ORMOCER®s for leather finishing

Leather is produced by tanning animal skins. Besides its attractive outer appearance leather distinguishes itself by numerous valuable properties: a high water vapor permeability and good haptic properties which make it comfortable to wear. Therefore, leather products like clothes, bags or furniture are highly appreciated.

The demands towards its functional properties like scratch resistance and light fastness, hydrophobic and dirt repellent characteristics are, however, steadily increasing. In spite of this, the natural character of leather has to be preserved. But even high quality leather does not meet these requirements in all respects.

Properties

ORMOCER®s are inorganic-organic hybrid polymers synthesized by sol-gel processing. By finishing leather with relatively thin ORMOCER® coating systems (<4 µm), excellent functional properties (Table) are achieved, as for instance:

  • preservation of the natural optical and haptic properties
  • pronounced hydrophobicity combined with high water vapor permeability and water vapor absorption
  • low emissions
  • excellent scratch resistance, fastness to rubbing and improved abrasion resistance
  • sufficient heat resistance and light fastness

Moreover, ORMOCER® finishings show an extraordinarily good and durable adhesion to leather.

 

Parameter State of the art
ORMOCER®-coating Requirements
Adhesive stregth (IUF 470) [N/cm] >4,0 9,0

 >1,5 (furniture)

> 4,0 (automobiles)

Rub fastness of top side (DIN EN ISO 11640)
dry felt (500 cycles) 4 5 >4,0
wet felt(80 cycles)
4 5 >4,0
felt pH 8,0 4 5 >4
Abrasion resistance
(according to DIN 53109)
number of abrasion cycles with abrasion wheel CS 10 and load of 10 N  
visible abrasion after 10-20 abrasion cycles (furniture) slight visible abrasion after 60 cycles no visible abrasion after 500 cycles (only for automobiles)
fastness to water spotting (IUF 420)
absorption time [Min] 10-15 36 >10
change of color 4-5 5 5
Grey scale grade 5-1 *  
Water vapor pemeability    (DIN 53333) [mg/cm2h] 0,8 - 1,5 9

>1,5
(automobiles)

2,0 (furniture)
 

Water vapor absorption (DIN EN 344)  [mg/cm2 in 8h] 4,6-5,8   21 8,0 (furniture)
Emission (VDA 75201) [µg/cm2] 300-1000 113-123 <100
Fogging (VDA 75201) [mg/cm2] 5-10 3-4 <5 (automobiles)
Thermal stability (TL 52964) >3- 4 >3- 4 >3- 4 (automobiles)

Grey scale grade 5-1 *

Light stability

(DIN 54004

5-6 5-6 5
Blue scala grade 6-1 **

*   5= best ; 1= worst
** 6= best ; 1= worst