Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Reexamination Certificate
2001-12-18
2002-10-22
Truong, Duc (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
C528S162000, C528S176000, C528S192000, C528S196000, C525S391000, C525S392000, C525S397000, C525S534000
Reexamination Certificate
active
06469124
ABSTRACT:
BACKGROUND OF THE INVENTION
Polyphenylene ether resins (hereinafter “PPE”) are commercially attractive materials because of their unique combination of physical, chemical, and electrical properties. Furthermore, the combination of PPE with other resins provides blends that result in additional overall properties such as chemical resistance, high strength, and high flow.
One technical obstacle to the development of such blends is the lack of compatibility between PPE and many resins. This lack of compatibility manifests itself often through very poor physical properties as well as delamination in molded parts. Methods have been developed to improve the PPE compatibility with many resins such as, for example, with polyesters and polyamides. One of the more effective methods involves functionalizing PPE to make functionalized PPE containing moieties such as acid, anhydride, epoxy, orthoester, and the like that are reactive with the other resin in the blend. It is believed that the when the functionalized PPE is allowed to react with the other resin that relatively small amounts of copolymer between the resins are formed. The copolymer is believed to be in large part responsible for improved compatibility between the PPE and the other resin. Indications of improved compatibility include resistance to delamination, improved physical properties such as increased tensile and impact properties and a stabilized morphology between the blend component phases under static and/or low shear conditions.
Methods to prepare functionalized PPE have included solution functionalization with an acid halide containing compound, such as trimellitic anhydride acid chloride, to make an endcapped PPE containing at least one reactive moiety such as acid, anhydride, epoxy, orthoester, and the like. This method is rather limited in the variety of functionalized PPE that can be made. Also, the by-products from the capping reaction tend to cause emulsion and/or isolation issues in the solvent precipitation stage of the process.
Another known method to prepare functionalized PPE related to melt functionalization of the PPE in an extruder. This method involved melting and mixing PPE with a functionalizing agent to result in a functionalized PPE. The functionalizing agent is typically a compound containing a carbon-carbon double or triple bond and one of the aforementioned reactive moieties and is believed to react through the unsaturated bond to functionalize the PPE. Additional polymers could be fed into the same extruder or alternatively, the functionalized PPE could be isolated and subsequently used to prepare other compositions. Melt functionalization has issues, such as difficulty in feeding PPE into the extruder due to low bulk density and wide particle size distribution. Moreover, PPE are often powders and require special handling to avoid potential dust explosion.
As explained above, the methods known in the art teach functionalization of the PPE with reactive groups such as acid, anhydride, epoxy, orthoester, and the like. However, for blending PPE with resin systems that involve curing or polymerization reactions, including radical reactions, it would be highly desirable to have a PPE that contained residual aliphatic unsaturation and capped phenolic end groups at the same time. Incorporation of unsaturated species onto the PPE to result in an olefinic functionalized PPE may allow for chemical grafting to occur between the olefinic functionalized PPE and the other unsaturated species that are being polymerized. Moreover, the hydroxyl groups that exist on PPE may interfere with radical polymerization reactions of unsaturated monomers and lead to undesirable low polymerization rates of the unsaturated monomer species.
PPE known in the art typically are of fairly high molecular weight for blending in the melt phase with other polymers and generally have in excess of 50 repeat monomer units, most often in excess of 80 or more repeat monomer units. Consequently, functionalization reactions and isolation methods have been developed for high molecular weight PPE. Although many physical properties, such as tensile properties, are enhanced with the high molecular weight of the PPE in the polymeric blend, in other new resin blend compositions, such as, for example, the polymerization of vinyl-substituted aromatic monomers, the high viscosity of the PPE having more than 50 repeat monomer units is undesirable as it presents difficulty with mixing. Additionally, the overall number of available endgroups available for chemical modification becomes fairly limited as the molecular weight increases.
For blending PPE with resin systems that involve curing or polymerization reactions, including radical reactions, it would be highly desirable from the standpoints of low viscosity for mixing and a high endgroup number for functionalization to have a PPE that contained residual aliphatic unsaturation and that has less than 50 repeat monomer units on average, preferably less than about 35 repeat monomer units on average. It is therefore apparent that a need continues to exist for novel and improved methods to prepare functionalized PPE containing residual aliphatic unsaturation, especially low molecular weight PPE (i.e. PPE having an intrinsic viscosity less than about 0.30 dl/g as measured in chloroform at 30° C.).
SUMMARY OF INVENTION
The needs discussed above have been generally satisfied by the discovery of a process for preparing functionalized PPE containing aliphatic unsaturation. In one embodiment, the process comprises oxidative coupling in a reaction solution at least one monovalent phenol species using an oxygen containing gas and a complex metal catalyst to produce a PPE; and functionalizing the PPE, preferably prior to and/or during at least one isolation step for devolatilization of the reaction solvent, with an unsaturated compound of the formula (I):
wherein R
1
is an aliphatic or aromatic residue, for example, —CH
2
— but may be multiple —CH
2
— groups, e.g., n can vary from 1 to about 10 or more, or alternatively, n may equal zero wherein the formula is an acrylic residue, and wherein each of R
2
, R
3
, and R
4
are independently hydrogen, alkyl, or aryl, and wherein X is a residue of one of the following formulae (II):
or wherein X is a halogen or a residue of the formula (III):
wherein R
7
is an aliphatic or aromatic residue, for example, —CH
2
— but may be multiple —CH
2
— groups, e.g., m can vary from 1 to about 10 or more, or alternatively, m may equal zero (wherein if n and m both equal zero, the unsaturated compound is an acrylic anhydride), and wherein each R
8
, R
9
, and R
10
are independently hydrogen, alkyl, or aryl. In a preferred embodiment, the unsaturated compound is of the formula (IV):
wherein each of n, R
1
, R
2
, R
3
, and R
4
are as previously described. In an especially preferred embodiment, the unsaturated compound is of the formula (V):
The description that follows provides further details regarding various embodiments of the invention.
DETAILED DESCRIPTION
One embodiment of this invention provides for a process for the preparation of functionalized PPE containing aliphatic unsaturation, preferably having an intrinsic viscosity between about 0.08 dl/g and 0.60 dl/g, more preferably between about 0.10 dl/g and about 0.30 dl/g, by oxidative coupling at least one monovalent phenol species, preferably at least a portion of which have substitution in at least the two ortho positions and hydrogen or halogen in the para position, using an oxygen containing gas and a complex metal-amine catalyst, preferably a copper (I)-amine catalyst, as the oxidizing agent and, preferably extracting at least a portion of the metal catalyst as a metal-organic acid salt with an aqueous containing solution, and functionalizing the PPE with the addition of at least one unsaturated anhydride of the formula (I) prior to and/or during at least one isolation step for removal of the reaction solvent. In one embodiment, the functionalization is at least partly done in a flash process to concentrate th
Braat Adrianus J.F.M.
Chao Herbert Shin-I
Guo Hua
Liska Juraj
Yeager Gary William
General Electric Company
Truong Duc
LandOfFree
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