Polyurea particle dispersion for polyurethane foam applications

Abstract

The present disclosure provides for a method of forming a dispersion of polyurea particles in a polyol. The method can include providing a polyol dispersion formulation that includes: a base polyol; a polyisocyanate; and a mixture of amines, where the mixture of amines includes a first aliphatic amine having an amine functionality of 1; a second aliphatic amine having an amine functionality of 2 to 5; and an aromatic amine having an amine functionality of 1 to 4; and reacting the polyisocyanate and the mixture of amines in the base polyol to form the dispersion of polyurea particles in the polyol.

Description

[0001] POLYUREA PARTICLE DISPERSION FOR POLYURETHANE FOAM APPLICATIONS

[0002] Field of Disclosure

[0003]

[0001] The present disclosure relates generally to polyol dispersions for flexible polyurethane foam applications.

[0004] Introduction

[0005]

[0002] Flexible polyurethane foams can contain fillers to help increase density and load bearing properties of the foam. In the past, inorganic fillers such as barium sulfate have been used to achieve these properties, but the use of inorganic fillers has a variety of disadvantages, including difficulties in preparing and maintaining the dispersion. In their place, polymer filled polyols, also known as polyol dispersions, have been used to increase the load bearing properties or adjust processability of the flexible polyurethane foams. Polyol dispersions are polyols where solid particles are dispersed in a stable suspension. Examples of such polyol dispersions include dispersions of polyurethane particles in a polyol (PIPA polyols) or dispersions of styreneacrylonitrile particles in a polyol (Copolymer polyols).

[0006]

[0003] Other examples of a polyol dispersion include those formed from a polyaddition reaction of a polyisocyanate, a polyamine and a polyether polyol, which are known as polyhamstoff dispersion (PHD) polyols. Due to the high speed of the reaction between isocyanate and amines, the reaction that leads to the formation of PHD polyols can be very fast, requiring good mixing at the moment of reaction of the isocyanate with the amine, to ensure the formation of a stable dispersion.

[0007]

[0004] A drawback of PHD polyols, however, is that they are usually manufactured using hydrazine, which is a hazardous compound. Another drawback to the above described polyol dispersions is the unstable nature of the polyol particles in the dispersion over time. The dispersed polymer phase has a strong tendency to separate out from the liquid phase. Therefore, there is a need in the art for helping to stabilize polyol dispersions, especially PHD polyols. Summary

[0008]

[0005] The present disclosure provides for a method of forming a dispersion of polyurca particles in a polyol that can help in stabilizing polyol dispersions, especially PHD polyols. The synthesis of stable polyol dispersions, including PHD polyols, is achieved by using a polyether polyol, which is based on alkylene oxides as the base polyol, in conjunction with a specific mixture of amines for the synthesis of the polyurea particle dispersion via the reaction of the isocyanate and amines in the base polyol. Specifically, the embodiments of the present disclosure include a polyol dispersion formulation that includes a mixture of amines that allow for the stable polyol dispersion. Specifically, it has been surprisingly discovered that a stable polyurea dispersion is obtained when three specific amines, as discussed herein, are used together in the dispersion.

[0009]

[0006] As discussed herein, the present disclosure provides for a method of forming a dispersion of polyurea particles in a polyol. The method of the present disclosure includes providing a polyol dispersion formulation that includes: a base polyol: a polyisocyanate; and a mixture of amines. For the various embodiments, the mixture of amines includes 0.5 to 10 weight percent (wt.%) of a first aliphatic amine having an amine functionality of 1; 0.5 to 15 wt.% of a second aliphatic amine having an amine functionality of 2 to 5; 0.3 to 7 wt.% of an aromatic amine having an amine functionality of 1 to 4, where the wt.% are based on the total weight of the polyol dispersion formulation; and reacting the polyisocyanate and the mixture of amines in the base polyol at a NH / NCO equivalent ratio of 0.5 to 1.3 to form the dispersion of polyurea particles in the polyol having a total solids content of 5 to 40 wt.% based on the total weight of the polyurea particles in the polyol.

[0010]

[0007] With respect to the polyols, for the various embodiments the base polyol can be a polyether polyol. Specially, for the various embodiments the polyether polyol can be selected from the group consisting of a polyether polyol formed with (a) 100 wt.% propylene oxide (PO); (b) formed with PO and having end caps formed with ethylene oxide (EO); and (c) formed with a mixture of PO and EO (e.g., a random copolymer). For the various embodiments, the polyether polyol can have an equivalent weight of 200 to 3000 g / equivalent.

[0011]

[0008] With respect to the amines, for the various embodiments the weight average molecular weight of the first aliphatic amine and the molecular weight of the second aliphatic amine can each independently range from 59 to 4000 g / mol. For the various embodiments, the weight average molecular weight of the aromatic amine can range from 90 to 1000 g / mol. Preferably, the weight average molecular weight of the aromatic amine can range from 95 to 500 g / mol. In addition, for the various embodiments, the first aliphatic amine and the second aliphatic amine can each include at least one group selected from the group consisting of a hydroxyl moiety, a phosphorous based moiety, and combinations thereof. In one embodiment, the mixture of amines consists of the first aliphatic amine, the second aliphatic amine and the aromatic amine. In other words, in this one embodiment the mixture of amines only includes the first aliphatic amine, the second aliphatic amine and the aromatic amine as provided herein.

[0009] With respect to the isocyanate, for the various embodiments the polyisocyanate can be selected from the group consisting of toluene diisocyanate, diphenylmethane diisocyanate and combinations thereof. For the various embodiments, reacting the polyisocyanate and the mixture of amines in the base polyol is at a NH / NCO equivalent ratio of 0.5 to 1.3 to form the dispersion of polyurea particles in the polyol. In an additional embodiment, reacting the polyisocyanate and the mixture of amines in the base polyol is at a NH / NCO equivalent ratio of 0.75 to 1.3 to form the dispersion of polyurea particles in the polyol.

[0012]

[0010] In addition to the above discussion, for the various embodiments the use of a catalyst is not required. As such, for the various embodiments, a catalyst is not used in forming the dispersion of polyurea particles in the polyol. Similarly, for the various embodiments, hydrazine is not used in forming the dispersion of polyurea particles in the polyol. In other words, hydrazine is never used in forming the dispersion of polyurea particles in the polyol according to the present disclosure.

[0013] [Oi l] The present disclosure also provides for a polyol dispersion formed by the method as described herein. For the various embodiments, at least 90% by weight of the polyurea particles in the polyol have a diameter of 18 pm or less.

[0014]

[0012] The present disclosure also provides for a polyurethane foam comprising the reaction product of a reaction mixture, where the reaction mixture includes the polyol dispersion as provided herein, a blowing agent and at least one polyisocyanate.

[0015]

[0013] Other principal features and advantages of the disclosure will become apparent to those skilled in the art upon review of the following drawings, the detailed description, and the appended claims. Detailed Description

[0016]

[0014] The present disclosure provides for a method of forming a dispersion of poly urea particles in a polyol that can help in stabilizing polyol dispersions, especially PHD polyols. The synthesis of stable polyol dispersions, including PHD polyols, is achieved by using a polyether polyol, which is based on alkylene oxides as the base polyol, in conjunction with a specific mixture of amines for the synthesis of the polyurea particle dispersion via the reaction of the isocyanate and amines in the base polyol. Specifically, the embodiments of the present disclosure include a polyol dispersion formulation that includes a mixture of amines that allow for the stable polyol dispersion. Specifically, it has been surprisingly discovered that a stable polyurea dispersion is obtained when three specific amines, as discussed herein, are used together in the dispersion.

[0017]

[0015] The present disclosure provides for dispersions of polyurea particles in a polyol, also called PHD (poly-hamstoff dispersion) polyols. PHD polyols are traditionally made by the reaction of low equivalent weight (EW) isocyanate-reactive molecules with a polyisocyanate in the presence of a high EW polyol (also called “base polyol”). The resulting dispersed polymer phase consists of a polyurea polymer, where typically toluene diisocyanate (TDI) is the isocyanate and hydrazine is used as the low-molecular-weight polyamine. In contrast to the prior art, the present disclosure enables the manufacture of a dispersion of polyurea particles in a polyol without the need for hazardous polyamines such as hydrazine. As discussed herein, the present disclosure provides a method of forming a dispersion of polyurea particles in a polyol (e.g., a manufacturing process for PHD polyols) that can lead to stable dispersions of polyurea particles using different types of base polyols (e.g., ethylene oxide (EO) capped propylene oxide (PO), EO / PO mix feed, or all PO based polyols).

[0018]

[0016] As discussed herein, the present disclosure provides for a method of forming a dispersion of polyurea particles in a polyol. The method of the present disclosure includes providing a polyol dispersion formulation that includes: a base polyol: a polyisocyanate; and a mixture of amines. As discussed herein, the benefits of the present disclosure can provide for the possibility to manufacture polyurea dispersions using a wide variety of base polyols through the reaction of polyisocyanates with a specific combination of amines which achieves a stable polyol dispersion (e.g., a PHD polyol), without using certain hazardous amines such as hydrazine. The dispersions of polyurea particles (e.g., PHD particles) in the polyol according to the present disclosure can be formed in situ in the base polyol, as provided herein, where the dispersion of polyurca particles in the polyol have a total solids content of 5 to 40 wt.% based on the total weight of the polyurea particles in the polyol. Such a high solid content may be obtained while maintaining small particles. For example, in one embodiment, at least 90% by weight of the polyurea particles in the base polyol have a diameter of 18 pm or less. The in situ formation of the polyurea particles in the base polyol according to the present disclosure may be formed without the addition of any hydrazine.

[0019] Base Polyol

[0020]

[0017] For the various embodiments, the base polyol of the present disclosure may include a variety of polyols. The base polyol of the present disclosure can include those described herein as well as others known in the art, including commercially available polyols. Examples of such base polyols include polyether polyols, polyester polyols, polyhydroxyterminated acetal resins, hydroxyl-terminated amines, polyalkylene carbonate-based polyols, polyphosphate-based polyols and mixtures thereof.

[0021]

[0018] Preferably, the base polyol is a polyether polyol. For the various embodiments, the poly ether polyol can be prepared by adding an alkylene oxide, such as ethylene oxide (EO), propylene oxide (PO), butylene oxide or a combination thereof, to an initiator having from 2 to 8, preferably 2 to 6 active hydrogen atoms. Catalysis for the polymerization of the polyether polyol can be either anionic or cationic, where examples of such catalysts include KOH, CsOH, boron trifluoride, and double metal cyanide complex (DMC) catalysts such as zinc hexacyanocobaltate or quaternary phosphazenium compound.

[0022]

[0019] Examples of suitable initiator molecules include those with active hydrogen, such as water, polyhydric, in particular dihydric to octohydric alcohols or dialkylene glycols.

[0023] Additional initiator molecules can also include, for example, ethanediol, 1,2- and 1,3- propanediol, diethylene glycol, dipropylene glycol, 1 ,4-butanediol, 1 ,6-hexanediol, glycerol, pentaerythritol, sorbitol, sucrose, neopentylglycol; 1 ,2-propylene glycol; trimethylolpropane glycerol; 1,6-hexanediol; 2,5-hexanediol; 1,4-butanediol; 1,4-cyclohexane diol; ethylene glycol; diethylene glycol; triethylene glycol; 9(l)-hydroxymethyloctadecanol, 1,4- bishydroxymethylcyclohexane; 8,8-bis(hydroxymethyl)tricyclo[5,2, 1 ,02,6]decene; Dimerol alcohol (36 carbon diol available from Henkel Corporation); hydrogenated bisphenol; 9,9(10,10)-bishydroxymethyloctadecanol; castor oil; epoxidized seed oil; other modified seed oils containing reactive hydrogens; 1,2,6-hcxanctrio; and combination thereof.

[0024]

[0020] For the various embodiments, the polyether polyol can be selected from the group consisting of a polyether polyol (a) formed with 100 wt.% propylene oxide (PO); (b) formed with PO and having end caps formed with ethylene oxide (EO); and (c) formed with a mixture of PO and EO (e.g., a random copolymer formed from EO and PO). For example, the base polyol used for preparing the dispersion may, for example, be a poly(propylene oxide) homopolymer (e.g., the polyether polyol formed with 100 wt.% PO). In an additional embodiment, the polyether polyol can be a polypropylene oxide) based polyether polyol having end capping formed from EO. The poly ether polyol can also be formed as a random copolymer from PO and EO in which the poly (ethylene oxide) content is, for example, from about 1 to about 95% by weight. Additional examples can include, besides the ethylene oxide-capped poly(propylene oxide) polymers, ethylene oxide-capped random copolymers of propylene oxide and ethylene oxide.

[0025]

[0021] For the various embodiments, the polyether polyol of the present disclosure can have an equivalent weight per hydroxyl group of from 200 to 3000 g / equivalent. Preferably, the polyether polyol of the present disclosure can have an equivalent weight per hydroxyl group of from 200 to 1500 g / equivalent.

[0026]

[0022] For the various embodiments, the base polyol is not seeded with suspended particles to help with the formation of the polyurea particles through the reaction between the mixture of amines, as provided herein, and the polyisocyanate.

[0027] Polyisocyanate

[0028]

[0023] For the various embodiments, suitable polyisocyanates include aromatic polyisocyanates as are known in the art. Examples of such polyisocyanates include 4,4'-, 2,4’ and 2,2'-isomers of diphenylmethane diisocyante (MDI), mixtures thereof and polymeric and monomeric MDI mixtures; toluene-2,4- and 2,6-diisocyanates (TDI) and mixtures thereof; m- and p-phenylenediisocyanate, chlorophenylene-2,4-diisocyanate, diphenylene-4,4'-diisocyanate, 4,4'-diisocyanate-3,3'-dimehtyldiphenyl, 3-methyldiphenyl-methane-4,4'-diisocyanate and diphenyletherdiisocyanate and 2,4,6-triisocyanatotoluene and 2,4,4'-triisocyanatodiphenylether. Preferably, for the various embodiments the polyisocyanate can be selected from the group consisting of toluene diisocyanate, diphenylmethane diisocyanate and combinations thereof. Examples of the toluene diisocyanatc, TDI, and the diphcnylmcthanc diisocyanatc, MDI, arc provided herein. Mixtures of the above-mentioned polyisocyanates may also be used according to the present disclosure. For examples, mixtures of the above-described MDI and TDI polyisocyanates may be used, such as mixtures of 2,4- and 2,6-isomers of TDI and / or mixtures of 4,4'-, 2,4' and 2,2'-isomers of MDI. So-called prepolymers may also be used as the polyisocyanate, i.e., reaction products of low molecular weight and / or higher molecular weight compounds having hydroxyl groups, e.g., those discussed herein, with an excess of the polyisocyanates described above.

[0029]

[0024] The polyisocyanates as provided herein can have a functionality of at least 2. For example, polyisocyanates of MDI can have a functionality of 2 to 3.2, whereas poly isocyanates of TDI can have a functionality of 2 to 3.0. Such polyisocyanates can include any of the above described polyisocyanates, such as pure MDI, pure TDI, and modified versions that can include biuret-modified, carbodiimide-modified polyisocyanates.

[0030] Mixture of Amines

[0031]

[0025] For the various embodiments, the use of a specific combination of amines as provided herein has allowed for stabilizing polyol dispersions, especially PHD polyols as discussed herein. Specifically, it has been surprisingly discovered that a stable polyurea dispersion is obtained when three specific amines are used together in the dispersion. The specific combination of amines of the present disclosure includes specific aliphatic and aromatic amines. For the various embodiments, the mixture of amines includes 0.5 to 10 weight percent (wt.%) of a first aliphatic amine having an amine functionality of 1; 0.5 to 15 wt.% of a second aliphatic amine having an amine functionality of 2 to 5; and 0.3 to 7 wt.% of an aromatic amine having an amine functionality of 1 to 4, where the wt.% are based on the total weight of the polyol dispersion formulation. For the various embodiments, the mixture of amines consists of the first aliphatic amine, the second aliphatic amine and the aromatic amine. In other words, in some embodiments, the mixture of amines only includes the first aliphatic amine, the second aliphatic amine and the aromatic amine.

[0032]

[0026] For the various embodiments, the first aliphatic amine has an amine functionality of 1 (e.g., a NCO-reactive amine with a functionality 1). For the various embodiments, the first aliphatic amine can include those having either a primary aliphatic amine or a secondary aliphatic amine. For the various embodiments, the equivalent weight of the first aliphatic amine can be in a range of 59 to 4000 g / equivalent. Preferably, the equivalent weight of the first aliphatic amine can be in a range of 59 to 2000 g / equivalent. More preferably, the equivalent weight of the first aliphatic amine can be in a range of 100 to 600 g / equivalent.

[0033]

[0027] For the various embodiments, the first aliphatic amine can be selected from the group consisting of alkyl amines; cycloaliphatic amines, aralkyl amines; amine-terminated polyethers, substituted anilines, alkylethanolamine, and combinations thereof. Specific examples of the first aliphatic amine include, but are not limited to, propylamine, butylamine, ethanolamine, diethanolamine, polyetheramines, octylamine, dodecylamine, stearylamine, xylylamine, cyclohexylamine and dicyclohexylamine. Commercial examples of the first aliphatic amine can include, but are not limited to JEFF AMINE ™ M-series monoamines (e.g., M-600 and M-1000, Huntsman), among others.

[0034]

[0028] For the various embodiments, the second aliphatic amine has an amine functionality of 2 to 5 (e.g., a NCO-reactive amine with a functionality 2 to 5). Preferably, the second aliphatic amine has an amine functionality of 2 to 3 (e.g., a NCO-reactive amine with a functionality 2 to 3). For the various embodiments, the second aliphatic amine can include those having either a primary aliphatic amine, a secondary aliphatic amine or a combination thereof.

[0035]

[0029] For the various embodiments, the second aliphatic amine can be selected from the group consisting of ethylenediamine (EDA), 1,2- and 1,3-propylene diamine; 1,6- hexamethylenediamine (HMD A), diethylenetriamine (DETA), piperazine, N,N'-bis- aminoethylpiperazine; triazine; higher homologues of ethylene diamine such as diethylenetriamine; triethylenetetramine and tetraethylenepentamine; homologues of propylenediamine such as dipropylenetriamine, 1 ,4-diaminocyclohexane, tris(2- aminoethyl)amine, tetramethylenediamine, hexamethylenediamine, 4,7,10-trioxatridecane-l,13- diamine and combinations thereof. Commercially available examples of the second aliphatic amine can include Dytek A (Invista); Amicure IC (Albemarle); Dytek EP (Invista); Amicure CG-1200 (Albemarle); Polyamine D-230 (Huntsman); Quadrol (BASF); Polyamine AP (Huntsman); Anhydrous Piperazine (Huntsman); Piperazine Anhydrous (BASF);

[0036] JEFF AMINE™ T-403 (Huntsman); JEFF AMINE™ D-230 (Huntsman); JEFF AMINE™ D-400 (Huntsman); JEFFAMINE™ D-2000 (Huntsman); JEFFAMINE™ ED-600 (Huntsman); and JEFF AMINE™ ED-900 (Huntsman).

[0037]

[0030] For the various embodiments, the aromatic amine has an amine functionality of 2 to 4 (e.g., a NCO-reactive amine with a functionality 2 to 4). Preferably, the aromatic amine has an amine functionality of 2 (e.g., a NCO-reactive amine with a functionality of 2). For the various embodiments, the aromatic amine can include those having either a primary aromatic amine, a secondary aromatic amine or a combination thereof

[0038]

[0031] For the various embodiments, the aromatic amine can be selected from the group consisting of diethyltoluendiamine, lH-pyrrole-2, 5 -diamine, phenylene diamine, 4, d'methylenedianiline, 4,4'-Methylene-bis(3-chloro-2,6-diethylaniline) (MCDEA), phenylenediamines; naphthylene diamines, benzylamine, N,N,N',N'-tetramethyl-l,8- naphthalenediamine, 4-aminobenzylamine; 4-aminophenylethylamine; tolylene diamines; bisaminomethylbenzene and combinations thereof. Commercial examples of such aromatic amines can include Ethacure 300 (Albemarle), Ethacure 100 (Albemarle), among others.

[0039]

[0032] For the various embodiments, the weight average molecular weight of the first aliphatic amine and the molecular weight of the second aliphatic amine can independently range from 59 to 4000 g / mol. Preferably, the weight average molecular weight of the first aliphatic amine and the molecular weight of the second aliphatic amine can independently range from 59 to 2000 g / mol. For the various embodiments, the weight average molecular weight of the aromatic amine can range from 95 to 1000 g / mol. Preferably, the weight average molecular weight of the aromatic amine can range from 95 to 500 g / mol.

[0040]

[0033] For the various embodiments, the first aliphatic amine and the second aliphatic amine may or may not carry an additional functional group besides the amine that is reactive with the isocyanate. Examples of such an additional functional group can include those selected from the group consisting of a hydroxyl moiety, a phosphorous based moiety and combinations thereof.

[0041]

[0034] As discussed herein, hydrazine is not used in either the mixture of amines, as provided herein, or in any other aspect of the method of forming the dispersion of polyurea particles in a polyol according to the present disclosure.

[0042]

[0035] For the various embodiments, the use of catalysts in forming the dispersion of polyurea particles in a polyol according to the present disclosure is optional. In other words, in one embodiment a catalyst is not used in forming the dispersion of polyurea particles in the polyol of the present disclosure. If present, however, examples of such catalysts can include known organometallic compounds, metal salt catalysts and tertiary amine catalysts for use with polyols in forming the polyurea particles. When present, the catalyst is used to accelerate the reaction of isocyanate with the isocyanate reactive groups in the mixture of amines.

[0043] Forming the Dispersion of Polyurea Particles

[0044]

[0036] As discussed herein, the method of forming a dispersion of polyurea particles in the polyol includes providing the polyol dispersion formulation, which includes the base polyol, the polyisocyanate and the mixture of amines. The method further includes reacting the polyisocyanate and the mixture of amines in the base polyol at a NH / NCO equivalent ratio of 0.5 to 1.3 to form the dispersion of polyurea particles in the polyol having a total solids content of 5 to 40 wt.% based on the total weight of the polyurea particles in the polyol. In an additional embodiment, the polyisocyanate and the mixture of amines can be reacted in the base polyol at a NH / NCO equivalent ratio of 0.75 to 1.3 to form the dispersion of polyurea particles in the polyol. All individual values and subranges between 5 wt.% and 40 wt.% for the total solids content are included herein and disclosed herein; for example, the solid content may be from a lower limit of 5, 8, 10, 15,20, 25, or 30 wt.% to an upper limit of 20, 25, 30, 35, or 40 wt.% based on the total weight of the polyurea particles in the polyol. Additional fillers, such as mineral fillers, flame retarding agents such as melamine, or recycled foam powder can be incorporated in the polyol dispersion formulation at levels between 1 and 50 wt.% of the polyol dispersion formulation, or between 2 and 10 wt.% of the polyol dispersion formulation.

[0045]

[0037] Reacting the polyisocyanate and the mixture of amines in the base polyol can occur under mixing at a predetermined temperature and predetermined pressure. For example, the polyisocyanate can be added to the mixture of amines and the base polyol in stirred reactors or by using static mixers in series, as is known in the art, or more preferably continuously by using a high-pressure mixing head, such as those used in polyurethane foaming machines, with multiple streams for the base polyol, the polyisocyanate and the mixture of amines. For the various embodiments, the predetermined temperature can be in a range of about 20 to 120 °C, where the predetermined temperature is preferably in a range of about 20 to 60 °C. For the various embodiments, the predetermined pressure can be in a range of about 101.3 to 690 kPa. For the various embodiments, a polyol dispersion is formed by the method described herein. For the various embodiments, for the polyol dispersion at least 90% by weight of the polyurea particles in the polyol have a diameter of 18 pm or less.

[0046]

[0038] As discussed herein, hydrazine is not used in forming the dispersion of polyurea particles in the polyol. In an additional embodiment, a catalyst, as discussed herein, is not used in forming the dispersion of polyurea particles in the polyol.

[0047]

[0039] The present disclosure also provides for a polyurethane foam comprising the reaction product of a reaction mixture, where the reaction mixture includes the polyol dispersion as provided herein, a blowing agent and at least one polyisocyanate. For the various embodiments, the polyol dispersion as provided herein along with the least one polyisocyanate can be suitable for use in conventional slabstock, high resilience flex foam, or viscoelastic foam applications, among other polyurethane foam configurations.

[0048]

[0040] In general, the polyurethane foams of the present disclosure can be prepared by mixing a polyisocyanate, such as the polyisocyanates listed above, or combinations thereof, and the polyol dispersion of the present disclosure in the presence of a blowing agent, an optional catalyst(s) and other optional ingredients as desired. Additional polyols and / or polymer polyols may also be added to the polyol dispersion before reacting with the polyisocyanate. The conditions for the reaction are such that the polyisocyanate and the polyol dispersion react to form a polyurethane and / or polyurea polymer while the blowing agent generates a gas that expands the reacting mixture.

[0049]

[0041] Any suitable urethane catalyst may be used, including tertiary amine compounds, amines with isocyanate reactive groups and organometallic compounds. Exemplary tertiary amine compounds include triethylenediamine, N-methylmorpholine, N,N- dimethylcyclohexylamine, pentamethyldiethylenetriamine, tetramethylethylenediamine, bis (dimethylaminoethyl)ether, 1 -methyl-4-dimethylaminoethyl-piperazine, 3-methoxy-N- dimethylpropylamine, N-ethylmorpholine, dimethylethanolamine, N-cocomorpholine, N,N- dimethyl-N',N'-dimethyl isopropylpropylenediamine, N,N-diethyl-3-diethylamino- propylamine and dimethylbenzylamine. Exemplary organometallic catalysts include organomercury, organolead, organoferric, organobismuth and organotin catalysts, with no organometallic catalysts being preferred. A catalyst for the trimerization of isocyanates, resulting in a isocyanurate, such as an alkali metal alkoxide may also optionally be employed herein. The amount of amine catalysts can vary from 0.02 to 5 percent in the formulation or organometallic catalysts from 0.001 to 1 percent in the formulation can be used.

[0050]

[0042] Examples of blowing agents include physical blowing agents, such as carbon dioxide, air, nitrogen, methylene chloride, hydrofluorocarbons (HFCs) like HFC-134a, HFC- 245fa, hydrocarbons like n-pentane, isopentane, cyclopentane; and chemical blowing agents such as water and formic acid. The amount of blowing agent(s) used can be from 1 to 30 parts per hundred by weight of the polyol dispersion of the present disclosure.

[0051] Additionally, it may be desirable to employ certain other ingredients in preparing polyurethane foam. Among these additional ingredients are emulsifiers, silicone surfactants, preservatives, flame retardants, colorants, antioxidants, reinforcing agents, UV stabilizers, among other known additives.

[0052] EXAMPLES

[0053]

[0043] All components purchased from commercial vendors and used as received unless otherwise noted. Amounts provided for the Examples (EX) and Comparative Examples (CE) and the components used in forming the EX and CE are in weight percents (wt.%) unless otherwise noted. The components used in forming the EX and CE are provided in Table 1.

[0054] Table 1

[0055] Methods and Procedures

[0056]

[0044] The following are the methods and procedures for the Examples section.

[0057]

[0045] Procedure for preparing the PHD polyol dispersions. Base polyol and amines were mixed to homogeneity. Isocyanate was slowly added (0.1 g / s) under stirring. Once added, the mixture was stirred for another 2 minutes (min), thus completing the synthesis of the PHD polyol dispersion.

[0058]

[0046] Procedure for preparing the polyurethane foams. A hand-mix procedure was followed to prepare the foams. Foams were molded in a 11 liter (L) Al plaque mold at 45 °C after hand mixing for 1 s. The polyols were weighed and mixed together with the surfactants, water and the amino-based catalyst (Niax® Al and Dabco® 33 LV). The mixer speed was set at 2000 rpm: start stirring; addition of Dabco® T9; 10 s after Dabco® T9 addition add isocyanate; 10 s after isocyanate addition pour reactive mixture in open top box. After a demolding time of 5 min, the foams were mechanically crushed between two metal rolls having a 4 cm gap between the rolls through which the foam passes.

[0059]

[0047] Testing methods

[0060]

[0048] Particle size distribution (PSD) (d90): the meaning of d90 in PSD corresponds to the point in the particle size distribution, up to and including which, 90% of the total volume of material in the sample is 'contained'. For example, if the D90 is 10 pm, this means that 90% of the sample has a size of 10 pm or smaller.

[0061]

[0049] Procedure: 0.5 g of polyurea dispersion was dispersed in 50 mL of IPA (isopropanol). This solution was tested using Malvern Panalytical Mastersizer 3000 for the measurement of the PSD. The distributions are reported as dQ3 / dx, which is the change of the cumulative volume distribution (Q3) over the change of particle diameter (x).

[0062]

[0050] Molecular weight (MW) of the polyol: it is defined as the result from multiplying the equivalent weight (EW) with the functionality. The EW is obtained by dividing 56100 by the OH number of the polyol. The OH number (hydroxyl number) of the polyol is determined in accordance with ASTM D4274.

[0063]

[0051] Flammability Testing: UNI 9175 Class 1 IM. Foams (450 x 300 x 75 mrrP) were tested according to the Italian Flammability Standard UNI 9175 Class 1 IM. For the test, two foams were placed on a specific metal support resulting in a seat and a back. A propane flame with a height of 40 mm was placed in the junction of seat and back. For Class 1 IM, an ignition time of 140 seconds (s) was used, after which the foam has 120 s to self-extinguish. The foams were tested as one seat, which was ignited 3-5 times, each time in a pristine area. The fire results are reported as %pass, with 100% pass meaning all ignitions on the seat passed the standard.

[0064]

[0052] Density: determined according to ISO 845.

[0065]

[0053] Compression set and elongation at break: determined according to ASTM D 3574

[0066]

[0054] Compression Stress / Stain Characteristics (CLD) at 40 % : determined according to ISO 3386-1 Results

[0067]

[0055] Referring to Table 2, the comparative examples CE-A, CE-B and CE-C describe examples where one of the three amines (aliphatic monoamine, aliphatic polyamine or aromatic diamine) is missing, which results in particles with too high particle size distribution PSD (d90), hence the resulting polyurea dispersion is not stable.

[0068]

[0056] The solids % is a calculated number that refers to the amount of amines plus isocyanate used in preparing the polyol dispersion.

[0069]

[0057] The viscosity of CE-B (aromatic with capping polyol) was 11,000 mPa s. The viscosity of EX-1 to EX-5 was around 2500 mPa-s. The viscosity was measured according to ASTM D4289.

[0070]

[0058] EX-1 to EX-5 describe inventive examples where the three types of amines are used while keeping NH / NCO ratio in the range 0.91 - 0.97. All examples show formation of particles with low PSD (d90). EX-6 and EX-7 show inventive examples having a range of NH / NCO (equivalent ratio of amine vs isocyanate) of 1.21 and 0.85. Both examples produced particles with low PSD (d90) which supports the claim that the polyurea dispersion can be effectively manufactured when operating at NH / NCO ratio in the range 0.75 - 1.3. In fact, comparative example CE-D describes a PHD polyol with NH / NCO ratio = 1.4, which results in an unstable dispersion, with too high PSD (d90). EX-8 and EX-9 show inventive examples where high MW aliphatic amines are used: EX-9 uses a monoamine that also includes a hydroxyl group, while in EX-8 the monoamine does not have additional hydroxyl group (Jeffamine M-600 vs DEOA). In EX-9 the aliphatic polyamine is bifunctional rather than trifunctional. Both examples show formation of particles with low PSD (d90). EX- 10 is an example performed at higher solids content (21 % solids): also in this case the resulting polyol dispersion is characterized by low value of PSD (d90). EX-11 is an example performed using a different type of base polyether polyol (the all-PO polyol 2 has replaced the EO / PO mixfeed polyol 1).

[0071] Table 2

[0072]

[0073] Table 2

[0074]

[0075]

[0059] The viscosity is an aspect of the polyurea dispersion of the present examples that provides insights to the present disclosure, namely not only that the polyurea dispersion should have a low PSD, but that they should also have a low viscosity, such as for instance the viscosity as see in EX 1 to EX 5. For instance, considering EX 1, the resulting polyurea dispersion has viscosity at room temp around 2500 mPa-s: the base polyol, Polyol 1, has a viscosity of about 250 mPa-s, hence in the formation of the polyurea dispersion the viscosity has increased from about 250 to about 2500 mPa-s, which is acceptable. On the other hand, the increase in case of CE B is from about 250 to about 11000 mPa-s which is too high.

[0076]

[0060] Table 3 below shows an example of polyurethane foams prepared with the use of the polyurea polyol dispersion. The polyurea polyol used has the recipe as described in EX-11 in Table 2 and following the procedure described in the Procedure for preparing the polyurethane foams provided above.

[0077]

[0061] The foam shows good overall properties, such as good compression set, and ability to pass fire tests such as the class 1 IM.

[0078] Table 3

Claims

What is Claimed is:

1. A method of forming a dispersion of polyurea particles in a polyol, comprising: providing a polyol dispersion formulation that includes: a base polyol: a polyisocyanate; and a mixture of amines, wherein the mixture of amines includes:0.5 to 10 weight percent (wt.%) of a first aliphatic amine having an amine functionality of 1 ;0.5 to 15 wt.% of a second aliphatic amine having an amine functionality of 2 to 5;0.3 to 7 wt.% of an aromatic amine having an amine functionality of 1 to 4, wherein the wt.% are based on the total weight of the polyol dispersion formulation; and reacting the polyisocyanate and the mixture of amines in the base polyol at a NH / NCO equivalent ratio of 0.5 to 1.3 to form the dispersion of polyurea particles in the polyol having a total solids content of 5 to 40 wt.% based on the total weight of the polyurea particles in the polyol.

2. The method of claim 1, wherein the base polyol is a polyether polyol that has an equivalent weight of 200 to 3000 g / equivalent, and the polyether polyol is selected from the group consisting of the poly ether polyol formed with (a) 100 wt.% propylene oxide (PO); (b) formed with PO and having end caps formed with ethylene oxide (EO); and (c) formed with a mixture of PO and EO.

3. The method of any one of claims 1-2, wherein the weight average molecular weight of the first aliphatic amine and the weight average molecular weight of the second aliphatic amine are independently in a range from 59 to 4000 g / mol, and the weight average molecular weight of the aromatic amine is in another range from 95 to 1000 g / mol.

4. The method of any one of claims 1 -3, wherein the first aliphatic amine and the second aliphatic amine each include at least one group selected from the group consisting of a hydroxyl moiety, a phosphorous based moiety, and combinations thereof.

5. The method of any one of claims 1-4, where the mixture of amines consists of the first aliphatic amine, the second aliphatic amine and the aromatic amine.

6. The method of any one of claims 1-5, where reacting the polyisocyanate and the mixture of amines in the base polyol is at a NH / NCO equivalent ratio of 0.75 to 1.3 to form the dispersion of polyurea particles in the polyol.

7. The method of any one of claims 1-6, where a catalyst is not used in forming the dispersion of polyurea particles in the polyol.

8. A polyol dispersion formed by the method of any one of claims 1-7.

9. The polyol dispersion of claim 8, wherein at least 90% by weight of the polyurea particles in the polyol have a diameter of 18 pm or less.

10. A polyurethane foam comprising the reaction product of a reaction mixture, the reaction mixture comprising: the polyol dispersion of any one of claims 8-9; a blowing agent; and at least one polyisocyanate.

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