Patent ID: 6605183
Filing Date: 2003-08-12
Classification: B01D,C08G

Abstract:
An antifoam formulation containing(A) at least one antifoam based on siloxanes and (B) 0.1 to 40% by weight of a polyether/polysiloxane copolymer of the formula (R2R*SiO)2(RRâ€²SiO)x(R2SiO)y(RRâ€³SiO)zâ€ƒâ€ƒ(I) in which R, independently of one another, denote identical or different, optionally substituted hydrocarbon radicals having 1 to 30 carbon atoms, R* denotes either R, Râ€² or Râ€³; wherein Râ€² and Râ€³ are:R1Oâ€”(CH2CH2O)a[CH2CH(CH3)O]b[CH2CH(CH2CH3)O]câ€”R2â€”â€ƒâ€ƒ(Râ€²) or â€”R2Oâ€”(CH2CH2O)d[CH2CH(CH3)O]e[CH2CH(CH2CH3)O]fâ€”R2â€”â€ƒâ€ƒ(Râ€³) where R1 denotes either hydrogen, an alkyl, aralkyl, aryl or Râ€”C(O) radical, x is on average 0.1 to 200, y is 1 to 1000, z is on average 0.01 to 2.0, and a, b, c, d, e and f have values between 0 and 1000, with the proviso that the sum (a+b+c) and the sum (d+e+f) each have a value of 2 to 2000, R2 denotes an alkylene radical having 2 to 10 carbon atoms,Râ€³ is the divalent linking group in common with a group RRâ€³SiO, or when R* is Râ€³, the group R2Râ€³SiO in a first polyether/polysiloxane copolymer of the formula (I) and with a group RRâ€³SiO or R2Râ€³SiO in a second polyether/polysiloxane copolymer of the formula (I) such that said first and second polyether/polysiloxane copolymers (I) are linked together by an Râ€³ bridging unit, the antifoam based on siloxanes (A) and the polyether/polysiloxane copolymer (B) being different.