1083 RESIN, SYNTHETIC
taining largely asphaltic hydrocarbons. Also known sticky below the glass transition point. Most are
as asphaltum oil, liquid asphalt, black oil, petroleum soluble in alcohols, ethers and carbon disulfide, and
tailings, and residuum. Combustible. insoluble in water. The best known of these are rosin
Use: Roofing compounds, hot-melt adhesives, fric- and balsam, obtained from coniferous trees; these
tion tape, sealants, heating oil for large buildings, have a high acid content. Of more remote origin are
factories, etc. such resins as kauri, congo, dammar, mastic, sand-
See fuel oil. rac, and copal. Their use in varnishes, adhesives, and
Note: Gasoline of 94 octane can be produced from printing inks is still considerable, though diminish-
residual oil in a high-temperature catalytic process, ing in favor of synthetic products. (2) Miscellaneous
thus increasing the yield of gasoline from a barrel of types: shellac, obtained from the secretion of an
crude by 33% when full-scale production is Indian insect, is still in general use as a transparent
achieved. coating; amber is a hard, polymerized resin that
occurs as a fossil; ester gum is a modified rosin;
amorphous sulfur is considered an inorganic natural
residue. A single unit within a polymer, for exam-
resin; liquid resins, sometimes called resinoids, are
ple, an amino acid within a polypeptide chain.
represented by linseed and similar drying oils.
See gum, natural (note); resin, synthetic (note).
“Resimene” [Solutia]. TM for melamine and
ureaformaldehyde resins. Supplied in organic liquid
solutions. The melamine is also available in water-
resinoid. Any thermosetting synthetic resin, ei-
alcohol and soluble, spray-dry powders.
ther in its initial temporarily fusible state or its final
Use: Paint, varnish, lacquer for automobiles, ma-
infusible state (ASTM). Heat-bodied linseed oil,
chinery, appliances, construction, electronics, mis-
partially condensed phenol-formaldehyde and the
siles, chemicals, pulp and paper.
like are also considered resinoids.
resin. A semisolid or solid complex amorphous
resinol. A coal tar distillation fraction containing
mix of organic compounds.
phenols. It is the fraction soluble in benzene but
Properties: It has no definite melting point and no
insoluble in light petroleum, obtained by solvent
tendency to crystallize.
extraction of low-temperature tars or similar materi-
Derivation: Resins can be from animal, vegetable, or
als. Resinols are very sensitive to heat and oxidation.
synthetic origins.
resin, synthetic. A manufactured high polymer
resinamine. C
35
H
42
N
2
O
9
. Alkaloid from certain
resulting from a chemical reaction between two (or
species of Rauwolfia.
more) substances, usually with heat or a catalyst.
Properties: White or pale-buff to cream-colored,
This definition includes synthetic rubbers and sili-
crystalline powder; odorless; darkens slowly on ex-
cones (elastomers), but excludes modified, water-
posure to light, more rapidly when in solution. Mp
soluble polymers (often called resins). Distinction
238C (in vacuo). Partially soluble in organic sol-
should be made between a synthetic resin and a
vents; insoluble in water.
plastic; the former is the polymer itself, whereas the
Use: Medicine (antihypertensive).
latter is the polymer plus such additives as filters,
colorant, plasticizers, etc.
resinate. A salt of the resin acids found in rosin.
The first truly synthetic resin was developed by
They are mixtures rather than pure compounds.
Baekeland in 1911 (phenol-formaldehyde). This
Use: See soap (2).
was soon followed by a petroleum-derived product
called coumarone-indene, which did indeed have
resiniferatoxin.
the properties of a resin. The first synthetic elasto-
CAS: 57444-62-9. mf: C
37
H
40
O
9
.
mer was polychloroprene (1931) originated by
Hazard: A poison.
Nieuwland and later called neoprene. Since then
many new types of synthetic polymers have been
resin, ion-exchange. See ion-exchange resin.
synthesized, perhaps the most sophisticated of
which are nylon and its congeners (polyamides, by
resin, liquid. An organic, polymeric liquid that,
Carothers), and the inorganic silicone group (Kip-
when converted to its final state for use, becomes
ping). Other important types are alkyds, acrylics,
solid (ASTM). Example: linseed oil, raw or heat-
aminoplasts, polyvinyl halides, polyester, epoxies,
bodied (partially polymerized).
and polyolefins.
See drying oil; resinoid.
In addition to their many applications in plastics,
textiles, and paints, special types of synthetic resins
resin, natural. (1) Vegetable-derived, amor- are useful as ion-exchange media. See “Cumar”;
phous mixture of carboxylic acids, essential oils, plastic; paint; fiber; film; elastomer.
and terpenes occurring as exudations on the bark of Note: Because the term resin is so broadly used as to
many varieties of trees and shrubs. They are com- be almost meaningless, it would be desirable to
bustible, electrically nonconductive, hard and glas- restrict its application to natural, organo-soluble,
sy with conchoidal fracture when cold, and soft and hydrocarbon-based products derived from trees and