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Lu'anFirst MBT(M)-75

First Rubber MBT-75 is a pre-dispersed thiazole accelerator masterbatch with 75% 2-mercaptobenzothiazole active content. It provides very fast cure speed and a low vulcanization temperature of approximately 125°C, making it ideal for efficient, high-productivity rubber processing. Compatible with NR, SBR, NBR, EPDM, and CR. Non-staining and non-discoloring. Can be used alone or synergistically with secondary accelerators (guanidines, thiurams, dithiocarbamates). Also acts as a retarder in sulfur-free CR compounds. Dosage: as primary 0.5-3.0 phr; as secondary 0.2-0.8 phr.

Phone: 0750-6680778

Product Description

Pain point you may have faced
MBT powder has been a industry standard for decades – but it comes with trade‑offs. The powder is dusty, hard to weigh accurately, and tends to agglomerate in humid storage. Worse, MBT is known to be “scorchy.” In compounds with high furnace black loadings, the scorch safety window can be dangerously narrow, forcing you to slow down mixing or risk bin‑cure. You need the proven performance of MBT without the handling headaches and scorch anxiety.

Why MBT‑75 is different
First® MBT‑75 (2‑Mercaptobenzothiazole) is a general‑purpose thiazole accelerator for natural and synthetic rubbers, pre‑dispersed in an EPDM carrier as dust‑free granules. It delivers the same fast vulcanization speed and low activation temperature (125 °C) as traditional MBT powder, but with none of the dust, caking, or weighing errors. The granule form also ensures more uniform dispersion, eliminating the local over‑concentration that often triggers scorch with powder forms.

What you gain

Fast cure at low temperature – ideal for thick sections or heat‑sensitive compounds.

Broad vulcanization plateau – forgiving cure window, less sensitive to over‑cure.

Improved scorch management – while MBT is inherently scorchy, the pre‑dispersion helps avoid hot spots; for extra safety, use secondary accelerators like thiurams or guanidines to boost activity without sacrificing latency.

Versatility – works as a primary accelerator for general rubber goods, or as a secondary accelerator to fine‑tune cure systems.

Clean handling – no airborne dust, no sticky residue on mixing equipment.

Real‑world result
An EPDM profile extruder relied on powdered MBT for their general‑purpose compound. Dust plagued the weighing area, and occasional scorch occurred when factory temperatures rose in summer. After switching to First® MBT‑75 granules at the same dosage (1.2 phr), the shop floor became visibly cleaner. Scorch complaints dropped by 70%, and the production manager noted that the granules flowed freely through their automated weighing system.

Typical specifications

Appearance: yellow to light yellow granules

Active ingredient: 2‑Mercaptobenzothiazole (approx. 75%)

Carrier: EPDM/SBR

Vulcanization temperature: active above 125 °C

Recommended dosage: 0.5–2.0 phr (as primary accelerator; reduce when used as secondary)

Packaging: 25 kg carton with inner PE liner

Storage: 12 months in unopened packaging, cool and dry (below 40 °C)

Samples and technical data sheets are available. No hard selling — just for your evaluation.