Phenolic Laminating resin

For more corrosive environments, epoxy vinyl esters and phenolic laminating resins [10] are used quite successfully as well, particularly where fire retardancy is an issue, such as in the oil industry. The glass is normally E-glass roving, but some mats are used for more complicated shapes and an external surface veil is incorporated to produce an acceptable degree of outer smoothness. 

Chem. Deserp. Tricresyl phosphate CAS 1330-78-5 EINECS/ELINCS 215-548-8 Uses Flame retardant plasticizer for PVC, syn. rubbers, cellulosic resin (except cellulose acetate), nitrocellulose lacquers and coatings, phenolic laminating resins... 

The single largest use of methanol is in formaldehyde and dimethyl terephthalate production. Methanol is also used in the manufacture of methyl acrylate, methyl methacrylate, methyl chloride, dimethyl ether, dimethyl sulfate, and various other intermediates and dyes. Methanol is usehil in dissolving phenolic laminating resins, ethyl cellulose, cellulose nitrate, and a variety of other resins. Low-viscosity resin solutions are possible using methanol. 

Phenol—formaldehyde resins are used as mol ding compounds (see Phenolic resins). Their thermal and electrical properties allow use in electrical, automotive, and kitchen parts. Other uses for phenol—formaldehyde resins include phenoHc foam insulation, foundry mold binders, decorative and industrial laminates, and binders for insulating materials. 

The thermal stabiUty of epoxy phenol—novolak resins is useful in adhesives, stmctural and electrical laminates, coatings, castings, and encapsulations for elevated temperature service (Table 3). Filament-wound pipe and storage tanks, liners for pumps and other chemical process equipment, and corrosion-resistant coatings are typical appHcations using the chemically resistant properties of epoxy novolak resins. 

Laminating resins have been offered by Akzo (Diacryl 101), Dow (Derakane Vinyl Esters) and Showa (Spilac). Typical of these is Diacryl 101, which is manufactured by esterification of the addition product of ethylene oxide to bis-phenol A with methacrylic acid. They exhibit lower curing shrinkage than the polyester laminating resins during cure. The structure of Diacryl 101 is... 

Although phenolic resins are too dark for use in the surface layers of decorative laminates these resins are employed in impregnating the core paper. In the.se cases a melamine-formaldehyde resin is used for impregnating the top decorative layer. Phenolic laminates have also been used in aircraft construction and in chemical plant. 

Laminating resins. CNSL resins are added to laminates based on phenol-formaldehyde, epoxy, etc. to reduce brittleness and to improve flexibility of the product. The resins also exhibit better age hardening and improved bonding to the substrate [133,134,137,168]. 

Phenolics are also used in a variety of other applications such as adhesives, paints, laminates for building, automobile parts, and ion exchange resins. Global production of phenol-formaldehyde resins exceeded 5 billion pounds in 1997. 

Unlike phenol-formaldehyde polymers, the amino resins are not themselves deeply coloured, but are of a naturally light appearance. They can be easily pigmented to give a variety of shades, which leads to application in uses where good appearance is highly valued, for example in decorative tableware, laminated resins for furniture, and modem white electrical plugs and sockets. 

The route to crosslinked phenol-formaldehyde resins via resoles corresponds to that used by Baekeland in his original commercial technique. They now tend to be used for adhesives, binders, and laminates. The resole... 

It has been demonstrated that red oak OSL could be used to replace 35% to 40% of the phenol (or phenolic resin solids) in phenol-formaldehyde resins used to laminate maple wood and to bond southern pine flake boards (wafer-board and/or strandboard) without adversely affecting the physical bond properties. While this pulping process and by-product lignin do not commercially exist at this time in the United States, lignins from such processes are projected to cost 40% to 50% less than phenol as a polymer raw material. 

Phenolic Resins. Phenolic resins [9003-354] (qv) are thermosets prepared by the reaction of phenol with formaldehyde, through either the base-catalyzed one-stage or the acid-catalyzed two-stage process. The liquid intermediate may be used as an adhesive and bonding resin for plywood, particle board, fiberboard, insulation, and cores for laminates. The physical properties for typical phenolic laminates made with wood are listed in Table 1. 

The commonly used resins in the manufacture of decorative and industrial laminates are thermosetting materials. Thermosets are polymers that form cross-linked networks during processing. These three-dimensional molecules are of essentially infinite size. Theoretically, the entire cured piece could be one giant molecule. The types of thermosets commonly used in laminates are phenolics, amino resins (melamines), polyesters, and epoxies. 

Phenol-formaldehyde resins are used in the core assembly and in conjunction with the kraft paper give the characteristic brown colour to the back of the laminate. Features of these resins making them suitable for the purpose include ... 

In dry conditions decorative laminates will shrink, and in damp they will expand unless suitable precautions are taken the associated movements can give rise to stress cracking of laminates and the bowing of composite boards. Since the phenol-formaldehyde resins are more stable in this respect than melamine-formaldehyde, laminates with phenolic kraft cores have dimensional stability better than those with melamine core papers—and thick laminates incorporating many plies of phenolic core paper are more stable than thin laminates with fewer plies. 

Phenol-formaldehyde resins find numerous applications in such areas as wood composites, fiber bonding, laminates, foundry resins, abrasives, friction and molding materials, coatings and adhesives, and flame retardants (JL). From a specialty chemicals standpoint, they are also used as developer resins in carbonless papers (2.). Conventional methods of preparation involve condensation of a phenol with formaldehyde under either acidic (novolak) or basic (resole) conditions (2). Their typical molecular weight range is from 800-4000 daltons (D) and includes a wide variety of alkyl or aryl substituted phenols (A)- The... 

Applications for cold-setting, wood-laminating adhesives initially followed the same approach (47) used for laminating resins from western hemlock (38) (i.e., reaction of tannin with phenol-resorcinol-formaldehyde prepolymers). Improvements resulted through the application of Kreibich s Honeymoon technique (48) wherein one side of the material to be bonded is treated with resin and the other with catalyst. One of the preferred systems (49) was phenol-resorcinol-formaldehyde or tannin-resorcinol-formaldehyde at pH 8 with extra paraformaldehyde on the A-side and tannin at 53% solids or tannin-resorcinol-formaldehyde at pH 12 on the B-side. Such resin systems are currently used to laminate eucalyptus or pine in most South African timber-laminating plants. 

The phenol/furfural resins have a greater hydrocarbon solvent tolerance than phenol/formaldehyde resins. This is an advantage in the preparation of resin solutions used for the impregnation of paper or cloth for laminating. 

In the manufacture of bonded insulating materials, the fibers in the fleece shaft or on the conveyor belt are sprayed with an aqueous binder, generally a phenol-formaldehyde resin. The binder content in the bonded insulating material is 3 to 4%. Compaction to the desired density and hardening of the resin binder occurs in a tunnel kiln, through which the fibers are continuously transported on a conveyor belt. The compaction is achieved with a second belt which exerts the required pressure on the upper surface of the continuous sheet. This is often followed by laminating the sheet with e.g. paper, aluminum or plastic foil. Finally the product is rolled up or cut into sheets. 

Most of the formaldehyde produced is consumed in the production of urea-formaldehyde resins and phenol-formaldehyde resins. These cross-linked polymer products are in turn used in adhesive and laminate applications. 

A large fraction of the phenol product, currently ranked 34th in American volume of production, is directed toward the production of several types of phenol-formaldehyde resins of utility as plywood adhesives and as components of laminates (e.g., Arborite). Some is routed to the preparation of bis-phenol A enroute to epoxy resin production. 

The single largest use for the phenol-formaldehyde resins is in adhesive applications for the production of plywood, chipboard, and particle board. The resin can comprise as much as one-third of the weight of the board, particularly of particle boards, which contributes to a total demand for phenolics in the U.S.A. of over half a million metric tonnes per year. They are also used as the matrix adhesives for the production of several types of grindstones. In combination with paper, woven cotton, glass fiber, etc., components, phenolics contribute to the production of engineering and decorative laminates in the form of rods, tubes, and sheets. The sheet products Arborite and Formica are familiar as the finished surfaces of furniture, bathroom, and kitchen counter tops and other areas where attractive patterns and water resistance are important characteristics. Molded products from phenolics are also important where heat or electrical resistance is required, such as saucepan and toaster handles, switches, and the printed circuit boards used in computers. Recent phenolics production in the U.S.A. has totaled over 500,000 metric tonnes per year, not including fillers [38]. 

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. 

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. 

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