Resin-containing organosiloxane compositions curable to silicone elastomers having low weep

Claim 1

An organosiloxane composition curable to a silicone elastomer, the composition comprising: (A) 100 parts by weight of an alkenyl-containing polydiorganosiloxane having an average of at least two silicon-bonded alkenyl groups per molecule; (B) 0.5 to 100 parts by weight, per 100 parts by weight of component (A), of an organohydrogensiloxane having an average of at least two silicon-bonded hydrogen atoms per molecule, the amount of organohydrogensiloxane present being sufficient to provide a ratio of silicon-bonded hydrogen atoms in component (B) to silicon-bonded alkenyl groups in component (A) of 0.8:1 to 3:1; (C) a platinum group catalyst sufficient for curing the organosiloxane composition; and (D) 0.1 to 10 parts by weight per 100 parts of component (A) of a resinous organosiloxane copolymer having an average of at least two alkenyl groups per molecule, a number average molecular weight (Mn) between about 400 and about 15,000 g/mole having the empirical formula: (R.sub.3 SiO.sub.1/2).sub.a (R2SiO.sub.2/2).sub.b (RSiO3/2).sub.c (SiO4/2).sub.d wherein a>0,d>0,b≧0,c≧0,a+b+c+d=1,0≦(b+c)≦0.2, and R is a monovalent independently selected from the group consisting of hydrogen, hydroxyl, alkyl, alkenyl, and alkoxy; wherein the sum of the average number of silicon-bonded alkenyl groups per molecule in component (A) and the average number of silicon-bonded hydrogen atoms per molecule in component (B) is great than four.

Claim 22

A method of minimizing the leakage of hydrocarbon fluid from a container, the method comprising the steps of (I) preparing an organosiloxane composition comprising: (A) 100 parts by weight of an alkenyl-containing polydiorganosiloxane having an average of at least two silicon-bonded alkenyl groups per molecule; (B) 0.5 to 100 parts by weight, per 1 00 parts by weight of component (A), of an organohydrogensiloxane having an average of at least two silicon-bonded hydrogen atoms per molecule, the amount of organohydrogensiloxane present being sufficient to provide a ratio of silicon-bonded hydrogen atoms in component (B) to silicon-bonded alkenyl groups in component (A) of 0.8:1 to 3:1; (C) a platinum group catalyst sufficient for curing the organosiloxane composition; and (D) 0.5!0.1 to 10 parts by weight per 100 parts of component (A) of a resinous organosiloxane copolymer having an average of at least two alkenyl groups per molecule, a number average molecular weight (Mn) between about 400 and about 15,000 g/mole having the empirical formula: (R.sub.3 SiO.sub.1/2).sub.a (R2SiO.sub.2/2).sub.b (RSiO3/2).sub.c (SiO4/2).sub.d wherein a>0,d>0,b≧0,c≧0,a+b+c+d=1,0≦(b+c)≦0.2, and R is a monovalent independently selected from the group consisting of hydrogen, hydroxyl, alkyl, alkenyl, and alkoxy; wherein the sum of the average number of silicon-bonded alkenyl groups per molecule in component (A) and the average number of silicon-bonded hydrogen atoms per molecule in component (B) is great than four; and (II) applying the organosiloxane composition to a surface on the container; and (III) allowing the organosiloxane composition to cure.

Claim 23

A method of minimizing the leakage of hydrocarbon fluid from a container, the method comprising the steps of (I) preparing an organosiloxane composition comprising: (A) 100 parts by weight of an alkenyl-containing polydiorganosiloxane having an average of at least two silicon-bonded alkenyl groups per molecule; (B) 0.5 to 100 parts by weight, per 1 00 parts by weight of component (A), of an organohydrogensiloxane having an average of at least two silicon-bonded hydrogen atoms per molecule, the amount of organohydrogensiloxane present being sufficient to provide a ratio of silicon-bonded hydrogen atoms in component (B) to silicon-bonded alkenyl groups in component (A) of 0.8:1 to 3:1; (C) a platinum group catalyst sufficient for curing the organosiloxane composition; and (D) 0.5!0.1 to 10 parts by weight per 100 parts of component (A) of a resinous organosiloxane copolymer having an average of at least two alkenyl groups per molecule, a number average molecular weight (Mn) between about 400 and about 15,000 g/mole having the empirical formula: (R.sub.3 SiO.sub.1/2).sub.a (R2SiO.sub.2/2).sub.b (RSiO3/2).sub.c (SiO4/2).sub.d wherein a>0,d>0,b≧0,c≧0,a+b+c+d=1,0≦(b+c)≦0.2, and R is a monovalent independently selected from the group consisting of hydrogen, hydroxyl, alkyl, alkenyl, and alkoxy; wherein the sum of the average number of silicon-bonded alkenyl groups per molecule in component (A) and the average number of silicon-bonded hydrogen atoms per molecule in component (B) is great than four; and (II) applying the organosiloxane composition to a surface on the container; and (III) allowing the organosiloxane composition to cure.

Claim 27

A method of minimizing the leakage of hydrocarbon fluid from a container, the method comprising the steps of (I) preparing an organosiloxane composition comprising: (A) 100 parts by weight of an alkenyl-containing polydiorganosiloxane having an average of at least two silicon-bonded alkenyl groups per molecule; (B) 0.5 to 100 parts by weight, per 100 parts of component (A), of an organohydrogensiloxane having an average of at least two silicon-bonded hydrogen atoms per molecule, the amount of organohydrogensiloxane present being sufficient to provide a ratio of silicon-bonded hydrogen atoms in component (B) to silicon-bonded alkenyl groups in component (A) of 0.8:1 to 3:1, (C) a platinum group catalyst sufficient for curing the organosiloxane composition; and (D) 0.5 to 10 parts by weight, per 100 parts of component (A), of a resinous organosiloxane copolymer having an average of at least two alkenyl groups per molecule, a number average molecular weight (Mn) between about 400 and about 15,000. and having the empirical formula: (R.sub.3 SiO.sub.1/2).sub.a (R2SiO.sub.2/2).sub.b (RSiO3/2).sub.c (SiO4/2).sub.d wherein a>0,d>0,b≧0,c≧0,a+b+c+d=1,0≦(b+c)≦0.2, and R is a monovalent radical independently selected from the group consisting of hydrogen, hydroxyl, alkyl, alkenyl, alkoxy, --OZ and Z; wherein Z is a fluorine atom-containing group; wherein the sum of the average number of silicon-bonded alkenyl groups per molecule in component (A) and the average number of silicon-bonded hydrogen atoms per molecule in component (B) is great than four; (II) allowing the composition to cure to a silicone elastomer; and (Ill) sealing the container by securing the cured elastomer to a surface on the container.

Claim 28

A method of minimizing the leakage of hydrocarbon fluid from a container, the method comprising the steps of (I) preparing an organosiloxane composition comprising: (A) 100 parts by weight of an alkenyl-containing polydiorganosiloxane having an average of at least two silicon-bonded alkenyl groups per molecule; (B) 0.5 to 100 parts by weight, per 100 parts of component (A), of an organohydrogensiloxane having an average of at least two silicon-bonded hydrogen atoms per molecule, the amount of organohydrogensiloxane present being sufficient to provide a ratio of silicon-bonded hydrogen atoms in component (B) to silicon-bonded alkenyl groups in component (A) of 0.8:1 to 3:1, (C) a platinum group catalyst sufficient for curing the organosiloxane composition; and (D) 0.5 to 10 parts by weight, per 100 parts of component (A), of a resinous organosiloxane copolymer having an average of at least two alkenyl groups per molecule, a number average molecular weight (Mn) between about 400 and about 15,000. and having the empirical formula: (R.sub.3 SiO.sub.1/2).sub.a (R2SiO.sub.2/2).sub.b (RSiO3/2).sub.c (SiO4/2).sub.d wherein a>0,d>0,b≧0,c≧0,a+b+c+d=1,0≦(b+c)≦0.2, and R is a monovalent radical independently selected from the group consisting of hydrogen, hydroxyl, alkyl, alkenyl, alkoxy, --OZ and Z; wherein Z is a fluorine atom-containing group; wherein the sum of the average number of silicon-bonded alkenyl groups per molecule in component (A) and the average number of silicon-bonded hydrogen atoms per molecule in component (B) is great than four; (II) allowing the composition to cure to a silicone elastomer; and (Ill) sealing the container by securing the cured elastomer to a surface on the container.