In Japan METI began regulating hydrofluorocarbons (HFCs) in 2012. The Japanese Industrial Standards Committee (JISC) will publish its guidance on hydrofluoroolefins (HFOs) adoption in 2016.
HCFC Blowing Agents are under pressure to be phased out in other Asian countries
Most Asian countries are under “Article 5” in the Montreal Protocol, which requires gradual phase-out HCFCs from 2013 and leading to a complete phase-out of HCFC consumption and production by 2030.
In the EU-China forum, climate dialogue on the UNFCCC and other relevant forums such as the G20, MEF, Montreal Protocol, ICAO and IMO, the EU and China are cooperating on domestic policies and measures on HFCs and working with other countries to agree on a multilateral solution to phase down the production and consumption of HFCs.
Next Generation HFO Blowing Agents
In response to these HFCs phase-out and HCFCs phase-out proposals as well as the desire for better energy efficiency of the PU insulation material, new blowing agents have been promoted in the polyurethane industry, like HFO-1233zd(E) and HFO-1336mzz, which are designed for low global warming potential (GWPs) and energy efficiency such as low k-factor value.
These new HFOs only have atmospheric lifetime of weeks rather than years or decades. This class of chemicals, with chemical structures that breaks down quickly, is a “fourth-generation” family of compounds, developed to replace a long line of similar substances that had high ODP or GWP. However, these new HFO blowing agents are not very stable with conventional additives in the PU formulation and new ingredients are required for HFO blown system.
Air Products has been a leader in enabling new blowing agent technologies and continues to do so with this new generation
Introducing Polycat® 201 Catalyst
Polycat 201 catalyst was developed for low GWP blowing agents such as HFCO-1233zd. It is an amine based catalyst. In HFCO-1233zd blown system, it can provide excellent system stability, keeping the full blended B-side stable for more than 6 months. It can provide faster initial reaction, which is especially useful in spray application. As a reactive amine catalyst, it can reduce amine emission and help to reduce potential health concerns associated with “Blue Haze.”
In a medium density spray system, the stability of Polycat 201 catalyst was compared with another catalyst: Polycat® 12 catalyst is considered as the benchmark in 1233zd system, as its stability in 1233zd is good and acceptable. Dabco® EG catalyst is widely used in spray foam application as a standard catalyst. The full blended B-side is aged under 50oC for one week and two weeks. Polycat 201 catalyst showed the most stability (see chart below).
Polycat 201 catalyst is a medium-high active catalyst that can provide both fast initial reaction and gelling reaction. Cream time and gel time can be reduced by increasing the dosage of Polycat 201 catalyst (see chart below), which provides flexibility for formulation adjustment.
Polycat 201 catalyst was recommended for polyurethane systems with HFCO-1233zd as blowing agent, e.g. application of spray, panel etc. It showed fast initial reaction and excellent stability in the system. For spray foam an ideal complete catalyst solution would be Polycat 201 catalyst + Dabco® TMR-7 catalyst, or Polycat 201 catalyst. Both solutions provide good stability and foam properties.
Introducing additives package solution for LBA blown systems in appliance application
- Polycat® 215 blow catalyst, which is stable in LBA and can provide good flow-ability and lower density of the foam.
- Dabco® TMR-7 post cure catalyst, which is stable in LBA and can provide excellent de-molding property and flow-ability.
- Dabco® SI3102 silicone surfactant, which is stable in LBA. In LBA blown system, Dabco SI3102 can provide good surface quality and better thermal insulation.
An aging test was carried out based on appliance formulations. All the data was from High Pressure machine trial. The aging process of the polyol blend was carried out in the tank of the HP machine.
Additionally, all LBA blown system applications were stabilized for months at ambient temperature without the reactivity changing, or the de-molding property and thermal conductivity changing over time.