Melt Processable Multipoiymers of Acrylonitriie Monomer, Halogeoated Monomers and
Olefinicaiiy Unsaturated Monomers and the Process to Make Them and Products
Therefrom
Related Applications
This is a contmuation-in-paπ of USSN 08/703,718 filed on November 20, 1996 entitled. "Process for Making an Acrylonitriie and Olefinicaiiy Unsaturated Polymer", which is a divisional of 08/387,303 filed on February 27, 1995 entitled, "Process for Making an Acrylonitriie and Olefinicaiiy Unsaturated Polymer", which is a contmuation-in-paπ of 08/150.515 filed on November 10, 1993, entitled, "Process for Making an Acryionitπle and
Olefinicaiiy Unsaturated Polymer".
Field of the invention
The present invention relates to thermally stable, thermoplastic, melt processable multipoiymers of acrylonitriie monomer, halogenated monomers and optionally olefinicaiiy unsaturated monomers The unique assembly of acrylonitriie monomers, halogenated monomers and optionally olefinicaiiy unsaturated monomers provides for nitnle multipoiymers that can be thermally processed into nitnle fibers or rurrile articles. It is understood that the term "multipolymer" means polymers, copoiymers, lerpolymers and multipoiymers prepared from an acrylonitriie monomer and at least one of a vinyl halogen monomer and optionally an olefinicaiiy unsaturated monomer(s).
It is understood that the term "modacrylic" as defined by the U.S. Federal Trade Commission, for modacrylic fibers, is from 35% to 85% polymerized acrylonitriie units
Background of Invention
Nitπie polvmers are desirable in the production of fibers, films, molded objects, packaging and the like Nitnle polymers have excellent physical, chemical, and mechanical propeπies such as gas and moisture bamer, chemical resistance, rigidity, heat resistance, UV resistance and microorganism resistance However, nitnle polymers especially nitnle polymers containing halogenated monomers degrade when thermally processed because of the long
repeating sequences of both acrylorutnle monomer units and halogenated monomer units in the polymer chain. The polymers of nitnle monomers and halogen monomers are not melt processable and require the use of solvent because of the long sequences of mtπle monomer units and/or halogen monomer units.
The known processes for the manufacture of fibers and articles produced from polymers of nitnle monomers and halogenated monomers are based on solvent technology Polymers of nitnle monomers and halogenated monomers cannot be processed in the melt because they decompose at these processing temperatures. The polymers of nitnle monomers and halogenated monomers degrade at increasing rates above 150°C. The polymers become yellow, orange, red and eventually black as they thermally degrade. To avoid these problems, the state of the an conversion of polymers of nitnle monomers and halogenated monomers to nitnle fibers or articles is by solution processes. Only fibers or articles made from solution based processes are available by current technology. The broader range of thermally formed nitnle articles, i.e bottles, films, parts and the like are not possible from polymers of nitnle monomers and halogenated monomers made by current polymeπzation processes. The production of nitnle fibers or articles from solution based extrusion has numerous drawbacks. In the case of modacrylic fibers, the acrylonitriie monomer is copolymeπzed with halogenated monomers The incorporation of halogenated monomers bπngs about a decrease in the thermal stability of the modacrylic polymer. The use of solution based processes results in the need to remove the solvent from the resulting fibers or articles. The removal of solvent leads to voids in the structure and a decrease m the dimensional uniformity of the product resulting m the loss of mechanical and bamer properties in the product Furthermore, large quantities of solvent need to be recycled.
It is advantageous to produce a fiber or an article by a solvent free melt process from a thermally stable, thermoplastic, nitnle multipolymer. Further, it is desirable that the multipolymer and resulting product be uniform throughout and substantially void free The thermal stability of the multipolymer herein allows for thermal processing at higher operating speeds in the absence of solvent, while simultaneously producing fibers or articles with improved phvsical. mechanical and chemical properties Furthermore, fibers or articles of complex shape and cross section can be produced from melt processable, thermally stable, thermoplastic multipoiymers
Summary of the Invention
The present invention provides for a melt processable multipolymer compπsing about 20% to less than 50% polymeπzed acrylonitnle, about 80% to about 40% polymenzed halogenated monomers and about 0% to 10% of polymeπzed olefinicaiiy unsaturated monomer The resulting multipolymer is thermally stable, thermoplastic and thermally processable The multipolymer contains a relatively uniform distπbution of each of the monomers in the multipolymer chain The present invention provides for a multipolymer that is thermallv stable, thermoplastic and has excellent chemical, mechanical and physical properties
The present invention provides for a process for making the thermally stable, thermoplastic multipolymer by polymenzing an acrylonitnle monomer, at least one of a halogenated monomer and optionally at least one of an olefinicaiiy unsaturated monomer in which the rate of addition of the acrylonitnle monomer and the halogenated monomer and the optional olefinicaiiy unsaturated monomer is equal to or less than the rate of polvmeπzation to maintain a monomer starved process. The present invention further provides for melt processing the thermally stable, thermoplastic, multipolymer m the absence of solvents into fibers or articles The present invention further encompasses such processing steps such as melt spinning, resulting in fibers that may be used in woven knitted or non-woven applications, and articles that are thermally processed through thermo forming, compression molding, extrusion, injection molding, blow molding, calendeπng, thermo forming, fusion coating and the like
Specific Embodiment
The unique thermally processable multipolymer used in this invention compnses an acrylonitnle monomer, a halogenated monomer and optionally an olefinicaiiy unsaturated monomer, wherein the multipolymer is homogeneous with a substantially uniform microstructure Exemplary ways to make the thermally stable, thermoplastic, multipoiymers are found in USPN 5,618,901 entitled "A Process For Making A High Nitnle Multipolymer Prepared From Acrylonitnle and Olefinicaiiy Unsaturated Monomers", USPN 5,602,222 entitled "A Process For Making An Acrylonitnle Methacrylo tπle Olefinicaiiy Unsaturated Monomers", and USPN 5,596,058
entitled "Process for Making Acrylonitrile/Methacrylonitrile Co-polymers," all incorporated herein.
The multipolymer compnses about 20% to less than 50%, preferably about 30% to less than 50%, and more preferably about 40% to less than 50% of a polymenzed acrylonitnle monomer, at least one of about 80% to about 40%, preferably about 70% to about 40%. and more preferably about 65% to 40% of a polymerized halogenated monomer and one or more of
0% to about 20%, preferably 0% to about 15% and more preferably about 0.1% to about 10% of a polymeπzed olefinicaiiy unsaturated monomer.
The halogenated monomers employed in the multipolymer are one or more halogenated monomers polymeπzable with the acrylonitriie monomer. The halogenated monomers employed in the multipolymer can be a single monomer or combination of monomers. The choice of halogenated monomer or combination of monomers depends on the properties (i.e., flame retardancy) desired for the resulting multipolymer and products.
The halogenated monomers include but are not limited to vinyl chloride, vinyl bromide, vinyl fluoride, vmylidene chloride, vinylidene bromide, vinylidene fluonde, halogen substituted propylene monomers, aromatic halogen monomers such as the chlorostyrenes, and the like. The preferred halogenated monomers are vinyl chloride, vinyl bromide and vinylidene chloride.
The olefinicaiiy unsaturated monomer are employed in the multipolymer is one or more of an olefinicaiiy unsaturated monomer with a C=C double bond polymeπzable with acrylonitriie. The olefinicaiiy unsaturated monomer excludes halogenated monomer. The olefinicaiiy unsaturated monomer is optionally employed in the multimonomer mixture depending on the properties desired for the multipolymer and resulting products. The olefinicaiiy unsaturated monomer can be a single poly erizable monomer or a combination of polymeπzable monomers. The choice of olefinicaiiy unsaturated monomer or combination of monomers depends on the properties desired for the resulting multipolymer and product. The olefinicaiiy unsaturated monomer includes but is not limited to acrylates, methacrylates, acrylamide and its derivatives, methacrylamide and its derivatives, maleic acid and derivatives, vinyl esters, vinyl ethers, vinyl amides, vinyl ketones, styrenes, ionic monomers, acid containing monomers, base containing monomers, olefins and the like.
The acrylates include but are not limited to C, to C12 alkyl, aryl and cyclic acrylates. such as methyl acrylate, ethyl acrylate and functional denvatives of the acrylates such as 2-hydroxyethyl acrylate, 2-chloroethyl acrylate and the like. The preferred acrylates are methvl acrylate and ethyl acrylate.
The methacryiates include but are not limited to C, to C,*, alkyl, aryl and cyclic methacryiates; such as methyl methacrylate, ethyl methacrylate, phenyl methacrylate, butyl methacrylate, isobomyl methacrylate, 2-ethylhexyl methacrylate and functional denvatives of the methacryiates such as 2-hydroxyethyl methacrylate, 2-chloroethyl methacrylate and the like The preferred methacrylate is methyl methacrylate.
The acrylamides and methacrylamides and each of their N-substituted alkyl and aryl denvatives include but are not limited to acrylamide, methacrylamide, N-methyl acrylamide, N,
N-dimethyl acrylamide and the like.
The maleic acid monomers include but are not limited to maleic acid monododecyl maleate, didodecyl maleate, maleimide, N-phenyl maleimide.
The vmyl ethers include but are not limited to C, to C8 vinyl ethers such as ethyl vinyl ether, butyl vmyl ether and the like.
The vmyl esters include but are not limited to vinyl acetate, propionate, butyrate and the like The preferred vinyl ester is vinyl acetate.
The vmyl amides include but are not limited to vinyl pyrrohdone and the like The vmyl ketones include but are not limited to C, to C8 vmyl ketones such as ethyl v vl ketone, butyl vmyl ketone and the like.
The styrenes include but are not limited to substituted styrenes, multiple-substituted styrenes, methylstyrenes, styrene, indene and the like Styrene is of the formula
wherein each of A, B, D and E is independently selected from hydrogen (H), C, to C< alkyl groups and halogen.
The ionic monomers include but are not limited to sodium vmyl sulfonate. sodium styrene sulfonate, sodium methallyl sulfonate, sodium acrylate, sodium methacrylate and the like. The preferred ionic monomers are sodium vinyl sulfonate, sodium styrene sulfonate and sodium methallyl sulfonate.
The acid containing monomers include but are not limited to acrylic acid, methacryhc acid, vinyl sulfonic acid, ltacomc acid, styrene sulfonic acid and the like. The preferred acid coπtaimng monomers are ltacomc acid, stryrene sulfonate acid and vmyl sulfonic acid The base containing monomers include but are not limited to vmyl pyndme, 2- ammoethyl-N-acrylamide, 3-amιnopropyl-N-acrylamιde, 2-amιnoethyl acrylate, 2-ammoethvl methacrylate and the like.
The olefins include but are not limited to isoprene, butadene, C-, to Cg straight chained and branched alpha-olefins such as propylene, ethylene, isobutylene, diisobutylene, 1 -butene and the like The preferred olefins are isobutylene, ethylene and propylene. The choice of olefinicaiiy unsaturated monomer or combination of monomers depends on the properties desired for the resultmg multipolymer and its end use. Polymeπzmg monomers of acrylonitnle and the halogenated monomer increases the flame resistance of the multipolymer and flame retardancy its end products. For instance, polymeπzmg monomers of acrylonitnle, halogenated monomer and alpha methyl styrene and/or mdene results in a multipolymer and its end products with flame resistance and improved heat distortion temperature and glass transition temperature Polymeπzmg monomers of acrylonitnle, halogenated monomer, and isobutylene improves the flexibility of the multipolymer and its end products. Polymeπzing monomer of acrylonitnle, halogenated monomer and acrylates and/or methacryiates improves the processabi ty of the multipolymer and its end products. Polymenzing acid-containmg monomers, base containing monomers and/or hydroxyl group containing monomers with an acrylonitnle monomer and halogenated monomer provides useful dye sites which enhance the colorability of the resulting multipolymer
In the practice of the present invention the polymeπzation process is earned out as an emulsion, a solution, a suspension or in continuous addition bulk. The present invention can be practiced as a semibatch or continuous process. Preferably, the polymeπzation process is carried out as an emulsion or a suspension The process of the present invention is not earned out as
batch process, which batch process is defined herein as a process in which all the reactants are charged initially to the reaction vessel prior to the initiation of polymerization.
Initially, acrylonitriie monomers, halogenated monomers, and optionally the olefinicaiiy unsaturated monomers are contacted in an aqueous medium at about 0.1 % by weight to about 15% by weight of the total polymerization reaction media. The initial multimonomer mixture contains about 5% by weight to less than 50% by weight acrylonitriie monomer, about 10% by weight to about 90% by weight halogenated monomer and about 0% by weight to about 20% by weight olefinicaiiy unsaturated monomers.
The aqueous medium contains water and a suitable surfactant such as an emulsifier or a dispersing agent. The surfactants and their uses are known to those skilled in the art. A molecular weight modifier may be added to the initial multimonomer mixture in the range of about 0% by weight to about 5% by weight, preferably about 0.1% by weight to 4% by weight and most preferably about 0.1 % by weight to about 3% by weight of the total multimonomer mixture.
The initial multimonomer mixture is placed into a reaction vessel containing aqueous medium. The reaction vessel with the aqueous medium is purged with an inert gas, such as nitrogen, argon and the like. Preferably, but optionally, the inert gas purge is continued throughout the polymerization reaction. The initial multimonomer mixture is then heated to a temperature in the range of about 20°C to about 120CC and preferably about 10°C to about 80°C. The temperature of the polymerization reaction is maintained throughout the process in the range of about 20°C to about 120°C and preferably about 10°C to about 80°C.
An initiator is added to the initial multimonomer mixture to start the polymeπzation reaction. The initiator is added generally in the range of about 0.01% by weight to about 5% by weight of the total multimonomer mixture.
After the polymerization reaction commences, a multimonomer feed mixture of acrylonitriie monomer, halogenated monomer and optionally an olefinicaiiy unsaturated monomer, is continuously added to the polymerization reaction in the reaction vessel. The combined weight of the unreacted acrylonitriie monomer, unreacted halogenated monomer and unreacted optional olefinicaiiy unsaturated monomer present in the polymerizing mixture, at any time, is not greater than about 20% by weight, preferably not greater than about 15% by weight, and most preferably not greater than about 10% by weight of the polymerizing mixture.
The multimonomer feed mixture contains about 5% by weight to about less than 50% b% weight acrylonitnle monomer, about 10% by weight to about 90% by weight halogenated monomer and 0% by weight to about 20% by weight olefinicaiiy unsamrated monomer The molar ratio of the acrylonitnle monomer, halogenated monomer and the olefinicaiiy unsaturated monomer m the multimonomer feed mixture, is fixed and remains constant throughout the polymeπzation process resulting m a homogeneous multipolymer. The feed molar ratio of the acrylonitnle monomer to halogenated monomer to olefimcally unsaturated monomer depends on the desired multipolymer composition
A molecular weight modifier is optionally added to the polymeπzation mixture Preferably, the molecular weight modifier is added continuously to the polymenzation mixture The molecular weight modifier is preferably added to the polymenzation reaction media in the range of about 0% by weight to about 5% by weight, preferably about 0.1% by weight to about 4% by weight, and most preferably about 0.1% by weight to about 3% by weight of the total multimonomer mixture.
The molecular weight modifier includes but is not limited to mercaptans, alcohols, halogen compounds or any other chain transfer agent known to those skilled in the art
Mercaptans are the preferred molecular weight modifier and include mono-mercaptans, multifunctional mercaptans or combinations thereof. The mercaptans include but are not limited to C< to C,g alkyl mercaptans whether straight chained, branched, substituted or unsubstituted, d-hmonene dimercaptan, and the like The preferred mercaptans are the C5 to C*-, alkyl mercaptans whether straight chained, branched, substituted or unsubstituted, for example, t-dodecyl mercaptan and n-octyl mercaptan The molecular weight modifier can be employed singularly or in combination. The molecular weight modifier can be the same or a different molecular weight modifier as is employed with the initial multimonomer mixture
The molecular weight modifier that may be useful, controls the molecular weight of the polymerized multipolymer chain by terminating the growing chain The molecular weight modifier useful in the present invention produces a multipolymer with a molecular weight in the range of about 15,000 molecular weight to about 500,000 molecular weight.
The initiator is added typically as a single solution, continuously or incrementally, to the polvmeπzation mixture The initiator is added at a rate to maintain the polymenzation rate. which rate can be determined by those skilled in the art The concentration of the initiator is
generally in the range of about 0.01% by weight to about 5% by weight of the total multimonomer mixture.
The initiator is any free radical initiator known to those skilled in the an The initiator includes but is not limited to azo compounds, peroxides, hydroperoxides, alkyl peroxides, peroxydicarbonates, peroxyesters, dialkyl peroxides, persulfates, perphosphates, and the like Persulfates are the preferred initiators. The initiator can be employed singularly or in combination with reducing compounds to enhance their reactivity (redox). The initiator can be the same or a different initiator as is employed to start the polymeπzation reaction
The polymeπzation mixture is agitated by any known method, such as stimng, shaking and the like. The reaction is continued until polymeπzation has proceeded to the desired extent. generally from about 30% to about 90% conversion.
The polymenzation reaction is stopped by cooling; adding an inhibitor; such as diethyl hydroxylamine, 4-methoxyphenol and the like; discontinuing the multimonomer feed mixture, removing unreacted monomer, and the like The inhibitors and their use are known to those skilled in the art. At the conclusion of the polymenzation reaction the multipolymer is a solid, slurry or a latex Any known technique may be used to isolate the multipolymer such as crumb coagulation, spraying the solution of the multipolymer into a heated and/or evacuated chamber to remove the water vapors, stπppmg. filtration, centπfugation and the like.
The multipolymer produced by the process of the instant invention is a thermally stable. thermoplastic multipolymer containing polymeπzed acrylonitnle monomer and polymeπzed halogenated monomer and optionally polymeπzed olefimcally unsaturated monomer The multipolymer is homogeneous in that the composition and sequencing of the multipolymer produced is substantially the same throughout the process.
The process for producing a thermally stable, thermoplastic, melt processable multipolymer from the monomers is accomplished by controlling the rate of addition of the acrvlonitnle monomer, the halogenated monomer and the olefimcally unsaturated monomer relative to the rate of polymenzation The process of the invention is a monomer starved process in which the polymenzation reaction rate exceeds or equals the multimonomer feed mixture addition rate The low concentration of the unreacted multimonomers duπng the polymerization step generates a monomer starved condition which prevents long sequences of each of the monomers in the multipolymer chain The multipolymer chain contains short sequences of
polymeπzed halogenated monomer mterdispersed between short sequences of polymeπzed acrylonitriie monomer for example, AN-AN-Z-AN-AN-Z-Z-AN-Z-Z
![Figure imgf000011_0001](https://patentimages.storage.googleapis.com/83/a8/76/f9546bb2253f6f/imgf000011_0001.png)
unit and Z=halogen unit). The halogenated monomers are substantially uniformly mterdispersed among the acrylonitriie units in the multipolymer. These shorter acrylonitriie sequenced multipoiymers have a lower melting point and reduced melt viscosity which allows melt/thermal processing in the absence of solvent. The multipolymer allows for unique properties m the fibers or articles such as dimensional stability, improved orientation, substantially free of voids, uniformity, strength, toughness, flexibility, resistance to degradation by UV light, resistance to biologicaP attack and the like.
The thermally stable, thermoplastic multipolymer can be processed by a combination of one or more of any thermal processes and/or thermoforming techniques. The multipolymer is thermoplastic, thermally stable and thermally processable without the addition of any solvents The multipolymer of the present invention may be further thermal processed by spinning, molding, extruding and the like without the use of solvents. Such thermal processing steps include, but are not limited to, thermoforming, orientation, blowing, lamination, coating, extrusion, sealing, prestretching compression molding, injection molding, blow molding, calendeπng, fusion coating and the like. The thermal process temperature is higher than the glass transition temperature of the multipolymer from about 100°C to about 300°C and preferably about 130°C to about 240°C.
An exemplary method to make melt spun acrylonitriie olefinicaiiy unsaturated fibers and the process to make the fibers is described in USSNs 08/574,312 and 08/780,754 entitled "Melt
Spun Acrylonitriie Olefinicaiiy Unsaturated Fibers and the Process to Make the Fibers". An exemplary method to make thermally melt processable articles from multipolymer as descnbed in USSN 09/255,092 entitled "Thermally Melt Processable Multipoiymers of Acrylonitriie and Olefimcally Unsaturated Monomers". It will be readily apparent to one skilled in the art that the multipolymer and resulting products may be further modified by the addition of lubricants, dyes, leaching agents, pigments, delusteπng agents, stabilizers, static control agents, antioxidants, reinforcing agents such as fillers and the like. It is understood that any additive possessing the ability to function in such a manner can be used as long as it does not have a deleteπous effect on the thermal charactenstics of the multipolymer and products thereof.
The thermal processing occurs in the absence of solvent Such articles produced here include umaxial and/ or biaxial films, sheets, tapes, laminates, shaped articles, coated structures. composite structures, fibers and the like. The multipolymer may be utilized in numerous applications such as for use in filaments, fibers, fabncs, woven fabncs, non-woven fabncs, flame retardant fabncs, films, carbon sheets, carbon films, sheets, pipes, tub g, molded articles, coated laminates, wire coveπngs, substrates for xerography, packaging, tapes, bottles, coatings, laminates, barπer products, membranes, molded articles and the like The products of this invention may be further used in packaging, bamer applications, electncal insulators, photographic films, engmeeπng films and the like.
Examples
The following examples are presented to illustrate the present invention It should be understood, however, that the invention is not limited to the specific details set forth in the examples
Example 1 Preparation of 50/50, Acrylonitπle Vinyl Chloπde Copolymer
A 1 liter stainless steel polymenzation reactor capable of retaining about 150 psi. of pressure was equipped with a stirrer, electncal heater and control system, nitrogen purge and one monomer mixture feed line with pump. The reactor was initially charged with about 560 gm of water and about 22.9 gm of Dowfax 8390 (surfactant from Dow Chemical Co.), purged with nitrogen gas, sealed and brought to about 22°C An initiator system compπsed of about 1.28 gm ammonium persulfate, about 0.3 gm of sodium meta-bisulfite and about 0.08 gm of feπous sulfate was charged and immediately followed by an initial monomer mixture charge of about
0 94 gm acrylonitnle, about 15.1 gm of vinyl chloπde and about 0.32 gm of n-octyl mercaptan under pressure A monomer feed of 45.2 gm acrylonitnle, 105 4 gm of vmyl chlonde and about 3 0 gm of n-octyl mercaptan was then added to the reactor in a uniform manner over a period of three hours The reaction was allowed to proceed for one half hour after the feed was complete then the reactor was vented of excess vinyl chloπde gas and the resulting latex drained from the reactor The temperature of the reaction ranged from about 22 to about 28°C The latex was
coagulated in 3 liters of stirred water at about 95°C containing about 4 gm of magnesium sulfate. filtered and dned.
The final conversion to copolymer based on overall monomers was 60% and had a composition of about 48.7 weight percent acrylonitnle by 13C NMR and a molecular weight of 22,000 Mw by Gel Permeation Chromatography (GPC) and a Melt Index of 47 (g/10 mm ) at 200°C wιth a 10 kg load
Example 2 Preparation of 40/60, Acrylonitπle/Vmyl Chloπde Copolymer A 1 liter stainless steel polymenzation reactor capable of retaining 150 psi of pressure was equipped with a stirrer, electncal heater and control system, nitrogen purge and one monomer mixture feed line with pump The reactor was initially charged with about 560 gm of water and about 22.9 gm of Dowfax 8390 (surfactant from Dow Chemical Co ), purged with nitrogen gas, sealed and brought to about 22°C An initiator system compπsed of about 1.28 gm ammonium persulfate, about 0.3 gm of sodium meta-bisulfite and about 0.08 gm of ferrous sulfate was charged and immediately followed by an initial monomer mixture charge of about
0.94 gm acrylonitnle, about 15.1 1 gm of vmyl chloπde and about 0.32 gm of n-octyl mercaptan under pressure A monomer feed of 28.6 gm acrylonitnle, about 122.0 gm of vmyl chloπde and about 3 0 gm of n-octyl mercaptan then was added to the reactor m a uniform manner over a penod of three hours The reaction was allowed to proceed for one half hour after the feed was complete then the reactor was vented of excess vmyl chlonde gas and the resulting latex drained from the reactor The temperature of the reaction ranged from about 22 to about 28°C The latex was coagulated in 3 liters of stirred about 95°C water containing about 4 gm of magnesium sulfate, filtered and dned
The final copolymer had a composition of about 41.2 weight percent acrylonitnle by l3C NMR and a molecular weight of 50,000 Mw by Gel Permeation Chromatography (GPC) and a
Melt Index of 85 (g/20 mm ) at 200°C with a 10 kg load
Example 3 Preparation of Acrylonitnle and Vinylidene Chloride Copolymer (47/53, AN/VDC) A 2 liter glass polymenzation kettle equipped with a temperature controlled water jacket, flat blade stiner, inert gas purge line, and 3 feed lines with pumps was charged with 757gms of
distilled water, about 18.86gms of Dowfax 8390 (surfactant from Dow Chemical Co.), about
1 lgms of acrylonitnle, about 1 lgms of vinylidene chlonde and about O. lδgms of n-octyl mercaptan and brought to about 9°C under nitrogen gas. To this was added about 0.22gms of sodium meta-bisulfite, about 0 44gms of ferrous sulfate and about 0.22gms of ammonium persulfate to initiate the reaction. Upon initiation, three continuous streams were pumped into the reactor uniformly for a peπod of 5 hours. Stream one consisted of about 89.1 gms of acrylonitnle, about 108.9gms of vinylidene chloπde and about 1.58gms of n-octyl mercaptan Stream two consisted of about 0.55gms of ammonium sulfate in lOOgms of water. Stream three consisted of about 0.04gms of ferrous sulfate in lOOgms water.
After five hours the resulting latex was coagulated m 3 liters of hot water containing about 6gms of A1,(S04)3 The polymer was collected by filtration and dned by fluid bed at about
60°C for 5 hours. The conversion was 84.5% with a composition of about 47.3 weight percent AN and about 53.7 weight percent VDC with a molecular weight of 202,000 Mw by Gel Permeation Chromatography (GPC).
Example 4
Preparation of Terpolymer of Acrylonitnle, Vinylidene Chloπde and Methyl Acrylate A 2 liter glass polymenzation kettle equipped with a temperature controlled water jacket, flat blade stiπer, inert gas purge line, and one feed line with pump and charged with about 600gms of distilled water, about 28.57gms of Dowfax 8390 (surfactant from Dow Chemical Co ), about 7 6gms of acrylonitnle (AN), about 1 lgms of vinylidene chlonde (VDC), about
1 4gms of methyl acrylate (MA) and about 0.20gms of n-octyl mercaptan and brought to 18oC under nitrogen gas To this was added about 0.40gms of sodium meta-bisulfite, about 0 l Ogms of ferrous sulfate and about 1.2gms of ammonium persulfate to initiate the reaction Upon initiation, a continuous stream consisting of about 68 4gms of acrylonitnle, about 99 Ogms of vinvlidene chloπde about 12.6gms of methyl acrylate and about 1 8gms of n-octyl mercaptan was pumped into the reactor uniformly over a peπod of about 3 hours The reaction was continued for one half hour after the addition was complete
After three and one half hours the resulting latex was coagulated in 3 liters of hot water containing about 6gms of MGS04. The polymer was collected by filtration and dned by fluid bed at about 60°C for about 5 hours. The conversion was 82.45% with a composition of 43.3 weight percent AN, 48.2 weight percent VDC and 8.5 weight percent MA.
From the above descπption of examples and invention; those skilled in the art will perceive improvements, changes and modifications in the invention. Such improvements, changes and modifications are intended to be covered by the claims.