JP2001164017A - Porous resin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a porous film having a good absorbing property of water content becoming a solvent of an aqueous ink or aqueous paste, a recording medium capable of absorbing ink without irregularity even on close printing in the case of having a large amount of ink ejection in an ink jet printing and further a porous resin film constituting such a recording medium having such an excellent property. SOLUTION: This porous resin film consisting of a thermoplastic resin and inorganic or organic fine powder surface coated with a surface-treating agent, is characterized by having >=0.5 ml/m2 range of its liquid-absorbing volume measured by 'Japan TAPPI No. 51-87', and a laminated film having the porous resin film layer on at least one side surface of its base material layer is also provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a porous resin film excellent in water-based liquid absorption and ink absorption.
Furthermore, the present invention has particularly good ink jet recording characteristics,
The present invention also relates to a recording medium capable of forming a fine image.

[0002]

2. Description of the Related Art Conventionally, film-based synthetic paper having excellent water resistance is mainly composed of resin, such as offset printing or seal printing using oil-based ink or UV-curable ink, sublimation-type or melt-type thermal transfer. Paper has been mainly used. However, with the expansion of applications, there is an increasing demand for a printing method using a water-based ink and an improvement in suitability for an environment-friendly water-based paste. For this reason, water-based inks and water-based pastes, or synthetic papers having good absorbency for water serving as a solvent for these are required. In addition, with the recent technological advances in multimedia, inkjet printers have become widespread for both commercial and consumer use.
Ink jet printers have many features, such as easy multi-color and large-sized images and low printing cost. Above all, ink jet printers using water-based inks, which are less likely to cause environmental and safety problems than oil-based inks, have recently become mainstream.

[0003] Ink jet printers are widely used as a method of obtaining a hard copy including not only characters but also image processing. Therefore, the printed image is required to have higher definition. The image definition is
It depends on the drying properties of the ink printed on the recording medium.
For example, when printing continuously on a plurality of recording media, there is often a case where another recording medium overlaps the printed recording medium, at this time, if the ink absorption of the printed recording medium is insufficient, The ink adheres to the overlaid recording medium, causing image stains.

[0004] In order to enhance the definition of an image, a method of coating a recording medium such as synthetic paper, plastic film or paper with an ink receptive material having a hydrophilic resin or an inorganic fine powder has been widely adopted (particularly). Kaihei 3-
No. 82589, JP-A-9-216456).
On the other hand, an ink jet recording medium in which an ink receiving layer containing a hydrophilic resin as a main component is formed by a thermal lamination method or an extrusion lamination method has also been proposed (Japanese Patent Application Laid-Open Nos. 8-12871 and 9-1).
920, JP-A-9-314983). However, the recording medium for ink-jet formed by these methods has a case where the absorption capacity is insufficient when the discharge amount of the ink is large, so the coating layer needs to be thickened, and the coating process is required many times. There was a problem.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art. That is, the present invention provides a porous film having good water absorbability as a solvent for water-based inks and water-based pastes, and, in ink-jet recording, even when solid printing is performed when the ink ejection amount is large, there is no density unevenness. It is an object to provide a recording medium that can absorb ink. Another object of the present invention is to provide a porous resin film constituting a recording medium having such excellent properties.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies with the aim of solving the above-mentioned problems, and as a result, have found that inorganic and / or organic fine particles treated with a thermoplastic resin and a specific surface treating agent have been obtained. Made of powder, "Japan TAP
PI No. 51-87 "is a porous resin film characterized by having a liquid absorption volume in the range of 0.5 ml / m ² or more, has good water-based liquid absorption, and further has a water contact angle on the surface. The present inventors have found that a porous resin film of 110 ° or less can absorb ink without unevenness in density even when the amount of ejected ink is large, and is suitable as a recording medium such as an ink jet. Thus, the present invention has been completed.

That is, the present invention comprises a thermoplastic resin and an inorganic and / or organic fine powder surface-treated with a specific surface treating agent, and is described in “Japan TAPPI No. 5”.
1-87 "has a liquid absorption volume of 0.5 ml
/ M ² or more, and in a preferred embodiment, the film has an average contact angle to water of 110 ° or less, and more preferably has pores on the surface and inside. It is a porous resin film having a porosity of 10% or more. In a more preferred embodiment, the film has 1 × 10 ⁶ holes / m ² or more in the surface and the average diameter of the holes in the surface is 0.0
It is preferably in the range of 1 to 50 μm. In addition, at least a part of the inorganic or organic fine powder has a surface and / or
Alternatively, it is preferably present in an internal hole.

The thermoplastic resin is preferably a polyolefin resin, and the inorganic and / or organic fine powder preferably has an average particle diameter in the range of 0.01 to 20 μm. Furthermore, the specific surface area of the inorganic and / or organic fine powder is 0.5 m
Those having a range of ² / g or more are preferred. As a preferred embodiment of the mixing ratio of the constituent components, thermoplastic resins 30 to 9
0% by weight and 70 to 10% by weight of the surface-treated inorganic and / or organic fine powder, and the amount of the surface treating agent is 0.01 to 4 with respect to 100 parts by weight of the inorganic and / or organic fine powder.
It is in the range of 0 parts by weight.

Preferred surface treatment agents have an HLB value in the range of 5 to 100, which indicates the balance between inorganic and organic properties. Specific examples thereof include sulfones having an alkyl group having 4 to 40 carbon atoms. An acid salt is a quaternary ammonium compound having an alkyl group having 4 to 40 carbon atoms. In a more preferred embodiment, the porous resin film is stretched. The present invention includes a laminated film having a layer of a porous resin film on at least one surface of a base material layer, a recording medium using the same, and further includes an ink jet recording medium provided with a coloring material fixing layer. .

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the porous resin film and the recording medium of the present invention will be described in detail. The liquid absorption volume of the porous resin film of the present invention is 0.5 m
l / m ² or more, preferably 3~2600ml / m ^2, more preferably 5 to 100 ml / m ^2. 0.
If it is less than 5 ml / m ² , the absorption of the aqueous ink and the aqueous paste is insufficient. Further, in order to increase the absorption amount, it is necessary to consider the thickness of the porous film. Therefore, the upper limit is appropriately selected depending on the use.

The liquid absorption volume of the porous resin film of the present invention is "Japan TAPPI No. 51-87".
(Paper and Pulp Technology Association, Paper and Pulp Test Method No. 51-8)
7, Bristow method)
In the present invention, the measured value of the absorption time within 2 seconds is defined as the liquid absorption volume. The measurement solvent is measured using a solvent obtained by adding a coloring dye with a mixed solvent of 70% by weight of water and 30% by weight of ethylene glycol as 100% by weight. As a coloring dye, malachite green or the like is used, and the amount thereof is about 2 parts by weight with respect to 100 parts by weight of the mixed solvent. However, as long as the surface tension of the solvent used for the measurement is not largely changed, it is used. The type and amount of the coloring dye used are not particularly limited.

As a measuring instrument, for example, Kumagaya Riki Kogyo Co., Ltd.
Company made liquid absorption tester. Also shorter
The larger the liquid absorption volume during the absorption time, the
Etc., the amount of protrusion from the edge of the paper is reduced.
You. In the present invention, the liquid absorption volume within 40 milliseconds is
0.8ml / m^TwoAbove, more preferably 1-500ml
/ M ^TwoRange. Furthermore, the measurement of the liquid absorption volume described above
The liquid absorption rate measured accompanying the
It tends to give better results by absorbing and drying
You. In the present invention, between 20 milliseconds and 400 milliseconds
Absorption rate is generally 0.02 ml / ｛m^Two・
(Ms)^1/2｝ Or more, more preferably 0.
1-100ml / ｛m^Two・ (Ms)^1/2で over the range
is there.

The water-based surface contact angle of the porous resin film of the present invention is 110 ° or less, preferably 0-100.
°, more preferably in the range of 0 to 90 °. 110 °
If it exceeds the range, the liquid may not be sufficiently permeated such as a paste using an aqueous ink or an aqueous medium. Also, from the viewpoint of balancing the spread of the aqueous ink droplets in the direction parallel to the film paper surface and the penetration in the film thickness direction, the contact angle may have an appropriate range, depending on the type of ink. Selected as appropriate. In addition, the water contact angle of the film surface in the present invention is measured using a commercially available contact angle meter, and one minute after dropping pure water onto the film surface, using the same contact angle meter. Perform 10 measurements on one sample,
The average value of the contact angles measured by replacing the film with an unmeasured film whose surface is not wetted with pure water for each measurement is defined as a water contact angle. An example of a commercially available contact angle meter that can be used for the contact angle measurement of the present invention is Model CA-D manufactured by Kyowa Interface Chemical Co., Ltd.

Further, as the "difference between the maximum value and the minimum value" in the ten contact angle measurements is smaller, the absorption of the ink or the liquid using the aqueous medium tends to be more uniform,
It gives better print quality as a print medium, but as an example, the difference between the maximum value and the minimum value is within 40 °, preferably within 30 °, more preferably within 20 °. The porous resin film of the present invention has fine pores on the surface, and absorbs the aqueous ink or aqueous liquid coming into contact with the surface from the pores. The number and shape of pores on the porous film surface,
The presence of at least a part of the inorganic and / or organic fine powder in the surface pores can be known by observation with an electron microscope.

An arbitrary part of the porous film sample is cut out, attached to an observation sample stand, and gold or gold-coated on the observation surface.
By depositing palladium or the like, it is possible to observe the shape of pores on the surface at an arbitrary magnification that is easy to observe using an electron microscope, for example, a scanning electron microscope S-2400 manufactured by Hitachi, Ltd. It is possible to know the number of holes, the size of the holes, and the shape of the holes. The number of pores per unit area of the porous film surface is in a range of 1 × 10 ⁶ / m ² or more, and preferably 1 × 10 ⁷ / m ² from the viewpoint of faster absorption of an aqueous liquid. m ² or more, preferably 1 × 10 ⁸ pieces / m ² or more. From the viewpoint of improving the surface strength to a better level, the range is preferably 1 × 10 ¹⁵ / m ² or less, more preferably 1 × 10 ¹² / m ² or less.

The shape of the pores near the surface of the porous film is various, such as circular and elliptical. The maximum diameter (L) of each pore and the maximum diameter (M) in a direction perpendicular to it are shown. Are measured and averaged [[L + M) / 2] is defined as the average diameter of each hole. The measurement is repeated for at least 20 surface vacancies, and the average value is defined as the average diameter. From the viewpoint of obtaining a better level of liquid absorption, the average diameter is 0.01 μm or more, more preferably 0.1 μm or more.
It is at least 1 μm, more preferably at least 1 μm. To improve the surface strength of the porous film to a better level,
The average diameter is 50 μm or less, preferably 30 μm or less, more preferably 20 μm or less.

At least a part, preferably about 30% or more, of the pores on the surface or in the vicinity of the pores have inorganic and / or organic fine particles inside or around the pores. The presence of powder is preferred, and the greater the number, the better the absorption capacity tends to be. The porous resin film of the present invention has a porous structure having a large number of fine pores therein, and has a porosity of 10% from the viewpoint of improving the absorption and drying properties of the aqueous ink. Or more, preferably 20 to 75%, more preferably 3 to 75%.
It is in the range of 0-65%. When the porosity is 75% or less, the material strength of the film is at a good level. In addition, it is preferable that at least some of the pores in the inside have inorganic and / or organic fine powder inside the pores or in the vicinity of the pores. Capabilities tend to improve.

The presence of pores in the interior and the presence of at least a part of the inorganic and / or organic fine powder in the interior pores can be confirmed by observing a cross section with an electron microscope. The porosity in the present specification indicates the porosity represented by the following formula or the area ratio (%) occupied by vacancies in a region obtained by observing a cross-sectional electron micrograph.

(Equation 1)

Specifically, after a porous resin film is embedded in an epoxy resin and solidified, a cut surface parallel to the thickness direction of the film and perpendicular to the surface direction is produced using a microtome. After metallizing this cut surface, any magnification that is easy to observe with a scanning electron microscope,
For example, it can be observed at a magnification of 500 to 2000 times. As an example, the observed area is photographed, a hole is traced on a tracing film, and the filled figure is subjected to image processing with an image analyzer (Model: Luzex IID, manufactured by NIRECO Co., Ltd.). The porosity can also be determined by determining the area ratio. Further, in the case of a laminated film having a layer of the porous resin film of the present invention on the surface, the thickness and basis weight (g / m ² ) of the laminated film and the portion where the porous resin film layer of the present invention is removed therefrom. The thickness and basis weight of the porous resin film layer of the present invention are calculated, the density (ρ) is calculated from the thickness and the density (ρ ₀ ) of the non-porous portion from the composition of the constituent components, and the density (ρ ₀ ) is calculated by the above equation. You can also.

Further, the shape and size of the internal holes are determined at any magnification which is easy to observe with a scanning electron microscope, for example, 50 magnifications.
It can be observed at a magnification of 0 or 2000 times.
The dimensions of the internal holes are obtained by measuring the dimensions in the plane direction and the thickness direction of at least 10 internal holes and averaging the measured values. The average size in the plane direction of the pores of the porous film is 0.1 to 1000 μm, preferably 1 to 500 μm.
m. From the viewpoint of improving the mechanical strength of the porous film to a better level, the maximum dimension of the pores in the surface direction of the film is preferably 1000 μm or less. From the viewpoint of obtaining a higher level of water-based liquid absorbability, the maximum dimension of the film in the surface direction is preferably 0.1 μm or more.
The average size in the thickness direction of the pores of the porous film is usually in the range of 0.01 to 50 μm, preferably 0.1 to 10 μm. The larger the dimension in the thickness direction is, the better the absorption of the aqueous liquid is, but the upper limit can be selected according to the application from the viewpoint of obtaining appropriate mechanical strength of the film.

<Composition and Production Method of Porous Resin Film> The porous resin film of the present invention comprises, as constituents, a combination of a thermoplastic resin, an inorganic and / or organic fine powder, and a surface treating agent. As the thermoplastic resin used in the porous resin film of the present invention, high-density polyethylene, medium-density polyethylene, ethylene-based resin such as low-density polyethylene, or polyolefin-based resin such as propylene-based resin, polymethyl-1-pentene, Ethylene-cyclic olefin copolymer, nylon-6, nylon-6,6, nylon-6,10, nylon-6,1
2. Polyamide resin such as nylon-6, T, etc., thermoplastic polyester resin such as polyethylene terephthalate and its copolymer, polyethylene naphthalate, aliphatic polyester, polycarbonate, atactic polystyrene, syndiotactic polystyrene, polyphenylene sulfide, etc. Thermoplastic resin. These may be used in combination of two or more.

Among these, from the viewpoints of chemical resistance, low specific gravity, cost and the like, polyolefin resins such as ethylene resins and propylene resins are preferable, and propylene resins are more preferable. Examples of the propylene-based resin include an isotactic polymer or a syndiotactic polymer obtained by homopolymerizing propylene. In addition, ethylene, 1-butene, 1-hexene, 1-heptene, 4-methyl-1-pentene and other α-olefins and propylene copolymerized, polypropylene having various stereoregularities as a main component. Copolymers can also be used. The copolymer may be a binary system, a ternary system or more, or a random copolymer or a block copolymer. Propylene resins include:
A resin having a melting point lower than that of propylene homopolymer is 2 to 25.
It is preferable to use it by blending in% by weight. Examples of such a resin having a low melting point include high-density or low-density polyethylene.

The kind of the organic or inorganic fine powder used in the porous resin film of the present invention is not particularly limited, but specific examples thereof include the following. As the inorganic fine powder, heavy calcium carbonate, light calcium carbonate, aggregated light calcium carbonate, silica having various pore volumes, zeolite, clay, talc, titanium oxide, barium sulfate, zinc oxide, magnesium oxide, diatomaceous earth, Examples thereof include a composite inorganic fine powder having aluminum oxide or hydroxide around the core of a hydroxyl group-containing inorganic fine powder such as silicon oxide or silica. Among them,
It is preferable to use heavy calcium carbonate, clay, and diatomaceous earth because they are inexpensive, and when formed by stretching, they have good porosity.

The organic fine particles are selected from those having a higher melting point or a higher glass transition point than the thermoplastic resin used as the above-mentioned non-hydrophilic thermoplastic resin for the purpose of forming pores. Specific examples include polyethylene terephthalate, polybutylene terephthalate, polyamide, polycarbonate, polyethylene naphthalate,
Examples thereof include polymers and copolymers of polystyrene, acrylic ester or methacrylic ester, melamine resin, polyethylene sulfide, polyimide, polyethyl ether ketone, and polyphenylene sulfide. Among them, when using a polyolefin resin as the non-hydrophilic thermoplastic resin, polyethylene terephthalate, polybutylene terephthalate, polyamide,
Those obtained from polycarbonate, polyethylene naphthalate and polystyrene are preferred.

Among the inorganic and / or organic fine powders,
From the viewpoint that the amount of heat generated during combustion is small, inorganic fine powder is more preferable. Inorganic and / or used in the present invention
Or the average particle diameter of the organic fine powder is preferably 0.01
-20 μm, more preferably 0.1-10 μm, even more preferably 0.5-10 μm. The thickness is preferably 0.01 μm or more from the viewpoints of easy mixing with a thermoplastic resin and improving the absorbability of an aqueous solvent or an aqueous ink. In addition, in the case where pores are generated inside by stretching to improve the absorbency, from the viewpoint of making it difficult to cause troubles such as sheet breakage during stretching and a decrease in the strength of the surface layer, it is preferable to use 20%.
μm or less is preferred.

The particle diameter of the surface-treated inorganic and / or organic fine powder used in the present invention is, for example, a particle measuring apparatus, for example, a laser diffraction particle measuring apparatus “Microtrack” (manufactured by Nikkiso Co., Ltd. ) Can be measured by the particle size corresponding to 50% of the cumulative value (accumulated 50% particle size). The particle size of the fine powder dispersed in the non-hydrophilic resin or hydrophilic resin by melt-kneading and dispersion is determined by measuring at least 10 of the particles by observing the cross section of the porous film with an electron microscope. It is also possible to ask for.

The specific surface area of the inorganic and / or organic fine powder used in the present invention is measured by a BET method, and is, for example, 0.1 to 1000 m ² / g, more preferably 0.2 to 5 m ² / g.
00m ² / g, more preferably, 0.5 to 100 ² /
g. When inorganic and / or organic fine powder having a large specific surface area is used, absorption of an aqueous solvent or ink tends to be improved. In addition, in the case of mixing and dispersing with a hydrophilic thermoplastic resin or a non-hydrophilic thermoplastic resin, when there is a tendency that troubles such as insufficient dispersion by classification and foaming due to accompanying air tend to occur, a specific surface area suitable for use. The upper limit is appropriately selected.

Also, various oil absorptions can be used. For example, the oil absorption (JIS-K5101-199) can be used.
1) is 1 to 300 ml / 100 g, preferably 10 to 300 ml / 100 g.
It is in the range of 200 ml / g. As the fine powder used for the porous resin film of the present invention, one kind may be selected from the above and used alone, or two or more kinds may be used in combination. When two or more kinds are used in combination, a combination of an organic fine powder and an inorganic fine powder may be used.

The surface treating agent of the present invention is, for example, HL
The B value is in the range of 5 to 100, preferably 5.5 to 50. The surface treating agent having an HLB value in the above range has a large effect of improving the absorbability of the porous film of the present invention with an aqueous solvent or an aqueous ink. HL in the present invention
B value is Oda, Teijin Times, 22, No. 9 (195
2), Oda, Teramura, "Synthesis of Surfactants and Their Applications", 5
01, Maki Shoten, (1957), Fujimoto, "Introduction to New Surfactants", pp. 197-198, Sanyo Chemical Industries, (198
This is a ratio of inorganic and organic values determined by the method shown in 1) and the like, and determined by the following general formula. HLB =
10 × sum of inorganic value / sum of organic value

The organic and inorganic properties are determined by adding the values of the organic and inorganic properties of the structural units constituting the molecules of each surface treating agent. The numerical values of the organicity and inorganicity of the structural units constituting the surface treatment agent molecule are described in Fujita, “Chemical Experiments, Organic Chemistry, General Operation Methods”, p. 511, Kawade Shobo (1952), Fujita, “Chemical Domain”, 11, Page 719 (1
957), Fujimoto, "Introduction to New Surfactants", 197-198
Page, Sanyo Chemical Industries (1981) and the like. The quaternary nitrogen atom in quaternary ammonium is equivalent to an amine salt, sodium sulfonate and potassium salt are regarded as light metal salts, the inorganic value is set to 500, and the inorganic value of the amine salt and ammonium salt is set to 400. Consider In addition, some of the known metal soaps are in the above range, but are excluded from the object of the present invention because white powder may be easily attached to the device in the process of making the metal soap.

The following are specific examples of the surface treating agent, which are appropriately selected so as to obtain the effects of the present invention. That is, (K) a sulfonate having a hydrocarbon group having a carbon number of 4 to 40, (L) a phosphate ester salt having a hydrocarbon group having a carbon number of 4 to 40, and a range of 4 to 40 carbon atoms. Salts of phosphoric acid mono- or diesters of higher alcohols,
A salt of a phosphoric acid ester of an ethylene oxide adduct of a higher alcohol having 4 to 40 carbon atoms, (M) a higher aliphatic alcohol, alkylphenol, higher aliphatic amine or higher fatty acid amide having 4 to 40 carbon atoms; Ethylene oxide adducts having a molecular weight of about 3000 or less,
(N) Alkyl betaine or alkyl sulfobetaine having a hydrocarbon group having 4 to 40 carbon atoms, (P) N having an alkyl group having 4 to 30 carbon atoms on a nitrogen atom
-Salts of alkyl-α-, β- or γ-amino acids,
(Q) Ammonium compounds having at least one hydrocarbon group having 4 to 40 carbon atoms, and the like. The “salt” described above and below refers to lithium salt, sodium salt, potassium salt, calcium salt, magnesium salt, 1 to
A quaternary ammonium salt, a primary to quaternary phosphonium salt,
Preferred as salts are lithium, sodium, potassium and quaternary ammonium salts, more preferably sodium or potassium salts.

(K) The sulfonate having a hydrocarbon group having 4 to 40 carbon atoms includes a hydrocarbon having a linear, branched or cyclic structure having 4 to 40 carbon atoms, preferably 8 to 20 carbon atoms. A sulfonate having a group, a sulfoalkanecarboxylate, specifically, an alkylbenzenesulfonate having 4 to 40 carbon atoms, preferably 8 to 20 carbon atoms, a salt of naphthalenesulfonic acid, or a C4 to 30 carbon atom. , Preferably a salt of alkylnaphthalenesulfonic acid having a linear, branched or cyclic structure in the range of 8 to 20, having 1 to 3 carbon atoms
0, preferably a sulfonate of diphenyl ether or biphenyl having an alkyl group having a linear or branched structure in the range of 8 to 20;
Alkanesulfonic acid salts having a linear, branched or cyclic structure in the range of 20; having 1 to 30, preferably 8 to 2 carbon atoms.
A salt of an alkyl sulfate in the range of 0; a salt of a sulfoalkane carboxylate; a sulfonate of an alkylene oxide adduct of an alkyl alcohol having 8 to 30 carbon atoms, preferably 10 to 20 carbon atoms.

Specific examples thereof include alkanesulfonic acid and aromatic sulfonic acid, that is, octanesulfonic acid salt, dodecanesulfonic acid salt, hexadecanesulfonic acid salt, octadecanesulfonic acid salt, 1- or 2-dodecylbenzenesulfonic acid. Acid salt, 1- or 2-hexadecylbenzenesulfonate, 1- or 2-octadecylbenzenesulfonate, various isomers of dodecylnaphthalenesulfonate, salts of β-naphthalenesulfonic acid formalin condensate, octylbiphenyl Various isomers of sulfonates, dodecyl biphenyl sulfonate, various isomers of dodecyl phenoxybenzene sulfonate, dodecyl diphenyl ether disulfonate, dodecyl lignin sulfonate; alkyl sulfates, ie, dodecyl sulfate , Hexadecyl sulfate; sulfo salts of alkanecarboxylic acids, i.e., dialkyl esters of sulfosuccinic acid; an alkyl group 1 to carbon atoms
30, preferably having a linear or branched or cyclic structure in the range of 4 to 20,

More specifically, di (2-sulfosuccinate)
Ethylhexyl) salt, N-methyl-N- (2-sulfoethyl) alkylamide salt (the alkyl group has 1 to 1 carbon atoms)
30, preferably 12 to 18), for example, an amide compound derived from N-methyltaurine and oleic acid, a salt of 2-sulfoethyl ester of a carboxylic acid having 1 to 30 carbon atoms, preferably 10 to 18 carbon atoms; lauryl sulfate Triethanolamine, ammonium lauryl sulfate; polyoxyethylene lauryl sulfate, polyoxyethylene cetyl sulfate,
A sulfonate of an alkylene oxide adduct of an alkyl alcohol having 8 to 30 carbon atoms, preferably 10 to 20 carbon atoms, for example, a sulfate of an ethylene oxide adduct of lauryl alcohol, a sulfuric acid of an ethylene oxide adduct of cetyl alcohol Ester salts, sulfate salts of ethylene oxide adducts of stearyl alcohol,
And the like.

(L) mono- or diester phosphates or phosphate triesters having a hydrocarbon group having a linear, branched or cyclic structure having 4 to 40 carbon atoms;
Preferably, it is a phosphate mono- or di-ester salt or a phosphate triester having a hydrocarbon group having a linear, branched, or cyclic structure having 8 to 20 carbon atoms, and specific examples thereof include phosphorus. Dodecyl disodium salt or dipotassium salt, hexadecyl disodium phosphate,
Or dipotassium salt, didodecyl phosphate disodium salt or potassium salt, dihexadecyl phosphate sodium salt or potassium salt, phosphate triester of ethylene oxide adduct of dodecyl alcohol, and the like.

(M) Among ethylene oxide adducts of higher aliphatic alcohols, alkylphenols, higher aliphatic amines, and higher fatty acid amides, those having a molecular weight of about 3,000 or less, preferably 1,000 or less. , Lauryl alcohol ethylene oxide adduct, cetyl alcohol ethylene oxide adduct, stearyl alcohol ethylene oxide adduct, octylphenol ethylene oxide adduct, dodecylphenol ethylene oxide adduct, stearic acid ethylene oxide adduct, oleic acid Ethylene oxide adduct of lauric acid, ethylene oxide adduct of laurylamine, ethylene oxide adduct of stearylamine, ethylene oxide adduct of lauric amide, ethylene oxide adduct of stearic amide, olein Ethylene oxide adducts of amides, and the like.

(N) 4 to 30, preferably 10 to 10 carbon atoms
Alkyl betaine or alkyl sulfo betaine having a hydrocarbon group in the range of 20, and specific examples thereof include lauryl dimethyl betaine, stearyl dimethyl betaine,
Dodecyldimethyl (3-sulfopropyl) ammonium inner salt, cetyldimethyl (3-sulfopropyl) ammonium inner salt, stearyldimethyl (3-sulfopropyl) ammonium inner salt,
2-octyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, 2-lauryl-N-
Carboxymethyl-N-hydroxyethylimidazolinium betaine and the like.

(P) a salt of an N-alkyl-α-, β- or γ-amino acid having an alkyl group having 4 to 30, preferably 10 to 20 carbon atoms on the nitrogen atom, specific examples of which include , Laurylaminopropionic acid, cetylaminopropionic acid, stearylaminopropionic acid, or salts thereof, that is, laurylaminopropionate, cetylaminopropionate, stearylaminopropionate, and the like.

(Q) 4 to 30, preferably 10 to 10 carbon atoms
Ammonium compounds having a hydrocarbon group in the range of 20
Some examples are shown in the following general formula:
I can do it. R¹XN⁺R^TwoR^ThreeR^Four・ Y^- X: -CH_Two-, -CONHCH_TwoCH_Two-, -CON
HCH_TwoCH_TwoCH_Two-, -NHCOCH_Two-, -NH
COCH_TwoCH_Two-, -COOCH_TwoCH_Two-, -CO
OCH_TwoCH_TwoCH_Two-, -OCOCH_Two-Or-
OCOCH_TwoCH _TwoA group R such as-¹: An alkyl group R having 10 to 20 carbon atoms^Two: An alkyl group R having 1 to 20 carbon atoms^Three: Methyl, ethyl or polyalkyleneoxy group R^Four: Methyl, ethyl, or polyalkyleneoxy group Y^-: Chloride ion, bromide ion, hydroxide ion,
Methanesulfonic acid ion, ethanesulfonic acid ion,
Tyl sulfate ion, ethyl sulfate ion nitrate ion, sulfate ion
Anion selected from ON or acetate ion

Specific examples of R ¹ include undecyl, lauryl, tridecyl, cetyl, pentadecyl,
Examples include a stearyl group and an oleyl group. Specific examples of R ² include a methyl group, an ethyl group, a propyl group, a lauryl group, a cetyl group, and a stearyl group. R ³ and R
Specific examples of ⁴ include, in addition to a methyl group and an ethyl group,
-Hydroxyethyl group, 2- (2-hydroxyethyl)
Examples include an ethyl group, a trioxyethyleneoxy group, a tetraoxyethyleneoxy group, a pentaoxyethyleneoxy group, and a hexaoxyethyleneoxy group.

Further, ammonium derived from laurylamine or coconutamine, lauryldimethylbenzylammonium, imidazolinium-type quaternary ammonium, polydimethyldiallylammonium, polymethyldiallylammonium, polydiallylammonium, dimethyldiallylammonium-acrylamide copolymer Chloride, bromide, hydroxide, metosulfate, ethosulfate, nitrate, sulfate or acetate such as methyldiallylammonium-acrylamide copolymer, diallylammonium-acrylamide copolymer, and the like. Further, among these ammonium compounds, an ammonium compound having a hydrocarbon group in the range of 10 to 20 represented by the above general formula is preferable.

Of these, (K) a sulfonate having a hydrocarbon group having 4 to 40 carbon atoms,
Or (Q) preferably an ammonium compound having at least one hydrocarbon group in the range of 10 to 20, more preferably a sodium or potassium salt of dodecanesulfonic acid, a sodium salt of di (2-ethylhexyl) sulfosuccinate Or potassium salt, sodium or potassium salt of dodecylbenzenesulfonic acid, lauryltrimethylammonium chloride, lauryldimethylethylammonium ethosulfate, lauryltrimethylammonium methosulfate 3- (lauroylamino) propyldimethyl (2-hydroxyethyl) ammonium nitrate, Dilauryl di (polyoxyethylene oxyammonium chloride having a total number of added oxyethylene groups in the range of 2 to 4.

Further, a surface treatment aid can be used in combination with these surface treatment agents as long as the effect is not impaired. The amount of the surface treatment aid is 30% by weight or less, preferably 20% by weight or less, based on the total amount of the surface treatment agent and the surface treatment aid. Specific examples of the surface treatment aid (R) include amide compounds of higher fatty acids having 4 to 40 carbon atoms and higher alcohols. Specific examples thereof include stearic acid amide and ethylenebisstearic acid amide. , N-methylstearic acid amide, N-ethylstearic acid amide, oleic acid amide, behenic acid amide, lauroyl monoethanolamide, stearoyl monoethanolamide, lauryl diethanolamine, stearyl diethanolamine, lauryl alcohol, stearyl alcohol and the like.

(Surface Treatment Method for Inorganic and / or Organic Fine Powder) Various known methods can be applied as a method for preparing an inorganic and / or organic fine powder surface-treated with a surface treating agent in the present invention. There is no particular limitation, and the mixing device and the temperature and time during mixing are also appropriately selected according to the properties and physical properties of the components used. L / D of various mixers used
The (shaft length / shaft diameter), the shape of the stirring blade, the sending speed, the specific energy, the residence time, the treatment time, the treatment temperature and the like can be selected according to the properties of the components used.

Specifically, (I) the above surface treatment agent is dissolved or dispersed in powder, liquid, paste, water or an organic solvent, or the solvent is used when producing the surface treatment agent. When using, remove the solvent or remove part of it, add it to the fine powder in the form of a solution or dispersion of the surface treatment agent at an appropriate concentration, and mix by stirring at low or high speed. , A method of attaching a surface treatment agent around the fine powder,
(II) adding a surface treating agent to a fine powder suspended in water, an organic solvent, or the like, or conversely, dissolving the above cationic polymer surface treating agent in a solvent and then adding the fine powder; A method in which both are mixed and then the solvent is removed and dried to adhere to the periphery of the fine powder. (III) In the case of a fine powder produced by a dry or wet grinding method, a surface treatment is performed before or during the grinding. (IV) adding a required amount of a surface treating agent at a concentration higher than the required concentration to a part of the fine powder to be used, A method of preparing a master batch consisting of a fine powder and a surface treatment agent, mixing with the remaining fine powder, adhering to the periphery of the fine powder and mixing with a thermoplastic resin, (V) In the case of an organic fine powder produced by polymerization, Before or during polymerization Or after, with respect to a fine powder,
A method in which a surface treating agent is added in the form of powder, liquid, paste, or dissolved or dispersed in a solvent, and adhered to the periphery of the organic fine powder. (VI) Dispersed in a thermoplastic resin continuous phase by melt-kneading In the case of organic filler
A surface treatment agent is added to a thermoplastic resin or an undispersed organic filler or a mixture of a thermoplastic resin and an undispersed filler during melt kneading, and the surface around the organic filler is melted and kneaded to finely disperse the organic filler. And a method of attaching a treatment agent.

When the surface treating agent is dissolved or dispersed in a solvent, or when it is mixed with an inorganic and / or organic fine powder in the form of a paste, the mixing temperature can be appropriately selected depending on the properties of the fine powder and the surface treating agent. But, as an example,
Room temperature to 120 ° C, temperature when drying is required is 40 to 12
0 ° C, preferably in the range of 80 to 120 ° C. Also,
If necessary, drying under reduced pressure and use of a dry gas or hot air are also possible.

(Amount Ratio of Constituent Components) The preferred range of the amount of the components constituting the porous resin film of the present invention is 30 to 90% by weight of the thermoplastic resin, 70 to 90% of the surface-treated inorganic and / or organic fine powder. 10% by weight, and the amount of the surface treating agent is 0.01 to 40 parts by weight based on 100 parts by weight of the inorganic and / or organic fine powder. A more preferable range of the thermoplastic resin is 30 to 60% by weight, and further preferably 35% by weight.
~ 55% by weight. From the viewpoint of increasing the strength of the film (i), the content is 30% by weight or more, and in order to further enhance the absorbability of an aqueous solvent or ink, the content is 90% by weight or less.

The amount of the surface-treated organic or inorganic fine powder is, for example, 70 to 10% by weight. In the case of the inorganic fine powder, the amount is preferably 70 to 40% by weight, more preferably 65 to 45% by weight. % Range. It is better to increase the amount of the fine powder in order to increase the number of pores, but for the purpose of setting the strength of the surface of the porous resin film to a good level, the amount is 70% by weight or less. In the case of organic fine powder, the specific gravity is often low, preferably 10 to 50% by weight, more preferably 15 to 40% by weight. The amount of the surface treatment agent used varies depending on the use of the porous resin film, but is usually 0.01 to 40 parts by weight, preferably 0.1 to 20 parts by weight, more preferably 100 parts by weight of the inorganic or organic fine powder. Is in the range of 1 to 10 parts by weight. From the viewpoint of enhancing the absorbability of the aqueous solvent or the aqueous ink, 0.01 parts by weight or more is preferable. If the amount is more than 40 parts by weight, the effect of the surface treatment agent reaches a plateau, and the amount of the thermoplastic resin or inorganic and / or organic fine powder is reduced. In mixing and melt kneading,
In order to perform a smooth operation without troubles such as poor dispersion, the amount of the surface treatment agent is preferably 20 parts by weight or less.

(Optional components) When these fine powders are mixed and kneaded in a thermoplastic resin, a dispersant, an antioxidant, a compatibilizer, a flame retardant, an ultraviolet stabilizer, a coloring pigment, etc. are added as necessary. can do. When the porous resin film of the present invention is used as a durable material, it is preferable to add an antioxidant, an ultraviolet stabilizer and the like. The porous resin film of the present invention may contain a hydrophilic resin as an optional additional component in addition to the above components, as long as the effects of the present invention are not impaired. The hydrophilic resin is not particularly limited as long as it has a property of dissolving or swelling in water and has plasticity at a temperature of normal temperature or higher.

For example, polyvinyl resins such as polyvinyl alcohol and copolymers or crosslinked products thereof which are synthetic resins, polyvinyl pyrrolidone and copolymers thereof; and hydroxyalkyl groups such as 2-hydroxyethyl group and 2-hydroxypropyl group are included. Acrylic acid, methacrylic acid, or maleic acid ester polymer or copolymer or cross-linked product thereof, polyacrylamide or copolymer thereof, acrylonitrile polymer or cross-linked polymer hydrolyzate, acrylic acid or methacrylic acid Polyacrylic resins and their salts (eg, sodium salts, potassium salts, lithium salts, primary and quaternary ammonium salts, etc.) such as polymers or copolymers thereof or crosslinked products thereof; polymaleic acid and maleic acid copolymers Or a resin such as a crosslinked product thereof or a salt thereof (for example, a sodium salt, a potassium salt, Hydrolysates of copolymers of vinyl acetate and methyl methacrylate; water-soluble nylons; urethane resins, ie, water-soluble polyurethanes, superabsorbent polyurethanes, and thermoplastic polyurethanes; Use of polyalkylene oxide resins such as polyethylene oxide and its copolymer, polypropylene oxide and its copolymer; polyether amide, polyether ester amide, and polyester polyol; use of polyvinylamine, polyallylamine, and its copolymer Can be. It is also possible to select from those described in documents such as “Polymer Processing”, No. 9, 1984, pp. 32-38. Above all, it is preferable to use a resin that exhibits plasticity at a temperature equal to or higher than room temperature and is relatively easy to form a film, for example, a polyalkylene oxide resin.

Various known methods can be used for mixing the constituents of the porous resin film of the present invention, and are not particularly limited, and the temperature and time for mixing are appropriately selected according to the properties of the components used. You. Mixing in a state of being dissolved or dispersed in a solvent, a melt-kneading method, and the like can be given. After mixing a thermoplastic resin in the form of powder or pellets, inorganic and / or organic fine powder, and a surface treatment agent with a Henschel mixer, ribbon blender, super mixer, etc., melt and knead with a single or twin screw kneader. Then, there is a method of extruding into a strand shape and cutting to form pellets, and a method of extruding into water from a strand die and cutting with a rotary blade attached to the tip of the die. Various L / D (shaft length / shaft diameter), sending speed, specific energy, residence time, temperature, etc. can be selected as the single-shaft or twin-shaft kneader to be used according to the properties of the components used. It is.

The porous resin film and the recording medium of the present invention can be manufactured by combining various methods known to those skilled in the art. A porous resin film or a recording medium produced by any method is included in the scope of the present invention as long as a porous resin film satisfying the conditions of the present invention is used. As a method for producing the porous resin film of the present invention having a liquid absorption volume of 0.5 ml / m ² or more, various known film production techniques and combinations thereof are possible. For example, a stretched film method utilizing void generation by stretching, a rolling method or a calendering method for generating voids during rolling, a foaming method using a blowing agent, a method using void-containing particles, a solvent extraction method, A method of dissolving and extracting a mixed component is exemplified. Of these, the stretched film method is preferred.

When stretching, it is not always necessary to stretch only the porous resin film of the present invention. For example,
When finally manufacturing a recording medium in which the porous resin film of the present invention is formed on a base material layer, the unstretched porous resin film layer and the base material layer are laminated and summarized. It may be stretched. If they are laminated and stretched in advance, they are simpler and less expensive than the case where they are separately stretched and laminated. Further, the control of the pores formed in the porous resin film of the present invention and the substrate layer becomes easier. In particular, when used as a recording medium, the porous resin film of the present invention is controlled so that more pores are formed than the substrate layer, and the porous resin film is a layer that can improve ink absorbency. It is preferable to make it function effectively.

Various known methods can be used for stretching. The stretching temperature is higher than the glass transition temperature of the thermoplastic resin to be used in the case of non-crystalline resin, and is higher than the glass transition temperature of the non-crystal part in the case of crystalline resin, but is lower than the melting point of the crystalline part. It can be performed within a suitable temperature range. Specifically, longitudinal stretching using the peripheral speed difference of the roll group, transverse stretching using a tenter oven, rolling, inflation stretching using a mandrel on a tubular film, simultaneous biaxial stretching using a combination of a tenter oven and a linear motor Stretching can be performed by such methods.

The stretching ratio is not particularly limited, and is appropriately determined in consideration of the purpose of use of the porous resin film of the present invention and the characteristics of the thermoplastic resin used. For example, when using a propylene homopolymer or a copolymer thereof as the thermoplastic resin, when stretching in one direction, about 1.2 to 12 times,
It is preferably 2 to 10 times, and in the case of biaxial stretching, the area ratio is 1.5 to 60 times, preferably 10 to 50 times.
When using other thermoplastic resins, when stretched in one direction is 1.2 to 10 times, preferably 2 to 7 times, and in the case of biaxial stretching, 1.5 to 20 times in area magnification, Preferably it is 4 to 12 times.

Further, a heat treatment at a high temperature can be performed if necessary. The stretching temperature is a temperature 2 to 60 ° C. lower than the melting point of the thermoplastic resin to be used, and the stretching speed is 10 to 3
Preferably it is 50 m / min. The thickness of the porous resin film of the present invention is not particularly limited, but from the viewpoint of further increasing the absorption of the aqueous solvent or the aqueous ink, for example, 5μ
m or more, preferably 25 μm or more, more preferably 30 μm or more.
μm or more. The upper limit is appropriately selected according to the required absorption amount of the aqueous liquid, but is, for example, 1000 μm or less, preferably 500 μm, more preferably 300 μm.
It can be prepared as follows.

The porous resin film of the present invention may be used as it is, or may be another thermoplastic film,
It may be used by laminating it on laminated paper, pulp paper, nonwoven fabric, cloth and the like. Further, as another thermoplastic film to be laminated, for example, it can be laminated on a transparent or opaque film such as a polyester film, a polyamide film, and a polyolefin film. In particular, a recording medium can be obtained by forming an appropriate functional layer as described in Examples described later. For example, a recording medium can be prepared by forming a porous resin film of the present invention as a surface layer on a base material layer made of a thermoplastic film. The recording medium having the porous resin film of the present invention as a surface layer is particularly useful as a recording medium for inkjet recording. Although the type of the base layer is not particularly limited, for example, a film containing a polypropylene resin and an inorganic fine powder can be exemplified.

As described above, the recording medium formed by laminating the porous resin film of the present invention and another film can have, for example, an overall thickness of about 50 μm to 1 mm. The surface of the porous resin film or the laminate using the same can be subjected to an oxidation treatment as needed. The surface oxidation treatment may improve the hydrophilicity and absorptivity of the surface, improve the coating properties of the ink fixing agent and the ink receiving layer, and improve the adhesion to the substrate. Specific examples of the surface oxidation treatment include corona discharge treatment, flame treatment, plasma treatment, glow discharge treatment, a treatment method selected from ozone treatment, preferably corona treatment, flame treatment, more preferably corona treatment. is there.

The processing amount is 600 to 1 in the case of corona treatment.
2,000 J / m ² (10-200 W · min / m ² ), preferably 1200-9000 J / m ² (20-180 W
Min / m ² ). In order to sufficiently obtain the effect of the corona discharge treatment, the treatment effect is 600 J / m ² (10 W · min / m ² ) or more, and when it exceeds 12,000 J / m ² (200 W · min / m ² ), the effect of the treatment reaches a plateau. 12,000 J / m ²
(200 W · min / m ² ) or less is sufficient. For flame treatment, 8,000~200,000J / m ^2, preferably 20,000~100,000J / m ² is used. In order to obtain the effect of the frame processing clearly,
0 J / m ² or more, and if it exceeds 200,000 J / m ² , the effect of the treatment reaches a plateau, so that 200,000 J / m ²
The following is sufficient.

When the porous resin film of the present invention is used as a recording medium, a colorant fixing layer for fixing a dye and a pigment colorant and an ink receiving layer can be formed on the surface thereof. Compared to the case of coating on a resin film having low absorbency, the combination with the porous resin film of the present invention having good aqueous solvent absorbability reduces bleeding, improves absorbency and improves the colorant fixing layer and the ink receiving layer. It is also possible to reduce the thickness. The colorant fixing layer rounds the dot shape of the ink,
It has a function of obtaining a clearer image and preventing a colorant flow due to water or moisture. Therefore, the coloring agent fixing layer is particularly useful when the porous resin film of the present invention is used as an ink jet recording medium.

The colorant fixing layer and the ink receiving layer can be formed by coating or laminating. In order to improve the fixability of the colorant, it is preferable to use a hydrophilic resin having a cationic property and a fine powder. For example, as the cationic copolymer, those containing a cationic group such as an amino group, a modified product thereof, or a quaternary ammonium base in the main chain or side chain of the polymer can be used. As an ink receiving layer for inkjet, a porous ink receiving layer mainly composed of a pigment and an aqueous binder is used in a field requiring quick drying of the ink, and an aqueous binder is used when a high gloss is required. A swellable ink receiving layer as a main component can be provided. As pigments, synthetic silica, colloidal silica, alumina hydrosol, aluminum hydroxide,
Examples include talc, calcium carbonate, clay, plastic pigment, barium sulfate, titanium dioxide and the like. Among them, porous synthetic silica and alumina hydrosol are preferable.

Examples of the aqueous binder include polyurethane resins, polyester resins, vinyl acetate resins, acrylate resins, styrene-acrylate copolymers, vinyl acetate-acrylate copolymers, and styrene-butadiene copolymers. Aqueous emulsions such as polymers, methyl methacrylate-butadiene copolymer, etc., polyvinyl alcohol, ethylene-vinyl alcohol copolymer containing silanol groups, polyvinyl acetal, polyvinyl pyrrolidone, methyl ethyl cellulose, sodium polyacrylate, various starches, various types Water-soluble polymers such as gelatin. Among them, when the pigment is porous synthetic silica, alumina hydrosol, polyvinyl alcohol,
An ethylene / vinyl alcohol copolymer containing a silanol group is preferred.

When the ink receiving layer used in the present invention is required to have an ink fixing property, an ink setting agent is blended.
Examples of the ink setting agent include cationic polymers such as a tertiary ammonium salt of polyethyleneimine, an acrylic copolymer containing a quaternary ammonium group as a copolymerization component, and an epichlorohydrin adduct of polyamine polyamide. Further, the coloring material fixing layer and the ink receiving layer used in the present invention may contain, as additives, pigment dispersants, thickeners, defoamers, fluorescent brighteners, ultraviolet absorbers, antioxidants, preservatives, and water resistance. An agent and the like can be appropriately compounded. In the case of a porous ink receiving layer, the ratio of pigment / water-based binder / ink setting agent is preferably 50 to 90% by weight / 10 to 40% by weight / 0 to 20% by weight. In the case of the swellable ink receiving layer, the ratio of the aqueous binder / ink setting agent is 60 to 100.
% By weight / 0 to 40% by weight is preferred.

As the coating method of the ink receiving layer, general coating methods such as a blade method, a rod method, a wire bar method, a slide hopper method, a curtain method, an air knife method, a roll method, and a size press method are used. Can be The dry coating amount of the ink receiving layer varies depending on the required ink absorbency, gloss, absorbency of the support and the like, but is usually 0.05 to 100 g / m ² , preferably 0.1 to 50 g / m ² .
g / m ² . In the present invention, the ink receiving layer may be either a single layer or a multilayer of two or more layers. In the case of a multilayer, each layer can have a different composition or the same composition. When forming a multilayer, 2
More than one layer may be applied at a time or one layer at a time.

The porous resin film of the present invention can be subjected to printing other than ink jet printing depending on the purpose of use. The type and method of printing are not particularly limited. For example, printing can be performed by using known printing means such as gravure printing using an ink in which a pigment is dispersed in a known vehicle, aqueous flexo, and silk screen. In addition, printing can be performed by metal deposition, gloss printing, mat printing, or the like. The pattern to be printed can be appropriately selected from natural patterns such as animals, landscapes, lattices, polka dots, and abstract patterns.
In addition to printing applications, it can also be used for applications that need to absorb aqueous liquids. For example, pressure-sensitive adhesive labels using water-based pressure-sensitive adhesives, label paper for containers such as bottles and cans, water-absorbent films, wallpapers, surface decorative paper for plywood and gypsum boards, water-drop prevention films, food drip-proof wrapping paper, coasters , Work paper, origami, water retention sheet, soil drying prevention sheet, concrete drying auxiliary material, desiccant,
It can also be used as a dehumidifier.

[0066]

The present invention will be more specifically described below with reference to examples, comparative examples and test examples. The materials, usage amounts, ratios, operations, and the like shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore,
The scope of the present invention is not limited to the following specific examples. A porous resin film of the present invention, a recording medium using the same, and a recording medium using a comparative resin film were produced according to the following procedures.

(Experimental Example 1) Heavy carbon dioxide was used as the fine powder.
Lucium (average particle diameter 3 μm, specific surface area 1.8 m ^Two/
g, absorption measured according to JIS-K5101-1991.
Oil amount 31ml / 100g, abbreviation: charcoal 1) 100 weight
Do not heat the parts to 80-100 ° C with a super mixer.
Stirring, surface treatment agent (sodium dodecane sulfonate)
50% and sodium hexadecanesulfonate 50%
Mixture, HLB value 17.9, manufactured by Tokyo Chemical Industry Co., Ltd.
Drug grade, abbreviation: ST1) Add 4 parts by weight,
Heating and stirring to obtain surface-treated calcium carbonate
Was. The temperature inside the super mixer is about 100 ℃ ~ 110 ℃
Met. This is abbreviated as SC1. This specification
The particle size of the calcium carbonate powder used in the examples of the
Laser Diffraction Particle Measurement System "Microtrack"
Cumulative 50% measured by (Nikkiso Co., Ltd., trade name)
The particle size.

(Experimental Example 2) Oleic acid (H
Experimental Example 1 except that the LB value was changed to 4.7, abbreviation: ST2)
Thus, a surface-treated calcium carbonate was obtained by the same operation as described above (abbreviation: SC2). (Experimental example 3) Lauryl trimethyl ammonium methosulfate (HLB value 13.3, abbreviation: ST)
A calcium carbonate surface-treated was obtained in the same manner as in Experimental Example 1 except that the method was changed to 3) (abbreviation: SC3).

(Experimental Example 4) The same operation as in Experimental Example 1 was carried out except that the surface treating agent was changed to 3-lauroylaminopropyldimethyl (2-hydroxyethyl) nitrate (HLB value: 18.4, abbreviation: ST4). A surface-treated calcium carbonate was obtained (abbreviation: SC4). (Experimental Example 5) An experiment was conducted except that the surface treatment agent was changed to a mixture of dilauryl di (diethyleneoxy) ammonium chloride and dilauryl (2-hydroxyethyl) (trioxyethyleneoxy) chloride (HLB value 11.7, abbreviation: ST5). A surface-treated calcium carbonate was obtained in the same manner as in Example 1 (abbreviation: SC5).

(Example 1) <Preparation of base layer and longitudinal stretching> Melt flow rate (MF
R: 230 ° C., 2.16 kg load) 75% by weight of polypropylene at 1 g / 10 min and melt flow rate (MF
R: 190 ° C., 2.16 kg load) in a mixture with 5% by weight of high-density polyethylene of 8 g / 10 min.
A composition [A] containing 20% by weight of calcium carbonate of 20 μm was kneaded with an extruder set at a temperature of 250 ° C., extruded into strands, and cut into pellets. The pellets of the composition [a] were extruded into a sheet shape from a T-die connected to an extruder set at 250 ° C, and cooled by a cooling device to obtain a non-stretched sheet. Next, after heating this unstretched sheet to 145 ° C., it was stretched 4.5 times in the machine direction to obtain a stretched sheet.
In the melt kneading of the resin component or the mixture of the resin component and the fine powder in each of the examples, the total weight of the resin component and the fine powder was set to 100 parts by weight, and in addition, BHT (4- 0.2 parts by weight of methyl-2,6-di-t-butylphenol) and Irganox 1010
(Phenolic antioxidant, Ciba-Geigy, trade name) 0.1 part by weight was added.

<Formation of Porous Resin Film on Surface> Separately, polypropylene 4 having an MFR of 20 g / 10 min.
0% by weight (abbreviation: PP1) and 60% by weight of the surface-treated calcium carbonate (abbreviation: SC1) of Experimental Example 1 were sufficiently mixed in a powder state, and melt-kneaded by a twin-screw kneader set at 240 ° C. The mixture was extruded and cut into strands to obtain pellets (composition [b]). A pellet of this composition [b] was extruded into a sheet from a T-die connected to an extruder set at 230 ° C. (temperature a). The obtained sheet was laminated on both sides of the 4.5-fold stretched sheet prepared by the above operation, and cooled to 50 ° C. (temperature b).
C. (temperature c) and stretched 8.5 times in the transverse direction with a tenter. Thereafter, annealing treatment is performed at 155 ° C. (temperature d), the temperature is cooled to 55 ° C. (temperature e), and the ears are slit to form three layers (absorption layer [b] on the front side / base layer [a] / back side). Absorbing layer [b]: A laminate having a porous resin film with a total thickness of 137 µm having a structure of 45 µm / 56 µm / 36 µm in thickness was obtained. Hereinafter, evaluation of the laminates of Examples and Comparative Examples,
This was performed for the absorption layer on the front side. This was evaluated in the following manner.

<Evaluation> (1) Liquid Absorption Volume The liquid absorption volume of the above-mentioned porous resin film at 2 seconds was measured as "Japan TAPPI No. 5".
1-87 "(Paper and Pulp Technology Association, Paper and Pulp Test Method N)
o. 51-87, Bristow method), using a liquid absorption tester manufactured by Kumagai Riki Kogyo Co., Ltd. The measurement solvent is water 70% by weight and ethylene glycol 30% by weight.
Are mixed, and 2 parts by weight of malachite green is dissolved as a coloring dye in 100 parts by weight of the mixed solvent. (2) Average contact angle of porous resin film with water, difference between the maximum value and minimum value The contact angle of the surface of the porous film was measured by contact angle meter (Kyowa) one minute after dropping pure water on the film surface. Surface Chemistry Co., Ltd.
(Model CA-D). This measurement is
(The film was replaced with an unmeasured film whose surface was not wetted with pure water for each measurement), and the average value of the contact angles measured 10 times and the difference between the maximum value and the minimum value were determined.

(3) Confirmation of Existence of Surface Vacancies and Measurement of Surface Vacancy Number and Surface Vacancy A portion of the porous film was cut out, and it was confirmed that pores existed on the surface and in the cross section. Cut any part from the porous film sample, paste it on the observation sample table,
Gold or gold-palladium was vapor-deposited on the observation surface, and a scanning electron microscope S-2400 manufactured by Hitachi, Ltd. was used.
Confirm the presence of vacancies on the surface by magnifying 00 times, and the presence of inorganic fine powder in the majority of vacancies of at least about 50% or more of the total vacancies or at the ends of the vacancies. did. In addition, an electron microscope image was output or photographed on thermal paper, and the number of holes on the surface was measured. As a result, about 4.3 × 10 ⁹ / m ²
Met. Next, as a result of averaging the measured values of the 118 holes, the major axis was 13.3 μm, the minor axis was 8.2 μm, and the average diameter was 8.3 μm. When the two holes are connected to the left and right or up and down of the fine powder, it is assumed that the holes are formed around the fine powder and 2
One hole was measured as one connected hole.

(4) Confirmation of existence of internal pores and measurement of internal porosity After embedding the above-mentioned porous resin film with epoxy resin and solidifying it, using a microtome, the thickness of the film was measured in the thickness direction. After making a cut surface parallel and perpendicular to the surface direction, and metallizing this cut surface with gold-palladium,
Using a scanning electron microscope S-2400 manufactured by Hitachi, Ltd., the sample was observed at a magnification of 1000 times, and it was confirmed that internal voids existed and that fine powder was present in at least a part of the internal voids. confirmed.

The overall thickness and basis weight (g / m ² ) were measured,
Subsequently, the absorbent layer on the surface was peeled off in a certain area, the basis weight and thickness of the remaining film were measured, and the thickness and basis weight (g / m ² ) of the porous resin film layer were obtained from the difference between the ^two . From this, the basis weight was divided by the thickness to calculate the density (ρ) of the absorbing layer.
Next, the composition [b] was formed into a pressed sheet having a thickness of 1 mm at 230 ° C., the density (ρ ₀ ) was measured, and the porosity was calculated by the following equation.

(Equation 2)

(5) Ink Absorbency Evaluation Color Chart (2 cm × 2 cm 50% single color printing and 100% single color printing, 2 cm × 2 cm double color 20
(0% printing) was prepared and printed on a porous resin film as a surface layer of each recording medium by an ink jet printer (Graphtec Co., Ltd .: Model JP2115) using a pigment ink (yellow, magenta, cyan, black). Thereafter, the filter paper was pressed against the printed portion at regular intervals, and it was observed whether or not the ink returned to the filter paper. The time when the ink did not return to the filter paper was recorded, and the ink absorbency was evaluated according to the following criteria. 6: The time when the ink does not return to the filter paper is immediately after printing. 5: The time during which the ink does not return to the filter paper is within 1 minute. 4: The time when the ink does not return to the filter paper exceeds 1 minute,
Within 2 minutes. 3: The time when the ink does not return to the filter paper exceeds 2 minutes,
Within 3 minutes. 2: The time when the ink does not return to the filter paper exceeds 3 minutes,
Within 4 minutes. 1: The time when the ink does not return to the filter paper exceeds 4 minutes,
Within 5 minutes. 0: Even after more than 5 minutes, the ink returned to the filter paper and was not absorbed.

(Evaluation of density unevenness) Density unevenness after ink absorption was visually observed and evaluated according to the following criteria. 4: There is no density unevenness at all. 3: There is little density unevenness. 2: There is density unevenness. 1: Density unevenness is noticeable. (Evaluation of bleeding) The bleeding after absorbing the ink was visually observed and evaluated according to the following criteria. 4: There is no blur and the image is clear. 3: There is little bleeding and there is almost no hindrance to image identification. 2: There is bleeding, and there is a problem in image identification. 1: The bleeding is remarkable, and it cannot be used.

(Evaluation of Roughness of Paper After Printing) After printing, the paper was left in a room for 1 hour, and it was visually observed whether or not the paper had unevenness (unevenness), and evaluated according to the following criteria. 3: There is no unevenness, the paper surface is flat, and there is almost no change from before printing. 2: There is little unevenness. 1: Unevenness is noticeable. The results are shown in Table 1. Table 1 summarizes the above tests and evaluation results.

(Comparative Example 1) Instead of the surface-treated calcium carbonate SC1, the heavy calcium carbonate used in Experimental Example 1 (average particle size: 3 μm, specific surface area by BET method: 1.8 m ² / g, JIS K5101) A laminate film having a porous resin film on the surface was prepared in the same manner as in Example except that calcium carbonate having an oil absorption of 31 ml / 100 g as measured by -1991 was used without any surface treatment. , Was evaluated. The evaluation results are summarized in Table 1. (Comparative Example 2) Instead of surface-treated calcium carbonate,
A laminated film having a porous resin film on its surface was prepared and evaluated in the same manner as in Example 1, except that surface-treated calcium carbonate using stearic acid as a surface treating agent (Experimental Example 2, abbreviation SC2) was used. Was done. The evaluation results are summarized in Table 1.

Example 2 The same operation as in Example 1 was carried out except that the mixing ratio and the molding conditions were as shown in Table 1.
A laminated film having a porous resin film on the surface was prepared and evaluated. The evaluation results are summarized in Table 1. (Example 3) Table 1 shows the thickness of the porous resin film layer on the surface.
Except as described, by the same operation as in Example 1,
A laminated film having a porous resin film on the surface was prepared and evaluated. The evaluation results are summarized in Table 1.

(Example 4) The surface-treated calcium carbonate (abbreviated as S)
By the same operation as in Example 1 except that C3) was used,
A laminated film having a porous resin film on the surface was prepared and evaluated. The evaluation results are summarized in Table 1. (Example 5) Experimental example 3 using surface-treated calcium carbonate
The laminated film having a porous resin film on the surface was prepared and evaluated in the same manner as in Example 1 except that the surface-treated calcium carbonate (abbreviation SC4) shown in (1) was used. The evaluation results are summarized in Table 1. (Example 6) Experimental example 3 using surface-treated calcium carbonate
The laminated film having a porous resin film on the surface was prepared and evaluated in the same manner as in Example 1 except that the surface-treated calcium carbonate (abbreviation SC5) shown in (1) was used. The evaluation results are summarized in Table 1.

[0082]

[Table 1]

Example 7 The pellets used for forming the porous resin film on the surface of Example 4 were melted by a press molding machine set at 230 ° C., compressed at 50 kgf / cm ² , and
Cool to 0 ° C, length 120mm, width 120mm, thickness about 1
mm sheet was obtained. The density of this sheet is 1.5 g / c
m ³ . This sheet is heated to 159 ° C (temperature a1) by a small biaxial stretching machine (manufactured by Iwamoto Seisakusho), stretched 5.2 times in one direction, and cooled to 90 ° C (temperature b1) with cold air to obtain a thickness. A porous resin film having a size of 325 μm, a basis weight of 207 g / m ² and a density (ρ) of 0.64 g / cm ³ was obtained. This had an internal porosity of 58%. Then
The same evaluation as in Example 1 was performed. The evaluation results are shown in Table 2.

Comparative Example 3 The pellets used for forming the porous resin film on the surface of Comparative Example 1 were melted by a press molding machine set at 230 ° C., compressed at 50 kgf / cm ² , and
Cool to 0 ° C, length 120mm, width 120mm, thickness about 1
mm sheet was obtained. The density of this sheet is 1.5 g / c
m3. This sheet is heated to 160 ° C. (temperature a1) by a small biaxial stretching machine (manufactured by Iwamoto Seisakusho), then stretched 5.2 times in one direction, and cooled to 90 ° C. (temperature b1) with cold air to obtain a thickness. A porous resin film having a size of 306 μm, a basis weight of 208 g / m ² and a density (ρ) of 0.68 g / cm ³ was obtained. Its internal porosity was 55%. Then
The same evaluation as in Example 1 was performed. The evaluation results are shown in Table 2.

[0085]

[Table 2]

(Examples 8 and 9) 3600 J / m ² (60 Watt · min / m ² ) was applied to each surface of the laminate having the porous resin film shown in Example 1 and Example 3 on the surface.
Corona treatment was performed at a treatment density of, and the same evaluation as in Example 1 was performed. The evaluation results are shown in Table 3. It was subjected to corona treatment at a treatment density of Example 10 Example 3 was produced in the porous resin film to 3600J / m ² (60 watt min / m ^2). This was used as a support (designated on one side) and coated with a coating liquid for an ink receiving layer having the following composition so that the solid content became 5 g / m ² , dried, and then smoothed with a super calender to perform inkjet printing. Recording paper was obtained.

Coating liquid composition: 100 parts by weight of synthetic silica powder (Mizukasyl P-78D, Mizusawa Chemical Industry Co., Ltd.) 30 parts by weight of polyvinyl alcohol (Kuraray Co., Ltd. PVA-117) 30 parts by weight Polyamine polyamide epichlorohydrin adduct (Nippon PMC Co., Ltd.) ) WS-570) 10 parts by weight Sodium polyacrylate (Wako Pure Chemical Industries, Ltd. reagent) 5 parts by weight Water 1600 parts by weight Evaluation was performed in the same manner as in Example 1. Table 3 shows the evaluation results.

(Example 11) The porous film of Example 3 which had been subjected to the same corona treatment as in Example 10 was used as a support (designated on one side), and a coating liquid for an ink receiving layer having the following composition was solidified. The coating was performed so that the content of the component became 5 g / m ² and dried to obtain an ink jet recording paper. Coating liquid composition: Alumina sol (Nissan Chemical Industry Co., Ltd. Alumina Sol 100, solid content 10%) 100 parts by weight Polyvinyl alcohol (Kuraray Co., Ltd. PVA-117) 10 parts by weight Water 100 parts by weight The evaluation results are shown in Table 3.

(Example 12) The porous film of Example 3 was subjected to the same corona treatment as in Example 10, and was used as a support. The liquid was applied so that the solid content became 5 g / m ² , and dried to obtain an ink jet recording paper. Coating liquid composition: Urethane-based binder (Dainippon Ink and Chemicals Co., Ltd. SF coating agent 8310, solid content 13%) 100 parts by weight Polyamidine-based polymer (Hymo Co., Ltd. Himax SC700L solid content 30%) 2 parts by weight Evaluation result Are shown in Table 3. (Comparative Example 4) Commercially available pulp paper-based inkjet paper (Epson Sperfine paper MJA4SP1)
And the same evaluation as in Example 1 was performed. Table 3 shows the results
Shown in

[0090]

[Table 3]

As is evident from Tables 1 and 2, the porous resin films of the present invention (Examples 1 to 17) have little density unevenness and very good ink absorbability even when the ink ejection amount is large. It is. On the other hand, the films (Comparative Examples 1 and 2) whose liquid absorption amounts are out of the range of the present invention are all inferior in ink absorbency. Further, as is apparent from Examples 8 and 9, the porous resin film whose surface has been subjected to oxidation treatment has good ink absorption, and furthermore has less density unevenness in the printed portion, and the effect of the present invention is clear. Further, as is apparent from Examples 10 to 12, when the ink receiving layer was provided, the ink absorption was good, the bleeding was good, and the effect of the present invention was obvious. Furthermore, from the comparison between each example and Comparative Example 3, the porous film of the present invention has no unevenness on the paper surface after printing, and the effect of the present invention is clear.

[0092]

As described above, the porous resin film of the present invention has extremely good water-based solvent and ink absorbency. Further, the recording medium of the present invention using the porous resin film can form a fine image without density unevenness even when the ink ejection amount is large. Therefore, the porous resin film and the recording medium of the present invention can be suitably provided for a wide range of printing applications such as an inkjet recording medium, particularly for recording applications using aqueous inks, and for applications using aqueous solvents.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 23/02 C08L 23/02 101/00 101/00 (72) Inventor Seiichiro Iida Higashi Kamisu-cho, Kashima-gun, Ibaraki Prefecture 23 Wada Oji Oil Chemicals Co., Ltd. Kashima Mill F-term (reference) 2H086 BA15 BA19 BA31 BA33 BA36 BA41 BA45 BA48 4F074 AA16 AA24 AA97 AB05 AC26 AD13 AD15 AE01 AE06 AF03 AG20 CA01 CA03 CC02Y CD11 CE16 CE56 CE65 DA03 DA03 DA52 4F100 AA00A AA00H AH00A AH00H AK01A AK03A AK05A AK07A AL05A AR00C AT00B BA02 BA03 BA07 BA10A BA10B BA10C CA23A DE01A DE01H DJ01A DJ03A EJ12A EJ12H EJ64A EJ64H GB90 JA20A JA20H JB16A JD14A JD14C YY00A YY00H 4J002 AA011 BB001 BB031 BB101 BB121 BB171 BC031 BC032 BG042 BG052 CC182 CF031 CF061 CF062 CF072 CF081 CF082 CG001 CG002 CH092 CL002 CL011 CL031 CM042 CN011 CN012 CN022 D E076 DE106 DE136 DE236 DG046 DJ006 DJ016 DJ036 DJ046 FA082 FB082 FB086 FD016 GK03

Claims (19)

[Claims] Claims: 1. A method comprising a thermoplastic resin and an inorganic and / or organic fine powder surface-treated with a surface treating agent;
pan TAPPI No. 51-87 "is a liquid absorption volume of 0.5 ml / m < ² > or more, The porous resin film characterized by the above-mentioned. 2. The porous resin film according to claim 1, wherein the average contact angle with water is 110 ° or less. 3. The porous resin film according to claim 1, having pores on the surface and inside. 4. The porosity is 10% or more.
The porous resin film according to any one of the above. 5. The porous resin film according to claim 1, wherein the number of vacancies on the surface is 1 × 10 ⁶ / m ² or more. 6. An average diameter of pores on the surface is 0.01 to 50.
The porous resin film according to any one of claims 1 to 5, wherein the thickness is in a range of µm. 7. The method according to claim 1, wherein at least a part of the surface and / or the internal vacancy has an inorganic and / or organic fine powder present inside or around the vacancy. 4. The porous resin film according to 3. 8. The porous resin film according to claim 1, wherein the thermoplastic resin is a polyolefin resin. 9. The porous resin film according to claim 1, wherein the average particle size of the inorganic and / or organic fine powder is in the range of 0.01 to 20 μm. 10. The porous resin film according to claim 1, wherein the inorganic and / or organic fine powder has a specific surface area of 0.5 m ² / g or more. 11. The porous resin film according to claim 1, wherein the HLB value of the surface treatment agent is in the range of 5 to 100. 12. The surface treating agent is a sulfonate having a hydrocarbon group having 4 to 40 carbon atoms, or a sulfonate having 4 to 40 carbon atoms.
The porous resin film according to any one of claims 1 to 11, wherein the porous resin film is an ammonium compound having a hydrocarbon group in the range of 30. 13. A thermoplastic resin of 30 to 90% by weight and a surface-treated inorganic and / or organic fine powder of 70 to 10%.
The composition according to any one of claims 1 to 12, wherein the amount of the surface treating agent is in the range of 0.01 to 40 parts by weight based on 100 parts by weight of the inorganic and / or organic fine powder. Porous resin film. 14. The porous resin film according to claim 1, which is stretched. 15. The porous resin film according to claim 1, wherein the surface is subjected to an oxidation treatment. 16. The method according to claim 1, wherein at least one surface of the base material layer is provided.
A laminated film having a layer of a porous resin film according to any one of claims 15 to 15. 17. A recording medium using the porous resin film or the laminated film according to claim 1. 18. An ink jet recording medium using the porous resin film or the laminated film according to claim 1. 19. A colorant fixing layer on at least one of the surfaces of the porous resin film according to claim 1 or at least one of the surfaces of the layer of the porous resin film which is not in contact with the base material layer. An ink jet recording medium comprising: