Urea/aldehyde resin

Urea/aldehyde resins (Figures 9.7 and A3.23) (de la Rie et al., 2002) are made by condensing urea, formaldehyde and i-butyraldehyde. These resins wet pigment particles well because of their polar groups. 

Following extensive testing, the urea/aldehyde resin Laropal A-81 has been introduced to create light-stable retouching paints (Leonard et al., 2000), and has been used as a varnish component (Arslanoglu and Learner, 2001) in combination with Paraloid B-72. 

Urea-formaldehyde resins are the most prominent examples of the thermosetting resins usually referred to as amino resins, comprising ca. 80% of the amino resins produced worldwide. Melamine-formaldehyde resins constitute most of the remainder of this class of resins, with other minor amounts of resins being produced from the other aldehydes or amino compounds (especially aniline), or both. 

In far too many instances trade-name polymer nomenclature conveys very little meaning regarding the structure of a polymer. Many condensation polymers, in fact, seem not to have names. Thus the polymer obtained by the step polymerization of formaldehyde and phenol is variously referred to a phenol-formaldehyde polymer, phenol-formaldehyde resin, phenolic, phenolic resin, and phenoplast. Polymers of formaldehyde or other aldehydes with urea or melamine are generally referred to as amino resins or aminoplasts without any more specific names. It is often extremely difficult to determine which aldehyde and which amino monomers have been used to synthesize a particular polymer being referred to as an amino resin. More specific nomenclature, if it can be called that, is afforded by indicating the two reactants as in names such as urea-formaldehyde resin or melamine-formaldehyde resin. 

Among solid rocket propellants, Belgrano mentions the mixtures of Na Nitrate Amm Picrate with thermoplastic resin of urea-aldehyde type... 

Biirnmtfigg ji butyl urea-form aldehyde resin manuf during WWII by the Sharpies Solvent Co,... 

Great Britain BIP Chemicals Beetle Melmex Based on urea-formaldehyde resin and cellulose filler processable by moulding and injection moulding Based on melamine-form-aldehyde resin and cellulose filler... 

O-tethered P-keto esters, through the intermediacy of aiylidene keto esters, have been efficiently utilized for the construction of immobilized dihydropyridines. Ceric ammonium nitrate (CAN) oxidation to pyridines followed by acidolytic cleavage provides a facile entry into nicotinic acid derivatives 57 [42], A three-component Biginelli cyclization of ureas on resin with a solution mixture of aldehydes and P-keto esters provides dihydropyrimidines 58 in high yield and purity [43], Heterocycles such as dihydropyridines and pyrimidines have historically proven to be a rich source of antimicrobial, antitumor, antiviral, and cardiovascular agents. 

Besides, furfural polymerizes in the presence of an acid catalyst with phenol, urea, and acetone. In this regard, the phenol-furfural and urea-furfural resins are important [221-223], Furfural reacts usually as does all a-substituted aldehydes in this regard, with phenol it condenses in the presence of either alkali or acid to form synthetic resins in a reaction that is very similar to that of phenol with formaldehyde or acetaldehyde [223],... 

Alkyd and polyester resins, epoxy compounds, phenol-formaldehyde resin, urea and/or melamine-aldehyde resin, cyclic urea resin, carbamide acid ester formaldehyde resin, ketone formaldehyde resin, polyurethane, polyvinylester, polyvinyl acetate, polyvinyl chloride and polymer mixtures, polyethylene, polystryrene, styrene mixtures and graft copolymers, polyamide, polycarbonate, polyvinyl ether, polyacrylic and methacrylic acid esters, polyvinyl flouride, polyvinylidene chloride copolymers, UV and/or electron irradiated lacquers. 

Other types of resin modifiers compatible with resols may also be used. Examples include UF (urea-aldehyde condensation product) and epoxide. Japanese workers have found that the most effective and economical ingredients as modifiers for phenolic foam are resorcinol, o-cresol, and fulfuryl alcohol. 

Foundrez [Reichhold], TM for a group of water-soluble phenol-formaldehyde and urea-form-aldehyde resins for foundry applications. 

A cationic starch can be prepared by blending a condensate of formaldehyde plus an inorganic ammonium salt with starch and heating at 80 °C for up to 1 h.1316 A great interest was developed with urea-formaldehyde resins that were made to react with such polyalcohols as starch.1317-1319 It was reported that the reaction of starch with urea-formaldehyde resin required an acidic catalyst592,1320-1325 and the use of such dispersants as polyphosphates.1326 Ammonium metaphosphate catalyzed the reaction without the addition of any other acid catalyst.1327 A product that formed a paste was produced by controlling the proportion of starch to aldehyde (either up to 20% of formaldehyde or up to 30% of acetaldehyde) and urea (up to 15%) at pH 2 1.1328... 

Materials from starch crosslinked with melamine-formaldehyde, methylated melamine-formaldehyde, and other amine-aldehyde resins were patented as binders for filter paper,1336 milk filter sheet materials,1338 and aqueous papercoating compositions containing clay, titanium(IV) oxide, butadiene-styrene latex, and calcium octadecanoate.1396,1397 Foams for filters were developed.1398 A heatsetting adhesive was one of the first applications reported for starch crosslinked by urea-formaldehyde and phenol-formaldehyde resins.1331,1340-1342,1347,1372,1399... 

The main application fields of aldehyde scavengers are PET (more specifically wafer bottles made from PET), and polyacetals such as POM or polymers synthesized from formaldehyde such as urea-formaldehyde resins. 

CONTENTS OF VOLUME D, SECOND EDITION Chapter 1. Urea, Melamine, Benzoguanamine-Aldehyde Resins (Amino Resins or Aminoplasts)... 

HCOH) A colorless gaseous aldehyde. It is manufactured by the oxidation of methanol (500°C and a silver catalyst) 2CH3OH + 02 2HCOH + 2H2O The compound is used in the manufacture of urea-formaldehyde resins. A solution of methanal (40%) in water is called formalin. It is extensively used as a preservative for biological specimens. 

A great percentage of the sand binders used by the foundry industry are made of phenol- and urea-formaldehyde resins, phenolic- and oil-isocyanate resins, and furan resins. Almost all these binders and their decomposition products such as ketones, aldehydes and ammonia are toxic. The principal effect on man is dermatitis, which occurs not so much from completely polymerized resins, but rather from the excess of free phenol, free formaldehyde, alcohol or hexamethylenetramine used as... 

Xiao, H. Jiang, J. Tang, Y. Study on encapsulation of poly-alpha-olefin with PVA-modified urea-form-aldehyde resin. Huaxue Yanjiu Yu Yingyong (2008), 20(6), 696-699. 

Formaldehyde/urea condensate Formaldehyde/urea copolymer Form-aldehyde/urea polymer Formaldehyde/urea precondensate Formaldehyde/urea epolymer Formaldehyde/urea resin. See Urea-formaldehyde resin... 

CAS 68002-19-7 93686-54-5 EINECS/ELINCS 297-708-7 Synonyms Butylated polyoxymethylene urea (INCI) Butylated urea-form-aldehyde resin Poly (urea-co-formaldehyde), butylated Urea, polymer with formaldehyde, butylated Urea, reaction prods, with butyl alcohol and formaldehyde Classification Eormaldehyde copolymer... 

Formic acid propyl ester. See Propyl formate Formic acid sodium salt. See Sodium formate Formic aldehyde. See Formaldehyde Formic ether. See Ethyl formate Formimidic acid, 1-carbamoyl-. SeeOxamide Formol 55. See Urea-formaldehyde resin Formol. See Formaldehyde Formonitrile. See Hydrogen cyanide Formosa camphor. See Camphor Formosa camphor oil Formose oil of campor. See Camphor (Cinnamomum camphora) oil Formosol. See Sodium formaldehyde sulfoxylate... 

Aldehyde resin n. Synthetic resin made by treating various aldehydes with condensation agents. Phenol, urea, aniline, and melamine react readily with aldehydes, such as formaldehyde, which are also called Aldehyde Resins G Aldehydharz n, F resine... 

The catalysts required by plastics may be classified as (1) strong add catalysts (e.g., sulfuric acid, hydrochloric acid, and phosphoric acid alone or in combination with modifiers), (2) latent acid catalysts (e.g., ammonium salts of strong acids such as ammonium chloride generally useful in accelerating the setting of urea or melamine resins), (3) aldehydic catalysts (e.g., catalysts peculiar to phenol-formaldehyde and urea-formaldehyde resins such as paraformaldehyde and hexamethylenetetramine often used in urea and resorcinol adhesives), and (4) peroxide catalysts (e.g., benzoyl peroxide and dicumyl peroxide promote polymerization of polyesters through a free radical mechanism). 

FIGURE 9.7 Aldehyde resin. Condensate of urea, formaldehyde and i-butyraldehyde, indicative structure (e.g. Laropal A 81). 

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