JP2000355900A - Moistureproof laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moistureproof laminate capable of preventing the influence of friction on the packaged material, achieving high moistureproofness even by a high-speed coating process such as blade coating process and reclaimable as a waste paper. SOLUTION: A moistureproof layer composed of a plate pigment and a synthetic resin is formed on at least a surface of a paper substrate optionally after forming an undercoating layer. Spacer particles protruding on the surface of the outermost layer are included in the coating layer in the case of forming a coating layer containing a synthetic resin coating film component on the moistureproof layer or directly in the moistureproof layer without using a coating layer. The spacer particle has an average particle diameter of 10-100 μm and a Mohs hardness of <=3. The coating layer or the moistureproof layer contains the spacer particles in an amount of 1-20 pts.wt. based on 100 pts.wt. of the total solid content of the layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moisture-proof laminate having a moisture-proof layer formed on a paper support and capable of recovering waste paper. The laminate does not cause slippage between the surface of the moisture-proof layer and the surface opposite to the surface. In the case where the object is a coated paper for printing such as coated paper or art paper, it suppresses uneven gloss and scratches generated on the coated paper surface due to friction with the moisture-proof layer, and also for labels and the like. It provides a new moisture-proof laminate that is easy to attach and enables the use of a hot-melt adhesive with disintegration properties, and is particularly suitable for high-speed and high-productivity coating methods such as blade coating. is there.

[0002]

2. Description of the Related Art It is a known technique to laminate a film-forming polymer compound such as polyethylene, polypropylene, or polyvinylidene chloride on a paper support, or to laminate the film to prevent the permeation of water vapor. It is. However, this kind of paper has a strong moisture barrier function because the coating layer is strong, but when recovered paper is used, pulp fibers remain in flocks or the coating layer itself becomes a large sheet. At present, these used moisture-proof papers have to be disposed of by incineration or landfill, and have problems in terms of environmental protection and resource recycling.

On the other hand, a method for producing a moisture-proof laminate by applying an emulsion containing a paraffin wax having a specific composition to one or both sides of kraft paper as wrapping paper from which waste paper can be recovered (Japanese Patent Laid-Open No. 50-37111). ), A moisture-proofing composition for paper comprising a mixture of a synthetic hydrocarbon-based resin and wax and an emulsion obtained by dispersing the resin in water using a styrene-maleic acid-based copolymer and a surfactant (Japanese Patent Application Laid-Open No. No. 56-148997). Further, a paraffin wax having a specific melting point, an esterified product of maleated or fumarated rosin and a polyhydric alcohol, liquid polybutene, and a wax emulsion mainly containing rosin, or the wax emulsion and a synthetic rubber-based latex Is applied to the surface of a fibrous base material such as high-quality paper or kraft paper and dried under heating (Japanese Patent Application Laid-Open No. 61-47896). In addition, with respect to moisture-proof paper that can be recovered as waste paper, a production method based on applying a coating liquid obtained by mixing a certain kind of synthetic rubber-based latex and a wax-based emulsion on base paper has been disclosed. (Packaging technology, September 1982, 4
2-46).

[0004] All of the moisture-proof laminates using these paraffin waxes are moisture-proof papers having re-disintegration properties.
When such a moisture-proof laminate is wound into a roll, the wax contained in the surface of the moisture-proof layer is transferred to the opposite back surface, and as a result, the opposite surface of the moisture-proof layer becomes very slippery. If the package is packaged so as to be in contact with the package, serious problems will occur such that the packages are not aligned when they are lined up, slip down, and when a heavy product is packaged, it shifts from each other during transportation and falls during transportation. For this purpose, there are techniques such as providing an anti-slip layer on the back surface and winding in a roll at a specific winding pressure. However, there is no fundamental solution to slippage.

[0005] The moisture-proof laminate containing these waxes tends to have extremely low moisture-proof properties at the folded portion during packaging, probably because the moisture-proof properties depend on the extremely thin water-repellent layer formed by the wax. There is. In addition, bleeding of the wax on the surface of the moisture-proof layer is unavoidable, and there are problems such as peeling off when trying to attach a label to the surface.Furthermore, it contains wax other than hot melt adhesive which has a strong liquid adhesive at room temperature. However, there is also a problem that the hot-melt adhesive that can be used is very limited because the adhesion to the moisture-proof surface is poor and the open time is very short even when the adhesion is possible. There is also a method of using a pressure-sensitive adhesive tape with re-dispersing properties.However, when using an adhesive tape as compared to hot-melt bonding, there is a serious drawback that the workability at the time of packaging is significantly inferior. It is currently not used.

In order to solve the drawbacks of the moisture-proof laminate containing wax, the present inventors have previously provided a moisture-proof laminate comprising a paper support and a moisture-proof layer comprising a flat pigment and a synthetic resin latex. (JP-A-9-21096) was proposed. The present invention provides a moisture-proof layer by mixing a pigment which is supposed to be impervious to water vapor itself, for example, a flat pigment such as that found in phyllosilicate compound particles with a synthetic resin latex to form a moisture-proof layer. Means that the permeation area of water vapor is small, and that in the thickness direction, the plate-like pigments are arranged in parallel to the surface of the moisture-proof layer and laminated, so that the water vapor in the moisture-proof layer is transmitted while bypassing the plate-like pigment. Thus, it was found that the required permeation distance of water vapor was increased, and as a result, the moisture-proof performance was significantly improved.

In this type of moisture-proof laminate, in order to increase the water vapor transmission distance in the thickness direction, when the moisture-proof layer is formed at a high speed such as by a blade coating method, the unevenness of the paper support reduces the thickness of the moisture-proof layer. These blade-coated products are inferior in moisture-proof performance at the same coating amount, because they have to have a very small moisture-proof layer thickness, which affects the operation and partially. Further, in order to form a moisture-proof layer by blade coating, a coating material containing a large amount of a synthetic resin must be dried at a high concentration and at a high speed, and surface defects such as blisters tend to be easily generated. Therefore, in order to obtain a desired moisture-proof property, not only empirically setting the optimum particle diameter of the tabular pigment, etc., but also by setting the coating thickness excessively thick, always stable moisture-proof performance. Although it is possible to obtain the waste paper, in this case, not only is it economically disadvantageous, but also the disintegration after the recovery of the used paper may be greatly deteriorated.

In order to improve these drawbacks, the present inventors have previously filed a method of applying a water-soluble resin cross-linked body on a moisture-proof layer using a tabular pigment to greatly improve the moisture-proof property. (Japanese Patent Laid-Open No. 9-268494). In this method, a coating layer of the water-soluble crosslinked product is provided to fill the interface between the pigment and the resin formed at the time of forming the moisture-proof layer. But,
This method can fill the interfacial void generated when a moisture-proof layer of about 30 g / m ² is formed,
^With a moisture-proof layer of ² or less, especially about 15 g / m ² , the effect was insignificant.

On the other hand, the moisture-proof laminate containing these flat pigments is liable to be rubbed between the moisture-proof layer and the coated paper, especially when the coated paper for printing such as art paper or coated paper is wrapped in plain format. For example, gloss unevenness caused by partially promoting the orientation of the pigment on the surface of the coated paper, and scratches caused by the protruding plate-like pigment in the moisture-proof layer acting like a file appear. Have the problem of doing it.

[0010]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to eliminate the above-mentioned effects on the inclusions caused by friction, to have high moisture-proof properties even in a high-speed coating method such as blade coating, and to recover waste paper. It is to provide a possible moisture-proof laminate.

[0011]

A first aspect of the present invention is to form a moisture-proof layer comprising a flat pigment and a synthetic resin on at least one surface of a paper support, and to form a coating containing a synthetic resin film component on the moisture-proof layer. A moisture-proof laminate having a layer, wherein the coating layer contains spacer particles protruding from the plane of the coating layer. A second aspect of the present invention is a moisture-proof laminate in which an undercoat layer is formed on at least one surface of a paper support, and a moisture-proof layer comprising a flat pigment and a synthetic resin, and a coating layer are sequentially provided on the undercoat layer. A moisture-proof laminate comprising spacer particles projecting from the plane of the coating layer. A third aspect of the present invention is a moisture-proof laminate in which an undercoat layer is formed on at least one surface of a paper support, and a moisture-proof layer comprising a flat pigment and a synthetic resin is formed thereon.
A moisture-proof laminate, wherein the moisture-proof layer includes spacer particles protruding from the plane of the moisture-proof layer. A fourth aspect of the present invention is that the spacer particles have an average particle size of 10 to 10.
The moisture-proof layer according to any one of the above items 1 to 3, wherein the thickness is 0 μm. A fifth aspect of the present invention is the moistureproofing layer according to any one of the above items 1 to 4, wherein the coating layer or the moistureproof layer contains 1 to 20 parts by weight of the spacer particles based on 100 parts by weight of the total solid content of the layer. is there. A sixth aspect of the present invention is the moistureproof laminate according to any one of the above 1 to 5, wherein the spacer particles have a Mohs hardness of 3 or less. A seventh aspect of the present invention is that the spacer particles are an organic polymer,
It is a moistureproof laminated body of the description.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The present inventors have studied the mechanism of formation of the moisture-proof layer, and have found that the moisture-proof property exhibited by the plate-like pigment can be explained by a curved path theory in which moisture permeates around the plate-like pigment. According to the curve theory, since the water vapor permeates around the surface of the pigment that cannot transmit the water vapor, the water permeation distance becomes longer, and as a result, the same effect as when the film thickness is greatly increased is assumed. .

Further investigations on the moisture-proof effect based on this curved path theory show that even in the case of a low coating amount with a small number of plate-like pigments, surprising moisture-proof properties can be obtained when the film is formed very slowly and carefully. I found it. After examining the cause in more detail, in the low coating amount region described above, the flat pigments contained in the moisture-proof layer overlap because the effective film thickness is small, and when they act like a single plate. It turned out to be. Although this effect is called a lid effect, this state is preferable because the coating amount is the least for a moisture-proof layer using a flat pigment and the moisture-proof property is exhibited.

However, when actually coated with a practical coating machine,
In the aggregate of flat pigments formed by the lid effect, there are many defective parts and pinholes that follow the state of pulp fiber aggregation (formation) of the base paper as the support, so good moisture resistance is not easily obtained. That was the current situation. Such a phenomenon is particularly remarkable in the case of manufacturing by a high productivity method such as blade coating. However, even in the case of these moisture-proof layers having a low coating amount, when a coating layer is provided on the moisture-proof layer, the probability of overlapping of the above-described defective portions and pinholes is reduced, and the moisture-proof layer is further reduced. Is filled with the resin of the coating layer, so that a desired moisture-proof property can be exhibited at a low coating amount. Such a concept is the same as the method of providing a coating layer made of a water-soluble resin and a crosslinked body described in JP-A-9-268494, but the moisture-proof layer is discussed with a low coating amount as in the present invention. In this case, this coating layer does not exhibit its effect at all, and it is necessary to form a coating layer containing a resin component formed from a synthetic resin emulsion as in the present invention.

In the present invention, the synthetic resin latex used for such a coating layer includes styrene-butadiene copolymer, styrene-acryl copolymer, acrylate copolymer, methacrylate copolymer, and vinyl acetate copolymer. Polymer, ethylene vinyl acetate copolymer, styrene methacrylic acid copolymer, methacrylate butadiene copolymer, acrylonitrile butadiene copolymer, polyester resin, polyurethane resin, and the like,
Styrene-butadiene latex is preferred because it has good water resistance, has good elongation, and hardly causes cracks in the coating layer due to breakage. Styrene-butadiene latex is (meth) acrylic acid, (meth) acrylate,
Styrene-butadiene latex (modified SBR) modified with (meth) acrylonitrile, (meth) glycidyl acrylate, (meth) acrylamide, (meth) acryl glycidyl ether, or the like may be used. The glass transition point of these resins may be from −20 ° C. to + 50 ° C., as long as the film formability is maintained. The effects of the present invention cannot be expected with rosin emulsions, polystyrene balls, and the like that are difficult to maintain film-forming properties.

Further, in the present invention, the moisture-proof laminate using such a flat pigment has a potential problem as a general wrapping paper, that is, when the inclusion is a printing material such as art paper or coated paper. When the surface (coated surface) of these coated papers is in contact with the moisture-proof layer and is rubbed, the rubbed portion has a higher gloss than the non-rubbed portion due to the orientation of the pigment. As a result, streak or spot-like gloss unevenness, or a flat pigment protruding on the surface of the moisture-proof layer, acts like a kind of file, shaving off the coat layer of coated paper, For the purpose of preventing so-called scratches from occurring, spacer particles are contained in the coating layer. This is to reduce the contact area between the moisture-proof layer and the inclusions and reduce the frictional resistance to obtain the effect of suppressing the orientation of the pigment due to friction as described above and the contact with the protruding flat pigment. It is. In this case, the used spacer particles need to sufficiently project from the plane of the coating layer. In this case, the "sufficiently protruding" state described in the present invention can be confirmed by the following three methods.

1) Method for checking from the center line average roughness When the coating layer is applied without using the spacer particles, the center line average roughness Ra (μ) in a certain area of the coating layer surface is obtained.
m) and the value of the maximum height Rmax in the range, the value of the center line average roughness Ra (μm) and the maximum height Rmax of the coating layer surface when the coating layer containing the spacer particles is applied. However, any part of the surface of the coating layer must be sufficiently large.

The term "center line average roughness" as used herein refers to a section of a base material measured by a stylus-type roughness measuring instrument as a roughness curve, and a portion of the roughness curve extracted in a certain range (reference (Length), when an average line that bisects the area surrounded by the roughness curve in the reference length direction and is the center line of the cross-sectional waveform, A value obtained by dividing the sum of the areas enclosed by the curve f (x) by the reference length is expressed in micrometers (μm). The maximum height Rmax is defined as a value obtained when a roughness curve is sandwiched between two straight lines parallel to the center line in a reference length in a certain range (however, the roughness curve completely falls within the two straight lines). The value (μm) when the distance between these two straight lines is measured in the vertical direction (the thickness direction of the coating layer).

2) Smoothness (Oken type smoothness meter: J Tappi
Paper pulp test method No. Method to confirm from (5)) The smoothness of the surface containing the spacer particles is lower than the smoothness of the outermost surface of the moisture-proof laminate containing no spacer particles. For example, polyethylene particles of 18 μm are used as spacers for 1
The smoothness of the outermost surface of the moisture-proof laminate when 0 part was blended was 5 seconds, while that when the spacer was not added was 15 seconds.
Since it is seconds, it can be seen that a large difference occurs in the smoothness depending on the presence or absence of the spacer particles.

3) Method of calculating the protrusion height from the projected cross-sectional area From a projected photograph of the outermost surface of the moisture-proof laminate containing spacer particles obtained from an image analyzer or the like, half the diameter of the spacer particles as viewed from above on a plane. When the length is defined as the protrusion height, in the present invention, the average value of the protrusion height of 100 particles is preferably at least 5 μm or more, and more preferably in the range of 10 to 50 μm. preferable. If the spacer particles used are not spherical, the protruding height is calculated assuming a pseudo sphere calculated to have the same area.

Naturally, such spacer particles are buried in the coating layer unless the particles have an average particle diameter larger than the thickness of the coating layer containing the spacer particles. Needs to be sufficiently large. Thus, as described in the present invention, it is possible to provide spacer particles sufficiently projecting with respect to the plane of the coating layer on the outermost surface of the moisture-proof laminate. It is preferable to form an undercoat layer on at least one surface of the paper support for the purpose of eliminating the unevenness of the body and increasing the spacer effect by bringing the spacer particles into more uniform contact with the article to be packaged. In this case, the undercoat layer not only promotes smoothing of the paper support, but also has an effect of preventing the coating liquid from penetrating into the paper support during the application of the moisture-proof layer and preventing the effective thickness of the moisture-proof layer from decreasing. .

As described above, in the present invention, a structure in which a moisture-proof layer and then a coating layer are sequentially laminated directly on a paper support, or an undercoat layer is formed on at least one surface of the paper support and a moisture-proof layer is formed thereon A configuration in which a layer and then a coating layer are sequentially laminated is conceivable, but in addition to this, a configuration in which an undercoat layer is formed on at least one surface of a paper support and a moisture-proof layer containing spacer particles is sequentially laminated thereon is also available. Conceivable. In any case, the layer containing these spacer particles must always be provided on the outermost surface of the moisture-proof laminate for the purpose of protecting the packaged object.

The spacer particles used in the present invention are not particularly limited as long as they are so-called soft organic or inorganic particles having a Mohs hardness of 3 or less, typically represented as an index of hardness. is not. For example, soft inorganic particles such as kaolin, talc, and aluminum hydroxide, plastic pigments, and the like can be given. Among them, in the present invention, it is preferable to use an organic polymer, and starch and polyolefin, acrylic acid or acrylate copolymer, methacrylic acid or methacrylate copolymer, polystyrene, and plastic pigments such as nylon are more preferable. .

The preferred particle size range of these spacer particles is 10 to 100 μm. If the particle size of the spacer particles used is less than 10 μm, it is difficult to obtain the spacer effect expected by the present invention, and
When the ratio exceeds the above range, the number of spacer particles existing per unit area for the same compounding amount decreases, and the original spacer effect may be weakened. Of course, in the present invention, it is possible to obtain a sufficient spacer effect by mixing a predetermined amount of the spacer particles in the coating layer or the moisture-proof layer. However, it is more preferable that no spacer particles are mixed. It is desirable that a clear difference in smoothness (however, the latter has lower smoothness than the former) occurs.

The mixing amount of these spacer particles is as follows:
The content is preferably in the range of 1 to 20 parts by weight based on 100 parts by weight of the total solid content of the coating layer or the moisture-proof layer. At this time,
When the amount of the spacer particles is less than 1 part by weight, it is difficult to obtain a spacer effect as expected by the present invention,
Conversely, when the amount exceeds 20 parts by weight, the spacer effect no longer reaches its maximum, and it is economically disadvantageous.

In the present invention, for the purpose of preventing blocking or reducing costs, a general inorganic pigment can be mixed into the coating layer. In this case, the blending ratio is not particularly limited, but it is preferable that the pigment volume fraction is 0.25 or less. The coating layer having a pigment volume fraction of 0.25 or less has few voids between the synthetic resin to be used and the pigment, and has moisture resistance by itself. However, even when the pigment volume fraction exceeds 0.25,
Certainly, it is difficult to obtain the moisture-proof effect by itself, but when the coating amount of the moisture-proof layer is relatively large, the synthetic resin as a binder gathers at the interface between the coating layer formed on it and the moisture-proof layer. It can be said that this is not only a function of substantially filling the surface defects formed on the moisture-proof layer, but also a more preferable configuration when another function such as anti-slip property is formed on the coating layer.

The inorganic pigments used in the coating layer include kaolin, talc, clay, deckite, nacrite, aluminum hydroxide, calcined kaolin, calcium carbonate,
Barium sulfate, amorphous silica, titanium oxide, zinc oxide,
For example, pigments for general coated paper and inorganic layered compounds used for the following moisture-proof layer, so-called flat pigments, can also be used. Among them, mica group minerals such as muscovite, phlogopite and sericite are particularly preferred.

As the inorganic pigment used in the undercoat layer, kaolin, talc, clay, deckite,
Pigments for general coated papers such as naclite, aluminum hydroxide, calcined kaolin, calcium carbonate, barium sulfate, amorphous silica, titanium oxide, zinc oxide, etc. can be used.These binders include starch, casein ,
Water-soluble or water-dispersible synthetic resins such as polyvinyl alcohol, SBR latex, and acrylic emulsion can be used. Using these materials, the pigment is 50 to 9
A large amount of about 0% by weight increases the amount of coating to sufficiently cover the surface of the paper support,
A barrier layer that is hardly permeated can be formed at a concentration of 00% by weight.

The preferable average particle size of the inorganic pigment used in the coating layer or the undercoat layer is 0.1 to 50.
μm. In this case, particularly in the coating layer, the spacer particles to be blended need to sufficiently project from the plane of the coating layer, so that the average particle diameter of the pigment contained in the coating layer is larger than that of the spacer particles. Must be small enough. Therefore, if the average particle size of the inorganic pigment exceeds 50 μm, not only is the choice of spacer particles limited, but the spacer effect itself is undesirably weakened. However, for example, when a tabular pigment having an average particle size exceeding the above range, such as mica, is added to the coating layer, the pigment is applied to the coating layer plane by the average particle size measured for its high flatness. This is not necessarily the case, since the spacer particles are blended in such a state that only the thickness of the tabular pigment is buried in the coating layer without protruding.

The above materials are mixed to prepare a paint for use in the coating layer. At this time, if necessary, a dispersant such as polycarboxylic acid, an antifoaming agent, a surfactant, a water retention agent, various water-soluble Resins, color adjusting agents and the like can be added.

The tabular pigment used in the moisture-proof layer of the present invention is
It is a substantially flat crystalline material having an average particle diameter of several μm or more, and has an average particle diameter of 1 μm measured by a laser diffraction method.
２００200 μm. Among them, 3 μm to 100
μm is suitable, and more preferably 5 μm to 50 μm
It is. Particularly effective particle size for moisture-proof is 10 μm to 40 μm
m. When the particle size is less than 1 μm, the orientation of the tabular pigment in the coating layer is hardly parallel to the support, so that the moisture-proof effect is poor, and when it exceeds 200 μm, a part of the tabular pigment is coated. It is presumed that the effect of improving the moisture-proof performance is reduced because the number of layers of the oriented flat pigment decreases in the coating layer as it protrudes from the layer or the thickness of the flat pigment becomes about several μm.

The method for measuring the particle size of the tabular pigment includes a method for obtaining an average particle size by a microtrack laser diffraction method or a micro sieve mesh sieve method, and a method for obtaining the average particle size by observation with an electron microscope. Although there is a difference in the numerical value of the particle size depending on the measurement method, the microsieve sieve method and the electron microscope are close to the actual particle size, and the microtrack laser diffraction method has a slightly larger value than the actual value. However, the average particle size of the present invention was measured by a microtrack laser diffraction method because of the ease of measurement and the high reproducibility. In the present invention, the aspect ratio is obtained by dividing the average particle diameter of the tabular pigment by the thickness. In order to exhibit the effect of the present invention, the aspect ratio is preferably 5 or more. Particularly preferred are flat pigments having an aspect ratio of 10 or more. Those having an aspect ratio of less than 5 may be inferior in moisture-proof performance because they cannot be oriented in parallel to the coating surface,
As the aspect ratio increases, the number of layers in the coating layer of the tabular pigment increases, so that high moisture-proof performance is exhibited.

The thickness of the tabular pigment for calculating the aspect ratio was measured by observation with an electron microscope. The thickness of the tabular pigment varies depending on the type of the pigment, the pulverization method, and the average particle size. If the pigment type and the pulverization method are the same, the thickness increases as the average particle diameter of the pigment increases, and as a result, the aspect ratio hardly changes. Although the thickness can be reduced by pulverization, it is unavoidable that the particle diameter is simultaneously reduced in any pulverization method. For example, wet-pulverized muscovite having an average particle diameter of 40 μm has an average thickness of about 2 μm and an aspect ratio of 20. When wet pulverized to an average particle diameter of 20 μm, the thickness was about 1 μm and the aspect ratio was 20. Of course, even if the average particle diameter is 20 μm, it has a particle size distribution of about 2 to 60 μm, and the thickness also ranges from 0.1 μm to several μm, but is 1 μm on average.

When a tabular pigment having such a shape is used in the moisture-proof layer of the present invention, if the particle diameter is too small relative to the thickness of the coating layer, the pigment in the coating layer will Therefore, the number of particles oriented in parallel decreases, and as a result, it becomes necessary to increase the coating amount. Therefore, according to the study of the present inventors, it is preferable to use a tabular pigment having an average particle diameter of 20% or more with respect to the thickness of the coating layer after drying.
On the other hand, a tabular pigment having an average particle diameter of 200% or more with respect to the thickness of the coating layer may have a portion protruding from the coating layer during coating or forming voids in the coating layer during bending. It is not preferred and should be used in small quantities, if any.

The tabular pigment used in the present invention retains tabularity (tabular shape) even after coating, and has an aspect ratio (a value obtained by dividing the average particle diameter by the thickness) of the tabular pigment. Is not particularly limited as long as it is 5 or more, and among the plate-like pigments satisfying this condition, in particular, phyllosilicate compounds (layer silicate compounds having a layer structure)
It is preferred that Those belonging to the phyllosilicate compounds are plate-like or flaky and have distinct cleavages, and include kaolinite (kaolin mineral), mica, brittle mica, pyrophyllite, talc, smectite, vermiculite, chlorite, Septe chlorite, serpentine, stilp-no-melane, montmorillonite, etc. Of these, mica and talc are particularly preferred. Mica tribe includes muscovite (muscovite), sericite (sericite), biotite (flokopite), biotite (biotite), fluorophlogopite (artificial mica), red mica, soda mica, vanadin mica, illite, Chin mica, paragonite, brittle mica and the like.

Among these, as the most preferred tabular pigments, muscovite, phlogopite and sericite are preferred in view of the particle size, aspect ratio, cost and the like. If these pigments are described in more detail, the raw ore of mica powder is dry-pulverized with a hammer mill or the like and then classified to use a portion having a desired particle size distribution, or a sand mill or the like using glass beads as a pulverizing medium in water. Perform wet grinding to obtain mica having a desired particle size distribution. At this time, it is possible to obtain a mica powder having a high aspect ratio by taking measures such as pulverization so as not to apply an excessive force to maintain the aspect ratio or wet pulverization while applying ultrasonic waves (US Pat. No. 3,240,203). Can be. Usually, the aspect ratio obtained by these methods is 20 to 30 according to observation with an electron microscope. Although a part having an aspect ratio of about 100 can be obtained, industrial production is difficult and costs increase.

Sericite, which is referred to as sericite with respect to mica, has a similar chemical composition, ie, SiO ₂ / Al ₂ O ₃
Is slightly large and the content of K ₂ O is small. However, sericite has a finer ore compared to muscovite, so that sericite generally has an average particle size of 0.5 to
It is about 2 μm, and most of those commercially available fall within these ranges. Therefore, it is necessary to use sericite having a specific large particle size distribution in order to carry out the present invention. Classifying from
It is necessary to use a particle size distribution that has passed the required size mesh. Such sericite can obtain almost the same aspect ratio as muscovite, and the aspect ratio is 10 to 10.
Thirty are common.

As described above, the size of the raw mica is very large as compared with sericite and talc, and the particle size distribution can be freely selected by pulverizing and classifying. On the other hand, gemstones of sericite are small, but have high cleavage properties, and the pulverized material is preferably flat, like mica.

The synthetic resin used to form a layer of these flat pigments on a support must basically prevent the permeation of water vapor. 20g of various synthetic resins on kraft paper
When the water vapor transmission rate when m ^{2 was} applied was measured, the water vapor transmission rate showed a value of about 300 g / m ² · 24 hr, 800
g / m ² · 24 hr, 20
It can be roughly classified into those showing a value of 00 g / m ² · 24 hr or more. Here, the moisture permeability of the synthetic resin used in the present invention needs to be 500 g / m ² · 24 hr or less, more preferably 250 g / m ² · 24 hr or less by the same measuring method. Of course, as long as the effects of the present invention are not impaired, a latex having a moisture permeability of 500 g / m ² · 24 hr or more may be mixed and used.

Examples of the synthetic resin used in the moisture-proof layer of the present invention include styrene butadiene (SBR), acrylic styrene, methacrylate butadiene, acrylonitrile butadiene, polyester, polyurethane and the like, but they have good water resistance and good elongation. SBR is preferred because the coating layer is less likely to crack due to breaking. Here, the polymerizable monomer is mainly composed of styrene and 1,3-butadiene, but other monomers copolymerizable with styrene and 1,3-butadiene are used within a range not to impair the object of the present invention. be able to. Other monomers copolymerizable with styrene and 1,3-butadiene include aromatic vinyl monomers, (meth) acrylate monomers, cyano group-containing ethylenically unsaturated monomers, and ethylenic monomers. Examples thereof include glycidyl esters of unsaturated acids, glycidyl ethers of unsaturated alcohols, and (meth) acrylamide monomers. These polymerizable monomers can be used alone or in combination of two or more.

The glass transition temperature (Tg) of the synthetic resin
And the amount of gel (the remaining amount extracted with an organic solvent such as tetrahydrofuran, etc .; mainly composed of a polymer component having a molecular weight of several hundred thousand) is easy to block the coating layer (adhesion between the coated surface and the surface of the package) and the film forming property. Affect. When a resin having a low Tg and a low gel amount is used, blocking tends to occur, but film formability is improved. Conversely, when a resin having a high Tg and a high gel content is used, blocking becomes difficult, but the film formability is reduced. Usually, the range of Tg is −30 ° C. to 50 ° C., preferably −15 ° C. to 30 ° C., and the range of the gel amount is 30% to 95%.
%, Preferably in the range of 60% to 90%, the Tg and the gel amount are determined by the balance between the film forming property and the blocking. In the present invention, the resin used for the moisture-proof layer may be one that emphasizes film-forming properties, since the coating layer can be made less likely to cause blocking.

The mixing ratio of these tabular pigments and synthetic resin is preferably in the range of 30/70 to 70/30 by weight. When the content of the tabular substance is less than 30% by weight, the number of layers formed by the tabular pigment becomes small, or the distance between the pigments is too large, so that the moisture-proof property becomes insufficient, and it becomes necessary to increase the coating amount, which is not economical. In addition, blocking tends to occur. On the other hand, if the content exceeds 70% by weight, the voids between the tabular pigment and the latex in the coating layer become so large that the moisture resistance deteriorates.

In the present invention, when a coupling agent is used in the moisture-proof layer, the moisture-proof property is further improved. Examples of the coupling agent to be used include a silane coupling agent containing Si in a hydrophilic portion, a titanate coupling agent containing Ti in a hydrophilic portion, and an aluminum coupling agent containing Al in a hydrophilic portion. The structure of the coupling agent is roughly divided into a hydrophilic group that interacts with an inorganic compound such as a phyllosilicate compound, and a hydrophobic group that interacts with an organic compound such as a resin. And the like, and are obtained by hydrolyzing an alkoxy group bonded to a metal element such as Si or Si.

On the other hand, as for the hydrophobic group of the coupling agent, when the hydrophobic group is an organic oligomer, a high molecular organic film is formed on the surface of the inorganic compound and the surface is completely hydrophobized to adhere to the resin matrix. It has the effect of enhancing the nature. Further, when the hydrophobic group has a reactive organic functional group such as an epoxy group, a vinyl group, and an amino group, the functional group and the reactive functional group of the resin matrix are cross-linked, and the adhesiveness with the resin matrix is further increased. . The coupling agent includes γ-glycidoxypropyltrimethoxysilane, γ
-(2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, methyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, vinyl Examples include acetoxysilane, γ-chloropropyltrimethoxysilane, γ-anilinopropyltrimethoxysilane, and isopropyltri (N-aminoethylaminoethyl) titanate.

In the present invention, it is further desirable that the phyllosilicate compound is subjected to a surface treatment by an integral blend method, a pretreatment method, or the like with such a coupling agent before use. The integral blending method is a method in which a coupling agent is directly added to a coating solution containing a phyllosilicate compound and a synthetic resin. The pretreatment method is a method in which the surface of a phyllosilicate compound is treated in advance with a coupling agent. The addition amount of the coupling agent is 0.1 to 5 parts by weight, preferably 0.5 to 2 parts by weight based on 100 parts by weight of the phyllosilicate compound. If the amount is less than 0.1 part by weight, the surface of the phyllosilicate compound is not sufficiently coated with the coupling agent, which is not preferable. If the amount exceeds 5 parts by weight, the effect of the coupling agent will level off. Economy.

In the present invention, the moisture-proof property can be improved by adding an active hydrogen-reactive compound to the moisture-proof layer. The active hydrogen reactive compound used in the present invention reacts with an active hydrogen functional group such as a carboxyl group, an amide group or a hydroxyl group contained in the synthetic resin to crosslink the synthetic resin latex to polymerize (three-dimensional network structure). Things.

Examples of such active hydrogen-reactive compounds include (1) those having a methylol group and causing a dehydration condensation reaction with the hydrophilic functional group (melamine-formaldehyde resin, urea-formaldehyde resin, etc.); (2) aldehyde group Having an epoxy group and causing an addition reaction with the hydrophilic functional group (such as glyoxal); (3) having an epoxy group,
(4) Those which cause a ring-opening addition reaction with the above-mentioned hydrophilic functional group (eg, polyglycidyl ether); (4) Those which have a polyvalent metal and form a coordination bond and a covalent bond with the above-mentioned hydrophilic functional group (eg, zirconium carbonate) (5) those which show cationicity in an aqueous solution and form an ionic bond with an anionic functional group (cationic resins such as polyamine compounds, polyamideamine resins and polyamide epichlororesins).

The amount of the active hydrogen-reactive compound is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, per 100 parts by weight of the synthetic resin latex. When the amount of the active hydrogen-reactive compound is less than 0.01 part by weight, the reactivity between the active hydrogen-reactive compound and the active hydrogen functional group is remarkably reduced. This is not preferred because problems such as the effect on the anti-blocking property and the blocking resistance leveling out or the unreacted active hydrogen-reactive compound being precipitated occur.

The moisture-proof paint is prepared by dispersing a plate-like pigment in water and mixing it with a synthetic resin emulsion or a synthetic resin solubilized with alkaline water or a solvent, or in a synthetic resin emulsion or a synthetic resin solubilized with alkaline water or a solvent. The pigment is dispersed therein and adjusted to a predetermined solid content to obtain a paint.

[0050] In the present invention, the coating amount of the moisture barrier layer is preferably 5 to 25 g / m ^2, more preferably 10 to 20 g / m ^2. Coating amount when providing a coating layer is 1 to 15 g
/ M ² , preferably 3 to 8 g / m ² . The coating amount of the case where the undercoat layer is preferably from 1 to 25 g / m ^2, more preferably 5 to 20 g / m ^2. In the present invention, when the coating amount of the moisture-proof layer is small, it is naturally better to increase the coating amount of the coating layer. Conversely, when the coating amount of the moisture-proof layer is large, it is preferable to reduce the coating layer. When the moisture-proof layer and the coating layer are formed only on one side, it is preferable to apply water on the opposite side of the coated side to prevent curling.

The coating equipment for forming the moisture-proof layer, the coating layer and the undercoat layer is not particularly limited, but may be an air knife coater, bar coater, roll coater, blade coater, gate roll coater, gravure coater, curtain coater, slide coater. , Comma coater,
It can be arbitrarily selected from a die coater or the like. Particularly in the case of forming a moisture-proof layer, a blade coater, a bar coater,
A coating method such as an air knife coater that scrapes the coating surface is preferable because it tends to promote the orientation of the tabular pigment. Among them, a blade coater is particularly preferable because its high-speed coating is possible.

As the support, fine paper made of pulp selected from chemical pulp such as hardwood kraft pulp and softwood kraft pulp, mechanical pulp, etc. may be used as a support that is easily dispersed in water by mechanical disaggregation. Examples include medium-quality paper, single-gloss kraft paper, Ryoso kraft paper, kraft stretch paper, and the like. There is no particular limitation on the basis weight of these base papers, and those having a basis weight of 30 to 300 g / m ² are appropriately selected and used according to the purpose.

Since the coating layer of the present invention does not contain waxes, the coating surface as well as the opposite surface of the coating surface is not slippery because the waxes have not been transferred. Even when the moisture-proof paper is folded, resistance to the thickness of the entire layer is small, so that the moisture permeability at the time of folding is small. In addition, since the surface does not have a releasability like waxes, it does not fall off even when a label using a general-purpose glue is attached. Furthermore, hot-melt adhesives mainly composed of polyvinyl alcohol resin are preferably dispersible with water, so it is preferable to use such adhesives. However, since this moisture-proof paper does not use waxes, it is used in normal open time. can do. Of course, generally used hot melt adhesives such as synthetic rubbers and ethylene vinyl acetate can be used without any problem.

Since the moisture-proof laminate of the present invention uses a large amount of synthetic resin having good film-forming properties, it is natural to assume that there is a concern about the re-disintegration property. However, surprisingly, when having a tabular pigment having a large particle size as in the present invention, when the water slurry is stirred in the re-disaggregation step after recovery of waste paper, the tabular pigment becomes a starting point of breakage due to mechanical force. Collapses easily,
The coating layer of the synthetic resin film as well as the coating layer is broken and decomposed into extremely small pieces, which can be considered to be almost re-disintegrated.
That is, when the polylaminate paper laminated with polyethylene is defibrated, coarse flakes remain, whereas when the present moisture-proof laminated body is defibrated, the flakes can be defibrated to a state where no coarse flakes are recognized.

[0055]

EXAMPLES The present invention will be specifically described below with reference to examples, but the following examples do not limit the present invention. Further, “parts” in the examples all indicate weight-based values converted into solid contents or active ingredients. Tables 1 and 2 show the main composition and the like.

Example 1 100 parts of phlogopite (average particle diameter 40 μm, aspect ratio 30 to 40) and 100 parts of water were used as a tabular pigment in a Cowles disperser at a rotation speed of 200.
Dispersed at 0 rpm for 2 hours. The obtained pigment slurry
For 50 parts and 25 parts of SBR latex (Tg 20 ° C., gel fraction 84%, solid content concentration 50%), 0.5 part of ammonia and polyamide polyurea-formaldehyde condensation reaction product (trade name: SR302, Sumitomo 0.5 parts (Chemical Co., Ltd., solid content concentration: 60%) were mixed and stirred to prepare a moisture-proof coating. The coating amount of this paint on unbleached kraft paper using a blade is 15 g / m ² (solid content).
After hand-coating so that
After drying at 10 ° C. for 1 minute, a moisture-proof layer was formed. Then
To 100 parts of the same SBR latex used for the moisture-proof layer, 10 parts of polyethylene particles (average particle diameter: 18 μm, solid content concentration: 40%) were mixed and stirred as spacer particles to prepare a paint to be used for the coating layer. . The paint was hand-coated on the moisture-proof layer using a Mayer bar so that the coating amount was 6 g / m ² (solid content), and dried at 110 ° C. for 1 minute using a hot-air circulating drier to coat the coating. A layer was formed to obtain the desired moisture-proof laminate. Using the obtained moisture-proof laminate, measurement of moisture permeability and evaluation of scratches were performed. The results are shown in Table 3 or 4. (The same applies hereinafter.)

Evaluation Method of Moisture Permeability The moisture permeability was measured by a method based on the JIS-Z-0208B method (cup method) such that the coated surface was on the high humidity side. The preferred moisture permeability range in the present invention is 40 ° C., 9 ° C.
0 to 50 g / m ² · 24 hr in an environment of 0% RH
It is. In this case, those having a moisture permeability exceeding the upper limit value are not very useful because the practicality as a moisture-proof laminate targeted by the present invention is poor.

Evaluation method of abrasion The moisture-proof laminate was placed on a flat surface of a stainless steel weight (a rectangular parallelepiped of 10 cm × 10 cm × 2 cm, load: 2 kg).
It is applied in a size of 10 cm × 10 cm with the coated surface facing up. This weight is then placed on white coated paper,
It is placed so that the coated surface of the attached moisture-proof laminate and the coated surface of the coated paper are in contact with each other. In this state, the weight was rubbed back and forth on the coated paper 10 times with a span of 10 cm, and the occurrence of scratches and uneven gloss on the surface of the coated paper was visually evaluated in the rubbed area (the occurrence of scratches and uneven gloss:
X, slight occurrence of scratches / gloss unevenness: Δ, no scratch / gloss unevenness: ○). In the present invention, it is assumed that the evaluation up to Δ is a practical level.

Example 2 Kaolin (average particle size 9 μm)
m) 100 parts of water and 100 parts of water were sufficiently dispersed using a Cowles disperser, and 50 parts of pigment slurry and 50 parts of the same SBR latex used for the moisture-proof layer were mixed with polyethylene particles as spacer particles (average). Particle size 18μ
m) A desired moisture-proof laminate was obtained in the same manner as in Example 1 except that 10 parts were mixed and stirred to prepare a coating material used for the coating layer.

<Example 3> In the paint used for the coating layer, the synthetic resin used was changed from SBR latex to acrylic styrene emulsion (Tg 20 ° C, gel fraction 70%,
A target moisture-proof laminate was obtained in the same manner as in Example 2 except that the solid content concentration was changed to 47%.

Example 4 A desired moisture-proof laminate was obtained in the same manner as in Example 2, except that the amount of polyethylene particles (average particle diameter 18 μm) to be added as spacer particles was changed to 2 parts.

Example 5 A moisture-proof laminate was obtained in the same manner as in Example 2, except that the amount of polyethylene particles (average particle diameter: 18 μm) added as spacer particles was 0.5 part.

Example 6 Example 2 was performed except that the coating amount of the coating layer provided on the moisture-proof layer was 3 g / m ² (solid content).
In the same manner as in the above, an intended moisture-proof laminate was obtained.

Example 7 100 parts of aluminum hydroxide (average particle size: 12 μm) and 100 parts of water were sufficiently dispersed using a Cowles disperser, and 50 parts of a pigment slurry and the same as those used in the moisture-proof layer The desired moisture proofing was performed in the same manner as in Example 1 except that 10 parts of polyethylene particles (average particle diameter: 18 μm) were mixed and stirred with 50 parts of the SBR latex to prepare a paint used for the coating layer. A laminate was obtained.

Example 8 An intended moisture-proof laminate was obtained in the same manner as in Example 2 except that the spacer particles used in the coating material used for the coating layer were potato starch (average particle diameter 43 μm).

Example 9 A desired moisture-proof laminate was obtained in the same manner as in Example 2 except that the spacer particles used in the coating material used for the coating layer were polystyrene particles (average particle size: 55 μm).

Example 10 A moisture-proof laminate was obtained in the same manner as in Example 2, except that the spacer particles used in the coating material used for the coating layer were polyethylene particles (average particle size: 8 μm).

Example 11 A moisture-proof laminate was obtained in the same manner as in Example 2, except that the spacer particles used in the coating material used for the coating layer were polystyrene particles (average particle size: 120 μm).

<Example 12> Pigment slurry in which 100 parts of calcium carbonate (average particle diameter 27 μm) and 100 parts of water were sufficiently dispersed using a Cowles disperser, and 50 parts of a pigment slurry, and the same as those used for the moisture-proof layer A desired moisture-proof laminate was prepared in the same manner as in Example 1 except that 10 parts of potato starch (average particle diameter: 43 μm) as spacer particles was mixed and stirred with 50 parts of SBR latex to prepare a coating material used for the coating layer. I got a body.

Example 13 The coating amount of the moisture-proof layer provided on unbleached kraft paper was 12 g / m ² (solid content), and the coating amount of the coating layer provided on the moisture-proof layer was 8 g / m ^2. A desired moisture-proof laminate was obtained in the same manner as in Example 2 except that the solid content was changed.

Example 14 In the moisture-proof paint used for the moisture-proof layer, the synthetic resin used was changed from SBR latex to acrylic styrene emulsion (Tg 20 ° C., gel fraction 7).
(0%, solid content concentration 47%) in the same manner as in Example 2 except that the target moisture-proof laminate was obtained.

Example 15 Muscovite (average particle diameter 20 μm, aspect ratio 20 to 30) 10 as a tabular pigment
0 parts and 100 parts of water were sufficiently dispersed using a Cowles disperser to obtain 50 parts of a pigment slurry and SBR latex (Tg: 20 ° C., gel fraction: 84%, solid content: 50%).
%) 50 parts of ammonia and 0.5 part of an aminosilane coupling agent (trade name: KBM603, manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed and stirred to prepare a moisture-proof paint. In the same manner as in Example 2, a target moisture-proof laminate was obtained.

Example 16 Sericite (average particle size: 14 μm, aspect ratio: 10 to 20) 10 as a tabular pigment
0 parts and 100 parts of water were sufficiently dispersed using a Cowles disperser to obtain 50 parts of a pigment slurry and SBR latex (Tg: 20 ° C., gel fraction: 84%, solid content: 50%).
%) 50 parts of ammonia and 0.5 part of an aminosilane coupling agent (trade name: KBM603, manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed and stirred to prepare a moisture-proof paint. In the same manner as in Example 2, a target moisture-proof laminate was obtained.

Example 17 Clay (average particle size 5 μm)
m) 50 parts of pigment slurry in which 100 parts of water and 100 parts of water are sufficiently dispersed using a Cowles disperser, and 5 parts of gelatinized starch (solid content concentration: 20%) are mixed and stirred to be used as a coating material for an undercoat layer. After hand-coating the unbleached kraft paper with a blade so as to have a coating amount of 10 g / m ² (solid content), use a hot air circulating drier to prepare 110 g / m ² (solid content).
The obtained moisture-proof laminate was obtained in the same manner as in Example 2 except that the coating was dried at a temperature of 1 ° C. for 1 minute and an undercoat layer was previously formed.

Example 18 Phlogopite (average particle diameter 40 μm, aspect ratio 30 to 40) as a tabular pigment 10
0 parts and 100 parts of water using a Cowles disperser, and a rotation speed of 2 parts.
2,000 rpm for 2 hours. 100 parts of the obtained pigment slurry and SBR latex (Tg 20 ° C,
For 50 parts of a gel fraction of 84% and a solid content of 50%), 1.0 part of ammonia and a polyamide polyurea-formaldehyde condensation reaction product (trade name: SR302, manufactured by Sumitomo Chemical Co., Ltd., solid content concentration of 60) %) And polystyrene particles (average particle diameter 55
10 μm) to prepare a moisture-proof paint.
This coating material was applied to an undercoated unbleached kraft paper obtained in the same manner as in Example 17 by using a blade with a coating amount of 1
After hand-coating to 5 g / m ² (solid content), it was dried at 110 ° C. for 1 minute using a hot-air circulating drier to form a moisture-proof layer, thereby obtaining a desired moisture-proof laminate.

Comparative Example 1 A moisture-proof laminate was obtained in the same manner as in Example 1 except that no coating layer was provided.

Comparative Example 2 A moisture-proof laminate was obtained in the same manner as in Example 12 except that no coating layer was provided.

Comparative Example 3 A moisture-proof laminate was obtained in the same manner as in Example 2 except that no spacer particles were used in the coating layer.

Comparative Example 4 A moisture-proof laminate was obtained in the same manner as in Example 3 except that no spacer particles were used in the coating layer.

Comparative Example 5 A moisture-proof laminate was obtained in the same manner as in Example 17 except that no coating layer was provided.

[0081]

[Table 1]

[0082]

[Table 2]

[0083]

[Table 3]

[0084]

[Table 4]

As is clear from Tables 3 and 4, by adopting the composition and layer constitution according to the present invention, it is possible to obtain a moisture-proof laminate excellent in moisture-proof performance and free from scratches and abrasions. (Examples 1 to 18). However, in a configuration in which the layer containing the spacer particles is not provided on the outermost surface of the moisture-proof laminate, not only is the moisture-proof performance inferior (when there is no undercoat layer), but also rubbing due to the influence of the plate-like pigment in the moisture-proof layer. There is a possibility that scratches and uneven gloss may occur (Comparative Examples 1 to 5).

[0086]

According to the present invention, on at least one side of the paper support, a moisture-proof layer composed of a tabular pigment and a synthetic resin, then a coating layer composed of spacer particles and a synthetic resin, and if necessary, an undercoat layer beneath the moisture-proof layer. When used as wrapping paper in a moisture-proof laminated body that is sequentially laminated with, there is no fear of scratching the inclusions, and since no wax component is used,
An effect of providing a moisture-proof laminate that does not cause poor adhesion of a slip or a hot-melt adhesive and that can be collected as used paper is provided.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) D21H 21/50 D21H 21/50 A F-term (Reference) 4F100 AC05B AK01B AK04B AK04H AK73B BA02 BA10A BA10B CA13B CC00B DD03B DE02B DE02H DG10A JD04B JK12B JK12H JK16 JL00 JL02 YY00B YY00H 4L055 AG17 AG25 AG27 AG47 AG59 AG63 AG71 AG76 AG94 AG97 AH02 AH23 AH37 AJ04 BE09 EA16 EA27 EA32 FA11 FA19 FA30

Claims (7)

[Claims] 1. A moisture-proof layer comprising a paper substrate, a moisture-proof layer made of a flat pigment and a synthetic resin formed on at least one side of the paper support, and a coating layer containing a synthetic resin film component provided on the moisture-proof layer. A moisture-proof laminate, characterized in that the layer comprises spacer particles projecting relative to the plane of the coating layer. 2. An undercoat layer is formed on at least one side of a paper support, and a moisture-proof layer comprising a flat pigment and a synthetic resin is formed thereon.
And a moisture-proof laminate provided with a coating layer sequentially, wherein the coating layer contains spacer particles protruding from the plane of the coating layer. 3. A moisture-proof laminate in which an undercoat layer is formed on at least one surface of a paper support and a moisture-proof layer comprising a flat pigment and a synthetic resin is formed thereon, wherein the moisture-proof layer protrudes from the plane of the moisture-proof layer. A moisture-proof laminate comprising such spacer particles. 4. The spacer particles have an average particle size of 10 to 1.
4. The method according to claim 1, wherein the thickness is 00 μm.
The moisture-proof scoring body as described. 5. The moisture-proof according to claim 1, wherein the coating layer or the moisture-proof layer contains 1 to 20 parts by weight of the spacer particles based on 100 parts by weight of the total solid content of the layer. Grade body. 6. The moisture-proof laminate according to claim 1, wherein said spacer particles have a Mohs hardness of 3 or less. 7. The moisture-proof laminate according to claim 1, wherein the spacer particles are an organic polymer.