CA2177168A1 - Process for producing thermoplastic polyurethanes by combined thethermoplastic treatment of a hydroxyl- and an isocyanate polyurethane - Google Patents
Process for producing thermoplastic polyurethanes by combined thethermoplastic treatment of a hydroxyl- and an isocyanate polyurethaneInfo
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- CA2177168A1 CA2177168A1 CA 2177168 CA2177168A CA2177168A1 CA 2177168 A1 CA2177168 A1 CA 2177168A1 CA 2177168 CA2177168 CA 2177168 CA 2177168 A CA2177168 A CA 2177168A CA 2177168 A1 CA2177168 A1 CA 2177168A1
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- polyurethane
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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
- C08G18/08—Processes
- C08G18/10—Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
- C08G18/12—Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step using two or more compounds having active hydrogen in the first polymerisation step
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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)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
A process is disclosed for the production of thermoplastic polyurethanes by the combined thermoplastic treatment of a) a polyurethane and/or polyurethane polycarbamide with free hydroxyl groups and/or amino groups and b) a polyurethane and/or polyurethane polycarbamide obtainable by the isocyanate-polyaddition process with a characteristic number of above 100. The process is characterized by the fact that : i) in the production of component b) the characteristic number is between 110 and 150 and ii) in the thermoplastic treatment of components a) and b), the molar ratio of the theoretical isocyanate surplus of component b) to the free hydroxyl groups and/or amino groups content of component a) ranges from 1.02:1 (mol NCO:mol OH or NH2) to 100:1.
Description
~Le A 29 976-PC - 1 - 2177168 A ~rocess for ~roducinq thermoplastic polyurethanes by common thermoPlastic processinq of a hydroxyl ~olyurethane and an isocYanate polyurethane The present invention relates to a process for producing thermoplastic polyurethanes, according to which a hydroxyl polyurethane and an isocyanate polyurethane undergo common thermoplastic processing. The process products show very good properties within broad limits irrespective of the mixing ratio.
Thermoplastic polyurethanes (TPUs) have long been known.
As a rule, the higher their molecular weight, the better their properties.
The marked dependence of their molecular weight on dosing fluctuations during production means that these thermoplastics are not easily produced to a consistent quality.
US-PS 5 089 571 describes a process which enables off-specification thermoplastic polyurethanes to be processed despite this into moulded bodies having good properties.
Products having a free hydroxyl group content (hydroxyl polyurethane) are mixed with a TPU which has been produced with an index (that is to say NCO : OH ratio x 100) which is greater than 100 (isocyanate polyurethane), and are processed in the melt, for example by injection moulding or extrusion, into high molecular weight and hence high-strength moulded bodies. The hydroxyl polyurethane and/orisocyanate polyurethane may in this case be a TPU which is obtained off-specification as a result of incorrect dosing or thermal degradation, or which may also have been produced with appropriate functional groups specifically for the two-component thermoplastic processing.
~ 2177168 Le A 29 976-PC - 2 -According to the teaching of the latter US-PS 5 089 571, both components must conform to stringent requirements in terms of molecular weight, namely the average molecular weight Mw f the component containing free isocyanate must be between 100,000 and 200,000, that of the reagent containing the hydroxyl groups must be between 30,000 and 150,000, and the two components should be mixed such as to obtain a high molecular weight in the resulting end product. This is achieved according to the teaching of the aforementioned US patent specification (inter alia, column 3, lines 31 et seq.) by selecting for the end product a calculated molar ratio of NCO : OH of at least 0.96 to 1.04, preferably 0.98 to 1.02, and particularly preferably o.g9 to 1.01. Otherwise the molecular weight of the end products is too low; they are then unusable. According to the teaching of the aforementioned US patent specification, thermoplastic polyurethanes which have undergone thermal or hydrolytic (due to the action of water in heat) degradation may also be used as the hydroxyl component, yet this is difficult to envisage in terms of the mixing ratio, because their hydroxyl group content is unknown and cannot be determined readily.
It is moreover difficult to store the isocyanate component for a protracted period without changes taking place in the free isocyanate group content and hence also the molecular weight.
Improving on the formulation constraints named and the aforementioned shortcomings of the prior art process presents a challenge.
This object is achieved by a process for two-component thermoplastic processing of polyurethanes and polyurethane ureas, which may be utilised substantially universally and which necessitates less precise dosing.
`. 2177168 Le A 29 976-PC - 3 -It is in particular surprising not only that it is possible to produce thermoplastic polyurethanes which are highly processable even outside the molecular weight limits named in US-PS S 089 571, of 100,000 to 200,000 and 30,000 to 150,000, but also that the latter also show improved product properties, for example in terms of strength, solvent resistance and deflection temperature under load.
The present invention provides a process for producing thermoplastic polyurethanes by common thermoplastic processing of:
a) a polyurethane and/or polyurethane polyurea having free hydroxyl groups and/or amino groups and b) a polyurethane and/or polyurethane polyurea obtainable by the isocyanate polyaddition process with an index greater than 100, characterised in that:
i) an index of at least 110 is adhered to (isocyanate excess) during production of component b), and ii) during thermoplastic processing of components a) and b) the molar ratio of the calculated isocyanate excess of component b) to the free hydroxyl group and/or amino group content of component a) is from 1.02 : 1 (mole NCO : mole OH and/or NH2) to 100 : 1.
In a preferred embodiment a molar ratio of the calculated isocyanate excess of component b) to the free hydroxyl group and/or amino group content of at least 1.04 : 1, quite particularly preferably at least 1.05 : 1, is adhered to.
`. ~177168 ~_,e A 29 976-PC - 4 -The thermoplastic processing of components ~) and b) takes place preferably by injection moulding, extrusion or extrusion blow moulding.
According to the invention both polyurethanes which are already fully reacted and non-thermoplastic polyurethanes may advantageously be employed as raw materials for components a) and b). Recycled polyurethane material or scrap from polyurethane production may furthermore be used as raw materials.
The aforementioned components a) and b) are obtainable from the following raw materials:
1) one or more substantially linear polyols having molecular weights of between 400 and 10,000,
Thermoplastic polyurethanes (TPUs) have long been known.
As a rule, the higher their molecular weight, the better their properties.
The marked dependence of their molecular weight on dosing fluctuations during production means that these thermoplastics are not easily produced to a consistent quality.
US-PS 5 089 571 describes a process which enables off-specification thermoplastic polyurethanes to be processed despite this into moulded bodies having good properties.
Products having a free hydroxyl group content (hydroxyl polyurethane) are mixed with a TPU which has been produced with an index (that is to say NCO : OH ratio x 100) which is greater than 100 (isocyanate polyurethane), and are processed in the melt, for example by injection moulding or extrusion, into high molecular weight and hence high-strength moulded bodies. The hydroxyl polyurethane and/orisocyanate polyurethane may in this case be a TPU which is obtained off-specification as a result of incorrect dosing or thermal degradation, or which may also have been produced with appropriate functional groups specifically for the two-component thermoplastic processing.
~ 2177168 Le A 29 976-PC - 2 -According to the teaching of the latter US-PS 5 089 571, both components must conform to stringent requirements in terms of molecular weight, namely the average molecular weight Mw f the component containing free isocyanate must be between 100,000 and 200,000, that of the reagent containing the hydroxyl groups must be between 30,000 and 150,000, and the two components should be mixed such as to obtain a high molecular weight in the resulting end product. This is achieved according to the teaching of the aforementioned US patent specification (inter alia, column 3, lines 31 et seq.) by selecting for the end product a calculated molar ratio of NCO : OH of at least 0.96 to 1.04, preferably 0.98 to 1.02, and particularly preferably o.g9 to 1.01. Otherwise the molecular weight of the end products is too low; they are then unusable. According to the teaching of the aforementioned US patent specification, thermoplastic polyurethanes which have undergone thermal or hydrolytic (due to the action of water in heat) degradation may also be used as the hydroxyl component, yet this is difficult to envisage in terms of the mixing ratio, because their hydroxyl group content is unknown and cannot be determined readily.
It is moreover difficult to store the isocyanate component for a protracted period without changes taking place in the free isocyanate group content and hence also the molecular weight.
Improving on the formulation constraints named and the aforementioned shortcomings of the prior art process presents a challenge.
This object is achieved by a process for two-component thermoplastic processing of polyurethanes and polyurethane ureas, which may be utilised substantially universally and which necessitates less precise dosing.
`. 2177168 Le A 29 976-PC - 3 -It is in particular surprising not only that it is possible to produce thermoplastic polyurethanes which are highly processable even outside the molecular weight limits named in US-PS S 089 571, of 100,000 to 200,000 and 30,000 to 150,000, but also that the latter also show improved product properties, for example in terms of strength, solvent resistance and deflection temperature under load.
The present invention provides a process for producing thermoplastic polyurethanes by common thermoplastic processing of:
a) a polyurethane and/or polyurethane polyurea having free hydroxyl groups and/or amino groups and b) a polyurethane and/or polyurethane polyurea obtainable by the isocyanate polyaddition process with an index greater than 100, characterised in that:
i) an index of at least 110 is adhered to (isocyanate excess) during production of component b), and ii) during thermoplastic processing of components a) and b) the molar ratio of the calculated isocyanate excess of component b) to the free hydroxyl group and/or amino group content of component a) is from 1.02 : 1 (mole NCO : mole OH and/or NH2) to 100 : 1.
In a preferred embodiment a molar ratio of the calculated isocyanate excess of component b) to the free hydroxyl group and/or amino group content of at least 1.04 : 1, quite particularly preferably at least 1.05 : 1, is adhered to.
`. ~177168 ~_,e A 29 976-PC - 4 -The thermoplastic processing of components ~) and b) takes place preferably by injection moulding, extrusion or extrusion blow moulding.
According to the invention both polyurethanes which are already fully reacted and non-thermoplastic polyurethanes may advantageously be employed as raw materials for components a) and b). Recycled polyurethane material or scrap from polyurethane production may furthermore be used as raw materials.
The aforementioned components a) and b) are obtainable from the following raw materials:
1) one or more substantially linear polyols having molecular weights of between 400 and 10,000,
2) one or more organic polyisocyanates and
3) a chain extender exhibiting groups which are reactive vis-à-vis isocyanates, having a molecular weight of from 18 to 399, and optionally
4) auxiliary substances and additives of a type known per se.
1. The following are contemplated according to the invention as substantially linear polyols having molecular weights of between 400 and 10,000, preferably between 450 and 6,000: virtually all the polyesters, polylactones, polyethers, polythioethers, polyester amides, polycarbonates, polyacetals, vinyl polymers known per se, containing preferably 3, optionally 3, in subordinate quantities - or more Zerewitinoff-active groups (substantially hydroxyl groups), such as for example polybutadiene oils, polyhydroxyl compounds ~_~e A 29 976-PC - - 5 -which already contain urethane groups or urea groups, optionally modified natural polyols, and also other compounds containing Zerewitinoff-active groups such as amino, carboxyl or thiol groups. These compounds correspond to prior art and are described in detail in, for example, DE-OS 23 02 564, 24 23 764 and 25 49 372 (US Patent 3 963 679) and 24 02 840 (US Patent 3 984 607) and in DE-AS 24 57 387 (US Patent 4 035 213). Hydroxyl-group containing polyesters of glycols and adipic, phthalic and/or terephthalic acid and the hydrogenation products thereof, hydroxyl polycarbonates, polycaprolactones, polyethylene oxide, polypropylene oxide, polytetrahydrofuran and mixed polyethers of ethylene oxide and propylene oxide and/or tetrahydrofuran are preferred according to the invention.
2. Polyisocyanates to be used according to the invention are aliphatic, cycloaliphatic, araliphatic, aromatic and heterocyclic polyisocyanates, such as are described, for example, by W. Siefken in Justus Liebigs Annalen der Chemie [Annals of Chemistry], 562, pp. 75 to 136, for example those of the formula Q(NCO)n in which n denotes 2 to 4, preferably 2, and Q denotes an aliphatic hydrocarbon radical having 2 to 18, preferably 6 to 10 C atoms, a cycloaliphatic hydrocarbon radical having 4 to 15, preferably 5 to 10 C atoms, an aromatic hydrocarbon radical having 6 to 15, preferably 6 to 13 C atoms or an araliphatic hydrocarbon radical having 8 to 15, ` ~ 2177168 ~_~e A 29 976-PC - 6 -preferably 8 to 12 C atoms, for example polyisocyanates such as are described in DE-OS 28 32 253, pages 10 to 11. Q may also contain heteroatoms.
Particular preference is as a rule accorded to the industrially readily accessible diisocyanates, for example 2,4- and 2,6-tolylene diisocyanate and any mixtures of the latter isomers ("TDI"), dicyclohexylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate and any mixtures of the latter isomers and diisocyanates exhibiting carbodiimide groups, urethane groups, allophanate groups or urea groups ("modified diisocyanates"), in particular modified diisocyanates such as are derived from 2,4- and/or 2,6-tolylene diisocyanate or from 4,4'- and/or 2,4'-diphenylmethane diisocyanate.
The functionality of the isocyanates should be at least 1.8.
3. Chain extenders exhibiting groups which are reactive vis-à-vis isocyanates are compounds of a molecular weight of from 18 to 399 having a functionality of at least 1.8. Reactive groups which are contemplated are hydroxyl, amino, carboxyl and thiol groups. The following might be named by way of example:
bifunctional low molecular weight compounds such as dialcohols, diamines, aminoalcohols, ether alcohols and ester alcohols and dicarboxylic acids such as, for example, ethylene glycol, 1,4-butanediol and diethyl tolylene diamine or the isomer mixture thereof, but also water.
4. Auxiliary substances and additives for optional co-use which are contemplated are the fillers, reinforcements, antistats, anti-ageing substances, flame retardants, dyes and pigments, plasticisers, thermoplastics, inert solvents, lubricants and other aids to processing, ~I 7716~
Le A 29 976-PC - 7 -release agents, catalysts of in each case inorganic and/or organic type, which are known per se, conforming to prior art.
Implementation of the process according to the invention The aforementioned components a) and b) for thermoplastic processing are produced by the prior art methods which are known per se, in the case of b), however, adhering to an index of at least 110 in accordance with feature i).
It is immaterial for this purpose whether the chosen NCO
excess in the product is present in whole or in part in the form of NCO groups; it may also, for example, be reacted to allophanate and/or biuret. This makes the products to be processed according to the invention largely indifferent to storage. As is also the case with other polyurethanes, prolonged storage of products a) and b) in humid heat is not recommended.
In lieu of the fully reacted components a) and b), mixtures of linear polyols 1), isocyanates 2) and chain extenders 3) plus auxiliary substances and additives 4) may also be utilised for the process according to the invention.
The products may also contain monofunctional compounds which are frequently designated chain terminatGrs.
Individual components (polyols 1), isocyanates 2) and chain extenders 3)) may also have a functionality which is well below 1.8. This is in particular advantageous if other raw materials have a higher functionality, for exa~ple 6.
The raw materials named may be used to construct the component a) having free hydroxyl groups which is to be used according to the invention, as well as to construct ` ~177168 ~ Le A 29 976-PC - 8 -the component b) which is produced with an NCO excess.
Components a) and b) may for this purpose be constructed of the same or different raw materials.
The components a) and b) to be used according to the invention are produced by processes which are known per se, for example in a screw reactor. In a particular embodiment it is also possible to react in the melt with alcohols, alkanolamines, diamines, dicarboxylic acids, isocyanates, preferably diisocyanates, polyurethanes which are already fully reacted. Degradation of the molecular weight occurs in this case. This degradation process has the advantage over the degradation process described in US Patent Specification 5 089 571 that the molecular weight and functionality of the products to be utilised (in the process according to the invention) can be adjusted in targeted manner and can if necessary be easily determined.
It is an advantage of the process according to the invention that the analytical data of components a) and b) need not be determined with precision, because the mixing ratio of a) with b) is variable over a very broad range (feature ii), unlike the process described in US Patent Specification 5 089 571.
The degradation process described for producing components a) and b) according to the invention also enables reuse of, for example, crosslinked polyurethane scrap which is not per se thermoplastic, such as for example flexible foam or elastomers. Like polyurethane thermoplastics, these may also have been in use for some time already (recycled material) or may constitute production scrap, before they are used to produce components a) and/or b).
35 It is also possible, by utilising components a) and b) of different Shore hardness, to adjust in a targeted manner a 2~ 7716~
~Le A 29 976-PC - 9 -predetermined hardness in the process products according to the invention.
In some processing technologies, such as for example extrusion, it may be advantageous with a view to obtaining homogeneous process products, if components a) and b) have approximately the same melt viscosities at the processing temperature. This may be achieved by, for example, producing the harder component a) with a large NCO deficit, for example a NCO : OH ratio of 0.8 : 1 molar. The process according to the invention also enables polyurethanes and polyurethane ureas which have already deteriorated owing to ageing to be reprocessed into new products having good physical properties and good age-resistance.
Processing according to the invention of the two-component polyurethane mixture may take place in conventional melt processing machines, such as injection moulding machines, extruders, blow moulding plant, presses, using a sintering process or powder spraying process. It is naturally also sometimes possible to process in solution, dispersion or emulsion. Components a) and b) may also have very different melting ranges, so that for example one component is dispersed or suspended in the other during moulding and is not melted and reacted until a subsequent application of heat.
The process products are suitable for producing solid and foamed moulded bodies, coatings, sheet products, adhesive bonds.
The following Examples explain the invention without, however, limiting it. Unless otherwise indicated, quantities should be read as parts or percentages by weight.
` 2I77168 ~-Le A 29 976-PC - 10 -Examples of ~rocess implementation Comparative ExamPle 1 a) Hydroxyl polyurethane 1 part by weight of ethylenediamine bis-stearoyl amide is uniformly distributed, at 130C and with exclusion of moisture, in the mixture comprising 100 parts by weight of a polybutanediol adipate having an average molecular weight of 2,200 and 9.5 parts by weight 1,4-butanediol. The melt is cooled to 80C and 35.8 parts by weight of 4,4'-diphenylmethane diisocyanate heated to 60C are stirred in rapidly in an open can until homogeneous, and the melt is then poured into a PTFE
dish, held at 110C for one hour and then overnight at 80C, and granulated after cooling. The NCO : OH ratio in the product thus produced (lA) is 0.95.
b) Isocyanate polyurethane The procedure is as described in Example la), but using 39.7 parts by weight 4,4'-diphenylmethane diisocyanate, thus giving a product (lB) having an NCO : OH ratio of 1.05. Equal parts by weight of granulate of products (lA) and lB) are mixed until homogeneous and processed in an injection moulding machine of the Anker V14 type to form test specimens (lC), which are stored at 80C
for 16 hours; Table 1 shows the measured values obtained.
Example 2 The procedure is as described in Example la), but using 41.6 parts by weight 4,4'-diphenylmethane diisocyanate and obtaining in this case a product t2) having an NCO : OH
ratio of 1.10. 9 parts by weight of polyurethane (2) are ~_~e A 29 976-PC - 11 - 21 771 6 8 mixed with 1 part by weight of polyurethane (lA) in the form of a granulate, and the two are injected together in the injection moulding machine. The injection moulded pieces (2A) have a calculated NCO : OH ratio of 1.085 and are stored at 80C for 16 hours. The physical testing results are shown in Table 1.
Example 3 The procedure is as described in Example 2, but using 45.3 parts by weight 4,4'-diphenylmethane diisocyanate. The product obtained (3) has an NCO : OH ratio of 1.20 and is processed mixed with product la in the ratio by weight of 1 : 1 and 9 : 1 (= excess of product (3)), in the injection moulding machine to form products (3A) having an NCO : OH
ratio (calculated) of 1.075 and (3B) having an NCO : OH
ratio (calculated) of 1.175 (see Table 1 for results).
0 Table 1 Testing (lC) (2A) (3A) (3B) standard Elasticity (~) DIN 53 51246 42 42 39 Ultimate strength (MPa) DIN 53 50430 37 34 37 Elongation at break (5) DIN 53 504432 542 473 512 Shore hard-ness A DIN 53 50586 84 85 85 35 Permanent set (24 h, 70C, ~) DIN 53 51755 35 38 25 ~Le A 29 976-PC - 12 - 2177168 It is apparent from Table 1 that, in terms of ultimate strength and elongation at break and deflection temperature under load, the products according to the invention are superior to comparable polyurethanes (lC) produced in accordance with the teaching of US Patent Specification
1. The following are contemplated according to the invention as substantially linear polyols having molecular weights of between 400 and 10,000, preferably between 450 and 6,000: virtually all the polyesters, polylactones, polyethers, polythioethers, polyester amides, polycarbonates, polyacetals, vinyl polymers known per se, containing preferably 3, optionally 3, in subordinate quantities - or more Zerewitinoff-active groups (substantially hydroxyl groups), such as for example polybutadiene oils, polyhydroxyl compounds ~_~e A 29 976-PC - - 5 -which already contain urethane groups or urea groups, optionally modified natural polyols, and also other compounds containing Zerewitinoff-active groups such as amino, carboxyl or thiol groups. These compounds correspond to prior art and are described in detail in, for example, DE-OS 23 02 564, 24 23 764 and 25 49 372 (US Patent 3 963 679) and 24 02 840 (US Patent 3 984 607) and in DE-AS 24 57 387 (US Patent 4 035 213). Hydroxyl-group containing polyesters of glycols and adipic, phthalic and/or terephthalic acid and the hydrogenation products thereof, hydroxyl polycarbonates, polycaprolactones, polyethylene oxide, polypropylene oxide, polytetrahydrofuran and mixed polyethers of ethylene oxide and propylene oxide and/or tetrahydrofuran are preferred according to the invention.
2. Polyisocyanates to be used according to the invention are aliphatic, cycloaliphatic, araliphatic, aromatic and heterocyclic polyisocyanates, such as are described, for example, by W. Siefken in Justus Liebigs Annalen der Chemie [Annals of Chemistry], 562, pp. 75 to 136, for example those of the formula Q(NCO)n in which n denotes 2 to 4, preferably 2, and Q denotes an aliphatic hydrocarbon radical having 2 to 18, preferably 6 to 10 C atoms, a cycloaliphatic hydrocarbon radical having 4 to 15, preferably 5 to 10 C atoms, an aromatic hydrocarbon radical having 6 to 15, preferably 6 to 13 C atoms or an araliphatic hydrocarbon radical having 8 to 15, ` ~ 2177168 ~_~e A 29 976-PC - 6 -preferably 8 to 12 C atoms, for example polyisocyanates such as are described in DE-OS 28 32 253, pages 10 to 11. Q may also contain heteroatoms.
Particular preference is as a rule accorded to the industrially readily accessible diisocyanates, for example 2,4- and 2,6-tolylene diisocyanate and any mixtures of the latter isomers ("TDI"), dicyclohexylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate and any mixtures of the latter isomers and diisocyanates exhibiting carbodiimide groups, urethane groups, allophanate groups or urea groups ("modified diisocyanates"), in particular modified diisocyanates such as are derived from 2,4- and/or 2,6-tolylene diisocyanate or from 4,4'- and/or 2,4'-diphenylmethane diisocyanate.
The functionality of the isocyanates should be at least 1.8.
3. Chain extenders exhibiting groups which are reactive vis-à-vis isocyanates are compounds of a molecular weight of from 18 to 399 having a functionality of at least 1.8. Reactive groups which are contemplated are hydroxyl, amino, carboxyl and thiol groups. The following might be named by way of example:
bifunctional low molecular weight compounds such as dialcohols, diamines, aminoalcohols, ether alcohols and ester alcohols and dicarboxylic acids such as, for example, ethylene glycol, 1,4-butanediol and diethyl tolylene diamine or the isomer mixture thereof, but also water.
4. Auxiliary substances and additives for optional co-use which are contemplated are the fillers, reinforcements, antistats, anti-ageing substances, flame retardants, dyes and pigments, plasticisers, thermoplastics, inert solvents, lubricants and other aids to processing, ~I 7716~
Le A 29 976-PC - 7 -release agents, catalysts of in each case inorganic and/or organic type, which are known per se, conforming to prior art.
Implementation of the process according to the invention The aforementioned components a) and b) for thermoplastic processing are produced by the prior art methods which are known per se, in the case of b), however, adhering to an index of at least 110 in accordance with feature i).
It is immaterial for this purpose whether the chosen NCO
excess in the product is present in whole or in part in the form of NCO groups; it may also, for example, be reacted to allophanate and/or biuret. This makes the products to be processed according to the invention largely indifferent to storage. As is also the case with other polyurethanes, prolonged storage of products a) and b) in humid heat is not recommended.
In lieu of the fully reacted components a) and b), mixtures of linear polyols 1), isocyanates 2) and chain extenders 3) plus auxiliary substances and additives 4) may also be utilised for the process according to the invention.
The products may also contain monofunctional compounds which are frequently designated chain terminatGrs.
Individual components (polyols 1), isocyanates 2) and chain extenders 3)) may also have a functionality which is well below 1.8. This is in particular advantageous if other raw materials have a higher functionality, for exa~ple 6.
The raw materials named may be used to construct the component a) having free hydroxyl groups which is to be used according to the invention, as well as to construct ` ~177168 ~ Le A 29 976-PC - 8 -the component b) which is produced with an NCO excess.
Components a) and b) may for this purpose be constructed of the same or different raw materials.
The components a) and b) to be used according to the invention are produced by processes which are known per se, for example in a screw reactor. In a particular embodiment it is also possible to react in the melt with alcohols, alkanolamines, diamines, dicarboxylic acids, isocyanates, preferably diisocyanates, polyurethanes which are already fully reacted. Degradation of the molecular weight occurs in this case. This degradation process has the advantage over the degradation process described in US Patent Specification 5 089 571 that the molecular weight and functionality of the products to be utilised (in the process according to the invention) can be adjusted in targeted manner and can if necessary be easily determined.
It is an advantage of the process according to the invention that the analytical data of components a) and b) need not be determined with precision, because the mixing ratio of a) with b) is variable over a very broad range (feature ii), unlike the process described in US Patent Specification 5 089 571.
The degradation process described for producing components a) and b) according to the invention also enables reuse of, for example, crosslinked polyurethane scrap which is not per se thermoplastic, such as for example flexible foam or elastomers. Like polyurethane thermoplastics, these may also have been in use for some time already (recycled material) or may constitute production scrap, before they are used to produce components a) and/or b).
35 It is also possible, by utilising components a) and b) of different Shore hardness, to adjust in a targeted manner a 2~ 7716~
~Le A 29 976-PC - 9 -predetermined hardness in the process products according to the invention.
In some processing technologies, such as for example extrusion, it may be advantageous with a view to obtaining homogeneous process products, if components a) and b) have approximately the same melt viscosities at the processing temperature. This may be achieved by, for example, producing the harder component a) with a large NCO deficit, for example a NCO : OH ratio of 0.8 : 1 molar. The process according to the invention also enables polyurethanes and polyurethane ureas which have already deteriorated owing to ageing to be reprocessed into new products having good physical properties and good age-resistance.
Processing according to the invention of the two-component polyurethane mixture may take place in conventional melt processing machines, such as injection moulding machines, extruders, blow moulding plant, presses, using a sintering process or powder spraying process. It is naturally also sometimes possible to process in solution, dispersion or emulsion. Components a) and b) may also have very different melting ranges, so that for example one component is dispersed or suspended in the other during moulding and is not melted and reacted until a subsequent application of heat.
The process products are suitable for producing solid and foamed moulded bodies, coatings, sheet products, adhesive bonds.
The following Examples explain the invention without, however, limiting it. Unless otherwise indicated, quantities should be read as parts or percentages by weight.
` 2I77168 ~-Le A 29 976-PC - 10 -Examples of ~rocess implementation Comparative ExamPle 1 a) Hydroxyl polyurethane 1 part by weight of ethylenediamine bis-stearoyl amide is uniformly distributed, at 130C and with exclusion of moisture, in the mixture comprising 100 parts by weight of a polybutanediol adipate having an average molecular weight of 2,200 and 9.5 parts by weight 1,4-butanediol. The melt is cooled to 80C and 35.8 parts by weight of 4,4'-diphenylmethane diisocyanate heated to 60C are stirred in rapidly in an open can until homogeneous, and the melt is then poured into a PTFE
dish, held at 110C for one hour and then overnight at 80C, and granulated after cooling. The NCO : OH ratio in the product thus produced (lA) is 0.95.
b) Isocyanate polyurethane The procedure is as described in Example la), but using 39.7 parts by weight 4,4'-diphenylmethane diisocyanate, thus giving a product (lB) having an NCO : OH ratio of 1.05. Equal parts by weight of granulate of products (lA) and lB) are mixed until homogeneous and processed in an injection moulding machine of the Anker V14 type to form test specimens (lC), which are stored at 80C
for 16 hours; Table 1 shows the measured values obtained.
Example 2 The procedure is as described in Example la), but using 41.6 parts by weight 4,4'-diphenylmethane diisocyanate and obtaining in this case a product t2) having an NCO : OH
ratio of 1.10. 9 parts by weight of polyurethane (2) are ~_~e A 29 976-PC - 11 - 21 771 6 8 mixed with 1 part by weight of polyurethane (lA) in the form of a granulate, and the two are injected together in the injection moulding machine. The injection moulded pieces (2A) have a calculated NCO : OH ratio of 1.085 and are stored at 80C for 16 hours. The physical testing results are shown in Table 1.
Example 3 The procedure is as described in Example 2, but using 45.3 parts by weight 4,4'-diphenylmethane diisocyanate. The product obtained (3) has an NCO : OH ratio of 1.20 and is processed mixed with product la in the ratio by weight of 1 : 1 and 9 : 1 (= excess of product (3)), in the injection moulding machine to form products (3A) having an NCO : OH
ratio (calculated) of 1.075 and (3B) having an NCO : OH
ratio (calculated) of 1.175 (see Table 1 for results).
0 Table 1 Testing (lC) (2A) (3A) (3B) standard Elasticity (~) DIN 53 51246 42 42 39 Ultimate strength (MPa) DIN 53 50430 37 34 37 Elongation at break (5) DIN 53 504432 542 473 512 Shore hard-ness A DIN 53 50586 84 85 85 35 Permanent set (24 h, 70C, ~) DIN 53 51755 35 38 25 ~Le A 29 976-PC - 12 - 2177168 It is apparent from Table 1 that, in terms of ultimate strength and elongation at break and deflection temperature under load, the products according to the invention are superior to comparable polyurethanes (lC) produced in accordance with the teaching of US Patent Specification
5 089 571.
~Am~le 4 Scrap from a polyurethane obtained following reaction injection moulding and comprising 100 parts by weight polyethane diol adipate of average molecular weight 2,000, 4.5 parts by weight 1,4-butanediol, 0.3 parts by weight trimethylolpropane and 24 parts by weight naphthylene-(1,5)-diisocyanate are reacted at approximately 230C in a twin-screw reactor with 0.82 parts by weight 1,4-butanediol per 100 parts scrap (polyurethane (4)). The product is processed in an injection moulding machine to form test specimens. See Table 2 for physical values.
~m~le 5 Approx. 3-month old production scrap from a 2-component moulding process, comprising a polyurethane of 100 parts by weight polyethanediol butanediol adipate of average molecular weight 2,000, 5.9 parts by weight 1,4-butanediol and 27 parts by weight naphthylene-(1,5)-diisocyanate (NCO : OH ratio = 1.11) are granulated (product (5)) and mixed in a ratio of 2 parts by weight polyurethane (5) to 1 part by weight polyurethane (4), and are processed at approximately 220C in an injection moulding machine having a mould sprayed with release agent, to form test specimens (product 5A). See Table 2 for product properties.
` 2177168 _Le A 29 976-PC - 13 -Example 6 The procedure is as described in Example 4, but using for polyurethane (6A) 2.2 parts by weight 1,4-butanediol, and for product (6B) 14 parts by weight 4,4'-diphenylmethane diisocyanate in lieu of the 1,4-butanediol. Product (6C) is obtained by mixing and subsequently injection moulding (maximum processing temperature 220C) equal parts by weight of granulate of the polyurethanes (6A) and (6B).
The physical properties are set out in Table 2. Storage of the granulate mixture for 5 months results in injection moulded bodies having virtually the same properties.
Table 2 Properties of the products of Examples 4, 5 and 6 Product Test (4) (5A) (6C) standard Elasticity (~) DIN 53 512 38 40 40 Tensile strength (MPa) DIN 53 504 10 21 32 Elongation at break (~) DIN 53 504 250 420 535 Shore hardness A DIN 53 505 85 87 85 ExamPle 7 A thermoplastic polyurethane (7) of Shore D hardness 52 is produced from 100 parts by weight of a hexanediol neopentylglycol polyadipate having an average molecular weight of approximately 2,200, 25 parts by weight 1,4-butanediol, 0.5 parts by weight ethylene bis-stearoyl amide ~_Le A 29 976-PC - 14 - 2177168 and 65.45 parts by weight 4,4'-diphenylmethane diisocyanate. The NCO : OH ratio is about 0.81 (molecular weight Mn = 3,120). 68 parts by weight of a granulate of product (7) are mixed with 58 parts by weight of product (3) and processed by injection moulding to form test specimens (7A). See Table 3 for physical properties.
Table 3 Physical properties of product (7A) TestProduct (7A) standard Resilience (~) DIN 53 512 43 Tensile strength (MPa) DIN 53 504 28 Elongation at break (~) DIN 53 504 539 Modulus 100~ (MPa) DIN 53 504 9.7 Modulus 300~ (MPa) DIN 53 504 13.8 Shore hardness A DIN 53 505 92 The results set out in Table 3 show that it is also possible using the process according to the invention to mix a component having free NCO groups or Zerewitinoff-active groups with a different component of greater orlesser hardness, which reacts with the said component, and to process the latter mixture, thus in targeted manner -within certain limits - adjusting the hardness of the end product as desired. The NCO : Zerewitinoff-active group ratio is immaterial in this respect, provided that it is not substantially below 1.00 in the end product.
Le A 29 976-PC - 15 - 2177168 Example 8 A thermoplastic polyurethane is produced as described in Comparative Example 1. By contrast with Comparative Example 1, 38.6 parts by weight 4,4'-diphenylmethane diisocyanate are used, corresponding to an NCO : OH ratio of 1.02. Injection moulded bodies are produced from the granulate (product 8A), and these are stored in water at 80C for 14 days. After drying in air and then in the vacuum desiccator, the tensile strength of the injection moulded bodies due to hydrolysis is approximately 5 MPa.
The dried injection moulded bodies are granulated.
12 parts by weight 1,6-hexanediol are heated to 200C under nitrogen in the presence of 50 ppm titanium tetrabutylate in a three-necked flask fitted with a stirrer and a reflux condenser. 100 parts by weight of the granulate obtained from the dried, hydrolytically aged injection moulded bodies are added portion-wise such that the contents of the flask remain stirrable. The temperature is meanwhile slowly raised to 220C. Immediately a homogeneous melt is obtained, it is cooled to 180C, poured into a flat Teflon dish, allowed to solidify, and comminuted (product (8B)).
100 parts by weight of product (8B) are mixed with 488.5 parts by weight of product (3) in the form of granulates, the NCO : OH ratio of the mixture being about 1.05 (theoretical), - and processed in an injection moulding machine to form test specimens (product (8C)) (see Table 4 for results).
Le A 29 976-PC - - 16 - 21 771 68 Table 4 Physical properties of product (8C) Test Product (8C) standard Tensile strength (MPa) DIN 53 504 36 Elongation at break ~) DIN 53 504 484 As is apparent from Table 4, the process according to the invention is suitable for reusing polyester polyurethanes which have undergone marked hydrolytic degradation, in thermoplasts of virtually virgin quality.
ExamPle 9 The mixture of 100 parts by weight polybutanediol adipate of average molecular weight 2,000, 8.08 parts by weight 1,4-butanediol, 2.82 parts by weight diethyltolylene diamine (isomer mixture 2,6-isomer : 2,4-isomer = approx.
35 : 65) and 2 parts by weight ethylene bis-stearoyl amide is heated to 170C. 36.7 parts by weight 4,4'-diphenylmethane diisocyanate (corresponding to an NCO : OHratio of 0.94) are stirred in rapidly, and the mixture is poured into a flat PTFE dish, stored at 110C for 1 hour and 80C for 16 hours, and is granulated (product (9).
ExamPle 10 The procedure is as described in Example 9, but using 46.8 parts by weight 4,4'-diphenylmethane diisocyanate, thus obtaining product (10) (NCO : OH ratio = 1.20). The granulates of products (9) and (10) are mixed in a ratio by weight of 2 : 3 and processed by injection moulding to form test specimens (10A).
Le A 29 976-PC - 17 -Table 5 Physical properties of product (lOA) Unit Test Product standard (lOA) Modulus at 100~ elongation MPa DIN 53 504 6 Modulus at 300~ elongation MPa DIN 53 504 20.1 Tensile strength MPa DIN 53 504 54 Elongation at break ~ DIN 53 504 498 Shore hardness A DIN 53 505 84 Resilience ~ DIN 53 512 37 ExamPle 11 1655 parts by weight of a standard hot-moulded foam produced from the principal components propylene-ethylene oxide mixed polyether initiated on glycerol and having an OH number of 56, polypropylene oxide initiated on trimethylolpropane and having an OH number of 56 (polyether ratio 100 : 3.5) and tolylene diisocyanate (proportion of 2,4 isomer: 80~, remainder: 2,6 isomer), are stirred in 140 parts by weight 1,6-hexanediol at 230C under nitrogen until a homogeneous solution is obtained. Polyurethane (11) is obtained having a theoretical OH number of 74.
Example 12A
Product (11) is mixed with product (3) such that a theoretical NCO : OH ratio of 1.00 results. This mixture (12A) is injected in an injection moulding machine to form test specimens having an ultimate strength of 15.5 MPa and an elongation at break of 435~ at Shore A hardness 78.
~- Le A 29 976-PC - 18 - 2177168 ExamPle 12B
The procedure is as described in Example 12A, but with components (3) and (11) mixed such that a theoretical NCO : OH ratio of 1.05 results. The ultimate strength of the injection moulded bodies (12B) is 18.6 MPa.
Example 13A
The procedure is as described in Examples 1 to 3, but selecting an NCO : OH ratio of 0.97. After overnight tempering at 80C, product (13A), when dissolved at room temperature at a concentration of 20 wt-~ in a 4 : 1 ratio lS mixture of dimethylacetamide and methyl ethyl ketone, gives a solution viscosity at room temperature of 660 mPa.s. The melting range of the tempered polyurethane is about 195C.
ExamPle 13B
The procedure is as described in Example 13A, but selecting an NCO : OH ratio of 1.01, and with the solution viscosity of the product (13B) being 79,000 mPa.s measured under the same conditions.
ExamPle 13C
The procedure is as described in Example 13A, but selecting an NCO : OH ratio of 1.30. Product (13C) melts at approximately 214C. It is not soluble in the solvent mixture and under the conditions named in Example 13A, instead merely swelling.
`~ e A 29 976-PC - 19 - 21 7 71 6 8 ExamPle 13D
The granulates of Examples 13A and C are mixed in a ratio by weight of 1 : 2.3, thus resulting in a theoretical NCO : OH ratio of l : 2, and are then injected to form test specimens which are stored overnight at 80C (product (13D)). The test specimens are not soluble in the solvent mixture named in Example 13A and have a tensile strength of 27.8 MPa.
It is apparent from Examples 13A to D that crosslinked products may also be processed by the process according to the invention.
Comparative Example 14A
The procedure is analogous to that of Example 3A of US
Patent Specification 5 089 571, reacting 100 parts by weight polytetrahydrofuran of an average molecular weight of 1,000, 20.7 parts by weight 1,4-butanediol, 0.12 parts by weight ethylene bis-stearoyl amide (as conventional commercial mould release agent), 0.12 parts by weight of a conventional commercial antioxidant, in the presence of 0.01 part by weight tin(II) octoate with 78.4 parts by weight 4,4'-diphenylmethane diisocyanate. The molar NCO : OH ratio is about 0.95 (product (14A)), as described in the Example of US Patent Specification 5 089 571.
Comparative ExamPle 14B
The procedure is as described in Example 14A, but selecting an NCO : OH ratio of 1.06 as in Example 3B of US Patent Specification 5 089 571 (product (14B)).
~_~e A 29 976-PC - 20 - 2177168 Comparati~e ExamPle 14C
Products ( 14A) and ( 14B) are mixed in a ratio by weight of 4 : 1 (this corresponds to the ratio claimed as according to the invention in US Patent Specification 5 089 571, as in Claims 1, 3 and 4), and this mixture is processed in an injection moulding machine to form test specimens (product (14C)). The mechanical values are set out in Table 6.
ExamPle lS (accordinq to the in~ention) The procedure is as described in Comparative Example 14A, but selecting an NCO : OH ratio of 1.12 (product lS).
Products (15) and (14A) are mixed in a ratio by weight of 1 : 4 and the mixture is processed by injection moulding (product 15A)). In a different mixture these two polyurethanes (15) and (14A) are injected in a ratio by weight of 2 : 1 (product 15B)), mechanical values shown in Table 6.
Table 6 Physical properties of products (14C), (15A) and (15B) Unit (14C) (lSA) (15B) Modulus at 100% elongation MPa 11.9 11.0 11. 7 Modulus at 300~ elongation MPa - 18.9 16.1 Tensile strength MPa 12.0 24.3 20.3 Elongation at break ~ 126 398 404 Resilience ~ 35. 8 36.8 38.7 It is apparent from Table 6 that products (15A) and (15B) conforming to this invention show strength values which are far superior to those of the product (14C) according to Claims 1, 3 and 4 of US Patent Specification 5 089 571.
~Am~le 4 Scrap from a polyurethane obtained following reaction injection moulding and comprising 100 parts by weight polyethane diol adipate of average molecular weight 2,000, 4.5 parts by weight 1,4-butanediol, 0.3 parts by weight trimethylolpropane and 24 parts by weight naphthylene-(1,5)-diisocyanate are reacted at approximately 230C in a twin-screw reactor with 0.82 parts by weight 1,4-butanediol per 100 parts scrap (polyurethane (4)). The product is processed in an injection moulding machine to form test specimens. See Table 2 for physical values.
~m~le 5 Approx. 3-month old production scrap from a 2-component moulding process, comprising a polyurethane of 100 parts by weight polyethanediol butanediol adipate of average molecular weight 2,000, 5.9 parts by weight 1,4-butanediol and 27 parts by weight naphthylene-(1,5)-diisocyanate (NCO : OH ratio = 1.11) are granulated (product (5)) and mixed in a ratio of 2 parts by weight polyurethane (5) to 1 part by weight polyurethane (4), and are processed at approximately 220C in an injection moulding machine having a mould sprayed with release agent, to form test specimens (product 5A). See Table 2 for product properties.
` 2177168 _Le A 29 976-PC - 13 -Example 6 The procedure is as described in Example 4, but using for polyurethane (6A) 2.2 parts by weight 1,4-butanediol, and for product (6B) 14 parts by weight 4,4'-diphenylmethane diisocyanate in lieu of the 1,4-butanediol. Product (6C) is obtained by mixing and subsequently injection moulding (maximum processing temperature 220C) equal parts by weight of granulate of the polyurethanes (6A) and (6B).
The physical properties are set out in Table 2. Storage of the granulate mixture for 5 months results in injection moulded bodies having virtually the same properties.
Table 2 Properties of the products of Examples 4, 5 and 6 Product Test (4) (5A) (6C) standard Elasticity (~) DIN 53 512 38 40 40 Tensile strength (MPa) DIN 53 504 10 21 32 Elongation at break (~) DIN 53 504 250 420 535 Shore hardness A DIN 53 505 85 87 85 ExamPle 7 A thermoplastic polyurethane (7) of Shore D hardness 52 is produced from 100 parts by weight of a hexanediol neopentylglycol polyadipate having an average molecular weight of approximately 2,200, 25 parts by weight 1,4-butanediol, 0.5 parts by weight ethylene bis-stearoyl amide ~_Le A 29 976-PC - 14 - 2177168 and 65.45 parts by weight 4,4'-diphenylmethane diisocyanate. The NCO : OH ratio is about 0.81 (molecular weight Mn = 3,120). 68 parts by weight of a granulate of product (7) are mixed with 58 parts by weight of product (3) and processed by injection moulding to form test specimens (7A). See Table 3 for physical properties.
Table 3 Physical properties of product (7A) TestProduct (7A) standard Resilience (~) DIN 53 512 43 Tensile strength (MPa) DIN 53 504 28 Elongation at break (~) DIN 53 504 539 Modulus 100~ (MPa) DIN 53 504 9.7 Modulus 300~ (MPa) DIN 53 504 13.8 Shore hardness A DIN 53 505 92 The results set out in Table 3 show that it is also possible using the process according to the invention to mix a component having free NCO groups or Zerewitinoff-active groups with a different component of greater orlesser hardness, which reacts with the said component, and to process the latter mixture, thus in targeted manner -within certain limits - adjusting the hardness of the end product as desired. The NCO : Zerewitinoff-active group ratio is immaterial in this respect, provided that it is not substantially below 1.00 in the end product.
Le A 29 976-PC - 15 - 2177168 Example 8 A thermoplastic polyurethane is produced as described in Comparative Example 1. By contrast with Comparative Example 1, 38.6 parts by weight 4,4'-diphenylmethane diisocyanate are used, corresponding to an NCO : OH ratio of 1.02. Injection moulded bodies are produced from the granulate (product 8A), and these are stored in water at 80C for 14 days. After drying in air and then in the vacuum desiccator, the tensile strength of the injection moulded bodies due to hydrolysis is approximately 5 MPa.
The dried injection moulded bodies are granulated.
12 parts by weight 1,6-hexanediol are heated to 200C under nitrogen in the presence of 50 ppm titanium tetrabutylate in a three-necked flask fitted with a stirrer and a reflux condenser. 100 parts by weight of the granulate obtained from the dried, hydrolytically aged injection moulded bodies are added portion-wise such that the contents of the flask remain stirrable. The temperature is meanwhile slowly raised to 220C. Immediately a homogeneous melt is obtained, it is cooled to 180C, poured into a flat Teflon dish, allowed to solidify, and comminuted (product (8B)).
100 parts by weight of product (8B) are mixed with 488.5 parts by weight of product (3) in the form of granulates, the NCO : OH ratio of the mixture being about 1.05 (theoretical), - and processed in an injection moulding machine to form test specimens (product (8C)) (see Table 4 for results).
Le A 29 976-PC - - 16 - 21 771 68 Table 4 Physical properties of product (8C) Test Product (8C) standard Tensile strength (MPa) DIN 53 504 36 Elongation at break ~) DIN 53 504 484 As is apparent from Table 4, the process according to the invention is suitable for reusing polyester polyurethanes which have undergone marked hydrolytic degradation, in thermoplasts of virtually virgin quality.
ExamPle 9 The mixture of 100 parts by weight polybutanediol adipate of average molecular weight 2,000, 8.08 parts by weight 1,4-butanediol, 2.82 parts by weight diethyltolylene diamine (isomer mixture 2,6-isomer : 2,4-isomer = approx.
35 : 65) and 2 parts by weight ethylene bis-stearoyl amide is heated to 170C. 36.7 parts by weight 4,4'-diphenylmethane diisocyanate (corresponding to an NCO : OHratio of 0.94) are stirred in rapidly, and the mixture is poured into a flat PTFE dish, stored at 110C for 1 hour and 80C for 16 hours, and is granulated (product (9).
ExamPle 10 The procedure is as described in Example 9, but using 46.8 parts by weight 4,4'-diphenylmethane diisocyanate, thus obtaining product (10) (NCO : OH ratio = 1.20). The granulates of products (9) and (10) are mixed in a ratio by weight of 2 : 3 and processed by injection moulding to form test specimens (10A).
Le A 29 976-PC - 17 -Table 5 Physical properties of product (lOA) Unit Test Product standard (lOA) Modulus at 100~ elongation MPa DIN 53 504 6 Modulus at 300~ elongation MPa DIN 53 504 20.1 Tensile strength MPa DIN 53 504 54 Elongation at break ~ DIN 53 504 498 Shore hardness A DIN 53 505 84 Resilience ~ DIN 53 512 37 ExamPle 11 1655 parts by weight of a standard hot-moulded foam produced from the principal components propylene-ethylene oxide mixed polyether initiated on glycerol and having an OH number of 56, polypropylene oxide initiated on trimethylolpropane and having an OH number of 56 (polyether ratio 100 : 3.5) and tolylene diisocyanate (proportion of 2,4 isomer: 80~, remainder: 2,6 isomer), are stirred in 140 parts by weight 1,6-hexanediol at 230C under nitrogen until a homogeneous solution is obtained. Polyurethane (11) is obtained having a theoretical OH number of 74.
Example 12A
Product (11) is mixed with product (3) such that a theoretical NCO : OH ratio of 1.00 results. This mixture (12A) is injected in an injection moulding machine to form test specimens having an ultimate strength of 15.5 MPa and an elongation at break of 435~ at Shore A hardness 78.
~- Le A 29 976-PC - 18 - 2177168 ExamPle 12B
The procedure is as described in Example 12A, but with components (3) and (11) mixed such that a theoretical NCO : OH ratio of 1.05 results. The ultimate strength of the injection moulded bodies (12B) is 18.6 MPa.
Example 13A
The procedure is as described in Examples 1 to 3, but selecting an NCO : OH ratio of 0.97. After overnight tempering at 80C, product (13A), when dissolved at room temperature at a concentration of 20 wt-~ in a 4 : 1 ratio lS mixture of dimethylacetamide and methyl ethyl ketone, gives a solution viscosity at room temperature of 660 mPa.s. The melting range of the tempered polyurethane is about 195C.
ExamPle 13B
The procedure is as described in Example 13A, but selecting an NCO : OH ratio of 1.01, and with the solution viscosity of the product (13B) being 79,000 mPa.s measured under the same conditions.
ExamPle 13C
The procedure is as described in Example 13A, but selecting an NCO : OH ratio of 1.30. Product (13C) melts at approximately 214C. It is not soluble in the solvent mixture and under the conditions named in Example 13A, instead merely swelling.
`~ e A 29 976-PC - 19 - 21 7 71 6 8 ExamPle 13D
The granulates of Examples 13A and C are mixed in a ratio by weight of 1 : 2.3, thus resulting in a theoretical NCO : OH ratio of l : 2, and are then injected to form test specimens which are stored overnight at 80C (product (13D)). The test specimens are not soluble in the solvent mixture named in Example 13A and have a tensile strength of 27.8 MPa.
It is apparent from Examples 13A to D that crosslinked products may also be processed by the process according to the invention.
Comparative Example 14A
The procedure is analogous to that of Example 3A of US
Patent Specification 5 089 571, reacting 100 parts by weight polytetrahydrofuran of an average molecular weight of 1,000, 20.7 parts by weight 1,4-butanediol, 0.12 parts by weight ethylene bis-stearoyl amide (as conventional commercial mould release agent), 0.12 parts by weight of a conventional commercial antioxidant, in the presence of 0.01 part by weight tin(II) octoate with 78.4 parts by weight 4,4'-diphenylmethane diisocyanate. The molar NCO : OH ratio is about 0.95 (product (14A)), as described in the Example of US Patent Specification 5 089 571.
Comparative ExamPle 14B
The procedure is as described in Example 14A, but selecting an NCO : OH ratio of 1.06 as in Example 3B of US Patent Specification 5 089 571 (product (14B)).
~_~e A 29 976-PC - 20 - 2177168 Comparati~e ExamPle 14C
Products ( 14A) and ( 14B) are mixed in a ratio by weight of 4 : 1 (this corresponds to the ratio claimed as according to the invention in US Patent Specification 5 089 571, as in Claims 1, 3 and 4), and this mixture is processed in an injection moulding machine to form test specimens (product (14C)). The mechanical values are set out in Table 6.
ExamPle lS (accordinq to the in~ention) The procedure is as described in Comparative Example 14A, but selecting an NCO : OH ratio of 1.12 (product lS).
Products (15) and (14A) are mixed in a ratio by weight of 1 : 4 and the mixture is processed by injection moulding (product 15A)). In a different mixture these two polyurethanes (15) and (14A) are injected in a ratio by weight of 2 : 1 (product 15B)), mechanical values shown in Table 6.
Table 6 Physical properties of products (14C), (15A) and (15B) Unit (14C) (lSA) (15B) Modulus at 100% elongation MPa 11.9 11.0 11. 7 Modulus at 300~ elongation MPa - 18.9 16.1 Tensile strength MPa 12.0 24.3 20.3 Elongation at break ~ 126 398 404 Resilience ~ 35. 8 36.8 38.7 It is apparent from Table 6 that products (15A) and (15B) conforming to this invention show strength values which are far superior to those of the product (14C) according to Claims 1, 3 and 4 of US Patent Specification 5 089 571.
Claims (8)
1. A process for the production of thermoplastic polyurethanes by common thermoplastic processing of:
a) a polyurethane and/or polyurethane polyurea having free hydroxyl groups and/or amino groups and b) a polyurethane and/or polyurethane polyurea obtainable by the isocyanate polyaddition process at an index greater than 100, characterised in that i) an index of at least 110 (isocyanate excess) is adhered to during production of component b) and ii) the molar ratio of the calculated isocyanate excess of the component b) to the free hydroxyl and/or amino group content of component a) is within the range 1.02 : 1 (mole NCO : mole OH and/or NH2) to 100 : 1 during thermoplastic processing of components a) and b).
a) a polyurethane and/or polyurethane polyurea having free hydroxyl groups and/or amino groups and b) a polyurethane and/or polyurethane polyurea obtainable by the isocyanate polyaddition process at an index greater than 100, characterised in that i) an index of at least 110 (isocyanate excess) is adhered to during production of component b) and ii) the molar ratio of the calculated isocyanate excess of the component b) to the free hydroxyl and/or amino group content of component a) is within the range 1.02 : 1 (mole NCO : mole OH and/or NH2) to 100 : 1 during thermoplastic processing of components a) and b).
2. Process according to Claim 1, characterised in that the molar ratio of the isocyanate excess of component b) to the free hydroxyl group and/or amino group content of component a) is at least 1.04 : 1.
3. Process according to Claim 1, characterised in that the molar ratio of the isocyanate excess of component b) to the free hydroxyl group and/or amino group content of component a) is at least 1.05 : 1.
4. Process according to Claims 1 to 3, characterised in that the thermoplastic processing of components a) and b) is by injection moulding, extrusion or extrusion blow moulding.
5. Process according to Claims 1 to 4, characterised in that polyurethane which is already fully reacted is used as a raw material for the production of components a) and/or b).
6. Process according to Claim 5, characterised in that the polyurethane used as a raw material is not a thermoplastic polyurethane.
7. Process according to Claims 5 and 6, characterised in that the polyurethane used as a raw material is constituted by a recycled polyurethane material and/or scrap from polyurethane production.
8. Process according to Claim 7, characterised in that the polyurethanes A) and B) to be utilised according to the invention have different hardness values.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP4340352.2 | 1993-11-26 | ||
| DE4340352 | 1993-11-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2177168A1 true CA2177168A1 (en) | 1995-06-01 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2177168 Abandoned CA2177168A1 (en) | 1993-11-26 | 1994-11-14 | Process for producing thermoplastic polyurethanes by combined thethermoplastic treatment of a hydroxyl- and an isocyanate polyurethane |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0730614A1 (en) |
| JP (1) | JPH09505325A (en) |
| CA (1) | CA2177168A1 (en) |
| CZ (1) | CZ152096A3 (en) |
| HU (1) | HUT74769A (en) |
| PL (1) | PL314586A1 (en) |
| WO (1) | WO1995014723A1 (en) |
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| WO2019175151A1 (en) * | 2018-03-13 | 2019-09-19 | Basf Se | Thermoplastic polyurethane from recycled raw materials |
| JP2022516333A (en) * | 2019-01-04 | 2022-02-25 | ビーエーエスエフ ソシエタス・ヨーロピア | Thermoplastic polyurethane modified with hard phase |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1331217A (en) * | 1961-08-21 | 1963-06-28 | Mobay Chemical Corp | Polyurethane plastics and method of preparation |
| US3284539A (en) * | 1963-12-26 | 1966-11-08 | Mobay Chemical Corp | Polyurethanes from two distinct polyurethane polymers |
| GB1448933A (en) * | 1974-02-14 | 1976-09-08 | Shell Int Research | Process for preparing polyurethane products |
| US5089571A (en) * | 1990-12-04 | 1992-02-18 | The Dow Chemical Company | Regenerated, high molecular weight, thermoplastic resins and process for regenerating thermoplastic resins |
-
1994
- 1994-11-14 PL PL31458694A patent/PL314586A1/en unknown
- 1994-11-14 EP EP95901379A patent/EP0730614A1/en not_active Withdrawn
- 1994-11-14 CZ CZ961520A patent/CZ152096A3/en unknown
- 1994-11-14 JP JP7507810A patent/JPH09505325A/en not_active Ceased
- 1994-11-14 WO PCT/EP1994/003774 patent/WO1995014723A1/en not_active Application Discontinuation
- 1994-11-14 HU HU9601417A patent/HUT74769A/en unknown
- 1994-11-14 CA CA 2177168 patent/CA2177168A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| CZ152096A3 (en) | 1996-09-11 |
| JPH09505325A (en) | 1997-05-27 |
| EP0730614A1 (en) | 1996-09-11 |
| WO1995014723A1 (en) | 1995-06-01 |
| HUT74769A (en) | 1997-02-28 |
| PL314586A1 (en) | 1996-09-16 |
| HU9601417D0 (en) | 1996-07-29 |
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| Date | Code | Title | Description |
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| FZDE | Dead |