JPH11507405A - Hydrophilic end-capped polyurethane thickener - Google Patents

Abstract

  (57) [Summary] The present invention relates to polyurethane thickeners containing the reaction products of isocyanate-functional materials, polyether polyols and hydrophilic bifunctional endcapping materials which react with isocyanates, and in particular for use in paints and coatings.

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to hydrophilically end-capped polyurethane thickeners used in particular in paints, coatings and other aqueous systems. . Thickeners have long been known for use in paints and coatings. The thickener may be natural or synthetically produced. Examples of natural thickeners include alginates, casein, karaya gum, locust bean gum, cellulosic materials such as methylcellulose, hydroxyethylcellulose and hydroxypropylmethylcellulose. Examples of synthetic thickeners include U.S. Patent 4,079,028 (Emmons et al.), U.S. Patent 4,180,491 (Kim et al.), U.S. Patent 4,327,008 (Schimmel et al. U.S. Pat. No. 4,373,083 (Seiner et al.), U.S. Pat. No. 4,426,485 (Hoy et al.), U.S. Pat. No. 4,436,862 (Tetenbaum et al.), U.S. Pat. 708 (Dehm et al.) And US Pat. No. 4,514,552 (Shay et al.). U.S. Pat. No. 4,079,028 is intended to teach a latex system containing a low molecular weight polyurethane thickener characterized by at least three hydrophobic groups interconnected by hydrophilic polyether groups. . U.S. Pat. No. 4,180,491 is intended to teach a nonionic polyurethane thickener for paint pastes, the thickener being linked by a molecular weight of at least 10,000 and a hydrophilic polyether fragment. It has at least three hydrophobic branched groups. U.S. Pat. No. 4,327,008 is intended to teach rheology modifiers used in water-based and organic solvent-based compositions, the regulators being polyalkylene oxides, polyfunctional materials (e.g., , Polyols, amines, amine alcohols, thiols or polyisocyanates), diisocyanates, water and monofunctional active hydrogen-containing compounds or monoisocyanates. U.S. Pat. No. 4,373,083 is intended to teach a method of making rheology modifiers (particularly U.S. Pat. No. 4,079,028) for use in water and organic solvent based compositions. Are obtained by the reaction of polyalkylene oxides, polyfunctional substances (eg, polyols, amines, amine alcohols, thiols or polyisocyanates), diisocyanates, water and endcapping compounds in organic solvents. U.S. Pat. No. 4,426,485 is intended to teach a water-soluble thickener for aqueous systems characterized by a deliberately arranged group of hydrophobic substances attached to a water-soluble backbone. ing. U.S. Pat. No. 4,436,862 is intended to teach a thickener composed of a clay stabilizer and a water-dispersible polyurethane. U.S. Pat. No. 4,496,708 is intended to teach a water soluble comb polyurethane thickener having a hydrophilic polyether backbone and monovalent hydrophobic side groups. U.S. Pat. No. 4,514,552 discloses a non-ionic reaction product of an a, b-monoethylenically unsaturated carboxylic acid, a monoethylenically unsaturated monomer (e.g., ethyl acrylate), a monovalent surfactant and a monoisocyanate. It is intended to teach an alkali-soluble thickener, which is an aqueous emulsion copolymer of a water soluble urethane monomer and any polyethylene unsaturated monomer. In contrast to the above, the present invention relates to hydrophilic end-capped polyurethane thickener compositions, particularly suitable for use in paint and coating compositions. While all of the above patents teach the use of hydrophobic endcapping groups to increase the effectiveness of the thickener, the present invention utilizes hydrophilic end groups. SUMMARY OF THE INVENTION As noted above, the present invention is directed to a hydrophilic end-capped polyurethane thickener composition. In particular, the composition of the present invention comprises: (1) an isocyanate-functional material, preferably a diisocyanate; (2) a polyether polyol, preferably a polyalkylene oxide such as polyethylene glycol having a molecular weight of about 1000 to about 20,000; And (3) the reaction product of a hydrophilic bifunctional endcapping material that reacts with isocyanate groups, preferably a C4-C20 linear diol having a hydroxy group located at or near the end of the diol chain. The compositions of the present invention can be linear, branched, comb or other composite structures, with linear compositions being preferred. The compositions of the present invention are excellent thickeners and rheology modifiers. These compositions are characterized by hydrophilic endcaps that have a precise and desirable effect on their rheological control performance. DETAILED DESCRIPTION OF THE INVENTION As noted above, the composition of the present invention is a hydrophilically modified polyurethane thickener, comprising: (1) an isocyanate functional material, preferably a diisocyanate; (2) a polyether polyol, preferably A polyalkylene oxide such as polyethylene glycol having a molecular weight of about 1000 to about 20,000, and (3) a hydrophilic bifunctional endcapping material that reacts with isocyanate groups, preferably located at or near the end of the diol chain. It is a reaction product of a C4-C20 linear diol having a hydroxy group. The first starting material, an isocyanate-functional material, can be an aliphatic, cycloaliphatic or aromatic material and can be used alone or in combination with other isocyanate-functional materials. The isocyanate-functional material must have at least two or more reactive isocyanate groups. Examples of diisocyanates can include aliphatic, cycloaliphatic and aromatic diisocyanates, alone or in mixtures. Generally, such diisocyanates are of the formula OCN-R-NCO, where R is arylene (e.g., phenylene and diphenylene), alkylarylene (e.g., dimethylbiphenylene, methylenebisphenyl and dimethylmethylenebisphenylene), Having alkylene (eg, methylene, ethylene, tetramethylene, hexamethylene, 36 methylene species and trimethylhexylene) and cycloaliphatic (eg, isophorone and methylcyclohexylene), or R includes an ester or ether linkage. Specific examples of such diisocyanates include 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,2,4-trimethyl-1,6-diisocyanate. Hexane, 1,10-decamethylene diisocyanate, 1,4-cyclohexylene diisocyanate, 4,4'-methylene bis (isocyanate cyclohexane), p-phenylene diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, xylene diisocyanate , Isophorone diisocyanate, bispara-isocyanate cyclohexylmethane, 4,4-biphenylene diisocyanate, 4,4-methylene diphenyl isocyanate, 1,5-naphthalenediisocyanate, benzene 1,3-bis (1-isocyanate-1-methylethyl) and In the case of producing a branched composition, trimethylene is used as a suitable triisocyanate. Aromatic triisocyanate adduct of tolylene diisocyanate sold under the trade name of Rollpropane and Mondur CB-75, and hydrolysis of 1,6-hexamethylene diisocyanate sold under the trade name of Desmodur N Most preferred are dicyclohexylmethane-4,4'-diisocyanate, isophorone diisocyanate, sold under the trade name Desmodur W, sold under the trade name Mondur X P744. Isocyanurate trimer of hexamethylene diisocyanate sold under the trade name Desmodur N-3300.The isocyanate-functional material is from about 30.0% to about 50%. 0.0% (mole percentage of all reactants), preferably from about 35.0% to about 45.0%. It must be used as a percentage of the amount. The second starting material, polyether polyol, is preferably a polyalkylene oxide such as polyethylene glycol having a molecular weight of about 1000 to about 20,000. Suitable materials include the addition products of aliphatic, cycloaliphatic or aromatic polyhydric compounds such as polyhydric alcohols or polyhydric alcohol ethers, and alkylene oxides such as ethylene oxide or propylene oxide. Alternatively, it may be a hydroxyl-terminated prepolymer of an addition product thereof and an organic polyisocyanate. Mixtures of two or more of these substances are also acceptable. Polyhydric alcohols include simple glycols such as ethylene glycol, polyethylene glycol, propylene glycol and polypropylene glycol, as well as polyalkylolalkanes (eg, trimethylolpropane, pentaerythritol) and polyhydroxyalkanes (eg, glycerol, erythritol) Sorbitol, mannitol, etc.). Most preferred are polyethylene and polypropylene oxide having a molecular weight of about 4,000 to about 20,000. Most preferred is polyethylene glycol having a molecular weight of about 8,000. The polyether polyol component should be used in an amount from about 14.0% to about 35.0% (mole percentage of all reactants), preferably from about 17.5% to about 25.0%. The third starting material is a hydrophilic bifunctional endcapping material that reacts with isocyanate groups. This is preferably a C4-C20 linear diol with a hydroxy group located at or near the end of the diol chain, or a bifunctional amine with an amino group located at or near the end of the diamine chain. For example, 1,2-hexanediol is readily available, but is not acceptable for use herein due to the location of the hydroxy group next to the C1 and C2 carbons. Instead, diols such as 1,6-hexanediol and 1,10-decanediol are highly preferred. These diols have a hydroxy group located on the terminal carbon atom (C1, C6 and C1, C10, respectively). Unlike 1,2-hexanediol, which provides a thickener with five carbon pendant groups as shown in Formula 1, the use of 1,6-hexanediol results in a skeleton as shown in Formula II A hydroxy-terminated polymer having six carbon chains is obtained. Formula I: Formula II: HO—C—C—C—C—C—C—O — [— skeleton —] — O—C—C—C—C—C—OH Wherein the acceptable diamines are: 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,12 -Diaminododecane, 4,4'-diaminodicyclohexylmethane and mixtures thereof. Also suitable for use as hydrophilic endcapping materials are dithiols, dimercaptans, dicarboxylic acids and bisepoxys having functional groups at or near the end of the chain. For example, usable dithiols include 1,4-butanedithiol, 1,5-pentanedithiol, 1,6-hexanedithiol, 1,7-heptanedithiol, 1,8-octanedithiol, 1,9-nonanedithiol, and 1 , 10-decanedithiol. Examples of the dicarboxylic acid that can be used include 1,4-butanedicarboxylic acid, 1,5-pentanedicarboxylic acid, 1,6-hexanedicarboxylic acid, 1,7-heptanedicarboxylic acid, 1,8-octanedicarboxylic acid, and 1,9-dicarboxylic acid. Nonanedicarboxylic acid and 1,10-decanedicarboxylic acid are exemplified. Examples of diepoxy compounds that can be used include 1,4-butanediol diglycidal ether, 1,5-pentanediol diglycidal ether, 1,6-hexanediol diglycidal ether, 1,7-heptanediol diglycidal ether, and 1,8- Octanediol diglycidal ether, 1,9-nonanediol diglycidal ether, 1,10-decanediol diglycidal ether and bisphenol A diepoxide. Preferably, the hydrophilic endcapping material is used in an amount of about 4.5% to about 40.0% (mole percentage of all reactants), preferably about 30.0% to about 39.0%. The following illustrates one preferred method for producing the compositions of the present invention. It must be understood that additional procedures are available and can be employed to provide the compositions of the present invention. Furthermore, it should be understood that the choice of each starting material can and will have a unique effect on the reaction parameters. One skilled in the art can evaluate and compensate for such effects. General Reaction Method A preferred reaction method involves placing the polyether polyol, optionally but preferably with a solvent, in a reactor equipped with a nitrogen blanket. The solvent must be chosen to be non-reactive with the isocyanate-functional material. It must be compatible with the polyether polyol material and capable of dissolving the resulting urethane product. Examples of suitable solvents include benzene, toluene, xylene, other well-known inert hydrogen solvents rich in aromatic hydrocarbons such as Solvesso® 100 and Solvesso® 150, ethyl acetate, Examples thereof include dialkyl ethers of butyl acetate and alkylene glycol, dialkylene glycol, dipropylene glycol monomethyl ether acetate, and N-methylpyrrolidone. The polyether polyol must be stirred and heated to about 100-120C. Any water remaining in the reactor or reactants must be removed azeotropically at this point. Thereafter, the temperature of the reactor is reduced to about 65-75 ° C., the isocyanate functional material is added, and a catalyst such as dibutyltin dilaurate is added. The polymerization reaction is carried out for about 3 hours, the proportion of unreacted isocyanate being about 0.3-0.6% by weight of the reaction mixture present. Optionally, a diol is added to the reaction mixture, along with the polyether polyol and the isocyanate-functional material, to provide a hydrophobic moiety along the polymer backbone. The polyether polyol, isocyanate-functional substance and optional diol undergo a polymerization reaction to form a compound having an average molecular weight distribution of about 10,000 to about 30,000 (Mn by gel filtration chromatography). The molecular weight of this compound is adjusted in part by the equivalent ratio of starting OH: NCO. In another container, a hydrophilic endcapper is blended with any solvent selected from the above group, such as toluene. The mixture is added quickly into the reactor, preferably over less than about 5 minutes. The reaction temperature is maintained at 65-75C for about one and a half hours until the percentage of unreacted isocyanate is about 0%. The actual amount of unreacted isocyanate remaining after polymerization will depend on the concentration of endcapping material added to the reactor. Preferably, the hydrophilic end-capping material is present in an amount sufficient to provide about twice the equivalent required to theoretically react with all isocyanate-functional materials. Thereby, the ends of all the molecules become hydrophilic substances. At the end of the reaction, the solvent can be removed by standard methods known in the art, and the thickener can be diluted to the desired solids concentration in butyl carbitol and water. The following examples serve to illustrate the invention. They do not limit the scope of the invention. EXAMPLES A series of thickener compounds were prepared according to the method described above with varying amounts of materials as follows (solvents and their amounts are not listed in the table): Composition of thickener reactant (equivalent X100) In the table, PEG8000 is polyethylene glycol (Mw about 8,000) 1,6 DIOL is 1,6-hexanenediol NCO is Desmodur W (registered trademark) (dicyclohexylmethane-4,4'-diisocyanate) 1, 10 DIOL is 1,10-decanediol. Each of the above compounds was added to the exterior glossy latex paint in an amount of 251 bs (20% solids) per 100 gallons of paint. In addition, three commercially available thickeners: EXP-300 (trademark) from Rohm and Haas, RM-1020 from Rohm and Haas, and SCT-275 from Union Carbide, respectively, were used in the same manner. Three batches of paint were prepared. After 24 hours (excluding the following), the viscosity of the paint was measured using a Stormer viscometer (50-200 s ^-1 shear rate, Krebs units) and a cone and plate rheometer (10,000 s ^-1 shear rate). Measured and shown in the table below: *** Tested in "off-the-mill" mode immediately after preparation. ### No testing was performed with this formulation. Each of the above compounds was added to the glossy latex paint for external use in an amount of 251bs (20% solids) of a thickener per 100 gallons of the paint. Further, using three commercially available thickeners: EXP-300 manufactured by Rohm and Haas, RM-1020 manufactured by Rohm and Haas, and SCT-275 manufactured by Union Carbide, the same paint was used. Batch prepared. After 24 hours, the viscosities of the coatings were measured using a Stormer viscometer (50-200 s ^-1 shear rate, Krebs unit) and a cone and plate rheometer (10,000 s ^-1 shear rate) and are shown in the table below :

────────────────────────────────────────────────── ─── Continuation of front page    (81) Designated countries EP (AT, BE, CH, DE, DK, ES, FI, FR, GB, GR, IE, IT, L U, MC, NL, PT, SE), OA (BF, BJ, CF) , CG, CI, CM, GA, GN, ML, MR, NE, SN, TD, TG), AP (KE, LS, MW, SD, S Z, UG), UA (AM, AZ, BY, KG, KZ, MD , RU, TJ, TM), AL, AM, AT, AU, AZ , BB, BG, BR, BY, CA, CH, CN, CZ, DE, DK, EE, ES, FI, GB, GE, HU, I S, JP, KE, KG, KP, KR, KZ, LK, LR , LS, LT, LU, LV, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, S D, SE, SG, SI, SK, TJ, TM, TR, TT , UA, UG, US, UZ, VN (72) Inventor Kaima Paul M             United States Ohio 44136             Longsville Cross Trail Sa             Us 19808 (72) Inventor Charlotta Antony Be             United States Ohio 44202 Ohio             -Lora Eldridge Road 469 (72) Inventor Yoon Hyeong Chang             United States Ohio 44112             Leebrand Oak Hill Road             16281

Claims (1)

[Claims] 1. (A) an isocyanate-functional substance,     (B) a polyether polyol, and     (C) hydrophilic bifunctional endcapping substances that react with isocyanate groups A thickener composition containing the reaction product of the above. 2. The isocyanate-functional material is diisocyanate or triisocyanate The thickener composition according to claim 1, wherein: 3. The polyether polyol has a molecular weight of about 1000 to about 20,000 2. The thickener composition according to claim 1, which is a polyalkylene oxide. Stuff. 4. Hydrophilic bifunctional endcapping material located at or near the end of the chain C4 to C20 diols having isocyanate-reactive groups, Mines, dithiols, dimercaptans, dicarboxylic acids and diepoxides and the like 4. Thickening according to claim 3, characterized in that it is selected from the group consisting of: Composition. 5. When the hydrophilic bifunctional endcapping material is 1,6-hexanediol, , 10-decanediol, 1,4-diaminobutane, 1,5-diaminopentane , 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminohexane Butane, 1,9-diaminononane, 1,10-diaminodecane, 1,12-dia Minododecane, 4,4'-diaminodicyclohexylmethane, 1,4-butanedi Thiol, 1,5-pentanedithiol, 1,6-hexanedithiol, 1,7 -Heptanedithiol, 1,8-octanedithiol, 1,9-nonanedithiol 1,1,10-decanedithiol, 1,4-butanedicarboxylic acid, 1,5-pen Tandicarboxylic acid, 1,6-hexanedicarboxylic acid, 1,7-heptanedicarbo Acid, 1,8-octanedicarboxylic acid, 1,9-nonanedicarboxylic acid, 1,10 Decane dicarboxylic acid, 1,4-butanediol diglycidal ether, 1,5 -Pentanediol diglycidal ether, 1,6-hexanediol diglyci Darether, 1,7-heptanediol diglycidal ether, 1,8-octa Diol diglycidal ether, 1,9-nonane Diglycidal ether, 1,10-decanediol diglycidal ether, A bisphenol A diepoxide and a mixture thereof. The thickener composition according to claim 4, characterized in that: 6. If the hydrophilic bifunctional endcapping material is all isocyanate-functional Present in sufficient quantity to provide about twice the equivalent required to theoretically react with quality The thickener composition according to claim 5, wherein the thickener composition is used. 7. The isocyanate-functional substance is dicyclohexylmethane-4,4'-diiso Cyanate, isophorone diisocyanate, diphenylmethane-4,4'-di Isocyanurate trimer of isocyanate and hexamethylene diisocyanate 3. The thickener composition according to claim 2, wherein the composition is selected from the group consisting of: . 8. Polyether polyols are aliphatic, cycloaliphatic or aromatic polyhydroxylated Compounds and alkylene oxide addition products, their addition products and organic polyisocyanates A hydroxy-terminated prepolymer of a catenate, a blend of two or more of these substances Compounds, polyalkylolalkanes (eg, trimethylolpropane, pentae Risritol) and polyhydroxyalkanes (eg, glycerol, erythri) Tol, sorbitol, mannitol, etc.) 4. The thickener composition according to claim 3, wherein 9. The polyether polyol has a molecular weight of about 4,000 to about 20,000 Selected from the group consisting of oxidized polyethylene and oxidized polypropylene The thickener composition according to claim 8, wherein Ten. The polyether polyol has a molecular weight of about 4,000 to about 12,000 10. The method according to claim 9, wherein the polyethylene glycol is polyethylene glycol. Viscous composition. 11． (A) an isocyanate-functional substance,     (B) a polyether polyol, and     (C) diol   A reaction product of the above (a), (b) and (c) with a parent which reacts with isocyanate Contains the reaction product obtained by reaction with the aqueous bifunctional endcapping material. A thickener composition having 12． The isocyanate-functional substance is a diisocyanate or a triisocyanate. 12. The thickener composition according to claim 11, wherein the composition is provided. 13. The polyether polyol has a molecular weight of about 1000 to about 20,000 The thickener set according to claim 12, which is a polyalkylene oxide. Adult. 14. Hydrophilic bifunctional endcapping material located at or near the end of the chain C4 to C20 diols having isocyanate-reactive groups, Mines, dithiols, dimercaptans, dicarboxylic acids and diepoxides and the like 14. The method according to claim 13, wherein the mixture is selected from the group consisting of: Viscous composition. 15． When the hydrophilic bifunctional endcapping material is 1,6-hexanediol, , 10-decanediol, 1,4-diaminobutane, 1,5-diaminopentane , 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminohexane Butane, 1,9-diaminononane, 1,10-diaminodecane, 1,12-dia Minododecane, 4,4'-diaminodicyclohexylmethane, 1,4-butanedi Thiol, 1,5-pentanedithiol, 1,6-hexanedithiol, 1,7 -Heptanedithiol, 1,8-octanedithiol, 1,9-nonanedithiol 1,1,10-decanedithiol, 1,4-butanedicarboxylic acid, 1,5-pen Tandicarboxylic acid, 1,6-hexanedicarboxylic acid, 1,7-heptanedicarbo Acid, 1,8-octanedicarboxylic acid, 1,9-nonanedicarboxylic acid, 1,10 Decane dicarboxylic acid, 1,4-butanediol diglycidal ether, 1,5 -Pentanediol diglycidal ether, 1,6-hexanediol diglyci Darether, 1,7-heptanediol diglycidal ether, 1,8-octa Diol diglycidal ether, 1,9-nonanediol diglycidal ether , 1,10-decanediol diglycidal ether, bisphenol A diepoxy Claims selected from the group consisting of sids and mixtures thereof Item 15. The thickener composition according to Item 14. 16． If the hydrophilic bifunctional endcapping material is all isocyanate-functional Present in sufficient quantity to give twice the equivalent required to theoretically react with the quality The thickener composition according to claim 15, characterized in that: 17． The isocyanate functional material is dicyclohexylmethane-4,4'-diisocy Anate, isophorone diisocyanate, diphenylmethane-4,4'-dii Isocyanurate trimer of somocyanate and hexamethylene diisocyanate? 13. The thickener composition according to claim 12, which is selected from the group consisting of: 18． Polyether polyols are aliphatic, cycloaliphatic or aromatic polyhydroxylated Compounds and alkylene oxide addition products, their addition products and organic polyisocyanates A hydroxy-terminated prepolymer of a catenate, a blend of two or more of these substances Compounds, polyalkylolalkanes (eg, trimethylolpropane, pentae Risritol) and polyhydroxyalkanes (eg, glycerol, erythri) Tol, sorbitol, mannitol, etc.) 14. The thickener composition according to claim 13, wherein 19. The polyether polyol has a molecular weight of about 4,000 to about 20,000 Selected from the group consisting of oxidized polyethylene and oxidized polypropylene The thickener composition according to claim 18, wherein 20. The polyether polyol has a molecular weight of about 4,000 to about 12,000 20. The polyethylene glycol according to claim 19, wherein Thickener composition.