Note: Descriptions are shown in the official language in which they were submitted.
r~
BASF Aktiengesellschafk O. ~, 0050/40756
NON-AOUEOUS SY~rH~TIC RESIN COMPOStTIONS
s The present invention relates to non-aqueous synthetic resin composi-
tions essentially comprising
A)
from 20 to 95% w/w of at least one synthetic resin composed of
a)
from 90 to 99.95% w/w of at least one acrylate and/or
methacrylate of an alkanol containing from 1 to 12
carbon atoms,
b)
from 0.05 to 10% w/w of at least one monomer of the
general formula I
CH2=CI-C-O-R2-N=C=O I,
Rl
in which the variables have the following meanings:
Rl
hydrogen or methyl
R2
a hydrocarbon chain having up to 12 C-atoms, which
may be interrupted at one or more points by oxygen,
and
c)
from 0 to 10% w/w of one or more ethylenically unsatu-
~o rated monomers capable of undergolng radical copoly-
merization,
and
B)
from 5 to 80% w/w of at least one inorganic filler.
3s
The invention also relates to the use of these preparations as adhesive
compositions, sealing compounds and coating compositions.
DE-C 2, 915, 864 discloses non-aqueous synthetic resin compositions which
~o contain, as synthetic resins, the reaction products of low molecular
weight acrylic copolymers with organic diisocyanates. Such synthetic
resin preparations are recommended for use as single-component elastic
I~SF Alcti~nKo~011~ch,3e~ ,. UtJSO/4U/51;
sealing compounds which cure on ~xposure to molsture but are stable on
storage under dry conditions.
However, these sealing compounds suffer from the drawback that the sur-
s face of the cured compound shows increased tack and the preparation of
the synthetic resins contained therein demands a comp.licated manufac-
turing process. It is thus an object of the present invention to provide
non-aqueous synthetic resin preparations which contain, as synthetic
resins, polymers predominantly based on acrylates and/or methacrylates
o and containing isocyanate groups and which are obtainable by simple
methods and are stable on storage under dry conditions and are particu-
larly suitable for use as single-component elastic sealing compounds
which cure on exposure to moisture and show no surface tack in the cured
conditionO Accordingly, we have found the synthetic resin compositions
defined above.
The monomers a) contained in the synthetic resins A) as polymerizedunits are advantageously acrylates or methacrylates of alkanols contain-
ing from 1 to 8 carbon atoms, such as methanol, ethanol, isopropanol, n-
20 butanol, isobutanol, n-pentanol, n-hexanol and 2-ethyl hexanol, acry-
lates being preferred. Particularly preferred acrylates a) are ethyl
acrylate, n-butyl acrylate, n-hexyl acrylate and 2-ethylhexyl acrylate.
Compounds of the general formula I are known in the axt and are de-
~s scribed, for example, in DE-A 3,523,6~2. The proportion thereof in A ls
preferably from 0.2 to 8% and more preferably from 1 to 6%, by weight.
It is particularly advantageous for A to contain polymeri~ed units oE a
monomer b) of the general formula I whLch comprise ~-isocyanato-ethyl
acrylate or 5-isocyanato-3-oxapentyl methacrylate units.
Whilst the Lnclusion of copolymerized units of the monomers a) and b) in
A is obligatory, the monomer c) is merely an auxiliary monomer which
will usually be included when it is desired to impart a specific degree
of hardness to the polymer. Examples of possible monomers c) are
35 acrylonitrile, methacrylonitrile, vinyl ethers of Cl-C8-alkanols such as
vinyl C2-Cl~-n-alkanoates, e.g. vinyl acetate and vinyl propionate, vinyl
halides such as vinyl chloride, aromatic vinyl compounds such as
styrene, vinyl toluenes, chl.orostyrenes or t-butyl styrenes, and lower
unsaturated hydrocarbons such as ~-olefines or conjugated hydrocarbons
40 such as butadiene, the preferred monomers being acrylonitrile, mPth~
3--~
BASF ~kti~ 03~119ch~ft 3 ;;~ O.~.~J050/bl)75B
acrylonitrile and styrene. Advantageously, the proportions of a) and c),
by weight, are adjusted with reference to the Fox equation such that a
polymer containing polymerized units of these two monomers only would
have a glass temperature of from -70 to +20 , preferably from -50 to
s +20- and more preferably from -30 to -10C. ~ccording to Fox (T.G.Fox,
Bull. Am. Phys. Soc. [Ser. II~, l, 123 [1956]), the following equation
applies to the glass temperatures of copolymers, to a good degree of
approximation:
-- = ~ + i~ ~ ''''' T~n
where Xl, X2, ~ Xn are the mass fractions of monomers 1, 2, --- n and
T8l, Tg2, --- Tgn are the glass temperatures, in C, of polymers consist-
15 ing of polymerized units of one (respective) monomer only. ~he glasstemperatures of said homopolymers of the monomers a) and c) are ~nown
and are listed, for example, in J. Brandrup, E.H. Immergut, Polymer
Handbook lse Edition, J. Wiley, New York, 1966 and 2n~ Edition, J. Wiley,
New York, 1975.
The synthetic resins A are preferably prepared by radical polymeriza-
tion, preferably in solution.
Such solution polymerization may be carried out batchwise or continu-
25 ously. The latter method is preferred, the procedure being to start witha portion of the polymerization mixture and heat it up to tha polymer-
ization temperature and then to feed in the remaining mixture continu-
ously.
30 The solvent used i9 usually an ether such as tetrahydroEuran or dioxane,
an ester such as othyl or n-butyl acetate, a ketone such as acetone or
cyclohexanone, an N,N-d~alkyl carboxamide such as N,N-dimethyl for-
mamide, N,N-dimethyl acetamide or N-methyl-2-pyrrolidone, an aromatic
compound such as ~oluene or xylene, an aliphatic hydrocarbon such as
35 iso-octane, a chlorinated hydrocarbon such as t-butyl chloride, or a
plasticizer such as di-n-butyl phthalate.
The weight-mean molecular weight ~ of the synthetic resins A is gener-
.0 ally from 3,000 to 150,000, pre-ferably from 10,000 to 100,000.
Accordingly, the synthetic resins A usually have a K-value in tetra-
hydrofuran (THF) of from 15 to 90 and preferably from 25 to 60
~ASF A~ctiong~ Ll~cbaft ~ .Z,,OOSO/I~U/SG
The K-value is a relative viscosity index which is determined in a rnan-
ner similar to that specified in DIN 53,726 at 25 C. It denotes the ratio
of the velocity o~ flow of a O.Ol:l w/w resin A/THF mixture to that of
s pure THF and is a measure of the average degree of polymerization of
resin A, as can be controlled by varying the polymerization conditions
in known manner. A particularly suitable radical starter is an organic
azo compound or organic peroxide such as azo-diisobutyronitrile,
dibenzoyl peroxide or t-butyl perben~oate. This is advantageously used
~o in a concentration of from 0.05 to 5.0% and preferably from 0.3 to 1%,
by weight of the total monomers. The polymerization temperature is
usually 50 to 150 C and preferably 80 to 130 C. Other auxiliaries which
may be added are for example chain-transfer agents such as aliphatic,
aromatic or alicyclic mercaptans, e.g. n-butyl mercaptan or n-lauryl
mercaptan, or alkyl thioglycolates such as ethyl thioglycolate, a
suitable concentration being from 0 to 3% by weight of the total
monomers.
It is advantageous to work in an "anhydrous" polymerization medium, i.e.
20 a medium containing less than lO0 ppm of water. The solution polymeriza-
tion of the reactants, which are in themselves anhydrous, is advanta-
geously carried out in the presence of a small amount of a desiccant
such as a tetraalkoxy silane, e.g. tetramethoxy silane, or a trialkyl o-
formate, e.g. triethyl o-formate, optionally with the addition of a
25 Lewis acid. The solvent can be removed from the resulting solution of
the synthetic resins A either partially or completely, as requirecl, Eor
example by distillation in vacuo.
The component B to be added to the synthetic resin preparations of the30 invention is advantageously an aluminum siltcate, quartz, precipitated
or pyrogen-containing silicic acid (which may be hydrophobized), ].ight
or heavy spar, talcum, dolomite, calcium carbonate, lamp black or color-
ing pigments. Preferred whitening pigments are titanium white, lead
white, zinc white, lithopone and antimony white and preferred blackening
35 pigments are iron oxide black, manganese black, cobalt black and anti-
mony black. Preferred colored pigments are, for example, chromium yel-
low, red lead, zinc yellow, zinc green, pink salt, cadmium red, cobalt
blue, Prussian blue, ultramarine, manganese violet, cadmium yellow,
molybdate orange and strontium yellow. The filler is generally added in
~o the form of fine particles. The average particle size, taken as the
5--
E~ASF Alctione~ chaLt 5 ~ 3 O.Z.OOS0/40-/5~
arithmetic mean of the greatest diameters, is preferably from 0.01 to
200 ~m and more preferably from 0.01 to 10 ~m.
The compositions of the invention may additionally contain up to 15% w/w
s of a low ~olecular weight organic substance suitable to serve as exter-
nal plasticizer C, preferred compositions containing fro~ 2 to 15% w/w
thereof. Examples of suitable external plasticizers are phthalates such
as diethyl phthalate, di-n-butyl phthalate, diisoheptyl phthalate or
di(2-ethylhexyl) phthalate, adipates such as di(2-ethylhexyl) adipate or
10 diisooctyl adipate, sebacates such as di(2-ethylhexyl) sebacate, phos-
phates such as tri-n-butyl phosphate, triisobutyl phosphate or tri(~-
chloroethyl) phosphate, and chlorinated hydrocarbons.
The compositions of the invention may be used free from solvent, but to
improve their working properties and in particular to lower their vis-
cosity they can contain up to 40%, preferably from 2 to 40%, of their
weight, of an organic solvent. The solvent used is preferably one which
is also suitable for use in the solution polymerization carried out to
manufacture the synthetic resin A.
~0
The synthetic resin compositions of the invention may also contain minor
amounts of not more than 5% w/w of other auxiliaries, such as agents for
improving ageing resistance, e.g. fungicides, dyes, thickeners and
agents for accelerating curing under the action of molsture ~e.g. tetra-
25 n-butyl titanate, di-n-butyl-tin di-n-dodecanate, di-n-butyl-tin
diacetate or tertiary amines such as 1,4-diazo-bicyclo(2,2.2)octane arld
triethylamine).
The compositions oE the invention may by prepared in the form of single-
,o component systems by mixing together all ingredients and storing the
mixture in a sealed container ready for use. To this end, the ingredi-
ents B and, if used, C and any other auxiliaries to be used are prefer-
ably stirred into a solution of the synthetic resin A containing the or-
ganic solvent D or into a melt of synthetic resin A.
~s
Alternatively, the compositions of the invention may be used in the for~
13ASF Altti~n~os~llschnft ;~ 7~ o ~ o~ro/4u~sii
of a two-component system, the ingredients B and, if used, C and D and
any other auxiliarie5 bein~ mixed toget~er to ~orm one component, which
will be stirred, prior to use, into a r~elt or solution of the synthetic
resin A forming the second component. The use of a single-component
systcm necessitates meticulous exclusion of water to avoid prernature
curing of the composition. In the case of a two-component system, the
presence of small traces of water in the separate components is less
critical, which facilitates processing of the components and storage of
the system.
The preparations of the invention cure in a short time when exposed toatmospheric moisture. When cured, they show improved elasticity and have
improved stretching properties, but their surface is not tacky. In addi-
tion, the cured compositions show improved adhesion on substrates such
15 as aluminum, wood, glass, ceramics, concrete, building bricks and most
plastics. They also exhibit improved weathering resistance and can be
coated with domestic paints.
They are particularly well-suited ~or use as adhesive compositions,
20 sealing compounds and coating compositions, their use as moisture-curing
sealing compounds being especially preferred, Due to their improved
elasticity in the cured condition, they are preferably used when it is
desired to cover cracks in the surface of the substrate or to fill in
expansion gaps. For external applications, it is preferred to use a syn-
~s thetic resin composition of the invention which contains a syntheticresin A having a glass temperature of from -30 to -10 C.
Examples
30 _x~
Manufacture of various solutions Al to A12 of synthetic resins A
General procedure
A solution of 2 g o~ triethyl o-formate in 300 g of toluene was heatedto the polymerization temperature of lOO'C and held at this temperature
while 600 g of a mixture of monomers a to c optionally containing a
small amount of a chain-transfer agent were added over a period of 4
hours and a low-concentration solution of azo-diisobutyronLtrile in lOOg
7--~
~ASF Aktl~ne~s~llsch~ft 7 - ~.Z.0050/~l01~0
of toluene was added simultaneously through a separate feedline over a
period of 5 hours. The resulting mixture was then further polymeri~ed
for 2 hours at llO C. The solids contents of the resulting synthetic
resin solutions, the K-value of the associated synthetic resins in THF,
s the composition of the monomer mixtures used and the amoune of radical
starter used and of chain-transfer agent, if any, are listed in Table 1
below. With the exception of the nondimensional K-value, the data are
expressed as percentages by weight based on the mixture of ~onomers ex-
cept for the solids content, which is based on the synthetic resin solu-
tion.
Table 1
A1 A2 A3 A~ AS A6 A7 A8 A9 A10 A11A12
ethyl acrylate el.7 90 98 92 97 65 38 80 70 80
n-butyl acrylate 83 33 60 60 10
~ethyl ~ethacrylate 18.2
5-isocyanato-3-oxapentyl
methacrylate 1.6 2 2 2 1 3 2 1.8 2.5 2.520 ~-isocyanatoethyl acrylate 2 2
acrylonitrile 16.7 1~ 8 7 38 1017.5
styrene 7-5
azo-diisobutyronitrile 0.3 0.3 0.7 Q.7 0.3 0.2 0.5 0.4 0.5 0.6 0.3 O.g
ethyl thioglycolate 0.3 0.4 0.5
~5
K-value 39.5 ~2 36.6 26.1 43.4 37.3 35.1 24.1 32 25.1 33.4 42.
solids content 58.858.2 58.9 59.1 58 58.559.1 59.6 57.9 58.8 57.2 58
Examp].e 2
Various synthetic resi.n compositlons
To prepare various synthetic resin composltions of the invention, the
solutions A7 to A12 were distilled to remove the solvent, and various
35 additives were then addedt in each case, to 300 g of the resulting pure
synthetic resin. A sample was taken from each of the compositions thus
obtained and applied to a plate of glass to form a 2 mm layer thereon
and then left to cure for 3 weeks at room temperature and a relative
humidity of 60%.
.0
Table 2 below gives the ultimate tensile strength (N/mm2) and the
elongati.on at break (7O) (both determined as specified in DIN 53,50~ at a
chart speed of 100 mm/min using a test specimen type S3A) of the
resulting elastic films and their surface tack. Table 2 also lists the
45 quantities of additives used. Table 2 further contains data on a
8--~ .
DASi' A~tl~n8~1lollochllft ~ 0.1',.0050/bO15
comparative test using a synthetic resin composit.Lon :Lncorporating a
synthetic resin V obtained as speciiied in ~xample 1 of D~-C-2,915,864
by reacting 300 g of n-butyl acrylate, 10.2 g oE 2-hydroxyethyl
acrylate, 6.6 g of mercaptoethanol and 30 g of a mixture of 2,4- and
2,6-diisocyanatotoluene.
Table 2
Additives [g] A7 A8 A9 A10 All A12 V
hydrophobized pyrogen-containing
silicic acid 60 50 30 20 60
calciun carbonate 200 100
titaniuo white 20 30
diethyl phthalate 30 lO
di-n-butyl-tin-di-n-dodecanate2.5 3 3 3 3 3
1,4-diazo-bicyclol2.2.2]octane 2
Ulti~ate tensile strength 0.25 0.20.3 0.25 0.2 0.7
,0 Elongation at break 312 290 310277 338 410
Surface tack no no no no no no yes
Example 3
,s Weathering resistance oE cured synthetic resin compositions of the
invention as prepared in Example 2.
The weathering resistance was determined using the short-period
weathering tester X~NOTEST*1200 (Heraeus GmbH, Hanau, GFR) set to give a
30 cycle oE
"rainfall" 3 mLnutes
dry lnterva:L .L7 minutes.
The blackboard temperature measured ln the interior oE tha tester was
48 C.
~5
Test rssult: no changes were observed after a testing period of 2,000
hours.
* trade mark
A 9-~
