Showing papers on "Thermoplastic polyurethane published in 2002"

Thermoplastic polyurethane-silicone elastomers

Abstract: Re-processable thermoplastic elastomer composition comprising (A) a thermoplastic polyurethane polymer, and (B) a silicone elastomer, wherein the weight ratio of the silicone elastomer to the thermoplastic polyurethane polymer is from 5:95 to 85:15, are disclosed along with methods for making such compositions.

Thermoplastic polyurethane–carbon black compounds: Structure, electrical conductivity and sensing of liquids

Abstract: Thermoplastic polyurethane (TPU) copolymers are interesting host matrices for the incorporation of conductive carbon black (CB) particles. The two-phase character of the TPU systems provides an opportunity for the CB particles to distribute nonuniformly within the phases, owing to their different characteristics. Thus, in spite of its highly polar nature, the TPU/CB system percolates at a relatively low CB content. The CB presence affects the TPU two-phase structure, resulting in a large change of its low temperature loss modulus. CB-containing extruded filaments produced by a capillary rheometer at various shear rates were studied as sensing materials for different alcohols. All filaments displayed an increase in resistance upon exposure to various alcohols. Filaments exposed to methanol exhibited the highest sensitivity. This behavior was related to the sorption kinetics by the TPU/CB compound, which is affected by the different characteristics of the solvents. The resistance of filaments exposed to ethanol or methanol tended to reversibility during the drying cycle, returning to the initial values. The relatively rapid recovery to the filaments' initial resistance values (for methanol and ethanol) suggests that the structural changes due to solvent sorption mainly occur in the outer skin regions of the extruded filaments, whereas the core region remains essentially intact.

Polyurethane adhesive for windshield applications

Abstract: A polyurethane adhesive which is useful in bonding porous and non-porous surfaces is provided. The adhesive is especially useful in bonding windshield glass into automotive frames under a variety of environmental conditions, particularly in after market windshield replacement applications. The polyurethane includes at least one urethane prepolymer which is based on at least one thermoplastic polyol. In one embodiment, the urethane prepolymer may be formed from one or more polyisocyanates, one or more polyetherpolyols and one or more thermoplastic polyesterpolyols, wherein the prepolymer has a free isocyanate content of from about 0.6 to about 3.5% by weight, based on the weight of the polyurethane. In another embodiment, a one-part adhesive composition is provided which includes an isocyanate-functional and thermoplastic polyurethane prepolymer having a free isocyanate content of from about 0.6 to about 3.5% by weight, based on the weight of the polyurethane, and a combination of several catalysts which are capable of catalyzing the reaction of isocyanate moieties with isocyanate-reactive moieties while providing less temperature dependent catalyzing of the reaction between isocyanate moieties and water. Also provided is a process for bonding two or more substrates together utilizing the polyurethane adhesive. In automotive windshield replacement applications, the polyurethane adhesive allows for a sufficient working time and development of green strength to provide a safe drive-away time within 1 hour at a temperature from about 0 to about 100° C.

Stabilizing composition I

Abstract: A stabilizer composition is described and comprises a 3-arylacrylate, a polymeric compound with molecular weight at least 2000, bearing, on a polymeric framework, side groups having amine functions, where all of the substituents in the α-position to the amine nitrogen atom are other than hydrogen, and comprises a sterically hindered phenol. The stabilizer composition is particularly suitable for stabilizing thermoplastic polyurethane with respect to light, oxygen, and heat.

Thermoplastic composite reinforced thermoform and blow-molded article

Abstract: The present invention provides a reinforced thermoform or blow-molded article, and the process for preparing the same, where the reinforcement is provided by a fiber-reinforced thermoplastic composite that contains a thermoplastic resin, such as a rigid thermoplastic polyurethane, and a plurality of continuous reinforcing fibers impregnated with the resin. The reinforced thermoform blow-molded article is useful in a variety of products such as boat hulls, table tops, automotive and non-automotive seat structures, small vehicle structures such as golf carts and golf cart roofs, pallets, containers, and skis.

Printable film and coating composition exhibiting stain resistance

Abstract: The present invention relates to articles having a printed surface as well as flexible coating and film compositions that are printable in combination with exhibiting stain resistance. The composition comprises a hard component having an elongation of less than about 150 %, a soft component having an elongation of greater than about 200 %, and a cross-linking agent. The hard component preferably comprises a thermoplastic polyurethane, acrylic polymer, polymeric polyol or mixture thereof. The soft component preferably comprises a thermoplastic urethane, polymeric polyol, or mixture thereof; whereas the cross-linking agent is preferably an isocyanate.

High molecular weight thermoplastic polyurethanes made from polyols having high secondary hydroxyl content

Abstract: Thermoplastic polyurethane compositions are prepared from polyols having high secondary hydroxyl content, diisocyanates, chain extenders and catalysts. The resulting polyurethanes have high molecular weight and can be prepared by a one-shot process wherein the reactants and any additional desired components are brought together and reacted simultaneously or substantially simultaneously.

Polyurethane based inks for writing instruments

Abstract: A non-erasable ink composition suitable for use in writing instruments is described comprising an isocyanate free thermoplastic polyurethane resin, a colorant and an organic solvent. The ink composition may also include a second resin, plasticizers, antioxidants, corrosion inhibitors, lubricants, chemical dispersants, and surfactants. The inks of the present invention exhibit a smooth writing performance and non-seepage.

Photovoltaic modules with a thermoplastic adhesive layer and method for fabricating the same

Abstract: Thermoplastic aliphatic polyurethane with a hardness of 75 Shore A to 70 Shore D, a softening point of 90-150 degrees C and a tensile modulus of 2 MPa is used as the embedding material for solar cells in the middle layer of a photovoltaic module. A photovoltaic module comprises: (A) an outer layer facing the energy source, consisting of glass or impact-resistant, UV-resistant, weathering-resistant, transparent plastic with low water vapor permeability; (B) a synthetic adhesive interlayer with one or more embedded, electrically interconnected solar cells; and (C) a backing layer of glass or weather-resistant plastic with low water vapor permeability. The adhesive in (B) consists of an aliphatic thermoplastic polyurethane with a hardness of 75 Shore A to 70 Shore D, a softening point of 90-150 degrees C and an E' modulus of 2 MPa (by the DMS method), which is the reaction product of: (a) an aliphatic di-isocyanate; (b) Zerewitinoff-reactive polyol(s) with 1.8-3.0 reactive hydrogen atoms on average and a number-average molecular weight (Mn) of 600-10000; and (c) chain-extender polyol(s) with 1.8-3.0 reactive H atoms and an Mn of 60-500, using a mol ratio of (NCO groups):(reactive H atoms) = 0.85-1.2, preferably 0.9-1.1. An Independent claim is also included for a method for the production of a photovoltaic module as described in a vacuum hot press laminator.

Hot melt moisture cure polyurethane adhesive with wide range of open time

Abstract: A hot melt moisture cure polyurethane adhesive composition includes at least one polyurethane prepolymer. The prepolymer includes the reaction product of a polyol component and a polyisocyanate component. The polyol component includes a) at least one amorphous polyester polyol comprising the reaction product of neopentyl glycol, hexanediol and at least one of phthalic anhydride and phthalic acid; b) at least one liquid polyester polyol having a viscosity of greater than about 10,000 cps at 80 °C; c) at least one crystalline polyester polyol having a melting point of from mPas 40 °C to 120 °C; and d) at least one thermoplastic polyurethane.

Copolycarbonate diol and thermoplastic polyurethane obtained therefrom

Abstract: A copolycarbonate diol which comprises (a) repeating units represented by the following formula (1), (1) (b) repreating units each independently represented by the following formula (2) (2) (wherein n is 4, 5, or 6), and (c) a terminal hydroxyl group and has a number-average molecular weight of 300 to 20,000, and in which the content of the repeating units (a) is 10 to 90 mol% based on the sum of the repeating units (a) and (b); and a thermoplastic polyurethane obtained by copolymerizing the copolycarbonate diol with a polyisocyanate.

Polyoxymethylene composite resin composition and articles prepared therefrom

Abstract: Disclosed is a polyoxymethylene composite resin composition, including 40-99 parts by weight of a polyoxymethylene resin, and 1-60 parts by weight of a thermoplastic polyurethane resin containing 0.05-1 part by weight of an active isocyanate, with selective addition of 0.01-5 parts by weight of a compound containing maleic anhydride, which is advantageous in terms of generation of no carbides upon preparation thereof, excellent strength and elongation in a weld line, and superior formability. An article prepared from the polyoxymethylene composite resin composition is also provided.

Characterization of thermoplastic polyurethane adhesives with different hard/soft segment ratios containing rosin as an internal tackifier

Abstract: Three thermoplastic polyurethanes (TPUs) containing different hard/soft (h/s) segment ratios (105-14) were prepared using the prepolymer method MDI (diphenylmethane-4,4′diisocyanate) and polyadipate of 1,4-butanediol (M w = 2440) were allowed to react to produce the prepolymer To provide the polyurethanes with high immediate adhesion to different substrates, a rosin + 1,4-butanediol mixture (1 : 1 equivalent%) was used as chain extender (TPU-Rs) These TPU-Rs had two types of hard segments: (i) Urethane hard segments, produced by reaction of the isocyanate and the 1,4-butanediol, and (ii) Urethan-amide hard segments, produced by reaction of the isocyanate and the carboxylic acid functionality of the rosin The TPUs and TPU-Rs were characterized using FTIR spectroscopy, gel permeation chromatography, differential scanning calorimetry, stress-controlled plate-plate rheology, stress-strain measurements, and Brookfield viscosity The TPUs and TPU-Rs were used as raw materials to prepare solvent-based poly

Composition for clear gas barrier laminates

Abstract: Scrap material having both a thermoplastic polyurethane and a copolymer of ethylene and vinyl alcohol is recycled by blending the scrap material into a thermoplastic polyurethane composition and preparing a barrier membrane from the blended material. The virgin thermoplastic polyurethane and the thermoplastic polyurethane of the scrap material are polymerized using at least about 60 percent by weight, based on the weight of the polyurethane produced, of a polyester diol having a weight average molecular weight of at least about 500 and having from four to five carbon atoms between substantially all of the ester [—O—C(═O)—] groups. The blend material containing the virgin thermoplastic urethane and the scrap material is formed into a layer of a barrier membrane. The resulting membrane has a haze of no more than about 12%.

Extrudable highly crystalline thermoplastic polyurethanes

Abstract: A thermoplastic polyurethane composition having a high crystalline content which advantageously can be processed in an extruder. The composition includes a crystallization retarding component of a short chain or monomeric diol which is branched, substituted or contains further heteroatoms, or a combination thereof. The crystallization retarding component delays the onset of crystallization during extrusion processing until the composition has exited the extruder.

Chemical modification of polyurethane for two-component injection molding

Abstract: A thermoplastic polyurethane (TPU) was modified by reactive processing with 4,4'-diphenylmethane diisocyanate (MDI). The use of this modified polyurethane was investigated for improved adhesion in composites with polyamide 6 (PA 6). Specimens were prepared by two-component injection molding. With the modified polyurethane the tensile bond strength could be increased by about 50%. An insoluble and inseparable polyurethane residue on the PA 6 fracture surface found by ATR-FTIR spectroscopy gave evidence of chemical bonding between PA 6 and TPU. Allophanate bonds were formed by the chemical modification. These groups functioned as an inert source of highly reactive isocyanate groups. Urea groups in the polyurethane chain were formed by the modification, too. These groups may improve the compatibility between the two components. A change in the morphology of the polyurethane was observed, which was caused by the change in molecular structure by the chemical modification. The high level of bond strength may be due to a combination of these phenomena.

Mechanisms of Adhesion in Surface Chlorinated Thermoplastic Rubber/Thermoplastic Polyurethane Adhesive Joints

Abstract: Chlorination of a thermoplastic styrene-butadiene-styrene rubber (S0) with a solution of 2 wt% trichloroisocyanuric acid (TCI) in ethyl acetate improved its adhesion to polyurethane adhesives. The analysis of the failed surfaces (obtained after T-peel test of S0/PU joints) showed that the locus of failure in the rubber/polyurethane joints progresses from adhesion (in non chlorinated-S0/PU joint) to cohesion in the chlorinated layer (for chlorinated-S0/PU joint). The composition of this chlorinated layer differed from the composition of the non bonded-chlorinated rubber, i.e. the failure of the joint was located in a chlorinated layer with a distinctive chemistry. On the other hand, the analysis of the chlorinated rubber/PU adhesive interface showed that chlorination with TCI produces a crosslinking of the rubber surface as well as strong interactions between the uppermost-chlorinated layer and the PU adhesive.

Polyurethane elastomeric fiber and process for making the fiber

Abstract: This invention is comprised of a thermoplastic polyurethane elastomer fiber obtained by melt spinning a polyurethane having a rebound of 60 % or greater and a isocyanate-terminated polyether or polyester additive. The elastic fibers have low shrinkage, high heat resistance, low tensile set, and high elongation.

Movable transparent composite systems and a process for preparing the same

Abstract: The present invention is directed to transparent light-stable, movable composite systems which are composed of i) at least two rigid parts made of transparent, thermoplastic materials which are joined together by ii) at least one flexible connecting member made of transparent, light-stable thermoplastic polyurethane. The present invention is also directed to a process for preparing the transparent, light-stable movable composite systems of the present invention. Composite systems of the present invention are particularly useful in the building and construction industry. Upon being folded, composite systems of the present invention are very compact and, hence, easily transportable. In addition, composite systems of the present invention can be easily and reversibly folded or unfolded.

Permanent, Transparent, Non-Blooming and Non-Hygroscopic Antistatic Agents Based on Combined Neoalkoxy Organometallics

Abstract: Minor amounts of thermally and hydrolytically stable combined dissimilar polarity type neoalkoxy titanates and/or zirconates can be added directly into the polymer during the thermoplastic or thermoset compounding phase at temperatures in excess of 200°C to form bipolar layers that provide a transparent, non-blooming organometallic transfer circuit resulting in a volume as well as surface antistatic effect. The permanent antistatic effect depends upon a complete dispersion of the combined organometallics and thus works differently than conventional surface blooming hygroscopic antistats that rely on polymer incompatibilization and resultant surface blooming to attract ESD atmospheric moisture to the thermoplastic surface in environments having humidity greater than 25%. A transparent film results since the combined organometallics are of good color and solubilize into the polymer, and are not made of insoluble conductive particulate or cobalt-based metallocenes. Specifically, it will be shown that when using a combined trineoalkoxy dodecylbenzene sulfonyl zirconate/trineoalkoxy aliphatic amino zirconate antistatic agent, transparent olefin films remain clear after long-term aging tests. Atomic dispersion of the antistat will be shown to be critical. For example, data will show that when 1% of the new and novel antistat is added to polypropylene in an intensive mixer (Banbury) operating in the range of 160 to 190°C - and the mixer compounding conditions are changed (to increase specific energy input) from 30-second drop after flux occurs @ 50 rpm to 2-3 minutes drop after flux occurs at 100-125 rpm - the resistivity will be lowered from 10 13 to 10 11 Ω/sq. for 30 mil compression molded slabs. Differences in ESD effects in HDPE using a 2-roll mill vs. a twinscrew extruder will be discussed. In addition to PP and HDPE, ESD effects will be shown in various other polymer disciplines such as LLDPE, PVC, PVC/Nitrile, PETG, Nylon, PES, Acrylic, ABS, Ethyl Acetate (Nail Polish), Natural Rubber Latex, Acrylic Latex and Polyurethane. For example, a clear thermoplastic polyurethane having a surface resistivity and a volume resistivity of 1.3 x 10 16 Ω/sq. and 1.7 x 10 15 Ω-cm respectively will exhibit ESD properties of 7.4 X 10 12 Ω/sq. and 4.6 x 10 11 Ω-cm when 2% by weight of PU of a 60% active combined trineoalkoxy zirconate on silica powder masterbatch is used.

Continuous production of thermoplastic polyurethane elastomers

Abstract: A continuous process for the preparation of a thermoplastic polyurethane elastomer is disclosed. The process is carried out at 130 to 250°C and comprises reacting at least one polyether diol with at least one organic diisocyanate and 1,4-di-(2,2'-hydroxyethyl)-hydroquinone, in the presence of tin dioctoate as a catalyst. The resulting thermoplastic polyurethane has a glass transition temperature (T g) below 50°C. The inventive thermoplastic polyurethane is suitable for making injection molded or extruded articles.

Injection-moldable, thermoplastic polyurethane elastomer

Abstract: A thermoplastic polyurethane (TPU) elastomer and p-phenylene diisocyanate (PPDI)/polycaprolactone-based composition therefor having a unique chain extender combination for improved injection moldability. The elastomer is formed as the reaction product of: (A) from about 60 to 80% by weight of a hydroxyl-terminated poly(caprolactone) diol; (B) from about 17 to 22% by weight of a p-phenylene diisocyanate; (C) from about 3 to 10% by weight of a first hydroxyl-functional chain extender; and (D) less than about 2% by weight of a second hydroxyl-functional chain extender different from the first chain extender, the second chain extender being selected as effective to modify the crystallinity of the elastomer.