Quinacridone (Pigment Violet 19): Properties, Uses in Plastics and Regulatory Status

Quinacridone (C.I. Pigment Violet 19, CAS 1047-16-1) is a high-performance polycyclic organic pigment that colours plastics red to violet, and the same molecule is the classic beta nucleating agent for polypropylene. Because the shade depends on the crystal form supplied, two grades that share CAS 1047-16-1 can look different in the same compound, which raises the question of what the Colour Index name actually fixes.

Quinacridone is registered under REACH at 1,000 to 10,000 tonnes per year, is not a Substance of Very High Concern, is listed as quinacridone red in 21 CFR 178.3297 without a numeric limit, and sits outside the Union list of Regulation (EU) No 10/2011 because colorants fall outside its scope. Quinacridone is one of the colorant pages in our directory of plastic additives, each with the same identity, loading and regulatory fields.

This page carries the identity data of Pigment Violet 19, separates the beta and gamma crystal forms, sets out the loading evidence for the quinacridone class, names the 3 application areas, quantifies the nucleation and shrinkage effect, dates the regulatory matrix to 24 September 2026 and compares 5 red and violet pigments.

The identity table below carries the values a specification and a food-contact dossier ask for.

What Is Quinacridone (Pigment Violet 19)?#

Quinacridone is a fused five-ring aromatic pigment, 5,12-dihydroquino[2,3-b]acridine-7,14-dione, and it belongs to the polycyclic or high-performance class of organic pigments used in engineering plastics and masterbatch. The five rings lie in one plane, and the two N-H groups and the two C=O groups on that plane bind neighbouring molecules into a hydrogen-bonded crystal lattice. That lattice is why the substance behaves as a pigment at all: it is insoluble in polymer melts and in water, so it survives compounding as a particle instead of dissolving into the matrix.

Which class of colorant does quinacridone belong to, and why does that class matter inside a polymer? As an insoluble organic pigment, quinacridone sits in the pigment branch of colorants for plastics, beside the soluble dyes and the effect pigments. Organic pigments have a low refractive index compared with the inorganic pigments, so a quinacridone-coloured part is usually transparent in plastics rather than opaque.

What does the Colour Index name Pigment Violet 19 mean?#

Pigment Violet 19 is the Colour Index generic name of quinacridone, and C.I. 73900 is the constitution number that ties that name to one chemical structure. Colour Index International lists over 27,000 commercial products under about 13,000 C.I. Generic Names, is maintained jointly by SDC Enterprises and the American Association of Textile Chemists and Colorists, and was first printed in 1924.

The generic name and the constitution number fix the molecule, and they fix nothing else. Pigment Violet 19 covers both commercial crystal forms, so a Colour Index name on a data sheet does not tell a compounder which polymorph is in the bag. The two-part system of generic name and constitution number is explained on Colour Index (C.I.) pigment names and numbers.

Quinacridone, Pigment Red 122 and Pigment Red 202: one chemistry, three pigments#

The quinacridone class covers three commercial plastics pigments: unsubstituted quinacridone (PV19, CAS 1047-16-1), 2,9-dimethylquinacridone (PR 122, CAS 980-26-7) and 2,9-dichloroquinacridone (PR 202, CAS 3089-17-6). All three share the same fused ring skeleton and differ only in what sits at the 2 and 9 positions. The methylated derivative, Pigment Red 122 (quinacridone magenta), carries EC 213-561-3, the formula C22H16N2O2, a molecular weight of 340.4 g/mol and the constitution number C.I. 73915, and it is registered under REACH at 1,000 to 10,000 tonnes per year.

The chlorinated derivative, Pigment Red 202, carries EC 221-424-4, the formula C20H10Cl2N2O2 and a molecular weight of 381.2 g/mol, and it is registered at 100 to 1,000 tonnes per year. Both substituted quinacridones are named magenta, and both hold their own pages in this directory.

Is quinacridone a pigment or a dye?#

Quinacridone is a pigment, not a dye: it stays as insoluble crystals in the melt, while a solvent dye dissolves in the polymer. That difference decides hiding power, migration behaviour and every food-contact argument on this page, and the soluble counterpart of a pigment is covered under solvent dyes for plastics.

How Does Quinacridone Colour a Polymer?#

Quinacridone colours a polymer as an insoluble crystalline dispersion: the pigment particles absorb part of the visible spectrum and stay as discrete crystals held together by hydrogen bonds between the molecules. The colour is therefore a property of the particle rather than of a dissolved molecule, and it depends on how the molecules pack as much as on the molecule itself. Dispersion is the second half of the mechanism: the crystals have to be broken towards their primary particle size and wetted by the polymer, because agglomerates scatter light and shift the shade.

Why does a quinacridone compound stay transparent while a chromium-oxide compound turns opaque? Organic pigments have a low refractive index, close to that of the polymer around them, so they scatter little light and give transparent colour with limited hiding power. Inorganic pigments such as the chromium and copper oxides carry a much higher refractive index and give opaque colour, and that contrast is the pairing used in the 2023 study in the International Journal of Molecular Sciences, which compared a transparent phthalocyanine masterbatch against an opaque chromium and copper oxide masterbatch in polypropylene.

Beta and gamma quinacridone: why the crystal form decides the shade#

Beta-quinacridone and gamma-quinacridone are polymorphs of the same molecule: the gamma form gives a strong red and the beta form a maroon with better weathering. Both carry CAS 1047-16-1 and the name Pigment Violet 19, so a grade change inside one C.I. name can move the shade of a production run with no change to the chemistry on the certificate of analysis.

The consequence is a purchasing rule as much as a chemical fact: a compounder who re-orders on the CAS number alone can receive the other polymorph, and the colour match then fails at the first moulding trial. Our source library records no weathering hours, no lightfastness rating and no grade names for either crystal form, so the polymorph has to be named in the order and confirmed on the supplier data sheet.

What Are the Physical and Chemical Properties of Quinacridone?#

Quinacridone is a red to violet crystalline solid with a molecular weight of 312.3 g/mol, the formula C20H12N2O2 and a melting point of 390 °C (734 °F). The table below separates the values our source library holds from the properties buyers ask for that it does not hold.

The melting point of 390 °C (734 °F) is the PubChem value for the pure substance under CID 13976, and it is not a processing-temperature rating. Heat stability in a polymer is a different property, measured on the coloured compound and specific to supplier and polymer. Our source library holds no heat-stability figure in °C, no solubility value, no thermal-decomposition onset, no particle size and no oil absorption for Pigment Violet 19, and none of those values is taken here from a reseller data sheet.

Which Polymers Use Quinacridone, and at What Loading?#

Quinacridone is dosed at colorant level rather than at additive level: colorants make up 0.01 to 5 wt% of a finished plastic product, and the ECHA plastic additives initiative gives a typical concentration of 2 wt% for organic pigments. The 0.01 to 5 wt% range is the class figure reported by Chea and colleagues in 2025, adapted from Hahladakis and colleagues in 2018, and it covers every colorant in every polymer rather than quinacridone in one polymer.

Is there a published loading for Pigment Violet 19 itself? No. The ECHA mapping records the 2 wt% typical concentration for the substituted quinacridones Pigment Red 122 and Pigment Red 202 across eleven polymer groups and carries no row for PV19, so the figure in the table is a class value and a derivative value, never a quinacridone dosage.

Loadings for the whole additive package of each polymer are collected under additives by polymer, where the colorant line sits beside the antioxidant and light stabilizer lines for the same resin.

Quinacridone loading and dispersion in polyolefin masterbatch#

Quinacridone reaches the machine as a colour masterbatch rather than as a powder: masterbatch carries 40 to 65 wt% pigment or additive and is let down into the base polymer at 1 to 5 %. Extreme concentrates run from 15 to 80 wt%. The carrier resin is matched to the base polymer: wax serves as a universal carrier, EVA and LDPE are used for polyolefins and nylon, and polystyrene is used for ABS, SAN and sometimes polycarbonate. These are general values for pigment preparations of every kind, not measured values for a PV19 concentrate.

The let-down ratio sets the pigment concentration in the part, and dispersion decides whether that concentration produces the intended shade. Full dispersion is a measured property rather than an assumption: see dispersion testing of pigments and masterbatch for the filter-pressure and microtome methods that quantify it.

Quinacridone in engineering plastics and in fibres#

Quinacridone is one of the polycyclic pigment classes used in engineering plastics, alongside the phthalocyanines, the diketopyrrolopyrroles, the perylenes and the isoindolinones, because these classes are the ones selected for the higher melt temperatures of ABS, PA, PC and PET. The ECHA mapping records the quinacridones PR 122 and PR 202 across exactly those polymer groups, together with PMMA and (E)PS, and our substance record names fibres among the applications of PV19. No melt-temperature limit for quinacridone is recorded in our source library, so no processing ceiling in °C is given here.

What Is Quinacridone Used For in Plastics? 3 Application Areas#

Quinacridone is used in 3 plastics application areas: red, violet and magenta masterbatch, automotive plastics and fibres. The 3 areas are listed below in the order the substance record names them.

• Red, violet and magenta colour masterbatch, supplying packaging, housewares and general moulding
• Automotive plastics, where the weathering behaviour of the crystal form decides the grade
• Fibres and filaments, mainly polypropylene, where the pigment also acts on crystallisation

Automotive plastics#

Quinacridone is one of the red and violet pigments used in automotive plastics, where the beta crystal form is selected for its better weathering. Exterior and interior parts expose a colorant to sunlight and heat for the service life of the vehicle, which is why the high-performance polycyclic pigments rather than the azo classes are specified for coloured polypropylene, polyamide and ABS.

Our source library records no automotive material specification, no fogging value and no exposure-hour figure for Pigment Violet 19, so no OEM standard is named here. The full package for an exterior part, from the UV stabilizer to the impact modifier, is set out on additives for automotive plastics.

Colour masterbatch, packaging and housewares#

Red, violet and magenta colour masterbatch is the route by which most quinacridone enters packaging and housewares. Carrier choice, pigment loading and let-down are covered on color masterbatch.

An organic pigment is chosen over a cadmium or lead red in packaging for a regulatory reason as much as a technical one. The EU Packaging and Packaging Waste Regulation (EU) 2025/40 limits the sum of lead, cadmium, mercury and hexavalent chromium in packaging to 100 mg/kg under Article 5(4), applying from 12 August 2026, and that ceiling binds the packaging rather than the pigment, which rules out the heavy-metal reds for the whole article.

Fibres and filaments#

Quinacridone is used in polypropylene fibres, where the same nucleating behaviour that makes it useful in beta-nucleated PP also changes how the filament crystallises. In polypropylene fibres, the phthalocyanines showed slightly higher nucleating efficiency than the quinacridones, a comparison reported in the 2023 review in the International Journal of Molecular Sciences citing earlier work.

Nucleation in a spinning line changes crystallinity, and crystallinity changes tenacity, so a fibre producer treats the pigment as a process variable and not only as a colour. Spin finish, antistatic and pigment choices for filaments are covered on additives for synthetic fibres.

How Does Quinacridone Perform? Heat Stability, Lightfastness and Transparency#

Quinacridone belongs to the high-performance polycyclic pigments, the group selected when a colour has to survive engineering-plastics processing, in contrast to the diarylide yellows, which decompose into monoazo species above about 200 °C. The 2025 paper in Science Advances that reported that decomposition also measured a first TGA decomposition peak at 162 °C for the diarylide class. Our source library holds the class membership of quinacridone and the statement that the beta crystal form weathers better than the gamma form, and no quantified performance rating for PV19.

How heat stability and lightfastness are rated, and which pigment classes hold up, is set out on pigment fastness in plastics: heat stability, lightfastness. The table below names each performance indicator, states what our record holds and names the test method.

How is quinacridone colour measured and matched?#

Quinacridone shades are set numerically in the CIELAB L*a*b* space rather than by eye, because a red built from an organic pigment and a red built from an inorganic pigment can match under one illuminant and not under another. That failure mode is metamerism, and it becomes a project risk whenever heavy-metal pigments are replaced by organic ones in an existing colour.

Colour measurement in plastics runs on two systems, the CIE Yxy space of 1931 and the CIELAB L*a*b* space of 1976, and tolerances are agreed as colour differences rather than as visual verdicts. Delta E tolerances and illuminant pairs are explained on color measurement and matching of plastics.

How Does Quinacridone Interact with Polymers and Other Additives?#

Quinacridone is not inert in a semi-crystalline polymer: like other pigment crystals it nucleates crystallisation, which changes shrinkage, warpage and, in polypropylene, the crystal phase itself. The 2 interaction effects that formulators plan for are listed below.

• Nucleation of the melt, which raises shrinkage and warpage in injection-moulded polyolefin parts
• Crystal-phase change in polypropylene, where gamma-quinacridone induces the beta phase instead of the alpha phase

Does quinacridone nucleate polypropylene and cause warpage?#

Yes: quinacridone nucleates polypropylene, and nucleating pigments raise shrinkage and warpage in injection-moulded polyolefin parts. The size of the effect has been measured on other chemistries: in injection-moulded polypropylene coloured with green masterbatch at 1 to 5 wt%, the 2023 study in the International Journal of Molecular Sciences recorded relative shrinkage in the flow direction rising from 13.6 % to 22.3 % with a transparent phthalocyanine masterbatch and from 49.5 % to 58.3 % with an opaque chromium and copper oxide masterbatch, both against neat polypropylene.

Those ranges belong to the green masterbatches that were tested, and no equivalent measurement for a quinacridone masterbatch exists in our source library. Formulators answer it the same way either way: they select non-warping grades or treated pigments and qualify the colour on a moulded part. Which pigments warp which polymers is set out on pigment-induced warpage.

Gamma-quinacridone as a beta nucleating agent for polypropylene#

Gamma-quinacridone is the original beta nucleating agent for polypropylene: H. J. Leugering identified it as a beta nucleant in 1967 in Makromolekulare Chemie 109:204, and it works at very low content. That property separates quinacridone from every other red pigment in this directory, because it is specified twice over, once as a colour and once as a crystallisation modifier. Calcium pimelate, NU-100 and TMB-5 are the other beta nucleants compared with quinacridone on beta nucleating agents.

Beta-nucleated isotactic polypropylene has markedly higher impact strength and toughness than alpha-iPP, a result Varga set out in his 2002 review, and the beta phase is metastable: it converts to alpha on heating or under strain. Industrial beta-PP pipe practice combines about 0.02 % alpha nucleator with 0.2 % beta nucleator, a general practice not attributed to quinacridone, and no PV19 nucleant dosage is recorded here. Where nucleation sits in the PP formulation is shown on additives for polypropylene (PP).

Does quinacridone migrate or bleed in plastics?#

Quinacridone is an insoluble pigment rather than a soluble dye, and the US food-contact rule for colorants is written around exactly that property: a colorant may not migrate to food in amounts that contribute any colour apparent to the naked eye. That criterion in 21 CFR 178.3297 binds the finished article rather than the pigment powder.

The EU reaches the same question through the metals instead of the chromophore, because the Annex II metal migration limits of Regulation (EU) No 10/2011 apply to the finished coloured article whatever colorant produced the colour. Our source library holds no bleeding, blooming or plate-out result for Pigment Violet 19, so no migration value is printed. Bleeding, blooming and plate-out are separated mechanism by mechanism on colorant migration in plastics.

What Is the Regulatory Status of Quinacridone?#

Quinacridone is registered under REACH at 1,000 to 10,000 tonnes per year, is not a Substance of Very High Concern, is not restricted under REACH Annex XVII and is listed in 21 CFR 178.3297 as quinacridone red without a numeric limit (status 24 September 2026). The matrix below states each instrument, the Pigment Violet 19 status and the date or reference behind it.

The 100 mg/kg heavy-metal ceiling for packaging is explained on the EU Packaging and Packaging Waste Regulation (PPWR) page.

Is quinacridone REACH registered, and is it an SVHC?#

Yes, quinacridone is registered under REACH (Regulation (EC) No 1907/2006) in the 1,000 to 10,000 tonnes per year band, and no, it is not a Substance of Very High Concern: it is absent from the Candidate List as of 24 September 2026. What a tonnage band means for a pigment buyer is explained on REACH and plastic additives.

The contrast inside the red and yellow range is sharp. The lead chromate pigments, lead chromate (CAS 7758-97-6), Pigment Yellow 34 (CAS 1344-37-2) and Pigment Red 104 (CAS 12656-85-8), have been on the SVHC Candidate List since 13 January 2010 and on Annex XIV as entries 10 to 12 with a sunset date of 21 May 2015, while quinacridone has never been added.

Is quinacridone allowed in food-contact plastics?#

In the EU the question is framed differently than for other additives: colorants sit outside the Union list of Regulation (EU) No 10/2011, so quinacridone has no FCM number and no specific migration limit, while the Annex II metal limits still apply to the finished coloured article. Those limits are set in mg/kg of food or simulant: aluminium 1, barium 1, cobalt 0.05, copper 5, iron 48, lithium 0.6, manganese 0.6, zinc 5, nickel 0.02 and antimony 0.04, with arsenic, cadmium, chromium, lead and mercury required to be not detectable. Only the colorants that are also authorised additives keep an FCM entry, among them carbon black FCM 411 and titanium dioxide FCM 610, and quinacridone is not one. National rules and Council of Europe Resolution AP(89)1 fill the gap, and the purity limits of that resolution are not reproduced here because they could not be re-verified. Why colorants sit outside the Union list is explained on EU 10/2011.

In the United States, quinacridone red (C.I. Pigment Violet 19, C.I. 73900) is named in 21 CFR 178.3297 as a colorant for polymers with no numeric limitation, subject to good manufacturing practice and the no-visible-colour-migration rule. That listing is not an approval of a grade, and the related quinacridones differ: PR 202 carries a maximum of 1.0 % by weight of polymers and PR 122 is not listed. Conditions of use A to H and the GMP requirement are set out on FDA food contact rules for plastic additives (21 CFR).

Is quinacridone listed under California Proposition 65?#

The Proposition 65 status of quinacridone is being verified against the current OEHHA list and will be published here once confirmed. For context, the pigment substances Proposition 65 does list include cadmium and cadmium compounds since 1 October 1987 and lead and lead compounds since 1 October 1992, and the listing dates for every colorant are on California Proposition 65.

Is Quinacridone Safe in Plastics? Health and Environmental Profile#

Quinacridone is not listed under the Stockholm Convention, and our source library holds no hazard classification for it, which is a gap in the record rather than a statement that the substance is unclassified: the supplier safety data sheet is the authority. The record we hold consists of 3 items.

• Classification record: the GHS field for quinacridone is empty in our source library, so no CLP classification is stated here and none is denied; the supplier SDS and the ECHA classification and labelling inventory are the sources for CAS 1047-16-1
• Insolubility: quinacridone stays particulate in the polymer, the property the US colorant rule is built on
• Class context: the pigment classes with documented process-safety findings in plastics are the heavy-metal and the diarylide pigments, not the polycyclic pigments

The diarylide case is a contrast rather than a read-across. Diarylide pigments decompose into monoazo species above about 200 °C according to the 2025 Science Advances paper, and printing-ink pigments tested positive in miniaturised Ames tests after 30 minutes at 240 °C in the 2025 study published in Materials. Neither result has been reported for quinacridone. The pigment entries on toxic plastic additives are the heavy-metal and diarylide classes.

What Are the Alternatives to Quinacridone?#

The main alternatives to quinacridone in plastics are the diketopyrrolopyrrole red PR 254 and the perylene red PR 179 for reds, the substituted quinacridones PR 122 and PR 202 for magentas, and the dioxazine PV 23 for violets. All 5 are organic pigments, and the table compares them on the fields that decide a substitution: identity, class, molecular weight, REACH tonnage band and US food-contact status.

Footnote: perylene red PR 179 (CAS 5521-31-3) is cleared under 21 CFR 178.3297 at a maximum of 1 % by weight of polymers, conditions of use B through H.

The azo and polycyclic branches are compared side by side on organic pigments for plastics, the level at which a substitution is usually decided before a single C.I. number is chosen.

Quinacridone vs Pigment Red 254 (DPP red)#

Quinacridone and Pigment Red 254 are the two polycyclic reds that compete for the same slot in plastics: PR 254 is the brighter red and carries a US food-contact limit of 1 % by weight under conditions of use B through H, while quinacridone is listed without a numeric limit. Pigment Red 254 is the diketopyrrolopyrrole archetype, 3,6-bis(4-chlorophenyl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione, with CAS 84632-65-5, EC 401-540-3, the formula C18H10Cl2N2O2 and a molecular weight of 357.2 g/mol.

The two chemistries rest on the same structural principle, a planar chromophore locked by strong intermolecular hydrogen bonding, which is why both sit in the high-performance group. The DPP class has high stability to heat but not to acid and base, and PR 254 is registered under REACH at 1,000 to 10,000 tonnes per year, the same band as quinacridone.

Quinacridone vs Pigment Red 122 and Pigment Red 202#

Within the quinacridone class the choice is as much regulatory as chromatic: Pigment Red 202 is cleared under 21 CFR 178.3297 at a maximum of 1.0 % by weight of polymers, Pigment Red 122 is not listed there, and quinacridone itself is listed without a numeric limit. A magenta specified for a US food-contact article therefore cannot be met by the methylated derivative, while the unsubstituted pigment carries the widest clearance of the three.

The chromatic difference follows the substitution: quinacridone is named red to violet in our substance record and both substituted grades are named magenta, which is why the magenta queries belong to the derivatives. Pigment Red 122 is registered at 1,000 to 10,000 tonnes per year and PR 202 at 100 to 1,000 tonnes per year, and neither is on the Candidate List, as checked in ECHA CHEM on 22 September 2026.

Quinacridone vs perylene red and dioxazine violet#

For deeper violets the alternative is the carbazole dioxazine Pigment Violet 23 (CAS 6358-30-1), and for a bluer maroon the perylene Pigment Red 179 (CAS 5521-31-3), which is cleared in 21 CFR 178.3297 at a maximum of 1 % by weight under conditions of use B through H. Pigment Violet 23 (dioxazine violet) is the deeper violet and also a shading component, with EC 228-767-9, the formula C34H22Cl2N4O2 and a molecular weight of 589.5 g/mol. Its REACH registration status is not confirmed in our records, so no tonnage band is given, and it is not listed in 21 CFR 178.3297 when checked by CAS against the eCFR text current to 18 September 2026.

Perylene red covers the maroon end that the beta form of quinacridone also serves. Pigment Red 179 (perylene maroon) is cleared at a maximum of 1 % by weight under conditions of use B through H, so the numeric limit is the practical difference against a quinacridone listed without one.

Who Manufactures Quinacridone Pigments? Grades and Suppliers#

Quinacridone pigments are produced by the large organic-pigment houses: Sun Chemical, Sudarshan and DIC, alongside many Indian and Chinese producers. Sun Chemical is headquartered in Parsippany, New Jersey, and belongs to the DIC group, which closed its acquisition of the BASF pigments business in 2021 after agreeing the EUR 1.15 bn deal in 2019. Sudarshan is based in Pune and completed the Heubach acquisition on 3 March 2025, bringing the Heubach, Hostaperm, Hostatint and Sudaperm brands into one portfolio. More producers and their certifications are in the directory of pigment manufacturers and suppliers for plastics.

Footnote: grade names and crystal forms are not recorded in our source library; request them from the supplier.

Buyers should request the supplier's TDS and SDS, the crystal form and the heat-stability rating for the intended polymer, because none of the three follows from CAS 1047-16-1. How the pigment houses rank by sales and by family is shown under largest plastic additive companies.

How Do Quinacridones Fit into the High-Performance Organic Pigment Class?#

Quinacridone is one of the polycyclic pigment classes, the high-performance group that also contains the phthalocyanines, the diketopyrrolopyrroles, the perylenes, the isoindolinones and the dioxazines. It also contains the isoindolines, the perinones, the anthraquinones, quinophthalone and thioindigo, and it is defined by fused ring systems rather than by the azo bond of the other half of the organic pigment range.

Scale separates the two halves. World organic pigment production was about 250,000 tonnes in 2006, of which about 25 % were diarylide yellows, so the azo classes carry the volume while the polycyclic classes carry the performance. Quinacridone is one branch of the polycyclic group within organic pigments, and it is the branch that also supplies a nucleating agent.

The polycyclic pigment classes beside quinacridone#

The closest neighbour of the quinacridones is the phthalocyanine class, which supplies the highest-volume pigment in production and, like quinacridone, exists in more than one crystal form. Phthalocyanines account for about 25 % of all synthetic organic pigments. Pigment Blue 15:3 (phthalocyanine blue) belongs to the beta family of Pigment Blue 15, the alpha family covering PB15, PB15:1 and PB15:2 and the beta family PB15:3 and PB15:4, with the beta form the more stable of the two. The parallel with quinacridone is exact: one molecule, two crystal families, one shade per grade.

Quinacridone outside plastics: paints, coatings and printing inks#

Quinacridone reaches most people through paints and printing inks rather than through plastics: Du Pont first sold quinacridone pigments in 1958, and colour ranges, automotive coatings and inks have used them since. The crystal form decides the shade in those media exactly as it does in a polymer, which is why the same two polymorph names appear on an artists' colour chart and on a masterbatch specification. This reference covers additives in plastics, so coating and paint formulation, their own fastness rating scales and their product lines are out of scope.

What makes a colour quinacridone?#

A colour is a quinacridone when the pigment is built on the fused quinacridone ring system, which is one molecule with two commercial crystal forms and two common ring-substituted derivatives. The ring system is 5,12-dihydroquino[2,3-b]acridine-7,14-dione, it is insoluble, and the shade it produces is set by how the molecules pack rather than by a different chromophore.

What is another name for quinacridone red?#

Quinacridone red is the same substance as Pigment Violet 19: the Colour Index generic name is C.I. Pigment Violet 19 and the constitution number is C.I. 73900. The other names recorded for it are gamma-quinacridone and beta-quinacridone, which name the two crystal forms, and the systematic name 5,12-dihydroquino[2,3-b]acridine-7,14-dione under CAS 1047-16-1.