Page 98 - Handbook of Surface Improvement and Modification

6.3 Application data 93

Coating contains an ethylene vinyl acetate copolymer having a vinyl acetate (e.g., 63
32
wt%) and an ethylene (meth)acrylic acid copolymer (14 wt%). Composition also
includes tackifier which is based on rosin such as a glycerol ester of hydrogenated rosin
32
(21 wt%).
Conventional reactive polyurethane hot-melt adhesives are utilized in packaging,
paper converting, paper construction, bookbinding, cartons, case sealing, construction,
33
automotive, and the like. The reactive polyurethane hot-melt adhesives create a very
durable product and are particularly useful in the manufacture of packages and text-
33
books. The hot-melt adhesives are typically applied at elevated temperatures (100-
33
170°C). The unreacted monomeric diisocyanates are partly expelled in gaseous form at
33
the application temperatures of 85-200°C, typically 120-160°C. Adhesives for binding
33
books have reduced content of monomeric diisocyanates to prevent their emission. The
aromatic rosin esters (α-methyl styrene resins, C9 hydrocarbon resins, aliphatic-modified
aromatic C9 hydrocarbon resins, phenolic-modified aromatic resins, or C9 aromatic/ali-
33
phatic olefin-derived resins) are used as a tackifiers in these adhesives.
Rosin esters having suitable color, color stability, and low odor were developed to
34
make them useful for non-woven applications. The gum, wood, tall oil, and other rosins
34
may be employed in the processes. The rosin material may be subjected to distillation,
34
disproportionation, hydrogenation, or polymerization. The process of preparation
include melting of rosin under nitrogen, addition of disproportionation agent (e.g., Ros-
inox), fumaric acid, pentaerythritol, and trinonylphenyl phosphate and conducting reac-
34
tion under required temperature. The resultant product of reaction had softening point of
34
98.3°C, acid number of 4.9, a 2+ Gardner color, and a low odor intensity.
A hot-melt positioning adhesive is composed of a styrene-butadiene-styrene copoly-
mer having a relatively high diblock content and styrene content, a second styrenic block
copolymer having a lower diblock content than the styrene-butadiene-styrene polymer,
which is preferably a styrene-isoprene-styrene copolymer, together with tackifying resin,
35
and liquid plasticizer. The tackifying resin should have a ring and ball softening point
35
(measured by ASTM E28) equal to or greater than 130°C. A preferred tackifier is a
35
hydrogenated aromatically modified dicyclopentadiene resin (Escorez 5637). This hot-
melt positioning adhesive is used on feminine sanitary pads or adult incontinent products
35
having improved peel values on cotton, nylon and microfiber substrates.
A floor adhesive formulated as a waterborne product is based on a crosslinkable
binder resin having a glass transition temperature of less than +10°C; a crosslinking agent;
36
a tackifier and/or a plasticizer. The volatile organic compound level of this formulation
36
is less than 0.5 wt%. The crosslinkable binder resin should have a carbonyl functional
(meth)acrylate or vinyl copolymer prepared from a monomer mixture comprising alkyl
(meth)acrylate ester monomers and/or vinyl monomers, and diacetone acrylamide mono-
36
36
mers. The suitable tackifier is based on a rosin acid or its derivative.
The self-adhesive labels are suitable for use in adhering to wet surfaces or wet irreg-
37
ularly shaped surfaces such as those found on fruits and vegetables. The adhesive is dis-
continuously coated as a pattern onto the backing layer to provide areas of the adhesive
37
interspersed with areas which are free of adhesive. The adhesive is a mixture comprising
a polystyrene-butadiene copolymer, a styrene-isoprene-styrene copolymer, and an aromat-
ically-modified aliphatic tackifier having a 2-methyl-1-propene comonomer moiety and a