Binder systems

The binder system of a plastic encapsulant consists of an epoxy resin, a hardener or curing agent, and an accelerating catalyst system. The conversion of epoxies from the Hquid (thermoplastic) state to tough, hard, thermoset soHds is accompHshed by the addition of chemically active compounds known as curing agents. Flame retardants (qv), usually in the form of halogens, are added to the epoxy resin backbone because epoxy resins are inherently flammable. 

Solvents. Solvents in house paints serve several essential purposes. They keep the binder dispersed or dissolved and the pigments dispersed in an easy-to-use state. Solvents allow the paint to be appHed in the correct thickness and uniformity, and evaporate from the paint film after the paint is apphed. Solvent choice is limited mainly to a solvent that is compatible with the binder system and that has the desked evaporation rate and toxicity profile. The volatility or evaporation rate of a solvent determines to a large extent the open-time and dry-time properties of a paint (6). 

Plasticizers. Plasticizers (36—38) are often added to a binder to reduce cross-link density and increase flexibiHty. Plasticizers improve toughness, springback, and flexibiHty, but degrade overall green strength. Additionally, plasticizers can increase the sensitivity of a binder system to moisture. 

Floor paints, in a wide range of colors and based on a number of different binder systems, are used extensively for concrete floors in light industrial applications. 

When formulating a system for optimum abrasion resistance, both the epoxy/resin hardener binder system and the filler blends used appear to have an influence. The simulation of abrasive service loads on industrial floor toppings in a laboratory is not simple, and numerous wear test machines have been devised. Correlation between different wear test machines is not always good, although most... 

The paint technologist entrusted with the task of formulating a paint to meet a specified set of conditions must first decide what type of binders he should use and the type of solvent blend that this will require. In the particular case of a finish, he must then select the pigments most likely to give the required colour, bearing in mind any limitations imposed by his choice of binder system or by the conditions to which the paint will be subjected. 

In the case of a composite binder system, the optimum proportion of each. 

Macromolecular Materials and Engineering 286, No.ll, 30thNov.2001, p.695-704 UV CURABILITY AND MECHANICAL PROPERTIES OF NOVEL BINDER SYSTEMS DERIVED FROM POLY(ETHYLENE TEREPHTHALATE)(PET) WASTE FOR SOLVENTLESS MAGNETIC TAPE MANUFACTURING. I. ACRYLATED OLIGOESTERS Farahat M S Nikles D E Alabama,University... 

Air Products, a manufacture of latex binders, has completed a comprehensive study of flame retardants for latex binder systems. This study evaluates the inherent flammability of the major polymer types used as nonwovens binders. In addition, 18 of the most common flame retardants from several classes of materials were evaluated on polyester and rayon substrates. Two of the most widely recognized and stringent small scale tests, the NFPA 701 vertical burn test and the MVSS-302 horizontal burn test, are employed to measure flame retardancy of a latex binder-flame retardant system. Quantitative results of the study indicate clear-cut choices of latex binders for flame retardant nonwoven substrates, as well as the most effective binder-flame retardant combinations available. 

P.Y.117 is very lightfast and weatherfast. 1/3 to 1/25 SD formulations in an alkyd-melamine resin equal step 8 on the Blue Scale for lightfastness, while 1 200 SD samples still reach step 7. The weatherfastness of the pigment in this range of standard depths and in this binder system equals approximately that of P.Y.153, but is not quite as high as that of P.Y.129. P.Y.117 was also recommended for use in emulsion paints. 

Nonstabilized a-Copper Phthalocyanine Blue is utilized in the printing industry, to a certain extent in oil-based binder systems, such as offset printing inks for packaging and metal deco printing. Under standard conditions, P.B.15 is stable to a variety of organic solvents, such as alcohols, esters, ketones, aliphatic hydrocar-... 

Resinated types are supplied for use in so-called oily binder systems for offset printing inks. However, these are much fewer in number than corresponding P.R.57 1 types which are used to produce the standard shade of ruby, or azo yellow pigments, which are used for standard yellow. 

Deep shades of maroon tend to form water spots in certain binder systems, especially in media which are based on acrylic resin. More or less distinctive light spots appear on the coating. The effects that cause this phenomenon remain to be elucidated. Factors such as long-term weathering at elevated temperature, U V radiation, and the presence of demineralized water probably cause reduction and solvation effects within the coating. Products are available which are much less susceptible to these agents. Rub-out effects, especially flocculation, may also present problems in various binder systems. Special-purpose grades are therefore available which are more stable to flocculation. 

The basic constituents in a self-polishing antifouling paint are 1) the binder system, 2) the biocides and pigments and 3) the solvents. 

A powder coating is the result of the application of a powder binder system, which generally consists of a resin, a crosslinker, flow additives, degassing agents, pigments or dyes, charge control agents, etc. Such a binder system is ap-pHed to the substrate as a fine, extruded powder (Fig. 20, step A), then melted at... 

Fig. 20a-d. Schematic representation of the different phases of the application of a powder binder system left - the ideal case right - the unbalanced flow/cure of a system, resulting in an orange peel surface of the coating... 

In pigment printing the dyestuff pigments are bound to the textile by means of a polymer binder system and no additional washing is performed however, wastewater is released from the cleaning of the equipment and machinery. 

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