COMPOSITION FOR TRANSPARENT SHAPED BODIES BASED ON POLYURETHANE

Abstract

A composition comprising an isocyanate component A) comprising at least one cycloaliphatic or araliphatic diisocyanate, a polyol component B) comprising at least one polyol having an OH number of 80 to 1000 mg KOH/g, an additive component C) comprising at least one internal demoulding agent, and a catalyst component D) comprising at least one inorganic metal complex as thermally latent catalyst, characterized in that the thermally latent catalyst has a quotient of reaction rates between catalysed reaction and uncatalysed reaction at 30° C. of =5.0 and at 60° C. of =1.1. The present invention further provides a process for producing an elastomer and for the use of the composition for production of transparent shaped bodies.

Claims

1.-17. (canceled)

18. A composition comprising an isocyanate component A) comprising at least one cycloaliphatic or araliphatic diisocyanate, a polyol component B) comprising at least one polyol having an OH number of 80 to 1000 mg KOH/g, an additive component C) comprising at least one internal demolding agent, wherein the demolding agent is at least one mono- and/or dialkyl phosphate having 8 to 12 carbon atoms in the alkyl radical, and a catalyst component D) comprising at least one inorganic metal complex compound as a thermolatent catalyst, wherein the thermolatent catalyst exhibits a quotient of the reaction rates between catalyzed reaction and uncatalyzed reaction of ≦5.0 at 30° C. and of ≧1.1 at 60° C.

19. The composition as claimed in claim 18, wherein the inorganic metal complex compound comprises bismuth, titanium, zinc, zirconium or tin, preferably bismuth or tin and particularly preferably tin as the central atom.

20. The composition as claimed in claim 18, wherein the inorganic metal complex compound comprises at least one ligand which comprises at least one ether, thioether or amino group and/or is a chelate ligand, preferably comprises at least one amino group and/or is a chelate ligand and particularly preferably comprises at least one amino group and is a chelate ligand.

21. The composition as claimed in claim 18, wherein the inorganic metal complex compound is selected from the group of formulae I, II or III: ##STR00014## wherein: D represents —O—, —S— or —N(R1)—, wherein R1 represents a saturated or unsaturated, linear or branched, aliphatic or cycloaliphatic radical or an optionally substituted aromatic or aliphatic radical having up to 20 carbon atoms which may optionally comprise heteroatoms from the group of oxygen, sulfur, nitrogen or represents hydrogen or the radical ##STR00015## or R1 and L3 together represent —Z-L5-; D* represents —O— or —S—; X, Y and Z represent identical or different radicals selected from alkylene radicals having the formulae —C(R2)(R3)—, —C(R2)(R3)—C(R4)(R5)— or —C(R2)(R3)—C(R4)(R5)—C(R6)(R7)— or ortho-arylene radicals having the formulae ##STR00016## wherein R2 to R11 independently of one another represent saturated or unsaturated, linear or branched, aliphatic or cycloaliphatic or optionally substituted aromatic or aliphatic radicals having up to 20 carbon atoms which may optionally comprise heteroatoms from the group of oxygen, sulfur, nitrogen or represent hydrogen; L1, L2 and L5 independently of one another represent —O—, —S—, —OC(═O)—, —OC(═S)—, —SC(═O)—, —SC(═S)—, —OS(═O).sub.2O—, —OS(═O).sub.2— or —N(R12)—, wherein R12 represents a saturated or unsaturated, linear or branched, aliphatic or cycloaliphatic radical or an optionally substituted aromatic or aliphatic radical having up to 20 carbon atoms which may optionally comprise heteroatoms from the group of oxygen, sulfur, nitrogen or represents hydrogen; L3 and L4 independently of one another represent —OH, —SH, —OR13, -Hal, —OC(═O)R14, —SR15, —OC(═S)R16, —OS(═O).sub.2OR17, —OS(═O).sub.2R18 or —NR19R20 or L3 and L4 together represent -L1-X-D-Y-L2-, wherein R13 to R20 independently of one another represent saturated or unsaturated, linear or branched, aliphatic or cycloaliphatic or optionally substituted aromatic or aliphatic radicals having up to 20 carbon atoms which may optionally comprise heteroatoms from the group of oxygen, sulfur, nitrogen or represent hydrogen.

22. The composition as claimed in claim 18, wherein the internal demolding agent comprises at least one compound having a pK.sub.A of ≦4.60.

23. The composition as claimed in claim 18, wherein the isocyanate component A) comprises a mixture of a) at least one cycloaliphatic or aliphatic diisocyanate and b) at least one acyclic, aliphatic di- or triisocyanate or one oligomer of an aliphatic diisocyanate.

24. The composition as claimed in claim 23, wherein the mixture in the isocyanate component A) is present in a weight ratio of a) to b) between 55:45 and 94:6.

25. The composition as claimed in claim 23, wherein the oligomer of an aliphatic diisocyanate comprises at least one allophanate, one biuret, one uretdione, one isocyanurate and/or one urethane group.

26. The composition as claimed in claim 25, wherein the aliphatic diisocyanate is a linear aliphatic diisocyanate.

27. The composition as claimed in claim 18, wherein the isocyanate component A) comprises at least 3,5,5-trimethyl-1-isocyanato-3-isocyanatomethylcyclohexane, 4,4′-methylenebis(cyclohexyl isocyanate), 1,3-bis(isocyanatomethyl)benzene, 1,4-bis(isocyanatomethyl)benzene, 2,5-bis(isocyanatomethyl)bicyclo[2.2.1]heptane, 2,6-bis(isocyanatomethyl)bicyclo[2.2.1]heptane, 1,3-diisocyanato-2-methylcyclohexane and/or 1,3-diisocyanato-6-methylcyclohexane.

28. The composition as claimed in claim 18, wherein the polyol component B) comprises at least one polyether polyol or one polyester polyol, or mixtures of a trimethylolpropane-initiated polyether polyol with at least one further polyether polyol.

29. The composition as claimed in claim 18, wherein the isocyanate groups of the isocyanate component A) and the hydroxyl groups of the polyol component B) are in a ratio of 1.50:1.00 to 1.00:1.50.

30. A process for producing an elastomer where a composition according to claim 18 is cured, optionally with heating.

31. An elastomer obtained by the process as claimed in claim 30.

32. A method comprising utilizing the composition as claimed in claim 18 for producing transparent molded articles.

33. The method of claim 32, wherein the transparent molded article is an optical lens or a part of an optical lens, wherein the optical lens may be a converging lens, a diverging lens, a glazing, a headlight or an eyeglasses lens.

34. A transparent molded article comprising a composition as claimed in claim 18.

Description

EXAMPLES

[0094] All reported percentages are based on weight unless otherwise stated.

[0095] All viscosity measurements were taken with a Physica MCR 51 rheometer from Anton Paar Germany GmbH (DE) according to DIN EN ISO 3219 at the temperatures reported in each case.

[0096] Refractive indices and Abbe numbers were measured using an AR4D Abbe refractometer from A.KRÜSS Optronic GmbH at 23° C.

[0097] Transmission measurements according to ASTM D 1003 were performed with a Byk Haze-Gard Plus using standard light type D65 (defined in DIN 6173).

[0098] NCO contents were determined by titration according to DIN 53 185.

[0099] Raw Materials Employed in Examples:

[0100] Desmodur® N 3300: an isocyanurate-containing polyisocya.nate of 1,6-hexamethylene diisocyanate, Bayer MaterialScience AG, Leverkusen, DE

[0101] 2-ethylhexanol: product of Aldrich, Taufkirchen, DE

[0102] Desmodur® I: 3,5,5-trimethyl-1-isocyanate-3-isocyanatomethylcyclohexane (isophorone diisocyanate), Bayer MaterialScience AG, Leverkusen, DE

[0103] Desmodur® N 3200: a biuret-containing polyisocyanate of 1,6-hexamethylene diisocyanate, Bayer MaterialScience AG, Leverkusen, DE

[0104] Desmophe® 4011 T: trifunctional polyether polyol, Bayer MaterialScience AG, Leverkusen, DE

[0105] Zelec® UN: Internal acidic phosphate ester demolding agent, Stepan Company, Northfield, Ill., USA

[0106] Determination of Catalyst Activity (Thermolatency)

[0107] All reactions for determining catalyst activity were performed under a dry nitrogen atmosphere. The catalysts from table 1 were obtained by standard literature procedures (cf. Chem. Heterocycl. Comp. 2007 43 813-834 and literature cited therein), DBTL was obtained from Kever Technologie, Ratingen, DE, zinc naphthenate from Alfa Aesar GmbH & Co KG, DE.

[0108] For better comparability of the activity of the catalysts for use in accordance with the invention and the catalysts from the comparative examples the catalyst amount was reported as μmol of Sn or Zn per kg of polyisocyanate hardener.

[0109] Desmodur® N 3300 was employed as the polyisocyanate hardener and precisely one equivalent of 2-ethylhexanol (based on the free isocyanate groups of the polyisocyanate hardener) was employed as the model compound for the isocyanate-reactive component. Addition of 10% (based on Desmodur® N 3300) of n-butyl acetate ensured that over the entire course of the reaction samples of sufficiently low viscosity could be taken which allow precise capture of the NCO content by titration according to DIN 53 185. The NCO content calculated at the beginning of the reaction without any NCO-OH reaction whatsoever is 12.2%.

[0110] For the experiments the mixtures were stored at a constant 30° C. and subsequently heated to 60° C. for 2 h in each case. Table 2 shows the reduction in the NCO content. Quotients Q.sub.30 und Q.sub.60 were determined as elucidated in detail in the description.

TABLE-US-00001 TABLE 1 Overview of employed catalysts for determination of catalyst activity (DBTL and also cat. 1 and zinc naphthenate comparative, cat. 2 to 5 inventive) Molar Empirical Weight Sn Catalyst Structural formula formula [g/mol] content DBTL (comparative) [00008] C32H64O4Sn 631.55 18.79% Cat. 1 (comparative) [00009] C12H23NO4Sn 364.01 32.61% Cat. 2 (inventive) [00010] C11H25NO4Sn 354.02 33.53% Cat. 3 (inventive) [00011] C32H66N2O4Sn 661.58 17.94% Cat. 4 (inventive) [00012] C26H31NO8Sn 604.23 19.64% Cat. 5 (inventive) [00013] C26H35NO6Sn 576.26 20.60% Zinc 0% naphthenate (comparative)

TABLE-US-00002 TABLE 2 Overview of determination of catalyst activity (Example a-c and h: comparative examples, examples d to g: inventive) NCO content of the mixture after [hh:mm] Cat. 30° C. 60° C. No. Cat Conc..sup.1) 00:30 1:00 1:30 2:00 2:30 3:00 3:30 4:00 Q.sub.30 Q.sub.60 a none 0 11.9 11.7 11.6 11.4 10.5 9.0 7.6 6.6 b DBTL 177 7.9 6.4 5.9 5.3 2.7 1.8 1.3 1.1 8.6 2.0 c cat. 1 185 8.9 7.1 5.7 4.7 0.9 0.3 0.2 0.1 9.4 2.2 d cat. 2 194 11.9 11.6 11.4 11.3 9.2 7.8 6.1 4.3 1.1 1.4 e cat. 3 168 12.0 11.6 11.5 11.1 9.1 7.4 5.9 4.1 1.4 1.4 f cat. 4 168 11.6 11.2 10.9 10.7 8.9 6.6 4.8 4.1 1.9 1.4 g cat. 5 168 11.8 11.7 11.5 11.2 104 7.6 6.7 5.8 1.3 1.1 h Zn 180 8.15 3.8 1.35 5.1 1.7 naphthenate .sup.1)μmol of Sn/Zn per kg of polyisocyanate hardener

[0111] Demolding Tests:

[0112] A casting mold was initially produced by fixing a silicone seal between two glass sheets (float glass, 4 mm) to form a casting cavity having a thickness of 4 mm and an area of about 50 cm.sup.2.

[0113] The isocyanate component A) consisting of 43.7 parts by wt of Desmodur® I and 11 parts by wt of Desmodur® N 3200 was admixed with two parts by wt of Zelec® UN as additive component C) and stirred at room temperature for 16 hours. The respective catalysts (50 mg of Sn based on 1 kg of the total composition, DBTL, catalyst 6: (4,12-dibutyl-2,6,10,14-tetramethyl-1,7,9,15-tetraoxa-4,12-diaza-8-stannaspirol[7.7]pentadecane), catalyst 7: (2,4,6,10,12,14-Hexamethyl-1,7,9,15-tetraoxa-4,12-diaza-8-stannaspirol[7.7]pentadecan)) of the catalyst component D) were dissolved in 43.4 parts by wt of Desmophen® 4011 T as polyol component B) and subsequently mixed at 23° C. with component produced above. The mixture was degassed for 30 minutes at 10 mbar and subsequently introduced into the casting mold. The mixture was cured in a circulating air drying cabinet according to the reported temperature profile and demolded after one day at room temperature.

TABLE-US-00003 TABLE 3 Results of performed tests for demolding of the elastomers produced. Example Catalyst Curing profile Demolding 1 (comparative) none short no 2 (comparative) DBTL short no 3 (inventive) catalyst 6 short yes 4 (inventive) catalyst 7 short yes 5 (comparative) none long no 4 (comparative) DBTL long no 5 (inventive) catalyst 6 long yes 6 (inventive) catalyst 7 long yes

[0114] Short curing profile: 4 h at 20° C., linear heating to 60° C. over 0.5 h, 2 h at 60° C., linear heating to 105° C. over 0.5 h, 2 h at 105° C., cooling to room temperature over 1 h.

[0115] Long curing profile: 4 h at 20° C., linear heating to 105° C. over 13 h, 2 h at 105° C., cooling to room temperature over 1 h.

[0116] Without catalyst or with DBTL as catalyst the polyurethane adhered to the glass so strongly that demolding was not possible and the glass sheets shattered under the stress during demolding. By contrast, the inventive elastomers are very readily demolded irrespective of the chosen temperature profile.

[0117] Viscosity Measurements:

[0118] The isocyanate component A) from table 4 was admixed with 2 wt %, based on the total mass of isocyanate component A) and polyol component B), of Zelec UN and stirred for one day at room temperature. The respective catalysts (50 mg of Sn based on 1 kg of the total composition, DBTL, catalyst 6: (4,12-Dibutyl-2,6,10,14-tetramethyl-1,7,9,15-tetraoxa-4,12-diaza-8-stannaspirol[7.7]pentadecane)) were dissolved in the relevant amount of Desmophen® 4011 T as polyol component B) and subsequently mixed at 23° C. with the previously produced mixture of the isocyanate component A) and the additive component C). The thus obtained mixtures were transferred into the rheometer and continuously measured at 20° C. and 80° C. (1 datapoint every 15 minutes at 20° C. and I datapoint every minute at 80° C.).

TABLE-US-00004 TABLE 4 Results of performed tests for viscosity of the inventive composition at 20° C. and at 80° C. Amount of isocyanate Amount Amount Ex. component of Zelec of polyol Catalyst Temperature 7 80 g Desmodur ® I 3.74 g 74.5 g none 20° C. (comparative) 20 g Desmodur ® N3200 8 80 g Desmodur ® I 3.74 g 74.5 g 0.049 g 20° C. (comparative) 20 g Desmodur ® DBTL N3200 9 80 g Desmodur ® I 3.74 g 74.5 g 0.039 g 20° C. (inv.) 20 g Desmodur ® cat. 6 N3200 10 80 g Desmodur ® I 3.74 g 74.5 g none 80° C. (comparative) 20 g Desmodur ® N3200 11 80 g Desmodur ® I 3.74 g 74.5 g 0.049 g 80° C. (comparative) 20 g Desmodur ® DBTL N3200 12 80 g Desmodur ® I 3.74 g 74.5 g 0.039 g 80° C. (inv.) 20 g Desmodur ® cat. 6 N3200

[0119] The viscosity measurements at 20° C. depicted in Graph 1 show that even at this low temperature DBTL results in an accelerated reaction compared to the uncatalyzed reaction since the viscosity of the sample with DBTL undergoes a stronger increase than the viscosity of the sample without catalyst.

[0120] Use of the inventive catalyst 6 results in a slower increase in viscosity compared to the uncatalyzed system at 20° C. This means that the inventive composition exhibits an extended potlife even compared to the uncatalyzed system. This is particularly advantageous since this extends the processing time of the inventive composition.

[0121] Not only the extended potlife at 20° C. but also the increased catalytic activity of the inventive catalyst at 80° C. compared to the uncatalyzed system as is evident from Graph 2 is a further advantage of the inventive composition.

[0122] Production of an Eyeglasses Lens Blank

[0123] The casting mold was initially assembled by clipping together two glass shell molds (diameter 85 mm, internal radius 88 mm, Shamir Insight, Inc.) with a plastic sealing ring so as to form a molding cavity.

[0124] The casting system consisted of a mixture 1: 80 g of Desmodur® I, 20 g of Desmodw N 3200 and 3.76 g of Zelec® UN which was mixed and left to stand overnight.

[0125] Mixture 2 were mixed together from 73,9 g of Desmophen® 4011 T and 0.04 g of catalyst 6: (4,12-dibutyl-2,6,10,14-tetramethyl-1,7,9,15-tetraoxa-4,12-diaza-8-stannaspirol[7.7]pentadecane) and likewise left to stand overnight

[0126] Thereafter, mixture 1 was transferred into a flask and evacuated at 10 mbar for 30 minutes. Mixture 2 was then added to the flask and the final mixture 3 was stirred and degassed at 10 mbar for 30 minutes. Mixture 3 was then filtered through a 5 μm filter and filled into a syringe and the casting mold was then completely filled.

[0127] The filled casting mold was dried in a drying cabinet with the following temperature profile: 4 hours at 20° C.; linearly heated to 100° C. over 13 hours; heat treated at 100° C. for 2 hours; heat treated at 120° C. for 2 hours. The casting mold was finally cooled to room temperature and after complete cooling first the collar and then the two glass bodies were manually removed.

[0128] In this way a completely clear, transparent and streak-free eyeglasses lens blank was obtained. Transmission was 93% for standard light type D65. Refractive index e was 1.50 at 23° C.