Celcon® copolymer

ALTERNATIVE NAMES, TRADE NAMES Polyacetal, polyoxymethylene, acetal, Delrin , Celcon (copolymer). Ultraform (copolymer)... 

Throughout the remainder of this article the term homopolymer refers to Delrin acetal resin manufactured and sold by Du Pont the term copolymer refers to Celcon acetal copolymer resins (registered trademark of Hoechst Celanese Corporation). 

Property ASTM method Delrin 500 homopolymer resin Celcon M90 copolymer resin ... 

The first commercially available acetal resin was marketed by Du Pont in 1959 under the trade name Delrin after the equivalent of ten million pounds had been spent in research or polymers of formaldehyde. The Du Pont monopoly was unusually short lived as Celcon, as acetal copolymer produced by the Celanese Corporation, became available in small quantities in 1960. This material became commercially available in 1962 and later in the same year Farbwerke Hoechst combined with Celanese to produce similar products in Germany (Hostaform). In 1963 Celanese also combined with the Dainippon Celluloid Company of Osaka, Japan and Imperial Chemical Industries to produce acetal copolymers in Japan and Britain respectively under the trade names Duracon and Alkon (later changed to Kematal). In the early 1970s Ultraform GmbH (a joint venture of BASF and Degussa) introduced a copolymer under the name Ultraform and the Japanese company Asahi Chemical a homopolymer under the name Tenal. 

The electrical insulation properties of the acetal resins may be described as good but not particularly outstanding. There are available alternative materials which are better insulators and are also less expensive. There are, however, applications where impact toughness and rigidity are required in addition to good electrical insulation characteristics, and in these instances acetal resins would be considered. Table 19.3 lists some of the more important electrical characteristics of Delrin acetal resin. Data for the trioxane-based copolymer resin (e.g. Celcon) are virtually identical. 

Celanese came out a year later with a similar product under the trade name Celcon. Celanese circumvented DuPont s patent on the basis of employing a copolymer variation that allowed enhanced stabilization against thermal depolymerization (structure 4.74). The copolymer has a of 170°C ... 

Celcon Trade name of copolymer of formaldehyde and dioxolane. 

For example, Celanese announced Celcon acetal copolymer in February 1961. By the last half of 1962 and the first half of 1963 we carried through on a specific advertising and promotion program which consisted of ... 

The copolymers, eg, Celcon M 90 [95327-43-8], aie produced by the cationic catalyzed reaction of 1,3,5-trioxane [110-88-3] and an ethylene oxide. 

Polyoxymethylene (POM) is, again, a crystalline polymer, with a melting point of about 180 °C. Its mechanical properties enable it to gradually replace metals in a number of applications. Many technical parts are being made from POM, such as gear wheels, bars, automotive accessories, parts of several apparatuses and machines. The polymer is used as such (e.g. Delrin ), but also as a copolymer with a small amount of ethylene oxide (e.g. Celcon and Hostaform ). 

Acetal translucent crystalline polymer is one of the stiffest TPs available. It provides excellent hardness and heat resistance, even in the presence of solvents and alkalies. Its low moisture sensitivity and good electrical properties permit direct competition with die-cast metal in a variety of applications. In addition, acetal has extremely high creep resistance and low permeability. Acetal is also available as a copolymer (Hoechst Celanese Corp. s Celcon) for improved processability. The homopolymer (DuPont s Delrin) has a very low coefficient of friction and its resistance to abrasion is second only to nylon 6/6. Acetals are frequently blended with fibers such as glass or fluorocarbon to enhance stiffness and friction properties. Acetal is not particularly weather-resistant, but grades are available with UV stabilizers for improved outdoor performance. Acetal, whether homopolymer or copolymer, is not used to any significant degree in forming structural foams. 

Acetal Copolymer (CELCON ) As with DELRIN , this is a highly crystalline polymer with excellent solvent resistance. It is somewhat more amenable to solvent cementing than the homopolymer, however. The solvent cement recommended by the manufacturer, Hoechst Celanese, is hexafluoroacetone sesquihydrate, available from Allied Signal, Inc. This solvent is a severe eye and skin irritant, however, and should be handled with care (7). 

Acetal Copolymer (CELCON ) Two types of non-solvent adhesives are used, structural and non-structural. Most structural adhesives are based on thermoset resins and require the use of a catalyst and/or heat to cure. This type of adhesive is normally used in applications which require maximum bond strength and minimum creep of the adhesive joint under sustained loading. Many structural adhesives can be used continuously at temperatures up to 350 F, which is higher than the... 

Celanese Plastics Co., Chatham, NJ, The CELCON Acetal Copolymer Design Manual, (undated). 

Stable acetal copolymers of formaldehyde, called Hostoform and Celcon were also produced commercially by the cationic copolymerization of formaldehyde with ethylene oxide — ... 

Celanese joined Du Pont in the market with their proprietary Celcon polyacetal polymer within a year (Figure 3). Celanese managed to obtain basic patent coverage, despite Du Font s prior filing, on the basis of a copolymer variation that led to an enhanced stabilization against thermal depolymerization... 

Random acetal copolymers (Celcon) have the following repeating unit ... 

CELCON Acetal Copolymer Properties, Brochure 10M, Celanese Corp., New York, June 1983. 

Polyacetal can be divided into two basic types, acetal homoploymer and acetal copolymer. Both homopolymer and copolymer are available in a range of molecular weights (M = 20 000-100 000). The homopolymer is a polymer of formaldehyde with a molecular structure of repeated oxymethylene units (Staudinger, 1932). Large-scale production of polyformaldehyde, i.e. polyacetal, commenced in 1958 in the USA (US Patent 2 768 994,1956) (British patent 770 717,1957). Delrin (1959) was the first trade mark for this polymer by Du Pont Company. The copolymers were introduced by the Celanese Corporation of America, and the first commercial product named Celcon (1960). One of the major advantages of copolymerization is to stabilize polyacetal because the homopolymer tends to depolymerize and eliminate formaldehyde. The most important stabilization method is structural modification of the polymer by, for example, copolymerization with cyclic ether. 

Celanese Corp., Ticona Engineering Polymers, Celcon Acetal Copolymer Literatnre, www.Ticona.com, 2006. 

A room-temperature solvent, hexafluoroacetone sesquihydrate, when used at full strength, is a very effective bonding agent for bonding acetal copolymer to itself, to nylon, and to ABS. This solvent is available from the Allied Corporation. Bond strengths (in shear mode) for acetal copolymer to itself and acetal copolymer to nylon >5.86 MPa have been obtained on Celcon to ABS. Hexafluoroacetone sesquihydrate is a severe eye and skin irritant and care should be taken in its use. ... 

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