MXPA98009739A - Extended polyurethane with urea elastomeric thermoplastic extrui - Google Patents

Abstract

The present invention relates to an elastomer of thermoplastic polyurethane extended with extrudable urea of at least one aliphatic diisocyanate, at least one polyester glycol or polyether glycol and at least one diamine hardening agent. At least one second diamine hardening agent and / or at least one extrusion processing aid may be included. The polyurethane has high temperature resistance and is thus extrudable at high temperatures. The polyurethane is also strong and durable. The polyurethane can be liquid cast, injection molded, transfer molded, sprayed and extruded without changing either the chemistry or stoichiometry of the polyurethane. Polyurethane can be used to make vehicle air bags or other application for thermoplastic urethanes that require increased thermal stability

Description

EXTENDED POLYURETHANE WITH UREA ELASTOMERIC EXTRAVIBLE THERMOPLASTIC DESCRIPTION PE hh INVENTION This application claims the priority of United States Provisional Patent Application Serial No. 60 / 018,042 filed May 21, 1996 The present invention relates to an extrudable polyurethane, thermoplastic, elastomeric improved for use in products of efficient manufacturing such as air bags with excellent properties, and a process to manufacture them. The technology of new air bags demands a polyurethane elastomer which combines high temperature resistance with excellent physical properties, processing parameters, and resistance to hydrolysis, oxygen and ozone. In particular, for use in airbags or any other related use, some of the most important properties are extrusion capability, high temperature resistance, low temperature flexibility, high strength, elongation, low to moderate tensile modulus, Good environmental resistance, excellent tear resistance, with an "A" durometer of approximately 80. The extrudable urethane elastomers currently commercially available are typically extended with hydroxyl and do not have the thermal resistance necessary to withstand the temperature of the gas generator during the deployment of the airbag. It is believed that there are currently no available thermoplastic urethane elastomer compositions that are prolonged with urea and that can be extruded with a combination of excellent temperature, physical and environmental resistance. It has been believed in the art that a processable thermoplastic urethane can not be obtained by using a diamine chain extender since the resulting urea segments give the urethane a very high melting point. As such, the polyurethanes can not be processed by typical methods used in the processing of thermoplastic elastomeric materials, such as extrusion, without decomposition of the urethane. Extrusion of the thermoplastic polyurethane elastomers may be desie to allow flexibility in the formation of various product shapes and sizes, including air bag air chambers and the like. Extrusion is also a less expensive and faster processing method compared to other forming processes such as liquid emptying. Taub, U.S. Patent No. 3,600,358, discloses a polyurethane elastomer prepared from 4,4'-methylenebis (cyclohexyl isocyanate), neopentyl adipate and aromatic diamine. After the addition of the aromatic diamine to the urethane prepolymer, the mixture is heated and emptied into a mold for hardening. Taub does not indicate that the urethane can be extruded. Taub also does not disclose or suggest the inclusion of a mixture of diamine materials to improve the extrudability of a prolonged urethane with urea. Slagel, U.S. Patent No. 3,866,242, discloses a protective coating comprising polyurethane made of a polyester or polyether glycol material, a diisocyanatodicyclohexylmethane and a primary amine such as 4,4"-methylenebis (2-chloroaniline). cast between glass plates and hardened to form the protective cover The polyurethane described by Slagel is not elastomeric, as evidenced by the description since the material has a hardness on the "D" scale of 77-80 (col 3) , line 30) Slagel does not indicate that the polyurethane can be extruded, Slagel also does not disclose or suggest the inclusion of a mixture of diamine materials to improve the extrusion capacity of a prolonged urethane with urea. The present invention provides a thermoplastic polyurethane elastomer having high temperature resistance, and which is strong and due for use in the manufacture of product. urethane glasses such as air bags and the like. It is a further object of the present invention to provide a process for manufacturing such polyurethanes, as well as a process for extruding such polyurethanes. Novel features of the invention, together with advantages thereof, will be better understood from the following descriptions in which embodiments of the invention are illustrated for example form. The polyurethanes of the present invention comprise an extrudable reaction product of at least one aliphatic diisocyanate with at least one hydroxy-containing intermediate selected from polyester glycols, polyether glycols and mixtures thereof, and at least one hardener. diamine. The polyurethanes may also include an extrusion processing aid. A process of the present invention comprises reacting at least one aliphatic diisocyanate with at least one hydroxy-containing intermediate to form a prepolymer, and then reacting the prepolymer with at least one diamine curing agent to form a thermoplastic polyurethane elastomer . Alternatively, at least one aliphatic diisocyanate with less than one equivalent of the hydroxy-containing intermediate can be reacted to form a prepolymer, and then the remaining equivalents of the hydroxy-containing intermediate together with at least one diamine hardener can be added. to form a hardened elastomer. In addition, the present invention relates to a process for extruding polyurethanes of the invention, as well as extruded polyurethane products. The polyurethanes of the present invention comprise a reaction product of at least one aliphatic diisocyanate with at least one hydroxy-containing intermediate selected from polyester glycols, polyether glycols and mixtures thereof, and at least one diamine curing agent. . Preferably, the diamine hardening agent system is a mixture of at least one first diamine hardening agent and at least one second diamine hardening agent. However, the polyurethane can be hardened with only the at least one diamine hardening agent. An extrusion processing aid can also be included in the polyurethane. The polyurethane of the present invention are thermoplastic elastomers that can be easily extruded into various urethane products. The polyurethanes present are extrudable because they possess an excellent melt flow property while at the same time having high thermal stability. Compared with commercially available thermoplastic urethane elastomers having an anchor hardness of about 80, the polyurethanes according to the invention having a similar anchor toughness A have a lower melt flow temperature in the order of 10 to 70. ° C less, when measured according to ASTM method D-1238. The melt flow rate of the polyurethanes of the present invention is in the range of about 5 to 40 inches per minute, more preferably about 8 to 25 inches per minute, when measured according to the modified ASTM D-1238 method described in Example 9. In this manner, the embodiments of the inventive polyurethanes are extrudable within the range of 215 ° C to 310 ° C, preferably about 235 ° C to 260 ° C. Commercially available polyurethanes, on the other hand, liquefy at such processing temperatures. Typically, commercially available polyurethanes, such as Pellethane (a hydroxyl-extended extrudable grade polyurethane commercially available from Dow), are extruded through a melt flow meter at temperatures of about 224 ° C, using a load of 2 to 6 kg. . Higher extrusion temperatures can not be used since these commercially available polyurethanes are destabilized and liquefied at higher temperatures. The polyurethanes of the present invention, however, can be extruded at very high temperatures without degradation. Without wishing to link to any theory, it is believed herein that the present urea-extended polyurethanes possess such superior properties and are extrudable because the polyurethane includes aliphatic diisocyanate, preferably a saturated aliphatic diisocyanate. As such, the polyurethane exhibits thermoplastic properties and does not form any side reactions, for example it does not form biurets, after hardening, different from the polyurethanes formed with aromatic diisocyanates. Polyurethanes in this way can be hardened to a solid product with excellent properties, but can also be re-melted and re-extruded due to the absence and / or low level of biurets. The water included in the polyurethane manufacturing process can cause side reactions, which degrades the extrusion capacity of the formed polyurethane. In this way it is preferred that the polyurethane starting materials contain a low amount of water, if any. For example, the polyurethane is preferably prepared in an environment containing water in an amount of not more than 0.03 weight percent of the polyurethane materials. In addition to the aliphatic diisocyanate, it is also believed that the present properties and extrudability are realized in part by the use of diamine chain extension agents. The extensions with urea in the polyurethane chain provide the polyurethanes with superior thermal stability, as discussed above, allowing extrusion at high temperatures. Diamine Hardeners The diamine hardeners, or chain extenders, are preferably primary amines. Preferably, the at least one diamine hardening agent is a mixture of two or more diamine hardening agents. Preferably, a first diamine hardening agent is an amine having high thermal stability and capable of providing excellent melt flow properties to the polyurethane. Examples of the first diamine hardening agent include 2,4-diamino-3,5-diethyl toluene and 2,6-diamino-3,5-diethyl toluene (collectively diethylene toluene diamine (DETDA)), methylenedianiline (MDA), and mixtures thereof . For example, a first hardening agent used in the process of the present invention is diethylene glycol diadem (DETDA), which is sold by Albermarle Corporation under the trademark Ethacure 100. This diamine hardening agent is liquid at room temperature. This has the following formula: 2,6 isomer 2,4 isomer Another preferred first diamine hardening agent that can be used alone or in combination with other first diamine hardening agents is methylenediamine (MDA). MDA is available from Aldrich and has the following formula: Although a good product is obtained using only the first diamine hardening agents mentioned above, the extrudability of the urethane polymer can be dramatically improved by adding a second diamine hardening agent which acts as a reactive processing aid. For example, the second of diamine hardening agent can have the following formula: Where Ri and R2 are each independently selected from methyl, ethyl, propyl, and isopropyl groups and R3 is selected from hydrogen and chlorine. Examples of these diamine hardening agents include the following compounds manufactured by Lonza Ltd. (Basel, Switzerland). LONZACURE® M-DIPA R1 = C3H7; R2 = C3H7; R3 = H LONZACURE® M-DMA R? = CH3; R2 = CH3; R3 = H LONZACURE® M-MEA R -. = CH3; R2 = C2H5; R3 = H LONZACURE® M-DEA R! = C2H5; R2 = C2H5; R3 = H LONZACURE® M-MIPA R? = CH3; R2 = C3H7; R3 = H LONZACURE® M-CDEA R _. = C2H5; R2 = C2H5; R3 = C1 Where Rl t R2 and R3 refer to the chemical formula above. The chemical names of these materials are as follows: M-DIPA is 4,4 '-methylene-bis (2,6-diisopropylaniline), M-DMA is 4,4' -methylene-bis (2,6-dimethylaniline), M-MEA is 4,4'-methylenebis (2-ethyl-6-methylaniline), M-DEA is 4,4'-methylenebis (2,6-diethylaniline), M-MIPA is 4,4'-methylenebis (2-isopropyl-6-methylaniline), and M-CDEA is 4,4 'methylene-bis (2,6-diethyl-3-chloroaniline). Lonzacure® M-CDEA is available in the United States from Air Products and Chemicals, Inc. (Allentown, Pennsylvania). Particularly preferred second diamine hardeners are M-DIPA (methyldiisopropylaniline) and M-DEA (methyldiethyl aniline). Another diamine that can be used as a second diamine hardening agent is trimethylene glycol diparaaminobenzoate, which is sold by Air Products and Chemicals, Inc. under the brand Placure 740M. This has the following formula: O or H2N - < ^ > - C-O - (CH2) 3 -O-C - < ^ > ~ NH2 The second diamine hardening agent is preferably added to the first curing agent in an amount of, for example, 2 to 80 percent, based on equivalents, with a preferred range being 2 to 60 percent. A more preferred amount of the second diamine hardening agent is 10 to 50 percent equivalents. The first diamine hardening agent is present in an amount of, for example, 20 to 98 percent equivalents, and more preferably 50 to 90 percent equivalents. A preferred diamine hardening agent system is a combination of DETDA and either M-DIPA or M-DEA. Preferably, DETDA comprises 70 to 100 percent, more preferably 80 to 90 percent by weight, and more preferably about 85 percent by weight of the total weight of the diamine hardening agent system. The M-DEA or M-DIPA with M-DEA which is most preferred, is preferably in an amount of 5 to 30 percent, more preferably 10 to 20 percent, and more preferably 15 percent by weight of the total weight of the diamine hardening agents. Aliphatic diisocyanates Aliphatic diisocyanates have the basic formula 0 = C = N-A-N = C = 0, wherein A is a linear, branched and / or cyclic aliphatic group, having, for example, 6 to 13 carbon atoms. The aliphatic diisocyanates are preferably saturated diisocyanates. A preferred aliphatic diisocyanate for use in the process of the present invention is 4,4'-dicyclohexylmethane diisocyanate. Three isomers of 4,4'-dicyclohexylmethane diisocyanate are shown below: cis, trans An example of such a diisocyanate is Desmodur, a product commercially available from Bayer Corporation. Desmodur w contains 20 percent of the trans isomer, trans of 4,4 '-dicyclohexyl ethane diisocyanate, with the remaining 80 percent comprising the cis, trans and cis, cis isomers of 4,4' -dicyclohexyl ethane diisocyanate. XP-7041E, also available from Bayer Corporation, contains 50 percent of the trans, trans isomer of 4,4 '-dicyclohexylmethane diisocyanate, with the remaining 50 percent comprising the cis, trans and cis, cis 4, 4' isomers -dicyclohexylmethane diisocyanate. Increasing the content of the trans isomer, trans of 20 to 50 percent improves the thermal properties and chemical resistance of the system with some degree of improvement in physical properties. Increasing the content of the trans isomer, trans above 80 percent further improves the thermal stability and chemical resistance of the system with excellent physical properties and processing parameters. Additional aliphatic diisocyanates that may be used include the following: First, the isocyanate of 3-isocyanato-methyl-3,5,5-trimethylcyclohexyl, which is available from Huís and has the following structural formula: Second, tetramethylxylene diisocyanate (either meta or para), which is available from Cytex and has the following structural formula: Intermediates containing hydroxy The intermediates containing hydroxy which can be used in the process of the invention are preferably polyester glycols and polyether glycols having a weight average molecular weight of, for example, about 500 to about 3000. Polyester glycols which are useful in the present invention preferably have a weight average molecular weight of, for example, about 1250 to about 2000 and include polycaprolactones and polyesters based on the esterification of aliphatic dicarboxylic acids of 2 to 12 carbon atoms, such as adipic, succinic acids and sebacic in the presence of aliphatic glycols preferably having 2 to 12 carbon atoms, such as ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, 1,10-decanediol and 1,12- dodecanediol. Suitable polycaprolactones are preferably prepared by the addition reaction of E-caprolactone in the presence of aliphatic glycols having preferably 2 to 12 carbon atoms such as ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6- hexanediol, 1, 10-decanediol and 1,12-dodecanediol. The resulting polycaprolactone has the following formula: Where R = (CH2) 2-? 2 and n is selected such that the average molecular weight of the prepolymer is within the preferred range of about 500 to 3,000, with an exemplary average molecular weight that is about 1,900. Polyesters of dicarboxylic acids and glycols can be prepared by esterification or transesterification processes which are well known in the art. The polyether glycols which are useful in the present invention preferably have a weight average molecular weight of, for example, about 1000 to about 3000 and include poly-1, 2-propylene ether glycol, poly-1,3-propylene ether glycol and polytetramethylene ether glycol (PTMEG). These polyether glycols can be prepared by condensing epoxies or other cyclic ethers according to procedures that are well known in the art. Preferred hydroxy-containing intermediates for use in the process of the invention are polycaprolactones, especially the polycaprolactones prepared by the addition reaction of E-caprolactone in the presence of neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, 1.10 -decanodiol or 1,2-dodecanediol. The most preferred polycaprolactones are polycaprolactones initiated by neopentyl glycol. Reaction Process In the preferred method, the aliphatic diisocyanate is first mixed with at least one hydroxy-containing intermediate in an equivalent ratio of, for example, approximately two NCO groups, per OH group. The mixture is then heated, for example at a temperature of 82 ° C to 127 ° C (180 ° F to 260 ° F), more preferably 93 ° C to 115 ° C (200 ° F to 240 ° F), for about 10 to 60 minutes, more preferably 30 to 45 minutes to form a prepolymer. The prepolymer is then reacted with a diamine hardening agent at a temperature of about 71 ° C to 107 ° C (160 ° F to 225 ° F) for about 4 to 20 hours to form the hardened elastomer. Preferably, the diamine hardening agent is added to the prepolymer in an equivalent ratio of, for example, 0.95-1.06 NH2 groups per 1.0 of NCO group, with the range of 0.98 to 1.0 NH2 groups per 1.0 of NCO group which is more preferred. Alternatively, the aliphatic diisocyanate can be reacted with 0.3 to 0.8 equivalents of the hydroxy-containing intermediate to form a prepolymer, and then the remaining 0.2 to 0.8 equivalents of the hydroxy-containing intermediate are added with the diamine hardening agent to form the hardened elastomer. . The hardened elastomer is then granulated and / or formed into pellets prior to extrusion of the final product. Anti-blocking agents / extrusion processing aids can optionally be added, such as for example N, N'-ethylenebistearamides (Acrawax C) or N, N'-dioleoylethylenediamine (Glycolube VL), both available from Lonza Specialty Chemicals, to improve processing characteristics and minimize or eliminate extrusion blockage. Levels that are in the range of, for example, 0.25% to 2.0% by weight during the manufacture of the thermoplastic polyurethane can be added. The test has shown that the excellent anti blockade of the extrudate takes place with the addition of 0.5% to 1.0% by weight of Glycolube VL without change in the physical properties of the system. The above anti-block agents Acrawax C or Glycolube VL are preferably used in conjunction with diatomaceous earth calcined by stripping, available from Celite Corporation. The diatomaceous earth alone can also be used alone as the antiblocking agent / extrusion processing aid. Diatomaceous earth can be added in amounts in the range of, for example, 2.0 to 4.0% by weight to give excellent results. These antiblocking agents / extrusion processing aids are added in the form of a concentrate to either the granular elastomer or during the formation of the pellets. While the addition of the diatomaceous earth does not improve the processability of the polyurethanes, this can cause the moisture levels in the polyurethanes to increase, which can lead to undesirable effects such as hydrolysis and swelling of the polymer. The resulting extruded urea-containing polyurethanes combine excellent thermal properties with excellent physical properties in an "A" durometer of about 80. The polyurethanes of the present invention can be extruded using conventional extrusion devices well known in the art and commercially available. The polyurethanes are preferably extruded at a temperature of, for example, from about 215 ° C to about 310 ° C (about 420 ° F to about 590 ° F), more preferably from about 235 ° C to about 260 ° C (about 455 ° C). ° F to approximately 500 ° F). Typical pressure conditions of extrusion through a melt flow index meter are, for example, a load of about 6 to about 20 kg (corresponding to about 2.475 to about 8.249 psi of pressure), more preferably a charge of about 8 to about 13 kg (which corresponds to about 3,299 to about 5,362 psi of pressure). The polyurethanes can preferably be extruded in, for example, inflatable tubular structures or air chambers for air bags. After extrusion, the polyurethanes will be fixed to full stabilization and maximum hardening properties in about 3 to 21 days under ambient conditions. Preferably, the post extrusion is carried out by subjecting the extruded products to a high temperature in order to accelerate the stabilization and hardening process. For example, the extruded products may be subjected to a temperature of about 70 ° C to 165 ° C (about 160 ° F to 325 ° F), more preferably about 95 ° C to 110 ° C (about 220 ° F to 230 ° C). F), for a period of about 4 to 24 hours, more preferably about 12 to 16 hours. The process of the present invention is illustrated by the following examples. EXAMPLE 1 A clean reactor equipped with heating, cooling, vacuum, dry N2, and an agitator with Desmodur (4,4 '-dicyclohexyl ethane diisocyanate containing 20% trans, trans isomer) is charged. The agitator is turned on. The temperature of the Desmodur is increased to 71 ° C. A mixture of initiated polycaprolactones is prepared with diethylene glycol, Tone 0240 (equivalent weight 1,000) and Tone 0230 (equivalent weight 625) both available from Union Carbide. A sufficient quantity of Tone 0230 is added to Tone 0240 in such a way that when they are melted and mixed at 80 ° C an equivalent weight of about 950 is achieved. The polycaprolactone mixture is then added to the Desmodur W in an equivalent ratio of two. NCO groups to an OH group. The heating and the vacuum turn on. When the temperature reaches approximately 100 ° C, the heating is turned off, the reaction is allowed to be exothermic at 110 to 121 ° C. When the reaction is complete and the temperature decreases to about 77 ° C, the resulting prepolymer is discharged from the reactor and filtered through a 20 mesh filter in clear containers. The containers are then purged with dry N2 and sealed.

The prepolymer is then reacted with Ethacure 100 as the diamine hardening agent in an equivalent ratio of 0.99 NH2 groups to 1.0 NCO groups. With the prepolymer at a temperature of about 7 | ° C, Ethacure 100 is added at room temperature, and the components are thoroughly mixed. The mixture is then evacuated to 250 to 1,000 millitorr until it is free of bubbles or only a few bubbles are on the surface. The evacuated mixture is then emptied into molds and hardened for 8 to 16 hours at 105 ° C. The molten covers are then granulated and formed into pellets to form extrudable thermoplastic elastomer pellets. It is believed that the resulting elastomer has the following formula: This formula shows the polycaprolactone / Desmodur prepolymer with one of its NCO groups reacted with the NH2 group of the Ethacure 100 diamine hardening agent. Table 1 shows a comparison of the rheological properties of (1) Pellethane 2102-80A, a polyester. of prolonged caprolactone with urethane-grade extrudable hydroxyl commercially available from Dow with (2) the urethane polymer prolonged with urea resulting from the process of the present invention. TABLE 1 As can be seen from Table 1, the rheological properties of the polymer resulting from the process of the present invention are superior to those of the polyurethane composition of the prior art. EXAMPLE 2 The physical properties of a sample of the molten polymer sheet resulting from Example 1 are determined and indicated in Table 2. The molten sheet is approximately 70-75 mils thick. The urethane polymer granules resulting from Example 1 are melted and extruded to form inflatable tubular structures (ETI) which are post-hardened after extrusion. The post-hardening / temperature time profiles evaluated are 2 and 4 hours at 110 ° C, 1.5 hours at 132 ° C, and 1 and 2 hours at 150 ° C. The physical properties of the extruded samples are then determined. The post hardened samples give very similar results. The sample thickness of the extruded material is in the range of 22 to 28 thousandths. The physical properties of a representative sample of the post-hardened extruded polymer are shown in Table 2, which shows a comparison of the physical properties of Pellethane 2102-80A with the physical properties of the molten and extruded samples resulting from the present process. invention. TABLE 2 In Table 2, psi represents pounds per square inch, and pli represents pounds per linear inch. As can be seen from Table 2, the physical properties of the composition resulting from the process of the present invention are superior to those of the polyurethane composition of the prior art. In addition, while Pellethane 2102 -80A is formulated for extrusion only, the polyurethane resulting from the process of the present invention can be liquid drained, injection molded, transfer molded, sprayed, and / or extruded without changing its chemistry or stoichiometry . EXAMPLE 3 Additional samples of the urethane polymer are prepared by the process of the invention using additional E-caprolactone polyesters in order to evaluate the physical properties and processing parameters of the resulting polymers. The polyesters of E-caprolactone are esterified using 1,6-hexanediol and neopentyl glycol as initiators. These polyesters of E-caprolactone are available from Solvay Interox of the United Kingdom. The polyesters of E-caprolactone which are used in this example are as follows: CAPA 162/034 and CAPA 306/001 are polycaprolactones initiated by 1,6-hexanediol; CAPA 216 and CAPA 225 are polycaprolactones initiated by neopentyl glycol. In addition, the effect of increasing the trans, trans proportion of the diisocyanate on the properties of the hardened elastomer is evaluated. The diisocyanate used for this evaluation is XP-7041E, which contains 50% of the trans, trans, isomer of 4,4'-dicyclohexylmethane diisocyanate. The same process is used as in Example 1 to prepare the prepolymers, except that XP-7041E is melted at 80 ° C and completely mixed before use. The respective E-caprolactone polyesters are melted at 80 ° C and then mixed to give an equivalent weight of 950 before reacting with the diisocyanate to form the prepolymer. The polyesters of E-caprolactone are added to the diisocyanate (XP-7041E) in an equivalent ratio of two NCO groups for an OH group. While this process substantially duplicates the preparation process of the prepolymer in Example 1, it provides a better understanding of the effect on the physical, thermal and processing properties related to the change of initiators in the esterification of E-caprolactone and increase the trans , trans diisocyanate. The curing agents used in this example are diethylene glycol diamine (DETDA) (samples ETI-7 to ETI-10) and a 95: 5 equivalent mixture of DETDA and M-DIPA (sample ETI-10G-1). The ratio of NH2 groups to NCO groups is maintained at 1: 1. The samples are mixed, evacuated, melted and hardened as in Example 1. The physical properties of the resulting hardened elastomer samples are then determined. The results are indicated in Table 3. TABLE 3 The physical properties of the systems documented in Table 3 are excellent. The thermal resistance of the samples that are prepared using XP-7041E, which contain 50 percent of the trans, trans isomer, is higher than that of the samples prepared using Desmodur, which contain only 20 percent of the trans, trans isomer of the 4, 4 '-dicyclohexylmethane diisocyanate. EXAMPLE 4 The thermal stability and blocking characteristics of the samples resulting from Examples 2 and 3 are determined by maturation with heating in a Blue M forced air circulation oven for 410 hours at 110 ° C. The blocking evaluation consists of placing samples of the molten material or extruded air chamber in the oven both with and without a weight being applied. The weight is placed between the center of the sample, and in the case of the extruded samples, parallel to the extrusion. The applied force is approximately 2.0 psi. After 410 hours, the samples are removed from the oven, allowed to cool to room temperature, and the material of the air chamber to block is evaluated. No blockage of the samples occurs during the thermal maturation test 410 hours / 110 ° C. Table 4 shows the physical properties of the heat-matured samples: TABLE 3 As shown in Table 4, all the samples that are evaluated show good retention of physical properties without blocking the molten or extruded material after maturation by heat at 110 ° C for 410 hours. EXAMPLE 5 Additional polyurethane samples are prepared according to the process of Example 1 using polycaprolactones initiated with neopentyl glycol (CAPA 216 and CAPA 225) as the hydroxy-containing intermediate and Desmodur W as the aliphatic diisocyanate. The diamine hardening agents used in this example are diethylene toluene diamine (DETDA) (sample 10G) and a 70:30 equivalent mixture of DETDA and M-DIPA (sample 10G-3). The diamine endurance agent is added to the prepolymer in an equivalent ratio of 1.02 NH2 groups to 1.0 NCO groups or 1.06 NH2 groups to 1.0 NCO groups (see Table 5). The hardened polymer is emptied into a sheet of 72 mils thick. The hardened sheets are post-hardened for 16 hours at 105 ° C followed by maturation for 7 days at room temperature. Then another group of samples is exposed to hydrolytic maturation for 30 days in distilled water at 71 ° C. The physical properties of the molten sheets are indicated in Table 5. TABLE 5 In Table 5, "E" refers to standard unmatured samples; UT "refers to thermal matured samples, and" H "refers to hydrolytic matured samples EXAMPLE 6 An additional polyurethane sample is prepared in the same manner as in Example 5, except that the diamine hardener used in this example is a 70:30 equivalent mixture of DETDA and M-DIPA, and the diamine hardening agent is added to the prepolymer in an equivalent ratio of 0.98 NH2 groups by 1.0 NCO groups. Additionally, a sample is prepared without the addition of any antiblocking agents / extrusion processing aids, while another 0.25% by weight sample of Acrawax C ("Wax") and 2.0% by weight of diatomaceous earth calcined by flow ("Floss") is added. of molten polyurethane to form a sheet of 21 to 25 thousandths of thickness.The post-hardened extruded sheet is exposed to hydrolytic maturation for 43 days in distilled water at 71 ° C. The physical properties of the samples are indicated hydrolytically matured in Table 6.

TABLE 6 EXAMPLE 7 An additional polyurethane sample is prepared according to the process of Example 1, using polytetramethylene ether glycol (PMTEG) having a weight average molecular weight of 1000 as the hydroxy-containing intermediate. PTMEG is added to Desmodur W in an equivalent ratio of 1.45-1.65 NCO groups to 1.0 OH groups. The prepolymer is reacted with a 70:30 equivalent mixture of DETDA and M-DIPA as the diamine hardening agent, which is added to the prepolymer in an equivalent ratio of 0.98-1.0 NH2 groups to 1.0 NCO groups. The hardened polymer is emptied into a sheet of 72 mils thick. The resulting polyurethane has excellent extrusion parameters and an "A" clamping hardness of 75. The physical properties of the cast sheet are indicated in Table 7. TABLE 7 EXAMPLE 8 Example 7 is repeated using polytetramethylene ether glycol (PTMEG) having a weight average molecular weight of 2000 as the hydroxy-containing intermediate, which is reacted with Desmodur W in an equivalent ratio of 2.0 NCO groups to 1.0 QH groups. The physical properties of a cast sheet 72 mils thick are indicated in Table 8. TABLE 8 Hardness A 85 85 82 83 84 86 83 EXAMPLE 9 The ASTM method D-1238 is modified to measure the melt flow index to reduce the life time. The following procedure is used to measure the melt flow index of polyurethanes of the present invention. A temperature of 220 ° C to 250 ° C and a load of 7.0 kg to 12.5 kg are used depending on the composition of the polyurethane. A five gram sample of the polyurethane elastomer is charged to the melt flow index meter. A 30-second structure is used to pack the pellets or granulated elastomer, after which an additional life time of 150 seconds (for a total of 3 minutes) is used before the weight is piled up. The load of five grams total is extruded for evaluation. The evaluation consists of appearance, change in diameter from start to finish, time to extrude and resistance to pulling on the extruded tape. In general, the evaluation according to this method of samples prepared according to the present invention has shown that the first portion of the extrusion is very strong, while the last portion is weak. However, after 24 hours, there is a significant increase in the strength of the last portion, and after 7 to 14 days, all the properties have been fully recovered in such a way that the extrusion resistance is the same from the front. to the extreme. The above description of the embodiments of the invention has been presented for the purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise form described. Variations and modifications of the embodiments described herein will be obvious for a person with ordinary skill in the art. The scope of the invention is defined only by the claims appended thereto

Claims (42)

1. CLAIMS 1. An expanded polyurethane with extrudable thermoplastic elastomeric urea characterized in that it comprises the reaction product of: (a) a polyurethane prepolymer comprising the reaction product of at least one aliphatic diisocyanate with at least one hydroxy-containing intermediate selected of the group consisting of polyester glycols, polyether glycols and mixtures thereof, (b) at least one first diamine hardening agent selected from the group consisting of 2,4-diamino-3,5-diethyl-toluene, , 6-diamino-3,5-diethyl toluene, and methyleneaniline and (c) at least one second diamine hardening agent selected from the group consisting of 4,4'-methylenebis- (2,6-diisopropylaniline), 4,4'-methylene-bis (2,6-dimethylaniline), 4,4'-methylene-bis (2-ethyl-6-methylaniline), 4,4'-methylenebis (2,6-diethylaniline),, 4 '-methylene-bis (2-isopropyl-6-methylaniline), 4,4'-methylene-bis (2,6-diethyl-3-chloroaniline) and trimethylene glycol di- for aminobenzoate.
2. 2. The polyurethane according to claim 1, characterized in that the at least first diamine hardening agent comprises 20 to 98 percent by equivalents of a total amount of diamine hardening agents, and the at least one second hardening agent. hardened diamine comprises 2 to 80 percent by equivalents of the total amount of the diamine hardeners.
3. 3. The polyurethane according to claim 1, characterized in that the at least one diamine hardening agent comprises 40 to 98 percent by equivalents of a total amount of diamine hardening agents, and the at least one second diaminating agent. hardened diamine comprises 2 to 60 percent by equivalents of the total amount of the diamine hardeners.
4. The polyurethane according to claim 1, characterized in that the at least aliphatic diisocyanate is selected from the group consisting of 4,4'-dicyclohexylmethane diisocyanate, 3-isocyanato-methyl-3,5,5-trimethylcyclohexyl isocyanate and tetramethylxylene diisocyanate.
5. 5. The polyurethane according to claim 1, characterized in that the at least aliphatic diisocyanate is 4,4'-dicyclohexylmethane diisocyanate.
6. The polyurethane according to claim 5, characterized in that the 4,4'-dicyclohexylmethane diisocyanate contains at least 20 weight percent of the trans, trans isomer of 4,4'-dicyclohexylmethane diisocyanate.
7. The polyurethane according to claim 5, characterized in that the 4,4'-dicyclohexylmethane diisocyanate contains at least 50 weight percent of the trans, trans isomer of 4,4'-dicyclohexylmethane diisocyanate
8. 8. The polyurethane in accordance with claim 5, characterized in that the 4,4'-dicyclohexylmethane diisocyanate contains at least 80 weight percent of the trans, trans isomer of 4,4'-dicyclohexylmethane diisocyanate.
9. 9. The polyurethane according to claim 1, characterized in that the at least intermediate containing hydroxy has a weight average molecular weight of about 500 to about 3000.
10. 10. The polyurethane according to claim 9, characterized in that the the least intermediate containing hydroxy is a polyester glycol comprising at least one polycaprolactone which has been prepared by the addition reaction of caprolactone in the presence of at least one aliphatic glycol having 2 to 12 carbon atoms.
11. The polyurethane according to claim 10, characterized in that the at least aliphatic glycol is selected from the group consisting of ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, 1,10-decanediol, 1,2-dodecanediol and mixtures thereof.
12. 12. The polyurethane according to claim 9, characterized in that the at least intermediate containing hydroxy is a polyester glycol comprising at least one polyester which has been prepared by condensing at least one aliphatic dicarboxylic acid having 2 to 12 carbon atoms. carbon in the presence of an aliphatic glycol having 2 to 12 carbon atoms.
13. 13. The polyurethane according to claim 12, characterized in that the at least aliphatic dicarboxylic acid is selected from the group consisting of adipic acid, succinic acid, sebacic acid and mixtures thereof.
14. The polyurethane according to claim 12, characterized in that the at least aliphatic glycol is selected from the group consisting of ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, 1,10-decanediol, 1,2-dodecanediol and mixtures thereof.
15. 15. The polyurethane according to claim 9, characterized in that the at least intermediate containing hydroxy is a polyether glycol comprising polytetramethylene ether glycol.
16. The polyurethane according to claim 1, characterized in that the extrudable thermoplastic urethane has a tie-in hardness of about 80 and a melt flow index of about 5 to 40 inches per minute when measured in accordance with ASTM D- 1238 modified to reduce the time of life.
17. 17. Prolonged polyurethane with extrudable thermoplastic elastomer urea characterized in that it comprises the reaction product of: (a) A polyurethane prepolymer comprising the reaction product of at least one aliphatic diisocyanate with at least one hydroxy-containing intermediate selected from the group consisting of group consisting of polyester glycols, polyether glycols and mixtures thereof, (b) At least one diamine hardening agent, and (c) At least one extrusion processing aid.
18. 18. The polyurethane according to claim 17, characterized in that the curing agent comprises at least one member selected from the group consisting of 2,4-diamino-3,5-diethyl-toluene, 2,6-diamino-3. , 5-diethyl-toluene and methyleaniline.
19. The polyurethane according to claim 17, characterized in that the extrusion processing aid comprises at least one member selected from the group consisting of N, N'-ethylenebistearamides, N, N'-diioleoylethylenediamine and diatomaceous earth.
20. 20. The polyurethane according to claim 17, characterized in that the at least aliphatic diisocyanate is 4,4'-dicyclohexylmethane diisocyanate.
21. The polyurethane according to claim 17, characterized in that the at least intermediate containing hydroxy is a polyester glycol comprising at least one polycaprolactone which has been prepared by condensing caprolactone in the presence of at least one aliphatic glycol which It has 2 to 12 carbon atoms.
22. 22. The polyurethane according to claim 18, characterized in that the curing agent additionally comprises at least one member selected from the group consisting of 4,4'-methylene-bis (2,6-diisopropylaniline), 4,4 '. -methylene-bis (2,6-dimethylaniline), 4,4 '-methylene-bis (2-ethyl-6-methylaniline), 4,4' -methylene-bis (2,6-diethylaniline), 4, 4 ' -methylene-bis (2-isopropyl-6-methylaniline), 4,4'-methylene-bis- (2,6-diethyl-3-chloroaniline) and trimethylene glycol di-aminobenzoate.
23. The polyurethane according to claim 17, characterized in that the extrudable thermoplastic urethane has a tie-in hardness of about 80 and a melt flow rate of about 5 to 40 inches per minute when measured in accordance with ASTM D- 1238 modified to reduce the time of life.
24. 24. A process for manufacturing an expanded polyurethane with extrudable thermoplastic elastomeric urea characterized in that it comprises the steps of: (a) Reacting at least one aliphatic diisocyanate with at least one hydroxy-containing intermediate selected from the group consisting of polyester glycols and polyether glycols for forming a prepolymer, and (b) Reacting the prepolymer with at least one first diamine hardening agent selected from the group consisting of 2,4-diamino-3,5-diethyl-toluene, 2,6-diamino 3, 5-diethyl-toluene and methyleaniline, and with at least one second diamine hardening agent selected from the group consisting of 4, '-methylene-bis (2,6-diisopropylaniline), 4,4'-methylene-bis (2,6-dimethylaniline), 4,4 '-methylene-bis (2-ethyl-6-methylaniline), 4,4'-methylene-bis (2,6-diethylaniline), 4,4'-methylene-bis (2-isopropyl-6-methylaniline) ), 4, 4 '-methylene-bis (2,6-diethyl-3-chloronailine () and trimethylene glycol di-para aminobenzoate
25. 25. The process according to the claim 25, characterized in that the process is carried out in an environment that does not contain more than 0.03 weight percent water based on the weight of total ingredients.
26. 26. The process according to claim 24, characterized in that the at least aliphatic diisocyanate is mixed with the at least intermediate containing hydroxy in an equivalent ratio of two NCO groups to an OH group.
27. 27. The process according to claim 24, characterized in that the process further comprises forming the formed polyurethane into tablets.
28. 28. The process according to claim 24, characterized in that the process further comprises extruding the formed polyurethane.
29. 29. A process for manufacturing an expanded polyurethane with extrudable thermoplastic elastomeric urea characterized in that it comprises the steps of: (a) Reacting at least one aliphatic diisocyanate with at least one hydroxy-containing intermediate selected from the group consisting of polyester glycols and polyether glycols and mixtures thereof to form a prepolymer, and (b) Reacting the prepolymer with at least one first diamine hardening agent, (c) Wherever at any point before, during or after either the reaction steps , at least one extrusion processing assistant is added.
30. 30. The process according to claim 29, characterized in that the diamine hardening agent comprises at least one member selected from the group consisting of 2,4-diamino-3,5-diethyl-toluene, 2,6-diamino. 3, 5-diethyl toluene and methyleaniline.
31. 31. The process according to claim 30, characterized in that the curing agent additionally comprises at least one member selected from the group consisting of 4,4'-methylene-bis (2,6-diisopropylaniline), 4,4 '. -methylene-bis (2,6-dimethylaniline), 4,4'-methylene-bis (2-ethyl-6-methylaniline), 4,4'-methylene-bis (2,6-diethylaniline), 4,4 ' - ethylene-bis (2-isopropyl-6-methylaniline), 4,4'-methylene-bis- (2,6-diethyl-3-chloroaniline) and trimethylene glycol di-para aminobenzoate.
32. 32. The process according to claim 30, characterized in that the extrusion processing aid comprises at least one member selected from the group consisting of N, N'-ethylenebistearamides, N, N'-dioleoylethylene diamine and diatomaceous earths.
33. 33. The process according to claim 29, characterized in that the process further comprises forming the formed polyurethane into pellets.
34. 34. A process for forming a product, characterized in that it comprises: (a) Heating an expanded polyurethane with thermoplastic elastomeric urea comprising the reaction product of at least one aliphatic diisocyanate, at least one hydroxy-containing intermediate selected from the group consists of polyether glycols, polyester glycols, and mixtures thereof, and at least one diamine hardening agent, and comprising at least one member selected from the group consisting of 2,4-diamino-3,5-diethyl. toluene, 2,6-diamino-3,5-diethyl toluene and methyleneaniline, and at least one member selected from the group consisting of 4,4'-methylene-bis (2,6-diisopropylaniline), 4,4 '-methylene-bis (2,6-dimethylaniline), 4,4'-methylene-bis (2-ethyl-6-methylaniline), 4,4'-methylene-bis (2,6-diethylaniline), 4,4 '-methylene-bis (2-isopropyl-6-methylaniline), 4,4'-methylene-bis (2,6-diethyl-3-chloroaniline) and trimethylene glycol di-aminobenzoate. (b) Extrude the heated polyurethane to form an extruded product
35. 35. The process according to claim 34, characterized in that the diamine hardening agent comprises at least one member selected from the group consisting of 2,4-diamino-3. , 5-diethyl-toluene, 2,6-diamino-3,5-diethyl-toluene and methyleaniline.
36. 36. The process according to claim 35, characterized in that the curing agent additionally comprises at least one member selected from the group consisting of 4., 4 '-methylene-bis (2,6-diisopropylaniline), 4,4'-methylene-bis (2,6-dimethylaniline), 4,4'-methylene-bis (2-ethyl-6-methylaniline), , 4 '-methylene-bis (2,6-diethylaniline), 4,4'-methylene-bis (2-isopropyl-1-6-methylaniline), 4,4' -methylene-bis- (2,6-diethyl-3) -chloroaniline) and trimethylene glycol di-para aminobenzoate.
37. 37. The process according to claim 34, characterized in that the extrusion is carried out at a temperature of about 215 ° C to about 310 ° C.
38. 38. The process according to claim 34, characterized in that the extrusion is carried out at a pressure of about 3299 to about 5363 psi.
39. 39. The process according to claim 34, characterized in that the process further comprises post-hardening the extruded product.
40. 40. An extruded polyurethane product formed by the process according to claim 34.
41. 41. An extruded polyurethane product according to claim 40, characterized in that the product is an inflatable tubular structure.
42. 42. The polyurethane according to claim 2, characterized in that the first diamine hardening agent is selected from the group consisting of 2,4-diamino-3,5-diethyl toluene, 2,6-diamino-3,5-diethyl. -toluene, and mixtures thereof, and the second diamine hardening agent is 4,4'-methylene-bis (2,6-diisopropylaniline).