Halogen-free flame retardant for polycarbonate & its alloys

  • > A much cheaper substitute for KSS
  • > Combination with phosphate ester, siloxane, PTFE, and KSS to further boost flame-retarding performance for PC
  • > Achieving UL94-V0 @ 1.6mm or below in PC alloy for lower cost and with higher HDT by combination with phosphate ester
  • > Not included in the REACH-SVHC list
  • > Not hygroscopic at all and hence easy to handle and store
  • > Contributing to transparency

LIMAX CHEMICAL engages in developing and producing cost-efficient flame retardants for use in polycarbonate (PC) and its alloys.

PC and PC alloy are both versatile engineering plastics. Normally, in order to achieve UL94 V-0, flame retardants need to be added directly or through a master-batch into the resin before compounding or processing into a final product.

As a player in processing or compounding of PC and/or PC alloys, are YOU currently facing any challenge regarding use of flame retardants? We, LIMAX CHEMICAL, provide a novel flame retardant, LC-160, for PC and PC alloys.

What merits does LC-160 have?

  • LC-160 is a halogen-free flame retardant. It conforms to RoHS and is not listed in REACH – SVHC.
  • Generally, when used alone without any adjuncts, the FR efficiency of LC-160 can match and even exceed that of a sulfonate-type flame-retardant such as KSS, HES and KPFBS (e.g. FR-2025 from 3M and RM65 from MITENI) at a lower dosage, but for a much lower price than KSS.
  • LC-160 shows strong synergy with a siloxane, PTFE, phosphate ester FR and sulfonate FR in formulation of pure PC.
  • LC-160 is widely used in a unique combination with a phosphate ester flame retardant like RDP or BDP in transparent PC, PC thin film or PC alloys such as PC/ABS , PC/PBT , PC/PET and PC/PS to significantly reduce the amount of the original phosphate ester FR, thus boosting cost-efficiency and raising heat deflection temperatures (HDT).
  • Use of LC-160 contributes to high transparency of PC & PC alloy.
  • LC-160 disperses well in PC melt during processing. Unlike KSS, HES or KPFBS, LC-160’s extremely low level of moisture-absorption further facilitates its use and storage.

Dosage of LC-160: generally suggested at 0.10 ~ 0.20% in PC or PC alloy. (A further increase is likely depending on trial outcome. However, just like KSS, HES and KPFBS, a relatively high dosage of LC-160 might cause some degree of degradation during processing.)

Adding by a Master-batch: the concentration of LC-160 in a PC master-batch is recommended to be around 2.00 ~ 4.00%.

Formulation Guides for LC-160

  1. Transparent Pure PC (UL94 V0 1.6mm 10MFI) Example One: PC resin (10MFI) — 96.90%; LC-160 — 0.10%; **BDP  — 3.00%
  2. Transparent Pure PC (UL94 V0 1.6mm 10MFI) Example Two: PC resin (10MFI) — 97.90%; LC-160 — 0.10%; ***Siloxane — 2.00%
  3. Transparent Pure PC (UL94 V0 3.2mm 10MFI): PC resin (10MFI) — 99.90%; LC-160 — 0.10%
  4. Modified PC (UL94 V0 1.6mm 20MFI): PC resin (20MFI) — 91.50%; ABS — 5.00%; **BDP —  3.00%; LC-160 — 0.20%;  PTFE — 0.30%
  5. PC/ABS (75/25 UL94 V0 1.6mm): PC/ABS(75/25) — 93.80%; **RDP — 6.00%; LC-160 — 0.20%
  6. PC/ABS (60/40 UL94 V0 1.6mm): PC/ABS(60/40) — 89.80%; **RDP — 10.00%; LC-160 — 0.20%
  7. PC/PET (67/33 UL94 V0 1.6mm): PC/PET(67/33) — 93.80%; **RDP — 6.00%; LC-160 — 0.20%
  8. Thin Film PC (UL94 V0 0.8mm 20MFI): PC resin (20MFI) — 93.60%; **RDP — 6.00%; LC-160 — 0.10~0.20%; PTFE — 0.30%
  9. Black Pure PC (UL94 V0 1.6mm 10MFI): PC resin (10MFI) — 99.30%; LC-160 — 0.20%; PTFE — 0.40%; carbon black dispersion — 0.10%
  10. GF-Enforced PC (UL94 V0 1.6 mm 20MFI): PC resin (20MFI) — 88.00%; glass fiber — 10.00%; LC-160 — 0.20%; PTFE — 0.30%; ***Siloxane — 1.50%

*The dosages of the components in the above formulae should be regarded as formulation guides  and may need to be adjusted. **BDP and RDP are both common phosphate ester flame retardants. ***Siloxanes include Dowsil-40-001, FCA-107, X-40-9805 and so on.

Generally, use of LC-160 alone can result in UL94 V0 @3.2mm for pure PC, either opaque or clear, and when combined with PTFE, phosphate and/or siloxane, help achieve UL94 V0 @1.6mm or below for pure PC and PC alloys. LC-160 can also be treated as a much cheaper direct replacement for KSS, HES and, especially, KPFBS (e.g. FR-2025 from 3M and RM65 from MITENI). Moreover, combinations of LC-160 and phosphorous-containing FRs, including phosphate esters, are particularly synergistic and cost-efficient.

Problems LC-160 is targeted at

  • Flame-retarding performance ends up being not so sufficient or so consistent as to ensure UL94 V0 at 1.6 mm or below for PC when customers are using their halogen-free flame retardants in hand: Addition of LC-160 on top of the halogen-free flame retardants already in use helps enhance flame-retarding performance and meet the specific target. Moreover, the amounts of those expensive halogen-free FRs such as siloxane and phosphate could be significantly reduced by combined use of LC-160.
  • Flame-retarding performance is insufficient, or cost is relatively high, or HDT is too low when customers are using phosphate ester FRs, including TPP, BDP, RDP and so on, for halogen-free PC alloys such as PC/ABS: Combination of LC-160 with a phosphate FR can either enhance FR performance to achieve UL94 V0 or cut cost while increasing HDT by reducing the phosphate amount.
  • Even though efficient and popular, KSS and the like are very expensive halogen-free flame retardants for PC: Cost of producing flame-retardant PC compounds can be reduced by replacing KSS and the like with LC-160, which is much cheaper.

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