JP2005232373A - Hydrophilic polyurethane resin composition containing dispersed particulate alumina and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a hydrophilic polyurethane resin composition containing a large amount of uniformly dispersed particulate alumina to keep transparency and capable of forming a film exhibiting excellent adhesiveness to various substrates and having water-absorptivity, anticlouding property, transparency, flexibility, writability with water-based ink, water-resistance, blocking resistance and slipperiness, and provide a method for producing the composition. <P>SOLUTION: The composition is composed of a hydrophilic polyurethane resin and the particulate alumina. The hydrophilic polyurethane resin is produced by reacting an organic polyisocyanate, a hydrophilic polyol and/or polyamine having a high molecular weight and a compound having at least one reactive group and at least one hydrolyzable silyl group in the same molecule. The particulate alumina is stably dispersed in a solution of the hydrophilic polyurethane resin. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fine particle alumina-dispersed hydrophilic polyurethane resin composition comprising a hydrophilic polyurethane resin and fine particle alumina and a method for producing the same, more specifically, excellent adhesion to various materials, and excellent water absorption, antifogging, Fine particle alumina-dispersed hydrophilicity that is transparent and flexible, and suitable for the formation of water-based inks with excellent writability, water resistance, blocking resistance, and slipperiness (ink receiving layer of ink jet recording sheet, etc.) The present invention relates to a polyurethane resin composition and a method for producing the same.

  Polyurethane resin is excellent in abrasion resistance, adhesion, flexibility, chemical resistance, etc., and is also excellent in applicability to various processing methods, so it can be used as a binder for various coating agents, paints, inks, etc. It is widely used as a resin for producing sheets and other molded articles, and a polyurethane resin suitable for each application is provided. Here, the polyurethane resin is a generic term for a polyurethane resin, a polyurea resin, and a polyurethane-polyurea resin. These polyurethane resins are basically obtained by reacting a high molecular weight polyol and an organic polyisocyanate in the presence of a chain extender, if necessary. By combining them, polyurethane resins having various physical properties can be produced.

However, for polyurethane resins, for example, surface treatment agents such as antifogging paints for agricultural resin sheets and resin wallpaper for interiors, fiber coating agents, and coating agents for forming ink-receiving layers for inkjet recording sheets, etc. In general, hydrophilicity and blocking resistance are usually required simultaneously with the above characteristics.
However, a polyurethane resin obtained by using polyethylene glycol obtained from ring-opening polymerization of ethylene oxide as a high molecular weight hydrophilic polyol has high strength, high elasticity, and excellent hydrophilicity, but has poor water resistance, A film formed using a resin swells or whitens due to moisture, resulting in a decrease in strength, and has a problem that it is not suitable for uses such as binders, molded articles, films, and sheets of various paints and printing inks.

In order to solve these problems, the above polyurethane resin was synthesized by adding a fine particle filler such as calcium carbonate, alumina, titanium oxide, or by dispersing the fine particle filler in the raw material high molecular weight polyol component in advance. It is common practice to use a polyurethane resin.
However, in any of the above cases, the fine particle filler can be satisfactorily dispersed in the polyurethane resin only at most about 5% by mass, and it has been difficult to favorably disperse a large amount of the fine particle filler in the polyurethane resin.

  The reason is that the powdered fine particle filler is widely known as a thickener or thixotropic agent for various resin solutions, and when it is dispersed in a large amount in a polyurethane resin or a high molecular weight polyol, This is because the viscosity of the dispersion becomes extremely high. In addition, the fine particle filler is generally used as a matting agent of a polyurethane resin, and when dispersed in a polyurethane resin, the transparency of the polyurethane resin is lowered, and a small dispersion amount of 5% by mass or less. Even so, the transparency is significantly reduced. However, a technique for dispersing a fine particle filler in a polyurethane resin in an amount of 5% by mass or more without reducing the transparency of the polyurethane resin has not been known yet.

  The present invention has been made in view of the above circumstances, and the object of the present invention is to adhere to various materials without causing the above-mentioned dispersion problem even when a large amount of fine particle filler is dispersed in a polyurethane resin. Fine-particle-dispersed hydrophilic polyurethane resin composition capable of forming a film with excellent water absorption, anti-fogging properties, transparency, flexibility, water-based ink writing properties, water resistance, blocking resistance and slipperiness It is providing a thing and its manufacturing method.

  As a result of repeated studies to achieve the above-mentioned object, the inventors of the present invention have prepared a high-molecular-weight polyol in which fine-particle alumina is added in advance as a high-molecular-weight polyol and / or polyamine as a raw material when producing a hydrophilic polyurethane resin. Alternatively, by using a polyamine, the resulting hydrophilic polyurethane resin composition has a dispersion in which fine particle alumina is stably dispersed in the solution of the hydrophilic polyurethane resin in the solution even when the content of fine particle alumina is large. And the film formed using the same was found to be transparent, thereby completing the present invention.

  That is, according to the present invention, an organic polyisocyanate, a high molecular weight hydrophilic polyol and / or polyamine (hereinafter referred to as “hydrophilic component”), at least one reactive group and at least one hydrolyzable silyl group. Is a composition comprising a hydrophilic polyurethane resin obtained by reacting a compound having the same in the same molecule with fine particle alumina, in which the fine particle alumina is stably dispersed in the hydrophilic polyurethane resin solution. A particulate alumina-dispersed hydrophilic polyurethane resin composition (hereinafter referred to as “the composition of the present invention”) is provided.

  Further, according to the present invention, it is obtained by reacting an organic polyisocyanate, a hydrophilic component, and a compound having at least one reactive group and at least one hydrolyzable silyl group in the same molecule. A method for producing a composition comprising a hydrophilic polyurethane resin and fine-particle alumina, comprising synthesizing a hydrophilic polyurethane resin using a hydrophilic component to which fine-particle alumina is added as the hydrophilic component. It is a manufacturing method of the composition of invention.

  According to the present invention as described above, the film is excellent in adhesiveness to various materials and excellent in water absorption, antifogging property, transparency, flexibility, water-based ink writing property, water resistance, blocking resistance and lubricity. As a coating agent for forming an ink receiving layer of an ink jet recording sheet, as an antifogging paint for various films, a surface treatment agent for preventing condensation on an interior resin wallpaper, or a water-absorbing clothing coating agent, Provides a composition comprising a hydrophilic polyurethane resin and fine particle alumina, which are useful as a synthetic artificial leather material.

Next, the present invention will be described in more detail with reference to the best mode for carrying out the invention.
The composition of the present invention is composed of a hydrophilic polyurethane resin and fine particle alumina. The hydrophilic polyurethane resin used in the present invention requires an organic polyisocyanate, a hydrophilic component, and a compound having at least one reactive group and at least one hydrolyzable silyl group in the same molecule. Accordingly, it is a hydrophilic polyurethane resin obtained by reacting in the presence of a chain extender.

  In the present invention, the fine particle alumina is contained in the hydrophilic polyurethane resin to be produced by synthesizing the polyurethane resin by adding fine particle alumina in advance to the hydrophilic component when the hydrophilic polyurethane resin is synthesized ( Distributed). The fine particle alumina is stably dispersed in the obtained solution of the hydrophilic polyurethane resin without being separated or settled although a dispersant is not used. A film formed from this solution is also characterized by being transparent even when the amount of fine particle alumina dispersed is large. In the present invention, the polyurethane resin is a general term for a polyurethane resin, a polyurea resin, and a polyurethane-polyurea resin.

  In the present invention, as the mixture of the hydrophilic component and the fine particle alumina, a mixture obtained by mechanically mixing and dispersing the fine particle alumina in the hydrophilic component can be used. From the mixture of the hydrophilic component and the alumina sol, the alumina sol It is preferable to use one obtained by removing the dispersion medium. When the hydrophilic component is used as a solution of the soluble organic solvent, the soluble organic solvent is also removed from the mixture together with the alumina sol dispersion medium. The alumina sol in the present invention is a dispersion in which fine particle alumina is usually stably dispersed in water and / or alcohol as a dispersion medium. As the dispersion medium, ketones, esters and other organic solvents are also used. The average particle diameter of the fine particle alumina in the alumina sol is usually 1 μm or less, particularly preferably 1 to 300 mμm (nm).

  Usually, even if alumina sol is added and dispersed in a hydrophilic polyurethane resin solution, the dispersion stability of the particulate alumina in the resin solution is low, and the particulate alumina easily separates and settles from the resin solution with time. This is because, for example, the compatibility (affinity) between the hydrophilic polyurethane resin and the alumina sol, the stability of both of them against changes in pH, and the properties of the hydrophilic polyurethane resin and the surface of the particulate alumina particles are different. Moreover, when synthesizing a hydrophilic polyurethane resin with an alumina sol, a method of adding it to the synthesis reaction system is also conceivable, but water or alcohol, which is a dispersion medium of the alumina sol, reacts with polyisocyanate which is a raw material of the polyurethane resin. Of course, even if other solvent-based alumina sols are used, a hydrophilic polyurethane resin solution having excellent dispersion stability of fine particle alumina cannot be obtained.

  However, the hydrophilic component described later used in the present invention has extremely high compatibility (affinity) with the alumina sol due to its hydrophilicity, and can be stably mixed with the alumina sol at an arbitrary ratio. Then, by removing the dispersion medium of the alumina sol from this mixture by an arbitrary method, a hydrophilic component in which the particulate alumina is dispersed extremely stably (hereinafter referred to as “particulate alumina dispersed hydrophilic component”) is obtained. Even if the dispersion amount of the fine particle alumina in the hydrophilic component is increased, the increase in the viscosity of the hydrophilic component is small, and the hydrophilic polyurethane is obtained by reacting the fine particle alumina dispersed hydrophilic component with another polyurethane raw material in a solvent. A dispersion in which fine-particle alumina is stably dispersed in the resin solution without using a dispersant can be obtained. When the hydrophilic polyurethane resin is synthesized without a solvent, the same stable dispersion as above can be obtained by dissolving the obtained hydrophilic polyurethane resin in the soluble organic solvent. All of these dispersions are extremely transparent, and the film (film) formed from them is also transparent.

  The removal of the dispersion medium of the alumina sol from the mixture of the hydrophilic component and the alumina sol can generally be easily performed under reduced pressure. In this case, the dispersion medium is preferably distilled off under reduced pressure and at a low temperature, and the dispersion medium is particularly preferably distilled off at a temperature of 70 ° C. or lower. When the dispersion medium is distilled off at a higher temperature than this, aggregation of fine particle alumina in the alumina sol may occur, and the dispersion stability of the fine particle alumina is lowered and a finely divided fine particle alumina dispersed hydrophilic component is generated. Sometimes. When the hydrophilic component is used as a solution of the organic solvent, the organic solvent is removed together with the dispersion medium of the alumina sol. The mixing ratio of the hydrophilic component and the fine particle alumina is preferably an amount occupying 5 to 95% by mass in the composition comprising the hydrophilic polyurethane resin and the fine particle alumina in which the fine particle alumina is finally obtained, and more preferably 10 to 10%. The amount occupying 90% by mass.

  In the present invention, the hydrophilic polyurethane resin constituting the composition of the present invention comprises a hydrophilic segment having a hydrophilic component in the resin molecule as a structural unit, and a component having at least one hydrolyzable silyl group as a structural unit. And a hydrolyzable silyl group-containing segment. When a chain extender is not used during the synthesis of the hydrophilic polyurethane resin, these segments are bonded at random by urethane bonds, urea bonds, or urethane-urea bonds, respectively. When a chain extender is used during the synthesis of the hydrophilic polyurethane resin, a short chain that is a residue of the chain extender exists between these bonds, in addition to the above bonds.

  By introducing a hydrolyzable silyl group into the hydrophilic polyurethane resin, the resin can be crosslinked by moisture, and the composition of the present invention is imparted with excellent adhesion to various materials by crosslinking, and The film formed using the above composition is imparted with excellent water absorption, antifogging properties, transparency, flexibility, water-based ink writing properties, water resistance, blocking resistance and slipperiness. The site for introducing the hydrolyzable silyl group in the hydrophilic polyurethane resin is not particularly limited, but is usually a molecular chain terminal and / or a side chain of the resin.

  The hydrolyzable silyl group introduced into the molecular chain terminal and / or side chain of the hydrophilic polyurethane resin crosslinks the resin with moisture by, for example, the reaction shown in the following formula (I) and / or (II). be able to. By the crosslinking, the resin has improved water resistance, the surface strength of the resin film is improved, and the blocking resistance is also improved.

  The crosslinking of the hydrophilic polyurethane resin used in the present invention is caused by moisture. However, since the resin is hydrophilic, it can be crosslinked using moisture in the air. Crosslinking is performed by converting a hydrolyzable silyl group into a silanol group by moisture as described above, and condensing this silanol group. Therefore, a catalyst is added to the composition of the present invention to promote silanol condensation. It is preferable to keep it. Such a catalyst is generally preferably a tin carboxylate, an acidic catalyst or a basic catalyst, and the amount used is preferably in the range of 0.0001 to 10% by mass relative to the hydrophilic polyurethane resin.

Next, the raw material of the hydrophilic polyurethane resin used in the present invention will be described.
Examples of the compound used for introducing a hydrolyzable silyl group into the hydrophilic polyurethane resin in the present invention include, for example, at least one reactive group such as an amino group, an epoxy group, a hydroxyl group, and a mercapto group. , A silane coupling agent having a reactive group such as a carboxyl group or an isocyanate group and a hydrolyzable silyl group, or a reaction product of the above silane coupling agent and an organic polyisocyanate. Typical examples of the hydrolyzable silyl group in the silane coupling agent are alkoxylated silyl groups such as a methoxylated silyl group, an ethoxylated silyl group, and a methoxyethoxylated silyl group. Of course, it can be used.

（式中のＲ₁は低級アルキル基、Ｒ₂は低級アルキル基、低級アルコキシ基又はイソシアネート基を、Ｘは、何もないか、又は２価の有機基、好ましいものはＣ₀〜Ｃ₅₀のアルキレン鎖、芳香族環又は脂肪族環であり、これらの基はその中に連結基として、−Ｎ−、−Ｏ−、−ＣＯ−、−ＣＯＯ−、−ＮＨＣＯ−、−Ｓ−、−ＳＯ−、−ＳＯ₂−等を含んでいてもよい。又、ｍ＝０〜３の整数、ｎ＝３−ｍである。） Examples of the silane coupling agent having a reactive group used in the present invention include the following compounds.
[1] A silane coupling agent represented by the general formula (1) having at least one free isocyanate group.

Wherein R ₁ is a lower alkyl group, R ₂ is a lower alkyl group, a lower alkoxy group or an isocyanate group, X is nothing or a divalent organic group, preferably a C _{0 to} C ₅₀ An alkylene chain, an aromatic ring or an aliphatic ring, and these groups include —N—, —O—, —CO—, —COO—, —NHCO—, —S—, —SO as a linking group therein. -, - SO ₂ - and the like may also contain the addition, m = 0 to 3 integers and n = 3-m)..

Preferred specific examples of the compound represented by the general formula (1) are as follows.

（式中のＹは、−ＮＨ−、−ＮＲ₃−、−Ｏ−、−Ｓ−であり、Ｒ₁、Ｒ₂、Ｘ、ｍ、ｎは前記定義の通りである。Ｒ₃は低級アルキル基である。） [2] A reaction product of a silane coupling agent having an active hydrogen-containing group and an organic polyisocyanate, wherein the product has at least one free isocyanate group in the molecule.
As said silane coupling agent, what is represented by following General formula (2) is mentioned, for example.

(In the formula, Y is —NH—, —NR ₃ —, —O—, —S—, and R ₁ , R ₂ , X, m, and n are as defined above. R ₃ is lower alkyl. Group.)

Preferred specific examples of the silane coupling agent represented by the general formula (2) are as follows. In addition, the epoxy group in the following compound is used by opening the ring.

以上のシランカップリング剤は、本発明において使用する好ましいシランカップリング剤の例示であって、本発明はこれらに限定されるものではない。
従って、上記の例示の化合物のみならず、その他公知の現在市販されており、市場から容易に入手し得る化合物は、いずれも本発明において使用することができる。

The above silane coupling agents are examples of preferred silane coupling agents used in the present invention, and the present invention is not limited thereto.
Therefore, not only the above-exemplified compounds, but also other known compounds that are currently commercially available and can be easily obtained from the market can be used in the present invention.

Hydrophilic polyurethane resins can be introduced with hydrolyzable silyl groups at the time of synthesis, but after synthesizing hydrophilic polyurethane resins into which hydrolyzable silyl groups have not been introduced, the molecular chain ends and / or sides are synthesized. It is preferable to introduce a hydrolyzable silyl group into these sites by reacting the reactive group in the chain with the silane coupling agent as described below, for example.
[1] Introduction to molecular chain end

（上記式中のＲ₁、Ｒ₂、Ｘ及びＹは前記と同じであり、Ｚは−Ｏ−、−Ｓ−、−ＮＲ₃−、−ＮＨ−であり、〔Ｐ〕は重合体１分子当たり少なくとも２つのウレタン結合及び／又はウレア結合を含有する親水性ポリウレタン樹脂の分子鎖を表す。又、Ｒ₃は低級アルキル基であり、ｍ及びｎは前記定義の通りである。） [2] Introduction to molecular chain side chain

(R ₁ , R ₂ , X and Y in the above formula are the same as above, Z is —O—, —S—, —NR ₃ —, —NH—, and [P] is one molecule of polymer. This represents a molecular chain of a hydrophilic polyurethane resin containing at least two urethane bonds and / or urea bonds per unit, R ₃ is a lower alkyl group, and m and n are as defined above.

  As the organic polyisocyanate used in the present invention, any conventionally known ones in the synthesis of polyurethane resins can be used and are not particularly limited. Preferred 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 polyurethane obtained by reacting these organic polyisocyanates with low molecular weight polyols or polyamines to form terminal isocyanates A prepolymer or the like can also be used.

As the hydrophilic component used in the present invention, those having a hydroxyl group, an amino group, a carboxyl group and the like and having a weight average molecular weight in the range of 400 to 8,000 are preferable.
Examples of the polyol having a terminal hydroxyl group and hydrophilicity include polyethylene glycol, polyethylene glycol / polytetramethylene glycol copolymer polyol, polyethylene glycol / polypropylene glycol copolymer polyol, polyethylene glycol adipate polyol, polyethylene glycol succinate polyol, polyethylene Examples include glycol / polyε-lactone copolymer polyol, polyethylene glycol / polyvalerolactone copolymer polyol, and the like. Particularly preferred is polyethylene glycol.

  Examples of the polyamine having a terminal amino group and hydrophilicity include polyethylene oxide diamine, polyethylene oxide propylene oxide diamine, polyethylene oxide triamine, and polyethylene oxide propylene oxide triamine. Other examples include ethylene oxide adducts having a carboxyl group or a vinyl group.

  In the present invention, in order to impart water resistance to the hydrophilic polyurethane resin, it is also possible to use other polyols, polyamines, polycarboxylic acids and the like not having a hydrophilic chain together with the above hydrophilic component.

  As the chain extender used as necessary in the present invention, for example, any conventionally known chain extender such as a low molecular weight diol or diamine can be used, and it is not particularly limited. For example, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, ethylenediamine, hexamethylenediamine and the like can be mentioned.

  The composition of the present invention is obtained by removing the dispersion medium of the alumina sol from the mixture of the hydrophilic component and the alumina sol, that is, the fine particle alumina-dispersed hydrophilic component, the organic polyisocyanate, and the at least one of the above. A compound having one active hydrogen-containing group and at least one hydrolyzable silyl group in the same molecule, in the presence of a chain extender, if necessary, according to a conventionally known method for producing a polyurethane resin Can be obtained. The reaction may be performed in an organic solvent or without a solvent. When performed in an organic solvent, the resulting composition of the present invention is in a state in which fine-particle alumina is stably dispersed in an organic solvent solution of a hydrophilic polyurethane resin. When the reaction is performed in the absence of a solvent, the resulting composition of the present invention is solid, and the solid composition is dissolved in the soluble organic solvent of the hydrophilic polyurethane resin constituting the composition. And use it. The soluble organic solvent is not particularly limited, and examples thereof include dimethylformamide and methyl ethyl ketone. As the soluble organic solvent, a solvent used for the synthesis of a hydrophilic polyurethane resin can also be used.

  The molecular weight of the hydrophilic polyurethane resin constituting the composition of the present invention is not particularly limited, and the weight average molecular weight measured by GPC is preferably in the range of 3,000 to 800,000, more preferably. Is in the range of 5,000 to 500,000.

  In the composition of the present invention, the content of the particulate alumina is preferably an amount occupying 5 to 95% by mass, more preferably 10 to 90% by mass in the composition (solid content). When the content of the fine particle alumina is less than 5% by mass, the surface properties such as blocking resistance and slipperiness with respect to the coating formed using the hydrophilic polyurethane resin which is the object of the present invention are insufficient, while 95% by mass. If it exceeds%, the strength of the coating film, the adhesiveness to the substrate sheet and the like are inferior. Surprisingly, when the content of the fine particle alumina occupies 75 to 95% by mass, when the coating liquid using the composition of the present invention is coated on the base sheet, a microporous size of several m μm (nm) is obtained. A film having quality and excellent transparency is formed.

  The content of the hydrolyzable silyl group in the hydrophilic polyurethane resin in the present invention is preferably in the range of 0.001 to 10 meq (milli equivalent) / g, more preferably 0.01 to 1.0 meq / g. When the content of the hydrolyzable silyl group is less than 0.001 meq / g, that is, less than 0.01 per 10,000 molecular weight, the ratio of the hydrophilic segment in the resin becomes relatively large, When the film formed using the resin, which is the purpose of the period, has insufficient expression of properties such as water resistance and blocking resistance, while the hydrolyzable silyl group content exceeds 10 meq / g, When the molecular weight exceeds 10,000 per 10,000, the ratio of hydrophilic segments in the resin is relatively reduced, and the water resistance of the coating is increased due to the cross-linked structure of the resin. It is not preferable because it becomes inferior to.

  Further, the content of the hydrophilic segment in the hydrophilic polyurethane resin in the present invention is preferably in the range of 30 to 80% by mass, more preferably in the range of 50 to 75% by mass. When the content of the hydrophilic segment is less than 30% by mass, a film formed using the resin is inferior in water absorption and anti-fogging properties. On the other hand, when the content exceeds 80% by mass, the film is water resistant. It becomes inferior to blocking resistance and is not preferable.

  The film formed using the composition of the present invention as described above has adhesiveness to various materials, water absorption, antifogging property, transparency, flexibility, water-based ink writing property, water resistance, blocking resistance and Excellent lubricity. Therefore, the composition of the present invention is used as a coating agent for forming an ink receiving layer of an ink jet recording sheet, as an antifogging paint for imparting antifogging properties to various films, and as a surface treatment agent for preventing dew condensation on interior resin wallpaper. It is very useful as a coating agent for clothing that gives water absorption to clothing, as a material for synthetic leather, or as a water-based ink writing treatment for synthetic paper. Moreover, the composition of this invention can be used also for manufacture of a various molded object in a solid state.

  Next, the present invention will be described in more detail with reference examples, examples and comparative examples. In the text, “part” or “%” is based on mass unless otherwise specified.

Reference example 1
700 parts of polyethylene glycol (molecular weight: 1,000) and 750 parts of alumina water sol (average particle diameter of alumina: 150 to 160 nm, solid content: 40%) are mixed thoroughly, and the resulting mixture is decompressed at 70 ° C. while stirring. Dehydration was performed. After the theoretical amount of water was distilled off, the temperature was raised to 120 ° C. and water was further removed under reduced pressure of 133.3 Pa or less to obtain a white solid polyol (A) having an alumina content of 30%. This polyol (A) had a hydroxyl value of 76 mgKOH / g, a moisture content of 0.15%, was transparent at 80 ° C., and had a viscosity of 380 dPa · s.

Reference example 2
100 parts of polyethylene glycol (molecular weight 590) and 500 parts of alumina water sol (average particle size of alumina 10-20 nm, solid content 20%) are thoroughly mixed, and the resulting mixture is stirred under reduced pressure at 70 ° C. under reduced pressure. went. After the theoretical amount of water was distilled off, the temperature was raised to 120 ° C. and water was further removed under reduced pressure of 133.3 Pa or less to obtain a white solid polyol (B) having an alumina content of 50%. This polyol (B) was softened at 90 ° C. with a hydroxyl value of 95 mgKOH / g, a moisture content of 0.12%.

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 alumina water sol (alumina average particle size 150 to 160 nm, solid content 40%) were sufficiently mixed, and the resulting mixture was obtained. The mixture was stirred 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 further removed under reduced pressure of 133.3 Pa or less to obtain a white solid polyamine (C) having an alumina content of 90%. This polyamine was softened at an amine equivalent of 30 g / mol, a moisture content of 0.20%, and 110 ° C.

Example 1
(Production of the composition of the present invention)
30 parts of polyethylene glycol (molecular weight 2,040), 120 parts of polyol (A) of Reference Example 1 and 12 parts of 1,3-butylene glycol in a mixed solvent of 200 parts of methyl ethyl ketone and 200 parts of dimethylformamide The solution in which 60 parts of hydrogenated MDI was dissolved in 100 parts of methyl ethyl ketone was gradually added dropwise while stirring well at 60 ° C., and reacted at 80 ° C. for 8 hours after the completion of the addition. The obtained polyurethane resin was analyzed with an infrared spectrophotometer. In the infrared absorption spectrum, the absorption of hydroxyl groups was not observed, and the hydroxyl groups were also confirmed by quantification by the pyridine method (JISK-0070 2.5). Was not.

Next, 8 parts of a silane coupling agent having an isocyanate group [(C ₂ H ₅ O) ₃ Si (CH ₂ ) ₃ NCO] is added to the resin solution and reacted at 80 ° C. for 8 hours. Was confirmed to have disappeared, dimethylformamide was added to adjust the solid content to 20%, and a solution of the composition of the present invention was obtained.
The solution of this composition had a viscosity of 22 dPa · s (25 ° C.). Measured by GPC of the hydrophilic polyurethane resin constituting the composition, the weight average molecular weight in terms of standard polystyrene (the same applies to the following examples) is 65,000, and the alumina in the composition (solid content) The content was 15.6%, the content of hydrolyzable silyl groups in the resin was 0.47 meq / g, and the content of the hydrophilic segment was 58.7%.

Example 2
(Production of the composition of the present invention)
(1) Production of isocyanate-terminated silane coupling agent 270 parts of an adduct of hexamethylene diisocyanate and water (Duranate 24A-100: manufactured by Asahi Kasei Co., Ltd., NCO% = 23.5) was thoroughly stirred at 25 ° C. 111 parts of γ-aminopropyltriethoxysilane were gradually added dropwise and reacted to give a colorless and transparent liquid product (D). The obtained product has a free isocyanate group of 10.5% [theoretical value (the amount of the group in the reaction product generated stoichiometrically when reacted 100%) is 11.2%]. Theoretically, it seems to have the following structure.

(2) 8 parts of the above liquid product (D), 35 parts of toluene diisocyanate and 150 parts of polyol (B) of Reference Example 2 were added to 200 parts of dimethylformamide / methyl ethyl ketone (= 1/1 (mass ratio)). Was reacted at 80 ° C. for 5 hours to obtain an isocyanate-terminated polyurethane resin. Next, the temperature of the resin solution was adjusted to 20 ° C., 5 parts of 1,4-diaminobutane dissolved in 50 parts of methyl ethyl ketone was gradually added dropwise, and reacted at the same temperature for 1 hour after completion of the addition. Further, 10 parts of γ-aminopropyltrimethoxysilane dissolved in 50 parts of methyl ethyl ketone was gradually added dropwise and reacted at 30 ° C. for 1 hour to confirm that the isocyanate group had disappeared from the resulting resin, and then dimethylformamide. Was added to adjust the solid content to 20% to obtain a solution of the composition of the present invention.
The solution of this composition had a viscosity of 28 dPa · s (25 ° C.). The hydrophilic polyurethane-polyurea resin constituting the composition has a weight average molecular weight of 58,000, the content of alumina in the composition (solid content) is 36%, and the hydrolyzable silyl in the resin. The group content was 0.35 meq / g, and the hydrophilic segment content was 56.3%.

Example 3
(Production of the composition of the present invention)
12 parts of hydrogenated MDI, 5 parts of polyethylene oxide diamine (Jephamine ED; molecular weight 2,000) and 145 parts of polyamine (C) of Reference Example 3 in 30 parts of dimethylformamide at 30 ° C. Reaction was performed for 4 hours to obtain an isocyanate-terminated polyurea resin. Next, the temperature of the resin solution was adjusted to 20 ° C., and 1 part of 1,4-diaminobutane dissolved in 50 parts of methyl ethyl ketone was gradually added dropwise. After completion of the addition, the mixture was reacted at the same temperature for 1 hour. Further, 4 parts of γ-aminopropyltrimethoxysilane dissolved in 50 parts of methyl ethyl ketone was gradually added dropwise and reacted at 30 ° C. for 1 hour. After confirming that the isocyanate group had disappeared from the resulting resin, dimethylformamide Was added to adjust the solid content to 20% to obtain a solution of the composition of the present invention.
The solution of this composition had a viscosity of 18 dPa · s (25 ° C.). The hydrophilic polyurea resin constituting the composition has a weight average molecular weight of 42,000, the alumina content in the composition (solid content) is 79%, and the hydrolyzable silyl group in the resin has a content of 79%. The content was 0.62 meq / g, and the content of the hydrophilic segment was 54.9%.

Comparative Example 1
A polyurethane resin solution was obtained with the same material and formulation as in Example 1 except that the silane coupling agent having an isocyanate group was not used and the polyol of the polyol (A) in Reference Example 1 except for alumina 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.

Comparative Example 2
A polyurethane having the same material and formulation as in Example 2 except that the isocyanate-terminated silane coupling agent and γ-aminopropyltriethoxysilane are not used, and the polyol (B) of Reference Example 2 except for the alumina is used. -A solution of polyurea resin was obtained.
This resin solution had a solid content of 20%, a viscosity of 40 dPa · s (25 ° C.), and the polyurethane-polyurea resin had a weight average molecular weight of 55,000.

Comparative Example 3
A solution of a polyurea resin was obtained by the same material and formulation as in Example 3 except that γ-aminopropyltrimethoxysilane was not used and the polyamine (C) of Reference Example 3 except for the polyamine was used.
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.

Comparative Examples 4-6
The alumina water sols of Reference Examples 1 to 3 were added to the resin solutions of Comparative Examples 1 to 3, respectively, while stirring, but fine-particle alumina precipitated and the solutions became opaque.

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

About the composition of this invention obtained in Examples 1-3 and the solution of the resin obtained in Comparative Examples 1-7, the following characteristics were evaluated with the following method.
[1] Application to inkjet recording sheet Each of the compositions and resin solutions obtained in Examples 1 to 3 and Comparative Examples 1 to 7 was dried on a 100 μm thick PET film so that the thickness after drying would be 25 μm. The ink receiving layer was formed by coating and drying, and the resulting recording sheet was printed and recorded with a color ink jet printer (PM-800C manufactured by Seiko Epson Corporation), and the following items were evaluated.

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

(2) Transparency The haze on the surface of the ink receiving layer was visually determined. The results are displayed as follows:
○: Completely transparent △: Slightly cloudy ×: Completely opaque

(3) Colored vividness After color printing was performed on the ink receiving layer with an inkjet printer, the colored vividness of the obtained color image was visually observed. The results are displayed as follows:
○: Clear with no blurring △: Slightly blurring and slightly blurry

(4) Ink drying property After color printing on the ink receiving layer with an ink jet printer, the filter paper was pressed for 5 seconds under 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 on the ink receiving layer with an ink jet printer, the recording sheet is immersed in water (20 ° C., 1 hour) and then dried at room temperature. The change was observed visually. The results are displayed as follows:
◯: No blurring or color development of the image Δ: Change is observed in the image and the ink receiving layer ×: The image can be considerably taken or taken together with the ink receiving layer The above evaluation results are shown in Table 1.

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

Comparative Example 9
100 parts of polyvinyl butyral (degree of polymerization 700: manufactured by Sekisui Chemical Co., Ltd.), 50 parts of trioctyl phosphate, and 3 parts of polyoxyethylene lauryl ether ester (phosphate ester surfactant: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) It was mixed and dissolved in 400 parts.

[2] Application to anti-fogging / antistatic coatings The compositions and resin solutions obtained in Examples 1 to 3, Comparative Example 1, Comparative Example 8, and Comparative Example 9 were each dried on a transparent acrylic resin plate. Brush coating and drying are performed so that the thickness afterwards becomes 25 μm, and a coating film is formed to form a sample. The hardness, antifogging property, water resistance, and antistatic property of the coating film surface of each sample are evaluated as follows. Went in the way.

(1) Surface hardness It evaluated by the surface damage of the coating film by a pencil hardness test (JISK5400.88.4).

(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. The results are displayed as follows:
○: No cloudiness △: Partially cloudy ×: Cloudy

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

(4) Antistatic property The adhesion of the charged carbon to the coating film was evaluated by a dust chamber test. The results are displayed as follows:
○: No carbon adhesion Δ: Some carbon adhesion ×: Carbon adhesion Table 2 shows the above evaluation results.

The composition of the present invention has various moldings, films, sheets and the like due to its excellent adhesion to various materials, water absorption, water resistance, anti-fogging properties, transparency, flexibility, blocking resistance, slipperiness, etc. As a raw material for coatings, as a binder for paints, printing inks, and inkjet inks, coating agents for forming ink-receiving layers for inkjet recording sheets, fiber coating agents, antifogging coatings for agricultural resin sheets, and resin wallpaper for interiors, etc. It can be used as a surface treatment agent.

Claims (11)

  Hydrophilic property obtained by reacting an organic polyisocyanate, a high molecular weight hydrophilic polyol and / or polyamine, and a compound having at least one reactive group and at least one hydrolyzable silyl group in the same molecule. A fine particle alumina-dispersed hydrophilic polyurethane resin composition comprising a polyurethane resin and fine particle alumina, wherein the fine particle alumina is stably dispersed in the hydrophilic polyurethane resin solution. .   The fine particle alumina-dispersed hydrophilic polyurethane resin composition according to claim 1, wherein the content of the fine particle alumina is an amount occupying 5 to 95% by mass in the composition.   The fine particle alumina-dispersed hydrophilic polyurethane resin composition according to claim 1, wherein the fine particle alumina is added to the high molecular weight hydrophilic polyol and / or polyamine when the hydrophilic polyurethane resin is synthesized.   The fine particle alumina-dispersed hydrophilic polyurethane resin composition according to claim 1, wherein the fine particle alumina is fine particle alumina having an average particle diameter of 1 to 300 nm.   The fine particle alumina-dispersed hydrophilic polyurethane resin composition according to claim 1, wherein the content of the hydrophilic segment and the hydrolyzable silyl group in the hydrophilic polyurethane resin is 30 to 80% by mass and 0.001 to 10 meq / g, respectively. Stuff.   The fine particle alumina-dispersed hydrophilic polyurethane resin composition according to claim 1, wherein the hydrophilic segment is a polyethylene oxide segment.   Hydrophilic property obtained by reacting an organic polyisocyanate, a high molecular weight hydrophilic polyol and / or polyamine, and a compound having at least one reactive group and at least one hydrolyzable silyl group in the same molecule. In a method for producing a composition comprising a polyurethane resin and fine particle alumina, a hydrophilic polyurethane using the high molecular weight hydrophilic polyol and / or polyamine to which fine particle alumina is added as the high molecular weight hydrophilic polyol and / or polyamine. A method for producing a fine particle alumina-dispersed hydrophilic polyurethane resin composition comprising synthesizing a resin.   The fine particle alumina according to claim 7, wherein the high molecular weight hydrophilic polyol and / or polyamine added with the fine particle alumina is obtained by removing the dispersion medium of the alumina sol from the mixture of the high molecular weight hydrophilic polyol and / or the polyamine and the alumina sol. A method for producing a dispersed hydrophilic polyurethane resin composition.   The method for producing a fine particle alumina-dispersed hydrophilic polyurethane resin composition according to claim 7, wherein the content of the fine particle alumina is an amount occupying 5 to 95% by mass in the composition.   The method for producing a fine particle alumina-dispersed hydrophilic polyurethane resin composition according to claim 7, wherein the fine particle alumina is fine particle alumina having an average particle diameter of 1 to 300 nm. The fine particle alumina-dispersed hydrophilic polyurethane resin composition according to claim 7, wherein the content of the hydrophilic segment and the hydrolyzable silyl group in the hydrophilic polyurethane resin is 30 to 80% by mass and 0.001 to 10 meq / g, respectively. Manufacturing method.