DINP DI-ISONONYL PHTHALATE

Diisononyl phthalate, also known as DINP and phthalic acid diisononyl ester, is a high molecular weight ortho-phthalate plasticizer supplied under CAS numbers 28553-12-0 or 68515-48-0, with C26H42O4 representing its principal C9 diester composition, and is used mainly in flexible polyvinyl chloride (PVC). Its compatibility with PVC, relatively low volatility and balance of processing and flexibility make DINP useful in flooring, cables, coated fabrics and hoses. By distributing between PVC chains without becoming covalently bonded to them, the phthalate ester increases chain mobility and reduces material stiffness.

CAS No: 28553-12-0 / 68515-48-0
EC No: 249-079-5 / 271-090-9, respectively
Molecular formula: C26H42O4, representative C9 diester composition
Molecular weight: approx. 418.6 g/mol for the C9 diester, composition-dependent for commercial mixtures

WHAT IS DINP DI-ISONONYL PHTHALATE?

Diisononyl phthalate (DINP, CAS 28553-12-0 or 68515-48-0) is an external plasticizer used primarily to turn rigid PVC into flexible compounds and plastisols. Also called phthalic acid diisononyl ester, DINP is a commercial mixture of branched alkyl esters rather than one chemically uniform isomer.

Within flexible PVC, the ester helps adjust softness, elongation and processing behavior. The required DINP loading depends on the resin, filler content, target hardness and service conditions, so a single dosage cannot describe every application.

Industrial manufacture involves esterification of phthalic anhydride with isononyl alcohol mixtures. Water is removed during the reaction, and subsequent purification reduces residual alcohol, acidity and other impurities. The alcohol feedstock influences the resulting DINP isomer distribution.

Commercial grades differ in branching pattern, ester purity, moisture, acid value, color and stabilizer content. An antioxidant-stabilized DINP grade and an unstabilized material should not automatically be treated as identical purchasing specifications.

For identification, CAS 28553-12-0 denotes diisononyl phthalate, while CAS 68515-48-0 denotes C9-rich di-C8-10 branched alkyl phthalate esters. Neither identity should be reduced to a single bis(7-methyloctyl) structure as a complete description of the commercial product.

COMMON PRODUCT & CHEMICAL NAMES OF DINP DI-ISONONYL PHTHALATE:

Diisononyl phthalate
Di-isononyl phthalate
DINP
Phthalic acid diisononyl ester
1,2-Benzenedicarboxylic acid, diisononyl ester
1,2-Benzenedicarboxylic acid, di-C8-10-branched alkyl esters, C9-rich
Palatinol N
Jayflex DINP

The abbreviation DINP and the first five entries describe the diisononyl phthalate family or its chemical identity. The C9-rich C8-10 description specifically identifies CAS 68515-48-0. The last two entries are commercial grade names and do not define every DINP product on the market.

Diisodecyl phthalate (DIDP), di(2-ethylhexyl) phthalate (DEHP), diethyl phthalate (DEP) and di(2-ethylhexyl) terephthalate (DEHT, also called DOTP) are different plasticizers. Their names, CAS numbers, regulatory status and performance must not be substituted for those of DINP.

CAS NO, EC / EINECS NO AND CHEMICAL IDENTIFICATION OF DINP DI-ISONONYL PHTHALATE

Product name: Diisononyl phthalate
Common abbreviation: DINP
Chemical name for CAS 28553-12-0: 1,2-Benzenedicarboxylic acid, diisononyl ester
Chemical name for CAS 68515-48-0: 1,2-Benzenedicarboxylic acid, di-C8-10-branched alkyl esters, C9-rich
CAS / EC pair 1: 28553-12-0 / 249-079-5
CAS / EC pair 2: 68515-48-0 / 271-090-9
Molecular formula: C26H42O4, representative C9 diester composition
Molecular weight: approx. 418.6 g/mol for the C9 diester
Chemical class: Branched alkyl ortho-phthalate ester plasticizer
Main functions: PVC plasticization, flexibility adjustment and modification of processing behavior

The CAS number identifies the DINP substance description, but it does not specify hardness, migration behavior or the performance of a finished article. The actual identity and composition of the supplied grade should be recorded in procurement documents.

CHEMICAL STRUCTURE AND MOLECULAR PROPERTIES OF DINP DI-ISONONYL PHTHALATE

The DINP structure consists of an aromatic phthalate core with two adjacent ester groups linked to branched alkyl chains. Ester groups provide polar interactions with PVC, while the hydrocarbon chains contribute the nonpolar portion of the molecule.

Because commercial diisononyl phthalate contains multiple branched constituents, a representative structure is not an exhaustive molecular specification. For the C8-10, C9-rich identity, the molecular weight distribution also reflects variation in alkyl-chain length.

HOW DOES DINP DI-ISONONYL PHTHALATE WORK AT THE MOLECULAR LEVEL?

During PVC processing, DINP penetrates the resin and becomes distributed through the polymer matrix. Its presence reduces the effective interactions restricting PVC chain movement, lowers the glass transition temperature and allows greater flexibility.

Main functions:

Reducing the stiffness of PVC
Adjusting hardness and elongation
Supporting plastisol formation and processing
Balancing flexibility with plasticizer retention

As an external plasticizer, the phthalic acid diisononyl ester remains physically incorporated rather than covalently attached to PVC. Migration, extraction and evaporation are therefore possible. Their extent depends on temperature, contact medium, article thickness, formulation and exposure time.

Increasing DINP loading usually changes softness and mechanical strength together. Resin selection, fillers, other plasticizers and the degree of fusion also influence the result, so equal additions do not guarantee equal performance in different systems.

PHYSICAL AND CHEMICAL PROPERTIES OF DINP DI-ISONONYL PHTHALATE

General technical specifications:

Physical appearance: Clear, nearly colorless to slightly yellow oily liquid
Chemical character: High molecular weight phthalate ester mixture
Representative molecular formula: C26H42O4
Representative molecular weight: approx. 418.6 g/mol
Density at 20 °C: approx. 0.97-0.98 g/cm3
Dynamic viscosity at 20 °C: approx. 68-82 mPa.s for a published commercial grade
Ester content: A published commercial grade specifies a minimum of 99.5% by GC area
Acid value: A published commercial grade specifies a maximum of 0.06 mg KOH/g
Water content: A published commercial grade specifies a maximum of 0.05% by weight
Color: A published commercial grade specifies a maximum of 30 platinum-cobalt units
Refractive index at 20 °C: approx. 1.484-1.488 for a published commercial grade
Water solubility: Very low, approx. 0.06 mg/L at 20 °C in a substance assessment
Boiling behavior: Reported above 400 °C in a substance assessment
Flash point: Generally above 200 °C, dependent on grade and test method

For DINP transfer and metering, viscosity must be compared at the same temperature. The neat-liquid viscosity is not the same measurement as the viscosity of a PVC plastisol, which also depends on resin particles, filler and storage history.

Ester content describes composition, while acid value measures titratable acidity. Moisture can affect processing consistency, and color is relevant to transparent or lightly colored PVC. GC, acid-value titration, Karl Fischer water analysis and color measurement answer different quality-control questions.

The boiling point of diisononyl phthalate must always be interpreted together with pressure. A value near 244 °C measured under reduced pressure must not be presented as an atmospheric boiling point. Likewise, the reported vapor pressure of 1 mmHg at 200 °C must not be assigned to 20 °C.

These figures combine indicative substance data and explicitly identified commercial-grade limits. They are not universal DINP specifications or a binding guarantee for material supplied by Ataman Kimya.

USE OF DINP DI-ISONONYL PHTHALATE IN PVC COMPOUNDS AND PLASTISOLS

In melt-processed PVC, DINP is incorporated with the resin, stabilizers and other additives before final shaping. In a plastisol, dispersion-grade PVC particles are suspended in a liquid plasticizer phase and subsequently gelled and fused by heating.

Resin compatibility alone does not establish a suitable processing window. The diisononyl phthalate formulation should be assessed for viscosity development, fusion, surface quality and retained mechanical properties after aging.

SECTORS AND INDUSTRIAL APPLICATIONS OF DINP DI-ISONONYL PHTHALATE

The combination of PVC compatibility and plasticizer permanence makes DINP relevant to flexible vinyl products in several sectors.

Main areas of use:

Flooring and wall coverings
Wire and cable compounds
Synthetic leather and coated fabrics
Flexible hoses, sheets and films
Automotive PVC parts and plastisol systems
Selected adhesives, sealants, inks and coatings

FLOORING AND COATED FABRICS

Purpose: Produce flexible PVC layers with suitable feel and processing behavior.
Function of DINP: Plasticize the resin and contribute to plastisol flow.
Performance effect: Adjust flexibility and assist coating or forming operations.
Limitations: Wear, staining, emissions and migration require finished-product evaluation.

WIRE AND CABLE COMPOUNDS

Purpose: Develop flexible PVC insulation or sheathing compounds.
Function of diisononyl phthalate: Provide the plasticizing phase in a balanced compound.
Performance effect: Adjust flexibility and support suitable processing.
Limitations: Electrical performance, thermal aging and fire behavior depend on the entire formulation and relevant cable standard.

HOSES AND AUTOMOTIVE PVC

Purpose: Provide flexibility in shaped or coated components.
Function of the phthalate ester: Reduce rigidity and modify processing behavior.
Performance effect: Help achieve a selected balance of softness and durability.
Limitations: Oil resistance, fogging and long-term service life cannot be guaranteed from the DINP identity alone.

IS DINP DI-ISONONYL PHTHALATE USED IN COSMETIC, FOOD, AND PHARMACEUTICAL APPLICATIONS?

DINP should not be described as a general-purpose cosmetic ingredient, nutritional supplement ingredient or pharmaceutical excipient on the basis of its use in PVC. These are distinct uses requiring separate evidence and authorization.

Food-contact use of the phthalate ester concerns the finished material, applicable authorization, migration and intended contact conditions. It does not mean that industrial DINP may be added directly to food. For a requested food-contact or medical application, please contact Ataman Kimya for grade-specific documentation before making suitability claims.

WHICH PROBLEMS CAN DINP DI-ISONONYL PHTHALATE HELP SOLVE?

Excessive rigidity in PVC
DINP can increase flexibility, but the required level must be established against hardness and strength targets.

Unsuitable plastisol handling
The phthalic acid diisononyl ester can provide a useful liquid phase, while resin choice and other additives still determine practical rheology.

Loss of flexibility during service
Relatively low volatility makes DINP relevant to retention-focused formulations. Extraction and migration testing remain necessary.

Replacement of an existing plasticizer
Diisononyl phthalate may be evaluated against DEHP in suitable industrial PVC applications. Equal-weight substitution does not establish equivalent performance or regulatory acceptability.

THINGS TO CONSIDER WHEN USING DINP DI-ISONONYL PHTHALATE

A frequent error is confusing a DINP dosage expressed in phr with the percentage of the complete formulation. Fifty phr means 50 parts plasticizer per 100 parts PVC resin, not 50% of the final compound.

Specify the exact DINP CAS/EC pair and grade.
Measure hardness and tensile properties after conditioning.
Check compatibility with adjoining plastics, coatings and adhesives.
Evaluate migration, extraction and thermal aging for the intended use.
Control plastisol viscosity and storage-related changes.
Assess finished-article restrictions before selecting the formulation.

Avoid creating DINP-containing mist. Low room-temperature volatility does not remove exposure risks during spraying, heating or handling contaminated dust.

INITIAL FORMULATION APPROACHES FOR DINP DI-ISONONYL PHTHALATE

These illustrative compositions are starting points for controlled development and are not validated commercial recipes. Every percentage is by weight of the complete formulation. Both examples use DINP at 50 phr relative to PVC, a loading represented in published plastisol comparisons. Resin and additive choices require application-specific optimization.

EXAMPLE 1: FLEXIBLE PVC COMPOUND SCREEN

Components:

Suspension PVC resin: 60.0%
DINP: 30.0%
Calcium carbonate filler: 7.0%
Calcium/zinc stabilizer package: 2.0%
Compatible lubricant package: 1.0%
Total: 100.0%

Evaluation criteria:

Shore A hardness
Tensile strength and elongation
Fusion and surface quality
Plasticizer exudation and mass loss after aging
Low-temperature flexibility

Safety note: Assess additive compatibility and ventilation during hot processing. This example establishes no cable, food-contact or child-product compliance.

EXAMPLE 2: PVC PLASTISOL COATING SCREEN

Components:

PVC dispersion resin: 64.0%
DINP: 32.0%
Calcium/zinc stabilizer package: 2.0%
Fine calcium carbonate filler: 2.0%
Total: 100.0%

Evaluation criteria:

Initial viscosity and viscosity after storage
Gelation and fusion behavior
Film flexibility and tensile properties
Surface defects and substrate adhesion
Migration into contacting materials

Safety note: Use a controlled laboratory coating method that avoids aerosol generation. Thermal conditions and stabilizer selection must be developed for the actual resin system.

DINP DI-ISONONYL PHTHALATE SIMILAR PRODUCTS AND ALTERNATIVES

Compare DINP alternatives by compatibility, efficiency, volatility, extraction, processing, total formulation cost and the destination market's requirements.

DINP DI-ISONONYL PHTHALATE AND DEHP

DEHP is a different ortho-phthalate plasticizer. Diisononyl phthalate can be assessed as an alternative in appropriate PVC applications, but performance and legal requirements require separate review.

DINP DI-ISONONYL PHTHALATE AND DIDP

DIDP has predominantly longer alkyl groups. Selection between the two phthalate esters should consider service temperature, permanence and processing rather than chemical-name similarity.

DINP DI-ISONONYL PHTHALATE AND DOTP / DEHT

DOTP, also called DEHT, is a terephthalate rather than an ortho-phthalate. Substitution for DINP requires confirmation of fusion behavior, flexibility and finished-product requirements.

DINP DI-ISONONYL PHTHALATE AND DINCH

DINCH is a cyclohexane dicarboxylate plasticizer with a different core structure. Its suitability must be demonstrated for the intended application rather than assumed from a non-phthalate description.

Every change from diisononyl phthalate should be verified through laboratory and application trials.

QUALITY CONTROL AND PURCHASING CRITERIA FOR DINP DI-ISONONYL PHTHALATE

Before comparing DINP prices, define the finished product and required technical and regulatory performance.

Information to clarify and review before purchasing:

Exact CAS/EC identity and commercial grade
Ester content, moisture and acid value
Viscosity, density and color with test conditions
Stabilized or unstabilized supply form
Batch traceability and packaging condition
Required application and destination market
TDS, current local SDS and batch COA
Quantity, delivery location and specification agreement

A COA reports batch conformity or results, while a TDS describes technical characteristics and an SDS communicates hazards and handling requirements. None alone certifies compliance of a finished DINP-containing article.

Grade requirements, quantity, packaging and delivery terms should be aligned before comparing quotations for the phthalate ester. For current pricing and availability, please contact Ataman Kimya.

STORAGE AND HANDLING OF DINP DI-ISONONYL PHTHALATE

Store DINP in tightly closed, clean containers protected from moisture, excessive heat and contamination. Suitable tank and packaging materials should be selected to preserve the required purity and color. Keep the phthalate ester away from strong oxidizing agents.

For bulk handling, clean transfer lines and moisture control help maintain diisononyl phthalate quality. Confirm the offered grade's storage temperature and shelf life with Ataman Kimya instead of assigning one universal storage period.

Published manufacturer information for an unstabilized DINP grade identifies it as not regulated as dangerous goods for the listed transport modes, with no applicable UN number. The delivered grade and transport route still require confirmation.

Contain spills with suitable absorbent material, prevent DINP from entering drains and recover contaminated material for authorized disposal. Oil-like residues can create a slipping hazard.

SAFETY INFORMATION OF DINP DI-ISONONYL PHTHALATE

Low acute toxicity does not justify describing DINP as harmless. In January 2025, the US EPA identified unreasonable human-health risk driven by worker exposure to mist from certain spray-applied DINP-containing adhesives, sealants, paints and coatings. This finding does not establish a blanket ban on all DINP uses.

Use closed transfer where practicable, local extraction where needed, protective gloves and eye protection. Respiratory protection for DINP mist must follow the workplace exposure assessment. Wash contaminated skin, rinse exposed eyes promptly and obtain medical attention for persistent symptoms or significant exposure.

Under EU REACH Annex XVII Entry 52, DINP is restricted above 0.1% by weight of plasticized material in toys and childcare articles that children can place in the mouth. US rules prohibit DINP above 0.1% in accessible plasticized components of covered children's toys and childcare articles. The scopes differ.

California lists diisononyl phthalate under Proposition 65 for cancer. Warning obligations depend on exposure and applicable provisions, not merely the appearance of the DINP name on an invoice.

Supplier hazard classification, product restrictions and exposure-based assessments are distinct. For the offered grade's current local CLP classification and any applicable H statements, please contact Ataman Kimya. Prevent environmental releases, control combustible-liquid fire risks and arrange disposal under local requirements.

SUPPLY OF DINP DI-ISONONYL PHTHALATE FROM ATAMAN KIMYA

For DINP supply inquiries, contact Ataman Kimya with the intended application and required specifications. The offered identity, documentation, packaging and delivery conditions should be confirmed at quotation stage.

Sharing the following information in a quotation request helps evaluate the correct DINP product:

PVC compound, plastisol or other intended use
Required CAS/EC identity and quality parameters
Target market and compliance documentation
Requested quantity and packaging
Delivery destination and schedule

FREQUENTLY ASKED QUESTIONS ABOUT DINP DI-ISONONYL PHTHALATE

What is DINP?
Diisononyl phthalate is an external plasticizer used mainly in flexible PVC.

Is DINP one pure isomer?
No. Commercial diisononyl phthalate is a mixture of branched alkyl phthalate constituents.

Why are two CAS numbers used?
CAS 28553-12-0 and 68515-48-0 describe different commercial DINP substance identities.

Which EC number belongs to each CAS number?
28553-12-0 pairs with 249-079-5, and 68515-48-0 pairs with 271-090-9.

What is the formula of DINP?
C26H42O4 represents the C9 diester composition, rather than every constituent of all commercial mixtures.

Does DINP react chemically with PVC?
The plasticizer is physically incorporated and is not covalently bonded to PVC chains.

Is DINP soluble in water?
Diisononyl phthalate has very low water solubility and does not form a simple aqueous solution.

What does 50 phr mean?
It means 50 parts DINP by weight per 100 parts PVC resin.

How much DINP should be used?
Select loading from the resin system, desired hardness and verified end-use performance.

Is DINP the same as DOP or DEHP?
No. Diisononyl phthalate and di(2-ethylhexyl) phthalate are different substances.

Can DINP migrate from PVC?
Yes. Its physical incorporation permits migration or extraction under suitable contact conditions.

Can DINP be used freely in children's products?
No. Applicable toy and childcare restrictions must be assessed for the destination market.

Does food-contact use mean DINP is a food additive?
No. Material authorization and migration requirements are different from direct food use.

Does low volatility remove inhalation risk?
No. DINP-containing mist can create significant occupational exposure.

What is the UN number of DINP?
A published manufacturer transport assessment assigns no UN number to the reviewed grade. Confirm the delivered grade's status with Ataman Kimya.

What documents should accompany a purchase?
Request the DINP TDS, current local SDS, batch COA and application-specific compliance information.

DINP DI-ISONONYL PHTHALATE - TECHNICAL SUMMARY

Diisononyl phthalate, abbreviated DINP, is a high molecular weight ortho-phthalate plasticizer used mainly in flexible PVC compounds and plastisols. Commercial material contains branched ester constituents rather than one uniform isomer.

Grade selection should consider ester content, viscosity, density, moisture, acidity, color and any stabilizer addition. A representative formula does not replace a commercial DINP composition description.

The identity pairs are CAS 28553-12-0 with EC 249-079-5 and CAS 68515-48-0 with EC 271-090-9. DEHP, DIDP, DOTP and DINCH must be distinguished from diisononyl phthalate.

Typical application families include flooring, cables, coated fabrics, hoses and automotive PVC. The ester adjusts flexibility, while final performance depends on resin, loading, additives and processing.

Control DINP mist exposure, evaluate migration and confirm destination-market requirements. Ataman Kimya can be contacted to clarify the offered grade, documentation and supply conditions.

Diisononyl phthalate can be sourced from ATAMAN KİMYA. For further information and supply inquiries about diisononyl phthalate, please contact ATAMAN KİMYA.