The present invention relates to hyperbranched polyesters, to a process for the manufacture thereof, to their use in unsarurated polyester preparations and to curable resins comprising hyperbranched polyesters.

The conventional curable polyester resins generally comprise oligomers and comono- mers, and oligomers usually consist of linear molecular chains. The viscõsity of the resin increases significantly with increasing chain length of the oligomer. Thus, large amounts of multidimensional comonomers are required for viscosiry control of formulas especially for applications, such as spraying, dipping and roll coating.

Traditionally used comonomers affect the curing reaction and the properties 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. The legislation in several countries covering environmental protection and occupational safery has tightened during the recent years and set limitations on emissions of volatile organic compounds (VOC), such as styrene, which is a commonly used comonomer in unsaturated polyester resins. Styrene content ranges from 35 % to 50 % in conventional resins. Several methods have been evaluated in order to reduce the amount of styrene in unsaturated polyester resins, and low styrene emission (LSE) resins have been developed with sryrene contents below 35 %. 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 partly 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 signifi- cantly 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 molecu- le, while the hyperbranched polyester is a compact spherical molecule with many branches which carry a high number of terminal functional groups on each molecule.

These unique features of the hyperbranched polyesters yield interesting and special properties which make these compounds very attractive and useful in several applications. The spherical shape yields the compounds favourable and different rheological properties, such as lower viscosity, when compared with the conven- tional linear oligomers. The high number of terminal, functional groups, which can be modified, results in a variety of physical and chemical properties. 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.

A series of hyperbranched (meth) acrylated polyesters with different number of terminal double bonds per molecule has been presented and methods for the manu- facture thereof have been disclosed in the patent application WO 96/07688. This publication discloses'a hyperbranched polyester of a polyol with 3 to 10 reactive hydroxyl groups and an aromatic polycarboxylic anhydride with 2 to 4 carboxyl groups, each hydroxyl group of the polyol forming an ester linkage with one anhydride group of the polycarboxylic anhydride, and further glycidyl (meth) acrylate or allyl glycidyl ether forming ester linkages with the remaining carboxyl groups of the anhydride and free hydroxyl groups. Further, in the hyperbranched polyester, (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 UV-radiation. The method for the manufacture of said hyper- branched 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 glycidyl (meth) acrylate or allyl glycidyl 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 further 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 properties, and the curing can be performed applying any suitable curing methods.

The objects of the invention are achieved by a method for the manufacture of hyperbranched polyesters, by new hyperbranched polyesters and by resins comprising them, as claimed in the claims.

Characteristics of the method, the polyesters, the resins and the use are stated in the claims.

It has been found that according to the invention new hyperbranched polyesters can be manufactured and an improved method for the manufacture of the hyperbranched polyesters can be provided. Thus, 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 glycidyl (meth) acrylate or allyl glycidyl ether forming ester linkage with the remain- ing carboxyl groups of the anhydride and free hydroxyl groups, and further unsatu- rated, 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 starts at the center of the hyperbranched polyester.

The process comprises the following steps: First step a) reacting a polycarboxylic anhydride with 2 to 4 carboxyl groups, preferably free carboxyl groups, with a polyol with 2 to 10 reactive hydroxyl groups, preferably of equivalent reactivity, in the presence of an amine, the amount of anhydride being at least 1 mol of anhydride per hydroxyl group of the polyol, Second step b) reacting the product from step a) with glycidyl (meth) acrylate or allyl glycidyl ether in an amount of at least corresponding g to 1 mol of glycidyl (meth) acrylate or allyl glycidyl ether per free carboxylic acid group of the product of a), Third step c) the product from the second step b) is further reacted with an unsaturated, aromatic or aliphatic anhydride in an amount sufficient to esterify a part or all free hydroxyl groups of the product from step b).

In the first reaction step, 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 tertiary aliphatic or aromatic amine, preferably triethylamine as a catalyst and under inert gas atmosphere, preferably under nitrogen atmosphere. The polycarboxylic anhydride is

preferably an aromatic anhydride, such as trimellitic anhydride or phthalic anhydride. Suiiab) e potyots are po) yo) s 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. Examples of suitable polyols are pentaeryhtritol, dipenfaerythritoi, irimethytoyl 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 550 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.

In the second step, the intermediate from the first reaction step is allowed to react with glycidyl (meth) acrylate or allyl glycidyl ether in an amount at least corresponding to one mol of glycidyl (meth) acrylate or allyl glycidyl ether per free carboxylic acid group of the formed polyester, preferably in an excess amount of about 520 wt%. Preferred reactant is glycidyl (meth) acrylate. The reaction is carried out in a solvent, such as dimethyl formamide or 1-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 tem- perature is below 100 °C, preferably below 80 °C. The obtained second interme- diate reaction mixture can be used without further purification in the following reaction step.

In the third reaction step, the hydroxy ! groups of the hyperbranched polyester with terminal double bonds are reacted further by ester formation with an unsarurated, aromatic or aliphatic anhydride, preferably acetic anhydride or (meth) acrylic anhydride, in an amount sufficient to esterify part or all of the free hydroxyl groups in order to prepare the hyperbranched polyester molecules with aceryl groups or further 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--pvrrolidinone or a mixture thereof. Conveniently the solvents used in the previous reaction steps and remaining in the reaction mixture may act as solvents without additional solvents. After the reaction is completed, 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 further 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.

Alternatively the third step c) may be omitted if hydroxy functional hyperbranched polyesters are desired. After the reaction is completed in step b), 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 art. 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 properties especially suitable to serve as reactive blendable comonomers in resins because of their favourable rheological properties.

The hyperbranched polyesters according co 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 properties of high solids un- saturated resins with low conomomer contents while still retaining good mechanical properties of the resin. Thus, styrene contents 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 distortion 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 properties 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 UV-light or by radiation inititated curing by EB-radiation.

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%. As 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, tri- methyloyl propane triacrylelher and pencaerythritol tetraacrylether are suitable. As monofunctional comonomers vinyl aromatic monomers, such as styrene, p-methylstyrene or vinyl toluene are suitable. Also 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.

The following examples illustrate the invention in more detail however they are not intended to be limiting the invention.

Preparation and results of analvsis of hyperbranched methacrylated polyesters Example 1 1. Synthesis procedure of D1 Step 1. Synthesis of intermediate I PEBTCA 40.0 g (0.294 mol) of pentaerythritol (PE) and 40 ml of triethylamine (TEA) are dissolved in 400 ml of dimethylformamide (DMF). Then 248.0 g (1.29 mol, 10 % excess) of trimelliticanhydride (TMA) is added in portions within 30 min at a temperature below 55 °C. After the addition the reaction mixture is stirred at 50... 55 °C under nitrogen atmosphere for 6 hours and cooled down to room temperature overnight.

The reaction mixture containing the intermediate I PEBTCA is analyzed by HPLC, lHNMR and acid number nitration (TAN).

Typical analysis Composition by high pressure iiquid chromacography (HPLC) : %Tetraester85...87 Triescer 1.3 % acid10...11%TMA+ Titrated acid number (TAN): KOH/g(217theoretical)213...220mg The reaction mixture is used in the next process step without further purification.

Step 2. Synthesis of intermediate II D1-OH 2. 0 2 of hydroquinone monomechyl ether (inhibitor) is added into the PEBTCA- reaction mixture from step 1 and che mixture is warmed up co 50... 55 °C. Then 400.0 ml (2.94 mol. 10 % excess) of alycidyl methacrylate (GMA) is slowly added during 1...2 hours at a temperarure below 75 °C. The reaction mixture is further

scirred ac 70... 75 °C for about 10 hours uncit T. AN of he mixture is < 10 mg KOH/g. mixturecontainingtheintermediateD1-OHisanalyzedbyGPC.Thereac tion 1HNMRnumbertitration(TAN).acid The isusedinthenextstepwithoutfurtherpurification.mixture Step 3a. Synthesis of final product D1 (60 % solution in styrene)

350.0 g of the reaction mixture containing the infermediare Dl-OH from step'is warmed up to 50... 55 °C. 75.0 ml (0.80 mot) of acectc anhydride (. NA) is slowly added minat50...70°C.Aftertheadditionthemixtureisstirredat20 68...7 2 °C for 3 hours. Then 550 ml of styrene is added co dissolve the product and the solution is washed with 700 ml of 10 % Na2CO3 at 55... 60 °C. After separation of the layers another 150 ml of sevrene is added and the mixture is washed with 700 mi of water at 55...60 °C. Then 0. 25 g of benzoquinone is added and the product

is distilled under vacuum below 70 °C/50 mbar in order to remove residual water (abouc L3 ml) and a part or serene (about'. 550 ml) from the mixcure.

380gofabout60%D1-solutioninstyrene.Yieldis The structure of the product is confirmed by 1HNMR and GPC.

Alcemadvety DL can be obtained as a viscous oil according co che following procedure Step 3b.

Step 3b. Synthesis of D1

ofthereactionmixturecontainingtheintermediateDI-OHfromstep2i s350.0g warmed up °C.75.0ml(0.80mol)aceticanhydride(AA)isslowlyadded50...55 during 20 min at 50... 70 °C. After the addition, the mixture is stirred at 68... 72 °C for 3 hours. Then, 550 ml of coluene is added co dissolve the product and the

solution is washed with 700 ml of 10 % Na2CO3 at 55...60 °C. After separation of the layers another 150 ml of toluene is added and the mixture is washed with 700 ml of water at 55... 60 °C. Then 0.25 g of benzoquinone is added and the product is distille under vacuum below 70 °C/30 mbar in order to remove residual water (about 10 ml) and toluene (about 700 ml) from the mixture.

Yield is 250 g of D1 (highly viscous oil).

The structure of the product is confirmed by lHNMR and GPC.

Preparation of hyperbranched methacrylated polyesters starting from polyols Example 2 Intermediates II: PGL-OH, DPGL-OH, DD1-OH, TMPA-OH, DTMP-OH and NGL-OH are synthetisized and analyzed in the same way as D1-OH described in Example 1. No intermediate I is isolated and Steps 1 and 2 are combined. Table 1 summarizes average amounts of starting materials used in the synthesis of inter- mediates II.

Table 1 Intermediate II Starting materials PGL-OH DPGL-OH DD1-OH TMPA-OH DTMP-OH NGL-@ Dimethylformamide 300 ml 400 ml 400 ml 400 ml 380 ml 400 m Pentaerythritol 69 g Dipentaerythritol 80 g 50 g Trimethyloylpropane 80 g 50 g Neopentyl glycol 60 g Triethylamine 30 ml 35 ml 40 ml 30 ml 37 ml 35 m Trimellitic anhydride 240 g 235 g 235 g Phthalic anhydride 280 g 300 g 280 g HQ-monomethylether 2 g 2 g 2 g 2 g 1.7 g 2 g Glycidyl methacrylate 300 ml 320 ml 385 ml 300 ml 380 ml 375 m

Final products PGL, PMA, DPGL, DPMA, DD1, DD3, TMPA, TMPM, DTMP, NGL and NMA are synthetisized and analyzed in the same way as Dl described in Example 1, Step 3. Table 2 summarizes the average amounts of starting materials used in the synthesis of the earlier mentioned final products.

The chemical structures of obtained hyperbranched polyesters Dl (mw 2378), DTMP (mw 1815), PGL (mw 1465), PMA (mw 1569), DPGL (mw 2248), DPMA (mw 2404), DD3 (mw 3929), DD1 (mw 3617), NMA (mw 1329), NGL (mw 1225), TMPM (mw 1209) and TMPA (mw 1131) are presented in the follo- wing.

All the processes described above, can easily be scaled up to larger industrial scales with commercial batch sizes.

Table 2 Final product Starting material PGL PMA DPGL DPMA DD1 DD3 TMPA TMPM D1 PGL-OH reaction mixture 250 g 250 g DPGL-OH reaction mixture 250 g 250 g DD1-OH reaction mixture 250 g 350 g TMPA-OH reaction mixture 250 g 350 g DTMP-OH reaction mixture 20 NGL-OH reaction mixture Acetanhydride 44 ml 44 ml 55 ml 43 ml 43 Methacrylic anhydride 70 ml 70 ml 122 ml 95 ml Benzoquinone 0.1 g 0.1 g 0.1 g 0.1 g 0.1 g 0.2 g 0.1 g 0.15 g 0 Toluene 500 ml 500 ml 500 ml 500 ml 500 ml 500 ml 40@ Styrene 700 ml 700 ml 10% Na-carbonate 500 ml 500 ml 500 ml 500 ml 500 ml 700 ml 500 ml 700 ml 400 Yield 169 g 188 g 174 g 189 g 177 g 420 g1) 170 g 415 g1) 142 1)60 % solution in styrene

Example 3 Testing of mechanical properties The mechanical properties of blends of hyperbranched polyesters and unsaturated polyesters are tested from castings prepared as follows: Resin mixture preparation Resin blends are prepared by mixing the unsaturated polyester resin with various amounts of hyperbranched polyesters. The styrene content is 30 % in all blends. The unsaturated 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 mixture of cobalt octoate, dimethyl aniline and methyl hydroquinone) and 1 wt% methyl ethyl ketone peroxide. As a reference, a commercial monomer trimethyloylpropane trimethacrylate is blended with the same polyester in the same way.

Preparation of castings The casting is prepared at room temperature 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.

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 temperature.

The casting is then checked for residual stresses between two Polaroid plastic films, on a light table.

Mechanical testing Specimens for mechanical testing are cut using a machine saw.

After cutting 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 temperature (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.

Heat distortion temperature The heat distortion temperature (HDT = temperature of deflection under load) is measured from specimens cut from the castings, size 10 mm x 110 mm 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 temperature at which the specimen bends is registered as the HDT value.

Results of cured resins containing hyperbranched polyesters are provided in the following Tables 3-15.

Table 3 Resin with D1 A B C D Amount of D1 (wt%) 0 5 10 15 Tensile strength (MPa) 43 48 50 53 Tensile modulus (MPa) 2393263527292778 Tensile elongation (%) 5. 3 3.7 3.7 3. 7 Heat distortion temperature 53 58 64 64 HDT(°C) Table 4 Resin with PGL A B C D Amount of PGL (wt%) 0 5 10 15 Tensile strength (MPa) 52 55 61 59 Tensile modulus (MPa) 2791 2911 3000 3152 Tensile elongation (%) 2.72. 83. 52.9 Bending (mm) 7.89. 310. 28.1 Bending strength (MPa) 112 114 119 122 Bending modulus (MPa) 2684 2680 2690 2929 Heat distorion temperature 63656462 (°C) Table 5 Resin with PMA ABC Amount of PMA (wt%) 0 5 10 15 Tensile strength (MPa) 52 50 54 46 Tensile modulus (MPa) 2917 2931 3108 3161 Tensile elongation (%) 2.6 2.2 2.2 1.7 Bending (mm) 8.3 8.6 6.3 7.9 Bending strength (MPa) 105 107 100 118 Bending modulus (MPa) 2645 2660 2850 2978 Heat distortion temperature HDT 63 66 69 72 (°C) Table 6 Resin with DPGL ABC Amount of DPGL (wt%) 0 5 10 15 Tensile strength (MPa) 52 55 60 54 Tensile modulus (MPa) 2917 2964 3334 3226 Tensile elongation (%) 2.6 2.5 2.82. 2 Bending (mm) 8. 3 8.1 9.2 8.4 Bending strength (MPa) 105 112 116 116 Bending modulus (MPa) 2645 2886 2886 2898 Heat distortion temperature 66706963 (°C) Table 7 Resin with DPMA ABC Amount of DPMA (wt%) 0 5 10 Tensile strength (MPa) 52 50 49 Tensile modulus (MPa) 2917 2952 3058 Tensile elongation (%) 2.6 2. 3 2 Bending (mm) 8.3 7. 2 8.1 Bending strength (MPa) 105 108 115 Bending modulus (MPa) 2645 2783 2852 Heat distortion temperature HDT 65 65 69 (°C) Table 8 Resin with DD1 ABC Amount of DD1 (wt%) 0 5 10 Tensile strength (MPa) 46 46 43 Tensile modulus (MPa) 2560 2604 2588 Tensile elongation (%) 2.9 2.7 2 Bending strength (MPa) 82 86 82 Bending modulus (MPa) 2175 2338 2336 Heat distortion temperature HDT 63 64 67 (°C) Table 9 Resin with DD3 ABCD Amount of DD3 510150 Tensile strength (MPa) 46 46 34 28 Tensile modulus (MPa) 2560 2726 2846 2995 Tensile elongation 2.21.312.9 Bending strength (MPa) 82 78 79 88 Bending modulus (MPa) 2175 2259 2292 2433 Heat distortion temperature HDT 6 65 67 68 (°C) Table 10 Resin with TMPA CAB Amount of TMPA (wt%) 105 Tensile strength (MPa) 46 49 50 Tensile modulus (MPa) 2560 2578 2690 Tensile elongation (%) 2.9 3. 2 3.1 Bending strength (MPa) 82 88 88 Bending modulus (MPa) 175 2401 2410 Heat distortion temperature HDT 63 64 64 Table 11 Resin with TMPM ABC Amount of TMPM (wt%) 0 5 10 15 Tensile strength (MPa) 46 46 47 46 Tensile modulus (MPa) 2560 2657 2801 2880 Tensile elongation (%) 2. 9 2.6 2.2 2. 1 Bending strength (MPa) 82 86 95 95 Bending modulus (MPa) 2175235625092562 Heat distortion temperature HDT 63 65 67 69 (°C) Table 12 Resin with DTMP ABC Amount of DTMP (wt%) 0 5 10 Tensile strength (MPa) 50 53 52 Tensile modulus (MPa) 2501 2667 2546 Tensile elongation (%) 3.9 3. 8 3.4 Bending (mm) 9.4 10.3 10 Bending strength (MPa) 90 98 100 Bending modulus (MPa) 2233 2340 2412 Heat distortion temperature HDT 58 59 63 (°C) Table 13 Resin with NGL ABC Amount of NGL 5100 Tensile strength (MPa) 53 55 51 Tensile modulus (MPa) 2899 3025 2783 Tensile elongation (%) 3. 1 3 2.8 Bending strength (MPa) 89 70 85 Bending modulus (MPa) 2428 1726 2245 Heat distortion temperature HDT 61 64 64 (°C) Table 14 Resin with NMA ABC Amount of NMA (wt%) 0 5 10 Tensile strength (MPa) 53 53 46 Tensile modulus (MPa) 2899 2957 2803 Tensile elongation (%) 3.1 2. 6 2.1 Bending strength (MPa) 89 87 91 Bending modulus (MPa) 2428 1915 2527 Heat distortion temperature HDT 61 62 65 (°C) Table 15 Reference resin containing trimethyloylpropane trimethacrylate (TMPTMA) A B C D Amount of TMPTMA 510150 Tensile strength (MPa) 50 46 34 32 Tensile modulus (MPa) 2830 2967 2961 3045 Tensile elongation (%) 2.4 2 1.3 1.2 Bending (mm) 8.4 7.8 6.8 6.6 Bending strength (MPa) 102 110 103 104 Bending modulus (MPa) 2520 2755 2858 2870 Heat distortion temperature HDT63 66 70 (°C)