Mitsui Petrochemical Industries, Ltd.

Mitsui Chemicals, Inc.

Nippon Steel Corporation

Nippon Paper Industries Co., Ltd.

Mitsui Petrochemical Co., Ltd.

Hiroji Niimi

Susumu Hatabu

Kunio Tomita

Masayuki Sakai

Koji Nakamachi

Hidenori Kaya

Takashi Hiraoka

Yoji Yamamoto

Kazuhito Yamamoto

Shoji Hiraoka

Ryoichi Yoshihara

Ryousuke Wake

Koji Takahashi

Hitoshi Tsuboi

Takashi Satake

Eiji Takahashi

Mikio Hashimoto

Tadao Yatsu

Shigemi Shiraki

Hiroshi Kondo

Hisashi Matsumoto

Masaki Kohsaka

Eiichi Kato

Yoshimitsu Moritani

Mitsuaki Masumoto

Kazuhito Yammoto

Nobuyasu Kumura

A process for preparing polyester pellets which involves blending polyethylene terephthalate and polyethylene isophthalate copolymer before solid state polymerization, the polyethylene isophthalate copolymer being composed of dicarboxylic acid constituent units derived from dicarboxylic acids containing terephthalic acid and isophthalic acid and diol constituent units derived from diols containing ethylene glycol and 1,3-bis(2-hydroxyethoxy)benzene, palletizing the blend and crystallizing the pellets.

Process of making polyester pellets

The present invention provides a polyester resin composition comprising (A) a polyethylene terephthalate composed mainly of repeating units derived from a dicarboxylic acid containing terephthalate acid and/or an esterified derivative thereof and a diol containing ethylene glycol and/or esterified derivative thereof, and (B) an ethylene/(meth) acrylic acid copolymer and, optionally, (C) polyethylene. The polyethylene terephthalate contains diethylene glycol units in a ratio of 0.5 to 2.0% by weight and a cyclic trimer in an amount not greater than 0.5% by weight based on polyethylene terephthalate. The ethylene/ (meth) arcylic acid coploymer is in an amount of 0.1 to 10,000 ppb based on the composition. Also provided are a perform formed from the composition and a blow molded container produced therefrom.

Polyester resin composition and hollow molded container made therefrom

Disclosed are polyester pellets made of a polyester which comprises dicarboxylic acid constituent units derived from dicarboxylic acids containing terephthalic acid and isophthalic acid and diol constituent units derived from diols containing ethylene glycol and 1,3-bis(2-hydroxyethoxy)benzene, and which has the properties: constituent units derived from terephthalic acid are 15 to 99.5% by mol and constituent units derived from isophthalic acid are 0.5 to 85% by mol, both based on the total amount of dicarboxylic acid isophthalic acid constituent units (i); constituent units derived from ethylene glycol are 25 to 99.5% by mol and constituent units derived from 1,3-bis(2-hydroxyethoxy)benzene are 0.5 to 75% by mol, both based on the total amount of the diol constituent units (ii); the intrinsic viscosity is in the range of 0.5 to 1.5 dl/g; and the melting point (Tm (&deg;C.)), as measured by a differential scanning calorimeter, satisfies the formula &lsqb;1/527&minus;0.0017&middot;ln(1&minus;(m,&plus;m,)/200)&rsqb;,&minus;273<Tm&lE;265; said polyester pellets having a density of not less than 1,350 kg/m,. Also disclosed is a process for preparing the polyester pellets. The polyester pellets are excellent in gas barrier properties, transparency and heat resistance and hardly generate acetaldehyde.

Polyester pellets

The refillable polyester bottle of the invention has a mean crystallinity of 32 to 70% at the bottle body, a methanol adsorption of 1,500 ppm or less at the same portion and a paraxylene adsorption of 300 ppm or less at the same portion. Therefore, the bottle is excellent in non-adsorptivity and heat resistance. According to the method of removing adsorbates on a polyester bottle of the invention, the adsorbates can be rapidly desorbed by holding the bottle in air of 40 to 150.degree. C. or bringing the bottle into contact with water or water vapor heated at 40 to 150.degree. C.

Polyester bottle and method of removing adsorbates on the bottle

A method of producing a resin-coated steel sheet for drawn-and-ironed cans. The resin-coated steel sheet has a steel sheet with a tin-coat on each side and a resin layer of a first crystalline thermoplastic polyester resin on one of the tin-coats and a second non-crystalline thermoplastic polyester resin on the first crystalline thermoplastic polyester resin. The first crystalline thermoplastic polyester resin has an alloying ratio of: 50.ltoreq.alloying ratio&lt;100. The second non-crystalline thermoplastic polyester resin has an alloying ratio of 0&lt;alloying ratio&lt;50. The method includes thermal fusion of a mixture of 95-5 percent by weight of a crystalline polyester resin and 5-95 percent of a non-crystalline polyester resin to produce the first crystalline thermoplastic polyester resin and the second non-crystalline thermoplastic polyester resin. The first crystalline thermoplastic polyester resin and the second non-crystalline thermoplastic polyester resin are coated onto the tin-coated steel sheet using two-layer extrusion T-die and then cooled quickly.

Method for manufacturing a resin-coated steel sheet for drawn-and-ironed

A resin-coated steel sheet for drawn-and-ironed cans and a method of producing the resin-coated steel sheet. The resin-coated steel sheet has a steel sheet with a tin-coat on each side and a resin layer of a first crystalline thermoplastic polyester resin on one of the tin-coats and a second non-crystalline thermoplastic polyester resin on the first crystalline thermoplastic polyester resin. The first crystalline thermoplastic polyester resin has an alloying ratio of: 50.ltoreq.alloying ratio &lt;100. The second non-crystalline thermoplastic polyester resin has an alloying ratio of 0&lt;alloying ratio &lt;50. The method includes thermal fusion of a mixture of 95-5 percent by weight of a crystalline polyester resin and 5-95 percent of a non-crystalline polyester resin to produce the first crystalline thermoplastic polyester resin and the second non-crystalline thermoplastic polyester resin. The first crystalline thermoplastic polyester resin and the second non-crystalline thermoplastic polyester resin are coated onto the tin-coated steel sheet using two-layer extrusion T-die and then cooled quickly.

Resin-coated steel sheet for drawn-and-ironed cans and drawn-and-ironed

A method of removing adsorbates on a polyester bottle, the body of the bottle having a mean crystallinity of 32 to 70%, a methanol adsorption of 1,500 ppm or less and a paraxylene adsorption of 300 ppm or less. As a result, the bottle has excellent non-adsorptivity and heat resistance. According to the method, the adsorbates can be rapidly desorbed by holding the bottle in air of 40.degree. to 150.degree. C. or bringing the bottle into contact with water or water vapor heated at 40.degree. to 150.degree. C.

Method of removing adsorbates from a polyester bottle

The refillable polyester bottle of the invention has a mean crystallinity of 32 to 70% at the bottle body, a methanol adsorption of 1,500 ppm or less at the same portion and a paraxylene adsorption of 300 ppm or less at the same portion. Therefore, the bottle is excellent in non-adsorptivity and heat resistance. According to the method of removing adsorbates on a polyester bottle of the invention, the adsorbates can be rapidly desorbed by holding the bottle in air of 40.degree. to 150.degree. C. or bringing the bottle into contact with water or water vapor heated at 40.degree. to 150.degree. C.

In accordance with the present invention, there are provided blow molded articles which are composed of specific copolyesters or specific polyester resin compositions and which are highly oriented so that the stretch index as defined by the following equations becomes not less than 130 cm. ##EQU1## The blow molded articles thus provided are excellent in transparency and also excellent in moldability and gas barrier properties and, moreover, excellent also in economical efficiency.

Blow molded articles

A packaging laminate material comprises a paper substrate and a polyester resin layer provided on at least the innermost surface side of the substrate, wherein the polyester resin comprises dicarboxylic acid units comprising terephthalic acid and adipic acid and dihydroxy compound units comprising ethylene glycol and a second different dihydroxy compound. The polyester may also contain polyfunctional units derived from a polycarboxylic acid having a valence of 3 or more and/or derived from a polyglycol having a valence of 3 or more. The packaging laminate has a high heat-sealing strength, a small decrease in the heat-sealing strength even after the laminate is subjected to a hot water treatment or a hot hydrogen peroxide treatment, and is excellent in scent (odor) retention properties.

Packaging laminate material

A machine for molding a starting crystalline saturated polyester resin such as polyethylene terephthalate includes a device for first drying and then preheating the starting resin to a temperature above its melting point to lower the viscosity of the resin to such an extent that the resin is not substantially degraded in the compression section of the molding machine. A feed section is provided for quantitatively feeding the molten starting resin to the main body of the molding machine. Accordingly, the starting resin is molded into a desired shape in a molding machine under conditions such that the crystallization temperature of the resulting molded article is within 20.degree. C. of the crystallization temperature of the starting saturated crystalline polyester resin. By avoiding reductions in the crystallization temperature of the molded resin, the resin can be shaped by, for example, blow molding into a bottle or other configuration while satisfying simultaneously the requirements for transparency and dimensional stability. The molded polyester articles obtained using this molding apparatus are substantially free from chalking and variation in internal volume and are excellent in heat resistance.

Method for molding saturated crystalline polyesters and molding

Polyethylene terephthalates of the present invention are excellent in mechanical strength, heat resistance and transparency, and therefore blow molded containers molded from the present polyethylene terephthalate are excellent in high temperature filling properties when they are filled with juice, refrigerant beverage, carbonated beverage, seasonings, etc. Furthermore, the blow molded containers prepared from the present polyethylene terephthalates have such characteristic features that they are free from thermal deformation at the time when they are subjected to high temperature filling, they are readily subjected to sterilization treatment and hence excellent in high speed filling properties.

Polyethylene terephthalate and uses thereof

The present invention relates to a bottle made of a saturated polyester comprising a mouth, an upper shoulder, a barrel, a lower shoulder and a bottom, characterized in that the saturated polyester at the upper and/or lower shoulders has an orientation degree of not more than 0.6, the saturated polyester at the upper and lower shoulders has an orientated crystallinity of not more than 50%, and the thickness of the upper and lower shoulders is not less than 0.25 mm.

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Yamaguchi, Japan

Hiroji Niimi