occurring in the presence
of air, usually involving a free radical mechanism and is
preferably metal-catalysed resulting in covalent bonds. Suitable
autoxidation is provided by for example fatty acid residues
comprising unsaturated bonds, allyl functional residues and/or
.beta.(beta)-keto ester groups, preferably by fatty acid residues
comprising unsaturated bonds.
[0055] As used herein `fatty acid residue` (or FA residue), means
fatty acids, simple derivatives thereof (such as esters (e.g.
C.sub.1-4alkyl esters), salts, soaps, oils, fats and/or waxes) and
mixtures thereof. As used herein `fatty acid` means any
predominately unbranched, non-cyclic (preferably substantially
linear) aliphatic carboxylic acid that substantially comprises,
preferably consists of an aliphatic hydrocarbon chain and at least
one carboxy group, preferably a single terminal carboxyl group
(i.e. located at the end of the chain). Fatty acids may comprise a
limited number of other substituents such as hydroxyl and may be
saturated, mono-unsaturated or poly-unsaturated.
[0056] The fatty acid residue may be obtained from one or more
natural and/or artificial source. Natural sources include animal
sources and/or plant sources. Animal sources may comprise animal
fat, butter fat, fish oil, lard, liver fats, sperm whale oil and/or
tallow oil and waxes. Examples of waxes are beeswax, candelia
and/or montan. Plant sources may comprise waxes and/or oils such as
vegetable oils and/or non-vegetable oils. Examples of plant oils
are: bitter gourd, borage, calendula, canola, castor, china wood,
coconut, conifer seed, corn, cottonseed, dehydrated castor,
flaxseed, grape seed, Jacaranda mimosifolia seed, linseed, olive,
palm, palm kernel, peanut, pomegranate seed, rapeseed, safflower,
snake gourd, soya(bean), sunflower, tung, and/or wheat germ.
Artificial sources include synthetic waxes (such as micro
crystalline and/or paraffin wax), distilling tall oil (a by-product
of processing pine wood) and/or synthesis (for example by chemical
and/or biochemical methods). Fatty acid residues having conjugated
double bonds may be obtained by catalytic isomerisation of natural
fatty acids and/or dehydrated castor oil. Conjugated oils are
preferably obtained by dehydration of castor oil. Fatty acid
residues may be obtained and/or obtainable from a plurality of the
above sources and/or other sources not listed herein.
[0057] Preferred fatty acid residues may comprise fatty acid(s)
having from 4 to 36, more preferably from 8 to 26, most preferably
from 10 to 24, especially 12 to 22 carbon atoms. Generally fatty
acids obtained from natural sources have an even number of carbon
atoms due to their method of bio-synthesis, however fatty acids
with an odd number of carbon atoms may also be useful in the
present invention. Fatty acid residues may comprise fatty acids
with one or more carboxylic acid groups, for example dimer or
trimer fatty acids. Preferred fatty acids are mono functional, more
preferably C.sub.10-24mono functional carboxylic acids, most
preferably C.sub.12-22 linear mono functional terminal carboxy
acids.
[0058] As long as oxidative drying of the polymer is not impaired
the fatty acid residue may comprise one or more saturated fatty
acids and/or oils, however at least some unsaturated fatty acid(s)
is needed for auto-oxidation to occur. In general the more
unsaturation present the more rapid the autoxidiative drying.
[0059] An iodine number may be used to indicate the amount of
unsaturation contained in fatty acids where a higher the iodine
number indicates more unsaturated double bonds are present.
Preferably the fatty acid residue used herein has an average iodine
value greater than or equal to 50, more preferably .gtoreq.80 and
most preferably .gtoreq.100 g I.sub.2/100 g fatty acid. Preferably
the fatty acid residue used herein has an average iodine value less
than or equal to 200, more preferably .ltoreq.180 and most
preferably .ltoreq.150 g I.sub.2/100 g fatty acid. The iodine value
may be measured conventionally or preferably as described in the
test methods herein.
[0060] For the purpose of determining the amount of fatty acid
residue used to obtain the vinyl polymer of the invention, it is
convenient to calculate the weight of the fatty acid reactant by
including the carbonyl group, but excluding the hydroxyl group of
the terminal acid group of the fatty acid molecule.
[0061] Preferably the minimum amount of fatty acid residues in the
autoxidisable vinyl polymer is greater than or equal to 30%, more
preferably .gtoreq.38%, most preferably .gtoreq.43% and especially
.gtoreq.50% by weight of the polymer.
[0062] Preferably the maximum amount of fatty acid residue in the
autoxidisable vinyl polymer is less than or equal to 70%, more
preferably .ltoreq.65%, most preferably .ltoreq.59% by weight of
the polymer.
[0063] Preferably the fatty acid residue comprises C.sub.10-30
fatty acids, more preferably C.sub.16-20 fatty acids, in an amount
greater than or equal to 80% by weight of the fatty acid residue.
More preferably the fatty acid residue substantially comprises,
most preferably consists of C.sub.10-30 fatty acids, especially
C.sub.16-20 fatty acids.
[0064] If the fatty acid residue comprises saturated fatty acids
they may be present in an amount less than or equal to 40%, more
preferably .ltoreq.20% and most preferably from 3% to 18% by weight
of the fatty acid residue.
[0065] Preferred vinyl polymers are those in which the
autoxidisable groups are mainly derived from fatty acid residue.
More preferably the fatty acid residue mainly comprises, most
preferably substantially comprises unsaturated fatty acids. Useful
unsaturated fatty acids have two or more double bonds and more
usefully are conjugated fatty acids.
[0066] Preferably at least 40% by weight, more preferably at least
60% by weight of the unsaturated fatty acids in the fatty acid
residue are fatty acids that contain at least two ethylenically
unsaturated groups (i.e. are polyunsaturated).
[0067] Preferred fatty acid residues comprise at least one
conjugated fatty acid. The total amount of conjugated fatty acid
may be greater than 0%, preferably .gtoreq.10% by weight of the
unsaturated fatty acid. The total amount of conjugated fatty acid
may be less than or equal to 70%, preferably .ltoreq.55%, more
preferably .ltoreq.40%, by weight of the unsaturated fatty acid.
The autoxidisable vinyl polymer may be obtained from a mixture of
conjugated and non-conjugated unsaturated fatty acids.
[0068] A known problem with many autoxidisable coating compositions
is that the resultant coatings have a tendency to yellow, in
particular where the autoxidisable groups are derived from
polyunsaturated fatty acids (e.g. those described herein). This may
be unacceptable depending on the desired color of the resultant
coating.
[0069] Therefore in another embodiment of the invention to reduce
yellowing, preferred autoxidisable vinyl polymers are those where
the unsaturated fatty residue comprises low amounts of highly
polyunsaturated fatty acids. For example vinyl polymers that are
more resistant to yellowing may be obtained and/or obtainable from
fatty acid residue that comprise by weight of total fatty acid less
than or equal to 10%, more preferably .ltoreq.7%, most preferably
.ltoreq.4% and especially .ltoreq.2% of fatty acids with three or
more double bonds. Examples of fatty acids that include three or
more double bonds are given herein.
[0070] Preferred compositions of the invention have an initial
yellowness value of less than or equal to 10, more preferably
.ltoreq.7 and most preferably .ltoreq.4, when measured using the
test method described herein. Preferred compositions show only a
small increase in yellowness (.DELTA.b value) after being held in
darkness for 3 weeks at 52.degree. C., more preferably .DELTA.b is
less than or equal to 10, still more preferably is .ltoreq.7, most
preferably .ltoreq.5 and especially .ltoreq.3.
[0071] In yet another embodiment of the invention (e.g. where
yellowing is not a concern) preferred autoxidisable vinyl polymers
are those where the unsaturated fatty residue comprises higher
amounts of highly polyunsaturated fatty acids (such as fatty acids
with three or more double bonds) as this can improve the speed of
autoxidative drying.
[0072] Preferably the unsaturated fatty acid is covalently bound to
the vinyl polymer in a one step process, either though the use of a
fatty acid functional vinyl monomer or through a reaction of the
fatty acid with the vinyl polymer.
[0073] It is preferred that glycidyl esters of unsaturated fatty
acids are not used in the preparation of the autoxidisable vinyl
polymer as the synthesis of these glycidyl esters requires toxic
raw materials like for instance epichlorohydrine which will also
give chlorine containing waste material which is undesirable. A
glycidyl ester of an unsaturated fatty acid is an epoxy functional
fatty acid material (usually with a number average molecular weight
(M.sub.n) below 400) where the acid group has been reacted to
obtain a glycidyl end group.
[0074] Optionally the fatty acid residue may also comprise one or
more alkynyl group(s) and/or one or more (non carboxy) hydroxyl
group(s).
[0075] Non limiting examples of some common fatty acids that may be
used in the present invention are listed below as their systematic
(IUPAC) names with their trivial name(s) in square parentheses
where known. It will be appreciated that in practice most fatty
acid residues (especially those obtained from natural sources) will
comprise a mixture of many of these acids as well as other acids
not specifically listed herein.
[0076] Saturated fatty acids may be selected from: butanoic
[butyric] acid (C.sub.4H.sub.8O.sub.2), pentanoic [valeric] acid
(C.sub.5H.sub.10O.sub.2), hexanoic [caproic] acid
(C.sub.6H.sub.12O.sub.2), heptanoic [enanthic] acid
(C.sub.7H.sub.14O.sub.2), octanoic [caprylic] acid
(C.sub.8H.sub.16O.sub.2), nonanoic [pelargonic] acid
(C.sub.9H.sub.18O.sub.2), decanoic [capric] acid
(C.sub.10H.sub.20O.sub.2), dodecanoic [lauric] acid
(C.sub.12H.sub.24O.sub.2), tetradecanoic [myristic] acid
(C.sub.14H.sub.28O.sub.2), hexadecanoic [palmitic] acid
(C.sub.16H.sub.32O.sub.2), heptadecanoic [margaric also daturic]
acid (C.sub.17H.sub.34O.sub.2), octadecanoic [stearic] acid
(C.sub.18H.sub.36O.sub.2), eicosanoic [arachidic] acid
(C.sub.20H.sub.40O.sub.2), docosanoic [behenic] acid
(C.sub.22H.sub.44O.sub.2), tetracosanoic [lignoceric] acid
(C.sub.24H.sub.48O.sub.2), hexacosanoic [cerotic] acid
(C.sub.26H.sub.52O.sub.2), heptacosanoic [carboceric] acid
(C.sub.27H.sub.54O.sub.2), octacosanoic [montanic] acid
(C.sub.28H.sub.56O.sub.2), triacontanoic [melissic] acid
(C.sub.30H.sub.60O.sub.2), dotriacontanoic [lacceroic] acid
(C.sub.32H.sub.64O.sub.2), tritriacontanoic [ceromelissic also
psyllic] acid (C.sub.33H.sub.66O.sub.2), tetratriacontanoic
[geddic] acid (C.sub.34H.sub.68O.sub.2) and/or pentatriacontanoic
[ceroplastic] acid (C.sub.35H.sub.70O.sub.2).
[0077] Mono-unsaturated fatty acids may be selected from:
(Z)-decan-4-enoic [obtusilic] acid (C.sub.10H.sub.18O.sub.2),
(Z)-decan-9-enoic [caproleic] acid (C.sub.10H.sub.18O.sub.2),
(Z)-undecan-10-enoic [undecylenic also 10-hendecenoic] acid
(C.sub.11H.sub.20O.sub.2), (Z)-dodan-4-ecenoic [linderic] acid
(C.sub.12H.sub.22O.sub.2), (Z)-dodecan-5-enoic (lauroleic) acid
(C.sub.12H.sub.22O.sub.2), (Z)-tetradecan-4-enoic [tsuzuic] acid
(C.sub.14H.sub.26O.sub.2), (Z)-tetradecan-5-enoic [physeteric] acid
(C.sub.14H.sub.26O.sub.2), (Z)-tetradecan-9-enoic [myristoleic]
acid (C.sub.14H.sub.26O.sub.2), (Z)-hexadan-6-enoic [sapienic] acid
(C.sub.16H.sub.30O.sub.2), (Z)-hexadan-9-enoic [palmitoleic] acid
(C.sub.16H.sub.30O.sub.2), (Z)-octadecan-6-enoic [petroselinic]
acid (C.sub.18H.sub.34O.sub.2), (E)-octadecan-9-enoic [elaidic]
acid (C.sub.18H.sub.34O.sub.2), (Z)-octadecan-9-enoic [oleic] acid
(C.sub.18H.sub.34O.sub.2), (Z)-octadecan-11-enoic [vaccenic also
asclepic] acid (C.sub.18H.sub.34O.sub.2), (Z)-eicosan-9-enoic
[gadoleic] acid (C.sub.20H.sub.38O.sub.2), (Z)-eicosan-11-enoic
[gondoic] acid (C.sub.20H.sub.38O.sub.2), (Z)-docosan-11-enoic
[cetoleic] acid (C.sub.22H.sub.42O.sub.2), (Z)-docosan-13-enoic
[erucic] acid (C.sub.22H.sub.42O.sub.2) and/or
(Z)-tetracosan-15-enoic [nervonic] acid
(C.sub.24H.sub.46O.sub.2).
[0078] Di-unsaturated fatty acids may be selected from:
(5Z,9Z)-hexadeca-5,9-dienoic acid (C.sub.16H.sub.28O.sub.2),
(5Z,9Z)-octadeca-5,9-dienoic [taxoleic] acid
(C.sub.18H.sub.32O.sub.2), (9Z,12Z)-octadeca-9,12-dienoic
[linoleic] acid (C.sub.18H.sub.32O.sub.2),
(9Z,15Z)-octadeca-9,15-dienoic acid (C.sub.18H.sub.32O.sub.2)
and/or (7Z,11Z)-eicosa-7,11-dienoic [dihomotaxoleic] acid
(C.sub.20H.sub.36O.sub.2).
[0079] Tri-unsaturated fatty acids may be selected from:
(5Z,9Z,12Z)-heptadeca-5,9,12-trienoic acid
(C.sub.17H.sub.28O.sub.2), (3Z,9Z,12Z)-octadeca-3,9,12-trienoic
acid (C.sub.18H.sub.30O.sub.2),
(5Z,9Z,12Z)-octadeca-5,9,12-trienoic [pinolenic] acid
(C.sub.18H.sub.30O.sub.2), (6Z,9Z,12Z)-octadeca-6,9,12-trienoic
acid [.gamma.(gamma)-linolenic acid also GLA]
(C.sub.18H.sub.30O.sub.2), (8E,10E,12Z)-octadeca-8,10,12-trienoic
[calendic] acid (C.sub.18H.sub.30O.sub.2),
(8Z,10E,12Z)-octadeca-8,10,12-trienoic [jacaric] acid
(C.sub.18H.sub.30O.sub.2), (9E,11E,13E)-octadeca-9,11,13-trienoic
[.beta.(beta)-eleostearic also .beta.-oleostearic] acid
(C.sub.18H.sub.30O.sub.2), (9E,11E,13Z)-octadeca-9,11,13-trienoic
[catalpic] acid (C.sub.18H.sub.30O.sub.2),
(9Z,11E,13E)-octadeca-9,11,13-trienoic [.alpha.(alpha)-eleostearic
also .alpha.-oleostearic] acid (C.sub.18H.sub.30O.sub.2) (where
.alpha.-eleostearic acid comprises >65% of the fatty acids of
tung oil), (9Z,11E,13Z)-octadeca-9,11,13-trienoic [punicic also
trichosanic] acid (C.sub.18H.sub.30O.sub.2),
(9Z,11E,15Z)-octadeca-9,11,13-trienoic [rumelenic] acid
(C.sub.18H.sub.30O.sub.2), (9Z,13E,15Z)-octadeca-9,13,13-trienoic
acid (C.sub.18H.sub.30O.sub.2),
(9Z,12Z,15Z)-octadeca-9,12,15-trienoic acid
[.alpha.(alpha)-linolenic acid also ALA] (C.sub.18H.sub.30O.sub.2),
(5Z,8Z,11Z)-eicosa-5,8,11-trienoic
[dihomo-.gamma.(gamma)-linolenic] acid (C.sub.20H.sub.34O.sub.2),
(5Z,11Z,14Z)-eicosa-8,11,1 4-trienoic [sciadonic] acid
(C.sub.20H.sub.34O.sub.2) and/or
(8Z,11Z,14Z)-eicosa-8,11,14-trienoic [Mead] acid
(C.sub.20H.sub.34O.sub.2).
[0080] Tetra-unsaturated fatty acids may be selected from:
(6Z,8Z,10Z,12Z)-hexadeca-6,8,10,15-tetraenoic acid
(C.sub.16H.sub.24O.sub.2),
(6Z,8Z,10Z,12Z)-octadeca-6,8,10,12-tetraenoic acid
(C.sub.18H.sub.28O.sub.2),
(6Z,9Z,12Z,15Z)-octadeca-6,9,12,15-tetraenoic [stearidonic] acid
(C.sub.18H.sub.28O.sub.2),
(9Z,11E,13E,15Z)-octadeca-9,11,13,15-tetraenoic
[.alpha.(alpha)-parinaric] acid (C.sub.18H.sub.28O.sub.2),
(9Z,11Z,13Z,15Z)-octadeca-9,11,13,15-tetraenoic
[.beta.(beta)-parinaric] acid (C.sub.18H.sub.28O.sub.2),
(5Z,8Z,11Z,14Z)-eicosa-5,8,11,14-tetraenoic acid [arachidonic acid
also AA] (C.sub.20H.sub.32O.sub.2),
(6Z,8Z,10Z,12Z)-eicosa-6,8,10,12-tetraenoic acid
(C.sub.20H.sub.32O.sub.2),
(8Z,11Z,14Z,11Z)-eicosa-8,11,14,17-tetraenoic acid
(C.sub.20H.sub.32O.sub.2),
(6Z,8Z,10Z,12Z)-docosa-6,8,10,12-tetraenoic acid
(C.sub.22H.sub.36O.sub.2) and/or
(7Z,10Z,13Z,16Z)-docosa-7,10,13,16-tetraenoic acid
(C.sub.22H.sub.36O.sub.2).
[0081] Penta-unsaturated fatty acids may be selected from:
(x,6Z,8Z,10Z,12Z)-hexadeca-x,6,8,10,12-pentaenoic acid(s)
(C.sub.16H.sub.22O.sub.2) where x denotes a fifth double bond
optionally in a position which does not conjugate with the other
four conjugated ethylenic double bonds,
(x',6Z,8Z,10Z,12Z)-eicosa-x',6,8,10,12-pentaenoic acid(s)
(C.sub.20H.sub.30O.sub.2) where x' denotes a fifth double bond
optionally in a position which does not conjugate with the other
four ethylenic double bonds,
(5E,7E,9E,14Z,17Z)-eicosa-5,8,11,14,17-pentaenoic acid
(C.sub.20H.sub.30O.sub.2),
(5Z,7E,9E,14Z,17Z)-eicosa-5,8,11,14,17-pentaenoic acid
(C.sub.20H.sub.30O.sub.2),
(5Z,8Z,11Z,14Z,17Z)-eicosa-5,8,11,14,17-pentaenoic acid [EPA]
(C.sub.20H.sub.30O.sub.2),
(7Z,10Z,13Z,16Z.19Z)-docosa-7,10,13,16,19-pentaenoic [clupanodonic]
acid (C.sub.22H.sub.34O.sub.2),
(4Z,7Z,10Z,13Z,16Z)-docosa-4,7,10,13,16-pentaenoic [osbond] acid
(C.sub.22H.sub.34O.sub.2) and/or
(7Z,10Z,13Z,16Z,19Z)-docosa-7,10,13,16,19-pentaenoic acid [DPA]
(C.sub.22H.sub.34O.sub.2).
[0082] Hexa-unsaturated fatty acids may be selected from:
(x'',y'',6Z,8Z,10Z,12Z)-eicosa-x'',y'',6,8,10,12-hexaenoic acid(s)
(C.sub.20H.sub.28O.sub.2) where x'' and y'' denote fifth and sixth
double bonds optionally in positions which do not conjugate with
the other four conjugated ethylenic double bonds,
(4Z,7Z,10Z,13Z,16Z,19Z)-docosa-4,7,10,13,16,19-hexaenoic acid [DHA]
(C.sub.22H.sub.32O.sub.2) and/or
(6Z,9Z,12Z,15Z,18Z,21Z)-tetracosa-6,9,12,15,18,21-hexaenoic
[nisinic] acid (C.sub.24H.sub.36O.sub.2).
[0083] Hepta-unsaturated fatty acids may be selected from:
(w''',x''',y''',6Z,8Z,10Z,12Z)-eicosa-w''',x''',y''',6,8,10,12-heptaenoic
acid(s) (C.sub.22H.sub.30O.sub.2) where w''', x''' and y''' denote
fifth, sixth and seven double bonds optionally in positions which
do not conjugate with the other four conjugated ethylenic double
bonds, and/or
(4Z,7Z,9Z,11Z,13Z,16Z,19Z)-docosa-4,7,9,11,13,16,19-heptaenoic
[stellaheptaenoic] acid (C.sub.22H.sub.30O.sub.2).
[0084] Alkynyl-functional fatty acids may be selected from:
(9Z)-octadeca-9-en-12-ynoic [crepenynic] acid
(C.sub.18H.sub.30O.sub.2).
[0085] Hydroxy-functional fatty acids may be selected from:
12-hydroxy-(9Z)-octadeca-9-enoic [ricinoleic] acid
(C.sub.18H.sub.34O.sub.3).
[0086] The cross-linking of the vinyl polymer herein is by
autoxidation. In a preferred embodiment, metal ion cross-linking is
used in combination with the autoxidation mechanism, e.g. by use of
coordinative driers as is well known by those skilled in the art.
Optionally (although less preferred) autoxidation is used in
combination with other cross-linking mechanisms as are known in the
art. Other cross-linking mechanisms known in the art include the
reaction of alkoxysilane functional groups, Schiff base
cross-linking, epoxy groups reacting with amino, carboxylic acid or
mercapto groups, the reaction of amine or mercapto groups with
ethylenically unsaturated groups such as fumarate and acryloyl
groups, the reaction of masked epoxy groups with amino or mercapto
groups, the reaction of isothiocyanates with amines, alcohols or
hydrazines, the reaction of amines (for example ethylene diamine or
multifunctional amine terminated polyalkylene oxides) with
.beta.(beta)-diketo (for example acetoacetoxy or acetoamide) groups
to form enamines.
[0087] The drying process of a coating composition can be divided
into stages for example the period of time necessary to achieve
dust-free and/or tack-free, coatings using the tests described
herein.
[0088] Preferably the dust free time is less than or equal to 4
hours, more preferably .ltoreq.2 hours and most preferably
.ltoreq.1 hour.
[0089] Preferably the tack-free time is less than or equal to 10
hours, more preferably .ltoreq.6 hours, most preferably .ltoreq.4
hours and particularly preferred <3 hours.
[0090] A problem often encountered in waterborne autoxidisable
vinyl polymers is they have poor hydrolytic stability. This is a
particular problem when polymer bound carboxylic acid groups are
introduced by reaction with anhydrides, especially when in
neutralized form. This problem can be reduced significantly by
reducing the degree of water solubility of the autoxidisable resin.
However in practice a balance between hydrolytic stability and
water solubility is required.
[0091] The autoxidisable vinyl polymer may contain bound
hydrophilic water-dispersing groups. Suitable hydrophilic groups
are well known in the art, and can be ionic water-dispersing groups
or non-ionic water-dispersing groups. Preferred non-ionic
water-dispersing groups are polyalkylene oxide groups, more
preferably polyethylene oxide groups. A small segment of the
polyethylene oxide group can be replaced by a propylene oxide
segment and/or butylene oxide segment, however the polyethylene
oxide group should still contain ethylene oxide (EO) as a major
component. When the water-dispersible group is polyethylene oxide,
the preferred EO chain length is .gtoreq.4, more preferably
.gtoreq.8 and most preferably .gtoreq.15 EO units. Preferably if
the autoxidisable vinyl polymer contains polyalkylene oxide groups,
the vinyl polymer has a polyalkylene oxide (optionally EO) content
which is at least .gtoreq.0%, more preferably .gtoreq.2%, most
preferably .gtoreq.3.5% and especially .gtoreq.5% and/or is no more
than .ltoreq.50%, more preferably .ltoreq.30%, most preferably
.ltoreq.15% and especially .ltoreq.9% by weight of the
autoxidisable vinyl polymer. Preferably the polyalkylene oxide
(optionally EO) group has a M.sub.w from 175 to 5000 g/mol, more
preferably from 350 to 2200 g/mol, most preferably from 660 to 2200
g/mol.
[0092] Preferred ionic water-dispersing groups are anionic
water-dispersing groups, especially carboxylic, phosphate,
phosphonate or sulphonic acid groups. Most preferred are
carboxylic, phosphate or phosphonate groups. The anionic
water-dispersing groups are preferably fully or partially in the
form of a salt. Conversion to the salt form is optionally effected
by neutralisation of the autoxidisable vinyl polymer with a base,
preferably during the preparation of the autoxidisable vinyl
polymer and/or during the preparation of the composition of the
present invention. The anionic dispersing groups may in some cases
be provided by the use of a monomer having an already neutralised
acid group in the autoxidisable vinyl polymer synthesis so that
subsequent neutralisation is unnecessary. If anionic
water-dispersing groups are used in combination with a non-ionic
water-dispersing group, neutralisation may not be required.
[0093] If the anionic water-dispersing groups are neutralised, the
base used to neutralise the groups is preferably, an amine or an
inorganic base. Suitable amines include tertiary amines, for
example triethylamine or N,N-dimethylethanolamine. Suitable
inorganic bases include alkali hydroxides and carbonates, for
example lithium hydroxide, sodium hydroxide, or potassium
hydroxide. Generally a base is used which gives the required
counter ion desired for the composition. For example, preferred
counter ions include tertiary amines or Li.sup.+, Na.sup.+,
K.sup.+, NH.sub.4.sup.+ and substituted ammonium salts (for example
a quaternary ammonium hydroxide
.sup.+N(CH.sub.3).sub.4OH.sup.-).
[0094] Cationic water dispersible groups can also be used, but are
less preferred. Examples include pyridine groups, imidazole groups
and or quaternary ammonium groups which may be neutralised or
permanently ionised. Due to the influence that neutralisation
agents have on yellowing, tertiary amines and/or LiOH, NaOH and KOH
are especially preferred.
[0095] The autoxidisable vinyl oligomer when in an aqueous coating
composition preferably has an acid value (AV, also referred to as
an acid number [AN]) from 0 to 28, more preferably from 0 to 18,
most preferably from 0 to 12 mg KOH/g.
[0096] The autoxidisable vinyl oligomer, if carboxylic acid
functional, preferably conforms to the following relationship
(where ND denotes the degree to which the acid groups of the
oligomer are neutralised):
ND.times.AV.ltoreq.22, more preferably .ltoreq.12 and most
preferably =8 mg KOH/g.
[0097] ND is a dimensionless fraction from 0 to 1 that indicates of
the amount of neutralizing agent present in the polymer. For
example if 80% of the acid groups on the polymer are neutralised,
then the ND value is 0.8. AV is reported in units of mg KOH/g so
the product ND.times.AV has units of mg KOH/g. When the polymer is
not neutralised ND is 0 and so is ND.times.AV is also 0.
[0098] The autoxidisable vinyl polymer preferably has a hydroxyl
number which is at least .gtoreq.25, more preferably .gtoreq.48
and/or is no more than .ltoreq.135, more preferably .ltoreq.110 mg
KOH/g.
[0099] The aqueous coating composition of the invention preferably
has a pH which is at least .gtoreq.2.0, more preferably .gtoreq.3.4
and most preferably .gtoreq.4.1 and especially .gtoreq.4.8 and/or
is no more than .ltoreq.9.7, more preferably .ltoreq.8.4 and most
preferably .ltoreq.7.6.
[0100] Preferably the weight average (M.sub.w) of the autoxidisable
vinyl oligomer is at least .gtoreq.4000, more preferably
.gtoreq.5000, most preferably .gtoreq.8000 and/or is no more than
.ltoreq.40000 more preferably .ltoreq.35000, most preferably
.ltoreq.20000 and especially .ltoreq.15000 g/mol. M.sub.w is
measured by GPC using polystyrene standards as described
herein.
[0101] Preferably the majority of any cross-linking reaction only
takes place after application of the aqueous coating composition to
a substrate, to avoid an excessive molecular weight build up which
may lead to an increased viscosity of the aqueous coating
composition on the substrate in the early stages of drying.
[0102] The molecular weight distribution (MWD) of the vinyl
oligomer has an influence on the viscosity of the oligomers in the
composition and hence an influence on the telegraphing. MWD is
conventionally described by a polydispersity index (PDi). PDi is
defined as the weight average molecular weight (M.sub.w) divided by
the number average molecular weight (M.sub.w/M.sub.n) and is
dimensionless. It has been found that a lower PDi often results in
a lower viscosity and improved flow for an oligomer of given
M.sub.w. The autoxidisable vinyl oligomer may have a PDi which is
no more than .ltoreq.8.3 preferably .ltoreq.7, more preferably
.ltoreq.5 and more preferably .ltoreq.4.5 and/or is at least
.gtoreq.2.5.
[0103] Preferably the weight average particle size of the
autoxidisable vinyl oligomer dispersed in an aqueous coating
composition is at least .gtoreq.50 nm, more preferably .gtoreq.80
nm, most preferably .gtoreq.120 nm and especially .gtoreq.150 nm.
Preferably at least 80% of the particles have a weight average
particle size .ltoreq.1000 nm, more preferably .ltoreq.750 nm, most
preferably .ltoreq.550 nm and especially .ltoreq.400 nm.
[0104] Weight average particle size can be measured by any suitable
method such as that described in the test methods herein.
[0105] The glass transition temperature (T.sub.g) (as measured by
DSC of a solid material) of the autoxidisable vinyl oligomer may
vary within a wide range and preferably is at least
.gtoreq.-50.degree. C., more preferably .gtoreq.-40.degree. C.,
more preferably .gtoreq.-25.degree. C. and/or preferably is no more
than .ltoreq.+15.degree. C., more preferably .ltoreq.+10.degree. C.
, most preferably .ltoreq.+5.degree. C. and especially
.ltoreq.0.degree. C. Conveniently the T.sub.g of the autoxidisable
vinyl oligomer may be from -45.degree. C. to -10.degree. C.
[0106] If the T.sub.g can not be measured by DSC because the first
derivative of the DSC curve does not show any identifiable maximum,
an alternative method for determining the T.sub.g is by calculating
the T.sub.g using the following equation that relates viscosity of
the pure vinyl oligomer to its T.sub.g (which is derived from the
Williams-Landau-Ferry [WLF] equation):
Ln(.eta.)=27.6-[40.2.times.(T-T.sub.g)]/[51.6+(T-T.sub.g)]
where: [0107] Ln(.eta.)=Natural logarithm of the viscosity of the
pure oligomer expressed in Pas (measured at ambient temperature
using a shear rate from 0.005 and 1 s.sup.-1) [0108] T=23.degree.
C..+-.1.degree. C. (i.e. ambient temperature is used to measure the
viscosity of the pure oligomer) and [0109] T.sub.g=glass
temperature expressed in .degree. C.
[0110] Functional groups (such as fatty acid residue or
water-dispersing groups) may be introduced into the autoxidisable
vinyl oligomer using two general methods: i) by using monomers
carrying the functional group in the polymerisation process to form
autoxidisable oligomer carrying the functional group; or ii) using
monomers bearing selected reactive groups where monomer is
subsequently reacted with a compound carrying the functional group
and also a reactive group of the type which will react with the
selected reactive groups on the monomer to provide attachment of
the functional group to the autoxidisable vinyl oligomer via
covalent bonding. Thus the autoxidisable vinyl oligomer may be
obtained by polymerising autoxidisable vinyl monomers with other
vinyl monomers, or, the autoxidisable groups may be attached to the
vinyl oligomer after radical polymerisation of vinyl monomers to
make a vinyl oligomer. Preferably the autoxidisable groups are
reacted with a vinyl oligomer. More preferably the vinyl oligomer
comprises epoxy functional groups, most preferably
glycidyl(meth)acrylate monomers such as GMA.
[0111] The autoxidisable vinyl oligomer may be prepared from free
radically polymerisable ethylenically unsaturated monomer(s), and
can contain polymerised units of a wide range of such monomers,
especially those commonly used to make binders for the coatings
industry. By a vinyl oligomer herein is meant a homo- or co-polymer
derived from addition polymerisation, using a free radical
initiated process which may be carried out in an aqueous or
non-aqueous medium, of one or more ethylenically unsaturated
monomers. Therefore by a vinyl monomer is meant an ethylenically
unsaturated monomer.
[0112] Examples of vinyl monomers which may be used to form a vinyl
oligomer include but are not limited to: 1,3-butadiene, isoprene,
styrene, .alpha.-methyl styrene, divinyl benzene, acrylonitrile,
methacrylonitrile, vinyl ethers, vinyl esters such as vinyl
acetate, vinyl propionate, vinyl laurate, and vinyl esters of
versatic acid such as VeoVa 9 and VeoVa 10 (VeoVa is a trademark of
Shell), heterocyclic vinyl compounds, alkyl esters of
mono-olefinically unsaturated dicarboxylic acids (such as
di-n-butyl maleate and di-n-butyl fumarate) and, in particular,
esters of acrylic acid and methacrylic acid of Formula I
CH.sub.2.dbd.CR.sup.1--COOR.sup.2 Formula I
where R.sup.1 is H or methyl and R.sup.2 is optionally substituted
C.sub.1-20 alkyl (preferably C.sub.1-8alkyl) or optionally
substituted C.sub.3-20 cycloalkyl (preferably C.sub.3-8
cycloalkyl), examples of which are methyl acrylate, methyl
methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate,
n-butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl
methacrylate, isopropyl acrylate, isopropyl methacrylate, n-propyl
acrylate, n-propyl methacrylate, and hydroxyalkyl(meth)acrylates
such as hydroxyethyl acrylate, hydroxyethyl methacrylate,
2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate,
4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate and their
modified analogues like Tone M-100 (Tone is a trademark of Union
Carbide Corporation).
[0113] Ethylenically unsaturated monocarboxylic, sulphonic and/or
dicarboxylic acids, such as acrylic acid, methacrylic acid,
.beta.-carboxy ethyl acrylate, fumaric acid and/or itaconic acid
may be used. Ethylenically unsaturated monomers such as
(meth)acrylamide and/or methoxypolyethyleneoxide(meth)acrylate may
also be used.
[0114] The vinyl monomer may optionally contain functional groups
to contribute to the cross-linking of the vinyl polymer(s) in the
coating. Examples of such groups include: maleic, epoxy, fumaric,
acetoacetoxy, .beta.(beta)-diketone, acryloyl, methacryloyl,
styrenic, (meth)allyl groups, mercapto groups, keto or aldehyde
groups (such as methyl vinyl ketone [MEK], diacetone acrylamide and
(meth)acrolein).
[0115] Preferred vinyl polymers have a backbone made from a monomer
system comprising at least 40% of one or more monomers of Formula I
by weight of the polymer. Such a preferred backbone for the vinyl
polymer is defined herein as an (meth)acrylic polymer. A
particularly preferred autoxidisable vinyl polymer is an
autoxidisable acrylic polymer (i.e. based predominantly on at least
one ester of acrylic and/or methacrylic acid). More preferably, the
monomer system for the vinyl backbone comprises at least 50%, most
preferably at least 60% of such monomers by weight of polymer. The
other monomer(s) in such acrylic autoxidisable vinyl polymers
(where used) may include one or more of the other vinyl monomers
mentioned above, and/or may include monomer(s) different to such
other monomers.
[0116] Particularly preferred monomers include butyl acrylate (all
isomers), butyl methacrylate (all isomers), methyl methacrylate,
ethyl hexyl methacrylate, esters of (meth)acrylic acid,
acrylonitrile, vinyl acetate and styrene.
[0117] Preferably the vinyl polymer contains less than 40% styrene,
more preferably less then 20%, most preferably less than 12% and
especially less than 5% by weight of polymer.
[0118] Preferably the vinyl polymer prepared in step I (before
fatty acid functionalisation) is substantially free of chlorine
containing monomers. Substantially free means such monomers are in
an amount .ltoreq.1%, more preferably .ltoreq.0.5% and especially
0% by weight of the vinyl polymer prepared in step I.
[0119] Alternatively vinyl functional monomers with an
autoxidisable moiety can be used, like the reaction product of GMA
and fatty acid or the monomer SerAD FX522 available commercially
from Servo Condea under that trade name.
[0120] In a preferred embodiment first a vinyl oligomer is
prepared, which is subsequently reacted to obtain an autoxidisable
vinyl oligomer of the invention.
[0121] Monomers "G" which are useful for reacting the fatty acid
onto the vinyl oligomer to give fatty acid residues include
hydroxylalkyl(meth)acrylates, such as hydroxyethyl(meth)acrylate,
hydroxypropyl(meth)acrylate and ToneM-100 and epoxy functional
vinyl monomers like glycidyl(meth)acrylate (GMA) or
3,4-epoxy-cyclohexyl methyl-acrylate.
[0122] In a preferred embodiment 30% to 70% of monomer G (by weight
of the total monomers) is used, before functionalisation, to obtain
an autoxidisable vinyl oligomer of the invention. Preferably the
vinyl oligomer comprising monomer G is then reacted with fatty
acid, where typically between 0.4 and 1.0 equivalent of fatty acid
is reacted with the graftable groups present on the vinyl oligomer.
For this purpose, it is considered that a hydroxyl graftable group
can react once with a fatty acid, whereas a epoxy graftable group
can react twice, due to the additionally formed hydroxyl group on
ring opening. A particularly preferred monomer G is GMA.
[0123] The autoxidisable vinyl oligomer is preferably prepared by
free radical polymerisation, although in some circumstances anionic
polymerisation may be utilised. The free radical polymerisation can
be performed by techniques known in the art, for example as
emulsion polymerisation, solution polymerisation, suspension
polymerisation or bulk polymerisation.
[0124] The autoxidisable vinyl oligomer is preferably prepared in
one or more solvents before being dispersed in water.
[0125] The autoxidisable vinyl oligomer is preferably made in a
non-continuous process to allow for improved control during
polymerisation.
[0126] Preferably less then 10% and more preferred less then 5% of
the autoxidisable vinyl oligomer solids (by weight of solids)
should consist of oligomeric vinyl material which is covalently
bound to a fatty acid, whereby the covalent bond is generated
through a grafting reaction of a propagating vinyl radical onto the
unsaturated fatty acid.
[0127] In the latter case the fatty acid can either be a free
unsaturated fatty acid or an unsaturated fatty which is part of a
polymeric structure.
[0128] Most preferably there is no grafting of vinyl monomers to
the fatty acid at all.
[0129] A free-radical polymerisation of vinyl monomer(s) to form a
crosslinkable vinyl autoxidisable vinyl oligomer or precursor vinyl
autoxidisable vinyl oligomer will require the use of a
free-radical-yielding initiator(s) to initiate the vinyl
polymerisation. Suitable free-radical-yielding initiators include
inorganic peroxides such as K, Na or ammonium persulphate, hydrogen
peroxide, alkyl hydroperoxides such as t-butyl hydroperoxide and
cumene hydroperoxide; dialkyl peroxides such as di-t-butyl peroxide
and the like; mixtures may also be used. The peroxy compounds are
in some cases advantageously used in combination with suitable
reducing agents (redox systems) such as Na or K pyrosulphite or
bisulphite, and iso-ascorbic acid.
[0130] It may be desirable to control the molecular weight by
addition of a chain transfer agent to the free radical
polymerisation process. Conventional chain transfer agents may be
utilised and include mercaptans, sulphides, disulphides and
halocarbons. In particular however the technique known as catalytic
chain transfer polymerisation (CCTP) may be used to provide low
molecular weights. In this case a free radical polymerisation is
carried out using a free radical forming initiator and a catalytic
amount of a selected transition metal complex acting as a catalytic
chain transfer agent (CCTA), and in particular a selected cobalt
chelate complex. Such a technique has been described for example in
N. S. Enikolopyan et al, J. Polym. Chem. Ed., Vol 19, 879 (1981),
U.S. Pat. No. 4,526,945, U.S. Pat. No. 4,680,354, EP-A-0196783,
EP-A-0199436, EP-A-0788518 and WO-A-87/03605.
[0131] The use of catalytic chain transfer agents provide four
important benefits: [0132] a) very low concentrations of catalytic
chain transfer agent (typically 1 to 1000 ppm by weight of vinyl
monomer used) are required to attain the preferred low molecular
weight oligomer and do not have the odour often associated with
conventional chain transfer agents; [0133] b) a vinyl autoxidisable
vinyl oligomer prepared by CCTP contains a terminal unsaturated
group on many, if not every vinyl oligomer molecule. This terminal
unsaturation can participate in autoxidation reactions for example
in fatty acid crosslinking systems. Thus the crosslinkable vinyl
autoxidisable vinyl oligomer of the present invention could have
autoxidisable crosslinker groups comprising the unsaturated groups
from fatty acids as well as terminal unsaturated groups resulting
from CCTP. [0134] c) CCTP allows the preparation of a vinyl
autoxidisable vinyl oligomer which has a narrower PDi than is
achievable by the use of conventional chain transfer agents for low
Mw autoxidisable oligomer. [0135] d) Especially when epoxy
functional monomers are used, CCTP has the benefit compared to e.g.
chain transfer agents with mercaptan groups, that the CCTA does not
react with the epoxy groups.
[0136] The solids content of the aqueous coating composition of the
invention is at least preferably .gtoreq.45% and more preferably
.gtoreq.49% and/or is no more than preferably .ltoreq.72%, more
preferably .ltoreq.65% and most preferably .ltoreq.63% by weight of
the composition.
[0137] The autoxidisable vinyl oligomer may be dispersed in water
using techniques well known in the art. The crosslinkable
autoxidisable vinyl oligomer normally requires the use of an
external surfactant when being dispersed into water. Surfactants
and or high shear can be utilised in order to assist in the
dispersion of the autoxidisable vinyl oligomer in water. Suitable
surfactants include but are not limited to conventional anionic,
cationic and/or non-ionic surfactants such as Na, K and NH.sub.4
salts of dialkylsulphosuccinates, Na, K and NH.sub.4 salts of
sulphated oils, Na, K and NH.sub.4 salts of alkyl sulphonic acids,
Na, K and NH.sub.4 alkyl sulphates, alkali metal salts of sulphonic
acids; fatty alcohols, ethoxylated fatty acids and/or fatty amides,
and Na, K and NH.sub.4 salts of fatty acids such as Na stearate and
Na oleate. Other anionic surfactants include alkyl or (alk)aryl
groups linked to sulphonic acid groups, sulphuric acid half ester
groups (linked in turn to polyglycol ether groups), phosphonic acid
groups, phosphoric acid analogues and phosphates or carboxylic acid
groups. Cationic surfactants include alkyl or (alk)aryl groups
linked to quaternary ammonium salt groups. Non-ionic surfactants
include polyglycol ether compounds and polyethylene oxide
compounds. The surfactants may also be polymeric surfactants which
are also described as wetting agents.
[0138] The amount of total surfactants used in aqueous compositions
of the invention is preferably at least .gtoreq.0.1%, more
preferably .gtoreq.1%, most preferably .gtoreq.3% and/or is
preferably no more than .ltoreq.11%, more preferably .ltoreq.9% and
most preferably .ltoreq.7% by weight of the autoxidisable vinyl
oligomer. Preferably a mixture of anionic and non-ionic surfactants
are used.
[0139] If the aqueous composition comprising anionic surfactant,
the anionic surfactant may comprise ethylene oxide (EO) groups in
an amount which is preferably no more than .ltoreq.90%, more
preferably .ltoreq.70%; most preferably .ltoreq.55% and/or is
preferably at least .gtoreq.10% and/or .gtoreq.20% EO groups by
weight of the surfactant. Preferred anionic surfactants comprise
sulphate, sulphonate, phosphate and/or phosponate groups.
[0140] The aqueous composition may comprise non-ionic surfactant in
an amount of preferably at least .gtoreq.0.1%, more preferably
.gtoreq.0.5%, still more preferably .gtoreq.1% and most preferably
.gtoreq.1.5% and/or preferably no more than .ltoreq.12%, more
preferably .ltoreq.9%, still more preferably .ltoreq.5% and most
preferably .ltoreq.3.5% by weight of vinyl oligomer solids.
[0141] Optionally to reduce the effect of cissing the composition
comprises ionic surfactant in an amount of at least preferably
.gtoreq.0.1%, more preferably .gtoreq.0.5%, still more preferably
.gtoreq.1% and most preferably .gtoreq.1.5% and/or no more than
preferably .ltoreq.12%, more preferably .ltoreq.9%, most preferably
.ltoreq.5% by weight of vinyl polymer solids.
[0142] Dispersants (such as dispersing compounds and/or dispersing
resin) which preferably are autoxidisable (such as W-3000 available
from Perstorp or as described in EP1870442) could also be employed
instead of or combined with more conventional surfactants.
Optionally where used the dispersant (such as a dispersing resin)
is present in amount of at least preferably .gtoreq.0.1%, more
preferably .gtoreq.3% and most preferably .gtoreq.5% and/or no more
than preferably .ltoreq.30%, more preferably .ltoreq.20% and most
preferably .ltoreq.12% by weight of solid resin.
[0143] The aqueous coating composition of the invention is
particularly useful as or for providing the principle component of
coating formulations (i.e. composition intended for application to
a substrate without further treatment or additions thereto) such as
protective or decorative coating compositions (for example paint,
lacquer or varnish) wherein an initially prepared composition
optionally may be further diluted with water and/or organic
solvents, and/or combined with further ingredients or may be in
more concentrated form by optional evaporation of water and/or
organic components of the liquid medium of an initially prepared
composition.
[0144] An organic solvent may optionally be added before, during
and/or after the polymerisation process for making the
autoxidisable vinyl oligomer to control the viscosity. Examples of
solvents include water-miscible solvents such as propylene glycol
based solvents, especially propylene glycol mono methyl ether and
dipropylene glycol mono methyl ether and glycol ethers such as
butyldiglycol. Optionally no organic solvents are added.
[0145] A co-solvent, as is well known in the coating art, is an
organic solvent employed in an aqueous composition to ameliorate
the drying characteristics thereof, and in particular to lower its
minimum film forming temperature. The co-solvent may be solvent
incorporated or used during preparation of the autoxidisable vinyl
oligomer or may have been added during formulation of the aqueous
composition.
[0146] The aqueous composition of the invention may have a
co-solvent content in an amount of at least preferably .gtoreq.2%,
more preferably .gtoreq.3.5%, and most preferably .gtoreq.5% and/or
no more than preferably .ltoreq.18%, more preferably .ltoreq.15%
and most preferably .ltoreq.9% by weight of oligomer solids. Most
preferably substantially no co-solvent is used as this gives
improved storage stability and a better ecological profile.
[0147] An advantage of the current invention is that co-solvent
can, as is often required for environmental and safety reasons, be
present at a very low concentrations because of the plasticising
nature of the autoxidisable oligomer.
[0148] Preferably the use of a nitrogen containing solvent is less
desired for reasons of toxicity profile, yellowing and odour.
[0149] In general, aromatic or heterocyclic nitrogen-containing
ligands or aromatic and aliphatic primary and secondary (di)amines
were found to prolong the drying time to a considerable extent (as
reported in Coordination Chemistry Reviews 249 (2005) 1709-1728).
An example includes heterocyclic nitrogen-containing solvents such
as N-methylpyrrolidone (NMP) and N-ethylpyrrolidone.
[0150] Preferably the aqueous coating composition comprises NMP in
an amount of no more than .ltoreq.13%, more preferably .ltoreq.10%,
most preferably .ltoreq.5% and especially .ltoreq.0.5% by weight of
oligomer solids.
[0151] Preferably the aqueous coating composition comprises only a
small amount of nitrogen containing molecules with an evaporation
rate .ltoreq.0.1, more preferably .ltoreq.0.05 (as calculated
below), the molecules being aromatic, heterocyclic or aliphatic
primary and secondary di-amines where the weight % of nitrogen is
.gtoreq.5% and more preferably .gtoreq.10%.
[0152] Preferably such nitrogen containing molecules are present in
the aqueous coating composition in an amount .ltoreq.13%, more
preferably .ltoreq.8%, most preferably .ltoreq.5% and especially
.ltoreq.0.5% by weight of oligomer solids.
[0153] Values for evaporation rates were published by Texaco
Chemical Company in a bulletin Solvent Data; Solvent Properties
(1990). These values are relative to the evaporation rate of
n-butyl acetate for which the evaporation rate is defined as 1.00.
Determination of evaporation rates of solvents not listed in this
bulletin is as described in ASTM D3539. Co-solvents with low
evaporation rates give undesired effects in the final coatings
resulting in slow hardness development acting as a plasticizer.
[0154] It is preferred to have <16% by weight of oligomer solids
of a co-solvent with an evaporation rate between 0.05 and
0.005.
[0155] Preferably when the aqueous composition is formulated as
paint, the composition comprises 2% to 10%, more preferably 3% to
9% of solvent by weight of the total paint composition. Preferably
at least 50%, more preferably .gtoreq.80%, most preferably
.gtoreq.95% by weight of the total solvent are solvent(s) having an
evaporation rate (as defined herein) higher than 0.012, more
preferably from 0.018 to 0.25, most preferably lower than 0.21.
[0156] The aqueous coating composition of the invention may be
applied to a variety of substrates including wood, board, metals,
stone, concrete, glass, cloth, leather, paper, plastics, foam and
the like, by any conventional method including brushing, dipping,
flow coating, spraying, and the like. They are, however,
particularly useful for providing coatings on wood and board
substrates. The aqueous carrier medium is removed by natural drying
or accelerated drying (by applying heat) to form a coating.
Accordingly in a further embodiment of the invention there is
provided a coating obtainable from an aqueous coating composition
of the present invention.
[0157] The aqueous coating composition of the invention may contain
other conventional ingredients including pigments, dyes,
emulsifiers, surfactants, plasticisers, thickeners, heat
stabilisers, levelling agents, anti-cratering agents, fillers,
sedimentation inhibitors, UV absorbers, antioxidants, dispersants,
reactive diluents, waxes, neutralising agents, adhesion promoters,
defoamers, co-solvents, wetting agents and the like introduced at
any stage of the production process or subsequently. It is possible
to include fire retardants like antimony oxide in the dispersions
to enhance the fire retardant properties.
[0158] Preferred reactive diluents (which may or may not be the
autoxidisable) may also have one or more of the following
properties: M.sub.n>1000 g/mol, more preferably >1500 g/mol
and most preferably >2000 g/mol; M.sub.n<5000 g/mol, more
preferably <4000 g/mol and especially <3500 g/mol; and/or
optionally (e.g. where the reactive diluent is autoxidisable) from
60 to 90 wt %, more preferably 75 to 90%, most preferably 80 to 90%
of fatty acid residues with an iodine value from 50 to 175, more
preferably from 80 to 150 gl.sub.2/100 g by weight of sample.
[0159] In particular, the aqueous coating compositions of the
invention and formulations containing them advantageously include
at least a drier salt. Drier salts are well known to the art for
further improving curing in unsaturated film-forming substances.
Generally speaking, drier salts are metallic soaps, that is salts
of metals and long chain carboxylic acids. It is thought that the
metallic ions effect the curing action in the film coating and the
fatty acid components confer compatibility in the coating medium.
Examples of drier metals are cobalt, manganese, zirconium, lead,
neodymium, lanthanum and calcium. The level of drier salt(s) in the
composition is typically that to provide an amount of metal within
the range of from 0.01 to 0.5% by weight based on the weight of
autoxidisable oligomer.
[0160] Drier salts are conventionally supplied as solutions in
solvents for use in solvent-borne alkyd systems. They may, however,
be used quite satisfactorily in aqueous coating compositions since
they can normally be dispersed in such systems fairly easily. The
drier salt(s) may be incorporated into the aqueous coating
composition at any convenient stage. For example the drier salt(s)
may be added prior to dispersion into water. Drier accelerators may
be added to the drier salts. Suitable drier accelerators include
2,2'-bipyridyl and 1,10-phenanthroline.
[0161] In an embodiment of the present invention there is provided
an aqueous autoxidisable coating composition with reduced
telegraphing as defined herein comprising an autoxidisable vinyl
oligomer obtained by a process comprising steps:
[0162] I) polymerising ethylenically unsaturated vinyl monomers
comprising: [0163] i) 30% to 70% of at least one monomer G selected
from hydroxylalkyl(meth)acrylates and epoxy functional vinyl
monomers; [0164] ii) 30% to 70% of at least one other ethylenically
unsaturated vinyl monomer; and [0165] iii) <1% of chlorine
containing monomers; [0166] where the percentages are by weight of
total monomers;
[0167] II) reacting the oligomer obtained in step I) with fatty
acids having an average iodine value in the range of 80 to 180
gl.sub.2/100 g fatty acid; [0168] wherein the autoxidisable vinyl
oligomer comprises by weight of oligomer: 35% to 62% of polymeric
backbone; and 38% to 65% of fatty acid residue; and [0169] where
the autoxidisable vinyl oligomer has: [0170] i) a T.sub.g from
-50.degree. C. to 15.degree. C.; [0171] ii) a M.sub.w from 6500 to
25000 g/mol; and [0172] iii) a PDi from 2 to 8; [0173] said
composition having [0174] a) a co-solvent content .ltoreq.15% by
weight of solids; [0175] b) a N-methylpyrrolidone content
.ltoreq.13% by weight of solids; [0176] c) heterocyclic amine
containing solvent content of 0 wt % by weight of solids; [0177] d)
a solids content .gtoreq.38% by weight of the composition; [0178]
e) a pH from 4.1 to 8.4. [0179] and [0180] where said composition
when in the form of a film has a telegraphing value (as defined
herein) or less than 10 gloss units and optionally the film has a
tack free time <6 hours.
[0181] In an another embodiment of the invention there is provided
an aqueous emulsion coating composition with a telegraphing value
(as defined herein) of less than 10 gloss units, said composition
comprising: [0182] i) 38% to 65% of the autoxidisable vinyl
oligomer described herein; [0183] ii) 0 to 20%, more preferably 0
to 15%, most preferably 0 to 10% and especially 0 to 5% of
co-solvent; and [0184] iii) 15% to 58% of water; [0185] where all
percentages are by weight of the composition and
i)+ii)+iii)=100%.
[0186] In another embodiment of the invention there is provided an
aqueous emulsion coating composition with a telegraphing value (as
defined herein) of less than 10 gloss units said composition
comprising: [0187] i) 20% to 45%, preferably 25 to 40%, of
TiO.sub.2; [0188] ii) 20% to 45%, preferably 25 to 40%, of the
autoxidisable vinyl oligomer as described herein; [0189] iii) 0 to
10%, preferably 0 to 5%, of co-solvent; [0190] iv) 0.1% to 3% of
thickener; [0191] v) 0 to 5% of dispersing agent; and [0192] vi)
25% to 60% water; [0193] where all percentages are by weight of the
composition and i)+ii)+iii)+iv)+v)=100%.
[0194] If desired the aqueous dispersion of the invention can be
used in combination with other polymer dispersions or
solutions.
[0195] Preferably such other dispersions or solutions comprise less
than or equal to 35%, more preferably .ltoreq.20%, most preferably
.ltoreq.10% and especially preferably .ltoreq.4% by weight of the
total autoxidisable vinyl oligomer.
[0196] Preferably the aqueous coating composition when coated onto
a substrate is water resistant, in the tests as described herein,
for 30 minutes, more preferably for 1 hour and most preferably for
3 hours.
[0197] Preferably the aqueous coating composition when coated onto
a substrate is block resistant in the tests as described herein at
ambient temperature with a rating of 3 or more preferably at
52.degree. C. with a rating of 3 or more.
[0198] Preferably the aqueous coating composition is a one
component system, meaning that preferably no additional
crosslinking agents, like polyaziridines, polycarbodiimides or
polyisocyanates or melamines are added to the aqueous coating
composition, prior to applying the composition to a substrate.
[0199] Preferably the aqueous coating composition is free from
photoinitiators and is cured without the use of radiation curing
equipment.
[0200] A further aspect of the invention provides a coating
obtained and/or obtainable by a coating composition of the
invention and having a telegraphing value (as defined herein) of
less than 10 gloss units.
[0201] Another aspect of the invention provides a substrate coated
with a coating of the invention.
[0202] A still other aspect of the invention provides a method of
coating a substrate comprising the steps of i) applying a coating
composition of the invention to the substrate; ii) drying the
substrate to form a coating thereon; where the coating has a
telegraphing value (as defined herein) of less than 10 gloss
units.
[0203] Yet another aspect of the invention provides use of an
autoxidisable vinyl polymer and/or a coating composition of the
invention for the purpose of obtaining coatings having a
telegraphing value (as defined herein) of less than 10 gloss
units.
[0204] A still yet other aspect of the invention provides a method
of manufacture of an autoxidisable vinyl polymer and/or a coating
composition of the invention for the purpose of obtaining coatings
having a telegraphing value (as defined herein) of less than 10
gloss units.
[0205] Many other variations embodiments of the invention will be
apparent to those skilled in the art and such variations are
contemplated within the broad scope of the present invention.
Further aspects of the invention and preferred features thereof are
given in the claims herein.
[0206] The present invention is now illustrated by reference to the
following non-limiting examples. Unless otherwise specified, all
parts, percentages and ratios are on a weight basis. The prefix C
before an example denotes that it is comparative. The term
"working" means that the example is according to the invention. The
term "non-working" means that it is not according to the invention
(i.e. comparative).
[0207] Various registered trademarks, other designations and/or
abbreviations are used herein to denote some of ingredients used to
prepare polymers and compositions of the invention. These are
identified below by chemical name and/or trade-name and optionally
their manufacturer or supplier from whom they are available
commercially. However where a chemical name and/or supplier of a
material described herein is not given it may easily be found for
example in reference literature well known to those skilled in the
art: such as: `McCutcheon's Emulsifiers and Detergents`, Rock Road,
Glen Rock, N.J. 07452-1700, USA, 1997 and/or Hawley's Condensed
Chemical Dictionary (14th Edition) by Lewis, Richard J., Sr.; John
Wiley & Sons. [0208] `AIBN` denotes azobisisobutyronitrile;
[0209] `Additol VXW4940` denotes the drying pigment commercially
available from Elementis under this trade name; [0210] `Atlas
G5000` denotes the nonionic polyalkylene glycol ether available
commercially from Uniqema under this trade designation; [0211] `BA`
denotes n-butyl acrylate [0212] `3,5-BHT` denotes
3,5-di-tert-butyl-4-methylphenol (also known as butyl hydroxy
toluene); [0213] `BMA` denotes n-butylmethacrylate; [0214] `CoF`
denotes the catalyst Co II (bis 4,4'-dimethylbenzil dioxime)
diborondifluoride, as described in EP1742973-A, US2007219328 and
WO2005105855; [0215] `Dehydran 1293; denotes a solution of a
special modified polydimethyl siloxane defoamer that is
commercially available from Cognis under this trade name; [0216]
`Disperbyk 190" denotes that a solution of a high molecular weight
block copolymer with pigment affinic groups that is a dispersing
additive for pigments that is commercially available from BYK
Chemie under this trade name; [0217] `Dow PnP` denotes that
propylene glycol n-propyl ether mixture commercially available from
Dow Chemicals under the trade name Dowanol PnP; [0218] `dtAP`
denotes di-tert-amylperoxide [0219] `dtBP` denotes
di-tert-butylperoxide [0220] `FES77` denotes the dispersant which
is a sodium salt of a fatty alcohol gycol ether sulphate and is
available commercially from Cognis under the trade name Disponil
FES 77; [0221] `FES993` denotes the dispersant which is a sodium
salt of a fatty alcohol gycol ether sulphate and is available
commercially from Cognis under the trade name Disponil FES 993 IS;
[0222] `GMA` denotes glycidyl methacrylate; [0223] `HHPA` denotes
hexahydro phtalic anhydride; [0224] `Kronos 2190` denotes a
titantium dioxide pigment commercially available from Kronos under
this trade name; [0225] `MMA` denotes methyl methacrylate; [0226]
`MSA` denotes methane sulphonic acid [0227] `PAA` denotes a
conventional polyacrylic acid with weight average molecular weight
(Mw) of from 200-250 KDalton which has been prepared by the
applicant; [0228] `PVC` denotes polyvinyl chloride [0229] `Sefose`
denotes a soyate made from partially hydrogenated soybean oil which
is commercially available from P&G Chemicals under the trade
name Sefose 1618SC, [0230] `Sun-FA` denotes sunflower fatty acid;
[0231] `tBP` denotes tert-butyl peroxide [0232] `tBPD` denotes
t-butyl peroxybenzoate [0233] `TEA` denotes triethyl amine; [0234]
`THF` denotes tetrahydrofuran; and [0235] `TRAP` denotes triphenyl
ethyl phosphonium bromide.
Test Methods:
Standard Conditions
[0236] As used herein, unless the context indicates otherwise,
standard conditions (e.g. for drying a film) means a relative
humidity of 50%.+-.5%, ambient temperature (23.degree.
C)..+-.2.degree. and an air flow of .ltoreq.0.1 m/s.
Particle Size
[0237] The particle sizes given herein are the size of a weight
averaged particle and are quoted as a linear dimension which is a
particle diameter as the particles can be considered to be
essentially spherical. Weight average particle size may be measured
using Scanning/Transmission Electron Microscope and Photon
Correlation Spectroscopy.
Iodine Number
[0238] The iodine value (also referred to herein as iodine number)
is a measure of the amount of ethylenic unsaturated double bonds in
a sample and increases with a greater degree of unsaturation.
Iodine value may be defined according to DIN 53241-1 as the
quotient of that mass m.sub.I of iodine which is added on to the
olefinic double bonds, with decolourisation, of a sample to be
analysed and the mass m.sub.B of this sample (mass of the solid in
the sample in the case of solutions or dispersions). Iodine values
may be quoted either in units of centigrams of iodine per gram of
sample (cg I.sub.2/g) or in units of grams of iodine per 100 gram
of sample (g I.sub.2/100 g). Standard methods for analysis may be
used such as for example ASTM D5768-02(2006) and DIN 53241. One
common method (and that used to measure the iodine values given
herein) is the Wjjs method in which iodine absorption is determined
by titrating unreact reagent with sodium thiosulfate and the iodine
value is then calcuated as follows:
Iodine value = ( 12.69 ) .times. ( ml of thiosulfate ) .times. (
normality ) mass of sample ( g ) ##EQU00001##
Telegraphing
[0239] Two types of PVC substrates are used to determine the degree
of telegraphing of an unpigmented coating comprising the
autoxidisable resin:
[0240] The first PVC type is the 2 mm thick rough PVC substrate
with a well defined and uniform rough surface that is available
commercially from Vink Kunststoffen B.V (Didam, Holland) under the
trade name Vikupor white PVC film type JD11. An area of
1.9.times.2.5 mm of the substrate surface is analysed with a Wyko
optical profilometer NT1100 at a magnification of 2.5 to give
R.sub.z=25 .mu.m.+-.5 .mu.m. R.sub.z denotes the `ten-point
height`, which is the average of the five greatest peak-to-valley
separations in the scanned area, and is regarded as a general value
for surface roughness. The second PVC type is a 3 mm thick smooth
PVC substrate with a well defined smooth surface that is also
available commercially from Vink Kunststoffen under the trade name
Vikunyl white PVC film glossy type 206221. R.sub.z=1 .mu.m.+-.0.25
.mu.m. (measured as for rough PVC).
[0241] The unpigmented coating comprising (optionally comprising
flow and wetting agents and thickeners if needed) is cast on both
PVC substrates (rough and smooth) and a smooth and defect free film
is obtained, resulting in a theoretical dry film thickness between
52 .mu.m.+-.6 .mu.m. The film is dried under standard conditions
for 24 hours and the gloss is measured at a 20.degree. angle. This
gloss measurement is repeated after 4 days, 7 days and 14 days. The
difference in gloss readings between the films on rough and smooth
PVC is a quantitative measure of the extent to which the rough
surface of the PVC is telegraphed to the surface of the dried
coating. The smaller the difference in these gloss values, the
smaller the degree of telegraphing and the better the coating hides
the substrate roughness.
[0242] Also the absolute value for gloss reading on rough PVC
should not decrease significantly in time so that the reduced
telegraphing is maintained.
Drying Time:
[0243] To test the dust-free and tack-free drying times of the
compositions prepared in the Examples as described below, the
compositions are formulated and applied to a glass plate at a wet
film thickness of 80 .mu.m. Tests for drying times are performed at
regular time intervals under standard conditions.
Dust-Free Time:
[0244] The dust-free time (DFT) is determined by dropping a piece
of cotton wool (about 1 cm.sup.3 i.e. 0.1 g) on to the drying film
from a distance of 25 cm. If the piece of cotton wool can
immediately be blown from the substrate by a person without leaving
any wool or marks in or on the film, the film is considered to be
dust-free.
Tack-Free Time:
[0245] The tack-free time (TFT) is determined by placing a piece of
cotton wool (about 1 cm.sup.3, 0.1 g) on the drying film and
placing a weight of 1 kg onto the piece of cotton wool (for 10
seconds). If the piece of cotton wool can be removed from the
substrate by hand without leaving any wool or marks in or on the
film, the film is considered to be tack-free.
Blocking Test
[0246] A 100 .mu.m thick wet film is cast on a Leneta chart and
dried for 24 hours under standard conditions. Resistance to
blocking is determined using a block tester, where pairs of the
coated test charts are placed with the film coatings face to face
and left at ambient temperature for 4 hours or left at 52.degree.
C. for 2 hours with a pressure of 250 g/cm.sup.2. After cooling to
ambient temperature (if applicable), the test charts are peeled
apart and the degree of block resistance is assessed, ranging from
0 (very poor blocking resistance) to 5 (excellent blocking
resistance). When the test charts can be peeled apart using minor
force without damaging the surface of the film, blocking is
assessed as 3.
Measurement of Film Yellowing:
[0247] The yellowing of a coating exposed to daylight or darkness
for a specified time period is determined using a Dr Lange
Spectropen. The equipment is calibrated to the defined values of
the calibration plate and then the b-value is measured according to
the CIE L, a, b method. The dark-yellowing is defined as the
increase in the yellowness (.DELTA.b) of the coating during storage
at 52.degree. C., in the dark for 21 days.
Molecular Weight Determination:
[0248] Gel permeation chromatography (GPC) analysis for the
determination of polymer molecular weights are performed on an
Alliance Waters 2695 GPC with three consecutive PL-gel columns
(type Mixed-B, l/d=300/7.5 mm) using tetrahydrofuran (THF, HPLC
grade, stabilized with 3,5-di-tert-butyl-4-hydroxytoluene [BHT],
preferably with 1.0 vol. % acetic acid) as the eluent at 1
cm.sup.3/min and using an Alliance Waters 2410 refractive index
detector. A set of polystyrene standards (analysed according to DIN
55672) are used to calibrate the GPC. Samples corresponding to
about 16 mg of solid material are dissolved in 8 cm.sup.3 of THF.
The samples are regularly shaken and dissolved for at least 24
hours for complete "uncoiling" and placed on the auto-sampling unit
of the Alliance Waters 2695. The injection volume is 150 .mu.L and
the temperature of the column oven is established at 35.degree.
C.
Glass Transition Temperature (T.sub.g)
[0249] The T.sub.g is measured by DSC using the TA Instruments DSC
Q1000 with standard TA Instruments alumina cups of 50 .mu.l. The
flow rate is 50 ml/min of nitrogen and the sample is loaded at
ambient temperature. The sample is cooled until it reached an
equilibrium temperature of -90.degree. C. and then heated at a rate
of 10.degree. C./min to 100.degree. C., kept for 5 minutes at
100.degree. C., cooled to -90.degree. C. at a rate of 20.degree.
C./min, kept for 5 minutes at -90.degree. C. and subsequently
heated at a rate of 10.degree. C./min to 100.degree. C.
[0250] The T.sub.g values in the Examples and Tables herein are the
midpoint as measured by DSC as described above.
Water Resistance:
[0251] A 100 .mu.m thick wet film is cast on a Leneta chart and
dried for 24 hours under standard conditions. Then three drops of
water are placed on the film and one drop of water is removed after
30 minutes, one after 1 hour and one after 3 hours. The water
resistance is assessed immediately after removal of the water and
then after 24 hours. The rating for water resistance is from:
0=very poor, dissolved; 3=acceptable; 5=excellent, no damage of the
coating.
Gloss Measurement Method:
[0252] Gloss measurements are carried out on a BYK Gardner
micro-TRI-gloss 20-60-85 gloss meter in accordance with ASTM
D523-89.
[0253] The examples herein are prepared by the following common
method modified as indicated in the tables with reference to each
of the alphanumeric labels given below.
Common Method
Step (A1) Preparing an Epoxy Functional Vinyl Polymer (Alternative
1)
[0254] In one alternative (A1) of step a round bottom reaction
vessel (VOL) equipped with a stirrer, baffle and cooler, is loaded
with water (a), Na.sub.2SO.sub.4 (b) and PAA (c) in a nitrogen
atmosphere. The mixture is neutralized with NaOH until the pH is
>8 and the mixture temperature is brought to 60.degree. C. A
homogeneous mixture of MMA (d), BMA (e), GMA (f), AIBN (g) and CoF
(h) is transferred to the reactor and the reaction temperature is
brought to 80.degree. C. After time t1 a mixture of FES993 (i) and
water (j) is added to the reactor. After time t2 the temperature is
raised to 85.degree. C. and is held there for 60 minutes. The
reaction vessel is then cooled to ambient temperature and polymer
beads are obtained that are washed and dried for use in the next
step (B).
[0255] The polymer obtainable in this step (A1) is characterised as
follows:
M.sub.n=k, M.sub.w=l, PDi=m, T.sub.g=n.
Step (A2) Preparing an Epoxy Functional Vinyl Polymer (Alternative
2)
[0256] A round bottom, optionally high pressure where specified
herein, reactor (VOL'), equipped with stirrer and cooler, is loaded
under nitrogen with a solvent (SOL1, a') and heated to T'1. A
homogeneous mixture of styrene (b'), GMA (c'), BA (dd'), BMA (d'),
d-BP (e') and t-BPB (f') is fed to the reactor using a pump over
time t'1 at pressure (g').
[0257] Optionally after the ingredients have been added to the
reactor the pump is rinsed with more solvent (SOL1, h'), and the
reactor is then heated to T'2 for time t'2, cooled to T'3 and then
dtAP (i') is added in small portions over time t'3.
[0258] The mixture is held at 140.degree. C. for time t'4 and then
the reactor is cooled to ambient temperature. Optionally further
solvent is added (SOL1, j')
[0259] The polymer obtainable in this step (A2) is characterised as
follows:
Solid content=k', M.sub.n=l', M.sub.w=m', PDi=n'
Step (B) Preparing an Aqueous Autoxidisable Vinyl Polymer
[0260] An amount (p) of vinyl polymer prepared as described in the
common method step (A1 or A2) above is dissolved in a solvent
(SOL2, q). SunFA (r) and TRAP (s) are added to the resulting
solution to form a mixture which is heated at 120.degree. C. under
nitrogen. The reaction is continued until an acid value (t) is
reached.
[0261] SOL2 is removed by distillation under reduced pressure and
the polymer obtained is characterised as follows:
M.sub.n=u, M.sub.w=v, PDi=w, T.sub.g=x.
Step (C) Dispersing Vinyl Polymer Obtainable from Step (B)
[0262] To an amount (y) of a polymer prepared as described in the
common method step (B) is added Atlas G5000 (z), ALES (aa) and
Ingredient1 (IGD1, ab). Then water (ac) is added slowly to form a
dispersion which is stirred for 30 minutes before being stored
under nitrogen. The dispersion is characterised as follows:
solids content=ad, pH=pH2, ND.times.AV=ae
[0263] All the examples were prepared as described in the common
methods with reference to the data in the Tables (as shown below).
In the Tables NM indicates a parameter is not measured and NA that
that parameter is not applicable to that example.
[0264] The properties of coatings made from the examples and
pigment pastes PP1 prepared by mixing the ingredients as indicated
in Table 7 are also tested and the results given in Table 8
below.
TABLE-US-00001 TABLE 1 Common method Step A - Alternative 1 -
Process conditions Item Vessel Rtn. Add. size Water
Na.sub.2SO.sub.4 PAA MMA BMA GMA AIBN CoF time FES993 water time
Units litres grams grams grams grams grams grams grams grams mins
grams grams mins Label Ex VOL a b c d e f g h t1 l j t2 C1a 2 867.8
1.59 0.79 381.59 0 254.39 4.77 0.01 45 0.53 79.50 15 C2a 2 867.8
1.59 0.79 190.79 159.00 286.19 4.77 0.006 60 0.53 79.50 15 Ex 1a 2
867.8 1.59 0.79 190.79 127.19 317.99 4.77 0.064 90 0.53 79.50 10 Ex
2a 10 4911.75 9.00 4.47 1076.36 719.90 1799.82 27.00 0.36 105 3.00
449.97 10 Ex 3a 10 4932.00 8.94 4.44 1073.21 715.48 1788.69 26.83
0.36 90 2.98 447.19 10
TABLE-US-00002 TABLE 2 Common method Step A - Alternative 1 -
Characterization of product Item M.sub.n M.sub.w PDi T.sub.g Units
g/mol g/mol none .degree. C. Ex Label k l m n C1a 4991 22107 4.43
97 C2a 19048 39989 2.1 71 Ex1a 1736 3589 2.07 24 Ex2a 2221 4943
2.23 37 Ex3a 2081 4256 2.04 34
TABLE-US-00003 TABLE 3a Common method Step A - Alternative 2 -
Process conditions Item High pressure Solvent Solvent Mix Reactor
vessel name amount temp Stryene GMA BA BMA dtBP tBPB feed time
Pressure Units none None grams .degree. C. grams Grams grams grams
grams grams hours bar Label Ex none SOL1 a' T'1 b' c' dd' d' e' f'
t'1 g' C3a NO Xylene 219.99 140 319.59 213.06 0 0 27.33 20.03 4 1
Ex 4a YES Toluene 500.0 150 0 475.3 475.3 0 38.0 0 2.5 2.8
TABLE-US-00004 TABLE 3b Item Reactor More heat Further Reactor cool
Further Solvent temp reaction time temp dtAP dtAP time Hold time
Solvent Units Grams .degree. C. mins .degree. C. grams hours mins
grams Label Ex h' T'2 t'2 T'3 i' t'3 t' j' C3a 0 NA 0 NA 0 0 120 0
Ex 4a 20.0 150 30 140 38.0 2 90 101.04
TABLE-US-00005 TABLE 4 Common method Step A - Alternative 2 -
Characterization of product Item Solids M.sub.n M.sub.w PDi Units %
g/mol g/mol none Ex Label k' l' m' n' C3a NM 3123 7497 2.4 Ex4a
60.0 2548 7720 3.0
TABLE-US-00006 TABLE 5 Common method Step B Item Polymer Solvent
Solvent from A name amount SunFA TRAP AN M.sub.n M.sub.w PDi
T.sub.g Units grams none grams grams grams mg KOH/g g/mol g/mol
none .degree. C. Label Ex p SOL2 q r s t u v w x C1b 500.0 Toluene
300.34 397.06 3.97 5.9 5856 43337 7.4 26 C2b 500.0 Toluene 344.45
531.33 5.31 14.0 44460 233091 5.24 4 C3b 678.0 Xylene 0 450.0 4.5
13.6 3383 13533 4.0 -14 Ex 1b 500.0 Toluene 332.59 492.85 4.93 5.7
2736 7662 2.8 -12 Ex 2b 550.0 Toluene 365.85 542.13 5.42 10.2 2531
11052 4.4 -13 Ex 3b 1000.0 Toluene 665.18 985.70 9.86 8.9 3601 9044
2.51 -16 Ex 4b 583.3 Toluene 0 342.0 3.42 4.3 2331.95 19122 8.2 -44
When q is 0 this means solvent is present from the previous step
(which is removed as described) but no more solvent added in this
step
TABLE-US-00007 TABLE 6 Common method Step C Item Ingredient
Ingredient Polymer from B Atlas G5000 FES77 Name Amount water
solids pH Units grams grams grams None grams grams % none Label Ex
y z aa IGD1 ab ac ad pH 2 C1c 97.0 2.43 11.76 None 0 76.6 55 5.4
C2c 100.8 2.52 12.22 Dow PnP 10.08 98.03 52.4 6.3 C3c 112.0 2.8
13.58 None 0 88.5 45 5.0 Ex 1c 117.0 2.93 14.18 DowPnP 23.90 118.89
45 6.0 Ex 2c 100.0 2.50 12.12 Sefose 20.00 95.38 55 5.9 Ex 3c 500.0
12.50 60.61 None 0 395.08 55.6 6.6 Ex 4c 100.07 2.50 12.13 None 0
79.07 55.0 5.5
TABLE-US-00008 TABLE 7 Composition pigment paste PP1 Compound
Pigment paste PP1 Water 4.8 Dehydran 1293 0.4 Disperbyk 190 0.7
Kronos 2190 24.1
TABLE-US-00009 TABLE 8 Application properties of water-based
binders Ex Ex 1 Ex 2 C1 C2 C3 Ex 1 pigment Ex 2 pigment Ex 3 Ex 4
Binder (wt %) 100 100 100 100 70 100 70 100 100 Particle size [nm]
985 555 370 265 n.a. 320 n.a. 380 354 Additol VXW4940/water 1:1 2.2
2.2 1.8 1.8 1.4 2.2 1.4 2.2 2.2 PP1 (wt %) -- -- -- -- 30 -- 30 --
-- DFT [hr] 1 0.25 1.5 1 1 2 1 2 TFT [hr] 2 0.75 7 3 2 3.5 2 3.5
G(s) 81.6 73.5 70.1 78.2 76.6 73.8 79.7 82.4 78.4 G(r) 40.0 19.1
59.3 77.6 72.7 72.6 77.3 78.3 72 Telg. 41.6 54.4 10.8 0.6 3.9 1.2
2.4 4.1 6.4 G decay (4 d) 1.9 3.4 10.1 4.2 2.4 0.8 0.2 2.1 9.8 G
decay (7 d) 1 3.6 13.5 4.6 4.4 5.7 3.9 4.3 13.9 G decay (14 d) 4.6
4.2 26.3 9.3 4.7 9.4 8.0 9.2 28.3 Initial yellowness [.DELTA.b] 3.8
3.1 4.5 4.7 1.0 3.4 2.2 3.8 3.7 Dark yellowing .DELTA.b 6.6 14.6
21.4 6.1 5.7 9.2 3 wks 52.degree. C. Water resistance 30 min after
recovery n.d. n.d. n.d. 5/5 4/5 n.d. 4/5 n.d. n.d. 1 hr after
recovery n.d. n.d. n.d. 4.5/5 3/5 n.d. 3/5 n.d. n.d. 3 hrs after
recovery n.d. n.d. n.d. 4/5 1/5 n.d. 2/5 n.d. n.d. Blocking 4 hrs
at amb. temp. n.d. n.d. n.d. n.d. 4.5 n.d. 4 n.d. n.d. 2 hrs at
50.degree. C. n.d. n.d.. n.d.. n.d. 4 n.d. 3 n.d.. n.d.. KEY FOR
TABLE 6 `DFT` denotes dust free time defined and measured as
described herein `TFT` denotes tack free time defined and measured
as described herein `G(r)` denotes the initial rough gloss value as
defined herein (measured in gloss units 1 day after film formation)
`G(s)` denotes the initial smooth gloss value as defined herein
(measured in gloss units 1 day after film formation) `Telg.`
denotes the telegraphing value as defined herein in gloss units
(i.e. G(s).sub.- G(r)) `G decay (`n` d)` denotes the gloss decay
value as defined herein after `n` days (i.e. G(r) minus the rough
gloss measured `n` days after film formation).
* * * * *