Consumer products multiply as production and saves totals level. Novel applications equipment introduced
THE PICTURE FOR PROTECTIVE HARRY BURRELL
late spring prevented many from accomplishing The genera1 business recession during the early part.of the year was not alleviated by the expected increase in trade sales. Therefore, no records were broken in 1961 for the sales or production oforganic coatings. . The moderate upturn during the last half of the year was helped to some extent by price reductions in a number of important raw materials. Phthalic anhydride, for example, at 15 cents per pound (molten, bulk) was at its lowest in many years. Vinyl chloride (7 cents), styrene (11 cents), and acryloitrile (14 cents) reached new lows. Maleic, adipic, methylolpropane, and dipentaerythritol were also duced. However, such reductions were not sufficient eliminate the serious price squeeze prevalent in much the chemical industry.
A their traditional house-painting chore.
‘
“spray upholstery” which is a floc coating for interior side walls and ceiling, but is not recommended for seats. Epoxy resins continue to form the base for a number of special maintenance coatings such as wear-resistant topcoats for concrete- and abrasion-resistant aisle marking paints. Three companies marketed fast curing, chemical resistant metal coatings in a variety of colors. Among the perennial assortment of fire-resistant paints are prefoamed and intumescent prodrlcts claimed to be resistant to rocket blasts and a polyester gel coat recommended for shower pans, drain boards, and boats. Also offered were insulating finishes resistant to carbonizing or tracking up to 15,000 volts or conductive silver coatings applicable by spray or brush for electronic equipment such as printed circuits. Other industrial coatings included a transparent ultravioletabsorbing alkyd-based typef or window glass and a self-
dushial Finisher
automotive painting, more attention is being paid to e coats because of the severe corrosion resulting
om municipal snow and ice control chemicals. An age of 5 quarts of primer per car was used in 1961. the more expensive models this was apt to be a high zinc content typb. Latex primers were formulated which were sufficiently inexpensive so that a “ditized” frame could he dipped to coat interior surfaces, followed by washing the primer off the exterior surfaces and replacing it with a more corrosion-resistant type. One production line is equipped with a combination degreaser-phosphatizer-primer device which keeps the parts in a hot trichloroethylene atmosphere throughout. This prevents contamination after cleaning and allows almost instantaneous dryingof the primer. . General Motors has reportedly reverted .to alkyd fortified lacquers as the finish coats for much of their l i e . Buick hoods and fenders only will have acrylic lacquer, and the hoods will receive an extra huffing operation. Small parts will be finished with alkydamine enamel. The average automobile currently requires nearly 4 gallons of paint (including primer) which adds up to a total production of about 26 million gallons. An interesting item for refurbishing used cars is a 52
INDUSTRIAL A N D ENGINEERING CHEMISTRY
Cotutonrpresmre onosol bomb can ba attached lo contaiw qfsprayable point. Baric paint ingrcdienh con be mixed as &sired lo wry and fat effccfivccoaling propntics
COATINGS
tion in aerosol spraying was the advent of a type of bomb which can be attached to a container of any sprayable paint. Also of interest to antique refinishers are Stain Drops which are wood stains in tablet form which can be dissolved in water or solvent. Mothers of young children might consider a rubber paint which waterproofs leather and can be used as a sort of permanent overshoe. An aptly named product, "4-the-Birds" is a permanently sticky substance which can be applied to ledges, roofs, and statues to discourage pigeons and starlings. A potentially extensive market appears possible for an emulsion spray used for mulching. It is said to hold seeds in place while germinating and to last 3 times longer than conventional mulches.
'
N.ur V.hlC*S
curing latex carpet backing. One manufacturer sought a market in his own back yard by offering an aerc-sol spray which prevents inks or paint from drying over night on roller mills, presses, or roller coaters, reducing cleanup and shutdo- time. Tm& S a k s
Very few new items were offered in the trade sales line in 1961. Popularity of acrylic latex paints continued to grow, as exemplified by their approbation by mural artists. Multicolor finishes prevalent in public buildings were made available in aerosol containers. An innova-
Harry Bwell is Manager, Resin Dcvdoptnarf Laborofmy, Intnchmual Cmp. From 1955 through #60 hs authored ICYECs Janumy annual round-up a Rotectivc Coof ings.
AUTHOR
In spite of the many application difficulties encountered with water reducible industrial paints, raw material suppliers continue to develop new resins. Many specialty end uses have appeared which apparently make the aggregate market interesting, although volume of individual items is probably small. Recent offerings are listed in the table on the next page. Latex paints for brush application are of course pro- ' duced in large volume, and progress continues to be noteworthy in this field. Acrylic latexes are available which have good adh&on and improved resistance to grain cracking when applied to bare wood. For interior use, types with improved opacity and wet edge time have been developed. Acrylics available for solvent application indude styrene copolymers which are soluble in low cost hydrocarbons, a vinyl acetate copolymer, and several thermosetting acrylics. An interesting methacrylate copolymer has an unusually high softening point of 250' F. Hydrocarbons also came in for considerable attention in 1961 because of low cost raw materials. Several types of polybutadiene and polyisobutylene were pmmoted. An ethylene-vinyl acetate copolymer has interesting rubbery properties and is also somewhat more soluble than straight polyethylene. Chlorinated polypropylene while similar to chlorinated rubber in physical and chemical properties, has better color and is more stable. Organosol grades of polyethylene are also available now. Several types of flexible epoxy resins were developed, as well as a E-stage precatalyzed type. Improved amine resins have faster curing speeds and better hardness VOL 5 4
NO. 5
MAY 1962
53
WATER REDUCIBLE VEHICLES Trods
N-
w
ROdW8l
SpKCid ROp6rti~
Emulsions
Dylex KCD- K0PP-a
styrene-
Low foam, for
butadiene paper eaatings Enjay Butyl Enjay Chemical Butyl rubber Flexible, ad154
Evdcx
MF W. R. Grace
Piecopale
Viiyl aeetate
which allows more alkyd resin to be incorporated in enamels. Two cresol-based phenolics were offered, and a special carboxy modified grade of poly(viny1 chloride) has food-packaging approval.
hesive Stable to Ca ion
Pcnn. Industrial Hydmearbon Lowcastex-
Pigments ond Additives
Two new titanium dioxide plants were proposed, one to use the Mojave Desert sands and the other to use the economical reaction TiCI'
tend-
Rain D-243 ShaRinigan Vinyl aceRedin tatc Reap 1066 National Starch Vinyl acetatc Thix-a-pol T. F. Washbum Vinyl ace-
co.
x-3339
Dow Chemical
Borax stable, for paper mat@ For inhlmcaeent coatinga
Thixowpic
tatc
Stycnebutadiene
High hiding with low Ti02
Solutions Aqualon
BcnsonPmeeas Engineering
Linqua
Spenar-Kcllogg ~ a x d oil
House paint, in-
Melagua
American Cyanamid
Mdamincacrylic
Heat convertible,
Momanto
Mdaminc
Alkyd
Varied end uses
co. duding primer 600
Resimene
RL-015
Chemical
outdoor durability Butylated, alkyd compatible
+ 0%
--t
TiO,
+ Clr
where the chlorine is recycled. Colloidally fine particle size TiOs and AlrOs were also prepared. A special flame-resistant pigment consisting of silica coated with antimony oxide was developed. Nontarnishing, precolored aluminum bronzes were also made available. Two unusual pigments were urea-formaldehyde microballoons and flaked glass. Among the special purpose additives worthy of note were three dispersing agents, three antistatic agents, and five stabilizers. Research chemicals with possibilities in coatings included dibromopropyl phosphate as a fire retardant, aminoethylaminohydroxystearylamine to improve gloss and impact resistance of epoxy resins, and N,4-dinitroso-N-methyl aniline for cross-linking a wide variety of functional groups. Equipment
Miniahin oir-driuen ngitnror con be otlnchcd to a cuprfid spray gun.
It keeps dispersed particles in SUIp m r i o n until opplicd to surf... to ba coated
54
INDUSTRIAL AND E N G I N E E R I N G C H E M I S T R Y
One of the most significant developments in paint application has been trichloroethylene phosphatizing mentioned earlier. This permits automatic conveyor line operation of cleaning, metal treatment, and painting in sequence. The painting section requires a coating containing trichloroethylene as the sole solvent. The work is flow coated just below the boiling point of the solvent (about 190" F.). As the work is withdrawn from the paint area, the trichloroethylene flashes off allowing almost instantaneous drying of the paint. The nonflammable solvent is easily recovered by condensing the vapors. Curtain maters have continued to grow in popularity, and at least three firms now manufacture these devices. The fluidized bed method of solid particle application is also under intensive development. At least five companies are producing airless atomization spray guns, and a sixth will supply an electrostatic floccing gun which charges solid particles and projects them onto the work. All of these methods aim to prevent loss of paint by application of a uniform coat confined solely to the desired surface. Related equipment is an easily cleaned roller coater especially designeil for high viscosity coatings and a special machine for spraying stripes on wheels or round parts. Surface preparation is often as important as the paint in producing good appearance. A device which removes static held dust, dirt, and lint operates by blowing a jet of ionized air on the surface. Large size magnetic masks are available for multiple color work, and masking plugs prevent paint from running into threaded holes.
