Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
  • C08G63/02—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds
  • C08G63/12—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds derived from polycarboxylic acids and polyhydroxy compounds
  • C08G63/16—Dicarboxylic acids and dihydroxy compounds
  • C08G63/18—Dicarboxylic acids and dihydroxy compounds the acids or hydroxy compounds containing carbocyclic rings
  • C08G63/181—Acids containing aromatic rings
  • C08G63/185—Acids containing aromatic rings containing two or more aromatic rings
  • C08G63/187—Acids containing aromatic rings containing two or more aromatic rings containing condensed aromatic rings
  • C08G63/189—Acids containing aromatic rings containing two or more aromatic rings containing condensed aromatic rings containing a naphthalene ring
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
  • C08G63/02—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds
  • C08G63/12—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds derived from polycarboxylic acids and polyhydroxy compounds
  • C08G63/16—Dicarboxylic acids and dihydroxy compounds
  • C08G63/18—Dicarboxylic acids and dihydroxy compounds the acids or hydroxy compounds containing carbocyclic rings
  • C08G63/181—Acids containing aromatic rings
  • C08G63/185—Acids containing aromatic rings containing two or more aromatic rings

Definitions

• the invention relates to an object shaped in the melt from a copolyester composition containing monomer units derived from 2 , 6-naphthalenedicarboxylic acid, 4 , 4 ' -diphenyldicarboxylic acid and ethylene glycol and optionally less than 50 mole% of the total amount of diacids of one or more other diacids .
• Such an object is known from WO 93/02122, in which high-modulus fibres and films and a high- strength monofilament are disclosed.
• the aforementioned objects which are characterized by at least one dimension of a minimal size, often ⁇ 100 ⁇ m and which are shaped by applying a force in one direction or forces in 2 directions to the melt outside a fixed mould, are not covered by the definition of objects shaped in the melt, which are understood to be objects whose sizes cover considerable distances in 3 dimensions, for example greater than at least 0.2 mm, preferably at least 0.5 mm, even more preferably at least 2 mm.
• the upper limit of the sizes is determined predominantly by the technical feasibilities of the moulding equipment and may amount to up to the order of 1 metre.
• Example 31 examples of moulding techniques for producing objects that are shaped in the melt are injection moulding, rotational moulding, extrusion, optionally followed by blow moulding, etc.
• Example obtained through injection moulding the objects of Example 31 have inferior properties. Only a slightly higher tensile modulus, approx. 50%, relative to isotropic polyethylene terephthalate, PET, is obtained; the other mechanical properties are of the same order or inferior relative to PET.
• a properties pattern comparable with liquid crystalline polyester is not present, not even in a thin (0.32 mm) test plate. This is indeed to be expected because no crystalline areas, which are characteristic of liquid crystalline polyesters, can be demonstrated with polarized light in a melted copolyester composition of WO 93/02122.
• the inventors have, however, most surprisingly succeeded in obtaining objects shaped in the melt from chemical compositions of the copolyester WO 93/02122 with mechanical properties that are superior to those of the usual isotropic thermoplastic polyesters and approximate the mechanical properties of liquid crystalline polyester objects.
• the object shaped in the melt from a copolyester composition containing monomer units derived from ethylene glycol and 2,6- naphthalenedicarboxylic acid, (NDC) , 4,4'- diphenyldicarboxylic acid, (BB) , and optionally less than 50 mole% of the total amount of diacids of one or more other diacids according to the invention is characterized in that the relative viscosity of the copolyester in the object, measured in a solution of 1 gram of copolyester in 125 grams of a trichlorophenol/phenol (7:10 parts by weight) mixture at 25°C, is greater than 1.8, preferably greater than 1.9.
• a particular advantage of the object according to the invention is that it does not show the weak weld line characteristic of objects obtained from liquid crystalline copolyesters.
• the chemical composition of the copolyester for the object to be shaped from the melt according to the invention is described in detail in WO-93/02122 and consists predominantly of units derived from ethylene glycol, 4 , 4 ' -bisphenyldicarboxylic acid and 2,6- naphthalenedicarboxylic acid. Minor amounts, i.e. less than 50 mole%, of units derived from one or more other dicarboxylic acids, for example terephthalic or isophthalic acid, or glycols may optionally be present.
• the ratio of the amounts of units derived from bisphenyldicarboxylic acid and from naphthalenedicarboxylic acid may vary within a wide range; preferably it is at least 1:3 and at most 4:1. At values below 1:3 the melting point is low and the mechanical properties of the object shaped in the melt are improved to a limited extent only; at a ratio greater than about 4:1 the melting point becomes so high that moulding with the usual processing techniques causes problems, partly as a result of accelerated polymer decomposition.
• the ratio of the dicarboxylic acids is chosen so that the melting point of the copolyesters lies between 260 and 320°C, most preferably between 270 and 315°C.
• the copolyester can be obtained using the process described in WO-93/02122 in a 2-step process in which first a low-molecular prepolymer is formed in a polymerization in the melt at 200-240°C starting from the monomers in an inert gas atmosphere and in the presence of a reesterification catalyst. After 2 to 3 hours this prepolymerization is followed by a polycondensation reaction at a temperature between 220 and 290°C, preferably under reduced pressure, in the presence of a polycondensation catalyst. The product obtained is then further condensed in the solid phase at a temperature between 220 and 270°C in an inert gas atmosphere or in a vacuum until the relative viscosity is at least 1.8.
• the relative viscosity of the copolyester must hence in practice amount to approx. 1.9, preferably approx. 2.0, for processing purposes.
• an post-condensation time of at least 2 hours at 250 °C is necessary, depending on the end group balance and the post-condensation conditions, e.g. the temperature. In general this time is 10-20 hours at 225°C.
• the copolyester composition that can be used for the products and the articles according to the invention may also contain the usual additives, for example fillers, for example mineral fillers such as chalk, clay, mica, reinforcing fibres, for example mineral fibres, for example between 5 and 50 wt . % glass fibres, and carbon fibres, flame-retardant additives, for example halogenated organic compounds, phosphorus- containing compounds, nitrogen-containing compounds and metal oxides or salts, processing aids, for example mould-release agents, stabilizers to prevent for example thermal decomposition and photodecomposition, substances that influence the electrical properties and optionally other polymers, for example polymers that improve the impact resistance.
• fillers for example mineral fillers such as chalk, clay, mica, reinforcing fibres, for example mineral fibres, for example between 5 and 50 wt . % glass fibres, and carbon fibres
• flame-retardant additives for example halogenated organic compounds, phosphorus- containing compounds, nitrogen-containing compounds and
• the articles according to the invention can in particular be used in the following fields. Electric and electronic parts for so-called surface mounting techniques (SMT) in which very high temperatures have to be endured during assembly.
• Multiple connectors e.g. SIMMS connectors, in which very good flow behaviour is desired for production and a great strength and dimensional stability in the product.
• SIMMS connectors in which very good flow behaviour is desired for production and a great strength and dimensional stability in the product.
• a great strength at a low weight is an important factor, but reliability is also a prerequisite, which because of the absence of weak weld lines gives the objects according to the invention a major advantage over objects produced using conventional liquid crystalline polyester.
• Another application is that in loudspeaker cones.
• the particularly good thermooxidative stability and high continuous use temperature (CUT) of approx. 185 °C and a high heat distortion temperature, HDT 250°C, make the objects according to the invention particularly suitable for use in car parts.
• Copolyester was prepared in the manner described in WO 93/02122. The composition and the after-condensation times were varied.
• Figure 1 shows the relation between the intrinsic viscosity measured according to the method of WO 93/02122 and the relative viscosity according to the method indicated above.
• Copolyester was prepared using as a starting material a mixture of ethylene glycol, 4,4'- diphenyldicarboxylic acid and 2 , 6 -naphthalene- dicarboxylic acid according to the process described in
• the two dicarboxylic acids were present in equimolar amounts.
• the post-condensation was carried out at a reduced pressure of 0.3 kPa and at 2 temperature levels, namely 227.5 and 250°C.
• the relative viscosity of the granulate obtained was determined in TCP/P after different post-condensation times.
• Copolyesters 1, 2 and 3 were obtained using as a starting material 4,4'- diphenyldicarboxylic acid from different producers.
• the copolyesters had a melting point of between 280 and 282°C.
• copolyesters 1, 2 and 3 are probably attributable to differences in the end group balance caused by the different origins of the 4,4'- diphenyldicarboxylic acid.
• Example II The differences between copolyesters 1, 2 and 3 are probably attributable to differences in the end group balance caused by the different origins of the 4,4'- diphenyldicarboxylic acid.
• Copolyester 4 was synthesized using as a starting material ethylene glycol and naphthalene- dicarboxylic acid/diphenyldicarboxylic acid, 45/55 mole ratio. The copolyester obtained was post-condensed at different temperatures and for different times. The relative viscosity and the melt viscosity, expressed as the melt flow index, MFI [g/10 min.] , of the different products were measured at 310 °C according to ISO-1133.
• Example III Testing of tensile strength
• Test plates measuring 80x40 mm and having different thicknesses varying from 0.5 to 4 mm were injection-moulded from the copolyesters of Examples I and II.
• Tensile test bars (ISO 527-0,5) for tensile tests were milled from these plates (type 2) .
• tensile test bars (ISO 527-0,5) varying in thickness from between 0.75 and 3 mm were directly injection-moulded (type 1) .
• a mould temperature of 80°C, a melt temperature of 300-310°C, an injection rate of 12-14 cm 3 /sec. and a mould holding pressure of 600 bar were used.
• Deviating injection-moulding conditions are mentioned separately where relevant .
• Table 3 shows the results of tensile tests using the different types of tensile test bars for different materials .
• copolyester of Example 31 in WO 93/02122 in tensile test bars with a thickness of 3 mm shows a tensile strength of 45 MPa and a modulus of 3860 MPa, which is much lower than of the post- condensed copolyester 4 with ⁇ rel > 2.0.
• Vectra A130 Vectra A 950 + 30 wt.% GF
• the HDT-A values of injection-moulded test bars were 250 and 255°C, respectively. These values are surprisingly high and differ only little from one another.
• the HDT-A of a commercial liquid crystalline polyester Vectra A950 ® is only 170-180°C according to the product brochure and that of type A130 ® reinforced with 30% glass fibre 230°C.
• Example VI So-called Campus test bars, with a thickness of 4 mm, were injection-moulded in 2 ways. In the first method the bars were injected via one gate and in the second method the bars were injected via two gates, which led to the formation of a weld line in the middle of the bar.
• the tensile strength of the different types of bars was determined for glass-fibre- reinforced (30 wt.%) liquid crystalline polyester, (Vectra A130) , an isotropic polyester (PET +30% GF) and copolyester 1 + 30% GF.
• the following table shows the tensile strength of the weld line, expressed as a fraction of the tensile strength of test bars injected via one sprue, (thus without weld line) , of the different compositions.
• Copolyester 1 with 30% glass fibre was post -condensed for different times. The relative viscosity of the post-condensed granules was determined. Next, test bars were injection-moulded from these granules at an injection temperature of about 320-325°C. The relative viscosity of the test bars was again determined. The results are shown in the following table.
• Copolyester 45/55 NDC/BB 30% glassfibre.

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Polyesters Or Polycarbonates (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Manufacture Of Macromolecular Shaped Articles (AREA)

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Citations (2)

• 1997
  • 1997-12-30 NL NL1007934A patent/NL1007934C2/nl not_active IP Right Cessation
• 1998
  • 1998-12-23 AU AU17873/99A patent/AU1787399A/en not_active Abandoned
  • 1998-12-23 DE DE69830516T patent/DE69830516T2/de not_active Expired - Lifetime
  • 1998-12-23 EP EP98962702A patent/EP1044233B1/en not_active Expired - Lifetime
  • 1998-12-23 CN CNB988127644A patent/CN1158326C/zh not_active Expired - Fee Related
  • 1998-12-23 JP JP2000526568A patent/JP2001527144A/ja active Pending
  • 1998-12-23 WO PCT/NL1998/000730 patent/WO1999033898A1/en not_active Ceased
• 1999
  • 1999-01-12 TW TW88100414A patent/TWI237648B/zh active

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