Aqueous high gloss emulsion paint with long open time

Details Aqueous high gloss emulsion paint with long open time Aqueous high gloss emulsion paint with long open time

2001-03-08

2003-08-26

Wu, David W. (Department: 1713)

Synthetic resins or natural rubbers -- part of the class 520 ser

Synthetic resins

At least one aryl ring which is part of a fused or bridged...

C526S320000, C526S317100, C526S318400, C428S463000, C525S296000, C525S303000

Reexamination Certificate

active

06610776

ABSTRACT:

The present invention relates to the use of an aqueous emulsion paint having a pigment content of from 40 to 200 parts by weight per 100 parts by weight of polymer to coat buildings or building parts, wherein said polymer comprises an emulsion copolymer containing
from 0.5 to 30% by weight of monomers of the formula I
where R
1
is a hydrogen atom or a methyl group, X is a divalent organic polyalkylene oxide group comprising from 1 to 50 alkylene oxide units, and R
2
is a hydrogen atom or an aliphatic or aromatic hydrocarbon group having 1 to 20 carbon atoms.
The invention further relates to the use of the above emulsion copolymer as a binder for emulsion paints, especially high gloss emulsion paints.
EP-A-37150 discloses aqueous high gloss emulsion paints whose binder comprises an emulsion copolymer based on acrylates, styrene. Polymerization takes place in the presence of an emulsifier having from 60 to 100 ethylene oxide groups. The emulsifier may also be copolymerizable.
EP-A-389179 discloses aqueous dispersions of emulsion copolymers of two-stage construction. Attached to the copolymers, in particular to the core of the copolymer particles, are alkylene oxide chains. Use is made of amphiphilic compounds, e.g., long chain unsaturated alcohols whose alcohol group is alkoxylated, in particular ethoxylated.
EP-A-661306 describes emulsion copolymers for the coating of plastics surfaces, which comprise ethoxylated (meth)acrylic esters. The coating obtained has improved performance properties, in particular an improved chemical resistance.
For the processing of emulsion paints, especially high gloss emulsion paints, it is important to maximize the open time. The open time is the time within which the emulsion paint remains processible so that irregularities in the surface of the coating following application to substrates can still be retouched. The open time possesses particular significance in connection with substrates of large surface area, such as in the construction industry, for example. In the case of coatings on building parts, e.g., internal walls, wood paneling, etc., a uniform appearance is a particular requirement. To achieve this, it must be possible to retouch and adapt the coating for as long as possible after the entire area or part thereof has been completed.
It is an object of the present invention to provide emulsion paints, especially high gloss emulsion paints, having an open time which is as long as possible.
We have found that this object is achieved by the emulsion paint defined at the outset.
Essential constituents of the aqueous emulsion paint used in accordance with the invention include a polymer as binder, and a pigment.
The polymer comprises an emulsion copolymer containing from 0.5 to 30% by weight of monomers of the formula I.
The emulsion copolymer preferably contains at least 1% by weight, with particular preference at least 2% by weight, of monomers of the formula I. In general, the amount of monomers I need not exceed 20% by weight, in particular 15% by weight, in order to achieve the desired properties, in particular a long open time.
In the formula I, X is preferably a polyalkylene oxide group comprising ethylene oxide units, propylene oxide units, or mixtures of ethylene oxide and propylene oxide units. Ethylene oxide units and propylene oxide units may alternate, for example, or may be present in the form of polyethylene oxide and/or polypropylene oxide blocks.
The polyalkylene oxide group preferably comprises not more than 40, with particular preference not more than 30, with very particular preference not more than 20, alkylene oxide units.
The polyalkylene oxide group preferably comprises at least two, in particular at least 3, and with very particular preference at least 4, alkylene oxide groups.
The radical R
2
is preferably a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms; with particular preference, R
2
is a C
1
to C
8
alkyl group, in particular a C
1
to C
4
alkyl group, or a hydrogen atom.
Particularly preferred monomers of the formula I are, for example, compounds of the formula II
where R
1
and R
2
are as defined above in their preferred definitions and n is an integer from 1 to 20, in particular from 3 to 15, and with particular preference from 4 to 12.
Preferably, the emulsion copolymer comprises in total
a) from 40 to 99.5% by weight of principal monomers selected from
 C
1
to C
18
alkyl (meth)acrylates, vinylaromatic compounds having up to 20 carbon atoms, vinyl esters of carboxylic acids having 1 to 20 carbon atoms, vinyl halides, vinyl ethers, ethylenically unsaturated nitriles, nonaromatic hydrocarbons having 2 to 8 carbon atoms and 1 or 2 double bonds,
b) from 0.5 to 30% by weight of monomers of the formula I,
c) from 0 to 50% by weight of further monomers.
With particular preference, the emulsion copolymer comprises
a) from 50 to 98% by weight of principal monomers,
b) from 2 to 20% by weight of monomers of formula I, and
c) from 0 to 40% by weight of further monomers.
With very particular preference, the emulsion copolymer comprises
a) from 60 to 97% by weight of principal monomers,
b) from 3 to 15% by weight of monomers of formula I, and
c) from 0 to 30% by weight of further monomers.
Examples of principal monomers are C
1
-C
8
alkyl (meth)acrylates such as methyl methacrylate, methyl acrylate, n-butyl acrylate, ethyl acrylate, and 2-ethylhexyl acrylate.
In particular, mixtures of the alkyl (meth)acrylates are also suitable.
Vinyl esters of carboxylic acids having 1 to 20 carbon atoms are, for example, vinyl laurate, vinyl stearate, vinyl propionate, versatic acid vinyl ester, and vinyl acetate.
Suitable vinylaromatic compounds include vinyltoluene, &agr;- and p-methylstyrene, &agr;-butylstyrene, 4-n-butylstyrene, 4-n-decylstyrene and, preferably, styrene.
Examples of nitriles are acrylonitrile and methacrylonitrile.
The vinyl halides are ethylenically unsaturated compounds substituted by chlorine, fluorine or bromine, preferably vinyl chloride and vinylidene chloride.
Examples of vinyl ethers include vinyl methyl ether or vinyl isobutyl ether. Preference is given to vinyl ethers of alcohols containing from 1 to 4 carbon atoms.
Hydrocarbons having 2 to 8 carbon atoms and one or two olefinic double bonds that may be mentioned include butadiene, isoprene and chloroprene; those having one double bond are, for example, ethene or propene.
Preferred principal monomers are the alkyl (meth)acrylates, especially the C
1
-C
8
alkyl (meth)acrylates, vinylaromatic compounds having up to 20 carbon atoms, especially styrene, and mixtures of the aforementiond monomers.
Further monomers are, for example, hydroxyl-containing monomers, especially C
1
-C
10
hydroxyalkyl (meth)acrylates, (meth)acrylamide, ethylenically unsaturated acids, especially carboxylic acids, such as (meth)acrylic acid or itaconic acid, and their anhydrides, dicarboxylic acids and their anhydrides or monoesters, examples being maleic acid, fumaric acid, and maleic anhydride.
The emulsion copolymer preferably has a glass transition temperature Tg of less than 30° C., with particular preference less than 25° C.
In particular, the Tg is, for example, from −20 to +20° C., with particular preference from 0 to 20° C., and with very particular preference from 10 to 20° C.
The glass transition temmperature T
g
here is the midpoint temperature determined by differential thermal analysis (DSC) in accordance with ASTM D 3418-82 (cf. Ullmann's Encyclopedia of Industrial Chemistry, 5th Edition, Volume A 21, VCH Weinheim 1992, p. 169 and also Zosel, Farbe und Lack 82 (1976), pp. 125-134; see also DIN 53765).
According to Fox (see Ullmanns Enzyklopädie der technischen Chemie, 4
th
edition, Volume 19, Weinheim (1980), p. 17, 18) it is possible to estimate the glass transition temperature T
g
. For the glass transition temperature of copolymers with little or no crosslinking, at high molecular masses, it is the case in good approximation that:
1
T
g
=
X
1
Tg
1
+
X
2
Tg
2
+
…
⁢
 
⁢
X
n
Tg
n
where X
1
, X
2

Affiliated with

Also associated with

Rating

Aqueous high gloss emulsion paint with long open time does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Aqueous high gloss emulsion paint with long open time, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Aqueous high gloss emulsion paint with long open time will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3080313