联系人 Mr. Sam
No.4065,Mingshang Tiandi 4th Floor,Yuexiu District,No.222,Guangyuan West Road,Guangzhou., Guangzhou, Guangdong
In the production of mineral tanned and/or re-tanned leather it is
desired to keep the yield and efficiency of the mineral tanning
agent as high as possible, be it in order to achieve a high-yield
mineral(re)tanning or in order to decrease as far as possible the
residual mineral tanning agent content of the back-water. In the
after-treatment of leather with fatting agents*-particularly such
with hydrophobizing properties*-that are fixed with polyvalentmetal
cations, it is also desired to improve the yield and efficiency of
the treatment.
It has now been found that using defined anionic polymeric
compounds these aims can be attained in a surprisingly high
degree.
The invention thus provides a process for the production of mineral
tanned or/and retanned or/and after-treated leather or pelt,
wherein before a mineral tanning, directly after a mineral tanning,
directly before a mineral re-tanning, after amineral re-tanning
or/and with the after-treatment of a fatliquoring with a polyvalent
metal cation, the substrate is treated with
(A) a polymeric carboxylic acid containing .alpha.-hydroxyacrylic
acid units, optionally in salt form, as constituent units of the
polymer.
As polymeric carboxylic acids (A) or their salts come principally
into consideration (co)poly-.alpha.-hydroxyacrylic acids,
optionally further containing non-ionic and/or other anionic
co-monomeric units as constituents of the polymer or theirsalts.
The other anionic co-monomeric units*-indicated in the free acid
form*-are advantageously derivatives of ethylenically unsaturated
monomeric carboxylic acids (principally of aliphatic C.sub.**5
-carboxylic acids), in particular (meth)acrylicacid, crotonic acid,
maleic acid, itaconic acid, aconitic acid and citraconic acid,
among which maleic acid and (meth)acrylic acid are preferred,
especially acrylic acid. As non-ionic monomeric units come
principally into consideration the derivativesof (meth)acrylamide,
(meth)acrylonitrile and/or vinylmethylether. Copolymers comprising
.alpha.-hydroxyacrylic acid units and acrylic acid units and/or
their salts or, in particular, consisting thereof are preferred. As
"derivatives" of the monomersare meant here monomer units deriving
from the copolymerisation of the mentioned monomers.
The numerical average molecular weight M.sub.n of the polymers (A)
is advantageously in the range of **0 to **0,**0, preferably **0 to
*0,**0. Of the polymers to be employed are furthermore preferred
those whose weight average molecular weightM.sub.w is in the range
of ***0 to **0,**0, preferably ***0 to **0,**0. The indicated
molecular weights are intended in the form of the sodium salts of
the polymeric acids.
国家: | China |
型号: | A590ï¼A663, A646, A686, A711, A713, G1121 |
离岸价格: | 获取最新报价 |
位置: | - |
最小订单价格: | - |
最小订单: | - |
包装细节: | - |
交货时间: | - |
供应能力: | - |
付款方式: | Other |
產品組 : | - |