Californium Curium R915 Polyester-Grade Transparent Halogen-Free Flame Retardant: Technical Data Sheet and Processing Window

R915 is a transparent halogen-free flame retardant developed specifically for PET/PETG by Californium Curium, and belongs to the flame retardant series. The core component is polyol phosphate ester (an additive-type organophosphorus system, halogen-free and free of heavy metals). It appears as a white crystalline fine powder, with a phosphorus content of 18%, a melting point of 210℃, and an onset temperature of thermal decomposition ≥260℃. It is an additive-type flame retardant and does not participate in the polyester copolymerization reaction. With a fineness expressed as a 325-mesh pass rate ≥98%, it is recommended for use within a barrel temperature window of 240–275℃. Each data item below is annotated with the source document name and data basis.

“Who we are” on this article: Californium Curium’s additives are organized into three lines—dispersants (with chemical dispersion as the main line, represented by the R1800 series paste-form hyperdispersants; used in combination with wetting-type dispersion agents such as wax, stearic acid and EBS (ethylene bis-stearamide) to raise dispersibility to a new level [company statement]), the flame retardant series to which R915 belongs, and the comprehensive series. R915 addresses one specific question: how to make polyester transparent and halogen-free flame retardant. It does not address dispersion problems.

1Model positioning

1

The documentation defines it as follows:

A high-efficiency halogen-free flame retardant developed specifically for PET and PETG high-transparency polyester materials. It has no negative impact on the light transmittance or haze of the base resin, does not cause whitening, yellowing or exudation during processing, and is perfectly suited to high-transparency finished articles such as transparent sheet, film, injection-moulded optical parts and extruded profiles.

(Based on official product data)

2Three frequently asked questions about transparent articles: yellowing, whitening and exudation

2

These three terms are the most common customer complaints for transparent polyester articles. The documentation provides a qualitative commitment plus processing boundaries for R915, which can be checked item by item:

Phenomenon (customer's wording)	Source text on R915	Source
“The moulded part comes out yellow”	“Does not cause whitening, yellowing or exudation during processing”; boundary on the reverse side: “prolonged residence at temperatures above 290℃ is prohibited, to avoid slight thermal degradation of the flame retardant causing yellowing”	Official product data
“Transparency dropped, with fogging / rainbow patterns”	“The molecular structure matches the polarity of polyester; after addition, the haze of the finished article does not increase and the light transmittance does not decline; the finished product remains highly transparent, with no whitening, fogging or rainbow pattern problems”	Official product data
“Surface exudation, oily fog”	“High-molecular-weight polyol phosphate ester structure; no blooming and no exudation at room temperature or under 85℃/85% RH hygrothermal ageing; no oily fog on the finished article surface”	Official product data

The boundary must be clearly stated: all three rows above are qualitative statements. The documentation provides no corresponding percentage values for light transmittance, haze or yellowing, and does not present any comparative test data for these three items. This article does not convert qualitative descriptions into numerical values. If your acceptance criteria are specific numerical values (e.g. haze ≤X%, ΔYI ≤Y), you need to conduct trials and measurements using your own resin and wall thickness.

3Core composition

The documentation describes the composition verbatim as follows:

Polyol phosphate ester (additive-type organophosphorus system, halogen-free and free of heavy metals)

(Based on official product data)

This product is an additive-type flame retardant and does not participate in the polyester copolymerization reaction.

Not listed in the documentation: molecular weight, degree of polymerization, the chemical environment of phosphorus (e.g. whether it is a phosphate ester oligomer), and specific structural differences from other phosphorus-based flame retardants. The documentation also provides no elemental spectrum other than bromine/chlorine, and no quantitative composition table.

4Key parameter table

The following table is taken item by item from the [Key physical and chemical indicators] section of the documentation; the test standard column is also reproduced as written:

Key parameter …

Test item	Technical parameters	Test standard	Source
Appearance	White crystalline fine powder	Visual inspection	Official product data
Phosphorus content	18%	Phosphorus elemental analysis	Same as above
Melting point	210℃	DSC differential scanning calorimetry	Same as above
Halogen content	Not detected (halogen-free)	IEC 61249-2-21	Same as above
Onset temperature of thermal decomposition	≥260℃	TGA thermogravimetric analysis	Same as above
Moisture	≤0.2%	GB/T 6284	Same as above
Fineness (325-mesh pass rate)	≥98%	Sieving method	Same as above
Compatibility	Fully compatible with PET and PETG, does not affect transparency	Light transmission test on extruded specimens	Same as above

Items not listed in the documentation (not supplemented or inferred in this article): specific values for light transmittance and haze, limiting oxygen index (LOI) values, melt flow rate, volume resistivity, toxicity data (LD50), UL yellow card number, or third-party test report numbers.

phosphorus content 18%

limiting oxygen index (LOI) increased to above 38%

5Recommended dosage and typical applications

X-axis = dimension %; colored band = target interval where the object can fall; points outside the band = portions that cannot be reached.

01.252.53.755%Target band012345UL94 V-21–2%UL94 V-02–4%X-axis same dimension % ·X-axis scale based on this article's max (1–4 %); do not directly compare lengths across articles.

• Target band
• UL94 V-2
• UL94 V-0
• X-axis same dimension % ·
• X-axis scale based on this article's max (1–4 %); do not directly compare lengths across articles.

• UL94 V-21–2 %
• UL94 V-02–4 %

Chart data (source text verbatim)

Object	Range
UL94 V-2	1–2 %
UL94 V-0	2–4 %

Source textScale 0–5 %

Scale = criterion limit (unit ppm); the side marked in red = exceedance direction; values are taken directly from source criteria.

Both tiers satisfiedNeither tier satisfied025050075010001250ppmBr+Cl ＜ 900 ppm…Fig. Halogen-free criterion ppm red line← Lower value means more "halogen-free"; dashed line = red line from source, segment = judgment interval cut by red lineClaim permitted only below the red line: Halogen-free threshold

• Br+Cl ＜ 900 ppm
• Fig. Halogen-free criterion ppm red line
• ← Lower value means more "halogen-free"; dashed line = red line from source, segment = judgment interval cut by red line
• Claim permitted only below the red line:

• Br+Cl＜ 900 ppm

Chart data (source text verbatim)

Criterion	Limit	Description
Br+Cl	＜ 900 ppm	Criterion: Br+Cl 900 ppm

Main text criteria layerScale 0–900 ppm

Moved from the bodyConfirm before selection: Is TPU in the substrate? · whole paragraph

1. 01Whether TPU is present in the substrate: R912’s applicable substrates explicitly include TPU, while R915 and R912B only list PET/PETG (R912B only lists PET). For TPU, the documentation supports only R912.
2. 02Whether the article is a high-transparency product: R915’s transparency statement is “does not affect transparency”; R912’s is “light transmittance loss approx. 20%”; R912B has no transparency statement. For optical parts and high-transparency films, the documentation points to R915.
3. 03Processing temperature window: R915 states barrel 240–275℃ and prohibits long-term retention above 290℃; R912B states recommended 230–280℃. If the line temperature is near the upper limit, the two models differ in their statements and should be selected according to your own measured temperature.

Recommended dosage (reproduced verbatim, including tiered conditions):

Target flame retardant rating	Article thickness	Recommended dosage
UL94 V-2	1.5 mm	1%–2%
UL94 V-0	1.0–1.5 mm	2%–4%

The document further notes: a small amount of phosphorus-nitrogen synergist may be added as needed to reduce the dosage, without affecting transparency throughout the process. (Based on official product data)

Processing window (reproduced verbatim):

Extrusion/injection moulding barrel temperature: 240–275℃

Die/mould temperature

60–90℃

Long-term retention above 290℃ is prohibited to avoid mild thermal degradation and yellowing of the flame retardant

Mixing points (reproduced verbatim): Dry PET/PETG substrate at 120℃ for 4–6 h in advance; moisture ≤0.03%; high-speed mix R915 with PET/PETG pellets for 5–8 min; use a low-shear polyester-specific screw; a 20%–30% concentration PET/PETG flame retardant masterbatch may be prepared first.

(Based on official product data)

Typical applications (reproduced verbatim): transparent PET/PETG injection-moulded articles (lamp housings, transparent electronic enclosures, cosmetic packaging, instrument viewing windows); extruded transparent sheet/board (advertising light-transmitting panels, decorative transparent sheet/board, equipment protective panels); cast PET film, high-transparency flame-retardant packaging film, optical protective film; transparent flame-retardant polyester pipe, profiles, and 3D printing PETG filament. (Based on official product data)

Packaging and storage: 25 kg composite woven bag with inner PE liner; cool, dry warehouse; temperature ≤30℃; sealed and moisture-proof; shelf life 12 months; transported as ordinary chemical non-hazardous goods. (Based on official product data)

Environmental compliance statement (reproduced verbatim; this section is the original text in the documentation, not an inference drawn in this article):

Halogen-free

meets the IEC 61249 halogen-free standard, Br+Cl < 900ppm, total halogen < 1500ppm;

RoHS 2.0

does not contain lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls (PBB), or polybrominated diphenyl ethers (PBDE);

REACH

does not contain SVHC substances of very high concern;

Combustion behaviour

halogen-free low smoke; does not generate toxic dioxin-type products.

(Based on official product data)

6How to choose among comparable products

halogen-free flame retardant

Model	Applicable substrate	Transparency-related statement	Thermal decomposition/processing temperature
R915	PET, PETG	“Completely compatible with PET and PETG, does not affect transparency” (extruded sample light transmittance test)	Onset temperature of thermal decomposition ≥260℃; barrel 240–275℃
R912	PET, PETG, TPU	“Substrate light transmittance loss approx. 20%”	Thermal decomposition temperature ≥285℃
R912B	PET	— (documentation does not list a transparency statement)	Recommended 230–280℃

(Based on official product data)

Based on this table, 3 selection boundaries can be established:

Areas left open (not listed in the documentation; not compared in this article):

• R915 and R912 do not have light transmittance values under the same test conditions; therefore, it cannot be concluded “how much more transparent R915 is than R912”, and this article does not make such a comparison.
• The three products have no same-system LOI or UL94 measured comparison data for flame retardant efficiency.
• R915’s “phosphorus content 18%” and R912’s “phosphorus content ≥9.8%” are two registered values under different test scopes; the documentation does not state that the two are convertible or comparable.

halogen-free · transparent · synergistic

7Californium Curium’s main dispersant line: chemical dispersion × wetting-type dispersion

dispersion / agglomeration / gel spot

Relationship with R915: R915 belongs to the flame retardant line. If a PET/PETG formulation requires both transparent flame retardancy and colour (colour masterbatch/colour paste) at the same time, the two lines are each dosed according to their own TDS, the processing windows are intersected, and a small-scale trial is carried out first.

8Technical Documentation and Sample Acquisition

Californium Curium

• Address: Room 109-110, Building 2, No. 42, Mulun Chuangye 1st Road, Changping Town, Dongguan City, Guangdong Province, China
• Tel: +86 136 3650 0188
• E-mail: kj9896@126.com

In the documentation, the Notes state: for finished articles of different thicknesses, equipment and process conditions, and synergistic systems, the dosage may be slightly adjusted; customers are advised to conduct a small-scale trial in advance to determine the optimal formulation. The product technical data are laboratory typical values; please carry out a small-scale trial for verification before mass production.

The documentation contains 2 verbatim statements on the service approach: "Based on the customer's extrusion production equipment, provide the customer with a hyperdispersant suitable for that equipment" and "our company's technical personnel go to the customer's production site to provide the most suitable production process parameters"; when the customer's production is unstable, "our technical personnel will arrive at the customer's site as soon as possible." (Based on official product data)

If UL Yellow Cards, third-party test reports, or measured data matched to a specific resin system are required, please request them from the technical party via the contact details above — the public documentation on this site does not contain such document numbers.

9Data and Basis Notes

All parameters and descriptions in this article come from official product data; items not listed in the official materials are annotated individually in the article. This article contains no prices, customer names, certificate numbers or performance commitments; the publicly available materials on this site contain no third-party test-report numbers — for such documents, please contact the technical team.