Toyo Seikan Kaisha, Ltd.

Tsukishima Kikai Co., Ltd.

Mitsui Toatsu Chemicals, Incorporated

Lion Hamigaki Kabushiki Kaisha

Jinichi Yazaki

Kozaburo Sakano

Muneki Yamada

Sadao Hirata

Toru Suzuki

Shunsaku Hirata

Yoshitsugu Maruhashi

Junichi Matsuo

Akira Kishimoto

Fumio Kano

Kazuho Tanaka

Akihiko Tamura

Nobuyuki Funakoshi

Takashi Miyazaki

Shinichi Miyazaki

Isao Tanikawa

Shigezo Nohara

Hideo Amemiya

Toru Ueki

Takesi Sugimoto

Kazuhiko Tsurumaru

This invention provides a process a process for recovering terephthalic acid from pulverized products of spent polyethylene terephthalate. This process comprises (1) a decomposition reaction step where the pulverized products of spent polyethylene terephthalate are continuously subjected to decomposition reaction in ethylene glycol in the presence of alkali, which is equimolar or excessmolar relative to the polyethylene terephthalate, so that salt of terephthalic acid and ethylene glycol can be continuously obtained; (2) a solid-liquid separation, dissolution, impurities-removing step where the ethylene glycol is separated from decomposition reaction slurry of salt of terephthalic acid and ethylene glycol, and the solid salt of terephthalic acid is dissolved into water, while insoluble impurities are removed; (3) a neutralization, crystallization step, where solution of said salt of terephthalic acid is neutralized with acid so that terephthalic acid can be crystallized; (4) a solid-liquid separation, washing stop where slurry of terephthalic acid crystals is subjected to solid-liquid separation so that the terephthalic acid crystals can be obtained and washed; and (5) a drying, pulverization step where the washed terephthalic acid crystals are dried and pulverized.

Process for recovering terephthalic acid from pulverized product of spent polyethylene terephthalate and system for use in such process

This invention provides a process a process for recovering terephthalic acid from pulverized products of spent polyethylene terephthalate. This process comprises (1) a decomposition reaction step where the pulverized products of spent polyethylene terephthalate are continuously subjected to decomposition reaction in ethylene glycol in the presence of alkali, which is equimolar or excessmolar relative to the polyethylene terephthalate, so that salt of terephthalic acid and ethylene glycol can be continuously obtained; (2) a solid-liquid separation, dissolution, impurities-removing step where the ethylene glycol is separated from decomposition reaction slurry of salt of terephthalic acid and ethylene glycol, and the solid salt of terephthalic acid is dissolved into water, while insoluble impurities are removed; (3) a neutralization, crystallization step, where solution of said salt of terephthalic acid is neutralized with acid so that terephthalic acid can be crystallized; (4) a solid-liquid separation, washing step where slurry of terephthalic acid crystals is subjected to solid-liquid separation so that the terephthalic acid crystals can be obtained and washed; and (5) a drying, pulverization step where the washed terephthalic acid crystals are dried and pulverized.

A stabilizer selected from alkaline earth metal hydroxides, oxides and silicates and alkaline earth metal salts of higher fatty acids and an antioxidant are incorporated into a resin composition comprising an ethylene/vinyl alcohol copolymer and a propylene resin or a carbonyl group-containing thermoplastic resin. The stability of the resin composition is improved, and deterioration of the resin composition such as gelation, discoloration or reduction of the gas barrier property is prevented when this composition is heat-molded into a vessel.

Vessel comprising resin composition

A polypropylene resin composition is provided by incorporating a metal salt of a fatty acid and the oxide or hydroxide of an alkaline earth metal, each, in an amount of 0.05-1 part by weight based on 100 parts by weight of polypropylene. The polypropylene resin composition shows excellent thermal processing stability even when subjected to remelting and extrusion molding after mixing of a scrap recycled from the production of multi-layered containers or sheets each of which is formed of a gas barrier layer made of nylon or an ethylene-vinyl alcohol copolymer and another layer made of a polypropylene resin composition.

Polypropylene resin composition, a multi-layered sheet comprised thereof

In a thermoplastic polyester, a compound having at least two ethylenically unsaturated groups and/or oxirane rings in one molecule is coated as a crosslinking agent on the outer surface of the polyester substrate, or a polyester composition containing this crosslinking agent is laminated on the polyester substrate as the inner surface layer, and the crosslinking agent or the crosslinking agent-containing polyester composition is irradiated with ionizing radiant rays or ultraviolet rays. In this processed vessel, the dimension stability and rigidity are highly improved, and deformation under heat and/or pressure can be effectively prevented.

Polyester vessel having improved dimension stability and process for

Disclosed is a hot-melt adhesive composed of a composition comprising an acid-modified olefin resin formed by graft modification of an ethylenically unsaturated carboxylic acid or its anhydride or a resin composition containing said modified olefin resin and an oxirane ring-containing compound, wherein said composition has a carbonyl group concentration of 1 to 600 millimoles per 100 g of the composition and an oxirane oxygen concentration of 0.01 to 50 millimoles per 100 g of the composition.

Hot-melt adhesive as intermediate layer of a laminate structure

Disclosed in a packaging material having at least one layer comprising an ethylene-vinyl alcohol copolymer having a vinyl alcohol content of 40 to 80 mole % and a residual vinyl ester content lower than 4 mole %, wherein the ethylene-vinyl alcohol copolymer consists of a composition comprising a plurality of copolymers differing in the vinyl alcohol content, said composition shows a plurality of endothermic peaks in a fusion curve by a differential scanning calorimeter, the composition has fusion characteristics satisfying requirements represented by the following formulae: ##EQU1## wherein Sc represents an area of a triangle defined by a base line connecting the skirt of a high temperature side peak to the skirt of a low temperature side peak in two adjacent peaks in said fusion curve and lines connecting the skirts of both the peaks to the trough between both the peaks, Sa represents an area of the high temperature side peak above said triangle, Sb represents an area of the low temperature side peak above said triangle, Ta represents a peak temperature of the high temperature side peak and Tb represents a peak temperature of the low temperature side peak, and the composition has a molecular weight distribution (Mw/Mn) of at least 2.5. This packaging material is excellent in the gas barrier property, especially the oxygen permeation resistance under a high humidity condition, and the mechanical properties and processability.

Packaging material

Hot-melt adhesive

Disclosed is a multi-layer drawn plastic vessel comprising at least one layer composed mainly of at least one crystalline olefin resin selected from crystalline polypropylene and crystalline propylene/ethylene copolymers having an ethylene content of 1 to 20 mole %, at least one oxygen-barrier layer composed mainly of an ethylene/vinyl alcohol copolymer having an ethylene content of 25 to 60 mole %, and an adhesive resin layer interposed between said two resin layers, said adhesive resin layer containing an acid- or acid anhydride-modified, linear, low-density polyethylene or a mixture of said polyethylene with an acid- or acid anhydride-modified propylene resin and said crystalline olefin resin layer being molecularly oriented in at least one direction.

Multi-layer drawn plastic vessel

Disclosed is a multi-layer plastic vessel comprising a laminate including at least one layer composed mainly of a moisture-resistant thermoplastic resin, at least one layer composed mainly of an ethylene-vinyl alcohol copolymer and a thermoplastic resin adhesive layer interposed between both the resin layers, wherein said adhesive layer is composed of a composition comprising an acid- or acid anhydride-modified olefin resin and an epoxidized unsaturated carboxylic acid ester.

Multi-layer plastic vessel

Disclosed is a laminated plastic container in the form of a bottle, the wall of which comprises a substrate formed of a melt-moldable plastic material, a coating layer formed on at least one surface of the substrate, said coating layer being composed of a copolymer consisting essentially of 99 to 70% by weight of vinylidene chloride and 1 to 30% by weight of at least one acrylic or methacrylic monomer and further including up to 100 parts by weight of at least one member selected from other ethylenically unsaturated monomers per 100 parts by weight of the total amount of said two monomers, said copolymer having an oxygen permeation coefficient of less than 9.times.10.sup.-14 cc.multidot.cm/cm.sup.2 .multidot.sec.multidot.cmHg as measured at a temperature of 20.degree. C. and a relative humidity of 100% and a water vapor permeability coefficient of less than 3.times.10.sup.-3 g.multidot.cm/m.sup.2 .multidot.day as determined according to the method of JIS Z-0208, and a protecting surface layer of a film-forming synthetic resin other than a vinylidene chloride resin, which is formed contiguously to said coating layer. This laminated plastic container is excellent in the barrier property to various gases such as oxygen, water vapor, nitrogen and carbon dioxide gas and other properties required for plastic containers. The humidity dependency of the oxygen barrier property is highly improved in this laminated plastic container.

Laminated plastic container and process for preparation thereof

A molded container having a wall composed of a thermoplastic resin oriented in at least one direction on the wall face, wherein the container wall has a layer of a blend composed mainly of a plurality of melt-extrudable thermoplastic resins, each of which has a solubility parameter (Sp) of at least 9.5, at least one of said thermoplastic resins has an oxygen permeability lower than 5.times.10.sup.-11 cc.multidot.cm/cm.sup.2 .multidot.sec.multidot.cmHg, said thermoplastic resins are chosen so that the difference (.DELTA.Sp) of the solubility parameter in said thermoplastic resins is not greater than 4.5, the elongation of said resin blend is higher than the arithmetic mean (.epsilon.) of elongations of the respective thermoplastic resins, and wherein the container has a thermal shrinkability (.delta.) of at least 5% in the orientation direction of said container wall.

Molded container having wall composed of oriented resin blend

Disclosed is a squeeze vessel having a good combination of deformability, memory property and interlaminar peel resistance, suitable for squeezing out the content, and being excellent in content preserving property, flavor retaining property and appearance characteristics. This squeeze vessel comprises a laminate structure including at least one layer composed mainly of at least one member selected from the group consisting of ethylene-vinyl alcohol copolymers and polyamides, at least one layer composed mainly of an olefin resin having an elasticity of 900 to 9000 Kg/cm.sup.2 and an adhesive layer interposed between said two layers, said adhesive layer comprising a modified olefin resin having an elasticity (Ea) lower than the elasticity (Eb) of said oxygen barrier resin but higher than the elasticity (Eo) of said olefin resin, wherein the thickness of the layer composed mainly of the olefin resin is larger than the sum of the thickness of said oxygen barrier resin layer and the thickness of said adhesive layer and in the layer composed mainly of the olefin resin the product of the elasticity (Eo, Kg/cm.sup.2) and the thickness (to, cm) is in the range of from 9 to 170 Kg/cm.

Squeeze vessel

A transparent multi-layer container comprising a co-extrudate of an oxygen-barrier resin layer and an orienting resin layer which is monoaxially or biaxially oriented is disclosed. An adhesive resin layer is preferably interposed between the oxygen-barrier layer and the orienting resin layer, and this co-extrudate is drawn and molded at a specific temperature determined relatively to the melting points and softening points of the respective resins. This container is excellent in the combination of transparency, rigidity, mechanical strength, gas-barrier property and interlaminar peel strength.

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Tokyo, Japan

Jinichi Yazaki