| PATENT NUMBER | This data is not available for free |
| PATENT GRANT DATE | January 11, 2005 |
| PATENT TITLE |
Extruded styrene resin foam and process for producing the same |
| PATENT ABSTRACT |
An extruded styrene resin foam which is produced by using a blowing agent imposing a reduced load on the environment and has outstandingly excellent thermal insulating property and flame retardant property adapted for construction use. The foam is obtained by extrusion-foaming of a styrene resin and characterized by containing at least, one or more of saturated hydrocarbons having 3 to 5 carbon atoms as a blowing agent, and containing (A) a halogenated flame retardant, and (B) at least one compound selected from the group consisting of phosphorus type flame retardants containing nitrogen atom in a molecule; tetrazole compounds; specific nitrogen-containing compounds; metal borates; boron oxides; phosphoric acid ester compounds, and having a cell structure constituting the foam wherein a cell anisotropic ratio k, which is defined by the formula: k=a/(a.times.b.times.c).sup.1/3 wherein, in sections of the foam, a (mm) is an average cell size in the thickness direction, b (mm) is an average cell size in the transverse direction and c (mm) is an average cell size in the longitudinal direction, satisfies the relationship: k.ltoreq.1.1, and a satisfies the relationship: 0.05.ltoreq.a.ltoreq.0.30, and the method for producing the same. |
| PATENT INVENTORS | This data is not available for free |
| PATENT ASSIGNEE | This data is not available for free |
| PATENT FILE DATE | May 20, 2003 |
| PATENT FOREIGN APPLICATION PRIORITY DATA | This data is not available for free |
| PATENT REFERENCES CITED | International Search Report Corresponding to International Application No. PCT/JP01/11248 From the Japanese Patent Office Dated Apr. 2, 2002. |
| PATENT PARENT CASE TEXT | This data is not available for free |
| PATENT CLAIMS |
What is claimed is: 1. An extruded styrene resin foam obtained by extrusion-foaming of a styrene resin, the extruded styrene resin foam containing at least, one or more of saturated hydrocarbons having 3 to 5 carbon atoms as a blowing agent, and containing (A) a halogenated flame retardant, and (B) at least one compound selected from the group consisting of phosphorus type flame retardants containing nitrogen atom in a molecule; tetrazole compounds; nitrogen-containing compounds selected from cyanuric acid, isocyanuric acid, and derivatives thereof; metal borates; boron oxides; and phosphoric acid ester compounds, the extruded styrene resin foam having a cell structure constituting the foam wherein a cell anisotropic ratio k, which is defined by the formula: k=a/(a.times.b.times.c).sup.1/3 wherein, in sections of the foam, a (mm) is an average cell size in the thickness direction, b (mm) is an average cell size in the transverse direction and c (mm) is an average cell size in the longitudinal direction, satisfies the relationship: k.ltoreq.1.1, and a satisfies the relationship: 0.05.ltoreq.a.ltoreq.0.30. 2. The extruded styrene resin foam of claim 1, wherein the nitrogen-containing compounds selected from cyanuric acid, isocyanuric acid, and derivatives thereof are at least one member selected from the group consisting of nitrogen-containing compounds having the following general formula 1, and nitrogen-containing compounds having the following general formula 2: ##STR15## wherein R.sup.1, R.sup.2 and R.sup.3 are selected from hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an organic group represented by the formula: --Y--X (wherein Y is an alkylene group having 1 to 6 carbon atoms, a phenylene group, or a cycloalkylene group, and X is an epoxy group, a carboxyl group, a hydroxyl group, an amino group, a phenyl group, or a monovalent organic group having phosphorus atom), and a phenyl group, and may be different from each other; ##STR16## wherein R.sup.4, R.sup.5 and R.sup.6 are selected from hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an organic group represented by the formula: --Y--X (wherein Y is an alkylene group having 1 to 6 carbon atoms, a phenylene group, or a cycloalkylene group, and X is an epoxy group, a carboxyl group, a hydroxyl group, an amino group, a phenyl group, or a monovalent organic group having phosphorus atom), and a phenyl group, and may be different from each other. 3. The extruded styrene resin foam of claim 1, which contains, as the blowing agent, 100 to 20% by weight of at least one of saturated hydrocarbons having 3 to 5 carbon atoms and 0 to 80% by weight of other blowing agent other than flon type blowing agent, based on the total amount of the blowing agent. 4. The extruded styrene resin foam of claim 1, wherein the cells constituting the foam comprise mainly small cells having a cell size of 0.25 mm or less and large cells having a cell size of 0.3 to 1 mm, and the area of the small cells having a cell size of 0.25 mm or less accounts for 10 to 90% of a sectional area of the foam. 5. The extruded styrene resin foam of claim 1, which contains 0.1 to 10 parts by weight of the halogenated flame retardant (A) and 0.1 to 10 parts by weight of the compound (B), based on 100 parts by weight of the styrene resin. 6. The extruded styrene resin foam of claim 1, wherein the compound (B) is at least one compound selected from the group consisting of the nitrogen-containing compounds having the foregoing general formula 1 and the nitrogen-containing compounds having the foregoing general formula 2. 7. The extruded styrene resin foam of claim 1, wherein the compound (B) is isocyanuric acid and/or bis(2-carboxyethyl) isocyanurate among the nitrogen-containing compounds having the foregoing general formula 2. 8. The extruded styrene resin foam of claim 3, wherein other blowing agent is at least one compound selected from the group consisting of dimethyl ether, methyl chloride, ethyl chloride, water, and carbon dioxide. 9. The extruded styrene resin foam of claim 4, which further contains a smectite. 10. The extruded styrene resin foam of claim 9, wherein the smectite is bentonite. 11. A method for producing an extruded styrene resin foam comprising the steps of heating and melting a styrene resin, adding a blowing agent to the styrene resin, and extrusion-foaming the resultant through a die, wherein the extrusion-foaming is carried out in a condition where (A) a halogenated flame retardant, and (B) at least one compound selected from the group consisting of phosphorus type flame retardants containing nitrogen atom in a molecule; tetrazole compounds; nitrogen-containing compounds selected from cyanuric acid, isocyanuric acid, and derivatives thereof; metal borates; boron oxides; and phosphoric acid ester compounds, and further a blowing agent comprising 100 to 20% by weight of at least one of saturated hydrocarbons having 3 to 5 carbon atoms and 0 to 80% by weight of other blowing agent other than flon type blowing agent, are made coexist in the styrene resin, thereby giving a foam having a cell structure constituting the foam wherein a cell anisotropic ratio k, which is defined by the formula: k=a/(a.times.b.times.c).sup.1/3 wherein, in sections of the foam, a (mm) is an average cell size in the thickness direction, b (mm) is an average cell size in the transverse direction and c (mm) is an average cell size in the longitudinal direction, satisfies the relationship: k+.ltoreq.1.1, and a satisfies the relationship: 0.05.ltoreq.a.ltoreq.0.30. 12. The method for producing an extruded styrene resin foam of claim 11, wherein the nitrogen-containing compound selected from cyanuric acid, isocyanuric acid, and derivatives thereof is at least one member selected from the group consisting of nitrogen-containing compounds having the following general formula 1, and nitrogen-containing compounds having the following general formula 2: ##STR17## wherein R.sup.1, R.sup.2 and R.sup.3 are selected from hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an organic group represented by the formula: --Y--X (wherein Y is an alkylene group having 1 to 6 carbon atoms, a phenylene group, or a cycloalkylene group, and X is an epoxy group, a carboxyl group, a hydroxyl group, an amino group, a phenyl group, or a monovalent organic group having phosphorus atom), and a phenyl group, and may be different from each other; ##STR18## wherein R.sup.4, R.sup.5 and R.sup.6 are selected from hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an organic group represented by the formula: --Y--X (wherein Y is an alkylene group having 1 to 6 carbon atoms, a phenylene group, or a cycloalkylene group, and X is an epoxy group, a carboxyl group, a hydroxyl group, an amino group, a phenyl group, or a monovalent organic group having phosphorus atom), and a phenyl group, and may be different from each other. 13. An extruded styrene resin foam obtained by extrusion foaming of a styrene resin, the extruded styrene resin foam containing at least, one or more of saturated hydrocarbons having 3 to 5 carbon atoms as a blowing agent, and containing (A) a halogenated flame retardant, and (B) at least one compound selected from the group consisting of phosphorus type flame retardants containing nitrogen atom in a molecule; tetrazole compounds; nitrogen-containing compounds selected from cyanuric acid, isocyanuric acid, and derivatives thereof; metal borates; boron oxides; and phosphoric acid ester compounds, the extruded styrene resin foam having a foam density wherein an entire density X of the foam is 20 to 45 kg/m.sup.3, and a density Y of each of both surface layer portions corresponding to up to 20% on the upper side and up to 20% on the lower side, respectively, of the overall thickness of the foam satisfies the relationship: Y.gtoreq.1.05.times.X. 14. The extruded styrene resin foam of claim 13, wherein the nitrogen-containing compound selected from cyanuric acid, isocyanuric acid, and derivatives thereof is at least one member selected from the group consisting of nitrogen-containing compounds having the following general formula 1, and nitrogen-containing compounds having the following general formula 2: ##STR19## wherein R.sup.1, R.sup.2 and R.sup.3 are selected from hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an organic group represented by the formula: --Y--X (wherein Y is an alkylene group having 1 to 6 carbon atoms, a phenylene group, or a cycloalkylene group, and X is an epoxy group, a carboxyl group, a hydroxyl group, an amino group, a phenyl group, or a monovalent organic group having phosphorus atom), and a phenyl group, and may be different from each other; ##STR20## wherein R.sup.4, R.sup.5 and R.sup.6 are selected from hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an organic group represented by the formula: --Y--X (wherein Y is an alkylene group having 1 to 6 carbon atoms, a phenylene group, or a cycloalkylene group, and X is an epoxy group, a carboxyl group, a hydroxyl group, an amino group, a phenyl group, or a monovalent organic group having phosphorus atom), and a phenyl group, and may be different from each other. 15. The extruded styrene resin foam of claim 13, which contains, as the blowing agent, 100 to 20% by weight of at least one of saturated hydrocarbons having 3 to 5 carbon atoms and 0 to 80% by weight of other blowing agent other than flon type blowing agent, based on the total amount of the blowing agent. 16. The extruded styrene resin foam of claim 13, which has a cell structure constituting the foam wherein a cell anisotropic ratio k, which is defined by the formula: k=a/(a.times.b.times.c).sup.1/3 wherein, in sections of the foam, a (mm) is an average cell size in the thickness direction, b (mm) is an average cell size in the transverse direction and c (mm) is an average cell size in the longitudinal direction, satisfies the relationship: k.ltoreq.1.1, and a satisfies the relationship: 0.05.ltoreq.a.ltoreq.0.30. 17. The extruded styrene resin foam of claim 13, wherein the cells constituting the foam comprise mainly small cells having a cell size of 0.25 mm or less and large cells having a cell size of 0.3 to 1 mm, and the area of the small cells having a cell size of 0.25 mm or less accounts for 10 to 90% of a sectional area of the foam. 18. The extruded styrene resin foam of claim 13, which contains 0.1 to 10 parts by weight of the halogenated flame retardant (A) and 0.1 to 10 parts by weight of the compound (B), based on 100 parts by weight of the styrene resin. 19. The extruded styrene resin foam of claim 13, wherein the compound (B) is at least one compound selected from the group consisting of the nitrogen-containing compounds having the foregoing general formula 1 and the nitrogen-containing compounds having the forgoing general formula 2. 20. The extruded styrene resin foam of claim 13, wherein the compound (B) is isocyanuric acid and/or bis(2-carboxyethyl) isocyanurate among the nitrogen-containing compounds having the forgoing general formula 2. 21. The extruded styrene resin foam of claim 15, wherein other blowing agent is at least one compound selected from the group consisting of dimethyl ether, methyl chloride, ethyl chloride, water, and carbon dioxide. 22. The extruded styrene resin foam of claim 17, which further contains 0.2 to 10 parts by weight of a smectite based on 100 parts by weight of the styrene resin. 23. The extruded styrene resin foam of claim 22, wherein the smectite is bentonite. 24. A method for producing an extruded styrene resin foam comprising the steps of heating and melting a styrene resin, adding a blowing agent to the styrene resin, and extrusion-foaming the resultant through a die, wherein the extrusion-foaming is carried out in a condition where (A) a halogenated flame retardant, and (B) at least one compound selected from the group consisting of phosphorus type flame retardants containing nitrogen atom in a molecule; tetrazole compounds; nitrogen-containing compounds selected from cyanuric acid, isocyanuric acid, and derivatives thereof; metal borates; boron oxides; and phosphoric acid ester compounds, and further a blowing agent comprising 100 to 20% by weight of at least one of saturated hydrocarbons having 3 to 5 carbon atoms and 0 to 80% by weight of other blowing agent other than flon type blowing agent, are made coexist in the styrene resin, thereby giving a foam having a foam density wherein an entire density X of the foam is 20 to 45 kg/m.sup.3, and a density Y of each of both surface layer portions corresponding to up to 20% on the upper side and up to 20% on the lower side, respectively, of the overall thickness of the foam satisfies the relationship: Y.gtoreq.1.05.times.X. 25. The method for producing an extruded styrene resin foam of claim 24, wherein the nitrogen-containing compound selected from cyanuric acid, isocyanuric acid, and derivatives thereof is at least one member selected from the group consisting of nitrogen-containing compounds having the following general formula 1, and nitrogen-containing compounds having the following general formula 2: ##STR21## wherein R.sup.1, R.sup.2 and R.sup.3 are selected from hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an organic group represented by the formula: --Y--X (wherein Y is an alkylene group having 1 to 6 carbon atoms, a phenylene group, or a cycloalkylene group, and X is an epoxy group, a carboxyl group, a hydroxyl group, an amino group, a phenyl group, or a monovalent organic group having phosphorus atom), and a phenyl group, and may be different from each other; ##STR22## wherein R.sup.4, R.sup.5 and R.sup.6 are selected from hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an organic group represented by the formula: --Y--X (wherein Y is an alkylene group having 1 to 6 carbon atoms, a phenylene group, or a cycloalkylene group, and X is an epoxy group, a carboxyl group, a hydroxyl group, an amino group, a phenyl group, or a monovalent organic group having phosphorus atom), and a phenyl group, and may be different from each other. 26. A method for producing an extruded styrene resin foam comprising the steps of heating and melting a styrene resin, adding a blowing agent to the styrene resin, and extrusion-foaming the resultant into a lower pressure region through a die, wherein a blowing agent comprising 1) 2 to 6 parts by weight of one or more saturated hydrocarbon selected from the group consisting of saturated hydrocarbons having 3 to 4 carbon atoms, 2) 1 to 6 parts by weight of at least one ether selected from the group consisting of dimethyl ether, methyl ethyl ether and diethyl ether, and 3) 0 to 3 parts by weight of at least one member selected from the group consisting of water and alcohols having carbon atoms 1 to 4, based on 100 parts by weight of the styrene resin, is used as the blowing agent, and a pressure drop in a die slit portion is not less than 4 MPa and a resin residence time in the die slit portion is not more than 0.4 second. 27. The method for producing an extruded styrene resin foam of claim 26, wherein the foam has a density of 20 to 40 kg/m.sup.3 and the cells constituting the foam have an average cell size of 0.05 to 0.3 mm. 28. The method for producing an extruded styrene resin foam of claim 26, wherein the cells constituting the foam comprise mainly small cells having a cell size of 0.25 mm or less and large cells having a cell size of 0.3 to 1 mm, and the area of the small cells having a cell size of 0.25 mm or less accounts for 10 to 90% of a sectional area of the foam. 29. The method for producing an extruded styrene resin foam of claim 26, wherein a halogenated flame retardant is contained in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the styrene resin, and at least one compound selected from the group consisting of phosphorus type flame retardants containing nitrogen atom in a molecule; tetrazole compounds; nitrogen-containing compounds selected from cyanuric acid, isocyanuric acid, and derivatives thereof; metal borates; boron oxides; and phosphoric acid ester compounds, is contained in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the styrene resin. 30. The method for producing an extruded styrene resin foam of claim 29, wherein the nitrogen-containing compound selected from cyanuric acid, isocyanuric acid, and derivatives thereof is at least one member selected from the group consisting of nitrogen-containing compounds having the following general formula 1, and nitrogen-containing compounds having the following general formula 2: ##STR23## wherein R.sup.1, R.sup.2 and R.sup.3 are selected from hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an organic group represented by the formula: --Y--X (wherein Y is an alkylene group having 1 to 6 carbon atoms, a phenylene group, or a cycloalkylene group, and X is an epoxy group, a carboxyl group, a hydroxyl group, an amino group, a phenyl group, or a monovalent organic group having phosphorus atom), and a phenyl group, and may be different from each other; ##STR24## wherein R.sup.4, R.sup.5 and R.sup.6 are selected from hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an organic group represented by the formula: --Y--X (wherein Y is an alkylene group having 1 to 6 carbon atoms, a phenylene group, or a cycloalkylene group, and X is an epoxy group, a carboxyl group, a hydroxyl group, an amino group, a phenyl group, or a monovalent organic group having phosphorus atom), and a phenyl group, and may be different from each other. 31. The method for producing an extruded styrene resin foam of claim 26, wherein a foam which has a cell structure constituting the foam wherein a cell anisotropic ratio k, which is defined by the formula: k=a/(a.times.b.times.c).sup.1/3 wherein, in sections of the foam, a (mm) is an average cell size in the thickness direction, b (mm) is an average cell size in the transverse direction and c (mm) is an average cell size in the longitudinal direction, satisfies the relationship: k.ltoreq.1.1, and a satisfies the relationship: 0.05.ltoreq.a.ltoreq.0.30, is obtained. |
| PATENT DESCRIPTION | available on request |
| PATENT EXAMPLES | available on request |
| PATENT PHOTOCOPY | available on request |
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