Epoxy Catalysts

September 14, 2009

Epoxy Acrylate Resins and Vinyl Hydroxy Esters

Filed under: Hycat Catalysts — Tags: , , , , , , — Dimension Technology Chemical Systems @ 9:13 pm

Improved Reaction Conditions for Epoxy Resin Acrylate Ester Formation.

A better way to Vinyl Hydroxy Esters using Hycat™ Catalysts.

Literature is replete with references on how to prepare epoxy acrylates and epoxy methacrylates.

Reaction of a saturated carboxylic acid

 The reaction of a saturated carboxylic acid with an epoxide is also well known and many different catalysts to accelerate this reaction is also shown in literature and practiced in the industry. But the current catalysts used for the saturated carboxylic acid reaction don’t always work that well when making the acrylate/vinyl ester. For example, when using a trialkyl amine base or an imidazole, usually at an elevated temperature, it is difficult to prevent some polymerization of the acrylate to form the poly-acrylates or homo-polymerization to form the ether. Furthermore, typically with amine catalysts, the conversions generally stop or it significantly slows down after 75-85% conversion due to the formation of an adduct of the hydroxyl group hydrogen and the nitrogen amine. Also, elevated reaction temperature (e.g., 75 to 100 OC) conditions are necessary to achieve these conversions.

Because of the highly active nature of the Hycat™ catalysts and especially Hycat™ 2000S and Hycat™ OA, these synthesis issues are eliminated or significantly reduced. Using the Hycat™ catalysts conversion of over 90% of the predominantly β-hydroxy ester is realized with little or no homopolymerization. As with the amine or imidazole type catalysts, a radical scavenger, like hydroquinone, is still needed to prevent the polymerization of the acrylate group but because the reaction can be conducted at a lower temperature, e.g., 25 to 60 OC, this side-reaction is significantly minimized

August 31, 2009

Epoxy Silanes

Filed under: Uncategorized — Tags: , , , , , , , — Dimension Technology Chemical Systems @ 10:22 pm

In a recent Switzerland patent to Sika Technology (Frick, Karsten et. al.; PCT Int. Application WO 2009 65,914; 28 May 2009) a carboxy terminated polybutadiene-acrylonitrile copolymer (CTBN), modified with epoxy functionality and terminated with carboxy end groups was described. It was shown that these polymers were extremely effective as agents for improving the impact strength of epoxy resin compositions. These formulations are especially efficient adhesives for gluing on metal surfaces. It was shown in our labs that the reaction silyl epoxides or silicone diepoxides, such as PC-1000 [bis-2-(3,4-epoxycyclohexylethyl)-1,3-tetramethyldisiloxane] with CTBN could be greatly accelerated using Hycat™ 2000 or Hycat™ OA. Complete reaction was achieved either at elevated (ca. 80 OC) or at ambient temperature giving cured polymers with excellent adhesive attributes. The photo shows typical polymer properties (just taken from the curing oven), at elevated temperature, after ten minutes. These polymers may have beneficial use in armor protection (bullet proof vests).

Elastomeric Properties Just Out of Oven

August 24, 2009

Epoxy Resin Applications

Filed under: Hycat Catalysts — Tags: , , , , , , , , — Dimension Technology Chemical Systems @ 6:10 pm

The global market for epoxy resins is approximately 2.1 billion pounds.  Primary market focus and strength is in the production of technologically advanced products where epoxy resins can be used in epoxy polymer formulas for specialized coatings for vehicles, construction and industrial equipment, or in semiconductor laminates and resins used in advanced composites and reinforced plastics.  Target epoxy formulation has use in electronic components, motor vehicles, industrial products, appliances and aerospace equipment. Of particular interest is the epoxy-anhydride or the epoxy-carboxylic acid formulations where beta hydroxy polyesters are required.  Hycat™ catalysts, especially those based on the environmentally friendly and essentially non-toxic Chromium(III) carboxylates, can be used as an accelerator in other applications including epoxy filament winding, epoxy composites and toughened epoxy systems. For more information about Epoxy Resins or Hycat™ catalysts, visit www.Hycat.com

August 17, 2009

Epoxy catalyst

Filed under: Uncategorized — Tags: , , , , , , , , — Dimension Technology Chemical Systems @ 8:18 pm

Dimension Technology Chemical Systems

To read technical data or to request a free lab sample visit www.Hycat.com

CHROMIUM (III) HYCAT™ CATALYSTS
The active ingredient in Hycat™ 2000S, Hycat™ 3000S, and Hycat™ OA is based on an activated
(DTCS Proprietary Process) oxo-centered-trinuclear [chromium III] complex. Chromium III
compounds are generally considered to be non-toxic by the EPA. Depending on catalyst concentration
and formulation, cured products range in color from light to dark green. Typical catalyst loadings range
from 1 to 5 % however higher or lower concentrations can be used depending on the formulation and
desired end result. Cures and gels are typically realized at low to moderate temperatures (15-50O C.)
Fast cures, from seconds to a couple of minutes are realized with temperatures higher than 50O C.
It is important to note that non-toxic Chromium (III) derivatives should not to be confused with the
hazardous chromium (VI) valency compounds. Large quantities of chromium (III) compounds are
used by the general public and various industries. For example, chromium (III) picolinate, a vitamin
supplement, is sold in drug stores and health food stores. Chromium (III) compounds are also used
by the petroleum industry in a number of applications and are considered to be environmentally friendly.
A recently published EPA report [Toxicological Review of Trivalent Chromium] addresses this issue.
This report can be acquired from: http://www.epa.gov/iris/toxreviews/0028-tr.pdf. Clearly, chromium (III)
compounds, found in the Hycat™ 2000S, Hycat™ 3000S and Hycat™ OA should not be confused with
the hazardous chromium (VI) compounds.

Hycat™ OA, Hycat™ 2000S and Hycat™ 3000S are commonly used to accelerate the reaction of
epoxy compounds with carboxylic acids, anhydrides and imides. These catalysts are especially effective
in polymer cure systems at room temperature or slightly elevated temperatures. Studies show that
when epoxide systems are catalyzed with these Hycat™ Catalysts, very little homopolymerization
occurs. By using compounds with monomeric, dimeric or trimeric functional groups, the degree of
cross-linking and therefore the mechanical properties of the resulting product can be advantageously
modified.

Both the Hycat™ 2000S and Hycat™ 3000S are designed to have non-corrosive properties in their
final composition. This attribute makes Hycat™ Catalysts useful in coatings, electronic circuit boards
and other systems that require low-corrosion properties.
Hycat™ 3000S acts similarly to Hycat™ 2000S except that it has additional cure-system modifiers that
enhance its performance in a variety of epoxy-anhydride formulas. Hycat™ 3000S improves the
solubility characteristics in difficult epoxy-anhydride formulas resulting in uniform cures.
Hycat™ OA shows similar performance (e.g., gel time vs. temperature) as Hycat™ 2000S and Hycat™
3000S but was developed to meet certain European regulatory requirements; especially products that
may come in contact with humans, e.g., toys, packaging, laminates, etc.

Hycat™ OA, Hycat™ 2000S and Hycat™ 3000S are all pre-registered and REACH compliant.

To read technical data or to request a free lab sample visit www.Hycat.com

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