Casein-formaldehyde resin

For use from the size press it is necessary for the FBA to be compatible with the chosen size, such as starch, casein or urea-formaldehyde resin. Since sizes tend to be yellowish and to absorb ultraviolet radiation, brighteners are generally less effective in sized paper. 

Results of a 2-year paint study indicate acetylated wood is a better painting surface (37) than untreated wood. UV radiation darkens unacetylated wood, but there is no change or a slight bleached effect with acetylated wood (37). In general, acetylation reduces the adhesive strength of wood (48). Adhesive strength is reduced with urea-formaldehyde resins (54, 55) and casein glues (55), but there is very little effect with resorcinol-formaldehyde resins (55). 

UF, urea-formaldehyde resin MUF, melamine fortified UF resin MF/MUF, melamine and melamine-urea resins (MF resins are only used mixed/coreacted with UF resins MUPF, melamine-urea-phenol-formaldehyde resin PF/PUF, phenol and phenol-urea-formaldehyde resin (P)RF, resoreinol-(phenol-)formaldehyde resin PMDI, polymeric methylenediisocyanate PVAc, polyvinylacetate adhesive old nat.adhesives, old (historic) natural adhesives (e.g., starch, glutin, casein adhesives) nat.adhesives, natural adhesives (e.g., tannins, lignins, carbohydrates) inorg.adhesives, inorganic adhesives (e.g., cement, gypsum) activation activation constituents of wood to function as adhesives (i.e., lignin). 

Uses Mfg. of phenolic and thermosetting resins, furan polymers, urea-formaldehyde resins wetting agent foundry sand binders corrosion-resist, resins intermediate for esterification and etherification paints solvent, plasticizer for phenolic resins solvent for dyes and resins nonreactive epoxy resin diluent vise, reducer, cure promoter, and carrier in amine-cured epoxy resins gel retarder in casein/protein glues polymer sealants/cements synthetic flavoring agent in foods and pharmaceuticals cosmetics ingred. in food-pkg. adhesives... 

Hydrolyzed casein Hydrolyzed milk protein binder, nylon Epoxy-novolac binder, oil cosmetics Hydrolyzed rice protein binder, oil hair care Hydrolyzed rice protein binder, oil oil-absorbent formulations Hydrolyzed rice protein binder, oil skin care Hydrolyzed rice protein binder, oil-well sands Phenol-formaldehyde resin Phenolic resin binder, organic solvent systems Ethyl hydroxyethyl cellulose binder, outdoor paints Potassium silicate binder, paints... 

Particleboards Wood particles, shives of flax flakes, saw dust, bagasse, hemp, kenaf, jute, cereal straw, coconut coir, corn and cotton stalks, rice husks, vetiver roots, and other fiber sources Urea, melamine, phenol formaldehyde resin, isocyanate, resorcinol, vinyl polyacetate resins and natural polymers, tannins, protein, casein, soybeans, modified starch, lignin activated by enzymatic system polylactic and polyhydroxyhutyric acid... 

D-4689. Specification for Adhesives, Casein-Type. D-4690. Specification for Urea-Formaldehyde Resin Adhesives. ... 

The first applications of adhesives for bonding aircraft structure probably date back to about 1920, when light-weight airframes were fabricated with plasticized nitrocellulose-impregnated fabric stretched over a framework of wooden stringers. The wood adhesives used for these applications were first based on casein, then urea formaldehyde resins, and finally phenol formaldehyde resins. 

Casein is a dry protein obtained from cow s milk. It is obtained by precipitation when lowering the pH of the milk. The raw product is light in color it has a poor resistance to water, chemicals, and mold growth. Additives are commonly used to improve these properties. Water resistance is achieved through the use of urea formaldehyde resin or hexamethylenetetramine. Thickeners, thinners, inert organic fillers, nondrying oils, preservatives, humectants, and other additives are used. It is possible to hlend the casein with other adhesive substances such as soybean meal, blood albumin, latex, and synthetic rubber. 

The first man-made polymer was nitrocellulose (NC). The main use of the NC resins was a replacement of the natural and expensive materials, viz., ivory, tortoise shell products, amber, ebony, onyx or alabaster. The use of cellulose acetate (CA) as a thermoplastic began in 1926. Cellulose ethers and esters became commercially available in 1927. Casein crosslinked by formaldehyde gave horn-like materials — Galalith has been used to manufacture shirt buttons, or as imitation of ivory and porcelain [Pontio, 1919]. 

Furan resins have been extensively used as foundry binders in combination with formaldehyde, urea, phenol, and casein, for decades [12,13]. The main two monomers used in this field are 1 and 2. Table 3 summarizes their proportions in different commercial phenolic resins [12],... 

Water-based dispersions or emulsions such as polyvinyl acetate, acrylics, polyvinyl chloride and polyvinyl alcohol with plasticizers and tackifiers. In addition, this range can include urea formaldehyde and phenolic adhesives, resins, natural adhesives produced from starch, dextrin, casein, animal glues (see Polyvinyl alcohol in adhesives, Phenolic adhesives single-stage resoles. Phenolic adhesives two-stage novolacs. Animal glues and technical gelatins) and rubber latex (see Emulsion and dispersion adhesives). Solvent-free 100% solids such as polyurethane. Hot melt adhesives include Ethylene-vinyl acetate copolymers, polyolefins, polyamides, polyesters with tackifiers and waxes. More recent additions include cross-linkable systems. 

Protein-aldehyde resins n. Plastic derived from casein and formaldehyde. 

A wide range of adhesive types and chemistries are used to bond wood elements to one another (Table 2), but relatively few adhesive types are utilized to form the composites themselves. The vast majority of pressed-wood products use synthetic thermosetting adhesives. In North America the most important wood adhesives are the amino resins (qv), eg, urea-formaldehyde (UF) and melamine-formaldehyde (MF), which account for 60% by volume of adhesives used in wood composite products, followed by the phenolic resins (qv) eg, phenol-formaldehyde (PF) and resorcinol-formaldehyde (RF), which account for 32% of wood composite adhesives (12,13). The remaining 9% consists of cross-linked vinyl (X-PVAc) compounds, thermoplastic poly(vinyl acetates) (PVA), soy-modified casein, and polymeric diphenylmethylene diisocyanate (pMDI). Some products may use various combinations of these adhesives to balance cost with performance. 

Resins are also produced by molding compositions containing so bean protein and formaldehyde. Procedures similar to those previously mentioned for the production of casein resins may apparently be employed -. ... 

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