Adhesives Magazine

VANDEMARK

February 1, 2004


For more than 60 years, VanDeMark has produced specialty chemicals to meet the needs of business and industry. Located in Lockport, N.Y., VanDeMark is a subsidiary of ISOCHEM/Groupe SNPE, and is certified in accordance with ISO 9000 quality standards.

VanDeMark strives to provide customers with quality products that meet or exceed expectations. Significant investments are made in product research and development, advanced production technology, safe and efficient transportation methods, and to adhere to the highest standards of worker safety and environmental protection.

VanDeMark is a member of the Synthetic Organic Chemical Manufacturers Association (SOCMA), serves on the Phosgene Panel of the Chemical Manufacturers Association (CMA), and participates in Responsible CareĀ® to promote safety, health and concern for the environment.

VanDeMark introduced PTSI in 1993 to protect the quality of urethane products. PTSI (p-toluenesulfonyl isocyanate) is a low-viscosity reactive additive used as a water scavenger in the formulation of specialty urethane products, including adhesives, sealants and coatings. It presents the formulator of specialty urethane products with an expedient and efficient alternative to physical methods of dehydration. PTSI also provides storage stabilization of purified diisocyanates against deterioration and discoloration.

Water is introduced during the formulation process in the form of dissolved water solvents, adsorbed water in fillers and pigments, and ambient moisture. Subsequent reaction with alkyl and aryl isocyanates leads to the formation of undesirable byproducts such as bubbles and urea linkages that can adversely affect product quality. These problems are aggravated by the low equivalent weight of water and the irreversible nature of its reactions with isocyanates.

The use of PTSI in the formulation process prevents moisture-related problems. PTSI reacts rapidly with excess water to form the corresponding carbamic acid, which in turn undergoes immediate decomposition to form carbon dioxide and non-reacting p-toluenesulfonamide.

PTSI is used for:

  • Moisture-Curing Prepolymers - removing moisture both in the formulation and packaging of moisture-curing coatings and sealants.
  • Catalyzed Prepolymers - in systems where catalyst activity and curing are not affected by tolu-enesulfonamide, PTSI dehydrates solvents and solvent/filler/pigment mixtures prior to the addition of polyol and polyisocyanate components.
  • Prepolymer and Polyol Systems - PTSI is added to solvents and solvent/
  • filler/pigment mixtures prior to treatment with polyol and polyisocyanate components.
  • Urethane Alkyd Production - PTSI is used in the dehydration of solvents and solvent/pigment mixtures prior to their incorporation with either the isocyanate or hydroxyl portions of the alkyd formulation.
  • Urethane Lacquer Production - PTSI may be used to ensure anhydrous conditions during the formulation of the urethane resins.



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