KR20010030855A - Reactive extrusion of tailored liquid polymers(TLPS) - Google Patents

Abstract

The present invention relates to a process for producing polyurethane polymers by extruding free flowing liquid polyurethane (TLP). TLPs are prepared from polyisocyanates and polyols at low temperatures. Elastomeric polyurethane polymers can be obtained from TLP by reactive extrusion methods. The elastomeric polyurethane polymer thus obtained can be reprocessed (melt processing) many times as a melt and the polymer can be molded into various useful forms.

Description

Reactive extrusion of tailored liquid polymers (TLPS)

The present invention relates to a polyurethane polymer. In particular, the present invention relates to polyurethane polymers and methods for their preparation.

It is known to prepare polyurethanes from polyols, polyisocyanates and other adducts by combining an isocyanate "A side" mixture with a polyol "B side" mixture. Isocyanates and polyols are typically combined to make polyurethanes using methods known in the art to make polyurethane polymers as "A / B" polyurethane chemistry. Polyurethane polymers are useful as plastic foams, rigid foams, elastomers, coating resins, adhesives, sealants, fibers and films.

Conventional preparation of polyurethane polymer materials using typical “A / B” chemistries requires manufacturers of polyurethane polymer products to make polymers on site. This may present problems for certain manufacturers of polyurethane products.

Extrusion methods of thermoplastic polymers such as polystyrene and acrylate polymers such as poly (methyl methacrylate) are well known methods. Reference: James M. McKelvey, Plastics Processing, John Wiley & Sons, New York, 1962; A.S. Haisser, "Extrusion", in Modern Plastics Encyclopedia 1982-1983, Vol. 59, No. 10A, McGraw-Hill, New York, 1982; Paul N. Richardson, Introduction to Extrusion, John Wiley & Sons, New York, 1974 (each of which relates to the teaching of extrusion methods). The extrusion method is thus a production method in which the polymeric material is molded or re-molded into useful and inexpensive polymeric materials. Typically, in the extrusion process, the polymer is melted and compressed in a region of high pressure and high temperature while being continuously pushed along the screw. Finally, the polymer is forced through a die that imparts the final form to the polymer. For example, the polymer having a form including tubing, hoses, sheets and films can be produced by the extrusion method.

It may be desirable in the art to make polyurethane polymers to make such polymers from materials with low viscosity and low chain extension. It may also be desirable in the art to prepare polyurethane polymers to obtain foams, films, gels, adhesives and hard elastomers directly from the extruder by the extrusion method.

In one aspect, the present invention provides a process for preparing a melt processable elastomer comprising a urethane bond from an isocyanate-terminated prepolymer, wherein the polymer comprises: (a) feeding a liquid prepolymer to an extruder device; (b) passing the prepolymer of step (a) through an extruder while heating, and (c) extruding the elastomer.

In another aspect, the present invention is a polyurethane polymer obtained by preparing a melt processable elastomer comprising a urethane bond from an isocyanate-terminated prepolymer, wherein the polymer is (a) feeding a liquid prepolymer to the extruder device. And (b) passing the prepolymer of step (a) through an extruder while heating, and (c) extruding the elastomer.

The polyurethane polymers described herein can be prepared from Tailored Liquid Polymer (TLP) prepolymers in the absence or presence of a polyurethane catalyst. TLPs can be crosslinked in a reactive extrusion process, where the TLPs are fed to the extruder and processed as liquid, and crosslinked to form a polymer while being forced through the screw hollow. The polymers of the present invention are melt processable because they are polymers that can be processed above T _g of polymeric material. For the purposes of the present application, the melt processable polymer of the invention can be formed from the reactants in the substantial absence of solvent at temperatures above T _g of the product obtained, and the polymer product can subsequently be processed as a melt. The melt processable polymer may be heated above the T _g of the polymer and physically modified as a molded, melted or otherwise polymer melt.

The term "polyurethane" as used herein is not limited to polymers comprising only urethanes or polyurethane bonds. Those skilled in the art of making polyurethanes also find that the polyurethane polymers are also in addition to urethane bonds, with allophanates, biurets, carbodiimides, oxazolinyls, isocyanurates, uretidinediones and ureas; Familiarize yourself with the combination.

In one embodiment, the melt processable polymer of the invention can be obtained by reactive extrusion of TLP. The reactive extrusion method is similar to the conventional extrusion method, except that the material fed to the extruder is chemically reacted and materially modified inside the extruder. In a conventional extrusion process, no chemical reaction is carried out in the extruder. Typically, the preformed polymeric material is physically modified by softening the polymer and reforming it into specific forms.

TLPs are free flowing liquid oligomeric polyurethane materials prepared by the reaction of polyisocyanates with polyols. The reaction between the polyisocyanate and the polyol is carried out in the absence of a catalyst at low temperatures. The viscosity of the TLP thus obtained is low and there is little chain extension. The preparation of TLP is known and described in International Patent Publication No. W09634904-A1. By low temperature it is meant that the TLP material can be prepared at a temperature of about 150 ° C. or less. Preferably, the TLP is prepared at a temperature of 20 to 125 ° C. More preferably, the TLP is prepared at a temperature of 25 to 115 ° C, most preferably at a temperature of 25 to 100 ° C.

As long as the TLP is a free flowing liquid prepolymer material, the TLPs of the present invention may have any molecular weight. Suitable TLPs for use in the practice of the present invention may be a single TLP prepolymer or a mixture of two or more prepolymers. Whether single components or mixtures, the TLPs of the invention optionally have a functionality in the range of 2-6. In a preferred embodiment, one of the prepolymers in the prepolymer mixture can have a functionality of about 2 while having a molecular weight of about 10,000 or less and another prepolymer can have multiple functionality with a molecular weight of about 12,000 or less. More preferred are prepolymer mixtures having a functionality of at least one prepolymer of about 2, a molecular weight of 2000 to 10,000, a functionality of a second prepolymer of the mixture of about 6 and a molecular weight of 3,000 to 12,000. In the practice of the present invention, it is preferred to have a functionality and molecular weight to the extent that the TLP is a free flowing liquid at about 50 ° C. or less, and more preferably the TLP has a molecular weight and functionality to a degree which is a free flow liquid at about 20 ° C. or less. The prepolymer components used in the mixtures herein can be formulated in ratios that can provide an average prepolymer functionality suitable for the practice of the present invention. Prepolymers having a low monomer content are preferred for the practice of the present invention. It may be desirable for the practice of the present invention that the monomer content is at most 20%, preferably at most 15%, more preferably at most 10%.

By feeding the TLP to the extruder and processing the TLP at a screw speed of 10 to 200 rmp, the TLP can be extruded reactively and an elastomeric polyurethane polymer can be obtained. TLP can be processed in an extruder at a temperature of 25-250 ° C. Preferably, the TLP is passed through the extruder at a screw speed of 50 to 200 rpm at a temperature of 50 to 160 ° C. More preferably, the TLP is passed through the extruder at a screw speed of 100 to 150 rpm at a temperature of 60 to 140 ° C.

Suitable polyisocyanates for use in the practice of the present invention may be polyisocyanates known to be useful in the preparation of polyurethane foams. Suitable polyisocyanates can be aliphatic or aromatic. Aromatic polyisocyanates suitable for use herein include phenyl diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, ditoluene diisocyanate, naphthalene 1,5-diisocyanate, 2,4'- and / Or 4,4'-diphenylmethane diisocyanate (MDI), polymethylene polyphenylenepolyisocyanate (polymeric MDI), analogous compounds and mixtures thereof. Suitable aliphatic polyisocyanates include hydrogenated derivatives of suitable aromatic polyisocyanates such as 1,6-hexamethylene diisocyanate, isophorone diisocyanate, 1,4-cyclohexyl diisocyanate, analogous compounds and mixtures thereof. In addition, as known in the art, prepolymers prepared from the polyisocyanates and polyols described herein are suitable for use in the practice of the present invention. Preferred for the practice of the present invention is TDI.

TLPs can be prepared by the reaction of polyisocyanates with polyols, for example low molecular weight diols, triols, and also using polyhydric active hydrogen compounds, for example di- and tri-amines with di- and tri-thiols. It may be prepared by. Separate examples contain urethane groups, preferably 0 to 40% by weight, more preferably 1 to 35% by weight, with diisocyanates and / or polyisocyanates, for example low molecular weight diols, tri Aromatic polyisocyanates obtained by reaction with all, oxyalkylene glycols, dioxyalkylene glycols or polyoxyalkylene glycols.

The "B" cotton composition of the present invention may comprise, in addition to any other optional ingredient, an active hydrogen containing compound capable of reacting with isocyanate functional groups. As the term is used herein, an active hydrogen containing compound is a compound having a functional group that is reactive with a Zerewitinoff reagent. In general, active hydrogen containing compounds include, for example, alcohols, amines and mercaptans. Polyols are active hydrogen containing compounds suitable for use in the practice of the present invention. Representative examples of polyols suitable for use with the methods of the present invention are generally known and described in the publications [High Polymers, Vol. XVI, "Polyurethanes, Chemistry and Technology" by Saunders and Frisch, Interscience Publishers, New York, Vol. I, pp. 32-42, 44-54 (1962) and Vol. II, pp. 5-6, 198-199 (1964); Organic Polymer Chemistry by KJ Saunders, Chapman and Hall, London, pp. 323-325 (1973), and Developments in Polyurethanes, Vol. I, JM Buist, ed., Applied Science Publishers, pp. 1-76 (1978)] It is described in Examples of such materials include the following classes of compositions; (a) alkylene oxide adducts of polyhydroxyalkanes, (b) alkylene oxide adducts of non-reducing sugars and sugar derivatives, (c) alkylene oxide adducts of polyphenols, and (d) polyester polyols. Ones alone or in mixtures. Also preferred are those blocked with poly (oxypropylene) glycol, triol, tetrol and hexol, and ethylene oxide. These polyols also include poly (oxypropyleneoxyethylene) polyols.

The catalyst is optional in the practice of the present invention but is preferably included. Catalysts suitable for use in the practice of the present invention include trimerization catalysts known to those skilled in the art of making polyurethane polymers. The trimerization catalyst may be included in the composition at 0.01 to 1.0 wt% (wt%), preferably 0.25 to 1.0 wt%, more preferably 0.25 to 0.75 wt%, most preferably 0.25 to 0.5 wt% of the mixture. .

The present invention includes chain extenders. Chain extenders useful in the practice of the present invention are preferably liquid at room temperature and may have a molecular weight of about 8,000 or less. Preferably, the molecular weight of the chain extender is between 50 and 8,000. Most preferably, the molecular weight of the chain extender is between 50 and 600. Chain extenders useful in the practice of the present invention have hydroxyl functionality. More preferably, the chain extenders useful herein are diols. Diol chain extenders useful herein are most preferably primary hydroxyl functional groups. Preferred chain extenders include, but are not limited to, ethylene glycol, diethylene glycol, diols derived from polyethylene oxide having a molecular weight of 200, 400 or 600, ethylene oxide-blocked polypropylene oxide diols having a molecular weight of 400 to 4000 Do not. The chain extender of the present invention should be included to such an extent that the isocyanate / hydroxyl ratio is in the range of 1.00 to 100, preferably in the range of 1.00 to 10.0, more preferably in the range of 1.50 to 2.00.

TLP can be mixed with another component. For example, the TLP can be mixed and extruded with another polymer to provide a copolymer product. TLPs can be mixed with polyacrylates, polystyrenes, polyacrylonitriles, for example. In addition, TLPs can be mixed with standard polyurethane prepolymers, MDIs or another polyol.

The present invention may include another optional ingredient. For example, the present invention optionally includes a filler material. Conventional fillers such as ground glass, calcium carbonate, ATH, talc, bentonite clay, antimony trioxide, kaolin, fly ash or other known fillers can be used in the practice of the present invention. The polyurethane forming compositions of the present invention may optionally include surfactants, flame retardants, pigments, antistatic agents, reinforcing fibers, antioxidants, preservatives, water trapping agents, acid trapping agents.

In another aspect, the present invention is a method for obtaining a melt processable polymer by a reactive extrusion method in a first step, a second step or a subsequent step, the polymer which can be used in various applications by melt processing of the polymer thus obtained. To form. The polymer obtained in the first step can be repeatedly reworked without adversely affecting the polymer obtained in the first step as in the second step. In the second or subsequent reprocessing step of the invention, the polymer can be passed through the extruder at a temperature of 100 to 280 ° C. and a screw speed of 5 to 50 rpm. Preferably, the screw speed is 10 to 50 rpm and the temperature of the extruder is 150 to 280 ° C. Most preferably, the extruder screw speed is 20 to 40 rpm and the temperature of the extruder heating zone is in the range of 180 to 270 ° C.

The polyurethane elastomers obtained in the practice of the present invention may be useful in a variety of products, including foams, films, gels, adhesives, nonwovens and rigid elastomers. The elastomers obtained according to the practice of the present invention can demonstrate 50-1000% elongation.

The following examples are merely illustrative of the invention. It is not intended to represent the full scope of the invention claimed herein, nor is it intended to be.

Example 1

TLP is prepared by combining 2000 equivalents of a polyol made from sorbitol, a 60:40 mixture of ethylene oxide and propylene oxide and toluene diisocyanate. TLP is fed to the extruder and extruded at a rate of 35 rpm at zone temperature settings of 150, 165, 245 and 245 ° C. to obtain a polymeric material.

Example 2

The mixture prepared by combining 100 parts of TLP of Example 1 and 25 parts of HEMA modified TLP was fed to an extruder and extruded at a speed of 35 rpm at zone temperature settings of 150, 165, 195 and 225 ° C. to obtain a polymeric material.

Example 3

The TLP of Example 1 was fed to an extruder and extruded using an extruder at a rate of 35 rpm at heating zone temperatures of 150, 165, 225 and 225 ° C. to give a viscous gelling polymer.

Example 4

The TLP of Example 1 is fed to an extruder and extruded into a vessel of stirred water using an extruder at a rate of 35 rpm at heating zone temperatures of 150, 165, 225 and 225 ° C. The extruded material forms a foamed soft polymer separated from water.

Example 5

A mixture of conventional 2 and usually 6 functional TLP prepolymers having a weight average functionality of 2 to 3, incorporating 0.5 wt% of trimerization catalyst, was fed to the extruder and zone temperatures of 80, 110, 80 and 70 ° C. respectively. At a screw speed of 150 rpm to yield an elastomeric material.

Example 6

A mixture of usually two and three functional TLP prepolymers having a weight average functionality of 2 to 3, incorporating 0.75% by weight of trimerization catalyst, was fed to the extruder and zone temperatures of 80, 110, 80 and 70 ° C. respectively. Extruded at a screw speed of 100 rpm in order to obtain an elastomeric material.

Example 7

A mixture of usually two and six functional TLP prepolymers having a weight average functionality of 2 to 3, incorporating 1.0% by weight of diethylene glycol and 0.5% by weight of trimerization catalyst, was fed to an extruder and 80, 110, Extruded at a screw speed of 150 rpm at zone temperatures of 80 and 70 ° C. to yield an elastomeric material.

Example 8

A mixture containing typically 2 functional TLP prepolymers, 1.0 wt% diethylene glycol and 0.5 wt% trimerization catalyst was fed to an extruder and extruded at a screw speed of 150 rpm at zone temperatures of 80, 110, 80 and 70 ° C., respectively. And an elastomeric material is obtained.

Example 9

A mixture of usually two and usually six functional TLP prepolymers having a weight average functionality of 2 to 3, incorporating 2.0 weight percent of trimerization catalyst, was fed to an extruder and fed at 90, 110, 110, 140 and 120 ° C., respectively. Extrusion at a screw speed of 20-40 rpm at zone temperature yields an elastomeric material.

Example 10

The polymer derived from Example 7 is fed into an extruder hopper in the form of granules / chips / pellets and extruded at a screw speed of 20-40 rpm at a zone temperature of 240, 260, 260, 250 ° C. to obtain an elastomeric material.

Example 11

The polymer derived from Example 8 is fed into an extruder hopper in the form of granules / chips / pellets and extruded at a screw speed of 20 to 40 rpm at a zone temperature of 240, 240, 240, 200 ° C. to obtain an elastomeric material.

Example 12

The polymer derived from Example 9 is fed into an extruder hopper in the form of granules / chips / pellets and extruded at a screw speed of 20 to 40 rpm at zone temperatures of 80, 110, 120, 140 and 120 ° C. to obtain an elastomeric material.

Claims (21)

From isocyanate-terminated prepolymers, (a) feeding the liquid prepolymer into the extruder apparatus, (b) passing the prepolymer of step (a) through an extruder while heating, and (c) a process for producing a melt processable elastomer obtained by a reactive extrusion method comprising extruding an elastomer and comprising a urethane bond. The method of claim 1 wherein the isocyanate index is at least 1.1. The method of claim 2, wherein the prepolymer is heated in the range of 25 to 250 ° C. 4. The method of claim 3 wherein the prepolymer is heated in the range of 50-160 ° C. 5. The method of claim 4 wherein the prepolymer is heated in the range of 60-140 ° C. 6. The process according to any one of claims 1 to 5, wherein the prepolymer is fed to the extruder at a screw speed of 10 to 200 rpm. 7. The process of claim 6 wherein the prepolymer is fed to the extruder at a screw speed of 50 to 200 rpm. 8. The process of claim 7, wherein the prepolymer is fed to the extruder at a screw speed of 100 to 150 rpm. The process according to claim 1, wherein the elastomer obtained is reextruded at or above the softening point of the polymer. 10. The method of claim 9, wherein the polymer is reextruded at a screw speed of 5 to 50 rpm at a temperature of 100 to 280 ° C. The method of claim 10, wherein the polymer is reextruded at a screw speed of 10 to 50 rpm at a temperature of 150 to 280 ° C. The method of claim 11, wherein the polymer is reextruded at a screw speed of 20 to 40 rpm at a temperature of 180 to 270 ° C. Elastomer obtained by the process according to claim 1. (a) a polyurethane prepolymer (A) having a functionality of 2 and a molecular weight of about 10,000 or less, (b) a second polyurethane prepolymer (B) having a functionality of at least 2 and a molecular weight of about 12,000 or less, (c) a chain extender having hydroxyl functionality and a molecular weight of about 8,000 or less and liquid at room temperature, and (d) A polyurethane polymer composition comprising a trimerization catalyst. 15. The monomer according to claim 14, wherein the monomer content of the prepolymer A is 20% or less, the molecular weight is 2,000 to 10,000, the monomer content of the prepolymer B is 20% or less, the molecular weight is 3,000 to 12,000, and the chain extender is the first hydroxyl functional group. And a diol having a molecular weight of 50 to 8,000. 16. The polymer composition of claim 15, wherein the prepolymer A comprises 90% by weight and the prepolymer B comprises 10% by weight. The polymer composition of claim 14, wherein the chain extender is included such that the ratio of isocyanate to hydroxyl functional groups is 1.00: 100. 18. The polymer composition of claim 17, wherein the chain extender is included such that the ratio of isocyanate to hydroxyl functional groups is 1.00: 10.0. 19. The polymer composition of claim 18, wherein the chain extender is included such that the ratio of isocyanate to hydroxyl functional groups is 1.50: 2.00. 20. The polymer composition of claim 14, wherein the functionality of prepolymer B is 2-6. 21. The polymer composition of claim 20, wherein the functionality of the prepolymer B is from 2 to 3.