MXPA98001576A - Pet resin co-polyesteries containing portions of succinic acid and naftalendicarboxilic acid, which have improved barred properties - Google Patents

Abstract

Terpolymers having improved barrier properties and tensile strength relative to PET resin are described, which comprise copolyesters derived from acidic components comprising 45 to 85% mol of terephthalic acid, 10 to 40 mol% of at least one naphthalenedicarboxylic acid and 5 to 15 mol% of at least one aliphatic dicarboxylic acid having from 1 to 6 carbon atoms and a glycol component comprising ethylene glycol. The copolyesters of the present invention can be formed into a variety of articles such as blood tubes, serum bottles, containers and film.

Description

PET RESIN COPOLYESTERES CONTAINING PORTIONS OF SUCCINIC ACID AND NAFTALENDICARBOXYLIC ACID, WHICH HAVE IMPROVED BARRIER PROPERTIES.

FIELD OF THE INVENTION The present invention relates to terpolymers which have improved gas barrier properties and which comprise, inter alia, succinic and naphthalenedicarboxylic acid portions.

BACKGROUND OF THE INVENTION PET resin is currently useful for the manufacture of injection-molded vacuum blood tubes. PET resin has good gas barrier properties and as a result blood tubes made from this resin have adequate vacuum retention for selected applications. However, improved gas barrier properties are desirable to extend the shelf life of these tubes in select applications. It has been found that the copolyesters of polyethylene terephthalate (PET), naphthalenedicarboxylic acid and at least one aliphatic dicarboxylic acid have improved gas barrier properties relative to PET resin. Surprisingly these copolyesters also maintain the heat resistance and impact properties of the PET resin.

Traditionally blood tubes for use in the medical industry have been manufactured from glass. In recent years, the possibility that infectious diseases are transmitted by contact with blood from broken tubes has caused the medical industry to rely more and more on plastic tubes. The tubes are now being manufactured from injection molded resins such as PET resin. These tubes are manufactured and maintained under reduced pressure to allow a convenient blood sampling method. Due to the need to maintain a reduced pressure in these tubes, there is a need for resins that provide improved barrier properties relative to PET resin and, therefore, provide the extended shelf life that is required in selected applications. .

Poly (ethylene-2,6-naphthalenedicarboxylate) (PEN) exhibits improved barrier properties relative to PET resin. However, this resin is quite expensive and due to its increased melting point and its melt viscosity requires high process temperatures in relation to the PET resin.

The U.S. Patent No. 4,401, 805 discloses PET resin copolyesters containing 1-45 mol% of aliphatic dicarboxylic acids containing from 3 to 8 carbon atoms and which are reported to have good barrier properties. However, the addition of only aliphatic dicarboxylic acids reduces the heat resistance properties of the resulting polyester relative to those of the PET resin. The addition of aromatic dicarboxylic acids other than terephthalic acid has not been described.

The Description of the Investigation no. 36009 (April 1994) discloses PET resin copolyesters containing either 10-50% mol of isophthalic acid, or 10-30% mol of either succinic acid, glutaric acid, adipic acid or mixtures of these aliphatic acids. These copolyesters are reported as useful for the manufacture of blood tubes.

Research Description No. 36903 (January 1995) describes PET resin copolyesters containing glutarate, succinate, adipate or mixtures thereof which have been reported to have improved shelf life in blood tubes. Also described are terpolymers of PET resin and isophthalic and naphthalenedicarboxylic acids.

Research Description No. 29484 (October 1988) describes vain esters of PEN Detailed Description of the Invention The present invention provides novel flake esters derived from acid components comprising from 45 to 85 mol% terephthalic acid, from 10 to 40 mol% from at least one naphthalenedicarboxylic acid and from 5 to 15 mol% from at least an aliphatic dicarboxylic acid having from 2 to 8 carbon atoms and a glycol component comprising ethylene glycol Also described are injection molded, blow molded and extruded articles which are manufactured from these Preferably said copolyesters comprise from 60 to 75% mol of terephthalic acid, 20 to 30 mol% of at least one naphthalenedicarboxylic acid and 5 to 10 mol% of said aliphatic dicarboxylic acid The isomer of naphthalenedicarboxylic acid is selected from 1, 4-, 1, 5-, 2,6-, 2.7-, 1, 2-, 1, 3-, 1, 7-, 1, 8-, 2,3-, 2,4-, 2,5-, and isomers of 2,8-naphthalenedicarboxylic acid Mixtures of the various isomers can also be used. The selected (s) isomer (s) can be added to the reaction either as an acid or an ester. Preferably, the naphthalenedicarboxylic acid is isomer of 2,6-naphthalend? carboxylic acid The aliphatic dicarboxylic acid is preferably selected from the oxalic, succinic, malonic, glutaric, adipic, 1,4-c-clohexanedicarboxylic acids and the like. More preferably the aliphatic dicarboxylic acid is selected from the succinic, glutaric and adipic acids, and more preferably is succinic acid The copolyesters are easily manufactured by polycondensation processes either batchwise or continuous, which are well known to those skilled in the art. The dicarboxylic acid moieties can be derived from the acids or their lower alkyl esters, such as the dimethyl esters. Useful copolyesters will have values of inherent viscosity (IV) from 0 4 to 1 1 Typical catalysts that can be used in the polymerization of these flake esters include titanium alkoxides, tin dibutyl laurate, combinations of zinc, manganese or magnesium acetates or benzoates with antimony oxide or antimony tpacetate.

In general, up to 20 mol% of other aliphatic and aromatic diols may be used to prepare the polyesters so long as as much as 80 mol% is ethylene glycol Examples of said diols include propylene glycol, diethylene glycol, 1,2-propylene glycol, 2,4-d? Met? L-2-et? L-hexane-1,3-d? Ol, 2,2,4-tpmet? L-1, 3-pentanod? Ol, 2,2-d? methylene, 3-propanod? ol, 2-et? l-2-butyl? -1,3-proponate, 2,2-d? et? -1,3-propanod? ol, 2- METHL-2-propyl-1,3-propanediol, 2-et? l-2? -butbutyl-1, 3-propanediol, 1,3-butanedione, 1, 4 -butanediol, 1,5-pentanedione, 1,6-hexanedione, 2,2,4-methyl-1, 6-hexanedione, 1,2-cyclohexanedimethanol, 1,3-c-clohexanod? methanol, 2,2,4,4-tetramethyl-l, 3-cyclobutanediol, o-, m- and p-xylene diols, 4,4'-sulfon? ld? phenol, 4,4'-ox? d? phenol, 4,4'-isopropylidenediphenol, and 2,5'-naphthalene? ol The compositions of the present invention have excellent barrier properties and are easily susceptible to being processed at temperatures similar to those of PET resin. For example, such copolyesters can be injection molded in the form of blood tubes, serum bottles, bottles of laboratory and the like, at temperatures ranging from 250 ° C to 280 ° C Copolyesters can also be formed into a variety of other articles such as containers, films and sheets by well-known molding techniques such as injection molding, blow molding Extrusion, Extrusion Molding and Stretch Extrusion Molding The heat deflection temperature and other high temperature properties of these copolyesters are at least equal to those of the PET resin. Moreover, the copolyesters of the present invention are clear. It is essential in vain applications, including tubes to bleed and Small amounts of other ingredients may be added to the composition of the present invention to improve its performance properties. For example, lubricants, stabilizers, antioxidants, ultraviolet light absorbing agents, molding release agents, metal deactivators, zeros, fillers. , and similar that can be used as long as they do not hinder the invention in the fulfillment of the objectives Examples The esters and copolyesters made in the Examples were extruded in thin film (nominally 10 mil) using a Killion single screw extruder of 3? inch for use in permeability tests. These materials were also molded onto tensile and flexible rods using a Toyo 90 injection molding machine for use in mechanical properties testing. Inherent viscosity (IV) was measured at 25 ° C using 0 5 grams of ester per 100 ml of a solvent consisting of 60% weight of phenol and 40% weight of tetrachloroethane Examples 1-5 Polyesters of terephthalic acid (T), 2,6-naphthalend? Carboxyl? Co (N), succinic acid (S) and ethylene glycol (EG) as listed in Table 1 were prepared by polycondensation as follows. Excess ethyleneol was reacted with the acid components listed at approximately 200 to 220 ° C to remove water and methanol from the reaction mixture The dimethyl ester of terephthalic acid and naphthalenedicarboxylic acid were used Succinic acid was used in its acid form The polymerization was carried out under reduced pressure at 285 ° C.

Table 1 The properties of the resulting polyesters were measured as follows: IVs (described above), oxygen transmission rates (ASTM D3985), hardness (elongation under tension to break-up - ASTM D638) and heat-deflection temperature (HDTs - ASTM D648) and are shown in Table 2 below.

Table 2 These examples show that the PET resin gas barrier properties can be significantly improved by the addition of the combination of succinic and 2,6-naphthalene dicarboxylic acids. Surprisingly, these improvements can be obtained without the pernicious effects of decreased hardness and increase in the melt viscosity that are obtained in PET resin containing only 2,6-naphthalene dicarboxylic acid (> 50 mol%). Also, these improvements can be obtained without the detrimental effects of decreased HDT that are obtained in PET resin containing only succinic acid.

Claims (10)

1. Novelty of the Invention 1 A copolyester derived from acid components, which comprises from 45 to 85 mol% of terephthalic acid, 10 to 40 mol% of at least one naphthalenedicarboxylic acid and 5 to 15 mol% of at least one aliphatic dicarboxylic acid which has from 2 to 8 carbon atoms and a glycol component comprising ethylene cabbage
2. The copolyester of claim 1, wherein said acid components comprise from 60 to 75 mol% of terephthalic acid, 20 to 30 mol% of at least one naphthalenedicarboxylic acid and from 5 to 10 mol% of said aliphatic dicarboxylic acid
3. The copolyester of claim 1, wherein said naphthalenedicarboxylic acid is selected from the group consisting of 1, 4-, 1, 5-, 2,6-, 2,7-, 1, 2-, 1, 3-, 1 , 7-, 1, 8-, 2,3-, 2,4-, 2,5-, 2,8-naphthalend? Carboxylic acid and mixtures thereof
4. 4 The codend of claim 1, wherein said aliphatic dicarboxylic acid is selected from the group consisting of succinic acid, malonic acid, glutaric acid, adipic acid and 1,4-c-cethohexanedicarboxylic acid.
5. The co-ester of claim 4, wherein said aliphatic dicarboxylic acid is selected from the group consisting of oxalic, succinic, glutaric, and adipic acids
6. The copolyester of claim 4, wherein said aliphatic dicarboxylic acid is succinic acid 7 The coding ester of claim 1, wherein said ghcol component further comprises up to 20 mol% of at least one second ghcol
7. The copolyester of claim 7, wherein said second glycol is selected from the group consisting of propylene glycol, diethylene glycol, 1,2-pro ?? legl? Col,
8. 2,4-d? Met? L-2-et? L-hexane-1,3-d? Ol, 2 2,4-tr? Met? L-1, 3-pentanod? Ol, 2,2-d ? met? M, 3-propanediol, 2-et? l-2-but? l-1, 3-propopad? ol, 2,2-d? et? l-1, 3-propanod? ol, 2-met L-2-propyl-1,3-propanediol, 2-et? l-2-? sobutyl-l, 3-proponod? ol, 1,3-butanediol, 1, 4- butapodiol, 1,5-pentanedione, 1,6-hexanedione, 2,2,4-tr? met? l-1,6-hexanedione, 1,2-cyclohexanedimethanol, 1,3-c? clohexanod? methanol, 2,2,4,4-tetramethyl-l, 3-cyclobutanediol, o-, m- and p-xylene diols, 4,4'-sulfon? ld? phenol, 4,4'- ox? d? phenol, 4,4'-isopropylidenephenol, and 2,5'-naphthalene? ol
9. 9 A formed article made from the copolyester of claims 1 to 8

   The article of claim 9, wherein said article is selected from the group consisting of blood tubes, serum bottles, laboratory bottles, containers, films and sheets

   Extract of the Description Terpolymers having improved barrier properties and tensile strength relative to PET resin are described, which comprise copolyesters derived from acid components comprising 45 to 85 mol% terephthalic acid; 10 to 40 mol% of at least one naphthalenedicarboxylic acid and 5 to 15 mol% of at least one aliphatic dicarboxylic acid having 1 to 6 carbon atoms and a glycol component comprising ethylene glycol. The copolyesters of the present invention can be formed into a variety of articles such as blood tubes, serum bottles, containers and films.