Foamed and Coloured TPU Pellets

Patent Title: PROCESS FOR DYEING AND FOAMING THERMOPLASTIC POLYURETHANE

 Number/Link: WO2018/091446

Applicant/Assignee:  Huntsman

Publication date: 24 May 2018

Gist”: TPU pellets are both coloured and foamed using supercritical carbon dioxide.

Why it is interesting: According to this invention, coloured and foamed thermoplastic polyurethanes can be prepared by saturating TPU pellets (in an autoclave under controlled temperature and pressure) with supercritical CO2 together with a dye.  After impregnation is complete the pressure is dropped at a temperature between the TPU’s Tg and Tm, resulting in expanded TPU pellets or ‘beads’.  The process has the advantage of allowing for the use of a wider range of dyes as compared to conventional pigment-based colours. The TPU beads are said to be especially useful for the production of shoe-soles colour-matched with textiles.

azo compound

Typical azo compound used in dispersion dyes

Fluorinated Thermoplastic Polyurethanes

Patent Title: SHOE UPPERS & CASE FOR PORTABLE DEVICES

 Number/Link: WO2018/007359  WO2018007360

Applicant/Assignee:  Solvay

Publication date:  11 January 2018

Gist”:  F-TPUs are prepared by incorporating perfluoro diols

Why it is interesting: The current inventions are about fluorinated TPU and its applications. The F-TPUs are prepared by replacing part of the polyol with hydroxyl-ended fluorinated polyethers. In the examples fluorinated polyether diols are used in different ratios to conventional polyester-, PTMEG-, CAPA- and polycarbonate diols and reacted with MDI or HDI and BDO or HDO as chain extenders. The F-TPUs can be used as uppers for footwear and as cases for smartphones and are said to have improved stain resistance and – surprisingly- a soft feel to the touch.

case

F-TPU smartphone case

 

Low Density Foamed TPU

Patent Title: FOAMED THERMOPLASTIC POLYURETHANE AND MICROWAVE MOLDED ARTICLE THEREOF

 Number/Link: US2017/0073490

Applicant/Assignee: Sunko Ink; Tayin R&D

Publication date: 16-mar-2017

Gist”: Blown TPU pellets are subjected to a second foaming process using microwaves

Why it is interesting: Thermoplastic polyurethane is extruded together with an excess of blowing agent using a single screw extruder and a pelletizer. The foamed pellets are then put in a mould together with water and subjected to microwave radiation which causes the pellets to expand and sinter into a moulded part. In the examples expandable microspheres are used as blowing agent in amounts of 5 to 25 php of TPU. The pellets are irradiated for 20 to 180 s at a power of up to 5000 W. Moulded densities as low as 170 kg/m³ are achieved.

SEM picture of moulded TPU according to the invention

 

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 polyesters are said to be highly hydrolysis resistant in both acidic and basic environments.

Cyclohexane-1,1-dimethanol

Cyclohexane-1,1-dimethanol

TPU-Silicone TPVs

Patent Title: THERMOPLASTIC POLYURETHANE COMPOSITE MATERIAL COMPOSITION, THERMOPLASTIC POLYURETHANE COMPOSITE MATERIAL AND MANUFACTURING METHOD THEREOF, SHOE MATERIAL AND WEARABLE APPARATUS

 Number/Link: US2017 /0015825

Applicant/Assignee: Evermore Chem. Ind.

Publication date: 19-jan-2017

Gist”: A blend of TPU and unsaturated silicone gum is dynamically vulcanized

Why it is interesting: A thermoplastic polyurethane is blended (in a kneader) with 1 to 5% w/w of double-unsaturated silicone rubber gum. The blend is then dynamically vulcanized by extruding (and pelletizing) it together with a peroxide curing agent like e.g. 1,3-bis-(t-butylperoxyisopropyl)benzene. The resulting thermoplastic is said to have improved slip resistance without reducing the TPU properties like abrasion resitance and is therefore said to be especially useful for the production of shoe-soles. It is ‘contemplated’ that the resulting material is a semi-IPN, but (i.m.o.) it is more likely that a seperate crosslinked silicone  phase -and therefore a thermoplastic vulcanizate (TPV)- is formed.

perox

1,3-bis-(t-butylperoxyisopropyl)benzene