Additives to lower melt PVC processing temperatures and PVC formulations with lower melt processing temperatures

Abstract

Disclosed is a composition comprising a matrix comprising a polyvinyl chloride resin and ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer wherein the ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer is present in an amount effective to reduce the melt processing temperature of the polyvinyl chloride composition. A process for reducing the fusion temperature of a polyvinyl chloride composition is also disclosed.

Description

ADDITIVES TO LOWER MELT PVC PROCESSING TEMPERATURES AND PVC FORMULATIONS WITH LOWER MELT PROCESSING TEMPERATURESFIELD OF THE INVENTION

[0001] The invention relates to additives to lower melt PVC processing temperatures and PVC formulations with lower melt processing temperatures.BACKGROUND

[0002] Rigid polyvinyl chloride (PVC) is an energy intensive process as the PVC is currently processed at a general temperature range between 165 to 195 °C depending on the processing technique, such as, for example, extruding, calendaring, injection molding, etc.

[0003] There is an industry-wide focus on sustainability and identifying ways to reduce the carbon footprint of manufacturing processes. There arc various ways to lower carbon footprints including recycling, reusing, reduction in materials, and developing more energy efficient processes. To meet sustainability targets, there have been attempts to develop additives that can help increase recycled content, as well as to develop additives that improve the carbon footprint in other ways, such as reducing energy requirements.

[0004] Because the energy required for processing PVC to produce a final product depends on the processing temperature, lowering the PVC processing temperature presents an opportunity to lower energy usage and the overall carbon footprint of the product.

[0005] Lowering the processing temperature of existing processes with currently used additives, however, results in various issues such as inferior quality, higher scrap or waste production, higher downtime, and lower production yield.

[0006] Therefore, a need exists for additives and processes that allow for PVC production at lower temperature. The present invention attempts to solve one or more of these problems.SUMMARY OF THE INVENTION

[0007] Disclosed herein is a composition comprising a polyvinyl chloride resin, and an ethylene / alkyl (meth)acrylateZcarbon monoxide terpolymer, wherein the ethylene / alkyl(meth)acrylate / carbon monoxide terpolymer is present in an amount effective to reduce the melt processing temperature of the polyvinyl chloride composition.

[0008] Also disclosed herein is a process for reducing the fusion temperature of a polyvinyl chloride resin comprising adding an ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer to a polyvinyl chloride resin, wherein the ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer added to the polyvinyl chloride resin in an amount effective to reduce the melt processing temperature of the polyvinyl chloride resin composition.DETAILED DESCRIPTION OF THE INVENTION

[0009] Disclosed herein is a composition comprising a matrix comprising a polyvinyl chloride resin, and an ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer, wherein the ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer is added in an amount effective to lower the melt processing temperature of the polyvinyl chloride resin composition.

[0010] The polyvinyl chloride resin may form all or a part of a continuous phase (i.e., the matrix) in the composition for preparing a polymer article and the article prepared therefrom. The selection of the polyvinyl chloride resin is typically a function of the desired end use application of the polymer composite article formed with the composition, as various polymers have different melting point temperatures (and / or glass transition temperatures) and physical / mechanical properties, as well as suitable or acceptable continuous use application temperatures. The polyvinyl chloride resin preferably has a softening point temperature that is less than a degradation temperature of other components in the composition. For example, the polyvinyl chloride resin may have a softening point temperature of less than 250 °C, alternatively less than 225 °C, alternatively less than 200°C. The softening point temperature may also be referred to as the processing temperature. In at least one embodiment, the polyvinyl chloride resin has a softening point temperature ranging from 150 to 250°C, such as from 160 to 220°C or from 170 to 210°C. The polyvinyl chloride resin may be in the form of pellets or a powder.

[0011] The polyvinyl chloride resin may be a rigid polyvinyl chloride resin. As used herein, the phrase “rigid polyvinyl chloride resin” means that a plasticizer is not added to the polyvinyl chloride resin, i.e., the polyvinyl chloride resin does not comprise an added plasticizeror the composition comprising the polyvinyl chloride resin does not comprise an added plasticizer. Preferably, the polyvinyl chloride resin is a rigid polyvinyl chloride resin.

[0012] Elastomers and / or rubbers can be added to or compounded with the polyvinyl chloride resin to modify or improve properties, such as impact strength. Preferably, the polyvinyl chloride resin comprises at least one acrylic processing additive. Additives may include those known in the art, such as the additives disclosed by Stevenson et al., Journal of Vinyl Technology, December 1993, Vol. 15, No. 4, pages 244-251, which is incorporated herein by reference.

[0013] In certain embodiments, the matrix in the polyvinyl chloride composition consists essentially of a polyvinyl chloride resin. By consist essentially of, it is meant that the matrix can include one or more additional polymers other than a polyvinyl chloride resin so long as such additional polymers can be processed along with the polyvinyl chloride resin to form the polymer article. When the matrix does not consist of a polyvinyl chloride resin, the matrix includes a polyvinyl chloride resin in an amount of at least 50, alternatively at least 60, alternatively at least 65, alternatively at least 70, alternatively at least 75, alternatively at least 80, alternatively at least 85, alternatively at least 90, alternatively at least 95, alternatively at least 96, alternatively at least 97, alternatively at least 98, alternatively at least 99, wt.% based on the total weight of the matrix utilized in the composition.

[0014] The polyvinyl chloride resin may further comprise an elastomer. Non-limiting examples of elastomers include styrene-butadiene rubber, polyether urethane rubber, polyester urethane rubber, butyl rubber, nitrile rubber, chloroprene rubber (neoprene), poly acrylate rubber, ethylene acrylate rubber, ethylene-propylene rubber, ethylene -propylene-diene rubber, ethylene propylene diene monomer (EPDM), ethylene propylene rubber (EPR), fluoro silicone rubber, fluorocarbon rubber, perfluorinated elastomer, styrene butadiene rubber, chlorosulfonated polyethylene, polyisoprene rubber, polysulfide rubber, ethylene acrylate rubber, epichlorohydrine rubber, perfluoroelastomer (e.g. Kalrcz™), polysulfide rubber, chlorinated polyethylene (e.g. chlorinated polyethylene comprising up to 40 weight percent chlorine), and combinations thereof.

[0015] When the matrix comprises a polymer in addition to a polyvinyl chloride resin, the matrix may further comprise at least one polymer that is fully or partially thermodynamically miscible with polyvinyl chloride resin. Such polymers include, but are not limited to,poly(methyl methacrylate) (PMMA), polyethylene oxide (PEO), thermoplastic polyurethane (TPU), polycaprolactonc (CPL), and styrcnc-acrylonitrilc resin (SAN). Other thermodynamically miscible polymers are known in the art and are disclosed, for example, Robeson, L. M. (1990), Miscible polymer blends containing poly(vinyl chloride). J. Vinyl Addit. Technol., 12: 89-94, which is incorporated herein by reference.

[0016] The polyvinyl chloride resin can comprise virgin polymer and / or recycled polymer. The recycled polymer, if utilized, may be sourced from industrial production streams, as well as from post-industrial and / or post-consumer sources. The selection of the polyvinyl chloride resin, as well as any ratio of virgin polymer to recycled polymer, if utilized in concert, is typically a function of cost and desired properties of the polymer composite article formed therewith.

[0017] It is noted that recycled polyvinyl chloride may contain some level of plasticizer. As defined above, a rigid polyvinyl chloride resin does not comprise an added plasticizer. Therefore, a rigid polyvinyl chloride resin according to the present invention may comprise recycled polyvinyl chloride containing a plasticizer so long as no additional plasticizer is added.

[0018] An ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer is added to the matrix to form the polyvinyl chloride composition. The ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer lowers the melt processing temperature of the of the polyvinyl chloride resin composition.

[0019] The ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer comprising copolymerized units derived from ethylene, an alkyl (meth)acrylate and carbon monoxide. As used herein, the term “alkyl (meth)acylate” includes both the alkyl acrylate and the alkyl methacrylate, e.g., methyl (meth)acrylate comprises both methyl acrylate and methyl methacrylate.

[0020] The ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer comprises 40 to 80 wt% of copolymerized units of ethylene relative to the total weight of the ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer,.

[0021] The ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer comprises 5 to 60 wt% of copolymerized units of alkyl (meth)acrylate relative to the total weight of the ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer. Preferably the ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer comprises 5 to 50 wt%, more preferably 10 to 35wt% relative to the total weight of the ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer.

[0022] The ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer comprises copolymerized units of carbon monoxide in an amount ranging from 3 to 30 wt% relative to the total weight of the ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer. Preferably, the ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer comprises 3 to 30 wt%, more preferably 3 to 20 wt%, and even more preferably 3 to 10 wt%, copolymerized units of carbon monoxide relative to the total weight of the ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer.

[0023] The alkyl of the alkyl (meth) acrylate contains 1 to 8 carbon atoms, preferably 1 to4 carbon atoms. Preferably the alkyl (meth)acrylate comprises butyl acrylate.

[0024] The ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer is present in an amount effective to reduce the melt processing temperature of the polyvinyl chloride resin composition. As used herein, the phrase “effective amount” means an amount of ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer in the polyvinyl chloride resin composition that reduces the melt processing temperature by at least 1% when compared to a polyvinyl chloride resin composition that does not contain the ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer. Preferably, the amount of ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer in the composition is at least 1 wt%, more preferably at least 2 wt%, and even more preferably at least 3 wt% relative to the total weight of the polyvinyl chloride resin composition. Preferably, the amount of ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer in the composition is less than 10 wt%, more preferably 8 wt% or less, relative to the total weight of the polyvinyl chloride resin composition. When the amount of ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer is 10 wt% or more, no improvement in fusion temperature is observed. The polyvinyl chloride resin composition may be in a concentrated form and then mixed with a polyvinyl chloride resin to get to the desired amount of ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer in the composition that is being processed (e.g. extruded, injection molded). In concentrated form, the amount of ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer may comprise a significant portion of the composition, for example up to 60 or 50 or 40 weight percent. For use in processing, to get the benefits of higher melt flow index (lower viscosity),the composition may according to certain embodiments comprise the polyvinyl butyral polymer in amounts up to 30 or 25 or 20 weight percent.

[0025] The composition may further comprise a filler. The filler may be a single filler or a combination of two or more fillers that differ in at least one property such as type of filler, method of preparation, treatment or surface chemistry, filler composition, filler shape, filler surface area, average particle size, and / or particle size distribution.

[0026] The shape and dimensions of the filler is also not specifically restricted. For example, the filler may be spherical, rectangular, ovoid, irregular, and may be in the form of, for example, a powder, a flour, a fiber, a flake, a chip, a shaving, a strand, a scrim, a wafer, a wool, a straw, a particle, and combinations thereof. Dimensions and shape are typically selected based on the type of the filler utilized, the selection of other components included within the composition, and the end use application of the polymer composite article formed therewith.

[0027] Non-limiting examples of fillers include quartz and / or crushed quartz, aluminum oxide, magnesium oxide, silica (e.g. fumed, ground, precipitated), hydrated magnesium silicate, magnesium carbonate, dolomite, silicone resin, wollastonite, soapstone, kaolinite, kaolin, mica muscovite, phlogopite, halloysite (hydrated alumina silicate), aluminum silicate, sodium aluminosilicate, glass (fiber, beads or particles, including recycled glass, e.g. from wind turbines or other sources), clay, magnetite, hematite, calcium carbonate such as precipitated, fumed, and / or ground calcium carbonate, calcium sulfate, barium sulfate, calcium metasilicate, zinc oxide, talc, diatomaceous earth, iron oxide, clays, mica, chalk, titanium dioxide (titania), zirconia, sand, carbon black, graphite, anthracite, coal, lignite, charcoal, activated carbon, nonfunctional silicone resin, alumina, silver, metal powders, , magnesium oxide, magnesium hydroxide, magnesium oxysulfate fiber, aluminum trihydrate, aluminum oxyhydrate, coated fillers, carbon fibers (including recycled carbon fibers, e.g. from the aircraft and / or automotive industries), poly-aramids such as chopped KEVLAR™ or Twaron™, nylon fibers, mineral fillers or pigments (e.g. titanium dioxide, non-hydrated, partially hydrated, or hydrated fluorides, chlorides, bromides, iodides, chromates, carbonates, hydroxides, phosphates, hydrogen phosphates, nitrates, oxides, and sulfates of sodium, potassium, magnesium, calcium, and barium); zinc oxide, antimony pentoxide, antimony trioxide, beryllium oxide, chromium oxide, lithopone, boric acid or a borate salt such as zinc borate, barium metaborate or aluminum borate, mixed metal oxides such as vermiculite, bentonite, pumice, perlite, fly ash, clay, and silica gel;rice hull ash, ceramic and, zeolites, metals such as aluminum flakes or powder, bronze powder, copper, gold, molybdenum, nickel, silver powder or flakes, stainless steel powder, tungsten, barium titanate, silica-carbon black composite, functionalized carbon nanotubes, cement, slate flour, pyrophyllite, sepiolite, zinc stannate, zinc sulphide), and combinations thereof. Preferably, the filler is selected from the group consisting of calcium carbonate, glass fibers, carbon fibers, mica, graphite, talc, kaolin, aluminum trihydrate, and combinations thereof. More preferably, the filler comprises talc.

[0028] The filler is present in an amount of at least 1 wt% relative to the total weight of the polyvinyl chloride composition. Preferably, the filler is present in an amount of at least 10 wt%, more preferably of at least 20 wt%%, still more preferably at least 30 wt%, even more preferably at least 40 wt%, yet more preferably at least 50 wt%, and still even more preferably at least 60 wt%, relative to the total weight of the polyvinyl chloride composition. The filler is present in an amount of 80 wt% or less, preferably 75 wt% or less, relative to the total weight of the polyvinyl chloride composition.

[0029] The composition may further comprise additional additives as are desired for the final product. Examples of such additives include heat and / or UV light stabilizers, antioxidants, pigments, impact modifiers, and processing aids. According to certain embodiments that additives are selected such that the composition remains transparent. Examples of UV light stabilizers include benzophenones, benzotriazoles, trianzines, benzoxazinones, hindered amine light stabilizer (HALS) and hindered benzoates. Commercially available UV and light stabilizers are exemplified by Cyasorb Light Absorbers, and Light Stabilizers, and Cyasorb Cynergy Solutions from Solvay, TINUVIN FROM BASF, LowLite from Chemtura, OnCap from PolyOne, and Light Stabilizer 210 from E. I. du Pont de Nemours and Company of Delaware, U.S.A. Examples of antioxidants include phenolic antioxidants, and combinations of phenolic antioxidants with phosphites, thioethers or organic sulfides. Phenolic antioxidants include fully sterically hindered phenols and partially hindered phenols; and sterically hindered amines such as tetramethyl-piperidine derivatives. Suitable phenolic antioxidants include vitamin E and IRGANOX™ 1010 from BASF. IRGANOX™ 1010 comprises pentaerythritol tetrakis(3- (3,5-di-t-butyl-4-hydroxyphenyl)propionate).

[0030] The composition may be made by conventional melt compounding to process the components.

[0031] The composition is useful in extruding, and injection molding applications due to the favorable melt flow index.

[0032] It has been found that adding the ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer to a polyvinyl chloride resin can reduce the fusion temperature and fusion energy, which directly reduces the amount of energy consumed when producing articles from the polyvinyl chloride compositions according to the present invention.EXAMPLESPolyvinyl Chloride MasterbatchA PVC masterbatch was prepared by adding the materials in Table 1 sequentially, wherein the amounts are based on weight in parts per hundred resin. The dry blends were prepared by adding the PVC at room temperature to a Gunther Papenmeier / Welex blender, ramping the power to 15A, adding the heat stabilizer at 125°F, adding the lubricant package at 150°F, adding the acrylic processing aids and impact modifiers at 170°F, adding CaCCL at 195°F. After the powder blended was cold to room temperature. The PVC masterbatch had a composition as shown in Table 1, where the amounts are based on weight in parts per hundred resin. Table 1PVC Compositions with Polymer Additive

[0033] Polymer compositions comprising the PVC masterbatch and an ethylene / butyl acrylate / carbon monoxide terpolymer were prepared by bag mixing the PVC masterbatch and thepolymer additive. A control was also prepared with no additive. The formulations are shown in Table 2, where the values arc weight percentages based on the total weight of the formulation.Table 2Fusion data was measured bya torque rheometer. 80g of a pre-mix of PVB and PVC masterbatch was fed to torque rheometer at 180°C. Speed of the torque rheometer was 45rpm. The time at which powder started compacting to start fusion process (bottom of the fusion peak) was recorded as compaction time and the torque at that point was recorded at compaction torque. The time at which fusion process was completed (top of the fusion peak) was recorded as fusion time. The consequent torque was recorded as fusion torque. The temperature and energy at the fusion time is also recorded. The equilibrium torque is the value of torque at the end of the fusion test, i.e. at 7 min. The consequent temperature is recorded as equilibrium temperature. All above data is captured by Brabender software on the torque rheometer. As shown in Table 4, the fusion temperature dropped from 182 °C (Control) to as low as 158 °C. Energy also decreased from 12 kmg to 5.2 kmg. Example 2 showed decreases in the equilibrium temperature and the time to fusion, indicating that less energy was required to process the formulation.Table 3

[0034] In addition to fusion data, capillary viscosity was also measured. The addition of the cthylcnc / butyl acrylatc / carbon monoxide terpolymer additive lowered the melt viscosity at constant pressure. Melt viscosity was maintained at lower temperatures indicating reduced melt processing temperatures.

Claims

What is claimed is:

1. A polyvinyl chloride composition comprising: a matrix comprising a polyvinyl chloride resin, and an ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer, wherein the ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer is present in an amount ranging from 1 wt% to less than 10 wt% based on the total weight of the polyvinyl chloride composition.

2. The composition of claim 1 wherein the ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer is present in an amount ranging from 1 wt% to less than 10 wt% relative to the total weight of the polyvinyl chloride composition.

3. The composition of claim 1 or claim 2 wherein the ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer comprises 40 to 80 wt% copolymerized ethylene, 5 to 60 wt% copolymerized alkyl (meth)acrylate, and from 3 to 35 wt% copolymerized carbon monoxide relative to the total weight of the ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer.

4. The composition of claim 1 or claim 2 wherein the alkyl group of the alkyl (meth)acrylate contains 1 to 8 carbon atoms.

5. The composition of claim 4 wherein the alkyl group of the alkyl (meth)acrylate contains 1 to 4 carbon atoms.

6. The composition of claim 5 wherein the alkyl (meth)acrylate is butyl acrylate.

7. The composition of any one of the preceding claims further comprising a filler, wherein the filler is present in an amount ranging from 1 to 80 wt% of the total weight of the polyvinyl chloride composition.

8. The composition of any one of the preceding claims further comprising at least on additive selected from the group consisting of thermal stabilizers, UV light stabilizers, antioxidants, pigments, impact modifiers, and processing aids.

9. An article comprising the composition of any one of the preceding claims.

10. A process for reducing the fusion temperature of a polyvinyl chloride resin composition comprising adding an ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer to a polyvinyl chloride resin, wherein the ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer is addedin an amount effective to reduce the melt processing temperature of the polyvinyl chloride resin composition.

11. The process of claim 10 wherein the ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer is added in an amount ranging from 1 wt% to less than 10 wt% relative to the total weight of the polyvinyl chloride composition.

12. The process of claim 10 or claim 11 wherein the polyvinyl chloride resin composition comprises a filler, wherein the filler is present in an amount ranging from 1 to 80 wt% relative to the total weight of the polyvinyl chloride resin composition.

13. The process of any one of claims claim 10 to 12 wherein the ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer comprises 40 to 80 wt% copolymerized ethylene, 5 to 60 wt% copolymerized alkyl (meth)acrylate, and from 3 to 35 wt% copolymerized carbon monoxide relative to the total weight of the ethylene / alkyl (meth)acrylate / carbon monoxide terpolymer.

14. The process of any one of claims 10 to 13 wherein the alkyl group of the alkyl (meth)acrylate contains 1 to 8 carbon atoms.

15. The process of claim 14 wherein the alkyl (meth) acrylate is butyl acrylate.

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