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中文简体A procurement manager at a flexible PVC compounding plant is evaluating DINP chemical for a new wire and cable insulation line. The specification sheet looks familiar, but questions remain: will the plasticizer keep migration low at elevated operating temperatures, will it pass the customer's material compliance screening, and can the supplier maintain the same viscosity batch after batch? Answering those questions requires more than a technical data sheet. Here is what DINP is, how it behaves, where it is used, and what practical details to check before you commit to a supplier.
What DINP Chemical Is and Why It Is Specified
DINP stands for diisononyl phthalate. It belongs to the phthalate family of plasticizers and is produced by reacting isononyl alcohol with phthalic anhydride. The final product is not a single molecule but a mixture of esters made from different isononyl alcohol isomers. This is why commercial CAS numbers for DINP include 28553-12-0 and 68515-48-0.
The main job of DINP is to make polyvinyl chloride (PVC) flexible. When added to rigid PVC resin, the plasticizer molecules enter the polymer chains and reduce intermolecular forces. The result is a softer, more workable material that can be processed into films, sheets, profiles, and molded parts.
Compared with general-purpose phthalates such as DOP, DINP has a higher molecular weight. That gives it lower volatility, better resistance to extraction, and improved permanence in finished goods. For buyers in the wire and cable sector, those properties translate into less plasticizer loss during heat aging and better long-term electrical performance.
Diisononyl Phthalate Plasticizer for Flexible PVC Applications DINP offers good compatibility with PVC, higher plasticizing efficiency, and better insulation than DOP. It ensures lower volatility and improved permanence, making it suitable for wire, cable, gloves, and other flexible vinyl products. View Product → DINP chemical works effectively across a wide range of flexible vinyl formulations. It is often selected when you need a reasonable balance between processability, performance, and regulatory acceptance. It also handles high filler loadings well, which can help control formulation cost without sacrificing flexibility.
Key DINP Chemical Properties That Influence Compounding
Choosing the right DINP grade is usually a matter of matching key physical parameters to your process and end use. The table below shows typical target values for a commercial diisononyl phthalate. Actual values will depend on the supplier's raw material control and production process.
| Parameter | Typical Value | Why It Matters |
|---|---|---|
| Molecular weight | ~418.6 g/mol | Determines volatility and permanence |
| Specific gravity at 20°C | 0.972 to 0.978 | Affects volume dosing and formulation weight |
| Viscosity at 20°C | 80 to 120 mPa·s | Influences mixing, flow, and processing ease |
| Flash point | Above 215°C | Relevant for storage and handling safety |
| Refractive index at 20°C | 1.484 to 1.490 | Used as a rapid identity check |
| Acid value | Below 0.1 mg KOH/g | Impurity indicator that affects electrical properties |
| Ester content | Above 99.5% | Direct measure of purity and plasticizer activity |
Low acid value matters especially for wire and cable insulation because residual acidity can react with stabilizers and reduce volume resistivity. High ester content gives you more plasticizer activity per kilogram, which helps control dosage costs. Viscosity consistency from lot to lot is another critical specification in continuous compounding. If one shipment arrives with viscosity outside the agreed window, the extruder will produce varying throughput and finish.
For buyers, the practical takeaway is simple: request the full specification sheet, not just the test method summary. Look for the supplier's internal control limits, not only a reference range. A few units of difference in acid value or color index can shift the processing parameters of a whole production line.
Main Applications of DINP in Manufacturing
DINP chemical is widely used wherever flexible PVC is needed. The main end-use sectors include:
- Wire and cable insulation. DINP's low volatility reduces plasticizer migration during heat aging, so insulation retains its flexibility over service life. This becomes more important when the cable is expected to operate near its temperature rating for years.
- Flooring and wall coverings. The good compatibility with PVC and low color change under heat make DINP suitable for vinyl flooring layers, especially in commercial applications where UV stability and wear resistance are required.
- Automotive interior parts. Dashboard skins, door panels, and seat trim require plasticizer permanence at high interior temperatures. DINP performs better than lower-molecular-weight phthalates in migration and fogging tests.
- Coated fabrics and flexible film. Tarpaulins, tents, and laminated films benefit from DINP's low volatility and good low-temperature flexibility. The plasticizer does not migrate out of the film as quickly under repeated flexing.
- Consumer and industrial goods where phthalate use is permitted. Regulatory constraints in some jurisdictions limit DINP in certain toys and childcare articles, so product compliance must be confirmed before specifying it.
When you compare DINP with alternatives, the selection usually depends on the operating temperature range. DINP offers better permanence than DOP but slightly higher initial viscosity, which affects the glass transition temperature of the finished compound. The practical result is a stiffer feel at the same hardness compared with a lower-molecular-weight plasticizer, which makes DINP a better fit for applications where long-term stability matters more than initial softness.
Regulatory Considerations for DINP Chemical Buyers
Regulatory status is often the deciding factor in a DINP purchase. Different regions have taken different approaches to phthalate regulation.
- The U.S. EPA completed a TSCA risk evaluation for DINP. The findings are relevant for companies that import or process phthalates, because the evaluation can trigger downstream risk management measures.
- In California, DINP is listed under Proposition 65 for a cancer-related endpoint. Products sold into California may require warning labels or alternative formulations.
- In the European Union, DINP is authorized under REACH for certain uses. It is restricted in toys and childcare articles that can be placed in the mouth, so buyers must verify the final application.
The best way to handle compliance is to ask your supplier for a current safety data sheet, REACH registration number where applicable, and a statement on each market's regulatory status. A supplier that tracks these rules actively is a stronger sourcing partner than one that only provides a generic compliance letter. If you are working through a material review, you can look for practical buying tips for DINP that cover common requests from compound buyers.
What to Check Before You Commit to a DINP Supplier
Once the technical and regulatory picture is clear, the remaining question is supply. A good DINP supplier must be able to demonstrate three things:
- Consistent quality over time. Ask for historical certificates of analysis from the last 12 months. Look at how tightly acid value, moisture, and viscosity are controlled. Wide swings in those numbers will cause your quality control team to spend more time rejecting batches.
- Real production capacity and raw material planning. A plasticizer manufacturer with its own phthalic anhydride production line can absorb raw material price swings more easily than a simple trader. Check whether the supplier runs separate plants or has backup capacity for peak demand.
- Logistics capability that fits your delivery method. DINP can be supplied in drums, ISO tank containers, or bulk tanker loads. A plant located near a major port makes export scheduling easier and reduces freight uncertainty.
Before awarding a contract, schedule a technical discussion with the supplier's team. Ask them to explain how they handle lot changes, what the maximum moisture content is, and how they prove batch traceability. Also investigate how the raw material quality affects the finished plasticizer. Understanding the production process of DINP and its main raw materials gives you a more accurate basis for judging supplier capability.
Final Recommendation
DINP chemical remains one of the most practical choices for flexible PVC in high-performance applications. Its higher molecular weight provides better permanence and lower volatility than general-purpose phthalates, while remaining economical compared with non-phthalate alternatives. The key to a successful procurement is to combine a clear specification with a supplier that offers consistent quality, real regulatory documentation, and reliable logistics.
If you are currently evaluating diisononyl phthalate, review the product specifications in detail, compare them against your process requirements, and ask your supplier about lot-to-lot consistency before making a final decision. A short technical call can save months of compounding trials.
