Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
^`-` 2~ 80 ~z~ 0050/43909
~ardensrs for two-eom~ene~t ~olrur-thane ~Yot~m~,
es~eclallY two-eom~on~nt ~olYuret~ane ~uraee co~tl~ao,
and the ~roduction thore~of
The pre~ent ln~entlon relates to h~rdeners for
S two-component polyurethano sy~tema, e~peeially two-
cemponent polyurethane surfaee eoating3, and to a process
~or producing them.
~ he isocyanate eomponent employed for two-com-
ponent polyurethane aurface eoating~, called the
10 hardener, i5 usually 4 polyisocyanate which contain0
biuret or isocyanurate groups and ur-tdione groups and in
no~t cases is aliphatic.
These products are preferably produced by eataly~
tic oligomerization of allphatic and/or eyeloaliphatic
dii~ocyanates, eg. 1-isocyanato-3,3,5-trimethyl-
5-i~ocyanatomethylcyclohexane ~I2DI) or hexamethylene
dii~ocyanate (HDI).
Examples of eatalyst~ which can be omployed are
hydroxides or organic ~alt~ of weak seids ~ith tetra~
alkylammonium group~, hydroxide~ or organie salts of weak
acids with hydroxyalkylammonium group~, alkali metal
~alts or tin, zinc or lead salts of alkanecarboxylic --~
acids.
It is proposod in GB-A-2 221 465 to earry out the
isocyanuration of aliph~tic dii00cyanates ~t elevated
temperatureR in the presonce of catalytic ~mounts of an
organic co~pound wh~e~ eontains at least ono aliphatic
t~rtiary m~no group and at least one aliphat~e hydroxyl
group. -
3 0 This entails the aliphatic a~d/or eyeloaliphatic
dii~ocya~at0s being reaet~d i~ the pr~senee of the
eatalyst, with or without ~olvents a~d/or ~uxiliaries or
biur~tization agent~, until tho re~uirod eo~ver~ion is
reachod. Tho roaction is thon stopped by inactivæting the
catalyst, and the excess monomeric diioocyanato is
re~oved by di~tillation. Tho resulting polyisocyanate
~ixtures contain diff~rent proportions of uretdione and
2211~080
_ _ O.Z. OOS0/439~9
biuret or isocyanurato group~ depond~ng on tho type of
catalyst used and tho re~ction conditlons mployed.
~ wo-component polyurethane ~urfaco eoatingJ are
produced by reacting the poly~socyanat~ mixtures whieh
have been produced in this way and eontain uretd~one
group~ and biuret or isocyanurate groups in a conven-
tional manner with polyhydroxy compou~d~, e~pecially with
polyhydroxy acrylates. The euring take~ place by a~r
drying and can be accelerated therm~lly or catalytically.
The problem i~ that the addition of co~ventional
catalysts, eg. dibutyltin dilaurat~, drast~cally reduces
the pot life of the system.
There i~ thus a ~eed for two-co~ponent poly-
urethane ~ystems which undergo fa~ter euring than known
systems but, neverthelos~, di~play an ~dequate pot life
and need no external cataly~is.
It i~ an objoct of the pre~ent in~ention to
develop a ~uitable harde~r for two-~omponent poly-
urethane systems, especially two-compon~nt polyurethane
~urface coatins ~y~tems, which ~void~ the prior ~rt
disad~antages described.
We ha~e found that this ob~ect i~ achie~ed by
hardeners for two-component polyurethane syste~s,
espec~ally two-compo~ent polyurethano ~ur~ace coatings,
which are compooed of organ~c, ~n particular aliphatic,
polyisocyanate~ which contain biur~t or i~ocyanurate
group~ and uretdione groups, urethane groups and tertiary
amino groups.
T~e pre~ent lnvention accordi~gly rolate~ to
hardeners for two-compone~t polyurothane systems,
especially two-ccmponent polyurethane surf~ce coatings,
composed of organic, in particular aliphatic, polyi~o-
cyanates which contaln biuret or isocyanurat- groups and
uretdione group~, urothano group6? and t~rtiary amino
groups, ~nd to the production theroof.
The hardeners according to th~ in~ention are pro-
duced by con~entional method~ of catalytic oligomerization
?~; ` . : ::,
2 ~i ~ 0 8 0 o.z. oo50/43909
-- (isocyanuration and b~uretizAtion) o~, ln particular,
alip~atic and/or cycloaliphatic dii~ocy~nate~, removal of
the unreacted monomers, and ~ubsoquent traatment of the
re~ulting polyisocya~ate mixtures.
The initial diisocyanate~ are gen~rally aliphatic
and/or cycloaliphatic diisocyanate~, og. 1,4-diiso-
cyanatohexane, 1,6-dii~ocyanatohexane (~DI), 1,12-diiso-
cyanatododecane, 1-iso~yanato-3,3,5-trimethyl-
5-isocyanato~ethylcyclohexan~ (IPDI), 4,4'-diisocyanato-
dicyclohexylmethane, 1,5-diisocyanato-2,2-dimethyl-
pentane, 1,5-dii~ocyanato-2-Qthyl-2-propylpentane,
1,6-diisocyanato-2,4,4-trimethylhexa~e and 1,5-diiso-
cyanato-2-methylpentane, but e~pæcially ~DI.
The oligomerization o~ the diisocyanates is
preferably carried out at ~rom 0C to 100C while passing
in an inert gas, preferably nitrogen. The reaction r~te
is too low at lower temperatures, and there ar~ more side
reaction~ at higher t~m2eratures.
Catalysts which c~ b~ ~mployod ara all catalysts
suitable for the oligo~erization of aliphatic a~d/or
cycloaliphatic diisocyanates, for ~xample hydroxides or
organic ~alts of wea~ acids with tetraalkylammoaiu~
groups, ~ydrox$de~ or organia salt~ of weak acids with
hydroxyalkylammonium groups, al~ali ~etal ~altB or tin,
zinc or lead salt~ of alkanocar~oxylic acids. The
catalysts are normally ~mployed in an amount of fro~
0.05% by weight to 2% by weight, ba~d on the dii~o-
cyanats.
~t ia pos~ible to reduc~ th~ amount of catalyst
by addlng to th~ diisocyanat~s before t~e oligomerization
in a conventional way a ~mall amount, up to about 1% by
weight, based on the di$~ocyanate, of a diol, in
particular of a polye~ter diol.
The diisocyanato i~ then heat~d while ~tirrlng to
the reaction temperature, and the cataly~t i8 810wly
added. Ths catalyst can be dissolved in a solvent to
improve ~anipulation. Suitabl~ examples are alcohols,
- 21~ ~ O ~ o.z. 0050/43909
espocially diola, ketone~, ther~ ~ud at-ra
After the requirod dogree of conversion has b-en
reached, t~e reaction i8 stopped by lnactivating the
catalyst, for examplo by adding a catalyst ~oison or by
thermal decomposition of the catalyst. Sub~equently, the
monomeric diiaocyanates ax- remo~d ~ro~ the reaction
~ixture in a ~uitable conventlonal way, for example by
distillation, eg. in a thin-~ilm evaporator.
The polyisocyanat- m~xtures obtained in this way
are reacted according to the irve~tion w~th monohydric
and/or polyhydric Alcohols subst~tuted by ~t least one
tertiary amino group.
Exa~ples of such amino alcohol~ this ca~ ~e
employed are tertiary amine~ to w~o8e nitrogen atom at
least one hydroxyalkyl group i8 bonded. The~e ca~ be
aliphatic and/or cycloaliphatic compounds, a~d the
tertiary nitrogen atom can also be i~corporated in a
ring.
~xamples which ~ay be mentionad are N-al~yl-
dialkanolamines, N,N-dial~ylalka~olamines, trialkanol-
a~ine~ as well as N-hydroxyalkyl-substitutod pyrroles or
pyrrole derivatives aad N-hydroxyal~yl-aubstituted
imidazole or derivatives ther~of.
Preferably used aro a~ino~tha~ol deriv~tives such
25 a8 triethanolamine, ~ethyldiothanolamine and dimethyl-
ethanolamine.
Th~ monohydric or polyhydr~c alco~ol~ sub~t~tuted
by at l~ast one tertiary ~mlno group ca~ b~ uaed singly
or in t~ form of mixtur~J.
~t is ~180 possible to add the appropria~e a~ino
alcohol to the dii~ocyanat~ ~efor~, during or immediat~ly
a~ter the oligomerizatio~ and b~fore the removal of
monomers. ~owe~er, in this ca~e, th~ ~n~no alcohols may
react with ~onomeric diisocyanat~ Products of th~s type
di~play di~tinctly poorer char~cteristic~ in th~ poly-
urethane ~ystems.
The a~ount of the monohydric or polyhydric
_ 5 _ o,z, 0050/43909
- alcohol subst~tuted by at least one tertiary ~mino group
which is added is 0.1-30% ~y weight based on tho poly-
isocyanate mixture. Prefer~bly us-d are 1-20% by woight,
based on the polyi~ocyanate m~xture, at 10-100C, pre-
ferably 20-80C.
We have found, ~urpri~ingly, that $ncorporat~on
o~ tertiary amino alcohol~ into polylsocy~nates results
in a hardener which, when usod in a two-component poly-
urethane 8y8tem, produces a ~ystem which hardQns faster
and whose processability is as good as when a convon-
tional polyisocyanate ~8 used. The pot l~fe is reover
considerably longer than on use of ~ conventional poly-
i~ocyanate to whi~h are added, shortly ~-fore the pro-
ces~ing in two-component polyurethane ~urface coating
systems, prior art cataly~ts (for ~x~myle tertiary amine~
and tin oompounds) which accelerate the hardening of the
surface coating.
The hardener~ according to the invent$on are
used, in particular, for the production of two-component
polyurethane ~urface coatings.
The ~nvention is illustratsd by the following
examples:
~XAMPLE 1
Reaction o~ a polyi~oeyanurate based o~ hexa-
methylene diisocyanate (EDI) with an a~i~o alcohol.
1000 g of a 90% strQngt~ ~olutlon in Solv~sso~100/n-butyl acetate (1:1) of a poly~30cyanurate which is
bas~d on ~DI a~d haJ the following characterlJtic~:
NC0 co~tent: 20.4~
Visco~ity: 393 mPa.s
was mixod wlth variou~ umounts of dimethyla~inoethanol
and stirred at 40C for 1 h (Tablo 1).
21i30~0
- 6 - Z- 50/43909
Re;ction of ~DI poly~ocy~nurat
ExampleAmount NC0 Vi~cosi y
~dd~d Contant
tg~ r%~ ~mPa .8J ¦
1.1 3 19.9 403
1.2 9 19.4 418
.3_ 18 18.3_
~XAMP~E 2
Reaction of a polybiuret bas~d o ~DI with d~methylamlno
350 g of biur~tiz~d ~DI w~t~ ~ho following charac-
NC0 content- 23.7%
Viscosity: 374 mPa. 3
were reacted w~th 25 g of dimethylaminoot~a~ol at 40C to
r sult in a modified polyisocya~at~ wit~ th~ ~ollowi~g
NC0 content: 15.4%
Viscosity: 1137 DPa.s
E~AMPL~ 3
Production of surface coating~ ~Gd applicat~o~ tests
The polyi~ocya~urate roact~on products producod
a~ in Examplo 1 wer~ mixod a~ hardener compon~t with a
hydroxyacrylat~ copolymer corre~ponding to an NC0/0~
equi~alsnt ratio of 1:1. Th~ ~urface coating Vi~08ity
_ 7 2 1 1 ~ 0 8 ~ o.z. 0050/43909
~R~ ~u~t~ con~tant 20 ~ (DIN cup, 4 mm or~flce)
by aU~ t. Tho ~ncr-a~ ~n v~co~ity Of the
ro~l~ c~hr ~urfaco coatlng~ wa~ moacurod at constant
ti9~ ~ntrnnl~ She hardening ch~ract-ri~tics of t~e
5 8~ O~U~g~ ~fter ~nifo hppl~cat~o~ to glas~ plates
and en~XU~t~ o~ the solv~nt wore determined a~ a
fUn~tion of ~ n a sta~dardized climate (23C, 50%
rel- hu ~ . The exact proced~re for tho tests is
8~ ~ of hydroxyacrylate poly~er, 70% ~trength
yl ac~tate, 0~ ~umber . 1353, w~ro mixed
~ith 28-~ g o~ tbe isocyanate harda~er from Example 1,
ana tha ~istux~ ~a~ diluted with butyl acetate until the
IN ~ ~up ~isc&~ity (DIN 53211) wa~ 20 ~.
5h~ vi~codty of the surface coating wa~ measured
a~a~n at l-ho~r int~rval0
Sh~ clear curface coating applied using ~ box -
~fe to a gla~ to llay~r thick~e~s about 40 ~m after
~ Porati~ o~ tho ~olve~t) Wa8 stor~d in a ~tandardized
Cli~ate- Th~ hardo~ing characteri~tic~ were d~termined by
mea0uring the ~oe~ig pendulum damping (D$N 53157) at time
i~tervalu.
C#~parico~ ~a~ with th~ unmodified initial
~BCYanurat- in all caJ~. The r~ults ar~ compiled in
Tables 2-4.
A~ iJ ~idant fro~ the ta~l~s, ~he 0urfaca
Coat~g harden~rg according to the i~enti~ ~how~d
d~ ~Ctly impro~ed hardeni~g ~haracteri~tic~ i~ applled
for~ whQ~ the vi~co~ity c~aracturi-tic~ of the surface
30 coat~ng ~olution~ wQre g~m~lar- ;
211~0~3Q.z. ooS0/43909
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