High-purity silicone ladder polymer and process producing the same
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsShigeyuki Yamamoto, Hiroshi Adachi
Life of this patent
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Abstract
High-purity silicone ladder polymer a weight average molecular weight of 600-1,000,000 and a molecular weight distribution of no more than 10 and it contains no more than 1 ppm each of sodium, potassium, iron, copper, lead and chlorine and no more than 1 ppb each of uranium and thorium. This silicone ladder polymer is very pure, has high molecular weight and yet can be produced easily. Hence, it can advantageously be used as a material for making surface protective or inter-level insulation films in semiconductor devices.
Claims16
A high-purity silicone ladder polymer that contains no more than 1 ppm each of sodium, potassium, iron, copper, lead and chlorine and no more than 1 ppb each of uranium and thorium, that is represented by general formula (I):
- ##STR8## where R.sub.1 and R.sub.2 represent the same or different lower alkyl groups;
- R.sub.3, R.sub.4, R.sub.5 and R.sub.6 each represent a hydrogen atom or a lower alkyl group;
- and n is an integer corresponding to a weight average molecular weight of 600-1,000,000, and that has a molecular weight distribution of no more than 10.
A process for producing a high-purity silicone ladder prepolymer that has a terminal alkoxy group and a molecular weight distribution of no more than 10, that contains no more than 1 ppm each of sodium, potassium, iron, copper, lead and chlorine and no more than 1 ppb each of uranium and thorium, and that is represented by the general formula (I):
- ##STR9## where R.sub.1 and R.sub.2 represent the same or different lower alkyl groups;
- R.sub.3, R.sub.4, R.sub.5 and R.sub.6 represent a hydrogen atom or a lower alkyl group;
- and n is an integer corresponding to a weight average molecular weight of 600 to less than 30,000;
- which process comprises dissolving an organotrialkoxysilane compound of the general formula (II):
- R.sub.7 SiOR.sub.8 OR.sub.9 OR.sub.10
- where R.sub.7, R.sub.8, R.sub.9 and R.sub.10 each represent a lower alkyl group, in an organic solvent, hydrolyzing said compound with hydrogen chloride containing ultrapure water having a specific resistance of about 16 M.OMEGA..multidot.cm or above, under cooling, and then washing the resulting hydrolyzate with ultrapure water.
A process for producing a high-purity silicone ladder prepolymer that has a terminal hydroxyl group and a molecular weight distribution of no more than 10, that contains no more than 1 ppm each of sodium, potassium, iron, copper, lead and chlorine and no more than 1 ppb each of uranium and thorium, and that is represented by the general formula (I):
- ##STR10## where R.sub.1 and R.sub.2 represent the same or different lower alkyl groups;
- and n is an integer corresponding to a weight average molecular weight of 600 to less than 30,000, which process comprises dissolving an organotrichlorosilane compound of the general formula (III):
- R.sub.11 SiCl.sub.3
- where R.sub.11 represents a lower alkyl group, in an organic solvent, hydrolyzing said compound with ultrapure water having a specific resistance of about 16 M.OMEGA..multidot.cm or above, under cooling, and then washing the resulting hydrolyzate with ultrapure water.
Dependencies are inferred from the claim text.