WO2009079826A1

WO2009079826A1 - Thermoplastic polyurethane elastomer with hydrolytic stability and preparing method thereof

Info

Publication number: WO2009079826A1
Application number: PCT/CN2007/003604
Authority: WO
Inventors: Richard Wang; Jerry Fu; George Zhang; Maxy Yang; Louie Liu; David Zhao; Cosmo Wang; Becky Wang; Jack Ma
Original assignee: Wanthane Polymers Co., Ltd.; Yantai Wanhua Polyurethanes Co., Ltd.
Priority date: 2007-12-14
Filing date: 2007-12-14
Publication date: 2009-07-02

Abstract

A hydrolysis-resistant thermoplastic polyurethane elastomer comprises carbodiimide-modified organic diisocyanate used as hydrolysis-resistant aids and thermoplastic polyurethane elastomer matrix. A method for preparing thermoplastic polyurethane elastomer comprises mixing hydrolysis-resistant aids and raw materials for thermoplastic polyurethane elastomer matrix, and then reacting the mixture by means of pre-polymer process, conveyor band process or twin-screw reactive extruder process.

Description

Thermoplastic polyurethane elastomer with hydrolytic stability and preparation method thereof

The present invention relates to a thermoplastic polyurethane elastomer having hydrolytic stability containing a hydrolysis-resistant auxiliary agent and a process for producing the same. . Background technique

Thermoplastic polyurethane elastomer (TPU) has the advantages of rubber and plastic, and has excellent comprehensive performance. It is widely used in the fields of shoe materials, pipes, fire hoses, oil pipelines, melt-spun spandex, sealing rings, etc., but its hydrolytic stability. Poor, the scope of application is limited.

The reason for the poor hydrolysis stability of thermoplastic polyurethane elastomers is that after water penetrates into the elastomer

The group in the TPU undergoes a chemical reaction that produces chemical degradation, the chemical composition and physical structure of the elastomer are destroyed, and the hydrolysis is irreversible. Schol lenberger et al. pointed out that the most sensitive groups for hydrolysis in TPU are ester groups, carbamates and urea groups. The mechanism is as follows:

0 o

— RC-0-R— + H ₂ 0 ~ - — RC-OH + HO-R—

O O

— R- -CNR— + H ₂ 0 ~ »- — R- -C-OH + H ₂ N- —

H

_H oo

— RNCOR — + H ₂ 0 ——— R-N'C-OH + HO-R—

H

In terms of improving the hydrolysis stability of TPU, it is mainly solved by enhancing the hydrophobicity of the polyurethane elastomer or "replanting" the broken segment. There are two aspects in the following: First, changing the thermoplastic polyester elastomer Structure, but due to its complicated process, high cost, and also weakened the inherent properties of thermoplastic polyester elastomer, it is limited in application; Second, it is a chemical additive, which is widely used in industry. The hydrolysis-resistant additives mainly include epoxy compounds and carbodiimides. The epoxy compounds can be roughly classified into two types: glycidyl derivatives and hydrocarbon-substituted oxirane compounds. The mechanism of action is as follows:

0 0

__ _R _^_0_ _R _ + H ₂ 0 —— *- -RC-OH + HO-R— O _u

― _R _ ₀ _C-N^ _R — ⁺ H ₂ 0 —— — R-OH + ~R-NH ₂ + C0 ₂ -CH-CH ₂ + RCOH — C— C — O—C—R—

O OH

HH ₂ H ₂ H

2 -CH-CH ₂ + H ₂ NR—C-C - -C -C—

O OH OH

I · The epoxy compound acts as a proton acceptor and "seamage" in the elastomer, and can convert both the terminal carboxyl group and the terminal hydroxyl group (or amino group); however, it is used in a large amount and easily affects other properties of the material.

The carbodiimide compounds are as follows: di- 2-phenylcarbodiimide, di- 1-(4-chloronaphthyl)carbodiimide, oligocarbodiimide, etc., and the mechanism of action is as follows:

0 0

— RC-0-R— + H ₂ 0 — — RC-0H + H0-R—

-R-

The carbodiimide captures the carboxylic acid groups produced during the hydrolysis, eliminates the catalytic hydrolysis of the carboxylic acid, and also has a "seam, or recoupling effect on the ruptured polyester PU chain, so the carbodiimide compound acts as a water resistant Decomposition aids are widely used. Low-molecular weight compounds such as monocarbodiimide are easily decomposed during processing, produce irritating odor components, cause environmental pollution, or decrease due to gasification, so that the addition effect is not obvious. Therefore, polycarbodiimides are currently being used more and more.

ZL03106134. 6 discloses a mixture of carbodiimide and a process for preparing a polyurethane comprising an ester structure-containing compound and a carbodiimide having 12 to 4 Gwt% of ethylene oxide units. Although the hydrolysis resistance of the material is improved, the preparation process of the additive is complicated and expensive, and the production cost of the polyurethane elastomer is greatly increased.

U.S. Patent No. 3,714, 502 discloses a method of adding a small amount of acid silica to improve the hydrolytic stability of the polyurethane. However, when the method is applied to a thermoplastic polyurethane elastomer, particularly a porous polyurethane elastomer, the acid silica is difficult to disperse uniformly.

US Pat. No. 6,529,266 discloses a process for the preparation of a thermoplastic polyurethane elastomer which is first mixed with a polyol or a mixture of TPUs prepared from different polyols, which allows the producer The complexity of the art has led to a significant increase in production costs.

How to effectively improve the hydrolysis resistance of thermoplastic polyurethane elastomers and greatly reduce the production cost is a technical problem that needs to be solved. Summary of the invention

In view of the above technical deficiencies, the present invention provides a thermoplastic polyurethane elastomer having hydrolytic stability and a process for producing the same.

The thermoplastic polyurethane elastomer of the present invention comprises a hydrolysis-resistant auxiliary agent and a thermoplastic polyurethane elastomer body, wherein the hydrolysis-resistant auxiliary agent is a carbodiimide-modified organic diisocyanate; preferably a carbodiimide-modified liquefied organic second Isocyanate; thermoplastic polyurethane elastomer body refers to various thermoplastic polyurethane elastomers conventional in the art without hydrolysis-resistant additives; carbodiimide modification means that organic diisocyanate partially removes carbon dioxide under the action of a catalyst. A carbodiimide group and a small amount of a uretonimine group.

The hydrolysis-resistant auxiliary of the present invention is further preferably a carbodiimide-modified liquefied diphenylmethane diisocyanate (also referred to as liquefied MDI) which converts the -NH 0 group moiety in diphenylmethane diisocyanate into The product obtained by carbodiimide and ureton groups is in a pale yellow liquid state at room temperature.

05-50%; further preferably 1-15 of the weight of all organic diisocyanates in the thermoplastic polyurethane elastomer, in the present invention, the amount of the organic diisocyanate in the thermoplastic polyurethane elastomer is 0. %.

Wherein, the calculation method of the amount of the hydrolysis-resistant auxiliary agent used in the present invention is: The amount of the carbodiimide-modified organic diisocyanate used in the present invention accounts for the modification of the carbodiimide in the thermoplastic polyurethane elastomer containing the hydrolysis-resistant auxiliary agent. Weight percent of total organic diisocyanate and organic diisocyanate.

The thermoplastic polyurethane elastomer of the present invention may be any type of thermoplastic polyurethane elastomer, but is preferably a polyester type or a polyether type.

The thermoplastic polyurethane elastomer of the present invention is mainly prepared from a linear macromolecular diol, an organic diisocyanate, a chain extender and a hydrolysis resistant auxiliary agent under the action of a catalyst; it may further comprise other than the above enumerated Raw materials and chemical additives, such as stabilizers, Antioxidants, etc.

In the thermoplastic polyurethane elastomer of the present invention, the linear macrodiol is selected from the group consisting of polyester diols or polyether diols or combinations thereof, wherein the polyester diol is a small molecule dicarboxylic acid and a small molecule binary The reaction product of an alcohol. Suitable dicarboxylic acids may be aliphatic, alicyclic or aromatic dicarboxylic acids which generally contain a total of from 4 to 15 carbon atoms. Suitable dicarboxylic acids may be succinic acid, pentane Diacid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanoic acid, isophthalic acid, terephthalic acid or cyclohexanedicarboxylic acid, etc., may also be the above An acid anhydride of a dicarboxylic acid such as phthalic anhydride, terephthalic anhydride or the like; a suitable glycol may be an aliphatic, aromatic diol which usually contains a total of 2 to 12 carbon atoms. , for example, ethylene glycol, 1, 2-propanediol, 1, 3-propanediol, 1, 3-butanediol, 1, 4-butanediol, 1, 5-pentanediol, 1,6-hexanediol, 2,2-dimethyl-1, 3-propanediol, 1, 4-cyclohexanedimethanol, 1, 10-decanediol, 1, 12-dodecanediol, etc.;

The polyester diol further includes a product obtained by reacting various lactones with a glycol, such as a polycaprolactone diol prepared by reacting caprolactone with diethylene glycol;

The polyester diol further includes a polycarbonate diol prepared by reacting a carbonate with a glycol; the polyester diol of the present invention is preferably a polyester diol having a molecular weight of 500 to 10,000, further preferably having a molecular weight of 700 a polyester diol of -4000; when the polyester diol of the present invention is a polycarbonate diol, a polycarbonate diol having a molecular weight of 500 to 2,500 is preferred; and the polyester diol is further preferred in the present invention. It is a polyadipate type polyester diol.

The polyether diol is obtained by ring-opening polymerization of an epoxy compound in the presence of an active hydrogen compound as a starter and a catalyst. Usually, the epoxy compound contains 2 to 6 carbon atoms, and may be, for example, polyethylene glycol formed by reacting ethylene oxide with ethylene glycol, polypropylene glycol formed by reacting propylene oxide with propylene glycol, by propylene oxide, and Poly(propylene glycol-ethylene glycol) formed by reacting ethylene oxide with propylene glycol or polytetramethylene glycol formed by reacting water with tetrahydrofuran; other suitable polyether polyols include polyether polyols of alkylene oxide Alcohols; Copolyethers can also be used in the present invention. Typical copolyethers include the reaction product of tetrahydrofuran with ethylene oxide or tetrahydrofuran with propylene oxide.

In the present invention, the polyether diol is preferably a polyether diol having a molecular weight from 500 to 10,000; more preferably ^700-3000 molecular weight polyether diols; more preferably a polyether diol Polytetrahydrofuran ether glycol.

In the thermoplastic polyurethane elastomer of the present invention, the organic diisocyanate may be an aromatic diisocyanate or an aliphatic/alicyclic diisocyanate or a combination thereof. Wherein the aromatic diisocyanate is selected from the group consisting of diphenylnonane diisocyanate (MDI), m-phenylenediethylene diisocyanate (XDI), phenylene-1,4-diisocyanate, naphthalene-1, 5-di One or more of isocyanate, diphenylmethane-3,3,-dimethoxy-4,4'-diisocyanate and toluene diisocyanate (TDI); aliphatic/alicyclic diisocyanate selected from isofluoride One or more of ketone diisocyanate (IPDI), 1, 4-cyclohexyl-diisocyanate (CHDI), decane-1, 10-diisocyanate, and dicyclohexylmethane-4,4-diisocyanate ;

The organic diisocyanate of the invention is preferably an aromatic diisocyanate, specifically selected from the group consisting of diphenylmethane diisocyanate (MDI), m-phenyldisionylene diisocyanate (XDI), phenylene-1,4-diisocyanate, naphthalene - one or more of 1, 5-diisocyanate, diphenylmethane-3,3'-dimethoxy- 4,4,-diisocyanate and toluene diisocyanate (TDI); organic diisocyanate of the invention further Preferred is diphenylnonane diisocyanate, which is also known as pure MDI.

The catalyst of the invention is selected from the group consisting of organic or inorganic acid salts of cerium, tin, iron, lanthanum, cobalt, lanthanum, aluminum, zinc, nickel, lanthanum, molybdenum, vanadium, copper, manganese and zirconium or organometallic derivatives thereof and phosphines thereof And one or more of the organic tertiary amines; wherein the organic acid salt of tin or the organic metal 4 thereof is organotin, and the organic germanium is selected from the group consisting of stannous octoate, dibutyltin dioctoate and dibutyltin dilaurate One or more; the organic tertiary amine is selected from the group consisting of triethylamine, triethylenediamine, N, N, N, N, -tetramethylethylenediamine, N, N, hydrazine, N, -tetraethyl Ethylenediamine, N-methylmorpholine, N-ethylmorpholine, N, N, N, N'-tetramethylguanidine, N, N, N, N'-tetramethyl-1, 3 One or more of butylenediamine, N,N-dimethylethanolamine and N,N-diethylethanolamine; the catalyst of the invention is preferably organotin, an organic tertiary amine or a combination thereof; more preferably organic The tin catalyst is specifically selected from one or more of stannous octoate, dibutyltin dioctoate and dibutyltin dilaurate.

The chain extender of the present invention is a lower aliphatic or short chain diol having from about 2 to about 10 carbon atoms; specifically selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1, 4- Butylene glycol (BD0), 1,6-hexanediol, 1, 3-butanediol, 1, 5-pentanediol, 1, 4-cyclohexanedimethanol hydroquinone di-hydroxyethyl ether and new One or more of pentanediol; the chain extender of the present invention is further preferably 1,4-butanediol. The thermoplastic polyurethane elastomer containing the hydrolysis-resistant auxiliary agent of the present invention can be prepared by a method conventional in the art, such as mixing the hydrolysis-resistant auxiliary agent of the present invention with the raw material of the thermoplastic polyurethane elastomer body, using a prepolymer method, a conveyor belt method or a double Prepared by the screw reaction extrusion method, that is, the TPU product is obtained; however, the present invention is preferably prepared by the following method: adding the carbodiimide-modified organic diisocyanate to the organic diisocyanate, mixing uniformly, and then expanding with the macromolecular diol; The chain agent, the catalyst and the like are mixed and reacted in a certain ratio, and are prepared by a prepolymer method, a conveyor belt method or a twin-screw reaction extrusion method, that is, a TPU product is obtained.

Since the hydrolysis-resistant auxiliary agent of the present invention has good compatibility with the thermoplastic polyurethane elastomer body, the other aspects of the thermoplastic polyurethane elastomer body are not lowered by the addition of the hydrolysis-resistant auxiliary agent, so the thermoplastic polyurethane elastomer of the present invention is greatly While improving hydrolysis resistance, it still maintains other aspects of its original properties.

Compared with thermoplastic polyurethane elastomers containing commercial carbodiimide hydrolysis-resistant auxiliaries such as Stabaxol I, the thermoplastic polyurethane elastomers of the present invention not only satisfy the requirements for hydrolysis resistance of low-end products on the market. Need: Such as general labor insurance shoes, air cushion, pneumatic tube and other fields; and because the hydrolysis-resistant additives in the invention are low in price (comparable to the price of pure MDI), there is no need to change the original production process, and no additional auxiliary equipment is needed. In this way, at least tens of thousands of yuan can be saved per ton of the product of the invention, the cost of the thermoplastic polyurethane elastomer of the invention is greatly reduced, and the product competitiveness is remarkably improved. detailed description

The invention is further illustrated by the following examples and test examples which are not intended to limit the invention. Example 1 Polyester Thermoplastic Polyurethane Elastomer

0. 785 kg of liquefied MDI was added to 7. 065 kg of pure MDI and then mixed with 68.25 kg of polyester diol (molecular weight 2000), 23. 90 kg of chain extender (1, 4 - Butanediol), an appropriate amount of stannous octoate is added to the twin-screw reaction extruder for reaction, directly granulated underwater, and dried and matured to obtain TPU particles. Example 2 Polyether Thermoplastic Polyurethane Elastomer

1. 98 kg of liquefied MDI was added to 31.06 kg of pure MDI and then mixed with 60.29 kg of polyether diol (PTMEG, molecular weight 1000), 6. 63 kg of chain extender (1 , 4-butanediol), and an appropriate amount of stannous octoate (T-9) are added to the twin-screw reaction extruder for reaction, directly granulated underwater, and dried and matured to obtain TPU particles. Test Example 1 Comparative test of hydrolysis resistance test of polyester thermoplastic polyurethane elastomer

1. Test sample:

A: a sample to which a hydrolysis resistant agent is added: prepared according to Example 1 of the present invention;

B: Sample without hydrolyzing agent: The same amount of liquefied MDI was replaced with pure MDI, except that it did not contain liquefied MDI, and the rest were identical to Example 1 of the present invention.

2. Test method:

The TPU particles were injection molded into a sample having a thickness of about 2 Å, and the hardness of the sample was measured to be 80 A Shore. The sample is cut into a bell-type standard test strip, and then sample A and comparative sample B are simultaneously placed in a 70 ± 2 ° C water tank for hydrolysis resistance test, every one week according to ASTM D412 (American Society for Testing and Materials The physical property test was carried out, and the results are shown in Table 1. Table 1 Polyester TPU hydrolysis stability test

3. Conclusion:

It can be seen from the above table that for the sample A to which the hydrolysis resistant agent is added, the tensile strength is maintained at 26% after six weeks, and the tensile strength is maintained only 16% after five weeks for the sample B without the hydrolysis-resistant agent. At the end of the week, the physical property was completely lost. For sample A with hydrolysis resistance, elongation at break was maintained at 18% of the original sample after six weeks, for sample B without hydrolysis resistance. After five weeks, it remained at around 7%, and after six weeks, it completely lost its physical properties. Test Example 2, Comparative test of hydrolysis resistance test of polyether thermoplastic polyurethane elastomer

1, test sample

C: a sample added with a hydrolysis resistant agent: prepared according to Example 2 of the present invention;

D: Sample without hydrolysis resistance: The same amount of liquefied MDI was replaced with pure MDI, except that it did not contain liquefied MDI, and the others were identical to Example 2 of the present invention.

2, try ^ r method

The TPU pellets were injection molded into a sample having a thickness of about 2 legs, and the hardness of the sample was measured to be 80 A Shore. The sample was cut into a dumbbell-type standard test strip, and then sample C and comparative sample D were simultaneously placed in a water tank at 70 ± 2 ° C for hydrolytic stability experiments, every other week according to ASTM D412 (American Society for Testing and Materials) Standard) Physical property test, the results are shown in Table 2. Table 2 Hydrolysis stability test of polyether TPU

3. Conclusion

It can be seen from the above table that for the product C with the hydrolysis resistant agent (modified MDI), the hydrolysis resistance test was maintained for more than 90% after six weeks, and the experiment was stopped because the test sample was used up. For the sample D without the hydrolysis-resistant agent, the tensile strength of the sample decreased by 83% after five weeks; the elongation at break of the sample C after five weeks became the original 1.34 times, and the D sample was the same. The time became the original 1. 06 times.

Claims

Rights request

A thermoplastic polyurethane elastomer comprising a hydrolysis-resistant auxiliary agent and a thermoplastic polyurethane elastomer body, wherein the hydrolysis-resistant auxiliary agent is a carbodiimide-modified organic diisocyanate. '

The thermoplastic polyurethane elastomer according to claim 1, wherein the hydrolysis-resistant auxiliary agent is a carbodiimide-modified liquefied organic diisocyanate, preferably a carbodiimide-modified liquefied diphenyl group. Methane diisocyanate.

The thermoplastic polyurethane elastomer according to claim 2, wherein the hydrolysis-resistant auxiliary agent is used in an amount of from 0.05 to 50% by weight based on the total of the organic diisocyanate in the thermoplastic polyurethane elastomer.

The thermoplastic polyurethane elastomer according to claim 3, wherein the hydrolysis-resistant auxiliary agent is used in an amount of from 1 to 15% by weight based on the total of the organic diisocyanate in the thermoplastic polyurethane elastomer.

The thermoplastic polyurethane elastomer according to claim 4, wherein the thermoplastic polyurethane elastomer is a polyester type or a polyether type. '

The thermoplastic polyurethane elastomer according to any one of claims 1 to 5, wherein the thermoplastic polyurethane elastomer is mainly composed of a linear macrodiol, an organic diisocyanate, a chain extender, and a hydrolysis preventing agent. Prepared by the action of a catalyst, wherein

The linear macrodiol is selected from the group consisting of polyester diols having a molecular weight of 500 to 10,000, polyether diols, or a combination thereof;

The organic diisocyanate is selected from the group consisting of aromatic organic diisocyanates or aliphatic/alicyclic organic diisocyanates or combinations thereof, wherein the aromatic organic diisocyanate is diphenylmethane diisocyanate, m-xylylene diisocyanate, sub One or more of phenyl-1,4-diisocyanate, naphthalene-1,5-diisocyanate, diphenylmethane-3,3,-dimethoxy-4,4,-diisocyanate and toluene diisocyanate Aliphatic/alicyclic organic diisocyanate is isophorone diisocyanate, 1, 4-cyclohexyl-diisocyanate, decane-1, 10-diisocyanate and dicyclohexylmethane-4,, 4-di One or more of the isocyanates;

The chain extender is selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1, 4-butanediol, 1,6-hexanediol, 1, 3-butanediol, 1, 5-pentanediol, 1, 4-cyclohexanedithiol hydroquinone One or more of -hydroxyethyl ether and neopentyl glycol;

The catalyst is selected from the group consisting of organic or inorganic acid salts of cerium, tin, iron, cerium, cobalt, cerium, aluminum, zinc, nickel, cerium, molybdenum, vanadium, copper, manganese and zirconium or an organometallic derivative thereof;

Phosphine; and

One or more of organic tertiary amines;

Wherein, the organic acid salt of tin or an organic metal derivative thereof is organotin, and the organic germanium is selected from one or more of stannous octoate, dibutyltin dioctoate and dibutyltin dilaurate; the organic tertiary amine is triethyl Amine, triethylenediamine, N, N, W, N'-tetramethylethylenediamine, N, N, Ν', N, -tetraethylethylenediamine, N-methylmorpholine, N- Ethylmorpholine, N, N, N, N, -tetramethylguanidine, N, N, N', N'-tetramethyl-1, 3-butanediamine, N, N-dimethylethanolamine and One or more of N, N-diethylethanolamine.

The thermoplastic polyurethane elastomer according to claim 6, wherein the linear macrodiol is selected from a polyester diol having a molecular weight of 700 to 4000 or a polyether having a molecular weight of 700 to 3000. An alcohol or a combination thereof, wherein the polyester diol is a polyadipate type polyester diol; the polyether diol is a polytetrahydrofuran ether diol;

The organic diisocyanate is selected from the group consisting of diphenylmethane diisocyanate, m-phenyldisionylene diisocyanate, phenylene-1,4-diisocyanate, naphthalene-1,5-diisocyanate, diphenylmethane-3,3, One or more of dimethoxy- 4,4,-diisocyanate and toluene diisocyanate;

The catalyst is selected from the group consisting of organic, tertiary organic amines or combinations thereof, wherein the organotin is one or more of stannous octoate, dibutyltin dioctoate and dibutyltin dilaurate; the organic tertiary amine is triethylamine, triethylene glycol Diamine, N, N, N, N'-tetramethylethylenediamine, N, N, N', N'-tetraethylethylenediamine, N-methylmorpholine, N-ethyl? Porphyrin, N, N, N, N'-tetramethylguanidine, N, N, N', N, -tetramethyl-1, 3-butanediamine, N, N-dimethylethanolamine and N, N One or more of diethylethanolamine;

The chain extender is selected from the group consisting of 1,4-butanediol.

The thermoplastic polyurethane elastomer according to claim 7, wherein the linear macrodiol is selected from the group consisting of polyester diols having a molecular weight of from 700 to 4000; wherein the polyester diol is selected from the group consisting of Polyadipate type polyester diol; The organic diisocyanate is selected from the group consisting of diphenylmethane diisocyanate;

The catalyst is selected from one or more of stannous octoate, dibutyltin dioctoate and dibutyltin dilaurate.

A method for preparing a thermoplastic polyurethane elastomer according to any one of claims 1 to 8, characterized in that the hydrolysis-resistant auxiliary agent and the raw material of the thermoplastic polyurethane elastomer body are mixed by a prepolymer method, a conveyor belt method or a double Prepared by screw reaction extrusion.

The preparation method according to claim 9, wherein the carbodiimide-modified organic diisocyanate is added to the organic diisocyanate and uniformly mixed, and then mixed with a macromolecular diol, a chain extender, and a catalyst. Prepared by prepolymer method, conveyor belt method or twin-screw reaction extrusion method.