Oil-in-water emulsions of aminosiloxanes
Oil-in-water emulsions which contain (i) 100 parts by weight of a polydimethylsiloxane (P) having aminoalkyl groups and having an amine number of at least 0.1 meq/g of polydimethylsiloxane (P), composed of units of the general formula I R 1 a R 2 b SiO (4−a−b/2) , (I) in which R 2 are aminoalkyl radials of the formula II —R 3 —NR 4 R 5 ,, (II) (ii) protonating agent, (iii) water and (iv) not more than 5 parts by weight of emulsifier, are stable and provide for improved water repellency of porous and nonporous, absorptive and non-absorptive substrates treated therewith.
1. A process for treating leather or sizing paper, leather and paper being a substrate, comprising contacting the surface of said substrate with an oil-in-water emulsion, comprising
(i) 100 parts by weight of a polydimethylsiloxane (P) having aminoalkyl groups and having an amine number of at least 0.1 meq/g of polydimethylsiloxane (P), and comprising units of the formula I
R 1 a R 2 b SiO (4−a−b/2) (I),
in which
R 1 are optionally halogen-substituted alkyl radicals having 1-40 carbon atoms, or are —OR or —OH radicals,
R are optionally halogen-substituted alkyl radicals having 1-40 carbon atoms,
R 2 are aminoalkyl radicals of the formula II
—R 3 —NR 4 R 5 (II),
R 3 are divalent hydrocarbon radicals having 1-40 carbon atoms,
R 4 are monovalent hydrocarbon radicals having 1-40 carbon atoms or are H,
R 5 is a radical of the formula III
—(R 6 —NR 4 ) x R 4 (III),
R 6 is a divalent radical of the formula IV
—(CR 4 R 4 —) y (IV),
x is 0 or a value from 1 to 40,
y is 1 or 2,
a is 0, 1, 2 or 3,
b is 0, 1, 2 or 3 and
a+b on average is from 1.5 to 2.5, not more than 9 mol % of the radical R 1 being OH or OR,
(ii) at least one MQ silicone resin,
(iii) at least one protonating agent,
(iv) water, and
(v) not more than 5 parts by weight of emulsifier(s),
and drying the substrate.
2. The process of claim 1 , wherein R 4 are alkyl radicals having 1 to 6 carbon atoms.
3. The process of claim 1 , wherein the radicals R 2 are selected from the group consisting of —(CH 2 N(R 4 ) 2 , —(CH 2 ) 3 N(R 4 ) 2 , —(CH 2 ) 3 N(R 4 ) (CH 2 ) 2 N(R 4 ) 2 , and mixtures thereof.
4. The process of claim 1 , further comprising mono- or polyalcohols and ethers thereof, which have a boiling point or boiling range of not more than 260° C. at 0.10 MPa.
5. The process of claim 1 , wherein protonating agent(s) are selected from the group consisting of formic acid, acetic acid, sulfuric acid, hydrochloric acid, citric acid, and mixtures thereof.
6. The process of claim 1 containing from 80 mol % to 95 mol % of structural units of the formulae (V) and VI:
R 7 3 SiO 1/2 (V),
SiO 4/2 (VI),
in which
R 7 are optionally halogen-substituted hydrocarbon radicals having 1-40 carbon atoms or H, —OR or —OH radicals, and the ratio of the units of the general formulae V and VI is from 0.5 to 2.0, and not more than 3% by weight of the radicals R 7 are —OR and —OH.
7. The process of claim 1 , which contains from 1 to 200 parts by weight of MQ silicone resin based on 100 parts of polydimethylsiloxane (P).
8. The process of claim 1 , comprising contact a paper substrate with the aqueous emulsion and drying to form a sized paper.
9. The process of claim 1 , wherein treating comprises contacting leather with said aqueous emulsion.
10. The process of claim 1 , wherein the protonating agent consists essentially of water soluble acid.
11. The process of claim 1 , wherein the protonating agent is a water soluble acid selected from the group consisting of formic acid, acetic acid, sulfuric acid, hydrochloric acid, citric acid, and mixtures thereof.
12. The process of claim 1 , wherein no emulsifier is employed.