×

Sulfur-containing polyorganosiloxane compositions and related aspects

  • US 10,351,704 B2
  • Filed: 11/06/2015
  • Issued: 07/16/2019
  • Est. Priority Date: 11/13/2014
  • Status: Active Grant
First Claim
Patent Images

1. A degradation-inhibited hydrosilylation-curable composition comprising the following constituents:

  • (i) a hydrosilylation-curable polyorganosiloxane prepolymer,(ii) a metal component of a hydrosilylation catalyst, and(iii) a sulfur compound having a boiling point greater than 150 degrees Celsius (°

    C.);

    wherein the atomic amount, in moles, of sulfur atoms of the sulfur compound is from 5 to 10,000 times greater than the atomic amount, in moles, of (ii) the metal component of a hydrosilylation catalyst; and

    wherein the composition either has the hydrosilylation-curable polyorganosiloxane prepolymer, as described below, for constituent (i-a) or the composition has the sulfur compound, as described below, for constituent (iii-a) or the composition has both constituents (i-a) and (iii-a);

    (i-a) the hydrosilylation-curable polyorganosiloxane prepolymer is a hydrosilylation-curable resin-linear organosiloxane block copolymer comprising;

    40 to 90 mole percent D-type units of the formula [R12SiO2/2],10 to 60 mole percent T-type units of the formula [R2SiO3/2],0.5 to 35 mole percent silanol groups [Si—

    OH];

    wherein each R1 and R2 independently is a (C1-C30)hydrocarbyl that has 0 aliphatic unsaturated bond or a (C1-C30)hydrocarbyl which comprises at least 1 aliphatic unsaturated bond, wherein the hydrosilylation-curable resin-linear organosiloxane block copolymer comprises from 0.5 to 5 mole percent of the (C1-C30)hydrocarbyl comprising at least one aliphatic unsaturated bond;

    wherein the D-type units [R12SiO2/2] are arranged in linear blocks having an average of from 100 to 300 D-type units [R12SiO2/2] per linear block and the T-type units [R2SiO3/2] are arranged in non-linear blocks having a molecular weight of at least 500 grams per mole (g/mol), wherein at least 30 mole percent of the non-linear blocks are crosslinked with each other and wherein each linear block is linked to at least one non-linear block via a divalent linker comprising a D-type or T-type siloxane unit; and

    wherein the hydrosilylation-curable resin-linear organosiloxane block copolymer has a weight average molecular weight (Mw) of at least 20,000 g/mol;

    or(iii-a) the sulfur compound is a sulfur-functional organosiloxane of formula (I);

    (R3R4R5SiO1/2)a1(R3R4SiO2/2)b1(R3SiO3/2)c1(O3/2Si—

    R6

    S—

    (S)m

    R7

    SiO3/2)d1(SiO4/2)e1 (I), wherein subscript m is 0, 1, 2, or 3;

    subscripts a1+b1+c1+d1+e1=1, a1 is from 0 to 0.5, b1 is from 0 to <

    1, c1 is from 0 to 1, d1 is from 0 to 1, and e1 is from 0 to 0.2;

    wherein each of R3, R4, and R5 independently is a (C1-C30)hydrocarbyl, a mercapto-functional ((HS)-functional) (C1-C30)hydrocarbyl, or a (C1-C30)heterohydrocarbyl containing a sulfide group, a disulfide group, a trisulfide group, or a tetrasulfide group; and

    wherein each of R6 and R7 independently is a bond, a (C1-C30)hydrocarbylene, or a (C1-C30)heterohydrocarbylene containing a sulfide group, a disulfide group, a trisulfide group, or a tetrasulfide group; and

    with the proviso that d1 is >

    0 or at least one of R3, R4, and R5 independently is a mercapto-functional (C1-C30)hydrocarbyl or a (C1-C30)heterohydrocarbyl containing a sulfide group, a disulfide group, a trisulfide group, or a tetrasulfide group.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×