DD159990A1 - METHOD FOR PRODUCING POLYURETHANE ELASTOMERS - Google Patents

Abstract

The invention relates to a process for the preparation of polyurethane elastomers from Copolyetherpolyolen, di- or polyisocyanates, chain extenders, catalysts and other known additives. The resulting elastic polyurethanes are characterized by improved mechanical properties over a wide temperature range, by increased hydrolytic stability and good Wasserdampfermeationsverhalten. Their production takes place according to the invention by mixing two prepolymers which are composed of a copolyether diol or copolyether triol with excess isocyanate groups, where the equivalent weights of the starting materials are largely compatible and at least one component ethylene oxide content which is present as 30 to 100% of the total ethylene oxide endblock Reacting with the chain extender, consisting of short chain diols and polyester diols, optionally with the addition of a catalyst and subsequent hardening. The products according to the invention are particularly suitable as coating compositions for leather, fabrics or fabrics, as films or films, as elastomers of high stress in terms of mechanical and hydrolytic properties, for membranes in liquid and gas separation processes and also as cellular elastomers with the addition of blowing agents.

Description

Title of the invention

Process for the preparation of polyurethane elastomers

Field of application of the invention

The invention relates to a process for the preparation of polyurethane elastomers, which are used as coating compositions for materials such as leather, fabrics or fabrics, as films or films, as elastomers for high stresses in terms of mechanical and hydrolytic properties, for membranes in liquid and gas separation processes and are used as cellular elastomers in the presence of blowing agents.

Characteristic of the known technical solutions

Processes for the preparation of elastic polyurethanes from polyesters, polycaprolactones, polytetrahydrofurans, polypropylene glycols and from copolymers of lower alkylene oxides with different functionality or mixtures thereof by reaction with isocyanates, chain extenders and / or hardeners, optionally with the addition of catalysts and / or additives, have long been. known"

When using only difunctional products,

optionally with the addition of small molar fractions of

Honey alcohols, thermoplastic polyurethanes are obtained «,

VV@rd.en these are made of polyoxypropylene-polyoxyethylene-copolyiner «- 'glycols, so the strength values are lower! Hardening, d "o _rie high elasticity, generally for much © Applications inadequate _f while the low" temperature eiger properties and hydrolytic stability are sufficient as u "? a "from d®r DE-Z 824 641 and US patents 4,098,772 and 4,133,943 is known *

If polyester diols are used instead of the above-mentioned polyether alcohols based on the alkylene oxides, the products have inadequate hydrolytic stability and insufficient low-temperature behavior (W * Goyert and Hittepspe Kunststoffe 68 {1978}, 819-825) Crosslinked products, which are not thermoplastically processable, are produced in spite of the fact that they are segmented block copolymers, since the segmental structure of the polyurethanes is retained. The cross - linking can now take place in the hard or soft grades "It has been shown, however, that hard graphene crosslinking brings about a drastic drop in almost all property values." Crosslinking in the soft segment should represent a combination of the properties of the diol and triol. * The property values of such blends are however, as R * Bonart proved (Angev \ u Makromole Chenu 58/59 (1977) " 25S), below the imaginary line" 6er Ausgangskorfiponenten ",

From DE-OS 2,842,805 a method for the production of elastomeric, "polyurethanes is known, wherein the prepolymer based on a diol triol mixture of polyether, the polyol functionality 2.5 to 3 having secondary OH groups and a molecular weight expectant reacted 1000-4500 using a polyester diol in the presence of a monomeric diols and an amine '@ n _o The elastomers obtained, however, have a low tensile strength and elongation at break _e

Is known from DE-AS 2 753 ₀ 3SS.ist known DSSS properties for the shanks of the Polyurethanelestomeren the position of the chain in Ethylesioxids great importance attributed to "The after beaehriobener" polyol manufactured method can, for example, when -the ethylene oxide present as EndabschluS and can not be found in the Inn & ren of the chain is "incompatible amounts" of certain low molecular 'chain' tolerate extension agents without processing problems, since the resulting mixture selbstemulgierende properties »Furthermore, the elastomers prepared from such polyols have an unexpectedly satisfactory hydro lytic stability, if the ethylene oxide AMSTEL inside öor chain

According to US Pat. No. 4,102,773, a mixture of di- and trifunctional polyether alcohols is particularly suitable for the derivation of an artificial leather. Polyether alcohols whose molar masses are the same and relatively low (at 1000) are used here.

The curing of polyether diisocyanate Prepolyraeren carried out with aitsines, short-chain diols such as 1,4-butanediol, mixtures of short-chain diols (DE-OS 2,817,456) or diols of different molecular weight (DD-AP 77 324), mixtures of polyester diols with short-chain Diolen (DE ~ OS 2 442 753) or with short-chain diols and monomeric triols (DE-OS 2,826,232) and with mixtures of amines and short- or long-chain diols (DE-OS 3,013,553 ), the use o®r mixtures is generally used to increase the elasticity and to improve the processing properties of the components. "

The catalysis of polyether urethanes for elastomers or foams by roetallorganische compounds (Le Thiele, Acta Polymorica 30 (1979), 323) * In particular, compounds of divalent and tetravalent tin is known to use, namely, these are usually mixed substituted tin compounds. With. Allyl and organic acid residues (US Patent No. 4,087,412 and 4,131,606, Canadian Patent No. 1 OSQ 699, GB-PS .1 332700) *

More recently, more and more sulfur-containing organic tin compounds have been used as catalysts with delayed action in the polyurethane industry. Examples include reaction products of diethanolamine and dibutyltin sulfide (US Pat. No. 4,119,585), mercaptoalcohol-tin compounds (OPT). OS 55073695), and Dialkylzi'nnsulfide Dlalkylzinndlmercaptide (DE-OS 2,832,313 and 2,832,315) or di-n-octyl-zlnnmercaptid. (DE-AS 1,769,367, US-PS 3 64-5 S27) to be named.

Furthermore, a method for the production of polyurethane Waichsehaumstoffen is known from DE-OS 2,657,413 is known in which the reaction in the presence of latent Gelkatalysötoren occurs "are used tin compounds which also contain phosphorus, sulfur and oxygen in addition to nitrogen *

The disadvantages of the known technical solutions are in particular in too low mechanical strengths when using high molecular weight Poiyetheralkoholgemisehe, too high Glasöbergangstensperaturen in poor hydrolytic stability when using polyesters and generally in low bending fatigue resistance of films at low temperatures justified The sulfur-containing tin catalysts used the application for the production of sheet-like structures are usually for actively and be in carrying out the process at elevated temperature therefore does not apply "

Object of the invention

The object of the invention is to develop an uncomplicated process with which highly elastic polyurethanes of improved mechanical properties can be obtained over a wide temperature range and increased hydrolytic stability with very good water vapor permeation behavior *

τ-3 1 7Λ b

Explanation of the essence of the invention

The object of the invention is achieved, de from Copoiy- = · etherpolyoXetif Dl »or polyisocyanates, chain extenders and / or Hartem or mixtures thereof optionally with addition of catalysts and other known additives such as blowing agents, pigments» fillers, flame retardancy », sliding And stabilizing agents polyurothane elastomers are prepared by preparing a copolyether diol prepared in accordance with the invention initially from two or more lower alkylene oxides with a diisocyanate or polyisocyanate excess in the ratio OH to NCO such as 1: 2.2 to 1:13 to form a prepolymerizer A and from a trifunctional initiator such as glycerol or trimethylolpropane and two or more lower alkylene oxides are prepared with a Di = or PolyisocyanatoberschuB ratio of OH to NCO such as 1: 2.2 to 1: 13 to a prepolymer B, then the two prepolymers in the ratio A: B wis 100: 1 b is mixed 1: 1 so that, in an equivalent range of 300 to 3000, the difference of the equivalent is at most equal to or more preferably less than 25 % of the equivalent of the copolyether triol; and wherein in each gopolyether polyol at least one component is ethylene oxide, which is distributed randomly to the chain and 30 to 100 % of the total ethylene oxide content as endblock to 0 to 70 % dss total ethylene oxide content, then the prepolymer mixture by short-chain diols or mixtures of karzkettigen diols and polyester diols in the ratio of equivalent equivalent as 1000: 1 to 4: 1, in particular 20: 1 to 9: 1, optionally in the presence of a catalyst, preferably special, organotin compounds with delayed at low temperatures effectiveness of the general formula I _1st

1 2 in the R and R are the same or different aliphatic radicals

W. 8 _: 6 '

with 1 to 20 C atoms, mean cycloaliphatic or araliphatic radicals or aliphatic radicals with CC double bonds, and η can assume the value % to 3 and m the value t to 18, the temperatures between 20 and 55 ⁰ C is mixed, in the temperature range of 20 to 200 ⁰ C in a time of 1 to 300'Minuten hardened »

It is also possible to react a copolyether diol "copolyether triol" with a diisocyanate or polyisocyanate excess to give a prepolymer and then to cure it. "In particular, lower alkylene oxides are used to prepare the gopolyether polyols. These are, for example, ethylene oxide and propylene oxide.

The polyurethanes W8r.deη are preferably produced using the 2-stage process, but you can use a "stage technology" or a special step process »·

The products produced by the process according to the invention can be further processed in a known manner or applied directly to flexible supports such as paper, fabric, felt, leather or polymers and are characterized by high adhesive strength * In addition to their high elasticity, the elastomers

High strengths, which are significantly higher than the maintenance of the polyurethanes from individually used polyether alcohols,

good low-temperature behavior, since the glass transition temperature of the polyurethanes from the mixtures is lower than those of the polyether alcohols due to an improvement in the order in the soft segment matrix .

»High hydrolytic resistance despite. Use © ineo share polyester alcohols through the shielding in the ordered softness matrix and

· flexible Ve.rarbeitbarkeit by determining Oer reaction rate through the mixing temperature and Kstalysatonsgnge, since the catalysts used are extremely potent in the cold and relatively little catalytically under the curing however.

Execution bfii games

In the individual examples mean:

Polyether alcohol I; A linear polyether alcohol

Propylene oxide, with 30 percent by _e - '% ethylene' oxide present as end block, equivalent weight 1170, functionality 1.96

Hi A linear polyether of propylene oxide having 20 wt _e «% ethylene 'oxide distributed randomly in the chain and 10 G © w * ~% ethylene oxide end block present, equivalent weight 1150, functionality 1.97

III: A linear polyether alcohol

Propylene oxide with 10 wt .-% of ethylene oxide statistically distributed to the chain and 20 wt .-% ethylene oxide present as an end block, equivalent weight 1100, functionality 1.97

IV: A polyether triol from glycerine and propylene oxide containing 10 wt _e «% ethylene oxide in the chain and 5 percent by _e -% ethylene oxide present as end block, Äquivalentgswicht. 1310, functionality ".2.78 ·

- Prepolymer I to IVs PoiyetheralkohoX I to IV, respectively

with 4,4'-diphenylmethane diisocyanate in the equivalency ratio 1; 4.2

uragesetsit

Polyester alcohol A: an iinoaric polyester alcohol

Adipic acid, ethylene glycol and diethylene glycol, .Equivalent weight

Bi A linear polyester alcohol sus adipic acid, ethylene glycol and butanediol 1 , 4, equivalent 1020

The preparation of the polyether alcohols I to IV, of the prepolymers I to IV as well as the polyester alcohols A and B he "· follows by known methods of the prior art"

example 1

Prapolyraer I and IV C are mixed in the ratios listed in the table bai 80 together, degassed and reacted with an index of 99 A corresponding amount of butane-1 "is then hardened · the resulting product hours at 145 ⁰ C.

Mixing ratio 1 ϊ IV

Comparison a 1: 0 Comparison b Oil Invention 0.7: 0.3

Giss-

gangstemper "

• 43 ⁰ C »48 ⁰ C

strength

Breaking strain

Shore A hardness

12.3 MPa 515 % 12.6 MPa 265 % 21.0 MPa 640 %

81 84 83

". _ - - - - U -9 Example 2

Analogously to Example 1 , the prepolymers II and IV are implemented «

• Mixing ratio . II: IV 0 1 0.15 Glssbà © r »gange-temper« Tensile strenght MPa MPa MPa Breaking strain % % % Shore "A hardness Comparison a Comparison b Invention 1: P: 0.85: -32 ⁰ C -43 ⁰ C -42 ⁰ C 16.5 12.6 19.8 650 265 705 79 84 82 Example 3

The Prepolyraeren vjerden analogous to Example 1 III and IV urnge = eetzt "

* a Mixed, Condition III: IV O Most common? Per _c Tensile strenght MPa Breaking strain Shore A hardness comparison b 5.: 1 -42 ⁰ C 5.8 MPa 295 % 85 comparison a O ί 0.3 -43 ⁰ C 12.6 MPa 265 % 84 invention b 0.7: 0.2 -40 ⁰ C 17,1- MPa 475 % 83 invention 0.8: -45 ⁰ C 20.2 1565 % 84

The advantageous properties of the products according to the invention become very clear from these examples; they were obtained by a broad assessment of the equivalent weight of the starting materials. "

Example 4

The mixture from Example 1 are added prior to curing 0.05 * -% of catalyst ^(C ₈ ^H ₁ 7) 2 ^{Sn (CH} 2 ^{s C00C} 8 ^H 17 ^ 2 ^{0setzt at 40} ° ^{C 2u} 9 and then 30 minutes at 140 ⁰ C hardened After only 4 minutes , the Pölyursthan films were tack-free and could be easily separated from the carrier paper They have the following properties:

Tensile strength 22.5 MPa

Breaking strain 720 %

83

Example 5

, Analog "Example 1 are respectively 1 ~ NCO Gramtsäquivalent Prepolytner III and IV are mixed with degassing 'at 80 ⁰ C and 0.1 Torr one another" After a Stund® be of Frepolyroergemisch 0 _e 95 moles of 1,4-butanediol and 0.05 Moles of polyester alcohol B ", which had previously been mixed at 80 ^° C., were added and converted into films before, 100% by weight of starch , followed by curing at 150 ° C. for about ¹ hour.

The films have the following properties j

Tensile strength 17.2 MPa, breaking elongation -453 % - Shore A hardness 73

glass transition

temperature -37 C

.Water intake (4 days) 3 * 9 % ''

  Steam-

• permeable »= '- ₉

278 mg / 10 cm x 24 h

Example 6

The procedure is as in Example 5, but as a chain extender mixture is a mixture of 0.9 mol of butanediol »! _t 4 and 0.1 mol polyester alcohol B used The resulting films have the following properties:

tensile strenght 20 8 MPa elongation 461 % Shore A hardness ™ 61 Glesöbergangs- temperature -37 ° c IWasseraufnahm © (4 Days) 3 "7 0 / ί '/ 0 Water vapor permeability 268 mq / 1

,. J j / L · b

Example 7

The procedure is as in Example 5, but as a chain extender , a mixture of the same is used. But the mixture is also dissolved in water. Butene diol , 4, and 0.1 mol Polygseralkobol A varksndct. Further, before the shepherd, 0.01 wt _c - Added% catalyst from Example 4 »

The resulting films have the following properties:

tensile strenght 17.0 MPa % "24 hours elongation 453 Shore "A" hardness 61 ⁰ C Glass transition temperature -35 3 % Water intake (4 days) 3, mg / 3.0 cm Moisture vapor permeability , 332

Claims (1)

, £ ό I. £ I η 8 ⁱ² Erfindwngsanspruch • ttenverlsngerern l _e process for the production of polyurethane Elastoniaren from copolyether polyols, · Di "or polyisocyanates, Ke and / or hard or mixtures thereof, optionally with the addition of catalysts and other known additives such as blowing agents, pigments, fillers, flame ·, Lubricants and stabilizers, characterized as by "that first prepared from two or more lower alkylene« Copolyetherdioi with a Di ° or PolyisocyanetüberschuS in the ratio OH to NGO such as 1 i 2.2 to 1 ι 13 to a prepolymer A and © in from a Trifunktiorsellen starter such as glycerol or tri? raethylolpropan and two or more lower alkylene oxides produced Copolyethertriol with a di- or PolylsocyanatöberschuS in the ratio OH to MGO as • 1: 2.2 to 1; 13 reacted to a prepolymer B and then the two prepolymers. j in a ratio of A B as 100 i 1 to 1: mixing 1 ", wherein x is at most equal to or preferably less than 25% of the equivalent weight of the copoly in an equivalent range of 300 to 3000, a difference of the equivalent weights" is ethertriols and wherein in each Copolyethsrpolyol at least one component is ethylene oxide, which is randomly distributed to 0 to 70 % of the total ethylene oxide content on the chain and to 30 to 100 % of the total ethylene oxide content as an end block, then the Prepolymerengeraisch by short-chain diols or by mixtures of short-chain diols and polyester diols ira ratio of equivalent weightings such as 1000 ί 1 to 4: 1, in particular 20: 3 to 9 σ 1, if appropriate in the presence of a catalyst, preferably of special organotin compounds having a delayed action at low temperatures of general formula I, R ^, Sn (S- (CH ₂ J _1n COOR ² J ₄ ^ _n - j Wherein R and R equal or unequal © aliphatic radicals having 1 to 20 carbon atoms, cycloaliphatic or aliphatic radical or radicals araiipha'cische © mean with CC-Qoppeibindungen and η clon value 1 bia 3 as the value of ra 1 to 18 accept · can "is mixed at psrsturen'zwischen 20 and 55 ⁰ C, in the temperature range of 20 to 200 ⁰ C. iri a time of 1 to 300 Hinuten is cured" A process according to item i, characterized in that a copolyetherdiol copolyether triol mixture is reacted with a di- or polyisocyanate excess to form a prepolymer and the catalyst is anecludarily cured, 3 · Process according to items 1 and 2, characterized in that as the lower alkylene oxides for the preparation of Copolyetherpolyoie preferably Przpylenoxid and ethylene oxide are used, «. ·