Multi-functional carbamate having soft-segments, polyisocyanate obtained via subsequent non-phosgene synthesis methods, urethane prepolymer and elastomeric urethane having soft-segments derived therefrom, and preparation method thereof

Abstract

Method for producing flexographic printing plates from a photopolymerizable flexographic printing plate with a dimensionally stable support, photopolymerizable, relief-forming layer(s), and a digitally imagable layer. The method comprises (a) producing a mask by imaging the digitally imagable layer, (b) exposing the flexographic printing plate with a plurality of UV-LEDs on a UV-LED strip through the mask with actinic light, and photopolymerizing the image regions of the layer, and (c) developing the photopolymerized layer. In the UV-LED strip or in a separate strip, at least one ultrasonic sensor is arranged for determining the thickness of the flexographic printing plate for exposure. Depending on the measured thickness of the flexographic printing plate, the exposing of the flexographic printing plate is controlled in respect of: (i) number of exposure steps, exposure intensity, energy input per exposure step, duration of the individual exposure steps, and/or overall duration of exposure.

Claims

1. A non-phosgene method for synthesizing a polyisocyanate having siloxanyl group iii its backbone, comprising: thermally cracking a multi-functional carbamate having a siloxanyl group in its backbone.

2. The method according to claim 1, wherein the multi-functional carbamate having a siloxanyl group in its backbone is prepared by reacting a polyamine having a siloxanyl group with a diaryl carbonate.

3. The method according to claim 2, wherein the polyamine having a siloxanyl group is a diamine of Formula (2) below: ##STR00018## in which each R independently represents a linear or branched C.sub.1-16 hydrocarbylene or a C.sub.3-16 cyclohydrocarbylene, and n is from 2 to 30.

4. The method according to claim 2, wherein the diaryl carbonate is represented by Formula (3) below: ##STR00019## in which R.sup.1 and R.sup.2 independently represent an aromatic group having 6 to 30 carbon atoms.

5. The method according to claim 2, wherein the molar ratio of the diamine having a siloxanyl group to the diaryl carbonate is in the range of from 1:2 to 1:6.

6. The method according to claim 2, which is a one-pot method.

7. A method for synthesizing a polyurethane having a siloxanyl group in its backbone, comprising reacting a polyisocyanate having a siloxanyl group in its backbone, a polyol, and an optional chain extender, wherein the polyisocyanate having a siloxanyl group in its backbone is prepared by the method according to claim 1.

8. The method according to claim 7, wherein the polyisocyanate having a siloxanyl group in its backbone is reacted with the polyol to form a prepolymer before the reaction to form the polyurethane is carried out.

9. The method according to claim 7, which is a one-pot method comprising the following steps carried out in the same reactor: reacting a polyamine having a siloxanyl group with a diaryl carbonate to produce a multi-functional carbamate having a siloxanyl group in its backbone; thermally cracking the multi-functional carbamate to produce a polyisocyanate having a siloxanyl group in its backbone; and further adding a polyol and an optional chain extender and reacting under suitable reaction conditions to produce a polyurethane having a siloxanyl group in its backbone.

10. The method according to claim 7, wherein the polyurethane comprises a hard segment and wherein the percentages by weight of the hard segment are from 20 to 70%.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be described according to the appended drawings, in which:

(2) FIGS. 1a to 1c are FT-IR spectra for monitoring the synthesis of 130C, 430C, and 800C.

(3) FIGS. 2a to 2c are FT-IR spectra for monitoring the synthesis of 130I, 430I, and 800I.

PREFERRED EMBODIMENTS OF THE PRESENT INVENTION

(4) The concepts of the present invention are further illustrated by way of examples, which, however, are not intended to limit the scope of the present invention, and are provided for the purpose of making the disclosure of the present invention more readily apparent to those skilled in the art to which the present invention pertains.

(5) Reagents

(6) TABLE-US-00001 Amine equivalent: 130 Density: 0.9 g mol.sup.-1 Viscosity (25 C): 4 mm.sup.2/s Molecular weight: 260 Amine equivalent: 430 Density: 1 g mol.sup.-1 Viscosity (25 C): 12 mm.sup.2/ Molecular weight: 860 Amine equivalent: 800 Density: 0.97 g mol.sup.-1 Viscosity (25 C): 25 mm.sup.2/s Molecular weight: 1600

(7) 1,6-Hexamethylene diisocyanate (HDI)

(8) 4,4-Methylenediphenyl diisocyanate (MDI)

(9) Isophorone diisocyanate (IPDI)

(10) Dicyclohexyl methane diisocyanate (H.sub.12MDI)

(11) m-Tetramethylxylene diisocyanate (TMXDI)

(12) Toluene

(13) Di-n-butyl amine

(14) Isopropanol (IPA)

(15) Butanediol (BDO)

(16) Bromo cresyl blue (BPB)

(17) Stannous octoate (T9)

(18) Instruments and Methodologies

(19) Fourier Transform-Infrared Spectroscopy (FT-IR)

(20) Fourier Transform Infrared Spectrometer, Model: Perkin Elmer Spectrum One FT-IR Spectrometer

(21) Nuclear Magnetic Resonance Spectroscopy (NMR)

(22) Nuclear Magnetic Resonance Spectrometer, Model: Varian Unity Inova FT-NMR Spectrometer (400 Hz)

(23) Gel Permeation Chromatography (GPC)

(24) Chromatographic column: MBLMW-3078 (Viscotek ViscoGEL Column)

(25) Standard: Polystyrene, M.sub.p=683-1,670,000 g/mol

(26) Mobile phase: NMP-CHROMASOLV Plus, HPLC grade, 99%

(27) Test conditions: flow rate of 1 mL/min, at a constant temperature of 40 C.

(28) Eluting solvent: NMP

(29) Determination of Contact Angle

(30) Horizontally orientated contact angle meter

(31) Model: FTA1000B

(32) Test conditions: The samples are cut to a size of 2 cm in both length and width and placed on an instrument platform, and about 5 L of liquid drips down to form a droplet on the sample at room temperature. Five measurements of each sample were made.

(33) Differential Scanning Calorimetry (DSC)

(34) Differential Scanning Calorimeter, Model: Seiko S II model SSC/6200

(35) Test conditions: heating rate of 10 C./min and cooling rate of 50 C./min, under a nitrogen atmosphere.

(36) Dynamic Mechanical Analysis (DMA)

(37) Dynamic Mechanical Analyzer, Model: Perkin-Elmer Pyris Diamond

(38) Test conditions: heating rate: 3 C./min, frequency: 1 Hz, test method: tension, and amplitude: 25 m.

(39) Tensile Test

(40) Tensile tester, Model: Shimadzu EZ-SX

(41) Test conditions: The test sample has a size as specified for an ASTM D638 standard dumbbell-shaped test specimen, and is tested at a stretch speed of 100 mm/min at room temperature. Tensile strength (MPa) and elongation (%) are calculated.

EXAMPLES

Example 1: Synthesis of a Biscarbamate Having a Siloxanyl Group in its Backbone

(42) A 150 ml round-bottom three-neck reactor was used, into a neck of which was inserted a thermometer, and nitrogen was introduced therethrough. Another neck was fitted with a condensation tube into which cold water was introduced for condensation. A third neck was plugged with a glass stopper so that it could be opened at times for sampling to monitor the reaction by IR. 84.45 g (0.394 mol) of diphenyl carbonate (DPC) was added to the reactor and heated to 80 C. until it melted and became a liquid. 50 g (0.192 mol) of 130 A diamine was dropwise and slowly introduced via a feed tube, and the mixture was mixed by vigorous magnetic stirring in the absence of a solvent, and reacted for 1 hr. at a temperature controlled at 80 C., during which the decrease of intensity of a carbonate absorption peak at 1780 cm.sup.1 in the reactant and the increase of, and eventually constant, intensity of a polyurethane absorption peak at 1717 cm.sup.1 were indicated to monitor the reaction by IR spectroscopy. When the intensity of these peaks in the IR spectrum remained unchanged, the reaction was regarded as complete. Upon completion of the reaction, the structure was identified by NMR, and the product was a light-yellow liquid. The crude product was directly used in the preparation of a polyisocyanate. Biscarbamates having a siloxanyl group in their backbone were prepared following the same process by using various polysiloxane-diamines as raw material. The formulation is shown in Table 1.

(43) TABLE-US-00002 TABLE 1 Biscarbamate prepared Polysiloxane-diamine DPC 130 C. 130 A 84.45 g (0.394 mol) 50 g (0.192 mol) 430 C. 430 A 25.53 g (0.119 mol) 50 g (0.058 mol) 800 C. 800 A 13.72 g (0.064 mol) 50 g (0.031 mol)

(44) As shown in FIGS. 1a to 1c, it can be seen that the absorption peak of the CO functional group (at 1780 cm.sup.1) in the reactant diphenyl carbonate disappears, and the absorption peak of the CO functional group (at 1717 cm.sup.1) in the carbamate appears. After about 1 hr. after initiating the reaction, the IR spectrum does not change over time, indicating completion of the reaction. The reaction products are all in a liquid state at normal temperature. All of the hydrogen absorption peaks can be identified by .sup.1H-NMR analysis, and the integral areas thereof meet with the identification of the structure.

Example 2: Synthesis of a Diisocyanate Having a Siloxanyl Group in its Backbone

(45) The condensation tube in the apparatus used in the synthetic experiment in Example 1 was removed from the reactor, and replaced with a combined distillation tube (fitted with a thermometer). At one end of the tube, a one-neck flask was connected for receiving the by-product phenol produced during cracking. Then, a vacuum pump was connected, such that the cracking reaction was carried out with rapid stirring at a reduced pressure (7 cmHg). The reaction temperature was raised to 170 C. for 2 hrs., and the 130C/430C/800C biscarbamates synthesized above were cracked into products mainly characterized by isocyanate functional groups, which were 130I/430I/800I respectively. During the reaction process, the by-product phenol produced via decomposition was collected at the same time, and the cracking reaction was monitored by IR spectroscopy, until the absorption peak of the biscarbamate (at 1717 cm.sup.1) disappeared, and the intensity of the absorption peaks of the isocyanate (at 2270 cm.sup.1) and other co-products (for example, a trimer (at 1701 cm.sup.1) and an allophanate (at 1730 cm.sup.1)) remained unchanged. The resulting products, without further purification, were directly used in the content determination by the titration of isocyanates, and in the preparation of PU.

(46) NCO % of the isocyanates prepared is shown in Table 2 below.

(47) TABLE-US-00003 TABLE 2 Equivalent NCO % 130I 645 6.5% 430I 700 6% 800I 1220 3.5%

(48) As shown in FIGS. 2a to 2c, it can be found that during the cracking process, the absorption peak of the carbamate (at 1717 cm.sup.1) disappears, and the absorption peaks of the isocyanate (NCO) (at 2273 cm.sup.1) and a small amount of other co-products (for example, a trimer (at 1701 cm.sup.1) and an allophanate (at 1730 cm.sup.1)) appear. In addition, the IR spectrum of the phenol thus collected is consistent with that of the standard, and 92 to 97% of phenol is recovered. It is suggested that the reaction is complete, the yield is extremely high, and the recovery rate of the by-product phenol is also good. The prepared isocyanate, without further processing or refining, was directly used in the synthesis of a polyurethane (PU).

(49) During the synthesis of the isocyanate having a soft segment in the present invention, no undesired by-product urea was detected, and the reaction can take place without needing to add any solvent or catalyst, which meets the demand for green chemical synthesis of isocyanates. Moreover, in the green chemical synthesis of isocyanates, the synthesis efficiency is not impacted, the yield of the product is extremely high, and the recovery rate of the by-product phenol can be up to 90%, or even 97% or above.

Example 3: Synthesis of a Polyurethane Having a Siloxanyl Group in its Backbone (Isocyanate: 130I; and Chain Extender: IPDI)

(50) A disconnecting-type 150 ml four-neck round-bottom flask was used; a right central neck of which was fitted with a mechanically stirred reactor, into another neck of the reactor was inserted a thermometer and nitrogen was introduced therethrough. Yet another neck was fitted with a condensation tube into which cold water was introduced. A fourth neck was plugged with a glass stopper, so that a small amount of sample could be taken out for monitoring the progress of reaction if needed. 23 g of toluene was added as a solvent to the round-bottom flask, then 1.35 g of excessive butanediol (BDO) and 6.45 g of 130I were added, and a drop of T9 was added, and the mixture was reacted at 80 C. for 1 hr. The reaction of 130-I with BDO to form a prepolymer having a soft segment and containing a terminal hydroxyl group was determined to be complete by FT-IR. Subsequently, 2.22 g of IPDI was added and reacted for 2 hrs. at 80 C. with stirring for chain extension. Then, the solution was poured into an aluminum dish and placed for 24 hrs. in an oven at 60 C., and toluene was removed by volatilization to form a PU film, which was designated as 130BI-30.

(51) The contents of BDO, IPDI, and the solvent toluene were adjusted, and 130BI-40 and 130BI-50 having a different proportion of hard segments were prepared following the same synthesis process. The details are given in Table 3-1.

(52) TABLE-US-00004 TABLE 3-1 Raw material BDO + 130I BDO IPDI Toluene IPDI, wt. % Product (g) (g) (g) (S.C = 30%) (calculated) 130BI-30 6.45 1.35 2.22 23 36 Equivalent ratio 1 3 2 130BI-40 6.45 1.8 3.34 27 44 Equivalent ratio 1 4 3 130BI-50 6.45 2.7 5.56 34 56 Equivalent ratio 1 6 5

(53) The properties of the prepared PU films (130BI-30, 130BI-40, and 130BI-50) comprising a different proportion by weight of hard segments were respectively tested. The results are shown in Table 3-2.

(54) TABLE-US-00005 TABLE 3-2 Tensile Contact T.sub.g ( C.) strength Elongation Mn Mw PD angle DSC DMA (Mpa) (%) 130BI- 52200 75800 1.45 90 7 50 4.9 285 30 130BI- 9800 20000 4.8 88 6 66 11 200 40 130BI- 8000 14000 1.73 86 12 81 13.6 153 50

Example 4: Synthesis of a Polyurethane Having a Siloxanyl Group in its Backbone (Isocyanate: 430I; and Chain Extender: IPDI)

(55) Following the same synthesis method as that in Example 3, 430BI-30, 430BI-40, and 430BI-50 having a different proportion of hard segments were prepared with 430I as a reactant, where the amounts of the reagents and the solvent are shown in Table 4-1.

(56) TABLE-US-00006 TABLE 4-1 Raw material 430I BDO IPDI Toluene BDO + IPDI wt. % Product (g) (g) (g) S.C = 30%) (calculated) 430BI-30 7 1.35 2.22 25 34 Equivalent ratio 1 3 2 430BI-40 7 1.8 3.33 28 42 Equivalent ratio 1 4 3 430BI-50 7 2.7 5.56 35 54 Equivalent ratio 1 6 5

(57) The properties of the prepared PU films (430BI-30, 430BI-40, and 430BI-50) comprising a different proportion by weight of hard segments were respectively tested. The results are shown in Table 4-2.

(58) TABLE-US-00007 TABLE 4-2 Tensile Contact T.sub.g ( C.) strength Elongation Mn Mw PD angle DSC DMA (Mpa) (%) 430BI-30 23700 35400 1.5 96 20 35 2.1 290 430BI-40 9300 16200 1.74 98 5 55 2.7 260 430BI-50 11300 20000 1.74 100 25 72 6.8 90

Example 5: Synthesis of a Polyurethane Having a Siloxanyl Group in its Backbone (Isocyanate: 800I; and Chain Extender: IPDI)

(59) Following the same synthesis method as that in Example 3, 800BI-30, 800BI-40, and 800BI-50 having a different proportion of hard segments were prepared with 800I as a reactant, where the amounts of the reagents and the solvent are shown in Table 5-1.

(60) TABLE-US-00008 TABLE 5-1 Raw material BDO + 800I BDO IPD1 Toluene IPDI wt. % Product (g) (g) (g) (S.C = 30%) (calculated) 800BI-30 6.1 0.9 1.67 20 30 Equivalent ratio 1 4 3 800BI-40 6.1 1.35 2.78 24 40 Equivalent ratio 1 6 5 800BI-50 6.1 2.03 4.45 30 52 Equivalent ratio 1 9 8

(61) The properties of the prepared PU films (800BI-30, 800BI-40, and 800BI-50) comprising a different proportion by weight of hard segments were respectively tested. The results are shown in Table 5-2.

(62) TABLE-US-00009 TABLE 5-2 Tensile Contact T.sub.g ( C.) strength Elongation Mn Mw PD angle DSC DMA (Mpa) (%) 800BI- 114500 142800 1.24 92 55 52 5.1 350 30 800BI- 113800 153900 1.35 93 50 79 6.2 310 40 800BI- 100500 187600 1.86 97 43 98 10.6 200 50

Example 6: Synthesis of a Polyurethane Having a Siloxanyl Group in its Backbone (Isocyanate: 130I; and Chain Extender: TMXDI)

(63) A disconnecting-type 150 ml four-neck round-bottom flask was used; a right central neck of which was fitted with a mechanically stirred reactor, into another neck of the reactor was inserted a thermometer and nitrogen was introduced therethrough. Yet another neck was fitted with a condensation tube into which cold water was introduced. A fourth neck was plugged with a glass stopper, so that a small amount of sample could be taken out for monitoring the progress of reaction if needed. 24 g of toluene was added as a solvent to the round-bottom flask, then 1.35 g of excessive butanediol (BDO) and 6.45 g of 130I were added, and a drop of T9 was added, and the mixture was reacted at 80 C. for 1 hr. The reaction of 130-I with BDO to form a prepolymer having a soft segment was determined to be complete by FT-IR. Subsequently, 2.44 g of TMXDI was added and reacted for 2 hrs. at 100 C. with stirring, for chain extension. Then, the solution was poured into an aluminum dish and placed for 24 hrs. in an oven at 60 C., and toluene was removed by volatilization to form a PU film, which was designated as 130BT-30.

(64) The contents of BDO, TMXDI and the solvent toluene were adjusted, and 130BT-40 and 130BT-50 having a different proportion of hard segments were prepared following the same synthesis process. The details are given in Table 6-1.

(65) TABLE-US-00010 TABLE 6-1 Raw material BDO + TMXDI 130I BDO TMXDI Toluene wt. % Product (g) (g) (g) (S.C = 30%) (calculated) 130BT-30 6.45 1.35 2.44 24 37 Equivalent ratio 1 3 2 130BT-40 6.45 1.8 3.66 28 46 Equivalent ratio 1 4 3 130BT-50 6.45 2.7 6.11 36 58 Equivalent ratio 1 6 5

(66) The properties of the prepared PU films (130BT-30, 130BT-40, and 130BT-50) comprising a different proportion by weight of hard segments were respectively tested. The results are shown in Table 6-2.

(67) TABLE-US-00011 TABLE 6-2 Tensile Contact T.sub.g ( C.) strength Elongation Mn Mw PD angle DSC DMA (Mpa) (%) 130BT-30 3500 8400 2.4 99 5 47 0.8 665 130BT-40 40700 61300 1.5 106 10 54 3.8 440 130BT-50 42200 66200 1.6 90 15 53 6.4 455

Example 7: Synthesis of a Polyurethane Having a Siloxanyl Group in its Backbone (Isocyanate: 430I; and Chain Extender: TMXDI)

(68) Following the same synthesis method as that in Example 6, 430BT-30, 430BT-40, and 430BT-50 having a different proportion of hard segments were prepared with 430I as a reactant and TMXDI as a chain extender, where the amounts of the reagents and the solvent are shown in Table 7-1.

(69) TABLE-US-00012 TABLE 7-1 Raw material BDO + TMXDI 430I BDO TMXDI Toluene wt. % Product (g) (g) (g) (S.C = 30%) (calculated) 430BT-30 7 1.35 2.44 25 35 Equivalent ratio 1 3 2 430BT-40 7 1.8 3.66 29 44 Equivalent ratio 1 4 3 430BT-50 7 2.7 6.11 37 56 Equivalent ratio 1 6 5

(70) The properties of the prepared PU films (430BT-30, 430BT-40, and 430BT-50) comprising a different proportion by weight of hard segments were respectively tested. The results are shown in Table 7-2.

(71) TABLE-US-00013 TABLE 7-2 Tensile Contact T.sub.g ( C.) strength Elongation Mn Mw PD angle DSC DMA (Mpa) (%) 430BT-30 9800 20700 2.1 112 10 26 1.5 1100 430BT-40 38800 55000 1.4 98 0 38 2 1200 430BT-50 36300 45400 1.3 95 12 57 9 590

Example 8: Synthesis of a Polyurethane Having a Siloxanyl Group in its Backbone (Isocyanate: 800I; and Chain Extender: TMXDI)

(72) Following the same synthesis method as that in Example 6, 800BT-30, 800BT-40, and 800BT-50 having a different proportion of hard segments were prepared with 800I as a reactant and TMXDI as a chain extender, where the amounts of the reagents and the solvent are shown in Table 8-1.

(73) TABLE-US-00014 TABLE 8-1 Raw material BDO + TMXDI 800I BDO TMXDI Toluene wt. % Product (g) (g) (g) (S.C = 30%) (calculated) 800BT-30 6.1 0.9 1.83 21 31 Equivalent ratio 1 4 3 800BT-40 6.1 1.35 3.05 25 42 Equivalent ratio 1 6 5 800BT-50 6.1 2.03 4.89 30 53 Equivalent ratio 1 9 8

(74) The properties of the prepared PU films (800BT-30, 800BT-40, and 800BT-50) comprising a different proportion by weight of hard segments were respectively tested. The results are shown in Table 8-2.

(75) TABLE-US-00015 TABLE 8-2 Contact T.sub.g ( C.) Tensile Elongation Mn Mw PD angle DSC DMA strength (Mpa) (%) 800BT- 8400 13500 1.6 105 40 38 2.6 730 30 800BT- 8300 12800 1.6 113 30 55 3.2 500 40 800BT- 10300 18600 1.8 93 20 65 7.6 253 50

Example 9: Synthesis of a Polyurethane Having a Siloxanyl Group in its Backbone (Isocyanate: 130I; and Chain Extender: H12MDI)

(76) A disconnecting-type 150 ml four-neck round-bottom flask was used; a right central neck of which was fitted with a mechanically stirred reactor, into another neck of the reactor was inserted a thermometer and nitrogen was introduced therethrough. Yet another neck was fitted with a condensation tube into which cold water was introduced. A fourth neck was plugged with a glass stopper, so that a small amount of sample could be taken out for monitoring the progress of reaction if needed. 24 g of toluene was added as a solvent to the round-bottom flask, then 1.35 g of excessive butanediol (BDO) and 6.45 g of 130I were added, and a drop of T9 was added, and the mixture was reacted at 80 C. for 1 hr. The reaction of 130-I with BDO to form a prepolymer having a soft segment was determined to be complete by FT-IR. Subsequently, 2.62 g of H.sub.12MDI was added and reacted for 1 hr. at 100 C. with stirring, for chain extension. Then, the solution was poured into an aluminum dish and placed for 24 hrs. in an oven at 60 C., and toluene was removed by volatilization to form a PU film, which was designated as 130BH.sub.12-30.

(77) The contents of BDO, H.sub.12MDI and the solvent toluene were adjusted, and 130BT-40 and 130BT-50 having a different proportion of hard segments were prepared following the same synthesis process. The details are given in Table 9-1.

(78) TABLE-US-00016 TABLE 9-1 Raw material BDO + H.sub.12MDI 130I BDO H.sub.12MDI Toluene wt. % Product (g) (g) (g) (S.C = 30%) (calculated) 130BH.sub.12-30 6.45 1.35 2.62 24 38 Equivalent ratio 1 3 2 130BH.sub.12-40 6.45 1.8 3.94 28 47 Equivalent ratio 1 4 3 130BH.sub.12-50 6.45 2.7 6.56 37 59 Equivalent ratio 1 6 5

(79) The properties of the prepared PU films (130BH.sub.12-30, 130BH.sub.12-40, and 130BH.sub.12-50) comprising a different proportion by weight of hard segments were respectively tested. The results are shown in Table 9-2.

(80) TABLE-US-00017 TABLE 9-2 Tensile Contact T.sub.g ( C.) strength Elongation Mn Mw PD angle DSC DMA (Mpa) (%) 130BH.sub.12- 48300 89800 1.9 108 3 48 4.4 254 30 130BH.sub.12- 45600 86200 1.9 110 5 52 10 163 40 130BH.sub.12- 35000 49300 1.8 112 10 50

Example 10: Synthesis of a Polyurethane Having a Siloxanyl Group in its Backbone (Isocyanate: 430I; and Chain Extender: H12MDI)

(81) Following the same synthesis method as that in Example 9, 430BH.sub.12-30, 430BH.sub.12-40, and 430BH.sub.12-50 having a different proportion of hard segments were prepared with 430I as a reactant and H.sub.12MDI as a chain extender, where the amounts of the reagents and the solvent are shown in Table 10-1.

(82) TABLE-US-00018 TABLE 10-1 Raw material BDO + H.sub.12MDI 430I BDO H.sub.12MDI Toluene wt. % Product (g) (g) (g) (S.C = 30%) (calculated) 430BH.sub.12-30 7 1.35 2.62 26 36 Equivalent ratio 1 3 2 430BH.sub.12-40 7 1.8 3.94 30 45 Equivalent ratio 1 4 3 430BH.sub.12-50 7 2.7 6.56 38 57 Equivalent ratio 1 6 5

(83) The properties of the prepared PU films (430BH.sub.12-30, 430BH.sub.12-40, and 430BH.sub.12-50) comprising a different proportion by weight of hard segments were respectively tested. The results are shown in Table 10-2.

(84) TABLE-US-00019 TABLE 10-2 Tensile Contact T.sub.g ( C.) strength Elongation Mn Mw PD angle DSC DMA (Mpa) (%) 430BH.sub.12- 9600 16300 1.7 106 15 28 4.2 97 30 430BH.sub.12- 43300 67400 1.6 110 10 82 10.6 89 40 430BH.sub.12- 27800 41300 1.5 108 5 108 14.8 38 50

Example 11: Synthesis of a Polyurethane Having a Siloxanyl Group in its Backbone (Isocyanate: 800I; and Chain Extender: H12MDI)

(85) Following the same synthesis method as that in Example 9, 800BH.sub.12-30, 800BH.sub.12-40, and 800BH.sub.12-50 having a different proportion of hard segments were prepared with 800I as a reactant and H.sub.12MDI as a chain extender, where the amounts of the reagents and the solvent are shown in Table 11-1.

(86) TABLE-US-00020 TABLE 11-1 Raw material BDO + H.sub.12MDI 800I BDO H.sub.12MDI Toluene wt. % Product (g) (g) (g) (S.C = 30%) (calculated) 800BH.sub.12-30 6.1 0.9 1.97 21 32 Equivalent ratio 1 3 2 800BH.sub.12-40 6.1 1.35 3.28 25 43 Equivalent ratio 1 4 3 800BH.sub.12-50 6.1 2.03 5.25 31 54 Equivalent ratio 1 6 5

(87) The properties of the prepared PU films (800BH.sub.12-30, 800BH.sub.12-40, and 800BH.sub.12-50) comprising a different proportion by weight of hard segments were respectively tested. The results are shown in Table 11-2.

(88) TABLE-US-00021 TABLE 11-2 Tensile Contact T.sub.g ( C.) strength Elongation Mn Mw PD angle DSC DMA (Mpa) (%) 800BH.sub.12-30 54600 91200 1.7 107 55 43 1.8 60 800BH.sub.12-40 101300 151200 1.5 110 46 38 110 7.3 89 800BH.sub.12-50 87200 122100 1.4 112 30 33 105 8.3 58

(89) Therefore, the polyisocyanate having a soft segment synthesized by a non-phosgene method provided in the present invention can be used as a raw material in the synthesis of polyurethanes having a soft segment, and can be used in combination with various polyols and chain extenders to synthesize polyurethanes which meet the practical requirements. For example, the mechanical properties can be strengthened by increasing the molecular weight. Better elongation or phase separation can also be achieved by the use of different chain extenders.

(90) The polyurethane synthesized in the present invention has properties such as low degree of dyeing, high transparency, high thermal stability, smooth tactile feel and hydrophobicity compared with conventional polyurethanes. Particularly, the polyurethane synthesized in the present invention has a tensile strength of up to 15 Mpa, which is comparable to that (>10 Mpa) exhibited by conventional polyurethanes. In addition, all the polyurethanes exhibit a glass transition temperature over a wide range, and a variety of polyurethanes exhibit a phase change, thus having tolerability to temperatures over a wide range. The present polyurethane has an elongation up to 1200%, which meets the physical property requirement for common polyurethane products, and can be applied in areas requiring high softness, such as in fabric treatment or in disposable gloves, and the working temperature range is wider than traditional polyurethane products. On the other hand, because of the presence of a hydrophobic soft segment, the synthesized polyurethane exhibits a contact angle (at least 90, for example >1000, and up to 110 to 115 or higher) required for hydrophobicity, and thus can be further applied to products requiring hydrophobic properties.

(91) It will be apparent to those skilled in the art that various changes and modifications may be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the above, the present invention is intended to contemplate modifications and variations of the present invention provided that such modifications and variations are within the scope of the following claims and equivalents thereof.

(92) The above-described embodiments of the present invention are intended to be illustrative only. Numerous alternative embodiments may be devised by persons skilled in the art without departing from the scope of the following claims.