Blowing agents: product lines reviewed.

BLOWING AGENTS PRODUCT LINES REVIEWED

ACCURATE COLOR, INC.

Offers a full line of chemical blowing agent dispersions in solid concentrate or liquid, designed for sink reduction and resin extension, available separately or incorporated with other additives. A series of azo-based concentrates (1600 Series) in an LLDPE carrier contains 12.5% azo for letdowns from 100:1 to 40:1 in LLDPE extrusion and rotomolding. Company also offers a proprietary, multifunctional liquid carrier.

AKZO ENGINEERING PLASTICS

Wil-Foam chemical blowing agent concentrates are offered for all types of thermoplastics, including vinyls, polyolefins, styrenics, acrylics, polyesters and nylons.

A variety of generic types of chemical blowing agents are available in custom-made, multicomponent concentrates that are said to feature high concentration, maximum potency, and excellent dispersion. CBA concentrates are offered for wire and cable, fibers, film, sheeting, custom extrusions, injection/ blow molded parts, and structural foam molding.

ALLIED COLOR INDUSTRIES, INC.

Offers pelletized concentrates of blowing agents, such as benzene sulfonyl hydrazide, azodicarbonamide, and modified azodicarbonamide, in a variety of thermoplastics.

AMERICHEM, INC.

Custom-formulated concentrates of blowing agents are produced for most thermoplastics. One such product is a reportedly nontoxic blowing-agent concentrate for food-contact applications, available containing only the blowing agent or as a multifunctional concentrate incorporating other additives and color according to customer's need.

AMPACET CORP.

Offers three LDPE-based foaming-agent concentrates, designated 10123, 10112 and 10349. Concentrate 10123 is recommended for LDPE, HDPE or PP homopolymers. Concentrate 10112 is for PE/ EVA copolymers. "Universal" concentrate 10349 has been introduced for engineering applications and is compatible with polar and nonpolar resin systems.

These products are specially designed for thin-gauge blown, cast or coextruded films and have been extensively field tested. Applications include tablecloths, placemats, merchant bags, and shopping bags.

ATOCHEM NORTH AMERICA INC.

Offers a line of Isotron CFCs and HCFCs, alternatives used as physical blowing agents for producing foamed PU, PS and PE.

ATOCHEM NORTH AMERICA INC.

ORGANIC PEROXIDES DIV.

Luperfoam t-butyl hydrazine derivative foaming-agent solutions are available for room-temperature or elevated-temperature foaming of unsaturated polyester resins. The system is also adaptable for use with auxiliary blowing agents, such as fluorocarbons, to yield very low-density foams.

BIDDLE SAWYER CORP.

Distributes azodicarbonamide products made by Otsuka Chemical Co. of Japan, designed to produce PVC foams with expansion ratios of 9:1 to 25:1. Onifine C is a combination of modified azodicarbonamide, Ba/Zn stabilizer, and a crosslinkable PVC resin; the latter is said to provide greater mechanical strength and chemical and heat resistance to calendered flexible PVC foam. Onifine CC, while similar in composition, is for flexible crosslinked PVC foam, and provides 10-25:1 expansion. Onifine CE has a similar composition and is for highly crosslinked, extruded PVC foam. All three products are supplied in powder form. Onifine P decomposes by an endothermal instead of an exothermal reaction.

BOEHRINGER INGELHEIM See Henley Chemicals, Inc.

CAROLINA COLOR CORP.

Custom formulations of blowing-agent concentrates for many thermoplastics are offered. They are compounded with other additives, according to the customer's specifications.

CHROMA CORP.

Offers line of dry-powder or pellet blowing agents, available in bulk or smaller packages, and a line of pelletized concentrates containing blowing agents and other additives, including colors.

CLARK-COOPER CORP.

Offers highly concentrated, high-viscosity, nonsettling liquid/paste blowing-agent dispersions. Chemocel 550 is for materials processed below 450 F, while Chemocel 700 is for those processed above that temperature. Custom dispersions with other additives are also available.

COLORCO, INC.

Offers colored or noncolored additive concentrates for most thermoplastics to meet individual specifications for blowing agents, lubricants, colors, stabilizers, and slip agents.

DONG JIN (USA), INC.

Distributes a broad line of chemical blowing agents manufactured by Dong Jin Chemical Industry Co., Ltd., Seoul, Korea. Products are:

* Unicell D: Azodicarbonamide in particle sizes from 2 to 25 microns.

* Unicell DX: Multiple grades of modified azo for medium and low temperatures.

* Unicell D300 SD: Modified azo for self-dispersing applications.

* Unicell NP: Modified azos for nucleating, nonplating applications in injection molding and extrusion.

* Unicell FF: Modified azos for injection molding, said to inhibit undersirable by-products and die build-up during processing.

* Unicell OH: Oxybis-benzene sulfonyl hydrazide for LLDPE, PVC, and PVC plastisols.

* Unicell TSH: Toluene solfonyl hydrazide for polyester, PVC, and cellular rubber.

* Unicell AD: Modified azo mixture for EVA and other elastomers.

* Unicell TS: Toluene sulfonyl semi-carbazide for high temperatures.

Company also offers several other CBA grades, primarily for elastomers.

DOW CHEMICAL CO.

Manufactures methylene chloride, urethane grade, a modified methylene chloride specially designed for use as a blowing agent in flexible PU slabstock foam. It contains an inhibitor that minimizes foam oxidation and scorching and can be used as the sole auxiliary blowing agent. It is said to offer advantages such as high volatility, low flammability, lower raw-material and handling costs, and relatively low toxicity.

Dow Plastics plans (mid-1991) to license technology for a new non-CFC alternative to HCFCs or hydrocarbon blowing agents that allows use of 100% carbon dioxide to produce foam sheet in thicknesses up to 1/4 in. and densities comparable to those produced with hydrocarbon or HCFC-22 blowing agents (2-10 lb/cu ft). It may require some retrofitting of existing extrusion lines, but throughputs can be the same as with other blowing agents. Although [CO.sub.2] has been blended with other blowing agents in the past, this is believed to be the first commercial all-[Co.sub.2] approach for PS. Its nonflammable and nonpolluting nature are key advantages. In licensing the technology, Dow will charge both an initial licensing fee and a royalty.

DU PONT CO.

Company's Freon line of fluorocarbon blowing agents is supplied for making high-performance cellular plastics. Company markets Formacel S-Food Grade, a highly purified form of HCFC-22, for use in PS food packaging foams. This product, which is said to be very low in ozone-depleting potential, is intended as a substitute for CFC-12. Du Pont has filed a Generally Recognized As Safe (GRAS) petition with FDA on this product. Du Pont is developing other non-ozone-depleting alternatives to standard CFCs for various foam applications.

EASTMAN CHEMICAL PRODUCTS

Foamable concentrates in a PP base are supplied for blending with PP in the manufacture of molded or extruded foamed products.

CHARLES B. EDWARDS & CO., INC.

Compounds blowing agents for specific color/polymer blends and FDA applications in powder and liquid concentrates. Color Flo liquids come with blowing agent alone or with color and other additives.

EXPANCEL-NOBEL INDUSTRIES

Offers its Expancell line of expandable thermoplastic microspheres used as blowing agents in systems where heat between 200-250 F is available. The microspheres are white, spherically formed particles. The thermoplastic shell encapsulates a gas and, when heated, softens; the increased vapor pressure results in expansion of the sphere. Expansion factor is 40-60 times the original volume. Other features in the use of Expancel as a blowing agent are defined pore size, closed-cell structure, and a suede surface. Alternative grades and particle sizes are available and suitable for a range of applications. Expancel is also suitable as a blowing agent in plastisols, elastomers and thermosets.

EXTECH CORP.

Offers Tracel chemical blowing agents, proprietary formulations of Tramaco GmbH & Co. KG of Germany, which provides a line of exothermic and endothermic blowing and nucleating agent concentrates (10-70% loadings) in pellet and powder form (including dry blends) for most engineering plastics, as well as paste and pellet concentrates for the rubber industry:

* Modified azodicarbonamide systems compatible with PS, Modified PPO/PPE, HDPE, LDPE, PP, TPEs, TPUs, EVA, polyester and PVC. Low letdown ratios. Suitable for injection molding, profile, sheet and film extrusions. FDA-approved.

Special grades for wire/cable extrusions, TPE/TPU low-density foams, EVA and PE compression molding, PVC calendering and PVC plastisol techniques. Self-dispersing and dust-free powders also available.

* Encapsulated endothermic compounds for structural foam, profile, sheet and film extrusions. Low letdown ratios, ammonia-free processing, finer cell structure, smoother skin, faster cycle times and no plate-out are most outstanding characteristics. FDA-approved.

Special grades for sink mark removal, molded or extruded ABS, PP film, and PS, PE and PP sheet extrusion.

* Exothermic-endothermic formulations for critical dimensional stability requirements. FDA-approved components.

* Powders, dry blends, pellets and high- or low-viscosity pastes for molded or extruded natural, synthetic and silicone rubbers.

FERRO CORP.

ROSEMAR OPERATION

Offers liquid chemical blowing-agent dispersions, sold under the Spectraflo brand. The firm's specialty is activating or modifying a material to suit a particular requirement. One example of the line is a nonactivated, modified ABFA type designed specifically for ABS foam-core pipe. Other developments include blowing agents to be used as nucleating agents in conjunction with nitrogen.

GE PLASTICS

Blowing-agent concentrates are offered for all GE structural-foam resins. Lexan FL-C95 concentrate is specially tailored for molding foamable Lexan polycarbonate resin; Noryl FN-C20 concentrate is for molding foamable Noryl polyphenylene oxide-based resins; Valox FV-C60/ 65 concentrate is for molding foamable Valox thermoplastic polyester resins.

Blowing-agent concentrates are said to expand processing flexibility, since they can be used with any type of structural-foam molding or standard injection molding equipment. They also eliminate dust from blowing-agent powders, enhance dispersion, improve part quality by providing more uniform cell size and distribution, and give better control of skin surfaces, which can reduce secondary finishing costs.

HARWICK CHEMICAL CORP.

Offers a variety of azodicarbonamide-based blowing agents in various plasticizers. These blowing agents can be used to foam various polymers, including ABS, acrylics, EVA, nylon, PE, PS and vinyl.

HENLEY CHEMICALS, INC.

Offers Hydrocerol, an endothermic blowing and nucleating agent system manufactured in Germany by Boehringer Ingelheim. Available in both powder and concentrate, it is suitable for most thermoplastics. A special liquid grade is also available for high-temperature polymers, such as polycarbonate. Due to its self-nucleating properties, the product is said to offer finer cells, resulting in improved surface appearance and physical properties, and is reportedly an efficient nucleator in direct-gassed systems, regardless of the type of gas used to foam.

HITECH POLYMERS, INC.

Offers concentrates of blowing agents in specific polymers in pelletized form. Blowing agents may be incorporated into a variety of elastomers, engineering thermoplastics and commidity polymers, end use. Special materials may be compounded at the operational level of blowing agent for special uses.

HOECHST CELANESE CORP.

SPECIALTY CHEMICALS GROUP

Polymer Additives Division offers a variety of endothermic foaming systems. All systems are supplied in pelletized concentrate form and are based on proprietary carriers compatible with most thermoplastics. All Hostraton systems come in ready-to-use pellet form and are said to be odorless, physiologically harmless, and FDA sanctioned. Hostraton system P1941 is recommended for fine-celled extrusion applications, e.g., HIPS and PP sheet. Hostraton P9947 is mainly used for structural foam molding of HIPS, SMA, ABS, HDPE and PP.

KUM YANG CO., LTD. See Plastics & Chemicals, Inc.

LNP ENGINEERING PLASTICS

UNIT OF ICI ADVANCED MATERIALS

Company has two foam concentrates that can be tumbled with reinforced or unreinforced thermoplastics for molders requiring a specific level of foaming or sink control. Products are tradenamed Foam-Kon 20 and 28. Foam-Kon 20 is designed for use in resins and compounds processed below 450 F, such as ABS, SAN, PP and acetal. Foam-Kon 28 is formulated for resin systems processed above 450 F and is suggested for use with most nylons, PPS, polysulfone, and polyethersulfone.

LAROCHE CHEMICALS, INC.

Company supplies fluorocarbon 11 and 12 blowing agents for use by foam product manufacturers.

MOBAY CORP.

PLASTICS AND RUBBER DIV.

Company's Porofor ADC azodicarbonamide is a line of chemical blowing agents for rigid and flexible vinyls and for crosslinked PE foam and other thermoplastic foams such as ABS and PS.

OTSUKA CHEMICAL CO. See Biddle Sawyer Corp.

PMC SPECIALTIES GROUP, INC.

DIV. OF PMC, INC.

Company supplies a line of chemical blowing agents said to produce no corrosive by-products. Line includes:

* KemTec 500 for nylon, polyesters, ABS and polycarbonate.

* KemTec 550 for nylon 66, polycarbonate and PPS.

* KemTec 600 for PES and PPS.

* KemTec 350 for ABS and PP.

PMS CONSOLIDATED

Offers specialty additive concentrates, either solid or liquid (with or without colorants) or blowing agents, slip agents, antistats, fillers, antioxidants, uv stabilizers, silicones or fire retardants. Company has production and laboratory facilities at 11 locations in the U.S. and Puerto Rico.

PLASTICS & CHEMICAL, INC.

Represents Kum Yang Co., Ltd. (Korea), which produces a line of chemical blowing agents called Cellcom. With over forty Cellcom products developed, each is formulated for virtually all rubbers and plastics, and processes, including calendering, extrusion and blow molding, transfer/compression molding, plastisol, and injection molding. The use of blowing agents results in uniform cell structure and improved surface appearance in rubber and plastics. Kum Yang Co. also offers laboratory systems to customers who require advice and assistance in the use of their products.

POLYCOM HUNTSMAN INC. Supplies foaming concentrates. Also see listing under Colorants.

POLYVEL INC.

Offers custom-formulated blowing-agent concentrates for thermoplastics. Products available are:

* BA20T: Recommended for use in EVA and LDPE; operating temperature ranges from 290 to 340 F.

* BA210: Recommended for LDPE, HDPE, and PS; operating temperature ranges from 350 to 400 F.

* BA20: Recommended for PP, PE, PS, PPO blends, and ABS; operating temperature ranges from 380 to 440 F.

* BA205PT: Recommended for use in nylon, polyester, polycarbonate, and PPO blends; operating temperature ranges from 440 to 540 F.

* BA2575: For polymers processed at maximum blowing-agent decomposition temperatures. Recommended processing temperature of 700 F.

RTP CO.

Company manufactures five concentrates for a variety of foam resins. The system include:

* FCX 2721 for PP, PE, acetal, and nylons 11 and 12.

* FCS 27310 for nylon 6, 66 and 612, PBT and PET.

* FCX 27312 for polycarbonate and polycarbonate alloys.

* FCX 27314 for PS, ABS and SAN.

* FCX 27315 for polythersulfone, PPS, polysulfone and polyetherimide.

REED PLASTICS DIV.

SANDOZ CHEMICALS CORP.

Offers custom-formulated blowing-agent concentrates for thermoplastic molding and extrusion. In all cases, the customer is informed of the exact blowing agent used and what amount will be needed to produce the desired density reduction. Company also makes multifunctional concentrates containing both blowing agent and colorants.

REEDY INTERNATIONAL CORP.

Offers Safoam (manufactured by Balchem Corp. exclusively for Reedy), a new endothermic nucleating agent and chemical blowing agent with a GRAS (generally recognized as safe) status by the FDA. The product is currently available in two powdered forms:

* Safoam FP - a fine powder designed for extremely fine cells.

* Safoam P - a regular powder for most general applications.

Safoam powders are recommended for applications in polystyrene, polyolefins, ABS, PPO and PPE. As a nucleating agent, it is recommended for direct-gassed systems using freons, pentane, butane, isobutane, nitrogen and carbon dioxide. Company reports that the benefits of Safoam include heat absorption, faster cycle and extrusion times, smoother surfaces, in-line paintable, white foams, FDA-approved, and small 25 micron cell size.

Safoam is also available in two nucleator forms:

* Safoam PT - a regular powder and talc for direct-gassed applications.

* Safoam FPT - a fine powder and talc for direct-gassed applications.

Nucleators are recommended for direct-gassed applications in polystyrene, polyolefins, ABS, PPO, PPE, using freons, pentane, butane, isobutane, nitrogen, and carbon dioxide.

Safoam Masterbatches are also available in three different forms:

* Safoam P/20 - 20% Safoam P in low-molecular-weight polystyrene carrier.

* Safoam P/50 - 50% Safoam P in low-molecular-weight polystyrene carrier.

* Safoam FP/50 - 50% Safoam FP in low-molecular-weight polystyrene carrier.

Masterbatches are recommended for ABS, HIPS, PS, PPO/PPE, PET/PBT, PA applications.

SANTECH, INC.

A new line of blowing-agent concentrates is being used in PE foam and foam/skin telephone insulation compounds for optical-fiber cables and both copper-conductor and coaxial cable. Santechem OT-20 is based on OBSH chemical blowing agent in a cable-grade PE carrier. Controlled uniformity is a key feature of this product. Also available is a 20% concentrate of nonplating azodicarbonamide in cable-grade PE. It can be used as a nucleating agent for molding with direct nitrogen gas injection for making crosslinkable LDPE foam sheet and for density reduction in large flat parts such as ABS and HIPS shower bases. In addition, Telefoam concentrates are CBA/color combinations matched to Munsell standards for telephone cable uses.

SCHERING BERLIN POLYMERS INC.

Offers Ficel azodicarbonamides for use in vinyl floor-covering, fabric coating, crosslinked polyolefin foam, structural foam, pipe, profiles and cable insulation. Line includes different particle sizes, modified azos designed for injection molding and extrusion, and preactivated grades for chemical embossing and low-temperature applications.

A SCHULMAN, INC.

Polybatch additive concentrates are designed to improve specific properties. The range includes different carriers, and all possible modifications are offered: slip and antiblock, antistatic and uv resistance, anti-fogging, foaming, and antioxidant.

SYNTHETIC PRODUCTS CO.

SYNPRO-WARE DISPERSIONS

Supplies concentrated dispersions of organic blowing agents or sodium bicarbonate. Products are said to ensure uniform cell structure.

TEKNOR COLOR CO.

SUB. TEKNOR APEX CO.

Manufactures blowing-agent concentrates for all resins in solid and liquid forms and as part of a multifunctional concentrate with color. Ultracolor is a special high-loading concentrate of blowing agent/colorant formulated for letdown ratios up to 100:1.

Also offers custom-formulated concentrates that can contain blowing agents, lubricants, uv stabilizers, and fire retardants. Production and laboratory facilities are located in Rhode Island, Texas, Kentucky, California, Massachusetts and Ohio.

THERMOFIL, INC.

Offers its Thermofoam line of foam concentrates. Six concentrates are supplied for use in most thermoplastics:

* Thermofoam I is for use in styrenic and polyolefin resins. * Thermofoam II is for nylons, TP polyesters, and other resins with processing temperatures of 405-600 F.

* Thermofoam III is for nylons and TP polyesters at higher concentrations for structural foam.

* Thermofoam IV is designed exclusively for use in polycarbonate. Since it is based on that resin and can therefore tolerate the high drying temperatures necessary, preblending of the concentrate is possible.

* Thermofoam V is for high-temperature engineering thermoplastics such as polysulfone, PPS and polyethersulfone.

*Thermofoam VI contains a non-ammonia-releasing chemical blowing agent and is specifically formulated for use in modified-PPO.

USI DIV.

QUANTUM CHEMICAL CORP.

Chemical blowing agent pellet concentrates with loadings of 10-40%, based on exothermic, endothermic or chemically reactive systems, are produced for injection molding, wire and cable, and other extrusion applications. The concentrates contain a proprietary system of activating and nucleating agents said to ensure complete decomposition of the blowing agent, provide a consistently uniform cell structure, and minimize die and mold buildup problems. The exothermic systems are based on azodicarbonamide blowing agents.

Concentrates MF-1037-H, MF-1035-H and MF-1039-H are recommended for injection molding where weight reduction and/or sink removal is required. MF1276H is used for polystyrene and structural-foam applications. MF-1062-FA is specially formulated for foamed blown film applications. For wire and cable, MF-1253WC is used for weight reduction, and MF-1237NC where a nucleating agent is required.

The concentrates are compatible with polyolefins, PVC, PS and ABS. Generally recommended letdown ratios vary from 40:1 to 100:1, depending on the desired density reduction.

Compay's endothermic systems are incorportaed into MF-1570-H and recommended for use in polyolefins, polystyrenes, modified-PPO and modified-PPe. Improved surfaces, more rapid degassing and more uniform cell size are said to be achieved.

The 1770 series is based on a chemically reactive system and reportedly offers the optimum in surface appearance, degassing and cell-size uniformity. It is recommended where significant weight reduction is required.

A high-temperature CBA pellet concentrate, containing 5-phenyl tetrazole and a proprietary carrier with nucleating agent, is also available. Its decomposition temperature is around 450-550 F and use level is 1-1.5% in polycarbonate and ABS.

UNIROYAL CHEMICAL CO., INC.

Reportedly the largest supplier of azodiacarbonamide-type chemical blowing agents. Company's Celogen family of chemical blowing agents includes products which can foam plastics at temperatures from 200-650 F. They are:

* Celogen AZRV and AZ 3990 for extruded profiles - rigid and flexible PVC, ABS, high-impact PS.

* Celogen AZ 130 for pipe - rigid PVC, ABS, HDPE, PP.

* Celogen AZNP 130 for sheet - ABS, HDPE, rigid and flexible PVC.

* Celogen AZ 760 for wire and cable - LDPE, HDPE, PP, flexible PVC, thermoplastic rubber.

* Celogen AZNP 130, RA for injection molding, structural foam - EVA, LDPE, HDPE, PP, HIPS, ABS, TP rubber, acetal, flexible and rigid PVC, modified-PPO, nylon, TP polyester, polycarbonate, polysufone.

* Celogen AZ 3990 for rotational and expansion casting - LDPE, HDPE, PP, PVC, ABS, and PVC plastisols and calendering.

* Celogen AZ 754 is a formulated azo used traditionally in rubber, which reportedly can be used in extruding skinned, flexible PVC, and TP elastomers.

* Celogen XP-100, a proprietary sulfone hydrazide powder blowing agent that is said to be relatively safe to use and to require no special equipment for spray-up of unsaturated (thermoset) polyesters and vinyl esters. The additive can be mixed with resin in advance and reacts with standard MEK peroxides in the presence of cobalt and copper promoters. Foaming, gelling and curing takes place within 1-2 min.

* Celogen OT 4,4 oxybis (benzenesulfonehydrazide) is used for LDPE coaxial cables and elastomer-resin blends in pipe insulation and sporting goods. It yields nondiscoloring, odorless products and is said to be nontoxic and suitable for FDA-regulated applications. Operating range is 260-300 F.

* Expandex 5-phenyl tetrazole in three grades is for high-melting thermoplastic such as nylon, ABS, polycarbonate, acetal, PPS, SAN and phenylene oxide-based resins. Expandex 5-PT has an operating range of 464-482 F; Expandex 150, 650-670 F; Expandex 175, 720-730 F.

WASHINGTON PENN PLASTIC CO.

Offers its PE-8FC foam concentrates for dry blending with ABS, acrylic, EVA, HDPE, LDPE, PP and impact PS.