PCM Containing PU Gels

Title: Temperature Regulating Polyurethane Gels

Number/Link: US2017/0210961

Applicant/Assignee: Technogel

Publication Date: 27 july 2017

“Gist”: Fatty acid ester PCMs are incorporated into Technogel-type gels without encapsulation

Why it is interesting: Polyurethane gels have been discussed before in this blog. The current invention is about “Technogel-type”  gels, made at low NCO-index and high functionality, that contain phase change materials (PCMs). The PCMs are esters of fatty acids that can be blended in molten state with the low EO polyol to form a clear solution, which is then reacted with isocyanate to form the gel. Despite not being encapsulated or forming a separate phase, the PCMs can reversibly melt and crsytallize while in the fluid phase of the gel. In the examples blends of lauryl laurate (C12-C12) and myristyl myristate (C14-C14) are used as PCM such that the phase change temperature is about 22-38°C.  The gels are said to be useful for ‘close to body’ comfort applications especially for use in matresses to improve sleeping comfort.

Lauryl laurate

 

Tack-Free Polythiourethane Gels

Patent Title: SOFT ISOCYANATE-CROSSLINKED POLYMER SUBSTANCE AND ASSOCIATED PRODUCTS

 Number/Link: WO2017/054797 (German)

Applicant/Assignee: Technogel

Publication date: 6-april-2017

Gist”: Tack-free polyurethane gels are made from polythiols

Why it is interesting: Very soft polyurethane elastomers or “gels” can be made using high functionality isocyanate and monols (as co-invented by myself – e.g. EP1389222 ) or by reacting a high functionality polyol/siocyanate system at low isocyanate-index (as invented by Bayer – later spun off as Technogel).  PU gels are useful as shock dampers, gaskets and cushions but are always tacky and need to be covered or wrapped, which changes their damping and hardness characteristics. According to this invention tack-free gels without the need for covering can be produced by using polythiols instead of polyols, resulting in poly(thiolurethanes) instead of polyurethanes. This is interesting and surprising and I wonder if it would work with the monol-gels as well.

thiolurethane

Thiolurethane linkage

SiC-PU Nanocomposites

Patent Title: POLYURETHANE/UREA SILICON CARBIDE NANOCOMPOSITE

 Number/Link: WO2017/027231

Applicant/Assignee: 3M

Publication date: 16-feb-2017

Gist”: Surface modified SiC particles are dispersed in and covalently bound to a polyurethane matrix

Why it is interesting: Silicon carbide (carborundum) particles with an average particle size of about 500 nm are NCO-functionalized by reacting with a surface modfifying agent, e.g 2-triethoxysilylpropylisocyanate. The modified particles are then dispersed and covalently reacted into a polyurethane/polyurea matrix in an amount of 50-55% (w/w) on the composition. The composites can be made into highly erosion resistant films, for use on the outer surface of aircraft.

3-triethoxysilylpropylisocyanate

3-triethoxysilylpropylisocyanate

Hydrolysis Resistant Polyester Urethane

Patent Title: HIGHLY DURABLE POLYESTER POLYOL

 Number/Link: US2017/0022143

Applicant/Assignee: Kuraray

Publication date: 26-jan-2017

Gist”: PU from polyester polyol with bulky side groups

Why it is interesting: The invention is about polyester polyols prepared from a dibasic acid (e.g adipic acid) and a mixture of two diols: 3-methyl-1,5-pentanediol and cyclohexane-1,1-dimethanol. The diols are used in a molar ratio of about 1:1 (25-75 to 75-25 pref.). Polyurethanes prepared with these polysters are said to be highly hydrolysis resistant in both acidic and basic environments.

Cyclohexane-1,1-dimethanol

Cyclohexane-1,1-dimethanol

Liquid Crystalline Polyurethane Elastomers

Patent Title: LIQUID CRYSTALLINE POLYURETHANE ELASTOMER AND METHOD FOR PRODUCING SAME

 Number/Link: US 2016/0376396

Applicant/Assignee: Toyo Tire & Rubber

Publication date: 29-dec-2016

Gist”: Specific mesogenic diols are used together with high MW polyols and high functionality isocyanate

Why it is interesting: The invention is about thermotropic liquid crystalline PU elastomers, where the liquid crystalline (LC) phase is formed at relatively low temperatures (e.g. near room temperature). This is accomplished by preventing the mesogen to crystallize, such that it shows no melting point between its Tg and Ti (LC phase -to- isotropic phase transition temperature). This, in turn, is accomplished by using a high molecular weight polyol together with a high functionality isocyanate and a mesogenic diol of the structure shown below where Y represents -N=N-, -CO-, -CO-O- or -CH=N- and X represents a C3 to C20 alkylene.  Under stress the elastomer extends in the orientation direction by increasing the LC content and shrinks by reducing LC content.  It can therefore be used as a temperature-controlled actuator.

General structure of the mesogenic diol of the invention

General structure of the mesogenic diol of the invention