All posts tagged automotive

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

High Resiliency Polyurethane Foams

Title: HIGH RESILIENCY POLYURETHANE FOAMS MADE WITH HIGH FUNCTIONALITY, HIGH EQUIVALENT WEIGHT POLYOLS WITH MAINLY SECONDARY HYDROXYL GROUPS

Number/Link: WO2017/062150

Applicant/Assignee: Dow

Publication Date: 13 April 2017

“Gist”: Use of high functionality polyols increases the resilience of flex foams

Why it is interesting: According to this invention the resilience of flexible PU foams can be increased by using, as part of the polyol composition, a random EO/PO polyether polyol which has an equivalent weight of at least 1500, a functionality of at least 5, a secondary hydroxyl group content of at least 70%, an unsaturation value of at most 0.01 meq/g and an EO content between 5 and 30%. In the examples, sorbitol initiated polyols are used in both MDI and TDI-based systems, resulting in ball rebound values of up to 60% at densities of about 30 kg/m³. As I have shown in the past (US5521226) the same (or arguably an even stronger) effect on resilience can be obtained with other high functionality polyols, indicating that the unsaturation value, primary OH content, EO content and equivalent weight are probably not relevant to the resilience increase.

Sorbitol

Reactive Polyurethane Plasticizer

Patent Title: REACTIVE POLYURETHANE PLASTICIZERS AND ADHESIVES MADE THEREFROM

Number/Link: W02016179131

Applicant/Assignee: Dow

Publication date: 10-11-2016

“Gist”: An EO/PO monol is reacted with an excess of 4,4′-MDI

Why it is interesting: The invention is about reactive PU plasticizers which are said to be especially useful for polyurethane moisture curing adhesives used in automotive glass bonding. As opposed to conventional plasticizers they will supposedly not migrate and therefore not degrade adhesive properties over time or cause window fogging. The reactive plasticizers are prepared by reacting a slight excess of 4,4′-MDI with and EO/PO monol of MW between 500 and 2000 Da and an EO:PO ratio of about 1:1, such that the resulting in NCO content is between 0.1 and 1%. Obviously at such low NCO values most of the MDI will have reacted twice with monol, and the resulting non-reactive plasticizer may (in my opinion) well migrate depending on the composition of both monol and adhesive.

4,4′-MDI

Innovation in Polyurethanes

All posts tagged automotive

Matte, Self-Healing Polyurethane Powder Coatings

High Resiliency Polyurethane Foams

Reactive Polyurethane Plasticizer

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