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
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/65—Low-molecular-weight compounds having active hydrogen with high-molecular-weight compounds having active hydrogen
  • C08G18/66—Compounds of groups C08G18/42, C08G18/48, or C08G18/52
  • C08G18/6603—Compounds of groups C08G18/42, C08G18/48, or C08G18/52 with compounds of group C08G18/32 or polyamines of C08G18/38
  • C08G18/6607—Compounds of groups C08G18/42, C08G18/48, or C08G18/52 with compounds of group C08G18/32 or polyamines of C08G18/38 with compounds of group C08G18/3203
• • 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
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/65—Low-molecular-weight compounds having active hydrogen with high-molecular-weight compounds having active hydrogen
  • C08G18/66—Compounds of groups C08G18/42, C08G18/48, or C08G18/52
  • C08G18/6633—Compounds of group C08G18/42
  • C08G18/6637—Compounds of group C08G18/42 with compounds of group C08G18/32 or polyamines of C08G18/38
  • C08G18/664—Compounds of group C08G18/42 with compounds of group C08G18/32 or polyamines of C08G18/38 with compounds of group C08G18/3203
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B9/00—Making granules
  • B29B9/02—Making granules by dividing preformed material
• • 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
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/42—Polycondensates having carboxylic or carbonic ester groups in the main chain
  • C08G18/4236—Polycondensates having carboxylic or carbonic ester groups in the main chain containing only aliphatic groups
  • C08G18/4238—Polycondensates having carboxylic or carbonic ester groups in the main chain containing only aliphatic groups derived from dicarboxylic acids and dialcohols
• • 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
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
  • C08G18/72—Polyisocyanates or polyisothiocyanates
  • C08G18/74—Polyisocyanates or polyisothiocyanates cyclic
  • C08G18/76—Polyisocyanates or polyisothiocyanates cyclic aromatic
  • C08G18/7657—Polyisocyanates or polyisothiocyanates cyclic aromatic containing two or more aromatic rings
  • C08G18/7664—Polyisocyanates or polyisothiocyanates cyclic aromatic containing two or more aromatic rings containing alkylene polyphenyl groups
  • C08G18/7671—Polyisocyanates or polyisothiocyanates cyclic aromatic containing two or more aromatic rings containing alkylene polyphenyl groups containing only one alkylene bisphenyl group

Definitions

• the present invention relates to a hydrophobic thermoplastic polyurethane (TPU) which has increased clarity and reduced haze.
• TPU thermoplastic polyurethane
• the hydrophobic TPUs of this invention have lower specific gravity than normal commercial hydrophilic TPU.
• the TPUs of this invention have several uses in molding and extrusion processes to make a wide variety of products, including products for medical applications.
• TPU thermoplastic polyurethane
• a hydroxyl terminated polyether or hydroxyl terminated polyester a chain extender, such as a short chain diol
• an isocyanate compound a chain extender, such as a short chain diol
• US 2009/0192262 Al discloses a hydrophobic TPU which uses a polyester polyol made with a dimerized fatty acid.
• the TPUs made in US 2009/0192262 Al are opaque.
• US 2010/0056682 Al also discloses a hydrophobic TPU which uses a polyester polyol made with a dimerized fatty acid and mineral oil as an additive to the TPU.
• the TPUs made in US 2010/0056682 are also opaque.
• hydrophobic polyol is a diacid polyester polyol made with a dimerised fatty acid containing from 26 to 44 carbon atoms;
• At least one branched diol chain extender having from 8 to 12 carbon atoms and wherein at least 2 carbon atoms of said branched chain extender are in the branch, wherein the weight ratio of said linear chain extender to said branched chain extender is from about 70:30 to about 85:15;
• the hydrophobic polyol is made with a dimerised fatty acid containing 36 carbon atoms reacted with 1,6 hexane diol to provide a hydroxyl terminated polyester polyol.
• the linear diol chain extender is 1,12-dodecane diol (12 carbon atom). It is preferred to use 2-butyl-2-ethyl propane diol and/or 1,4-cyclohexane dimethanol as the branched diol chain extender. A blend of two or more branched chain extenders may be used.
• the diisocyanate used is 4,4'-methylene bis-(phenyl isocyanate).
• a urethane catalyst is used for the softer grades of TPU, such as from 70-90 Shore A hardness. For harder grades of TPU, such as 91 to 98 Shore A hardness, a catalyst is not desired.
• the hydrophobic TPUs of this invention have low specific gravity (lower than typical TPUs) of from about 0.90 to about 1.10 g/cc, and preferably from about 0.95 to about 1.07 g/cc.
• the process to make the hydrophobic TPU of this invention can be any of the normal processes to make a TPU.
• the most common types of processes are the one- shot process where the reactants are fed to a twin screw extruder and the reaction occurs in the extruder.
• the most preferred process is a batch process where the at least two chain extenders (linear chain extender and branched chain extender) are mixed together and heated to form a clear homogenous liquid mixture.
• hydrophobic polyol is added to the reaction vessel and the heated chain extender mixture is added to the reaction vessel and mixed with the polyol.
• the diisocyanate is added to the reaction vessel to form the reaction mixture and the reaction is allowed to proceed for about 1 to about 3 minutes.
• the reaction temperature reaches a temperature of from 80°C to 100°C and the reaction mixture is still in a pourable state, the reaction mixture is transferred to a container and the container containing the reaction mixture is transferred into a heated oven to complete the reaction.
• the oven is usually heated to a temperature of from about 120°C to about 130°C and the reaction is complete in 3 to 5 hours.
• hydrophobic TPUs of the invention are used in products where increased clarity is desired, such as medical applications, especially medical applications which have exposure to body fluids.
• the processes, polymers and compositions of the present invention may suitably comprise, consist of, or consist essentially of the reactants, process steps and process delineations described herein.
• the invention illustratively disclosed herein may be practiced in the absence of any reactant or process step which is not specifically disclosed herein.
• the first necessary reactant to make the TPU composition of this invention is at least one hydroxyl terminated hydrophobic polyol.
• the hydrophobic polyol is made from a dimerized fatty acid or esters thereof.
• the dimerized fatty acid contains from 26 to 44 carbon atoms preferably 36 carbon atoms.
• the dimerized fatty acid is reacted with a short chain diol to create the hydroxyl terminated hydrophobic polyol.
• Dimer fatty acids are a well known commercially available class of dicarboxylic acids (or esters). They can, for example, be prepared by dimerising unsaturated long chain aliphatic monocarboxylic acids, usually of 13 to 22 carbon atoms, or their esters (alkyl esters). The dimer fatty acid will usually contain from 26 to 44 carbon atoms, preferably 36 to 44 carbon atoms, and most preferably 36 carbon atoms. Dimer fatty acids derived from Ci 8 unsaturated acids, which include linoleic and lindenic are particularly desirable to produce C 36 dimer fatty acids.
• the dimer fatty acids will normally also contain proportions of trimer fatty acids (C 54 acids when using Ci 8 starting acids), possibly even higher oligomers and also small amounts of the monomer acids.
• trimer fatty acids C 54 acids when using Ci 8 starting acids
• oligomers C 54 acids when using Ci 8 starting acids
• monomer acids Several different grades of dimer acids are available from commercial sources and these differ from each other primarily in the amount of monobasic and trimer acid fractions and the degree of unsaturation.
• PriplastTM polyester polyols are branched C 36 dimerized fatty acids which are particularly useful as the hydrophobic polyol of this invention.
• PriplastTMpolyols are commercially available from Croda Uniqemna Inc. of Gouda, The Netherlands.
• the hydrophobic polyol used in synthesizing the TPUs of this invention will typically have a number average molecular weight in the range of about 1,000 to about 8,000 Daltons, preferably from about 1,500 to about 4,000, and more preferably have a number average molecular weight of from about 2,000 to about 3,000 Daltons.
• the dimerized fatty acid is reacted with a short chain diol.
• Short chain diols having from 2 to 12 carbon atoms are used, with 1,6-hexane diol being the most preferred.
• the second necessary ingredient to make the enhanced clarity hydrophobic TPUs of this invention is a chain extender mixture having at least two chain extenders.
• the first chain extender used in the chain extender mixture is at least one linear diol chain extender having from 10 to 14 carbon atoms, preferably 12 carbon atoms. 1,12- dodecane diol is the preferred linear chain extender.
• the use of the linear chain extender as the only chain extender gives good physical properties but is not clear.
• a second chain extender is required in the chain extender mixture to improve clarity and reduce haze.
• the second chain extender used in the chain extender mixture is a branched diol chain extender having from 8 to 12 carbon atoms, with at least 2 of the carbon atoms in the branch.
• the preferred branched diol chain extenders are 2-butyl-2 ethyl propane diol and 1,4-cyclohexane dimethanol, and mixtures thereof.
• the use of the branched diol chain extender as the only chain extender gives good clarity but is not stable and results in a sticky TPU, which is not desirable.
• the preferred linear chain extender 1, 12-dodecane diol (DDO)
• DDO 1, 12-dodecane diol
• the melting point of DDO is too high of a temperature to start the batch process reaction, because there would not be enough time to thoroughly mix the reactants before the reactants become too thick to transfer out of the reaction vessel.
• a branched chain extender such as 2-butyl-2-ethyl propane diol (BEPD), which has a melting point of from 45-50°C, is added to the DDO chain extender. This causes the chain extender mixture to be liquid at less than about 70°C, and preferably less than 65°C. This allows the batch process reaction to be started at from about 63-68°C and thus allows for enough time to mix the reactants before the reaction becomes too thick to pour out of the reaction vessel into the container.
• BEPD 2-butyl-2-ethyl propane diol
• the weight ratio of the linear chain extender to the branched chain extender is from about 70:30 to about 85:15, preferably about 75:25 weight ratio. Weight ratio outside the range stated above do not give acceptable TPUs having improved clarity, reduced haze, and stable polymers (not sticky).
• the at least two chain extenders used are miscible at less than 90°C.
• the linear chain extender is not a liquid at room temperature, but when heated to its melting point ( ⁇ 90°C) in the presence of the branched chain extender a miscible liquid is obtained.
• the third necessary reactant to make the increased clarity hydrophobic TPUs is at least one diisocyanate.
• Suitable diisocyanates include aromatic diisocyanantes such as : 4,4'-methylene bis-(phenyl isocyanate) (MDI), M-xylene diisocyanate (XDI), phenylene-1, 4-diisocyanate, naphthalene-l,5-diisocyanate, diphenylmethane-3,3'- dimethoxy-4,4'-diisocyanate, and toluene diisocyanate (TDI); as well as aliphatic diisocyanates such as isophorone diisocyanate (IPDI), 1,4-cyclohexyl diisocyanate (CHDI), decane-l,10-diisocyyanate, and dicyclohexylmethane-4,4'-diisocyanate. Dimers and trimers of the above
• the diisocyanates used in this invention may be in the form of a low molecular weight polymer or oligomer which is end capped with an isocyanate.
• the hydroxyl terminated dimerized fatty acid polyol described above may be reacted with the diisocyanate to create a low molecular weight polymer end capped with isocyanate.
• such materials are normally referred to as pre- polymers.
• Such pre-polymers normally have a number average molecular weight of from about 1,500 to about 10,000 Daltons. It is preferred to use the diisocyanate directly, rather than a pre-polymer.
• the hydrophobic TPU polymers of this invention will preferably have a durometer hardness of from 70 to 98 Shore A as measured according to ASTM D2240, and mole preferably from 75 to 95 Shore A.
• the hardness can also be measured on a Shore D scale. Shore D is usually used for harder materials and the Shore D value is usually about 50 points less than the Short A value. For example, a 90 Shore A would be about 40 Shore D. This correlation does not hold well at the extremes of the scale, such as a 98 Shore A.
• the TPU polymers of this invention also have a specific gravity lower than normal hydrophilic TPU. The specific gravity will be from about 0.90 to about 1.10 g/cc, preferably from about 0.95 to about 1.07 g/cc.
• PriplastTM 3196 is a 3000 MW C 36 dimer fatty acid reacted with 1,6-hexane diol.
• PriplastTM 1838 is a 2000 MW C 36 dimer fatty acid reacted with 1,6-hexane diol.
• 3 DDO is 1,12 dodecane diol.
• Example 5 the TPU was too sticky and could not be further processed.
• Example 11 a 50/50 weight mixture of BEPD/DDO was used as the chain extender. A lower start temperature of the TPU reaction was realized due to the BEPD lowering the melting temperature of the chain extender mixture. The TPU was homogenous and semi-clear in appearance.
• Examples 12, 13, and 14 are examples of the present invention where a low reaction start temperature is required for a batch process and a clear TPU product, that is not sticky, is desired.
• Examples 12, 13 and 14 were repeated in a production facility with a batch size of 150 pounds, which are shown below as Examples 15, 16, and 17. All three examples use a 25:75 weight ratio mixture of BEPD/DDO for the chain extender mixture. MDI was used as the diisocyanate at a stoichiometry of 1.0. The TPU produced was measured for physical properties, as shown in Table 2 below.
• the PriplastTM polyol is a thick viscous liquid at room temperature and is heated to about 85°C to make it easier to pour and weigh.
• the polyol is added to the reactor. Small amounts of antioxidant can be added to the polyol if desired while mixing.
• the hot (about 100°C) chain extender is then poured into the reactor vessel and mixed for 1 minute using a mixer set at 900 rpm. While mixing, MDI is added. MDI is also a solid at room temperature but melts at 37°C. A drum of MDI is melted and used at 55°C.
• melt index 3 to 4 grams of pellets are put in a small mesh bag and dried for at least 4 hours at 200°F. Melt index is determined using a plastometer.
• the plastometer is a furnace with a capillary die at the bottom. The furnace and the die are heated to 200°C. The pellets are then fed to the furnace and pushed through the die using a 8700g load. Melt index (Ml) is obtained in grams/10 minutes.
• Durometer of the TPU is determined by injection molding bars per ASTM D2240. Durometers are measured after 5 days.
• Examples 18-20 in Table 3 used a laboratory batch process similar to Examples 1-14 above. Examples 18 and 19 are examples of this invention, whereas Example 20 is a comparative example.
• % haze was measured using a BYK-Gardner Haze-Gard Plus meter. All samples were 250 mil (0.25 in.) in thickness. The sample is placed in the path of the sample beam on the haze meter, the start button is pushed, and the % transmission haze is recorded to the nearest 1%.
• the meter is the industry standard and follows ASTM D1003 in design. The meter has an internal reference beam to compare to the sample beam.
• Example 18 a chain extender mixture of 85 wt. % DDO and a 15 wt. % CHDM was used. The TPU produced was clear and had a low haze value of 37.2%.
• Example 19 a chain extender mixture of 80 wt. % DDO and a 20 wt. % CHDM was used.
• the TPU produced was clear and had a low haze value of 44.0%.
• Example 20 a chain extender mixture of 87 wt. % DDO and a 13 wt. % of CHDM was used.
• the TPU was fairly opaque and not clear and had a haze value of 81.1%.

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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)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Polyurethanes Or Polyureas (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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• 2014
  • 2014-02-03 US US14/765,657 patent/US20150368392A1/en not_active Abandoned
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  • 2014-02-03 WO PCT/US2014/014373 patent/WO2014121174A1/en not_active Ceased
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