JPS6225753A - photo resin coated paper - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides that at least one side of the paper size or synthetic paper substrate is
It relates to a photographic resin-coated paper coated with a resin composition comprising at least a titanium dioxide pigment and a resin,
More specifically, the appearance of microgrit was almost observed on the damaged resin surface of the nuclide 1 fat-broken paper, and the surface quality of the photographic resin-covered paper was [A]. It is.

The term microgrit referred to here refers to the microgrit that appears on the surface of the coated resin in photographic resin-coated paper in which at least one side of the low-base substrate is coated with a resin composition. Refers to minute foreign matter or minute grains ◇ The main cause of microgrit is various, but the first one is photographic thermoplastic resin, which is coated by bath melt extrusion on at least one side of the paper or synthetic paper substrate. The main causes of microgrit appearing in photographic layer '41 paper produced by
(1) If the thermoplastic resin used itself generates a lot of gel, (2) If the thermoplastic resin used is a
When the melted resin is extruded into a film, it cannot be maintained at the proper temperature and becomes uneven. (3) If the screen attached to the breaker plate in the melt extruder is dirty. (4) If there are cracks in the barrel liner inside the melt extruder, (5) If there is insufficient bending in the melt extruder, these can be resolved fairly easily by skilled engineers. It is often done.

However, the most difficult type of microgrit pair is a resin coating for BX in which a paper or synthetic paper substrate is coated with a resin composition consisting of at least a thermoplastic resin and a pigment.
This is a case where microgrit is generated in the recycled paper.

In the first place, the method of incorporating a pigment into a thermoplastic 11 resin, preferably a polyolefin VtIIIR, is to prepare a so-called master punch containing the pigment in the resin in advance, and then add the pigment to the resin in a desired proportion. It is normal to use it by diluting and mixing it with the resin, or by preparing a so-called compound in which the face t4 is contained in the resin at the original composition ratio. When preparing a master bunch or compound by melt-kneading a thermoplastic resin and a pigment using an ordinary melt-kneading machine, VC is an agglomeration of relatively coarse pigment particles or titanium dioxide pigments in a thermoplastic resin. Materials tend to remain dispersed rather than being dispersed in fine particles, thus resulting in the presence of coarse pigment particles, etc. in the master patch or compound.As a result, the paper or synthetic paper substrate Microgrit is generated on the resin surface of photographic resin-coated paper, at least one surface of which is coated with a resin composition comprising a resin and a resin produced using the masterbatch or nuclear compound. Become.

The occurrence of microgrit in 4g1 fat-broken paper (as a photographic support) causes serious photographic defects.

That is, when a person is photographed on a photographic paper using a resin-coated paper containing microgrit as a photographic support, if microgrit appears in areas such as the face, the photograph has no commercial value.

By the way, titanium dioxide pigments are usually used as pigments contained in the resin layer on the emulsion-coated side of resin-coated paper used as a photographic support because they have excellent whiteness, hiding power, resolution, etc. is well known.

Furthermore, resin-coated paper for photographs is already known.
For example, as disclosed in U.S. Pat. No. 3,501,298, both sides of a paper substrate are coated with a polyolefin resin, particularly a polyethylene resin, and the polyolefin resin layer on the emulsion-coated side is coated with titanium dioxide pigments, colored pigments, Products containing fluorescent brighteners and the like are well known. Another type of photographic resin-coated paper is JP-A-57-30830.
Photographic resin-coated papers are also known in which a paper substrate is coated with a resin composition containing a white pigment, such as titanium dioxide, which is polymerized and cured by electron beam irradiation, as disclosed in No.

However, for photographic resin-coated paper in which at least one side of the paper or synthetic paper substrate is coated with a resin composition comprising at least a titanium dioxide pigment and a resin, a masterbatch or compound of titanium dioxide pigment as described above is used. As mentioned above, microgrit tends to occur frequently on the resin surface of the photographic resin-coated paper, which is caused by coarse particles of the pigment, in this case titanium dioxide pigment. There was a serious problem.

Accordingly, an object of the present invention is to provide a photographic resin-coated paper containing a titanium dioxide pigment in the resin layer and having a good surface quality, in which the generation of microgrit is not present or is significantly suppressed.

That is, in a photographic resin-coated paper in which at least one surface of a paper or synthetic paper substrate is coated with a resin composition consisting of at least a titanium dioxide pigment and a resin, the titanium dioxide pigment is present in one molecule. At least 1 of each of the two substituents NiA and NiB described in claim 1
An object of the present invention is to provide a photographic resin-coated paper whose surface is treated with a polyether-modified siloxane containing polyether-modified siloxane.

As a titanium dioxide surface treatment agent that significantly suppresses the generation of microgrit in the photographic resin +*p@paper of the present invention, the specific polyether-modified siloxane (
(Hereinafter, it may be abbreviated as siloxane in the present invention) is effective, and as an example,
Organosilicones such as those disclosed in No. 0, for example, siloxanes such as alkyl polysiloxanes, alkylaryl polysiloxanes, alkylhydrodiene polysiloxanes, etc., sufficiently suppress the generation of microgrit for use in resin-coated paper for printing and ¥C printing. It's not worth it.

As the siloxane of the present invention, any polyether-modified siloxane containing at least one of the two substituents 2A and 2B described in this specification can be used, but specific compounds are listed below. Then it will be as follows.

Titanium dioxide pigment (size, usually, coarse pigment - wet grinding 1 class 1 surface treatment A! (Inorganic surface treatment agent 1 (by) - filtration / trail / dehydration - drying = (coarse grinding) - fine grinding. Ru.

In the present invention, the surface treatment method for siloxane (titanium dioxide) may be carried out at any point after the drying step (2), the beating drying step (2), the pounding drying step (2), and after the pulverization.
It is preferable to carry out the process before crushing or during the imitation powder, and
It may be performed after f1 crushing. If surface treatment is performed after pulverization, pulverization may be performed if necessary.

The siloxane in the present invention has the following characteristics with respect to titanium dioxide:
You can process the long surface as it is, or use an organic solvent,
For example, the surface treatment may be carried out after diluting it with ethanol, acetone, etc. as appropriate.

As a surface treatment method, for example, when processing with a steam mill, the siloxane according to the present invention and the steam mill are mixed with titanium dioxide and the siloxane of the present invention to obtain the desired treatment result.
・While crushing, Table 1. [Ij processing may be performed. In addition, as a surface treatment method, for example, α with a Henschel mixer.
When treating eζ, titanium dioxide may be ground by a grinder such as a steam mill, and then mixed with the siloxane of the present invention in a Henschel mixer for surface treatment. or,
Depending on your safety, you may also perform pulverization using a pulverizer such as an air mill.・If necessary, before fine pulverization) ・Coarse pulverization may be performed using an immersion mill etc. 〇The surface treatment basket of siloxane for titanium dioxide in the present invention is 0.05 to 1.0 ik% of titanium dioxide. However, if the amount is less than 0.05% by weight, the effect of the present invention cannot be obtained, and if the amount exceeds 1.0% by weight, resulting in an excessive surface treatment, it may be necessary to mix it with the resin using, for example, a Banbury mixer. However, there is a tendency for slippage to occur, and sufficient fractionality cannot be obtained.

Normally, when a master punch is prepared by kneading a titanium dioxide pigment into a thermo-OT plastic resin, such as a polyethylene resin shell, using a Banbury mixer or the like, the number of stitches containing titanium dioxide increases. In cases where it is difficult to knead and sufficient fractionality is not obtained to prevent the formation of microgrits using only resins and titanium dioxide, a lubricant is often used. For example, in the dispersibility test disclosed in Japanese Patent Publication No. 60-3430, in order to obtain sufficient dispersibility, only about 1% of the titanium nitride pigment was added to the resin.
Lead stearate as a lubricant is added in an amount of 10% based on the titanium dioxide pigment.

In general, master punches used in the photographic industry, etc., contain 30 to 50% by weight of titanium dioxide pigment in the resin for ease of handling and cost. Even with organic surface treatment, a considerable amount of lubricant is required to obtain good dispersibility. Even so, when the above-mentioned masterbatch is repeatedly applied to photographic resin-coated paper used as a photographic support, only a level that cannot sufficiently suppress the generation of microgrit can be obtained. Lubricants such as fatty acid metal salts such as zinc stearate are exposed to high temperatures of 300°C or higher when being melt-extruded and coated on the surface of a substrate such as paper through the die of a melt-extruder, causing thermal decomposition. The decomposed gas components condense when they come into contact with the hood or exhaust hole on the goo, and sometimes fall onto the resin-coated surface that is melt-extruded onto the surface of a substrate such as paper, producing relatively large speck-like foreign objects. (This is sometimes referred to as resin sauce). If such foreign matter occurs, the paper can no longer be used as a resin-coated photographic paper.

Therefore, in order to sufficiently suppress the generation of microgrit, it is necessary to use a relatively large amount of a lubricant (for example, zinc stearate) when preparing a masterbatch. The problem of resin dripping occurred,
The reality is that manufacturers of resin-coated photographic paper are constantly troubled by the contradiction between the two.

In order to solve this problem, the present inventors conducted extensive research and were able to overcome the above-mentioned contradiction by applying the siloxane of the present invention to titanium dioxide surface treatment. That is, the titanium dioxide pigment of the present invention, which is surface-treated with 0.05 to 1.0% by weight of siloxane based on titanium dioxide, produces less microgrit without using any particular lubricant, and has almost no resin sag. It has been found that a photographic resin-coated paper can be obtained. Furthermore, in order to prepare a masterbatch with less microgrit generation, it is advantageous to include a small amount of fatty acid metal salt.
In this case, in order to suppress the occurrence of resin sag as much as possible, for example, when kneading with a Banbury mixer, etc., add fatty acid metal salt such as lead stearate to the titanium dioxide pigment by 0.1 to 5 degrees. It is sufficient to add about % by weight.

The titanium dioxide pigment used in the practice of the present invention includes:
Whether it is made using the chlorine method or the sulfuric acid method,
Further, both rutile type and anatase type can be used, but it is advantageous to use anatase type from the viewpoint of whiteness. In addition, even if titanium dioxide is untreated titanium dioxide which has not been subjected to any surface treatment, or before surface treatment with siloxane in the present invention, various inorganic surface treatment agents such as hydrated aluminum oxide, hydrated aluminum oxide, etc. It may be so-called inorganic surface-treated titanium dioxide which has been surface-treated with silicon oxide, hydrated titanium oxide, hydrated zirconium oxide, zinc hydroxide, magnesium hydroxide, a manganese compound, a phosphoric acid compound, or a combination of several of these.

The treatment t of these inorganic surface treating agents is preferably 0.2 to 1.2% by weight, and particularly preferably 0.2 to 0.6% by weight (calculated in the form AJto) based on titanium dioxide.

According to the results of studies conducted by the present inventors, hydrated aluminum oxide is preferable as the inorganic surface treatment agent, and the treatment amount thereof is preferably 0.2 to 1.2% by weight based on titanium dioxide, and 0. 2 to 0.6% by weight (calculated in the form Aj!!O,) is particularly preferred. In this way, hydrated aluminum oxide is used as an inorganic surface treatment agent, and 0.2 to 1.2% by weight, particularly preferably 0.2 to 1.2% by weight, based on titanium dioxide, is used as an inorganic surface treatment agent.
0.6% by weight (A), calculated in the form of 03)) has been surface-treated, not only has very little microgrit generation, but also the generation of gripp stains has been significantly suppressed.
It was found that troubles during processing operations were also significantly reduced.

Die lip stains are needle-shaped or icicle-shaped green matter or stains that occur at the tip of the die lip when a thermoplastic resin composition containing Niahichi titanium pigment is melt-extruded into a film form from a slit die. This is called die lip stain, and when it occurs, it tends to grow larger and larger as the melt extrusion time progresses.

If this type of stain occurs during extrusion coating, vertical streaks may appear on the surface of the photographic resin-coated paper produced as is, or streak-like unevenness may occur due to uneven coating amount. Sometimes, dirt adheres to the film and is coated, causing foreign matter to appear. As a result, the surface quality of resin-coated paper manufactured as a photographic support, for example, is significantly impaired, making it completely unsuitable as a photographic support that requires excellent surface quality, and resulting in a product with no 1'1IlI value. . Father, -
ti All generated dye lip stains? The only way to completely remove it is to stop production and clean the die lip.
Cleaning them requires a great deal of effort and time, resulting in a significant drop in productivity.

Resins used in the present invention include homopolymers or copolymers such as polyolefins, polystyrene, polyvinyl chloride, polyacrylic esters, linear polyesters such as polyethylene terephthalate, polycarbonates, polyamides such as nylon, cellulose esters, and polyacrylonitrile. For example, any resin can be used as long as it is possible to coat paper with a resin film, such as ethylene-vinyl acetate copolymer and mixtures thereof, but in particular thermoplastic resins such as polyolefin, polystyrene, polyethylene terephthalate, and polyvinyl chloride can be used. are preferred, and among them, polyolefin resins are particularly advantageous in terms of extrusion coating properties, good adhesion to the base paper, and cost. The polyolefin resin in the present invention refers to a homopolymer such as low-density polyethylene, medium-density polyethylene, high-definition polyethylene, polypropylene, polybutene, polybentene, or a copolymer consisting of two or more olefins such as ethylene-propylene copolymer. is a linear low-density polyethylene that is a copolymer of ethylene and α-olefin, and a mixture thereof. You can use a mixture of them.

In the present invention, the content of the titanium dioxide pigment to be contained in the resin layer of the photographic resin-coated paper is as follows:
If it is less than 5% by weight, the hiding power is insufficient as a photographic support, while if it is more than 40% by weight, the fluidity etc. decreases and it is not suitable, and particularly preferably 7.5% by weight to 25% by weight.
% by weight.

It is preferable that a fatty acid metal salt is contained in the resin layer of the photographic resin-coated paper in the present invention.

Examples of these fatty acid metal salts include stearite, calcium stearate, aluminum stearate, magnesium stearate, zirconium octylate, sodium palmitate, calumium palmitate, and sodium laurate. In addition, the amount of addition should be low to reduce resin sag as much as possible, and 0.1 weight f for titanium dioxide is recommended.
% to 5% by weight is preferred.

In addition to the titanium dioxide pigment and, if necessary, the fatty acid metal salt, the resin layer of the photographic resin-coated paper of the present invention further contains white pigments such as nitrous oxide, talc, and calcium carbonate, stearic acid amide, Fatty acid amides such as araxinamide, tetrakis[methylene-3 (3,s-di-butyl-4-hydroxy-phenyl) flobionate) methane, a6-di+ert-butyl-4
-Antioxidants such as methyl-phenol, coloring pigments such as cobalt blue, navy blue, ultramarine, cobalt violet, fluorescent whitening agents, etc. may be added.

The photographic resin-coated paper according to the present invention is produced by melt-extruding a resin composition containing heated and melted titanium dioxide face #+ onto a paper or synthetic paper base (hereinafter simply referred to as base paper) that is normally run, into a film through a slit die. Manufactured by coating. When the resin is polyolefin 1 resin, the bath melt extrusion temperature is 200
It is preferable that the temperature is between 350°C and 350°C. However, it is preferable to subject the base paper to an activation treatment such as corona discharge treatment or flame treatment before coating the resin composition on the base paper.There are no particular restrictions on the thickness of the resin layer of the resin-coated paper. No, but generally 5
Extrusion coatings to a thickness of the order of microns to 50 microns are advantageous. In addition, in ordinary resin-coated paper in which both sides of the base paper are coated with resin, the resin surface containing titanium dioxide pigment has a glossy surface, a matte surface, a grained surface, etc., depending on the use, and the opposite side The back surface is usually a matte surface, and if necessary, the front surface or both the front and back surfaces can be subjected to activation treatment such as corona discharge treatment or flame treatment.

The base paper used in the practice of the present invention is ordinary natural pulp paper,
Although synthetic fibers or so-called synthetic paper made of synthetic resin film may be used, natural pulp paper whose main component is wood pulp such as softwood pulp, hardwood pulp, or mixed softwood/wood pulp is advantageously used. Further, there is no particular restriction on the thickness of the base paper, but a base paper with good surface smoothness is preferable, and its basis weight is 501/rn" to 25
01/m'' is preferred.

The base paper mainly composed of natural pulp, which is advantageously used in carrying out the present invention, can contain various polymeric compounds and additives. For example, dry paper strength enhancers include cationized starch, cationized polyacrylamide, anionized POIJ acrylamide, carboxy-modified polyvinyl alcohol, gelatin, etc., sizing agents, fatty acid salts, rosin derivatives, dialkyl ketene dimer emulsions, etc. Pigments include clay, kaolin, calcium carbonate, barium sulfate,
Wet paper strength enhancers such as titanium oxide, melamine resins, urea resins, epoxidized polyamide resins, fixing agents such as polyvalent metal groups such as aluminum sulfate and aluminum chloride, cationic modified polymers such as cationized starch, etc.
As a pH adjuster, caustic soda, soda carbonate, chlorine, etc. As an inorganic electrolyte, salt, mirabilite, etc., dyes, etc.
A fluorescent brightener, latex, etc. can be contained in an appropriate combination.

Various types of silver halide photographic emulsion layers can be provided on the photographic resin-coated paper of the present invention.

For example, silver chloride, silver bromide, silver chlorobromide, silver iodobromide, and silver chloroiodobromide emulsion layers can be provided. Furthermore, a multilayer silver halide photographic constituent layer can be provided by incorporating a color coupler in the silver halide photographic emulsion layer. In addition to ordinary gelatin, binders for these silver halide emulsion layers include polyvinylpyrrolidone, polyvinyl alcohol,
Hydrophilic polymeric substances such as polysaccharide sulfate ester compounds can be used. Further, the silver halide emulsion layer described above can contain various additives. For example, as a sensitizing dye, cyanine dye, merocyanine dye,
Chemical sensitizers such as water-bathable gold compounds and sulfur compounds; anti-capri agents or stabilizers such as hydroxy-triazolopyrimidine compounds and mercaptol heterocyclic compounds; hardeners such as formalin and vinylsulfuryl hexanes compounds; , azide+7zine compounds, etc., as coating aids, benzene sulftates, sulfosuccinates, etc., as stain preventive agents, dialkylhydroquinone compounds, etc., as development accelerators, hydroquinone, phenidone, etc., as ultraviolet absorbers, In addition to benzotriazole compounds, fluorescent whitening agents, sharpness-enhancing dyes,
An antistatic agent, a pH adjuster, and further a water-soluble iridium compound, a water-soluble rhodium compound, etc. can be contained in appropriate combinations during the production and dispersion of silver halide.

Further, on the back side of the photographic resin-coated paper in the present invention, that is, on the support surface opposite to the side on which the photographic constituent layer, in most cases the silver halide photographic constituent layer, is coated, anti-curl, antistatic, etc. A coating layer consisting of a hydrophilic colloid layer called a back coat layer can be provided for the purpose of preventing adhesion and slipping.

Such a back coat layer may contain a binder, a protective colloid, a curing agent, an antistatic agent, a surfactant, a matting agent, a latex, and the like.

Next, in order to further specifically explain the present invention, examples will be described.

Example 1 Crude pigment - Wet grinding - Classification - Filtration, washing, water-drying - Fine grinding to produce anatase-type nigrinated titanium face #+ by the sulfuric acid method, untreated titanium dioxide and The predetermined amounts of siloxane [exemplified compound (5)] according to the present invention shown in Table 1 were supplied to a steam mill, and surface treatment was performed while pulverizing them. After that, the titanium dioxide pigment of the 7f111 type obtained in this way was made into a fine powder by passing it through an air mill.
7) Thoroughly knead the 701 Saibe and 30 overlapped portions of the titanium dioxide shaft material at 150°C using a Banbury mixer.
Master punches containing different types of titanium dioxide pigments were obtained.

On the other hand, a mixture aN' of 50 coulometric parts of hardwood bleached kraft pulp and 50-fK quantity m of needle-4 tree-marked sulfurized pulp
! Defined to Canadian Standard Freeness 310-, and further added to 100 parts by weight of pulp, 3 parts by weight of cationized starch, 0.2 parts by weight of anionized polyacrylamide (part J, alkyl ketene dimer emulsion (as ketene dimer content)) 0.4 parts by weight of polyaminopolyamide epichlorohydrin resin, 0.4 parts by weight was added, and the basis weight was 1609.
The wet paper obtained was dried at 110°C, and then added with a triple-wall portion of chicarpoxy-edible polyvinyl alcohol, 005 parts by weight of fluorescent brightener, 02 parts by weight of blue dye, and 0 parts by weight of citric acid. .2 parts by weight and 97 parts by weight of water, dried with hot air at 110°C, calendered at a linear pressure of 90 kg/em, and then corona exposed on both sides. te, photo monthly '@
A base paper of 4 skins + 1 paper was produced.

Next, apply high-density polyethylene (density 0, 96
1 layer M1=7) and low density polyethylene (density 0.9
A 1:1 mixture of 21/cvL M I = 3) was coated to a thickness of 30a using a melt extrusion coater at a resin temperature of 320°C. Next, 301 parts of the master bunch of the titanium dioxide pigment described above, high density polyethylene (density 0.96 jl/dSMI=7120 heavy liquid part) and low density polyethylene (density 0929 mm MI=5) were then applied to the surface of the base paper.
) 50 parts by weight of the resin composition at a resin temperature of 320 parts by weight.
The polyethylene resin-coated paper containing titanium dioxide pigment was coated at 30° C. and molded in each case. The surface of the polyethylene containing titanium dioxide pigment was treated to a completely smooth glossy 1-diameter surface, and the surface of the back polyethylene was processed to have a paper-like cloak surface.

Table 1 shows the number of microgrits when using a resin composition containing these titanium dioxides #+.

The number of microgrits was determined by the following method.

Number of microgrits> The number of microgrits generated on the resin surface containing titanium dioxide pigment of the photographic resin-coated paper produced by the method described in the examples was visually counted.

Table 1 From the results in Table 1, it can be seen that the siloxane [exemplified compound (5)] in the present invention was 0°05 to 1% relative to untreated titanium dioxide.
．． It can be seen that all of the 0 weight % surface-treated papers had less microgrit generation, and good photographic resin-coated papers could be obtained.

Titanium dioxide surface-treated with 10,000, 0.02, and 2.0% by weight all produced a large amount of microgrit and were unsuitable for use as resin-coated paper for photographs.

Example 2゜Coarse pigment → Wet grinding - Classification → Inorganic surface treatment (excluding untreated titanium dioxide) → Filtration, washing, dehydration - Drying → Coarse grinding (hammer mill) → Fine grinding, and then anatase type dioxide by sulfuric acid method When producing a titanium pigment, prior to surface treatment with siloxane [exemplified compound (1)] in the present invention, in the inorganic surface treatment step in the above process, aluminic acid is added in the amount shown in Table 2. Inorganic surface treatment was performed using soda solution. After that, in the same manner as in Example 1,
Treatment t listed in Table 2 (each is 0.0% for titanium dioxide).
The siloxane surface treatment in the present invention was carried out so that the amount of siloxane was 5% by weight. Furthermore, after that, fine pulverization was performed by passing it through an air mill.

Also, for comparison, the same procedure as the surface treatment with siloxane in the present invention was carried out, except that the siloxane in the present invention was changed to dimethylpolysiloxane and methylhydrodiene polysiloxane, and the surface treatment was performed using siloxane.
Siloxane surface-treated titanium dioxide was prepared for comparison.

A photographic resin-coated paper was prepared according to the procedure, and the microgrit was measured in the same manner as in Example 1.

The results obtained are shown in Table 2.

Furthermore, die lip staining was measured using the resin formulation described in Example 1 containing six types of siloxane surface-treated titanium dioxide according to the present invention by the following method.

The results obtained are shown in Table 2.

<Number of die lip stains> A masterbatch containing the six types of titanium dioxide pigments listed in Table 2 was determined using the resin formulation described in Example 1 under the following conditions.

Scree set extruder with extrusion opening diameter of 65 mm and T with width of 750 mm
Using a melt extruder with a die, the melt temperature was 320°C,
The number of stains generated on the die lip after melt extrusion for 2 hours at a scree rotation of IO rpm is shown.

From the results in Table 2, it can be seen that after the hydrous aluminum oxide surface treatment was performed prior to the 70 xane surface treatment, the /
It can be seen that those subjected to the loxane surface treatment are in good condition with less microgrit generation.

10,000, After similarly performing hydrous aluminum oxide surface treatment, dimethylpolysiloxane (1K 17
~19) and methylhydrodiene polysiloxane (・
20 to 22) Surface-treated paper exhibits a large amount of microgrit and is therefore unsuitable for use as resin-coated paper for photography.

In addition, in the case of the present invention, in which the surface treatment amount of hydrous aluminum oxide is relatively large, the number of die lip stains increases as the amount of aluminum oxide increases, and in particular, the number of stains on the die lip increases by 2.0 car weight% (16 per liter). It can be seen that this occurs significantly.

In addition, a fetometer manufactured by Suga Test Instruments (F A
The irradiated surface of each sample was then irradiated with IJ! Dot 11V when celebrating
Compared to each sample of iF;, 12 to 16, a slight tendency towards yellowing was observed.

Therefore, for photographic resin-coated paper, prior to the siloxane surface treatment in the present invention, 0.2 to 1.2% by weight of hydrated aluminum oxide relative to titanium dioxide, especially 0.2 to 1.2% by weight,
It can be seen that after applying the siloxane surface treatment in an amount of 0.6% by weight, 05% by weight of the siloxane surface treatment according to the present invention is preferable to alligators.

Example 3 When producing anatase titanium dioxide by the sulfuric acid method through the same titanium dioxide production process as in Example 2, prior to surface treatment with the siloxane [exemplified compound (3)] of the present invention, In the surface treatment step, inorganic surface treatment was performed using an aluminium soda solution so that the amount was 0.6% by weight (calculated in the form of A4o) based on titanium dioxide. After that, filtration, washing, dehydration, drying, and coarse pulverization (
Titanium dioxide was obtained through a hammer mill)-pulverization (steam mill) process. Next, surface treatment was carried out by mixing with titanium dioxide in a Henschel mixer so that the amount of siloxane surface treatment according to the present invention as shown in Table 3 was obtained.

Furthermore, after that, fine pulverization was performed by passing it through an air mill.

For comparison, two comparative siloxane surface treatments were carried out in exactly the same manner as the siloxane surface treatment in the present invention, except that the siloxane in the present invention was replaced with dimethylpolysiloxane. Created a titanium watch.

The four types of siloxane surface-treated titanium dioxide obtained in this way and the three types of siloxane surface-treated titanium dioxide for comparison were prepared in the same manner as in Example 1. A master bunch was prepared by 'kj. However, at this time, each zinc stearate listed in Table 3 was added as a lubricant so as to give the same effect.

Thereafter, photographic resin-coated paper was prepared in the same manner as in Example 1, and the microgrit was measured.

In addition, during the production of photographic resin-coated paper, the degree of sagging that adhered to the hood on the bath-melt extruder die or fell from the hood after a certain period of time was also determined.

The results obtained are shown in Table 3.

From the results in Table 3, it can be seen that in the case of the photographic resin-coated paper using siloxane surface-treated titanium dioxide according to the present invention, microgrit tends to increase slightly as the lubricant (zinc stearate) decreases. It can be seen that the number of microgrits generated is small, and a good photographic resin-coated paper can be obtained. However, even when the siloxane of the present invention is used, when the lubricant is added in an amount of 10% by weight based on the titanium dioxide pigment (31 to 1), resin sag occurs significantly, and the operating condition deteriorates significantly. I understand.

On the other hand, in the case of photographic resin-coated paper using dimethylpolysiloxane surface treatment, which is outside the scope of the present invention, even though the lubricant 1 has a mold content of 10% by weight based on the titanium dioxide pigment, microscopic Many blits occurred, and the resulting paper was unsuitable for use as a photographic resin-coated paper. Furthermore, the occurrence of resin sagging was significant, and the operating conditions were seriously deteriorated.

Proceedings (self-proposal) September 178, 1985 1. Indication of the case 1985 Patent Application No. 166375 2. Name of the invention Resin-coated paper for photographs 3. Person making the amendment Mitsubishi Paper Mills Co., Ltd. Patent Department (600) 2111 4. Correction target 1) Correct to the right side of (2) structural formula on page 10.

2) Page 12, No. 11 (1st item) Correct "exceed" to "super".

3) Page 18, line 16 Correct "olefin" to "olefin".

4) 1st line of page 22 "Preferably" should be corrected to "preferably."

Claims (1)

[Scope of Claims] 1. A photographic resin-coated paper in which at least one surface of a paper or synthetic paper substrate is coated with a resin composition comprising at least a titanium dioxide pigment and a resin, wherein one molecule of the titanium dioxide pigment A photographic resin-coated paper characterized in that the paper is surface-treated with a polyether-modified siloxane containing at least one substituent of the following two types of formulas A and B. Formula A; ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, x is an integer from 0 to 4, a is a number from 1 to 50 on average,
b represents a number on average from 0 to 50, and R' represents a hydrogen atom, an alkyl group, or an acyl group. ) Formula B; ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, y is an integer from 0 to 4, and R″ and R″′ include terminal unsaturated bonds. z represents an integer of 2 to 30. 2. The amount of surface treatment of the polyether-modified siloxane relative to the titanium dioxide pigment is 0.05 to 1.0% by weight. 3. The photographic resin-coated paper according to claim 1, wherein the titanium dioxide is surface-treated with an inorganic surface treatment agent prior to the polyether-modified siloxane surface treatment. The photographic resin-coated paper according to claim 1 or 2. 4. The photographic resin-coated paper according to claim 1, 2 or 3, wherein the inorganic surface treatment agent is hydrated aluminum oxide. 5. The amount of inorganic surface treatment agent treated is 0 for titanium dioxide.
．． 2-1.2% by weight, preferably 0.2-0.6% by weight (
Claim 1, which is (calculated in anhydrous form)
The photographic resin-coated paper according to item 2 or 3. 6. The amount of hydrous aluminum oxide treated is 0.2 to 1.2% by weight, preferably 0.2 to 0.6% by weight (calculated in the form of Al_2O_3), based on titanium dioxide. The photographic resin-coated paper according to item 1, 2, 3, or 4. 7. Claim 1, wherein the resin is a thermoplastic resin;
The photographic resin-coated paper according to item 2, item 3, item 4, item 5, or item 6. 8. The photographic resin-coated paper according to claim 7, wherein the thermoplastic resin is a polyolefin resin. 9. The photographic resin-coated paper according to claim 8, wherein the polyolefin resin is a polyethylene resin. 10. The photographic resin-coated paper according to claim 1, wherein the resin composition contains a fatty acid metal salt. 11. The photographic resin-coated paper according to claim 10, wherein the content of the fatty acid metal salt in the resin composition is 0.1 to 5.0% by weight based on the titanium dioxide pigment.