CA2267629A1 - Preparation of thermoplastic polyurethanes - Google Patents
Preparation of thermoplastic polyurethanes Download PDFInfo
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- CA2267629A1 CA2267629A1 CA002267629A CA2267629A CA2267629A1 CA 2267629 A1 CA2267629 A1 CA 2267629A1 CA 002267629 A CA002267629 A CA 002267629A CA 2267629 A CA2267629 A CA 2267629A CA 2267629 A1 CA2267629 A1 CA 2267629A1
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- Prior art keywords
- chain extenders
- polyisocyanate polyaddition
- isocyanates
- propanediol
- reaction
- Prior art date
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- 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
-
- 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
- C08G18/30—Low-molecular-weight compounds
- C08G18/32—Polyhydroxy compounds; Polyamines; Hydroxyamines
- C08G18/3203—Polyhydroxy compounds
- C08G18/3206—Polyhydroxy compounds aliphatic
-
- 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
- C08G18/30—Low-molecular-weight compounds
- C08G18/32—Polyhydroxy compounds; Polyamines; Hydroxyamines
- C08G18/3203—Polyhydroxy compounds
- C08G18/3215—Polyhydroxy compounds containing aromatic groups or benzoquinone groups
-
- 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
- C08G18/6633—Compounds of group C08G18/42
- C08G18/6637—Compounds of group C08G18/42 with compounds of group C08G18/32 or polyamines of C08G18/38
- C08G18/664—Compounds of group C08G18/42 with compounds of group C08G18/32 or polyamines of C08G18/38 with compounds of group C08G18/3203
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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)
- Sealing Material Composition (AREA)
Abstract
In a process for preparing polyisocyanate polyaddition products by reacting (a) isocyanates with (b) compounds which are reactive toward isocyanates and have a molecular weight of from 451 to 8000 in the presence of (c) chain extenders and, if desired, (d) crosslinkers, (e) catalysts and/or (f) customary auxiliaries and/or additives, use is made of 1,3- and/or 1,2-propanediol as chain extender (c) and the reaction is carried out at an index of ~104.
Description
Yi H
Preparation of thermoplastic polyurethanes The present invention relates to processes for. preparing polyisocyanate polyaddition products by reacting (a) isocyanates , with (b) compounds which are reactive towards isocyanates and have a molecular weight of from 451 to 8000 in the presence of (c) chain extenders and, if desired, (d) crossiinkers, (e) to catalysts and/or (f) customary auxiliaries and/or additives and also to the polyisocyanate polyaddition products which can be prepared using this process. in particular, the invention relates to processes for preparing thermoplastic polyisocyanate polyaddition products by reacting (a.) isocyanates with (b) .compounds Which are reactive towards isocyanates and have a molecular weight of from 451 to 8000 and a mean functionality of from 1.8 to 2.6 in the presence of (c) chain extenders) (e) catalysts and/or (f) customary auxiliaries and/or additives and also to the thermoplastic products obtainable in this way.
ao Polyisocyanate polyaddition producte~ and processes for their preparation are generally known and have been described many ''' times. A subgroup of these polyaddit:ion products is the thermoplastic polyisocyanate polyaddition products, generally Zg .also referred to as thermoplastic polyurethanes (TPUs). These TPUs are partially crystalline materials and belong to the class of thermoplastic elastomers. They comprise a partially crystalline hard block built up fronn the isocyanate and low molecular weight chain extenders and an amorphous soft block 30 which is typically built up from the. relatively high molecular weight compounds which are reactive toward isoeyanates, customarily polyester diols and/or polyether diols. A very good micromorphological demixing of these: phases is the necessary prerequisite for the elastic behaviour of the TPUs. The hard ~g block ants, owing to its partial cr,~stallinity, a~ physical crosslinking which is reversibly broken above the melting point of the hard block, thus making thermoplastic forming of the material possible. The soft block i;s in a plastic or liquid state nt room temperature and is responsilble for the ready 40 deformability of the Tpvs. After deformation, the physical crosslinking enables elastic recovery to the initial state. The TPUS have a combination of advantageous material properties such as low abrasion, good chemical resistance and high flexibility with simultaneously high strength. In addition, they offer 45 advantages in terms of inexpensive production) for example by the belt process or extrusion, which can be carried out continuously or discontinuously, and simple thermoplastic processing.
a variation of the starting components enables products having a broad range of properties over a wide hardness range to be ~ .
prepared. The heat distortion resistance and thus also the use properties of the material at temperatures above, in particular, 80~C are determined predominantly by the melt behaviour of the hard segment block, i.e. the quality of the ~hys~.cal crossiinking. ' ' Thermoplastic polyurethanes which are prepared on the basis of (a) MDI, (b) polyester diois and/or polyether diols and (c) butanedioi partly lose their heat distortion resistance at above 80 ~C, i.e. the material no longer returns to its initial state.
Zn order to be able to use TpUs under static ox dynamic load at relatively high temperatures, the heat distortion resistance of i5 the material has to bQ improved over that of .known TPUs.
To improve the modulus of elasticity of TPUs, particularly at high temperatures, the use of 1,3-pro~panediol as chain extender ~0 has already been described, with the ~TPUs being prepared at an index of 102 (Forschner et al., Polyurethane 'World Congrese 1997, page 371). However, the improvement in the modulus of ~lasticity t.
,,.,: .
.. ~,.
of TPUs prepared in this way is still unsatiefaotory, so that further ways of improving the heat distortion resistance have to 25 be sought.
Further publications describe improvement of the heat distortion resistance of Tsos (Ep-A 718 335) or improved dimensional stability of TpU fibres under~load at high temperatures (IT-A 733 30 216). Sp-A 718 335 discloses aromatic chain extenders in combination with alkane diois having from 4 to 44 carbon atoms for achieving this aim. =T-A 733 216 ~dsscribes the use of various chain extenders including 1,3-propane~diol and 1,4-bis(hydroxymethyl) benzene at an index of from 98 to 102. In 35 both these disclosures, the heat distortion resietanoe could be improved but is not sufficient to meevt the requirements of the most demanding applications.
=t is an object of the present invention to develop a process for ~0 prepaxing polyisoeyanate polyaddition products, in particular thermoplastic polyisoc anate of addition y p y products, hereinafter y also referred to as thermoplastic pol;Yurethanes, TpUs for short, by means of the reactions described at the outset, which process makes it possible to obtain products '.having an improved, i.e.
45 increased, heat distortion resistance.
' 3 we have found that this object is achieved by using 1,3- and/or 1,2-propanediol, preferably 1,3-propane~diol) as chain extender (c) and carrying out the reaction at an index of X104.
The process of the present invention is~ preferably used for ;r'~
preparing TPUB. Processes for preparincE TPtTs are generally known and differ from processes for preparing polyisocyanate , polyaddition products which are not thermopiastioaily processable mainly by largely avoiding chemical crosslinks in the product end thus using isoeyanate-reactive compounds (b) which have a mean functionality of from 1.8 to 2.6, prefelrably from 1.9 to 2.2, particularly preferably 2, and preferably largely, particularly preferably completely, omitting crossliLnkers, i.e. compounds v which are reactive towards isocyanates and have a molecular weight of x450 and a functionality of a~.3.
According to the present invention, 1,'.3- and/or 1,2-propanediol, preferably 1,3-propanediol) is used as chain extender.
In addition to the 1,3- and/or 1,2-pro~panediol, preferably 1) 3-propanediol, preference is given to using at least one . :~~_'' r ~, aromatic chain extender, i.e. at least one compound having a , .;
molecular weight of x450 g/mol, two groups which are reactive Z$ towards isocyanates and at least one aromatic :yatem in the . .;
molecule, as (c).
The molar ratio of 1,3- andlor 1,2-pro;panedioi to the compound.or compounds (b) is usually from 0.1:1 to 8:1, preferably from 1:1 30 to 4:1.
As aromatic chain extenders, preference is given to using 1,4-bis(hydroxymethyi)benzene (eHMB), 1,3-bis(hydroxymethyl)benzane, 1,2-bis(hydroxymethyl)benzene, $ 1,2-bis(~-hydroxyethoxy)benzene, 1,3-bis(2 -hydroxyethoxy)benzene, 1,4-bis(~ -hydroxyethoxy)benzene (HQEE), diesters of terephthalic arid with alkanediols having from 2 to~ 4 carbon atoms, e.g.
b~a(ethanedioi) terephthalate or bis(1,4-butanediol) terephthalate, aromatic diamines such as Z,4- and 4~ 2,6-tolylenediamine, 3,5-diethol-2,4-amd -2,6-tolylenediamine and primary ortho-dialkyl-, -trialkyl- and/or -tetraalkyl-substituted ;;._ 4;4'-diamino--ciiphenylmethanes, piperaz;ine and/or mixtures v comprising at least two of the aromatic chain extenders mentioned.
' ~ 4 Barticular preference is given to using 1.4-bis(hydroxymethyl)benzene as aromatic chain extender.
The molar ratio of aromatic chain extenders to 1,3- and/or referabi from.
s 1,2 propanediol is usually from~0.~01:1 to lsl, p y 0.05:1 to 0.55:1.
=n addition to the chain extenders mentioned, it is possible, if-desired, to use further generally known chain extenders (c) which will be described by way of example at a later point. Preferably;
the chain extenders used are exclusively 1,2- and/or 1.3- .propanediol with or without at least one aromatic chain extender.
' To adiust the hardness and melting point of the TPtJs, the molar ratios of the formative components (k) and (c) can be varied within a relatively wide range. Molar ratios of component (b) to the total of chain extenders (c) of from 1s0.5 to isl2, in Particular from 1:1 to 1:6.4 have been found to be useful= the hardness and the melting point of the TPUs increasing with increasing dioi content.
According to the present invention, the reaction is carried out ~ .;'<k at.an index of >_104, preferably forms 104 to 120, particularly'. ~:.'a preferably from 105 to 110. The index is defined as the ratio of all the isocyanate groups of the component (a) used in the reaction to the groups which are reactive towards isoeyanates; it i.e. the active hydrogens, in components (b), (c) and, if used, ' v'~
(d). At an~index of 100, there is one active hydrogen atom, i~:e.
one function which is reactive towards isocyanates. of the components (b), (c) and, if used, (c!) present. per one isocyanate group of the component (a).
3s T?i~ isQpyanate index) also known as index, is the actual amount of isocyanate groups used divided b;r the amount of isocyanate groups theoretically required for complete reaction of all OH
groups multiplied by 100.
In the following, the starting components and methods of preparing the preferred TPua are described by way of example.
The components (a), (b). (c) and also (e) and/or (f) which are customarily used or may be used in the preparation of the TPtTs are described below by way of example:
S
a) Suitable organic isocyanates (a) axe preferably aliphatic., cycloaliphatic and in particular ai:omatic diisocyanates.
Specific examples are: aliphatic diisocyanates such as hexamethylene-1,6-diisocyanate, 2-rnethyipentamethylene 1.5-diisocyanate, Z-ethylbutylene :1.4-diisocyanate or . mixtures of at least 2 of the C6>a7.kylene diisocyanates , ~;x mentioned, pentamethylene 1,5-diisocyanate and butylene '~~' L,4-diisocyanate, cycloaliphatic da.isocyanates such as 1-isocyanato-3,3,5-trimethyl-5-isonyanatomethylcycloh~xane i0 (isophorone diisocyanate), 1,4- and/or 1,3-bis(isocyanatomethyl)eyclohexane (HXDI)) cyclohexane , 1,4-diisocyanate, 1-methylcyciohexane 2,4- and 2,6-diisocyanate and also the corresponding isomer mixtures, dicyclohexylmethane 4,4'-, 2,4'- a;nd 2,2'-diisocyanate and also the corr~sponding isomer mixtures and preferably aromatic diisocyanates such as tolylene 2,4-diisocyanate,~
mixtures of tolylene 2,4- and 2,6-diisocyanate, 3,3'-dimathylbiphenyl 4,4'-diisocyanate (TOO=), p-phenylene - diisocyanate (pDI). m-, p-xylylene diisocyanats (XDI), Z0 diphenylmethane 4,4'-, 2,4'- and 2,2'-diisocyanate (MD=), mixtures of diphenylmethane 2,4'- and 4,4'-diisocyanato, urethane-modified liquid diphenyltr~sthane 4,4'- apd/or 2,4'-diisocyanates, 1,2-di(4-isocyanatophenyl)ethane (EDZ) and naphthylene 1,5-diisocyanate. preference ie~ given to Z5 using hexamethylene 1,6-diisocyana~te, diphenylmethane 4,4'-diisocyanate, p-phenylene dii.socyanate (8DI)) v~"
1,2-di(4-isocyanatvphenyl)ethane pED~), naphthylene 1,5- .diisocyanate and 3,3'-dimethy7.biphenyl 4,4'-diisocyanate (TODD.
'.
b) As compounds (b)-which are reacti~~e towards isocyanates, it is possible to. use, for example, polyhydroxyl compounds having molecular weights of from 451 to 8000, preferably from 600 to 6000, in particular from 800 to 4000, and a mean functionality of from 1.8 to 2.6, preferably from 1.9 to 2.2, in particular 2. As (b)) preferenne is given to using polyetherols and/or polyesterols, particularly preferably polyether diols and/or polyester ~diols.
Hm"~ever, other suitable isocyanate-reactive compounds (b) are hydroxyl-containing polymers, for example polymethacrylate diols, polydimethylsiloxane polyols, hydroxyl-containing polyethylene-butylene copolymers, hydroxyl-containing hydrogenated polyisvprenes, pviya,cetals such as polyoxymethylene and water-insoluble formals, e.g.
polybutanediol formal and polyhex:anedioi formal, and aliphatic polycarbonates) in particular those prepared from , 1,6-hexanedivl by transesterification and having the abovementioned molecular weights. Ths compounds mentioned can be employed as individual components or in.the form of mixtures.
The mixtur~s for preparing the TPUs or the TPUs themselves have to be based at least predominantly on difunctioaal substances which are reactive towards isocyanates. The TPUs prepared using these mixtures are thus predominantly unbranched, i.e. predominantly not crossiinked.
Suitable polyetherols can be prepared by known methods, for example by addition of alkylene oxides onto at least one initiator molecule containing at least 2 reactive hydrogen atoms in bonded form, preferably in the presenos of known catalysts, for example alkali metal hydroxides such as sodium or potassium hydroxide or alkali meaal alkoxides such as sodium methoxide, sodium or potassium ethoxide or potassium isopropoxide, Lewis acids such as antimony pentachloride,.
boron fluoride etherate, bleaching earth, basic salts of cesium, e.g. cesium hydroxide. and,~or bass,c salts and/or hydroxides of alkaline earth metal:a. Preference is given to using cesium hydroxide and/or calc:~um hydroxide as catalysts in the alkoxylation in order to obtain polyether polyols having a low content of unsaturated units. Exampls9 of alkylene oxides are: ethylene oxid~~, 1,2-propylene oxide, tetrahydrofuran, 1,2- and 2,3-butylene oxide. Preference is given to using ethylene oxide and mixtures of 1,2-propylene oxide and ethylene oxide. The aikylene oxides can be used' individually, alternately in succession or as a mixture.
Examples of suitable initiator molecules eras water, amino.
alcohols, such as N-alkyidialkanolamines,~for example , N-methyidisthanolamine, and preferably diols, e.g.
alkanediols or dialkylene glycols having from 2 to 1Z carbon 35 stoles, preferably 2 to 6 carbon atoms, e.g. ethane diol.
1,3-propanediol. 1,4-butanediol and 1,6-hexanediol. If desired, mixtures of initiator mol.eculea can also be used.
Further suitable polyetheroia are the hydroxyl-containing, pol~;rmerization products of tetrahydrofuran (polyoxytetramethylene glycols). F~referenca is given to using polyetherols which ire prepared ue:ing 1,2-propylene oxide and ethylene oxide and in which~more than 50%) preferably from to 100%, of the os groups are primary hydroxyl groups and, in which at least part of the ethylene oxide is arranged as a 45 terminal block; particular preference is given to using polyoxytetramethylene giycols (po:lytetrahydrofuran). such polyetherols can be obtained by, Eor example, (first polymerizing the 1,2-propylene oxide onto the initiator molecule and subsequently polymerizing on the ethylene oxide or first copolymerizing all the i,a-propylene oxide in a mixture with part of the ethylene oxide and subsequently polyrneri2ing on the remainder of the ethylene oxide or, stepwise, first polymerizing part of the ethylene oxide onto the initiator molecule, then polymerizing on all of the 1,2-propylene oxide and then the remainder of the ethylene oxide.
The initiator substances and the catalysts can b~ reacted, ~x;, preferably after removing any water present, with the propylene oxide and, if desired, further alkylene oxides at elevated temperature and reduced p:ressure,. in a customary reactor or autoclave, for example a stirred tank reactor or.
tube reactor with customary facilities for cooling the reaction mixture. The oataly:t is usually used in an amount of from 0 to 10 ppm, based on the total formulation, in the reaction mixture. The alkoxylation is preferably carried out 'at a temperature in the reaction mixture within a range from 70~C to 150oC, particularly preferably from 80~C to lOS~C..The .
reaction is carried out at generally known pressures. The alkylene oxides can, in general, be added to the reaction mixture over a period of from 4 to 20 hours, depending on the Z5 desired molecular weight of the polyoi. preferably, propylene oxide is added at the beginning of the reaction so that a block of polyoxypropylene units having a molecular weight of at least 700 g/mol is added onto the initiator substance. The reaction time can be from 1 to 8 hours, preferably such that complete reaction of the alkylene oxides is ensured. After complete reaction of the, for example, propylene oxide and ~;~~r~w any further alkylene oxides, polyc~xyethylene units are particularly preferably added vntc~ the end of the polyol by addition of ethylene oxid~. Subgeq~uently,~the reaction.
mixture is, as~a rule, cooled, preferably under reduced pressure, and worked up in a known manner. For example. the cesium catalyst can be removed frcnn the polyol by adsorption on, for example, silicates and subsequent,filtration.
Alternatively. the basic catalyst salts, for example the abovementioned hydroxides, can be neutralized, e.g. by a , suitable acid such as phosphoric e~cid) and left in the polyol. Known stabiliz~rs, e.g. against oxidation, can subsequently be added to the polyols.
The polyetherols preferably have an unsaturation of leas than 0.07 meq/g, preferably from 0.001 to 0.05 meq/g, particularly preferably from 0.001 to 0.04 meq/g, in particular from 0.001 to 0.01 meq/g. Th~ unsatuxation, which is usually given in meq per g of polyether polyalcohol, can be determined by generally known methods, for example by the known method of Raufmann by bromination of the double bonds and subsequent S titration with iodine. she unit m~eq/g generally corresponds to the content of double bonds in mmol per g of polyether polyaicohol.
Suitable polyesterolea can be prepared, for example, from l0 dicarboxylic acids having from Z to 12 carbon atoms, preferably from 4 to 8 carbon atoms, and polyhydric alcohois.' r r~
Examples of suitable dicarboxyiic 'acids are: aliphatic v ~~:
dicarboxylic acids such as succinic acid, giutaric acid, suberic acid, azelaic acid, sebbacic acid and preferably 15 adipic acid and aromatic dirarboxylic acids such as phthalic ,x,:
acid, isophthalic acid and terephthalic acid. The dicarboxylic acids can be used individually or ae mixtures) e.g. in the form of a succinic, glutaric and adipic acid mixture. Likewise, mixtures of aromatic and aliphatic ZO dicarboxylie acids can be used. To prepare the polyesterois, it may be advantageous to replace.the dicaxboxylic acids with the corresponding dicarboxylic acid derivatives, e.g.
dicarboxylic esters having from 1 to 4 carbon atoms in the alcohol radical, dicarboxylic anh,ydrides,or dicarboxylic acid 25 chlorides. Examples of polyhydric alcohols are alkane diola having from 2 to 10, preferably from 2 to 6, carbon atoms, e.g. ethanedioi, 1,3-propanediol, 1,4-butanedioi, 1,5-pentanediol, 1.6-hexanediol, 1,10-decanediol, 2,2 -dimethylpropane-1,3~dioi, 3,3-dimethylpentane-1,5-.diol, 30 1,2-propanediol and dialkylene ether glycols such as diethylene glycol sad dipropylenes glycol. Depending on the desired properties, the polyhydri.c alcohols can be used alone or in admixture with one another.
Further suitable polysaterols are esters of carbonic acid with the abovementioned diola, in particular those having from 4 to 6 Carbon atoms, e.g. 1,4~butanediol and/or 1,,6-hexanedioi, condensation products of w-hydroxycarboxylic acids, for example w-hydroxycaproic acid, and preferably polymerization products of lactones, for example substituted or unsubstituted w-caprolactones.
Polyesterole which are praferabiy used are alkanediols Po~.Yadipates having from 2 to 6 carbon atoms in the aikylene radical, s.g. ethanediol polyadipates, 1,4-butanediol polyadipatea, ethanediol-1,4-but;snediol polyadipates, .. ;.:.:
1,6-hexanedioi~(neopentyl glycol) polyadipates, 3,3-dimethyl-1,5-pentanediol polyadipates~, poly(e-caprolactone) and, in particular, 1,6~hexanediol-1,4-butanediol po7.yadipates.
c) As chain extenders (c) which may, if desired, be used in addition to the chain extenders used according to the present invention, which additional chain extenders usually hay~,' molecular weights of s450 g/mol, preferably from 60 to 300 g/mol. preference is given to using aikanediois having from 2 to 12 carbon atoms, preferably 2,4,6 or 8 carbon atoms, e.g. ethanediol, 1,6-hexanediol, 1,4-cyclohexanedioi, 1,4-bis(hydroxymethyi)cyclohexane:diol, isosorbide . ~a~~
(1,4:3,6-dianhydro-D-sorbitol), 3-(hydroxymethyl)-5-nitrobenzylalcohol, pyridinedxmethanol and, in particular, 1,4-butanediol and dialkylene ether glycol such as diethylene glycol and dipropylene giyool. - . ~''''''~
However, other suitable chain exi:enders are dicarboxylic, acids such as adipic acid, malonac acid, octanedioic acid, terephthalic acid and (cyclo)aliphatic diamines such as piperazine, 4,4'..diaminodicyclohnxylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 1-amino-3,3,5-trimethyl-5-aminomethylcyc;lohexane. ethylendiamine, 1,2-, or 1,3 propylenediamine, N-~nethyipropylene-1,3-diamine--Z5 andlor N,N'-di.methylethylenediam.ine.
Additional chain extenders which are particularly preferably used are alkanediols having from 2 to 10 carbon atoms in the alkylene radical, in particular 1,4- butanediol and/or dialkylene glycols having from 4 to 8 carbon atoms.
.., ,.,.;,.;:
e). suitable catalysts which, in particular, accelerate they .
reaction between the NCO groups of the diisocyanates (a) and the hydroxyl groups of the formative components (b) and (c) are the catalysts known and customary in the prior art, wiz:
tertiary amines such as triethylamine, dimethylcyclohexylamine, N-methylmorpholine, ' N,N'-dimethylpiperazine, 2..(dimethylaminoethoxy)ethanoi, diazabicycio[2.2.2~octane and the like and also, in particular. organic metal compounds such as titanate est~ra, iron compounds such as iron(=Ir) aeetylacetonate, tin compounds such as tin diacetate, tin dioctoate, tin dilaurate or the dialkyitin salts of aliphatic carboxylic acids, e.g.
,is dibutyltin diacetate, dibutyitin dilaurate or the like. The catalysts axe usually used in amounts of from 0.0001 to 0.1 r .. . :;.,;;,, parts by weight per 100 parts by Weight of polyhydroxyl compounds (b). , f) Apart from catalysts, it is also possible to add oustomaxy auxiliaries and/or additives (e) to the formative components (a) to (d). Examples which may bs mentioned are surface-active substances) foam stabilizers, cell regulators, flame retardants. nucleating agents, oxidation inhibitors, stabilizers, lubricants and mould release agents, dyes and pigments, inhibitors, stabilizers against hydrolysis, light, heat or diecoloratioa, preservatives to prsvont microbial degradation, inorganic and/or organic fillers, reinforcing materials and plasticizers. ,''.
. .,_:,,,-,~;
~k'hq Further details regarding the abovementioned auxiliaries and additives may be found in the specialist literature.
,;;;::,':v',.
All molecular weights mentioned in this document have the unit I9/mol].
TpUs can be prepared by known methods by the~ona-shot process either continuously on belt units or using reaction extruders or ' batchwise by the casting process or by the known prepolymer process. In these processes, the components (a), (b) and if desired, (c) which are reacted can bye mixed in succession or simultaneously) with the reaction commencing immediately.
The resotion is preferably carried out by the one-shot process.
As already mentioned. the reaction mixture comprising (a), (b) (c) and, if desired, (e) and/or (f) can be reacted by the ~ ~ v;r extruder process or preferably by the belt process. Speoifically, the belt process is carried out as hollows:
The formative components (a) to (e) and, if desired (e) and/or '.
(f) are continuously mixed at temperatures above the melting point of the formative components (.~) to (c) by mean= of a mixing ,10 head. The reaction mixture is appliE~d to a support, preferably a conveyor belt, and conveyed through a heated zone. The reaction temperature in the heated zone can be from 60 to 200~C, preferably from 100 to 180~C, and the residence time is generally fromØ05 to 0.5 hours, preferably from 0.1 to 0.3 hours. After the 4S reaction is complete, the TPU is allowed to cool and is subsequently commiauted or granulat~sd.
y,:'=,~, =n the extruder process, the formative components (a) to (c) and, if desired, (e) and (f) are fed individually or as a mixture into the extruder, reacted at, for example, from 100 to 250°C, preferably from 140 to 220~C, th~ TPU obtained.is extruded, cooled and granulated.
The processing of the TPUs prepared according to.the prss~nt invention, which are usually in the form of granulQS or powder, to produce the desired cable sheathing,. fibres; mouldings, linings in automobiles, seals, cable p:Lugs, bellows, hoses, films. rollers, towing cables, straps «r damping s,lements is carried out by customary methods, e.g. injection moulding or extrusion.
=f crosslinked polyisocyanat~ polyaddition products, for example , flexible. semi rigid or rigid, compact or cellular, for example '**rt microceilular, polyurethanes and/or polyisocyanurates ar~
prepared by the process of the present invention, preference is given to getting compounds (b) having a functionality of from 2 30 to 6, crosslinkers (d) having a functionality of from 3 to 6 and a molecular weight of x450, preferably from 60 to 300, and in,the case of foamed polyurethane and/or polyisocyanurate products also generally known blowing agents, for example wet~r, fluorinated hydrocarbons and/or (cyclo)alkanes having a boiling point at Z5 1013 mbar of usually <50°C. The preparation of these products is generally known.
The polyisocyanate products which can be prepared by the process of the present invention, in particular the thermoplastic 30 polyurethanes, have the desired incr~ased heat distortion resistance.
The advantages of the invention are illustrated by the following examples.
3 5 ~ ~"
Preparation of the TPUs The Tpus were prepared using the starting components shown in , Table 1. The isocyanate-reactive compounds were initially charged 40 in the liquid state at 100°C, in the case of BHMB at 110°C, and the isocyanate, which had been preheated to SO~C, was added, and the components were intensively mixed by stirring. After reaching a temperature of 115°C, the exothermi~cally reacting mixture was g5 poured into a dish in which it was cured at 120°C for a residence time of 20 minutes. After heating at 100°C for 24 hours, thQ
lZ
material was granulated and injection moulded at 210~c, when using sHl~lB at 230~C, to produce test apecirnens .
Table 1 :y, :
~
. :: :
, , :. ~a Example 1 2 3 4 5 6 7 1,3-propanediol Ig] - 97.5 98.7 99.9 101.1 - -108HM8 [g) - - - - -- 115,s I3QEE (g] - - _ _ - 130.3 -1,4-eutanediol (g) 108,1 - - - - -15poly(t-caprolacto- 1000 1000 1000 1000 1000 1000 1000 ne)) mol~cular weight = 2,000 [g]
Elastoetab~ HOl [g] 8 8 8 8 8 8 8 Z~4,4'-MDI (g] 456 451 9;69 487 505 313 360 Il7dex 106 100 1.03 106 109 106 106 ,;
~SElastoBtab~: hydrolysis a stabilizer base:d carbodiimide on (Elaetogran Gaibii ) Examples 4 and s are according to preseat examples the invention.
W
The TPLJS prepared to their in the examples were determine tested 30properties, in particular regards heat distortion as the resistance. The properties the pocim~ens of test are s indicated in Tabla 2.
d0 i3 Table 2 Exam-DensityShore Vicat Abra- tear props-TensileElon-Ple. A Temperatu-siom gation re- atreagthga- ~:'u hard- re sistance tion . ~:;.~,:
ness at .'... .:.,~.':,'4 break I9/cm~] [~C] (mtn3J(p/mm) (lv/amv]
( J
1 1.18 84 l44 35 62 44 510 2 1.17 82 138 25 58 41 420 3 1.17 82 156 25 56 42 400 4 1.18 84 160 27 67 44 480 5 1.18 84 160 24 62 48 510 6 1.18 83 128 45 52 44 590 7 1.18 81 144 47 59 30 580 The significantly improved heat distortion resistance of the samples 4 and 5 which are according to the present invention is shown particularly clearly by the vicat temperatures (see also Figure 1]. The Vicat temperature indicates the temperature at which a pin which is loaded with a weight of 10 N and has a . :,~;;.,' 5 contact area of 1 mma has penetratQd to a depth of 1 mm into the lw specimen which is heated at iZO~C/h. This mesaurement is carried . out in accordance with DIN EN ISO 306.
. :;.;..
The properties of the TPUs according t;o the present invention are shown in Table 2. These data support the assessment of the prior art given at the outset. Only the TpUa; prepared according to the present invention have a heat distortion resistance which meets the requirements of the most demanding applications. ~t is considerably improved compared to that. of the comparative 3s samples. In addition, the aampies 4 and 5 have significantly unproved values for the abrasion and tear propagation resistance, partic~lariy compared to the samples which wore prepared using -: sxclusively aromatic chain extenders (Examples 6 and 7). The priparation of the TPUs at a known, lc~w index leads to a ~p diterioration in the heat distortion =resistance, the tensile strength, the tear propagation resistance and the elongation at break (Examples 2 and 3). TpU prepared. using Only 1,4-butanediol as chain extender displays) in particular) a poorer heat distortion resistance and increased abrasion. v 4 The improved heat distortion resistance resulting from the use of a relatively high index and 1,3-propan,ediol as chain extender can also be seen from the shape of the vicat curve (cf. Figure 1)..
=t can clearly be seen that the penetration of,the test pin is shifted to a higher temperature in the case of a higher index.
It is~thus demonstrated that the object, of the present invention, namely to provide polyisocyanate polyaddition products, in particular TBUs, having improved props:'ties, in particular an i0 improved heat di.gtortion resistance, hays been able to be achieved by the technical teachings of the present invention. The TPVs.
according to the present invention have: significantly improved properties compared to known TPVs.
.., ;v ,, ~0 ~0
Preparation of thermoplastic polyurethanes The present invention relates to processes for. preparing polyisocyanate polyaddition products by reacting (a) isocyanates , with (b) compounds which are reactive towards isocyanates and have a molecular weight of from 451 to 8000 in the presence of (c) chain extenders and, if desired, (d) crossiinkers, (e) to catalysts and/or (f) customary auxiliaries and/or additives and also to the polyisocyanate polyaddition products which can be prepared using this process. in particular, the invention relates to processes for preparing thermoplastic polyisocyanate polyaddition products by reacting (a.) isocyanates with (b) .compounds Which are reactive towards isocyanates and have a molecular weight of from 451 to 8000 and a mean functionality of from 1.8 to 2.6 in the presence of (c) chain extenders) (e) catalysts and/or (f) customary auxiliaries and/or additives and also to the thermoplastic products obtainable in this way.
ao Polyisocyanate polyaddition producte~ and processes for their preparation are generally known and have been described many ''' times. A subgroup of these polyaddit:ion products is the thermoplastic polyisocyanate polyaddition products, generally Zg .also referred to as thermoplastic polyurethanes (TPUs). These TPUs are partially crystalline materials and belong to the class of thermoplastic elastomers. They comprise a partially crystalline hard block built up fronn the isocyanate and low molecular weight chain extenders and an amorphous soft block 30 which is typically built up from the. relatively high molecular weight compounds which are reactive toward isoeyanates, customarily polyester diols and/or polyether diols. A very good micromorphological demixing of these: phases is the necessary prerequisite for the elastic behaviour of the TPUs. The hard ~g block ants, owing to its partial cr,~stallinity, a~ physical crosslinking which is reversibly broken above the melting point of the hard block, thus making thermoplastic forming of the material possible. The soft block i;s in a plastic or liquid state nt room temperature and is responsilble for the ready 40 deformability of the Tpvs. After deformation, the physical crosslinking enables elastic recovery to the initial state. The TPUS have a combination of advantageous material properties such as low abrasion, good chemical resistance and high flexibility with simultaneously high strength. In addition, they offer 45 advantages in terms of inexpensive production) for example by the belt process or extrusion, which can be carried out continuously or discontinuously, and simple thermoplastic processing.
a variation of the starting components enables products having a broad range of properties over a wide hardness range to be ~ .
prepared. The heat distortion resistance and thus also the use properties of the material at temperatures above, in particular, 80~C are determined predominantly by the melt behaviour of the hard segment block, i.e. the quality of the ~hys~.cal crossiinking. ' ' Thermoplastic polyurethanes which are prepared on the basis of (a) MDI, (b) polyester diois and/or polyether diols and (c) butanedioi partly lose their heat distortion resistance at above 80 ~C, i.e. the material no longer returns to its initial state.
Zn order to be able to use TpUs under static ox dynamic load at relatively high temperatures, the heat distortion resistance of i5 the material has to bQ improved over that of .known TPUs.
To improve the modulus of elasticity of TPUs, particularly at high temperatures, the use of 1,3-pro~panediol as chain extender ~0 has already been described, with the ~TPUs being prepared at an index of 102 (Forschner et al., Polyurethane 'World Congrese 1997, page 371). However, the improvement in the modulus of ~lasticity t.
,,.,: .
.. ~,.
of TPUs prepared in this way is still unsatiefaotory, so that further ways of improving the heat distortion resistance have to 25 be sought.
Further publications describe improvement of the heat distortion resistance of Tsos (Ep-A 718 335) or improved dimensional stability of TpU fibres under~load at high temperatures (IT-A 733 30 216). Sp-A 718 335 discloses aromatic chain extenders in combination with alkane diois having from 4 to 44 carbon atoms for achieving this aim. =T-A 733 216 ~dsscribes the use of various chain extenders including 1,3-propane~diol and 1,4-bis(hydroxymethyl) benzene at an index of from 98 to 102. In 35 both these disclosures, the heat distortion resietanoe could be improved but is not sufficient to meevt the requirements of the most demanding applications.
=t is an object of the present invention to develop a process for ~0 prepaxing polyisoeyanate polyaddition products, in particular thermoplastic polyisoc anate of addition y p y products, hereinafter y also referred to as thermoplastic pol;Yurethanes, TpUs for short, by means of the reactions described at the outset, which process makes it possible to obtain products '.having an improved, i.e.
45 increased, heat distortion resistance.
' 3 we have found that this object is achieved by using 1,3- and/or 1,2-propanediol, preferably 1,3-propane~diol) as chain extender (c) and carrying out the reaction at an index of X104.
The process of the present invention is~ preferably used for ;r'~
preparing TPUB. Processes for preparincE TPtTs are generally known and differ from processes for preparing polyisocyanate , polyaddition products which are not thermopiastioaily processable mainly by largely avoiding chemical crosslinks in the product end thus using isoeyanate-reactive compounds (b) which have a mean functionality of from 1.8 to 2.6, prefelrably from 1.9 to 2.2, particularly preferably 2, and preferably largely, particularly preferably completely, omitting crossliLnkers, i.e. compounds v which are reactive towards isocyanates and have a molecular weight of x450 and a functionality of a~.3.
According to the present invention, 1,'.3- and/or 1,2-propanediol, preferably 1,3-propanediol) is used as chain extender.
In addition to the 1,3- and/or 1,2-pro~panediol, preferably 1) 3-propanediol, preference is given to using at least one . :~~_'' r ~, aromatic chain extender, i.e. at least one compound having a , .;
molecular weight of x450 g/mol, two groups which are reactive Z$ towards isocyanates and at least one aromatic :yatem in the . .;
molecule, as (c).
The molar ratio of 1,3- andlor 1,2-pro;panedioi to the compound.or compounds (b) is usually from 0.1:1 to 8:1, preferably from 1:1 30 to 4:1.
As aromatic chain extenders, preference is given to using 1,4-bis(hydroxymethyi)benzene (eHMB), 1,3-bis(hydroxymethyl)benzane, 1,2-bis(hydroxymethyl)benzene, $ 1,2-bis(~-hydroxyethoxy)benzene, 1,3-bis(2 -hydroxyethoxy)benzene, 1,4-bis(~ -hydroxyethoxy)benzene (HQEE), diesters of terephthalic arid with alkanediols having from 2 to~ 4 carbon atoms, e.g.
b~a(ethanedioi) terephthalate or bis(1,4-butanediol) terephthalate, aromatic diamines such as Z,4- and 4~ 2,6-tolylenediamine, 3,5-diethol-2,4-amd -2,6-tolylenediamine and primary ortho-dialkyl-, -trialkyl- and/or -tetraalkyl-substituted ;;._ 4;4'-diamino--ciiphenylmethanes, piperaz;ine and/or mixtures v comprising at least two of the aromatic chain extenders mentioned.
' ~ 4 Barticular preference is given to using 1.4-bis(hydroxymethyl)benzene as aromatic chain extender.
The molar ratio of aromatic chain extenders to 1,3- and/or referabi from.
s 1,2 propanediol is usually from~0.~01:1 to lsl, p y 0.05:1 to 0.55:1.
=n addition to the chain extenders mentioned, it is possible, if-desired, to use further generally known chain extenders (c) which will be described by way of example at a later point. Preferably;
the chain extenders used are exclusively 1,2- and/or 1.3- .propanediol with or without at least one aromatic chain extender.
' To adiust the hardness and melting point of the TPtJs, the molar ratios of the formative components (k) and (c) can be varied within a relatively wide range. Molar ratios of component (b) to the total of chain extenders (c) of from 1s0.5 to isl2, in Particular from 1:1 to 1:6.4 have been found to be useful= the hardness and the melting point of the TPUs increasing with increasing dioi content.
According to the present invention, the reaction is carried out ~ .;'<k at.an index of >_104, preferably forms 104 to 120, particularly'. ~:.'a preferably from 105 to 110. The index is defined as the ratio of all the isocyanate groups of the component (a) used in the reaction to the groups which are reactive towards isoeyanates; it i.e. the active hydrogens, in components (b), (c) and, if used, ' v'~
(d). At an~index of 100, there is one active hydrogen atom, i~:e.
one function which is reactive towards isocyanates. of the components (b), (c) and, if used, (c!) present. per one isocyanate group of the component (a).
3s T?i~ isQpyanate index) also known as index, is the actual amount of isocyanate groups used divided b;r the amount of isocyanate groups theoretically required for complete reaction of all OH
groups multiplied by 100.
In the following, the starting components and methods of preparing the preferred TPua are described by way of example.
The components (a), (b). (c) and also (e) and/or (f) which are customarily used or may be used in the preparation of the TPtTs are described below by way of example:
S
a) Suitable organic isocyanates (a) axe preferably aliphatic., cycloaliphatic and in particular ai:omatic diisocyanates.
Specific examples are: aliphatic diisocyanates such as hexamethylene-1,6-diisocyanate, 2-rnethyipentamethylene 1.5-diisocyanate, Z-ethylbutylene :1.4-diisocyanate or . mixtures of at least 2 of the C6>a7.kylene diisocyanates , ~;x mentioned, pentamethylene 1,5-diisocyanate and butylene '~~' L,4-diisocyanate, cycloaliphatic da.isocyanates such as 1-isocyanato-3,3,5-trimethyl-5-isonyanatomethylcycloh~xane i0 (isophorone diisocyanate), 1,4- and/or 1,3-bis(isocyanatomethyl)eyclohexane (HXDI)) cyclohexane , 1,4-diisocyanate, 1-methylcyciohexane 2,4- and 2,6-diisocyanate and also the corresponding isomer mixtures, dicyclohexylmethane 4,4'-, 2,4'- a;nd 2,2'-diisocyanate and also the corr~sponding isomer mixtures and preferably aromatic diisocyanates such as tolylene 2,4-diisocyanate,~
mixtures of tolylene 2,4- and 2,6-diisocyanate, 3,3'-dimathylbiphenyl 4,4'-diisocyanate (TOO=), p-phenylene - diisocyanate (pDI). m-, p-xylylene diisocyanats (XDI), Z0 diphenylmethane 4,4'-, 2,4'- and 2,2'-diisocyanate (MD=), mixtures of diphenylmethane 2,4'- and 4,4'-diisocyanato, urethane-modified liquid diphenyltr~sthane 4,4'- apd/or 2,4'-diisocyanates, 1,2-di(4-isocyanatophenyl)ethane (EDZ) and naphthylene 1,5-diisocyanate. preference ie~ given to Z5 using hexamethylene 1,6-diisocyana~te, diphenylmethane 4,4'-diisocyanate, p-phenylene dii.socyanate (8DI)) v~"
1,2-di(4-isocyanatvphenyl)ethane pED~), naphthylene 1,5- .diisocyanate and 3,3'-dimethy7.biphenyl 4,4'-diisocyanate (TODD.
'.
b) As compounds (b)-which are reacti~~e towards isocyanates, it is possible to. use, for example, polyhydroxyl compounds having molecular weights of from 451 to 8000, preferably from 600 to 6000, in particular from 800 to 4000, and a mean functionality of from 1.8 to 2.6, preferably from 1.9 to 2.2, in particular 2. As (b)) preferenne is given to using polyetherols and/or polyesterols, particularly preferably polyether diols and/or polyester ~diols.
Hm"~ever, other suitable isocyanate-reactive compounds (b) are hydroxyl-containing polymers, for example polymethacrylate diols, polydimethylsiloxane polyols, hydroxyl-containing polyethylene-butylene copolymers, hydroxyl-containing hydrogenated polyisvprenes, pviya,cetals such as polyoxymethylene and water-insoluble formals, e.g.
polybutanediol formal and polyhex:anedioi formal, and aliphatic polycarbonates) in particular those prepared from , 1,6-hexanedivl by transesterification and having the abovementioned molecular weights. Ths compounds mentioned can be employed as individual components or in.the form of mixtures.
The mixtur~s for preparing the TPUs or the TPUs themselves have to be based at least predominantly on difunctioaal substances which are reactive towards isocyanates. The TPUs prepared using these mixtures are thus predominantly unbranched, i.e. predominantly not crossiinked.
Suitable polyetherols can be prepared by known methods, for example by addition of alkylene oxides onto at least one initiator molecule containing at least 2 reactive hydrogen atoms in bonded form, preferably in the presenos of known catalysts, for example alkali metal hydroxides such as sodium or potassium hydroxide or alkali meaal alkoxides such as sodium methoxide, sodium or potassium ethoxide or potassium isopropoxide, Lewis acids such as antimony pentachloride,.
boron fluoride etherate, bleaching earth, basic salts of cesium, e.g. cesium hydroxide. and,~or bass,c salts and/or hydroxides of alkaline earth metal:a. Preference is given to using cesium hydroxide and/or calc:~um hydroxide as catalysts in the alkoxylation in order to obtain polyether polyols having a low content of unsaturated units. Exampls9 of alkylene oxides are: ethylene oxid~~, 1,2-propylene oxide, tetrahydrofuran, 1,2- and 2,3-butylene oxide. Preference is given to using ethylene oxide and mixtures of 1,2-propylene oxide and ethylene oxide. The aikylene oxides can be used' individually, alternately in succession or as a mixture.
Examples of suitable initiator molecules eras water, amino.
alcohols, such as N-alkyidialkanolamines,~for example , N-methyidisthanolamine, and preferably diols, e.g.
alkanediols or dialkylene glycols having from 2 to 1Z carbon 35 stoles, preferably 2 to 6 carbon atoms, e.g. ethane diol.
1,3-propanediol. 1,4-butanediol and 1,6-hexanediol. If desired, mixtures of initiator mol.eculea can also be used.
Further suitable polyetheroia are the hydroxyl-containing, pol~;rmerization products of tetrahydrofuran (polyoxytetramethylene glycols). F~referenca is given to using polyetherols which ire prepared ue:ing 1,2-propylene oxide and ethylene oxide and in which~more than 50%) preferably from to 100%, of the os groups are primary hydroxyl groups and, in which at least part of the ethylene oxide is arranged as a 45 terminal block; particular preference is given to using polyoxytetramethylene giycols (po:lytetrahydrofuran). such polyetherols can be obtained by, Eor example, (first polymerizing the 1,2-propylene oxide onto the initiator molecule and subsequently polymerizing on the ethylene oxide or first copolymerizing all the i,a-propylene oxide in a mixture with part of the ethylene oxide and subsequently polyrneri2ing on the remainder of the ethylene oxide or, stepwise, first polymerizing part of the ethylene oxide onto the initiator molecule, then polymerizing on all of the 1,2-propylene oxide and then the remainder of the ethylene oxide.
The initiator substances and the catalysts can b~ reacted, ~x;, preferably after removing any water present, with the propylene oxide and, if desired, further alkylene oxides at elevated temperature and reduced p:ressure,. in a customary reactor or autoclave, for example a stirred tank reactor or.
tube reactor with customary facilities for cooling the reaction mixture. The oataly:t is usually used in an amount of from 0 to 10 ppm, based on the total formulation, in the reaction mixture. The alkoxylation is preferably carried out 'at a temperature in the reaction mixture within a range from 70~C to 150oC, particularly preferably from 80~C to lOS~C..The .
reaction is carried out at generally known pressures. The alkylene oxides can, in general, be added to the reaction mixture over a period of from 4 to 20 hours, depending on the Z5 desired molecular weight of the polyoi. preferably, propylene oxide is added at the beginning of the reaction so that a block of polyoxypropylene units having a molecular weight of at least 700 g/mol is added onto the initiator substance. The reaction time can be from 1 to 8 hours, preferably such that complete reaction of the alkylene oxides is ensured. After complete reaction of the, for example, propylene oxide and ~;~~r~w any further alkylene oxides, polyc~xyethylene units are particularly preferably added vntc~ the end of the polyol by addition of ethylene oxid~. Subgeq~uently,~the reaction.
mixture is, as~a rule, cooled, preferably under reduced pressure, and worked up in a known manner. For example. the cesium catalyst can be removed frcnn the polyol by adsorption on, for example, silicates and subsequent,filtration.
Alternatively. the basic catalyst salts, for example the abovementioned hydroxides, can be neutralized, e.g. by a , suitable acid such as phosphoric e~cid) and left in the polyol. Known stabiliz~rs, e.g. against oxidation, can subsequently be added to the polyols.
The polyetherols preferably have an unsaturation of leas than 0.07 meq/g, preferably from 0.001 to 0.05 meq/g, particularly preferably from 0.001 to 0.04 meq/g, in particular from 0.001 to 0.01 meq/g. Th~ unsatuxation, which is usually given in meq per g of polyether polyalcohol, can be determined by generally known methods, for example by the known method of Raufmann by bromination of the double bonds and subsequent S titration with iodine. she unit m~eq/g generally corresponds to the content of double bonds in mmol per g of polyether polyaicohol.
Suitable polyesterolea can be prepared, for example, from l0 dicarboxylic acids having from Z to 12 carbon atoms, preferably from 4 to 8 carbon atoms, and polyhydric alcohois.' r r~
Examples of suitable dicarboxyiic 'acids are: aliphatic v ~~:
dicarboxylic acids such as succinic acid, giutaric acid, suberic acid, azelaic acid, sebbacic acid and preferably 15 adipic acid and aromatic dirarboxylic acids such as phthalic ,x,:
acid, isophthalic acid and terephthalic acid. The dicarboxylic acids can be used individually or ae mixtures) e.g. in the form of a succinic, glutaric and adipic acid mixture. Likewise, mixtures of aromatic and aliphatic ZO dicarboxylie acids can be used. To prepare the polyesterois, it may be advantageous to replace.the dicaxboxylic acids with the corresponding dicarboxylic acid derivatives, e.g.
dicarboxylic esters having from 1 to 4 carbon atoms in the alcohol radical, dicarboxylic anh,ydrides,or dicarboxylic acid 25 chlorides. Examples of polyhydric alcohols are alkane diola having from 2 to 10, preferably from 2 to 6, carbon atoms, e.g. ethanedioi, 1,3-propanediol, 1,4-butanedioi, 1,5-pentanediol, 1.6-hexanediol, 1,10-decanediol, 2,2 -dimethylpropane-1,3~dioi, 3,3-dimethylpentane-1,5-.diol, 30 1,2-propanediol and dialkylene ether glycols such as diethylene glycol sad dipropylenes glycol. Depending on the desired properties, the polyhydri.c alcohols can be used alone or in admixture with one another.
Further suitable polysaterols are esters of carbonic acid with the abovementioned diola, in particular those having from 4 to 6 Carbon atoms, e.g. 1,4~butanediol and/or 1,,6-hexanedioi, condensation products of w-hydroxycarboxylic acids, for example w-hydroxycaproic acid, and preferably polymerization products of lactones, for example substituted or unsubstituted w-caprolactones.
Polyesterole which are praferabiy used are alkanediols Po~.Yadipates having from 2 to 6 carbon atoms in the aikylene radical, s.g. ethanediol polyadipates, 1,4-butanediol polyadipatea, ethanediol-1,4-but;snediol polyadipates, .. ;.:.:
1,6-hexanedioi~(neopentyl glycol) polyadipates, 3,3-dimethyl-1,5-pentanediol polyadipates~, poly(e-caprolactone) and, in particular, 1,6~hexanediol-1,4-butanediol po7.yadipates.
c) As chain extenders (c) which may, if desired, be used in addition to the chain extenders used according to the present invention, which additional chain extenders usually hay~,' molecular weights of s450 g/mol, preferably from 60 to 300 g/mol. preference is given to using aikanediois having from 2 to 12 carbon atoms, preferably 2,4,6 or 8 carbon atoms, e.g. ethanediol, 1,6-hexanediol, 1,4-cyclohexanedioi, 1,4-bis(hydroxymethyi)cyclohexane:diol, isosorbide . ~a~~
(1,4:3,6-dianhydro-D-sorbitol), 3-(hydroxymethyl)-5-nitrobenzylalcohol, pyridinedxmethanol and, in particular, 1,4-butanediol and dialkylene ether glycol such as diethylene glycol and dipropylene giyool. - . ~''''''~
However, other suitable chain exi:enders are dicarboxylic, acids such as adipic acid, malonac acid, octanedioic acid, terephthalic acid and (cyclo)aliphatic diamines such as piperazine, 4,4'..diaminodicyclohnxylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 1-amino-3,3,5-trimethyl-5-aminomethylcyc;lohexane. ethylendiamine, 1,2-, or 1,3 propylenediamine, N-~nethyipropylene-1,3-diamine--Z5 andlor N,N'-di.methylethylenediam.ine.
Additional chain extenders which are particularly preferably used are alkanediols having from 2 to 10 carbon atoms in the alkylene radical, in particular 1,4- butanediol and/or dialkylene glycols having from 4 to 8 carbon atoms.
.., ,.,.;,.;:
e). suitable catalysts which, in particular, accelerate they .
reaction between the NCO groups of the diisocyanates (a) and the hydroxyl groups of the formative components (b) and (c) are the catalysts known and customary in the prior art, wiz:
tertiary amines such as triethylamine, dimethylcyclohexylamine, N-methylmorpholine, ' N,N'-dimethylpiperazine, 2..(dimethylaminoethoxy)ethanoi, diazabicycio[2.2.2~octane and the like and also, in particular. organic metal compounds such as titanate est~ra, iron compounds such as iron(=Ir) aeetylacetonate, tin compounds such as tin diacetate, tin dioctoate, tin dilaurate or the dialkyitin salts of aliphatic carboxylic acids, e.g.
,is dibutyltin diacetate, dibutyitin dilaurate or the like. The catalysts axe usually used in amounts of from 0.0001 to 0.1 r .. . :;.,;;,, parts by weight per 100 parts by Weight of polyhydroxyl compounds (b). , f) Apart from catalysts, it is also possible to add oustomaxy auxiliaries and/or additives (e) to the formative components (a) to (d). Examples which may bs mentioned are surface-active substances) foam stabilizers, cell regulators, flame retardants. nucleating agents, oxidation inhibitors, stabilizers, lubricants and mould release agents, dyes and pigments, inhibitors, stabilizers against hydrolysis, light, heat or diecoloratioa, preservatives to prsvont microbial degradation, inorganic and/or organic fillers, reinforcing materials and plasticizers. ,''.
. .,_:,,,-,~;
~k'hq Further details regarding the abovementioned auxiliaries and additives may be found in the specialist literature.
,;;;::,':v',.
All molecular weights mentioned in this document have the unit I9/mol].
TpUs can be prepared by known methods by the~ona-shot process either continuously on belt units or using reaction extruders or ' batchwise by the casting process or by the known prepolymer process. In these processes, the components (a), (b) and if desired, (c) which are reacted can bye mixed in succession or simultaneously) with the reaction commencing immediately.
The resotion is preferably carried out by the one-shot process.
As already mentioned. the reaction mixture comprising (a), (b) (c) and, if desired, (e) and/or (f) can be reacted by the ~ ~ v;r extruder process or preferably by the belt process. Speoifically, the belt process is carried out as hollows:
The formative components (a) to (e) and, if desired (e) and/or '.
(f) are continuously mixed at temperatures above the melting point of the formative components (.~) to (c) by mean= of a mixing ,10 head. The reaction mixture is appliE~d to a support, preferably a conveyor belt, and conveyed through a heated zone. The reaction temperature in the heated zone can be from 60 to 200~C, preferably from 100 to 180~C, and the residence time is generally fromØ05 to 0.5 hours, preferably from 0.1 to 0.3 hours. After the 4S reaction is complete, the TPU is allowed to cool and is subsequently commiauted or granulat~sd.
y,:'=,~, =n the extruder process, the formative components (a) to (c) and, if desired, (e) and (f) are fed individually or as a mixture into the extruder, reacted at, for example, from 100 to 250°C, preferably from 140 to 220~C, th~ TPU obtained.is extruded, cooled and granulated.
The processing of the TPUs prepared according to.the prss~nt invention, which are usually in the form of granulQS or powder, to produce the desired cable sheathing,. fibres; mouldings, linings in automobiles, seals, cable p:Lugs, bellows, hoses, films. rollers, towing cables, straps «r damping s,lements is carried out by customary methods, e.g. injection moulding or extrusion.
=f crosslinked polyisocyanat~ polyaddition products, for example , flexible. semi rigid or rigid, compact or cellular, for example '**rt microceilular, polyurethanes and/or polyisocyanurates ar~
prepared by the process of the present invention, preference is given to getting compounds (b) having a functionality of from 2 30 to 6, crosslinkers (d) having a functionality of from 3 to 6 and a molecular weight of x450, preferably from 60 to 300, and in,the case of foamed polyurethane and/or polyisocyanurate products also generally known blowing agents, for example wet~r, fluorinated hydrocarbons and/or (cyclo)alkanes having a boiling point at Z5 1013 mbar of usually <50°C. The preparation of these products is generally known.
The polyisocyanate products which can be prepared by the process of the present invention, in particular the thermoplastic 30 polyurethanes, have the desired incr~ased heat distortion resistance.
The advantages of the invention are illustrated by the following examples.
3 5 ~ ~"
Preparation of the TPUs The Tpus were prepared using the starting components shown in , Table 1. The isocyanate-reactive compounds were initially charged 40 in the liquid state at 100°C, in the case of BHMB at 110°C, and the isocyanate, which had been preheated to SO~C, was added, and the components were intensively mixed by stirring. After reaching a temperature of 115°C, the exothermi~cally reacting mixture was g5 poured into a dish in which it was cured at 120°C for a residence time of 20 minutes. After heating at 100°C for 24 hours, thQ
lZ
material was granulated and injection moulded at 210~c, when using sHl~lB at 230~C, to produce test apecirnens .
Table 1 :y, :
~
. :: :
, , :. ~a Example 1 2 3 4 5 6 7 1,3-propanediol Ig] - 97.5 98.7 99.9 101.1 - -108HM8 [g) - - - - -- 115,s I3QEE (g] - - _ _ - 130.3 -1,4-eutanediol (g) 108,1 - - - - -15poly(t-caprolacto- 1000 1000 1000 1000 1000 1000 1000 ne)) mol~cular weight = 2,000 [g]
Elastoetab~ HOl [g] 8 8 8 8 8 8 8 Z~4,4'-MDI (g] 456 451 9;69 487 505 313 360 Il7dex 106 100 1.03 106 109 106 106 ,;
~SElastoBtab~: hydrolysis a stabilizer base:d carbodiimide on (Elaetogran Gaibii ) Examples 4 and s are according to preseat examples the invention.
W
The TPLJS prepared to their in the examples were determine tested 30properties, in particular regards heat distortion as the resistance. The properties the pocim~ens of test are s indicated in Tabla 2.
d0 i3 Table 2 Exam-DensityShore Vicat Abra- tear props-TensileElon-Ple. A Temperatu-siom gation re- atreagthga- ~:'u hard- re sistance tion . ~:;.~,:
ness at .'... .:.,~.':,'4 break I9/cm~] [~C] (mtn3J(p/mm) (lv/amv]
( J
1 1.18 84 l44 35 62 44 510 2 1.17 82 138 25 58 41 420 3 1.17 82 156 25 56 42 400 4 1.18 84 160 27 67 44 480 5 1.18 84 160 24 62 48 510 6 1.18 83 128 45 52 44 590 7 1.18 81 144 47 59 30 580 The significantly improved heat distortion resistance of the samples 4 and 5 which are according to the present invention is shown particularly clearly by the vicat temperatures (see also Figure 1]. The Vicat temperature indicates the temperature at which a pin which is loaded with a weight of 10 N and has a . :,~;;.,' 5 contact area of 1 mma has penetratQd to a depth of 1 mm into the lw specimen which is heated at iZO~C/h. This mesaurement is carried . out in accordance with DIN EN ISO 306.
. :;.;..
The properties of the TPUs according t;o the present invention are shown in Table 2. These data support the assessment of the prior art given at the outset. Only the TpUa; prepared according to the present invention have a heat distortion resistance which meets the requirements of the most demanding applications. ~t is considerably improved compared to that. of the comparative 3s samples. In addition, the aampies 4 and 5 have significantly unproved values for the abrasion and tear propagation resistance, partic~lariy compared to the samples which wore prepared using -: sxclusively aromatic chain extenders (Examples 6 and 7). The priparation of the TPUs at a known, lc~w index leads to a ~p diterioration in the heat distortion =resistance, the tensile strength, the tear propagation resistance and the elongation at break (Examples 2 and 3). TpU prepared. using Only 1,4-butanediol as chain extender displays) in particular) a poorer heat distortion resistance and increased abrasion. v 4 The improved heat distortion resistance resulting from the use of a relatively high index and 1,3-propan,ediol as chain extender can also be seen from the shape of the vicat curve (cf. Figure 1)..
=t can clearly be seen that the penetration of,the test pin is shifted to a higher temperature in the case of a higher index.
It is~thus demonstrated that the object, of the present invention, namely to provide polyisocyanate polyaddition products, in particular TBUs, having improved props:'ties, in particular an i0 improved heat di.gtortion resistance, hays been able to be achieved by the technical teachings of the present invention. The TPVs.
according to the present invention have: significantly improved properties compared to known TPVs.
.., ;v ,, ~0 ~0
Claims (8)
1. A process for preparing polyisocyanate polyaddition products by reacting (a) isocyanates with (b) compounds which are reactive toward isocyanates and have a molecular weight of from 451 to 8000 in the presence of (c) chain extenders and, if desired, (d) crosslinkers, (e) catalysts and/or (f) customary auxiliaries and/or additives, wherein 1,3- and/or 1,2-propanediol are used as chain extenders (c) and the reaction is carried out at an index of ~104.
2. A process for preparing thermoplastic polyisocyanate polyaddition products by reacting (a) isocyanates with (b) compounds which are reactive toward isocyanates and have a molecular weight of from 451 to 8000 and a mean functionality of from 1.8 to 2.6 in the presence of (c) chain extenders, (e) catalysts and/or (f) customary auxiliaries and/or additives, wherein 1,3- and/or 1,2-propanediol are used as chain extenders (c) and the reaction is carried out at an index of ~104.
3. A process as claimed in claim 1, wherein aromatic chain extenders are used in addition to the 1,3- and/or 1,2-propanediol.
4. A process as claimed in claim 3, wherein 1.4-bis(hydroxymethyl)benzene is used as aromatic chain extender.
5. A polyisocyanate polyaddition product obtainable by a process as claimed in claim 1.
6. A thermoplastic polyisocyanate polyaddition product obtainable by a process as claimed in claim 2.
7. The use of thermoplastic polyisocyanate polyaddition products as claimed in claim 6 as cables sheathing, fibres, moldings, linings in automobiles, seals, cable plugs, bellows, hoses, films, rollers, towing cables, straps or damping elements.
8. A cable sheath, fibre, moulding, lining in an automobile, seal, cable plug, bellows, hose, film, roller, towing cable, strap or damping element comprising a thermoplastic polyisocyanate polyaddition product as claimed in claim 6.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19816525.0 | 1998-04-15 | ||
| DE19816525A DE19816525A1 (en) | 1998-04-15 | 1998-04-15 | Process for the production of thermoplastic polyurethanes |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2267629A1 true CA2267629A1 (en) | 1999-10-15 |
Family
ID=7864494
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002267629A Abandoned CA2267629A1 (en) | 1998-04-15 | 1999-04-14 | Preparation of thermoplastic polyurethanes |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0950674A1 (en) |
| JP (1) | JPH11322887A (en) |
| KR (1) | KR19990083197A (en) |
| BR (1) | BR9901265A (en) |
| CA (1) | CA2267629A1 (en) |
| DE (1) | DE19816525A1 (en) |
| NO (1) | NO991764L (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110291126A (en) * | 2017-02-13 | 2019-09-27 | 巴斯夫欧洲公司 | Thermoplastic polyurethane |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8076445B2 (en) * | 2000-01-11 | 2011-12-13 | Robert Shane Porzio | Oligocarbodiimides for the formation of crosslinked latex films |
| DE10053060A1 (en) * | 2000-10-26 | 2002-05-08 | Volkswagen Ag | Device for installing a glass or plastic pane into a bodywork opening with a set back flange, comprises a sealing unit which is glued to the pane and consists of two different materials |
| DE10116592A1 (en) * | 2001-04-03 | 2002-10-17 | Getzner Werkstoffe Ges M B H | Elastomer II |
| US6780958B2 (en) * | 2001-07-24 | 2004-08-24 | Radicispandex Corporation | Spandex compositions |
| WO2010140566A1 (en) * | 2009-06-02 | 2010-12-09 | 宇部興産株式会社 | Polyurethane polymer solution and method for manufacturing the same |
| ES2959200T3 (en) * | 2013-06-04 | 2024-02-21 | Basf Se | Soft polyurethane thermoplastic elastomers and process for their preparation |
| EP3122795B1 (en) * | 2014-03-25 | 2022-06-15 | Basf Se | Tpu pneumatic tube |
| US20180016385A1 (en) * | 2015-04-01 | 2018-01-18 | Samyang Corporation | Polyurethane, and its preparation method and use |
| KR20190112025A (en) * | 2017-02-13 | 2019-10-02 | 바스프 에스이 | Thermoplastic polyurethane |
| CN109942788A (en) * | 2019-02-21 | 2019-06-28 | 唯万科技有限公司 | Self-lubricating hydrolysis resistant polyurethane elastic material and preparation method thereof |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4517326A (en) * | 1981-06-15 | 1985-05-14 | Freeman Chemical Corporation | Aqueous liquid filled polyurethane gels and method of making the same |
| CN1033635A (en) * | 1988-10-13 | 1989-07-05 | 中国人民解放军海军工程学院 | The wide temperature zone high damping polyurethane material |
| US4980445A (en) * | 1989-01-17 | 1990-12-25 | The Dow Chemical Company | Thermoplastic polyurethanes |
| DE3930838A1 (en) * | 1989-09-15 | 1991-03-28 | Bayer Ag | METHOD FOR PRODUCING TPU-CONTAINING CHEMICAL MATERIALS |
| KR910011978A (en) * | 1989-12-22 | 1991-08-07 | 리챠드 지.워터만 | Thermoplastic Polyurethane and Method of Making the Same |
| US5290036A (en) * | 1993-04-12 | 1994-03-01 | Frank Fenton | Cavity back iron with vibration dampening material in rear cavity |
| US5670601A (en) * | 1995-06-15 | 1997-09-23 | Arco Chemical Technology, L.P. | Polyurethane elastomers having improved green strength and demold time and polyoxyalkylene polyols suitable for their preparation |
-
1998
- 1998-04-15 DE DE19816525A patent/DE19816525A1/en not_active Withdrawn
-
1999
- 1999-04-12 EP EP99107087A patent/EP0950674A1/en not_active Withdrawn
- 1999-04-14 CA CA002267629A patent/CA2267629A1/en not_active Abandoned
- 1999-04-14 NO NO991764A patent/NO991764L/en not_active Application Discontinuation
- 1999-04-15 BR BR9901265A patent/BR9901265A/en not_active Application Discontinuation
- 1999-04-15 KR KR1019990013217A patent/KR19990083197A/en not_active Application Discontinuation
- 1999-04-15 JP JP11108062A patent/JPH11322887A/en not_active Withdrawn
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110291126A (en) * | 2017-02-13 | 2019-09-27 | 巴斯夫欧洲公司 | Thermoplastic polyurethane |
Also Published As
| Publication number | Publication date |
|---|---|
| KR19990083197A (en) | 1999-11-25 |
| DE19816525A1 (en) | 1999-10-21 |
| NO991764L (en) | 1999-10-18 |
| EP0950674A1 (en) | 1999-10-20 |
| BR9901265A (en) | 2000-03-21 |
| NO991764D0 (en) | 1999-04-14 |
| JPH11322887A (en) | 1999-11-26 |
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