JP3430616B2 - Matting agent for photographic paper and photographic paper - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographic printing paper having improved smoothness while maintaining glossiness.

[0002]

2. Description of the Related Art Generally, when printing paper, the "cutting phenomenon" is a phenomenon in which the printing papers come into close contact with each other during storage and cannot be easily peeled off.
In order to prevent breakage of the printing paper due to poor transportability and scratches due to rubbing of the surface of the printing paper, at least one surface of the printing paper contains fine particles having an average particle size of 1 to 10 μm (hereinafter referred to as “matting agent”). Forming layers. By forming the layer containing the matting agent, the back surface of the printing paper is roughened and smoothness can be improved. Further, the matting agent can enhance the discriminating property of the back surface of the photographic printing paper and can impart good writability to various writing instruments. Examples of these matting agents include inorganic substances such as crystalline or non-crystalline silica, titanium dioxide, magnesium oxide, calcium carbonate, barium sulfate, magnesium aluminate silicate, acrylic acid-ethyl acrylate copolymer, and acrylic resin. Known organic substances. In these general matting agents, in order to improve the smoothness of the printing paper, it was necessary to increase the amount of the matting agent added, but if the amount of the matting agent added is increased, the affinity with the binder is poor, Agglomeration causes deterioration of transparency, resulting in deterioration of gloss of the printing paper.

[0003]

The present invention has been made against the background of the above-mentioned conventional technical problems, and contains a matting agent for photographic paper having improved smoothness while maintaining glossiness, and a matting agent for the same. It is an object of the present invention to provide a photographic printing paper having a layer for forming.

[0004]

Means for Solving the Problems The present invention is heavy in the molecule
The content of the crosslinkable monomer having two or more groups having a compatible double bond is 10% by weight or more , and the rest is the crosslinkable monomer.
On the surface of the crosslinked polymer particles (A) obtained by polymerizing a polymerizable monomer other than the above-mentioned , the content of the above-mentioned crosslinkable monomer is less than 10% by weight and the rest is other than the crosslinkable monomer.
That partially or is entirely covered by a polymer obtained by polymerizing monomer by polymerizing (B), an average particle diameter of 0.0
1 to 10 μm, and the weight ratio of (A) / (B) is 10
The present invention provides a matting agent for photographic paper comprising composite crosslinked polymer particles of 0 / 0.01 to 900 , and photographic paper having a layer containing the composite crosslinked polymer particles. Hereinafter, the present invention will be described in detail. In the present invention, the crosslinked polymer particles are polymerized such that the content of the crosslinkable monomer having two or more groups having a polymerizable double bond in the molecule (hereinafter, simply referred to as “crosslinkable monomer”) is 10% by weight or more. Obtained by polymerizing a volatile monomer, and having an average particle diameter of 0.01 to 10 μm. As the crosslinkable monomer,
The following compounds having two or more copolymerizable double bonds such as a non-conjugated vinyl compound typified by divinylbenzene or a polyvalent acrylate compound typified by trimethylene propane trimethacrylate are listed below.
It is used in one kind or two or more kinds.

Specific examples of the crosslinkable monomer include polyethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,6-butylene glycol diacrylate, 1,6-hexanelen glycol diacrylate and neopentyl glycol diacrylate. ,
Polypropylene diacrylate, 2,2'-bis (4-
Acryloxyproproxyphenyl) propane, 2,
Diacrylate compounds such as 2′-bis (4-acryloxydiethoxyphenyl) propane, trimethylolpropane triacrylate, trimethylolethane triacrylate, triacrylate compounds such as tetramethylolmethane triacrylate, ditrimethylolpropane tetraacrylate, Tetramethylolmethane tetraacrylate, tetraacrylate compounds such as pentaerythritol tetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate,
Polyethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, 1,6-hexane glycol dimethacrylate, neopentyl glycol dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, 2 ，
Examples thereof include methacrylate compounds such as 2-bis (4-methacryloxydiethoxyphenyl) propane, trimethylolpropane trimethacrylate, trimethacrylate compounds such as trimethylolethanetrimethacrylate, methylenebisacrylamide, and divinylbenzene. Of the above, divinylbenzene, ethylene glycol dimethacrylate, or trimethylolpropane trimethacrylate is preferably used, and divinylbenzene is particularly preferable.

Among the polymerizable monomers other than the crosslinkable monomer, examples of the monomer having no functional group include the following compounds, which may be used alone or in combination of two or more.
Aromatic monovinyl compounds such as styrene, ethyl vinyl benzene, α-methyl styrene, fluorostyrene, vinyl pyridine, butyl acrylate, 2-ethylhexyl acrylate, β-methacryloyloxyethyl hydrogendiene phthalate, N, N′-dimethylaminoethyl acrylate, etc. Acrylic acid ester monomer,
2-ethylhexyl methacrylate, methoxydiethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, N, N'-
Methacrylic acid ester monomers such as dimethylaminoethyl methacrylate, silicon-modified monomers, macromonomers, etc. Further, conjugated double bond compounds such as butadiene and isoprene, vinyl ester compounds such as vinyl acetate, 4-methyl-1-pentene and other α-olefin compounds can be mentioned. Further, as the monomer having a functional group among the polymerizable monomers other than the crosslinkable monomer, a mono- or dicarboxylic acid monomer such as acrylic acid, methacrylic acid, maleic acid or itaconic acid, 2-acryloyloxyethyl-2-hydroxyethylphthale acid,
Amido compounds such as 2-hydroxy-3-phenoxypropyl acrylate, 2-hydroxyethyl methacrylate, N-methylol acrylamide, sodium styrenesulfonate, maleic anhydride, glycidyl acrylate, glycidyl methacrylate, acrylamide, methacrylamide, methylenebisamide, acrylonitrile, Examples thereof include vinyl cyanide compounds such as methacrylonitrile.

In the crosslinked polymer particles, the content of the crosslinkable monomer in the polymerizable monomer used is 10% by weight.
Or more, preferably 15% by weight or more, more preferably 2
It is 0% by weight or more. When the content of the crosslinkable monomer is less than 10% by weight, the matting agent has poor smoothness. As a preferable combination of the polymerizable monomers constituting the crosslinkable polymer particles, a crosslinkable monomer such as a non-conjugated vinyl compound or a polyvalent methacrylate compound and an aromatic monovinyl compound, a polymerizable monomer such as an acrylic acid ester monomer or a methacrylic acid ester monomer is used. And a combination of a non-conjugated vinyl compound and an aromatic monovinyl compound is particularly preferable. In the present invention, the average particle size of the crosslinked polymer particles is 0.01 to 10 μm, preferably 0.01 to 5 μm, and more preferably 0.01.
~ 2 μm. If the average particle size is less than 0.1 μm, the smoothness is poor, while if it exceeds 10 μm, the gloss is poor.
The average particle diameter here is measured by the following method. The average particle diameter of the crosslinked polymer particles was measured by directly measuring 100 particles by a transmission electron micrograph (when the particles are not spherical, the long diameter and the short diameter were measured and the average value was obtained. ) Was carried out by obtaining the average value of. In the present invention, in order to further improve the affinity with the binder, the surface of the crosslinked polymer particles is made of a polymer having a content of the crosslinkable monomer of less than 10% by weight (hereinafter referred to as “polymer (B)”). The particles are partially or entirely coated to give composite crosslinked polymer particles. As the monomer for forming the polymer (B), the same monomer as for forming the crosslinkable polymer particles can be used. The preferred glass transition temperature of the above polymer (B) is
It is 200 ° C. or lower, particularly 150 ° C. or lower.

The content of the crosslinkable monomer in the polymerizable monomer used in the polymer (B) is less than 10% by weight, preferably 8% by weight or less, more preferably 5% by weight or less. If the content of the crosslinkable monomer in the polymerizable monomers constituting the polymer (B) is 10% by weight or more, the affinity with the binder cannot be improved. The amount of the polymer (B) laminated partially or entirely on the surface of the crosslinked polymer particles is 0.01 to 100 parts by weight of the crosslinked polymer particles.
The amount is 900 parts by weight, preferably 0.1 to 400 parts by weight, more preferably 0.5 to 200 parts by weight. When the amount of the polymer (B) is less than 0.01 part by weight, the affinity with the binder is poor. Further, the polymer (B) is a group having chemical reactivity or ionicity in the molecule, and has a functional group (hereinafter, simply referred to as “functional group”) excluding a group containing a polymerizable double bond. In that case, the affinity with the binder with the resin is further excellent. Here, examples of the functional group include a reactive functional group such as a carboxyl group, a hydroxyl group, an N-methylol group, a sulfone group, a maleic anhydride unit, an epoxy group, an amino group, an amide group, and a nitrile group. Preferred functional groups are carboxyl group, hydroxyl group, amino group and amide group. In the present invention, the functional group-containing monomer is contained in the monomer constituting the polymer (B) in an amount of 0.05 to 20% by weight, particularly 0.1 to 15% by weight.
It is preferable to include it from the viewpoint of improving the affinity of the obtained composite crosslinked polymer particles with the binder.

As the monomer having a functional group, the same ones as described above can be mentioned. Among the polymerizable monomers other than the above-mentioned crosslinkable monomers, preferred as the monomer for constituting the polymer B are aromatic vinyl, acrylic acid ester, methacrylic acid ester, monomers having a functional group, and specifically, Styrene, ethyl vinyl benzene, acrylonitrile, methyl methacrylate,
Examples include butyl acrylate and (meth) acrylic acid.
It is also possible to impart a functional group to the above polymer (B) by chemical treatment, for example, by obtaining a polymer (B) having an epoxy group and then treating with ammonia, methylamine or the like. An amino group can be added or a sulfone group can be added by treatment with sodium hydrogen sulfite or sulfuric acid. Further, as a preferable combination of the polymerizable monomers constituting the polymer (B), a non-conjugated vinyl compound, a crosslinkable monomer such as a polyvalent methacrylate compound and an aromatic monovinyl compound, an acrylic acid ester monomer, a methacrylic acid ester monomer, etc. A combination of a polymerizable monomer and a monomer containing a functional group can be mentioned, and a combination of a non-conjugated vinyl compound, an aromatic monovinyl compound and a di- or monocarboxylic acid is particularly preferable. In the present invention, the content of the crosslinkable monomer is 10
A polymerizable monomer in an amount of at least wt% is polymerized, preferably by an emulsion polymerization method, to obtain crosslinked polymer particles. Also,
The composite crosslinkable polymer particles are the crosslinked polymer particles (A) 1
In the presence of 00 parts by weight, the content of the crosslinkable monomer is 10
0.01 to 900 parts by weight of a polymerizable monomer having a content of the monomer having a functional group of less than 0.05% by weight, preferably less than 0.05% by weight, is polymerized, preferably by an emulsion polymerization method. In the present invention, partially coating the surface of the crosslinked polymer particles with the polymer (B) means that less than 100% of the total surface area of the crosslinked polymer particles, preferably 0.00001% or more and less than 100% of the polymer ( It shows that it coats with B).

The method of adding the polymerizable monomer in the polymerization to obtain the above-mentioned crosslinked polymer particles and composite crosslinked polymer particles is preferably a method of continuously or intermittently adding a part or the whole amount. The polymerization initiator used in the above emulsion polymerization is not particularly limited as long as it is used in ordinary emulsion polymerization and suspension polymerization, but potassium persulfate, sodium persulfate, persulfate salts such as ammonium persulfate are used. The initiator, azo-based initiator, hydrogen peroxide, organic peroxide and the like may be used alone or in combination with various reducing agents such as ascorbic acid. In the above emulsion polymerization, in order to enhance the stability of the polymerization reaction system,
Suspension protectants or surfactants are used. Usual surfactants can be used, for example, dodecylbenzene sulfonate, dodecyl sulfate, lauryl sulfate, dialkylsulfosuccinate, polyoxyethylene alkylphenyl ether sulfate, polyoxyethylene alkylpropenylphenyl. Examples thereof include anionic surfactants such as ether sulfates and formalin condensates of naphthalene sulfonic acid. Here, sodium, ammonium, potassium, etc. can be mentioned as a salt. Furthermore, it is also possible to use nonionic surfactants such as polyoxyethylene nonylphenyl ether, polyethylene glycol monostearate, polyoxyethylene alkylpropenyl phenyl ether, sorbitan monostearate. Further, it is possible to use a generally known reactive emulsifier such as sodium naphthalenesulfonate alone or in combination with the above-mentioned surfactant. As a preferable suspension protector, water-soluble polymers such as polyvinyl alcohol, polyvinylpyrrolidone, carboxymethyl cellulose, sodium polyacrylate, and hydroxypropyl cellulose can be used. These may be used alone or in combination. A preferable combination is a combination of an anionic surfactant, a nonionic surfactant and a water-soluble polymer.

The matting agent of the present invention is obtained as described above.
Composite crosslinked polymer particles . The matting agent of the present invention is applied as a matting agent dispersion liquid in which water or an aqueous solvent is dispersed together with a surfactant and a hydrophilic colloid, if necessary. The matting agent is 0.1 to 2% by weight in this dispersion.
Is preferred. If the amount of the matting agent is less than 0.1% by weight, the smoothness is poor, and if it exceeds 2% by weight, the gloss is poor. As the surfactant used here, any of nonionic, cationic or anionic can be used. The amount of the surfactant used is usually 0.001 to 2% by weight of the dispersion liquid. As the hydrophilic colloid, gelatin, colloidal albumin, protein such as casei, cellulose derivative such as carboxymethyl cellulose, agar, sodium alginate, sugar derivative such as starch, synthetic polymer such as polyvinyl alcohol, polyacrylamide, etc. are preferable. Examples include gelatin. The amount of hydrophilic colloid used is usually 0.1 to 50% by weight of the dispersion liquid. The matting agent of the present invention is a high-speed rotating mixer containing the above-mentioned components and, if necessary, a hardening agent, a thickener, an antistatic agent, an ultraviolet ray Kyushu agent, a plasticizer, a dye, a color former, a known matting agent, and the like. It can be dispersed by a homogenizer, ultrasonic dispersion, ball mill, or the like. The coating amount of the matting agent of the present invention is 1 m of printing paper.
0.5 to 300 mg per ² , preferably 0.5 to 20
It is 0 mg. If the coating amount is 0.5 mg / m ² , the smoothness is poor, and if it exceeds 300 mg / m ² , the gloss is poor.

The matting agent dispersion of the present invention can be applied to any printing paper such as known printing paper. The matte dispersion containing the matting agent of the present invention can be applied to either the front or back of photographic paper. In the present invention, the photographic paper refers to a support having a photosensitive layer formed on one surface. here,
As the support, a paper obtained by laminating the surface of paper with cellulose acetate, polyethylene terephthalate, baryta, polyethylene, polypropylene or the like can be used. The photosensitive layer is a layer in which a silver halide emulsion and, if necessary, a sensitizing dye, a stabilizer, a surfactant and a development accelerator are added to the same hydrophilic colloid as described above.
Here, the silver halide emulsion is specifically an emulsion of silver halide, for example, silver bromide, which is produced by the double jet method or the like. The silver halide emulsion can be used after being sensitized by a known method such as chemical sensitization or spectral sensitization. In this chemical sensitization, a sulfur sensitizer or a noble metal can be used, and for spectral sensitization, a cyanine dye, a merocyanine dye, etc. can be used. The coating amount of hydrophilic colloid in the photosensitive layer is about 0.2 to 6 g / m ² . The photographic paper of the present invention can be used in any application such as a film, a photosensitive material for plate making, a photosensitive material for silver complex salt diffusion transfer, in addition to black and white or color photographic paper.

[0013]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited thereto. In the following description, "part" means "part by weight" and "%" means "% by weight". Measurement method of particle size The average particle size of the composite crosslinked polymer particles is measured by measuring the particle size of 100 particles directly by a transmission electron micrograph (if the particles are not spherical, measure the major axis and the minor axis) The average value was calculated.). Method for observing particle dispersibility in resin The dispersibility of the composite crosslinked polymer particles in the resin is determined by kneading the composite crosslinked polymer particles in a methyl methacrylate resin with a ruder and then injecting a resin plate Visual observation was made by observing with a transmission electron microscope.

Example 3 Divinylbenzene (commercial product, purity 55%, balance 40%
Is ethyl vinyl benzene, the remaining 5% is diethylbenzene) 50 parts, styrene 50 parts, sodium dodecylbenzene sulfonate 5 parts, polyvinyl alcohol 0.5 parts,
1000 parts of ion-exchanged water and 1 part of α, α′-azoisobutyronitrile were charged into a reaction vessel, and the mixture was mixed with a homomixer to 1
The mixture was stirred at 2,000 rpm for 60 minutes to make it uniform. Then, while blowing nitrogen gas, the mixture was heated to 80 ° C. and continuously stirred for 3 hours to carry out polymerization. Then, as a second step, 1 part of potassium persulfate was charged into the reaction vessel, and 70 parts of methyl methacrylate and 20 parts of n-butyl acrylate were added.
An emulsion prepared by mixing 9 parts of methacrylic acid, 1 part of ethylene glycol methacrylate, 40 parts of ion-exchanged water, 0.5 part of dodecylbenzenesulfonic acid, and 1 part of polyvinyl alcohol was continuously added for 3 hours to complete the polymerization, and the average. A printing paper matting agent c composed of polymer fine particles having a particle diameter of 2.3 μm was produced.

Example 4 10 parts of polystyrene particles having a weight-average molecular weight of 15,000 and an average particle size of 0.25 μm, 5 parts of sodium dodecylbenzenesulfonate, divinylbenzene (purity and the like are the same as in Example 3) 65 parts , 35 parts of styrene, 1 part of sodium persulfate, and 700 parts of ion-exchanged water were charged into a reaction vessel, and polymerization was carried out at 80 ° C. for 1 hour while stirring while blowing nitrogen gas. Then, in the second step, 1 part of styrene, 1 part of methacrylic acid, 0.5 part of 2-hydroxyethyl methacrylate and 0.5 part of sodium persulfate are added, and the temperature is 80 ° C.
Polymerization is continued for 3 hours to complete the polymerization. Average particle size 0.6μ
A matting agent d consisting of polymer fine particles of m was produced. After laminating the obtained films, at a constant load of 50 ° C,
It was left for 48 hours. After that, when the film was peeled off, it peeled off easily and the blocking resistance was good. Comparative Example 1 100 parts of methyl methacrylate, 3 parts of sodium dodecylbenzenesulfonate, 0.5 parts of polyvinyl alcohol
Parts, 1000 parts of ion-exchanged water, and 1 part of α, α′-azoisobutyronitrile were charged in a reaction vessel and homogenized with a homomixer at 15,000 rpm for 60 minutes. Then, the mixture was heated to 80 ° C. while blowing nitrogen gas and stirred for 3 hours to carry out suspension polymerization to obtain a printing paper matting agent e composed of polymer fine particles having an average particle diameter of 1.9 μm.

Example 5 A photographic printing paper was produced by the following method using the photographic printing paper matting agents of Examples 3 to 4, Comparative Example 1 and Comparative Example 2 (silicon dioxide having an average particle diameter of 3.5 μm). (1) Preparation of photosensitive layer material A silver halide emulsion containing 15 mol% of silver bromobromide having an average grain size of 0.3 μm produced by the double jet method is chemically sensitized by a conventional method to obtain a sensitizing dye and a stabilizer. , A hardener, and a surfactant were added. (2) Preparation of Matting Agent-Containing Compositions c to f 0.5 parts of photographic printing paper matting agents c to f, 1 part of a hardening agent and 0.2 parts of a surfactant are added to 98.3 parts of an aqueous gelatin solution having a concentration of 7%. Parts were added and mixed. (3) Production of photographic paper The photosensitive layer material obtained in (1) above was coated on one surface of a support made of paper laminated on both sides with a polyethylene terephthalate film so that the amount of silver was 3.2 g / m ^2. After coating and drying, the matting agent-containing compositions c to f obtained in (2) above were coated by a slight hopper method so that the amount of gelatin was 0.8 g / m ^2, and dried. Next, the matting agent dispersion obtained in (2) above was applied to the other surface of the support so that the amount of gelatin would be 0.8 g / m ^2, and dried to obtain printing papers c to f. . Next, the haze value, the scratching degree and the coating state of the obtained printing paper were evaluated as follows. The results are shown in Table 1.

Haze degree Unexposed photographic printing paper is commercialized with a lith developer at 20 ° C. for 2 minutes 30.
After developing for one second, fixing, washing with water and drying, the transparency is measured with a haze meter. Haze value = (scattered light / total transmitted light)
× 100 (%), and the smaller the haze value, the better the transparency and the gloss of the photographic paper. Kutsuki degree photographic paper is cut into 5 cm x 5 cm to make a set of 2 and 35
After conditioning the humidity at 80 ° C. RH (relative humidity) for 24 hours, one surface of the same set on which the photosensitive layer is formed and the back surface are overlapped and then 1
A load of Kg was applied and the mixture was left at 35 ° C. and 80% RH for 24 hours. Next, the load was removed, and the area of the adhesive portion remaining on the surface of the photographic paper was measured. The evaluation rank is as follows. Rank A Area of bonded part 0 to 25% Rank B Area of bonded part 26 to 50% Rank C Area of bonded part 51 to 75% Rank D Area of bonded part 75 to 100% Coating state was visually observed.

[0018]

[Table 1]

[0019]

According to the present invention, while maintaining the glossiness,
A matte agent for photographic paper having improved smoothness and a photographic paper having a layer containing the matte agent can be provided.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-61-230136 (JP, A) JP-A-61-14632 (JP, A) JP-A-2-55351 (JP, A) JP-A-3- 79604 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G03C 1/95 G03C 1/32 B32B 27/20 G03C 1/79

Claims (2)

(57) [Claims] 1. A group containing a polymerizable double bond in a molecule
On the surface of the crosslinked polymer particles (A) obtained by polymerizing a polymerizable monomer having a content of two or more crosslinkable monomers of 10% by weight or more and the rest being other than the crosslinkable monomer ,
If the content of the crosslinkable monomer is less than 10% by weight , the balance is
The polymer (B) obtained by polymerizing a polymerizable monomer other than the crosslinkable monomer is partially or entirely coated, and has an average particle diameter of 0.01 to 10 μm, and (A).
The weight ratio of / (B) is 100 / 0.01 to 900. A matting agent for photographic paper comprising composite crosslinked polymer particles. 2. A group containing a polymerizable double bond in the molecule
On the surface of the crosslinked polymer particles (A) obtained by polymerizing a polymerizable monomer having a content of two or more crosslinkable monomers of 10% by weight or more and the rest being other than the crosslinkable monomer ,
If the content of the crosslinkable monomer is less than 10% by weight , the balance is
The polymer (B) obtained by polymerizing a polymerizable monomer other than the crosslinkable monomer is partially or entirely coated, and has an average particle diameter of 0.01 to 10 μm, and (A).
A photographic paper having a layer containing a composite cross-linked polymer, wherein the weight ratio of / (B) is 100 / 0.01 to 900 .