PVC formulations containing high inorganic filler content and hydroxyl-functional organopolysiloxanes.

Abstract

A polyvinyl chloride (PVC) composition and method for preparing a polymer composite article. The composition includes (A) an inorganic filler in an amount of 47.5 to 75 weight percent. The composition also includes (B) a PVC polymer in an amount of 25 to less than 50 weight percent, wherein the amount of (A) the inorganic filler is greater than the amount of (B) the PVC polymer. The composition further includes (C) an organopolysiloxane in an amount of greater than 0 to 5 weight percent, wherein the organopolysiloxane has at least one silicon-bonded hydroxyl group and a viscosity of 1,000 to 60,000 mPas at 25°C. The ranges of components (A) through (C) are based on the total weight of components (A), (B), and (C) in the composition.

Description

[Technical field]

[0001] The present invention relates generally to polyvinyl chloride (PVC) compositions, and more specifically to PVC compositions for preparing polymer composite articles, methods for preparing PVC compositions and polymer composite articles therewith, and polymer composite articles formed thereby. [Background technology]

[0002] Polymer composite articles are known in the art and are utilized in a variety of end use applications. Polymer composite articles have become increasingly popular with consumers due to the cost and desirable properties associated with polymer composite articles, including physical and mechanical properties.

[0003] In the PVC industry, it is common to include fillers in composite articles. Fillers are relatively inexpensive and are often used to reduce cost. Such composite articles are typically produced by thoroughly mixing the filler with PVC to obtain a mixture. However, high levels of fillers can adversely affect the properties of the composite article. For example, large amounts of fillers can affect important properties such as density, percent elongation, impact strength, surface finish, melt flow, melt viscosity, melt strength, and processability.

[0004] Due to the nature of PVC, it cannot be processed by itself. Other additives such as stabilizers, processing aids, lubricants, etc. are required to obtain the processability and performance of the polymer. Typically, these additives can be mixed in a high speed mixer / blender to create a dry blend. High filler levels make it difficult to form a uniform dry blend. The system often becomes dusty and dirty and difficult to handle. Fillers also tend to stick to the walls and blades of the mixer, resulting in less of the desired amount of filler in the blend. Filler sticking also increases equipment cleaning times and can increase contamination of the next batch.

[0005] Conventional low-cost organic processing aids generally suffer from the drawback of requiring high loadings to achieve faster production rates, thereby affecting cost and / or performance characteristics. In addition, many conventional processing aids can adversely affect the physical properties of the composite article, reducing mechanical properties (impact resistance, flexural strength, flexural modulus), especially in high temperature applications. Conventional processing aids can also migrate out of the polymer composite article, thus adversely affecting one or more properties of the polymer composite article over time, such as physical properties, appearance, feel, ability to overmold, ability to coextrude, ability to adhere to the surface of the polymer composite article, ability to print on the surface, and ability to paint on the surface. In addition, some of the organic processing aids can volatilize at higher application temperatures, causing the formation or bubbles and cracks in the polymer composite article, which can impair the long-term performance of these articles.

[0006] High filler levels also tend to increase the density of the polymer system, which increases the weight of the final composite article, which in turn can increase associated shipping costs. Upon foaming, high filler levels also inhibit the expansion of the polymer.

[0007] High filler levels typically make polymer systems shear sensitive: these systems demonstrate higher shear thinning behavior.

[0008] While the use of inorganic fillers can increase the char content and improve smoke and flame characteristics, mechanical properties such as percent elongation and impact strength are often decreased.

[0009] Current PVC compositions require the sacrifice of at least one property for the benefit of another, for example, a PVC composition may be formulated to improve impact strength but at the expense of a reduced percent (%) elongation, or to improve surface finish but at the expense of reduced throughput, or to provide a desired density but at the expense of impacting other physical properties.

[0010] It would be desirable to provide a polymer system with a high filler content that addresses one or more of the above problems. Summary of the Invention

[0011] The present invention provides a PVC composition for preparing a polymer composite article. The composition includes (A) an inorganic filler in an amount of 47.5 to 75 wt %. The composition also includes (B) a polyvinyl chloride polymer in an amount of 25 to less than 50 wt %. The amount of (A) inorganic is greater than the amount of (B) polyvinyl chloride polymer. Additionally, the composition includes (C) an organopolysiloxane in an amount of greater than 0 to 5 wt %, the (C) organopolysiloxane having at least one silicon-bonded hydroxyl group and a viscosity of 1,000 to 60,000 mPa·s at 25° C. The range of components (A) to (C) is based on the total weight of components (A), (B), and (C) in the composition.

[0012] Also provided is a method of preparing the composition, comprising combining (A) an inorganic filler, (B) a polyvinyl chloride polymer, and (C) an organopolysiloxane, thereby preparing the composition.

[0013] Further provided by the present invention is a method for preparing a polymer composite article, the method comprising preparing a polymer composite article from a PVC composition. Additionally, a polymer composite article formed according to the method is also provided. [Brief description of the drawings]

[0014] [Figure 1] 1 shows a graph of viscosity and shear rate for a formulation according to an embodiment of the present invention. [Diagram 2] 1 shows an optical microscope image of a formulation according to the present invention. [Diagram 3] 1 shows an optical microscope image of a formulation according to the present invention. [Figure 4] 1 shows a graph of the Rabinowitsch correction required for formulations according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The present invention provides a PVC composition for preparing a polymer composite article, which has excellent physical properties and is suitable for a myriad of end use applications, as described below. Methods for preparing the polymer composite article, and the polymer composite article formed thereby, are also provided and described below.

[0016] A composition for preparing a polymer composite article comprises: (A) an inorganic filler in an amount of 47.5 to 75 weight percent; (B) a polyvinyl chloride polymer in an amount of 25 to less than 50 weight percent, wherein the amount of (A) the inorganic filler is greater than the amount of (B) the polyvinyl chloride polymer; and (C) an organopolysiloxane in an amount of greater than 0 to 5 weight percent, each based on the total weight of components (A), (B), and (C) in the composition.

[0017] Component (A) Inorganic filler The composition includes (A) an inorganic filler capable of forming a discontinuous phase in the composition for preparing a polymer composite article and in the composite article so prepared.

[0018] The (A) inorganic filler may be untreated, pretreated, or added in combination with an optional filler treatment agent, and when so added, the (A) inorganic filler may be treated in situ or prior to incorporation of the (A) inorganic filler into the composition. When treated, the (A) inorganic filler may be treated by any conventional filler treatment agent known in the art. The (A) inorganic filler may be a single filler or a combination of two or more fillers that differ in at least one characteristic, such as filler type, preparation method, treatment or surface chemistry, filler composition, filler shape, filler surface area, average particle size, and / or particle size distribution.

[0019] Preferably, the (A) inorganic filler comprises at least 90% by weight of the total weight of fillers in the PVC composition, i.e., the PVC composition may comprise up to 10% by weight of non-inorganic fillers. More preferably, the (A) inorganic filler comprises at least 95% by weight of the total weight of fillers in the PVC composition. Even more preferably, the fillers in the PVC composition consist essentially of or consist of at least one inorganic filler. As used herein, "consists essentially of" means that any filler other than the inorganic filler present in the PVC composition does not adversely affect any of the physical properties of the PVC composition and / or the processability of the PVC composition. Preferably, the PVC composition comprises less than 5% by weight of lignocellulosic or organic fillers. More preferably, the PVC composition does not comprise lignocellulosic or organic fillers.

[0020] The shape and dimensions of the (A) inorganic filler are also not specifically limited. For example, the (A) inorganic filler can be spherical, oblong, ovoid, irregular, and can be in the form of, for example, powder, dust, fiber, particle, and combinations thereof. The dimensions and shapes are typically selected based on the type of (A) inorganic filler utilized, the selection of other components contained in the composition, and the end use application of the polymer composite article formed therewith.

[0021] Non-limiting examples of inorganic fillers that may function as extending or reinforcing fillers include quartz and / or crushed quartz, aluminum oxide, magnesium oxide, silica (e.g., fumed, crushed, precipitated), hydrated magnesium silicate, magnesium carbonate, dolomite, silicone resins, wollastonite, soapstone, kaolinite, kaolin, mica muscovite, and the like. muscovite), phlogopite, halloysite (hydrated aluminum silicate), aluminum silicate, sodium aluminosilicate, glass (e.g., fibers, beads or particles, including recycled glass from wind turbines or other sources), clay, magnetite, hematite, calcium carbonate such as precipitated, fumed, and / or ground calcium carbonate, calcium sulfate, barium sulfate, calcium metasilicate, zinc oxide, talc, diatomaceous earth, iron oxide, clay, mica, chalk, titanium dioxide (titania), zirconia, graphite, anthracite, lignite, magnesium oxide, magnesium hydroxide, magnesium oxysulfate fibers, aluminum trihydrate, aluminum oxyhydrate, pigments (e.g., non-hydrated, partially hydrated, or hydrated fluorides, chlorides, bromides, iodides, chromates, carbonates, hydroxides, phosphates, hydrogen phosphates, nitrates, oxides, and sulfates of titanium dioxide, sodium, potassium, magnesium, calcium, and barium); borates such as antimony pentoxide, antimony trioxide, beryllium oxide, chromium oxide, lithopone, zinc borate, barium metaborate, or aluminum borate, mixed metal oxides such as vermiculite, bentonite, pumice, perlite, fly ash, clay, and silica gel; pyrophyllite, sepiolite, zinc stannate, zinc sulfide, and combinations thereof. Alternatively, the extending or reinforcing filler may be selected from the group consisting of calcium carbonate, talc, and combinations thereof.

[0022] Extending fillers are known in the art and are commercially available, for example, ground silica sold under the name MIN-U-SIL by US Silica of Berkeley Springs, WV. Suitable precipitated calcium carbonates include Winnofil™ SPM from Solvay, and Ultra-pflex™ and Ultra-pflex™ 100 from SMI.

[0023] The (A) inorganic filler is present in the composition in an amount of 47.5 to 75, alternatively 50 to 70, alternatively 50 to 65, alternatively 52 to 60 weight percent, based on the total weight of (A), (B), and (C) in the composition. All endpoints and subranges between 47.5 and 70 weight percent are included and disclosed herein. Alternatively, in certain applications, it may be desirable to maximize the relative amount of (A) inorganic filler in the composition, which will reduce the overall cost of the polymer composite article formed therewith while maintaining or obtaining desirable properties thereof. Those skilled in the art will appreciate that the amount of (A) filler may be varied to this end, including a balance of cost and properties obtained, as well as the presence or absence of other optional ingredients, as described below.

[0024] (B) PVC polymer The composition further comprises a (B) PVC polymer. The PVC polymer may form all or part of the continuous phase in the composition for preparing the polymer composite article and in the composite article prepared therefrom. The choice of the (B) PVC polymer typically varies with the desired end use application of the polymer composite article formed with the composition, as various polymers have different melting point temperatures (and / or glass transition temperatures) and physical / mechanical properties, as well as suitable or acceptable continuous use application temperatures. In certain embodiments, the (B) PVC polymer has a softening point temperature that is lower than the decomposition temperature of the other components in the composition. In these embodiments, the (B) PVC polymer has a softening point temperature of less than 250°C, alternatively less than 225°C, alternatively less than 200°C. The softening point temperature may also be referred to as the processing temperature. In at least one embodiment, the (B) PVC polymer has a softening point temperature in the range of 150-250°C, such as 160-220°C or 170-210°C. Preferably, the (B) PVC polymer is a powder.

[0025] Elastomers and / or rubbers may be added to or compounded with the (B) PVC polymer to improve or improve properties such as impact strength. Preferably, the (B) PVC polymer includes at least one acrylic processing additive. The additives may include those known in the art, such as those disclosed by Stevenson et al., Journal of Vinyl Technology, December 1993, Vol. 15, No. 4, pages 244-251, which is incorporated herein by reference.

[0026] In certain embodiments, the polymer in the PVC composition consists essentially of PVC polymer. By consisting essentially, it is meant that the (B)PVC polymer can include one or more additional polymers other than polyvinyl, but only if such additional polymers can be processed with the (B)PVC polymer to form a polymer composite article. When the (B)PVC polymer does not consist of PVC polymer, it typically comprises at least 50, alternatively at least 60, alternatively at least 65, alternatively at least 70, alternatively at least 75, alternatively at least 80, alternatively at least 85, alternatively at least 90, alternatively at least 95, alternatively at least 96, alternatively at least 97, alternatively at least 98, alternatively at least 99 weight percent of PVC polymer, based on the total weight of the (B)PVC polymer utilized in the composition.

[0027] When the (B)PVC polymer comprises a polymer other than PVC and in addition to PVC, the (B)PVC polymer may further comprise at least one polymer that is fully or partially thermodynamically miscible with PVC. Such polymers include, but are not limited to, poly(methyl methacrylate) (PMMA), polyethylene oxide (PEO), thermoplastic polyurethane (TPU), polycaprolactone (CPL), and styrene-acrylonitrile resin (SAN). Other thermodynamically miscible polymers are known in the art and are disclosed, for example, in Robeson, LM (1990), Miscible polymer blends containing poly(vinyl chloride). J. Vinyl Addit. Technol., 12:89-94, which is incorporated herein by reference. The (B)PVC polymer may further comprise an elastomer. Non-limiting examples of elastomers include styrene-butadiene rubber, polyether urethane rubber, polyester urethane rubber, butyl rubber, nitrile rubber, chloroprene rubber (neoprene), polyacrylate rubber, ethylene acrylate rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene propylene diene monomer (EPDM), ethylene propylene rubber (EPR), fluorosilicone rubber, fluorocarbon rubber, perfluorinated elastomer, styrene butadiene rubber, chlorosulfonated polyethylene, polyisoprene rubber, polysulfide rubber, ethylene acrylate rubber, epichlorohydrin rubber, perfluorinated elastomer (e.g., Kalrez™), polysulfide rubber, chlorinated polyethylene (e.g., chlorinated polyethylene containing up to 40 weight percent chlorine), and combinations thereof.

[0028] Regardless of the (B)PVC polymer utilized, the (B)PVC polymer may include virgin polymer and / or recycled polymer. Recycled polymer, if utilized, may be sourced from industrial production streams as well as from post-industrial and / or post-consumer sources. The selection of the (B)PVC polymer and any ratio of virgin to recycled polymer, if utilized in concert, typically varies depending on the cost and desired properties of the polymer composite article formed therewith.

[0029] The amount of (A) inorganic filler is greater than the amount of (B) PVC polymer in the PVC composition, i.e., the ratio of (A) inorganic filler to (B) PVC polymer is greater than 1.

[0030] The (B) PVC polymer may be present in the composition in an amount of 25-50 or less, alternatively 30-50 or less, alternatively 35-50 or less, alternatively 40-48 weight percent, based on the total weight of (A), (B), and (C) in the composition. In certain embodiments, it may be desirable to minimize the relative amount of the (B) PVC polymer in the composition, which may reduce the overall cost of the polymer composite article formed therewith, depending on the selection, while maintaining or obtaining desirable properties. Those skilled in the art will appreciate that the amount of the (B) PVC polymer may be varied to this end, including a balance of cost and properties obtained, as well as the presence or absence of other optional ingredients, as described below.

[0031] (C) Organopolysiloxane The composition further comprises (C) an organopolysiloxane. The (C) organopolysiloxane has at least one silicon-bonded hydroxyl group. The (C) organopolysiloxane has a viscosity of at least 120 mPa·s, alternatively from 120 mPa·s to 250,000 mPa·s at 25° C. In certain embodiments, the (C) organopolysiloxane has a viscosity of 1,000 to 60,000, alternatively from 1,000 to 50,000, alternatively from 2,000 to 50,000 mPa·s at 25° C. The viscosity may be measured on a Brookfield DV-III cone and plate viscometer with a #52 spindle at 0.1 to 50 RPM at 25° C. One skilled in the art will appreciate that as the viscosity of the organopolysiloxane increases, the RPM of the viscosity test method decreases from 50 to 0.1 RPM.

[0032] Alternatively, in the (C) organopolysiloxane, the silicon-bonded OH groups may be present in an amount of at least 50 ppm based on the weight of the (C) organopolysiloxane. Alternatively, the silicon-bonded OH groups may be present in an amount of 50 ppm to 15,000 ppm, alternatively 50 ppm to 10,000 ppm, alternatively 2,500 ppm to 7,500 ppm, alternatively 10,000 to 15,000 ppm, on the same basis. The silicon-bonded OH content may be measured by Fourier transform infrared (FTIR) spectroscopy.

[0033] (C) organopolysiloxane may include two or more different organopolysiloxanes that can be independently selected. Typically, (C) organopolysiloxane functions as a processing aid in the composition and polymer composite article. Without wishing to be bound by theory, (C) organopolysiloxane may be an internal and / or external processing aid. However, (C) organopolysiloxane may function for other purposes, for example, in addition to or as an alternative to functioning as a processing aid to improve the physical or mechanical properties of the composition and polymer composite article.

[0034] In general, various advantages can be realized by the combination of (A) inorganic filler, (B) PVC polymer, and (C) organopolysiloxane. For example, when the composition is mixed in an extruder, the combination of (A) inorganic filler, (B) PVC polymer, and (C) organopolysiloxane generally reduces the melting temperature of the composition in the extruder. The reduction in melting temperature refers to the temperature of the composition in the extruder and Brabender, as opposed to the melting point temperature of any one individual component in the composition (and in the extruder). Importantly, this allows the composition to be processed at low temperatures, providing a myriad of benefits, including cost and aesthetics. For example, certain fillers, such as lignocellulosic fillers, can carbonize or decompose at certain high processing temperatures of the composition, which are typically required to make the composition flowable. The use of a combination of (A) inorganic filler, (B) PVC polymer, and (C) organopolysiloxane allows the polymer composite article to be prepared at low temperatures without decomposing, charring, or otherwise adversely affecting (A) inorganic filler and other aspects of the polymer composite article. Furthermore, when the composition is mixed in an extruder, the torque of the extruder is generally reduced by the combination of (A) inorganic filler, (B) PVC polymer, and (C) organopolysiloxane. The reduced torque allows for greater output, which is particularly important in terms of production throughput.

[0035] The (C) organopolysiloxane may be linear, branched, partially branched, cyclic, resinous (i.e., having a three-dimensional network), or may contain a combination of different structures. For example, the (C) organopolysiloxane may contain any combination of M, D, T, and / or Q siloxy units, so long as the (C) organopolysiloxane contains at least one silicon-bonded hydroxyl group. These siloxy units may be combined in various ways to form cyclic, linear, branched, and / or resinous (three-dimensional network) structures.

[0036] In one particular embodiment, the (C) organopolysiloxane has the average unit formula: [R3SiO 1 / 2 a [R2SiO 2 / 2 b [RSiO 3 / 2 c [SiO 4 / 2 d In the formula, each R is independently selected from OH and hydrocarbyl groups, provided that in at least one molecule, at least one R is OH, and 0 < a ≤ 0.99, 0 < b ≤ 0.99, 0 ≤ c ≤ 0.2, and 0 ≤ d ≤ 0.2, provided that a + b + c + d = 1.

[0037] Each R that is not OH can independently be linear, branched, cyclic, or a combination thereof. Cyclic hydrocarbyl groups include aryl groups and saturated or non-conjugated cyclic groups. The aryl group may be monocyclic or polycyclic. Linear and branched hydrocarbyl groups can independently be saturated or unsaturated. An example of a combination of a linear and a cyclic hydrocarbyl group is an aralkyl group. When R is not an aryl group, R is saturated, i.e., R does not contain ethylenic unsaturation.

[0038] Hydrocarbyl groups can be exemplified by methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, or similar alkyl groups; and phenyl, tolyl, xylyl, naphthyl, or similar aryl groups; benzyl, phenethyl, or similar aralkyl groups.

[0039] The silicon-bonded OH group(s) is / are present in any M, D, and / or T siloxy units present in the (C) organopolysiloxane and can be bonded to the same silicon atom (in the case of M and / or D siloxy units). The (C) organopolysiloxane has, for example, as M siloxy units, (R3SiO 1 / 2 ), (R2(OH)SiO 1 / 2 ), (R(OH)2SiO 1 / 2 ​​​​), and / or ((OH)SiO 1 / 2 The organopolysiloxane (C) may contain, for example, as the D siloxy unit, (RSiO 2 / 2 ), (R(OH)SiO 2 / 2 ), and / or ((OH)SiO 2 / 2 The organopolysiloxane (C) may contain, for example, (RSiO 3 / 2 ) and / or ((OH)SiO 3 / 2 Such siloxy units may be combined in any manner, optionally with Q siloxy units, to provide an organopolysiloxane having at least one silicon-bonded OH group.

[0040] (C) organopolysiloxane is branched or resinous when it contains T siloxy units and / or Q siloxy units. When (C) organopolysiloxane is branched or resinous, (C) organopolysiloxane is typically a copolymer containing T siloxy units and / or Q siloxy units in combination with M siloxy units and / or D siloxy units. For example, (C) organopolysiloxane can be DT resin, MT resin, MDT resin, DTQ resin, MTQ resin, MDTQ resin, DQ resin, MQ resin, DTQ resin, MTQ resin, or MDQ resin. Alternatively, in certain embodiments, (C) organopolysiloxane is linear, in which case (C) organopolysiloxane contains D siloxy units in combination with M siloxy units.

[0041] In one particular embodiment, the (C) organopolysiloxane has the average unit formula: [R 1 3-n (OH) n SiO 1 / 2 ] a’ [R 1 2-m (OH) m SiO 2 / 2 ] b’ [R 1 SiO 3 / 2 ]c’ [SiO 4 / 2 d’ In the formula, each R 1 is an independently selected hydrocarbyl group, n is 0, 1, 2, or 3, m is 0, 1, or 2, provided that n and m are not both 0 at the same time, 0 < a' < 1, 0 < b' < 1, 0 ≤ c' ≤ 0.1, and 0 ≤ d' ≤ 0.1, provided that a' + b' + c' + d' = 1. In this average unit formula, at least one silicon-bonded OH group is present in the M and / or D siloxy units of the (C) organopolysiloxane.

[0042] In certain embodiments, the (C) organopolysiloxane is substantially linear or linear. In these embodiments, the (C) organopolysiloxane substantially does not contain or does not contain T siloxy and / or Q siloxy units. For example, in these particular embodiments, the (C) organopolysiloxane may have the following average unit formula: [R 1 3-n (OH) n SiO 1 / 2 a’’ [R 1 2-m (OH) m SiO 2 / 2 b’’ In the formula, each R 1 is an independently selected hydrocarbyl group, n is 0, 1, 2, or 3, m is 0, 1, or 2, provided that n and m are not both 0 at the same time, 0 < a'' < 1, 0 < b'' < 1, provided that a'' + b'' = 1. In certain embodiments, n is 1, 2, or 3. In these or other embodiments, m is 0 such that the silicon-bonded OH group(s) is / are located in the M siloxy unit and is / are thus terminal. Considering the viscosity of the (C) organopolysiloxane, typically b'' > a'' as introduced above and described below. Each R 1 is typically methyl.

[0043] ​​​ When the (C) organopolysiloxane is substantially linear, or linear, and contains terminal silicon-bonded OH group(s), the (C) organopolysiloxane may have the average unit formula: R 1 3-x (OH) x SiO[SiR 1 2O] c’’ Si(OH) y R 1 3-y In the formula, each R 1 are independently selected hydrocarbyl groups, x is 0, 1, 2, or 3, y is 0, 1, 2, or 3, with the proviso that x and y are not simultaneously 0, and c'' has a value sufficient to provide the desired viscosity of (C) the organopolysiloxane, or c'' is 60 to 1200, or alternatively 100 to 1200. In certain embodiments, x is 1, 2, or 3, and y is 1, 2, or 3. The subscript c'' relates to the number of repeating D units and the degree of polymerization (DP) of (C) the organopolysiloxane. As understood in the art, R 1 Both the selection of and the DP affect the viscosity of the (C) organopolysiloxane.

[0044] Regardless of the (C) organopolysiloxane utilized, the (C) organopolysiloxane has a viscosity of at least 1,000 mPa·s measured on a Brookfield DV-III cone and plate viscometer equipped with a #52 spindle in the range of 0.1 to 50 RPM at 25° C. For example, the (C) organopolysiloxane may have a viscosity of 120 to 250,000, alternatively 10,000 to 100,000 mPa·s at 25° C. tested under the conditions described above. Typically, the (C) organopolysiloxane has a viscosity of 1,000 to 60,000, alternatively 1,000 to 50,000, alternatively 2,000 to 50,000 mPa·s at 25° C. tested under the conditions described above.

[0045] The (C) organopolysiloxane may typically be utilized in an amount of from greater than 0 to 5, alternatively from 0.05 to 3, alternatively from 0.1 to 2.5, alternatively from 0.25 to 2.0 weight percent, based on the total weight of (A), (B), and (C) in the composition.

[0046] The (C) organopolysiloxane may be utilized in neat (pure) form, or may be provided in any other suitable form, for example, in a dilute liquid form combined with a carrier vehicle, or alternatively in a solid form, such as in pellet form (e.g., blended with a PVC polymer and pelletized) or as a powder (e.g., blended with a filler). In certain embodiments, the (C) organopolysiloxane is a liquid at 25°C.

[0047] In certain embodiments, in addition to components (A) inorganic filler, (B) PVC polymer, and (C) organopolysiloxane, the composition for preparing the above polymer composite article further comprises one or more additives selected from colorants (e.g., pigments and / or dyes), blowing agents (e.g., chemical and / or physical), UV and / or light stabilizers, processing aids, preservatives, biocides (e.g., fungicides, herbicides, pesticides, antimicrobials), flame retardants and / or smoke suppressants, impact modifiers, heat stabilizers, and lubricants. These components are known in the art and may be used according to conventional practices. Each additive, if utilized, may be present in the composition in an amount of greater than 0 to 30 weight percent, based on the total weight of the composition. The composition may also include other optional additives, as known in the art. Such additives are described, for example, in Walker, Benjamin M., and Charles P. Rader, eds. Handbook of thermoplastic elastomers. New York: Van Nostrand Reinhold, 1979; Murphy, John, ed. Additives for plastics handbook. Elsevier, 2001, which are incorporated herein by reference.

[0048] A method for preparing a polymer composite article is also provided. The method includes preparing a polymer composite article from the composition. In certain embodiments, the method further includes forming the composition. The composition is formed by combining at least components (A) inorganic filler, (B) PVC polymer, and (C) organopolysiloxane, along with any optional components present in the composition.

[0049] The components of the composition can be combined in any order and through any suitable manner. In certain embodiments, for example, the (B) PVC polymer can be melted before, during, and / or after forming the composition. For example, the (B) PVC polymer can be heated before and / or during the combination of the components, so that the (A) inorganic filler and the (C) organopolysiloxane are combined with the molten form of the (B) PVC polymer. The (A) filler and the (C) organopolysiloxane can be combined with the molten form of the (B) PVC polymer in any order, for example, individually, sequentially, together, or simultaneously. However, alternatively, the (B) PVC polymer can be combined with the (A) inorganic filler and the (C) organopolysiloxane before heating or melting the (B) polymer, so that the (B) PVC polymer is in a solid, unmelted or unsoftened form when preparing the composition. Alternatively, (A) the inorganic filler and (C) the organopolysiloxane may be combined and heated and then added to the (B) PVC polymer in solid or liquid form when the composition is prepared.

[0050] Preferably, (A) the inorganic filler, (B) the PVC polymer, and (C) the organopolysiloxane are added simultaneously.

[0051] The melting point temperature (or glass transition temperature) of the (B) PVC polymer typically varies depending on the (B) PVC polymer utilized. For example, certain types of polymers have different melting point temperatures than other types of polymers. In certain embodiments, the (B) PVC polymer is heated before, during, and / or after formation of the composition to a temperature greater than the melting point temperature of the (B) PVC polymer, for example, 10 to 90, or 10 to 40° C. greater than the melting point temperature of the (B) PVC polymer. This ensures melting rather than merely softening of the (B) PVC polymer. Alternatively, a lower temperature may be utilized in combination with shear or mixing to ensure softening and / or melting of the (B) PVC polymer.

[0052] The composition for preparing the polymer composite article can be formed, for example, under mixing or shear using suitable mixing equipment. For example, the composition can be formed in a vessel equipped with an agitator and / or mixing blade. The vessel can be, for example, an internal mixer such as a Banbury, Sigma (Z) blade, or cavity transfer style mixer. Alternatively or additionally, the composition can be formed in or processed by any extruder, for example, a single screw extruder equipped with rotating and / or reciprocating (co-kneader) screws, as well as a multi-screw device equipped with two or more screws that can be aligned tangentially or partially / fully intermeshing and rotate in the same or counter-rotating direction. Alternatively, a conical extruder can be used to form the composition described herein.

[0053] As introduced above, the method also includes preparing a polymer composite article from the composition for preparing the polymer composite article. The composition may, for example, be formed in a container and then removed from the container to form the polymer composite article in a separate device. Alternatively, the same device may be utilized to prepare the composition and then form the polymer composite article. For example, the composition may be prepared and / or mixed in an extruder, and the extruder may be utilized to prepare the polymer composite article with the composition. Alternatively, the polymer composite article may be formed via molding, for example, using a compression, injection molding, or transfer molding process. The composition may be formed in situ in a mold or formed independently and placed in a mold once formed. Alternatively, and further, the polymer composite article may be a film. In such an embodiment, the composition may be formed or placed in a container, optionally under mixing at elevated temperature, and placed in or on an equipment for preparing a film from the composition. Such equipment and techniques for preparing a film from a composition, particularly those that include a thermoplastic material such as (B) PVC polymer of the composition, are well known in the art.

[0054] In certain embodiments, preparing a polymer composite article from the composition further comprises forming the composition into a desired shape. The desired shape depends on the end use application of the polymer composite article. Those skilled in the art will understand how extrusion dies and molding dies can be selected and created based on the desired shape of the polymer composite article.

[0055] In certain embodiments, the method is carried out continuously or semi-continuously in an extruder such as a twin-screw extruder (screws rotate simultaneously, partially or fully intermeshing, or counter-rotating, aligned tangentially, partially or fully intermeshing). In one embodiment, the (C) organopolysiloxane is placed in the extruder simultaneously with the (A) inorganic filler and the (B) PVC polymer. Alternatively, the (C) organopolysiloxane can be placed in the extruder after the (B) PVC polymer is melted and before the (A) inorganic filler is added. Alternatively, the (C) organopolysiloxane can be placed in the extruder after the (A) inorganic filler and the (B) PVC polymer exit the extruder and before the polymer composite article exits the extruder. Alternatively, (A) inorganic filler can be placed in the extruder simultaneously with (C) organopolysiloxane, where they are heated to effect surface treatment of (A) inorganic filler with (C) organopolysiloxane, and then (B) PVC polymer is placed in the extruder to obtain a mixture, the temperature of which is increased to a suitable temperature for compounding the mixture and forming the polymer composite article. The extruder can have one or more zones, for example, 1 to 3, or 3 to 8, or 1 to 12 zones, where starting materials can be added. The zones can be heated at different temperatures.

[0056] The polymer composite article of the present invention is not limited and can be customized for a myriad of end-use applications and industries.Just as an example, the polymer composite article can be used in or as pipes; plumbing; hoses; insulation (e.g., thermal and / or electrical insulation) articles; interior components, such as automotive components or applications, including floor mats; consumer products and applications, industrial or commercial products and applications, aerospace products and applications, transportation products and applications, aircraft products and applications, electronic products and applications, residential or commercial building and construction products and applications, such as decks, railings, siding, fences, window frames, flooring, tiles, skirting boards, etc.

[0057] The invention has been described in an illustrative manner, and it is to be understood that the terminology used is intended to be in the nature of words of description rather than of limitation. Obviously, many modifications and variations of the invention are possible in light of the above teachings. The invention may be practiced otherwise than as specifically described.

[0058] Industrial Applicability Without wishing to be bound by theory, it is believed that the combination of (A) inorganic filler, (B) PVC polymer, and (C) organopolysiloxane may provide one or more benefits to the polymer composites described herein and / or the processes for making them. These include:

[0059] Reduced density of the foamed polymer composition, leading to lower costs; Higher expansion of foamed polymer compositions resulting in thicker products at the same blowing agent and processing aid loading levels, efficient and cost-effective formulations; Better mixing due to lower levels of dust and / or filler adhesion to the blender and blades, easier cleaning of the blender; Improved melt strength leading to robust processing, maximizing expansion, and maximum gas containment; Increased charcoal content resulting in better flame retardant and smoke suppression performance; Improved tribological properties, better wear resistance Lower shear thinning leading to a wider processing window; Improved cell structure in foamed articles; Lower torque during compounding leads to lower power consumption for processing, allowing higher throughput and improving production; Increased compounding throughput and / or lower energy consumption; Better filler dispersion and reduced glass fiber breakage during compounding and molding (if glass fiber is used); Ability to mold thinner walls due to improved melt flow; Ability to contain high filler loadings resulting in cost savings; Lower reject rate at demolding, Better surface quality and / or finish, which can be a challenge at higher filler levels; Improved elongation despite higher filler loading Improved impact strength despite higher filler loading Improved fusion features, Maintain or improve key properties at higher filler loadings, resulting in better performance and processing while lowering formulation costs Improved melt rheology resulting in more shear-insensitive formulations that provide robust processing Improved hydrophobicity; The ability to utilize a greater proportion of recycled polymer or different grades of polymer; and / or Allowing for additives that improve strength and other properties such as improved modulus and stiffness. EXAMPLES

[0060] Exemplary polyvinyl chloride formulations were prepared by sequentially adding the materials in Table 1. Dry blends were prepared by adding PVC to a Gunther Papenmeier / Welex blender at room temperature, increasing the power to 15A, adding TM 181 at 125° F., adding a lubricant package containing siloxane at 150° F., adding acrylic processing aids at 170° F., adding TiO2 at 190° F., and CaCO3 at 195° F. The blended powders were then allowed to cool to room temperature. [Table 1-1] [Table 1-2]

[0061] The compositions in Table 1 were milled at 170°C for 5 minutes on an electric Collin Roll mill with a 0.3 mm gap to obtain milled sheets from each composition, and the milled sheets were then compression molded into 3.2 mm thick plaques at 175°C. Samples were cut for notched Izod impact strength (measured according to ASTM D256), tensile strength (ASTM D 638), and heat distortion temperature (ASTM D648). For density, expansion, and processing condition studies, foam rods were extruded using a Polylab RS 5000 laboratory twin screw extruder with a 4.78 mm rod die. Extrusion temperature settings were 175C / 185C / 190C / 160C (die) with a screw speed of 60 RPM. Time to floor was reported as the time it took for the melt / rod to reach the floor from the die. Fusion studies were performed on a Brabender Intelli Torque 7150 at 190°C, 60 rpm, 7 minutes, 74 grams for 100 PHR CaCO3, 76 grams for 120 PHR CaCO3, and 78 grams for 140 PHR CaCO3. The material from the Brabender was pressed into flat plaques, which were cut into pieces and fed into the capillary of a rheometer to provide melt viscosity measurements at 190°C. Thermogravimetric analysis (TGA) was performed on the molded plaques from 50 to 800°C at a ramp rate of 20°C / min. The samples according to the invention had a visually improved surface finish. Results from the analysis are provided in the table below. [Table 2]

[0062] As can be seen in Table 2 above, samples containing high filler levels in combination with polysiloxane surprisingly showed lower density compared to samples without polysiloxane. Furthermore, the higher time to bed values ​​indicate that the formulations according to the invention showed improved melt strength even at higher filler loadings. The time to bed value is a measure of the time it takes for the extrudate to reach the bed as it leaves the die. Formulations with poor melt strength will fall under their own weight and take less time to reach the bed. The formulations of the invention also surprisingly showed improved or comparable expansion. Generally, increased filler levels result in lower expansion, but the compositions of the invention actually demonstrated improved or comparable expansion. The formulations of the invention also maintained and / or provided a slight improvement in heat distortion temperature (HDT). The control showed an HDT of 63.4°C. [Table 3]

[0063] Typically, higher levels of filler increase fusion and balance torque and make processing difficult. The formulations according to the invention maintained torque even at increased filler levels. [Table 4]

[0064] As shown in Table 4 above, no significant changes in torque, pressure, melt temperature, and throughput were observed. Thus, no changes are required during processing at the manufacturing site. As shown in Figures 1A to 1C, the formulations maintained their melt viscosity at higher filler levels. Typically, higher filler levels increase melt viscosity, resulting in higher torque and pressure, which can limit overall production. High melt viscosity can limit throughput and flow, affecting the ability to fill thin walls. The formulations without siloxanes showed significant shear thinning at higher shear rates, resulting in very low viscosity, which can also affect processing, requiring changes in processing conditions, and can also affect product quality such as cell structure, expansion, and surface finish. The formulations with siloxanes matched the original (at low filler levels) with minimal shear thinning, and did not result in changes in rheology while adding more filler. [Table 5]

[0065] As can be seen in Table 5, the formulations of the present invention provide increased char content, which may result in improved smoke suppression and flame retardancy. [Table 6]

[0066] As shown in Table 6, the formulations according to the invention maintained their surface energy. Changes in surface energy can affect the printability of the surface. Surface energy is also important for multi-layer structures, as it can affect lamination and interlayer adhesion. Thus, the formulations according to the invention maintained their processing and surface energy even at high filler levels.

[0067] Table 6 also shows that the compounds according to the invention showed improved percent elongation even at higher filler levels. Higher levels of necking were observed in the compounds according to the invention. Izod impact strength was also improved and modulus was maintained.

[0068] Cell structure analysis was performed by optical microscope images. As shown in Figures 2 and 3, the formulation according to the present invention showed improved cell structure. The optical microscope images showed no cell rupture or collapse, which means that the formulation allows the gas generated by the blowing agent to be retained.

[0069] Tribological evaluation was performed on an Anton-Paar MCR 502 equipped with a ball-on-three-plate fixture for tribological measurements. The formulation according to the invention improved the tribological properties by lowering the coefficient of friction at room temperature and also at elevated temperatures during melt processing. As shown in Figures 4A and 4B, the formulation according to the invention with a higher polysiloxane content requires a lower Rabinowitsch correction indicating different wall slip.

[0070] Definitions and Usage of Terms Unless otherwise indicated by the context of the specification, all amounts, ratios, and percentages are by weight and all test methods are as of the filing date of this disclosure. The articles "a", "an", and "the" each refer to one or more. It is understood that the appended claims are not limited to the language of the "Description of the Invention" and the specific compounds, compositions, or methods described therein, which may vary among the specific embodiments of the appended claims. With respect to any Markush group relied upon in this specification to describe specific features or aspects of various embodiments, different, special, and / or unexpected results may be obtained from each member of the respective Markush group independent of all other Markush members. Each member of the Markush group may be relied upon individually and / or in combination to provide appropriate support for specific embodiments of the appended claims.

[0071] Moreover, any ranges and subranges relied upon in the description of various embodiments of the present invention are understood to be individually and collectively included in the appended claims and to describe and contemplate all ranges including their whole and / or fractional values, even if such values ​​are not expressly written herein. Those skilled in the art will readily recognize that the recited ranges and subranges fully describe and enable various embodiments of the present invention, and that such ranges and subranges may be further detailed into related halves, thirds, quarters, fifths, etc. As merely an example, a range "from 0.1 to 0.9" may be further detailed into a lower third, i.e., 0.1 to 0.3, a middle third, i.e., 0.4 to 0.6, and an upper third, i.e., 0.7 to 0.9, which are individually and collectively within the appended claims and may be relied upon individually and / or collectively to provide appropriate support for specific embodiments of the appended claims. In addition, with respect to terms defining or modifying a range, such as "at least," "greater than," "less than," "less than or equal to," it is understood that such terms include subranges and / or upper or lower limits. As another example, the range "at least 10" inherently includes subranges of at least 10 to 35, at least 10 to 25, 25 to 35, etc., each of which may be relied upon individually and / or collectively to provide appropriate support for specific embodiments of the appended claims. Finally, individual numbers within the disclosed ranges may be relied upon to provide appropriate support for specific embodiments of the appended claims. For example, the range "1 to 9" includes various individual integers, such as 3, as well as individual numbers including decimal points (or fractions), such as 4.1, which may be relied upon to provide appropriate support for specific embodiments of the appended claims.

[0072] As used herein, the term "composition" includes the material(s) which comprise the composition, as well as reaction products and decomposition products formed from the materials of the composition.

[0073] The term "comprising" and its derivatives are not intended to exclude the presence of any additional components, steps, or procedures, whether or not they are disclosed herein. For the avoidance of any doubt, all compositions claimed herein through the use of the term "comprising" may include any additional additives, adjuvants, or compounds, whether polymeric or otherwise, unless stated to the contrary. In contrast, the term "consisting essentially of" excludes any other components, steps, or procedures from the scope of any succeeding description, except those that are not essential to operability. The term "consisting of" excludes any component, step, or procedure not specifically defined or listed.

[0074] As used herein, the term "polymer" refers to a polymeric compound prepared by polymerizing monomers, whether of the same kind or different types. Thus, the generic term polymer encompasses the term homopolymer (used to refer to a polymer prepared from only one type of monomer, with the understanding that minor amounts of impurities may be incorporated into the polymer structure), and the term interpolymer, as defined herein below. Minor amounts of impurities may be incorporated into and / or within the polymer.

[0075] "Blend," "polymer blend," and like terms refer to a composition of two or more polymers. Such blends may or may not be miscible. Such blends may or may not be phase separated. Such blends may or may not contain one or more domain configurations as determined from transmission electron spectroscopy, light scattering, x-ray scattering, and any other method known in the art. Blends are not laminates, although one or more layers of a laminate may contain a blend.

Claims

1. A polyvinyl chloride composition for preparing a polymer composite article, said composition comprising: (A) an inorganic filler in an amount of 50 to 70% by weight; (B) a polyvinyl chloride polymer in an amount of 25 to less than 50% by weight, wherein the amount of said (A) inorganic filler is greater than the amount of said (B) polyvinyl chloride polymer; (C) an organopolysiloxane in an amount of greater than 0 to 5 weight percent, said organopolysiloxane having at least one silicon-bonded hydroxyl group and a viscosity of 1,000 to 60,000 mPa·s at 25° C.; each based on the total weight of components (A), (B), and (C) in said composition.

2. 2. The composition of claim 1, wherein: (i) the (C) organopolysiloxane exists as a liquid at 25° C.; (ii) the (C) organopolysiloxane has a viscosity of 2,000 to 50,000 mPa·s at 25° C.; or (iii) a combination of (i) and (ii).

3. The organopolysiloxane (C) has the following average unit formula: [R １ ３－ｎ (OH) ｎ SiO １／２ ] ａ’ [R １ ２－ｍ (OH) ｍ SiO ２／２ ] ｂ’ [R １ SiO ３／２ ] ｃ’ [SiO ４／２ ] ｄ’ In the formula, each R １ are independently selected hydrocarbyl groups; n is 0, 1, 2, or 3; m is 0, 1, or 2, with the proviso that n and m are not simultaneously 0; and 0<a'<1, 0<b'<1, 0≦c'≦0.1, and 0≦d'≦0.1, with the proviso that a'+b'+c'+d'=1.

4. The organopolysiloxane (C) has the following average unit formula (I) or (II): [R １ ３－ｎ (OH) ｎ SiO １／２ ] ａ’’ [R １ ２－ｍ (OH) ｍ SiO ２／２ ] ｂ’’ (I) In the formula, each R １ are independently selected hydrocarbyl groups, n is 0, 1, 2, or 3, m is 0, 1, or 2, with the proviso that n and m are not simultaneously 0, and 0<a''<1, 0<b''<1, with the proviso that a''+b''=1; or R １ ３－ｘ (Oh) ｘ Si[SiR １ ２ O] ｃ’’ Si (OH) ｙ R １ ３－ｙ (II) In the formula, each R １ are independently selected hydrocarbyl groups; x is 0, 1, 2, or 3; y is 0, 1, 2, or 3, with the proviso that x and y are not simultaneously 0; and c'' is 60 to 1,200.

5. The composition of any one of claims 1 to 4, wherein (i) the (A) inorganic filler is present in an amount of 50 to 65 weight percent, (ii) the (B) polyvinyl chloride polymer is present in an amount of 30 to less than 50 weight percent, and (iii) the (C) organopolysiloxane is present in an amount of greater than 0 to 5 weight percent.

6. The composition of any one of claims 1 to 4, wherein (i) the (A) inorganic filler is present in an amount of 50 to 60 weight percent, (ii) the (B) polyvinyl chloride polymer is present in an amount of 35 to less than 50 weight percent, and (iii) the (C) organopolysiloxane is present in an amount of greater than 0 to 5 weight percent.

7. The composition according to any one of claims 1 to 6, wherein the inorganic filler is selected from calcium carbonate, talc, and combinations thereof.

8. 8. The composition of any one of claims 1 to 7, further comprising one or more additives selected from colorants, foaming agents, UV and / or light stabilizers, processing aids, preservatives, biocides, flame retardants and / or smoke suppressants, impact modifiers, heat stabilizers, and lubricants.

9. A method for preparing a composition according to any one of claims 1 to 8, comprising the steps of: combining (A) said inorganic filler, (B) said polyvinyl chloride polymer, and (C) said organopolysiloxane, thereby preparing said composition.

10. 1. A method for preparing a polymer composite article, comprising: A method comprising preparing said polymer composite article from the composition of any one of claims 1 to 8.

11. The method further comprising: combining, with mixing, the (A) inorganic filler, the (B) polyvinyl chloride polymer, and the (C) organopolysiloxane at an elevated temperature to obtain a flowable mixture; forming the polymeric composite article from the flowable mixture.

12. 12. The method of claim 11, wherein (i) said (C) organopolysiloxane is liquid when said flowable mixture is combined with said (C) organopolysiloxane.

13. 13. The method of any one of claims 10-12, wherein (i) preparing the polymer composite article from the composition further comprises forming the composition into a desired shape; (ii) preparing the polymer composite article from the composition comprises extruding the composition; (iii) preparing the polymer composite article from the composition comprises molding the composition; or (iv) any combination of (i)-(iii).

14. 14. The method according to claim 10, wherein the method is carried out in an extruder, and (i) the extrusion temperature of the composition in the extruder is reduced compared to the extrusion temperature of a mixture of the (A) inorganic filler and the (B) polyvinyl chloride polymer that does not contain the (C) organopolysiloxane, and / or (ii) the torque of the extruder when mixing the composition is reduced compared to the torque of the extruder when extruding a mixture of the (A) filler and the (B) polymer that does not contain the (C) organopolysiloxane.

15. The method of any one of claims 10 to 14, wherein the article is selected from the group consisting of decking, railings, siding, fences, window frames, flooring, tiles, and baseboards.

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