JP4138638B2 - Method for producing silica-dispersed hydrophilic polyurethane resin composition - Google Patents

Description

The present invention relates to a method for producing a silica-dispersed hydrophilic polyurethane resin composition, and more specifically, has excellent adhesion to various materials, and has water absorption, antifogging properties, transparency, flexibility, water-based ink writing properties and water resistance. The present invention relates to a method for producing a silica-dispersed hydrophilic polyurethane resin composition having excellent properties, blocking resistance, and lubricity.

Polyurethane resin is excellent in abrasion resistance, adhesiveness, flexibility, chemical resistance, etc., and is also excellent in applicability to various processing methods, so various binders such as coating agents, paints, inks, films, sheets, Others are widely used as molded articles, and polyurethane resins suitable for each application have been proposed.
This polyurethane resin is a generic term for polyurethane resin, polyurea resin, and polyurethane-polyurea resin.
These polyurethane-based resins are basically obtained by reacting a high-molecular-weight polyol component, an organic polyisocyanate component, and, if necessary, a chain extender component. A polyurethane resin having physical properties is provided.

However, depending on the use of the polyurethane-based resin, for example, hydrophilic properties such as anti-fogging paints for agricultural resin sheets, surface treatment agents for interior resin wallpaper, fiber coating agents, coating agents for inkjet image-receiving sheets, etc. Usually, blocking resistance is also required at the same time.
Among the polyurethane resins, when polyethylene glycol obtained from the reversion polymerization of ethylene oxide is used as the high molecular weight hydrophilic polyol component, a polyurethane resin having high strength, high elasticity and excellent hydrophilicity can be obtained. The water resistance is poor, and swelling, whitening, and strength reduction occur due to moisture, and there is a problem that it is not suitable for various paints, binders for printing inks, molded products, films, sheets and the like.

For these problems, it is generally known to obtain a polyurethane resin by dispersing a fine particle filler such as calcium carbonate, silica, titanium oxide in a polyurethane resin or by dispersing it in a high molecular weight polyol component as a raw material. is there.
However, in the above known examples, the fine particle filler can be dispersed only at most about 5% by mass in the entire polyurethane resin, and it is difficult to disperse a large amount of the fine particle filler in the polyurethane resin.
This is because, as fine powdery particles are widely known as thickeners and thixotropic agents, the viscosity of polyurethane resins and high molecular weight polyols in which a large amount of fine particle filler is dispersed becomes extremely high. .
In addition, the fine particle filler generally lowers the transparency so that it is generally used as a matting agent (matting agent), and even if the dispersion amount is as small as 5% by mass or less, the transparency is significantly reduced. To do.

The present invention has been made in view of the above circumstances, and the object of the present invention is excellent in adhesiveness to various materials, and has water absorption, antifogging properties, transparency, flexibility, water-based ink writing properties, and The object is to provide a method for producing a silica-dispersed hydrophilic polyurethane resin composition having excellent water resistance, blocking resistance, and lubricity.
As a result of repeated studies to achieve the above-mentioned object, the present inventors have produced a hydrophilic polyurethane-based resin having a hydrophilic segment and a polysiloxane segment. Alternatively, by using a high molecular weight hydrophilic polyol and / or polyamine in which silica sol is dispersed in advance as a polyamine, a composition in which fine particle silica is dispersed in the obtained hydrophilic polyurethane-based resin is a fine particle silica in the solution. Formed a stable dispersion without separation / sedimentation even when the amount was large, and the film was transparent, and it was found that the above object was achieved, thereby completing the present invention.

The above object is achieved by the present invention described below.
That is, the present invention comprises an organic polyisocyanate, any of the following high molecular weight hydrophilic polyols and / or polyamines having a weight average molecular weight of 400 to 8,000, and at least one active hydrogen-containing group in the molecule. A silica-dispersed hydrophilic polyurethane resin composition comprising a hydrophilic polyurethane resin having a hydrophilic segment obtained by reacting a polysiloxane compound having a polysiloxane segment and fine particle silica having an average particle size of 1 μm or less is produced. The hydrophilic polyurethane resin is a mixture of silica sol and the polyol and / or polyamine as at least a part of the high molecular weight hydrophilic polyol and / or polyamine in the raw material component, the polyol and / Or from a mixture of polyamine and silica sol A method for producing a silica dispersion hydrophilic polyurethane resin composition characterized in that prepared using the obtained by removing a dispersion solvent Kazoru.
Polyethylene glycol,
Polyethylene glycol / polytetramethylene glycol copolymer polyol,
Polyethylene glycol / polypropylene glycol copolymer polyol,
Polyethylene glycol adipate,
Polyethylene glycol succinate,
Polyethylene glycol / polyε-lactone copolymer polyol,
Polyethylene glycol / polyvalerolactone copolymer polyol,
Polyethylene oxide diamine,
Polyethylene oxide, propylene oxide diamine,
Polyethylene oxide triamine,
Polyethylene oxide propylene oxide triamine

  The silica-dispersed hydrophilic polyurethane resin composition of the present invention has excellent adhesion to various materials, and is excellent in water absorption, antifogging properties, transparency, water-based ink writing properties, water resistance, blocking resistance, and lubricity. As an image-receiving coating agent for inkjet image-receiving sheets, as an anti-fogging paint for various films, as a surface treatment agent for preventing condensation on interior resin wallpaper, as a water-absorbing clothing coating material, or as a synthetic artificial leather material Useful.

  The present invention is described in more detail below.

  The silica-dispersed hydrophilic polyurethane resin composition of the present invention is a composition comprising a hydrophilic polyurethane resin having a hydrophilic segment and a polysiloxane segment and fine particle silica. In the solution, the fine particle silica is stably dispersed in the above hydrophilic polyurethane resin solution without separation or sedimentation even when the amount thereof is large or without using a dispersant. The film formed from is characterized by being transparent. In the present invention, the polyurethane resin is a general term for polyurethane resin, polyurea resin, and polyurethane-polyurea resin.

Silica Dispersion hydrophilic polyurethane resin composition of the above-described present invention, an organic polyisocyanate, a high molecular weight hydrophilic polyol and / or polyamine, polysiloxane compound having at least one active hydrogen-containing groups in the molecule When a hydrophilic polyurethane resin is synthesized by reacting with a chain extender as necessary, a mixture of the above polyol and / or polyamine and silica sol is used as at least part of the high molecular weight hydrophilic polyol and / or polyamine. You can get it.

The mixture of high molecular weight hydrophilic polyol and / or polyamine and silica sol, was mixed with high molecular weight hydrophilic polyol and / or polyamine and a silica sol, to use mixtures obtained by removing the dispersion solvent silica sol from the mixture The The high molecular weight hydrophilic polyol and / or polyamine can also be mixed with the silica sol as a solution. In this case, all the solvent is removed after mixing.

Silica sol and the in the present invention, which fine particulate silica or particulate silica compound is stably dispersed in the dispersion solvent, the average particle size of the fine silica mosquito this silica sol is usually 1μm or less, particularly 1~300mμm (nm ) Is preferred. The dispersion medium in silica sol is usually water and / or alcohol, but ketones, esters and other organic solvents are also used.

  Usually, even if silica sol (stable dispersion) is added to and dispersed in a polyurethane resin solution, the dispersion stability of the fine particle silica is low, and both are easily separated with time. This is due to the compatibility (affinity) with the polyurethane-based resin, the stability of both of them against changes in pH, and the properties of the polyurethane-based resin and the silica surface being different. A method of adding silica sol to the reaction system at the time of the synthesis reaction of the polyurethane resin is also conceivable. However, since the silica sol water or alcohol-based dispersion medium reacts with isocyanate, it cannot be used. Even when silica sol is used, the dispersion stability of the silica fine particles cannot be obtained.

  However, the high molecular weight hydrophilic polyol and polyamine described later used in the present invention have extremely high compatibility (affinity) with the silica sol due to their hydrophilicity, and can be stably mixed with the silica sol at an arbitrary ratio. Then, the dispersion medium is removed from the mixture by an arbitrary method to obtain a high molecular weight hydrophilic polyol and / or polyamine in which silica fine particles are dispersed very stably, and the fine particles in the high molecular weight hydrophilic polyol and / or polyamine are obtained. Even if the silica content is increased, the viscosity of the polyol and / or polyamine is small and a very transparent mixture is obtained.

  In the synthesis of the polyurethane-based resin, this mixture is used as at least a part of the high molecular weight hydrophilic polyol and / or polyamine in the raw material component, so that the fine particle silica can be used even during and after the synthesis (polymerization) reaction. Can be stably present in the reaction system without separation and sedimentation, and a hydrophilic polyurethane resin composition in which fine-particle silica is stably dispersed in the polyurethane resin solution can be obtained.

  A mixture of high molecular weight hydrophilic polyol and / or polyamine and silica sol is usually prepared by removing water or water and an organic solvent, which is a dispersion solvent of silica sol in a mixture of high molecular weight hydrophilic polyol and / or polyamine and silica sol under reduced pressure or the like. It can be obtained by easily distilling off. In this case, the distillation is preferably carried out under reduced pressure at a low temperature, particularly preferably at 70 ° C. or lower. When the temperature is higher than this, the fine particle silica may be agglomerated, the dispersion stability of the fine particle silica is lowered, and the low molecular weight silica-dispersed high molecular weight hydrophilic polyol and / or polyamine is produced. There is. The mixing ratio of the high molecular weight hydrophilic polyol and / or polyamine and the silica sol is preferably such that the amount of the fine particle silica in the resulting silica-dispersed hydrophilic polyurethane-based resin composition (solid content) is 5 to 95% by mass. Is an amount of 10 to 90% by mass.

  The silica-dispersed hydrophilic polyurethane resin composition of the present invention is obtained by removing the silica sol dispersion solvent from a mixture of these and silica sol as a part or all of the high molecular weight hydrophilic polyol and / or polyamine. It is obtained by using a high molecular weight hydrophilic polyol and / or polyamine in which fine particle silica is dispersed and reacting it with a polysiloxane compound, polyisocyanate and, if necessary, a chain extender according to a conventionally known method for producing a polyurethane resin. be able to. The reaction may be solventless or a reaction in an aqueous solution or an organic solvent. In the case of no solvent, the obtained silica-dispersed hydrophilic polyurethane resin composition can be used by dissolving in a soluble solvent of the hydrophilic polyurethane resin. Also in this case, the dispersion stability of the fine particle silica in the hydrophilic polyurethane resin solution is maintained. The polymerization solvent and the hydrophilic polyurethane resin-soluble solvent are not particularly limited, and preferred examples include dimethylformamide and methyl ethyl ketone. The silica-dispersed hydrophilic polyurethane resin composition of the present invention is used in a solution state or in a solid state depending on the application.

  The hydrophilic polyurethane resin in the silica-dispersed hydrophilic polyurethane resin composition of the present invention has a hydrophilic segment having a high molecular weight hydrophilic polyol and / or polyamine in the molecule and a polysiloxane compound as the structural unit. And polysiloxane segments. When no chain extender is used, these segments are bonded at random by urethane bonds, urea bonds, or urethane-urea bonds. When a chain extender is used, there is a bond in which a short chain that is a residue of the chain extender exists between these bonds together with these bonds.

  The hydrophilic polyurethane-based resin in the present invention has excellent adhesion to various materials and excellent water absorption, antifogging properties, transparency, flexibility, aqueous properties by introducing a polysiloxane segment in the molecule. Ink writing properties and excellent water resistance, blocking resistance, and lubricity are imparted.

Introducing polysiloxane segments that are inherently hydrophobic (water repellent) into the resin structure should not be expected to give good results for water absorption and hydrophilicity.
However, the film surface formed from a resin having a low polysiloxane segment content is completely covered with a polysiloxane component in a dry state, but when the film is immersed in water, the polysiloxane component is buried in the resin. It is known that there is a phenomenon that causes environmental responsiveness. (Polymer Journal, Vol. 48 [No. 4], p. 227 (1991), etc.).

  The hydrophilic polyurethane resin having a polysiloxane segment of the present invention utilizes this phenomenon. By appropriately controlling the content of the polysiloxane segment in the resin, printing with high humidity or water-based ink or the like is possible. The surface shows hydrophilicity due to environmental response, and the surface during or after drying is covered with a polysiloxane component, and exhibits excellent water resistance, blocking resistance, lubricity and the like. The present inventors have already clarified these in Japanese Patent Application No. 10-235545, Japanese Patent Application No. 10-240811, Japanese Patent Application No. 10-170296, and others.

  In the present invention, the polysiloxane compound used for introducing the polysiloxane segment into the molecular chain constituting the hydrophilic polyurethane resin is a reactive group (active hydrogen) having one or more active hydrogens in the molecule. A polysiloxane compound having an amino group, an epoxy group, a hydroxyl group, a mercapto group, a carboxyl group, and the like. Preferable examples of the polysiloxane compound having such a reactive group include the following compounds.

(1) Amino-modified polysiloxane compound

(2) Epoxy-modified polysiloxane compound

(3) Alcohol-modified polysiloxane compound

(4) Mercapto-modified polysiloxane compound

(5) Carboxyl-modified polysiloxane compound

The polysiloxane compounds having reactive organic functional groups listed above are examples of preferred compounds used in the present invention, and the present invention is not limited to these exemplified compounds.
Accordingly, not only the above-exemplified compounds but also any other compounds that are currently commercially available and can be easily obtained from the market can be used in the present invention.

  As the organic polyisocyanate used in the present invention, any conventionally known polyisocyanate can be used and is not particularly limited. Preferable examples include 4,4′-diphenylmethane diisocyanate (MDI), hydrogenated MDI, isophorone diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, 2,4-tolylene diisocyanate, 2, 6-tolylene diisocyanate, 1,5-naphthalene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, etc., or obtained by reacting these organic polyisocyanates with low molecular weight polyols or polyamines to be terminal isocyanates Also usable are polyurethane prepolymers and the like.

The high molecular weight hydrophilic polyol or polyamine used in the present invention, the weight-average molecular weight having a hydroxyl group or an amino group is in a range of 400～8,000, as polyol terminated with a hydrophilic in hydroxyl, specifically In terms of
Polyethylene glycol Polyethylene glycol / polytetramethylene glycol copolymer polyols polyethylene glycol / polypropylene glycol copolymer polyols polyethylene glycol adipate polyethylene glycol succinate polyethylene glycol / poly ε- lactone copolymer polyol polyethylene glycol / poly-valerolactone copolymer a polyol Le is,
As a polyamine having a terminal amino group and hydrophilicity, specifically ,
Polyethylene oxide diamine, polyethylene oxide propylene oxide diamine, polyethylene oxide triamine polyethylene oxide-propylene oxide birds Amin and the like.
However, in order to impart other performance, it is possible to copolymerize other polyols, polyamines, polycarboxylic acids and the like that do not have a hydrophilic chain.

The silica-dispersed hydrophilic polyurethane resin composition of the present invention is a fine particle silica obtained by removing the dispersion solvent of silica sol from a mixture of these and silica sol as a part or all of the high molecular weight hydrophilic polyol and / or polyamine. It can be obtained by using a dispersed high molecular weight hydrophilic polyol and / or polyamine, using a polysiloxane compound, polyisocyanate, and, if necessary, a chain extender, and reacting them according to a conventionally known method for producing polyurethane resins. The reaction may be solventless or a reaction in an aqueous solution or an organic solvent.
In the silica-dispersed hydrophilic polyurethane resin of the present invention, the hydrophilic polyurethane resin having a hydrophilic segment and a polysiloxane segment in the molecular chain has a weight average molecular weight (in terms of standard polystyrene measured by GPC) of 3,000 to 3,000. The range of 800,000 is preferable, and the range of 5,000 to 500,000 is more preferable.

In the silica-dispersed hydrophilic polyurethane resin composition of the present invention, the content of the fine particle silica is preferably 5 to 95% by mass, more preferably 10 to 90% by mass with respect to the hydrophilic polyurethane resin.
If the content of the fine-particle silica is less than 5% by mass, the surface properties such as blocking resistance and lubricity, which are the objects of the present invention, will be insufficient. On the other hand, if it exceeds 95% by mass, the strength of the film and the adhesion to the substrate It is not preferable because it becomes inferior.
Even more surprisingly, when the content of fine-particle silica is 75 to 95% by mass, the silica dispersed hydrophilic polyurethane resin composition of the present invention is coated with the solution on a base material, and after film formation, several m μm ( nm) size microporous material is formed, and a film having excellent transparency can be obtained.

The polysiloxane segment in the hydrophilic polyurethane resin of the present invention may be contained in the main chain, the side chain, or both. The content of the polysiloxane segment in the hydrophilic polyurethane resin is preferably 0.1 to 10% by mass, more preferably 2 to 10% by mass.
If the content of the polysiloxane segment is less than 0.1% by mass, the surface properties such as water resistance, blocking resistance, and lubricity, which are the objects of the present invention, are insufficient. On the other hand, if the content exceeds 10% by mass, the polysiloxane segment is insufficient. This is not preferable because the water repellency due to the water becomes stronger and the environmental responsiveness utilized by the present invention becomes poor, resulting in poor water absorption, antifogging properties and transparency.

  Moreover, the preferable content of the hydrophilic segment in the hydrophilic polyurethane resin of the present invention is 30 to 80% by mass, and more preferably 50 to 75% by mass. If the content of the hydrophilic segment is less than 30% by mass, the water absorption and antifogging properties are inferior. On the other hand, if it exceeds 80% by mass, the water resistance and blocking resistance are inferior.

  The silica-dispersed hydrophilic polyurethane-based resin composition obtained in the present invention as described above is excellent in adhesion to various materials, and has water absorption, antifogging properties, transparency, flexibility, water-based ink writing properties and water resistance. Excellent in blocking resistance and slipperiness, as an image-receiving layer coating agent for inkjet image-receiving sheets, as an anti-fogging paint for various films, and as a surface treatment agent for preventing condensation on interior resin wallpaper, for water-absorbing clothing As a coating agent, it is very useful as a material for synthetic leather, a water-based ink writing treatment for synthetic paper, and the like.

  Next, the present invention will be described in more detail with reference examples, examples and comparative examples. In addition, the part or% in a sentence is a mass reference | standard.

Reference example 1
700 parts of polyethylene glycol (molecular weight 1,000) and 1,500 parts of silica water sol (silica average particle size 10 to 20 nm, solid content 20%) were mixed and dehydrated under reduced pressure at 70 ° C. with stirring.
After the theoretical amount of water was distilled off, the temperature was raised to 120 ° C. and water was removed under reduced pressure of 133.3 Pa or less to obtain a white solid polyol (A) having a silica content of 30%. This polyol had a hydroxyl value of 76 mgKOH / g, a moisture content of 0.15%, was transparent at 80 ° C., and had a viscosity of 450 dPa · s.

Reference example 2
100 parts of polyethylene glycol (molecular weight 590) and 333 parts of silica water sol (silica average particle size 200-230 nm, solid content 30%) were mixed and dehydrated under reduced pressure at 70 ° C. with stirring.
After the theoretical amount of water was distilled off, the temperature was raised to 120 ° C. and water was removed under reduced pressure of 133.3 Pa or less to obtain a white solid polyol (B) having a silica content of 50%. This polyol is softened at a hydroxyl value of 95 mgKOH / g, a moisture content of 0.12% and 110 ° C.

Reference example 3
100 parts of polyethylene oxide diamine (Jefamine ED manufactured by Texaco Chemical Co., Ltd .; molecular weight 600) and 2,250 parts of silica methanol sol (silica average particle size 20-30 nm, solid content 40%) are mixed and reduced in pressure at 70 ° C. with stirring. Dehydration was performed.
After the theoretical amount of water was distilled off, the temperature was raised to 120 ° C. and methanol was removed under a reduced pressure of 133.3 Pa or less to obtain a white solid polyamine (C) having a silica content of 90%. This polyamine is softened at an amine equivalent of 30 g / mol, a moisture content of 0.20%, and 130 ° C.

上記構造のポリジメチルシロキサンポリオール（分子量３，２００）５部と、参考例１のポリオール（Ａ）１５０部、エチレングリコール５部を、２００部のメチルエチルケトンと２００部のジメチルホルムアミドとの混合溶媒中に溶解し、６０℃でよく攪拌しながら、４８部の水素添加ＭＤＩを１００部のメチルエチルケトンに溶解したものを徐々に滴下し、滴下終了後８０℃で８時間反応させた後、ジメチルホルムアミド３３０部を加えて本発明のシリカ分散親水性ポリウレタン樹脂組成物の溶液を得た。
この溶液は固形分２０％で、３０ｄＰａ・ｓ（２５℃）の粘度を有し、ポリウレタン樹脂のＧＰＣで測定し、標準ポリスチレン換算の重量平均分子量（以下の例においても同様）は４２，０００であり、ポリシロキサンセグメントの含有量は２．１％、親水性セグメントの含有量は５０．５％、微粒子シリカの含有量は２１．６％であった。
この溶液から形成したフィルムは透明で、破断強度は３５．５Ｍｐａ、破断伸度は３０％、且つ軟化点は１７５℃であった。 Example 1
(Production of silica-dispersed hydrophilic polyurethane resin composition)

5 parts of polydimethylsiloxane polyol (molecular weight 3,200) having the above structure, 150 parts of polyol (A) of Reference Example 1 and 5 parts of ethylene glycol are mixed in a mixed solvent of 200 parts of methyl ethyl ketone and 200 parts of dimethylformamide. Dissolve and with stirring well at 60 ° C., gradually add 48 parts of hydrogenated MDI dissolved in 100 parts of methyl ethyl ketone. After completion of the addition, react at 80 ° C. for 8 hours, and then add 330 parts of dimethylformamide. In addition, a solution of the silica-dispersed hydrophilic polyurethane resin composition of the present invention was obtained.
This solution has a solid content of 20%, a viscosity of 30 dPa · s (25 ° C.), and is measured by GPC of a polyurethane resin. The weight average molecular weight in terms of standard polystyrene (the same applies to the following examples) is 42,000. The content of the polysiloxane segment was 2.1%, the content of the hydrophilic segment was 50.5%, and the content of the fine particle silica was 21.6%.
The film formed from this solution was transparent, the breaking strength was 35.5 Mpa, the breaking elongation was 30%, and the softening point was 175 ° C.

上記構造のポリジメチルシロキサンジアミン（分子量３，８８０）５部、参考例２のポリオール（Ｂ）１２０部及びポリエチレンオキサイドジアミン（分子量２，０００）２５部を１００部のメチルエチルケトン及び２００部のジメチルホルムアミド混合溶剤中に溶解し、６０℃でよく攪拌しながら、３０部の水素添加ＭＤＩを１００部のメチルエチルケトンに溶解した溶液を徐々に滴下し、滴下終了後８０℃で８時間反応させた後、ジメチルホルムアミド３２０部を加えて本発明のシリカ分散親水性ポリウレタン−ポリウレア樹脂組成物の溶液を得た。
この樹脂溶液は、固形分２０％で、８０ｄＰａ・ｓ（２５℃）の粘度を有していた。
ポリウレタン−ポリウレア樹脂の重量平均分子量は５１，０００であり、ポリシロキサンセグメントの含有量は２．５％、親水性セグメントの含有量は４７．２％、シリカの含有量は３３．３％であった。
この溶液から形成したフィルムは、透明で、破断強度は２８．５Ｍｐａ、破断伸度は２０％、且つ軟化点は１８３℃であった。 Example 2
(Production of silica-dispersed hydrophilic polyurethane-polyurea resin composition)

5 parts of polydimethylsiloxane diamine (molecular weight 3,880) having the above structure, 120 parts of polyol (B) of Reference Example 2 and 25 parts of polyethylene oxide diamine (molecular weight 2,000) were mixed with 100 parts of methyl ethyl ketone and 200 parts of dimethylformamide. While dissolving in a solvent and stirring well at 60 ° C., a solution of 30 parts of hydrogenated MDI dissolved in 100 parts of methyl ethyl ketone was gradually added dropwise. After completion of the addition, the mixture was reacted at 80 ° C. for 8 hours, and then dimethylformamide. 320 parts was added to obtain a silica-dispersed hydrophilic polyurethane-polyurea resin composition solution of the present invention.
This resin solution had a solid content of 20% and a viscosity of 80 dPa · s (25 ° C.).
The weight average molecular weight of the polyurethane-polyurea resin was 51,000, the polysiloxane segment content was 2.5%, the hydrophilic segment content was 47.2%, and the silica content was 33.3%. It was.
The film formed from this solution was transparent, its breaking strength was 28.5 Mpa, its breaking elongation was 20%, and its softening point was 183 ° C.

Example 3
(Production of silica-dispersed polyurea resin composition)
5 parts of polydimethylsiloxane diamine (molecular weight 3,880) of Example 2 and 145 parts of polyamine (C) of Reference Example 3 are dissolved in 250 parts of dimethylformamide, and the internal temperature may be kept at 0 to -5 ° C and stirred. Then, a solution prepared by dissolving 6 parts of hydrogenated MDI in 100 parts of dimethylformamide was gradually added dropwise to react.
After the completion of the dropwise addition, the internal temperature was gradually raised, and after a further 5 hours when the temperature reached 50 ° C., 275 parts of dimethylformamide was added to obtain a solution of the silica-dispersed polyurea resin composition of the present invention.
This resin solution has a solid content of 20%, a viscosity of 170 dPa · s (25 ° C.), the polyurea resin has a weight average molecular weight of 41,000, and a polysiloxane segment content of 2.8%, The hydrophilic segment content was 9.3% and the silica content was 83.6%.
The film formed from the resin solution is slightly translucent and porous. The breaking strength was 8.2 Mpa, the breaking elongation was 5%, and the softening point was 220 ° C.

Comparative Example 1
A polyurethane resin solution was obtained by the same material and formulation as in Example 1 except that the polydimethylsiloxane polyol was not used and the polyol of the polyol (A) in Reference Example 1 except for the silica was used.
This resin solution had a solid content of 20%, a viscosity of 50 dPa · s (25 ° C.), and the weight-average molecular weight of the polyurethane resin was 68,000.
The film formed from this solution had a breaking strength of 35.0 MPa, a breaking elongation of 450%, and a softening point of 103 ° C.

Comparative Example 2
A polyurethane-polyurea resin solution was obtained by the same material and formulation as in Example 2 except that polydimethylsiloxane diamine was not used and the polyol of the polyol (B) in Reference Example 2 was removed.
This resin solution had a solid content of 20%, a viscosity of 40 dPa · s (25 ° C.), and the weight-average molecular weight of the polyurethane-polyurea resin was 55,000.
The film formed from this resin solution had a breaking strength of 25.3 Mpa, a breaking elongation of 400%, and a softening point of 95 ° C.

Comparative Example 3
A polyurea resin solution was obtained using the same material and formulation as in Example 3 except that polydimethylsiloxane diamine was not used and that the polyamine (C) of Reference Example 3 was used except for the polyamine.
This resin solution had a solid content of 20%, a viscosity of 25 dPa · s (25 ° C.), and the polyurea resin had a weight average molecular weight of 32,000.
The film formed from this resin solution had a breaking strength of 22.7 Mpa, a breaking elongation of 350%, and a softening point of 115 ° C.

Comparative Examples 4-6
Each silica water sol or silica methanol sol of Reference Examples 1 to 3 was added to each of the resin solutions of Comparative Examples 1 to 3 with stirring, but the particles precipitated and the solution became opaque.

Comparative Example 7
A 5% aqueous solution of polyvinyl alcohol having a saponification degree of 98.5% (polymerization degree 550) was prepared.

It was evaluated obtained silica dispersion polyurethane resin composition such as the above in the following manner. The evaluation results are shown in Table 1.
[1] Application to Inkjet Image Receiving Layer Each of the resin solutions obtained in Examples 1 to 3 and Comparative Examples 1 to 7 was applied to a 100 μm thick PET film so that the thickness after drying was 25 μm. A transparent sheet was prepared and recorded by a color ink jet printer (PM-800C manufactured by Seiko Epson Corporation), and the following items were evaluated.

(1) Blocking property An untreated PET film was layered on the resin coating surface, and blocking property was evaluated after standing for one day at a load of 0.29 Mpa and a temperature of 40 ° C.
The results are displayed as follows.
○: No blocking property Δ: Some blocking property ×: Blocking property

(2) Transparency The haze on the resin coating surface was judged visually.
○: Completely transparent △: Slightly cloudy ×: Completely opaque

(3) Colored sharpness After color printing with an inkjet printer, the color sharpness of the obtained color image was visually observed.
○: no blur and clear △: no blur but slightly blurred ×: blur

(4) Dryability of ink After color printing with an ink jet printer, the filter paper was pressed for 5 seconds with a load of 50 g / m ² , and the time until the ink was not transferred to the filter paper was measured.

(5) Water resistance of printed image After color printing with an ink jet printer, the recording sheet was immersed in water (20 ° C, 1 hour) and then dried at room temperature. .
○: No change Δ: Change is observed in ink and film ×: Ink can be considerably removed or the entire film can be taken Table 1 shows the above evaluation results.

Comparative Example 8
The resin obtained in Comparative Example 1 was mixed with a nonionic surfactant (polyoxyethylene nonylphenyl ether: manufactured by NOF Corporation) so that the solid content mass ratio was 95: 5.

Comparative Example 9
Polyvinyl butyral (degree of polymerization 700: manufactured by Sekisui Chemical Co., Ltd.), trioctyl phosphate 50 parts and polyoxyethylene lauryl ether acid ester (phosphate ester surfactant: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) in 400 parts of ethanol Mixed and dissolved.

[2] Application to anti-fogging / anti-static coating material Brush the resin solutions obtained in Examples 1 to 3 and Comparative Examples 1, 8, and 9 to a transparent acrylic resin plate to a thickness of 25 μm after drying. Samples were evaluated for surface hardness, antifogging properties, and antistatic properties.

(1) Surface hardness Pencil hardness test (8.4 of JIS K5400) was evaluated by surface scratches.

(2) Anti-fogging property The fogging of the coating film was evaluated when a sample plate was set at 5 cm on an 80 ° C. warm bath and exposed to water vapor for 10 minutes.
○: No cloudiness △: Partially cloudy ×: Cloudy

(3) Water resistance The state of the coating film was evaluated when a sample plate was set at 5 cm on an 80 ° C. warm bath and exposed to water vapor for 10 minutes.
○: No change △: Some change in coating film ×: Peeling or dissolution of coating film

(4) Antistatic property Adhesiveness of charged carbon was evaluated by a dust chamber test.
○: No carbon adhesion Δ: Partial carbon adhesion ×: Carbon adhesion Table 2 shows the above evaluation results.

Claims (4)

An organic polyisocyanate, any of the following, a high molecular weight hydrophilic polyol and / or polyamine having a weight average molecular weight of 400 to 8,000, and a polysiloxane compound having at least one active hydrogen-containing group in the molecule In the method for producing a silica-dispersed hydrophilic polyurethane-based resin composition comprising a hydrophilic polyurethane-based resin having a hydrophilic segment and a polysiloxane segment obtained by reaction and a fine particle silica having an average particle diameter of 1 μm or less, And a mixture of a silica sol and the polyol and / or polyamine as at least a part of the high molecular weight hydrophilic polyol and / or polyamine in the raw material component, the polyol and / or the polyamine and the silica sol A dispersion of silica sol from a mixture of Method for producing a silica dispersion hydrophilic polyurethane resin composition characterized in that to produce using what were removed.
Polyethylene glycol,
Polyethylene glycol / polytetramethylene glycol copolymer polyol,
Polyethylene glycol / polypropylene glycol copolymer polyol,
Polyethylene glycol adipate,
Polyethylene glycol succinate,
Polyethylene glycol / polyε-lactone copolymer polyol,
Polyethylene glycol / polyvalerolactone copolymer polyol,
Polyethylene oxide diamine,
Polyethylene oxide, propylene oxide diamine,
Polyethylene oxide triamine,
Polyethylene oxide propylene oxide triamine The method for producing a silica-dispersed hydrophilic polyurethane resin composition according to claim 1, wherein an average particle diameter of silica in the silica sol is 1 to 300 nm. The silica-dispersed hydrophilic polyurethane resin composition according to claim 1 , wherein the silica content in the mixture from which the dispersion solvent has been removed is an amount such that the silica content in the product composition is 5 to 95% by mass. Manufacturing method.   2. The silica-dispersed hydrophilic polyurethane resin composition according to claim 1, wherein the content of the hydrophilic segment in the hydrophilic polyurethane resin is 30 to 80 mass% and the content of the polysiloxane segment is 0.1 to 10 mass%. Manufacturing method.