Patent Application
20130102723
Priority is claimed to German Patent Application No. 102011085182.8, filed Oct. 25, 2011 which is incorporated herein by reference, in its entirety, for all useful purposes.
The present invention relates to thermoplastic polyurethane moulding compositions with very high surface resistance (write resistance, scratch resistance and abrasion resistance), very good weathering resistance, UV resistance and hydrolysis resistance, very little blooming behaviour, very good technical processibility with a large processing window, and also to the use thereof, in particular for producing large-area injection mouldings for external applications.
On account of their good elastomer properties and thermoplastic processibility, thermoplastic polyurethanes (TPU) are of great technical significance. An overview of the production, properties and applications of TPU is given, for example, in the Kunststoff Handbuch [G. Becker, D. Braun], Volume 7, Polyurethane, Munich, Vienna, Carl Hanser Verlag, 1983.
TPU are mostly synthesised from linear polyols (macrodiols) such as polyester diols, polyether diols or polycarbonate diols, organic diisocyanates and short-chain, mostly difunctional alcohols (chain extenders). They can be produced continuously or discontinuously. The most well-known production processes are the belt process (GB-A 1 057 018) and the extruder process (DE-A 19 64 834).
Synthesis of the thermoplastically processible polyurethane elastomers may be undertaken either stepwise (prepolymer process) or by the simultaneous reaction of all the components in one stage (one-shot process).
In DE-A 102 30 020 the use of polyorganosiloxanes for improving the rub resistance and scratch resistance (mechanical surface resistance) for TPU is described. In the course of the processing of the TPU that contain these additives, however, surface defects appear after some time (after a few shots) in the injection-moulding process, which result in undesirable increased reject-rates.
In EP-A 2 083 026 the use of special mixtures of low-molecular and high-molecular polyorganosiloxanes for improving the rub resistance and scratch resistance (mechanical surface resistance) for TPU is described. In the course of the processing of the TPU that contains these additive mixtures, however, at low processing temperatures (<180° C.) surface defects and delamination occasionally appear in the injection-moulding process, which result in undesirable increased reject-rates.
The object of the present invention was therefore to make thermoplastic polyurethanes (TPU) available that have a very good mechanical surface resistance and at the same time possess a particularly high weathering resistance, UV resistance and hydrolysis resistance and also exhibit outstanding technical processibility, in particular a broad processing window with respect to the processing temperature, and also no surface defects, in particular delamination, in the course of processing.
This object was able to be achieved by means of compositions on the basis of special TPU containing a special additive mixture.
The present invention therefore provides compositions containing thermoplastic polyurethanes that are obtainable from
a) an isocyanate component, substantially consisting of
b) a low-molecular polyol component, substantially consisting of
with
c) a polyol component, substantially consisting of
e) optionally catalysts,
f) optionally additives and/or auxiliary substances,
g) optionally monofunctional chain terminators, and that additionally contain
Preferred embodiments are such compositions containing thermoplastic polyurethane that is obtainable from
a) an isocyanate component, substantially consisting of
b) a low-molecular polyol component, substantially consisting of
Further preferred embodiments are such compositions containing thermoplastic polyurethane that is obtainable from
a) an isocyanate component, substantially consisting of
b) a low-molecular polyol component, substantially consisting of
c) a polyol component, substantially consisting of
e) optionally catalysts,
f) optionally additives and/or auxiliary substances,
g) optionally monofunctional chain terminators, and that further contain
d) 0.4 to 10 wt. %, relative to the total weight of the composition, of a mixture consisting of
Further preferred embodiments are such compositions containing thermoplastic polyurethane that is obtainable from
a) an isocyanate component, substantially consisting of 1,6-hexamethylene diisocyanate
b) a low-molecular polyol component, substantially consisting of
c) a polyol component, substantially consisting of at least one polycarbonate diol with a number-average molecular weight
e) optionally catalysts,
f) optionally additives and/or auxiliary substances,
g) optionally monofunctional chain terminators, and that contain
d) 0.4 to 10 wt. %, relative to the total weight of the composition, of a mixture consisting of
wherein R represents an organic hydrocarbon residue which may be either of linear or of branched structure and exhibits 1 to 27 carbon atoms, and n is an integer from 3 to 8000, wherein the polyorganosiloxane mixture consists of
As used herein, the singular terms “a” and “the” are synonymous and used interchangeably with “one or more” and “at least one,” unless the language and/or context cleary indicates otherwise. Accordingly, for example, reference to “a polyol component” herein or in the appended claims can refer to a single polyol or more than one polyol. Additionally, all numerical values, unless otherwise specifically noted, are understood to be modified by the word “about.”
Within the scope of this application, “substantially consisting of signifies “consisting of in a predominant proportion (more than 50%)”, preferably “consisting of” in a proportion amounting to more than 80%”, particularly preferably “consisting of in a proportion amounting to more than 90%”, likewise particularly preferably “consisting of in a proportion amounting to more than 95%”, and quite particularly preferably “consisting of in a proportion amounting to 99-100% or totally consisting of”.
By way of organic diisocyanates (a), use may be made of aliphatic, araliphatic and cycloaliphatic diisocyanates or any mixtures of these diisocyanates (cf. HOUBEN-WEYL Methoden der organischen Chemie, Volume E20, Makromolekulare Stoffe, Georg Thieme Verlag, Stuttgart, New York 1987, pp. 1587-1593 or Justus Liebigs Annalen der Chemie, 562, pages 75 to 136).
In detail, the following may be mentioned in exemplary manner: aliphatic diisocyanates such as ethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,12-dodecane diisocyanate; cycloaliphatic diisocyanates such as isophorone diisocyanate, 1,4-cyclohexane diisocyanate, 1-methyl-2,4-cyclohexane diisocyanate and 1-methyl-2,6-cyclohexane diisocyanate and also the corresponding isomer mixtures, 4,4′-dicyclohexylmethane diisocyanate, 2,4′-dicyclohexylmethane diisocyanate and 2,2′-dicyclohexylmethane diisocyanate and also the corresponding isomer mixtures; araliphatic diisocyanates such as m- and p-xylylene diisocyanate or m- and p-tetramethylxylylene diisocyanate. Used preferentially are 1,6-hexamethylene diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate. The stated diisocyanates may find application individually or in the form of mixtures with one another. They may also be used together with up to 15 mol % (calculated with respect to total diisocyanate) of a polyisocyanate, but at most so much polyisocyanate may be added that a product arises that is still thermoplastically processible. Polyisocyanates are products with an isocyanate functionality of ≧2, such as, for example, modifications of the stated diisocyanates, for example dimers, trimers, allophanates, biurets and urethanes.
The chain-extending agents b) possess, on average, preferentially 1.8 to 3.0 Zerewitinoff-active hydrogen atoms and have a molecular weight from 60 to 450. Preferentially understood by this are those having two to three hydroxyl groups, particularly preferably having two hydroxyl groups.
By way of chain extender b), preferably one or more compounds are employed from the group of the aliphatic diols with 2 to 14 carbon atoms, such as, for example, ethanediol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, 1,12-dodecanediol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanediol, 1,4-dimethanolcyclohexane and neopentyl glycol. Also suitable, however, are diesters of terephthalic acid with glycols having 2 to 4 carbon atoms, for example terephthalic acid-bis-ethylene glycol or terephthalic acid-bis-1,4-butanediol, hydroxyyalkylene ethers of hydroquinone, for example 1,4-bis(β-hydroxyethyl)hydroquinone, ethoxylated bisphenols, for example 1,4-bis(β-hydroxyethyl)bisphenol A. The stated diols may also be converted with differing molar quantities of ε-caprolactone, accompanied by ring-opening reaction, so that corresponding chain extenders with higher molecular weight arise. Particularly preferably by way of chain extenders use is made of 1,4-butanediol, 1,6-hexanediol, 1,4-dimethanolcyclohexane, 1,4-bis(β-hydroxyethyl)hydroquinone or 1,4-bis(β-hydroxyethyl)bisphenol A and conversion products thereof with ε-caprolactone. Quite particularly preferred is a chain-extender combination consisting of 1,4-bis(β-hydroxyethyl)hydroquinone and a conversion product derived from hexanediol and ε-caprolactone. In addition, relatively small quantities of triols, such as, for example, trimethylolpropane, glycerin or conversion products thereof, with ε-caprolactone and also mixtures of these trifunctional alcohols may also be added.
Particularly preferred chain extenders b) are mixtures containing
Examples of chain extenders b2) and their production are described, for example, in EP 1 854 818 A1.
By way of polyol component c), those having, on average, at least 1.8 to at most 3.0 Zerewitinoff-active hydrogen atoms and having a number-average molecular weight
In particular, compounds exhibiting two to three, preferentially two, hydroxyl groups are preferred, especially those having number-average molecular weights
Suitable polycarbonate diols can be produced by chemical reaction of glycols with dimethyl carbonate or diphenyl carbonate, accompanied by elimination of methanol or phenol. Preferred are glycols with 2 to 12, preferentially 2 to 6, carbon atoms, for example ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,4-dimethanolcyclohexane, 1,10-decanediol, 1,12-dodecanediol, 2,2-dimethyl-1,3-propanediol, or dipropylene glycol or conversion products thereof, being converted with ε-caprolactone. Particularly suitable polycarbonate diols have a molecular weight
Suitable polyether diols can be produced by one or more alkylene oxides with 2 to 4 carbon atoms in the alkylene residue being converted with a starter molecule that contains two active hydrogen atoms in bonded form. By way of alkylene oxides, the following may be mentioned, for example: ethylene oxide, 1,2-propylene oxide, epichlorohydrin and 1,2-butylene oxide and 2,3-butylene oxide. Ethylene oxide, propylene oxide and mixtures consisting of 1,2-propylene oxide and ethylene oxide preferentially find application. The alkylene oxides may be used individually, alternately in succession, or in the form of mixtures. By way of starter molecules there enter into consideration, for example: water, amino alcohols, such as N-alkyldiethanolamine, for example N-methyldiethanolamine, and diols, such as ethylene glycol, 1,3-propylene glycol, 1,4-butanediol and 1,6-hexanediol. Optionally, mixtures of starter molecules may also be employed. Suitable polyether polyols are furthermore the hydroxyl-group-containing polymerisation products of tetrahydrofuran. Trifunctional polyethers in proportions from 0 to 30 wt. %, relative to the bifunctional polyethers, may also be employed, but at most in such a quantity that a product arises that is still thermoplastically processable. The substantially linear polyether diols preferentially possess number-average molecular weights
Suitable polyester diols can, for example, be produced from dicarboxylic acids with 2 to 12 carbon atoms, preferentially 4 to 6 carbon atoms, and polyhydric alcohols. By way of dicarboxylic acids there enter into consideration, for example: aliphatic dicarboxylic acids, such as succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid and sebacic acid, or aromatic dicarboxylic acids, such as phthalic acid, isophthalic acid and terephthalic acid, or possible cyclic anhydrides thereof. The dicarboxylic acids may be used individually or in the form of mixtures, for example in the form of a mixture of succinic acid, glutaric acid and adipic acid. For the purpose of producing the polyester diols it may, where appropriate, be advantageous to use, instead of the dicarboxylic acids, the corresponding dicarboxylic-acid derivatives, such as carboxylic acid diesters with 1 to 4 carbon atoms in the alcohol residue, carboxylic acid anhydrides or carboxylic acid chlorides. Examples of polyhydric alcohols are glycols with 2 to 10, preferentially 2 to 6, carbon atoms, for example ethylene glycol, diethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, 1,12-dodecanediol, 2,2-dimethyl-1,3-propanediol, 1,3-propanediol or dipropylene glycol. Depending on the desired properties, the polyhydric alcohols may be used on their own or in a mixture with one another. Suitable furthermore are esters of carbonic acid with the stated diols, in particular those having 4 to 6 carbon atoms, such as 1,4-butanediol or 1,6-hexanediol, or esters of carbonic acid with conversion products of the stated diols and ε-caprolactone, condensation products of w-hydroxycarboxylic acids, such as w-hydroxycaproic acid, or polymerisation products of lactones, for example optionally substituted ε-caprolactones. Used preferentially by way of polyester diols are ethanediol polyadipates, 1,4-butanediol polyadipates, ethanediol-1,4-butanediol polyadipates, 1,6-hexanediol-neopentyl glycol polyadipates, 1,6-hexanediol-1,4-butanediol polyadipates and polycaprolactones. The polyester diols possess number-average molecular weights
By way of products d1) in d), standard commercial compounds of the general formula SiO2 may be employed. Meant by this are all forms of silicon dioxide (also designated as silica). Mention may be made, in exemplary manner, of modified and unmodified pyrogenic silicic acids, kieselguhr, diatoms, silica glass, non-crystalline amorphous SiO2 such as occurs in nature, for example, in geyserite, tachylite or tektite, crystalline SiO2 such as occurs in nature, for example, in moganite, quartz or tridymite, or amorphous, synthetically produced SiO2.
By way of polyorganosiloxanes d2) and d3) in d), compounds of the general formula (R2SiO)n, wherein R represents an organic hydrocarbon residue which may be either of linear or of branched structure and exhibits 1 to 27 carbon atoms, are employed. Of the repeat units, at least 3 and at most 8000 are present. The polyorganosiloxanes d2) and d3) may be added in bulk or by way of master batch in a carrier substance. By way of carrier substance, thermoplastic elastomers enter into consideration, such as, for example, polyether esters, polyester esters, thermoplastic polyurethanes (TPU), styrene-ethylene-butadiene-styrene (SEBS), acrylonitrile-butadiene-styrene (ABS), styrene-acrylonitrile (SAN), polyamide (PA), acrylate-styrene-acrylate block copolymer (ASA), polybutylene terephthalate (PBT), polycarbonate (PC), polyether block amide (PEBA), polymethylmethacrylate (PMMA), polyoxymethylene (POM) or polyvinyl chloride (PVC). Preferred are thermoplastic polyurethanes, particularly preferably aliphatic thermoplastic polyurethanes.
Component d) may be added already in the course of production of the TPU, for example into a housing of a reaction extruder, to the TPU raw materials, for example to the polyol mixture or to an individual polyol with separate metering, to the chain extender or to the chain-extender mixture in the case of more than one chain extender, or after production of the TPU to the finished TPU, for example by means of compounding. Component d) is preferably added by means of compounding.
The relative quantities of the Zerewitinoff-active compounds are preferably so chosen that the ratio of the number of isocyanate groups to the number of groups that are reactive towards isocyanate amounts to 0.9:1 to 1.1:1.
Suitable catalysts e) are the tertiary amines that are known and conventional in accordance with the state of the art, such as, for example, triethylamine, dimethylcyclohexylamine, N-methylmorpholine, N,N′-dimethylpiperazine, 2-(dimethylaminoethoxy)ethanol, diazabicyclo[2,2,2]octane and similar, and also, in particular, organic metal compounds such as titanic acid esters, iron compounds, bismuth compounds or tin compounds such as tin diacetate, tin dioctoate, tin dilaurate or the dialkyltin salts of aliphatic carboxylic acids, such as dibutyltin diacetate or dibutyltin dilaurate or similar. Preferred catalysts are organic metal compounds, in particular titanic acid esters, iron compounds, tin compounds and bismuth compounds. The total quantity of catalysts in the TPU according to the invention amounts, as a rule, preferentially to 0 to 5 wt. %, preferably 0 to 2 wt. %, relative to the total quantity of TPU.
The thermoplastic polyurethanes according to the invention may contain auxiliary substances and additives f). Typical auxiliary substances and additives are lubricants and mould-release agents, such as fatty-acid esters, metallic soaps thereof, fatty-acid amides, fatty-acid ester amides, antiblocking agents, flameproofing agents, plasticisers (as described, for example, by M. Szycher in M. Szycher's Handbook of Polyurethanes, 1999, CRC Press, pages 8-28 to 8-30; the following may be mentioned in exemplary manner: phosphates, carboxylates (such as, for example, phthalates, adipates, sebacates), silicones and alkylsulfonic acid esters), inhibitors, stabilisers against hydrolysis, heat and discoloration, light stabilisers (preferentially UV stabilisers, antioxidants and/or HALS compounds; further details can be gathered from the specialist literature and are described, for example, in Plastics Additives Handbook, 2001 5th. Ed., Carl Hanser Verlag, Munich), dyestuffs, pigments, inorganic and/or organic fillers, fungistatically and bacteriostatically acting substances and mixtures thereof.
Further details concerning the stated auxiliary substances and additives can be gathered from the specialist literature, for example from the monograph by J. H. Saunders and K. C. Frisch entitled “High Polymers”, Volume XVI, Polyurethane, Parts 1 and 2, Interscience Publishers 1962 and 1964, from the Taschenbuch for Kunststoff-Additive by R. Gachter and H. Müller (Hanser Verlag Munich 1990) or from DE-A 29 01 774.
Further additives that can be worked into the TPU are thermoplastics, for example polycarbonate and acrylonitrile/butadiene/styrene terpolymers (ABS), in particular ABS. Use may also be made of other elastomers such as rubber, ethylene/vinyl-acetate copolymers, styrene/butadiene copolymers and also other TPU.
The addition of the auxiliary substances and additives f) may be undertaken during the process for producing the TPU and/or during an additional compounding of the TPU.
Monofunctional compounds reacting towards isocyanates can be employed in proportions up to 2 wt. %, relative to the TPU, as so-called chain terminators g). Suitable are, for example, monoamines, such as butylamine and dibutylamine, octylamine, stearylamine, N-methylstearylamine, pyrrolidine, piperidine or cyclohexylamine, monoalcohols such as butanol, 2-ethylhexanol, octanol, dodecanol, stearyl alcohol, the various amyl alcohols, cyclohexanol and ethylene glycol monomethyl ether.
The compositions according to the invention are preferentially employed in the injection-moulding process, extrusion process and/or powder-slush process.
The compositions according to the invention are preferably employed for producing heat-resistant mouldings and coatings with very good mechanical and chemical surface resistance, in particular high scratch resistance, very high resistance to light and weather, and very good resistance to solvents and chemicals.
The compositions according to the invention are preferably employed for producing heat-resistant, large-area mouldings with very good mechanical and chemical surface resistance, in particular high scratch resistance, very high resistance to light and weather, and very good resistance to solvents and chemicals.
The compositions according to the invention are preferably used for the interior trim of motor vehicles and as external attachments thereof. Particularly preferably, the compositions according to the invention are used as external attachments of motor vehicles.
The invention will be elucidated in greater detail on the basis of the following Examples.
Abbreviations used:
Production of an Aliphatic TPU (TPU-1):
A mixture consisting of 984.2 g Desmophen® C 2201, 297.3 g HQEE, 231.8 g Cap-HDO, 6.1 g Irganox® 1010 and 0.98 g DBTL was heated to 110° C. subject to stirring with a paddle agitator at a rotational speed of 500 revolutions per minute (rpm). Then 504.0 g HDI were added in one portion. Subsequently stirring was effected up to the maximally possible rise in viscosity and then the TPU was poured out. The material was thermally aftertreated for 30 min. at 80° C. and subsequently granulated. This material was used as base material for Examples 1 to 3 and 10.
Production of an Aliphatic TPU (TPU-2):
A mixture consisting of 1029.4 g Desmophen® C XP 2613, 202.5 g DDO and 4.5 g Irganox® 1010 was heated to 110° C. subject to stirring with a paddle agitator at a rotational speed of 500 revolutions per minute (rpm). Then 252.0 g HDI were added. Subsequently stirring was effected up to the maximally possible rise in viscosity and then the TPU was poured out. The material was thermally aftertreated for 30 min. at 80° C. and subsequently granulated. This material was used as base material for Examples 4 to 6.
Production of an Aliphatic TPU (TPU-3):
A mixture consisting of 1001.8 g Desmophen® C. 2201, 177.3 g HDO, 4.5 g Irganox® 1010 and 1.0 g K-Kat 348 was heated to 110° C. subject to stirring with a paddle agitator at a rotational speed of 500 revolutions per minute (rpm). Then 333.5 g HDI were added in one portion. Subsequently stirring was effected up to the maximally possible rise in viscosity and then the TPU was poured out. The material was thermally aftertreated for 30 min. at 80° C. and subsequently granulated. This material was used as base material for Examples 7 to 9.
Production of an Aliphatic TPU (TPU-4):
A mixture consisting of 984.2 g Desmophen® C. 2201, 297.3 g HQEE, 179.5 g C12®DM, 5.9 g Irganox® 1010 and 0.98 g DBTL was heated to 110° C. subject to stirring with a paddle agitator at a rotational speed of 500 revolutions per minute (rpm). Then 492.2 g HDI were added in one portion. Subsequently stirring was effected up to the maximally possible rise in viscosity and then the TPU was poured out. The material was thermally aftertreated for 30 min. at 80° C. and subsequently granulated.
Production of an Aliphatic TPU (TPU-5):
A mixture consisting of 1001.8 g Desmophen® C. XP 2613, 297.3 g HQEE, 231.8 g Cap-HDO and 6.1 g Irganox® 1010 was heated to 110° C. subject to stirring with a paddle agitator at a rotational speed of 500 revolutions per minute (rpm). Then 504.0 g HDI were added in one portion. Subsequently stirring was effected up to the maximally possible rise in viscosity and then the TPU was poured out. The material was thermally aftertreated for 30 min. at 80° C. and subsequently granulated.
Production of an Aliphatic TPU (TPU-6):
A mixture consisting of 1001.8 g Desmophen® C. XP 2613, 297.3 g HQEE, 179.5 g C12®DM and 5.9 g Irganox® 1010 was heated to 110° C. subject to stirring with a paddle agitator at a rotational speed of 500 revolutions per minute (rpm). Then 492.2 g HDI were added in one portion. Subsequently stirring was effected up to the maximally possible rise in viscosity and then the TPU was poured out. The material was thermally aftertreated for 30 min. at 80° C. and subsequently granulated.
Production of an Aliphatic TPU (TPU-7):
A mixture consisting of 1001.8 g Desmophen® C XP 2613, 423.6 g C12 DM and 5.7 g Irganox® 1010 was heated to 110° C. subject to stirring with a paddle agitator at a rotational speed of 500 revolutions per minute (rpm). Then 452.8 g HDI were added in one portion. Subsequently stirring was effected up to the maximally possible rise in viscosity and then the TPU was poured out. The material was thermally aftertreated for 30 min. at 80° C. and subsequently granulated.
Production of an Aliphatic TPU (TPU-8):
A mixture consisting of 984.2 g Desmophen® C 2201, 423.6 g C12®DM, 5.6 g Irganox® 1010 and 0.98 g DBTL was heated to 110° C. subject to stirring with a paddle agitator at a rotational speed of 500 revolutions per minute (rpm). Then 452.8 g HDI were added in one portion. Subsequently stirring was effected up to the maximally possible rise in viscosity and then the TPU was poured out. The material was thermally aftertreated for 30 min. at 80° C. and subsequently granulated.
Production of an Aliphatic TPU (TPU-9):
A mixture consisting of 506.5 g Desmophen® C 2201, 242.1 g Acclaim 2220N, 214.7 g HQEE, 167.4 g Cap-HDO, 4.5 g Irganox® 1010 and 0.70 g DBTL was heated to 110° C. subject to stirring with a paddle agitator at a rotational speed of 500 revolutions per minute (rpm). Then 364.0 g HDI were added in one portion. Subsequently stirring was effected up to the maximally possible rise in viscosity and then the TPU was poured out. The material was thermally aftertreated for 30 min. at 80° C. and subsequently granulated.
Production of an Aliphatic TPU (TPU-10):
A mixture consisting of 541.5 g Desmophen® C 2201, 206.7 g PE225B, 214.3 g HQEE, 167.1 g Cap-HDO, 2.1 g Stabaxol® P200, 4.5 g Irganox® 1010 and 0.70 g DBTL was heated to 110° C. subject to stirring with a paddle agitator at a rotational speed of 500 revolutions per minute (rpm). Then 363.2 g HDI were added in one portion. Subsequently stirring was effected up to the maximally possible rise in viscosity and then the TPU was poured out. The material was thermally aftertreated for 30 min. at 80° C. and subsequently granulated.
Production of an Aliphatic TPU (TPU-11):
A mixture consisting of 524.1 g Desmophen® C 2201, 139.2 g Terathane® 1000, 239.3 g HQEE, 186.6 g Cap-HDO, 4.5 g Irganox® 1010 and 0.70 g DBTL was heated to 110° C. subject to stirring with a paddle agitator at a rotational speed of 500 revolutions per minute (rpm). Then 405.6 g HDI were added in one portion. Subsequently stirring was effected up to the maximally possible rise in viscosity and then the TPU was poured out. The material was thermally aftertreated for 30 min. at 80° C. and subsequently granulated.
Production of an Aliphatic TPU (TPU-12):
A mixture consisting of 588.7 g Desmophen® C 2201, 147.2 g Terathane® 2000, 218.4 g HQEE, 170.3 g Cap-HDO, 4.5 g Irganox® 1010 and 0.70 g DBTL was heated to 110° C. subject to stirring with a paddle agitator at a rotational speed of 500 revolutions per minute (rpm). Then 370.2 g HDI were added in one portion. Subsequently stirring was effected up to the maximally possible rise in viscosity and then the TPU was poured out. The material was thermally aftertreated for 30 min. at 80° C. and subsequently granulated.
Master batches or silicone oil (the exact formulations can be gathered from Table 1) and carbon black (2 wt. %, relative to TPU, Elftex® 435 produced by Cabot) were added to the TPU granulated materials produced in accordance with the general descriptions. In an extruder of type DSE 25, 4 Z, 360 Nm with the following structure:
Determination of Technical Processibility:
In the course of injection moulding, special attention was paid to the technical processibility at various temperatures (180 to 230° C.) and pressures (650 to 750 bar). In this connection the feed behaviour, for example, in the funnel of the injection-moulding machine was rated. It was checked whether delamination, defects and/or a bloom on the moulding became visible. Likewise it was assessed how quickly a bloom on the moulding was formed and how thick said bloom was. In this connection the following grading system was introduced for the purpose of assessing the formation of a bloom:
Grade 1: no bloom visible;
Grade 2: little bloom visible and also does not become thicker;
Grade 3: little bloom visible, but after further shots becomes thicker and thicker;
Grade 4: a lot of bloom quickly, which also rapidly becomes thicker with further shots; Only a grading with 1 is very good; a grading with 2 is acceptable.
Determination of Surface Sensitivity
For the determination of surface sensitivity two tests were carried out:
Crockmeter test: These tests were carried out with a crockmeter manufactured by James H. Heal & Co. Ltd., Richmond Works, Halifax, West Yorkshire, HX3 6EP, England, Model 255A, with rubbing finger on an injection-moulded article with a grained surface, to be specific under the following conditions:
rubbing pressure: 10N, rubbing distance: 260 mm, time per rub: 15 sec., number of strokes: 100.
Implementation: The cotton scouring fabric was stretched under the bearing surface, and the test was carried out under the conditions described above. In this connection the damage to the surface was assessed qualitatively.
The grading “poor” signifies a visually distinctly visible abrasion of the surface. The grading “good” signifies no abrasion or barely visible abrasion.
Scratch test: This test was carried out with an Erichsen hardness-testing rod, model 318 with engraving tip Nr. 2 (following the model of ISO 1518, 1.0 mm diameter) with a stroke and with a force of 10 N on a grained surface (line of 10 mm length at a speed of 10 mm/s). In this connection the damage to the surface was assessed qualitatively. The grading “poor” signifies visually distinctly visible damage to the surface. The grading “good” signifies no surface damage or barely visible surface damage.
Determination of the Blooming Behaviour of the Compositions
For the purpose of determining the blooming behaviour three test conditions were chosen, to which the injection-moulded plates produced from the compositions of the Examples were subjected. The plates were subsequently examined qualitatively with regard to bloom formation. The test conditions were the following:
Determination of the Thermal-Storage Resistance and Hydrolysis Resistance of the Compositions:
Thermal storage: The injection-moulded plates were stored suspended at 120° C. (±2° C. tolerance) for 500 hours.
Hydrolysis storage: The injection-moulded plates were stored suspended at 80° C. (±2° C. tolerance) in de-ionised water for 500 hours.
The results of the investigations can be gathered from the following Table 2.
The percentage change in tear resistance and elongation at break is calculated as follows: value of tear resistance or elongation at break after hydrolysis storage or thermal storage divided by value of tear resistance or elongation at break before hydrolysis storage or thermal storage multiplied by 100 yields % tear resistance or % elongation at break, respectively.
Discussion of Test Results:
In Examples 1, 4 and 17 no siloxane-containing master batch and no silicone oil was used. The technical processibility and the surface resistance of the plates obtained are poor. In Examples 7 and 12 no siloxane-containing master batch was used, but silicone oil was used. The technical processibility is good, but the scratch test was not passed. With the use of MB50-827® (contains high-molecular polyorganosiloxane) (Examples 2, 5, 13, 15 and 19) the results from the crockmeter test were good and the scratch test was passed, though the technical processibility was not optimal: delamination appeared.
The compositions from Examples 3, 6, 8 to 11, 14, 16 and 18 according to the invention, which contain both a siloxane-containing and silica-containing master batch (MB40-817®) and silicone oil, satisfied all the requirements in terms of surface sensitivity, displayed very good technical processibility with a large processing window, and at all temperature and pressure settings in the course of injection-moulding processing there were no delamination problems. A problem-free continuous processing was possible.
With respect to formation of a bloom, in the course of room-temperature storage the compositions from all the Examples were good. Examples 7 and 12 with relatively high quantity of silicone oil displayed a slight colourless bloom in the case of 30° C. water storage and in the case of 60° C. storage. Examples 2, 13, 15 and 19 displayed a slight colourless bloom in the case of 60° C. storage.
After thermal storage and hydrolysis storage, Examples 3, 11, 14, 16 and 18 according to the invention displayed distinctly better results with respect to tear resistance and elongation at break than the comparative example on the basis of a polyol composition not according to the invention. These results demonstrate the very good hydrolysis-resistance and heat-resistance levels of the TPU products according to the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2011 085 182.8 | Oct 2011 | DE | national |
