Compositions containing very low odour vinylidene-substituted aromatic polymers

Abstract

Disclosed is a composition comprising: a) one or more polymers comprising monomer units derived from vinylidene-substituted aromatic monomers; b) one or more antioxidants; and c) one or more additives including a zinc salt, a colorant, a release agent, a filler, reinforcing fibers, a flame retardant additive, a stabilizer, an adsorbent, an antistatic agent, a silicone oil, a flow enhancer, or a combination thereof; wherein the one or more polymers, antioxidants, and additives do not release volatile sulfur compounds when exposed to temperatures of 200 DEG C or higher and release less than 0.02 [mu] gC / g of volatile sulfur compounds according to the test procedure VDA 277. Methods of making articles from the compositions and the articles made are disclosed.

Description

Technical Field

[0001] Disclosed are vinylidene substituted aromatic polymer compositions that do not form or release volatile sulfur-containing compounds when exposed to elevated temperature environments. Disclosed are methods of reducing total volatile sulfur-containing compounds in compositions containing vinylidene substituted aromatic polymers or reducing the release of total volatile sulfur-containing compounds in such compositions. Disclosed are methods of preparing fabricated structures containing such compositions. Disclosed are fabricated structures containing vinylidene substituted aromatic polymer compositions that do not release volatile sulfur-containing compounds. Background Art

[0002] Polymers prepared from vinylidene-substituted aromatic monomers (e.g., styrene) are used in many polymer systems, including foams, packaging (food packaging), medical, electronic, optical, household appliances, and automotive applications. Polymers of vinylidene-substituted aromatic monomers do not exhibit very good impact properties, and modified polymers containing vinylidene-substituted aromatic monomers have been developed to improve impact resistance. Such modified polymers also include conjugated diene (e.g., butadiene)-based rubbers, such as polymers of styrene and acrylonitrile modified with polybutadiene rubber, commonly referred to as acrylonitrile-butadiene-styrene and high-impact polystyrene containing polybutadiene rubber. Such modified vinylidene-substituted aromatic polymers are used for a variety of purposes, such as automotive interior parts. Co-owned application WO 2020 / 143929 discloses vinylidene-substituted aromatic polymer-based compositions containing zinc salts to reduce the odor of such polymer-based compositions.

[0003] Compositions containing vinylidene substituted aromatic polymers may contain odorous volatile sulfur compounds or may release such volatile sulfur compounds during and after high temperature processing, which makes use in odor-sensitive environments (e.g., automotive interior parts) problematic. There is a need for vinylidene substituted aromatic polymer-based compositions that have or release low amounts of total volatile sulfur compositions, especially when exposed to high temperature environments. There is a need for methods of preparing vinylidene substituted aromatic polymer-based compositions and structures prepared therefrom that do not contain or release volatile sulfur compounds or that contain or release low amounts of volatile sulfur compounds. Summary of the invention

[0004] The vinylidene-substituted aromatic polymer compositions and articles disclosed herein exhibit lower amounts of volatile sulfur compounds and therefore release lower levels of volatile sulfur-containing compounds that increase the odor emitted from such compositions and structures. A composition is disclosed comprising: a) one or more polymers containing monomer units derived from vinylidene-substituted aromatic monomers; b) one or more antioxidants; and c) one or more additives, including zinc salts, colorants, mold release agents, fillers, reinforcing fibers, flame retardant additives, stabilizers, adsorbents, antistatic agents, silicone oils, flow enhancers, or combinations thereof; wherein the one or more polymers, antioxidants, and optional additives do not release volatile sulfur compounds when exposed to temperatures of 200° C. or higher, and release less than 0.02 μg C / g of volatile sulfur-containing compounds according to test procedure VDA277. Articles prepared from the disclosed compositions are disclosed, which exhibit desired levels of volatile sulfur compounds. The composition may contain only one or more polymers containing monomer units derived from vinylidene-substituted aromatic monomers. Component a) may consist of one or more polymers comprising monomer units derived from vinylidene-substituted aromatic monomers.

[0005] Vinylidene substituted aromatic monomers contain vinylidene groups directly bonded to aromatic structures. For example, styrene and alpha-methylstyrene. The polymer can be a copolymer containing one or more (meth) acrylates, one or more unsaturated nitriles, one or more conjugated dienes, one or more α- or β-unsaturated monoacids, one or more vinyl halides, one or more vinyl esters, one or more ethylenically unsaturated dicarboxylic acids or anhydrides, one or more dialkyl maleates or fumarates, or one or more comonomers in N-phenylmaleimide. The polymer can be a copolymer containing one or more (meth) acrylates, one or more unsaturated nitriles, one or more conjugated dienes, one or more α- or β-unsaturated monoacids, or one or more comonomers in N-phenylmaleimide. The copolymer can contain vinylidene substituted aromatic monomers and one or more conjugated dienes. The copolymer can contain acrylonitrile butadiene styrene or high impact polystyrene. The copolymer can be prepared by bulk polymerization. The disclosed composition can be in the form of pellets or in the form of a final structure prepared from pellets. The copolymer may contain polybutadiene, wherein the polybutadiene is incorporated into the copolymer during bulk polymerization. The antioxidant in some polybutadienes may contain sulfur.

[0006] The antioxidant may be any antioxidant that does not contain volatile sulfur compounds or does not release volatile sulfur compounds. The antioxidant may be any antioxidant that does not release volatile sulfur compounds when exposed to high temperature conditions (e.g., 200° C. or higher or 250° C. or higher). The antioxidant may be a compound that does not contain a sulfur group. The antioxidant may be one or more of phenol, phosphorus, hydroquinone and alkylated hydroquinone, tocopherol, O- and N-benzyl compounds, alkylene bisphenols, hydroxybenzylated malonates, aromatic hydroxybenzyl compounds, triazine compounds, benzyl phosphonates, acylaminophenols, esters and amides of propionic acid, ascorbic acid or amine antioxidants. The antioxidant may be one or more of phenol, phosphorus, hydroquinone and alkylated hydroquinone, tocopherol, O- and N-benzyl compounds, alkylene bisphenols, hydroxybenzylated malonates, aromatic hydroxybenzyl compounds, triazine compounds, benzyl phosphonates, acylaminophenols, esters and amides of propionic acid, ascorbic acid or an amine-based antioxidant that does not contain a sulfur-containing group.

[0007] Antioxidants can be present in any amount in the composition and structures formed therefrom to retard oxidation of the polymer. Based on the weight of the disclosed composition, the antioxidant can be present in an amount of about 100 parts per million or greater, about 200 parts per million or greater, about 300 parts per million or greater, about 500 parts per million or greater, or about 1000 parts per million or greater. Based on the weight of the disclosed composition, the antioxidant can be present in an amount of about 10,000 parts per million or less, about 8,000 parts per million or less, or about 6,000 parts per million or less.

[0008] Volatile sulfur-containing compounds are any compounds formed and / or released from the compositions disclosed in the present application. Such compounds may be formed or released during processing. Volatile sulfur-containing compounds may be formed during processing, or may be released during processing or after processing. Volatile sulfur-containing compounds may have an unpleasant odor, which may cause problems when processing and / or using the composition. Volatile sulfur-containing compounds can be any sulfur-containing compound that is volatile at processing temperatures. Such compounds may be released or formed at temperatures of about 200° C. or higher or 250° C. or higher. Volatile sulfur-containing compounds may be volatile at ambient temperatures (about 15 to 40° C.), and therefore may be released from the structure prepared for the disclosed composition when used. Such release may cause the structure to emit an unacceptable odor during use. Volatile sulfur-containing compounds can be any sulfur-containing compound having a molecular weight of about 200 g / mole or less. Volatile sulfur-containing compounds can be alkyl mercaptans, such as octyl mercaptan.

[0009] A method of forming an article is disclosed, comprising contacting elements of the composition disclosed herein and forming a structure from the contacted elements, wherein either or both of the contacting step and the forming step result in the contacted elements being exposed to a temperature of about 200°C or higher, provided that exposure to a temperature of about 200°C or higher does not form volatile sulfur compounds or releases small amounts of volatile sulfur compounds. A method is disclosed, comprising contacting elements of the composition disclosed herein in an extruder and pelletizing the extrudate. The contacting step or the forming step may be performed at a temperature of about 250°C or higher.

[0010] Disclosed are methods for preparing vinylidene-substituted aromatic polymers, compositions and articles containing one or more zinc salts. The methods include the steps of mixing vinylidene-substituted aromatic polymer pellets with a zinc salt, feeding the mixture into an extruder, collecting the extrudate and preparing extrudate pellets.

[0011] The disclosed compositions and structures made from such compositions exhibit low odor. According to test procedure VDA277, such compositions release less than 0.02 μgC / g of volatile sulfur compounds. According to the VDA270 odor test procedure, articles formed from the compositions disclosed herein exhibit an odor rating of 3.5 or less. The structures can be used in automobiles, trains, buses, recreational vehicles (RVs), and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The correlation between octanethiol concentration (VDA 277) and measured odor (VDA 270) is shown. DETAILED DESCRIPTION

[0013] While the present disclosure has been described in conjunction with certain embodiments, it should be understood that the present disclosure is not limited to the disclosed embodiments, and is intended to cover various modifications and equivalent arrangements included within the purview of the appended claims, the scope of which is to be given the broadest interpretation so as to encompass all such modifications and equivalent structures permitted by law.

[0014] As used herein, one or more means that at least one or more than one of the listed components can be used as disclosed. As used herein, a hydrocarbyl group refers to a group containing one or more carbon atom backbones and hydrogen atoms, which group may optionally contain one or more heteroatoms. When a hydrocarbyl group contains heteroatoms, the heteroatoms may form one or more functional groups known to those skilled in the art. The hydrocarbyl group may contain any combination of alicyclic, aliphatic, aromatic or such segments. The aliphatic segment may be straight chain or branched. The aliphatic and alicyclic segments may contain one or more double bonds and / or triple bonds. The hydrocarbyl group includes alkyl, alkenyl, alkynyl, aryl, cycloalkyl, cycloalkenyl, alkaryl and aralkyl groups. The alicyclic group may contain both cyclic and non-cyclic parts. Hydrocarbylene means a hydrocarbyl group or any described subset having more than one valence state, such as alkylene, alkenylene, alkynylene, arylene, cycloalkylene, cycloalkenylene, alkarylene and aralkylene. As used herein, valence refers to a covalent bond between a hydrocarbyl or hydrocarbylene group and another group such as a carbonyl, oxygen, nitrogen or sulfur containing group or atom or the base compound mentioned. Unless otherwise indicated, weight % or weight parts as used herein refer to or are based on the weight of the composition. Tg is the temperature or temperature range at which a sudden change in the physical properties of a polymeric material (including, for example, mechanical strength) occurs. Tg can be determined by differential scanning calorimetry (DSC).

[0015] Disclosed are compositions comprising one or more polymers containing vinylidene-substituted aromatic monomers and structures prepared from such polymers, wherein the compositions and structures prepared from the compositions do not release or release low levels of odorous volatile sulfur-containing compounds. The polymer may be a copolymer. Such copolymers may contain one or more (meth)acrylates, one or more unsaturated nitriles, one or more conjugated dienes, one or more α- or β-unsaturated monobasic acids, one or more vinyl halides, one or more vinyl esters, one or more ethylenically unsaturated dicarboxylic acids or anhydrides, one or more dialkyl maleates or fumarates, or N-phenylmaleimide. The composition may contain only one or more polymers containing monomer units derived from vinylidene-substituted aromatic monomers. Such compositions and structures are suitable for avoiding unpleasant odors emanating therefrom. The composition contains an antioxidant. The structure contains one or more additives. The additives that can be used in the composition may be zinc salts, colorants, release agents, impact modifiers, fillers, reinforcing fibers, or combinations thereof. The source of the volatile sulfur-containing compounds may be any component of the composition, including polymers, antioxidants, or additives. Sulfur-containing chain transfer agents are commonly used in the preparation of polymers. Some common antioxidants contain sulfur. During the processing of polymers, compositions and the formation of structures, volatile sulfur compounds may be formed and / or released. Some volatile sulfur compounds may produce unpleasant odors. The composition can be modified with an impact modifier, which may contain an antioxidant. The elements of the composition are selected to reduce the formation and / or release of volatile sulfur compounds that may cause unpleasant odors. The disclosed composition can be mixed or reacted with other known polymer systems (e.g., polycarbonates, polyester carbonates, polyolefins and other styrene-based polymers). The important issue is that the disclosed composition must meet the odor requirements disclosed herein before being mixed or reacted with other polymer systems.

[0016] The polymer disclosed herein contains vinylidene-substituted aromatic monomers. Vinylidene-substituted aromatic monomers contain vinylidene groups, alkenyl groups directly bonded to aromatic structures. Vinylidene-substituted aromatic monomers may contain one or more aromatic rings, may contain one or two aromatic rings, or may contain one aromatic ring. The aromatic ring may be unsubstituted or substituted with a substituent that does not interfere with the polymerization of vinylidene-substituted aromatic monomers or the manufacture of polymers to form the desired structure. The substituent may be a halogen or alkyl group, such as bromine, chlorine, or a C1 to C4 alkyl group; or a methyl group. Alkenyl groups include straight or branched carbon chains having one or more double bonds, or one double bond. Alkenyl groups that can be used for vinylidene-substituted aromatic monomers may include those alkenyl groups that can be polymerized to form polymers when bonded to aromatic rings. Alkenyl groups may have 2 to 10 carbon atoms, 2 to 4 carbon atoms, or 2 carbon atoms. Exemplary vinylidene substituted aromatic monomers include styrene, α-methylstyrene, N-phenylmaleimide and chlorostyrene or α-methylstyrene and styrene. The vinylidene substituted aromatic monomer can be a monovinylidene aromatic monomer containing one unsaturated group. Vinylidene aromatic monomers include, but are not limited to, those described in U.S. Pat. Nos. 4,666,987; 4,572,819 and 4,585,825, which are incorporated herein by reference. The monomer may correspond to the following formula:

[0017]

[0018] Where R 1is independently hydrogen or methyl at each occurrence; and Ar is independently an aromatic group at each occurrence. Ar may contain one or more aromatic rings, may contain one or two aromatic rings, or may contain one aromatic ring. n is independently 1 to 3, 1 to 2 or 1 at each occurrence. The aromatic ring may be unsubstituted or substituted with a substituent that does not interfere with the polymerization of the vinylidene-substituted aromatic monomer or the manufacture of a polymer to form a desired structure. The substituent may be a halogen or an alkyl group, such as a bromine, a chlorine or a C1 to C4 alkyl group; or a methyl group. The vinylidene-substituted aromatic monomer may be present in the polymer in a sufficient amount so that the polymer exhibits favorable properties associated with polymers of vinylidene-substituted aromatic monomers (e.g., polystyrene). Advantageous properties of polymers of vinylidene-substituted monomers include a glass transition temperature of about 100°C or higher, transparency required for use, a high heat distortion temperature, and the like. Other favorable properties of polymers of vinylidene-substituted monomers include processability, rigidity, and thermal stability. The polymers disclosed herein contain vinylidene substituted aromatic monomers in an amount of about 10% by weight or more, about 15% by weight or more, or about 20% by weight or more of the polymer. The polymer of the one or more vinylidene aromatic monomers may contain vinylidene substituted aromatic monomers in an amount of about 100% by weight or less, about 90% by weight or less, or about 60% by weight or less of the polymer.

[0019] The composition can contain branching agents commonly used in polymers based on vinylidene aromatic compounds. The branching agent can be an aromatic monomer substituted with vinylidene groups having 2 or more vinylidene groups. Other branching agents can include other difunctional and generally multifunctional (functionality>2) monomers, multifunctional initiators and multifunctional chain transfer agents, etc. The branching agent can be present in the polymer in an amount of about 0.001% by weight or more, about 0.002% by weight or more, or about 0.003% by weight or more of the composition. The branching agent can be present in the polymer in an amount of about 0.5% by weight or less, about 0.2% by weight or less, or about 0.1% by weight or less of the composition.

[0020] The copolymer may include two or more monomers, vinylidene substituted aromatic monomers and / or one or more (meth) acrylates, one or more unsaturated nitriles, one or more conjugated dienes, one or more α- or β-unsaturated monoacids, one or more vinyl halides, one or more vinyl esters, one or more ethylenically unsaturated dicarboxylic acids or anhydrides, or one or more dialkyl maleates or fumarates. The copolymer may contain styrene and N-phenylmaleimide. The copolymer may contain one or more (meth) acrylates, one or more unsaturated nitriles, one or more conjugated dienes, one or more α- or β-unsaturated monoacids, or N-phenylmaleimide. The copolymer may contain vinylidene substituted aromatic monomers and one or more conjugated dienes. The copolymer contains acrylonitrile butadiene styrene or high impact polystyrene. The copolymer may be impact modified with an impact modifier. The impact modifier may be a polymerized conjugated diene. The impact modifier may be polybutadiene.

[0021] The polymer disclosed herein may include one or more (meth)acrylates. As used herein, (meth)acrylates refer to compounds having a vinyl group bonded to the carbonyl portion of an alkyl ester, wherein the carbon of the vinyl group bonded to the carbonyl group also has a hydrogen or methyl group bonded thereto. The term (methyl) as used in this context refers to a compound having a hydrogen or methyl group on the carbon of the vinyl group bonded to the carbonyl group. Useful (meth)acrylates include those corresponding to the following formula:

[0022]

[0023] Where R a is independently H or -CH3 at each occurrence; and R b Can be C1 to C- 30 Alkyl group or C 1-10Alkyl groups. The examples of the one or more (meth) acrylates include low-level (meth) alkyl acrylates, such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) (acrylate) and hexyl (meth) acrylate. The one or more (meth) acrylates in the polymer can be present in sufficient amounts to provide the desired properties of the polymer, such as processability, practical toughness, refractive index, environmental stress cracking resistance, hydrolytic stability, thermal stability, UV stability, impact resistance, weather resistance, etc. The polymer disclosed herein contains (meth) acrylates in an amount of about 0 weight % or more, about 1 weight % or more, or about 2 weight % or more of the polymer. The polymer disclosed herein contains (meth) acrylates in an amount of about 20 weight % or less, about 15 weight % or less, about 10 weight % or less, about 8 weight % or less, or about 5 weight % or less of the polymer.

[0024] Polymer can comprise one or more unsaturated nitriles. Unsaturated nitriles include but are not limited to acrylonitrile, methacrylonitrile, ethacrylonitrile, fumaronitrile and their mixture. Unsaturated nitriles can be acrylonitrile. Unsaturated nitriles are used to improve glass transition temperature, transparency, chemical resistance etc. in polymer. Polymer disclosed herein can contain one or more unsaturated nitriles in an amount of about 0 wt % or more, about 1 wt % or more or about 2 wt % or more of polymer. Polymer can contain one or more unsaturated nitriles accounting for about 40 wt % or less, about 35 wt % or less, about 30 wt % or less or about 20 wt % or less of the amount of polymer.

[0025] Other vinyl monomers may also be included in the polymer in amounts sufficient to provide the desired properties as disclosed herein, including conjugated 1,3 dienes (e.g., butadiene, isoprene, etc.); α- or β-unsaturated monoacids and their derivatives (e.g., acrylic acid, methacrylic acid, etc.); vinyl halides, such as vinyl chloride, vinyl bromide; vinylidene chloride, vinylidene bromide; vinyl esters, such as vinyl acetate, vinyl propionate, etc.; ethylenically unsaturated dicarboxylic acids and anhydrides and their derivatives, such as maleic acid, fumaric acid, maleic anhydride, dialkyl maleates or fumarates, such as dimethyl maleate, diethyl maleate, dibutyl maleate, the corresponding fumarate, etc. These additional comonomers may be incorporated into the composition in several ways, including cross-polymerization with the copolymer containing the vinylidene-substituted aromatic compound, and / or polymerization into a polymer component that can be combined (e.g., blended with the polymer). If present, the amount of such comonomers may be about 20 wt % or less, about 10 wt % or less, or about 5 wt % or less, based on the total weight of the polymer. Such comonomers may be present in an amount of about 1 wt % or more of the polymer.

[0026] The disclosed composition may contain an impact modifier. The terms impact modifier and rubber are used interchangeably herein. Various impact modifiers can be used in the disclosed composition; such as diene rubber, ethylene propylene rubber, ethylene propylene diene (EPDM) rubber, ethylene copolymer rubber, acrylate rubber, polyisoprene rubber, silicone rubber, silicone-acrylate rubber, polyurethane, thermoplastic elastomer, halogen-containing rubber, and mixtures thereof. Also suitable are interpolymers of rubber-forming monomers and other copolymerizable monomers. The rubber may be present in a sufficient amount in the formulated composition to provide the desired impact properties to the composition. The desired impact properties include increased izod, charpy, gardner, stretching, falling dart, etc. The amount of the impact modifier (rubber) that the composition disclosed herein may contain is about 0.5% by weight or more, about 1% by weight or more, about 2% by weight or more, or about 7% by weight or more of the composition. The compositions disclosed herein may contain an impact modifier (rubber) in an amount of about 50% by weight or less, about 45% by weight or less, about 40% by weight or less, about 30% by weight or less, about 20% by weight or less, or about 10% by weight or less of the composition. The compositions disclosed herein may contain a copolymer in an amount of about 50% by weight or more of the composition. The compositions disclosed herein contain a copolymer in an amount of about 99.5% by weight or less of the composition, about 93% by weight or less of the composition, about 80% by weight or less of the composition, or about 60% by weight or less of the composition. As used in this context, a formulated composition is a formulated composition containing all ingredients for the intended use.

[0027] The rubber can be a mixture of diene rubbers such as polybutadiene, polyisoprene, polypentadiene, polychloroprene, etc. or diene rubbers, i.e., any rubbery polymer of one or more conjugated 1,3-dienes such as 1,3-butadiene. Such rubbers include homopolymers of 1,3-butadiene and polymers of 1,3-butadiene and one or more copolymerizable monomers such as vinylidene-substituted aromatic compounds (styrene). The diene rubber can be a homopolymer of 1,3-butadiene. Exemplary polymers of 1,3-butadiene are at least about 30% by weight of 1,3-butadiene, about 50% by weight, about 70% by weight, or about 90% by weight of 1,3-butadiene and up to about 70% by weight of vinylidene-substituted aromatic monomers, up to about 50% by weight, up to about 30% by weight, or up to about 10% by weight of vinylidene-substituted aromatic monomers Block or tapered block rubber, weight based on the weight of the 1,3-butadiene copolymer.

[0028] The impact modifiers employed may be those that exhibit a secondary transition temperature (sometimes referred to as a glass transition temperature (Tg)) that is no greater than 0°C or no greater than -20°C for the diene segment as determined using conventional techniques (e.g., ASTM test method D746-52T). The diene rubber may have a weight average molecular weight of at least about 100 kilograms per mole (kg / mol) or a weight average molecular weight of at least about 300 kg / mol. The diene rubber may have a weight average molecular weight equal to or less than about 900 kg / mol or a weight average molecular weight equal to or less than 600 kg / mol. The diene rubber may have a solution viscosity of at least 10 centistokes (cSt) (ten percent (10%) solution in styrene) or a solution viscosity of about 30 cSt. The diene rubber may have a solution viscosity of about 500 cSt or about 400 cSt or less. The rubber with the grafted and / or occluded polymer (if present) is dispersed in the continuous matrix phase in the form of discrete particles.

[0029] The rubber particles may include a range of sizes with unimodal, bimodal or multimodal distributions. The average particle size of the rubber particles refers to the volume average diameter. The volume average diameter of a group of particles may be the same as the weight average. The average particle diameter measurement includes polymer grafted to the rubber particles and occlusions of the polymer within the particles. Unless otherwise indicated, the rubber particle sizes disclosed and claimed herein are those with ACCUCOMP TM The following method is used to measure the particle size of a polymer sample on a Coulter Multisizer II or II e with software version 2.01: About 3 polymer sample pellets (30-70 mg) are dissolved in 5 milliliters (ml) of dimethylformamide (DMF) by stirring using an ultrasonic bath for about 15 minutes to 20 minutes. 10 ml of electrolyte solution (DMF containing 1% NH4SCN) is mixed with 0.2 ml of sample solution. A plow measuring station is used with a 20-micron Coulter tube and a 1.16-micron calibration material. The coincidence level indicator reading of the device should be between 5% and 10%. If the reading is higher than 10%, dilute the sample with electrolyte solution in a beaker, or if the reading is too low, add more drops of polymer solution in DMF. The volume average particle size is reported. The average particle size of the rubber particles may be about 0.05 microns (micrometers) (μm) or less, about 0.1 microns or less, or about 0.6 microns or less. The rubber particles may have an average particle size diameter of about 10 microns or less, about 5 microns or less, or about 2 microns or less.

[0030] The disclosed compositions may contain one or more additives commonly used in compositions of this type. Exemplary additives include: zinc salts, colorants, mold release agents, fillers, reinforcing fibers, flame retardant additives, stabilizers, adsorbents (e.g., zeolites, activated carbon, bamboo charcoal, etc.), antistatic agents, silicone oils, flow enhancers, etc. Exemplary anti-ignition additives include halogenated hydrocarbons, halogenated carbonate oligomers, halogenated diglycidyl ethers, organophosphorus compounds, fluorinated olefins, antimony oxides, and metal salts of aromatic sulfur, or mixtures thereof may be used. Compounds that stabilize the rubber-modified vinylidene-substituted aromatic copolymer compositions to prevent degradation caused by, but not limited to, heat, light, and oxygen, or mixtures thereof may be used. Fillers and reinforcing agents may also be present. Exemplary fillers include talc, clay, wollastonite, mica, glass, or mixtures thereof. Some of these additives may adsorb volatile organic compounds, such as zeolites, activated carbon, bamboo charcoal, etc.

[0031] The additive and / or filler and / or adsorbent may be present in the formulated composition in an amount of about 0.01 % by weight or more, about 0.1 % by weight or more, about 1 % by weight or more, about 2 % by weight or more, or about 3 % by weight or more, based on the weight of the composition. The additive and / or filler may be present in an amount of about 40 % by weight or less, about 30 % by weight or less, about 20 % by weight or less, about 15 % by weight or less, about 10 % by weight or less, about 5 % by weight or less, based on the weight of the composition. Based on the weight of the composition, additives and adsorbents may be present independently in an amount of up to 5 % by weight, and fillers may be present in an amount of up to about 40 % by weight.

[0032] The disclosed compositions contain one or more antioxidants. Any antioxidant that does not form or release volatile sulfur compounds can be used. The antioxidant can be any antioxidant that does not contain volatile sulfur compounds or does not release volatile sulfur compounds. The antioxidant can be any antioxidant that does not release volatile sulfur compounds when exposed to high temperature conditions (e.g., 200° C. or higher or 250° C. or higher). The antioxidant can be a compound that does not contain a sulfur group. The antioxidant can be introduced into the composition from the ingredients used (e.g., impact modifiers). The antioxidant can be added to the composition alone.

[0033] The antioxidant may be one or more of phenol, phosphorus, hydroquinone and alkylated hydroquinone, tocopherol, O- and N-benzyl compounds, alkylene bisphenols, hydroxybenzylated malonates, aromatic hydroxybenzyl compounds, triazine compounds, benzyl phosphonates, acylaminophenols, esters and amides of propionic acid, ascorbic acid, or an amine-based antioxidant. The antioxidant may be one or more of phenol, phosphorus, hydroquinone and alkylated hydroquinone, tocopherol, O- and N-benzyl compounds, alkylene bisphenols, hydroxybenzylated malonates, aromatic hydroxybenzyl compounds, triazine compounds, benzyl phosphonates, acylaminophenols, esters and amides of propionic acid, ascorbic acid, or an amine-based antioxidant that does not contain a sulfur-containing group.

[0034] Phenol-based antioxidants include 2,6-di-tert-butyl-4-methylphenol; 2,6-diphenyl-4-methoxyphenol; 2,2′-methylenebis(6-tert-butyl-4-methylphenol); 2,2′-methylenebis(6-tert-butyl-4-methylphenol); 2,2′-methylenebis[4-methyl-6-(α-methylcyclohexyl)phenol]; 1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)butane; 2,2′-methylenebis(4-methyl-6-cyclohexylphenol); 2,2′-methylenebis(4-methyl-6-nonylphenol); 1,1, 3-Tris(5-tert-butyl-4-hydroxy-2-methylphenyl)butane; 2,2-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)-4-n-dodecylmercaptobutane; ethylene glycol bis[3,3-bis(3-tert-butyl-4-hydroxyphenyl)butyrate]; 1,1-bis(3,5-dimethyl-2-hydroxyphenyl)-3-(n-dodecylthio)butane; 4,4′-thiobis(6-tert-butyl-3-methylphenol); 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene; 2,2-bis(3,5-di-tert-butyl Hydroquinone and alkylated hydroquinone antioxidants include 2,6-di-tert-butyl-4-methoxyphenol, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone, 2,6-diphenyl-4-octadecyloxyphenol, 2,6-di-tert-butylhydroquinone, 2,6-di-tert-butyl-4-hydroxyphenyl propionate ... Antioxidants based on tocopherol include α-tocopherol, β-tocopherol, γ-tocopherol, δ-tocopherol and mixtures thereof (vitamin E). Antioxidants based on O- and N-benzyl compounds include, for example, 3,5,3′,5′-tetra-tert-butyl-4,4′-dihydroxydibenzyl ether and tris(3,5-di-tert-butyl-4-hydroxybenzyl)amine.Alkylene bisphenol-based antioxidants include: 2,2'-methylenebis(6-tert-butyl-4-methylphenol), 2,2'-methylenebis(6-tert-butyl-4-ethylphenol), 2,2'-methylenebis[4-methyl-6-(α-methylcyclohexyl)phenol], 2,2'-methylenebis(4-methyl-6-cyclohexylphenol), 2,2'-methylenebis(6-nonyl-4-methylphenol), 2,2'-methylenebis(4,6-di-tert-butylphenol), 2,2'-ethylenebis(4,6-di-tert-butylphenol), 2,2'-ethylenebis(6-tert-butyl-4-isobutylphenol), 2,2'-methylenebis[6-(α-methylbenzyl)-4-nonylphenol], 2,2'-methylenebis[6-(α,α-dimethylbenzyl)-4-nonylphenol], 4,4'-methylenebis(2 ,6-di-tert-butylphenol), 4,4′-methylenebis(6-tert-butyl-2-methylphenol), 1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)butane, 2,6-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol, 1,1,3-tri(5-tert-butyl-4-hydroxy-2-methylphenyl)butane, ethylene glycol bis[3,3-bis(3′-tert-butyl- The antioxidants based on hydroxybenzylated malonate include dioctadecyl-2,2-bis(3,5-di-tert-butyl-2-hydroxybenzyl)malonate, dioctadecyl-2-(3-tert-butyl-4-hydroxy-5-methylbenzyl)malonate, bis[4-(1,1,3,3-tetramethylbutyl)phenyl]-2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate. Aromatic hydroxybenzyl-based antioxidants include 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, 1,4-bis(3,5-di-tert-butyl-4-hydroxybenzyl)-2,3,5,6-tetramethylbenzene, and 2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)phenol.The antioxidants based on triazine compounds include 2,4-bis(octylmercapto)-6-(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine, 2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine, 2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,3,5-triazine, 2,4,6-tris-(3,5-di-tert-butyl- isocyanurate, 2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenylethyl)-1,3,5-triazine, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)-hexahydro-1,3,5-triazine and 1,3,5-tris(3,5-dicyclohexyl-4-hydroxybenzyl) isocyanurate. Benzylphosphonate-based antioxidants include dimethyl-2,5-di-tert-butyl-4-hydroxybenzylphosphonate, diethyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate, dioctadecyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate, dioctadecyl-5-tert-butyl-4-hydroxy-3-methylbenzylphosphonate, and the calcium salt of 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid monoethyl ester. Acylaminophenol-based antioxidants include, for example, 4-hydroxylauroylanilide, 4-hydroxystearylanilide, and octyl N-(3,5-di-tert-butyl-4-hydroxyphenyl)carbamate. Exemplary antioxidants include esters of D-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid with monohydric or polyhydric alcohols (e.g., methanol, ethanol, n-octanol, isooctyl alcohol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propylene glycol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol), tris(hydroxyethyl)isocyanurate, N,N'-bis(hydroxyethyl)oxamide, 3-thioundecanol, 3-thiopentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane. Exemplary antioxidants include esters of β-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic acid with monohydric or polyhydric alcohols (e.g., methanol, ethanol, n-octanol, isooctyl alcohol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propylene glycol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol), tris(hydroxyethyl)isocyanurate, N,N′-bis ... ethyl)oxalamide, 3-thioundecanol, 3-thiopentadecanol, trimethyl hexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane; 3,9-bis[2-{3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]-undecane.Exemplary antioxidants include esters of β-(3,5-dicyclohexyl-4-hydroxyphenyl)propionic acid with monohydric or polyhydric alcohols (e.g., methanol, ethanol, octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propylene glycol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol), tris(hydroxyethyl)isocyanurate, N,N'-bis(hydroxyethyl)oxamide, 3-thioundecanol, 3-thiopentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane. Exemplary antioxidants include esters of 3,5-di-tert-butyl-4-hydroxyphenylacetic acid with monohydric or polyhydric alcohols (e.g., methanol, ethanol, octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propylene glycol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol), tris(hydroxyethyl)isocyanurate, N,N′-bis(hydroxyethyl)oxamide, 3-thioundecanol, 3-thiopentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane. Exemplary antioxidants include amides of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, such as N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexamethylene diamide, N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)trimethylene diamide, N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazide, N,N′-bis[2-(3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionyloxy)ethyl]oxalamide (. XL-1, provided by Uniroyal). An exemplary antioxidant is ascorbic acid (vitamin C). Amine antioxidants include N,N′-diisopropyl-p-phenylenediamine, N,N′-di-sec-butyl-p-phenylenediamine, N,N′-bis(1,4-dimethylpentyl)-p-phenylenediamine, N,N′-bis(1-ethyl-3-methylpentyl)-p-phenylenediamine, N,N′-bis(1-methylheptyl)-p-phenylenediamine, N,N′-dicyclohexyl-p-phenylenediamine, N,N′-diphenyl-p-phenylenediamine, N,N′-bis(2-naphthyl)-p-phenylenediamine, N-isopropyl-N′-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine, N-( 1-methylheptyl)-N'-phenyl-p-phenylenediamine, N-cyclohexyl-N'-phenyl-p-phenylenediamine, N,N'-dimethyl-N,N'-di-sec-butyl-p-phenylenediamine, diphenylamine, N-allyl diphenylamine, 4-isopropoxy diphenylamine, N-phenyl-1-naphthylamine, N-(4-tert-octylphenyl)-1-naphthylamine, N-phenyl-2-naphthylamine, octylated diphenylamine, p,p'-di-tert-octyl diphenylamine, 4-n-butylaminophenol, 4-butyrylaminophenol, 4-nonanoylaminophenol, 4-dodecylaminophenol, 4-octadecanoylaminophenol, bis(4 -methoxyphenyl)amine, 2,6-di-tert-butyl-4-dimethylaminomethylphenol, 2,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, N,N,N',N'-tetramethyl-4,4'-diaminodiphenylethane, 1,2-bis[(2-methylphenyl)amino]ethane, 1,2-bis(phenylamino)propane, (o-tolyl)biguanide, bis[4-(1',3'-dimethylbutyl)phenyl]amine, tert-octylated N-phenyl-1-naphthylamine, mixtures of mono- and di-alkylated tert-butyl / tert-octyl diphenylamines, mono- and di-alkylated mixture of monoalkylated nonyldiphenylamine, mixture of monoalkylated and dialkylated dodecyldiphenylamine, mixture of monoalkylated and dialkylated isopropyl / isohexyldiphenylamine, mixture of monoalkylated and dialkylated tert-butyldiphenylamine, N,N,N′,N′-tetraphenyl-1,4-diaminobut-2-ene, N,N-bis(2,2,6,6-tetramethylpiperidin-4-yl-hexamethylenediamine, bis(2,2,6,6-tetramethylpiperidin-4-yl)sebacate, 2,2,6,6-tetramethylpiperidin-4-one, 2,2,6,6-tetramethylpiperidin-4-ol.Phosphorus antioxidants include tetrakis(2,4-di-tert-butylphenyl)-4,4-biphenylene phosphite, tris(2,4-di-tert-butylphenyl)phosphite, 2,2'-methylenebis(4,6-di-tert-butylphenyl)octylphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, di(nonylphenyl)pentaerythritol diphosphite, phenyl-bisphenol A-pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, dioctyl pentaerythritol diphosphite, dilauryl pentaerythritol diphosphite, Phosphites, diphenyl pentaerythritol diphosphites, dicyclohexyl pentaerythritol diphosphites, bis(2,4,6-tri-tert-butylphenyl)pentaerythritol diphosphites, 2,2'-ethylenebis(4,6-di-tert-butylphenyl)fluorophosphites, triisodecylphosphites, tridodecylphosphites, phenylisooctylphosphites, phenylisodecylphosphites, phenyldodecylphosphites, diphenylisooctylphosphites, diphenylisodecylphosphites, diphenyldodecylphosphites, triphenylphosphites, tri(monononylphenyl)phosphites and tri(dinononylphenyl)phosphites. The antioxidant may be octadecyl 3,5-di-(tert-)-butyl-4-hydroxyhydrocinnamate, which may be commercially available from BASF as IRGANOX 1076.

[0035] Antioxidants can be present in any amount in the composition and structures formed therefrom to retard oxidation of the polymer. Based on the weight of the disclosed composition, the antioxidant can be present in an amount of about 100 parts per million or greater, about 200 parts per million or greater, about 300 parts per million or greater, about 500 parts per million or greater, or about 1000 parts per million or greater. Based on the weight of the disclosed composition, the antioxidant can be present in an amount of about 10,000 parts per million or less, about 8,000 parts per million or less, or about 6,000 parts per million or less.

[0036] Volatile sulfur-containing compounds are any compounds formed and / or released from the compositions disclosed in the present application. Such compounds may be formed or released during processing. Volatile sulfur-containing compounds may be formed during processing, or may be released during processing or after processing. Volatile sulfur-containing compounds may have an unpleasant odor, which may cause problems when processing and / or using the disclosed compositions. Volatile sulfur-containing compounds may be any sulfur-containing compounds that are volatile at processing temperatures. Such compounds may be released or formed at temperatures of about 200° C. or higher or 250° C. or higher. Volatile sulfur-containing compounds may be volatile at ambient temperatures (about 15 to 40° C.), and therefore may be released from the structure prepared for the disclosed composition when used. Such release may cause the structure to emit an unacceptable odor during use. Volatile sulfur-containing compounds may be any sulfur-containing compounds having a molecular weight of about 200 g / mole or less. Volatile sulfur-containing compounds may be alkyl mercaptans, such as octyl mercaptan. The source of the volatile sulfur-containing compound can be any component of the composition, including the polymer, antioxidant or additive. Sulfur-containing chain transfer agents are often used in the preparation of polymers. Some common antioxidants contain sulfur in their molecules.

[0037] Also disclosed herein are exemplary vinylidene substituted aromatic copolymers, including acrylonitrile and styrene monomers in various ratios. The disclosed acrylonitrile-styrene polymers may contain a concentration of about 25 wt % or more, about 50 wt % or more, or about 70 wt % or more styrene monomers and a concentration of about 25 wt % or more, or about 50 wt % or more, or about 70 wt % or more acrylonitrile monomers. The disclosed acrylonitrile-styrene polymers may contain a concentration of about 80 wt % or less, about 55 wt % or less, or about 30 wt % or less styrene monomers and a concentration of about 80 wt %, about 55 wt % or less, or less, or about 30 wt % or less acrylonitrile monomers.

[0038] Also disclosed herein are exemplary vinylidene-substituted aromatic polymers composed of different proportions of nitrile monomers, diene monomers, and vinylidene-substituted aromatic monomers, which may result in distinct physical properties. The disclosed polymers may contain vinylidene-substituted aromatic monomers at a concentration of about 50% by weight or more, about 65% by weight or more, about 70% by weight or more, diene monomers at a concentration of about 6% by weight or more, about 9% by weight or more, about 12% by weight or more, about 15% by weight or more, and nitrile monomers at a concentration of about 10% by weight or more, about 20% by weight or more, about 30% by weight or more. The disclosed polymers may contain vinylidene-substituted aromatic monomers at a concentration of about 55% by weight or less, about 60% by weight or less, or about 75% by weight or less, diene monomers at a concentration of about 8% by weight or less, about 13% by weight or less, or about 18% by weight or less, and nitrile monomers at a concentration of about 15% by weight or less, about 25% by weight or less, or about 35% by weight or less. The disclosed polymers may contain a vinylidene-substituted aromatic monomer in a concentration of about 60 weight percent, a diene monomer in a concentration of about 12 weight percent or less, and a nitrile monomer in a concentration of about 23 percent.

[0039] Also disclosed herein are exemplary vinylidene-substituted aromatic polymers comprising various proportions of acrylonitrile, butadiene and styrene monomers. The disclosed acrylonitrile-butadiene-styrene polymers may contain a styrene monomer having a concentration of about 50% by weight or more, about 65% by weight or more, about 70% by weight or more, a butadiene monomer having a concentration of about 6% by weight or more, about 9% by weight or more, about 12% by weight or more, about 15% by weight or more, and an acrylonitrile monomer having a concentration of about 10% by weight or more, about 20% by weight or more, about 30% by weight or more. The disclosed acrylonitrile-butadiene-styrene polymers may contain a styrene monomer having a concentration of about 55% by weight or less, about 60% by weight or less, or about 75% by weight or less, a butadiene monomer having a concentration of about 8% by weight or less, about 13% by weight or less, or about 18% by weight or less, and an acrylonitrile monomer having a concentration of about 15% by weight or less, about 25% by weight or less, or about 35% by weight or less. The disclosed acrylonitrile-butadiene-styrene polymer may contain a styrene monomer concentration of about 60 wt%, a butadiene monomer concentration of about 12 wt% or less, and an acrylonitrile monomer concentration of about 23%. The disclosed acrylonitrile-butadiene-styrene polymer may be analyzed by several different methods, including, for example, FTIR (i.e., Fourier transform infrared spectroscopy, which can be used to characterize the peaks of functional groups of acrylonitrile, styrene, and butadiene rubber), PGC-MS (i.e., pyrolysis gas chromatography-mass spectrometry), and EG-MS (i.e., thermal outgassing analyzer-mass spectrometry).

[0040] The disclosed polymers may optionally include an acrylate comonomer and / or a maleimide comonomer. The comonomer may be n-butyl acrylate or N-phenylmaleimide or a combination thereof. n-butyl acrylate may be present in an amount less than about 10 wt %, and N-phenylmaleimide may be present in an amount less than about 10 wt %.

[0041] The disclosed compositions may include zinc salts. The disclosed polymers, compositions and articles may contain from about 0.05% by weight to about 2% by weight of a zinc salt. The zinc salt may be a zinc salt of a long chain fatty acid. The long chain acid may contain 20 or more carbons or 30 or more carbons. The long chain acid may contain 40 or less carbons. The zinc salt may be zinc ricinoleate, zinc stearate, zinc palmitate, zinc laurate, zinc oxide, zinc carbonate, or a combination thereof.

[0042] The composition may optionally include a component that adsorbs volatile organic compounds. The component may be zeolite, activated carbon, bamboo, charcoal, or a combination thereof.

[0043] The disclosed composition may contain one or more zinc salts in a concentration sufficient to reduce the amount of volatile sulfur compounds in the polymer. The disclosed composition may contain one or more zinc salts in a concentration of about 0.05 wt % or more, about 0.1 wt % or more, about 0.5 wt % or more, or about 1 wt % or more. The disclosed composition may contain a zinc salt in a concentration of about 4 wt % or less, about 3 wt % or less, or about 2 wt % or less, or 1.5 wt % or less. The zinc salt may be zinc ricinoleate.

[0044] Various techniques for producing polymers are disclosed. Examples of these known polymerization processes include bulk polymerization, bulk solution polymerization, or bulk-suspension polymerization, commonly referred to as bulk polymerization processes. For a detailed discussion of how to prepare compositions containing monovinylidene aromatic copolymers, see "Modern Styrenic Polymers" of Series In Polymer Science (Wiley), edited by John Scheirs and Duane Priddy, published in 2003, see pages 43-72, ISBN 0471 497525. Also, for example, U.S. Patent Nos. 3,660,535, 3,243,481, and 4,239,863, the relevant portions of which are incorporated herein by reference. Continuous bulk polymerization techniques are advantageously used to prepare polymers. The polymerization may be carried out in one or more substantially linear, stratified flow or so-called "plug flow" type reactors, such as described in U.S. Pat. No. 2,727,884, which is sometimes referred to as a multi-zone plug flow bulk process, which may or may not include recycling of a portion of the polymer product, or, alternatively, the polymerization may be carried out in a stirred tank reactor in which the contents of the reactor are substantially uniform throughout, which reactor is typically used in combination with one or more plug flow type reactors. The stirred tank reactor may be a boiling reactor and / or a coil reactor. Such reactors may be used in series. Methods for preparing polymers using stirred tank reactors have been described above. Modern Styrenic Polymers The polymers may also be prepared using a parallel reactor arrangement as taught in EP 412801.

[0045] The multi-zone plug flow bulk process includes a series of polymerization vessels (or towers) that are connected in series to provide multiple reaction zones. A monomer mixture for preparing a copolymer is formed and then fed into the reaction system. The rubber (e.g., butadiene rubber) may be dissolved in the monomer mixture before being fed into the reaction system. The polymerization may be initiated by thermal or chemical means, and the viscosity of the reaction mixture will gradually increase. During the reaction process, when present, the rubber may be grafted with the copolymer, and a bulk copolymer (also referred to as a free copolymer or matrix copolymer or non-grafted copolymer) is also formed in the rubber solution. When the free copolymer cannot be "kept" in a single continuous "phase" of the rubber solution, the free copolymer begins to form copolymer domains dissolved in the monomer and solvent. The polymerization mixture is now a two-phase system. As the polymerization continues, more and more free copolymers are formed, and the rubber phase begins to disperse itself (rubber domains) in the matrix of the growing free copolymer phase. Eventually, the free copolymer becomes a continuous phase. Some copolymers are also encapsulated inside the rubber particles. Pre-phase inversion means that the rubber solution is the continuous phase and no rubber particles are formed, and post-phase inversion means that substantially all of the rubber phase has been converted to rubber domains and a continuous copolymer phase exists. After the phase inversion, more matrix copolymer may be formed.

[0046] A feed with a functional monomer (such as N-phenylmaleimide) that can increase the Tg of the matrix and the heat resistance of the product can be added at one or more locations throughout the polymerization process, which can be the same or different from the location where the copolymer is added, for example, see U.S. Pat. Nos. 5,412,036 and 5,446,103. A feed with a functional additive (such as ethylene-bisstearamide, dialkyl adipate, polydimethylsiloxane) or other lubricant or release agent that increases the processability of the product can be added at one or more locations throughout the polymerization, devolatilization and conveying process, which can be the same or different from the location where the comonomer is added.

[0047] When the desired monomer conversion level and the base copolymer having the desired molecular weight distribution are obtained, the polymerization mixture, in the presence of rubber, can then be subjected to conditions sufficient to crosslink the rubber and remove any unreacted monomers and solvents. Such crosslinking and removal of unreacted monomers and removal of diluents or solvents (if employed) and other volatile materials are advantageously carried out using conventional devolatilization techniques, such as introducing the polymerization mixture into a devolatilization chamber, flashing off the monomers and other volatiles at elevated temperatures, e.g., 130° C. to 300° C. and / or under vacuum, and removing them from the chamber. The polymer can thereafter be extruded and bulk pellets obtained from the pelletizer.

[0048] The temperature at which the polymerization is carried out depends on a variety of factors, including the type and concentration of the specific initiator and rubber, the comonomer, the reactor setting (e.g., linear, parallel, recyclable, etc.), and the reaction solvent (if any) employed. A polymerization temperature of about 60°C to about 160°C may be employed before phase inversion, and a temperature of about 100°C to about 200°C may be employed after phase inversion. Bulk polymerization is continued at such elevated temperatures until the desired monomer to polymer conversion is obtained. It is desirable that the conversion rate (sometimes also referred to as solid percentage) of the monomer added to the polymerization system (i.e., the monomer added to the feed and any additional stream (including any recycle stream)) to the polymer is 55% to 90% by weight or 60% to 85% by weight. The solid percentage is the ratio of the weight of the solid (e.g., rubber plus matrix (co)polymer) to the weight of the reaction mixture (e.g., one or more unpolymerized monomers) expressed as a percentage at any given time during the polymerization reaction.

[0049] The molecular weight of the polymer is directly related to the entanglement effect due to its rheology and physical properties. The molecular weight of the matrix copolymer produced in the grafting reactor during the production of the rubber-modified vinylidene aromatic substituted copolymer can be adjusted by adding a suitable chain transfer agent. Chain transfer agents or molecular weight regulators are substances that can undergo atom or group transfer or addition-elimination. Organic molecules with unstable hydrogen are well known, such as α-methylstyrene dimer, methyl sulfide (mercaptan) or thiol (thiol) (such as n-dodecyl methyl sulfide (nDM) and thioglycolate / salt), disulfide, dithiourea disulfide, monosulfide, halide or halocarbon, common solvents and some unsaturated compounds (such as allyl peroxide, allyl halide, allyl sulfide and terpenes (such as terpinene)). Transition metal complexes such as cobalt (II) porphyrin complexes can be used as transfer agents. The chain transfer agent is added in an amount of about 0.0001 wt % to 10 wt % based on the weight of the reaction mixture (i.e., the rubber, one or more monomers, and solvent (if any)). The chain transfer agent may be added in an amount equal to or greater than about 0.001 wt %, about 0.002 wt %, or about 0.003 wt % based on the weight of the reaction mixture. The chain transfer agent may be added in an amount equal to or greater than about 0.5 wt %, about 0.2 wt %, or about 0.1 wt % based on the weight of the reaction mixture.

[0050] Chain transfer agent can be added once in one reactor zone, or it can be added in two or more reactor zones. Chain transfer agent can be added before phase inversion, during rubber particle size measurement, more can be added after particle size measurement to help control matrix molecular weight, and more can be optionally added later to fine-tune matrix molecular weight / molecular weight distribution. Chain transfer agent can be added at the beginning of polymerization (in other words, when the solid percentage of the reaction mixture is equal to the weight percentage of the rubber) in a first amount (based on the weight of the reaction mixture) equal to or greater than 0.001 wt%, about 0.002 to about 0.1 wt%, or about 0.003 to about 0.05 wt%. The amount of chain transfer agent added later (e.g., after about 40% solids, 30% solids) is added in a second amount equal to or less than about 0.7 wt%, about 0.001 wt% to about 0.6 wt%, or about 0.002 wt% to about 0.5 wt% based on the weight of the reaction mixture. The molecular weight of the matrix copolymer depends, among other things, on how much chain transfer agent is used and when it is added.

[0051] The present invention discloses a method for preparing a vinylidene-substituted aromatic polymer, the polymer comprising about 0.05% to about 2.0% by weight of a zinc salt. The method comprises the steps of mixing pellets of a vinylidene-substituted aromatic copolymer with a zinc salt and optionally about 0% to about 5% of an adsorbent, feeding the mixture into an extruder (which may be an intermeshing co-rotating twin-screw extruder), collecting the extrudate, and forming extrudate pellets. The barrel temperature of the extruder may be about 210° C. to about 240° C., and the screw speed may be about 250 rpm to about 350 rpm.

[0052] A method for forming an article is disclosed, comprising contacting elements of a composition disclosed herein and forming a structure from the contacted elements, wherein any one or both of the contacting step and the forming step result in the contacted elements being exposed to a temperature of about 200°C or higher, provided that exposure to a temperature of about 200°C or higher does not form volatile sulfur compounds. The structure forming step can be any step commonly used to form a structure from a polymer containing a vinylidene-substituted aromatic monomer. These steps may include extrusion, mixing in a mixer and / or extruder, thermoforming, molding, granulation, and the like. The structure forming step may involve granulation, extrusion, molding, or thermoforming. The ingredients of the composition may be mixed at an elevated temperature in some cases and then subjected to one or more processes commonly used to form a structure. In the contacting and forming steps, the contacted elements may be exposed to a temperature of about 250°C or higher. Some structures can be formed by contacting the elements of the composition disclosed herein in an extruder and forming the extrudate into pellets. The pellets can be used to further form a structure by one or more of extrusion, molding, and thermoforming. The pellets can be extruded into sheets. These sheets may include layers of other polymeric materials to form structures having two or more layers.The formed sheets may be formed into structures by a thermoforming process.

[0053] Disclosed is a structure including a sheet having a polymer layer, the polymer layer comprising a composition as disclosed herein. The sheet may have multiple layers. The sheet may be formed by extrusion or multilayer extrusion. Exemplary extrusion and multilayer extrusion processes are disclosed in US20110274900A1 or US10018406B2, which are incorporated herein by reference in their entirety. The sheet may be used as a refrigerator lining. The refrigerator lining may be formed by thermoforming the sheet to form a final shape for the refrigerator lining, and the process for thermoforming is disclosed in US5716581A or US10018406B2, which are incorporated herein by reference in their entirety in their entirety. An example of forming a multilayer thermoformed sheet is disclosed. The hardware includes a main extruder and a coextruder, which are combined to form the beginning of a multilayer thermoformable sheet. In either order, the components are added to the hopper of the main extruder to form a first melt blend, and the components are added to the second hopper of the coextruder to form a second melt blend. The components may include any component, monomer, additive, rubber, copolymer or polymer described herein, including any type of monovinylidene aromatic monomer and optional comonomer described herein. The main extruder feeds the first melt blend into a multilayer feed block to form at least one layer of a thermoformable sheet. The coextruder feeds the second melt blend into a multilayer feed block, which can divert the second melt into one or more streams. Another coextruder can feed the third melt blend into a multilayer feed block to form another layer of a thermoformable sheet. Subsequently, these layers are fed into the mold for extruding the thermoformable sheet. Multilayer feed blocks can be replaced with multi-manifold molds to manufacture multilayer thermoformable sheets. The hardware includes a main extruder and one or more coextruders, which combine to form the beginning of a multilayer thermoformable sheet. The main extruder or coextruder can be operated at any temperature sufficient to blend one or more components to be fed into a multilayer manifold or feed block. For example, the main extruder or co-extruder may be operated at 200°C or more, 215°C or more, or 230°C or more. The main extruder or co-extruder may be operated at 240°C or less, 225°C or less, or 210°C or less. The multi-layer manifold or feed block may be operated at any temperature sufficient to organize and form the multi-layer thermoformable sheet. For example, the multi-layer manifold or feed block may be operated at a temperature of 200°C or more, 220°C or more, 235°C or more, or 250°C. The multi-layer manifold or feed block may be operated at a temperature of 300°C or less, or less, or 275°C or less.

[0054] The compositions disclosed herein can be mixed in an extruder as disclosed above and then fed into a mold to form the desired shape. The mold can be open or closed. The mold can inject the molten mixed composition into the mold. The mold can be allowed to cool and then the formed structure can be removed from the mold.

[0055] Polymer molecular weights can be measured by gel permeation chromatography (GPC) using narrow molecular weight polystyrene standards and tetrahydrofuran (THF) as solvent, standard integration software distributed with a UV-detector. All molecular weights are determined by GPC using the same analysis (Mw, Mn, MWD, Mz, Mz+1, etc.).

[0056] Articles prepared from the compositions disclosed herein are disclosed. Such articles can be made in any known manner, which is typically used with polymers containing one or more vinylidene-substituted aromatic compounds. The articles can be made by molding, extrusion, thermoforming, foaming, blow molding, injection molding, extrusion blow molding, and combinations thereof. The articles can be extruded and molded, etc. The disclosed articles can exhibit a glass transition temperature of about 100° C. or higher. The disclosed articles can be transparent or opaque. All patent and literature references disclosed herein are fully incorporated for all purposes.

[0057] Implementation

[0058] The following are embodiments of the disclosed compositions and methods.

[0059] 1. A composition comprising: a) one or more polymers containing monomer units derived from vinylidene-substituted aromatic monomers; b) one or more antioxidants; and c) one or more additives including zinc salts, colorants, mold release agents, fillers, reinforcing fibers, flame retardant additives, stabilizers, adsorbents, antistatic agents, silicone oils, flow enhancers, or combinations thereof; wherein the one or more polymers, antioxidants, and additives do not release volatile sulfur compounds when exposed to temperatures of 200° C. or more and release less than 0.02 μg C / g of volatile sulfur-containing compounds according to test procedure VDA 277.

[0060] 2. The composition of embodiment 1, wherein the antioxidant is present in an amount of about 100 to about 10,000 ppm, 100 to 8000, or 100 to 6000 ppm based on the weight of the composition.

[0061] 3. The composition of claim 1 or 2, wherein the vinylidene-substituted aromatic monomer comprises a vinylidene group bonded directly to an aromatic structure.

[0062] 4. The composition of any one of the preceding embodiments, wherein the vinylidene-substituted aromatic monomer corresponds to the formula:

[0063]

[0064] wherein each occurrence of R1 is independently hydrogen or methyl; each occurrence of Ar is independently an aromatic group, and each occurrence of n is independently 1 to 3.

[0065] 5. A composition according to any of the preceding embodiments, wherein the polymer is a copolymer containing comonomers of one or more (meth)acrylates, one or more unsaturated nitriles, one or more conjugated dienes, one or more α- or β-unsaturated monoacids, one or more vinyl halides, one or more vinyl esters, one or more ethylenically unsaturated dicarboxylic acids or anhydrides, or one or more dialkyl maleates or fumarates.

[0066] 6. A composition according to any one of the preceding embodiments, wherein the comonomer comprises one or more of one or more (meth)acrylates, one or more unsaturated nitriles, one or more conjugated dienes, one or more α- or β-unsaturated monoacids, or N-phenylmaleimide.

[0067] 7. A composition according to any one of the preceding embodiments, wherein the antioxidant is one or more of phenol, phosphorus, hydroquinone and alkylated hydroquinone, tocopherol, O- and N-benzyl compounds, alkylene bisphenols, hydroxybenzylated malonates, aromatic hydroxybenzyl compounds, triazine compounds, benzyl phosphonates, acylaminophenols, esters and amides of propionic acid, ascorbic acid or amine-based antioxidants.

[0068] 8. The composition according to any one of the preceding embodiments, wherein the composition does not form volatile sulfur compounds when exposed to temperatures of about 200°C or higher.

[0069] 9. The composition according to any one of the preceding embodiments, wherein the composition is in the form of pellets.

[0070] 10. An article formed from the composition according to any one of the preceding embodiments, wherein the article exhibits an odor rating of 3.5 or less according to the VDA 270 odor test procedure.

[0071] 11. A method of forming an article comprising contacting elements of the composition of any one of embodiments 1 to 9 and forming a structure from the contacted elements, wherein either or both of the contacting step and the forming step results in exposure of the contacted elements to a temperature of about 200°C or greater, provided that volatile sulfur compounds are not formed by exposure to a temperature of about 200°C or greater.

[0072] 12. The method according to embodiment 11, wherein the structure forming step is selected from pelletizing, extrusion, molding or thermoforming.

[0073] 13. The method of embodiment 11 or 12, wherein the contacted elements are exposed to a temperature of about 250°C or higher.

[0074] 14. A process comprising contacting the elements of the composition according to any one of embodiments 1 to 8 in an extruder and pelletizing the extrudate.

[0075] 15. A method comprising forming a structure from pellets according to embodiment 9, wherein the structure is formed by one or more of extrusion, molding, and thermoforming.

[0076] 16. The composition of any one of embodiments 1 to 9, wherein the composition does not release volatile sulfur-containing compounds at a temperature of about 250°C or higher.

[0077] 17. The composition according to any one of embodiments 1 to 9, wherein the volatile sulfur compound is a compound that volatilizes at a temperature of 200° C. or higher.

[0078] 18. The composition according to any one of embodiments 1 to 9, wherein the volatile sulfur compound is a compound that volatilizes at a temperature of 250° C. or higher.

[0079] 19. The composition of any one of embodiments 1 to 9, wherein the volatile sulfur compound comprises an alkyl mercaptan.

[0080] 20. The composition of any one of embodiments 1 to 9, wherein the volatile sulfur compound has a molecular weight of 200 g per mole or less.

[0081] 21. The composition of any one of embodiments 1 to 9, wherein the volatile sulfur compound comprises an alkyl mercaptan having a molecular weight of 200 g per mole or less.

[0082] 22. The composition according to any one of the preceding embodiments, wherein the copolymer is prepared by bulk polymerization.

[0083] 23. The composition of any one of the preceding embodiments, wherein the copolymer comprises a vinylidene-substituted aromatic monomer and one or more conjugated dienes.

[0084] 24. The composition of embodiment 23, wherein the copolymer comprises acrylonitrile butadiene styrene or high impact polystyrene.

[0085] Example

[0086] The following examples are provided only to illustrate the present invention and are not intended to limit the scope thereof. Unless otherwise indicated, all parts and percentages are by weight.

[0087] Testing Procedure

[0088] Test procedure VDA-277

[0089] About 2 grams of pellets prepared as described herein were weighed in a 25 mL headspace bottle and statically balanced at 120° C. for 5 hours (using helium as carrier gas) and analyzed in triplicate. Quantification was performed based on external calibration performed by acetone. The method used headspace gas chromatography with FID as detector. Quantitative data were obtained by comparing the area sum of all peaks with the toluene external standard area.

[0090] Test procedure VDA-270

[0091] 1 or 3 liter glass test cups with odorless seals and lids; cups, seals and lids are cleaned before use in the test procedure. The sample quantity is specified in three steps as described in the table below. The allocation of variants A / B / C is made according to the proportional amount of material used in the vehicle interior. Variant B uses 20 g of pellet sample in a 1 liter container. The container is closed and stored in a preheated hot room.

[0092]

[0093] )1This is the maximum amount used for testing when the total amount of samples (parts) in the vehicle is less than 10g.

[0094] )2Applicable to large area materials with thickness less than 3mm

[0095] The following table provides three storage conditions: In Example 4, variant 3 was used, ie the sample was heated at 80°C for 2 hours.

[0096] Variants temperature Storage duration 1 (23±2)℃ (24±1)h 2 (40±2)℃ (24±1)h 3 (80±2)℃ 2h±10min

[0097] To begin the odor level assessment, remove the test container from the hot chamber and cool to a test temperature of 60°C before the assessment. The certification test is performed by at least three testers. When performing the odor test, the lid of the test container is opened as little as possible to minimize air exchange with the environment. Variant B is evaluated for odor using a grading system from 1 to 6, allowing for half grades. Odor ratings made according to the following scale are expressed as the arithmetic mean of the individual grades, which are rounded to half grades, and indicate the test method and the variant used.

[0098] Assessment Scale:

[0099] Level 1: Unnoticeable Level 2: Noticeable, not disturbing

[0100] Level 3 Clearly noticeable, but not disturbing

[0101] Level 4 Disturbing Level 5 Strongly Disturbing Level 6 Unacceptable

[0102] Example 1: Injection molding of ABS parts

[0103] The molded panels were made from two compositions. Composition 1 contained ABS prepared by the method described by Shields et al. in International Publication No. WO2007047120A2), wherein the polybutadiene used contained two antioxidants, Irganox 1076 (a phenol-based antioxidant) and Irganox 1520 (a sulfur-containing phenol), which are shown in the following formula:

[0104]

[0105] Composition 2 contains ABS prepared as disclosed, wherein the polybutadiene used contains an antioxidant Irganox 1076, which is a sulfur-free phenol-based antioxidant. The pellets containing the composition were dried in a ventilated oven at 80°C for 4 hours. They were then used to prepare test specimens on a 110-ton CREATOR CI-110 injection molding machine, and the injection molding conditions were as follows: barrel temperature 260°C; nozzle temperature 250°C; mold temperature 50°C, injection time: 3 seconds; holding time: 9 seconds; cooling time 20 seconds.

[0106] Example 2: ABS molded parts test

[0107] The pellets used to prepare the plates were tested in accordance with VDA 270 and VDA 277. The plate samples were prepared according to the method described in Example 1. The dimensions of the sample plates were 60 mm x 90 mm x 2 mm. The samples were sealed in aluminum foil bags before testing. The molded parts were cut into 20 g samples and tested in accordance with VDA-270, variant B and VDA277. The container volume was 1 liter. The results are shown in the table below. The fourth to eighth columns show the results in accordance with VDA 277 in μgC / g. TVOC is total volatile organic compounds, na means not applicable.

[0108]

[0109] The examples show the correlation between VDA 270 test results and volatile mercaptan (octanethiol) levels. Figure 1 A graph of odor data is provided. Figure 1 A linear correlation between octanethiol (VDA 277) and odor (VDA 270) was demonstrated.

Claims

1. A composition comprising: a) one or more polymers comprising monomer units derived from vinylidene-substituted aromatic monomers, wherein the polymers are prepared by bulk polymerization; b) one or more antioxidants; and c) one or more additives including zinc salts, colorants, mold release agents, fillers, reinforcing fibers, flame retardant additives, stabilizers, adsorbents, antistatic agents, silicone oils, flow enhancers, or combinations thereof; The one or more polymers, antioxidants and optional additives do not release volatile sulfur compounds when exposed to temperatures of 200°C or higher and release less than 0.02 μg C / g of volatile sulfur compounds according to test procedure VDA 277.

2. The composition of claim 1, wherein the antioxidant is present in an amount of about 100 to about 10,000 ppm, 100 to 8000, or 100 to 6000 ppm based on the weight of the composition.

3. The composition of claim 1 or 2, wherein the vinylidene-substituted aromatic monomer comprises a vinylidene group bonded directly to an aromatic structure.

4. The composition of any one of the preceding claims, wherein the vinylidene-substituted aromatic monomer corresponds to the formula: in, R 1 Each occurrence is independently hydrogen or methyl; Ar is independently an aromatic group at each occurrence, and n is independently 1 to 3 at each occurrence.

5. A composition according to any one of the preceding claims, wherein the polymer is a copolymer containing comonomers of one or more (meth)acrylates, one or more unsaturated nitriles, one or more conjugated dienes, one or more α- or β-unsaturated monoacids, one or more vinyl halides, one or more vinyl esters, one or more ethylenically unsaturated dicarboxylic acids or anhydrides, or one or more dialkyl maleates or fumarates.

6. The composition of any one of the preceding claims, wherein the comonomer comprises one or more of one or more (meth)acrylates, one or more unsaturated nitriles, one or more conjugated dienes, one or more α- or β-unsaturated monoacids, or N-phenylmaleimide.

7. A composition according to any one of the preceding claims, wherein the antioxidant is one or more of phenol, phosphorus, hydroquinone and alkylated hydroquinones, tocopherol, O- and N-benzyl compounds, alkylene bisphenols, hydroxybenzylated malonates, aromatic hydroxybenzyl compounds, triazine compounds, benzyl phosphonates, acylaminophenols, esters and amides of propionic acid, ascorbic acid or an amine-based antioxidant.

8. The composition of any one of the preceding claims, wherein the composition does not form volatile sulfur compounds when exposed to temperatures of about 200°C or greater.

9. The composition according to any one of the preceding claims, wherein the composition is in the form of pellets.

10. The composition according to any one of the preceding claims, wherein component a) consists of one or more polymers comprising monomer units derived from vinylidene-substituted aromatic monomers.

11. An article formed from the composition of any one of the preceding claims, wherein the article exhibits an odor rating of 3.5 or less according to the VDA 270 odor test procedure.

12. A method of forming an article comprising contacting elements of the composition of any one of claims 1 to 10 and forming a structure from the contacted elements, wherein either or both of the contacting step and the forming step results in exposure of the contacted elements to a temperature of about 200°C or greater, provided that exposure to a temperature of about 200°C or greater does not form volatile sulfur compounds.

13. The method of claim 12, wherein the structure forming step is selected from pelletizing, extrusion, molding or thermoforming.

14. The method of claim 12 or 13, wherein the contacted elements are exposed to a temperature of about 250°C or greater.

15. A method comprising forming a structure from the pellets of claim 9, wherein the structure is formed by one or more of extrusion, molding and thermoforming.

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