JP4310527B2 - Ink-jet glossy recording paper and method for producing the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides a glossy recording paper for inkjet, and a method for producing the same, which can have both excellent glossiness and ink absorptivity (printability).
[0002]
BACKGROUND OF THE INVENTION
Conventionally, the following are known as inkjet recording paper.
(a) A material in which starch or the like and a surface sizing agent are mixed with a general paper mainly composed of pulp or a cationic agent is applied.
(b) A base paper such as general fine paper provided with an ink absorbing layer using a porous pigment.
(c) A synthetic resin film or a film and paper laminated with an ink absorbing hydrophilic resin or porous pigment ink absorbing layer.
[0003]
In recent years, with the increase in recording color or printing of photographic images (that is, printing with a subtle halftone), more advanced characteristics are required even for inkjet recording media, and in particular, surface gloss is high. The demand for recording media is increasing.
However, in the recording papers shown in the above (a) to (c), the surface of the paper is an ink-absorbing porous surface, so that incident light is scattered on the surface with many voids, which is totally glossy. Only a matte surface with no surface can be obtained.
[0004]
[Prior art]
Therefore, the following are examples of conventional technologies for inkjet recording paper for the purpose of imparting gloss.
(1) A synthetic resin film coated with a hydrophilic resin.
(2) As shown in JP-A-63-265680, JP-A-2-113986, JP-A-6-305237, etc., a specially formulated pigment and binder coating solution is applied to fine paper Then, while this coating solution is in a wet state, it is applied to a heated dryer mirror surface and dried, and the smoothness of the mirror surface is copied onto the surface of the coating layer.
[0005]
(3) Inkjet recording paper produced by thermal calendering, as shown in JP-A-11-48604 and JP-A-11-268405, in which a coating layer containing fine particles of white pigment or pigment silica is provided as the uppermost layer.
Since these conventional technologies are systems in which a mirror surface finish is performed by pressure-bonding to a cast drum, or a thermal calendar and a cast coating process are used in combination (for example, refer to the respective embodiments 1), It is essentially cast coated paper. This cast-coated paper is generally used for obtaining the highest gloss in offset printing and gravure printing using oil-based ink.
[0006]
(4) As shown in JP-A-7-101142, a glossy layer comprising colloidal fine particles such as silica, alumina fine particles, polystyrene, styrene-butadiene copolymer, acrylic ester-methacrylic ester copolymer and latex. Is a recording paper that is manufactured by thermal calendering.
[0007]
(5) As shown in JP-A-7-25134 and JP-A-7-47761, an ink receiving layer containing thermoplastic fine particles or thermoplastic multilayer fine particles is provided on the outermost layer of the recording paper, and these particles A recording paper in which the ink absorptivity is adjusted by partial fusing. Also, as shown in JP-A-7-25135, a recording paper in which particles are cross-linked with a cross-linking agent or an electron beam after forming a coating layer of fine particles having a functional group on the outermost layer of the recording paper.
[0008]
[Problems to be solved by the invention]
However, the film using the film shown in (1) above cannot be reused like paper and cannot cope with future environmental problems.
The above (2) high quality paper etc. provided with an ink absorbing layer by the cast coating method can provide high gloss, but on the other hand, because it is a smooth, dense and thick surface layer, it can be used for printing with oil-based ink. Is applicable to ink-jet printing based on water-based inks, the surface layer tends to be blocked by the thickness of the surface layer and the water-based ink tends to be absorbed slowly. By the way, in inkjet printing, if the recording paper does not absorb the water-based ink ejected from the nozzles at high speed without delay, ink bleeding and image defects will occur. It is an important requirement.
Further, since the mirror surface dryer is dried while copying the smoothness of the mirror surface onto the surface of the coating layer, the drying speed cannot be increased, the productivity is poor, and the cost is high.
On the other hand, the above recording paper (3) cannot avoid these problems.
[0009]
In the recording paper of the above (4), if the ratio of the inorganic colloidal fine particles is large, the hydrophilicity is high, so that the printing is liable to occur. Conversely, when the ratio of the binder such as latex is increased, the water-based inkjet ink is changed to the binder. Absorption speed that passes through the film is slow, and troubles such as print stains and full color boundary bleeding are likely to occur.
[0010]
In the partially fused recording paper described in (5) above, it is necessary to adjust the drying conditions within a narrow temperature range in order to partially fuse the fine particles. Under actual drying conditions, the temperature distribution of the drying device necessarily occurs. It is very difficult to produce a recording paper having a certain ink absorbability.
Further, with the cross-linking type recording paper (5), the post-cross-linking process tends to be complicated. Incidentally, all the recording papers of (5) are formed with an ink receiving layer by interconnecting fine particles of multilayer structure, and the object of the invention is water resistance, ink drying property, dot reproducibility, print sharpness, etc. Therefore, it is not possible to improve the gloss of the recording paper.
[0011]
On the other hand, as a method for imparting gloss to an ink jet recording medium, it is conceivable to simply pass the paper through a roll under pressure or temperature by a super calender or gloss calender method. In this method, the surface is smoothed. As a result, even if the gloss is improved, the voids in the coating layer are reduced and the ink absorptivity is slowed. Conversely, if a fast ink absorptivity is to be ensured, the voids increase and the gloss is lowered.
For the above reasons, it has been extremely difficult to achieve both ink absorbency and glossiness of recording paper by a method other than cast coating.
An object of the present invention is to produce an ink jet recording paper that can achieve both glossiness and ink absorptivity without using a cast coating method.
[0012]
[Means for Solving the Problems]
The present applicant has previously polymerized monomers such as styrene and / or methyl methacrylate in the presence of an anionic emulsifier in JP-A-4-272297 (hereinafter referred to as Prior Art 1). A paper emulsion finishing agent with a copolymer emulsion having a glass transition temperature of 80 ° C. or higher was proposed.
However, as can be seen from the fact that the processing agent of Prior Art 1 uses an oleophilic styrene butadiene rubber latex or the like in the base paper undercoat coating liquid (see paragraph 42 of the same publication), offset printing, etc. It is suitable for high-gloss printing with oil-based inks, and when applied to water-based inks for inkjet printing, the hydrophobicity is too strong, resulting in slow ink absorption, and may cause print stains and full-color border bleeding .
[0013]
The inventors have Prior art 1 As a starting point, as a result of intensive research, a styrene-acrylic polymer dispersion was laminated on the ink receiving layer provided on the base paper, and (meth) acrylamide was added as a monomer component to this ink-permeable polymer dispersion. In addition, the coated paper is not a high-cost cast coating method, but can be smoothly finished with a simple thermal calendering process to provide a good balance between gloss and ink absorbency, and styrene containing acrylamide, which has a fast reaction rate. In the emulsion polymerization reaction of acrylic polymer, the present invention was completed by finding out that the use of a water-soluble chain transfer agent greatly contributes to the production of an appropriate polymer dispersion.
[0014]
That is, according to the present invention, an ink receiving layer mainly composed of a pigment composed of fine silica and / or fine calcium carbonate having an average particle size of 0.5 μm or less and a hydrophilic binder is provided on the base paper, and the outermost layer of the base paper is provided. An ink jet recording paper coated with an ink permeable polymer dispersion, dried and subjected to a heat calendar finish,
The above ink permeable polymer dispersion contains (meth) acrylamide as a monomer component. At a content of 2 to 15% by weight A glossy recording paper for inkjet, which is a styrene / acrylic polymer dispersion copolymerized under the above conditions.
[0015]
The present invention 2 is an inkjet recording paper in which a hydrophilic polymer layer is coated on a base paper, an ink-permeable polymer dispersion is coated on the outermost layer of the base paper, and drying and thermal calendar finishing are performed.
The above ink permeable polymer dispersion contains (meth) acrylamide as a monomer component. At a content of 2 to 15% by weight A glossy recording paper for inkjet, which is a styrene / acrylic polymer dispersion copolymerized under the above conditions.
[0016]
In the present invention 3, the hydrophilic polymer of the present invention 2 is selected from the group consisting of polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene oxide, cationic polyacrylamide, water-soluble cationic polyacrylate, and cationic polyacrylate dispersion. It is a glossy recording paper for ink jet, which is at least one of polymers.
[0017]
Invention 4 is characterized in that, in any of Inventions 1 to 3, the styrene / acrylic polymer dispersion containing (meth) acrylamide is emulsion-polymerized in the presence of a water-soluble chain transfer agent. Ink-jet glossy recording paper.
[0019]
Invention 5 Is the above Any of the present invention 1-4 In styrene / acrylic polymer dispersion containing (meth) acrylamide,
(a) (Meth) acrylamide 2 to 15% by weight
(b) Styrene 35-60% by weight
(c) Methyl methacrylate 30-60% by weight
(d) Other ethylenic monomers 20% by weight or less
It is a glossy recording paper for inkjet, characterized by being an emulsion polymer of the above.
[0020]
Invention 6 Is the above Inventions 1-5 In any of the above, the glossy recording paper for ink jet is characterized in that a styrene / acrylic polymer dispersion containing (meth) acrylamide is emulsion-polymerized in the presence of a reactive emulsifier.
[0021]
Invention 7 Is the above Inventions 1-6 In any of the above, the glossy recording paper for ink jet is characterized in that the average particle diameter of the styrene / acrylic polymer dispersion containing (meth) acrylamide is 40 to 150 nm.
[0022]
Invention 8 The present invention 1, 4-7 A method for producing a glossy recording paper for ink jet, wherein the ink receiving layer and the ink permeable polymer dispersion layer are coated in a laminated form, dried, and then subjected to a heat calendering process.
[0023]
Invention 9 On the base paper Inventions 2-7 A method for producing a glossy recording paper for ink-jet printing, comprising: applying any one of the hydrophilic polymer layer and the ink-permeable polymer dispersion layer in a laminated form, drying, and applying a thermal calendar treatment.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides an ink receiving layer or hydrophilic polymer coating layer on the base paper that serves as a cushion for receiving ink and smoothing the surface of the base paper with fine irregularities. An ink jet recording paper in which a polymer dispersion is laminated.
As the base paper of the recording paper, general acid paper, neutral paper, synthetic paper, etc., mainly cellulose pulp such as chemical pulp, mechanical pulp, or waste paper pulp can be used. From the standpoint of adjusting the properties, inorganic and organic fillers can be optionally contained.
In addition, rosin-based, alkyl ketene dimer-based, alkenyl succinic anhydrides, together with polyacrylamide and starch-based paper strength enhancers, to adjust the strength of the base paper or the ink absorbency and coating liquid absorbency. It is desirable to use various sizing agents such as a cationic polymer and a cationic polymer.
[0025]
Furthermore, in the production of base paper, surface sizing agents such as anionic, nonionic, and cationic polymers are used together with starch, polyvinyl alcohol, and polyacrylamide surface paper strength agents, as in the case of ordinary fine paper and coated base paper. The surface strength and sizing degree can be adjusted in advance by a coating machine such as a size press or a gate roll coater.
[0026]
In the recording paper of the present invention 1, the ink receiving layer provided on the surface of the base paper contains a pigment and a hydrophilic binder.
As the pigment, fine silica and / or fine calcium carbonate having an average particle size of 0.5 μm or less are used.
As the fine silica, generally used synthetic silica can be used. Typically, the secondary particle diameter is 1.5 to 5 μm, and the BET specific surface area is 200 to 500 m. ² / G of silica is preferred.
As the fine calcium carbonate, cubic synthetic calcium carbonate having an average particle size of 0.07 to 0.5 μm is preferable.
The ink-permeable polymer layer of the present invention is preferably applied very thinly. For this reason, if the particle diameter of the fine silica or calcium carbonate is large, the ink absorbability increases, but on the other hand, it serves as an undercoat ink receiving layer. When an ink-permeable polymer layer with a small coating amount is laminated due to a decrease in surface smoothness, the uneven shape of the undercoat layer reaches this outermost layer, and there is a risk that the gloss will not be improved.
[0027]
Examples of the hydrophilic binder for binding the pigment include polyvinyl alcohols such as polyvinyl alcohol, cation-modified polyvinyl alcohol and silyl-modified polyvinyl alcohol, modified starches, polyvinyl pyrrolidone, casein, cellulose derivatives such as carboxymethylcellulose and methylcellulose. Can be mentioned. Also, the binder is hydrophilic, and naturally oleophilic binders such as styrene butadiene rubber latex are excluded.
However, a styrene / butadiene copolymer emulsion, an acrylic copolymer emulsion, or an ethylene / vinyl acetate copolymer emulsion may be used in combination for adjusting the hydrophilicity.
In addition to the pigment and the hydrophilic binder, the ink-receiving layer may contain a cationic compound in order to improve printing water resistance. Moreover, you may mix | blend well-known additives, such as a pigment dispersant, a thickener, an antifoamer, a penetrating agent, a fluorescent white agent, a ultraviolet absorber, and an antiseptic | preservative, as needed.
[0028]
The coating method for the ink receiving layer is described as follows. A paint containing a pigment and a hydrophilic binder, and a paint containing a hydrophobic binder or a cationic compound as necessary are generally solid. After adjusting the partial concentration to 5 to 50% by weight, the dry weight on the base paper is 1 to 15 g / m. ² Degree, preferably 2-10 g / m ² It is applied under the condition of the degree.
Coating is performed using a blade coater, a roll coater, an air knife coater, a bar coater, and other various known coating machines. As needed, after single-sided coating or double-sided coating, it is dried. Furthermore, if necessary, smoothing processing can be performed using a calendar device such as a super calendar or a soft calendar.
[0029]
On the other hand, as described above, the hydrophilic polymer of the recording paper of the second aspect of the invention first serves to receive ink. Second, if only the ink-permeable polymer layer with a small coating amount is applied on the base paper, the fine irregularities on the surface of the base paper may reach the outermost layer. This hydrophilic polymer layer has the role of a cushion for smoothing the paper surface.
The hydrophilic polymer coating layer includes at least one polymer selected from the group consisting of polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene oxide, cationic polyacrylamide, water-soluble cationic polyacrylate, and cationic polyacrylate dispersion. Can be used. If necessary, a cationic compound can be added to the hydrophilic polymer coating layer for printing water resistance.
The hydrophilic polymer coating solution is adjusted to a solid content concentration of 1 to 20% by weight and 0.5 to 2 g / m per side on the base paper. ² It is better to apply with a dry weight of.
If the coating amount of the hydrophilic polymer is small, there is a risk that the gloss will be little improved, or the adhesion of the ink permeable polymer dispersion in the outermost layer will be weak and peel off.
On the other hand, if the coating amount is too large, the ink absorbability is delayed, and there is a risk of image smearing and full color boundary bleeding.
Coating is performed using a roll coater, bar coater, and other various coating machines, but it can also be applied with general on-machine coating machines such as size presses and gate roll coating machines. Dried. Normally, double-sided coating is used, but single-sided coating may be performed as necessary.
Various additives that can be blended in the ink receiving layer may be appropriately added to the water-soluble polymer layer.
[0030]
In the ink jet recording paper of the present invention, the ink-permeable polymer dispersion coated on the outermost layer is an emulsion polymer containing 2 to 15% by weight of (meth) acrylamide as a monomer component. And Preferably, the monomer component is an emulsion polymer having the following content ( Invention 5 reference).
(a) (Meth) acrylamide 2 to 15% by weight
(b) Styrene 35-60% by weight
(c) Methyl methacrylate 30-60% by weight
(d) Other ethylenic monomers 0 to 20% by weight
However, the contents shown in the above (a) to (d) represent the range of the charged amount that each compound can individually take, and in the actual copolymerization reaction, the total of the compounds of (a) to (d) Each content of (a)-(d) is adjusted suitably so that content may be 100 weight%.
Further, (meth) acrylamide is a concept including both acrylamide and methacrylamide.
[0031]
When the amount of (meth) acrylamide is less than 2% by weight, the gloss improvement effect is reduced, and when it is 15% by weight or more, the ink absorbency is reduced, or the viscosity of the ink-permeable polymer dispersion becomes too high and the coating property is lowered. There is a fear.
Further, in the styrene and methyl methacrylate, if the amount of styrene is too much, the ink absorbability is lowered, and if the amount is too small, the gloss improvement effect may be reduced. If the amount of methyl methacrylate is too large, the gloss improving effect is decreased, and if it is small, the ink absorbability is decreased, and the peelability from the roll after the thermal calendar treatment may be decreased.
That is, in the ink permeable polymer dispersion, the balance between ink absorbency and gloss improvement is adjusted by the combined content of styrene and methyl methacrylate or the content of acrylamide. The amount ratio naturally has a preferred range.
[0032]
Examples of the other ethylenic monomers described above include acrylic esters such as methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, tertiary butyl acrylate, ethyl methacrylate, isopropyl methacrylate, and methacrylic acid. Methacrylic acid esters such as isobutyl and tertiary butyl methacrylate, carboxyl group-containing monomers such as acrylic acid, methacrylic acid, itaconic acid and maleic acid, sulfonic acid group-containing monomers such as sodium styrenesulfonate, α- Examples thereof include styrene derivatives such as methylstyrene.
These monomers can be copolymerized to such an extent that the ink permeability is not impaired. However, the use of a crosslinkable monomer is not preferred because the film becomes too hard due to crosslinking, and deformation such as shrinkage may occur on the particle surface, resulting in a decrease in gloss.
[0033]
Further, the copolymerized styrene / acrylic polymer dispersion containing (meth) acrylamide has a high reaction rate of acrylamide, and in order to control this, a water-soluble chain transfer agent is used in emulsion polymerization as shown in the present invention 4. The polymerization reaction is preferably carried out in the presence of.
As the water-soluble chain transfer agent, thioglycolic acid, thioglycerol, ethylene glycol dithioglycolate, sodium allyl sulfonate, or a compound having a similar structure can be used.
When a polymerization reaction is carried out without a water-soluble chain transfer agent, the molecular weight of the water-soluble monomer on the particle surface becomes too high due to the high reaction rate of acrylamide as described above, resulting in a high viscosity or gel state. There is a problem. When a water-soluble chain transfer agent is used, a low-viscosity polymer dispersion can be prepared, so that the workability of the coating liquid is good and a uniform coating layer can be formed. Further, when an oil-soluble chain transfer agent is used, there are the same harmful effects as those without the water-soluble chain transfer agent.
[0034]
Furthermore, the copolymerized styrene / acrylic polymer dispersion containing (meth) acrylamide is Invention 6 As shown in FIG. 1, those obtained by emulsion polymerization in the presence of a reactive emulsifier are preferred.
Examples of anionic reactive emulsifiers include allyl nonylphenol polyethylene oxide adduct ammonium sulfate (Aqualon HS, BC series; manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), nonylphenol propylene oxide adduct propenyl polyethylene oxide adduct ammonium sulfate (Adekalysoap SE series; Asahi Denka Kogyo Co., Ltd.) and other similar acrylic ester group-containing reactive emulsifiers (for example, Latemulu S series; manufactured by Kao Corporation).
[0035]
Copolymerized styrene / acrylic polymer particles containing (meth) acrylamide, which is an emulsion polymer, have a high secondary glass transition temperature, but when emulsion polymerization is performed using a reactive emulsifier, the temperature and pressure at which the polymer particles are not fused. Even when coated through a roll of the material, strong adhesion between particles, which is thought to be due to the adhesion between the emulsifier resins that are copolymerized and adhered to the particle surface, occurs, and particle peeling is effectively prevented. There is an effect. In this case, the polymer particles are arranged in a close-packed state while maintaining the voids between the particles by adhesion of only a part of the surface, so that they have excellent white paper gloss due to regular light reflection and high ink absorption. It can also have sex.
On the other hand, in general polymer particles using other non-reactive emulsifiers, the particles cannot be adhered unless high-temperature roll treatment is performed so as to melt and adhere. In addition, precise temperature control is required to fuse only a part. However, in an actual dryer or heating roll, the temperature distribution inevitably occurs, so it is practically difficult to achieve a certain degree of fusion.
Moreover, under temperature conditions that do not cause fusing, the emulsifier is only adsorbed to the particle surface with a weak force, and the strength of the emulsifier is also weak. End up.
[0036]
Emulsion polymerization of copolymerized styrene / acrylic polymer dispersions containing (meth) acrylamide is basically persulfates such as ammonium persulfate, potassium persulfate, sodium persulfate, redox initiators, or azo initiators. In the presence of a water-soluble polymerization initiator and an emulsifier. Preferably, it is carried out by a dropping emulsion polymerization method in which a water-soluble initiator and a monomer mixture are separately dropped and polymerized in a heated aqueous medium to which a water-soluble chain transfer agent and a reactive emulsifier are added.
However, the batch emulsion polymerization method in which the monomer mixture is batch-mixed in the presence of a water-soluble chain transfer agent and a reactive emulsifier in an aqueous medium and heated, and then the above-mentioned water-soluble polymerization initiator is added. Needless to say, polymerization may be performed by a known emulsion polymerization method or the like.
The polymer dispersion obtained by emulsion polymerization can be mixed with a pH adjuster such as aqueous ammonia, an antifoaming agent, a preservative, and other additives as necessary.
[0037]
Invention 6 As shown in Fig. 2, the average particle size of the copolymerized styrene / acrylic polymer dispersion containing (meth) acrylamide is 40 to 150 nm, preferably 50 to 120 nm. Incidentally, the wavelength of visible light is 400 to 700 nm, and the average particle size of the dispersion is considerably finer than this. The lower limit of the average particle diameter is about 40 nm in terms of manufacturing technology. If the average particle diameter exceeds 150 nm, the adhesion between the particles when heat calendering is performed is not good, and the opacity of the paper surface increases. May reduce glossiness.
[0038]
In order to produce glossy recording paper for ink jet using the above ink permeable polymer dispersion, as shown in the present invention 1, a fine silica or fine calcium carbonate-containing pigment and a hydrophilic binder are coated on the base paper. Then, a dried primer paper is prepared, or a hydrophilic polymer coating layer is provided on the base paper as shown in the present invention 2.
Next, an emulsion polymer of a copolymerized styrene / acrylic polymer containing (meth) acrylamide, or a release agent such as a calcium stearate emulsion, a lauryl phosphate salt aqueous dispersion, or a polyethylene wax emulsion, if necessary. A liquid mixed at a ratio of 10% by weight (based on solid content) is diluted to a concentration of 10 to 30% by weight, and this diluted liquid is applied to the surface of the primer paper or hydrophilic polymer-coated paper. .
[0039]
The dilution liquid is applied by using a coating machine such as a blade coater, air knife coater, roll coater, bar coater, etc., and the coating amount per side is 0.3 to 2.0 g / m in solid content. ² The coating is carried out under conditions of a certain degree and dried.
When applied uniformly, gloss is improved even if the coating amount is small, but 0.3 g / m ² If the amount is less than about 1, a uniform polymer particle layer may not be formed. On the other hand, if the coating amount is too large, the ink absorptivity decreases.
Inventions 8-9 As shown in FIG. 3, the coated paper that has been dried is smooth-finished by a normal thermal calendar process such as a super calender or a soft calender, unlike the cast coating method that is mainly employed in the prior art. That is, the ink-jet glossy recording paper of the present invention can be obtained by passing paper between rolls to which pressure or temperature is applied (for example, paper is passed under a roll temperature of 60 ° C. or lower and high linear pressure).
[0040]
[Action]
In the ink-permeable polymer of the present invention, since the basic monomer component constituting the polymer is styrene and an acrylic monomer (for example, methyl methacrylate), it becomes non-film-forming polymer fine particles having an appropriate hardness, In addition, since water-soluble (meth) acrylamide is included in the monomer component, a leveling effect can be expected in the process of water loss from swelling during drying of the ink permeable layer. It can be estimated that the surfaces are uniformly arranged in a close-packed state.
On the outermost surface on which the regularly arranged fine particles are regularly arranged, a repetitive uneven layer of particles having a size much smaller than the wavelength of visible light of 400 to 700 nm is formed, so that the light is not scattered but reflected by parallel light. For this reason, it feels glossy while having a particulate surface.
Further, since the outermost ink permeable polymer dispersion layer is a hydrophilic layer containing (meth) acrylamide as a monomer component, it does not prevent the inkjet aqueous ink from penetrating into the voids between the particles.
[0041]
On the other hand, by using a water-soluble chain transfer agent in emulsion polymerization, it is possible to suppress the increase in the molecular weight of acrylamide having a high reaction rate, and to smoothly prepare fine particles of a styrene / acrylic polymer having an appropriate viscosity.
In addition, when a reactive emulsifier is used for the polymerization, the outermost particle surface and the space between the particles are covered with a styrene / acrylic polymer layer containing acrylamide and a stronger emulsifier chain. By heating and linear pressure, it is possible to firmly adhere to a part of the particle surface and to form a strong fine particle dispersion layer in which particles are not peeled off by rubbing by hand.
[0042]
【The invention's effect】
(1) The ink jet recording paper of the present invention has a glossiness of 30% or more that could not be achieved by any method other than the cast coat method, and a smooth ink absorbability that could not be easily achieved with cast coat paper. It can be compatible.
That is, as shown in a test example to be described later, the gloss level of the recording paper of the present invention is considerably higher than that of commercially available exclusive inkjet paper and PPC / inkjet paper, and the image density is also high. It has excellent characteristics.
In addition, the recording paper of the present invention is a paper finished by a thermal calendering method, and unlike the above-described prior art cast-coated paper, the gap between the fine particles is crushed by pressure bonding to the mirror surface, and the ink absorbability is slow. This is suitable for ink jet recording papers that require rapid ink absorbency and has high production efficiency.
[0043]
(2) In the present invention 4, since styrene / acrylic polymer dispersion containing acrylamide is emulsion-polymerized in the presence of a water-soluble chain transfer agent, excessive polymerization of acrylamide with a high reaction rate is suppressed, and an appropriate viscosity is achieved. Styrene / acrylic polymer fine particles having the above can be effectively prepared, and a recording paper having both glossiness and ink absorbability can be produced smoothly.
[0044]
【Example】
Hereinafter, an example of producing an ink-permeable polymer dispersion and an example of producing an ink-jet glossy recording paper will be sequentially described, and various test examples such as white gloss and ink absorbability of the obtained recording paper will be described.
Further, “parts” and “%” shown in Examples and Test Examples all mean “parts by weight” and “% by weight”.
It should be noted that the present invention is not limited to the following examples and test examples, and can be arbitrarily modified within the scope of the technical idea of the present invention.
[0045]
<< Synthesis Example of Ink Permeable Polymer Dispersion >>
Therefore, first, Synthesis Examples 1 to 3 and Comparative Synthesis of Copolymerized Styrene / Acrylic Polymers Containing Acrylamide Produced by Emulsion Polymerization Reaction Using Styrene, Methyl (meth) acrylate, and (Meth) acrylamide as Monomer Components Examples 1-5 are described.
Incidentally, among the synthesis examples 1 to 3 and comparative synthesis examples 1 to 5, synthesis examples 1 to 3 are examples in which the monomer species including acrylamide, the water-soluble chain transfer agent species, the reactive emulsifier species, and the like are changed. is there. Comparative Synthesis Example 1 does not use acrylamide and chain transfer agent, and uses non-reactive emulsifier, Comparative Synthesis Example 2 does not use acrylamide and chain transfer agent, and uses reactive emulsifier, Comparative Synthesis Example No. 3 does not use a chain transfer agent, the monomer species is similar to Comparative Example 3 described in Prior Art 1 described above, and Comparative Synthesis Example 4 is an example in which acrylamide is added in the presence of a water-soluble chain transfer agent. An example in which the amount is increased to 15% or more and Comparative Synthesis Example 5 are examples of using an oily chain transfer agent.
[0046]
(1) Synthesis example 1
In a reaction vessel equipped with a stirrer, a dropping tank and a thermometer, 300 g of water and allyl nonylphenol polyoxyethylene oxide (EO addition 10 mol) adduct ammonium sulfate as a reactive emulsifier (Aqualon HS-10; Daiichi Kogyo Seiyaku Co., Ltd.) 9 parts), 26 parts of 50% acrylamide aqueous solution, and 1 part of thioglycolic acid as a water-soluble chain transfer agent were charged and mixed, then heated to 75 ° C. while blowing nitrogen gas, 145.6 parts of styrene, 244.4 parts of a mixture of 89.7 parts of methyl methacrylate, 10.4 parts of ethyl acrylate and 1.3 parts of acrylic acid was added dropwise over 2 hours. At the same time, 25 parts of a 2% aqueous solution of ammonium persulfate was added dropwise over 2 hours and 15 minutes.
Next, the polymerization was terminated by maintaining at 85 ° C. for 2 hours, and neutralized to pH 8.0 by adding ammonia water to obtain an ink-permeable polymer dispersion having a solid content concentration of 38% and a viscosity of 110 mPa · s.
[0047]
(2) Synthesis example 2
In a reaction vessel equipped with a stirrer, a dropping tank, and a thermometer, 300 g of water and ammonium sulfate propylene polyethylene oxide adduct propenyl polyethylene oxide adduct as a reactive emulsifier (Adekalysoap SE-10N; manufactured by Asahi Denka Kogyo Co., Ltd.) 6.5 Parts, 57.2 parts of a 50% acrylamide aqueous solution and 1.5 parts of thioglycerol as a water-soluble chain transfer agent were mixed and heated to 75 ° C. while blowing nitrogen gas. A mixture of 231.4 parts of 104 parts of methyl acid and 2.6 parts of acrylic acid was added dropwise over 2 hours. At the same time, 25 parts of a 2% aqueous solution of ammonium persulfate was added dropwise over 2 hours and 15 minutes.
Next, the polymerization was terminated by maintaining at 85 ° C. for 2 hours, and neutralized to pH 8.0 by adding ammonia water to obtain an ink-permeable polymer dispersion having a solid content concentration of 35% and a viscosity of 160 mPa · s.
[0048]
(3) Synthesis example 3
Based on Synthesis Example 1 above, 15.6 parts of 50% acrylamide, 117 parts of styrene, 133.9 parts of methyl methacrylate, 0 parts of ethyl acrylate, and 1.3 parts of acrylic acid were changed. The others were synthesized under the same conditions as in Synthesis Example 1 to obtain an ink-permeable polymer dispersion having a solid content concentration of 40% and a viscosity of 105 mPa · s.
[0049]
(4) Comparative synthesis example 1
In a reaction vessel equipped with a stirrer, a dropping tank and a thermometer, 300 g of water and 14 parts of 50% aqueous solution of disodium nonyldiphenyl ether disulfonate (Perex SS-H; manufactured by Kao Corporation) as a non-reactive emulsifier were mixed and mixed. The temperature was raised to 75 ° C. while blowing nitrogen gas, and 260 parts of a mixture of 176.8 parts of styrene, 75.4 parts of methyl methacrylate, and 7.8 parts of acrylic acid were added dropwise over 2 hours. At the same time, 25 parts of a 2% aqueous solution of ammonium persulfate was added dropwise over 2 hours and 15 minutes.
Next, the polymerization was terminated by maintaining at 85 ° C. for 2 hours, and neutralized to pH 8.0 by adding ammonia water to obtain a polymer dispersion having a solid content concentration of 40% and a viscosity of 30 mPa · s.
[0050]
(5) Comparative synthesis example 2
Based on the above Comparative Synthesis Example 1, instead of the non-reactive emulsifier, the reactive emulsifier allyl nonylphenol polyoxyethylene oxide (EO addition 10 mol) adduct ammonium sulfate (Aqualon HS-10; manufactured by Daiichi Kogyo Seiyaku) 9 parts, 156 parts of styrene, 98.8 parts of methyl methacrylate, 5.2 parts of acrylic acid, and the other conditions were synthesized under the same conditions as in Synthesis Example 4 above, solid content concentration 39%, viscosity 21 mPa A polymer dispersion of s was obtained.
[0051]
(6) Comparative synthesis example 3
In a reaction vessel equipped with a stirrer, a dropping tank, and a thermometer, 300 g of water and ammonium sulfate propylene polyethylene oxide adduct propenyl polyethylene oxide adduct as a reactive emulsifier (Adekalysoap SE-10N; manufactured by Asahi Denka Kogyo Co., Ltd.) 6.5 And 52 parts of a 50% acrylamide aqueous solution were charged and mixed, and no water-soluble chain transfer agent was added.
Then, the temperature was raised to 75 ° C. while blowing nitrogen gas, and 234 parts of a mixture of 130 parts of styrene, 78 parts of methyl methacrylate, 13 parts of ethyl methacrylate, and 13 parts of methacrylic acid were added dropwise over 2 hours. At the same time, 25 parts of a 2% aqueous solution of ammonium persulfate was added dropwise over 2 hours and 15 minutes.
As a result, the whole polymer became a thickened gel after 1 hour and 40 minutes of dropping, and the synthesis was stopped.
[0052]
(7) Comparative synthesis example 4
In a reaction vessel equipped with a stirrer, a dropping tank and a thermometer, 370 g of water and allyl nonylphenol polyoxyethylene oxide (EO addition 10 mol) adduct ammonium sulfate (Aqualon HS-10; Daiichi Kogyo Seiyaku Co., Ltd.) as a reactive emulsifier 6.3 parts, 50% acrylamide aqueous solution 72.8 parts, and 1.5 parts of thioglycerol as a water-soluble chain transfer agent were mixed and heated to 75 ° C. while blowing nitrogen gas. A mixture of 145.6 parts of .2 parts, methyl methacrylate 54.6 parts and acrylic acid 1.8 parts was added dropwise over 2 hours. At the same time, 18 parts of a 2% aqueous solution of ammonium persulfate was added dropwise over 2 hours and 15 minutes.
Next, the polymerization was terminated by maintaining at 85 ° C. for 2 hours, and neutralized to pH 8.0 by adding ammonia water to obtain an ink-permeable polymer dispersion having a solid content concentration of 22% and a viscosity of 370 mPa · s.
[0053]
(8) Comparative synthesis example 5
In a reaction vessel equipped with a stirrer, a dropping tank and a thermometer, 300 g of water, 8 parts of ammonium sulfate propylene polyethylene oxide adduct propenyl polyethylene oxide adduct as a reactive emulsifier (Adekalysoap SE-10N; manufactured by Asahi Denka Kogyo Co., Ltd.) 36.4 parts of a 50% acrylamide aqueous solution was charged and mixed, and no water-soluble chain transfer agent was added.
The temperature was raised to 75 ° C. while blowing nitrogen gas, and 243.8 parts of a mixture of 130 parts of styrene, 106.6 parts of methyl methacrylate, 5.2 parts of acrylic acid, and 2 parts of N-dodecyl mercaptan as an oil chain transfer agent. Was charged dropwise over 2 hours. At the same time, 25 parts of a 2% aqueous solution of ammonium persulfate was added dropwise over 2 hours and 15 minutes.
As a result, the whole polymer became a thickened gel after 1 hour and 20 minutes of dropping, and the synthesis was stopped.
The monomer compositions, chain transfer agent species, emulsifier species, and properties of polymer dispersions of Synthesis Examples 1 to 3 and Comparative Synthesis Examples 1 to 5 are summarized in FIG.
[0054]
Thus, after an ink-receiving layer or a hydrophilic polymer layer is undercoated on a base paper made from cellulose pulp, it is obtained in Synthetic Examples 1 to 3 and Comparative Synthetic Examples 1, 2, and 4 on this undercoated base paper. In addition, each ink-permeable polymer dispersion was coated in a layered form, dried, and subjected to thermal calendering to produce inkjet recording paper, and for each recording paper, blank paper glossiness, ink absorbency, surface peeling Various tests were conducted on the printability and print density. However, “parts” and “%” used below represent “absolute dry weight parts” and “absolute dry weight%” unless otherwise specified.
[0055]
Example 1
(1) Base paper making
100 parts of LBKP pulp (CFS: 450 ml), light calcium carbonate 15 parts, neutral rosin size 0.4 parts, cationic polyacrylamide (yield agent) 0.03 parts, cationic starch 0.5 parts, sulfate band After adding and preparing 1.0 part, the basis weight is 75 g / m using an automatic paper machine. ² Paper was made.
(2) Coating of ink receiving layer
Fine silica (Fine seal X37B; manufactured by Tokuyama, secondary agglomerated average particle size 3.7 μm, specific surface area 277 m ^Three / G) A coating composition comprising a pigment and a hydrophilic binder using 100 parts, polyvinyl alcohol (PVA117; manufactured by Kuraray Co., Ltd.) 60 parts, and cationic dye fixing agent (CP-4; manufactured by Harima Kasei Co., Ltd.) (Solid content 13%), and the coating composition is dried on a base paper with a bar coater at a dry coating amount of 6 g / m. ² After coating and drying, calendering was performed at room temperature under a linear pressure of 20 kg / cm.
(3) Coating of ink permeable polymer dispersion
97 parts of the ink-permeable polymer dispersion of Synthesis Example 1 and 3 parts of lauryl phosphate potassium salt as a release agent were mixed to prepare a coating liquid adjusted to a solid content of 20%. Using a bar coater on the base paper on which the ink receiving layer is formed, the dry coating amount is 0.7 g / m. ² It was applied to become.
After the coated paper was dried, it was passed twice with a mini super calender under the conditions of a roll temperature of 50 ° C. and a linear pressure of 100 kg / cm to obtain an ink jet recording paper.
[0056]
Example 2
(1) Coating of ink receiving layer
Fine calcium carbonate (Brilliant-15; manufactured by Shiraishi Kogyo Co., Ltd., average particle size 0.15 μm) 100 parts, cationic modified starch (Cato102; manufactured by NSC Japan) 30 parts, polyvinyl alcohol (PVA117; manufactured by Kuraray Co., Ltd.) 30 parts, A coating composition (solid content 12%) comprising a pigment and a hydrophilic binder was prepared using 15 parts of a cationic dye fixing agent (Haricoat CP-4; manufactured by Harima Kasei Co., Ltd.). Dry coating amount 6g / m on the same base paper as 1 with a bar coater ² After coating and drying, calendaring was performed at room temperature and a linear pressure of 20 kg / cm.
[0057]
(2) Coating of ink permeable polymer dispersion
97 parts of the ink-permeable polymer of Synthesis Example 2 and 3 parts of calcium stearate emulsion (Nopcoat C-104; manufactured by San Nopco) as a release agent were mixed to prepare a coating liquid having a solid content of 20%. Using a bar coater, apply a coating solution of 1.2 g / m on a base paper on which an ink receiving layer is formed. ² It was applied to become.
The coated paper was dried and then passed once with a mini super calender at a roll temperature of 50 ° C. and a linear pressure of 100 kg / cm to obtain an ink jet recording paper.
[0058]
Example 3
Based on the above Example 1, the Synthesis Example 1 was changed to the ink-permeable polymer dispersion of Synthesis Example 3, and the others were produced under the same conditions as in Example 1 to obtain an ink jet recording paper. .
[0059]
Example 4
(1) Coating of hydrophilic polymer
A 3% solid solution of polyvinyl alcohol (PVA117; manufactured by Kuraray Co., Ltd.) is dried on the base paper of Example 1 with a bar coater at a coating amount of 0.7 g / m. ² It was applied to become and dried.
(2) Ink permeable polymer coating
A coating liquid having a solid content of 20% was prepared by mixing 97 parts of the ink-permeable polymer of Synthesis Example 1 and 3 parts of lauryl phosphate potassium salt as a release agent. Then, the coating liquid was applied to the base paper coated with the hydrophilic polymer using a bar coater and the dry coating amount was 0.8 g / m. ² It was coated to become.
The coated paper was dried and then passed once with a mini super calender at a roll temperature of 50 ° C. and a linear pressure of 50 kg / cm to obtain an ink jet recording paper.
[0060]
Example 5
(1) Coating of hydrophilic polymer
Using the base paper of Example 1 above, 90 parts of cationic polyacrylate dispersion (Haricoat AE-4; manufactured by Harima Chemicals) and 10 parts of polyethylene oxide (Alcox R-400; manufactured by Meisei Chemical Co., Ltd.) A 5% coating solution was prepared, and this coating solution was dried with a bar coater to a dry coating amount of 0.7 g / m. ² It was applied to become and dried.
(2) Ink permeable polymer coating
A coating liquid having a solid content of 15% was prepared by diluting the ink-permeable polymer dispersion of Synthesis Example 3. Then, the coating liquid is applied to a base paper coated with a hydrophilic polymer using a bar coater and a dry coating amount of 1.0 g / m. ² It was applied to become.
The coated paper was dried and then passed twice with a mini super calendar at a roll temperature of 50 ° C. and a linear pressure of 50 kg / cm to obtain an ink jet recording paper.
[0061]
<< Comparative Example 1 >>
Based on Example 1 above, Synthesis Example 1 was changed to the polymer dispersion of Comparative Synthesis Example 1, and the others were produced under the same conditions as in Example 1, and the ink receiving layer and the polymer dispersion layer were formed on the base paper. An ink jet recording paper having a laminated structure was obtained.
[0062]
<< Comparative Example 2 >>
Based on Example 1 above, Synthesis Example 1 was changed to the polymer dispersion of Comparative Synthesis Example 2, and the others were produced under the same conditions as in Example 1, and the ink receiving layer and the polymer dispersion layer were laminated. An ink jet recording paper was obtained.
[0063]
<< Comparative Example 3 >>
Based on Example 4 above, Synthesis Example 1 was changed to the ink-permeable polymer of Comparative Synthesis Example 2, and the others were produced under the same conditions as in Example 4 to produce the hydrophilic polymer coating layer and the ink transmission. Inkjet recording paper having an adhesive polymer layer laminated thereon was obtained.
[0064]
<< Comparative Example 4 >>
Based on Example 1 above, Synthesis Example 1 was changed to the ink-permeable polymer of Comparative Synthesis Example 4, and the others were produced under the same conditions as in Example 1, and the ink receiving layer and the ink-permeable polymer layer were produced. An ink jet recording paper having a laminated structure was obtained.
[0065]
<< Comparative Example 5 >>
A 3% solid content aqueous solution of polyvinyl alcohol (PVA117; manufactured by Kuraray Co., Ltd.) was dried on the base paper of Example 1 with a bar coater at a coating amount of 1.0 g / m. ² It was applied to become.
The coated paper was dried and then passed once with a mini super calender at a roll temperature of 50 ° C. and a linear pressure of 100 kg / cm to obtain an ink jet recording paper having only a hydrophilic polymer coated layer.
[0066]
<< Comparative Example 6 >>
Commercially available inkjet high-quality paper (HR-101; manufactured by Canon Inc.) was used for the test as it was.
[0067]
<< Comparative Example 7 >>
Commercially available PPC / inkjet paper (manufactured by Canon Inc.) was used for the test as it was.
[0068]
<< Various test examples of inkjet recording paper >>
As described above, the ink jet recording papers of Examples 1 to 5 and Comparative Examples 1 to 7 were subjected to various tests on blank paper gloss, ink absorbability, surface peelability, and print density.
(1) Glossy white paper
In accordance with JIS P-8142 (75 ° reflection method), the surface of each recording paper was measured using a specular gloss measuring device.
(2) Ink absorption
Printing was performed on each recording paper using a commercially available ink jet printer (BJF-600; manufactured by Canon Inc.), and the ink absorbency and the presence or absence of boundary bleeding were visually observed. The evaluation criteria are as follows.
○: The ink absorption speed was comparable to that of the PPC / inkjet paper, and there was almost no boundary bleeding.
◇: The ink absorptivity was slightly slower than that of the PPC / inkjet paper, and the boundary bleeding was slight.
(Triangle | delta): The ink absorptivity was slower than PPC / inkjet co-paper, and there was a little border blur.
X: The ink absorptivity was much slower than that of the PPC / inkjet paper, and there was much boundary bleeding.
[0069]
(3) Surface peelability
A cellophane tape was applied on each recording paper and then peeled off, and the presence or absence of peeling of the coating layer was observed. The evaluation criteria are as follows.
○: The coating layer does not peel off.
X: Peeling of the coating layer was observed.
(4) Print density
Printing was performed on each recording paper using a commercially available ink jet printer (BJF-600; manufactured by Canon Inc.), and the Macbeth density (Macbeth RD-920) of the black and magenta solid print portion was measured.
[0070]
FIG. 2 shows the test results.
(1) Glossiness and ink absorption
In Examples 1 to 5 which are recording sheets of a laminated type of ink receiving layer / ink permeable polymer layer or laminated type of hydrophilic polymer coating layer / ink permeable polymer layer, the gloss of blank paper is 42 to 60%. The ink absorptivity was above the practical level in terms of absorption speed and ink bleeding, and it was confirmed that glossiness and ink absorptivity can both be effectively achieved. By the way, 75% or more of white paper gloss is available for commercial cast-coated paper, but 4% to 5% of white paper gloss is available for commercial inkjet special paper or PPC co-paper, compared to the level of these special paper or common paper. It can be seen that Examples 1 to 5 have excellent gloss.
[0071]
In contrast, this is a laminated recording paper of an ink receiving layer / polymer dispersion layer, and the polymer dispersion layer is a copolymerized styrene / acrylic polymer containing no acrylamide obtained by emulsion polymerization without a chain transfer agent. In Examples 1 and 2 (Comparative Example 1 uses a non-reactive emulsifier and Comparative Example 2 uses a reactive emulsifier, respectively), the white gloss was 33 to 24%, but the ink absorption rate was slow, and ink border bleeding was also observed. There was a little.
Comparative Example 3 is a laminated recording paper of hydrophilic polymer layer / polymer dispersion layer, and the polymer dispersion layer is a copolymerized styrene / acrylic polymer containing no acrylamide obtained by emulsion polymerization without a chain transfer agent. The white gloss was 27%, the ink absorption speed was very slow, and the ink boundary bleeding was also large.
Furthermore, it is a laminate type of ink receiving layer / ink permeable polymer layer, and the ink permeable polymer contains acrylamide at a high rate of 20% and is obtained by emulsion polymerization using a water-soluble chain transfer agent. In Comparative Example 4, which is an acrylic polymer, the white gloss was 46%, but the ink absorption speed was very slow and the ink boundary bleeding was also large.
On the other hand, Comparative Example 5 in which only the hydrophilic polymer coating layer was provided was inferior in ink absorptivity, and commercially available inkjet special paper (Comparative Example 6) and PPC / inkjet paper (Comparative Example 7) were inferior in gloss.
[0072]
(2) Surface peelability and print density
In Examples 1 to 5, the surface peelability was good, and the print densities of black and magenta were above the practical level. Incidentally, for example, if the black print density is about 1.2 or more, it is a practical level.
On the other hand, in Comparative Examples 1-7, there was an example inferior in surface peelability, and the black printing density was also generally lower than Examples 1-5.
[0073]
(3) Overall evaluation
Comparing Examples 1 to 5 and Comparative Examples 1 to 3, the styrene / acrylic polymer contains acrylamide as a monomer component in that the gloss and ink absorbability of the ink jet recording paper are compatible. Sex can be confirmed. Further, in Comparative Example 1, it seems that the point of using a non-reactive emulsifier also has an influence on the reduction of ink absorbency.
Furthermore, according to Comparative Example 4, it can be seen that when the content of acrylamide is too large, there is a detrimental effect on reducing ink absorbability.
On the other hand, according to the comparative synthesis example 3 similar to the prior art 1 described above, acrylamide 10%, styrene 50%, methyl methacrylate 30%, ethyl methacrylate 5%, methacrylic acid 5% as a monomer composition, When emulsion polymerization is performed without a water-soluble chain transfer agent, a thickened gel is formed during the reaction, and a styrene / acrylic polymer dispersion itself cannot be obtained. It can be seen that the presence of the chain transfer agent is important.
Further, according to Comparative Synthesis Example 4, in the emulsion polymerization of the styrene / acrylic polymer dispersion, when the type of chain transfer agent is oil-soluble, the viscosity increases as in the above Comparative Synthesis Example 3, and the polymer dispersion itself Therefore, the importance of making the type of chain transfer agent water-soluble is recognized.
[Brief description of the drawings]
FIG. 1 is a chart summarizing monomer compositions, chain transfer agent species, emulsifier species, polymer dispersion properties, and the like of each of the ink-permeable polymer dispersions of Synthesis Examples 1 to 3 and Comparative Synthesis Examples 1 to 5. .
FIG. 2 is a table showing various test results of white gloss, ink absorbability, surface peelability, and print density of each of the inkjet recording papers of Examples 1 to 5 and Comparative Examples 1 to 7.

Claims (9)

An ink receiving layer mainly composed of a pigment composed of fine silica and / or fine calcium carbonate having an average particle size of 0.5 μm or less and a hydrophilic binder are provided on a base paper, and an ink-permeable polymer dispersion is provided on the outermost layer of the base paper. It is an inkjet recording paper that has been coated, dried and heat calendered,
The ink permeable polymer dispersion is a styrene / acrylic polymer dispersion copolymerized under a condition containing (meth) acrylamide at a content of 2 to 15% by weight as a monomer component. The glossy recording paper for inkjet according to any one of claims 1 to 4. An ink jet recording paper in which a hydrophilic polymer layer is coated on a base paper, an ink permeable polymer dispersion is coated on the outermost layer of the base paper, and drying and thermal calendar finishing are performed.
The ink permeable polymer dispersion is a styrene / acrylic polymer dispersion copolymerized under a condition containing (meth) acrylamide at a content of 2 to 15% by weight as a monomer component. Glossy recording paper for inkjet.   The hydrophilic polymer according to claim 2 is at least one polymer selected from the group consisting of polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene oxide, cationic polyacrylamide, water-soluble cationic polyacrylate, and cationic polyacrylate dispersion. A glossy recording paper for ink-jet recording.   The styrene / acrylic polymer dispersion containing (meth) acrylamide is one obtained by emulsion polymerization in the presence of a water-soluble chain transfer agent. Glossy recording paper. Styrene / acrylic polymer dispersion containing (meth) acrylamide
(a) (Meth) acrylamide 2 to 15% by weight
(b) Styrene 35-60% by weight
(c) Methyl methacrylate 30-60% by weight
(d) The glossy recording paper for inkjet according to any one of claims 1 to 4, which is an emulsion polymer of 20% by weight or less of another ethylenic monomer. The gloss record for inkjet according to any one of claims 1 to 5 , wherein the styrene-acrylic polymer dispersion containing (meth) acrylamide is emulsion-polymerized in the presence of a reactive emulsifier. paper. The glossy recording paper for inkjet according to any one of claims 1 to 6 , wherein the average particle diameter of the styrene / acrylic polymer dispersion containing (meth) acrylamide is 40 to 150 nm. The ink-receiving layer according to any one of claims 1 and 4 to 7 and an ink-permeable polymer dispersion layer are coated on a base paper in a laminated form, dried, and then subjected to a heat calender treatment. A method for producing glossy recording paper for inkjet. The hydrophilic polymer layer according to any one of claims 2 to 7 and the ink-permeable polymer dispersion layer are coated on a base paper in a laminated form, dried, and then subjected to a heat calendar process. A method for producing glossy recording paper for inkjet.

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