DECITAN  SP 

Low pH High-performance Acid Acrylic Syntan

Appearance               :           Creamy  White,  moderately  viscous liquid

Total Solids               :           40% + 2%

pH (10%  Solution)    :           2.5  to  3

Colloidal  Charge     :           Anionic

Light  Stability           :           Excellent

Aging Stability           :           Excellent

Specific Gravity        :           1.13

DECITAN SP  shows  an advantage  over other retanning agents  in its  ability  to  plump  leather.

The temper of  leather  made  using  this  product  can  range  from a  soft  glovy  type  leather  to a firm

shoe side  upper leather  depending  upon  application  conditions.   In addition,  it has  excellent

levelling  properties  as  well  as  possessing  outstanding  light fastness  and stability  on aging.   These

superior  properties make DECITAN SP of  prime interest  and utility in  the  retanning  of  a  wide  variety of

chrome  tanned  leathers.  Chrome  leather  processed  with DECITAN SP  alone  or in combination  with

conventional retanning  materials  is more  receptive  to impregnation.   Furthermore,  certain  special 

formulations  with DECITAN SP  give  leather  with  unique properties.

PRINCIPLES OF APPLICATION OF  DECITAN SP 

I.  Astringency  :

DECITAN SP  reacts  very  readily  with chrome  tanned  leather.  As  a  result,  if  added  directly  to chrome

stock  at  higher  percentage  levels,  it  will tend to  pack  the  grain layer so that  its  elongation  is

reduced.  Therefore,  in  retanning  chrome  stock  with  DECITAN SP , conditions  for bringing  greater 

penetration  of the  Syntan  should be  employed.  This can be accomplished by  a  prior  treatment  with

1-2% of  a  sulfonated  syntan.  In  addition, lower  temperatures  favour  greater  penetration.

II. Float and Temperatures

Experience has shown that a 50 – 100% float yield satisfactory exhaustion.  A  temperature range  30^o -  40^oC  is  recommended  for  retannage.  For improved bleaching in making white leathers  temperature  upto  50^oC  may  be  used.

III. Running  Time  and Exhaustion

Ordinarily running  times of 30 to 60  minutes  are  sufficient  to exhaust  DECITAN SP  effectively. To  test  qualitatively  for  exhaustion, a  sample  of  liquor  should  be  filtered,  then tested  as  for a  syntan.  Acidity  the solution  with a few  drops  of  10%  formic  acid  and then  add  several  drops of a  1%  gelatin solution.  A  precipitate indicates presence of  DECITAN SP and  incomplete  exhaustion. If the  test  solution remains  clear,  DECITAN SP  has  been  completely  exhausted.

IV.  pH  Effects

Chrome  leather for  retanning should have a  spot  pH  of  3.7 to  4.4.  At  the higher  pH     range

more effective  beaching  is  obtained  for  white  leathers.  Once  leather has  be    retanned  with 

DECITAN SP  it  can  be  neutralized to  a  pH   of 5.5 maximum.

V.  Fatliquoring

Combination  of  fat  liquors  employing  a  “mayonnaise’   type  of  a  oil  along  with some  sulfated  oil  and  raw Neats foot  oil have been found to  be  generally applicable  on  leathers  made  using  DECITAN SP. Where  poor exhaustion   of  fat  liquor  is  encountered,  salt  may  be  added  to improve  the  exhaustion.   For  grain  lubrication,  cationic  topping  oils  may  be  used  with  beneficial effect.

VI. Dyeing

DECITAN SP   makes  leather  more  substantive  to  basic  dyestuffs  and less so  to acid  and direct  dyestuffs.  If   the leather  is  dyed  before  the  retanning step  the  effect on  acid  and direct  dyes  can  be  minimized.  Another alternative  is to  add the due  together with the first  application  of syntan  and  /  or  DECITAN SP.  As  would  be  expected,  the  results  are influenced  by  the individual dye used.

VII. Compatibility  with other Tanning Materials

DECITAN SP  may  be  used  in  conjunction  with  chrome  tanning  compounds,  unless  they  are unduly  concentrated, to  obtain  interesting  results.  In  addition, DECITAN SP is  compatible with a wide range  of  vegetable  extracts  and  syntans.

SOME  PROPERTIES  OF  CHROME  LEATHER  RETANNED WITH  SYN -  SP

Extensive studies  were  carried  out  to determine  changes  in  the  characteristics  of  chrome  leather which  are  brought  about  by  retanning  with  DECITAN SP.   The  results of  this  work  are  given below.

I. Thickness

DECITAN SP  plumps  leather  more than  the  other retans.

II. Temper

The  effect on  temper  imparted  by  DECITAN SP  is  comparable  to  the  decreases  in  temper

obtained  by a  chrome retannage.

III. Light  fastness

Since the light fastness of the product itself is outstanding, leathers retanned with it are much

superior in this property to those retanned with other retanning materials.

IV. Aging  Stability

Again,  because  of  the excellent  aging  stability  of this  unique  syntan,  leathers retanned  with it are

excellent  in this  respect  compared  to those  having other  retannages.