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
  • C08G63/78—Preparation processes
  • C08G63/82—Preparation processes characterised by the catalyst used
  • C08G63/85—Germanium, tin, lead, arsenic, antimony, bismuth, titanium, zirconium, hafnium, vanadium, niobium, tantalum, or compounds thereof
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/49—Phosphorus-containing compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/49—Phosphorus-containing compounds
  • C08K5/51—Phosphorus bound to oxygen
  • C08K5/53—Phosphorus bound to oxygen bound to oxygen and to carbon only

Definitions

• the invention relates to the field of thermoplastic polymers, particularly thermoplastic polymers containing polybutyleneterephthalate (PBT) repeat units.
• PBT polybutyleneterephthalate
• Thermoplastic resins having a polybutylene terephthalate (PBT) component such as PBT itself and copolyetherester elastomers having PBT blocks, are used increasingly as engineering polymers in diverse end uses, including the automotive industry. Such resins may in particular be used in automobile interiors. Copolyetherester elastomers, for example, are widely used in air-bag deployment doors.
• PBT polybutylene terephthalate
• thermoplastic resins suffer the disadvantage that moulded articles made from the resins exhibit a phenomenon known as outgassing.
• Outgassing is the emission of organic molecules of relatively low molecular weight into the surrounding environment. Outgassing is considered disadvantageous because many of the components that are emitted have unpleasant odours, or may be irritants.
• PBT- containing resins are particularly prone to emit tetrahydrofuran (THF), particularly within the first weeks after moulding. Outgassing is usually worsened if the resin is used under conditions of elevated temperature (i.e. above 100 0 C). Automobile manufacturers are adopting increasingly strict requirements as regards to outgassing in automobile interiors.
• EP 0 683201 (Polyplastics Co. Ltd.) describes a method, for reducing gas (particularly THF) in moulded articles made of PBT. The method involves adding a compound of Formula I, Il or III during polymerisation of the monomers to make PBT:
• the invention provides a method or process for reducing outgassing in a resin comprising at least one component having a polybutylene terephthalate (PBT) repeat unit, which resin is made by polymerising monomers in the presence of a titanium catalyst, the method or process comprising the step of: adding to the resin, after polymerisation of the monomers, a titanium catalyst deactivating compound.
• PBT polybutylene terephthalate
• the invention provides a use of a titanium catalyst deactivating compound for reducing outgassing in a resin comprising at least one component having a polybutylene terephthalate (PBT) repeat unit, which resin is made by polymerising monomers in the presence of a titanium catalyst.
• PBT polybutylene terephthalate
• the invention provides a resin comprising at least one component having a polybutylene terephthalate (PBT) repeat unit, the resin further comprising at or about 0.01 to 3 wt% of the compound of Formula IV":
• PBT polybutylene terephthalate
• phenyl phosphinate or at or about 0.01 to 3 wt% phenyl phosphinate , or at or about 0.01 to 3 wt% of a salt (preferably sodium) of 2,2'-methylenebis-(4,6-di-tert-butylphenyl)phosphate.
• a salt preferably sodium
• the invention provides a moulded, extruded or shaped article made from a resin comprising at least one component having a polybutylene terephthalate (PBT) repeat unit, the resin further comprising at or about 0.01 to 3 wt% of the compound of Formula IV":
• PBT polybutylene terephthalate
• phenyl phosphinate or at or about 0.01 to 3 wt% phenyl phosphinate, or at or about 0.01 to 3 wt% of a salt (preferably sodium) of 2,2'-methyleriebis-(4,6-di-tert-butylphenyl)phosphate.
• a salt preferably sodium
• PBT polybutylene terephthalate
• THF tetrahydrofuran
• PPG polypropylene glycol
• PEG polyethylene glycol
• the inventors have surprisingly found that total organic carbon emissions
• TOC tetrahydrofuran
• THF tetrahydrofuran
• a resin comprising at least one component having a polybutylene terephthalate (PBT) repeat unit, which resin is made by polymerising monomers in the presence of a titanium catalyst, by adding to the resin, after polymerisation of the monomers, a titanium catalyst deactivating compound.
• PBT polybutylene terephthalate
• Outgassing in the context of the present description refers to the emission of volatile organic substances from a resin, which substances can be detected, for example, according to the method of the Verband der Automobili'ndustrie [The German Association of the Automotive Industry (VDA)] standard VDA 277.
• VDA Verband der Automobili'ndustrie
• THF 1 which is a particular problem immediately after moulding, extruding or shaping of a resin comprising a PBT repeat unit.
• THF emissions from a resin may be measured, for example, using gas chromatography, for example with flame ionisation detection, or gas chromatography-mass spectrometry (GC-MS).
• GC-MS gas chromatography-mass spectrometry
• Thermoplastic resins comprising a PBT repeat unit are made by polymerising monomers (e.g. 1 ,4-butanediol and a terephthalate diester and/or isophthalate diester) in the melt in the presence of a catalyst, often a titanium catalyst, such as titanium tetra(f-butoxide), used either alone, or in the presence of other metal salt catalysts.
• a catalyst often a titanium catalyst, such as titanium tetra(f-butoxide), used either alone, or in the presence of other metal salt catalysts.
• a conventional .resin after polymerisation is complete, the resin is removed from the polymerisation vessel, the resin solidifies, and the titanium catalyst remains in active form in the solid resin at concentrations of from at or about 10 to 1000 ppm titanium (mass titanium to mass polymer).
• the titanium catalyst can catalyse the formation of outgassing components such as THF when the resin is in the melt, for example on remelting for moulding, extrusion or shaping.
• outgassing components such as THF
• the activity of the titanium catalyst is reduced. It is believed that this results in reduced outgassing of the solidified resin, particularly emission of THF.
• titanium-catalyst deactivating compound is meant to encompass all those compounds that when added to an active titanium catalyst result in a decrease of the titanium catalyst's polymerisation activity.
• the expression "after polymerisation of the monomers”, is used to describe the point in the process of manufacturing the resin that the titanium catalyst deactivating compound (e.g. a compound of Formula IV, IV or IV") is added.
• the expression is meant to encompass any point in time at or about which or after which the condensation polymerisation reaction has resulted in a polymer with the desired molecular weight and viscosity.
• the desired molecular weight and viscosity are selected to meet the subsequent use requirements of the resin.
• Particular examples of the resin comprising at least one component having a polybutylene terephthalate (PBT) repeat unit include: PBT, copolyether ester elastomers having PBT segments, co-PBT's (i.e. PBT's in which some of the 1 ,4- butane diol is replaced with, for example, one or more other diols, such as aliphatic, cycloaliphatic (for example 1 ,4-cyclohexanedimethanol), or aromatic diols (for example 2,2-bis[4-(hydroxyethoxyphenyi)J-propane as disclosed in US patent no.
• PBT polybutylene terephthalate
• PBT and copolyether ester elastomers having PBT segments such as those available under the tradenames Hytrel ® (Dupont), Arnitel ® (DSM) and Riteflex ® (Ticona).
• the titanium catalyst deactivating compound is preferably a compound of the general Formula IV, or salts thereof:
• R 1 , R 2 and R 3 are independently selected from H, OH, OM (wherein M is a positively charged counterion), optionally substituted C 1-2 O alkyl, optionally substituted C 2- io alkylene, optionally substituted C 6-2 oaryl, optionally substituted C 1-2 O alkyloxy, polyoxy(C 2 .4)alkylene, and optionally substituted C 6-2 oaryloxy, and wherein the optional substituents are independently 1 to 2 in number on any of R 1 , R 2 and R 3 , and are independently selected from OH, halogen, COOH, COOR 4 (wherein R 4 is Ci -4 alkyl) and NH 2 ; two or more of R 1 , R 2 and R 3 can optionally be linked together by a bridge; with the proviso that R 1 , R 2 and R 3 are not simultaneously H, and that R 1 , R 2 and R 3 are not simultaneously OH.
• the titanium catalyst deactivating compound is a compound of the general Formula IV, or salts thereof:
• R 1 and R 2 are independently selected from H, OH, OM (wherein M is a positively charged counterion), optionally substituted C 1-20 alkyl, optionally substituted C 2-20 alkylene, optionally substituted C 6-10 aryl, optionally substituted C 1-20 alkyloxy, polyoxy(C 2-4 )alkylene, and optionally substituted C ⁇ oaryloxy, and wherein the optional substituents are independently 1 to 2 in number on either of R 1 or R 2 , and are independently selected from OH, halogen, COOH, COOR 4 (wherein R 4 is C 1-4 alkyl) and NH 2 ; two or more of R 1 , R 2 and R 3 can optionally be linked together by a bridge; with the proviso that R 1 and R 2 are not simultaneously OH.
• M is a positively charged counterion
• Salts of compounds of Formula IV, IV and IV may be any acid or base addition salts, such as sodium salts, potassium salts, calcium salts, magnesium salts, barium salts, aluminium salts, tetraalkylammonium salts (e.g. tetrabutylammonium), hydrochloride salts, sulphate salts, oxalate salts, C 2-6 carboxylate salts (e.g. acetate, propionate), and the like.
• acid or base addition salts such as sodium salts, potassium salts, calcium salts, magnesium salts, barium salts, aluminium salts, tetraalkylammonium salts (e.g. tetrabutylammonium), hydrochloride salts, sulphate salts, oxalate salts, C 2-6 carboxylate salts (e.g. acetate, propionate), and the like.
• the OH group is in the form of a salt of Na + , K + , Ca ++ , Mg ++ or AP +* , since acidic compounds may degrade the PBT repeat units.
• R 1 in the compound of Formula IV or IV is selected from phenyl, ethyl, H, 2-(carboxy)ethyl, polyoxyethylene, hydroxy methyl, di- f-butoxyphenoxy, and ethoxy.
• R 2 in the compound of Formula IV or IV is selected from phenyl, ethyl, H, 2-(carboxy)ethyl, polyoxyethylene, hydroxymethyl, di-f-butoxyphe ⁇ oxy, and ethoxy.
• the bridge is preferably Ci-C 4 alkylene, more preferably ethylene or methylene.
• Particularly preferred are such bridged compounds in which R 1 and R 2 are selected from optionally substituted aryloxy, wherein the aryloxy groups are linked by an ethylene or methylene bridge, particulary a methylene bridge.
• Particularly preferably the aryloxy groups are substituted, preferably with C 1 - C 4 -branched or unbranched alkyl.
• Preferred examples of compounds of Formula IV are the following:
• Phenyl phosphinate (preferably the sodium salt), preferably used at or about 0.03 to 0.4 wt%, more preferably at or about 0.05 to 0.2 wt%:
• Sodium (or potassium) hypophosphite monohydrate preferably used at or about 0.03 to 0.4 wt%, more preferably at or about 0.05 to 0.2 wt%:
• 3-(hydroxyphenyl phosphinyl) propanoic acid (“3HPP”; compound of Formula IV”), preferably used at or about 0.05 to 0.8 wt%, more preferably at or about 0.1 to 0.5 wt%:
• Mono-, di- and tri-salts of phosphoric acid (particularly the sodium salts), preferably used at or about 0.05 to 0.4 wt%, more preferably at or about 0.1 to 0.2 wt%.
• Di(poiyoxyethylene)hydroxymethylphosphonate e.g. sold as Victastab HMP (Akzo Nobel)
• akzo Nobel e.g. sold as Victastab HMP (Akzo Nobel)
• a salt (preferably sodium) of 2,2'-methylenebis-(4,6-di-tert-butylphenyl)phosphate preferably used at at or about 0.01 to 3 wt%, more preferably at or about 0.05 to 0.5 wt%:
• Salts of diethylphosphinic acid in particular the aluminium salt (aluminium tris- diethylphosphinate), preferably used at at or about 0.01 to 1 wt%, more preferably at or about 0.05 to 0.5 wt%
• the titanium catalyst deactivating compound that is used is a compound of Formula IV" (3HPP):
• the method or process of the invention involves adding a titanium catalyst deactivating compound (e.g. a compound of Formula IV, IV or IV") to the resin comprising at least one component having a polybutylene terephthalate (PBT) repeat unit in the melt. Since the titanium catalyst deactivating compound deactivates the titanium catalyst, it is added after polymerisation of the PBT monomers is complete. This may be done immediately after polymerisation (i.e. by direct addition to the polymer melt in the polymerisation vessel, once the polymerisation process has reached the desired stage). Alternatively, the titanium catalyst deactivating compound may be added in a separate process by remelting granules of the resin comprising at least one component having a polybutylene terephthalate (PBT) repeat .
• a titanium catalyst deactivating compound e.g. a compound of Formula IV, IV or IV
• the polymerised resin comprising at least one component having a polybutylene terephthalate (PBT) repeat unit may be fed to a separate mixing apparatus (such as a single or twin-screw compounding extruder) immediately after polymerisation, for mixing with the titanium catalyst deactivating compound.
• a separate mixing apparatus such as a single or twin-screw compounding extruder
• the mixing of the resin and the titanium catalyst deactivating compound should be continued until the titanium catalyst deactivating compound is • homogeneously distributed in the resin.
• the titanium catalyst deactivating compound e.g. a compound of Formula IV,
• the titanium catalyst is usually added in a number of moles that is at least approximately stoichiometric to the number of moles of titanium catalyst that were used in the polymerisation of the resin.
• the titanium content (ppm in terms of mass of titanium per mass of polymer) is known from the amount of catalyst added at the start of polymerisation. Alternatively, it may be determined by analysing the resin, for example, by X-ray fluorescence (XRF) or atomic emission or absorption spectroscopy.
• the titanium catalyst is present in an amount of at or about 10 to 1000 ppm (i.e. approximately 0.2 to 21 moles Ti per 1000 kg resin), commonly in the range of at or about 100 to 400 ppm (i.e. approximately 2 to 8 moles Ti per 1000 kg resin).
• the catalyst deactivating compound e.g. a compound of Formula IV, IV or IV
• the catalyst deactivating compound is added in an amount of at or about 0.5 to 20 equivalents (phosphorus atoms:titanium atoms), more preferably at or about 1 to 10 equivalents.
• titanium catalyst deactivating compounds e.g. a compound of Formula IV, IV or IV
• Testing the resulting resin for outgassing may be done by a number of techniques.
• An example of a technique that may be used to evaluate total organic carbon emissions from a resin is described in the Verband der Automobfflndustrie fThe German Association of the Automotive Industry (VDA)] standard VDA 277.
• VDA Automotive Industry
• Hytrel® 5556 is a copolyetherester elastomer available from DuPont. It has a nominal hardness of 55 Shore D and comprises hard segments of PBT with soft segments of polyether terephthalate and contains a titanium based catalyst at approximately 100 to 400 ppm (mass Ti to mass polymer; i.e. approximately 2 to 8 moles Ti per 1000 kg resin). For this experiment the batch used had a titanium content of approximately 150 ppm.
• Hytrel® 5556 has a typical Melt Flow Rate (MFR) of approximately 7.5 g/10min when measured to ISO1133 at 220 0 C and with a load of 2.16 kg.
• MFR Melt Flow Rate
• the Hytrel® 5556 was melt compounded in a twin screw extruder with various levels of compounds of general Formula IV as listed in Table 1.
• the control resin was Hytrel® 5556 put through the same compounding process but without the addition of a compound of Formula IV.
• the inventive and control resins were injection moulded into bars of approximate overall dimensions of 75 mm X 12.5 mm X 2 mm, and of the form described as Test Specimen type 5A in the International Standard ISO 527-2: 1993(E). Immediately after moulding the bars were sealed in aluminium-lined polyethylene envelopes. The sealed envelopes maintain THF-conte ⁇ t at approximately the level immediately after moulding until analysis can de done. For analysis, the bars were removed from the envelopes and cut into four pieces and placed in septum-sealed vials. The control sample and inventive samples were treated in exactly the same fashion throughout the sample preparation process.
• TOC Total organic carbon emissions
• the vials containing the control and the inventive sample were heated for approximately 5 hours at 120 0 C.
• the "headspace" above the resin samples i.e. the air space in the vials above the resin
• the "headspace" above the resin samples i.e. the air space in the vials above the resin
• Detection was with a flame ionisation detector.
• the area under the peaks for the inventive sample was compared to the area under the peaks for the control, and the results reported as %TOC of control.
• the results are reported in Table 1 as "%TOC H .
• Control and inventive samples were prepared as above.
• the vials containing the control and the inventive sample were heated for approximately 5 hours at 120°C.
• the "headspace" above the resin samples i.e. the air space in the vials above the resin
• Detection was with flame ionisation detection (mass spectrometry may also be used).
• the area under the peak for THF for. the inventive sample was compared to the area under the peak for THF for the control, and the results reported as %THF of control. The results are reported in Table 1 as "%THF".
• Crastin ® 6131 is a PBT resin available from DuPont. It has an average melt flow rate (MFR) of 48 g/10 mins, ISO1133, 250 0 C, 2.16 kg and contains a titanium- based catalyst, at approximately 100 ppm (mass Ti to mass polymer; i.e. approximately 2 moles Ti per 1000 kg resin).
• the Crastin® 6131 was melt compounded in a twin screw extruder with various levels of compounds of general Formula IV as listed in Table 2.
• the control resin was Crastin® 6131 put through the same compounding process but without the addition of a compound of Formula IV.
• the inventive and control resins were injection moulded into plates of dimensions 80 x 80 x 3mm. Immediately after moulding the bars were sealed in aluminium-lined polyethylene envelopes. The sealed envelopes maintain THF- content at approximately the level immediately after-moulding until analysis can de done. For analysis, the plates were removed from the envelopes and cut into pieces of approximately 4 x 4 x 3mm. Approximately 1.5 g of these granules were placed in a septum-sealed vial. The control sample and inventive sample were treated in exactly the same fashion throughout the sample preparation process.
• TOC Total organic carbon emissions
• Example 3 The procedure of example 2 was followed using, in place of the Crastin® 6131, a PBT resin with an average melt flow rate (MFR) of 48 g/10 mins, ISO1133, 250 0 C, 2.16 kg and containing a titanium-based catalyst, at approximately 170 ppm (mass Ti to mass polymer; i.e. approximately 3.5 moles Ti per 1000 kg resin). The results obtained are reported in Table 3

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• 2007
  • 2007-03-15 US US11/724,454 patent/US8148489B2/en not_active Expired - Fee Related
  • 2007-03-20 WO PCT/US2007/006940 patent/WO2007111890A2/en not_active Ceased
  • 2007-03-20 JP JP2009502858A patent/JP2009531519A/ja active Pending
  • 2007-03-20 EP EP07753559.9A patent/EP1999181B2/en not_active Ceased
  • 2007-03-20 CA CA002641210A patent/CA2641210A1/en not_active Abandoned
• 2012
  • 2012-02-27 US US13/405,393 patent/US20120165443A1/en not_active Abandoned

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