Shandong Qilu Di-iso-nonyl Phthalate (DINP)

Shandong Qilu di-isononyl phthalate (DINP; CAS 28553-12-0 and 68515-48-0) is a branched C9 phthalate ester with a typical ester content not less than 99.5 % and a molecular weight near 418.6 g/mol. At 20 °C the product exhibits a density of approximately 0.97 g/cm³ and a dynamic viscosity commonly reported between 68 and 85 mPa·s. The plasticizer is characterized by low volatility and high PVC solvency relative to linear C8–C10 phthalates, and its application limits are defined by polarity, migration resistance, and regulatory status in defined article categories rather than by a single processing parameter. The profiles below are separated by downstream conversion route; identical plasticizer concentration across routes produces different failure modes because of differences in heat history, filler surface area, and end-use compliance obligations.

What Limits the Low-Temperature Flexural Response of DINP-Based Wire Insulation After Thermal Ageing?

A suspension-grade PVC resin with K-value in the range 70 to 72 is dry-blended with 45–60 phr DINP, 3–5 phr calcium/zinc stabilizer, 0.5–1.0 phr lubricant, and 5–10 phr calcined clay in a high-intensity mixer to 105–110 °C. The hot blend is then compounded in a co-rotating twin-screw extruder with an L/D ratio between 24:1 and 32:1, using a barrel temperature profile from 140 °C to 170 °C and a melt temperature below 190 °C to avoid early dehydrochlorination. During wire-line extrusion, a crosshead die is operated with a melt pressure of 90–140 bar; a sustained increase above 160 bar at constant screw speed is treated as a screen-pack plugging event caused by inadequate dispersion of filler or stabilizer agglomerates. The low-temperature flexural response is evaluated after thermal ageing because plasticizer loss and stabilizer depletion shift the brittle point more rapidly than tensile strength changes. Tensile retention is measured by IEC 60811-401 after oven ageing, while low-temperature brittleness is assessed by ISO 974 and ASTM D746. The compound is not placed in toy or child-care articles covered by REACH Annex XVII entry 52; for North American flexible cords, the finished insulation is evaluated under UL 62 and UL 1581, while European low-voltage cable constructions are manufactured to IEC 60227 series requirements. Finished articles include appliance wiring, industrial flexible cords, and light-duty power supply sheathing.

During high-shear dispersion of automotive PVC plastisols, the sequence of filler and plasticizer addition controls the onset of dilatancy in airless application systems. A typical formulation contains paste-grade PVC homopolymer with K-value 72–75, 50–80 phr DINP, 40–80 phr calcium carbonate with a median particle size of 1–3 µm, 2–6 phr calcium oxide as moisture scavenger, and 1–3 phr of a fumed silica or castor-oil thixotrope. The DINP is pre-blended with the liquid stabilizer and a portion of the filler before the remaining filler and PVC paste resin are added under a dissolver tip speed of 15–20 m/s; vacuum deaeration at about −0.090 MPa reduces entrained air that otherwise produces pinholes in gelation ovens. Application is performed through 55:1 ratio airless pumps at line pressures between 40 and 60 bar, and gelation is carried out in a forced-air oven at 180–200 °C for 20–40 min depending on metal substrate thickness. The principal compliance reference for interior emissions is VDA 278; the branched C9 ester remains in the condensable emission fraction rather than the high-volatility VOC fraction, which supports its use in underbody and wheelhouse areas where windshield fogging is evaluated by OEM material standards. The finished products are stone-chip protective coatings, weldable seam sealants, and battery tray sealants; DINP is not affected by EU ELV heavy-metal restrictions, but individual OEM specifications may impose additional emission or odour limits.

Calendered Flooring Wear Layers and Filler Interaction

In calendered sheet flooring, the plasticizer-pigment-filler distribution is controlled by two-stage fluxing before the material enters the calender. A flooring wear-layer or foam-layer compound typically consists of suspension PVC with K-value 65–68, 28–45 phr DINP, 2–3 phr epoxidized soybean oil as co-stabilizer and secondary plasticizer, 20–60 phr calcium carbonate, and a calcium/zinc stabilizer system. The dry-blend is fluxed in a Banbury internal mixer to 155–165 °C, then transferred to a two-roll mill with a front-roll temperature 5 °C lower than the back roll to prevent sticking, and finally passed through a four-roll or five-roll calender with roll temperatures between 165 °C and 185 °C. Filler loading above approximately 45 phr reduces calender bank height stability and increases embossment recovery time; below 20 phr the sheet surface becomes subject to blocking unless a separate topcoat is applied. The finished resilient floor covering is tested for dimensional stability and wear group classification under EN 649, while tensile properties are measured by ISO 527-3. Regulatory documentation for European architectural use must confirm that the article falls outside REACH Annex XVII entry 52, and for North American channels the formulation is not intended for children's toys or child-care articles under 16 CFR 1307. End products are luxury vinyl tile, heterogeneous sheet flooring, and commercial wall base profiles.

When Migration Resistance in High-Fill Coated Fabric Compound Is Tested by ASTM D3291

Synthetic leather and coated fabric compounds are produced from PVC paste resin with K-value 72, 65–80 phr DINP, 2–4 phr azodicarbonamide blowing agent for foamed intermediate layers, 1–2 phr potassium/zinc stabilizer, and 5–15 phr calcium carbonate. The paste is knife-over-roll coated onto release paper or fabric at line speeds of 10–25 m/min, gelled at 190–200 °C, and then embossed or topcoated with a polyurethane skin. Because the polyurethane topcoat is sensitive to plasticizer transfer from the foamed PVC layer, compatibility under compression is evaluated using ASTM D3291; specimens aged under the prescribed compression cycle at 70 °C are inspected for exudation, and a zero-exudation result at 80 phr cannot be assumed if filler dispersion is uneven. Volatile organic emission from finished upholstery is controlled through ISO 12219-4 or automotive OEM protocols that reference VDA 277; the low vapour pressure of the C9 ester reduces early emission peaks compared with lower-molecular-weight esters, but published data for this specific configuration is limited in public databases. The finished articles are automotive seat covers, technical upholstery, and coated fabric panels for contract furniture; these are outside the toy restrictions in REACH Annex XVII entry 52.

When industrial suction hose profiles are run at line speeds above 25 m/min, the limiting variable shifts from plasticizer solvency to the stability of the calibration vacuum. A dry-blend is produced from suspension PVC K-value 67, 40–55 phr DINP, 1–2 phr acrylic processing aid, 0.2–0.5 phr stearic acid, and 3–6 phr calcium carbonate; the mixture is pre-dried at 60 °C if ambient relative humidity exceeds 60 %. Extrusion is carried out on a counter-rotating twin-screw extruder with an L/D ratio of 25:1, a die temperature of 175–195 °C, and a vacuum calibrator maintained at 20–30 °C. The melt pressure upstream of the breaker plate is normally maintained between 120 and 160 bar; surface melt fracture appears when the die land temperature falls below 170 °C at high shear rates. The finished profile or hose is not a food-contact material and is not intended for children's articles; DINP is outside the restricted phthalate list in RoHS Directive 2011/65/EU Annex II, but the supplier must still confirm that the compound does not contain the four listed ortho-phthalates above 0.1 % by weight in homogeneous material. End products are industrial gasketing, low-pressure suction hose, and extruded edge trim.

Heat-Welded PVC Roofing Membrane Formulations Require Durable High-Boiling Plasticizer Retention

Because plasticizer loss governs field weldability and seam integrity, the formulation is compounded with suspension PVC K-value 70–72, 45–65 phr DINP, 10–30 phr calcium carbonate, 3–5 phr titanium dioxide, and a UV stabilizer package based on benzotriazole and hindered amine light stabilizer. Calendering or spread coating produces a membrane with a thickness between 1.2 and 2.4 mm; hot-air welding is conducted at nozzle temperatures of 320–420 °C with a contact pressure sufficient to form a fused seam without scorching. Seam shear strength is evaluated after heat ageing by ISO 527-3 or ASTM D638, while the product specification is written against ASTM D4434 and EN 13956. The high boiling point of DINP reduces plasticizer volatilization during thermal welding compared with C7–C8 phthalate esters, but migration into bitumen or expanded polystyrene must be assessed when the membrane is placed in direct contact with those materials. The finished membrane is installed as mechanically fastened or adhered roofing; it is outside the scope of REACH Annex XVII entry 52 and not intended for toy or child-care applications.