Modifier for hydrophilicity, hydrophilic modification method and aluminum material or aluminum alloy material modified hydrophilic thereby

1. A modifier for hydrophilicity which comprises a modified polyvinyl alcohol, with the degree of saponification of not less than 90%, containing a group represented by the formula (I) on a side chain thereof;

in the formula, n represents an integer of 1 to 500, R 1 represents a hydrogen atom or an alkyl group containing 1 to 4 carbon atoms, and R 2 represents a hydrogen atom or a methyl group,

said group represented by the above formula (I) accounting for 0.1 to 10 mole percent of the sum of hydroxyl groups and acetoxy groups in said modified polyvinyl alcohol, and

said modified polyvinyl alcohol accounting for 0.1 to 30% by mass relative to said modifier for hydrophilicity, and

said modifier for hydrophilicity further comprises a polyvinyl alcohol not containing any group represented by the formula (I) in an amount of 0.1 to 30% by mass relative to said modifier for hydrophilicity.

2. The modifier for hydrophilicity according to claim 1 ,

which further comprises at least one member selected from the group consisting of phosphorus compound salts and boron compound salts of Ca, Al, Mg, Fe and Zn in an amount of 0.1 to 200% by mass relative to a resin solid matter.

3. The modifier for hydrophilicity according to claim 2 ,

which further comprises at least one member selected from the group consisting of inorganic crosslinking agents and organic crosslinking agents.

4. The modifier for hydrophilicity according to claim 3 ,

wherein the inorganic crosslinking agents are selected from the group consisting of zirconium compounds, titanium compounds, chromium compounds, aluminum compounds, zinc compounds, and silica, and the organic crosslinking agents are selected from the group consisting of blocked isocyanates, phenolic resins, melamine, silane coupling agents, titanium coupling agents, epoxy compounds, carbodiimides, thiol compounds, silane compounds, amino resins, carboxylic acids, carboxylic anhydrides, amines, and aziridine compounds.

5. The modifier for hydrophilicity according to claim 2 ,

which further comprises particles of an organic compound or an inorganic compound, in an amount of less than 50% by mass relative to the resin solid matter, said particles having a mean particle diameter of 0.01 to 5 μm and said organic compound and said inorganic compound crosslinking agents, and coupling agents.

6. The modifier for hydrophilicity according to claim 2 ,

which further comprises less than 50% by mass, relative to the resin solid matter, of particles of an organic compound or an inorganic compound having a mean particle diameter of 0.01 to 5 μm,

said organic compound being at least one member selected from the group consisting of acrylic, silicone, melamine and cellulosic polymers, and

said inorganic compound being at least one member selected from the group consisting of titanium oxide, aluminum oxide, zirconium oxide, glass beads and silica.

7. The modifier for hydrophilicity according to claim 1 ,

which further comprises at least one member selected from the group consisting of inorganic crosslinking agents, and organic crosslinking agents.

8. The modifier for hydrophilicity according to claim 7 ,

which further comprises particles of an organic compound or an inorganic compound, in an amount of less than 50% by mass relative to the resin solid matter, said particles having a mean particle diameter of 0.01 to 5 μm and said organic compound and said inorganic compound excluding a hydrophilic organic compound, phosphorus compound salts boron compound salts, and crosslinking agents.

9. The modifier for hydrophilicity according to claim 7 ,

which comprises less than 50% by mass, relative to the resin solid matter, of particles of an organic compound or an inorganic compound having a mean particle diameter of 0.01 to 5 μm,

said organic compound being at least one member selected from the group consisting of acrylic, silicone, melamine and cellulosic polymers,

said inorganic compound being at least one member selected from the group consisting of titanium oxide, aluminum oxide, zirconium oxide, glass beads and silica.

10. The modifier for hydrophilicity according to claim 7 ,

wherein the inorganic crosslinking agents are selected from the group consisting of zirconium compounds, titanium compounds, chromium compounds, aluminum compounds, zinc compounds, and silica, and the organic crosslinking agents are selected from the group consisting of blocked isocyanates, phenolic resins, melamine, silane coupling agents, titanium coupling agents, epoxy compounds, carbodiimides, thiol compounds, silane compounds, amino resins, carboxylic acids, carboxylic anhydrides, amines, and aziridine compounds.

11. The modifier for hydrophilicity according to claim 1 ,

which further comprises particles of an organic compound or an inorganic compound, in an amount of less than 50% by mass relative to the resin solid matter, said particles having a mean particle diameter of 0.01 to 5 μm and said organic compound and said inorganic compound excluding a hydrophilic organic compound, phosphorus compound salts, boron compound salts, and crosslinking agents.

12. The modifier for hydrophilicity according to claim 1 ,

which further comprises less than 50% by mass, relative to the resin solid matter, of a hydrophilic organic compound having at least one member selected from the group consisting of hydroxyl, carboxyl, sulfo, amido, amino, phosphonic and nitrile groups and an ether bond.

13. The modifier for hydrophilicity according to claim 12 ,

wherein the hydrophilic organic compound has a polyoxyethylene chain.

14. The modifier for hydrophilicity according to claim 1 ,

which further comprises less than 50% by mass, relative to the resin solid matter, of particles of an organic compound or an inorganic compound having a mean particle diameter of 0.01 to 5 μm,

said organic compound being at least one member selected from the group consisting of acrylic, silicone, melamine and cellulosic polymers, and

said inorganic compound being at least one member selected from the group consisting of titanium oxide, aluminum oxide, zirconium oxide, glass beads and silica.