Between coating and substrate can be combined by mechanical, physical
adsorption (including wetting), the formation of hydrogen bonds and
bonds, diffusion effect such as each other together, its adhesion is
good or bad depends on the degree of the combination of coating and
substrate, there are many kinds of way to increase the adhesion (such as
with a variety of resin, the processing of the substrate, adding
adhesion accelerator, etc.), add
adhesion promoter
is a simple and efficient method.Adhesion on ordinary book has
introduced a lot of books, now let me talk to you to explore the
high-density polyolefin plastic PE, PP and nylon PA way to increase the
adhesion, and on how to increase the adhesion to glass:
One. Polyolefin plastic substrate PE, PP briefing:
PE and PP is inert organic material, its itself does not have polar
groups and surface energy is low.The surface tension in 1.0 * 10 ˉ &
sup2;Dagen below, or less, so ordinary paint doesn't wetting its
substrate, not to mention other chemical bonds can play a role.
1.
Increases on PP substrate adhesion method can be directly spray on the
surface of a thin and uniform layer of chlorinated polypropylene resin,
its theory is the same material through the miscibility, winding and HCL
free acid of PP substrate "erosion" and play a role, can increase the
surface of the substrate, to make the group of paint to "catch" to live.
2. The method of PE substrate: most by corona treatment (for other
treatment methods have defended side, such as flame, chromate treatment,
etc.).But corona equipment is very expensive, it makes little sense to
promote.Suggestion: use fluorocarbon flow ping agent on the PE substrate
wetting.Appropriate heated to a temperature of about 80 ℃, the paint
application polyamide resin and polyurethane.Add some appropriate split
darma resin.Of course there are other ways: with fluorocarbon class of
wetting agent wetting at the same time with something such as coupling
agent.Make the PE substrate above the polar groups, etc.The adhesive
agent for PP substrate has very mature, for PE material end remains to
be further discussed.
Two. PA (nylon) substrate to improve adhesion
method is to spray a thin and uniform layer of polyamide resin film, or
directly with polyamide resin as main resin add some adhesion promoter
directly spray can.
Three. Discussion on the adhesion of glass substrate:
Glass substrate is a kind of hydrophilic inorganic substrate.In the
general case, the glass is easy to combine with moisture in the air.Even
in the dry room can also be seen under a microscope on the glass
surface with a thin layer of water spray layer.In wet weather, could be
seen with the naked eye.Therefore the paint in the humidity environment
construction, the glass substrate is not firm, because there is a layer
of water blocking paint group, grasped the glass, even in the long time
can capture the glass will be off the paint.So the best way to attach is
can penetrate fog layer, with groups hold glass, known as the
hydrophilic, and wrapped with paint itself adhesion (That is
lipophilicity).
At present is proved with epoxy and amino adhesion
promoter can do more than two points.And, of course, many with both
epoxy group and amino group and other groups, such as ether bond, etc.)
or more groups of coupling agent.Above the adhesion promoter can
increase the adhesion to glass well.If the customer requirements more
stringent adhesion, can be sprayed on the glass substrate or
concentration of one for more than 5% with groups of adhesion promoter
and then add 1-2% of total amount of additives to paint adhesion.
