Propylene Glycol Monomethyl Ether, Methyl Propylene Glycol, Methylpropylenglykol, Methoxy Propanol, PGME, PM, 107-98-2

Propylene Glycol Monomethyl Ether, Methyl Propylene Glycol, Methylpropylenglykol, Methoxy Propanol, PGME, PM, 107-98-2

1-Methoxy-2-Propanol (Propylene Glycol Monomethyl Ether - PGME)
CAS No: 107-98-2 | EC No: 203-539-1 | Molecular Formula: C₄H₁₀O₂

1. Physical & Chemical Properties

2. Comparison with Alternative Solvents

1-Methoxy-2-Propanol stands out due to its low toxicity compared to other glycol ethers.

Conclusion: PGME is a safe alternative to hazardous solvents like EGME. It dries faster than DPM but has a lower solvency than PM Acetate for non-polar resins.

3. Formulation Examples (Industry-Specific)

Note: These are generic formulation principles. No brand names are used.

A. Industrial Degreaser (Oil & Grease Remover)

Leverages PGME's ability to dissolve both polar (salts) and non-polar (oils) soils.

• PGME (Solvent): 40-50%

• Alcohol (Ethanol or IPA): 20-30%

• Water: 20-30%

• Non-ionic Surfactant: 1-5%

B. Water-Based Paint & Coating (Coalescent Agent)

For film formation and flow control in acrylic/epoxy emulsions:

• Acrylic/Epoxy Emulsion: As per formulation

• PGME (Coalescent Aid): 2-8% on resin solids (depending on MFFT)

• Water: Balance

• Defoamer & Other Additives: As needed

C. Flexo/Gravure Printing Ink

To reduce surface tension and enable rapid resolubility:

• Pigment: 15%

• Binder (Resin - e.g., NC or Polyamide): 20%

• PGME (Co-solvent): 10-15% (for viscosity adjustment)

• Primary Solvent (EtOH or EtAc): Balance

D. Photolithography (Electronics)

• Active Component (Photo-resist): 20-30%

• PGME (Carrier Solvent): 70-80%

• Note: Ultra-high purity (UP grade) and particle filtration required.

4. Advantages & Disadvantages

Advantages:

• Low Toxicity: Much safer than ethylene glycol ethers (no CM R classification - Carcinogenic, Mutagenic, Reprotoxic). Hazard statement: H226 (Flammable liquid and vapor).

• Coupling Agent: Bridges high-boiling and low-boiling solvents effectively.

• Surface Tension Reduction: Excellent wetting properties on difficult substrates (plastics, metals).

Disadvantages:

• Flammability: Flash point 32°C; keep away from ignition sources during storage and use.

• Limited Non-Polar Solvency: Does not fully dissolve heavy paraffinic oils or pure hydrocarbons; may need co-solvent (xylene, toluene).

5. Frequently Asked Questions (FAQ)

Q1: Is 1-Methoxy-2-Propanol the same as Propylene Glycol?
A: No. Propylene Glycol (CAS 57-55-6) is a diol (two OH groups) and is a humectant/moisturizer. PGME is a glycol ether (one OH group converted to an ether). PGME is a much stronger solvent used in paints and inks, while Propylene Glycol is used as a humectant in food and cosmetics.

Q2: Can I use this product as a coalescent agent in water-based paints?
A: Yes. In water-based paints, PGME acts as a coalescent aid. It softens latex particles, allowing them to fuse into a continuous film. It lowers the Minimum Film Formation Temperature (MFFT), preventing cracking in cold weather.

Q3: Is 1-Methoxy-2-Propanol legally restricted in any applications?
A: For most industrial applications (paint, cleaning, electronics), there are no restrictions and it is widely used. However, caution is needed in Food and Cosmetics:

• Cosmetics: Some countries (e.g., Japan) limit concentration levels.

• Food: Not permitted as a direct food additive (FDA/EFSA restricts glycol ethers in food). Allowed only in food-contact cleaning products with proper rinsing.

Q4: What storage container material is recommended?
A: PGME can swell or dissolve certain plastics (e.g., Polystyrene, PVC, natural rubber). Recommended containers:

• HDPE (High-Density Polyethylene)

• Stainless Steel (SS304/316)

• Gaskets/Seals: Use PTFE (Teflon) or Viton, NOT natural rubber or Buna-N.

Q5: What is the difference between PGME and PM Acetate (PGMEA)? Which one should I choose?
A:

• PGME (this product): Alcohol ether. Faster water miscibility, lower odor, better wetting.

• PM Acetate (PGMEA): Ester of PGME. Higher boiling point (>145°C), much stronger solvent, preferred for photoresists and PCB cleaning.

• Selection Guide:

  • Choose PGME if: Your system contains water, or you are coating sensitive plastics (ABS, PC) that could crack with stronger solvents.

  • Choose PM Acetate if: You need very high solvency for tough resins (epoxies, polyimides), or you require a slower evaporation rate in a 100% solvent system.

Q6: How safe is PGME compared to Ethylene Glycol Monomethyl Ether (EGME / 2-ME)?
A: PGME is dramatically safer. EGME (Methyl Cellosolve) is a severe reproductive and developmental toxin (causes testicular atrophy, bone marrow suppression). PGME has NO CMR (Carcinogenic, Mutagenic, Reprotoxic) classification. PGME is the industry-standard safe substitute for EGME in all applications.

Q7: Can PGME be used in cosmetic or personal care products?
A: Yes, but with limitations. PGME is sometimes used as a solvent or carrier in small amounts in creams, lotions, and hair products due to its mild odor and low toxicity. However, always check local regulations (EU Cosmetics Regulation, Japan CSCI). For high-concentration use, consider Propylene Glycol or Propanediol as safer alternatives.

Q8: What is the UN number for transport?
A: UN 3092 (Flammable liquid, n.o.s. - not otherwise specified). Proper shipping name: "Flammable liquid, n.o.s. (1-Methoxy-2-propanol)". Packing group: III (lowest hazard among flammable liquids).