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
  • C08G83/00—Macromolecular compounds not provided for in groups C08G2/00 - C08G81/00
  • C08G83/002—Dendritic macromolecules
  • C08G83/003—Dendrimers
• • 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
  • C08G63/52—Polycarboxylic acids or polyhydroxy compounds in which at least one of the two components contains aliphatic unsaturation
  • C08G63/56—Polyesters derived from ester-forming derivatives of polycarboxylic acids or of polyhydroxy compounds other than from esters thereof
  • C08G63/58—Cyclic ethers; Cyclic carbonates; Cyclic sulfites ; Cyclic orthoesters
• • 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
  • C08G63/87—Non-metals or inter-compounds thereof
• • 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
  • C08G63/81—Preparation processes using solvents

Definitions

• the present invention relates to hyperbranched polyesters, to a process for the manufacture thereof, to their use in unsaturated polyester preparations and to curable resins comprising hyperbranched polyesters.
• the conventional curable polyester resins generally comprise oligomers and comonomers, and oligomers usually consist of linear molecular chains.
• the viscosity of the resin increases significantly with increasing chain length of the oligomer.
• large amounts of multidimensional comonomers are required for viscosity control of formulas especially for applications, such as spraying, dipping and roll coating.
• Traditionally used comonomers affect the curing reaction and the prope ⁇ ies of the final product, Comonomers often have low curing rate, they cause shrinkage of the film during curing, have high costs, limited shelf life and also many of them are volatile and toxic.
• LSE resins may contain additives which lower the emissions, or they are suppressed resins, new monomer resins, resins with reduced styrene contents, high solids resins or resins where styrene is totally or pa ⁇ ly replaced with another monomer.
• the most commonly used method to reduce styrene emissions is to use film forming additives, such as paraffin in the resins.
• Oligomers with a highly branched structure and with a spherical shape constitute a family of polymers, which has been increasingly studied during recent years. These oligomers are referred to as hyperbranched polyesters having three-dimensional molecular architecture and possessing starburst topology. These . polymers are also named as dendritic polymers or dendrimers.
• Hyperbranched polyesters differ significantly from conventional linear oligomers, because the linear oligomer of sufficient molecular weight for polyester resins usually contains an entanglement of flexible molecular chains, usually only with two terminal functional groups on each molecule, while the hyperbranched polyester is a compact spherical molecule with many branches which carry a high number of terminal functional groups on each molecule.
• the spherical shape yields the compounds favourable and different rheological prope ⁇ ies, such as lower viscosity, when compared with the conventional linear oligomers.
• the high number of terminal, functional groups, which can be modified, results in a variety of physical and chemical prope ⁇ ies.
• Oligomers with a strongly branched structure can be used in applications, such as catalysts, as carriers for drug substances in pharmaceutical industry, as pharmaceuticals, cosmetics, adhesives, coatings, composites, agricultural chemicals and as multi- functional crosslinking agents.
• (meth)acrylic anhydride and/or an aliphatic carboxylic anhydride form ester linkages with free hydroxyl groups.
• the said hyperbranched polyesters can be used as resins which are curable by UN-radiation.
• the method for the manufacture of said hyperbranched polyesters comprises reacting an aromatic polycarboxylic anhydride with a polyol with 3 to 10 reactive hydroxyl groups in the presence of an activating agent stannous chloride and reacting the obtained product with giycidyl (meth)acrylate or allyl giycidyl ether.
• An object of the present invention is to provide an improved, economical and on an industrial scale applicable process for the manufacture of hyperbranched polyesters.
• a further object of the invention is to present new hyperbranched polyesters.
• a fu ⁇ her object of the invention is to provide hyperbranched polyesters which in unsaturated polyester applications require low amounts of mono- or multifunctional comonomer while the resins still retain a low viscosity, a high curing rate, an acceptable degree of curing and the final products manufactured thereof exhibit good mechanical prope ⁇ ies, and the curing can be performed applying any suitable curing methods.
• the present invention relates to hyperbranched polyesters of a polyol with 2 to 10 reactive hydroxyl groups, preferably of equivalent reactivity, and a polycarboxylic anhydride with 2 to 4 carboxyl groups, preferably with 3 carboxyl groups, each hydroxyl group of the polyol forming an ester linkage with one anhydride group of the polycarboxylic anhydride, and further giycidyl (meth)acrylate or allyl giycidyl ether forming ester linkage with the remaining carboxyl groups of the anhydride and free hydroxyl groups, and further unsaturated, aromatic or aliphatic anhydride forming ester linkages with free hydroxyl groups.
• the present invention further relates to a process for the manufacture of said hyperbranched polyester.
• the process is a controlled stepwise divergent method with at least two reaction steps and the synthesis sta ⁇ s at the center of the hyperbranched polyester.
• the process comprises the following steps:
• step b) reacting the product from step a) with giycidyl (meth)acrylate or allyl giycidyl ether in an amount of at least corresponding to 1 mol of giycidyl (meth) aery late or allyl giycidyl ether per free carboxylic acid group of the product of a),
• the product from the second step b) is fu ⁇ her reacted with an unsaturated, aromatic or aliphatic anhydride in an amount sufficient to esterify a pa ⁇ or all free hydroxyl groups of the product from step b).
• a polycarboxylic anhydride with 2 to 4 carboxyl groups is heated to a temperature of about or below 100 °C, preferably below 80 °C in the presence of a solvent or a mixture of solvents, in the presence of a te ⁇ iary aliphatic or aromatic amine, preferably triethylamine as a catalyst and under ine ⁇ gas atmosphere, preferably under nitrogen atmosphere.
• the polycarboxylic anhydride is preferably an aromatic anhydride, such as trimellitic anhydride or phthalic anhydride.
• Suitable polyols are polyols having 2 to 10 hydroxyl groups and the hydroxyl groups are preferably of equivalent reactivity , which allows the esterification of each of the hydroxyl groups to proceed equally easily in order to start the building up of the regular molecule.
• suitable polyols are pentaeryhtritol, dipentaerythritol, trimethyloyl propane, neopentyl glycol and the like.
• the amount of added anhydride is at least one mol of anhydride per hydroxyl group of the polyol but preferably the anhydride is added in an excess amount. An excess of 5—50 mol% is suitable.
• a suitable solvent is dimethylformamide or 1- methyl-2-pyrrolidinone or a mixture thereof. The reaction mixture can be used as such without further purification for the following step of the process.
• the intermediate from the first reaction step is allowed to react with giycidyl (meth)acrylate or allyl giycidyl ether in an amount at least corresponding to one mol of giycidyl (meth)acrylate or allyl giycidyl ether per free carboxylic acid group of the formed polyester, preferably in an excess amount of about 5—20 wt% .
• Preferred reactant is giycidyl (meth)acrylate.
• the reaction is carried out in a solvent, such as dimethyl formamide or l-methyl-2-pyrrolidinone or a mixture thereof, in the presence of an inhibitor for radical polymerization.
• a suitable inhibitor is hydroquinone monomethyl ether.
• the amine from the previous reaction step preferably triethylamine acts as a basic catalyst.
• the reaction temperature is below 100 °C, preferably below 80 °C.
• the obtained second intermediate reaction mixture can be used without fu ⁇ her purification in the following
• the hydroxyl groups of the hyperbranched polyester with terminal double bonds are reacted further by ester formation with an unsaturated, aromatic or aliphatic anhydride, preferably acetic anhydride or (meth)acrylic anhydride, in an amount sufficient to esterify pa ⁇ or all of the free hydroxyl groups in order to prepare the hyperbranched polyester molecules with acetyl groups or fu ⁇ her end double bonds.
• the reaction is preferably performed at a temperature below 100 °C, preferably below 80 °C, in the presence of a solvent, such as dimethyl formamide or l-methyl-2-pyrrolidinone or a mixture thereof.
• the solvents used in the previous reaction steps and remaining in the reaction mixture may act as solvents without additional solvents.
• an inhibitor preferably benzoquinone is added and the product may optionally be dissolved in an organic solvent which is immiscible with water, such as an aromatic hydrocarbon or a chlorinated hydrocarbon or a mixture thereof, suitably toluene or methylene chloride, for fu ⁇ her processing.
• the product may also be dissolved in styrene in order to obtain a 40—70 % solution of the product in styrene.
• Styrene is especially favourable as the obtained solution can readily be used in unsaturated polyester resins without removal of the solvent.
• Other suitable solvents for the same purpose are p-methylstyrene or vinyltoluene. This solution can readily be used for the manufacture of resins and other applications.
• step c) may be omitted if hydroxy functional hyperbranched polyesters are desired.
• the product may optionally be dissolved in an organic solvent as described above in step c).
• the process according to the invention is specially suitable for industrial scale without the drawbacks of the small scale methods according to prior an.
• New amine catalysts can be used in the process instead of stannous chloride, no isolation of intermediates is required in the process and no distillation of the solvents is needed.
• the hyperbranched polyesters obtained with polyols containing two reactive hydroxyl groups, such as neopentyl glycol are new compounds with prope ⁇ ies especially suitable to serve as reactive blendable comonomers in resins because of their favourable rheological properties.
• the hyperbranched polyesters according to the invention based on a polyol core molecule, a polycarboxylic anhydride as a branching extender and an epoxyacrylate as an end group can be used to improve the mechanical prope ⁇ ies of high solids unsaturated resins with low conomomer contents while still retaining good mechanical properties of the resin.
• styrene content ' s of 30 % by weight or less can be used which is clearly an advantage from an environmental point of view as the styrene emissions will be reduced.
• the hyperbranched polyesters can also be used in styrene free unsaturated polyester resins, which are based on vinyl ether monomers.
• the heat disto ⁇ ion temperature, tensile and flexural strength of cured polyester resins manufactured using hyperbranched polyesters according to the invention are improved when up to 15 % of the hyperbranched polyester or a mixture thereof is added into the high solids unsaturated polyester.
• the mechanical prope ⁇ ies of the polyester resins thus obtained can be widely modified and adjusted according to the final use of the resin.
• the hyperbranched polyesters according to the invention can be used as resins which can be cured by conventional curing systems, such as thermally initiated curing using initiators, such as aliphatic azo compounds or organic peroxides, such as benzoyl peroxide, by a redox reaction initiated curing using organic peroxides, such as methyl ethyl ketone peroxide and metal salts, by photochemically initiated curing using UN-light or by radiation inititated curing by EB-radiation.
• initiators such as aliphatic azo compounds or organic peroxides, such as benzoyl peroxide
• organic peroxides such as methyl ethyl ketone peroxide and metal salts
• the resins have a lower viscosity than conventional oligomer resins and they can be used with or without comonomers.
• the resins may also comprise monofunctional or multifunctional comonomers or mixtures thereof, and a suitable amount of co- monomer is 5—20 wt%.
• multifunctional comonomers compounds with reactive double bonds, preferably with 1—6 (meth)acrylate or acrylate groups can be used, and such as trimethyloyl propane tri(meth)acrylate, hexanediol diacrylate, trimethylo- yl propane triallyl ether, pentaerythritol tri/tetraallylether, triallyl cyanurate, trimethyloyl propane triacrylether and pentaerythritol tetraacrylether are suitable.
• monofunctional comonomers vinyl aromatic monomers, such as styrene, p-methylstyrene or vinyl toluene are suitable.
• alkyl (meth)acrylates, such as methyl (meth)acrylate may be used.
• the resins according to the invention can be used in many different fields, such as coating, adhesives, laminates, foils, thin-films and composites.
• reaction mixture containing the intermediate I PEBTCA is analyzed by HPLC, 1HNMR and acid number titration (TAN). Typical analysis
• the reaction mixture is used in the next process step without further purification.
• reaction mixmre containing the intermediate D l-OH is analyzed bv GPC. l HNMR and acid number titration (TAN) .
• the reaction mixture is used in the next step wichout fu ⁇ her purification.
• Step 3a Synthesis of final product Dl (60 % solution in styrene)
• 350.0 g of the reaction mixture containing the intermediate D l-OH from step 2 is warmed up to 50...55 °C.
• 75 0 ml (0.80 mol) of acetic anhydride (AA) is slowly added during 20 min at 50 ..70 °C.
• the mixture is sti ⁇ d at 68...72 °C for 3 hours.
• 550 ml of styrene is added to dissolve the product and the solution is washed with 700 ml of 10 % Na 2 C0 3 at 55...60 °C.
• another 150 ml of styrene is added and the mixture is washed with 700 ml of water at 55...60 °C.
• Yield is 380 g of about 60 % D l -solution in styrene.
• D l can be obtained as a viscous oil according to the following procedure Step 3b. 0
• Resin blends are prepared by mixing the unsamrated polyester resin with various amounts of hyperbranched polyesters.
• the styrene content is 30 % in all blends.
• the unsamrated polyester is a low molecular weight polyester made from orthophthalic anhydride, maleic anhydride and 1 ,2-propanediol.
• the amount of hyperbranched polyesters is 5 wt%, 10 wt-% and 15 wt% .
• the resin blend is cured with 0.4 wt% of promoter (a mixmre of cobalt octoate, dimethyl aniline and methyl hydroquinone) and 1 wt% methyl ethyl ketone peroxide.
• promoter a mixmre of cobalt octoate, dimethyl aniline and methyl hydroquinone
• 1 wt% methyl ethyl ketone peroxide As a reference, a commercial monomer trimethyloylpropane trimethacryl
• the casting is prepared at room temperamre using a metal frame.
• the surface of the frame is Teflon treated in order to prevent sticking of the resin to the metal.
• the outer size of the frame is 25.5 x 40.5 cm, the inner size is 26 x 21 cm.
• the thickness of the frame is 4 mm.
• the frame is placed on a glass plate covered with Melinex (PET) foil. 400 g of resin is weighed, and air is removed with vacuum. The needed amount of peroxide is then added, and the resin is mixed without causing air-bubble formation.
• PET Melinex
• the resin is poured carefully into the mold, and the mold is then covered with a Melinex film, and a glass plate. A metal plate is put on top as a weight. The casting is left to cure overnight at room temperamre.
• the casting is then checked for residual stresses between two Polaroid plastic films, on a light table.
• Specimens for mechanical testing are cut using a machine saw.
• the specimens are post-cured at 50 °C for 24 hours.
• the specimens are placed between two glass plates in an oven.
• the specimens are cooled slowly to room temperamre (1 h) to decrease residual stresses.
• the tested samples are then checked between two Polaroid films for residual stresses, and the specimens with least residual stresses are selected. At least five specimens are selected.
• the mechanical test is made using an Instron 1175, with a 5 kN load cell.
• the crosshead speed is 2 mm/min.
• the specimens are post-cured and checked in the same way as the specimens for the mechanical testing.
• the HDT value is measured in a heating bath, which is heated from 20 °C at a rate of 2 C°/min.
• the specimen is loaded using a constant load.
• the temperamre at which the specimen bends is registered as the HDT value.
• TMPTMA trimethyloylpropane trimethacrylate

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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)
• Macromonomer-Based Addition Polymer (AREA)

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• 1999
  • 1999-04-01 FI FI990727A patent/FI990727A0/sv unknown
• 2000
  • 2000-04-03 AU AU38223/00A patent/AU3822300A/en not_active Abandoned
  • 2000-04-03 WO PCT/FI2000/000288 patent/WO2000059982A1/en not_active Application Discontinuation
  • 2000-04-03 EP EP00917103A patent/EP1171503A1/en not_active Withdrawn

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