Vol.2, No 5, 2005 pp. 393 - 400
UDC 667.629.2
DETERMINATION OF SOME PHYSICO-MECHANICAL
PROPERTIES
OF AQUEOUS TWO-COMPONENT VARNISH PAINTS BY
USE OF NON-TIN CATALYSTS
Suzana Cakić1, Časlav Lačnjevac2,
Ljiljana Rašković1
1Faculty of Technology, Leskovac
2Faculty of Agriculture, Zemun
E-mali: suza967@yahoo.com
Abstract. In last several years the use of water instead of organic
solvent in coating paints has increased considerably. It is the consequence
of the increasingly severe demands for environmental protection as well
as of the efficiency of aqueous coatings in the protection of materials
by means of organic coatings. The main aspect in developing the aqueous
two-component polyurethane (PU) systems is, first of all, finding methods
for preventing unwanted secondary reactions with water and obtaining the
best crosslinking.
In this paper, the polyol components, as well as the acrylic dispersions
with different hydroxyl numbers for crosslinking process, were used.
As suitable hardeners, the aliphatic polyfunctional isocyanates based
on hexamethylen diisocyanates with different content in the NCO-group were
used. In this study, the complex of zirconium commercial known as K-KATŽXC-6212
or manganese (III) complex with mixed ligands based on the derivative of
maleic acid was used as the catalyst. The coatings were characterized by
measurements of hardness by König and gloss by Lange using catalysts with
different selectivity. In this respect, the effect of different induction
times after the mixing of the components on the hardness and gloss of the
films has also been observed.
The obtained results show that the performances of the aqueous two-
component polyurethane coatings depend on the polymer structure of the
polyols and the polyisocyanates as well as on the selectivity of the used
catalyst.
Key Words: Aqueous coatings, crosslinking, induction time, hardness
according to König
ODREĐIVANJE NEKIH FIZIČKO-MEHANIČKIH KARAKTERISTIKA
U VODENIM DVOKOMPONENTNIM LAKOVIMA PRIMENOM
NEKALAJNIH KATALIZATORA
Poslednjih godina upotreba vode umesto organskog rastvarača u premaznim
sredstvima je znatno povećana. Ovo je posledica sve strožih zahteva za
zaštitu životne sredine, kao i uspešnosti vodenih premaza u zaštiti materijala
organskim prevlakama. Glavni aspekt u razvoju vodenih 2K-PU sistema je
prvobitno naći metode za sprečavanje neželjene sekundane reakcije sa vodom
i dobijanje najboljeg umrežavanja.
U ovom radu za umrežavanje od poliolnih komponenti korišćene su akrilne
disperzije sa različitom vrednošću hidroksilnog broja. Kao umreživači koričćeni
su vodoemulgujući poliizocijanati na bazi heksametilen diizocijanata
sa različitim sadržajem NCO-grupa. Od katalizatora koričćen je komercijalni
katalizator cirkonijuma (KATŽXC-6212) i manganov kompleks sa
mešovitim ligandima na bazi derivata maleinske kiseline. Premazi su okarakerisani
merenjem tvrdoće po Königu i sjaja po Lange-u korišćenjem katalizatora
različite
selektivnosti. U tom smislu praćen je i uticaj različitog indukcionog vremena
posle mešanja komponenti na tvrdoću i sjaj formiranih filmova.
Dobijeni rezultati pokazuju da performanse vodenih 2K-PUR premaza zavise
od polimerne strukture poliola i poliizocijanata kao i od selektivnosti
primenjenog katalizatora.
Ključne reči: Vodeni premazi, umrežavanje, indukciono vreme,
tvrdoća po König-u.
