Phenolic resin, adhesives

Phenolic novolacs, 18 760-761 Phenolic resin adhesives, 18 783-784 Phenolic resin can coatings, 18 38 Phenolic resin composites, 18 792-794 Phenolic resin drying-oil varnishes, 18 783 Phenolic resin fibers, 18 797-798 mechanical properties of, 18 798 Phenolic resin foam, 18 795-796 Phenolic resin manufacturers, U.S., 18 774 Phenolic resin polymerization, 18 760-765 alkaline catalysts in, 18 762-765 neutral catalysts in, 18 761-762 strong-acid catalysts in, 18 760-761 Phenolic resin prepregs, 18 793 Phenolic resin production unit, 18 766 Phenolic resins, 10 409 18 754-755, 756-802 22 10 26 763 in abrasive materials, 18 786-787 in air and oil filters, 18 790 additional reactants in, 18 759 analytical methods for, 18 774-779 applications of, 18 781-798 batch processes for, 18 766 from biomass and biochemical processes, 18 769-770... 

The efficiency of ethylene glycol-water as a delignifying solvent has been demonstrated by Gast and Puls (10). Results showed that sufficiently delignified pulps could be obtained. Also, the lignins produced showed promising results as extenders in phenolic resin adhesives. 

It is becoming apparent that wood components, especially lignin, are chemically modified by solvents during wood dissolution, and that the resulting wood tars or pastes become highly reactive. Attempts have therefore been made to prepare effective adhesives, moldable resins and other products from wood after dissolution in phenols or polyhydric alcohols. This review presents recent progress on wood dissolution, and on the preparation of epoxy and phenol resin adhesives from kraft lignin. 

Resol-Type Phenol Resin Adhesives from Kraft Lignin... 

Adhesives (qv) used to make plywood are classified as either the exterior adhesive or the lesser quality interior adhesive. The terms relate to the ability of the adhesive to survive exposure to moisture and weather. Phenolic resins (qv) are commonly used as adhesives to make plywood. The difference between interior and exterior phenolic resin adhesive is the filler level. Exterior rated plywood uses higher resin content adhesives. Interior rated plywood uses either highly extended (below 24% resin solids) or protein-based adhesives. The adhesive is applied to the veneer by roll coating, spraying, curtain coating, or foam extrusion. 

Experiment 2. Effect of Molar Ratio of Sodium Hydroxide to Phenol of Phenolic Resin on Strength Properties of Lignin-Phenolic Resin Adhesives. Sodium hydroxide has been the predominant chemical used as a catalyst in resol resin technology. Through variation in the amounts of the catalyst and the method of catalyst addition, a wide variety of resin systems can be formulated. This experiment examined the properties of phenolic resins formulated with various sodium hydroxide/phenol ratios and their effects on the bond properties of structural flakeboards made with lignin-phenolic resin adhesive systems. Variables for resin preparation were four molar ratios of sodium hydroxide/phenol (i.e., 0.2, 0.45,0.7, and 0.95). The formaldehyde/phenol ratio and solids content were fixed at 3/1 and 42%, respectively. 

From liquified solutions of untreated wood, almost the same products have been prepared as those from chemically modified wood [7,8,23,26]. For example, resol-type phenol resin adhesives prepared from five parts of wood chips and two parts of phenol, liquified at 250°C without catalyst, did not require severe adhesion conditions and were comparable to the corresponding commercial adhesives in their gluability. Acceptable waterproof adhesion was attained from the adhesives after gluing wood veneers at 120-130°C with a hot-pressing time of 0.5 min to 1 mm-thick plywood [27]. 

Resol-type phenol resin adhesives were also prepared from wood-phenol solutions liquified at ISO C with phenolsulfonic acid catalyst and their gluabili-ties were examined [12]. The results revealed that when these adhesives were used, it was easily possible to realize completely satisfactory waterproof... 

Phenolic Resin Adhesives. PF resin adhesives are low molecular weight prepolymers formed from phenol and formaldehyde, and are of the thermosetting type. The polymerization is controlled by the acid or alkaline conditions, i.e., pH, at which it is conducted. Another important reaction variable is the molar ratio of phenol to formaldehyde. By varying the time and temperature of reaction, and by choosing catalysts and phenols of varying reactivity, a wide variety of adhesives can be prepared for many applications and conditions. 

The main particle board used in the construction industry is made using phenol resin adhesive (P type), and its bending strength in both the longitudinal and width directions is more than 180 kgf/cm2 (200 type). It is the strongest and the most durable. 

Wheat Flour - secondary extender in phenolic resin adhesives in plywood industry... 

Phenolic Resins. Phenolic resins (qv) are formed by the reaction of phenol [108-95-2], C H O, and formaldehyde [50-00-0], CH20. If basic conditions and an excess of formaldehyde are used, the result is a resole phenolic resin, which will cure by itself liberating water. If an acid catalyst and an excess of phenol are used, the result is a novolac phenolic resin, which is not self-curing. Novolac phenolic resins are typically formulated to contain a curing agent which is most often a material known as hexamethylenetetraamine [100-97-0], C6H12N4. Phenolic resin adhesives are found in film or solution... 

Barth, B.P. Phenolic Resin Adhesives. Handbook ofTldhesives, Second ed. I. Skeist, Ed. Van Nostrand New York, 1977 pp. 382-416. 

Phenolic resin adhesive films (Resinous Products Chemical Co.) Poly(vinyl acetate) adhesives (Carbide Carbon Chemicals Co.) Chlorinated rubber adhesives... 

PF 3097 phenolic resin adhesive for exterior type softwood pl5rwood. Product Bulletin, Schedule PG 1976, Monsanto Company, Seattle, Wash., Dec, 6, 1968. 

III. CHEMISTRY AND TECHNOLOGY OF APPLICATION OF PHENOLIC RESIN ADHESIVES FOR WOOD... 

Recently, van Ooij et al. have reviewed adhesion of steel tire cord to rubber (van Ooij et al., 2009). The authors reviewed the literature extensively and provided an updated model for adhesion to brass-plated tire cord, which incorporated observations made by many techniques. They discussed the effects of different compounding ingredients and the possible alternatives to the current brass coatings. They note that the use of cobalt compounds improves the adhesion between rubber and brass-coated cords, but new adhesion promoters have been developed as replacements for Co, or for combined use with Co. They also discussed the use of phenolic-resin adhesion promoters. They describe the various techniques that have been developed to study the rubber-brass interface and its aging mechanism. 

Uses Binder, film-former in phenolic resin adhesives, printed circuit board coatings, coil coatings, marine paints, metal coatings, barrier primers, barrier coatings, printing inks (screen printing), sealers reactive resin in two-pack systems, e.g., crosslinked with melamine/phenolic resins Features Forms flexible, odorless, tasteless films thru solv. evaporation ... 

The use of adhesives/sealants in both the industrial and consumer spheres has increased dramatically in the past 20 years. In the industrial segment, both reactive and nonreactive systems are used in a wide variety of applications. The increasing use of reactive systems has, however, tended to overshadow that of the nonreactive systems. Most prominent amongst the reactive systems favored in industrial applications are anaerobic sealants (methacrylate ester based), instant adhesives (alkyl cyanoacrylate ester based), acrylic (toughened) adhesives, epoxy resin adhesives, polyurethane/isocyanate-based adhesives, silicone adhesives/sealants, and phenolic resin adhesives. 

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