WO2015041552A2

WO2015041552A2 - One-component composition for production of polyurethane foam, including that of reduced MDI content and density, and its application

Info

Publication number: WO2015041552A2
Application number: PCT/PL2014/050057
Authority: WO
Inventors: Marta KARGOL; Wojciech ZATORSKI
Original assignee: Wrocławskie Centrum Badań Eit+ Sp. Z O.O.; Centralny Instytut Ochrony Pracy Państwowy
Priority date: 2013-09-18
Filing date: 2014-09-18
Publication date: 2015-03-26
Also published as: WO2015041552A3; PL405383A1

Abstract

The object of the invention is a one-component composition for production of polyurethane foam with reduced MDI content, containing a prepolymer, conventional additives for polyurethane foams, and a porophor, characterized in that it contains, among others, layered aluminosilicates as additives to lower the density of the polyurethane foam, preferably based on montmorillonite. Further objects of the invention are its application for production of foams and the resulting foam based on the composition.

Description

One-component composition for production of polyurethane foam, including that of reduced MDI content and density, and its application .

The object of the inventions is a one-component composition for production of polyurethane foam, including that of reduced MDI content and density. The invention applies to the production of moisture cured polyurethane foam, specifically for fixing woodwork, producing construction materials, and in transporting vehicles.

In one-component foams, isocyanates, polyols, and additives are mixed together in the spray can. Known isocyanate excess is applied. As the result of catalyzed polyaddition reaction polyurethane prepolymer is formed with isocyanate terminal groups. During spraying processes, the prepolymer foams and extends its volume due to releasing physical porophors ( "propellants" ) . The terminal isocyanate groups contained in the prepolymer react with water present in the air, creating urea linkages. During that process carbon dioxide is released, which causes further foaming of the reaction mass. American patent application US20100210748A1 is known that concerns obtaining polyurethane prepolimers. In the invention referred to, a mixture of polymeric and monomeric MDI from Bayer marketed as Desmodur 2460M, Desmodur VKS 20, and Desmodur VK5 was used. According to embodiments of the invention, the components (isocyanates and polyethers) are mixed until reaching a constant MDI content at 80°C and then distilled at 0.03mbar pressure. As the result, a product containing 0.18wt% of free diisocyanates and viscosity (50°C) of 350200mPas (Example 1, [6/0075]) or 0.18wt% and viscosity (50°C) 25000mPas (Example 2, [6/0076]). Possible materials to use, according to the description of the invention, are preferably isocyanates: toluene-2 , 4-diisocyanate TDI, 1,5 naphthalene diisocyanate NDI, 1 , 3-phenylene diisocyanate or methylene diphenyl-4 , 4 ' -diisocyanate MDI (whereas at least 50% of the product is based on aromatic derivatives, preferably 90%) [4/0052], preferred polyols are listed in [3/0037], the catalysts are listed in [5/0060], the additives are listed in [5/0064] . Moreover, the application claims the composition (claim 1.) of 1- or 2-component composition undergoing crosslinking (embodiment according to the examples), with the number of functional groups greater than 2 and with at least two NCO groups. American patent US005880167 is known, disclosing a composition containing polyisocyanates that may be selected from the group consisting of trifunctional homologs of diphenyl methane diisocyanate, triphenyl methane- 4, 4 ' , 4"-triisocyanate, thiophosphoric acid tris-(p- isocyanato ) -phenyl esters, trimerization products of MDI, aliphatic triisocyanates , adducts of diisocyanates and low molecular weight triols. In examples 5 through 8, the patent holder concentrates on triphenyl methane-4, 4 ' , 4"-triisocyanate and table 1. The description indicates that the low isocyanate content is the result of the chemical process only. The obtained high pressure of MDI vapors was higher by about a magnitude. There is no information on MMT as the filler, wherein the reduction of MDI content, according to this solution, is caused by its lack. American patent application US20040014847A1 is known, disclosing the composition of the prepolymer, with the content of monomeric polyisocyanate at 2% maximum, obtained according to the process defined in claim 1. Both MDI and TDI were used in the examples. The MDI contents provided according to the examples are: A - 0.02%, B - 0.02%, C - 0.02, D - 0.02%. The excess MDI was removed by thin layer distillation. According to the solution, the ratio of the isocyanate groups number to the hydroxyl groups number is from 2:1 to 10:1 (the first claim) . The process of isocyanate excess removal is found in claim 11. There is no information on MMT as the filler. American patent application US20040162385A1 is known which concerns obtaining the prepolymer from the mixture of MDI isomers with polyols. According to the solution, the ratio of the isocyanate groups number to the hydroxyl groups number is from 1.05:1 to 2.0:1 (the first claim) . The process is carried out in the presence of a metallic catalyst (claim 5.) . The example referred to demonstrates the dependence of the free MDI content to the catalyst used (tin (IV) compounds - claim 6) . Application W02011134933 (Al ) discloses the composition of the polymer mixture wherein the content of MDI is not greater than 4%w/w (in dependent claim 2. the content is limited to l%w/w) . Claim 1 defines MDI as the isocyanate component, preferably 2.6-MDI, whereas as polyol, preferably with branched structure, in order to control the flexibility of the foam. In claim 4, the kind of TDI used in the composition was stated precisely - end-capped TDI. Claim 11. specifies the kinds of additives regulating the cell size/structure (silicone or paraffin surfactants) and additives (filler, pigment or color) . There is no definition of the type of the filler.

OCF foams with the lowest possible MDI content in the composition are obtained by application of a larger number of inert means (not entering into reactions during prepolymerization processes) . As diluting substance, chlorinated paraffin or tris ( 2-chloro-l-methylethyl ) phosphate (V) - TCPP (substances acting as flame retardants or plasticizers ) can be used. Additionally, other chemical compounds can be made use of, like: triethyl phosphate, dimethyl propyl phosphate, triphenyl phosphate, tricresyl phosphate. The ratio of A (polyol premix) to B (isocyanate) components is defined in such a way that the amount of free MDI in the prepolymer contained in the spray can is below 1% by weight. The reminder of the isocyanate groups necessary for polyurethane foam crosslinking comes from the produced prepolymer. In case of two low isocyanates content, additional isocyanate is applied to promote the crosslinking processes (2,4-toluene diisocyanate TDI, hexamethylene diisocyanate HDI, hydrogenated MDI HMDI, isophorone diisocyanate IPDI, unsaturated aliphatic isocyanate TMI), in the amount of about 1-10% by weight to the sum of components. The drawback of such formulation is too low prepolymer viscosity (large amount of diluting substances) and unsatisfactory performance parameters of the foam (high density, low expansion degree, bad cell structure) . The reason for the loss of preferable performance properties of the foam obtained by means of such system is too fast evaporation of gas propellants (LPG, DME) from the reaction mixture. Therefore, a viscosity regulator to lower the density of polyurethane foam with reduced MDI content by creating propellant traps to optimize the viscosity of the system (prepolymer) retaining performance parameters of the resulting polyurethane foam, and even to improve them (higher thermal stability and better mechanical properties) is being searched for. An additive is searched for that would enable the creation of a physical barrier limiting evaporation of propellants, that will increase the foam expansion degree (increased virtual density) and the improvement of the cell structure. Additionally, the resulting foam should be characterized by better mechanical properties and increased thermal stability. Unexpectedly, the presented problems have been solved by the present invention.

The first object of the invention is a one-component composition for production of polyurethane foam with reduced MDI content, containing a prepolymer, additives for polyurethane foams, and a porophor system, characterized in that it contains layered aluminosilicates as additives to lower the density of the polyurethane foam, preferably based on montmorillonite . Equally preferably, the composition according to the present invention is characterized by that the prepolymer contains free isocyanate groups selected from the group comprising polymeric MDI, preferably in the amount below 1% by weight of the composition and additional isocyanate groups of supporting isocyanate, selected from the group comprising 2,4-toluene diisocyanate TDI, hexamethylene diisocyanate HDI, hydrogenated MDI HMDI, naphthalene diisocyanate NDI, isophorone diisocyanate IPDI, unsaturated aliphatic isocyanate TMI, preferably in the amount of 0.5% to 20% of the system weight. Equally preferably, the composition according to the present invention is characterized in that it contains polyols of polyether and polyester class or combinations thereof, of the hydroxyl number ranging from 100 to 450, for example Rokopol® G1000 - polyoxyalkylene triol dedicated for production of one-component foams, wherein the preferable isocyanate index, i.e. stoichiometric isocyanate - polyol ratio, is from 0.7 to 2.0. In another preferable embodiment of the invention, as layered aluminosilicates , at least one compound from the group comprising amine modified montmorillonite derivative, ammonium salt modified montmorillonite derivative, amine and silane modified montmorillonite derivative, long-chain amine modified montmorillonite derivative, natural hydrophilic bentonite, bentonite family compounds modified with quaternary amines. As layered aluminosilicates, for example, Nanomer 1.30 E (1.30) by ALDRICH is used, i.e. a product from the silicate nanoclays family, amine modified montmorillonite derivative (25 - 30wt% of octadecylamine ) used to reduce flammability of plastics, to increase gas barrier properties of plastics, or Nanomer 1.34 TCN (1.34) by ALDRICH, i.e. a product from the silicate nanoclays family, ammonium salt modified montmorillonite derivative, used to reduce the flammability of plastics, to increase gas barrier properties of plastics, or Nanomer I.31PS TCN (1.31 PS) by ALDRICH, i.e. a product from the silicate nanoclays family, montmorillonite derivative, amine and silane modified (0.5 - 5 wt% of aminopropyl trietoxisilane, 15-35wt% octadecylamine ) , used to reduce the flammability of plastics, to increase gas barrier properties of plastics, or Nanomer I.44P by ALDRICH (I.44P), i.e. a product from the silicate nanoclays family, montmorillonite derivative, modified with long-chain amine (35-45wt% of dimethyl dialkyl C14-C18 amine), used to reduce the flammability of plastics, to increase gas barrier properties of plastics, or Nanomer I.28E (1.28 E) by ALDRICH, i.e. a product from the silicate nanoclays family, montmorillonite derivative, modified with long-chain amine (25-35wt% of trimethyl stearyl ammonium) or Nanoclay (BE) by ALDRICH, being a natural hydrophilic bentonite, or Nanofil 5 and 15 by StJD-CHEMIE AG, i.e. bentonite family products modified with quaternary (dimethyl dialkyl) amines, or Cloisite 10A, Cloisite 15A and Cloisite 20A, i.e. ammonium salt modified montmorillonite derivative by Southern Clay Products, being a part of Rockwood Specialties Inc. Equally preferably, the composition according to the invention is characterized in that it contains flame retardants as additives, preferably chlorinated paraffins, TCPP, triethyl phosphate, dimethyl propyl phosphate, triphenyl phosphate, tricresyl phosphate in the amount of 15% to 50%, emulsifiers, catalysts, surfactants and propellants. In another favorable embodiment, the composition according to the invention is characterized in that substances selected from the group containing alkanes, ethers, ketones, alkyl carboxylates , halogenated hydrocarbons and mixtures thereof are used as porophors, preferably propellants selected from the group comprising propane, butane, isobutane and dimethyl ether. Equally preferably, the composition according to the present invention is characterized in that it contains polymeric 4,4'- methylene diphenyl isocyanate PMDI, preferably with the NCO groups content of 27% to 34% and functionalities of 2.5 to 3.3 in the amount of 10% to 25% by weight, an additional isocyanate selected from the group comprising 2,4-toluene diisocyanate TDI, hexamethylene diisocyanate HDI, hydrogenated MDI HMDI, naphthalene diisocyanate NDI, isophorone diisocyanate IPDI, unsaturated aliphatic isocyanate TMI, preferably in the amount of 0.5 to 20% by weight, polyols, preferably polyols, e.g. Rokopol® G1000, in the amount of 30% to 50% by weight, additionally flame retardants, preferably chlorinated paraffins C14-C17-40, TCPP or alternatively mixtures of those compounds with triethyl phosphate, dimethyl propyl phosphate, triphenyl phosphate, tricresyl phosphate in the amount of 15% to 50% by weight, emulsifiers, preferably in the amount of 3% to 5% by weight, a catalyst, preferably in the amount of 0.5% to 2.5% by weight, a surfactant, preferably in the amount of 0.5% to 4% by weight, and layered aluminosilicates in the amount of 0.1% to 15% by weight. A propellants system of propane, butane, isobutane and dimethyl ether is preferably added to the resulting mixture, in the amount of 5% to 100% by weight as well as layered aluminosilicates in the amount of 0.1% to 15% by weight in relation to the resulting composition as above .

The second object of the invention is the application of the composition disclosed in the first object of the invention for production of wet cured polyurethane foam.

The third object of the invention is the application of the composition disclosed in the first object of the invention for production of polyurethane foam in construction joinery unit . The fourth object of the invention is the application of the composition disclosed in the first object of the invention for production of polyurethane foam in construction materials. The fifth object of the invention is the application of the composition disclosed in the first object of the invention for production of polyurethane foam in transportation vehicles . The sixth object of the invention is the polyurethane foam characterized in that it is based on the composition defined in the first object of the invention.

The composition according to the invention and the foam resulting from it allows to obtain reduced content of MDI and optimal polyurethane foam structure and viscosity characteristics. Additionally, thanks to the invention, the mechanical and thermal properties have been improved. Moreover, the advantage of the proposed solution is its easy implementation in production without the need to modify the machine stock, raw materials feeding method, spray can construction, and changing base raw materials. It should be noted that layered silicates are environment friendly unlike polymers modified with the use of halogens, phosphates, or aromatic compounds. It is vital in terms of emission of toxic incineration products, wherein burnt materials containing traditional flame retardants emit significant amount of carbon oxide and soot, which is not observed in case of case of highly flame resistant polymer nanocomposites containing montmorillonite . Examples

Prepolymers for production of the foam were obtained by mixing polyol and flame retardants in plastic vessel. Then, a selected layered aluminosilicate was added. The obtained mixture was homogenized be means of a rotating agitator (rotating speed of the agitator: 4,000 rpm) for 30 minutes in ambient temperature. Upon completion of the mixing process, a surfactant and the catalyst were added, while stirring again for two minutes. The resulting mixture was poured to the can, and isocyanates were added. The resulting mixture was poured into the spray can and sealed tightly. The contents were shaken for 5 minutes. A propellants system was added to the sealed can.

Surfactant

Niax Silicone L- 5348 2 2 2 2 2 2 2

Layered aluminosilicate

Nanomer I.44P 10

Nanomer 1.30 E 10

Nanomer 1.34 TCN 10

Nanomer I.28E 10

Porophors

Mixture of Propane, 137 137 137 137 137 137 137 Butane, Isobutane,

Diethyl ether (ratio

7:7:50:36 by weight)

The obtained foams were characterized by the following properties: working temperature: + 5 - +35°C; yield (free foaming: 35 - 45 L; yield in gap: 15 - 25 L; density (free foaming: about 15 kg/m³; flammability class B3.

Claims

1. One-component composition for production of polyurethane foam with reduced MDI content, containing a prepolymer, additives for polyurethane foams, and a porophor system, characterized in that it contains layered aluminosilicates as additives to lower the density of the polyurethane foam, preferably based on montmorillonite .

2. The composition of claim 1, characterized in that the prepolymer contains free isocyanate groups selected from the group comprising polymeric MDI, preferably in the amount below lwt% of the composition and additional isocyanate groups of supporting isocyanate, selected from the group comprising 2,4- toluene diisocyanate TDI, hexamethylene diisocyanate HDI, hydrogenated MDI HMDI, naphthalene diisocyanate NDI, isophorone diisocyanate IPDI, unsaturated aliphatic isocyanate TMI, preferably in the amount of 0.5 to 20wt% of the system mass .

3. The composition of claim 1 or 2, characterized in that it contains polyols of polyether and polyester class or combinations thereof, of the hydroxyl number ranging from 100 to 450, preferably polyoxyalkylene triol, wherein the preferable isocyanate index, i.e. stoichiometric isocyanate - polyol ratio, is from 0.7 to 2.0.

4. The composition of any of claims 1 to 3, characterized in that the layered aluminosilicates applied comprise at least one compound from the group comprising amine modified montmorillonite derivative, ammonium salt modified montmorillonite derivative, montmorillonite derivative, modified with amine and silane, montmorillonite derivative, modified with long-chain amine, natural hydrophilic bentonite, bentonite family compounds modified with quaternary amines.

5. The composition of any of claims 1 to 4, characterized in that it contains flame retardants as additives, preferably chlorinated paraffins, TCPP, preferably mixtures with triethyl phosphate, dimethyl propyl phosphate, triphenyl phosphate, tricresyl phosphate in the amount of 15 to 50wt%, emulsifiers, catalysts, surfactants, and propellants.

6. The composition of any of claims 1 to 5, characterized in that it contains porophors selected from the group comprising alkanes, ethers, ketones, alkyl carboxylates , halogenated hydrocarbons and mixtures thereof, preferably propellants selected from the group comprising propane, butane, isobutane and dimethyl ether.

7. The composition of any of claims 1 to 6, characterized in that it contains polymeric 4,4'- methylene diphenyl isocyanate PMDI, preferably with the NCO groups content of 27% to 34% and functionalities of 2.5 to 3.3 in the amount of 10% to 25% by weight, an additional isocyanate selected from the group comprising 2,4-toluene diisocyanate TDI, hexamethylene diisocyanate HDI, hydrogenated MDI HMDI, naphthalene diisocyanate NDI, isophorone diisocyanate IPDI, unsaturated aliphatic isocyanate TMI, preferably in the amount of 0.5 to 20% by weight, polyols, preferably in the amount of 30 to 50% by weight, additionally flame retardants, preferably chlorinated paraffins C14-C17-40, TCPP or mixtures of those compounds with triethyl phosphate, dimethyl propyl phosphate, triphenyl phosphate, tricresyl phosphate in the amount of 15 to 50wt%, emulsifiers, preferably in the amount of 3% to 5% by weight, a catalyst, preferably in the amount of 0.5% to 2.5% by weight, a surfactant, preferably in the amount of 0.5% to 4% by weight, and layered aluminosilicates in the amount of 0,1% to 15% by weight .

8. The application of the foam forming composition characterized in any of claims 1 to 7 for production of wet cured polyurethane foam.

9. The application of the composition characterized in any of claims 1 to 7 for production of polyurethane foam in construction joinery unit.

10. The application of the composition characterized in any of claims 1 to 7 for production of polyurethane foam in construction materials.

11. The application of the composition characterized in claims 1 to 7 for production of polyurethane foam in transporting vehicles .

12. Polyurethane foam characterized in that it is based on composition defined in any of claims 1 to 7.