Dow Industrial Specialty Polymers in Inks and Coatings

Duplicating inks
Flexographic and gravure inks
Gel lacquers
Heat transfer inks
Hot melt inks
Hot melt strippable coatings
Ink jet coatings
Paper coatings
Printing inks
Room temperature lacquers
Thermal paper coatings

Duplicating inks – In ink manufacture, CELLOSIZE™ Hydroxyethyl Cellulose is used for the production of waterborne duplicating inks that dry rapidly without setoff or bleeding.

Flexographic and gravure inks – ETHOCEL™ Ethylcellulose polymers are widely used in flexographic inks for packaging and in both publication and packaging gravure inks.

ETHOCEL Ethylcellulose polymers function as rheology modifiers, dispersants and binders for pigments, and as polymeric binders for pigment chips. They contribute to formation of tough, abrasion resistant films. Because films of ETHOCEL Polymers are permeable, they dry quickly. ETHOCEL Polymers reduce the tack of ink films and improve printability on difficult substrates.

ETHOCEL Ethylcellulose polymers are compatible with other ink components such as resins, solvents and pigments. ETHOCEL Polymers also function to improve gloss, adhesion and abrasion resistance. The resulting ink film is tough and pinhole-free even at coating thicknesses of a few microns.

ETHOCEL Standard 6, Standard 10, Standard 45, and Standard 200 Ethylcellulose polymers are more often used in flexographic and gravure inks.

As an example, a flexographic formulation could contain:

Component	Parts
Polyamide resin	13
ETHOCEL Standard 10 industrial	7
Organic pigment	15
Plasticizers, waxes	5
Solvent	60

As an example, a gravure formulation could contain:

Component	Parts
Pigments	8
ETHOCEL Standard 10 industrial	30
Solvents	56
Clay/filler	5
Others	1

Gel lacquers – A gel lacquer is a homogeneous liquid when hot, a tough gelatin-like mass when cool. When room-temperature objects, such as generator field coils or glass bottles, are dipped into the solution, a tight-fitting uniformly heavy plastic coating results. Typical gel lacquer formulations are simple-primarily comprised of ETHOCEL polymer, with a lesser amount of plasticizer, dissolved in an aromatic hydrocarbon-alcohol mixture.

Heat transfer inks – In heat transfer printing, the ink is printed or deposited onto paper and then transferred with heat to fabrics (e.g., polyesters, triacetate, and acrylics).

As an example, a heat transfer ink formulation could contain:

Component	Parts
Dye	1 - 5
ETHOCEL Std 10	12 - 20
Solvent	75 - 85
Thermoplastic binder (for tack)	0 - 10

Hot melt inks – ETHOCEL Ethylcellulose polymers may be used as the base resin in formulating solvent-free hot-melt inks, which are used to print textile fabrics and novelty designs and information on T-shirts, manufacturers' labels, and patterns for embroidery.

A general composition is:

Component	Parts
Castor oil	10
Paraffin wax	40
ETHOCEL Std 10	20
Pigments	20
Heat stabilizer	0 - 10

All ingredients except the ETHOCEL Polymer are heated to 150° C. The ETHOCEL Polymer is added slowly, with agitation. A homogeneous liquid ink results when the ETHOCEL Polymer melts.

Hot melt strippable coatings – Hot melt coatings are used to protect metal parts from corrosion or damage during handling, shipping, and storage. Parts are dipped into a hot dip-tank containing a solution typically made of ETHOCEL polymers mixed with oils, plasticizers, and other materials. When removed and cooled, the resilient, air-tight, strippable coating protects the parts until they are needed.

Ink jet coatings – POLYOX™ Water-Soluble Resins are used in high-end ink jet coatings for overheads and specialty paper for color images. They absorb water and act as binders. Technologies using POLYOX Water-Soluble Resins allow for more layers of ink to be added to a single sheet, which imparts greater color and definition. POLYOX WSR N-750, WSR N-10, and WSR N-3000 Water-Soluble Resins are most often recommended for ink jet coatings.

Paper coatings – ETHOCEL Ethylcellulose polymers create paper coatings with remarkable toughness, resistance to scuffing, and flexibility at both room temperature and low temperatures. Coatings made with ETHOCEL Polymers have better gloss, better block resistance, and retain low water vapor transmission rates.

The use of CELLOSIZE HEC also contributes to improved grease resistance. For oil- and grease-proof coatings, use about two pounds per 1000-square feet (10 grams per square meter) of surface. Coatings may be applied by blade, air-knife, or roll coating.

CELLOSIZE Hydroxyethyl Cellulose increases the water retention of coating colors, particularly with coatings containing high proportions of latex, where the penetration of adhesive into the base sheet must be controlled. As a starting point, add about 0.5 to 1.0 percent of CELLOSIZE HEC QP 09, based on pigment. If higher viscosity can be tolerated, substitute CELLOSIZE HEC QP 3 or QP 40 for CELLOSIZE HEC QP 09.

METHOCEL™ Cellulose Ethers are also used in pressure-applied paper coatings. The METHOCEL Polymer can be dissolved in methanol/water mixtures to form a high-viscosity paste which is then applied to the sheet under pressure.

Printing inks – METHOCEL Cellulose Ethers are used as thickeners and suspending agents for water-based inks.

Room temperature lacquers – Coating formulators have used ETHOCEL Ethylcellulose polymers to develop many different lacquer products over the past 60 years. The solubility and viscosity properties of ETHOCEL Polymers are well-known, reliable and predictable; they are compatible with a wide variety of solvents, aromatic hydrocarbon-alcohol mixtures, plasticizers, resins, pigments and dyes. And because ETHOCEL Ethylcellulose polymers are supplied in 19 industrial grades, coating formulators get unsurpassed freedom to create and modify lacquer products.

Thermal paper coatings – METHOCEL Cellulose Ethers are used as coatings for thermal printing papers used in receipts, airline tickets, and similar applications. METHOCEL A15LV Cellulose Ether is used in this application.