' Patented Feb. 7, i950 - 2,496,868

UNITED STATES PATENT‘ OFFICE 2,496,868 POLYMERS OF 3-VINYLPYRENE Ralph G. Flowers, Pitts?eld, Mass., assignm- to to General Electric Company, a corporation of New York No Drawing. Application May 13, 1948, ' , Serial No. 26,940 12 Claims. (Cl. 260—87.3) 2 This invention relates to polymers and co such as boron tri?uoride, are used. aperiod of polymers of vinyl compounds and to methods of time elapses between the addition of the catalyst , preparing same. More particularly, the inven and the beginning of the polymerization. This tion-ia concerned with new and useful composi tendency is particularly marked when the poly tions of matter comprising the product of poly merization is carried out at elevated tempera merization of a mass comprising 3-vinylpyrene. tures. A very large amount of solvent often in In my copending application, Serial No. 26,939, hibits or retards the polymerization of the mono ?led concurrently herewith and assigned to the mer or comonomers to the extent that polymer same assignee as the present invention, there are ization is not e?ected in a reasonable time. disclosed and claimed 3-vinylpyrene and methods 10 Another method which has been found effective - of preparing the same. I have now discovered in preparing the homopolymers and copolymers that this monomeric material may be polymer of the instant claimed invention includes ‘the ized or copolymerized with other polymerizable preparation of an intimate mixture of the mono compositions to yield valuable and useful com- ' meric materials by preparing a suspension or positions of matter. . 15 emulsion of the monomer or mixture of mono As described in the above-mentioned applica mers in a liquid medium as, for example, water. tion, 3-vinylpyrene may be prepared by ?rst With speci?c regard to the polymerization of acetylating pyrene with an acetylating agent, for the monomer, 3-vinylpyrene, itself, it may. be example, acetic acid or anhydride, acetyl chlo said that the readiness and speed of the polymeri ride or bromide, ketene, etc., to obtain 3-acetyl 20 zation depend upon the purity of the latter. The pyrene. It is, of course, understood that by fur purer the monomer, the greater is the ease and ther acetylization of the monoacetyl pyrene, it rate of polymerization and the higher the molec is possible to prepare polymeriza'ble divinyl py ular weight of the polymer. The physical prop renes from diacetyl pyrenes by employing the erties of the homopolymer are, to a large ex same method as that used for preparing the 25 tent, dependent upon the polymerization. For monovinylpyrene from monoacetyl pyrene. The example, polymerizations carried out at high acetylated pyrene is then reduced or hydrogen temperatures at a very rapid rate usually result ated to form a hydroxyethyl pyrene which may in polymers of low molecular weight. In order then be dehydrated by contacting it with a de to obtain suitable polymerization products, care ful control of the polymerization reaction is hydration catalyst to obtain the monovinylpyrene, 30 more speci?cally, 3-vinylpyrene, which has a necessary. i melting point of 87° to 89° C. In producing the claimed homopolymer or co Various methods of ‘polymerizing the mono polymers, the polymerization of the monomer or meric 3-vinylpyrene, either by itself or with other monomeric materials may be carried out by means copolymerizable materials, may be employed, the , of heat alone, or it may be accelerated by means more desirable method depending largely upon of vinyl polymerization catalysts usually em the properties desired in the ?nal composition. ployed for the purpose. Examples of such poly For example, the monomer, either by itself or merization catalysts are oxygen, ozone, ozonides, with other copolymerizable materials, may be hydrogen peroxide, organic and inorganic acids dissolved in -a suitable inert solvent, for example, 40 and acidic- substances, e. g.,' hydrochloric acid. an aromatic hydrocarbon solvent (such as ben hydro?uoric acid, sulfuric acid, boron ?uoride, zene, toluene, inrlene, etc.) which is also a solvent stannic chloride, antimony pentachloride, the for any other members of the mixture. halogens, etc.; organic and inorganic peroxides, A small amount of solvent has little retarding for instance, peroxides of the aromatic acid series, effect upon, and in some cases actually acceler 45 e. g., benzoyl peroxide, tertiary 'butyl hydro ates. the polymerization of monomer or mono peroxide, tertiary butyl perbenzoate, l-hydroxy mers. A moderately large amount of solvent cyclohexyl hydroperoxide, etc.; peroxides of the tends to yield polymers and copolymers of short aliphatic acid series, for example, acetyl peroxide, chain lengths and often results in a period of stearyl peroxide, lauryl peroxide, etc.; sodium induction so that even when very active catalysts, 50 peroxide, barium peroxide, etc.; various per 2,498,868 compounds such as the persulfates, perchlorates, perborates, etc. Heat, light (ultra-violet light) its. Although the proportions, by weight, ordi or heat and light may be used with or without narily will be within the range of from 10 to 90 a polymerization catalyst in accelerating the per cent of the 3-vinylpyrene to 90 to 10 per cent polymerization. of other monomer or monomers, I do not intend 5 Where a catalyst is employed for accelerating to be limited to such range since other propor the polymerization, the catalyst concentration tions of the S-vinylpyrene and the other copoly may be varied, for example, within the range of merizable ingredient or ingredients may be high from 0.05 to 3 or 4 per cent or more, by weight, er or lower, for instance, from 1 to 99 per cent, of the polymerization mixture including the sol by weight, of the 3-vinylpyrene, to from 99 to 1 vent or suspension or emulsion medium if such per cent, by weight, of the other monomeric are employed. Where no such media are em material or materials. I may preferably employ ployed and the monomers or polymers are em a copolymerizable mixture containing, by weight, ployed alone, I have found it advantageous to from 1 to 75 per cent of the 3-vinylpyrene, based on the total weight of the copolymerizable in use from 0.1 to 2 per cent of the catalyst based gredients. on the weight of the total weight of the monomer or monomers used. 3-virwlpyrene can be cross-linked by com The most effective temperatures at which the pounds such as divinyl and diallyl compounds, polymerization may be effected lie within the e. g., divinyl and diallyl esters of diethylene range of from about 45° C. to 200° 0., preferably glycol, to form products that have increased heat from 60° C. to 150° 0., depending upon the pres 20 resistance and can be readily machined and ence or absence of solvents, the type of poly worked. Such products tend toward insolubility merizable materials employed, and the proper and infusibility as the per cent of the divinyl or ties desired in the ?nally polymerized product. diallyl compound is increased. The copolymers Greater polymerization speeds are obtainable at of 3-vinylpyrene with other vinyl compounds higher temperatures but this usually results in 25 containing only one CH2=C< grouping, many an undesirable reduction in the molecular weight examples of which have been given previously, of the ?nally polymerized product. It is usually are thermoplastic and can be treated, in general, advantageous to displace the air in the polymer as any thermoplastic material since they can be injection- or compression-molded, cast into ?lms, izable systems and in the free space above the oriented and fused. same with an inert atmosphere, for example, ni 30 trogen ‘or carbon dioxide. In order that those s killed in the art may ~ The homopolymers of this invention possess, better understand how the present invention in general, the physical properties of polystyrene may be practiced, the following examples are except that the softening point of the homo given by way of illustration and not by way polymer is considerably higher than the soften 85 of limitation. All parts are by weight. ing point of polystyrene. The electrical prop Example 1 erties of the homopolymer likewise compare to those of polystyrene, making it valuable for use Ten parts 3-vin ylpyrene was dissolved in 50 in electrical insulation. The homopolymers can, parts benzene an d 1.0 part benzoyl peroxide in general, be treated in the same manner as any added. The solution w as heated in an oil bath other thermoplastic material. They may be cast, at 100 C. for ?ve hours. The resulting Polymer pressed, extruded, rolled, machined and indec of 3-viny1pyrene, which was precipitated from tion-_ or pressure-molded. the benzene solution by diluting the latter with The homopolymer is, in general, compatible 45 methanol, had a softening point of 185° C. with the same materials as pohrstyrene. For example, it may be plasticized by the same plas Example 2 ticizers where softening point and strength are of secondary importance. Materials simulat A solution of 10 parts 3-vinylpyrene and 50 ing synthetic elastic products may be prepared 50 parts benzene was mixed with 1.0 part tertiary from these homopolymers by adding relatively butyl hydroperoxide and heated in an oil bath large amounts of plasticizers. at 100° C. for five hours At the end of this . The monomeric 3-vinylpyrene may be copoly time a white polymer was obtained as a precipi merized with a great number of copolymerizable tate from the benzene solution by the addition CH:=C<-containing compounds. Examples of “ thereto of methyl alcohol. such compositions of matter are dienes, e. g., butadiene, isoprene, piperylene, etc.; a vinyl Example 3 substituted aromatic hydrocarbon, e. g., styrene, ‘ methyl styrene, divinyl benzene, vinyl ?uorenes, In this example a homopolymer of 3-vinyi acenaphthylene, etc.; acrylic acid and its de pyrene was obtained using the same ingredients rivatives, e. g., methacrylic acid, acrylonitrile, and procedure as employed in Example 2 with acrylamide, methacrylonitrile, methacrylamide, the exception that 1.0 part tertiary butyl per esters of acrylic and methacrylic acids, for ex benzoate was employed in place of the tertiary ample, methyl acrylate, ethyl acrylate, methyl butyl hydroperoxide. methacrylate, etc.; an ethylenically unsaturated halogenated or unhalogenated aliphatic hydro Example 4 carbon, e. g., ethylen , chloroethylenes, ?uoro ethylenes, chloro?uoroethylenes, etc., and the Ten parts of 3-vinylpyrene was dissolved in like. ' 150 parts benzene, and 2.0 parts boron tri?uoride The copolymerization products of the present etherate was added. Polymerization of the 3 invention may be varied in accordance with the 70 vinylpyrene was completed within 5 minutes with nature of the copolymerizable ingredient or in with the evolution of heat. The polymer was gredients which are copolymerized with the 3 precipitated as a white thermoplastic powder from vinylpyrene. The proportions of the copolymer the benzene solution by the addition of methyl izable monomers may be varied within broad lim alcohol. A disc molded from the above-prepared 75 powdered polymer of 3-vinylpyrene at 160 C. at 2,498,868 ‘ - 5 6 . 40,000 p. s. 1., when tested for electrical proper The above ingredients were mixed and heated ties, showed it to have a dielectric constant of in an oil bath at 100° C. for 20 hours. At the 3.2 and a power factor of 0.07 per cent at one end of this time an 80 per cent yield of the co megacycle. polymer was obtained by diluting the benzene so lution with methanol. This copolymer softened Example 5 ’ at approximately 210° C. In this example 'monomeric 3-vinylpyrene was heated in a vessel exposed to the air for 24 hours . Example 11 > in a 125° C. oven to yield a hard, brittle resin at Parts room temperature but which was pliable at tem 3-viny1pyrene 10 peratures above 200° C. Maleic anhydride _ 10 Example 6 ' Benzoyl peroxide ______.._ 1.0 Acetone 40 . - Parts 3-vinylpyrene 10 All the above ingredients were mixed together Vinyl acetate 10 and heated for 20 hours in an oil bath at a tem Benzoyl peroxide __1 ______v ______1.0 perature of 80° C. Upon dilution of the reaction" Benzene 50 mixture with methanol, there was-precipitated in The above ingredients were heated in an oil 20 a 90 per cent yield a white powder which com bath at 100° C. for 21 hours. At the end of this prised a copolymer of the 3'-v-inylpyrene and the time the resulting copolymer, which was precipi maleic anhydride. . tated from the benzene solution by dilution of the latter with methanol, was found to have a Example 12 softening point of around 180° C. 25 In a similar manner, but preferably using an Example? emulsion polymerization process, butadiene-1,3 . Parts may be copolymerized with 3-vinylpyrene to yield - 3-vinylpyrene 10 copolymers having certain desirable properties Acenaphthylene ______10 depending upon the proportions of the ingredi Benzoyl peroxide ______'____.. 1.0 ents. As the ratio of the butadiene-1,3 to 3-vinyl Benzene 50 pyrene increases, the resulting copolymers tend to The foregoing ingredients were heated for 21 become more tough and rubbery. hours. in an oil bath at a temperature of about The polymers and copolymers of this invention 100° C. to yield a benzene solution of a copoly ' may, in general, be modi?ed to ?ll the require mer of the two copolymerizable ingredients. Ad ments of specific applications for which they may dition of methyl alcohol to the benzene solution not ordinarily be suitable. For example,- plas resulted in the precipitation of a slightly yellow ticizers and ?llers may be added to the monomer ish thermoplastic powder which did not soften 40 or mixtures of monomers prior to polymerization - even at 220° C. softening point. thereof or they may be added after the polymeri zation has been completed. E¢ample8 In general, plasticizers commonly used for poly Parts mers and copolymers known to the art may be 3-vinylpyrene 10 _ employed in plastic-izing the polymeric materials - Styrene 10 embraced by this invention. The selection of the Benzoyl peroxide ____-______.. 1.0 proper‘ plasticizers depends largely upon the Benzene _ 50 properties desired in the final product. Useful molding compositions may also be prepared by The above ingredients were heated in the same 50 mixing the homopolymers or copolymers with manner as in Example '7 to yield a benzene solu suitable ?llers, such as, for example, alpha cellu tion of a copolymer which was precipitated as a lose, mica dust, titanium dioxide, talc, zinc oxide, white powder upon dilution of the benzene solu magnesium oxide, asbestos, quartz, wood ?our, tion with methanol. This copoly'mer had a sof cellulose, or wool ?bers, etc. . tening point of around 155° C. 55 Various pol'ymerizable compounds in addi-' 0 Example 9 tion to those heretofore speci?cally mentioned may be simultaneously polymerized or copoly I Parts merized with the 3-vinylpyrene to obtain new and 3-vinylpyrene , 10 useful synthetic compositions, for instance, any N-vinylphthalimide ______10 compound containing a polymeri’zable CH2=C< Benzoyl phthalimide ______- 1.0 grouping in its molecular structure, that is, com Benzene 50 - pounds containing a single CH2=C< grouping or ‘ The benzene solution of the above materials a plurality (two, three, four or more) of CH2=C< was heated for 20 hours in an oil bath at a groupings in the structure of the individual com temperature of 100‘ C. Dilution of the heated pound. Examples of such compounds are the solution with methanol precipitated a white ther esters, nitriles and amides of acrylic and a-Sllb moplastic powder, which softened at around stituted acrylic acids, vinyl esters and halides, 175° C’. metlwlene malonic esters, mono- and poly-allyl Example 10 70 compounds, e. g., the di-, tri-, tetra- (and higher) Parts allyl derivatives. For instance, the copolymer 3-vinylpyrene 10 izable material may be a polyallyl ester of an Acrylonitrile 10 inorganic polybasic acid, of a saturated or un Benzoyl peroxide ______-__.._.'._ 1.0 saturated aliphatic‘polycarboxylic acid or of an Benzene 50 75 aromatic polycarboxylic acid. Speci?c examples 2,400,“: 7 8 of compounds that may be employed, in addition and in numerous other electrical applications. to those‘ hereinbefore mentioned, are: The device to be treated may be impregnated Benzyl acrylate or ?lled with the polymerizable mixture (for Benzyl methacrylato example, the monomer, mixture of monomers, Methyl alpha-chloroacrylate mixture of partial polymers or copolymers, or Ethyl alpha-bromoacrylate mixture of monomer and partial polymer), and Propyl alpha-chloroacrylate polymerization effected in situ. Para-chlorostyrene What I claim as new and desire to secure by Aliyl‘acrylate Letters Patent oi.’ the United States is: Allyl methacrylate 10 1. A s-vinylpyrene polymer. Methallyl acrylate 2. A 3-vinylpyrene homopolymer. Di- and tri-chlorostyrenes 3. An interpolymer of (l) 3-vinylpyrene and Chlorinated divinylbenzenes (2) a different CHz=C<-containing compound Vinyl methyl ether which is copolymerizable with the 3-vinylpyrene, Vinyl ethyl ether the latter compound being present, by weight, in Divinyl ether an amount equal to from 1 to 99 per cent of the Methylene methyl malonate total weight of the interpolymer. Methylene ethyl malonate 4. An interpolymer 01' (l) 3-vinylpyrene and Vinyl chloride (2) styrene, the 3-vinylpyrene being present, by Vinylidene chloride 20 weight, in an amount equal to from 1 to 99 Diethylene glycol dimethacrylate (diethylene di per cent of the total weight of the interpoly methacrylate) mer. Glyceryl triacrylate 5. An interpolymer of (l) 3-vinylpyrene and Ethylene glycol diacrylate (ethylene diacrylate) (2) vinyl acetate, the 3-vinylpyrene being pres Diethylene itaconate 25 ent, by weight, in an amount equal to from 1 Diethyl maleate to 99 per cent of the total weight of the inter Dimethyl fumarate ' polymer. Para-chlorobenzyl acrylate 6. An interpolymer of (l) 3-vinylpyrene and Diallyl Iumarate (2) a diiferent CHz=C<-containing compound Diethyl itaconate 30 which is copolymerizable with the 3-vinylpyrene, Diallyl citraconate the latter comprising from 1 to 75 per cent, by Divinyl biphenyl weight, or the total weight of interpolymer. Vinyl methyl ketone 7. An interpolymer of (1) 3-vinylpyrene and Clyclopentadiene (2) styrene, the 3-vinylpyrene comprising from 2-chloro-butadiene-1,3 (chloroprene) 1 to '75 per cent, by weight, of the total weight 2,3-dimethyl-butadiene-1,3 of the interpolymer. Chlorinated methylstyrenes 8. An interpolymer of (l) 3-vinylpyrene and Chorinated vinylnaphthalenes (2) vinyl acetate, the 3-vinylpyrene comprising Hexadiene-l,5 from 1 to 75 per cent, by weight, of the total Octadiene-l,4 weight of the interpolymer. 2-cyano-butadiene-l,3 9. The process for preparing a 3-vinylpyrene Dimethallyl maleate polymer which comprises heating a polymeriz Dimethallyl itaconate able mass comprising 3-vinylpyrene in the pres Dimethallyl phthalate ence of a polymerization catalyst for the 3-vinyl Amyl acrylate 45 pyrene. Hexyl methacrylate 10. The process for preparing a homopoly Trlallyl citrate mer of 3-vinylpyrene which comprises heating Triallyl aconitate 3-viny1pyrene in the presence of a polymeriza Vinyl acetate tion catalyst for the 3-vinylpyrene at a temper Vinyl propionate 60 ature of from 45° to 200° C. Vinyl butyrate 11. The process for preparing an interpolymer The homopolymer or copolymers of this in of 3-vinylpyrene and a diil’erent CHz=C<-con vention have a wide variety of commercial ap taining compound which is copolymerizable with plications. They may be used alone or in com the 3-vinylpyrene, which processscomprises heat bination with other insulating materials, for ex 55 ing a, mixture comprising the foregoing two ample, paper, fabric materials formed of glass monomeric materials wherein the 3-vinylpyrene ?bers, cotton, silk, rayon, nylon, etc., sheet as is present, by weight, in an amount equal to bestos, cellulose esters (e. g., cellulose acetate, from 1 to 99 per cent of the total weight of the cellulose acetobutyrate, etc.), cellophane, etc., aforementioned copolymerizable mixture and in as dielectric materials in electrical apparatus. 60 the presence of a polymerization catalyst for the For instance, capacitors and other electrical de mixture of copolymerizable materials. vices may contain a dielectric material compris 12. The process as in claim 11 wherein the ing the products of polymerization of a polymer polymerization catalyst is benzoyl peroxide. izable mass containing 3-vinylpyrene as an es sential ingredient. RALPH G. FLOWERS. Paper-insulated capacitors wherein paper im REFERENCES CITED pregnated with a composition comprising a poly mer or copolymer of 3-vinylpyrene constitutes The following references are of record in the ?le of this patent: the dielectric material is a more specific example 70 01' the use of a composition of my invention in UNITED STATES PATENTS electrical applications. My new polymers and cODOlymers may also be employed as cable im- - Number Name Date pregnants, in impregnating electrical coils, as 2,34l,l86 Matheson et al _____ -- Feb. 8. 1944 ?lling compound in potheads and cable Joints, 2,371,499 Britton et al ______Mar. 13, 1945 76 2,427,337 Abbott et a1 ______Sept. 16. 1947