JPS62235944A - Production of resin coated paper for photography - Google Patents

Abstract

PURPOSE:To obtain the titled paper having high quality and good peeling property and capable of preventing generation of unevenness on the surface of the resin coated paper by melt-extruding a polyolefin resin on the surface of a paper substrate in a state of sticking droplets on a cooling roller, thereby coating on the substrate with it, and by making a fine unevenness on the resin covered surface. CONSTITUTION:The fine droplets are stick on the surface of the cooling roller by directly spraying steam on the surface of the cooling roller or by dewing on the substrate by cooling the cooling roller. By using the obtd. cooling roller, the polyolefin resin is melted and coated on the substrate, thereby forming the fine un-evenness on the resin coated surface of the substrate. A pigment, a dyesuff, an antioxidant, a fluorescent whitening dye and an U.V. absorbent, etc., are preferably added to the resin to be coated with melt-extruding. Various kinds of high polymers and additives may be incorporated to the substrate paper composed of a natural pulp as a main component.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Industrial Field of Application The present invention relates to photographic resin-coated paper, and particularly to resin-coated paper coated with polyolefin resin by melt extrusion. This is related to the "plane paper" method, and the photographic resin MFI produced by this method.
Paper is used as a support for photographic paper.

(R) Prior Art In recent years, polyolefin resin wLffix has been widely used as a support for photographic paper.

M-sided polyolefin resin-coated paper is generally used as a support for smooth surface type 11 drawing paper. There is. However, in the production of such smooth-surfaced polyolefin resin-coated paper, as the extrusion rate increases, the melt extrusion process (moon is not sufficiently cooled by the cooling roll, and the cooling roll peels off the paper). Therefore, the peelability between the coated resin surface and the cooling roll is poor, resulting in so-called "blocking".
There is a problem in that unevenness called "horizontal unevenness" occurs, which deteriorates the quality of the final product, clear surface photographic paper. In order to prevent such "blocking" and "horizontal unevenness" from occurring, the polyolefin resin contains
A method of adding a lubricant is generally known, but when this method is used, the amount of smoke emitted from the molten polyolefin resin increases when the polyolefin resin is melt-extruded, causing contamination of the cooling roll, and as a result, the resin This is not the best method as it causes secondary quality deterioration, such as a deterioration in the quality of the face and the occurrence of a so-called "pear-skinned surface."

In order to solve this problem, it has been proposed to use a cooling roll for micro-ul.

(Problems that 0 @ Ming tries to solve The present invention is simple (In the manufacturing process of placenta paper, it has good releasability even if the degree of extrusion is increased, so-called 1 blocking.)
This method prevents the occurrence of unevenness on the lateral surface of the resin coating, which is called "cross-column unevenness," and produces high-quality resin-coated paper, especially smooth resin-coated paper.

(In the process of melting fat and extruding it to coat the surface of the paper base material, a smooth cooling roll with minute droplets attached to the surface is used to coat the surface of the paper base material.) A method for producing resin-coated paper for photographs, which is characterized by cooling the stretched paper and at the same time forming minute irregularities on the surface of the coated resin.

The present invention, when manufacturing the Weiyuan-type Zhaozi for photographic paper,
In the process of extruding polyolefin (fat) onto a paper base material, steam is directly blown onto the surface, or by cooling with a cooling roll, condensation is caused by the temperature difference from the peak temperature. By using a cooling roll with a thin beak on the surface to which 100,000,000 microscopic g/- is attached, it is possible to simultaneously release a+4 on the resin surface in the bath without reducing the surface value of the product. The shape of the irregularities is shaped b!tξ. These @#I irregularities improve the releasability between the cooling roll and the constant (fat Mi IJIrtn) in the polyolefin m (Jjd bath melt extrusion coating process), and improve the so-called This prevents the occurrence of "blocking", "horizontal unevenness", and "pearly surface".

The presence of minute droplets on the surface of the cooling roll causes minute irregularities on the compound surface of the resin, and the reason why the peelability is improved is as follows: [(1) Contact of the droplets on the cooling roll with the molten resin. At the same time, the soft resin surface dents and solidifies while retaining its shape.

(2) The Pi that is sandwiched between #fat n11 and the surface of the cooling roll instantly vaporizes, and is written out in the opposite direction to the direction of the pressure-filled cooling roll, and the gas is discharged. The traces leaked onto the resin surface, resulting in minute dents.

(3) The vaporization of i' -6tm between the polyolefin resin surface and the cooling roll facilitates the -j granization with roll 1. This is thought to be due to the following.

There are no particular limitations on the thickness of the coating resin layer used in the present invention, but it is generally advantageous to have a thickness of about 5 microns to 50 microns.

The coating resin used in the method of the present invention may be any resin that can be coated by melt extrusion, such as polyolefin, polystyrene, or polyvinyl chloride, and is not particularly limited. It is particularly advantageous in terms of quality, cost, etc. The polyolefin resin in the present invention refers to homopolymers of olefins such as polyethylene, polypropylene, polybutene, and polybentene, or copolymers of two or more olefins such as ethylene-propylene copolymers, and mixtures thereof. Those having a density and a melt viscosity index (melt indenox 2 or less simply abbreviated as MI) can be used alone or in combination.

In the present invention, the resin to be melt-extruded includes titanium oxide, oxidized! e White pigments such as lead, talc, and calcium carbonate, fat amides such as stearic acid amide and arachidic acid amide, and fat agglomerates such as zinc stearate, calcium stearate, magnesium stearate, and calcium palmitate. It is preferable to add a suitable combination of various additives such as pigments such as , cobalt violet, dyes, antioxidants, fluorescent brighteners, and ultraviolet absorbers.

[The amount of titanium oxide added to the fat layer on the emulsion side of the paper is preferably 5 to 40% by weight, but if this amount is less than 5% by weight, it can be used as a heating support. The power is insufficient, -40,000
(If it is more than 1-N percent, the workability etc. will deteriorate and it is not preferable. Particularly preferably, it is 7 percent to 2 percent.
0m [range of percent.

The base paper used in the method of the present invention may be ordinary natural pulp paper, synthetic pulp paper, or so-called synthetic paper made of artificial paper made of synthetic resin film. , a natural pulp paper based on wood pulp of 1/2 mixed pulp of softwood broadleaf is advantageously used.

There are no particular restrictions on the thickness of the base paper, but paper with good surface smoothness is preferred, and its surface breakage is 50.9/m'
~250y/ml is preferred.

The base paper mainly composed of natural pulp, which is advantageously used in the present invention, can contain various molecular compounds and additives.

For example, starch derivatives, polyacrylamides, polyvinyl alcohol V/L carriers, dry paper strength agents such as gelatin, fatty acid groups, rosin compounds, sizing agents such as dialkyl ketene dimer emulsions, melamine resins, urine IA resins, and epoxidized polyamides. tM of resins, paper strength enhancers, stabilizers, pigments, dyes, fluorescent brighteners, latex, inorganic electrolytes,
It can be contained in an appropriate combination with a PH adjusting agent and the like.

The four-dimensional support produced according to the present invention can be provided with various silver halide photographic emulsions 1-, and can be used as various photographic prints.

According to the present invention, 3jl! The fabricated surface has fine irregularities as shown in Fig. 1, and the resin coating is carried out without adhering droplets to the cooling roll as shown in Fig. 2. This is clearly different from the case where the resin coating was used.

More specifically, the shape of the fine irregularities varies irregularly depending on the shape of the minute droplets slipped on the cooling roll, as well as the press pressure and damage speed, but the shape of the product after the emulsion coating process changes irregularly. Considering quality, the average depth of unevenness is approximately 0.
．． 0.05 mm to about 271111 mm, especially about 0.05 mm to 271111 mm.
One having a degree of 1 am to 1.5 arna is preferable. This is called "blocking" in the resin damage process when the unevenness on the 1!4 resin surface is smaller than 0.1 am.
It is necessary to prevent FIA14 unevenness such as "or 1 lateral depression unevenness", and if the unevenness is larger than 2arn,
This is the same as the so-called 1 pear-like texture, and the quality between the photographic paper after the photographic emulsion is coated deteriorates. The average pitch of the unevenness is about 0', 1 am or 1100 nm, and sometimes about lam to 40 m. It is preferable that the degree of

Resin plate (violet) The beauty of the fine irregularities on the surface is the small plate research PJr.
8) C-11 - Surface roughness meter determined 100 degrees.

The distance between A) 1 shown in Figure @3 was measured as the depth, and the average of the sum of the quietness of 40 arbitrary consecutive locations was taken as the average depth. The average pitch of the unevenness was determined by taking a photograph at a magnification of 1000 times using a scanning electron microscope, measuring the distance between the protrusions at 40 consecutive locations, and taking the average of the phases as the average pitch.

The droplets deposited on the surface of the cooling roll may be water droplets, droplets of aqueous solutions containing organic or inorganic substances, organic liquid axes, or droplets of organic solutions containing organic or inorganic substances. In order to improve the peelability, a simple amount of water with a water vapor force of px g is sufficient.

(The throat is layered with the above-mentioned cooling roll)
When polyolefin resin is melt-extruded on paper, small irregularities occur on one side of the resin plate, which improves the peelability between the resin surface and the cooling roll, so a coating of 2% or more is applied. In If, it is possible to significantly increase the speed at which "1 blocking" and "horizontal unevenness" occur so severely that they affect the final product number, that is, the upper limit speed for failure.

; After the corona discharge treatment on the back side in the first zone,
Using a melt extruder with a diameter of 150M, a resin composition consisting of 50 parts of low density polyethylene (density 0.918, Mxs) and 50 parts of high density polyethylene (density 0.965, M17) was melt extruded with a width of 1355B and a resin thickness of 30μ. Form a resin layer on the back side of the J4 substrate.

Diameter 115M after corona discharge treatment on the cover surface in the second zone
low density polyethylene (density 0.9
18, 30 parts of a masterbatch made by kneading 30% by weight of titanium oxide into MI8.5), 45 parts of low density polyethylene (density 0.918, M 5.0), high density polyethylene (density 0.965, M17) .0) A resin composition consisting of 25 parts was melt-extruded and coated with a width of 1355 ML and a resin thickness of 30 μm to form a resin layer on the surface.

, -” After spraying water vapor onto the entire surface of the cooling roll in the second zone to make minute water droplets adhere, 8! drops are deposited on the resin-coated paper coated with polyethylene resin and the cooling roll in the @2 zone. Separately coated with polyethylene resin (greasy coated paper)
Resin coating was carried out at several coating speeds.

Expression 1 of the resin-covered paper prepared under each protection condition was subjected to corona discharge treatment, then a color silver halide photographic emulsion was applied, and the surface of the developed photographic paper was observed with the naked eye.

The results are shown in Table 1. In the case of the present invention, in which droplets were attached to the surface of the cooling roll and the pupil pupil was applied, the upper limit speed of frame breaking was achieved without reducing the strength of the surface of the photographic paper. There will be a place to discuss.

((2) Effects of the invention The polyolefin resin-coated paper produced in the present invention is I
& Improving the peeling properties between the cooling roll and temporary DI 84 ribs in the resin coating process without affecting the quality of the photographic paper during processing into the final product photographic paper. I let it happen. This increased the maximum compensation speed and improved productivity.

f4 l Table ^: Liquid-liquid - use a cooling roll with H: l without

[Brief explanation of drawings]

Figure 1 shows the resin covered area using a cooling roll with a liquid droplet attached, and Figure 2 shows the resin covered area using a cooling roll that does not allow droplets to adhere at a magnification of 10,001 lbs.
Type 'ichi: This is a photo of the child's imitation. FIG. 3 is a schematic diagram showing the unevenness of the surface. 11j no 1

Claims (3)

[Claims] (1) In the process of melting and extruding resin onto the surface of the paper base material and coating it, a cooling roll with a smooth surface with minute droplets attached to the surface is used to cool the resin-coated paper and at the same time apply the coating resin. A method for producing resin-coated paper for photographs, which is characterized by molding minute irregularities on the surface. (2) For photography according to claim 1, in which in the step of adhering droplets to a cooling roll with a smooth surface, steam that becomes droplets is separately generated and the steam is sprayed uniformly onto the cooling roll. Manufacturing method for resin-coated paper. (3) In the process of depositing droplets on a cooling roll with a smooth surface, vapor that becomes droplets is present near the cooling roll, and by cooling the cooling roll, dew is formed uniformly on the cooling roll due to the temperature difference. A method for producing a photographic resin-coated paper according to claim 1.