Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/409—Dispersions of polymers of C08G in organic compounds having active hydrogen
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/4009—Two or more macromolecular compounds not provided for in one single group of groups C08G18/42 - C08G18/64
  • C08G18/4072—Mixtures of compounds of group C08G18/63 with other macromolecular compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/48—Polyethers
  • C08G18/4804—Two or more polyethers of different physical or chemical nature
  • C08G18/482—Mixtures of polyethers containing at least one polyether containing nitrogen
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/48—Polyethers
  • C08G18/487—Polyethers containing cyclic groups
  • C08G18/4883—Polyethers containing cyclic groups containing cyclic groups having at least one oxygen atom in the ring
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/48—Polyethers
  • C08G18/50—Polyethers having heteroatoms other than oxygen
  • C08G18/5021—Polyethers having heteroatoms other than oxygen having nitrogen
  • C08G18/5024—Polyethers having heteroatoms other than oxygen having nitrogen containing primary and/or secondary amino groups
  • C08G18/503—Polyethers having heteroatoms other than oxygen having nitrogen containing primary and/or secondary amino groups being in latent form
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/63—Block or graft polymers obtained by polymerising compounds having carbon-to-carbon double bonds on to polymers
  • C08G18/632—Block or graft polymers obtained by polymerising compounds having carbon-to-carbon double bonds on to polymers onto polyethers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/65—Low-molecular-weight compounds having active hydrogen with high-molecular-weight compounds having active hydrogen
  • C08G18/66—Compounds of groups C08G18/42, C08G18/48, or C08G18/52
  • C08G18/6666—Compounds of group C08G18/48 or C08G18/52
  • C08G18/667—Compounds of group C08G18/48 or C08G18/52 with compounds of group C08G18/32 or polyamines of C08G18/38
  • C08G18/6674—Compounds of group C08G18/48 or C08G18/52 with compounds of group C08G18/32 or polyamines of C08G18/38 with compounds of group C08G18/3203
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G2110/00—Foam properties
  • C08G2110/0025—Foam properties rigid
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G2110/00—Foam properties
  • C08G2110/0041—Foam properties having specified density
  • C08G2110/005—< 50kg/m3

Definitions

• the invention relates to a process for the preparation of polyurethanes, hereinafter also referred to as PU, in particular of rigid polyurethane foams, by reacting polyisocyanates with compounds having at least two isocyanate-reactive hydrogen atoms.
• PU polyurethanes
• the production of rigid polyurethane foams is known and described many times.
• composite or sandwich elements which are constructed of a rigid polyurethane foam and at least one cover layer of a rigid or elastic material, such as paper, plastic films, aluminum foil, metal sheets, glass fleeces, or chipboard.
• a rigid or elastic material such as paper, plastic films, aluminum foil, metal sheets, glass fleeces, or chipboard.
• foaming of cavities in household appliances such as refrigerators, for example, refrigerators or chests or hot water tanks, with PU rigid foam as thermal insulation.
• Other applications are insulated pipes, consisting of an inner tube made of metal or plastic, a Polyurethanandämm für and an outer sheath made of polyethylene.
• the insulation of large storage containers or transport ships for example, for the storage and transport of liquids or liquefied gases in the temperature range of 160 ° C to -160 ° C is possible.
• suitable heat and cold-insulating rigid PU foams can be known by reacting organic polyisocyanates with one or more compounds having at least two isocyanate-reactive groups, preferably polyester and / or polyether polyols, and usually with the concomitant use of chain extenders and / or crosslinking agents in the presence of Be prepared blowing agents, catalysts and optionally auxiliaries and / or additives.
• PU rigid foams with a low thermal conductivity and good mechanical properties can be obtained.
• the graft polyols described therein are prepared using 2-8-functional polyether alcohols and styrene and acrylonitrile, preferably in a weight ratio of 2: 1, and in admixture with other polyols, for example based on sugar and aromatic amines, such as toluenediamine , used for the production of rigid polyurethane foams.
• the rigid foams described there are characterized by good curing and mold release and good flow behavior.
• a disadvantage is the insufficient miscibility of the graft polyols with polyols and the blowing agents as well as the low storage stability of the polyol component, especially when using hydrocarbons.
• WO 2005/097863 describes a process for producing rigid polyurethane foams using graft polyols prepared using polyether alcohols having a high proportion of ethylene oxide in the chain. This should improve the compatibility with the polyols of the formulation.
• WO 2008/031757 describes a process for the production of rigid polyurethane foams using graft polyols with defined contents of styrene and acrylonitrile in the graft particles.
• EP 1 108514 describes a process for the production of hard foam panels in which a graft polyol is used. This is prepared using a polyol mixture comprising a polyether alcohol containing at least 40% by weight of ethylene oxide. These foams should have a reduced shrinkage.
• JP 2000 169541 describes rigid polyurethane foams having improved mechanical strength and low shrinkage.
• a graft polyol prepared solely by using acrylonitrile as a monomer was used.
• a polyether alcohol is used with a content of at least 40 wt .-% of ethylene oxide.
• a problem in the production of rigid polyurethane foams using graft polyols is the often inadequate phase stability of the feed compounds.
• the compounds having at least two isocyanate-reactive hydrogen atoms are mixed together before the reaction.
• the catalysts, blowing agents and the auxiliaries and / or additives are then usually added. This mixture is often called a polyol component.
• Polyol components for rigid polyurethane foams containing graft polyols are often not phase stable when physical blowing agents, particularly the commonly used carbon blacks, are used. hydrocarbons, in particular pentanes, are used. This makes most of the processing very disadvantageous noticeable.
• the object could be achieved by the addition of compounds which are usually used as thixotropic agents.
• the invention accordingly provides a process for the preparation of polyurethanes, in particular rigid polyurethane foams, by reacting a) polyisocyanates with b) compounds having at least two isocyanate-reactive hydrogen atoms, characterized in that component b) contains at least one polyol containing fillers ) and at least one thixotropic agent bii).
• the invention furthermore relates to the polyurethanes produced by the process according to the invention.
• the polyurethanes produced by the process according to the invention are preferably rigid polyurethane foams.
• the invention further provides the use of thixotropic agents and polyols containing fillers for the production of polyurethanes, in particular rigid polyurethane foams.
• the polylines bi) preferably have a hydroxyl number in the range from 40 to 250 mgKOH / g.
• the fillers in the polyol are bi) inorganic fillers.
• the inorganic fillers in the polyol bi) are selected from the group consisting of graphite, expandable graphite, melamine, calcium carbonate, carbon black, solid flame retardants containing phosphorus atoms, in particular selected from ammonium polyphosphate, glass beads and glass fibers.
• the fillers in polyol bi) are organic fillers.
• the organic fillers are mostly particles of polymers, in particular thermoplastic polymers. These can be added to the polyols in different ways. One known method is so-called melt emulsification. The fillers are melted and added in this form to the polyols in such a way that the fillers are present in the form of particles in the polyol. This method is described, for example, in WO 2009/138379.
• the thermoplastic polymer (P) is selected from the group consisting of polystyrene, substituted polystyrene, for example alkyl-substituted polystyrene, poly (styrene-co-acrylonitrile), polyacrylate, polymethacrylate, polyolefins, for example polyethylene, polypropylene, polybutadiene, Polyvinyl chloride, polyacrylonitrile, polyesters, for example polyethylene terephthalate, polyamides, for example nylon, polyethers solid at room temperature such as high molecular weight polyethylene glycol or high molecular weight polytetramethylene oxide, copolymers containing at least one of the monomers present in the aforementioned polymers, for example copolymers of styrene and Acrylates, styrene and acrylonitrile or styrene and ethylene, and mixtures thereof.
• polystyrene substituted polystyrene, for example alkyl
• thermoplastic polymer Especially preferred as the thermoplastic polymer are polystyrene and other polyolefins, polyesters and polyamides.
• thermoplastic polymer i. Polymers derived from a recycling process.
• recycling polymers may be, for example, polyethylene or polyethylene terephthalate.
• these dispersions are prepared by adding an emulsifier, preferably a copolymer, which makes it possible to fully and stably disperse the fusible solid in the polyol.
• the copolymers used are preferably those which are composed of at least one ⁇ , ⁇ -ethylenically unsaturated monomer and at least one polymerizable polymer from the class of liquid polymers.
• the fillers-containing polyols bi) can be prepared by in situ polymerization of olefinically unsaturated monomers in polyether alcohols.
• the polyols thus prepared are often referred to as graft polyols.
• the graft polyols are usually prepared by in situ polymerization of olefinically unsaturated monomers in polyether alcohols, also referred to below as carrier polyols.
• the carrier polyols used are preferably those having a functionality of from 2 to 4, in particular from 3 to 4. They are usually prepared by addition of alkylene oxides, in particular propylene oxide or mixtures of propylene oxide and ethylene oxide with a maximum of 20 wt .-%, based on the weight of the polyether alcohol b1 i), ethylene oxide to H-functional starter substances.
• the starting substances are usually alcohols or amines with the appropriate functionality.
• Preferably used starter substances are ethylene glycol, Propylene glycol, glycerin, trimethylolpropane, ethylenediamine and toluenediamine (TDA).
• the starter substance used is TDA, in particular the ortho-isomers, also referred to as vicinal TDA.
• the carrier polyols preferably have a hydroxyl number greater than 100 mgKOH / g, more preferably in the range between 40 and 300 mgKOH / g.
• the carrier polyols are prepared by the customary and known processes for the preparation of polyether alcohols, which are described in more detail below.
• the carrier polyols are preferably used individually, but it is also possible to use these in the form of any mixtures with each other.
• the alkylene oxide used is preferably a mixture of ethylene oxide and propylene oxide.
• moderators also referred to as chain transfer agents
• chain transfer agents are usually used.
• the use and function of these moderators is described, for example, in US 4,689,354.
• the moderators reduce the molecular weight of the forming copolymers by chain transfer of the growing radical, thereby reducing cross-linking between the polymer molecules, which affects the viscosity and dispersion stability as well as the filterability of the graft polyols.
• the proportion of moderators is usually 0.5 to 25 wt .-%, based on the total weight of the monomers used to prepare the graft polyol.
• Moderators commonly used to prepare graft polyols are alcohols such as 1-butanol, 2-butanol, isopropanol, ethanol and methanol, cyclohexane, toluene, mercaptans such as ethanethiol, 1-heptanethiol, 2-octanethiol, 1 - Dodecane thiol, thiophenol, 2-ethylhexyl thioglycolate, methyl thioglycolate, cyclohexylmercaptan and enol ether compounds, morpholines and o (benzoyloxy) styrene.
• alcohols such as 1-butanol, 2-butanol, isopropanol, ethanol and methanol
• cyclohexane toluene
• mercaptans such as ethanethiol, 1-heptanethiol, 2-octane
• peroxide or azo compounds such as dibenzoyl peroxide, lauroyl peroxide, t-amyl peroxy-2-ethylhexanoate, di-t-butyl peroxide, diisopropyl peroxide carbonate, t-butyl peroxy-2-ethylhexanoate, t-butyl perpivalate, t-butyl perneodecanoate, are usually used , t-butyl perbenzoate, t-butylpercrotonate, t-butylperisobutyrate, t-butylperoxy-1-methylpropanoate, t-butylperoxy-2-ethylpentanoate, t-butylperoxyoctanoate and di-t-butylperphthalate, 2,2'-azobis (2,4-bis) dimethyl-valeronitrile), 2,2'-azobis (2,4-bis) dimethyl-
• the radical polymerization for the preparation of graft polyols is usually carried out at temperatures of 70 to 150 ° C and a pressure of up to 20 bar due to the reaction rate of the monomers and the half-life of the initiators.
• Preferred reaction conditions for the preparation of graft polyols are temperatures of 80 to 140 ° C, at a pressure of atmospheric pressure to 15 bar.
• the graft polyols b1) preferably have a content of polymerized particles, also referred to as solids content, of at least 35% by weight, based on the weight of the graft polyol.
• a solids content of 65 wt .-% should not be exceeded, otherwise the viscosity of the polyols increases too much and it can lead to problems during processing.
• the graft polyols b1) preferably have a particle size of the polymers of 0.1 ⁇ to 8 ⁇ , preferably 0.2 ⁇ to 4 ⁇ with a maximum particle size at 0.2 to 3 ⁇ preferably at 0.2 to 2, 0 ⁇ .
• the particle size distribution is bimodal, that is, the distribution curve of the particle size has two maxima.
• Such graft polyols can be prepared, for example, by mixing graft polyols having a monomodal particle size distribution and different particle size in the corresponding ratio, but also by using a polyol as carrier polyol in the reaction template which already contains polymers of olefinically unsaturated monomers.
• the particle size is also in this embodiment in the range described above.
• the graft polyols b1) can be prepared in continuous processes and batch processes. The synthesis of graft polyols by both methods is known and described in a number of examples.
• graft polyols according to the semi-batch process is described, for example, in EP 439755.
• a special form of the semi-batch process is the semi-batch seed process, in which additionally a graft polyol is used as seed in the reaction template is described, for example, in EP 510533.
• the synthesis of graft polyols according to a continuous process is also known and is described inter alia in WO 00/59971.
• the macromers also referred to as stabilizers, are usually linear or branched polyether alcohols with molecular weights Mw 1000 g / mol, which contain at least one mostly terminal, reactive olefinically unsaturated group.
• the ethylenically unsaturated group can be synthesized by reaction with ethylenically unsaturated carboxylic acids and / or carboxylic acid anhydrides, such as maleic anhydride, fumaric acid, acrylate and methacrylate derivatives, and unsaturated isocyanate derivatives, such as 3-isopropenyl-1,1-dimethylbenzyl isocyanate, iso-isocyanate.
• cyanato-ethyl methacrylate be added to an existing polyol.
• Another approach is the preparation of a polyol by alkoxydation of propylene oxide and ethylene oxide using starting molecules having hydroxyl groups and ethylenic unsaturation.
• Macromers which can be used in accordance with the invention may also be prepared by reacting a linear or branched polyether alcohol or polyester alcohol having molecular weights Mw 1000 g / mol with an at least difunctional isocyanate, such as e.g.
• TDI 2,4- and 2,6-toluene diisocyanate
• MDI 4,4'-, 2,4'- and 2,2'-diphenylmethane diisocyanate
• MDI 4,4'- and 2,4'-diphenylmethane-diisocyanates
• polyphenyl-polymethylene-polyisocyanates mixtures of 4,4'-, 2,4'- and 2,2'-diphenylmethane-diisocyanates and polyphenyl-polymethylene-polyisocyanates
• Crude MDI and mixtures of crude MDI and toluene diisocyanates and subsequent reaction with a compound having at least one olefinically unsaturated group to give a stabilizer having at least one terminal, reactive olefinically unsaturated group.
• polar polymers such as hard or soft foam polyether alcohols rich in ethylene oxide, starting from starter compounds such as sorbitol, trimethylolpropane (TMP) or glycerol, prepolymers of ethylene oxide-rich hard or soft foam polyether alcohols with TDI and / or MDI, furthermore Sul polyols containing acrylic acid or sulphonate groups or containing acrylic or acrylate groups, acrylic acid or acrylate copolymers or block copolymers, polyesterols, ionic and nonionic block copolymers containing at least one terminal, reactive olefinic unsaturated group.
• polar polymers such as hard or soft foam polyether alcohols rich in ethylene oxide, starting from starter compounds such as sorbitol, trimethylolpropane (TMP) or glycerol, prepolymers of ethylene oxide-rich hard or soft foam polyether alcohols with TDI and / or MDI, furthermore Sul polyols containing acrylic acid or
• the ethylenically unsaturated group may be reacted with carboxylic acid anhydrides such as maleic anhydride, fumaric acid, acrylate and methacrylate derivatives, and isocyanate derivatives such as 3-isopropenyl-1,1-dimethylbenzyl isocyanate (TMI), isocyanato-ethyl methacrylate, to a polar polymer be inserted.
• carboxylic acid anhydrides such as maleic anhydride, fumaric acid, acrylate and methacrylate derivatives
• isocyanate derivatives such as 3-isopropenyl-1,1-dimethylbenzyl isocyanate (TMI), isocyanato-ethyl methacrylate
• the macromers are incorporated into the copolymer chain.
• This forms block copolymers with a polyether and a polyacrylonitrile-styrene block, which act as a phase mediator in the interface of continuous phase and dispersed phase and suppress the agglomeration of Graftpolyol particles.
• the proportion of macromers is usually 1 to 35 wt .-%, based on the total weight of the monomers used to prepare the graft polyol, preferably 1 to 15 wt .-%.
• the polyol bi) is used in an amount of 10 to 30 wt .-%, based on the weight of component b).
• thixotropic agents the compounds known in the art can be used. These may be inorganic compounds, such as fumed silica.
• organo layer silicates can be used. These are used in particular in the form of stock gels, consisting of about 10% organo layer silicate, digested in 85-87% solvent and 3-5% disintegrating agent.
• organic thixotropic agents are used.
• low molecular weight, in particular semicrystalline urea derivatives are used which are dissolved in organic solvents.
• a solution of urea group-containing polymers in an organic solvent is used as the thixotropic agent bii).
• the thixotropic agent bii) in an amount of 0.5 to 2 wt .-%, based on the weight of component b) is used.
• the thixotropic agent bii) can be added to one of the other starting materials of component b) before it is mixed with the other starting materials.
• all starting materials of component b) are first mixed with one another and then the thixotropic agent bii) is added to this mixture.
• the mixing can take place at room temperature. It is also possible to carry out the mixing at elevated temperatures, preferably up to 80 ° C., and then to cool the mixture.
• the thixotropic agent bii) must thixotropic the complete component b).
• the effect must be reversible, that is, the already thixotropic component b) must become low-viscosity again after stirring and then re-thixotropicize on re-storage.
• component b) contains a polyether alcohol biii) which has been prepared by reacting an aromatic amine with alkylene oxides. This preferably has a hydroxyl number in the range between 300 and 500 mgKOH / g.
• the aromatic amine may be diphenylmethanediamine. Preference is given to toluene lendiamin used, wherein the ortho-isomers, also referred to as vicinal TDA, are particularly preferred.
• alkylene oxides ethylene oxide and propylene oxide can be used.
• ethylene oxide or a mixture of ethylene oxide and propylene oxide is first used, wherein in this embodiment, preferably the ethylene oxide and then the propylene oxide is attached.
• propylene oxide is used as the alkylene oxide.
• an amine is preferably used as the catalyst.
• component b) contains a polyether alcohol biv) which has been prepared by reacting a sugar with alkylene oxides.
• sugar for example, sucrose, sorbitol, mannitol or glucose can be used.
• the sugars are used in combination with a liquid compound having at least one reactive with alkylene oxides hydrogen atom, preferably an amine and / or an alcohol, in particular an alcohol.
• alcohols it is possible to use glycols, such as ethylene glycol and / or propylene glycol, or higher-functional alcohols, in particular glycerol.
• the starter mixture also contains water.
• the alkylene oxides used are usually ethylene oxide and / or propylene oxide, preferably propylene oxide.
• the hydroxyl number of the polyether alcohols biv) is preferably between 300 and 700 mgKOH / g.
• Suitable organic polyisocyanates a) are preferably aromatic polyfunctional isocyanates.
• TDI 2,4- and 2,6-toluene diisocyanate
• MDI 4,4'-, 2,4'- and 2,2'-diphenylmethane diisocyanate
• MDI 4,4'-, 2,4'- and 2,2'-diphenylmethane diisocyanate
• the organic di- and polyisocyanates can be used individually or in the form of mixtures.
• modified polyvalent isocyanates i. Products obtained by chemical reaction of organic di- and / or polyisocyanates used. Examples include isocyanurate and / or urethane-containing di- and / or polyisocyanates.
• the modified polyisocyanates may optionally be reacted with each other or with unmodified organic polyisocyanates, e.g. 2,4'-, 4,4'-diphenylmethane diisocyanate, crude MDI, 2,4- and / or 2,6-toluene diisocyanate are mixed.
• reaction products of polyfunctional isocyanates with polyhydric polyols, as well as their mixtures with other di- and polyisocyanates can be used.
• the particle-containing polyol b1) can in principle be used as the sole compound having at least two isocyanate-reactive hydrogen atoms b). However, it is preferred to use this compound b1) in admixture with other compounds having at least two isocyanate-reactive hydrogen atoms.
• the customary and known compounds having at least two isocyanate-reactive hydrogen atoms can preferably be used.
• polyether alcohols and / or polyester alcohols are used.
• the polyester alcohols used together with the polyols b1) are usually obtained by condensation of polyfunctional alcohols, preferably diols, having 2 to 12 carbon atoms, preferably 2 to 6 carbon atoms, with polyfunctional carboxylic acids having 2 to 12 carbon atoms, for example succinic acid, glutaric acid, adipic acid, Suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, maleic acid, fumaric acid and preferably phthalic acid, isophthalic acid, terephthalic acid and the isomeric naphthalenedicarboxylic acids.
• polyfunctional alcohols preferably diols, having 2 to 12 carbon atoms, preferably 2 to 6 carbon atoms
• polyfunctional carboxylic acids having 2 to 12 carbon atoms
• succinic acid for example succinic acid, glutaric acid, adipic acid, Suberic acid, azelaic acid, sebacic acid, decanedicarboxylic
• the polyether alcohols used together with the polyols b1) usually have a functionality of 2 to 8, in particular from 3 to 8.
• polyether alcohols which are prepared by known processes, for example by anionic polymerization of alkylene oxides in the presence of catalysts, preferably alkali metal hydroxides, are used.
• alkylene oxides used are usually ethylene oxide and / or propylene oxide, preferably pure 1,2-propylene oxide.
• compounds having at least 3, preferably 4 to 8 hydroxyl groups or having at least two primary amino groups in the molecule are used as starting molecules.
• starting molecules having at least 3, preferably 4 to 8 hydroxyl groups in the molecule are preferably trimethylopropane, glycerol, pentaerythritol, sugar compounds such as glucose, sorbitol, mannitol and sucrose, polyhydric phenols, resoles, such as oligomeric condensation products of phenol and formaldehyde and Mannich condensates Phenols, formaldehyde and dialkanolamines and melamine used.
• Starting molecules having at least two primary amino groups in the molecule are preferably aromatic di- and / or polyamines, for example phenylenediamines, 2,3-, 2,4-, 3,4- and 2,6-toluenediamine (TDA) and 4,4 '. , 2,4'- and 2,2'-diaminodiphenylmethane and aliphatic di- and polyamines, such as ethylenediamine used.
• the polyether alcohols have a functionality of preferably 3 to 8 and hydroxyl numbers of preferably 100 mg KOH / g to 1200 mg KOH / g and in particular 240 mg KOH / g to 570 mg KOH / g.
• a mixture of the graft polyol b1), a sucrose-initiated polyether alcohol b2) and a polyether alcohol b3) started with a trifunctional alcohol or an aromatic amine is used as the compounds having at least two isocyanate-reactive hydrogen atoms.
• the polyether alcohol b2) preferably has a hydroxyl number in the range between 375 and 525 mg KOH / g and a functionality of 5 to 7.5.
• the sucrose is usually reacted with the alkylene oxides, preferably propylene oxide and / or ethylene oxide, in admixture with water and / or other dihydric to trifunctional alcohols which are liquid at room temperature, such as ethylene glycol, propylene glycol and / or glycerol.
• the reaction can be catalyzed with alkali metal or alkaline earth metal hydroxides or amines.
• the polyether alcohol b3) preferably has a hydroxyl number in the range between 100 and 250 mgKOH / g and a functionality of 3 to 4.
• the trifunctional alcohols used are preferably glycerol or trimethylolpropane.
• the aromatic amine used is preferably TDA, the 2,3- and 3,4-isomers being particularly preferably used.
• component b) consists of 10 to 25 wt .-% of component b1), 25 to 65 wt .-% of a sucrose-started polyether alcohol b2), and 10 - 40 wt .-% of a with an aromatic amine or a trihydric alcohol-initiated polyether alcohol b3).
• the compounds having at least two isocyanate-reactive hydrogen atoms b) also include the optionally used chain extenders and crosslinkers.
• the PU rigid foams can be produced without or with the concomitant use of chain extenders and / or crosslinking agents.
• chain extenders and / or crosslinkers used are preferably alkanolamines and in particular diols and / or triols having molecular weights of less than 400, preferably 60 to 300.
• Chain extenders, crosslinking agents or mixtures thereof are expediently used in an amount of 1 to 20% by weight, preferably 2 to 5% by weight, based on the compounds having at least two isocyanate-reactive hydrogen atoms b).
• the reaction is usually carried out in the presence of catalysts, blowing agents and customary auxiliaries and / or additives.
• the catalysts used are in particular compounds which greatly accelerate the reaction of the isocyanate groups with the groups reactive with isocyanate groups.
• Such catalysts are strongly basic amines, such as.
• secondary aliphatic amines imidazoles, amidines, and alkanolamines or organic metal compounds, especially organic tin compounds.
• isocyanurate groups are to be incorporated in the rigid polyurethane foam, special catalysts are required for this purpose.
• the isocyanurate catalysts used are usually metal carboxylates, in particular potassium acetate and its solutions.
• the catalysts can, depending on requirements, be used alone or in any mixtures with one another.
• propellant preferably water can be used which reacts with isocyanate groups with elimination of carbon dioxide.
• so-called physical blowing agents can also be used. These are compounds which are inert to the starting components and which are usually liquid at room temperature and evaporate under the conditions of the urethane reaction. Preferably, the boiling point of these compounds is below 50 ° C.
• the physical blowing agents also include compounds which are gaseous at room temperature and are introduced under pressure into or dissolved in the starting components, for example carbon dioxide, low-boiling alkanes and fluoroalkanes.
• the compounds are usually selected from the group consisting of alkanes and / or cycloalkanes having at least 4 carbon atoms, dialkyl ethers, esters, ketones, acetals, fluoroalkenes having 1 to 8 carbon atoms and tetraalkylsilanes having 1 to 3 carbon atoms in the alkyl chain, in particular tetramethylsilane ,
• Examples which may be mentioned are propane, n-butane, iso- and cyclobutane, n-, iso- and cyclopentane, cyclohexane, dimethyl ether, methyl ethyl ether, methyl butyl ether, methyl formate, acetone, as well as fluoroalkanes, which can be degraded in the troposphere and therefore for the ozone layer is harmless, such as trifluoromethane, difluoromethane, 1,1,1,3,3-pentafluorobutane, 1,1,1,3,3-pentafluoropropane, 1,1,1,2-tetrafluoroethane, difluoroethane and 1,1, 1, 2,3,3,3-heptafluoropropane and perfluoroalkanes such as: C3F8, C4F10, C5F12, CeF-u, and C7F17.
• the said physical blowing agents can be used alone or in any combination
• the propellant contains at least one aliphatic hydrocarbon, preferably containing at least 4 carbon atoms.
• Form of the method according to the invention is a combination of water and an aliphatic hydrocarbon used as a blowing agent.
• Preferred hydrocarbons are n-pentane, isopentane and cyclopentane.
• optimal incorporation of the particles can be made in the cell walls.
• the process according to the invention can be carried out in the presence of flame retardants and customary auxiliaries and / or additives.
• organic phosphoric acid and / or phosphonic acid esters can be used as flame retardants. Preference is given to using compounds which are not reactive toward isocyanate groups. Chlorine-containing phosphoric acid esters are also among the preferred compounds.
• Typical representatives of this group of flame retardants are triethyl phosphate, diphenyl cresyl phosphate, tris (chloropropyl) phosphate and diethyl ethane phosphonate.
• bromine-containing flame retardants can also be used.
• compounds having groups which are reactive toward the isocyanate group are esters of tetrabromophthalic acid with aliphatic diols and alkoxylation products of dibromobutenediol.
• Compounds derived from the brominated, OH group-containing neopentyl compounds may also be used.
• auxiliaries and / or additives are the substances known per se for this purpose, for example surface-active substances, foam stabilizers, cell regulators, fillers, pigments, dyes, flameproofing agents, hydrolysis protection agents, antistatic agents, fungistatic and bacteriostatic agents.
• the polyisocyanates a) and the compounds having at least two isocyanate-reactive hydrogen atoms b) are reacted in amounts such that the isocyanate index is in a range between 100 and 220, preferably between 15 and 195.
• the rigid polyurethane foams can be prepared batchwise or continuously by means of known mixing devices. In the production of polyisocyanurate foams, it is also possible to work with a higher index, preferably up to 350.
• the rigid polyurethane foams according to the invention are customarily produced by the two-component process.
• the compounds having at least two isocyanate-reactive hydrogen atoms b) with the flame retardants, the catalysts c), the blowing agents d), and the other auxiliaries and / or additives are mixed to form a so-called polyol and these with the polyisocyanates or mixtures from the polyisocyanates and optionally propellants, also referred to as isocyanate component, reacted.
• the starting components are usually mixed at a temperature of 15 to 35 ° C, preferably from 20 to 30 ° C.
• the reaction mixture can be poured into closed support tools with high or low pressure metering machines.
• reaction mixture can also be poured or sprayed freely on surfaces or in open cavities. Roofs or complicated containers can be insulated on site using this method.
• the rigid polyurethane foams produced by the process according to the invention can be produced with a very short demolding time on the basis of a phase-stable polyol component, which allows significantly shorter cycle times.
• large amounts of physical blowing agents are soluble so that foam densities in the component of less than 30 g / l can be achieved.
• the foam properties in terms of pressure resistance, thermal conductivity and quality of the foam surfaces (formation of voids) are excellent.
• the polyols, catalysts, blowing agents and additives shown in Tables 1 to 3 were combined by stirring at room temperature to form a polyol component. These were foamed with the specified isocyanate component (Table 1 and 2: isocyanate 1, Table 3: see text) at the indicated characteristic number with a high-pressure mixing head. The processing parameters and the mechanical properties of the resulting foams are also shown in Table 1.
• the incorporation of the thixotropic agent is carried out by mixing all the polyols and thixotropic agent at 70 ° C, allowed to cool, then mixing with the other additives Comp. 1 comparison 2 Compar. 3 Ex. 1 Ex. 2
• Polyol 3 Polyetheralcohol based on vicinal TDA, ethylene oxide and propylene oxide, hydroxyl number 160 mgKOH / g
• Polyol 4 Polyetheralcohol based on trimethylolpropane propylene oxide, hydroxyl number 160 mgKOH / g
• the viscosity of the polyols and isocyanates at 25 ° C was determined with a rotational viscometer.
• the thermal conductivity was determined according to DIN 52616. To prepare the test specimens, the polyurethane reaction mixture was poured into a mold measuring 200 ⁇ 20 ⁇ 5 cm (10% overfilling) and after a few hours a test specimen of dimension 20 ⁇ 20 ⁇ 2 cm was cut from the middle.
• the compressive strength was determined according to DIN 53421 / DIN EN ISO 604.
• the proportion of closed cells was determined according to ISO 4590.

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• 2012
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