Lots of new polyolefins on tap.

Lots of New Polyolefins On Tap

To accompany the opening of a spanking new R&D center at its Cincinnati headquarters, Quantum Chemical Corp.'s USI Div. announced several new materials developments, including a new family of "in-situ" TPO resins; a broader line of tie-layer adhesive resins; new LLDPE resins for stretch film, sheet, profiles, and blow molding; an HDPE for geomembrane sheet; super-high-flow EVAs for coatings; 100% recycled HDPE blow molding grades--and more. Included with these latest announcements are other recently released USE products that have not been reported previously. (Two other new Quantum resins for blow molding and extrusion were reported last month, pp. 10, 38.)

With the opening of the $31-million, 256,000-sq-ft Allen Research Center, Quantum will be able to turn up the heat on some long-range projects, like the new TPOs. Quantum has moved its basic and applied R&D from Rolling Meadows, Ill., and now maintains only process R&D at a separate location in Morris, Ill. Most unusual, Quantum also moved its polyolefins marketing staff into the new R&D center, hoping to achieve new synergies through close association of both groups.

HIGH-RUBBER, IN-SITU TPOs

A year ago, Quantum released the first details on its reactor-produced TPOs, which have now been produced in a commercial-scale reactor. (see PT, July '90, p. 31). Based on new catalyst and process technology, these are said to include grades with two to three times higher EP-rubber content than any TPOs yet made in a commercial reactor. Until now, such high rubber contents were only made commercially by conventional melt compounding of homopolymer PP with EP or EPDM rubber, which adds cost and degrades some resin properties. Quantum's director of process research William Bowles says the new TPO technology is equally applicable to making novel grades of rubber-modified PE.

Most noteworthy among Quantum's new TPOs are super-impact copolymers with 25-30% EP content by weight and "no-break" resins with 30-60% EP, which have extraordinary low-temperature impact. Over-40% EP materials, for instance, show no break in notched Izod impact tests at -70F. "For the highest rubber concentrations, 48% and 56%, failures don't appear until temperatures drop below -100 and -120 F respectively," reported Thaddeus Klimek, senior project leader for PP development, in a paper at last spring's SPE ANTEC meeting in Montreal. "It's estimated that these latter (48-56% EP) materials exhibit ductile/brittle transitions significantly below -120 F. This is a true milestone in the PP industry."

In addition to very high impact, the new TPOs reportedly offer low taste and odor and low hexene extractables, so even the highest-EP materials meet FDA food-contact requirements, opening applications in retortable food packaging, freezer-to-microwave trays, and high-impact food-packaging films. Melt indexes range from fractional to 30; flex-modulus range is also broad, including very soft grades down to 5000 psi. In fact, Klimek's paper notes that "a wide range of flexural modules can be achieved at a fixed level of notched Izod," allowing impact/stiffness combinations to be tailored to specific applications. HDT is also higher than with conventional melt-compounded TPOs. "Only modest changes in HDT occur in materials over the range of 37-60% rubber content," Klimek notes.

The majority of the new TPOs are in the pilot-plant stage (see Table 1). One developmental material, TR-077, has been makde in a commercial-size reactor, and is said to be very flexible compared with normal PP and to have excellent low-temperature resistance. Other developmental TPO grades target PVC replacement in wire and cable, hose, tubing, and impact modification of other resins. A few of the new TPOs are expected to be fully available in the third quarter. Table 2 compares a commercially available copolymer, PP1510HC, with a new experimental TPO, TP104250, targeted for blown film, where it imparts softness and improved impact and tear properties, Quantum says.

Table : TABLE 1 - SELECTED PROPERTIES OF NEW QUANTUM TPOS

GRADE TP104250 TP104251 TP104260 PP1510HC

Melt Flow, g/10 min 1.0 9.0 26.0 0.7

Flex. Mod., kpsi 51 48 37 115

Notched Izod, ft-lb/in.

@ -65 F           [NB.sup.a]   4.1        [NB.sup.a]   [NB.sup.a]
@ -85 F           3.4          2.0        2.2          3.0

Hardness,

Shore D 47 47 46 --

Low-Temperature

Brittleness, F -123 -109 -105 --

MORE TIE-LAYER ADHESIVES

Quantum also recently announced a new tie-layer adhesive-resin technology agreement with Mitsubishi Petrochemical Co. of Japan, allowing Quantum to produce and market Mitsubishi's Modic elastomeric PP tie-layer adhesives in the U.S. The deal, which includes patent rights to Mitsubishi's PE-based adhesives, complements Quantum's own Plexar adhesive business of over 30 grades. "By combining technologies, we think we can achieve products neither company could do alone," says Quantum business manager for special products Medardo Monzon. PP-based sheet and bottle grades will be among the first offerings, aimed at markets such as shelf-stable PP lunch buckets. Quantum thinks Mitsubishi PE-based adhesives may find application in gas-tank barrier layers.

Among Quantum's own new adhesive materials are two developmental grades. HDPE-based Plexar 5000, for bonding EVOH to PE in blown film, was developed to combine improved moisture barrier while retaining good adhesion (normally one must be traded off against the other). It has 1.1 MI and FDA direct food-contact approval and is aimed at meat, cheese, snack, cereal, baking-mix, and freeze-dried food packaging. (CIRCLE 37)

New EVA-based Plexar 5006, for improved bonding of BOPP to EVOH in good packaging films, is said to overcome limitations on adhesion to BOPP when coating corona-treated film, though coextrusion of PP/EVOH/LDPE before orientation provides the maximum bond. Plexar 5006 has a 6 MI and FDA approvals for direct and indirect food contact.

And new adhesive, Enathene EA720-009, an ethylene/n-butyl acrylate copolymer for extrusion lamination and coating, processes at relatively high melt temperatures. Optimum is 550-600 F, but it runs as high as 620 F without degrading, Quantum says. Since the resin has no stabilizer, surface oxidation is maximized and adhesion is good on a wide variety of substrates like BOPP, PET and nylon, as well as clay-coated board and aluminum foil. EA720-009 has 20% nBA content, 6 MI, good optical and strength properties, excellent drawdown characteristics (2.6 lb/ream coating weight at line speed of 2600 ft/min), and a seal-initiation temperature 86 [degrees] F lower than conventional LDPE with shorter dwell times required, Quantum says. It also meets FDA requirements for indirect food contact.

Quantum also has commercialized EVAs with 2500 MI at 14% and 28% VA levels, which are said to open up new opportunities in carpet coatings, sealants and adhesives, as well as highly filled compounds and flow modifiers for other resins. More linear and crystalline versions are available with higher tensile modulus at the same MI.

FRACTIONAL-MI HEXENE LLDPE

Quantum is also introducing new fractional-melt hexene LLDPEs for film that are said to achieve impact, tensile and tear properties comparable to those of more expensive octene copolymers. What's more, Quantum says extrusion trials show its new hexene resins (drawing lower amps at equal lb/hr output rate), and about the same as octene resin. A lubricating additive has been included to reduce melt fracture.

Quantum is determined to become a factor in the stretch-film business with at least one of these resins - developmental GATR116 with 0.5 MI and 0.916 density. New grades that are already commercial are "barefoot" GA609-130 with 0.5 MI and 0.918 density; GA609-132, the same with slip and antiblock additives; and GA607-133 with 0.4 MI and 0.923 density. Pricing is comparable to octenes.

FOR BLOW MOLDING,

EXTRUSION

Another new fractional-MI LLDPE with broad molecular weight distribution for blow molding and extrusion is GA818-070 with 0.92 density and 0.7 MI. It combines the melt strength and processability of conventional LDPE or HDPE with the excellent stress-crack resistance of LLDPE, Quantum says. GA818-070 is said to process like a typical 0.9-MI HDPE in reciprocating-screw screw extrusion blow molding machines, with higher viscosity than standard LLDPEs at low shear rate, preventing parison sag, and lower viscosity at high shear rate for easier processing. Melt fracture, a drawback of conventional LLDPEs, is said to be significantly less at high extrusion rates. Because of its high ESCR, GA818-070 targets sheet and coex bottles and tubes, drip irrigation tubing, drum liners, and geomembranes. It meets FDA food contact requirements.

A developmental LLDPE for flat sheet, designated GATR049, has a narrow molecular-weight distribution, 0.935 density, and 0.5 MI. It's aimed at geomembranes (pond and pit liners) in 20-120 mil sheets.

A new commercial HDPE for geomembranes (a PE market that Quantum sees growing at 17%/yr) is LP 5101-00. It has broad MWD for high throughput in blown film, 0.938 density, and 0.15 MI.

NEW 100% RECYCLED HDPE

Quantum's 40-million-lb/yr post-consumer recycling plant at Health, Ohio, began trial runs in late December, with the opening set for February (see PT, March '91, p. 83). Quantum is already sampling up to 1000-lb lots of its first 100% recycled material, trademarked Ecothene. (A 15%-recycled LLDPE film grade was introduced in June - see PT, July '91, p. 12.) Two HDPE grades include a natural-colored homopolymer, EC101, made from milk and water jugs (see table). Mixed-color copolymer EC102 is made from detergent bottles. EC101 is expected to be available in truck-load quantities in the first quarter, EC102 late in the quarter, says v.p. of resource recovery Bruce Kuiken. Preliminary pricing for EC101 homopolymer is 42 [cents]/lb tl delivered; EC102 is 42 [cents]/lb on the same basis.

Table : TABLE 2 - 2-MIL TPO BLOWN FILM

Grade TP104250 PP1510HC

Melt Flow, g/10 min 1.0 0.7

Elmendorf Tear,

MD, ft-lb          300          37
TD, ft-lb          460          132

TEDD(a)Impact,

Flat               [NB.sup.b]   1.55
Creased            [NB.sup.b]   1.26

Puncture,

Max Force, lb      >54          >54
Energy, in.-lb     >146         >100

Table : TABLE 3 - PRELIMINARY PROPERTIES OF NEW 100% PCR GRADES

                   EC101       EC102
                   Homopol     Copol
                   Natural     Colored
Density            0.960+      0.960+
Melt Index         0.60        0.52

Tensile Yield, psi 4375 3650

Flex. Modulus,

kpsi               202.5       160
Vicat Soft., F     257         253

Low-Temp.

Brittleness, F <-104 <-104

Hardness,

Shore D            68          66
HDT @ 66 psi, F    172         165

XLPE FOR WIRE

Petrothene XL7407 is a new non-halogenated, flame-retardant, highly-filled EVA compound for automotive and appliance wiring. It's steam-curable, formulated for low-voltage insulation and UL applications up to 257 F, and it reportedly eliminates wire corrosion after sonic welding. It contains a color-stable antioxidant and special peroxide crosslinker to ensure thermal stability during processing.