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Additives: technology for performance.


Additives are as old as the plastics industry and as new as tomorrow's successful applications. Additives suppliers, who frequently must be modern-day alchemists, are working under the pressures exerted by customers--resin companies, molders, end-product producers--in their continuous search for trouble-free processing and reliable functional properties. The efforts are paying off: Additive technology is creating a stream of new products to satisfy many tougher requirements.

Akzo Chemicals, Inc.

Akzo Chemicals has consolidated all R&D laboratories at their Corporate Research Center in Dobbs Ferry, N.Y. They have selected three major areas for stabilizer research: heavy-metal-free products for flexible applications; innovative tin technology for exterior profile or clear packaging areas; and the replacement of lead-based stabilizers for primary wire and cable insulation.

These programs have provided several commercial materials in the areas of heavy-metal-free products and tin technology. Initial R&D evaluations of heavy-metal-free alternatives for lead replacement have shown comparable volume resistivity values. The company is committed to this program and will be ready for field trials in the near future.

New products include:

* Interstab LT-4813, a liquid barium-zinc general-purpose stabilizer for flexible PVC, which acts as a color brightener to give surpassing initial color hold and maitenance;

* Interstab LT-4805R, a lubricating high-efficiency liquid barium-zinc heat and light stabilizer, which provides exceptional long term dynamic stability for high shear, high temperature applications;

* Interstab CZ4L-77, a liquid calcium-zinc stabilizer for applications approved by the U.S. Food and Drug Administration (FDA), and specifically tailored for glove-dipping operations, which allows economical, high quality, low pinhole production runs;

* Stanclere T-883, a liquid FDQ-approved octyltin, which provides improved early color control because of its unique omposition; and

* Stanclere T-4815. a liquid tin heat and light stabilizer for clear rigid packaging, which provides crisp early color control at good economics.

An improved version of Trigonox 101 organic peroxide initiator reduces volatile impurities and increases the flash point. Polypropylene producers are using the product for a range of melt flow index resins. Also for polypropylene, Akzo has introduced Perkadox 64-40PP-pd, Perkadox 64-20PP-pd, and Perkadox 64-40PP-pd, at 40%, 20%, and 10% peroxide concentrations, respectively, for ease of handling and improved dosing accuracy.

Development continues of organic peroxide emulsions and suspensions for PVC; they provide improved handling safety, enhanced purity, ease of dilution with water, and use in closed reactor technology. Perkadox 16-W40-GB5 is a new product with a 40% aqueous suspension. Trigonox 187-C30, for PVC and polyethylene copolymers, is an extremely fast initiator with a 1-hour half-life temperature of 36 [degrees] C. Also, Perkadox AIBN and Perkadox AMBN, free-flowing powders featuring ease of handling, are new for acrylic coatings.

Three products for unsaturated polyesters are Trigonox 121-bb75, which may be used with less reactive organic peroxides to optimize cure cycles; Trigonox 161, with improved handling in elevated temperature unsaturated polyester applications; and Trigonox 239A, for curing vinyl ester resins without gassing.

Akzo is developing custom initiator blends and solutions for shipment in bulk tankers. The preblended products offer reduced worker exposure and less waste and may help eliminate blending errors.

American Cyanamid Co.

Joseph Stretanski, technical service manager, Chemicals Group, says that because of the greater use of high activity catalysts without de-ashing the resin, suppliers must be more careful to recommend the proper acid acceptor system with their antioxidant systems. The optimum combination will provide the desired thermal stabilization while minimizing the color contronution of the antioxidants and their reaction by-products.

Also, because of the predominant use of basic hindered amine light stabilizers, to eliminate pinking it is advantageous to use phenolic antioxidants that are not base sensitive. Stretanski adds that because of the demand for greater control of polymer nelt stability, particularly in the higher melt flow polypropylenes, more phenolic-phosphite blends are needed to inhibit both the peroxides abd the hydroperoxides, which propagate the thermal oxidation of the polyolefin. Cyanamid's Cyanox 2777 antioxidant blend, at 0.08%, is said to outperform competitive blends at 0.10%, all evaluated in a 10 melt index polypropylene processed by multiple extrusion of 275 [degrees] C.

Stretanski sees a need to develop more hydrolysis-resistant phosphites, while maintaining strong performance with available phenolic antioxidants. Initial evaluations of the new phosphites (Ethyl's Ethanox 398 and GE's XR633) with Cyanamid's Cyanox 1790 phenolic antioxidant show excellent melt stabilizing activity in polyolefins.

Atochem North America Inc.

John M. Avento, business development director for the Plastics Additives Division, says that Thermolite 380 combines excellent color control and good thermal stability at low use levels. The high efficiency at low use levels. The high efficiency organotin stabilizer is for siding topcoat and profile applications. Thermolite 139 is for both siding topcoat and substrates; and Thermolite 172 is for siding substrate applications. Atochem has developed a number of products that combine multiple functions into one-pack systems. The products provide performance, help control additive inventories, improve formulation consistency, and reduce overall cost. One-pack systems are available for vinyl siding and foam-core PVC pipe.

Two new organotin stabilizers are for packaging. Thermolite 390, offering longterm heat stability at low use levels, is for calendered rigiv vinyl sheet. Thermolite 395 offers a balance of heat stability, low odor, and cost for rigid vinyl bottles.

Gerard Whelan, Jr., market manager, Metco North America, a joint venture between Atochem North America Inc. and Mitsubishi Ltd., says that Metablen P-530, a high molecular weight acrylic processing aid for PVC foam-core pipe, fosters hot melt strength to facilitate lowering foa, density while maintaining physical properties. The additive's high molecular weight permits reduction in use levels and enables direct production of heavy gage flexible vinyl sheet (40 mils or higher). Previously, in the higher thickness ranges, post-laminating of quality calendered sheet was required. For higher output rates for coextruded vinyl siding and profiles, Metablen P-750 provides fusion control and good surface characteristics.

BASF Corp.

With its manufacturing partner, Sterling Chemicals Inc., in Texas City, Tex., BASF is the market leader in linear phthalate plasticizers. Supported by a basic position in both phthalic anhydride and linear alcohol, their 285 million-lb plasticizer ester plant is second largest in the industry.

Linear phthalate plasticizers are known for their superior low temperature resistance, low processing volatility, and excellent outdoor weatherability in flexible PVC. BASF's line of linear plasticizers includes Palatinol 79P, the product of broadest use in the flexible PVC market, competing with other general-purpose commodity phthalates; Palatinol 711P, a premium perfromance product and the frequent choice in outdoor water containment film, vinyl tarpaulins, swimming pool liners, interior and exterior automotive parts, and jacketing for building wire; and Palatinol 111P-E (DUP), which provides the lowest volatility and the best low temperature flexibility of the three. Uses for 11P-E include high temperature wire insulation and automotive applications requiring low fogging values.

BASF closed two North American facilities in 1990. Together these sites were capable of producing 165 million lbs/yr of phthalic anhydride and plasticizer. While growth for the North American plasticizer market is not expected to keep pace with GNP in the 1990s, supply and demand should be in balance once the automotive and construction industries recover. According to Allan A. Sundberg, marketing manager, Plasticizers, "Production capacity of both phthalate esters and alcohols is sufficient to take the industry comfortably into the mid-1990s. However, phthalic anhydride production could be pushed beyond its nameplate capacity if domestic demand returns to 1988 levels."

Ciba-Geigy Corp.

Ciba-Geigy is now producing easier-to-process granular or free flowing forms of its leading antioxidant products, Irganox 1010 and Irganox 1076. Compaction and other granulation methods yield the free flowing product forms.

Tinuvin 765, a new liquid hindered amine light stabilizer (HALS), is effective in styrenics, polyurethanes, and polyolefins. Irganox 1520 liquid antioxidant and process stabilizer is efficient in adhesives, sealants, and elastomers. The trend toward liquids and easy flowing solid additives assists automation and waste reduction.

Antioxidant blend development improves performance of some processes, especially in polyolefins. Irganox B 215, B 225, B 900, and B 1171; blends of Irganox and Irgafos antioxidants; and other custom blends meet specialized needs.

Pigmented fibers enhance function and appearance of automotive fabrics and carpets. Ciba-Geigy's Chimassorb [TM] 944 and Tinuvin 234 light stabilizers provide UV light protection for nylon and polyester fibers. Chimassorb 944 and Tinuvin 622 also are polypropylene fiber light stabilizers.

For rigid and flexible PVC, Ciba-Geigy says in carboxylate thermal stabilizer, Irgastab T 634, combined with it hindered amine and benzotriazole light stabilizers, can outperform butyltin mercaptide in retaining weatherability and colorfastness, and helps reduce use of [TiO.Sub.2] in some applications.

Chimassorb [TM] 119, a high molecular weight monomeric HALS, has been developed for fibers, films, and color-critical uses. In fibers, it exhibits excellent resistance to extraction by spin finishing and post extrusion treatments. In thick-section polypropylene, Ciba-Geigy says, the additive has outstanding light and thermal stability.

Tinuvin 123, the first of a new class of hindered amine light stabilizers with low basicity, reduces stabilizer interaction with other components of the polymer system, such as flame retardants.

Ciba-Geigy is enhancing products for recycling. Light stabilizers and antioxidants currently are the primary focus.

Eastman Chemical Co.

The company has developed technology to convert polymer additives/stabilizers from different manufacturers to an aqueous form. Additives include antioxidants, UV inhibitors, hindered amine light stabilizers, acid acceptors, antistats, lubricants, nucleators, metal deactivators, antiblocking agents, optical brighteners and inorganic fillers. Currently being used to topically stabilize polypropylene, the products are applicable to a variety of polymer forms, including powder, granule, flake, spheres, or pellets, and can be applied to polymers either by continuous spray or in a batch blending process. They offer an alternative method of incorporating additives to either very low or very high melt flow polymers, which can be difficult to extrusion compound.

The Aquastab stabilizers are based on dispersions of polymer additives in an aqueous emulsion of a low molecular weight oxidized polyolefin wax. After application to the polymer, the wax acts as a binder, holding the additives to the polymer surface. All components of the Aquastab stabilizers are approved by the U.S. Food and Drug Administration for use with polypropylene intended for food contact applications.

Ethyl Corp.

John M. McChesney, marketing communications manager, says the high thermal stability of Ethanox 398 antioxidant guards against charring and the resultant "black specks" that can occur during extrusion processes. The antioxidant is unaffected by radiation used to sterilize polymers for medical and food use. Because of enviromental concerns, some polymers producers have moved to aqueous systems. The resistance of Ethanox 398 to hydrolysis allows use in water environments.

Ethanox 323 antioxidant is a bleaching and disproportionating agent for rosin and rosin-ester adhesive systems, allowing production of light colored adhesives required in many of today's applications.

Exxon Chemical Co.

A. R. Schimmenti, director of marketing, Intermediates, emphasizes the company's integrated raw material strengths and the industry's most extensive product slate of phthalate, adipate, and trimellitate plasticizers. Jayflex 911 was added in 1990 to the available line of linear plasticizers to meet automotive needs for low temperature flexibility and permanence.

Exxon Chemical has also announced plans to significantly expand, by 1993, its integrated Jayflex plasticizer and oxo alcohol manufacturing capability at the Baton Rouge, La., patrochemical complex. Current worldwide capacity for Jayflex plasticizers is over 900 million lbs, and the company's oxo alcohol capacity is currently in excess of 1.3 billion lbs. The proposed Baton Rouge projects will increase Exxon's worldwide production base to four plasticizer and four oxo alcohol plants, and will substantially increase linear plasticizer and specialty ester product capabilities.

Ferro Corp.

David W. Strunk, marketing manager, Flexible Vinyl Products, says mixed metal heat stabilizer development at Ferro deals with four major issues: elimination of cadmium carboxylates; more stringent shipping regulations governing liquids with flash points below 200 [degrees] F; increased amine stain resistance of automotive interiors, especially crash pads (to 21 days at 250 [degrees] F for the 1992 model year); and concerns about lead stabilizers in vinyl.

Ferro has offered a continuously improving series of barium-zinc and calcium liquid and powder heat stabilizers. Therm-Chek 138 and 139 are recently developed for general-purpose clear and filled extruded and calendered products. Therm-Chek 134 and 137 barium-zinc liquids are for optically clear, extruded semirigid and flexible sheets of 250 mil or more. Therm-chek 126, a barium-zinc product for flexible extrusion, responds to the need for liquid stabilizers with flash points over 200 [degrees] F.

Stabilization systems target color change resulting from amine staining after extended exposure to heat and sunlight. For slush molded vinyl crash pads, Therm-Chek 196 powder combines a heat stabilizer and amine scavenger; Therm-Chek 1180 liquid combines a heat and light stabilizer. All, including Therm-Chek 1149, a liquid heat stabilizer, are non-cadmium and, used in proper combination, low fogging.

Ferro's Therm-Chek 195 functions principally as an amine scavenger; Therm-Chek 923 is a process heat stabilizer booster; and Therm-Chek 1129 act as a liquid heat stabilizer. The non-cadmium heat stabilizers impart low fog characteristics to calendered sheets.

For automotive interior applications, such as sluch molded armrest, Ferro has developed a two-package system, consisting of Therm-Chek PS 380 liquid and Therm-Chek 195, to provide both process heat stability and amine stain resistance. For automotive interiors where vinyl is not in direct contract with polyurathane foam, two low fog, non-cadmium liquids, Therm-Chek 1159 and 1169, are available.

A Feffor program for replacement of lead-based heat stabilizer in wire and cable yields preliminary indications that comparable volume resistivity levels are achievable with new proprietary technology.

GE Specialty Chemicals

The company's process aids include high molecular weight acrylic, SAN, and styrenic polymers. blendex 590, the newest product, builds hot melt strength and dimensional stability, notably for foaming, blowmolding, and thermoforming.

Elyse Lewis, product manager, Polymer Additives, comments that formulators now expect secondary antioxidants to help maintain a range of physical properties as well as color stability. "Tests show that spiropentaerythritol-based phospites such as Utranox 626 (and XR-633, a new developmental product available for experimental evaluations), offer an excellent property balance," says Lewis. Ultranox 626 antioxidant, for example, improves molecular weight stability in processing of polyolefin carpet fibers, minimizing breakage during extrusion. Stabilizer loading levels can be reduced because of a synegism with phenolic antioxidants, which reduced color and molecular weight change and other viriables, such as melt flow rates and yellowing index. The company has just completed expansions to the world's largest phosphite manufacturing facility, in Morgantown, W. Va.

C.P. Hall Co.

Steven P. Hopper, marketing manager, sees the increasing demands on platicizers exemplified by higher and lower temperature extremes in service life and pressures for improved environmental aging and processing characteristics, which contribute to quality, cycle times, and efficient manufacturing practices.

C. P. Hall's range of monomeric and polymeric plasticizers includes derivatives of glutaric, adipic, sebacic, azelaic, phthatic, and phosphoric acids, which may be combined with a variety of alcohols and glycols, as well as a broad spectrum of monofunctional carboxylic acids.

The company's product development efforts include polymeric plasticizers for PVC performance gaskets, automobile interior and exterior systems, high-end electrical insulation applications, supported and unsupported upholstery, films, fabrics, and tapes.

Henkel Corp.

The Emery Group is introducing two new black polymeric plasticizers, based on Emery's azelaic acids. Marketing manager Robert Braw says, "Plastolein 9785 is an extremely good low temperature polymeric typical of azelate polyesters, but priced competitively with adipates. This could be used in areas requiring improved low temperature performance while maintaining permanence." Plastolein 9785 is a very compatible low cost, general-purpose plasticizer that could find use in wire and cable applications or nay other area in which permanence is required without light color. Henkel also will introduce Plastolein 9087; the diester exhibits the improved low temperature and volatility characteristics of Plastolein 9058, but at lower cost.

Huls America

The Plastics Additives Group will offer three new high performance plasticizers for PVC this year. Nuoplaz 6534, a benzoate plasticizer with low volatility and excellent fusion, imparts unusually good stain resistance to vinyl floor and wall covering.

Admex 1723, a medium-low molecular weight polymeric adipate plasticizer, provides excellent permanence and weatherability to vinyls in outdoor uses, such as single-ply roofing. Low volatility and efficiency are beneficial in plasticization of furniture upholstery, where resistance to body oils and cleaning detergents is required. The additive provides printability to decorative graphics and can be used for outerwear and sportswear, automotive landau roofs, and webbing for lawn furniture.

Admex 2632, also a medium-low molecular weight polymeric adipate plasticizer, may be used for food contact where plasticizer migration is a problem; in medical devices that contact other polymers; and to eliminate stress cracking from migration of monomeric plasticizers in flexible vinyl to neighboring ploymers. The additive also is applicable for baby pants, hospital sheeting, beverage tubing, and bottle cap liners.

ICI Specialty Chemicals

Topanol LVT 600 and LVT 11 liquids delivery systems are two new offerings in ICI Polymer Addtives' line of high molecular weight primary phenolic antionxidants. LVT 600, an aqueous antioxidant disperios, is designed for easy incorporation into polyolefin, styrenic, and engineering polymeer processes. LVT 11, an antioxidant/plasticizer solution, is targeted for vinyl applications in wire and cable, and automotive.

For UV light stabilization, Topanex 500H HALS functions in highly pigmented systems. David A. Vanzin, new business development specialist, Polymer Additives Business, says the product "offers equal performance at reduced concentrations or superior function at equivalent levels." The company also markets Topanex 100BT, a benzotriazole targeted a styrenic and vinyl applications.

ICI's Atmer 129 and 1010 lubricants meet stringent requirements in PVC bottle compounds and in other plasticizer and rigid vinyl markets. Vanzin says that Atmer 129, a solid material, offers outstanding thermal stability and lubricity, together with excellent color, clarity, taste, and odor properties. Atmer 1010, a liquid, maintains fluidity to 11 degrees C, and provides a performance spectrum similar to that of the 129 material. The company also offers Atmer 104 lubricant for use in rigid PVC sheeting.

Monsanto Chemical Co.

The mature U.S. plasticizer industry was estimated at 1.58 billion lbs/yr in 1990. Major issues basically revolve around raw material supply and costs and environmental/health factors. Also, the decision by BASF to close its Kearny, N.J., facility in late 1990 has severely tightened the supply ofphthalic anhydride, a basic raw material used in plasticizer production, and the market for general-purpose phthalate esters. While no new major environmental of health issues have surfaced, it is generally agreed that current environmental restraints will continue to affect the choice of plasticizers.

Especially relating to PVC, Monsanto's James T. Renshaw, manager, Marketing Technical Services, Polymer Modifiers, cites a continued movement from di-z ethylhexyl phthalate (DOP) to diisononyl phthalate (DINP) and the linear plasticizers, based primarily in improved performance, but also because of environmental pressures. He adds that the drive toward higher performance should also enhance trimellitate plasticizer growth for automotive and wire and cable. Low smoke generation, coupled with good flame retardant properties, will stimulate growth, for example, in building products. Interest in alternative feedstocks will continue, and, Renshaw believes, we will likely see more plasticizers based on alcohol derived from normal butylenes.

As a specialty plasticizer supplier, Monsanto produces a line of alkyl aryl phthalates, triaryl and alkyl aryl phosphates, and adipate esters. Butyl benzyl phthalate, the largest volume product for specialty plasticizers, is dominant in vinyl composition tile and sheet flooring applications. Other applications for the benzyl phthalates include PV acetate adhesive, acrylic caulks and coatings, urethanes, polysulfides, and ABS. The phosphate esters have a variety of PVC uses requiring good flammability and/or low smoke properties. Adipate esters in PVC-based meet wrap products offer very good low temperature properties.

Monsanto's Santicizer 2148, a high performance alkyl aryl phosphate, exhibits, according to the company, the best volatility and low temperature properties available in a phosphate ester.

Rohm and Haas Co.

Three new products in the Paraloid K-100 series, based on acrylic chemistry, will be offered this year. Paraloid K-130 combines clarity and processing efficiency and eliminates flow marks for blowmolded bottles and calendered vinyl sheet and film.

A processing aid for rigid vinyl foam, coming soo, improves melt strength and permits high speed processing of foam core pipe and other extrusions.

EXL 4151, an imide-copolymer blending resin in the company's EXL 4000 series, can alter nylon 6 rheology and improve melt strength, fostering possible blowmolding automotive applications. Improved melt strength also permits use of lower cost nylons in film and other extrusions.

Synthetic Products Co.

Customer pressures for cadmium-free heat stabilizers have also required equivalent performance with any substitutions. Richard F. Grossman, technical director, Synthetic Products Co., reports that key company experiments have revealed the bridging effects of ligands, such as 1, 3 diketones, that hold together different interacting metals, such as barium and zinc. Also better understood are the optimum ratios of the additive components to limit formaton of metal chlorides that promote stabilizer degration. Grossman says a result in commercially available barium-zinc stabilizers "with equivalent or better heat stability than existing barium-cadmium formulations." Preblending lubricants, such as partial fatty acid esters of glycerol and pentaerythritol, maximize the bridging effect of the barium-zinc combination. Grossman adds that it has recently become apparent that a number of ther bridging ligands increase stability of barium-zinc, and calcium-zinc, blends. The latitutde of stabilizer formulation, and heat stability, are superior to the capabilities of existing barium-cadmium technology. Initial uses are calendered and extruded film and sheet, profiles, and plastisols.

"the fact aht a particular metal can be considere primarily in the context of the presence of associated ligands has been reinforced by the studies carried out to optimize barium-zinc blends," Grossman says. "there appears to be not theoretical reason why a range of other elements, particularly light metals not considered hazardous, could not function, with the proper ligands, as PVC heat stabilizers for flexible and rigid products."

Witco Corp.

The Argus Division's non-cadium co-stabilizer, Mark 6055, can be used with' standard stabilizers to protect fluorescent dyes often used in vinyl plastisols. It also aids processing fo tin-stabilized rigid PVC that contains eithylene bistearamide lubricant, which tends to diminish vinyl heat stability. The product allows plastisol processors to use dyes that previously were to sensitive to heat and opens up more extrusion and calendering opportunities.

Mark 6718, a non-cadmium stabilizer, replaces lead compouns in vinyl jacketing of wire and cable. Mark 1979, an organotin heat stabilizer, has been introduced for injection molding of rigid vinyl pipe fittings. The Argus Division has also announced it will more than double production capacity for methyltin heat stabilizers for rigid vinyl sidings, door and window frames, and pipe. Additionally, the company's non-cadium Mark automotive standard stabilizers to protect fluorescent stabilizer system for vinyls provides improved resistance to polyurethane staining and meets tightened auto interior standards.

Argus offer Drapex epoxy plasticizers, including epoxidized octyl tallate, soybean oil, and linseed oil types, that improve heat and light stability when used with barium-cadmium and non-cadmium stabilizers. Drapez 6.8S, a new epoxidized soybean oil plasticizer, provides low taste and odor properties when used with powdered Mark 3704 magnesium/zinc stabilizer. The system provides good color hold for processing of vinyl bottles.

A new polymeric plasticizer, Drapex P-23, provides excellent low temperature properties. Other low odor, low temperature polymerics for refrigiration gasketing are being developed or sampled.

Among the latest MoldPro products from the Humko Chemical Division are lubricants for nylon 6, nylon 6/6, and styrene butadiene block copolymer, to aid flow and parte ejection.

Witco's Organics Division has introduced a grade of its zinc stearate lubricant in dust free pastille form to enhance bulk handling and for processing polyolefin and polystyrene. Also offered are metallic stearates in water compatible nonaqueous systems for specialized uses in polymerization of vinyl and chlorinated polyethylene resins. The company is increasing its stearate capacity by 35%.
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Title Annotation:successful manufacturers of additives for the plastics industry
Author:Wigotsky, Victor
Publication:Plastics Engineering
Date:Apr 1, 1991
Previous Article:New amorphous polyesters designed for extrusion and thermoforming.
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