All posts in category Adhesives-Coatings

Matte, Self-Healing Polyurethane Powder Coatings

Title: POLYURETHANE COATING COMPOSITION

Number/Link: WO2017/074835

Applicant/Assignee: Valspar

Publication Date: 4 May 2017

“Gist”: Coating composition comprising isocyanate and two polyester polyols having a similar Tg but a widely different equivalent weight.

Why it is interesting: Conventionally low gloss or “matte” coatings are the result of a microtextured surface achieved by certain fillers or by incompatible polymers and the like. According to this invention “ultra matte” finishes can also -surprisingly- be achieved from a (powder) coating composition comprising a (blocked) isocyanate and a mixture of two polyester polyols. Both polyols have a Tg between 40 and 60ºC prefereably differing not more than 5 to 8ºC, while the OHv of the first polyol is between 150 and 325 and that of the second between 15 and 35. The ratio between first and second polyol is from about 1:1 to 1:3 w/w. Also surprisingly, the resulting coatings are said to show self-healing properties. An interesting composition but no examples of the polyesters or isocyanates used are given.

Car with matte finish

Moisture Scavenger for Polyurethane Coatings

Title: PROCESSES FOR MOISTURE SCAVENGING IN PREPARING POLYURETHANE COATINGS AND COMPOSITIONS THEREFOR

Number/Link: US2017/0114247

Applicant/Assignee: Achiewell

Publication Date: 27-april-2017

“Gist”: Methoxysilicon compound with e-withdrawing group together with hydrophobic t-amine catalyst acts as moisture scavenger

Why it is interesting: Moisture in PU coating compositions can be a problem because it negatively affects both the properties of the composition (pot life and viscosity..) and of the final coating. Moisture scavengers like molecular sieves are well known but often have a negative impact as well. According to this invention, methoxyorganosilicon compounds with at least one electron withdrawing group attached to the silicon atom act as efficient moisture scavengers when used in combination with a hydrophobic tert-methylamine catalyst. Preferred organosilicon compounds have 3 methoxy substituents and one hydrocarbon-based e-withdrawing group, like e.g. fluoroethyltrimethoxysilane. A preferred catalyst is 1,3-bis[3-dimethylaminopropyl]urea (claimed). No examples are given.

1,3-bis[3-dimethylaminopropyl]urea

Non-Isocyanate Poly(Amide-Hydroxyurethanes)

Patent Title: NON-ISOCYANATE POLYURETHANES AND METHODS OF MAKING AND USING THE SAME

Number/Link: WO 2017/ 030880

Applicant/Assignee: ELEVANCE RENEWABLE SCIENCES

Publication date: 23-feb-2017

“Gist”: Telechelic cyclocarbonate-alkylesters are reacted with diamines in the melt

Why it is interesting: According to this invention (ω-) unsaturated alkylesters can be converted to mono-cyclocarbonate alkylesters and then reacted with diamines to prepare thermoplastic poly(amide-hydroxyurethanes) (PAHU). For example methyl-9-decenoate was first epoxidized and then reacted with CO2 to produce 9,10-cyclic carbonate-methyl decanoate. After separation and washing the cyclocarbonate was reacted – in the melt- with a mixture of dodecane diamine and a PTMO diamine (Jeffamine THF-100). It is said that the unsaturated alkylesters can be prepared from natural oils using (cross- or self-) metathesis followed (or preceded) by transesterifaction with alkanols.

PAHU preparation scheme

Innovation in Polyurethanes

All posts in category Adhesives-Coatings

Matte, Self-Healing Polyurethane Powder Coatings

Moisture Scavenger for Polyurethane Coatings

Non-Isocyanate Poly(Amide-Hydroxyurethanes)

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