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
  • C08G18/08—Processes
• • 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
  • C08G18/08—Processes
  • C08G18/10—Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
  • B01F23/40—Mixing liquids with liquids; Emulsifying
• • 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
  • C08G18/08—Processes
  • C08G18/0838—Manufacture of polymers in the presence of non-reactive compounds
  • C08G18/0842—Manufacture of polymers in the presence of non-reactive compounds in the presence of liquid diluents
  • C08G18/0861—Manufacture of polymers in the presence of non-reactive compounds in the presence of liquid diluents in the presence of a dispersing phase for the polymers or a phase dispersed in the polymers
  • C08G18/0866—Manufacture of polymers in the presence of non-reactive compounds in the presence of liquid diluents in the presence of a dispersing phase for the polymers or a phase dispersed in the polymers the dispersing or dispersed phase being an aqueous medium

Definitions

• This invention relates to an apparatus and process for dispersing isocyanate-terminated polyurethane prepolymers in water.
• Japanese Utility Model Patent No. 1148021 discloses turbine dynamic mixers which are designed to generate axial flow within the vessel.
• a product brochure entitled, "T.K. Homomic Line Flow” from Tokushu Kika Kogyo Co., Ltd, (Osaka, Japan) describes turbine dynamic mixers which are useful for emulsifying, homogenizing and dispersing materials which are transferable by metering feed pumps.
• the mixers are also described as being useful for continuously dissolving several kinds of resin solutions in solvent.
• the reference fails to disclose the use of said mixers for dispersing isocyanate terminated polyurethane prepolymers in water.
• water dispersible isocyanate-terminated polyurethane prepolymers are formed by reacting a stoichiometric excess of polyisocyanate with compounds containing active hydrogen atoms such as polyols and polyamines.
• the prepolymers are dispersed in water using mechanical agitation and then reacted with compounds such as water soluble amines.
• the resulting product is a water-based polyurethane-urea polymer.
• stator- rotor and pin dynamic mixers are designed to rapidly disperse the prepolymers in water using a high energy per unit volume input and short residence times.
• U.S. Pat. No. 4,742,095, Mobay Corporation (Pittsburg, PA) describes stator-rotor and pins dynamic mixers operating at a speed of about 500 revolutions per minute (rpm) to 8,000 ⁇ m, a mixing wattage of about 0.3 watts/cu.cm. to 10.0 watts/cu.cm. and a mixing volume of at least about 0.1 liters.
• the average residence time in said mixers being from about 1 -second to 30-seconds.
• a disadvantage with these dynamic mixers is that reduced residence times may not generate a uniform particle dispersion, and a high energy per unit volume input can cause shear induced destabilization generating increased sedimentation.
• To enhance the performance characteristics of water-based polyurethane-urea polymers it is often necessary to form isocyanate- terminated polyurethane prepolymers which are characterized as having increased hydrophobicity, crystallinity and viscosities. Such prepolymers are not easily dispersed in water, require extended residence times, and lower energy per unit volume input to generate uniform particle dispersions which are substantially free of sedimentation.
• the present invention is directed to an apparatus and process for dispersing isocyanate-terminated polyurethane prepolymers in water.
• the apparatus comprises: a) at least one reaction vessel containing a water dispersible NCO- terminated polyurethane prepolymer which is the reaction product of;
• At least one polyol and/or polyamine component which may be substituted with at least one hydrophilic moiety
• at least one supply vessel containing at least one compound such as water, organic materials and inorganic materials
• at least one dynamic mixer which has a pitched blade turbine within a draft tube to generate axial flow, configured to provide:
• the invention is further characterized by a process for dispersing NCO-terminated polyurethane prepolymers, comprising the steps of: a) combining an aqueous solution of organic and inorganic ingredients with at least one water dispersible isocyanate- terminated polyurethane prepolymer to form a materials mixture; b) feeding the materials mixture into at least one axial flow dynamic mixer and utilizing a dispersing process comprising;
• the inventive apparatus and process generates uniform prepolymer dispersions using extended residence times and lower energy per unit volume input.
• Figure 1 is a side fragmentary view, in partial cross-section, of a axial flow dynamic mixer used in the apparatus and process of the invention.
• Figure 2 is a schematic diagram of an apparatus ofthe invention.
• the present invention is directed to an apparatus and process for dispersing NCO-terminated polyurethane prepolymers.
• the apparatus is a turbine mixer which has a pitched blade turbine within a draft tube.
• the turbine mixers which generate axial flow within the mixing vessel, can be configured to provide a lower energy per unit volume, extended residence times and multiple passes through the mixing zone.
• Such mixers have proven useful for processing prepolymers which are difficult to disperse in water.
• Suitable dynamic mixers are commercially available from Tokushu Kika Kogyo Co., Ltd., Osaka, Japan under the product name T.K. Homomic Line Flow.
• Such mixers can be configured to provide:
• a mixing zone volume greater than from about 0.1 liters; 2) a tip speed of about 100 meters/min. to about 5,000 meters/min., and more preferably from about 250 meters/min. to about 1500 meters/min.;
• a power per unit volume input from about 0.01 watts/cu.cm. to about 0.60 watts/cu.cm., and more preferably from about 0.10 watts/cu.cm. to about 0.30 watts/cu.cm.;
• an average residence time from about 10-seconds to about 120- seconds, and more preferably from about 10-seconds to about 60-seconds;
• the average residence time and the average number of passes through the mixing zone can be varied with the material feed rates and the tip speed. If desired, greater quantities of dispersion may be produced per unit time by using more than one mixer at a time.
• FIG. 1 illustrates a dynamic mixer ofthe type used in the apparatus and process ofthe invention.
• the mixer includes a motor 12 mounted to a motor base 14 which is connected to a bearing case 16.
• the bearing case 16 mounts the motor on the vessel lid 18.
• a mixing vessel 20 is removably mounted to lid 18.
• Pitched blade turbine 26 and draft tube 28 define a mixing zone.
• the blade is mounted to a shaft 32 operatively connected to the motor shaft via a mechanical seal 34.
• the vessel is double chambered having a central mixing chamber 21 , a recirculation zone 22 and a smaller annular exit chamber 24.
• An inlet 36 provides feed access to the mixing chamber 21 while outlet 38 provides for exit ofthe dispersed product emerging from the mixing chamber.
• the direction of flow is indicated by the arrows. Material entering the vessel via inlet 36 is directed through the mixing zone 21 and cycles through the draft tube 28 and the recirculation zone 22 in an axial flow. The dispersed material exits from the recirculation zone through outlet 38.
• FIG. 2 is a schematic representation of an apparatus in accordance with the invention.
• a water dispersible isocyanate-terminated polyurethane prepolymer is prepared in reaction vessel 100 and fed via metering pump 110 into dynamic mixer 300.
• the contents of supply vessel 200 is fed to mixer 300 via meter pump 210, which joins conduit 1 10 to provide a single feed line into mixer 300.
• the prepolymer dispersion exiting mixer 300 is fed via conduit 310 to a stirred finishing vessel 500.
• the contents of supply vessel 400 can be added to the dispersion in several locations.
• the supply vessel contents can be fed into the mixing vessel 300 via meter pumped conduit 410 or into conduit 310 via meter pumped conduit 420 or into the finishing vessel 500 via meter pumped conduit 430.
• supply vessel 400, conduit 410, 420 and 430 can be omitted.
• the prepolymer dispersion is stirred to complete the isocyanate reaction and form a water-based polyurethane-urea polymer.
• At least one reaction vessel is used in the apparatus and process ofthe invention. If desired, multiple reaction vessels may be used. Such vessels may contain isocyanate-terminated polyurethane prepolymers of different composition.
• At least one axial flow turbine mixer which is mounted in a draft tube, is used in the invention.
• the term "draft tube” refers to an open cylinder which separates the mixing zone from the recirculation zone. The draft tube generates axial flow and allows recirculation through the mixing vessel. If desired, multiple mixers may be used to disperse large quantities of prepolymer thus increasing the total volume of dispersion produced per unit time.
• At least one supply vessel is used.
• the vessel contains at least one component which may include amines, antioxidants, biocides, coalescing aids, coloring agents, defoamers, dispersed pigments, emulsifiable waxes, fillers, fire retardant agents, fungicides, ionic and/or nonionic emulsifiers, natural polymer dispersions, non-polyurethane based emulsifiable synthetic resins, organic co-solvents, perfume-like materials, plasticizers, sequestering agents, UV stabilizers, water, wetting agents and their mixtures.
• component may include amines, antioxidants, biocides, coalescing aids, coloring agents, defoamers, dispersed pigments, emulsifiable waxes, fillers, fire retardant agents, fungicides, ionic and/or nonionic emulsifiers, natural polymer dispersions, non-polyurethane based emulsif
• the isocyanate-terminated polyurethane prepolymers and the supply vessel contents can be transferred using metering pumps which may include centrifugal pumps, diaphragm pumps, gear pumps, piston pumps, peristaltic pumps, progressive cavity pumps, lobe pumps, screw pumps and vane pumps.
• metering pumps which may include centrifugal pumps, diaphragm pumps, gear pumps, piston pumps, peristaltic pumps, progressive cavity pumps, lobe pumps, screw pumps and vane pumps.
• said materials may be transferred using gravity feed and/or compressed gasses including nitrogen which may require the use of control valves.
• a conduit system comprising pipes or tubes is used to channel the materials throughout the apparatus of the invention.
• At least one finishing vessel is used and is preferably equipped with mechanical agitation. Also, multiple finishing vessels may be used to react the prepolymer dispersions with dissimilar compounds having active hydrogen atoms. Such a process is used to generate water-based polyurethane-urea polymers which differ in composition.
• isocyanate- terminated polyurethane prepolymers having properties such as increased hydrophobicity, crystalinity and viscosity.
• examples include the hydrophobic prepolymers described in U.S. Pat. No. 5,354,807 (H.B. Fuller Company) and the crystalline polymers described in copending application Serial No. 08/528936, incorporated herein by reference.
• Said prepolymers can have viscosities ranging from about 10,000 m.Pas to about 100,000 m.Pas, and more preferably from about 15,000 m.Pas to about 50,000 m.Pas.
• prepolymers are more likely to develop a uniform particle dispersion when extended residence times and lower energy per unit volume inputs are utilized.
• the prepolymers are prepared by reacting a stoichiometric excess of polyisocyanate with at least one polyol and/or polyamine compound which may be substituted with at least one hydrophilic moiety.
• the materials can be
• the percent isocyanate, present in the finished prepolymer can be in a range from about 1.0% by weight to about 15.0% by weight, and more preferably from about 4.0% by weight to about 8.0% by weight, based on total prepolymer solids.
• the prepolymers are preferably dispersed using distilled and/or deionized water.
• the water temperature is greater than 0°C and preferably in a range from about 5°C to about 100°C, and more preferably from about 25°C to about 50°C.
• the water-based polymers ofthe present invention can have a solids content in the range from about 20.0% by weight to about 80.0% by weight, and preferably from about 30.0% by weight to about 50.0% by weight.
• the dispersion may be charged with the contents of a second supply vessel, which may contain de-ionized water and water soluble amines, to form a dispersion mixture.
• Said mixture may or may not be agitated and can be reacted at a temperature from about 5°C to about 100°C, and preferably from about 25°C to about 65°C.
• compositions is illustrative ofthe types of dispersible products which are advantageously prepared using the apparatus and process ofthe present invention. Those skilled in the art will recognize that alternative products may be formed using other reactants.
• the polyisocyanates may be linear aliphatic, cyclic aliphatic, aromatic, and mixtures thereof.
• the polyisocyanate is preferably a mixture including hindered polyisocyanate and non-hindered polyisocyanate.
• hindered polyisocyanate is defined as an isocyanate moiety which is less sensitive to the water-isocyanate reaction due to the proximity of adjacent aliphatic character.
• the hindered polyisocyanate may be present in the polyisocyanate mixture in a range from about 1 part to about 95 parts, and more preferably from about 25 parts to about 75 parts, based on 100 parts total polyisocyanates.
• Examples of commercially available hindered polyisocyanates include Vestanat IPDI which is 3-isocyanatomethyl-3,5,5- trimethylcyclohexyl isocyanate from HULS America, Inc. (Piscataway, NJ)
• JO and TMXDI which is 1,3-bis (1-isocyanato-l-methylethyl) benzene from Cyanamid (Wayne, NJ).
• non-hindered polyisocyanates include Luxate HM which is 1 ,6-hexamethylene diisocyanate from Olin Co ⁇ oration (Stamford, CT), diphenylmethane diisocyanate from Upjohn Polymer chemicals (Kalamazoo, MI), Desmodur ® W which is Dicyclohexylmethane- 4,4' -diisocyanate from Mobay Co ⁇ oration (Pittsburgh, PA) and toluene diisocyanate (TDI).
• Luxate HM which is 1 ,6-hexamethylene diisocyanate from Olin Co ⁇ oration (Stamford, CT)
• diphenylmethane diisocyanate from Upjohn Polymer chemicals (Kalamazoo, MI)
• Desmodur ® W
• the presence of a hindered polyisocyanate is preferred in the process ofthe invention. It is surmised such sterically hindered polyisocyanates are less likely to be completely reacted during prepolymer synthesis.
• the resulting isocyanate-terminated polyurethane prepolymers which are less sensitive to the isocyanate/water reaction, can be dispersed in water allowing further reaction with amines. If desired, the water dispersible isocyanate-terminated polyurethane prepolymers may be subjected to complete hydrolysis.
• Such prepolymers which are preferably based on sulfonate character, generate polyurethane-urea polymers having enhanced properties such as water- resistance and heat resistance and are described in the above mentioned copending application Serial No. 08/528936.
• polyisocyanates which may be used include modified polyisocyanates prepared from hexamethylene diisocyanate, isophorone diisocyanate and toluylene diisocyanate.
• the modified diisocyanates can have functionalities such as urethanes, uretdiones, isocyanurates, biurets and mixtures thereof.
• Examples of small molecular weight polyols which may be used in the preparation ofthe water dispersible isocyanate-terminated polyurethane prepolymers can have hydroxyl numbers, as determined by ASTM designation E-222-67 (Method B), in a range from about 130 to about 1250, and preferably from about 950 to about 1250.
• Examples of preferred small molecular weight polyols include trimethylolpropane, diethylene glycol, 1 ,4-butanediol, 1,6- hexanediol, glycerol and the aliphatic diols described in U.S. Pat. No. 5,039,732, Sherwin-Williams Company (Baltimore, MD), inco ⁇ orated herein by reference.
• the prepolymer of the invention may be rendered water dispersible by the chemical inco ⁇ oration of anionic moieties, non-ionic moieties, cationic moieties and mixtures thereof.
• Anionic polyurethane-urea polymers are preferred and prepolymers containing a combination of sulfonate and carboxylate groups are most preferred.
• Examples of ionic moieties which may be inco ⁇ orated into the prepolymer include dimethylopropionic acid and 1 ,4- dihydroxybutane sulfonic acid described in U.S. Pat No. 3,412,054 and U.S. Pat No. 4,108,814, inco ⁇ orated herein by reference.
• the anionic groups can be neutralized with bases such as alkali metal hydroxides, organic tertiary amines, ammonia and mixtures thereof. Conversion ofthe anionic groups to ionic groups (salts) may be accomplished before, during or after the prepolymer has been dispersed in water.
• Polymeric diols used in the preparation of the prepolymers can have hydroxyl numbers, as determined by ASTM designation E-222-67 (Method B), in a range from about 20 to about 140, and preferably from about 55 to about 110.
• the polymeric polyols can have melting temperatures from about 10°C to about 200°C, and more preferably from about 25°C to about 95°C.
• the polyols can be selected from the group consisting of polyester polyols, polyether polyols, polycarbonate polyols, polyurethane polyols, polyacetal polyols, polyacrylate polyols, polycaprolactone polyols, polyesteramide polyols, polythioether polyols, and mixtures thereof.
• the preferred polymeric polyols are those described in the above mentioned copending application Serial No. 08/528936 and U.S. Pat No. 5,334,690 (Hoechst Aktiengesellschaft,
• the inventive process generates water-based polyurethane-urea polymers which are characterized as having enhanced properties including heat and water resistance. Said process is also useful in the preparation of water-based polyurethane-urea polymer blends and hybrids containing polyacrylic and/or polyvinyl polymers. Examples include the compositions described in copending U.S. application 08/561 197, filed November 21 , 1995, H.B. Fuller Company (St. Paul, MN) inco ⁇ orated herein by reference.
• Example 1 describes the preparation of a highly crystalline water-based polyurethane-urea polymer.
• Rucoflex XS-5483-55 which is a sulfonated polyester polyol from Ruco Polymer Co ⁇ oration (Hicksville, NY), 2.13 kgs. (15.9 hydroxyl equivalence) dimethylolpropionic acid, 2.39 kgs. (53.0 hydroxyl equivalence) 1 ,4-butanediol, 6.60 kgs.
• the mixture was mildly agitated and heated to 70°C for approximately 2.5-hours then charged with 1.27 kgs. triethylamine and stirred an additional 15-minutes before dispersing.
• the prepolymer (80°C) and de-ionized water (60°C) were combined in ⁇ line and transferred to a T.K. Homonic Line Flow model 100S axial flow dynamic mixer from Tokushu Kika Kogyo Co., Ltd. (Osaka, Japan).
• the prepolymer was transferred from the reaction vessel using a gear pump set at a rate of 3.60 kgs. per minute while the water was transferred from a supply vessel using a progressive gravity pump set at a rate of 6.40 kgs. per minute.
• the mixer was configured to provide an average residence time of 61 -seconds using a shaft speed of 3,600 ⁇ m and a tip speed of 1,000 meters/min.
• the dispersion was transferred to a finishing vessel equipped with a turbine agitator and run at a circulation rate of about 10 min ' for approximately 20 minutes.
• a mixture containing ethylene diamine in de-ionized water was charged.
• the dispersion was stirred an additional 30-minutes at 60°C to generate a water-based polyurethane-urea polymer.
• Viscosity 40 m.Pas
• Example 2 describes the preparation of a hydrophobic water-based polyurethane-urea polymer.
• Rucoflex S-l 02-10 which is a polyester polyol from Ruco
• the pre-prepolymer was charged with 6.60 kgs. (47.0 amine equivalence) Tomah -14 which is isodecyloxypropyl-l,3-diaminopropane from Tomah Products (Milton, WI).
• the amine was charged to the reactor over a 1- hour period keeping the temperature below 90°C.
• the prepolymer which had a viscosity of approximately 15,000 m.Pas at 90°C, was processed as similarly described in Example 1. The exception being the prepolymer was metered at 4.4 kgs./min., the water (62°C) was metered at a rate of 7.0 kgs./min., the turbine tip speed was 1,000 meters/sec. and the average residence time was 53-seconds.
• the dispersion was transferred to a finishing vessel equipped with a turbine agitator and run at a circulation rate of about 10 min ' for approximately 20-minutes.
• a chain extender solution consisting of 12.65% diethylene triamine, 39.62% ethylene diamine and water.
• the dispersion was stirred an additional 30-minutes to generate a water-based polyurethane-urea polymer.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Health & Medical Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Dispersion Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Polyurethanes Or Polyureas (AREA)
• Mixers Of The Rotary Stirring Type (AREA)
• Processes Of Treating Macromolecular Substances (AREA)

Applications Claiming Priority (5)

Publications (1)

Family

ID=27062890

Family Applications (1)

Country Status (11)

Families Citing this family (5)

Family Cites Families (1)

• 1996
  • 1996-09-11 JP JP9512029A patent/JPH10506433A/ja active Pending
  • 1996-09-11 CN CN96191055A patent/CN1165526A/zh active Pending
  • 1996-09-11 BR BR9606647A patent/BR9606647A/pt unknown
  • 1996-09-11 NZ NZ318635A patent/NZ318635A/en unknown
  • 1996-09-11 MX MX9703541A patent/MX9703541A/es unknown
  • 1996-09-11 AU AU70164/96A patent/AU688695B2/en not_active Ceased
  • 1996-09-11 CA CA002203880A patent/CA2203880A1/en not_active Abandoned
  • 1996-09-11 WO PCT/US1996/014445 patent/WO1997010273A1/en not_active Application Discontinuation
  • 1996-09-11 EP EP96931499A patent/EP0792303A1/de not_active Withdrawn
• 1997
  • 1997-05-15 KR KR1019970703272A patent/KR970707195A/ko not_active Application Discontinuation
  • 1997-05-15 EA EA199700051A patent/EA199700051A1/ru unknown

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events