Slip and Mar

Some of these have already been discussed in the preceding sections. However, they will be reconsidered here with their relevance to wood coatings. 

Coalescents used in wood finishes include butoxy propanol, butoxy propoxy propanol, Texanol and propylene glycol. Butoxy ethanol (butyl glycol) was a very popular coalescent, but due to its toxicity, it is much less popular now. 

Conventional silica matting agents can be used. Some suppliers manufacture specific grades for use in water based systems, but, in general, standard grades are suitable. 

Care must be taken in selection as rheological properties can be affected by matting agents, especially if high levels or fine particle size grades are used, which can lead to poor flow or air entrapment. 

Waxes or wax dispersions are used to control sheen, to improve feel and to reduce hard settlement. These waxes and dispersions can produce greatly enhanced feel, slip and anti blocking properties as well as reducing sheen levels. 

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Uses Used in any type of coating (varnish, stain, solv.- or water-based, bake or air dry enamels) food pkg. coatings Features Exc. weather durability, water repellency, improved salt spray and humidity resist., improved slip and mar resist. min. effect on dirt pick-up, gloss, and clarity preserves integrity of thermoplastic coatings Reguiatory FDA 21CFR 175.300... 

Features Exc. compat. in common water-based binders very good release, slip, and mar resist. 

Surfactants are used, especially in water-based formulations, to improve wetting, dispersion, slip and mar properties and defoaming. The group includes ethoxylated products, acetylenic alcohols and diols and proprietary additives. 

The concepts of slip and mar (or scratch) resistance in coatings are very closely interrelated in that the same additive may perform both functions impart slip and provide scratch resistance. In addition, the principle underlying both is the same. A hard object touching a paint film containing an additive can be deflected due to the surface lubricity of the additive. This results in a greater apparent film hardness or scratch resistance. ... 

Slip and mar are important properties of the finished dried coating and can be significantly improved by the careful use of silicone additives and waxes. The wrong selection can lead to foaming problems. 

It is not necessary to have all of the above additives in a given formulation. Some additives may well fill multiple roles, e.g. a wax dispersion could have a matting effect and impart slip and mar resistance. It may also be necessary to have more than one from a given group, e.g. it may be necessary to have one defoamer in a millbase and another in the finished product. 

Uses Surfactant reducing surf, tens, antifoam, flow and leveling agent, slip and mar aid for solv,- and aq, coatings and inks based on alkyds, epoxy, urethanes, acrylics improves pigment and substrate wetting Properties Lt, amber cl, liq, sp,gr, 0,96-0.965 dens. 8.0 Ib/gal flash pt. (PMCC) > 54 C... 

Uses Surf, additive, slip agent, wetting agent, scratch and mar resistance aid for paints, printing inks Features Increases surface slip, substrate wetting Properties Colorless to bmsh. liq. mild ether-like odor sp.gr. 1.03 dens. 8.57 Ib/gal Hash pt. (Seta) 65 C ref. index 1.447 > 97% NV Toxicology TSCAIist ... 

Uses Surfactant, lubricant for fibers and plastics, metal-to-plastic wear interlaces antitack and mar resist, aid for urethane coatings slip agent in flexographic and gravure inks... 

Uses Surfactant, surf. tens, reducer, wetting agent, flow control agent, leveling agent, slip agent, mar aid tor solv- and water-based coatings and inte based on ali ds, epoxy, urethanes, acrylics Properties Lt. amber clear liq. sp.gr. 0.94-0.95 dens. 7.8-7.9 Ib/gal flash pt. (PMCC) 66 C nonionic Use Level 0.1-0.3%... 

Uses Slip agent, mar resist, aid for coil coatings, wood lacquers, powd. coatings, flexible and rigid pkg., UV clears, architectural paints food pkg. adhesives, coatings... 

Uses Anticaking agent flow control agent, slip agenL mar and scratch additive in solvent and solventless systems incl. alkyds, epoxies, acrylics, PVC, two-component PU... 

Chem. Descrip. Polysiloxane and butyl glycol Uses Flow control agent, leveling aid, slip aid, mar resist, aid in high-solids industrial coatings (alkyds, epoxies, acrylics, PVC, PU) Properties Gardner 2 color dens. 8.1 Ib/gal vise. 65 cps VOC 50.5% (EPA method 24) 50% act., 44.2% solids Use Level 0.1 -0.5% on total wt. 

Chem. Descrip. 100% Synthetic micronized wax blend CAS 8002-74-2 EINECS/ELINCS 232-315-6 Uses Surf, conditioner, abrasion resist, aid, antiblocking agent, slip agent, mar resist, aid for waterborne or solvent-borne coatings, wood furniture coatings, inks, overprint varnishes, food-contact coatings Features Exc. slip and product release Regulatory FDA 21 CFR 175.300... 

Mechanical properties such as hardness, scratch resistance and mar resistance of the coating surface as well as the surface slip are mainly defined by the binder of the system use of additives makes it possible to control such surface characteristics independently from the coating binder. 

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