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Microgel-containing compositionRelated Patent Categories: Synthetic Resins Or Natural Rubbers -- Part Of The Class 520 Series, Natural Rubber Compositions Having Nonreactive Materials (dnrm) Other Than: Carbon, Silicon Dioxide, Glass Titanium Dioxide, Water, Hydrocarbon, Halohydrocarbon, Ethylenically Unsaturated Reactant Admixed With A Preformed Reaction Product Derived From: (a) At Least One Polycarboxylic Acid, Ester, Or Anhydride; (b) At Least One Polyhydroxy Compound; And (c) At Least One Fatty Acid Glycerol Ester, Or A Fatty Acid Or Salt Derived From A Naturally Occurring Glyceride, Tall Oil, Or A Tall Oil Fatty Acid, At Least One Solid Polymer Derived From Ethylenic Reactants Only, Polymer Mixture Of Two Or More Solid Polymers Derived From Ethylenically Unsaturated Reactants Only; Or Mixtures Of Said Polymer Mixture With A Chemical Treating Agent; Or Products Or Processes Of Preparing Any Of The Above MixturesMicrogel-containing composition description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20080108755, Microgel-containing composition. Brief Patent Description - Full Patent Description - Patent Application Claims
[0001] This application is a continuation of U.S. patent application Ser. No. 10/947,874, filed Sep. 23, 2004, incorporated herein by reference. DESCRIPTION [0002] The present invention relates to a composition containing thermoplastic materials and crosslinked microgels that have not been crosslinked by high-energy radiation, to a process for its preparation, to its use in the production of thermoplastically processable molded articles, and to molded articles produced from the composition. BACKGROUND OF THE INVENTION [0003] The use of microgels for controlling the properties of elastomers is known (e.g. EP-A-405216, DE-A 4220563, GB-PS1078400, DE 19701487, DE 19701489, DE 19701488, DE 19834804, DE 19834803, DE 19834802, DE 19929347, DE 19939865, DE 19942620, DE 19942614, DE 10021070, DE 10038488, DE 10039749, DE 10052287, DE 10056311 and DE 10061174). EP-A-405216, DE-A-4220563 and GB-PS-1078400 disclose the use of CR, BR and NBR microgels in mixtures with double-bond-containing rubbers. DE 19701489 describes the use of subsequently modified microgels in mixtures with double-bond-containing rubbers such as NR, SBR and BR. [0004] None of these specifications teaches the use of microgels in the production of thermoplastic elastomers. [0005] Chinese Journal of Polymer Science, Volume 20, No. 2, (2002), 93-98 describes microgels that have been completely crosslinked by high-energy radiation and their use to increase the impact strength of plastics. Similarly, US 20030088036 A1 discloses reinforced heat-curing resin compositions in whose preparation radiation-crosslinked microgel particles are likewise mixed with heat-curing pre-polymers (see also EP 1262510 A1). In these publications, a radioactive cobalt source is mentioned as the preferred radiation source for the preparation of the microgel particles. The use of radiation crosslinking yields very homogeneously crosslinked microgel particles. However, this type of crosslinking has the particular disadvantage that it is not realistic to transfer this process from a laboratory scale to a large-scale installation both from an economic viewpoint and from the point of view of working safety. Microgels that have not been crosslinked by high-energy radiation are not used in the mentioned publications. Furthermore, when completely radiation-crosslinked microgels are used, the change in modulus from the matrix phase to the dispersed phase is immediate. In the case of sudden stress, this can lead to tearing effects between the matrix and the dispersed phase, with the result that the mechanical properties, the swelling behavior and the stress corrosion cracking, etc. are impaired. [0006] DE 3920332 discloses rubber-reinforced resin compositions which comprise (i) a matrix resin having a glass transition temperature of at least 0.degree. C. and (ii) from 1 to 60 wt. % of rubber particles dispersed in the matrix resin. The dispersed particles are characterized in that they consist of hydrogenated block copolymers of a conjugated diene and a vinyl aromatic compound. The particles inevitably have two glass transition temperatures, one being at -30.degree. C. or less. The particles exhibit a microphase structure of separate microphases with hard segments and soft segments, in which the hard segments and the soft segments are alternately laminated with one another in the form of concentric multiple layers. The preparation of these specific particles is very expensive because it is first necessary to prepare a solution of the starting materials for the particles (block copolymers) in organic solvents. In the second step, water and optionally emulsifiers are added, the organic phase is dispersed in suitable apparatuses, the solvent is then removed and the particles dispersed in water are then fixed by crosslinking with a peroxide. In addition, it is very difficult to produce particle sizes less than 0.25 .mu.m by this process, which is disadvantageous for the flow behavior. [0007] Polymeric materials can be divided into several groups according to their structure, their deformation-mechanical behavior and hence according to their properties and fields of use. Traditionally there are on the one hand the amorphous or semi-crystalline thermoplastics, which consist of long, uncrosslinked polymer chains. Thermoplastics are brittle to viscoelastic at room temperature. These materials are plasticized by pressure and temperature and can then be molded. On the other hand there are the elastomers or rubber materials. Elastomers are a crosslinked rubber product. It may be natural or synthetic rubber. Rubbers can only be processed in the uncrosslinked state. They then exhibit viscoplastic behavior. Only with the addition of crosslinking chemicals such as, for example, sulfur or peroxide is there obtained upon subsequent heating a vulcanization product or the elastic rubber. In this "vulcanization procedure", the loosely fixed individual rubber molecules are linked together chemically by the formation of chemical bonds. The amorphous preliminary product rubber changes hereby into the elastomer with typical rubber elasticity. The vulcanization procedure is not reversible, except by thermal or mechanical decomposition. [0008] The thermoplastic elastomers (abbreviated to TPE herein below) exhibit completely different behavior. These materials become plastic when heated and elastic again when cooled. In contrast to chemical crosslinking, crosslinking in the case of elastomers is physical. Accordingly, the TPEs stand between the thermoplastics and the elastomers in terms of their structure and their behavior, and they combine the ready processability of the thermoplastics with the fundamental properties of rubber. Above Tg to the melting point or to the softening temperature, the TPEs behave like elastomers, but they are thermoplastically processable at higher temperatures. As a result of physical crosslinking, for example via (semi-)crystalline regions, a thermoreversible structure with elastic properties is formed on cooling. [0009] In contrast to the processing of rubber, the processing of TPE materials is based not on a cold/warm process but on a warm/cold process. If in the case of soft, highly elastic TPE materials in particular the pronounced intrinsically viscous melting or softening behavior is taken into account, then it is possible when processing TPEs to use the typical thermoplastic processes such as injection molding, extrusion, blow molding and deep drawing. The product properties depend primarily on the structure and phase morphology; in elastomer alloys a large part is played, for example, by the particle size, the particle size distribution or the particle stretching of the disperse phase. These structural features can be influenced to a certain extent during processing. A further fundamental advantage of TPE materials over the conventional, chemically crosslinked elastomers can be seen in their fundamental suitability for recycling. As with all plastics, a fall in viscosity that increases with the number of processing steps is to be observed in the case of the TPE materials, but this does not lead to a significant impairment of the product properties. [0010] Since the discovery of the TPEs, this class of materials has been distinguished by the fact that it is formed by a combination of a hard phase and a soft phase. The TPEs known hitherto are divided into two main groups: [0011] block copolymerization products and [0012] alloys of thermoplastics with elastomers. Block Copolymerization Products: [0013] The composition of the comonomers determines the ratio of hard phase to soft phase, determines which phase constitutes the matrix and determines the final properties. A true morphology is recognizable at molecular level when, for example, the deficient component aggregates or crystallizes. The temperature dependence of this physical morphology fixing is a problem with these materials, that is to say there is a limit temperature at which the morphology fixing is undone. This can cause problems during processing owing to changes in the properties associated therewith. [0014] The block polymers include, for example, styrene block copolymers (TPE-S), such as butadiene (SBS), isoprene (SIS) and ethylene/butylene (SEBS) types, polyether-polyamide block copolymers (TPE-A), thermoplastic copolyesters, polyether esters (TPE-E) and thermoplastic polyurethanes (TPE-U), which are described in greater detail herein below in connection with the starting materials that can be used according to the present invention. [0015] The second main group of the material TPE are the elastomer alloys. Elastomer alloys are polymer blends which contain both thermoplastic and elastomeric constituents. They are prepared by "blending" the raw materials, that is to say mixing them intensively in a mixing device (internal mixer, extruder or the like). Very different mixing ratios between the hard phase and the soft phase can occur. The soft phase can be either uncrosslinked (TPE-0) or crosslinked (TPE-V). In the ideal TPE blend there are small elastomer particles which are uniformly distributed in finely dispersed form in the thermoplastic matrix. The finer the distribution and the higher the degree of crosslinking of the elastomer particles, the more pronounced the elastic properties of the resulting TPE. These TPE blends are prepared, for example, by so-called "dynamic vulcanization" or reactive extrusion, in which the rubber particles are crosslinked in situ during the mixing and dispersing process. The property profile of these blends is accordingly substantially dependent on the proportion, degree of crosslinking and dispersion of the rubber particles. Very different combinations can be produced by this blend technology. The physico-mechanical properties and the chemical resistance and compatibility with contact media are substantially determined by the individual properties of the blend components. By optimizing the "blend quality" and the degree of crosslinking it is possible to improve specific physical properties. Nevertheless, it is a characteristic of this class that the dispersed phase is present in irregular and coarsely dispersed form. The less compatible the polymers, the more coarse the resulting structure. The non-compatible combinations, such as, for example, a dispersed phase of NBR rubber in a PP matrix, are of particular technical interest. In order to improve the compatibility in such cases and accordingly influence the final properties of the resulting material in the desired manner, a homogenizing agent can be added prior to the dynamic vulcanization. About 1% of the homogenizing agent is sufficient for many applications. The homogenizing agents are generally based on block copolymers whose blocks are compatible with in each case one of the blend phases. Depending on the relative proportions, the two phases may constitute both the continuous and the discontinuous phase. Hitherto it has not been possible to adjust the morphology of this material in a reliable manner. In order to produce particularly finely divided dispersed phases, large amounts of the homogenizing agent may be necessary, which in turn adversely affects the boundary properties of the final material. Industrially produced and commercially available thermoplastic vulcanization products exhibit a maximum distribution of the diameter of the dispersed phase of from 2 am to 4 .mu.m with individual volume elements up to 30 .mu.m. [0016] Among the elastomer alloys, the most commonly used combinations are based on EPDM with PP. Other elastomer alloys are based on NR/PP blends (thermoplastic natural rubber), NBR/PP blends (NBR=acrylonitrile-butadiene rubber), IIR(XIIR)/PP blends (butyl or halobutyl rubbers as elastomeric phase constituents), EVA/PVDC blends ("Alcryn" blend of ethylene-vinyl acetate rubber (EVA) and polyvinylidene chloride (PVDC) as the thermoplastic phase) and NBR/PVC blends. A targeted adjustment of the morphology of the dispersed phase and hence a targeted adjustment of the desired properties of the TPEs in these polymer blend TPEs is virtually impossible, however, owing to the in situ formation of the dispersed phase and the many parameters involved therein. [0017] The present inventors relates to novel compositions having thermoplastic elastomer properties which can easily be prepared from starting materials known per se and whose properties can be adjusted in a simple and foreseeable manner. The novel compositions can be prepared on an industrial scale, and they should not give rise to problems relating to working safety. Furthermore, there should be no tearing effects in the compositions between the matrix and the dispersed phase on sudden stress so that the mechanical properties, the swelling behavior and the stress corrosion cracking, etc. are impaired. The preparation of the microgels for the composition should be simple and allow the particle size distributions of the microgel particles to be adjusted in a targeted manner to very small average particle sizes. SUMMARY OF THE INVENTION [0018] Surprisingly it has been found in the present invention that, by incorporating crosslinked microgels, which have not been crosslinked by high-energy radiation, based on homopolymers or random copolymers into thermoplastic materials, it is possible to provide compositions having a novel combination of properties. By the provision of the novel composition it is surprisingly possible to overcome the above-mentioned disadvantages of the known conventional thermoplastics and TPEs and at the same time provide thermoplastic elastomer compositions having outstanding use properties. Because thermoplastic elastomer compositions are obtained by the incorporation of microgels into the thermoplastic materials, it is possible to separate the adjustment of the morphology of the dispersed phase from the production of the TPE material in terms of both space and time. The morphology production can be reliably reproduced because the dispersed phase is a microgel whose morphology can be controlled in a manner known per se during preparation and which substantially does not change further on incorporation into the thermoplastic material. In the compositions prepared according to the invention, the polymer microstructure of both the dispersed phase and the continuous phase can be varied within wide limits, so that customized TPEs can be produced from any desired thermoplastic materials, which was not possible according to the known processes for the production of conventional TPEs. By controlling the degree of crosslinking and the degree of fictionalization in the surface and in the core of the dispersed microgels, the desired properties of the resulting TPEs can be controlled further. The glass transition temperature of the dispersed microgel phase can also be adjusted in a targeted manner within the range of from -100.degree. C. to less than 50.degree. C., as a result of which the properties of the resulting TPEs can in turn be adjusted in a targeted manner. As a result, the difference in glass transition temperature between the dispersed phase and the continuous phase can also be adjusted in a targeted manner and can be, for example, from 0.degree. C. to 250.degree. C. With the novel class of TPEs provided by the present invention it is additionally possible to combine thermodynamically compatible and thermodynamically incompatible polymers to form new TPEs which were not obtainable by conventional processes. In the novel TPEs provided by the present invention, the dispersed phase and the continuous phase may each constitute the hard phase and the soft phase. By controlling the properties of the microgels and the relative proportions, the dispersed phase can be present in the matrix in the form of aggregated clusters or in uniformly distributed form and in all intermediate forms. [0019] This is not possible in the TPEs prepared by conventional processes, in which the dispersed phase is formed in situ during the production of the TPEs. [0020] Furthermore, it has been surprisingly found not only that the incorporation of microgels into thermoplastic plastics permits the production of thermoplastic elastomers, but also that the incorporation of microgels into, for example, thermoplastic elastomers produced by conventional processes allows a targeted improvement in their properties, such as, for example, dimensional stability and transparency. Continue reading about Microgel-containing composition... Full patent description for Microgel-containing composition Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Microgel-containing composition patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. 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