Cresol novolac

Controlled Molecular Weight Cresol Novolac Oligomers... 

Figure 7.13 Synthesis of 2,6-dimethylphenol end-capped cresol novolac resin.

Biernath et al. concluded that phenolic novolac and epoxidized cresol novolac cure reactions using triphenylphosphine as the catalyst had a short initiation period wherein the concentration of phenolate ion increased, followed by a (steady-state) propagation regime where the number of reactive phenolate species was constant.85 The epoxy ring opening was reportedly first order in the steady-state regime. 

R. W. Biemath and D. S. Soane, Cure Kinetics of Epoxy Cresol Novolac Encap-sulant for Microelectronic Packaging, in Contemporary Topic in Polymer Science. Advances in New Material. Vol. 7, J. S. Salamone and J. S. Riffle (Eds.), Plenum, New York, 1992, pp. 103-160. 

PAR. See Polyarylate (PAR) para-Cresol (p-cresol), 384-385 para-Cresol novolac resin, 425 Paraformaldehyde, 377, 398 Para-para methylene linkages, 393, 395,... 

The literature on basic- and acid-catalyzed alkylation of phenol and of its derivatives is wide [1,2], since this class of reactions finds industrial application for the synthesis of several intermediates 2-methylphenol as a monomer for the synthesis of epoxy cresol novolac resin 2,5-dimethylphenol as an intermediate for the synthesis of antiseptics, dyes and antioxidants 2,6-dimethylphenol used for the manufacture of polyphenylenoxide resins, and 2,3,6-trimethylphenol as a starting material for the synthesis of vitamin E. The nature of the products obtained in phenol methylation is affected by the surface characteristics of the catalyst, since catalysts having acid features address the electrophilic substitution in the ortho and para positions with respect to the hydroxy group (steric effects in confined environments may however affect the ortho/para-C-alkylation ratio), while with basic catalysts the ortho positions become the... 

Cresex process, l 676t Cresol epoxy novolacs, 10 369 Cresol novolacs, 10 406 Cresols, from propylene, 20 786-787 m-Cresol, 20 268. See also 3-Methylphenol antimicrobial used in cosmetics, 7 831t o-Cresol. See also 2-Methylphenol... 

See also Epoxy coatings Epoxy chalcone, 10 450 12,13-Epoxy-cis-9-octadecenoic (vernolic) acid, physical properties, 5 35t Epoxy coatings, 10 436 450 17 845. See also Epoxy can coatings for corrosion protection, 7 199 markets for, 10 442-449 performance of, 10 423 waterborne, 10 439 Epoxy composites, 10 450, 451 Epoxy compounds, photoinitiated polymerization of, 23 716 Epoxy content analysis, 10 385 Epoxy cresol novolac (ECN) resins, 10 367, 369... 

Resist solutions of o-cresol novolac-siloxane copolymers were prepared as 15 w/v % solutions of the polymer in 2-methoxyethyl acetate using 20 wt % (based on polymer) of the positive sensitizer. Poly(hydroxystyrene) and 2-methyl resorcinol copolymers were spun into films from 2-methyl tetrahydrofuran. Solutions were filtered through successive 1.0, 0.5 and 0.2 pm filters and stored in... 

A series of o-cresol novolac-PDMSX materials with a range of silicon contents (3.2-16.1 wt %) were prepared to examine the O2 REE response and to determine whether a solubility limit existed as a function of wt % silicon. All copolymer preparations exhibited good solubility in dilute TMAH and an asymptotic relationship (12) between wt % silicon and film thickness loss (3,12) during an 02 plasma RIE process was found. 

THERMAL CHARACTERIZATION OF O-CRESOL NOVOLAC-DIMETHYL SILOXANE COPOLYMERS... 

Auger depth profiling results of (a) 2-methyl resorcinol-PDMSX, (b) o-cresol novolac-PDMSX, and (c) poly(hydroxy-styrene)-PDMSX. 

The incorporation of PDMSX into conventional novolac resins has produced potential bilevel resist materials. Adequate silicon contents necessary for O2 RIE resistance can be achieved without sacrificing aqueous TMAH solubility. Positive resist formulations using an o-cresol novolac-PDMSX (510 g/mole) copolymer with a diazonaphthoquinone dissolution inhibitor have demonstrated a resolution of coded 0.5 pm L/S patterns at a dose of 156 mJ/cm2 upon deep-UV irradiation. A 1 18 O2 etching selectivity versus hard-baked photoresist allows dry pattern transfer into the bilevel structure. 

Figure 7 Scanning electron microscope photographs of coded 0.5 (im line-space patterns obtained in the o-cresol novolac-PDMSX ( = 510 g/mole) based resist followed by O2 RIE pattern transfer.

Acetylated m-cresol novolac copolymers were prepared by acetylation of m-cresol novolac with acetic anhydride in the presence of sodium hydroxide. The following acetylation procedure is typical. 3.2g of sodium hydroxide (50 mmol) was added to 4.8g of cresol novolac (40mmol) in 10 ml. of water. The reaction mixture was stirred for 10 mins, until all polymer went into solution. The required amount of acetic anhydride was then added, the reaction mixture was stirred for 10 more mins, and poured in 150 ml. of iced water. The polymer was filtered and purified by reprecipitation from a chloroform/benzene (5 2 v/v) solution by the addition of hexane. The acetylation content was determined by H and 13C NMR. 

Ti incorporation was also found to be a function of the background (residual) pressure in the GFC. Table I lists Ti incorporations for 3 different m-cresol novolac polymers that were treated with TiCLt f°r 1 min. after evacuation of the reaction cell to 110 and 220 mtorr. The polymers that were treated at 220 mtorr had 1.5 times more Ti than those treated at 110 mtorr. Similar experiments conducted with HB-HPR 206 films show a linear relationship between the residual pressure in the GFC and thickness of the resulting Ti02 layer. 

Table V. Ti Concentrations on Acetylated m-Cresol Novolac Copolymers as a Function of mole % Acetyl Groups1...

Figure 5. RBS spectra of a m-cresol novolac film treated with TiCU for 2 mins, (dotted line) and then etched for 30 mins, by O2 RIE (solid line).

TiCU readily functionalizes hydrophilic polymers such as poly(vinyl alcohol), m-ciesol novolac and methacrylic acid copolymers as well as moderately hydrophobic polymers such as poly(methyl methacrylate), poly(vinyl acetate), poly(benzyl methacrylate) and fully acetylated m-cresol novolac. HCI4 did not react with poly(styrene) to form etch resistant films indicating that very hydrophobic films follow a different reaction pathway. RBS analysis revealed that Ti is present only on the surface of hydrophilic and moderately hydrophobic polymer films, whereas it was found diffused through the entire thickness of the poly(styrene) films. The reaction pathways of hydrophilic and hydrophobic polymers with HCI4 are different because TiCl is hydrolysed by the surface water at the hydrophilic polymer surfaces to form an etch resistant T1O2 layer. Lack of such surface water in hydrophobic polymers explains the absence of a surface TiC>2 layer and the poor etching selectivities. 

Varcum 29-801 (BTL Speciality Corp.) Ortho-Cresol Novolac 90-100 (a)... 

Table IV lists the planarization of 20 - 400 [im wide holes achieved by unbaked and baked films of positive photoresist, ortho-cresol novolac and poly(o>-methylstyrene).

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