Flexible polyurethane foam, process for its production, and seat for automobile using the flexible polyurethane foam

1. A flexible polyurethane foam obtained by reacting and molding in a closed mold a high molecular weight polyoxyalkylene polyol or a polymer-dispersed polyol comprising fine polymer particles in the high molecular weight polyoxyalkylene polyol, with a polyisocyanate compound, in the presence of a catalyst, a blowing agent consisting of water, a foam stabilizer, and an amino-modified silicone (F), wherein the amino-modified silicone (F) is present in an amount of from 0.00001 to 0.005 part by mass per 100 parts by mass of all active hydrogen compounds

wherein the amino-modified silicone (F) is a compound represented by the following formula (1) or (2):

provided that in the formula (1), R 1 is a C 1-10 alkylene group, R 2 is a C 1-10 alkyl group, and k is an integer of from 1 to 2,000, and

in the formula (2), m is an integer of from 0 to 100; n is an integer of from 1 to 2,000; each of R 3 , R 4 and R 5 which may be the same or different, is a group selected from the group consisting of a C 1-10 alkyl group, a C 1-10 alkoxy group and a C 1-10 alkyl group having a nitrogen atom, provided that when m is 0, at least one of R 3 and R 5 is an alkyl group having a nitrogen atom, and when m is from 1 to 100, at least one of R 3 , R 5 and a “m” number of R 4 's is an alkyl group having a nitrogen atom,

wherein said high molecular weight polyoxyalkylene polyol has an unsaturation value of at most 0.07 meq/g,

wherein the high molecular weight polyoxyalkylene polyol has an average number of hydroxyl groups of from 2 to 6,

wherein the high molecular weight polyoxyalkylene polyol has a molecular weight per hydroxyl group of from 1,000 to 5,000, and

wherein with respect to a foam obtained by foaming into a thickness of 100 mm, the 25% hardness (ILD) X (N/314 cm 2 ) measured in accordance with JIS K6400 (1997) and Y (mm), which is the value (difference in deflection on pressure side) obtained by subtracting the deflection on 500 N pressure side from the deflection on 900 N pressure side obtained from a load-deflection curve as measured by means of a pressure plate (Tekken Plate) in accordance with JIS E7104 (2002), satisfy a relation formula represented by the following formula (3):

Y≧−0.000370842 X 2 +0.225401 X− 10.5013   (3).

2. The flexible polyurethane foam according to claim 1 , wherein the amino equivalent of the amino-modified silicone (F) is from 100 to 100,000 g/mol.

3. The flexible polyurethane foam according to claim 1 , wherein the density of core portion is from 30 to 70 kg/m 3 .

4. The flexible polyurethane foam according to claim 3 , wherein the density of core portion is from 35 to 60 kg/m 3 .

5. The flexible polyurethane foam according to claim 1 , wherein with respect to a foam obtained by foaming into a thickness of 100 mm, when the deflection on 500 N pressure side obtained from a load-deflection curve as measured by means of a pressure plate (Tekken Plate) in accordance with JIS E7104 (2002), is from 5.0 to 55.0 mm, Y (mm), which is the value (the difference in deflection on pressure side) obtained by subtracting the deflection on 500 N pressure side from the deflection on 900 N pressure side, is from 22.5 to 33.0 mm.

6. The flexible polyurethane foam according to claim 1 , wherein with respect to a foam obtained by foaming into a thickness of 100 mm, when the deflection on 500 N pressure side obtained from a load-deflection curve as measured by means of a pressure plate (Tekken Plate) in accordance with JIS E7104 (2002), is from 18.0 to 55.0 mm, Y (mm), which is the value (the difference in deflection on pressure side) obtained by subtracting the deflection on 500 N pressure side from the deflection on 900 N pressure side, is from 22.5 to 33.0 mm.

7. A seat for an automobile, which is made of the flexible polyurethane foam as defined in claim 1 .

8. A process for producing a flexible polyurethane foam, which comprises reacting and molding in a closed mold a high molecular weight polyoxyalkylene polyol or a polymer-dispersed polyol comprising fine polymer particles in the high molecular weight polyoxyalkylene polyol, with a polyisocyanate compound, in the presence of a catalyst, a blowing agent consisting of water, a foam stabilizer, and an amino-modified silicone (F), wherein the amino-modified silicone (F) is present in an amount of from 0.00001 to 0.005 part by mass per 100 parts by mass of all active hydrogen compounds

wherein the amino-modified silicone (F) is a compound represented by the following formula (1) or (2):

provided that in the formula (1), R 1 is a C 1-10 alkylene group, R 2 is a C 1-10 alkyl group, and k is an integer of from 1 to 2,000, and

in the formula (2), m is an integer of from 0 to 100; n is an integer of from 1 to 2,000; each of R 3 , R 4 and R 5 which may be the same or different, is a group selected from the group consisting of a C 1-10 alkyl group, a C 1-10 alkoxy group and a C 1-10 alkyl group having a nitrogen atom, provided that when m is 0, at least one of R 3 and R 5 is an alkyl group having a nitrogen atom, and when m is from 1 to 100, at least one of R 3 , R 5 and a “m” number of R 4 's is an alkyl group having a nitrogen atom,

wherein said high molecular weight polyoxyalkylene polyol has an unsaturation value of at most 0.07 meq/g,

wherein the high molecular weight polyoxyalkylene polyol has an average number of hydroxyl groups of from 2 to 6,

wherein the high molecular weight polyoxyalkylene polyol has a molecular weight per hydroxyl group of from 1,000 to 5,000, and

wherein with respect to a foam obtained by foaming into a thickness of 100 mm, the 25% hardness (ILD) X (N/314 cm 2 ) measured in accordance with JIS K6400 (1997) and Y (mm), which is the value (difference in deflection on pressure side) obtained by subtracting the deflection on 500 N pressure side from the deflection on 900 N pressure side obtained from a load-deflection curve as measured by means of a pressure plate (Tekken Plate) in accordance with JIS E7104 (2002), satisfy a relation formula represented by the following formula (3):

Y≧−0.000370842 X 2 +0.225401 X− 10.5013   (3).

9. The process for producing a flexible polyurethane foam according to claim 8 , wherein the amino equivalent of the amino-modified silicone (F) is from 100 to 100,000 g/mol.

10. A flexible polyurethane foam obtained by reacting and molding a high molecular weight polyoxyalkylene polyol or a polymer-dispersed polyol comprising fine polymer particles in the high molecular weight polyoxyalkylene polyol, with a polyisocyanate compound, in the presence of a catalyst, a blowing agent consisting of water, a foam stabilizer, and an amino-modified silicone (F), wherein the amino-modified silicone (F) is present in an amount of from 0.00001 to 0.005 part by mass per 100 parts by mass of all active hydrogen compounds

wherein the amino-modified silicone (F) is a compound represented by the following formula (1) or (2):

provided that in the formula (1), R 1 is a C 1-10 alkylene group, R 2 is a C 1-10 alkyl group, and k is an integer of from 1 to 2,000, and

in the formula (2), m is an integer of from 0 to 100; n is an integer of from 1 to 2,000; each of R 3 , R 4 and R 5 which may be the same or different, is a group selected from the group consisting of a C 1-10 alkyl group, a C 1-10 alkoxy group and a C 1-10 alkyl group having a nitrogen atom, provided that when m is 0, at least one of R 3 and R 5 is an alkyl group having a nitrogen atom, and when m is from 1 to 100, at least one of R 3 , R 5 and a “m” number of R 4 's is an alkyl group having a nitrogen atom,

wherein said high molecular weight polyoxyalkylene polyol has an unsaturation value of at most 0.07 meq/g, and

wherein with respect to a foam obtained by foaming into a thickness of 100 mm, when the deflection on 500 N pressure side obtained from a load-deflection curve as measured by means of a pressure plate (Tekken Plate) in accordance with JIS E7104 (2002), is from 5.0 to 55.0 mm, Y (mm), which is the value (the difference in deflection on pressure side) obtained by subtracting the deflection on 500 N pressure side from the deflection on 900 N pressure side, is from 22.5 to 33.0 mm.

11. The flexible polyurethane foam according to claim 1 , wherein the amino-modified silicone (F) is represented by formula (1).

12. The flexible polyurethane foam according to claim 1 , wherein the amino-modified silicone (F) is represented by formula (2).

13. The process for producing a flexible polyurethane foam according to claim 8 , wherein the amino-modified silicone (F) is represented by formula (1).

14. The process for producing a flexible polyurethane foam according to claim 8 , wherein the amino-modified silicone (F) is represented by formula (2).