Base paper for vapor deposition, packaging material, and manufacturing method of vapor deposition paper

Abstract

To provide base paper for vapor deposition having excellent water resistance and capable of exhibiting excellent barrier property after vapor deposition processing, a packaging material including this base paper for vapor deposition, and a manufacturing method of vapor deposition paper including this base paper for vapor deposition.SOLUTION: The base paper for vapor deposition includes a filler layer including a water dispersible resin as a main component and a primer layer in this order at least on one face of a paper substrate. A packaging material includes vapor deposition paper having a vapor deposition layer on the primer layer of the base paper for vapor deposition and a heat-sealable resin layer laminated on at least one face of the vapor deposition paper. A manufacturing method of vapor deposition paper includes the steps of: coating a filler layer including a water dispersible resin as a main component at least on one face of a paper substrate; forming a primer layer using an aqueous coating on the filler layer; and forming a vapor deposition layer by vacuum deposition method on the primer layer.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a base paper for metallization. [Background technology]

[0002] Conventionally, metallized paper, which is a paper substrate that has been subjected to a metallization process, has been used for barrier applications. Since the paper substrate is inferior in smoothness compared to plastic films, a resin layer is provided on the paper substrate in order to form a homogeneous metallized layer. Since a large amount of coating is required to directly form a resin layer with a smooth surface on the paper substrate, a filler layer is generally provided between the paper substrate and the resin layer. For example, Patent Document 1 proposes an invention of an aluminum metallized paper having, in this order, a base base paper, a barrier layer (corresponding to a filler layer) made of a polyvinyl alcohol-based resin, an anchor coat layer (corresponding to a resin layer), and an aluminum metallized layer. Patent Document 2 proposes an invention of a base paper for metallized paper having, in this order, a paper substrate, a clay coat layer (corresponding to a filler layer) containing an inorganic pigment and a binder, and a resin layer.

[0003] In the filling layer of the base paper for deposition, binder resins such as polyvinyl alcohol resins, styrene-butadiene resins, styrene-(meth)acrylic resins, and olefin-unsaturated carboxylic acid copolymers, and inorganic pigments are generally used. However, the resins and inorganic pigments generally used in the filling layer have poor water resistance, and the filling layer cannot stop the moisture that penetrates from the paper base surface on the opposite side to the aluminum deposition layer, which reduces the barrier properties of aluminum, which is weak against water. On the other hand, resins with high water resistance tend to repel water, so they tend to repel the paint for forming the resin layer that is applied on the filling layer, making it difficult to apply the paint uniformly, and there is a problem that uneven coating can easily cause variations in the barrier performance within the surface. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 3-120600 [Patent Document 2] JP 2002-104487 A Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a deposition base paper that has excellent water resistance and is capable of exhibiting excellent barrier properties after deposition processing. [Means for solving the problem]

[0006] The means for solving the problems of the present invention are as follows. 1. A paper substrate having a sealing layer mainly composed of a water-dispersible resin on at least one surface thereof, The surface water absorption (Cobb 120 seconds) of the filling layer is 12 g / m 2 and the pure water contact angle (after 5 seconds) is 70° or more and 95° or less, A base paper for deposition, characterized in that it has a primer layer on the filling layer. 2. The coating amount of the filling layer is 1 g / m 2 1. The base paper for deposition according to 1., characterized in that: 3. The deposition base paper according to 1 or 2, wherein the filling layer contains calcium carbonate. 4. The base paper for deposition according to any one of 1. to 3., wherein the primer layer contains a polyurethane resin as a main component. Effect of the Invention

[0007] The metallization base paper of the present invention has excellent water resistance. Metallization paper obtained by subjecting the metallization base paper of the present invention to metallization processing has excellent barrier properties and can maintain high barrier properties even under high humidity conditions. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The base paper for deposition of the present invention has a filler layer mainly composed of a water-dispersible resin on at least one surface of a paper substrate, and the filler layer has a water absorbency (Cobb 120 seconds) of 12 g / m 2 or less, and the pure water contact angle (after 5 seconds) is 70° or more and 95° or less, and a primer layer is provided on this filling layer. In the present invention, the term "main component" means that the component accounts for 50% by mass or more on a dry weight basis.

[0009] (Paper base material) In the present invention, the paper base material is a sheet made of pulp, filler, and various auxiliary agents. The pulp may be selected from chemical pulps such as bleached hardwood kraft pulp (LBKP), bleached softwood kraft pulp (NBKP), unbleached hardwood kraft pulp (LUKP), unbleached softwood pulp (NUKP), sulfite pulp, and other mechanical pulps, wood fibers such as deinked pulp and recycled paper pulp, and non-wood fibers obtained from kenaf, bamboo, hemp, and other materials, which may be used in appropriate combinations. Among these, it is preferable to use chemical pulp or mechanical pulp made of wood fiber, and it is more preferable to use chemical pulp made of wood fiber, because it is difficult for foreign matter to be mixed into the paper base material, it has a high whiteness, and therefore the surface texture during printing is good, and it is particularly useful when used as a packaging material.

[0010] As the filler, known fillers such as white carbon, talc, kaolin, clay, heavy calcium carbonate, light calcium carbonate, titanium oxide, zeolite, synthetic resin filler, etc. Also, aluminum sulfate and various anionic, cationic, nonionic or amphoteric retention improvers, drainage improvers, paper strength enhancers, internal sizing agents, etc. may be used as necessary. Furthermore, dyes, fluorescent whitening agents, pH adjusters, defoamers, pitch control agents, slime control agents, etc. may also be added as necessary.

[0011] The method for producing the paper base material (papermaking) is not particularly limited, and the paper base material can be produced by acidic papermaking, neutral papermaking, or alkaline papermaking using a known Fourdrinier former, on-top hybrid former, gap former machine, etc. The paper base material may be one layer, or may be composed of two or more layers.

[0012] Furthermore, the surface of the paper substrate can be treated with various chemicals. Examples of chemicals that can be used include oxidized starch, hydroxyethyl etherified starch, enzyme-modified starch, polyacrylamide, polyvinyl alcohol, surface sizing agents, water-resistant agents, water retention agents, thickeners, and lubricants, and these can be used alone or in combination of two or more. Furthermore, these various chemicals can be used in combination with pigments. Examples of pigments include inorganic pigments such as kaolin, clay, engineered kaolin, delaminated clay, heavy calcium carbonate, light calcium carbonate, mica, talc, titanium dioxide, barium sulfate, calcium sulfate, zinc oxide, silicic acid, silicate salts, colloidal silica, and satin white, and organic pigments such as solid, hollow, or core-shell types can be used alone or in combination of two or more.

[0013] The method for treating the surface of the paper substrate is not particularly limited, but known coating devices such as a rod metering size press, a pond type size press, a gate roll coater, a spray coater, a blade coater, and a curtain coater can be used.

[0014] The basis weight of the paper substrate can be appropriately selected depending on the desired qualities and handling properties of the base paper for metallization or the metallized paper, but is usually 20 g / m 2 More than 500g / m 2 For metallized paper used for packaging purposes such as food packaging, containers, cups, etc., the thickness should be 25 g / m 2 More than 400g / m 2 The following is more preferable, and in particular for metallized paper used for soft packaging applications described later, it is 30 g / m 2 More than 110g / m 2The following is more preferred:

[0015] (Sealing layer) The filling layer is provided by coating on at least one surface of the paper base material. Whether or not the layer is a coating layer provided by coating can be determined by cross-sectional observation or the like. The filling layer is mainly composed of water-dispersible resin, and its surface water absorption (Cobb 120 seconds) is 12 g / m 2 and the pure water contact angle (after 5 seconds) is 70° or more and 95° or less.

[0016] The filling layer of the present invention is composed mainly of a water-dispersible resin, but has low hydrophilicity, and its surface water absorption (Cobb 120 seconds) is 12 g / m 2 and the pure water contact angle (after 5 seconds) is 70° or more and 95° or less. By satisfying the above-mentioned water absorbency and pure water contact angle, the filling layer of the present invention has high water resistance, can maintain high barrier properties under high humidity conditions after being processed into a metallized paper, and has excellent coating suitability when a primer layer is applied onto the filling layer. Cobb water absorbency is measured according to the Cobb method specified in JIS P8140:1998, by pouring 100 ml of distilled water onto a test area of ​​100 cm 2 The weight of water absorbed per unit area after contact with a filling layer of 100 g / m2 or more and a specified period of time. The pure water contact angle refers to the contact angle measured 5 seconds after 3.5 μL of pure water is dropped according to JIS R3257:1999 (static drop method).

[0017] The filling layer of the present invention is not particularly limited in type of water-dispersible resin as long as it satisfies the above-mentioned water absorbency and pure water contact angle, and any resin that is applied to paper can be used without any particular limitation. For example, styrene-(meth)acrylic resin, olefin-unsaturated carboxylic acid copolymer, styrene-butadiene resin, acrylic resin, ethylene-modified PVA, polyester resin, polyurethane resin, etc. can be mentioned, and one or more of these can be used. Among these, styrene-(meth)acrylic resin is preferred because it has excellent water resistance and coating suitability. The filling layer of the present invention may also contain a water-soluble resin such as polyvinyl alcohol, polyacrylic acid, or carboxymethyl cellulose within the range in which the above-mentioned water absorbency and pure water contact angle are satisfied.

[0018] The filling layer may contain a pigment. As the pigment, inorganic pigments such as kaolin, clay, engineered kaolin, delaminated clay, heavy calcium carbonate, light calcium carbonate, mica, talc, titanium dioxide, barium sulfate, calcium sulfate, zinc oxide, silicic acid, silicate salt, colloidal silica, satin white, and organic pigments such as solid, hollow, and core-shell types may be used alone or in combination of two or more. Among these, it is preferable to use calcium carbonate as the pigment. Since the hydrophilicity of the filling layer is increased (the contact angle is reduced) by blending calcium carbonate, even when a water-soluble resin or water-dispersible resin having excellent water resistance is blended, the coating suitability when applying a primer layer on the formed filling layer is excellent, and a homogeneous primer layer can be formed. The pigment is preferably one having an average particle size (D50 median size) of 1.5 μm or less, since the coating layer becomes dense and the filling property is improved. The average particle size is a value measured by a dynamic light scattering method.

[0019] When the pigment is contained in the filling layer, the blending amount of the pigment can be 0.01% by mass or more and less than 50% by mass in terms of dry weight with respect to the entire filling layer. When the pigment is calcium carbonate, the blending amount of calcium carbonate is preferably 40% by mass or less in terms of dry weight with respect to the entire filling layer. The blending amount of calcium carbonate is not particularly limited as long as it is within a range that satisfies the above-mentioned water absorbency and pure water contact angle, and can be, for example, 30% by mass or less, 25% by mass or less, 20% by mass or less, 1% by mass or more, 3% by mass or more, 5% by mass or more, 10% by mass or more, etc.

[0020] The surface water absorption of the sealing layer (Cobb 120 seconds) is 12 g / m 2 The water absorption of the surface of the sealing layer (Cobb 120 seconds) is 12 g / m 2If the water resistance of the filler layer is insufficient, the barrier properties of the metallized paper under high humidity conditions will decrease significantly. The water absorption of the filler layer surface (Cobb 120 seconds) is 10 g / m 2 Less than 8 g / m is preferable. 2 Less than 6 g / m is more preferable. 2 More preferably, 4 g / m 2 Even more preferably, 2 g / m 2 Even more preferably, 1 g / m 2 Even more preferably, 0.9 g / m 2 Even more preferably, 0.8 g / m 2 Even more preferably, 0.7 g / m 2 Even more preferred is the following:

[0021] The pure water contact angle of the surface of the filling layer (after 5 seconds) is 70° or more and 95° or less. When the pure water contact angle of the surface of the filling layer (after 5 seconds) is within the range of 70° or more and 95° or less, the coating suitability is excellent, and it is easy to form a homogeneous primer layer thereon by coating. The pure water contact angle of the surface of the filling layer (after 5 seconds) is preferably 72° or more, more preferably 74° or more, and even more preferably 76° or more, and is preferably 93° or less, more preferably 91° or less, and even more preferably 89° or less.

[0022] The filling layer may contain, in addition to the water-soluble or water-dispersible resin and the pigment, various commonly used auxiliaries such as a crosslinking agent, a dispersant, a thickener, a water retention agent, an antifoaming agent, a water-resistant agent, and a dye.

[0023] (Primer layer) The primer layer is formed on the filling layer by water-based coating. As the primer layer, those that have been used in conventional metallized paper can be used without any particular limitation, and examples thereof include water-dispersible resins such as acrylic, olefin, and polyurethane resins, and water-soluble resins such as polyvinyl alcohol, polyacrylic acid, and carboxymethyl cellulose, and one or more of these can be used. Among these, polyurethane resins are preferred because they maintain and improve the water resistance of the sealing paper and also have gas barrier properties.

[0024] (Coating) In the present invention, the coating method of the filling layer and the primer layer is not particularly limited, and they can be coated by a known coating device and coating system. For example, the coating device can be a blade coater, a bar coater, a roll coater, an air knife coater, a reverse roll coater, a curtain coater, a spray coater, a size press coater, a gate roll coater, etc. In addition, the coating system is a water-based coating, and the solvent can be a mixed solvent of water and an organic solvent such as methanol, ethanol, isopropanol, and ethyl acetate that is compatible with water. The coating layer can be dried by any of the usual methods, such as using a steam heater, a gas heater, an infrared heater, an electric heater, a hot air heater, a microwave, or a cylinder dryer.

[0025] In the present invention, it is preferable to apply the coating layer after performing a calendaring process on the filling layer. The calendaring process makes the surface of the filling layer smooth, and the smoothness of the coating layer formed thereon is also improved, making it easier to form a homogeneous vapor deposition layer. Furthermore, by improving the density of the paper, it is possible to increase the productivity and processing suitability in the subsequent processing steps. The calendaring conditions are preferably a linear pressure of 10 kg / cm or more, more preferably 30 kg / cm or more, and even more preferably 50 kg / cm or more, and also preferably 1000 kg / cm or less, more preferably 500 kg / cm or less, and even more preferably 300 kg / cm or less. When heating is performed during the calendaring process, the heating temperature is preferably 30°C or more, more preferably 40°C or more, and even more preferably 50°C or more, and also preferably 80°C or less, and more preferably 70°C or less. It is preferable to perform the calendaring process in multiple stages.

[0026] The coating weight of the filler layer is 1.0 g / m2 in dry weight. 2 More than 20g / m 2 The coating weight is preferably 1.0 g / m or less. 2 If it is less than 20 g / m, the smoothness of the surface of the filling layer may be insufficient, and a homogeneous vapor deposition layer may not be obtained. 2 If the amount is increased beyond 20 g / m, the physical properties are saturated and there is almost no change, and the drying load during coating increases and the material cost increases. 2 If the amount is more than this, it becomes necessary to maintain the strength of the filler layer itself (to prevent the occurrence of cohesive failure or cracks in the coating layer). From the viewpoints of cost, productivity, etc., it is preferable that the coating amount of the filler layer is small, and 12 g / m 2 Less than 8 g / m is more preferable. 2 More preferably, 6 g / m 2 Even more preferably, 4 g / m 2 Even more preferably, 3 g / m 2 Even more preferably, 2 g / m 2 More preferably, the coating amount is 4 g / m or less. 2 In the following cases, it is preferable to subject the filling layer to a calendar treatment.

[0027] The coating weight of the primer layer is 0.5 g / m2 on a dry basis. 2 More than 10g / m 2 The coating weight is preferably 0.5 g / m or less. 2 If the thickness is less than 10 g / m, a uniform deposition layer may not be obtained. 2 If the amount is more than this, the physical properties will saturate and will not change much, and the drying load during coating will increase, as well as the material costs. From the standpoint of cost, productivity, etc., the coating amount of the primer layer is set at 1 g / m 2 More than 3 g / m is preferable. 2 The following is preferred:

[0028] (Base paper for vapor deposition) The moisture content of the deposition base paper of the present invention is not particularly limited, but since a high moisture content leads to a low degree of vacuum when forming a deposition layer under vacuum conditions, a low moisture content is preferable. Specifically, it is preferably 8.0% by weight or less, more preferably 6.0% by weight or less, even more preferably 3.0% by weight or less, and most preferably 1.0% by weight or less. The lower limit of the moisture content is not particularly limited, but is about 0.1% by weight.

[0029] (deposited layer) A vapor deposition layer is provided on the primer layer of the base paper for vapor deposition to obtain a vapor deposition paper. The vapor deposition layer can contain metal, inorganic oxide, inorganic nitride, etc. Examples of the metal vapor deposition layer include aluminum, tin, nickel, copper, gold, platinum, silver, cobalt, chromium, etc., with aluminum being more preferred because it has high light shielding properties and is inexpensive. Examples of the inorganic oxide vapor deposition layer include oxides of silicon, aluminum, titanium, zirconium, tin, magnesium, lead, boron, sodium, etc., or mixtures thereof, and further composites with inorganic nitrides, with silicon oxide or aluminum oxide being more preferred because they have high barrier properties and transparency and are inexpensive. Any method can be used to form the deposition layer, including known methods such as vacuum deposition, ion plating, sputtering, plasma vapor deposition (CVD), transfer deposition, etc. The vacuum deposition method is preferred in terms of productivity, since it allows the deposition layer to be formed relatively easily. The thickness of the deposition layer is preferably 5 to 300 nm, and more preferably 10 to 150 nm. If the thickness is less than 5 nm, a uniform deposition layer cannot be formed, and sufficient barrier properties may not be obtained. On the other hand, if the thickness exceeds 300 nm, it becomes difficult to maintain the flexibility of the deposition layer, and there is a risk of cracks occurring due to external factors such as bending and pulling after film formation.

[0030] (Vapor deposition protective layer) A protective layer may be laminated on the deposition layer for the purpose of protecting the surface or improving suitability for post-processing such as lamination. In this case, for example, a water-soluble polymer is dissolved in water or a water / alcohol mixed solvent, and a metal alkoxide is mixed with the water-soluble polymer, either directly or after being hydrolyzed in advance, and the mixed solution is applied onto the deposition layer and dried to form the protective layer. In addition, an isocyanate compound, a silane coupling agent, a dispersant, a stabilizer, a viscosity modifier, a colorant, etc. may be added to the mixed solution as necessary.

[0031] (Resin layer) A resin layer can be provided on at least one side of the metallized paper, which can impart heat sealability. The resin layer can be provided on both sides of the metallized paper, but it is preferable to provide the resin layer at least on the side having the metallized layer. Resins for the resin layer can include resins derived from fossil resources such as polyester, polyvinyl alcohol, polypropylene, polyethylene, polystyrene, polyethylene terephthalate, polybutylene terephthalate, polymethylpentene, polyvinyl chloride, acrylonitrile-butadiene-styrene, acrylonitrile-styrene, polymethyl(meth)acrylic, polyvinylidene chloride, polyamide (nylon), polyacetal, and polycarbonate, as well as biologically derived resins such as polylactic acid (PLA), esterified starch, cellulose acetate, polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), biopolyethylene, biopolyethylene terephthalate, and biopolyurethane. Bioresins are polymeric materials with a number-average molecular weight (Mn) of 1,000 or more that contain substances derived from renewable organic resources such as plants and microorganisms and are obtained by chemical or biological synthesis.

[0032] In addition, as resins derived from fossil resources and biologically derived resins, any of the following can be used: biodegradable resins such as polylactic acid (PLA), esterified starch, cellulose acetate, polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), and non-biodegradable resins such as polyethylene, polypropylene, polyester, polyethylene terephthalate, polyamide (nylon), and biopolyethylene. A biodegradable resin is a resin that can be broken down to the molecular level by the action of microorganisms, and ultimately circulates back into nature as carbon dioxide and water.

[0033] In the present invention, the resin layer is preferably a resin laminate layer. Examples of the resin laminate layer include an extrusion laminate layer and a film attachment layer such as a barrier film. When the resin laminate layer is an extrusion laminate layer, the above-mentioned various resins are laminated as a resin laminate layer on at least one surface of the metal-deposited paper by an extrusion lamination method. When the resin laminate layer is a film attachment layer, the above-mentioned various resin films are attached as a resin laminate layer on at least one surface of the metal-deposited paper by a dry lamination method, a sand lamination method, etc. The resin layer can be provided on both sides of the metal-deposited paper, but it is preferable to have a resin layer at least on the surface having the metal-deposited layer. In the present invention, the film used for the film attachment layer may be any of the above-mentioned various resin films. Depending on the purpose, one or more of these films may be attached for use.

[0034] The metallized paper can be used as it is, or laminated with various resins, or pasted with various general-purpose films, barrier films, etc., to form a packaging material used for packaging applications such as food packaging, containers, cups, etc., or a laminate used for industrial materials, etc. Among these, the metallized paper can be suitably used as a packaging material used for packaging applications such as food packaging, containers, cups, etc., and can be particularly suitably used as a soft packaging material for food, etc. Note that the soft packaging material is a packaging material made of a highly flexible material, and generally refers to a packaging material made of thin, flexible materials such as paper, film, aluminum foil, etc., either alone or pasted together. In terms of shape, the soft packaging material refers to a packaging material such as a bag that maintains a three-dimensional shape by putting contents inside.

[0035] When the metallized paper is used as a packaging material for food and the like, particularly as a soft packaging material, laminating it with a resin having heat-sealing properties can enhance the airtightness of the packaging material, protect the contents from oxidation due to oxygen and deterioration due to moisture, and enable the shelf life to be extended. Furthermore, when used as a laminate for industrial materials, etc., it is possible to prevent putrefaction and deterioration by suppressing the intrusion of oxygen and moisture, and it is also expected to have effects such as flavor barrier properties that prevent the odor of solvents from leaking out. EXAMPLES

[0036] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In the examples, parts and % are by weight, respectively, unless otherwise specified. The obtained metallized paper substrate and metallized paper were subjected to tests based on the evaluation methods described below.

[0037] "Example 1" (Preparation of base paper) 75 parts by weight of hardwood kraft pulp (LBKP) and 25 parts by weight of softwood kraft pulp (NBKP) were mixed to prepare a raw pulp with a Canadian standard freeness (CSF) of 400 ml. The raw pulp slurry was added with 0.1% by weight of dry pulp of polyacrylamide (PAM) with a molecular weight of 2.5 million as a dry strength agent, 0.35% by weight of alkyl ketene dimer (AKD) as a sizing agent, 0.15% by weight of wet strength agent of polyamide epichlorohydrin (PAEH) resin, and 0.08% by weight of retention agent of polyacrylamide (PAM) with a molecular weight of 10 million. The paper was made using a fourdrinier multi-cylinder paper machine, and the basis weight was about 38 g / m. 2 Thus, a paper substrate of 100 g was obtained.

[0038] (Preparation of sealing coating liquid) A coating liquid for a filling layer was prepared by mixing 100 parts by weight of resin A (manufactured by BASF, product name: JONCRYL PDX7356, styrene acrylic resin, water dispersible) on an absolute dry basis with 0.06 parts by weight of an antifoaming agent (manufactured by BASF, product name: Foamaster WO2360). (Sealing layer coating) Using a blade coater, apply the coating solution for the filling layer to one side of the paper substrate until the target coating weight is 5 g / m2 (dry weight). 2 The coating was then dried.

[0039] (Calendar processing) The smoothing treatment was carried out using a hot soft nip calendar under the conditions of a temperature of 60° C., a linear pressure of 100 kN / m, two nips, and a speed of 200 m / min. (Primer layer coating) The primer layer was made of polyurethane resin (Mitsui Chemicals, Inc., product name: Takelac WPB-341) with a target coating weight of 2 g / m2 (dry weight). 2 The resulting coating was dried to obtain a base paper for deposition. (Preparation of metallized paper) On the primer layer of the obtained base paper for deposition, an aluminum deposition layer having a thickness of 50 nm was formed using a batch type vacuum deposition machine, to obtain a deposited paper.

[0040] "Example 2" A base paper for deposition and a deposited paper were obtained in the same manner as in Example 1, except that Resin A was replaced with Resin B (manufactured by Seiko PMC Corporation, product name: Hi-Los-X·NE2260, styrene-acrylic resin, water-dispersible). "Example 3" A base paper for metallization and a metallized paper were obtained in the same manner as in Example 1, except that the calendaring was not performed. "Example 4" The target coating weight for the filling layer is 2g / m 2 A base paper for deposition and a metallized paper were obtained in the same manner as in Example 1, except that the above-mentioned was used.

[0041] "Comparative Example 1" A base paper for deposition and a deposited paper were obtained in the same manner as in Example 1, except that Resin A was replaced with Resin C (manufactured by Michelman, product name: Vapercoat 2200, styrene-acrylic resin, water-dispersible). "Comparative Example 2" A base paper for deposition and a deposited paper were obtained in the same manner as in Example 1, except that Resin A was replaced with Resin D (manufactured by BASF, product name: ACRONAL S504, styrene-acrylic resin, water-dispersible). "Comparative Example 3" A base paper for metallization and a metallized paper were obtained in the same manner as in Example 4, except that the calendaring was not performed. "Comparative Example 4" A base paper for deposition and a deposited paper were obtained in the same manner as in Example 1, except that a primer layer was not formed. "Comparative Example 5" A base paper for deposition and a metallized paper were obtained in the same manner as in Example 1, except that the filling layer was not formed.

[0042] "Example 5" A coating solution for the filling layer was prepared by mixing 75 parts by weight of resin A on an absolute dry basis, 25 parts by weight of calcium carbonate (manufactured by Fimatec, product name: FMT-75, average particle size 1.3 μm), and 0.06 parts by weight of an antifoaming agent (manufactured by BASF, product name: Foamaster WO2360). Using this coating solution, the target coating weight was 7g / m 2 A base paper for deposition and a metallized paper were obtained in the same manner as in Example 1, except that the above-mentioned was used.

[0043] "Example 6" A base paper for metallization and a metallized paper were obtained in the same manner as in Example 5, except that Resin A was replaced with Resin B. Example 7 A base paper for deposition and a deposited paper were obtained in the same manner as in Example 5, except that Resin A was replaced with Resin C and that the amount of calcium carbonate was 40 parts by mass per 60 parts by mass of Resin C on an absolute dry basis. "Example 8" The target coating weight for the filling layer is 10g / m 2 A base paper for deposition and a metallized paper were obtained in the same manner as in Example 5, except that the above-mentioned was used.

[0044] "Example 9" 85 parts by weight of hardwood kraft pulp (LBKP) and 15 parts by weight of softwood kraft pulp (NBKP) were mixed to prepare a raw pulp with a Canadian standard freeness (CSF) of 400 ml. 0.3 parts by weight of cationic starch was added as a paper strength agent to 100 parts by weight of the raw pulp, and then 1.5 parts by weight of aluminum sulfate was added. After that, paper was made using a fourdrinier multi-cylinder papermaking machine equipped with a Yankee dryer in the drying section, and the paper had a basis weight of about 50 g / m. 2 A paper base material (Nippon Paper Industries Co., Ltd., bleached glossy paper) was obtained. Using this paper base material, a base paper for metallization and a metallized paper were obtained in the same manner as in Example 5, except that the calendar treatment was not carried out.

[0045] "Comparative Example 6" A base paper for deposition and a deposited paper were obtained in the same manner as in Example 5, except that the amount of calcium carbonate was 50 parts by mass per 50 parts by mass of Resin A on an absolute dry basis. "Comparative Example 7" A base paper for deposition and a deposited paper were obtained in the same manner as in Comparative Example 6, except that calcium carbonate was replaced with kaolin (Contour Xtreme, manufactured by Imerys). "Comparative Example 8" Resin A was replaced with Resin D, and Resin D was 40 parts by mass on an absolute dry basis to 60 parts by mass of kaolin, with the target coating weight being 12 g / m 2 A base paper for deposition and a metallized paper were obtained in the same manner as in Example 9, except that the above-mentioned was used.

[0046] <Evaluation and measurement methods> The following evaluations were carried out, and the results are shown in Tables 1 and 2. "Quality evaluation of filler coated paper before primer layer coating and base paper for deposition after primer layer formation" - Blocking property The sealing coated paper was cut out and laminated so that the coated side and the uncoated side were in contact with each other. 2 A load was applied and the sheets were left to stand for 24 hours under conditions of a temperature of 40°C and a humidity of 75%, after which the degree of adhesion of the overlapping sheets was evaluated. Good: No adhesion between overlapping sheets. △: The overlapping sheets are bonded together, but can be peeled off with a simple force. ×: The overlapping sheets are firmly bonded to each other and do not peel off. If peeled off, the paper will tear.

[0047] ·Smoothness (PPS roughness) The filler coated paper and metallization base paper were measured using a method conforming to JIS P 8151:2004 (print-surf tester method) (soft backing used, clamp pressure 980 kPa). Air resistance The filler coated paper and the base paper for metallization were measured using a method conforming to JIS P 8117:2009 (Oken type testing machine method).

[0048] ·Water resistance (Cobb120) The amount of water absorbed (Cobb120) was measured for the sealant coated paper and the base paper for deposition when the water-resistant layer was in contact with water for 2 minutes, based on the water absorption test method (Cobb method: JIS P 8140). Wettability (pure water contact angle) For the sealing coated paper and the base paper for deposition, 3.5 μl of pure water was dropped onto the surface (water-resistant coating layer) and the contact angle 5 seconds after the drop was measured using a contact angle measuring device (portable contact angle meter PGX+ manufactured by Matsubo Corporation).

[0049] "Quality evaluation of metallized paper" -Water vapor barrier properties (moisture permeability: WVTR) Measured according to JIS Z 0208 (cup method: 40°C, relative humidity 90%, vapor-deposited surface facing outward). The lower the value, the higher the water vapor barrier property of the vapor-deposited paper. The samples for evaluating the barrier property of folding resistance were prepared and evaluated by the following method. The sample is placed on a glass plate with the vapor-deposited surface facing inward and folded in a valley shape, and then creased by rolling it back and forth five times with a rubber roller weighing 500 g without applying any pressure. Open it once, then fold it perpendicular to the creases, with the vapor-deposited side facing inwards, and similarly roll it back and forth five times with a rubber roller to create a cross crease. The moisture permeability was measured so that the intersection of the cross folds was at the center.

[0050] -Oxygen barrier properties (oxygen permeability rate OTR) A resin layer made of low-density polyethylene (LC602A, manufactured by Japan Polyethylene Corporation) was laminated to a thickness of 30 μm on the vapor-deposited surface of the obtained vapor-deposited paper by extrusion lamination, and measurements were performed using an OX-TRAN2 / 21 manufactured by MOCON under conditions of 23°C-0% RH (dry conditions) and 23°C-85% RH (high humidity conditions).

[0051] [Table 1]

[0052] [Table 2]

[0053] The deposition base papers obtained in Examples 1 to 9 of the present invention were excellent in barrier properties, in particular in oxygen barrier properties under high humidity conditions. The deposition base papers obtained in Comparative Example 1, in which the pure water contact angle (after 5 seconds) exceeded 95°, and Comparative Example 2, in which the pure water contact angle was less than 70°, had poor coatability, and it was not possible to coat a good primer layer on them. The deposited paper substrate obtained in Comparative Example 4, which had no primer layer, and in Comparative Example 5, which had no filling layer, were significantly inferior in barrier property. The water absorption of the sealing layer is 12g / m 2 Comparative Examples 3 and 6 to 8, which exceeded this limit, were poor in oxygen barrier properties under high humidity conditions. Resin C used in Comparative Example 1 had such strong water resistance (water repellency) that it was not possible to form a coating layer on top of it when used alone. However, as shown in Example 7, by blending calcium carbonate, it was possible to form a filling layer onto which a homogeneous primer layer could be applied. As shown in Examples 5 to 9, it was confirmed that the barrier property was improved by blending calcium carbonate in the filling layer.

Claims

1. A base paper for deposition comprising a paper substrate and, on at least one surface thereof, a filling layer containing a water-dispersible resin as a main component and a primer layer, in that order.

2. 2. The base paper for deposition according to claim 1, wherein the moisture content is 8.0% by weight or less.

3. 2. The deposition base paper according to claim 1, wherein the contact angle of the filling layer with pure water (after 5 seconds) is 70° or more and 95° or less.

4. A metal-deposited paper having a metal-deposited layer on a primer layer of the metal-deposited base paper according to any one of claims 1 to 3; and a resin layer having heat sealability laminated on at least one surface of the metallized paper.

5. A step of coating at least one surface of the paper substrate with a filling layer mainly composed of a water-dispersible resin; forming a primer layer on the filling layer by aqueous coating; forming a deposition layer on the primer layer by a vacuum deposition method; A method for producing metallized paper, comprising the steps of:

6. The method for producing metallized paper according to claim 5, characterized in that the contact angle of the filling layer with pure water (after 5 seconds) is 70° or more and 95° or less.

Images