Cresol formaldehyde resin

Pale crepe, 20 cresol-formaldehyde resin, 2 hexamethylene tetramine, 3 dicumyl peroxide 50min at 140° C Methyl methacrylate 91 95 12 -—... 

The UV-absorption spectra of these Novolak resins vary widely depending upon substitution. However, the m-cresol-benzaldehyde Novolak resin is characteristic in its transparency within 300-320 nm in comparison with the cresol-formaldehyde resin. The chlorinated Novolak resin made of 2-chloro-5-methylphenol and formaldehyde has a slightly stronger UV absorption in this wavelength range, but weaker absorption in the range of 250 and 300 nm in comparison with a commercially available cresol-formaldehyde Novolak resin, as shown in Figure 4. 

These resins (Resole or Novolac) are used as curing agents or hardeners for epoxy molding compounds for electronics applications such as computer components. 0-cresol-formaldehyde resins have heen also used to modify phenol-formaldehyde resins, and in laminates. 

The major producers of cresol-formaldehyde resins are Borden Chemicals and Schenectady Chemicals USA. Approximately 1800 tpa of these resins are produced in USA. Reportedly in W. Europe and Japan, o-cresol is used along with phenol-formaldehyde resins. Three to five percent annual growth for these resins has heen projected. 

In India, hoth Cihatul (now Atul) and Hindustan Ciba Geigy have been producing some quantities of o-cresol-formaldehyde resins. 

It has been established that o-cresol-based o-cresol-formaldehyde resins have proved to be very effective as addition/substitution products in more popular phenol-formaldehyde resins for industrial laminates (printed circuit board), etc. 

E. Gipstein, A.C. Ouano and T. Tompkins, "Evaluation of pure novolak cresol-formaldehyde resins for deep UV lithography," J. Electrochem. Soc. 129, 201 (1982)... 

Next, test for phenols (see Section 6.1.3). They may result from phenol and cresol formaldehyde resins and also from epoxy resins or polycarbonates based on bisphenol A. 

Phenolic plastics. Collective designation for phenolic resin-based plastics. Phenolic resins are produced by condensation of phenol and/or its homologues, such as cresol, with an aldehyde, such as formaldehyde or with an aldehyde-releasing material such as hexamethylenetetramine. Phenol/formaldehyde and/or cresol/formaldehyde resins are used as binding materials in fibre board, laminated paper and fabrics. In phenolic moulding compounds, the proportion of filler (such as wood flour, rock flour, asbestos, stone powder, mica, glass fibre) can be equal to that of the resin. These thermosets can be processed by compression or injection moulding into black or dark-coloured products mainly for the electric industry. 

The monomer is obtained by reacting bisphenol A with epichlorohydrin. Compounds with q = 0.1-0.6 are liquids, those with q = 2-12 are solids. Other epoxide resins are based on epoxidized phenol/formaldehyde and cresol/formaldehyde resins, or on cycloaliphatic or heterocyclic structures. Commercially available epoxide resins are generally compounded, that is, they also contain plasticizers, diluents, pigments, etc. 

Examples of this can be found with phenol-formaldehyde, urea-formaldehyde, glyptal, and shellac resins (for formulae see p. 39). In Fig. 22 the change of highly elastic deformability is demonstrated for a cresol-formaldehyde resin and for shellac, showing that in both cases a certain degree of polymerisation is necessary for high-elasticity to be observed (the sol must ... 

Cellulose acetate Cellulose acetate-butyrate Cellulose acetate-propionate Cresol-formaldehyde resin Epichlorohydrin-ethylene oxide rubber Epichlorohydrin rubber (see also CO)... 

Polychlorotrifluoroethylene (also CFM, CTFEP, PCTFE) Cresol-formaldehyde resins (also reinforcing carbon fiber) Polychlorotrifluoroethylene (also CEM, CTFEP, PCTFE) Elastomeric copolymer from epichlorohydrin and ethylene oxide... 

Cresol kre- s61 [ISV, irreg. fi. cresote] (ca. 1869) (hydroxytoluene, methylphenol) n. H3CC6H4OH. An important family of coal-tar derivatives, occurring in ortho, meta, and para isomers, and used in the production of phenol-formaldehyde resins and tricresyl phosphate, an important plasticizer for PVC. Three cresols are possible, namely (a) o-cresol, mp 30°C bp, 19rC (b) m-cresol, mp 4°C bp, 205°C (c) p-cresol, mp 36°C bp, 201°C, and these are found together in the crude cresylic acid from coal tar. The main use of the cresols is in the manufacture of cresol-formaldehyde resins, and cresylic acid, rich in the meta isomer, is usually chosen for this purpose. 

For applications, where a high resolution is required, e.g. IC technology and optical recording, resist systems based on novolak (a cresol-formaldehyde resin) or poly(vinyl phenol) are utilized. These resists are developed in aqueous base, which causes no swelling of the polymer and therefore no loss of pattern definition. 

Pale crepe, 20 cresol-formaldehyde resin, 2 hexamethylene tetramine,... 

Multifunctional epoxy resins such as aromatic glycidyl ether resins and aromatic glycidyl amine resins are commercially available. Commercially important epoxy phenol Novolac resins and epoxy cresol Novolac resins are prepared from excess epichlohydrin and phenol-formaldehyde or o-cresol-formaldehyde resins. The high functionality of these Novolac resins increases crosslink density and improves thermal stability and chemical resistance ... 

Radiation-induced decomposition or chemical alteration of the dissolution inhibitor restores the solubility of the polymeric matrix. For example, certain polysulfones and polyaldehydes (for general structures, see Chart 5.10) will act as dissolution inhibitors when blended with phenol formaldehyde or cresol formaldehyde resins. 

Novolak (cresol-formaldehyde) resins were converted into positive working resists by partial esterification of the phenolic groups with di-t-butylcarbonate. 

BSH Benzene sulfonyl hydrazide (WTR) cresol-formaldehyde resin (ASTM, DIN,... 

CF cresol-formaldehyde resins (also reinforcing carbon fiber)... 

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