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
  • C08G18/42—Polycondensates having carboxylic or carbonic ester groups in the main chain
• • 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
  • C08G18/08—Processes
  • C08G18/10—Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
• • 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
  • C08G18/42—Polycondensates having carboxylic or carbonic ester groups in the main chain
  • C08G18/4236—Polycondensates having carboxylic or carbonic ester groups in the main chain containing only aliphatic groups
  • C08G18/4238—Polycondensates having carboxylic or carbonic ester groups in the main chain containing only aliphatic groups derived from dicarboxylic acids and dialcohols
• • 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
  • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
  • C08G18/72—Polyisocyanates or polyisothiocyanates
  • C08G18/74—Polyisocyanates or polyisothiocyanates cyclic
  • C08G18/76—Polyisocyanates or polyisothiocyanates cyclic aromatic
• • 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
  • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
  • C08G18/72—Polyisocyanates or polyisothiocyanates
  • C08G18/74—Polyisocyanates or polyisothiocyanates cyclic
  • C08G18/76—Polyisocyanates or polyisothiocyanates cyclic aromatic
  • C08G18/7657—Polyisocyanates or polyisothiocyanates cyclic aromatic containing two or more aromatic rings
  • C08G18/7664—Polyisocyanates or polyisothiocyanates cyclic aromatic containing two or more aromatic rings containing alkylene polyphenyl groups
  • C08G18/7671—Polyisocyanates or polyisothiocyanates cyclic aromatic containing two or more aromatic rings containing alkylene polyphenyl groups containing only one alkylene bisphenyl group

Definitions

• the present invention relates to new polyurethane (PUR) cast elastomers of NCO-functional prepolymers based on 2,4'-MDI and amine chain extenders and / or crosslinkers, a process for their preparation and their use.
• PUR polyurethane
• MDI diphenylmethane diisocyanate
• polyisocyanates is a technically important group of polyisocyanates; it is structurally very heterogeneous in composition and comprises monomer types characterized by having two aromatic moieties joined by only one methylene bridge and higher oligomers having more than two aromatic moieties and more than one methylene bridge , which are referred to as polymeric MDI.
• the ratio of monomer MDI to polymer MDI, as well as the proportions of the 2,4'- and 4,4'-isomers in the monomer MDI can be varied within wide limits by varying the synthesis conditions for the preparation of the precursor.
• the separation of the crude MDI obtained in the MDI synthesis is carried out by distillation to a large extent, depending on the technical complexity of both almost isomerically pure fractions with fractions, e.g. can be separated from 4,4'-MDI greater than 97.5 wt .-% or isomer mixtures with 4,4'- and 2,4'-shares of about 50 wt .-%.
• NCO prepolymers are NCO-terminated polyols, which are obtained by reacting a polyol with a polyisocyanate in, based on the NCO-reactive groups, molar NCO excess at room temperature to about 100 0 C. To this Manner-prepared NCO prepolymers always contain free, monomeric diisocyanate, depending on the molar ratios.
• the driving force for the preparation of low-monomer, up to practically monomer-free NCO prepolymers is due in the case of 2,4-TDI in its high vapor pressure and the resulting health hazards. More critical in this context are those on the aliphatic diisocyanates, e.g. Hexamethylene diisocyanate (HDI) or isophorone diisocyanate (IPDI) based NCO prepolymers to see. This aspect is also present in MDI, but due to its lower vapor pressure compared to TDI to a significantly reduced extent. In addition, the reduction of the monomer content of the prepolymer results in polyurethanes which are softer than those prepared from monomer-containing NCO prepolymers.
• HDI Hexamethylene diisocyanate
• IPDI isophorone diisocyanate
• the preparation of low-monomer NCO prepolymers can be done in several different ways:
• WO 01/40340 A2 (Crompton Corp.) gives examples of such combinations, wherein in a first step, the diisocyanate is reacted with the concomitant use of a selectivity-enhancing catalyst to form an NCO prepolymer, which is then freed from excess monomer by thin layers.
• a selectivity-enhancing catalyst for particularly critical applications, such as in the food sector, the argument of occupational hygiene, which applies to a large extent to TDI, also applies to MDI.
• the object of the present invention was therefore to provide polyurethanes based on 2,4'-MDI, which have advantages in terms of processing, for example in the form of extended casting times, lower prepolymer viscosities, compared to the prior art and at the same time in terms of their mechanical properties of the prior art at least equal.
• NCO prepolymers so are made of pure 2,4'-MDI, at least 1 wt .-% and max. 20 wt .-%, based on prepolymer, free monomeric diisocyanate having and not extracted or distilled NCO prepolymers meant.
• pure 2,4'-MDI is understood as meaning MDI types which have a content of 2,4'-isomer of at least 85% by weight, preferably at least 90% by weight, particularly preferably at least 95% by weight. , very particularly preferably at least 97.5 wt .-%.
• the present invention provides polyurethane elastomers (obtainable by the casting process) obtainable from
• the polyurethanes according to the invention are superior to the prior art because they have particularly favorable combinations of advantageous properties with respect to prepolymer viscosity, casting time, mechanical and mechanical-dynamic properties.
• Another object of the invention is a process for the preparation of the erfindunssieen polyurethane elastomers according to the casting process, which is characterized in that
• diphenylmethane diisocyanate having a 2,4'-isomer content of at least 85 wt .-%, preferably at least 90 wt .-%, more preferably at least
• B) are added to the prepolymer from A) aminic chain extenders and / or crosslinkers and optionally auxiliaries and additives for the preparation of the elastomer.
• the production of elastomers by the casting process is a generally important application of NCO-terminated prepolymers, wherein the prepolymers are reacted either directly after their preparation with a chain extender or cooled and stored the NCO prepolymers to a lower temperature (storage temperature) for the purpose of subsequent chain extension become.
• the prepolymers are first degassed by applying a reduced pressure at room temperature or at elevated temperature and then - usually at elevated temperature - stirred with a chain extender.
• the prepolymer is preferably heated to a temperature of 60 0 C to 1 10 ° C and degassed with stirring under vacuum.
• the chain extender and / or crosslinker is added in liquid form, which is optionally heated to temperatures of typically at least 5 ° C above its melting point.
• the reaction mixture is poured into preheated molds (preferably 90 0 C to 120 0 C) and baked for about 24 hours at 90 0 C to 140 0 C.
• polyether As polyols, it is possible to use polyether, polyester, polycarbonate and polyetherester polyols having hydroxyl numbers of from 20 to 200 mg KOH / g, preferably from 27 to 150, particularly preferably from 27 to 120.
• Polyether polyols are prepared either by alkaline catalysis or by double metal cyanide catalysis or optionally in stepwise reaction by alkaline catalysis and Doppelmetallcyanidkatalyse from a starter molecule and epoxides, preferably ethylene and / or propylene oxide and have terminal hydroxyl groups.
• Suitable starters are the compounds with hydroxyl and / or amino groups known to those skilled in the art, as well as water. The functionality of the starter is at least 2 and at most 4. Of course, mixtures of multiple starters can be used.
• mixtures of several polyether polyols can be used as polyether polyols.
• Polyether polyols may be hydroxyl-terminated oligomers of tetrahydrofuran.
• Polyester polyols are prepared in a conventional manner by polycondensation of alipahtic and / or aromatic polycarboxylic acids having 4 to 16 carbon atoms, optionally from their anhydrides and optionally from their low molecular weight esters, including ring esters, being used as the reaction component predominantly low molecular weight polyols having 2 to 12
• Carbon atoms are used.
• Polyester polyols here are preferably 2, but in individual cases may also be greater than 2, the components having functionalities greater than 2 being used only in small amounts, so that the arithmetic number average functionality of the polyester polyols is in the range from 2 to 2.5 2 to 2.1.
• Polyetheresterpolyole be prepared by concomitant use of polyether polyols in polyester polyol synthesis.
• Polycarbonate polyols are obtained according to the prior art from carbonic acid derivatives, for example dimethyl or diphenyl carbonate or phosgene and polyols by means of polycondensation. - o -
• aromatic aminic chain extenders such as e.g. Diethyl toluenediamine (DETDA), 3,3'-dichloro-4,4'-diamino-diphenylmethane (MBOCA), 3,5-diamino-4-chloro-isobutylbenzoate, 4-methyl-2,6-bis (methylthio) -l, 3-diaminobenzene (Ethacure 300), trimethylene glycol di-p-aminobenzoate (Polacure 740M) and 4,4'-diamino-2,2'-dichloro-5,5'-diethyldiphenylmethane (MCDEA) , Particularly preferred are MBOCA and 3,5-diamino-4-chloro-isobutylbenzoate. Aliphatic aminic chain extenders may also be used or co-used.
• DETDA Diethyl toluenediamine
• MOCA 3,3'-dichlor
• auxiliaries and additives such as catalysts, stabilizers, UV protectants, hydrolysis protectants, emulsifiers, preferably incorporable dyes and color pigments.
• catalysts are trialkylamines, diazabicyclooctane, tin dioctoate, dibutyltin dilaurate, N-alkylmorpholine, lead, zinc, calcium, magnesium octoate, the corresponding naphthenates and p-nitrophenolate.
• stabilizers are Broenstedt and Lewis acids, such as hydrochloric acid, benzoyl chloride, organomineric acids, e.g. Dibutyl phosphate, furthermore adipic acid, malic acid, succinic acid, grape acid or citric acid.
• Lewis acids such as hydrochloric acid, benzoyl chloride, organomineric acids, e.g. Dibutyl phosphate, furthermore adipic acid, malic acid, succinic acid, grape acid or citric acid.
• UV protectants and hydrolysis protectants are 2,6-dibutyl-4-methylphenol and sterically hindered carbodiimides.
• Incorporatable dyes are those which have Zerewitinoff-active hydrogen atoms, so can react with NCO groups.
• auxiliaries and additives include emulsifiers, foam stabilizers, cell regulators and fillers.
• emulsifiers include emulsifiers, foam stabilizers, cell regulators and fillers.
• foam stabilizers include emulsifiers, foam stabilizers, cell regulators and fillers.
• polyurethane elastomers according to the invention can be used in a wide variety of applications: for example as elastic molded parts produced by the casting process, as well as in coatings and adhesives produced by a spraying process, e.g. in parking deck coatings, concrete repairs, corrosion protection.
• Polyesterpolyol 1 poly (ethylene-co-butylene) adipate with an OH number of 56 mg KOH / g, Fa. Bayer MaterialScience AG; nominal functionality 2.0
• 4,4'-MDI 4,4'-diisocyanate, Desmodur ® 44M from Bayer MaterialScience AG;. 98.5% by weight of 4,4'-isomer
• 2,4'-MDI 2,4'-diphenylmethane diisocyanate (laboratory product) from Bayer MaterialScience AG; 98.5% by weight 2,4'-isomer
• Table 1 Formulations of MDI-based ester prepolymers (according to the invention and comparative examples)
• Prepolymer 1 from 100 parts by weight. Polyester polyol 1 and 25 parts by weight. 4,4'-MDI
• Prepolymer 2 from 100 parts by weight. Polyester polyol 1 and 25 parts by weight. 2,4'-MDI
• Table 2 Formulations, preparation and properties of the casting elastomers according to the invention
• Example 3 Production of Non-Inventive Casting Elastomers from Prepolymers IV, 3V, 4V and 6V from Example 1 The preparation was carried out as described under Example 2
• Tables 2 and 3 illustrates the advantages of the systems according to the invention: At comparable Prepolymertemperaturen (starting temperature) and comparable NCO contents, ie comparable formulations, the casting times of the prepolymers of the invention (Table 2) are up to a factor of 3 longer than those of the non-inventive systems (Table 3), which represents a significant processing advantage. The particularly favorable combinations of the properties "long casting time” and “low prepolymer viscosity" are only achieved by the systems according to the invention.
• the cast elastomers according to the invention also have advantages with respect to their mechanical properties:
• the systems according to the invention have a unique combination of advantageous properties with regard to prepolymer viscosity, casting time, mechanical and mechanical-dynamic properties.

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Polyurethanes Or Polyureas (AREA)

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• 2006
  • 2006-02-01 DE DE102006004527A patent/DE102006004527A1/de not_active Withdrawn
• 2007
  • 2007-01-19 CA CA002640685A patent/CA2640685A1/en not_active Abandoned
  • 2007-01-19 WO PCT/EP2007/000446 patent/WO2007087987A1/de active Application Filing
  • 2007-01-19 KR KR1020087018910A patent/KR20080097416A/ko not_active Application Discontinuation
  • 2007-01-19 BR BRPI0707383-6A patent/BRPI0707383A2/pt not_active IP Right Cessation
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