Functionalized processing aid blends for cellular PVC.

Abstract

A method for reducing foam density results in a foamed polyvinyl chloride (PVC) component exhibiting reduced density. The foamed PVC component includes at least a PVC resin and a processing aid blend. The processing aid blend includes 1% to 60% by weight (based on the weight of the blend) of a functionalized processing aid and 99% to 40% by weight (based on the weight of the blend) of a non-functionalized processing aid. The functionalized processing aid includes at least one base polymer functionalized with a reactive epoxy, hydroxyl, β-ketoester, β-ketoamide, or carboxylic acid functional group. When a foamed PVC component including the processing aid blend and a reference foamed PVC component including only the non-functionalized processing aid but no functionalized processing aid are produced under similar process conditions and additives, the foamed PVC component including the processing aid blend has a lower density.

Description

[Technical field]

[0001] The present disclosure relates to processing aids for use in polyvinyl chloride (PVC) formulations and other thermoplastic polymers. More specifically, the present disclosure relates to processing aids that can reduce the density of foamed PVC and other foamed thermoplastic polymer components. [Background technology]

[0002] Expanded polyvinyl chloride (PVC) resins are generally chemically inert, resistant to water and environmental corrosion, provide excellent electrical and thermal insulation, and can maintain performance over a wide temperature range. The commercial polymerization and post-polymerization process techniques (e.g., extrusion, injection molding, blow molding, etc.) used with polyvinyl chloride (commonly referred to as "PVC" or "vinyl") are mature. This manufacturing backbone, along with the fundamental properties that PVC exhibits, have led to a proliferation of expanded PVC-containing products. For example, expanded PVC members are used as structural and decorative building materials. Vinyl products are durable, recyclable, and easy to maintain. They are resistant to fungal and mold growth and are not affected by rot, corrosion, cracking, peeling, or insect infestation. Vinyl products exhibit excellent fire resistance and meet most building codes for ignition, flammability, heat generation, burn rate, fire spread, and smoke generation. Vinyl products are typically one color throughout, so minor scratches do not require painting or repair, and aesthetics can be easily maintained by washing with soap and water. Additionally, expanded PVC building products can be painted. When properly installed and maintained, vinyl products offer long-lasting aesthetics, reliable performance, and ongoing energy savings.

[0003] Pigments are dispersed into PVC formulations to provide color, while matting agents can be incorporated into the formulation to alter the surface sheen exhibited by the final PVC product. Summary of the Invention [Problem to be solved by the invention]

[0004] PVC can be used alone as the matrix resin in a formulation. PVC can also be blended with other thermoplastics such as polymethyl methacrylate, acrylonitrile styrene acrylate copolymers, polycarbonates, acrylonitrile butadiene styrene copolymers, and acrylics, including polyvinylidene fluoride, to form alloys. These PVC alloys can then be similarly compounded with various additives such as pigments and matting agents to achieve the desired appearance as a PVC formulation. These PVC alloys can also be used in similar volumes as PVC resins using similar post-polymerization processes to produce the final product.

[0005] Other thermoplastic resins can be used in similar volumes as PVC resins or PVC alloys using similar post-polymerization processes to produce the final foamed product, including acrylic polymers, styrenic resins, polyolefins, PVC blends, PVC alloys, polycarbonates, polyurethanes, fluoropolymers, and mixtures thereof.

[0006] U.S. Pat. No. 3,301,919 discloses a processing aid for polyvinyl chloride comprising a substantially linear copolymer obtained by polymerizing a mixture of 20-98.5% by weight methyl methacrylate, 0.5-40% by weight ethyl acrylate, and 1-40% by weight glycidyl methacrylate, wherein the oxirane ring in at least 85% of the glycidyl methacrylate units is retained.

[0007] Korean Patent No. 101030513 discloses a method for producing a methacrylic acid copolymer used as a processing aid for vinyl chloride resin. The method includes the following steps: polymerizing a monomer mixture in the presence of a water-soluble initiator and an emulsifier to prepare a polymer latex; and solidifying the polymer latex. The monomer mixture includes 60-85% by weight of methyl methacrylate, 15-30% by weight of an alkyl acrylate-based compound, and 1-10% by weight of an epoxide-based compound.

[0008] This application fully incorporates by reference U.S. Application No. 16 / 081,055, filed March 23, 2017, which claims priority to U.S. Provisional Application No. 62 / 313,187, filed March 25, 2016, and PCT / US2018 / 052624, filed September 25, 2018, which claims priority to U.S. Provisional Application No. 62 / 563,841, filed September 27, 2017. [Means for solving the problem]

[0009] The present invention generally provides foamed polyvinyl chloride (PVC) and other thermoplastic polymers and resins comprising a processing aid blend. The processing aid blend comprises from about 1% to about 60% by weight (based on the weight of the processing aid blend) of a functionalized processing aid, and from about 99% to about 40% by weight (based on the weight of the processing aid blend) of a non-functionalized processing aid. The functionalized processing aid comprises at least one base polymer functionalized with a reactive epoxy, reactive hydroxyl, reactive β-ketoester, reactive β-ketoamide, or reactive carboxylic acid functional group in an amount of from 0.5% to 35% by weight, based on the total weight of the functionalized processing aid.

[0010] In another embodiment, the processing aid blend comprises about 1 to about 24 wt%, preferably 10 wt%, more preferably about 1 to about 20 wt% of a functionalized processing aid, and about 99 to about 76 wt%, preferably 90%, more preferably about 80 to 99 wt% of a non-functionalized processing aid (based on the weight of the processing aid blend). The functionalized processing aid comprises at least one base polymer functionalized with a reactive epoxy, hydroxyl, β-ketoester, β-ketoamide, or carboxylic acid functional group in an amount of 0.1 wt% to 35 wt%, based on the total weight of the functionalized processing aid.

[0011] The foamed PVC or PVC alloy containing the processing aid blend of the present invention has a reduced density compared to a similar foamed PVC or PVC alloy containing only non-functionalized processing aids. The present invention also provides a method for reducing said density compared to such materials without the processing aid blend.

[0012] The foamed PVC or other thermoplastic polymer or blend or alloy containing the processing aid blend also exhibits improved cell structure compared to similar materials without the processing aid blend. The foamed PVC or other thermoplastic polymer / resin part contains a polymer or resin such as PVC; and a processing aid blend. The foamed part made with PVC or other thermoplastic polymer / resin and the processing aid blend has a lower density when compared to a similar foamed part in which the processing aid blend is not used. The parts made with PVC or other thermoplastic polymer / resin can be used in packaging for automotive products, building materials, household or kitchen products, flooring, medical or office supplies, electronic products, apparel, or personal care or other consumer products.

[0013] PVC or PVC alloys containing a blend of functionalized and non-functionalized processing aids exhibit increased melt viscosity and melt strength compared to foams made with only non-functionalized processing aids (no functionalized processing aids), which can contribute to lower density and improved cell structure of the resulting foam.

[0014] The functionalized processing aid comprises at least one base polymer functionalized with reactive epoxy, hydroxyl, β-ketoester, β-ketoamide, or carboxylic acid functional groups in an amount of about 0.1% to about 35% by weight based on the total weight of the functionalized processing aid. The blend of processing aids may be present in an amount of about 0.1 to about 25 parts by weight (phr), or about 0.1 to about 12 parts by weight for PVC formulations, and 0.1 to about 20 parts by weight for other (i.e., non-PVC) thermoplastic components. If desired, the functionalized processing aid may be functionalized with at least 0.1% by weight, or preferably at least 1% by weight, of reactive functional groups based on the total weight of the processing aid. The reactive epoxy, hydroxyl, β-keto ester, β-keto amide, or carboxylic acid functional groups in the functionalized processing aid may be derived from hydroxyl substituted alkyl esters of (meth)acrylic acid; vinyl esters of linear or branched carboxylic acids; unsaturated C3-C6 monocarboxylic acids and unsaturated C4-C6 dicarboxylic acids; epoxy group-containing monomers; β-keto esters of (meth)acrylic acid; β-keto amides of (meth)acrylic acid; or mixtures thereof.

[0015] A method for reducing the density of polyvinyl chloride (PVC) or other thermoplastic resin parts includes combining PVC or other base thermoplastic resin, a processing aid blend, a blowing agent (BA), and other additives, including, for example, stabilizers and lubricants. The blowing agent can be a chemical blowing agent (CBA) or a physical blowing agent or a combination thereof. The PVC resin, processing aid blend, and BA are then combined to form a foamable PVC composition. The foamable PVC composition can then be extruded or processed in polymer processing equipment as known in the art to form a foamed PVC part. One skilled in the art can readily appreciate that the combining and forming steps can be combined, such as, for example, a process in which the PVC, processing aid blend, and CBA are placed together in an extruder hopper and then mixed together and formed by an extrusion process. The resulting foamed PVC part exhibits a reduced density when compared to a similar foamed PVC part in which only non-functionalized processing aids (no functionalized processing aids) are used.

[0016] The density reduction method may include the blend of processing aids being present in an amount of about 0.1 to about 15 parts by weight of PVC resin or 0.1 to about 25 parts by weight of other thermoplastic resin components in the PVC formulation. If desired, the functionalized processing aid in the processing aid blend may be functionalized with at least 0.1 weight percent reactive functional groups, based on the total weight of the functionalized processing aid. The reactive epoxy, hydroxyl, β-ketoester, β-ketoamide, or carboxylic acid functional groups in the functionalized processing aid in the processing aid blend may be derived from hydroxyl-substituted alkyl esters of (meth)acrylic acid; vinyl esters of linear or branched carboxylic acids; unsaturated C3-C6 monocarboxylic acids and unsaturated C4-C6 dicarboxylic acids; epoxy group-containing monomers; β-ketoesters of (meth)acrylic acid; β-ketoamides of (meth)acrylic acid; or mixtures thereof. The reactive functionalized processing aid may contain multiple types of functional groups, such as when the functionalized processing aid is derived from glycidyl methacrylate (GMA) and / or (hydroxyethyl) methacrylate (HEMA), or from a mixture of any of the above compounds. The base polymer of the functionalized processing aid may be comprised of an acrylic polymer or copolymer. The base polymer of the non-functionalized processing aid may also be comprised of an acrylic polymer or copolymer. The acrylic polymer or copolymer may be derived from vinyl or (meth)acrylic containing monomers; styrene or styrene derivatives; olefins; dienes; or mixtures thereof. The functionalized processing aid may have a weight average molecular weight (M w ).

[0017] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

[0018] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a plot of the effect of various processing aid blends according to certain embodiments of the present disclosure, and the effect of comparative processing aids on the melt strength and extensibility of a PVC composition. [Diagram 2] FIG. 2 is a plot of the density of foamed PVC parts made using processing aid blends according to embodiments of the present disclosure and comparative processing aids. [Diagram 3] FIG. 3 shows representative optical microscope images of foamed PVC parts made using processing aid blends according to embodiments of the present disclosure and comparative processing aids. [Figure 4] FIG. 4 shows an optical microscope image of voids in the cell structure that form when the melt strength of the PVC is too low. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The following description is merely exemplary in nature and is not intended to limit the present disclosure or its applications or uses in any way. For example, polyvinyl chloride (PVC) formulations made and used in accordance with the teachings contained herein may be described throughout the present disclosure in conjunction with "PVC" or "vinyl" trim boards, moldings, windows, and doors to more fully describe their composition and use. The incorporation and use of such PVC formulations in other applications or products is considered to be within the scope of the present disclosure. Formulations made with other thermoplastic polymers / resins in other applications or products are also considered to be within the scope of the present disclosure. Such applications include, but are not limited to, automotive products, building materials, flooring, household or kitchen products, medical or office supplies, apparel, or packaging for personal care or other consumer products. It should be understood that corresponding reference numerals throughout the description indicate similar or corresponding parts and features.

[0021] The present disclosure provides a foamed polyvinyl chloride (PVC), foamed PVC alloy, or other foamed thermoplastic component that generally comprises a blend of functionalized and non-functionalized processing aids, and that exhibits reduced density compared to a similar foamed component made using only non-functionalized processing aids (no functionalized processing aids). More specifically, the foamed PVC, foamed PVC alloy, or other thermoplastic component comprises polyvinyl chloride (PVC) or other thermoplastic resin, and a processing aid blend. The processing aid blend comprises, consists essentially of, or consists of 1% to 60% by weight, based on weight Q, of a functionalized processing aid, and 99% to 40% by weight, based on weight Q, of a non-functionalized processing aid. The functionalized processing aid comprises, consists essentially of, or consists of at least one base polymer functionalized with reactive epoxy, hydroxyl, β-ketoester, β-ketoamide, or carboxylic acid functional groups in an amount of 0.1% to 35% by weight, based on the total weight of the functionalized processing aid. The non-functionalized processing aid is not particularly limited, but it does not contain reactive epoxy, hydroxyl, β-ketoester, β-ketoamide, or carboxylic acid functional groups. When a foamed PVC part containing a processing aid blend by weight Q and a reference foamed PVC part containing 100% by weight, based on weight Q, of the non-functionalized processing aid are produced under similar process conditions and additives, the foamed PVC part containing the processing aid blend will have a lower density than the reference foamed PVC part containing 100% by weight, based on weight Q, of the non-functionalized processing aid.

[0022] Blends of functionalized and non-functionalized processing aids (f-PA) can surprisingly reduce density, improve cell structure, morphology, and appearance of the resulting foam, and maintain or improve mechanical properties of foamed PVC or other thermoplastic components when compared to foamed components made using the same processing conditions, blowing agents, etc., but containing only non-functionalized processing aids and no functionalized processing aids. Furthermore, the cell structure, morphology, and appearance of foams made using blends of functionalized and non-functionalized processing aids are surprisingly superior to similar foams made by the same process (containing only functionalized processing aids and no non-functionalized processing aids). Thus, blends of functionalized and non-functionalized processing aids disclosed herein surprisingly produce better foamed PVC components in terms of at least one of density reduction, improved cell structure, improved cell morphology, and improved cell appearance than either processing aid used alone. Additionally, PVC or PVC alloys containing a blend of functionalized and non-functionalized processing aids exhibit improved melt viscosity and melt strength, which contributes to lower density and improved cell structure of the foams produced thereby, compared to foams made with only the non-functionalized processing aids.

[0023] Upon addition of the blend of processing aids, mechanical properties and melt rheology are either substantially unaffected or enhanced, including, but not limited to, impact properties and density, as well as parameters related to processability (e.g., extrusion) of foamed PVC or other thermoplastic formulations.

[0024] According to another aspect of the present disclosure, the reduction in density of a foamed PVC part containing a functionalized and non-functionalized processing aid blend compared to a similar foamed PVC part containing only non-functionalized processing aids and no functionalized processing aids can be characterized by a density that is at least 2% lower (e.g., 0.1 g / cc for a product with a density of 0.5 g / cc) in the composition containing the processing aid blend.

[0025] Processing Aid Blend Without wishing to be bound by theory, it is believed that the functionalized processing aids in the processing aid blends used in the foamed polyvinyl chloride processes defined herein affect the polyvinyl chloride matrix differently compared to conventional non-functionalized processing aids also included in the processing aid blends.

[0026] The functionalized processing aids in the blend of processing aids include acrylic polymers or copolymers synthesized with reactive epoxy, hydroxyl, β-ketoester, β-ketoamide, or carboxylic acid functional groups. Examples of methods that can form foamed PVC or other thermoplastic resin components include, but are not limited to, extrusion processes. Thus, PVC or PVC alloys containing a blend of functionalized and non-functionalized processing aids can exhibit substantially the same or even increased melt viscosity and increased melt strength, which can contribute to lower density and improved cell structure of the produced foam compared to such foams produced with only non-functionalized processing aids.

[0027] Non-functionalized processing aids used in processing aid blends that are foamed or expandable polyvinyl chloride (PVC) formulations are typically composed of acrylate and methacrylate monomers that are not reactive during such processing. Non-functionalized processing aids in processing aid blends may also include conventional processing aids as are known and used in the art of processing PVC and expanded PVC. Non-limiting examples are chlorinated polyethylene (PE-C), polyolefin-based processing aids (e.g., polyethylene oxide), EVA-based polymers, polyester-based polymers (e.g., Elvaloy® (Dow Chemical), which is a ketone ethylene ester), ABS, and / or styrene-based polymers.

[0028] The functionalized processing aids of the processing aid blends of the present disclosure can be made according to any method known in the art, including but not limited to emulsion polymerization. Similarly, the non-functionalized processing aids of the processing aid blends of the present disclosure can be made according to any method known in the art, including but not limited to emulsion polymerization.

[0029] Both functionalized and non-functionalized processing aids can be composed of "acrylic" polymers or copolymers based on it, with a variety of different compositions and molecular weights. They may have higher molecular weights than PVC resins or other thermoplastic resins. Especially with PVC resins, these processing aids (functionalized or non-functionalized) can help the interparticle mixing of PVC particles at the early stage of fusion (i.e., melting of polymer pellets or particles at the beginning of the molding process, for example, in the feed section of an extruder) because they are very compatible with PVC resins.

[0030] The functionalized processing aids of the processing aid blends of the present disclosure have a weight average molecular weight (molar mass (M w Alternatively, the processing aid may have a weight average molecular weight (M) of greater than about 100,000 g / mol. w ) is about 250,000 g / mol or more. Alternatively, the (M wThe weight average molecular weight of the functionalized processing aid is 60,000 g / mol, 70,000 g / mol, 80,000 g / mol, 90,000 g / mol, 100,000 g / mol, 150,000 g / mol, 200,000 g / mol, 250,000 g / mol, 300,000 g / mol, 350,000 g / mol, 400,000 g / mol, 450,000 g / mol, 500,000 g / mol, 600,000 g / mol, 700,000 g / mol, 800,000 g / mol, 90 ...0,000 g / mol, 150,000 g / mol, 200,000 g / mol, 250,000 g / mol, 300,000 g / mol, 350,000 g / mol, 400,000 g / mol, 450,000 g / mol, 500,000 g / mol, 600,000 g / mol, 700,000 g / mol, 800,000 g / / mol, 500,000g / mol, 550,000g / mol, 600,000g / mol, 650,000g / mol, 700,000g / mol, 750,000g / mol, 800,000g / mol, 850,000g / mol, 900,000g / mol, 950,000g / mol, 1,000,000g / mol, 1,500,000g / mol, 2 ,000,000 g / mol, 2,500,000 g / mol, 3,000,000 g / mol, 3,500,000 g / mol, 4,000,000 g / mol, 4,500,000 g / mol, 5,000,000 g / mol, 5,500,000 g / mol, 6,000,000 g / mol, 6,500,000 g / mol, 7,000,000 g / mol , 7,500,000 g / mol, 8,000,000 g / mol, 8,500,000 g / mol, 9,000,000 g / mol, 9,500,000 g / mol, 10,000,000 g / mol, 10,500,000 g / mol, 11,000,000 g / mol, 11,500,000 g / mol, or 12,000,000 g / mol.

[0031] The weight average molecular weight can be measured by any known method, including but not limited to gel permeation chromatography (GPC). The upper limit of the molecular weight measurement can be affected by the occurrence of crosslinking between the polymer processing aids.

[0032] The molecular weight of the soluble portion of the processing aid can be determined by various known methods and procedures using gel permeation chromatography (GPC). One such method utilizes a differential refractometer equipped with two PL gel mixed A columns and a guard column. A 150 μL injection volume of the soluble portion of the processing aid in THF solution at a concentration of 0.5 mg / mL is injected into the column at a temperature of 35° C. Elution of the processing aid through the column is carried out using a flow rate of THF solvent (HPLC grade) of 1.0 mL / min. Each sample of the processing aid is tested in an unfiltered state. A chromatogram of each sample tested is obtained and analyzed. Molar mass values ​​are calculated against a poly(methyl methacrylate) (PMMA) calibration curve. Details regarding the GPC methodology are described in ASTM D4001-13 (ASTM International, West Conshohocken, PA).

[0033] A total of three injections of each sample were averaged to obtain the average molecular weight (Mw). The average molecular weight (Mw) of the samples tested ranged from about 50,000 g / mol to about 5 million g / mol. The polydispersity, defined as the ratio of weight average to number average molecular weight (Mw / Mn), of each sample tested was measured to be about 10 to about 20.

[0034] In one embodiment, the functionalized processing aid of the present invention is surprisingly insoluble in organic solvents. In other words, the functionalized processing aid of the present invention can have soluble and insoluble fractions. In this case, the molecular weight of the insoluble fraction is considered infinite and cannot be measured by GPC. However, the molecular weight of the soluble fraction can be measured. The molecular weight range of the soluble fraction can be 500 g / mol to about 10 million g / mol, 500,000 to about 7 million g / mol, 500,000 to about 6 million g / mol, or 500,000 to about 5 million g / mol. The soluble and insoluble fractions of the processing aid can be determined using extraction techniques using solvents such as acetone, tetrahydrofuran (THF), or methyl ethyl ketone (MEK). The insoluble fraction of the processing aid can range from 1% to about 95%, 10% to about 90%, 40% to about 90%, 50% to about 90%, 60% to about 90%, or 60% to about 85% (by weight). Alternatively, the insoluble fraction can range from about 2% to about 70%; or from about 4% to about 55%, preferably from about 10 to 50%, more preferably from about 20 to 45%, and even more preferably from about 25 to 40%.

[0035] The functionalized processing aids have a glass transition temperature (T g ) or T of processing aids g The T of the processing aid is in the range of about 60°C to about 125°C, preferably about 60°C to about 85°C. g can be measured either as a powder or as a pressed bar formed from said powder using any known method, including differential scanning calorimetry (DSC).

[0036] Each DSC measurement is taken in the temperature range of -75°C to 160°C using a heating rate of 20°C / min and a cooling rate of 10°C / min. gis determined as the average of at least two measurements taken for each sample formulation. Details of the DSC methodology are described in ASTM E1356-08(2014) (ASTM International, West Conshohocken, PA). The glass transition temperature (T g ) can be determined as either a powder or a bar formed from the powder. The powder can be pressed into a bar when exposed to high pressure (e.g., 25 tons) and high temperature (e.g., 215° C.).

[0037] The functionalized processing aid comprises a base polymer or copolymer derived from an ethylenically unsaturated monomer. This includes, but is not limited to, vinyl and (meth)acrylic-containing monomers such as linear or branched alkyl esters of acrylic acid or methacrylic acid; styrene and styrene derivatives; olefins such as ethylene; dienes such as butadiene; and mixtures thereof. Linear or branched alkyl esters of acrylic acid or methacrylic acid are preferred. Some specific examples of vinyl and (meth)acrylic-containing monomers include, but are not limited to, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate (BMA), 2-ethylhexyl (meth)acrylate, and mixtures thereof. Methyl (meth)acrylate and ethyl (meth)acrylate are preferred. Alternatively, the base polymer or copolymer of the functionalized processing aid can be poly(methyl methacrylate), poly(butyl acrylate), poly(ethyl acrylate), poly(methyl methacrylate-styrene) copolymer, or mixtures thereof. Alternatively, the base polymer of the functionalized processing aid comprises poly(methyl methacrylate), which is preferred in terms of compatibility with the PVC matrix. Optionally, other acrylates such as poly(butyl acrylate) and poly(ethyl acrylate) can be added at levels of 10-30 wt.% to increase the glass transition temperature (T g ) and melting characteristics can be controlled.

[0038] In one embodiment, the base polymer is functionalized with glycidyl (meth)acrylate. In one embodiment, the base polymer is functionalized with reactive epoxy functional groups derived from glycidyl methacrylate, or glycidyl acrylate, or a mixture thereof.

[0039] The functionalized processing aids used in the processing aid blends added to the PVC or other thermoplastic formulations to form the foamed PVC or other foamed thermoplastic component are functionalized with reactive epoxy, hydroxyl, β-ketoester, β-ketoamide, or carboxylic acid functional groups, or mixtures thereof, in an amount of about 0.1% to about 35% by weight, based on the total weight of the functionalized processing aid. Alternatively, the functionalization loading of the reactive groups in the functionalized processing aid is about 1% to about 25% by weight. Alternatively, the functionalized processing aid comprises at least about 1% to about 20% by weight, or preferably 2% to about 20%, or preferably at least about 3% to about 20% by weight, more preferably about 5% to about 10% by weight, of reactive functional groups, based on the total weight of the functionalized processing aid. The functionalized processing aid may comprise at least about 0.1 wt.%, or about 0.2 wt.%, or about 0.3 wt.%, or about 0.4 wt.%, or about 0.5 wt.%, or about 0.6 wt.%, or about 0.7 wt.%, or about 0.8 wt.%, or about 0.9 wt.%, or about 1.0 wt.%, or about 1.5 wt.%, or about 2.0 wt.%, or about 2.5 wt.%, or about 3.0 wt.%, or about 3.5 wt.%, or about 4.0 wt.%, or about 4.5 wt.%, or about 5.0 wt.%, or about 6.0 wt.%, or about 7.0 wt.%, or about 8.0 wt.%, or about 9.0 wt.%, or about 10.0 wt.%, or about 11.0 wt.%, based on the total weight of the functionalized processing aid. may comprise about 12.0%, or about 13.0%, or about 14.0%, or about 15.0%, or about 16, or about 17, or about 18, or about 19, or about 20.0%, or about 21.0%, or about 22.0%, or about 23.0%, or about 24.0%, or about 25.0%, or about 26.0%, or about 27.0%, or about 28.0%, or about 29.0%, or about 30.0%, or about 31.0%, or about 32.0%, or about 33.0%, or about 34.0%, or about 35% by weight of reactive functional groups (or mixtures of such groups).

[0040] The weight ratio of functionalized processing aid to non-functionalized processing aid in the total amount of processing aid blend used in the composition is from 1:99 to about 60:40; alternatively, about 2:98; or about 3:97; or about 4:96; or about 5:95; or about 6:94; or about 7:93; or about 8:92; or about 9:99; or about 10:90; or about 11:89; or about 12:88; or about 13:87; or about 14:86; or about 15:85; or about 16:84; or about 17:83; or about 18:82; or about 19:81; or about 20:80; or about 21:79; or about 22:78; or about 23:77; or about 24:76; or about 25:75; or about 26:74; or about 27:73; or about 28: 72; or about 29:71; or about 30:70; or about 31:69; or about 62:78; or about 63:67; or about 34:66; or about 35:65:; or about 36:64; or about 37:63; or about 38:62; or about 39:61; or about 40:60; or about 41:59; or about 42:58; or about 43:57; or about 44:56; or or about 45:55; or about 46:54; or about 47:53; or about 48:52; or about 49:51 or about 50:50; or about 51:49 or about 52:48; or about 53:47; or about 54:46; or about 55:45; or about 56:44 or about; 57:43; or about 58:42; or about 59:41; or about 60:40.

[0041] The functionalized and non-functionalized processing aids of the processing aid blend can be used in powder or particle or pelletized form or combinations thereof. The processing aid blend can be a co-spray dried blend of functionalized and non-functionalized processing aids. The processing aid blend can be a melt blend and pelletized or powdered mixture of functionalized and non-functionalized processing aids, respectively, with the relative ratios as disclosed herein. The processing blend can also be a dry blend of pellets or particles or powders of functionalized and non-functionalized processing aids, respectively, with the relative ratios as disclosed herein. In one embodiment, the processing aid blend disclosed herein can be provided as a separate product that can be mixed or blended with PVC or other thermoplastic resin, for example, in the hopper of an extruder.

[0042] The powder or particle comprising the functionalized processing aid can be a solid particle comprising a base polymer substantially functionalized with reactive groups, or the functionalized processing aid can comprise a pseudo-core-shell particle. The functionalized processing aid (f-PA) can be prepared in a multi-stage polymerization process whereby the functionalized processing aid resembles a pseudo-core-shell particle comprising a core made of a non-functionalized base polymer, at least a portion of which is encapsulated with a shell comprising reactive epoxy, hydroxyl, or carboxylic acid functional groups, also in the form of a processing aid blend.

[0043] The reactive epoxy, hydroxyl, or carboxylic acid groups of the functionalized processing aid can be derived from the addition of epoxy, hydroxyl, β-ketoester, β-ketoamide, or carboxylic acid containing monomers or mixtures of such monomers to the base polymer. Examples of such monomers include, but are not limited to, hydroxyl-substituted alkyl esters of (meth)acrylic acid, such as 2-hydroxyethyl (meth)acrylate; β-ketoesters of (meth)acrylic acid; β-ketoamides of (meth)acrylic acid; vinyl esters of linear or branched carboxylic acids, including, for example, vinyl valerate, unsaturated C3-C6 monocarboxylic acids, such as acrylic acid (AA), and unsaturated C4-C6 dicarboxylic acids, such as maleic acid and itaconic acid; and epoxy group-containing monomers, such as glycidyl acrylate or glycidyl methacrylate (GMA). Unsaturated C3-C6 monocarboxylic acids such as acrylic acid (AA) and unsaturated C4-C6 dicarboxylic acids such as maleic acid and itaconic acid; and epoxy group-containing monomers such as glycidyl acrylate or glycidyl methacrylate (GMA) are preferred. Acrylic acid, glycidyl acrylate, and glycidyl methacrylate (GMA) are more preferred. Alternatively, functional groups can be incorporated into the base polymer of the processing aid through the addition of acrylic acid (AA), glycidyl methacrylate (GMA), or mixtures thereof, which are most preferred. Functionalized processing aids can also be prepared by a process comprising polymerizing at least one functionalized monomer composed of at least one functional group selected from the group consisting of: hydroxyl functionality, epoxy functionality, β-ketoester functionality, β-ketoamide functionality, and carboxylic acid functionality (optionally together with one or more non-functionalized monomers).The functionalized processing aid may also be prepared by a method comprising: polymerizing at least one monomer comprising at least one functional group that is a precursor of a functional group selected from the group consisting of a hydroxyl functional group, an epoxy functional group, a β-ketoester functional group, a β-ketoamide functional group, and a carboxylic acid functional group to obtain a polymer processing aid precursor comprising at least one functional group that is a precursor of a functional group selected from the group consisting of a hydroxyl functional group, an epoxy functional group, a β-ketoester functional group, a β-ketoamide functional group, and a carboxylic acid functional group; and converting at least a portion of the functional group selected from the group consisting of a hydroxyl functional group, an epoxy functional group, a β-ketoester functional group, a β-ketoamide functional group, and a carboxylic acid functional group present in the polymer processing aid precursor to at least one functional group selected from the group consisting of a hydroxyl functional group, an epoxy functional group, a β-ketoester functional group, a β-ketoamide functional group, and a carboxylic acid functional group to obtain the functionalized processing aid.

[0044] The amount of processing aid blend present in a foamed or expandable PVC formulation may range from about 0.1 parts by weight to about 15 parts by weight for PVC formulations, or 0.1 to about 25 parts by weight for other thermoplastic resin components. Alternatively, it may be from about 0.1 parts by weight to about 10 parts by weight for PVC formulations, or 0.1 to about 10 parts by weight for other thermoplastic resin components. Or, it may be 1 part by weight or more. In the context of this disclosure, the term "parts by weight (phr)" means parts per 100 parts by weight of the total resin blend excluding the plastic additive polymer (e.g., PVC and non-PVC polymers combined, if the PVC / non-PVC blend is equal to 100 parts by weight). The amount of processing aid blend present in a PVC or other thermoplastic resin formulation may also be expressed as a weight percent based on the total weight of the PVC or other thermoplastic resin formulation. The use level of the processing aid blend in a PVC formulation may vary depending on the type of PVC formulation selected and the specifications established for the application in which the foamed PVC or other foamed thermoplastic resin component is to be utilized. In other words, the amount of processing aid blend in the formulation can be predetermined based on the usage level required to achieve the density and cell morphology requirements of a given application utilizing the foaming component (e.g., siding, window profiles, pipes, foam sheets, etc.).

[0045] Without being bound by theory, the processing aid blend may facilitate melting of the PVC resin by altering the melt rheology of the PVC compound during extrusion or other processing operations where heat is applied. The processing aid blend may also help to control the viscosity of the melt, facilitate mixing of the components as melting of the PVC resin occurs, improve the strength and extensibility of the molten polymer blend, and control the volume increase or swelling that occurs immediately after the molten polymer blend leaves the die opening (including, but not limited to, die swell as the extruded portion foams), reduce the occurrence of plate-out and crystallinity, and improve long term impact strength and weatherability.

[0046] Processing aid blends containing functionalized and non-functionalized processing aids can increase the melt elongation / extensibility and elasticity of the molten polymer blend. Processing aid blends can also increase the initial melt strength of the molten polymer blend. These two properties (i.e., high melt strength combined with high elongation before break) are known to contribute to improved properties such as cell structure, cell appearance and cell morphology of foamed members. These properties of polymer foams contribute to reduced foam density, as well as improved mechanical properties and the ability of the composition to accept high levels of fillers. In general, processing aid blends disclosed herein that contain functionalized processing aids with higher weight average molecular weights tend to result in higher levels of die swell. When making foamed PVC members, higher levels of die swell can be beneficial. Cell morphology, i.e., the size and range of sizes of cells, including bubbles, in the foamed member, is affected by the relative amounts of functionalized and non-functionalized processing aids in the processing aid blend. In other thermoplastics and PVC, the amount of functionalized processing aids can reduce gloss.

[0047] Polyvinyl chloride (PVC) resin The PVC resins used to make the foamed members and combined with the processing aid blends disclosed herein can be made in several different molecular weights using any method known in the art, including but not limited to solution, suspension, or emulsion polymerization. The PVC resins can include, but are not limited to, rigid PVC resins, flexible PVC resins, PVC plastisols, and mixtures or combinations of PVC formed with one or more other thermoplastic and / or thermosetting resins. The PVC resin can be characterized by its molecular weight, which is generally reported as an inherent viscosity (IV) or K value. Generally, the higher the IV or K value of the PVC resin, the greater the impact strength of the PVC or other thermoplastic resin member made therefrom. However, PVC resins with high molecular weights are also more difficult to achieve fusion and polymer flow without the use of large amounts of heat or shear. The molecular weight of the PVC resin used in the formulation from which the PVC member is made can be predetermined based on the mechanical properties desired for the final product and economic factors. Typically, resins with K values ​​ranging from about 56 to about 72; alternatively from about 63 to about 67; alternatively about 65 are used to form PVC members with low molecular weight stiffness profiles used in foam applications. The molecular weight of the PVC resin is generally lower than the molecular weight of the processing aids with which it is used. The amount of PVC resin used in the formulation to form the foamed PVC or other thermoplastic resin member can range from about 20% to about 90%, 30% to about 85%, 40% to about 85%, or about 50% to about 80% by weight of the total PVC formulation.

[0048] Other Thermoplastics Other thermoplastics useful in the present invention for blending with PVC to form PVC blends or alloys to form foamed PVC parts include, but are not limited to, acrylic polymers, styrenic polymers, polyolefins, polycarbonates (PC), polyurethanes (PU), polyvinylidene fluoride polymers (PVDF), polylactic acid (PLA), and the like, and mixtures thereof. The other thermoplastics described herein can be used in combination with PVC or in any combination thereof with or without PVC, and further include the processing aid blend of the present invention to form foamed parts with reduced density, improved cell structure, appearance, and morphology compared to parts that include only non-functionalized processing aids in the processing aid blend and no functionalized processing aids. These other thermoplastics can be included in the PVC composition at up to 50% by weight, as a weight percentage of the total (non-processing aid) resins in the blend.

[0049] Styrenic polymers as used herein include, but are not limited to, polystyrene, high impact polystyrene (HIPS), acrylonitrile-butadiene-styrene (ABS) copolymers, acrylonitrile-styrene-acrylate (ASA) copolymers, styrene-acrylonitrile (SAN) copolymers, methacrylate-acrylonitrile-butadiene-styrene (MABS) copolymers, styrene-butadiene copolymers (SB), styrene-butadiene-styrene block (SBS) copolymers and their partially or fully hydrogenated derivatives, styrene-isoprene copolymers styrene-isoprene-styrene (SIS) block copolymers and their partially or fully hydrogenated derivatives, styrene-(meth)acrylate copolymers such as styrene-methyl methacrylate copolymer (S / MMA), and mixtures thereof. A preferred styrenic polymer is ASA. The styrene copolymers of the present invention have a styrene monomer content of at least 10% by weight, preferably at least 25% by weight.

[0050] Styrenic polymers can also be blended with other polymers to form compatible blends. Examples include ASA blended with PVC, SAN blended with PMMA, etc. Acrylic polymers as used herein include, but are not limited to, homopolymers, copolymers, and terpolymers containing alkyl (meth)acrylates. The alkyl (meth)acrylate monomer is preferably methyl methacrylate, which may comprise 60-100% by weight of the monomer mixture. 0-40% by weight of other acrylates, methacrylates, and / or other vinyl monomers may also be present in the monomer mixture. Other methacrylates, acrylates, and other vinyl monomers useful in the monomer mixture include, but are not limited to, methyl acrylate, ethyl acrylate and ethyl methacrylate, butyl acrylate and butyl methacrylate, isooctyl methacrylate and acrylate, lauryl acrylate and lauryl methacrylate, stearyl acrylate and stearyl methacrylate, isobornyl acrylate and methacrylate, methoxyethyl acrylate and methacrylate, 2-ethoxyethyl acrylate and methacrylate, dimethylaminoethyl acrylate and methacrylate monomers, styrene and its derivatives. Alkyl (meth)acrylic acids such as (meth)acrylic acid and acrylic acid may be useful in the monomer mixture. Small amounts of multifunctional monomers as crosslinkers may also be used. A preferred acrylic polymer is a copolymer of methyl methacrylate and 2-16% by weight of one or more C 1~4 It is an acrylate copolymer.

[0051] The thermoplastic polymers of the present invention can be produced by any means known in the art, including emulsion polymerization, solution polymerization, and suspension polymerization. In one embodiment, the non-PVC thermoplastic resin in the matrix has a weight average molecular weight of 50,000 to 500,000 g / mol, preferably 75,000 to 150,000 g / mol, as measured by gel permeation chromatography (GPC). The molecular weight distribution of the thermoplastic matrix can be unimodal or multimodal with a polydispersity index greater than 1.5.

[0052] Particularly preferred thermoplastics for the matrix polymer are styrenic polymers (including SAN, ABS, MABS, ASA, HIPS), acrylics, and PVDF polymers.

[0053] Impact Modifier If desired, the PVC formulations used to form the foamed PVC or other thermoplastic components may optionally contain at least one impact modifier. Impact modifiers enhance the toughness and resistance of the final foamed product to cracking or shattering during subsequent manufacturing operations performed on the foamed PVC or other thermoplastic components, such as cutting profiles or drilling holes in the foamed components. Impact modifiers typically function by absorbing energy or dissipating the energy of a propagating crack. Impact modifiers are used in block copolymers and soft rubbery cores (T-type) that have low compatibility with PVC resins. g <0℃) or hard core (T g The polymer particles may include any compatible polymer particles, including "core-shell particulate" polymers having a temperature of 0.1° C. (>0° C.) and a grafted compatible outer polymer shell. The polymer particles or compatible outer polymer shell may include methacrylate / butadiene / styrene (MBS), acrylic polymers (e.g., acrylic impact modifiers [AIMs]), or acrylate / butadiene / methacrylate, and acrylonitrile / butadiene / styrene (ABS); polymers of chlorinated polyethylene (CPE) and acrylic grafted CPE, and semi-compatible polymers such as ethylene vinyl acetate (EVA); and other polymers such as terpolymers of ethylene / vinyl acetate / carbon monoxide, ethylene / propylene / carbon monoxide, polymers of olefins and acrylates, various copolymers of butadiene and acrylonitrile, methacrylates or other rubbers, and even polysiloxane toughening materials. A preferred shell includes polymethyl methacrylate (PMMA).

[0054] Filler The PVC or other thermoplastic formulation used to form the foamed PVC component may also optionally or preferably include one or more inorganic fillers or particles, pigments, lubricants, stabilizers, or other desired additives. The inclusion of a processing aid blend can enhance the ability of the PVC composition to accept higher loading levels of fillers. For example, ultrafine CaCO3 particles can be used as a filler to increase low temperature impact resistance and improve UV stability of rigid foamed PVC products. Synthetic amorphous silica particles can also be incorporated into the PVC formulation to increase impact resistance and improve flow properties. Other solid fillers, including but not limited to kaolin clay, talc, mica, wollastonite, and calcium metasilicate, can also be incorporated into the formulation simply to reduce the cost of the formulation without substantially affecting the properties exhibited by the foamed PVC or other foamed thermoplastic member. The range of filler in the foam is from about 5 parts by weight to about 150 parts by weight.

[0055] Other Additives A variety of pigments can be included to provide color to the foamed PVC or other foamed thermoplastic components. These pigments generally exhibit stability at high temperatures and in the presence of hydrogen chloride. These pigments include, but are not limited to, various organic or ceramic pigments, such as titanium dioxide and other metal oxides, with or without silica or alumina surface treatments.

[0056] Various lubricants can be included in PVC formulations in relatively small amounts to reduce resistance to the flow of the polymer chains and other components present. These lubricants can function as external lubricants or metal release (slip) agents to facilitate the flow of "hot" material through polymer processing equipment, or as internal lubricants to reduce the melt viscosity of the material being processed. Lubricants are the main additive components that can be added to the formulation to help facilitate or speed the melting of the PVC resin. Some examples of lubricants include, but are not limited to, paraffin wax and long chain carboxylic acids or their esters, amides, and salts. The amount of lubricant used is usually below a level that would cause the occurrence of "plate-out." Plate-out occurs when the lubricant present in the formulation is squeezed out of the hot bulk material as the extrudate leaves the die or passes through a vacuum calibrator, thereby causing a plug or build-up of material.

[0057] To name a few, various stabilizers can be included in PVC or other thermoplastic formulations to increase the resistance of the foaming components to heat or UV light. Heat stabilizers can include, but are not limited to, lead-based or organotin compounds, mixed metal stabilizers, or organic stabilizers such as epoxides. UV stabilizers can include, but are not limited to, hindered amines or phenols.

[0058] Non-limiting aspects of the present invention can be summarized as follows.

[0059] Side 1: a) PVC resin; b) a processing aid blend, weight Q, per 100 parts by weight of said PVC resin, comprising 1% to 60% by weight, based on weight Q, of a functionalized processing aid, and 99% to 40% by weight, based on weight Q, of a non-functionalized processing aid; A foamed polyvinyl chloride (PVC) member comprising: the functionalized processing aid comprises at least one base polymer functionalized with 0.1 wt. % to 35 wt. % of a reactive epoxy, hydroxyl, β-ketoester, β-ketoamide, or carboxylic acid functional group, or mixtures thereof, based on the total weight of the functionalized processing aid; said foamed PVC component comprising weight Q of said processing aid blend and a reference foamed PVC component comprising 100% by weight, based on weight Q, of said non-functionalized processing aid are produced under similar process conditions and additives, said foamed PVC component comprising said processing aid blend has a lower density than said reference foamed PVC component comprising 100% by weight, based on weight Q, of said non-functionalized processing aid; Foamed polyvinyl chloride (PVC) material. Aspect 2: The foamed PVC member of aspect 1, wherein the processing aid blend comprises 1 wt.% to 25 wt.%, based on weight Q, of the functionalized processing aid, and 99 wt.% to 75 wt.%, based on weight Q, of the non-functionalized processing aid. Aspect 3: The foamed PVC member of aspect 1 or 2, wherein the functionalized processing aid comprises at least 1 wt. % of the reactive functional group. Aspect 4. The foamed PVC member of any one of aspects 1-3, wherein the functionalized processing aid comprises up to 25% by weight of the reactive functional groups. Aspect 5: The foamed PVC member according to any one of Aspects 1 to 4, wherein the weight Q is 0.1 to 15 parts by weight relative to 100 parts by weight of the PVC resin. Aspect 6: The foamed PVC member according to any one of Aspects 1 to 5, wherein the foamed PVC member comprising the processing aid blend has a density that is at least 2% lower than the density of the reference foamed PVC member. Aspect 7: The foamed PVC member of any one of aspects 1-6, wherein the base polymer of the functionalized processing aid is derived from one or more monomers including a (meth)acrylic-containing monomer. Aspect 8: The foamed PVC member of any one of Aspects 1-7, wherein the base polymer of the functionalized processing aid is derived from i) one or more monomers including a (meth)acrylic-containing monomer, ii) at least one monomer selected from the group consisting of vinyl-containing monomers, styrene and styrene derivatives, olefins, dienes, and mixtures thereof. Aspect 9: The foamed PVC member of any one of Aspects 1 to 8, wherein the reactive epoxy, hydroxyl, β-keto ester, β-keto amide, or carboxylic acid functional group is derived from a hydroxyl-substituted alkyl ester of (meth)acrylic acid; a vinyl ester of a linear or branched carboxylic acid; an unsaturated C3 to C6 monocarboxylic acid and an unsaturated C4 to C6 dicarboxylic acid; a β-keto ester of (meth)acrylic acid; a β-keto amide of (meth)acrylic acid; an epoxy group-containing monomer; or a mixture thereof. Aspect 10: The foamed PVC member of any one of aspects 1 to 9, wherein the base polymer is functionalized with reactive epoxy functional groups derived from glycidyl methacrylate, or glycidyl acrylate, or a mixture thereof. Aspect 11: The foamed PVC member of any one of aspects 1 to 10, wherein the non-functionalized processing aid comprises an acrylic polymer or acrylic copolymer. Aspect 12. The foamed PVC member of any one of aspects 1 to 11, wherein the functionalized processing aid has a weight average molecular weight of at least 50,000 g / mole. Aspect 13: The foamed PVC member of any one of aspects 1-12, wherein the non-functionalized processing aid comprises a polymer. Aspect 14. The foamed PVC member of any one of aspects 1-13, wherein the non-functionalized processing aid comprises a chlorinated polyethylene (PE-C). Aspect 15: The foamed PVC member according to any one of aspects 1 to 14, which is a building material or a flooring material. Aspect 16: A method for producing a foamed polyvinyl chloride (PVC) member, comprising: a) Polyvinyl chloride (PVC) resin; b) a processing aid blend, weight Q, per 100 parts by weight of the PVC resin, comprising 1% to 60% by weight, based on weight Q, of a functionalized processing aid, and 99% to 40% by weight, based on weight Q, of a non-functionalized processing aid; and c) Foaming agent (BA) to form a foamable PVC composition; and treating the expandable PVC composition to form the expanded PVC member; the functionalized processing aid comprises at least one base polymer functionalized with 0.1 wt. % to 35 wt. % of a reactive epoxy, hydroxyl, β-ketoester, β-ketoamide, or carboxylic acid functional group, or mixtures thereof, based on the total weight of the functionalized processing aid; said foamed PVC component comprising weight Q of said processing aid blend and a reference foamed PVC component comprising 100% by weight, based on weight Q, of said non-functionalized processing aid are produced under similar process conditions and additives, said foamed PVC component comprising said processing aid blend has a lower density than said reference foamed PVC component comprising 100% by weight, based on weight Q, of said non-functionalized processing aid; method. Aspect 17: The method of aspect 16, wherein the processing aid blend comprises 1 wt.% to 24 wt.%, based on weight Q, of the functionalized processing aid, and 99 wt.% to 76 wt.%, based on weight Q, of the non-functionalized processing aid. Aspect 18: The method of producing an expanded polyvinyl chloride (PVC) component according to aspect 16 or 17, wherein the functionalized processing aid comprises at least 1 wt.% of the reactive functional group. Aspect 19. The method for producing a foamed PVC member according to any one of aspects 16 to 18, wherein the functionalized processing aid comprises up to 25% by weight of the reactive functional groups. Aspect 20: The method for producing a foamed PVC member according to any one of Aspects 16 to 19, wherein the weight Q is 0.1 to 15 parts by weight relative to 100 parts by weight of the PVC resin. Aspect 21: A method for producing a foamed PVC member according to any one of Aspects 16 to 20, wherein the foamed PVC member comprising the processing aid blend has a density that is at least 2% lower than the density of the reference foamed PVC member. Aspect 22. The method for producing a foamed PVC member according to any one of aspects 16 to 21, wherein the base polymer of the functionalized processing aid is derived from one or more monomers including a (meth)acrylic-containing monomer. Aspect 23: A method for producing a foamed PVC member according to any one of Aspects 16 to 23, wherein the base polymer of the functionalized processing aid is derived from i) one or more monomers including a (meth)acrylic-containing monomer, ii) at least one monomer selected from the group consisting of vinyl-containing monomers, styrene and styrene derivatives, olefins, dienes, and mixtures thereof. Aspect 24: The method for producing a foamed PVC member according to any one of Aspects 16 to 23, wherein the reactive epoxy, hydroxyl, β-keto ester, β-keto amide, or carboxylic acid functional group is derived from a hydroxyl-substituted alkyl ester of (meth)acrylic acid; a vinyl ester of a linear or branched carboxylic acid; an unsaturated C3 to C6 monocarboxylic acid and an unsaturated C4 to C6 dicarboxylic acid; a β-keto ester of (meth)acrylic acid; a β-keto amide of (meth)acrylic acid; an epoxy group-containing monomer; or a mixture thereof. Aspect 25: A method for producing a foamed PVC member according to any one of aspects 16 to 24, wherein the base polymer is functionalized with a reactive epoxy functional group derived from glycidyl methacrylate, or glycidyl acrylate, or a mixture thereof. Aspect 26: The method for producing a foamed PVC member according to any one of aspects 16 to 25, wherein the non-functionalized processing aid comprises an acrylic polymer or acrylic copolymer. Aspect 27. The method for producing a foamed PVC member according to any one of Aspects 16 to 26, wherein the functionalized processing aid has a weight average molecular weight of at least 50,000 g / mol. Aspect 28: A method for producing a foamed PVC part according to any one of aspects 16, wherein the non-functionalized processing aid comprises a polymer. Aspect 29. The method for producing a foamed PVC member according to any one of Aspects 16 to 28, wherein the non-functionalized processing aid comprises a chlorinated polyethylene (PE-C). Aspect 30: The method for producing an expanded PVC member according to any one of Aspects 16 to 29, wherein the expanded PVC member is a building material. Aspect 31: A processing aid blend, the processing aid blend comprising: 1 wt.% to 60 wt.% of a functionalized processing aid, and 99 wt.% to 40 wt.% of a non-functionalized processing aid; The functionalized processing aid blend comprises at least one base polymer functionalized with 0.1 wt.% to 35 wt.% of a reactive epoxy, hydroxyl, β-ketoester, β-ketoamide, or carboxylic acid functional group, or mixtures thereof, based on the total weight of the functionalized processing aid. Aspect 32: The processing aid blend of aspect 31, wherein the processing aid blend comprises 1 wt% to 24 wt% of the functionalized processing aid, and 99 wt% to 76 wt% of the non-functionalized processing aid. Aspect 33: The processing aid blend of aspect 31 or 32, wherein the reactive functional groups account for at least 1 wt.% of the functionalized processing aid. Aspect 34. The processing aid blend of any one of aspects 31 to 33, wherein the reactive functional groups comprise up to 1 wt.% of the functionalized processing aid. Aspect 35: The processing aid blend of any one of aspects 31-34, wherein the base polymer of the functionalized processing aid is derived from one or more monomers including a (meth)acrylic-containing monomer. Aspect 36: The processing aid blend of any one of aspects 31-35, wherein the base polymer of the functionalized processing aid is derived from i) one or more monomers including a (meth)acrylic-containing monomer, ii) at least one monomer selected from the group consisting of vinyl-containing monomers, styrene and styrene derivatives, olefins, dienes, and mixtures thereof. Aspect 37: The processing aid blend of any one of aspects 31 to 36, wherein the reactive epoxy, hydroxyl, β-keto ester, β-keto amide, or carboxylic acid functional group is derived from a hydroxyl-substituted alkyl ester of (meth)acrylic acid; a vinyl ester of a linear or branched carboxylic acid; an unsaturated C3 to C6 monocarboxylic acid and an unsaturated C4 to C6 dicarboxylic acid; a β-keto ester of (meth)acrylic acid; a β-keto amide of (meth)acrylic acid; an epoxy group-containing monomer; or a mixture thereof. Aspect 38: The processing aid blend of any one of aspects 31 to 37, wherein the base polymer is functionalized with a reactive epoxy functional group derived from glycidyl methacrylate, or glycidyl acrylate, or a mixture thereof. Aspect 39: The processing aid blend of any one of aspects 31 to 38, wherein the non-functionalized processing aid comprises an acrylic polymer or acrylic copolymer. Aspect 40: The processing aid blend of any one of aspects 31-39, wherein the functionalized processing aid has a weight average molecular weight of at least 50,000 g / mole. Aspect 41: The processing aid blend of any one of aspects 31-40, wherein the non-functionalized processing aid comprises a polymer. Aspect 42: The processing aid blend of any one of aspects 31-41, wherein the non-functionalized processing aid comprises a chlorinated polyethylene (PE-C). Aspect 43: a) polyvinyl chloride (PVC) resin; b) a processing aid blend, weight Q, per 100 parts by weight of the PVC resin, comprising 1% to 60% by weight, based on weight Q, of a functionalized processing aid, and 99% to 40% by weight, based on weight Q, of a non-functionalized processing aid; and c) foaming agent (BA); A foamable PVC composition comprising: the functionalized processing aid comprises at least one base polymer functionalized with 0.1 wt. % to 35 wt. % of a reactive epoxy, hydroxyl, β-ketoester, β-ketoamide, or carboxylic acid functional group, or mixtures thereof, based on the total weight of the functionalized processing aid; When said foamed PVC composition and a reference foamed PVC composition comprising 100 wt. % of said non-functionalized processing aid, based on weight Q, are produced under similar process conditions and additives, the foamable PVC composition, when foamed, provides a foamed PVC part having a lower density, based on weight Q, than the reference foamed PVC part comprising 100 wt. % of said non-functionalized processing aid. Expandable PVC composition. EXAMPLES

[0060] Example 1: Melt strength and drawing speed The PVC formulations shown in Table 1 were blended in a 5 lb (2.27 kg) Henschel mixer with 3 parts by weight of the processing aid blends shown in Table 2. The powder form of the PVC formulations was then pelletized using a Brabender lab-scale conical twin screw extruder equipped with a pelletizer. The Brabender extruder used the following temperature profile for processing and pelletization: 162°C / 164°C / 164°C / 164°C (Zone 1 / Zone 2 / Zone 3 / Die), respectively. The extruder screw speed was set at 20 RPM. The resulting PVC compound pellets were used for Rheotens rheology evaluation. Rheotens tests were performed on a Goettfert Rheograph capillary rheometer using a 2000 bar transducer. The material was allowed to equilibrate in the test barrel for 5 minutes before the test began. Samples were run using a stainless steel pull-off wheel for a raised surface. The experimental conditions were as follows: The processing temperature was set at 190°C. The die geometry used for extruding the strands was a 30 / 2 L / D (mm / mm) die in a 180 degree configuration. The wheel gap was set at 0.2 mm and the wheel acceleration was 6 mm / s. 2 The capillary piston diameter was 12 mm and the piston velocity was 0.2 mm / s. Therefore, the capillary shear rate was 28.8 s -1 The initial wheel speed V0 was 5.2 mm / s.

[0061] The resulting curves are shown in Figure 1. These curves show the effect of each processing aid blend on initial melt strength and elongation. This data can be used to estimate the "foaming performance", i.e., how well the molten resin expands and maintains cell structure when a blowing agent (such as a chemical or physical blowing agent) is added to the PVC formulation during extrusion to produce a foamed PVC part.

[0062] [Table 1]

[0063] [Table 2]

[0064] As can be seen and understood from FIG. 1, the PVC composition containing only the non-functionalized processing aid (A) and no functionalized processing aid (B) exhibited good melt extensibility but poor initial melt strength. Poor initial melt strength results in poor foam quality when the PVC is foamed. In contrast, the PVC composition containing only the functionalized processing aid (B) and no non-functionalized processing aid (A) had good initial melt strength but poor melt extensibility as the extruded strand broke at a draw rate of about 25 mm / sec. The PVC composition utilizing a processing aid blend of both A and B with more than half functionalized processing aid (B) by weight exhibited better melt strength than 100% functionalized processing aid, but the melt extensibility was still too low to produce an acceptable foam. PVC formulations utilizing processing aid blends containing more than half by weight of non-functionalized processing aid (A) and the remainder of the processing aid blend being functionalized processing aid (B) surprisingly showed dramatically improved elongation and minimal degradation in initial melt strength compared to PVC compositions utilizing processing aid blends containing more than half by weight of functionalized processing aid. Thus, these results demonstrate the surprising effect that combinations of functionalized and non-functionalized processing aids, as well as specific ranges of relative amounts of each of the functionalized and non-functionalized processing aids, are necessary to achieve high quality foamed PVC parts.

[0065] Example 2: Foam Density and Cell Structure PVC foam samples were made using four different feed rates of chemical blowing agent (CBA) and two different processing aids. Foam PVC extrusion was performed using a Cincinnati Milacron CM-55 conical twin screw extruder. Foam extrusion utilized a barrel and die zone temperature profile set as follows: 285°F (140°C) / 300°F (150°C) / 320°F (160°C) / 385°F (200°C) / 360°F (180°C) (barrel zone 1 / zone 2 / zone 3 / zone 4 / die zone, respectively). Oil was used for cooling the screws and sheet die. The screw oil flowing through the extruder screw was set at 265°F (130°C) and the oil at the sheet die lip was set at 355°F (180°C). Extrusion of the PVC sheet was carried out using a Cloeren 9 inch (22.9 cm) wide sheet die with a 0.250 inch (0.64 cm) die opening. The PVC melt exiting the die was fed through a three-roll stack where a PVC foam sheet was formed to a thickness of approximately 0.500 inch (1.27 cm).

[0066] The PVC composition and processing conditions were the same, except for the addition of the processing aids. The PVC formulation was the same as shown in Table 1, except that the total amount of processing aid or processing aid blend was added at 5 parts by weight instead of the 3 parts by weight used in Example 1. The processing aids were as follows: 1) a 70:30 weight ratio of a non-functionalized processing aid (A) and a functionalized processing aid (B); and 2) 100% non-functionalized processing aid (A).

[0067] The density of each sample was measured as follows: A 1 inch long x 1 inch wide x 0.5 inch thick sample was cut from the center of a 9 inch wide x 3 ft long x 0.5 inch thick PVC foam board. An Alfa Mirage Electronic Densimeter MD-300S was then used to obtain the sample density value using "ASTM D792: Standard Test Method for Density and Specific Gravity of Plastics by Displacement (Relative Density), Test Method A - For Testing of Solid Plastics (Deionized) in Water." This process was repeated three times with three separate specimens taken over a five minute period to obtain an average density.

[0068] The results are shown in Figure 2.

[0069] Table 3 shows the measured density of the PVC samples and the percent density reduction with the use of the processing aid blends compared to the non-functionalized processing aid alone. The percent density reduction was calculated as follows: Density reduction rate = 100 × [(ρ nf -ρ b ) / ρ nf ] In the formula, ρ nf = Density of foamed PVC made with non-functionalized processing aids only And ρ b = Density of foamed PVC made with blends of functionalized and non-functionalized processing aids.

[0070] [Table 3]

[0071] A PVC foam sample made using 5 parts by weight of processing aid was analyzed under an optical microscope. A Nikon ME600 optical microscope and a Nikon D850 DSLR were used for the optical microscope analysis. Prior to imaging and analysis, the PVC foam sample was polished and painted with ink to aid in cell size measurement. WaveMetrics' IGOR Pro® 7 was used to analyze cell uniformity through measurement of average cell (2-D particle) size, showing differences in the resulting cell structure based on the processing aid blend used in the PVC foam formulation. The software applies a Hough transform to the image. Alternatively, the user can manually identify the cells to begin the analysis and examine the average cell size. After identifying the cells or voids in the PVC foam structure, the image is converted from 8-bit grayscale to a binary format. There, for example, foam cells are assigned a "1" and non-cell areas are assigned a "0". Then, using a reference, the pixels are scaled to known micrometer measurements and cell sizes can be assigned. A Nikon-provided scale bar was used to calibrate the samples shown in Figure 3 and Table 4. Table 4 shows the difference between foamed PVC using only non-functionalized processing aid (A) and the processing aid blend (70 / 30A / B). Cell size and uniformity analysis was done from the foam cell structure in the center of a 1 / 2 inch extruded PVC foam board. Additionally, images in Figure 3 show PVC foam using only non-functionalized processing aid (A) and the processing aid blend (70:30 A:B ratio). As can be seen, the PVC foam made using 100% non-functionalized processing aid is not only denser but also has less cell uniformity compared to the 70:30 weight ratio blend of non-functionalized and functionalized processing aids. With reference to Table 3 and Figure 2, when the melt strength of the PVC is no longer able to trap the gas evolved from the CBA used in the formulation, voids may start to appear in the foamed PVC product. Figure 4 shows an image of the voids in the cell structure. Voided foam products have a greater apparent density reduction due to the large open cell structure, but the cells are less uniform, which is undesirable.

[0072] [Table 4]

[0073] Within this specification, the embodiments have been described in a manner which makes it possible to write a clear and concise specification, but it is intended and understood that the embodiments can be variously combined or separated without departing from the invention, for example, it will be understood that all preferred features described herein are applicable to all aspects of the invention described herein.

[0074] The foregoing description of various forms of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Numerous modifications or variations are possible in light of the above teachings. The forms discussed have been selected and described in order to provide the best illustration of the principles of the invention and its practical application, thereby enabling those skilled in the art to utilize the invention in various forms and with various modifications suited to the particular uses envisioned. All such modifications and variations are within the scope of the invention, as determined by the appended claims, when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.

Claims

1. a) PVC resin; b) weight Q of a processing aid blend per 100 parts by weight of the PVC resin, the processing aid blend comprising 1% to 60% by weight, based on weight Q, of a functionalized processing aid, and 99% to 40% by weight, based on weight Q, of a non-functionalized processing aid; A foamed polyvinyl chloride (PVC) member comprising: the functionalized processing aid comprises at least one base polymer functionalized with 0.1 wt % to 35 wt % of a reactive epoxy, hydroxyl, β-ketoester, β-ketoamide, or carboxylic acid functional group or mixtures thereof, based on the total weight of the functionalized processing aid, except for those containing acetoacetoxyethyl (meth)acrylate (AAEM); the foamed PVC part containing weight Q of the processing aid blend and a reference foamed PVC part containing 100 weight percent of the non-functionalized processing aid, based on weight Q, are produced under similar process conditions and additives, the foamed PVC part containing the processing aid blend has a lower density than the reference foamed PVC part containing 100 weight percent of the non-functionalized processing aid, based on weight Q. Foamed polyvinyl chloride (PVC) components.

2. 2. The foamed PVC member of claim 1, wherein the processing aid blend comprises 1% to 25% by weight, based on weight Q, of the functionalized processing aid, and 99% to 75% by weight, based on weight Q, of the non-functionalized processing aid.

3. 10. The foamed PVC member of claim 1, wherein said functionalized processing aid comprises at least 1% by weight of said reactive functional groups.

4. 4. The foamed PVC member of claim 3, wherein said functionalized processing aid comprises up to 25% by weight of said reactive functional groups.

5. 2. The foamed PVC member according to claim 1, wherein the weight Q is 0.1 to 15 parts by weight relative to 100 parts by weight of the PVC resin.

6. 10. The foamed PVC part of claim 1, wherein the foamed PVC part containing the processing aid blend has a density at least 2% less than the density of the reference foamed PVC part.

7. 10. The foamed PVC member of claim 1, wherein the base polymer of the functionalized processing aid is derived from one or more monomers including a (meth)acrylic-containing monomer.

8. 10. The foamed PVC member of claim 1, wherein the base polymer of the functionalized processing aid is derived from i) one or more monomers including (meth)acrylic containing monomers, ii) at least one monomer selected from the group consisting of vinyl containing monomers, styrene and styrene derivatives, olefins, dienes, and mixtures thereof.

9. The reactive epoxy, hydroxyl, β-ketoester, β-ketoamide, or carboxylic acid functional groups may be selected from the group consisting of hydroxyl-substituted alkyl esters of (meth)acrylic acid; vinyl esters of linear or branched carboxylic acids; unsaturated C 3 ~C 6 Monocarboxylic acids and unsaturated C 4 ~C 6 2. The foamed PVC member of claim 1 which is derived from a dicarboxylic acid; a β-keto ester of (meth)acrylic acid; a β-keto amide of (meth)acrylic acid; an epoxy group-containing monomer; or mixtures thereof.

10. 10. The foamed PVC member of claim 1, wherein the non-functionalized processing aid comprises an acrylic polymer or acrylic copolymer.

11. 10. The foamed PVC member of claim 1, wherein the functionalized processing aid has a weight average molecular weight of at least 50,000 g / mole.

12. The foamed PVC component of claim 1 , wherein the non-functionalized processing aid comprises a polymer.

13. The foamed PVC member of claim 1, wherein the non-functionalized processing aid comprises chlorinated polyethylene (PE-C).

14. 2. The foamed PVC component of claim 1, wherein the foamed PVC component is a building material or a flooring material.

15. A method for producing a foamed polyvinyl chloride (PVC) member, comprising the steps of: a) polyvinyl chloride (PVC) resin; b) weight Q of a processing aid blend per 100 parts by weight of the PVC resin, the processing aid blend comprising 1% to 60% by weight, based on weight Q, of a functionalized processing aid, and 99% to 40% by weight, based on weight Q, of a non-functionalized processing aid; and c) Blowing agent (BA); to form a foamable PVC composition; and processing the expandable PVC composition to form the foamed PVC member; the functionalized processing aid comprises at least one base polymer functionalized with 0.1 wt % to 35 wt % of a reactive epoxy, hydroxyl, β-ketoester, β-ketoamide, or carboxylic acid functional group or mixtures thereof, based on the total weight of the functionalized processing aid, except for those containing acetoacetoxyethyl (meth)acrylate (AAEM); the foamed PVC part containing weight Q of the processing aid blend and a reference foamed PVC part containing 100 weight percent of the non-functionalized processing aid, based on weight Q, are produced under similar process conditions and additives, the foamed PVC part containing the processing aid blend has a lower density than the reference foamed PVC part containing 100 weight percent of the non-functionalized processing aid, based on weight Q. method.

16. 16. The method of claim 15, wherein the processing aid blend comprises 1 wt. % to 25 wt. %, based on weight Q, of the functionalized processing aid, and 99 wt. % to 75 wt. %, based on weight Q, of the non-functionalized processing aid.

17. 16. The method of claim 15, wherein the processing aid blend comprises at least 1 weight percent of the functionalized processing aid.

18. 20. The method of claim 17, wherein the processing aid blend comprises up to 25% by weight of the functionalized processing aid.

19. The method for producing a foamed PVC member according to claim 15, wherein the weight Q is 0.1 to 15 parts by weight relative to 100 parts by weight of the PVC resin.

20. 16. The method of claim 15, wherein the foamed PVC part containing the processing aid blend has a density at least 2% less than the density of the reference foamed PVC part.

21. 16. The method of making a foamed PVC member according to claim 15, wherein the base polymer of the functionalized processing aid is derived from one or more monomers including a (meth)acrylic-containing monomer.

22. 16. The method of claim 15, wherein the base polymer of the functionalized processing aid is derived from i) one or more monomers including (meth)acrylic containing monomers, ii) at least one monomer selected from the group consisting of vinyl containing monomers, styrene and styrene derivatives, olefins, dienes, and mixtures thereof.

23. The reactive epoxy, hydroxyl, β-ketoester, β-ketoamide, or carboxylic acid functional groups may be selected from the group consisting of hydroxyl-substituted alkyl esters of (meth)acrylic acid; vinyl esters of linear or branched carboxylic acids; unsaturated C 3 ~C 6 Monocarboxylic acids and unsaturated C 4 ~C 6 16. The method of claim 15, wherein the foamed PVC member is derived from a dicarboxylic acid; a β-keto ester of (meth)acrylic acid; a β-keto amide of (meth)acrylic acid; an epoxy group-containing monomer; or a mixture thereof.

24. 24. The method of claim 23, wherein the base polymer is functionalized with reactive epoxy functional groups derived from glycidyl methacrylate, or glycidyl acrylate, or a mixture thereof.

25. 16. The method of making a foamed PVC component according to claim 15, wherein the non-functionalized processing aid comprises an acrylic polymer or acrylic copolymer.

26. 16. The method of making a foamed PVC component according to claim 15, wherein the functionalized processing aid has a weight average molecular weight of at least 50,000 g / mole.

27. 16. The method of making a foamed PVC component according to claim 15, wherein the non-functionalized processing aid comprises a polymer.

28. 28. The method of claim 27, wherein the non-functionalized processing aid comprises chlorinated polyethylene (PE-C).

29. The method for producing a foamed PVC component according to claim 15, wherein the foamed PVC component is a building material or a flooring material.

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