Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From ketone or ketene reactant
Patent
1996-10-29
1998-03-31
Cooney, Jr., John M.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From ketone or ketene reactant
528223, 528224, 528225, 528226, 525242, 525280, 525309, C08G 802
Patent
active
057340056
DESCRIPTION:
BRIEF SUMMARY
This invention relates to aromatic polymers.
Aromatic polyethers are known, useful polymers which have been produced by a variety of methods. The methods are usually based on two reaction types, namely electrophilic aromatic substitution (e.g. the polycondensation of acid chlorides or carboxylic and/or sulphonic acids with aryl ethers to produce ketone or sulphone linkages) and nucleophilic aromatic substitution (e.g. the polycondensation of activated aryl fluorides with phenoxides to produce ether linkages). Examples of such methods as applied to ketone polymers have been reviewed by M J Mullins and E P Woo, J Macromolecular Science--Rev. Macromol Chem Phys, C27 (2), 313, 1987.
Polyaryletherketones are particularly useful since they are usually crystalline, have relatively high glass transition temperatures (Tg's) and melting temperatures (Tm's) and exhibit a variety of useful properties such as excellent electrical insulating and mechanical properties at high temperature and high strength, toughness and resistance to fire and chemicals.
One of the problems associated with making such polymers by the electrophilic route is that, unless the reaction is carried out in strongly acidic solvent systems such as HF/BF.sub.3 or perfluoroalkyl-sulphonic acids, the semi-crystalline nature of the polymers causes them to be precipitated from conventional organic solvents before high molecular weights can be achieved. Under typical conditions, the relatively low molecular weight polymers, complexed with the Friedel-Crafts acid such as AlCl.sub.3 which activates the reaction, precipitate out as gel-like materials which coat the walls and stirrer of the reaction vessel. Subsequent extraction, manipulation and purification is consequently difficult.
It has been proposed in U.S. Pat. No. 3,791,890, and is further illustrated in U.S. Pat. No. 4,704,448 and EP-A-0192260, to overcome this problem by mixing the reaction mixture with a fluid medium at a temperature above the temperature of the reaction mixture to effect dispersion of the mixture and to complete the polymerisation reaction.
It has also been proposed in U.S. Pat. No. 4,698,393 to overcome the problem by adding a dispersant to the reaction mixture, the dispersant having a portion compatible with the polymer and incompatible with the diluent in which the reaction is carried out and having a portion compatible with the diluent and incompatible with the polymer under the reaction conditions used.
U.S. Pat. No. 4,698,393 teaches that the dispersant can be a polymeric or a non-polymeric dispersant and identifies a wide variety of compounds which are alleged to be suitable dispersants. However, it only exemplifies a limited number of such compounds and, in particular, exemplifies using benzoylated Kraton G 1650 (Kraton G 1650 being a hydrogenated styrenebutadeine copolymer available from Shell Chemical Co.). U.S. Pat. No. 4,698,393 also teaches the amount of dispersant can be in the range 0.01% to 10% by weight based on the weight of monomers in the reaction. However, it only exemplifies reaction systems in which the amount of dispersant is about 2% or more.
However, it has been found that, under similar but not identical reaction conditions to those specifically exemplified in U.S. Pat. No. 4,698,393, a number of materials falling within the teaching of U.S. Pat. No. 4,698,393 do not act as dispersants or do not act as dispersants in relatively low quantities, i.e. not more than 2%, low quantities of dispersant being desirable to reduce the effort required to extract them from the polymer. Indeed, it was found that the minimum quantity of the apparently preferred dispersant benzoylated Kraton G 1650 required to obtain a dispersant effect was about 2% by weight.
It has now been found that selected materials are particularly effective as dispersants in the electrophilic preparation of polyarylketones, particularly at relatively low quantities of such materials.
According to the present invention, a process for making a polyarylketone comprises polycondensing at least on
REFERENCES:
patent: 4698383 (1987-10-01), Jansons et al.
patent: 4841011 (1989-06-01), Towle
patent: 4912195 (1990-03-01), Jansons et al.
patent: 5089596 (1992-02-01), Cliffton et al.
Daniels James Anthony
Stephenson Ian Richard
Cooney Jr. John M.
Victrex Manufacturing Limited
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