FLEXIBLE, OPEN-CELL THERMOSET FOAMS AND BLOWING AGENTS AND METHODS FOR MAKING SAME

Abstract

Disclosed are methods and compositions for forming a flexible, open cell molded foams based on MDI-based isocyanate comprising at least one polymer polyol present in the composition in an amount of at least about 6 pphp; one or more components capable of forming a thermoset matrix; and a blowing agent comprising at least one chemical blowing agent, such as water, and at least one physical blowing agent selected from the group consisting of trans-1-chloro-3,3,3-trifluoropropene (HFC0-1233zd(E)), 1,1,1,3,3-pentafluoropropane (HFC-245fa); 1,1,1,3,3-pentafluorobutane (365mfc), blends consisting essentially of at least about 80% of HFC-365mfc and 1,1,1,2,3,3,3-heptafluoropropane (227ea), and combinations of any two or more of these.

Claims

1. A method of forming a flexible, open cell, MDI-based polyurethane molded foam comprising: (a) providing a foamable, thermosetting composition capable of forming an open-cell, flexible MDI-based polyurethane foam, said composition comprising: (i) one or more isocyanate-reactive hydrogen containing compounds including at least one polymer polyol, wherein said polymer polyol is present in the formulation in an amount of greater than 6 pphp; and (ii) MDI-based isocyanate component; (iii) blowing agent, wherein the blowing agent comprises water and one or more co-blowing agents comprising one or more of trans-1-chloro-3,3,3-trifluoropropene (HFC0-1233zd(E)), 1,1,1,3,3-pentafluoropropane (HFC-245fa); 1,1,1,3,3-pentafluorobutane (365mfc), blends consisting essentially of at least about 80% of HFC-365mfc and 1,1,1,2,3,3,3-heptafluoropropane (227ea), wherein the amount of the co-blowing agent(s) is at least about 50% by weight of blowing agent composition; (iv) catalyst; (v) optionally surfactant; (vi) optionally foam modifier; and (vii) optionally other additives; (b) molding said foamable composition to form a molded foam having a density of not greater than about 3 PCF and at least one of IFD25% and IFD65% that is not more than 5% less than the IFD25% or IFD65% of said formulation but containing 2 pphp or less of said polymer polyol.

2. The method of claim 1 wherein said co-blowing agent comprises HFCO-1233zd(E).

3. The method of claim 1 wherein said co-blowing agent consists essentially of HFC0-1233zd(E).

4. The method of claim 1 wherein said co-blowing agent consists of HFCO-1233zd(E).

5. An automotive seat cushion containing a foam formed according to the method of claim 1.

6. The method of claim 1 wherein said blowing agent comprises from about 70 to about 99 mole percent water and from about 1 to about 30 mole percent of said one or more co-blowing agents.

7. A molded MDI-based foam formed from a foamable composition comprising: A) one or more polyisocyanates comprising at least about 50% by weight of di-isocyantes, polyisocyantes or combinations thereof; B) one or more isocyanate-reactive hydrogen containing compounds including at least one polymer polyol, wherein said polymer polyol is present in the formulation in an amount of greater than 6 pphp; C) blowing agent, wherein the blowing agent comprises water and one or more co-blowing agents comprising one or more of trans-1-chloro-3,3,3-trifluoropropene (HFC0-1233zd(E)), 1,1,1,3,3-pentafluoropropane (HFC-245fa); 1,1,1,3,3-pentafluorobutane (365mfc), blends consisting essentially of at least about 80% of HFC-365mfc and 1,1,1,2,3,3,3-heptafluoropropane (227ea), wherein the amount of the co-blowing agent(s) is at least about 50% by weight of blowing agent composition; D) catalyst; E) optionally but preferably surfactant; F) optionally but preferably foam modifier; and G) optionally other additives.

8. The foam of claim 7 wherein said co-blowing agent comprises HFCO-1233zd(E).

9. The foam of claim 7 wherein said co-blowing agent consists essentially of HFCO-1233zd(E).

10. The foam of claim 7 wherein said co-blowing agent consists of HFCO-1233zd(E).

11. The foam of claim 4 wherein said blowing agent comprises from about 70 to about 99 mole percent water and from about 1 to about 30 mole percent of said physical co-blowing agent.

12. A foamable composition comprising: A) one or more polyisocyanates comprising at least about 50% by weight of at least about 50% by weight of di-isocyantes, polyisocyantes or combinations thereof; B) one or more isocyanate-reactive hydrogen containing compounds including at least one polymer polyol, wherein said polymer polyol is present in the formulation in an amount of greater than 6 pphp; C) blowing agent, wherein the blowing agent comprises water and one or more co-blowing agents comprising one or more of trans-1-chloro-3,3,3-trifluoropropene (HFCO-1233zd(E)), 1,1,1,3,3-pentafluoropropane (HFC-245fa); 1,1,1,3,3-pentafluorobutane (365mfc), blends consisting essentially of at least about 80% of HFC-365mfc and 1,1,1,2,3,3,3-heptafluoropropane (227ea), wherein the amount of the co-blowing agent(s) is at least in preferred embodiments about 50% by weight of blowing agent composition; D) catalyst; E) optionally but preferably surfactant; F) optionally but preferably foam modifier; and G) optionally other additives.

13. The foamable composition of claim 12 wherein said co-blowing agent comprises HFC0-1233zd(E).

14. The foamable composition of of claim 12 wherein said co-blowing agent consists essentially of HFC0-1233zd(E).

15. The foamable composition of claim 12 wherein said co-blowing agent consists of HFC0-1233zd(E).

16. The foamable composition of claim 12 wherein said blowing agent comprises from about 70 to about 99 mole percent water and from about 1 to about 30 mole percent of said physical co-blowing agent.

17. The method of claim 1 wherein said foam has a density of not greater than about 2.5 pounds per cubic foot, said density of said foam being at least about 8 relative percent less than the density of said foam produced using the same method but without said co-blowing agent, and wherein the IFD at 25% as measured by ASTM D3574 Test B1 of the foam is not increased by more than 10 percent compared to the foam produced using the same method but without said co-blowing agent.

18. The method of claim 1 wherein said foam has a density of not greater than about 2.5 pounds per cubic foot, said density of said foam being at least about 8 relative percent less than the density of said foam produced using the same method but without said co-blowing agent, and wherein the CV of the foam is from about 2.2 to about 2.8.

19. The method of claim 1 wherein said foam has a density of not greater than about 2.5 pounds per cubic foot, said density of said foam being at least about 8 relative percent less than the density of said foam produced using the same method but without said co-blowing agent, and wherein the comfort factor is not degraded by more than about 10 relative percent compared to the foam produced using the same method but without said co-blowing agent.

20. The method of claim 1 wherein said foam has a density of not greater than about 2.5 pounds per cubic foot, said density of said foam being at least about 8 relative percent less than the density of said foam produced using the same method but without said co-blowing agent, and wherein the CFD hysteresis loss of said foam is not substantially increased relative to the foam produced using the same method but without said co-blowing agent.

Description

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0122] In general, the present invention is adaptable for use in connection with either the slabstock method and to foarnable compositions for use with the slabstock method, but it is preferred that the embodiments of the invention comprise the molding method of terming flexible polyurethane foams, and even more preferably in certain embodiments to cold cure molding of flexible, open cell foam and to foamable compositions for use with the molding method. Preferably, the foams of the present invention are polyurethane foams. As used herein, the terms polyurethane foam generally refers to cellular products as obtained by reacting polyisocyanates with one or more isocyanate-reactive hydrogen containing compounds, in the presence of a blowing agent, and in particular includes cellular products obtained with water as reactive or chemical .sup.blowing agent (involving a reaction of water with isocyanate groups yielding urea linkages and carbon dioxide). The term. polyurethane foamable compositions refers to compositions capable of being formed into a polyurethane foam.

[0123] As used herein, the term flexible polyurethane foam refers to cellular products which have a, substantial proportion of open cells, and even more preferably consists essentially of open cells, and which exhibit substantial shape recovery after deformation,

[0124] The preferred polyurethane foams comprise the reaction product of an aromatic polyisocyanate component and an isocyanate-reactive component, preferably comprising one or more hydroxyl functional materials, including preferably polyoxyalkylene polyether polyols. In general, the reaction mixture preferably includes one or more catalysts, one or more surfactants and a .sup.blowing agent component.

[0125] As used herein the term pphp means park by weight per hundred parts by weight of the total polyol components in the formulation.

[0126] Foamable Compositions For both slabstock and molded methods, the preferred foamable compositions and foams are polyurethane-based and will generally include the following components:

[0127] A) one or more polyisocyanates;

[0128] B) one or more isocyanate-reactive hydrogen containing compounds;

[0129] C) blowing agent

[0130] D) catalyst;

[0131] E) surfactant;

[0132] F) foam modifier;

[0133] G) other additives.

[0134] In general, it is contemplated that those skilled in the art will be able to select and adjust the type and amount of each of these components in view of the teachings contained herein to achieve advantageous foam, foamable compositions and methods of the present invention, and all such selections and adjustments are within broad scope of the present invention. According to preferred aspects of the invention, the materials and amounts described below have certain advantages.

[0135] A. Isocyanates

[0136] Those skilled in the art will appreciate that the type and amount of isocyanate can vary widely depending on many factors, including, whether the foamable composition is to be used in slabstock methods or molding methods, and the particular requirements of the methods involved and the expected end-use for the foam being formed.

[0137] Although many types of isocyanates are adapatable for use, in general, it is contemplated that the preferred compositions will comprise one or more aromatic polyisocyanate components, including preferably components based on MDI (diphenylmethane diisocyanate) c, TDI (toluene diisocyanate), mixtures of polymeric MDI and TDI, and modified versions of these, and combinations of these.

[0138] The terms polymethylene polyphenylene polyisocyanates and MDI are used herein to refer to polyisocyanates selected from diphenylmethane diisocyanate isomers, polyphenyl polymethylerie polyisocyanates and derivatives thereof bearing at least two isocyanate groups and containing carbodiimide groups, uretonimine groups, isocyanurate groups, urethane groups, allophanate groups, urea groups or biuret groups. They arc, obtainable, for example, by condensing aniline with formaldehyde, followed by phosgenation, which process yields what is called crude MDI, by fractionation of said crude MDT, which process yields pure MDI and polymeric MDI, and by autocondensation, of crude, pure or polymeric MD1, or reaction of excess of crude, pure or polymeric MIN with polyols or polyamines, which processes yield modified MDI, containing carbodiimide, uretonimine, isocyanurate, urethane, allophanate, urea or biuret groups. Examples of MDI that are adaptable for use in accordance with the present invention are provided in U.S. Pat. No. 5,399,594, which is incorporated herein by reference.

[0139] It is contemplated that in certain embodiments the isocyanate can include, 2,4-diphenylmethane diisocyanate (2,4-MDI, 4,4-diphenylmethane diisocyanate (4,4-MDI), H12MDI (hydrogenated. MD1).

[0140] The term TDI is used, herein to toluene dissocyanates general, and is intended to include but is not limited to 2,4-toluene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), H6TDI (hydrogenated TDI), and combinations of these.

[0141] It is also contemplated that the isocyanate in general, and the MDI and the TDI components in particular, can include materials known as urethane prepolymers obtained by the pre-reaction/reacting such isocyanate compounds with one or more of the polyol compounds, including those described below.

[0142] Other isocyantes can be used instead of or in addition to one or more of the MDI components or TDI components, including 1,4-phenylene diisocyanate, xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), tolidine diisocyanate (TODI), and 1,5-naphthalene diisocyanate. (NDI); aliphatic polyisocyanates such as hexamthylenc, diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, and norbornane diisocyanate methyl (NBDI); alicyclic polyisocyanates such as transcyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), H6XDI (hydrogenated XDI),

[0143] Once again, the type and the amount of the various isocyante components to be included can be determined by those skilled in the art in view of the teaching contained herein.

[0144] It is also contemplated that the amount of the isocyanate, relative to the other components of the foamable composition according to the present invention can vary widely within the scope hereof, and all such relative amounts are within the broad scope of the invention. In general, however, it preferred that the amount of isocyanate is selected relative to the amount of the one or more isocyanate-reactive hydrogen, containing compounds so as to obtain an Index of from about 75 to about 115, more preferably from about 80 to about 110 and even more preferably from about 85 to 105. The term index is used by those skilled in the art as a shortcut term to indicate the ratio of NCO (isocyanate) groups to OH, water and other isocyanate-reactive groups in the foam. For instance, an Index of 85 indicates a, ratio of 0.85, while an index of 105 indicates a ratio of 1.05.

[0145] In preferred embodiments, the isocyanate has an NCO percentage that can vary widely within the scope hereof. In certain preferred embodiments, the NCO of the isocyanate in the foamable composition is from about 20 to about 32%, more preferably from about 25 to about 32, and the NCO in the foam is from 12 to about 29%.

[0146] B. Isocyanate-Reactive Hydrogen Containing Compounds

[0147] As used herein, the term isocyanate:reactive hydrogen containing compounds or isocyanate-reactive compounds includes polyols as well as polyamines and combinations of these. The term polyurethane foam is thus intended also to include products which comprise urethane linkages together with urea linkages and even products which essentially comprise urea linkages with few or no urethane linkages. The isocyanate-reactive hydrogen containing compounds preferably comprising one or more hydroxyl functional materials, including preferably polyoxyalkylene polyether polyols.

[0148] Once again, it is contemplated that the type and amount of isocyanate-reactive hydrogen containing compounds, including the polyol, can, be readily selected for use with the present invention in view of the teachings contained herein. In certain preferred embodiments, polyol is used and is preferably selected from polyether polyol, a polyester polyol, or a, polyol chain extender.

[0149] In highly preferred embodiments the isocyanate-reactive hydrogen containing compounds comprise, more preferably comprise in major proportion, polyether polyol(s). Representative examples of polyether polyols are polyether diols such as polypropylene glycol, polyethylene glycol and polytetramethylene glycol; polyether triols such as glycerol triols; polyether tetrols and pentols such as aliphatic amine tetrols and aromatic amine tetrols; polyether octols such as sucrose octol; and others such as sorbitol, trimethylol propane, and pentaerythritol. Of course, any combination of any two or more of these may be used and combined or not with other isocyanate-reactive hydrogen containing compounds.

[0150] In preferred embodiments the isocyanate-reactive component comprises a polyol, and even more preferably a blend of polyols. In certain preferred embodiments, the polyol, comprises polyether polyol (such as may be formed by reacting polypropylene oxide and glycerol), and even more preferably in certain embodiments a polyether polyol having a molecular weight (MW) of from about 2,000 to about 10,000 preferably 3000 to 8000 and most preferably 4500 to 7500. With respect to functionality, it is preferred that the poly component has a functionality of from about 1 to about 6, more preferably from about 2 to about 5, and even more preferably from about 2 to about 4.

[0151] In preferred embodiments of the present invention the polyol component of the present invention comprises a combination of at least two polyols wherein a substantial portion of the polyol is a polymer polyol. As the term is used herein, polymer polyol refers to a stable dispersion of a solid polymer phase within the liquid polyol, polyol blend or polyol containing blend, wherein the solid polymer is preferably formed by in situ polymerization of low molecular weight compounds within the liquid phase, in preferred embodiments the polymer phase comprises, and in certain embodiments consists essentially of SAN polymer, preferably where the S AN polymer comprised from about 40 to about 75% by weight of the polymer polyoll, preferably from about 40 to about 55% by weight. One such polymer is described in US 2009/0281206, which is incorporated herein by reference.

[0152] Preferred SAN Polymer Polyols which are Commercially Available Include by Way of Preferred Examples:

TABLE-US-00001 SAN Polymer Polyol Properties Plura.col 1365 Nominal functionality, 2 from BASF OH No. (Avg) = 69 % Solids (wt % SAN) = 50 Viscosity (cps @ 25 C.) = 3800 EO Cap-No Pluracol 1528 FF Nominal functionality = 3 from BASF OH No. (Avg) = 19 % Solids (wt % SAN = 43 Viscosity cps @ 25 C.) = 5500 EO Cap-Yes Pluracol 5132 Nominal functionality = 3 from BASF OH No. (Avg) - 25 % Solids (wt % SAN) = 32 Viscosity (cps @ 25 C.) = 3300 EO Cap-Yes Pluracol 4600 Nominal functionality, 3 from BASF OH No Avg) = 31 % Solids (wt. % SAN) = 45 Viscosity (cps @ 25 C.) = 4200 EO Cap-No Pluracol 5250 Nominal functionality = 3 from BASF OH No. (Avg) = 28 % Solids (wt %) SAN) = 50 Viscosity (cps @ 25 C.) = 5700 EO Cap-No Arcot HS-100 OH No. (Avg) = 262-30.2 from Bayer % Solids (wt % SAN) = approx 45 or greater Viscosity (cps @ 25 C.) = 3100 Hyperlite @ E-852 OH No. (Avg) = 18.2-22.2 from Bayer % Solids (wt % SAN), approx, 45 or greater Viscosity (cps @ 25 C.) = 3100 Hypt.Tlite E-852 OH No. (Avg) - 18.222.2 from Bayer % Solids (wt % SAN), approx. 45 or greater Hyperlite E-850 OH No. (Avg) = 18.2-22.2 from Bayer % Solids wt % SAN) = approx. 45 or greater MW = 88,600

[0153] In certain preferred embodiments, the amount of the isocyanate-reactive hydrogen containing compounds, and in preferred embodiments the polyol components, comprise from about 20% to about 45% by weight, more preferably from about 25% to about 40% by weight, and even more preferably from about 30% to about 40%) by weight of the total weight of the foamable composition.

[0154] C. Blowing Agent

[0155] Applicants have found that unexpected by highly desirable advantage can be achieved by the use of blowing agent, especially in combination with the other preferred aspects of the invention, comprising: (a) at least one chemical blowing agent, preferably water; and (h) at least one physical blowing agent, which preferably comprises, and in certain embodiments consisting essentially of at least one co-blowing agent selected from the group consisting of trans-1-chloro-3,3,3-trifluoropropenc. (HFCO-1233zd(E)); 1,1,1,3,3-pentafluoropropane (HFC-245fa); pentafluorobutane (365mfc), blends consisting essentially of at least about 80% of HFC-365mfc and 1,1,1,2,3,3,3-heptalluoroproparie (227ea), and combinations of any two or more of these.

[0156] In general, it is preferred that the blowing agent component is present in the reaction mixture in an amount of from about 0.5% to about 10% by weight based on the total weight of the reaction mixture (including the aromatic polyisocyanate component and the isocyanate-reactive component), and more preferably from about 1% to about 8% by weight, and even more preferably from about 1.3 to about 4% by weight.

[0157] In certain embodiments the blowing agent preferably comprises from about 55 mol % to about 98 mol % of chemical or reactive blowing agent, preferably consisting essentially of water, and from about 2 mol % to about 45 mol % by of a physical blowing agent. In preferred embodiments the physical blowing agent is selected from the group consisting of trans-1-chloro-3,3,3-trifluoropropene (HFCO-1233zd(E)), 1,1,1,3,3-pentafluoropropane (HFC-245fa); 1,1,3,3-pentafluorobutane (365mfc), .sup.blends consisting essentially of at least about 80% of HFC-365mfc and 1,1,1,2,3,3,3-heptafluoropropane. (227ea), and combinations of any two or more of these. In certain preferred embodiments, the chemical or reactive blowing agent, preferably water, is present in amounts of from about 55 to about 98 mol %, more preferably from about 70 to about 96 mol %, and even more preferably in certain embodiments in amounts for from about 80 mol % to about 95 mol % based on the total blowing agent components, and the physical blowing agent, preferably selected from the group as identified herein, is present in an amount of from about 2 mol % to about 50 mol %, more preferably from 2 to about 30 mol % and even more preferably in amounts of from about 3 mol % to about 20 mol % and even more preferably from about 3 mole % to about 10 mol % based on the total blowing agent components. In certain embodiments the chemical or reactive blowing agent, preferably water, is present in amounts of from about 85 mol % to about 95 mol % based on the total blowing agent components, and the physical blowing agent, preferably selected from the group as identified herein, is present in an amount of from about 5 mol % to about 15 mol % of the total blowing agent components.

[0158] D. Foam Modifying Agent

[0159] Applicants have found that certain of the physical properties of the foams formed according to the present invention can he unexpectedly maintained and/or enhanced by incorporation into the foamable composition one or more foam modifying agents. More specifically, applicants have found that in certain embodiments a level of density reduction is desired, and can be achieved according to the present invention by use of the blowing agent as described herein, but one or more foam properties are altered in a manner that is undesirable and/or unacceptable for certain applications. The properties that can be negatively impacted in such situations include (a) IFD at 25%; (b) IFD at 65%; (c) comfort factor; (4) compression set; and (e) resilience. Applicants have found that including certain select compounds or combinations of compounds (referred to herein for convenience but not by way of limitation) a foam modifying agent of the present invention in the present compositions can interact in an unexpected manner with the other components of the composition during the foaming process to result in an improvement in one or more, and preferably at least two of these properties.

[0160] Applicants have found that certain diol, trials and combinations of these are capable of acting as effective reinforcing agents according to the preferred aspects of the present invention. For foaming modifying agents comprising diols, the molecular weight of the diol is preferably from about 60 to about 250, more preferably about 85 to about 180. In particularly preferred embodiments dial is 1,4 butane diol. For foaming modifying agents comprising trials. The molecular weight of the triol is preferably from about 70 to about 5000, more preferably about 80 to about 265. In particularly preferred embodiments the triol has at least a secondary and more preferably a tertiary amine. In highly preferred embodiments, the triol is selected from glycerol, triisopropanolamine, and polyether triol having a molecular weight of from about 250 to 275, and preferably of about 265. In preferred embodiments, the amount of the foam modifying agent is present in the composition in an amount of from greater than about 0 to about 1%.

[0161] E) Catalysts

[0162] In preferred embodiments the catalysts comprise, and in certain embodiments consist in major proportion of, tertiary amines containing hydroxyl, primary or secondary amines. Preferably the amine catalyst such as TEDA and Dabco BL-11 are used, in addition low-emissive or even non-emissive catalyst as would typically he used in open-cell flexible foam, and even more preferably molded foam used for auto or other transportation seat foam. Examples of catalyst that may be useful according to the present invention are: Dabco NE300, NE600, NE310, Polycat 140, NE1070 and NE1190, Jeffcat ZF-10, triediylene diamine, and 2-(2 dimethylaminoethyloxy)-N,N-dimethylethanamine Dabco BL-11). The catalyst may also comprise in certain embodiments other catalytic materials that are known for use in minor amounts in flexible foam applications, including organo-metallic catalysts used for rigid foam would be included such as those based on tin, zinc, and bismuth.

Foaming Methods

[0163] A) Molding Methods

[0164] It is contemplated that all known methods of forming open-cell, flexible polyurethane foam are adaptable for use in accordance with the present methods, and all such methods are within the broad scope of the present invention. In general, the molding aspects of the present invention include the step of providing a foamable, composition, preferably by mixing the polyol components and the isocyante components to form a reactive mixture, introducing the foamable composition into the mold, which is preferably a heated mold, and closing the mold. In preferred embodiments, the foamable composition sufficiently reactive to substantially fill the mold in a time period that is greater than about 2 seconds, and even more preferably in a time period greater than about 3 seconds and even more preferably in a time period that is greater than about 4 seconds. In certain embodiments, the time required to fill the mold is greater than one or more of preferred minimum mold-file time but less than about 15 seconds, more preferably less than about 10 seconds, and even more preferably less than about 8 seconds.

[0165] In preferred embodiments the mold is a heated mold heated to a temperature of at least about 120 C, and even more preferably from about 120 F to about 140 F.

[0166] In preferred embodiments, the amount of foamable composition introduced to the mold creates an overpack of from, about 0% to about 20%. As used herein, the term 0% overpack means introducing into the mold the theoretical amount of foamable composition that would be needed to fill the foam volume based on the free-rise density of the foamable composition. Other overpack values are based upon 0% overpack as this calculated.

[0167] Applicants have found that in certain preferred embodiments unexpected advantage can be achieved by conducting the molding step by using an overpack that is at least about 5%, more preferably at least about 10%, and even more preferably at least about 15%. More particularly, applicants have found that selection of relatively high overpack, including preferably an overpack value above about 10%, more preferably above about 12% and even more preferably above about 13%, can cause a substantial reduction in the compression set of the foam (whether the foam is MDI based, TIM based or a mixture of MIN and TIN) compared to a lower overpack value. Applicants have found that is unexpected advantage is desirable because in certain embodiments the use of the preferred co-blowing agent to achieve the desired free-rise density reduction can cause an unwanted, and in certain, cases, an unacceptable increase in compression set. This result is especially unexpected and advantageous in connection with Wet Compression Set (at 50 C. and 50% deflection and 95% Relative humidity (RH)), which in preferred embodiments of the present invention is less than 25% more preferably in certain embodiments of less than about 20%, preferably less than about 15%, preferably in certain embodiments less than 10%, and even more preferably in certain embodiments less than about 6%.

[0168] Articles

[0169] It is contemplated that any of the articles currently formed from flexible open-cell foam can be formed form the foams of the present invention. It is believed however that the molded foam formulations and the molding methods of the present invention are well suited to form automotive foams, including seat cushion foams, seat back foams, arm rest, dashboard, head rest, and head rest foams, as well as furniture foams, including particular office furniture.

[0170] It is believed however that the slab foam formulations and the slab forming methods of the pre-sent invention are well suited to form mattress foams, furniture foams, including sofas and large chairs and in airline seat foam.

EXAMPLES

Examples 1-3

[0171] In Examples 1-3 which follow, bench scale molded foams are prepared. The foamable compositions are all prepared using as the isocyanate component the MDI LUPRINATE M10 ((5 gal=31.8% NCO) and the indicated ingredients of the polyol master batch as listed in Table A below, unless specifically indicated herein.

TABLE-US-00002 TABLE A COMPONENT MATERIAL PROPERTIES POLYOL A DOW CP 6001 Density at 21 C.-1.03 glee Viscosity at 21 C.-1329 cp MW functionality approx. = 3Hydroxyl No. 26.5-28.5 KOH/g POLYOL B BASF Pluracol 1528 Density at 25 C.-1.02 g/cc FF Viscosity at 25 C.-5768 cp MW approx. 3600 45% graft polymer content, 3 functionality Hydroxyl No. 17-21 KOH/g POLYOL C BASF Pluracol 816 Density at 25 C.-1.02 g/cc Viscosity at 2.5 C.-900 cp MW - 4800 g/mol 3 functionality Total Acid No. <= 0.010 Hydroxyl No. 34-36 KOH/g SURFACTANT A Niax L3639 SURFACTANT B Niax L3640 ISOCYANATE A Lupranate, M10 Low Functionality Polymeric - (MDI) % NCO - 31.7 Nominal Functionality - 2.2 Viscosity (77 F.) - 60 cps BLOWING AGENTS WATER (Deionized) HFCO-1233ZD(E) HFC-245FA HFC-365MFC HFC-365MFC/HFC 227EA (93/7 wt. ratio) FOAM MODIFIERS Dipropylene. Glycol CATALYST A Niax EF 100 CATALYST B Niax EF 600 FOAM ADDITIVE Glycerol A FoAm ADDITIVE 1,4 Butane Diol B

[0172] A polyol master batch is created by introducing the Polyols A-C and Surfactants A and B into a container. These materials are then mixed until uniform. Then the foam modifier (diproplylene glycol), the water, and the catalyst are added. Mixing is resumed for several minutes to produce the polyol master batch as indicated in Control Table 1 below.

TABLE-US-00003 TABLE 1 Control - Polyol Master Batch WT % IN THE PARTS PER WEIGHT, MASTER BATCH HUNDRED COMPONENT grains FORMULATION POLYOL POLYOL A 1400 56.06 59.88 POLYOL B 48 1.92 2.05 POLYOL C 890 35.64 38.07 SURFACTANT A 8 0.32 0.34 SURFACTANT B 30 1.2 1.28 FOAM MODIFIER 27.5 1.1 1.18 BLOWING AGENTS WATER 76 3.04 3.25 CATALYST A 9 0.36 0.38 CATALYST B 9 .36 0.38 PHYSICAL PROPERTY 0 0 0 MODIFIER TOTAL 2497.5 1.00.00 106.82

[0173] An open cell, flexible polyurethane foam was formed to be used as a control for Examples 1-3 using the master batch formulation as indicated above. To produce the 90 index foam, 236.6 grams of the Lupranate M10 (MDI) isocyanate and 488 grams of the polyol master batch (as modified according to each of the examples) are mixed together for about 8 seconds at 3000 RPM to simulate the results of a machine molding process. Then the combined ingredients which form a foamable, reactive composition are poured into a 14144 inch aluminum mold preheated to and maintained during processing by a hot water jacket to about 130 F., with about 67 grams left in the can after the pour. Once the foam is poured into the mold the lid of the mold is immediately closed and sealed. The foam is maintained in the mold for 5 minutes; the foam is removed and immediately crushed to open many, and preferably substantially all, of any remaining closed cells. After crushing, the foam is allowed to cure at ambient conditions for about 24 hours. Indications of foam shrinkage are noted after this and then physical property measurements are made.

[0174] After being processed as indicated above to form a first foam, the procedure is repeated identically to form a second foam. The foams so produced are tested and found to have the average following physical properties,

TABLE-US-00004 Density (PCF) 3.22 IFD 25% 220 IFD 65% 598 CV (65/25) 2.7 Tensile Strength, psi. 12.3 Elongation 60.3 50% Compression Set 23.0 (at 95% RH and 50 C.) Resilience 43.6 CFD Hysteresis Loss 24.9%

Example 1

[0175] Open cell, flexible polyurethane foams were formed using the same procedures and materials indicated above in connection with the control, except that for each sample the blowing agent was modified to include a co-blowing agent HFCO-1233zd(E) in an amount of about 2% by weight based on the total components in the foam, such that the total blowing agent had the following concentrations, with the total weight of the water in the formulation remaining unchanged:

TABLE-US-00005 Wt % (based Mol % (based Grains per 100 on total on total BLOWING AGENT parts foam blowing agent) blowing agent) WATER 2.14 51.7 94.1 HFCO- 2.0 48.3 5.9 I 233ZD(E)

[0176] The amount of foamable composition use for pouring into the mold is adjusted to ensure filing of the mold and found to be about 658 grams (including the additional co-blowing agent), for a weight savings of approximately 9% in preparing the foam. The foams so produced are tested and found to have the following average physical properties and comparisons to the control:

TABLE-US-00006 CONTROL EXAMPLE 1 % CHANGE DENSITY, PCF 3.22 2.86 11.2 50% 23.0 20.6 10.4 COMPRESSION SET (at 95% RH and 50 C.) IFD 25% 220 168 23.6 IFD 65% 598 472 21.1 CV (25/65) 2.7 2.8 +4 Tensile Strength, psi 12.3 12.7 +3 Elongation 60.3 63 +4.5 CFD Hysteresis Loss 24.9 24.6 1.2

[0177] As can be seen from the above results, the addition of 1233zd(E) in approximately equal weight to the water blowing agent produces a highly desirable reduction in molded foam density (and associated weight savings). However, in this embodiment the foam exhibited an undesirably high reduction in MD 25% and 65%.

Example 2

[0178] Open cell, flexible polyurethane foams were formed using the same procedures and materials indicated above in connection with Example 1, except that the additional polymer polyol was added to the master batch formulation in an amount sufficient to increase the total proportion of polymer polyol (polyol 131 to six (6) pphp while maintaining all other ratios of components substantially the same. The amount of foamable composition is adjusted to ensure filing of the mold and found to be about 658 grams (including the additional co-blowing agent), for a weight savings of approximately 9%. The foams so produced are tested and found to have the following average physical properties and comparisons to the control:

TABLE-US-00007 CONTROL EXAMPLE 2 % CHANGE DENSITY, PCF 3.22 2.88 10.56 50% 23.0 22.9 0.4 COMPRESSION SET (at 95% RH and 50 C.) IFD 25% 220 180 48.2 IFD 65% 598 488 18.4 CV (25/65) 2.7 2.29 15.2 Tensile Strength, psi 12.3 12.1 +1.6 Elongation 60.3 62.6 +3.8 CFD Hysteresis 24.9 24.8 0 Loss

[0179] As can be seen from the above result, the modification to increase the polymer polyol by about 4 pphp as proportion of the polyol, total (for a total of 6 pphp produces about the same density reduction and only a slight improvement in IFD25% (18.4 percent loss for Example 2 compared to a 23.6% loss for Example 1) and for IFD65% (15.2% loss for Example 2 compared to a 21.1% loss for Example 1).

Example 3

[0180] Open cell, flexible polyurethane foams were formed using the same procedures and materials indicated above in connection with Example 1, except that the additional polymer polyol was added to the master batch formulation in an amount sufficient to increase the total of polymer polyol (polyol B) proportionally to ten (10) pphp while maintaining all other ratios of components substantially the same. The amount of foamable composition is adjusted to ensure filing of the mold and found to be about 658 grams (including the additional co-blowing agent), for a weight savings of approximately 9%. The foams so produced are tested and found to have the following average physical properties and comparisons to the control based on the average of the two samples tested:

TABLE-US-00008 CONTROL EXAMPLE 3 % CHANGE DENSITY, PCF 3.22 2.88 10.25 50% 23 22.8 COMPRESSION SET (at 95% RH and 50 C.) IFD 25% 220 215 2.2 IFD 65% 598 598 0 CV (25/65) 2.7 2.8 +3.7 Tensile Strength, psi 12.3 12.4 +0.8 Elongation 60.3 63.8 +5.8 CFD Hysteresis 24.9 24.8 0 Loss

[0181] As can be seen from the above results, modifying the formulation to achieve about 10 pphp of polymer polyol while maintain all other proportions produces about the same density reduction, about the same IFD 25% as the control, and about the same IFD65% as the control. This represents a dramatic and unexpected improvement in IFD25% (2.2 percent loss for Example 3 compared to a 23.6% loss for Example 1) and in IFD65% (0% Loss for Example 3 compared to a 21.1% loss for Example 1). This is an unexpected but highly advantageous result, indicating that it is possible to achieve density/weight improvements of approximately 8 15% for MDI molded foams while limiting the reduction in IFD25% and/or IFD65%, and preferably both, to about 5% or less, provided the amount of the polymer polyol in the formulation is proportionally greater than about 6 pphp, more preferably greater than about 8 pphp, and even more preferably at least about 10 pphp.

Examples 4 and 5

[0182] Examples 2 and 3 are repeated, except that the co-blowing agent consisting of HCFO-1233zd(E) is replaced by co-blowing agent consisting of HFC-24fa in the same amount by weight. Similar successful results are obtained.

Examples 6 and 7

[0183] Examples 2 and 3 are repeated, except that the co-blowing agent, consisting of HCFO-1233zd(E) is replaced by co-blowing agent consisting of a blend consisting essentially of about 80% by weight of HFC-365mfc and 2.0% by weight 1,1,1,2,3,3,3-heptafluoropropane (227ea) in the same amount by weight Similar successful results are obtained.

Examples 8 and 9

[0184] Examples 2 and 3 are repeated, except that the co-blowing agent consisting of HCFO-1233zd(E) is replaced by co-blowing agent consisting of HFC-365mfc in the same amount by weight. Similar successful results are obtained.

COMPARATIVE EXAMPLE

[0185] Example 1 is repeated, except that water replaces the 1233zd blowing agent on a one-to one molar basis. The foam produced has a reduced density similar to the density reduction achieved according to Example 1, but the IFD properties are considerably harderwhich frequently undesirable, than the foam produced according to Example 1. In addition, the hysteresis loss and 50% Compression Set are much higher, which is also undesirable, than the foam produced according to Example 1.

[0186] Although the invention has been described in detail in the foregoing for the purposes including explanation and illustration, it is to be understood, that all of the recited detail is not necessarily limiting of the invention and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims presented herein below and as amended hereinafter.