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Showing papers on "Vinyl acetate published in 1974"



Patent
28 Feb 1974
TL;DR: In this paper, a dual-functioning flow improver composition is proposed for middle distillates, which is a combination of two different wax modifying compounds, one of which functions as a wax growth arrester and the other functions as nucleating agent.
Abstract: The response of middle distillates to flow improvers can be substantially improved by utilizing a dual-functioning flow improver composition which is a combination of two different wax modifying compounds. One of these functions as a wax growth arrester. The other functions as nucleating agent. Specifically, for example, it has been demonstrated that a copolymer of ethylene with vinyl acetate in combination with another copolymer of ethylene with vinyl acetate where either the vinyl acetate monomer is present in different proportions and/or the molecular weights are different is a flow improver combination which imparts significant improvements in the filterability of middle distillate fuels.

66 citations


Patent
Edward Cooper Ballard1
30 Dec 1974
TL;DR: In this paper, an improved process for preparing ethylene/vinyl acetate copolymer based hot-melt adhesive backsized tufted carpet wherein polyethylene, polypropylene or EVC film is used as the secondary backing is described.
Abstract: Improved process for preparing ethylene/vinyl acetate copolymer based hot-melt adhesive backsized tufted carpet wherein polyethylene, polypropylene or ethylene/vinyl acetate copolymer film is used as the secondary backing. Such carpets have unexpectedly and significantly improved tuft pull strength.

57 citations


Patent
28 Aug 1974
TL;DR: In this paper, hot melt compositions containing copolymer of ethylene and vinyl acetate and/or alkyl acrylate wherein the alkyls group contains 1-18 carbon atoms; atactic polypropylene; and vulcanized rubber which are particularly useful as hot melt carpet backing adhesives and as hot-melt pressure sensitive adhesive.
Abstract: Hot melt compositions containing copolymer of ethylene and vinyl acetate and/or alkyl acrylate wherein the alkyl group contains 1-18 carbon atoms; atactic polypropylene; and vulcanized rubber which are particularly useful as hot melt carpet backing adhesives and as hot melt pressure sensitive adhesives.

56 citations


Patent
26 Apr 1974
TL;DR: In this paper, the authors describe polymeric laminates for packaging which contain an oxygen barrier layer which is composed of a hydrolysed olefin/vinyl ester copolymer, and other layers in the laminate protect the oxygen barrier from moisture and provide a heat-sealable surface layer.
Abstract: A B S T R A C T The invention relates to polymeric laminates for packaging. According to the invention, such laminates contain an oxygen barrier layer which is composed of a hydrolysed olefin/vinyl ester copolymer, preferably a hydrolysed ethylene/vinyl acetate copolymer. Other layers in the laminate protect the oxygen barrier layer from moisture and provide a heat-sealable surface layer. The laminates withstand the temperatures of 80-125°C employed in pasteurisation and sterilisation procedures, and are therefor of value in the preparation of pasteurised and sterilised packages of oxygen-sensitive foodstuffs.

56 citations


Patent
22 Feb 1974
TL;DR: A water-dispersible hot melt adhesive comprises 75-95 parts of a graft copolymer of about 40-80% vinyl monomer and about 20-60% by weight of water-soluble polyalkylene oxide polymer, and 5-25 parts by weight tackifying resin this article.
Abstract: A water-dispersible hot melt adhesive comprises 75-95 parts of a graft copolymer of about 40-80% vinyl monomer and about 20-60% by weight of water-soluble polyalkylene oxide polymer, and 5-25 parts by weight tackifying resin. The water-soluble polyalkylene oxide polymer has a molecular weight of about 3000 to 20,000 and a polymerized ethylene oxide content of at least 50% by weight. The vinyl monomer is preferably a vinyl acetate or low molecular weight alkyl-substituted acrylate. The adhesive is preferably 75-85% copolymer and 15-25% by weight tackifying resin.

52 citations


Journal ArticleDOI
TL;DR: In this article, a good agreement between the results of various methods for determination of compatibility was established for various methods involving dielectric and physico-mechanical properties and also thermal analysis.

51 citations


Patent
03 Jun 1974
TL;DR: In this paper, a method for the preparation of a laminated polypropylene laminated packaging film has been proposed, which is suitable for use in food packaging applications, and the method is described.
Abstract: A laminated film suitable as a food packaging film comprised of a base layer of an oriented polypropylene film, a layer of a vinylidene chloride polymer adhered to one surface of the base layer, a layer of first ethylene/vinyl acetate copolymer having a vinyl acetate content greater than 10 percent by weight adhered to the vinylidene chloride polymer layer and a top layer of a second ethylene/vinyl acetate copolymer having a vinyl acetate content less than 10 percent adhered to the first ethylene/vinyl acetate copolymer layer. BACKGROUND OF THE INVENTION 1. Field of the Invention This application is a continuation-in-part of copending application Ser. No. 81,941 filed Oct. 19, 1970, and now abandoned. This invention relates to an improved packaging film and more particularly relates to a laminated packaging film having low permeability to gases and a method for the preparation thereof. 2. The Prior Art Films and other shaped articles of polypropylene have found widespread use as a wrapping and packaging material for many articles of commerce because of their flexibility, transparency, low water vapor permeability and an excellent capability for being heat sealed to provide strong permanent joints. Although polypropylene films have low water vapor permeability, the films exhibit poor resistance to the permeation or transmission of air and oxygen and for this reason have not found wide application in food packaging where extended shelf-life is a requirement. Saran coatings which are basically vinylidene chloride polymers containing minor proportions of a copolymerized ethylenically unsaturated monomer such as vinyl chloride or acrylonitrile have the outstanding property in comparison to other synthetic coatings of their excellent resistance to the transmission of oxygen or air. For this reason, it has previously been the practice to coat polypropylene films with either saran emulsions or lacquers. These coatings once applied to the polypropylene films render the films sufficiently impervious to air and oxygen to permit the use of the films for food packaging applications. The application of saran coatings to polypropylene films has not been without problems. When saran emulsions are employed, at least two coating applications are required in order to eliminate pinholes in the saran coating that is deposited. The resultant high coating weight required when using the emulsions may result in impairment of the impact strength of the coated film. When saran lacquers are employed, the organic solvents used in the lacquers are absorbed by the polypropylene film producing objectionable odors which are difficult to eliminate. One approach to the solvent absorption problem has been to use lacquers containing extremely volatile solvents and to wind the saran coated polypropylene film into rolls. The rolls are then stored for time periods of at least 48 hours before any further use is made of the coated film. During this storage period, the solvents absorbed from the saran coating operation rapidly permeate the polypropylene film layer and concentrate between the roll windings. After the storage period, the film roll is unwound and subjected to a jet of high velocity air directed on the uncoated side of the polypropylene film layer which effectuates the removal of the absorbed solvent which has permeated out of the film. It has been found that excellent gas transmission properties can be imparted to polypropylene films with very low coating weights of saran, e.g. in the range of 0.3 to 0.5 pounds per 1000 square feet of film surface, using surface oxidized films fabricated from polypropylene and employing a saran lacquer as the coating medium. These saran coated polypropylene films cannot, however, without further modification, be employed as packaging films, as the saran layer is easily scratched or damaged during the packaging operation which causes a marked diminution in the gas barrier properties of the coated film. In order to protect the saran coating from damage by packaging operations, attempts have been made to laminate the saran coated polypropylene films to other film substrates such as those fabricated from nylon, polyethylene terephthalate or another polyolefin with the saran layer forming the intermediate layer of the laminate. In forming the laminated film, an adhesive agent such as synthetic rubber or polyurethane is generally applied in an organic solvent to the second film layer and then combined with the coated side of the saran coated polypropylene immediately after the solvent has been evaporated from the applied adhesive layer. Another method to effect lamination is to extrude a molten layer of nylon or a polyolefin onto the coated side of a saran coated polypropylene, after first priming the saran layer with an organic titanate or a polyurethane. Although the solvent absorption problem encountered in the saran coating of polypropylene films is substantially eliminated by the roll storage procedure discussed above, the solvent absorption problem is frequently encountered again when the saran coated polypropylene surface is laminated to a second film layer using adhesive solutions. Removal of the absorbed adhesive solvent from the laminated structure is extremely difficult and may not be apparent for several weeks after the structure is fabricated so that when the absorbed solvent slowly permeates through the structure, it can contaminate food stuffs packaged therein. The problem is particularly severe when the second film layer laminated to the saran coated polypropylene film is a film which has good gas barrier properties such as nylon or polyethylene terephthalate. However, the problem also exists when the second film layer is a polyolefin such as an ethylene/vinyl acetate copolymer, for although the ethylene/vinyl acetate copolymer films are readily permeable to many solvents, it has been found that the solvents such as the aliphatic and aromatic hydrocarbons used in preparing adhesive solutions commonly employed in film laminating operations are generally less volatile than the solvents used in the saran coating operations, and do not readily permeate out of the film during extended storage periods. SUMMARY OF THE INVENTION In accordance with the present invention there is provided a laminated film structure having improved gas barrier properties, the structure being comprised of a base layer of an oriented polypropylene film, a continuous layer of a saran polymer coated on one surface of the base layer, a layer of a first ethylene/vinyl acetate copolymer having a vinyl acetate content of greater than 10 percent by weight adhered to the saran layer and a top layer of a second ethylene/vinyl acetate copolymer having a vinyl acetate content less than 10 percent adhered to the first ethylene/vinyl acetate copolymer layer. The laminated films of the present invention do not require the use of adhesive solutions in their preparation. As no adhesive solutions are employed, there is no requirement for solvent removal during the laminating operation and the problem of solvent absorption is thereby substantially eliminated. The laminated film structures prepared in accordance with the present invention are substantially free of absorbed quantities of organic solvents and have particular utility as wrapping and packaging materials for foodstuffs and other articles where it is desirable to provide packages having maximum resistance to the permeation of gases.

45 citations


Journal ArticleDOI
TL;DR: In this article, a very efficient ESR spectrometer was applied to the measurement of the stationary concentration of macroradicals in homogeneous polymerization, and from these data the rate constants of chain propagation and chain termination for the polymerizations of methyl methacrylate and vinyl acetate were found in a direct way.
Abstract: A very efficient ESR spectrometer was applied to the measurement of the stationary concentration of macroradicals in homogeneous polymerization. From these data the rate constants of chain propagation and chain termination for the polymerizations of methyl methacrylate and vinyl acetate were found in a direct way. Activation energies of these elementary reactions were measured. Fur die Bestimmung der stationaren Konzentration von Makroradikalen bei der homogenen Polymerisation wurde ein sehr wirksames ESR Spektrometer eingesetzt. Aus den erhaltenen Daten wurden die Geschwindigkeitskonstanten des Kettenwachstums und Kettenabbruchs fur die Polymerisationen von Methylmethacrylat und von Vinylacetat auf direktem Weg erhalten. Die Aktivierungsenergien diese Elementarreaktionen wurden gemessen.

35 citations




Journal ArticleDOI
TL;DR: In this paper, the solubilities of several solvents were measured in four molten polymers by using an isobaric vapor-pressure apparatus, and a theory was analyzed with a theory which took into account adsorption of solvent by polymer in addition to differences in free volumes and intermolecular forces.
Abstract: Solubilities of several solvents were measured in four molten polymers by using an isobaric vapor-pressure apparatus. Solvent concentration ranged from 0.5 to 15 wt-%. The systems polyisoprene–benzene and polyisobutylene–benzene were studied at 80.0°C; polyisobutylene–cyclohexane was studied at 100.0°C; ethylene–vinyl acetate copolymer (EVA)–cyclohexane, EVA–isooctane, and poly(vinyl acetate)–isooctane were studied at 110.0°C. Of six polymer–solvent systems studied, all except poly(vinyl acetate)–isooctane appear to exhibit hysteresis in a single sorption–desorption cycle starting with dry polymer. The desorption curves of solvent activity plotted versus solvent weight fraction show an inflection point, suggesting localized adsorption of solvent molecules. Experimental data were analyzed with a theory which takes into account adsorption of solvent by polymer in addition to differences in free volumes and intermolecular forces. The theory gives a semiquantitative representation of the experimental data.

Patent
16 Jan 1974
TL;DR: This paper used aqueous emulsion copolymers of ethylene and vinyl acetate containing from 1.5-9% of cross-linking monomers and having a molecular weight of at least about 300,000.
Abstract: Crushed foam-backed fabrics possessing improved dry cleaning resistance and cold crack resistance are provided using aqueous emulsion copolymers of ethylene and vinyl acetate containing from 1.5-9% of cross-linking monomers and having a molecular weight of at least about 300,000.

Patent
03 Jun 1974
TL;DR: A water-insoluble particulate composition having controlled slow oil-solubility at temperatures in excess of 350° F is proposed in this paper, which is comprised of solid particles of a homogeneous mixture of polyethylene, ethylene-vinyl acetate copolymer containing about 15 to 30 weight percent vinyl acetate, or admixtures of these polymers.
Abstract: A water-insoluble particulate composition having controlled slow oil-solubility at temperatures in excess of 350° F. is disclosed. The composition is comprised of solid particles of a homogeneous mixture of (1) polyethylene, ethylene-vinyl acetate copolymer containing about 15 to 30 weight percent vinyl acetate, or admixtures of these polymers; (2) a polyamide having a melting point of between about 400° and 460° F.; and (3) a softening agent such as a long chain aliphatic diamide having a melting point between about 280° and 300° F., or a polyterpene resin having a melting point of between 230° and 275° F. Also disclosed is a method of using this particulate composition in well drilling and treating operations where formation temperatures of 350° F. or above are encountered.

Patent
Kathrine J. Lewis1
09 Apr 1974
TL;DR: The vulcanization of polymers in the presence of a peroxide curing system and an antioxidant system is accelerated by a butadiene/acrylonitrile polymer as mentioned in this paper.
Abstract: The vulcanization of ethylene/acrylic ester or ethylene/vinyl acetate polymers in the presence of a peroxide curing system and an antioxidant system is accelerated by the presence of a butadiene/acrylonitrile polymer. The vulcanizates are oilresistant and aging-resistant elastomeric products, which are useful in such applications as, for example, jacketing of automobile ignition cables.

Patent
09 Apr 1974
TL;DR: In this article, the dissolution of certain low molecular weight vinyl resins in radiation curable compositions of one or more polyfunctional polymerizable reactive solvent and, optionally, one or many monofunctional reactive solvent yields compositions having better adhesion to metals than is obtained with the same composition without the Vinyl resins and with better stain and abrasion resistance than could be obtained with vinyl resin alone.
Abstract: The dissolution of certain low molecular weight vinyl resins in radiation curable compositions of one or more polyfunctional polymerizable reactive solvent and, optionally, one or more monofunctional reactive solvent yields compositions having better adhesion to metals than is obtained with the same composition without the vinyl resins and with better stain and abrasion resistance than could be obtained with the vinyl resins alone. The low molecular weight vinyl polymer is preferably a vinyl acetate polymer having an inherent viscosity below about 0.25 and a glass transition temperature from about 25 DEG C. to about 55 DEG C.

Journal ArticleDOI
TL;DR: In this article, the migration of electronic excitation energy in films of copolymers rich in N-vinyl carbazole has been studied by fluorescence quenching experiments using dimethyl terephthalate and perylene as guest molecules.
Abstract: The migration of electronic excitation energy in films of copolymers rich in N-vinylcarbazole has been studied by fluorescence quenching experiments using dimethyl terephthalate and perylene as guest molecules. The efficiency of the singlet exciton migration is almost the same for the copolymers and for poly-N-vinylcarbazole.

Journal ArticleDOI
TL;DR: In this article, the degradation of binary polyvinylacetate/polyvinyl chloride (PVA/PVC) and poly(vinyl polyoxide/polychloroprene) blends was studied by using thermal volatilization analysis, thermogravimetry, evolved gas analysis for hydrogen chloride and acetic acid.
Abstract: The degradation of the binary polymer blends, poly(vinyl acetate)/poly(vinyl chloride), poly(vinyl acetate)/poly(vinylidene chloride) and poly(vinyl acetate)/polychloroprene has been studied by using thermal volatilization analysis, thermogravimetry, evolved gas analysis for hydrogen chloride and acetic acid, and spectroscopic methods. For the first two systems named, strong interaction occurs in the degrading blend, but the polychloroprene blends showed no indication of interaction. In the PVA/PVC and PVA/PVDC blends, hydrogen chloride from the chlorinated polymer causes substantial acceleration in the deacetylation of PVA. Acetic acid from PVA destabilizes PVC but has little effect in the case of PVDC because of the widely differing degradation temperatures of PVA and PVDC. The presence of hydrogen chloride during the degradation of PVA results in the formation of longer conjugated sequences, and the regression in sequence length at high extents of deacetylation found for PVA degraded alone is not observed.

Patent
30 Jan 1974
TL;DR: Moulding compositions consisting of A.5 - 95 PARTS by WEIGHT of a POLYCARBONATE, B. 5 - 95PARTS BY WEIGHT OF a VINYL CHLORIDE POLYMER and C.
Abstract: Moulding compositions consisting of A. 5 - 95 PARTS BY WEIGHT OF A POLYCARBONATE, B. 5 - 95 PARTS BY WEIGHT OF A VINYL CHLORIDE POLYMER AND C. 5 - 95 PARTS BY WEIGHT OF AN ABS graft polymer, a styrene/maleic anhydride copolymer or an ethylene/vinyl acetate copolymer.

Journal ArticleDOI
TL;DR: In this paper, a procedure for the separation of water-soluble wood polysaccharides on Bio-Glas (granular porous glass) and Bio-Gel P (polyacrylamide) packed columns using high-pressure liquid chromatography (HPLC) was described.

Patent
Robert P Braddicks1
14 Aug 1974
TL;DR: Filled vinyl compositions as discussed by the authors are a well-defined mixture of at least two normally solid thermoplastic vinyl chloride polymers, e.g., (i) vinyl chloride/vinyl acetate copolymer; (ii) vinylidene chloride/involving an antioxidant; (iii) polyethylene terpolymer.
Abstract: Filled vinyl compositions, useful as surface covering, comprising a well-defined mixture of at least two normally-solid thermoplastic vinyl chloride polymers, e.g., (i) vinyl chloride/vinyl acetate copolymer; vinylidene chloride/vinyl chloride copolymer; vinyl chloride/propylene copolymer; chlorinated polyethylene polymer; low molecular weight vinyl chloride/vinyl C2-C4 alkanoate/C2-C4alkene ramdon terpolymer or a mixture thereof and (ii) vinyl chloride/vinyl acetate/ethylene terpolymer. The inclusion of a thermoplastic oxyalkanoyl polymer, e.g., epsilon-caprolactone homopolymer, with/without an antioxidant, e.g., a hindered phenol, yields compositions having good processing characteristics as well as products exhibiting improved mechanical properties such as impact strength.

Patent
Roger L. Kaas1
29 Mar 1974
TL;DR: In this article, a styrene-acrylonitrile copolymer (SAN) surface is coated with a weatherable, transparent and abrasion-resistant material, which is formed on a SAN surface which has been chemically activated by direct contact with a strong oxidizing agent.
Abstract: In accordance with a preferred embodiment of this invention, a styrene-acrylonitrile copolymer (SAN) surface is coated with a weatherable, transparent and abrasion-resistant material. The film coating, which is typically less than one micron thick, is formed on a SAN surface which has been chemically activated by direct contact with a strong oxidizing agent. The coating consists essentially of the condensation reaction product of a partially hydrolyzed poly(vinyl acetate), equilibrated tetraethyl orthosilicate and a silane compound, which also acts as an adhesion promoting agent and which is selected from the group consisting of compounds with the general formula: ##EQU1## where x is from 1 to 10 and compounds with the general formula: ##EQU2## where x is from 1 to 10 and y is from 1 to 10. The trimethoxy functionality of the silane compound is initially hydrolyzed to a trisilanol functionality. Then by participating in a condensation reaction with the equilibrated silicate and the partially hydrolyzed acetate, the silane is chemically bound into the coating matrix. To complete the chemical link between the coating and the substrate, the epoxy functionality apparently reacts with the treated SAN substrate. By these two mechanisms the silane compound apparently provides a stable covalent chemical bond between the coating and the substrate.

Patent
18 Jun 1974
TL;DR: In this paper, a film or tube of a specific copolymer of ethylene with 3.0 to 18.0 mole % of a comonomer containing a polar functional group, for example, vinyl acetate is treated with a sulfonating agent at a lower temperature for a short time to give a hydrophilic membrane, which is useful as ion exchange membrane, separator for storage battery or dialysis diaphragm.
Abstract: A film or tube of a specific copolymer of ethylene with 3.0 to 18.0 mole % of a comonomer containing a polar functional group, for example, vinyl acetate is treated with a sulfonating agent at a lower temperature for a short time to give a hydrophilic membrane excellent in hydrophilic properties as well as other properties such as folding endurance or alkali resistance. The hydrophilic membrane is useful as ion-exchange membrane, separator for storage battery or dialysis diaphragm. It is also similar to cellophane in transparency as well as in properties and therefore can be used in, for example, processing of a smoked ham.

Patent
Roland Edgar Stahl1
12 Sep 1974
TL;DR: In this article, an aqueous ethylene copolymer dispersion from which an improved water-repellent coating can be applied is provided, and a fabric having thereon a coating of the dispersed phase of the dispersion and a process for preparing the coated fabric are also provided.
Abstract: An aqueous ethylene copolymer dispersion, from which an improved water-repellent coating can be applied, is provided. The dispersion comprises a dispersion of an ethylene ionic copolymer and a paraffin wax held in dispersed phase by an amine soap surfactant and a terpolymer of vinyl acetate, ethylene and Nmethylol acrylamide. A fabric having thereon a coating of the dispersed phase of the dispersion and a process for preparing the coated fabric are also provided.

Patent
29 Apr 1974
TL;DR: A thermoplastic composition which comprises an ethylene/vinyl acetate copolymer admixture, a small amount of modifier selected from specific combinations of stearamide, behenamide, stearic acid and paraffin wax is particularly suitable in the form of a packaging film having an antiblocking property provided by the synergistic effect of the special combinations of modifiers as discussed by the authors.
Abstract: A thermoplastic composition which comprises an ethylene/vinyl acetate copolymer admixture, a small amount of modifier selected from specific combinations of stearamide, behenamide, stearic acid and paraffin wax. Said composition is particularly suitable in the form of a packaging film having an antiblocking property provided by the synergistic effect of the special combinations of modifiers.

Patent
22 Jul 1974
TL;DR: In this article, a novel water-repellent and fire resistant fabric material, and a method of preparing such material by coating tentage fabric with the composition of the invention are also disclosed.
Abstract: A coating composition useful for imparting fire resistance and water-repellency to fabric comprises between about 5% and about 23% by weight of a liquid chlorinated paraffin, between about 20% and about 40% by weight of a resinous chlorinated paraffin, between about 4% and about 12% by weight of a copolymer of ethylene and vinyl acetate, between about 3% and about 18% by weight of a fire retardant, and up to about 15% by weight of an organic solvent. A novel water-repellent and fire resistant fabric material, and a method of preparing such material by coating tentage fabric with the composition of the invention are also disclosed.

Patent
04 Apr 1974
TL;DR: Granulates of a copolymer of ethylene and vinyl acetate in a molar ratio of polyethylene to polyvinyl acetate of from 10:1 to 1:2 are described in this paper, with an aqueous dispersion of a polymer based on methacrylic acid ester and, optionally, at least one ethyleneically unsaturated compound.
Abstract: Granulates of a copolymer of ethylene and vinyl acetate in a molar ratio of ethylene to vinyl acetate of from 10:1 to 1:2 coated with an aqueous dispersion of a polymer based on at least one methacrylic acid ester and, optionally, at least one ethyleneically unsaturated compound and process of producing the same.

Journal ArticleDOI
TL;DR: In this paper, a triallyl citrate was copolymerized with allyl benzoate (ABz), vinyl acetate (VAc), vinyl chloride (VC), acrylonitrile (AN), and styrene (St) at 60°C with benzoyl peroxide or 2,2′,azobisisobutyronitrile as the initiator; it was considered kinetically in terms of cyclocopolymerization.
Abstract: Triallyl citrate (TAC) was copolymerized with allyl benzoate (ABz), vinyl acetate (VAc), vinyl chloride (VC), acrylonitrile (AN), and styrene (St) at 60°C with benzoyl peroxide or 2,2′,-azobisisobutyronitrile as the initiator; it was considered kinetically in terms of cyclocopolymerization. The following monomer reactivity ratios were obtained: VAc: r1=1.29, r2=0.76, rc=0.61; ABz: r1=1.63, r2=1.10, rc=0.47; VC: r1=0.40; r2=1.90, rc=0.31; AN: r1=0.01, r2=8.7; St: r1=0.03, r2=53.0, where r1, rc and r2 denote the monomer reactivity ratio of the uncyclized, cyclized, and monovinyl radicals respectively. In the copolymerization of TAC with AN, the penultimate effect was also observed: r1=r1′=0.01, r2=k122⁄k121=11, r2′=k222⁄k221=5.

Patent
19 Dec 1974
TL;DR: An encapsulating material for drugs consisting of a modified polyvinyl alcohol which is a partially hydrolized graft copolymer of vinyl acetate on polyethylene oxide is described in this article.
Abstract: An encapsulating material for drugs consisting of a modified polyvinyl alcohol which is a partially hydrolized graft copolymer of vinyl acetate on polyethylene oxide.

Patent
24 Dec 1974
TL;DR: In this article, a crosslinked heteropolymer of vinyl acetate and maleic anhydride is presented, which is useful as aqueous thickeners for formulations such as cosmetics and latex paints.
Abstract: Novel crosslinked heteropolymers of vinyl acetate and maleic anhydride are provided which are useful as aqueous thickeners for aqueous formulations such as cosmetics and latex paints. Ester and amide derivatives of the combined maleic anhydride portion of the heteropolymer are also provided. The process for preparing the crosslinked heteropolymers comprises adding a maleic anhydride monomer, and crosslinking agent monomer, and catalyst in controlled amounts to a monomer solution of vinyl acetate.