JP2021046234A - Packaging paper - Google Patents

Abstract

To provide packaging paper that achieves a reduced amount of use of plastic, and is excellent in heat sealability, moisture proofness, water repellence, oil repellence, and oil resistance of a bent part.SOLUTION: This invention relates to packaging paper having at least one heat seal layer on at least one side of a paper substrate, the heat seal layer containing an ionomer, and a total amount of dry coating of the heat seal layer being 0.1-10 g/m2. The packaging paper has one or more undercoat layers containing at least a pigment and a binder between the heat seal layer and the paper substrate.SELECTED DRAWING: None

Description

The present invention relates to a wrapping paper in which the amount of plastic used is reduced.

In recent years, the plastic waste problem has become more serious. The world's plastic production is said to exceed 400 million tons / year, and the packaging sector is the largest producer of plastic, causing plastic waste. Plastic does not decompose semi-permanently, and the waste becomes microplastic in the natural environment, which has a serious adverse effect on the ecosystem. The most commonly used plastics for packaging containers are polyethylene terephthalate (PET) used for beverage bottles and the like, polyethylene (PE) and polypropylene (PP) used for laminating cash register bags and containers. .. Especially, the pollution of the ocean is remarkable, and it is said that the plastic waste cannot be collected. In the future, it is necessary for the global environment to reduce the use of plastics.

On the other hand, as a measure against plastic waste, applications of biodegradable plastics that can be completely decomposed by microorganisms have been proposed all over the world. Biodegradable plastics are decomposed in nature within a certain period of time, but until they are decomposed, they are still garbage, and unless their usage and disposal amount are reduced, it cannot be said to be an immediate measure ( See Patent Documents 1 and 2).

As a quick-acting countermeasure, it has been proposed to replace plastic with paper, but when processing paper into bags and containers, a large amount of polyethylene or polypropylene is laminated and used as a heat sealant. To. Laminates of these plastics, but different depending on the product concept, generally a 20 to 50 g / ^{m 2,} it may be extensive and 300 g / ^{m 2.} Therefore, even in a packaging container in which plastic is replaced with paper, there is still a problem that the amount of plastic used is not sufficiently reduced, and there is an urgent need for a means for directly reducing the use of plastic. In particular, there is a demand for wrapping paper that reduces the amount of plastic used and is excellent in heat sealability, moisture resistance, water repellency, oil repellency, and oil resistance of bent portions.

Japanese Unexamined Patent Publication No. 2012-148444 Japanese Unexamined Patent Publication No. 2013-141763

An object of the present invention is to provide a wrapping paper capable of reducing the amount of plastic used. In particular, it is an object of the present invention to provide a wrapping paper having excellent heat sealability, moisture resistance, water repellency, oil repellency, and oil resistance of a bent portion.

In the present invention, an ionomer is used in order to reduce the amount of polyethylene or polypropylene used in the conventional plastic laminated paper (hereinafter sometimes abbreviated as polylami paper). That is, the wrapping paper according to the present invention is a wrapping paper having at least one heat-sealing layer on at least one surface of the paper base material, the heat-sealing layer contains an ionomer, and the amount of coating of the heat-sealing layer is large. It is characterized by being 0.1 to 10 g / m ^2. Compared to the amount of polyethylene or polypropylene laminated in the conventional heat seal layer of polylami paper ^{exceeding 20 g / m 2} , the amount of plastic used in the heat seal layer is up to about 10 to 50% of the conventional amount. Can be reduced. Here, the ionomer is a synthetic resin in which a polymer is made into an aggregate by utilizing the cohesive force of metal ions, and is a synthetic resin in which acrylic acid or methacrylic acid is combined with ethylene or the like. For example, it is produced by adding an acrylic polymer and ethylene to an intermolecular bond by adding a metal cation such as sodium or zinc.

Further, in the present invention, it is necessary to have at least one or more underlayers containing at least a pigment and a binder between the heat seal layer and the paper base material. With such a configuration, a wrapping paper having more excellent water repellency and oil repellency can be obtained.

Further, in the present invention, the binder contained in the under layer is preferably in the range of 50 to 200 parts by mass with respect to 100 parts by mass of the pigment. With such a configuration, a wrapping paper having more excellent water repellency and oil repellency can be obtained.

Further, in the present invention, it is preferable that 40 to 100% by mass of the pigment contained in the under layer is kaolin clay. With such a configuration, a wrapping paper having more excellent water repellency and oil repellency can be obtained.

Further, in the present invention, the binder is selected from an acrylic resin, polyvinyl alcohol, and a styrene-butadiene copolymer, and it is preferable that the binder is a styrene-butadiene copolymer. With such a configuration, a wrapping paper having more excellent water repellency and oil repellency can be obtained.

Further, in the present invention, it is preferable that the dry coating amount of the under layer is ^{2 to 30 g / m 2 in all layers.} With such a configuration, a wrapping paper having more excellent water repellency and oil repellency can be obtained.

Further, in the present invention, the wrapping paper has a step of preparing a coating liquid for a heat seal layer containing an ionomer emulsion, a step of preparing a coating liquid for an under layer containing a pigment and a binder, and a paper base material. A step of applying the coating liquid for the under layer to at least one surface of the above, and a step of applying the coating liquid for the heat seal layer in the range of ^{0.1 to 10 g / m 2 in terms of solid content.} It is preferable that the product is produced by a production method having the above. With such a configuration, a wrapping paper having more excellent water repellency and oil repellency can be obtained.

According to the present invention, it is possible to produce a wrapping paper in which the amount of plastic used is reduced. With the container product using the wrapping paper of the present invention, even if it is improperly released as dust in the natural world, it is possible to reduce the adverse effect of plastic dust on the natural environment, and plastic. Helps solve the garbage problem. The wrapping paper of the present invention having excellent heat sealability, moisture resistance, water repellency, oil repellency, and oil resistance of bent portions is, for example, a bag, a food cup such as ice cream, a drinking cup such as coffee, and a hot snack. It can be appropriately processed and used for food containers such as trays, boxes, cases, vessels, and packaging containers such as envelopes.

Next, the present invention will be described in detail by showing embodiments, but the present invention is not construed as being limited to these descriptions. The embodiments may be modified in various ways as long as the effects of the present invention are exhibited.

In the present embodiment, ionomer is a general term for synthetic resins in which polymers are aggregates by utilizing the cohesive force of metal ions, and is a resin in which acrylic acid or methacrylic acid is combined with ethylene or the like. That is, the metal salts of ethylene / methacrylic acid copolymers, the metal salts of ethylene / acrylic copolymers, the metal salts of ethylene / urethane copolymers, the metal salts of ethylene / fluorine polymer copolymers, etc. All are called ionomers. Examples of the metal forming the salt include alkali metal ions and alkaline earth metal ions, specifically, sodium, potassium, calcium, magnesium, and zinc ions. In the present invention, it is preferable that the ionomer is a self-emulsifying emulsion which is a metal salt of an ethylene / methacrylic acid copolymer. A heat seal layer having a sufficient heat seal strength can be provided with a relatively small amount of the heat seal layer applied.

In the present embodiment, the heat seal layer can be provided by applying a coating liquid for a heat seal layer containing an ionomer emulsion to at least one surface of a paper base material and drying the coating liquid. By using the ionomer emulsion, the coating amount can be controlled to be relatively low, and by using the water-based ionomer emulsion, VOC emissions can be eliminated and the load on the natural environment can be reduced. The coating amount of the heat seal layer is 0.1 to 10 g / m ² in terms of solid content, preferably 1 to 8 g / m ² per one side of the paper base material. If it is less than 0.1 g / m ^2, sufficient heat seal strength cannot be satisfied. On the contrary, ^{when it exceeds 10 g / m 2} , the quality is excessive in terms of heat seal strength, and the plastic reduction effect becomes poor. In the wrapping paper of the present invention, the heat seal layer is usually provided not only on a part of the surface of the paper base material but on the entire surface. That is, the heat seal layer is provided not only on the portion necessary for adhesion by the heat seal, such as a net shape, an island shape, or a linear shape, but is provided so as to cover the entire surface of the paper base material. Is good.

In addition to the ionomer emulsion, various auxiliaries may be added to the coating liquid for the heat seal layer. For example, viscosity modifiers, antifoaming agents, leveling agents such as surfactants and alcohols, coloring pigments, coloring dyes and the like. However, since the addition of these auxiliaries tends to cause a decrease in heat seal strength, it is preferable to add them in a small amount. In the present embodiment, it is preferable that the coating liquid for the heat seal layer is composed only of the ionomer emulsion.

The method for applying the coating liquid for the heat seal layer is not particularly limited, and a generally used coating device can be used. For example, air knife coater, blade coater, gravure coater, rod blade coater, roll coater, reverse roll coater, bar coater, curtain coater, die slot coater, champlex coater, metering blade type size press coater, short dwell coater, spray. Various known coating devices such as a coater, a gate roll coater, and a lip coater can be used.

In the present embodiment, at least one or more underlayers containing at least a pigment and a binder are provided between the heat seal layer and the paper substrate. By providing the under layer, the ionomer emulsion is prevented from penetrating into the paper substrate, and the heat seal layer has few pinholes and defects, and has excellent water repellency and oil repellency. Further, since the under layer itself has an effect of preventing the penetration of water and oil, excellent water repellency and oil repellency can be obtained by the synergistic effect with the heat seal layer.

In the present embodiment, the content of the binder in the under layer is preferably in the range of 50 to 200 parts by mass with respect to 100 parts by mass of the pigment. Within this range, better water repellency and oil repellency can be obtained. The content of the binder is more preferably in the range of 60 to 150 parts by mass, and particularly preferably in the range of 70 to 130 parts by mass. If it is less than 50 parts by mass, the effect of preventing the permeation of water or oil of the under layer itself is lowered, and the ionomer emulsion permeates into the paper substrate, so that the water repellency and the oil repellency may be inferior. If it exceeds 200 parts by mass, the water repellency and oil repellency will not be further improved. Binders are also economically disadvantageous due to their high cost.

As the pigment in the under layer, a known pigment used for the coating layer of general printing coated paper can be used, and for example, calcium carbonate (heavy calcium carbonate, light calcium carbonate, etc.), kaolin clay, etc. can be used. (Including kaolin and clay), calcined clay, talc, magnesium carbonate, barium sulfate, calcium sulfate, titanium dioxide, zinc oxide, zinc sulfate, zinc carbonate, calcium silicate, aluminum silicate, magnesium silicate, diatomaceous soil, aluminum hydroxide, water Examples thereof include inorganic pigments such as magnesium oxide, acrylics, styrenes, vinyl chlorides, nylons themselves, and organic pigments (so-called plastic pigments) obtained by copolymerizing these. It is preferably an inorganic pigment, and particularly preferably kaolin clay, particularly fine kaolin clay. Among them, it is particularly preferable to use fine kaolin clay having a particle distribution of 90% or more, preferably 95% or more of particles having a particle size of less than 2 μM.

In the present embodiment, it is preferable that 40 to 100% by mass of the pigment contained in the under layer is the above kaolin clay, particularly fine kaolin clay. Within this range, better water repellency and oil repellency can be obtained. Kaolin clay has a flat plate-like structure with a high aspect ratio, and is considered to be more effective in preventing the penetration of water and oil due to the maze effect than the spherical pigment. More preferably, the above-mentioned kaolin clay may be 50 to 100% by mass, and particularly preferably 70 to 100% by mass, among the pigments contained in the under layer. The closer it is to 100% by mass, the greater the effect. If it is less than 40% by mass, the water repellency and oil repellency may be inferior. In the present embodiment, as the composition of the pigment contained in the under layer, for example, 40 to 100% by mass of kaolin clay and 0 to 60% by mass of calcium carbonate, particularly light calcium carbonate may be used in combination. Here, kaolin clay is used as a general term for flat pigments containing kaolin and clay, and may be kaolin or clay alone, or a mixture thereof.

In the present embodiment, the binder includes cross-linking agent-modified starch, oxidized starch, enzyme-modified starch, esterified starch, etherified starch, cationic starch, amphoteric starch and other starches, gelatin, casein, soybean protein, and polyvinyl alcohol. Examples thereof include water-soluble polymers such as vinyl acetate, ethylene vinyl acetate, polyurethane resins, acrylic resins, polyester resins, polyamide resins, and other synthetic resins. A binder selected from an acrylic resin, polyvinyl alcohol, and a styrene-butadiene copolymer is preferable. Furthermore, it is preferable that the binder is a copolymer containing styrene and butadiene. It is a so-called styrene-butadiene latex (SBR), and can give flexibility to the underlayer and the effect of preventing the penetration of water and oil.

The amount of coating of the under layer is preferably ^{2 to 30 g / m 2.} Within this range, better water repellency and oil repellency can be obtained. More preferably, it is 5 to 15 g / m ² . ^{If it is less than 2} g / m 2, the water repellency and oil repellency may be inferior. If it exceeds 30 g / m ² , the water repellency and oil repellency will not be further improved. In addition, the cost is high and it is economically disadvantageous.

The method of applying the coating liquid for the under layer is not particularly limited, and a generally used coating device can be used. For example, air knife coater, blade coater, gravure coater, rod blade coater, roll coater, reverse roll coater, bar coater, curtain coater, die slot coater, champlex coater, metering blade type size press coater, short dwell coater, spray. Various known coating devices such as a coater, a gate roll coater, and a lip coater can be used. It may be a so-called on-machine coater that is continuously connected to the paper machine.

The paper base material used in the present embodiment is not particularly limited, and a known paper base material containing pulp as a main component can be used. Pulps that are the main component of the paper base material include chemical pulps such as LBKP (bleached broad-leaved kraft pulp), NBKP (bleached coniferous kraft pulp), LUKP (unbleached broad-leaved kraft pulp), and NUKP (unbleached coniferous kraft pulp). GP (crushed wood pulp), PGW (pressurized crushed wood pulp), RMP (refiner mechanical pulp), TMP (thermomechanical pulp), CTMP (chemithermomechanical pulp), CMP (chemimechanical pulp), CGP (chemigrand pulp), etc. Machine pulp, wood pulp such as DIP (deink pulp) and non-wood pulp such as Kenaf, Bagus, bamboo, cotton and Manila hemp can be used. These can be used alone or in admixture in any proportion. In addition, synthetic fibers can be further blended as long as the desired effect of the present invention is not impaired. From the viewpoint of environmental conservation, ECF (Elemental Chlorine Free) pulp, TCF (Total Chlorine Free) pulp, unbleached pulp, used paper pulp, and pulp obtained from planted trees are preferable. Further, for example, an appropriate pulp beating degree is 300 to 750 ml CSF, for example, 450 to 600 ml CSF in Canadian standard freeness (JIS P 8121: 1995 "Pulp freshness test method"). .. Usually, it is preferable to use 85 to 100 parts by mass of hardwood pulp such as LBKP (hardwood bleached kraft pulp) and 0 to 15 parts by mass of softwood pulp in the whole pulp. Further, in addition to hardwood pulp, it is preferable to add softwood pulp in order to enhance moisture resistance, water repellency, oil repellency, and oil resistance of the bent portion. For example, it is preferable to use 85 to 100 parts by mass of softwood pulp such as NBKP (bleached softwood kraft pulp) and NUKP (unbleached softwood kraft pulp) and 0 to 15 parts by mass of broadleaf pulp in the whole pulp. Further, in the present invention, it is preferable to use only softwood pulp as the pulp.

As the paper base material, one containing a filler can also be used. Examples of the filler include light calcium carbonate, heavy calcium carbonate, talc, kaolin clay (including kaolin and clay), calcined clay, titanium dioxide, and aluminum hydroxide. The filler content in the paper substrate is, for example, 1 to 30 parts by mass with respect to 100 parts by mass of the dry mass of the pulp. For example, it is preferable to contain 1 to 10 parts by mass of light calcium carbonate with respect to 100 parts by mass of dry mass of pulp.

Further, the paper base material may contain various known additives for papermaking in addition to pulp and filler. Examples of the papermaking additive include an internal paper strength enhancer such as a sizing agent and a wet paper strength enhancer, a bulking agent, a yield improver, a drainage improver, a coloring dye, a coloring pigment, a fluorescent whitening agent, and fluorescence. There are decoloring agents, pitch control agents, etc. Further, a water-soluble polymer such as starch, polyvinyl alcohol, or polyacrylamide may be applied. In the present invention, it is preferable that the paper base material contains 0.05 to 1.0 part by mass, more preferably 0.1 to 0.5 part by mass of a neutral rosin sizing agent with respect to 100 parts by mass of pulp.

The paper-based paper-making method is not particularly limited, and is a long-net paper machine, a long-net multi-layer paper machine, a circular net paper machine, a circular net multi-layer paper machine, a long-net circular net combination multi-layer paper machine, and twin wire paper. It can be manufactured with various paper machines such as machines. Further, in the present invention, the paper base material may be a single-layer paper, a multi-layer paper, or a laminated product having a plurality of layers.

In the present embodiment, the basis weight of the wrapping paper is not particularly limited, but is, for example, 10 to 1000 g / m ² . Barrier properties, comprising highly water and oil repellency, as the basis weight of the wrapping paper can also be used in flexible packaging, preferably ^{10~500g / m 2, 20~300g / m} 2 is more preferable.

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Further, "parts" and "%" in the example indicate "parts by mass" and "% by mass", respectively, unless otherwise specified. The number of copies added is a value in terms of solid content.

(Example 1)
(Preparation of paper substrate)
Canadian Standard Freeness 520ml csf 100 parts of bleached kraft pulp, light calcium carbonate (trade name: TP-121, manufactured by Okutama Kogyo Co., Ltd.), 5 parts, cationized starch (trade name: Neotac 30T, manufactured by Nippon Food Processing Co., Ltd.) 0.2 Add water to 0.2 parts of a neutral rosin sizing agent (trade name: CC167, manufactured by Seiko PMC) to prepare a paper material, and use a long net multi-cylinder paper machine to make a basis weight of 58 g / m ² . A base paper was prepared. Oxidized starch (trade name: MS3800, manufactured by Nihon Shokuhin Kako Co., Ltd.) is applied to this base paper by a gate roll coater so that the dry coating amount per both sides is 2 g / m ^2, and the base is dried to 235 g / m ^2. I got the paper.

(Preparation of coating liquid for under layer)
Fine-grained kaolin clay (trade name: Hydragloss 90, manufactured by KaMin LLC, 96 to 100% of particles with a particle size of less than 2 μM) as a pigment, and 0.2 part of a dispersant (trade name: Aron T-50, manufactured by Toa Synthetic Co., Ltd.) Was added, and the mixture was water-dispersed using a choles disperser to prepare a pigment slurry. 80 parts of styrene-butadiene latex (trade name: L-1432, manufactured by Asahi Kasei Corporation) as a binder and water were further added to and dispersed in this pigment slurry to prepare a coating liquid for a pigment coating layer having a solid content concentration of 50%. ..

(Under layer coating)
On one side of the base paper obtained above, the coating liquid for the undercoating layer was applied and dried using a blade coater so that the ^{amount of dry coating per side was 10 g / m 2.} A paper base material (coated paper) having a basis weight of 245 g / m ^{2 was prepared.}

(Making wrapping paper)
Water-based ionomer emulsion (trade name: Chemipal S-300, manufactured by Mitsui Chemicals, Inc., composition: metal salt of ethylene / methacrylic acid copolymer, self-emulsifying emulsion) on the surface of the paper substrate obtained above on the underlayer side. , Microtrac method average particle size 0.5 μm) was ^{applied using an air knife coater so that the dry coating amount was 2 g / m 2} , and dried to provide a heat seal layer to prepare a wrapping paper.

(Example 2)
Example 1 except that the pigment of the coating liquid for the under layer was 40 parts of fine kaolin clay (trade name: Hydragloss 90, manufactured by KaMin LLC) and 60 parts of light calcium carbonate (trade name: TP-121, manufactured by Okutama Kogyo Co., Ltd.). A wrapping paper was prepared in the same manner as in the above.

(Example 3)
Example 1 except that the pigment of the coating liquid for the under layer was 30 parts of fine kaolin clay (trade name: Hydragloss 90, manufactured by KaMin LLC) and 70 parts of light calcium carbonate (trade name: TP-121, manufactured by Okutama Kogyo Co., Ltd.). A wrapping paper was prepared in the same manner as in the above.

(Example 4)
Example 1 except that the pigment of the coating liquid for the under layer was 0 parts of fine kaolin clay (trade name: Hydragloss 90, manufactured by KaMin LLC) and 100 parts of light calcium carbonate (trade name: TP-121, manufactured by Okutama Kogyo Co., Ltd.). A wrapping paper was prepared in the same manner as in the above.

(Example 5)
A wrapping paper was produced in the same manner as in Example 1 except that the binder of the coating liquid for the underlayer was 50 parts of styrene-butadiene latex (trade name: L-1432, manufactured by Asahi Kasei Corporation).

(Example 6)
A wrapping paper was produced in the same manner as in Example 1 except that the binder of the coating liquid for the underlayer was 150 parts of styrene-butadiene latex (trade name: L-1432, manufactured by Asahi Kasei Corporation).

(Example 7)
A wrapping paper was produced in the same manner as in Example 1 except that the binder of the coating liquid for the underlayer was 200 parts of styrene-butadiene latex (trade name: L-1432, manufactured by Asahi Kasei Corporation).

(Example 8)
A wrapping paper was produced in the same manner as in Example 1 except that the binder of the coating liquid for the underlayer was an acrylic emulsion (trade name: AE-852, manufactured by JSR Corporation) in 80 parts.

(Example 9)
A wrapping paper was produced in the same manner as in Example 1 except that the binder of the coating liquid for the under layer was 80 parts of polyvinyl alcohol (trade name: Poval 5-98, manufactured by Kuraray Co., Ltd.). ..

(Example 10)
A wrapping paper was prepared in the same manner as in Example 1 except that the pulp was 100 parts of unbleached softwood kraft pulp in the preparation of the base paper.

(Comparative Example 1)
A wrapping paper was produced in the same manner as in Example 1 except that the base paper was not provided with an underlayer.

The wrapping papers obtained in each Example and Comparative Example were evaluated by the methods shown below. The results obtained are shown in Tables 1 to 3.

(1) Heat-sealing strength Two sheets of the obtained wrapping paper are cut into a size of 8 mm in width and 15 cm in length, and the front and back surfaces of the wrapping paper are overlapped to form a heat-sealing device (manufactured by Palmec, model number: PTS-). Under 100), heat sealing was performed under certain conditions (adhesion width: 4 mm, temperature: 180 ° C., pressure 0.4 MPa, pressing time 0.5 seconds, pitch: 4 mm). Next, the heat-sealed sample is peeled off under certain conditions (peeling speed: 100 mm / min, peeling length: 10 cm) with a peeling strength tester (manufactured by Shimadzu Corporation, model number: Autograph AGS-X), and then paper. It was evaluated which surface of the base material, the inside of the heat seal layer, and the interface between the heat seal layer and the heat seal layer was peeled off. It is good that the inside of the paper base material is broken and peeled off (generally called material breaking).
⊚: The material is broken from the paper base material, which is a practical level.
〇: The material is broken from the paper base material, but some heat seal layer is peeled off. Practical level.
Δ: It is broken and peeled off in the heat seal layer. Practical level.
X: Peeled off at the interface between the heat seal layer and the heat seal layer. Practical level.

(2) Moisture proof The water repellency of the surface of the heat seal layer was evaluated in accordance with JIS K 7129-1: 2019 (Plastic-film and sheet-how to determine water vapor permeability). The lower the number, the higher the water repellency (difficult to get wet). When there were heat seal layers on both sides, the average value on both sides was used.
◎: ^50g / m less than 2 · 24hr ^〇: 50~100g / m 2 · 24hr
△: 100~150g ^/ m 2 · 24hr
×: 150~g ^/ m 2 · 24hr

(3) Water repellency The water repellency of the surface of the heat seal layer was evaluated according to JIS K 6768: 1999 (plastic-film and sheet-wetting tension test method). The lower the number, the higher the water repellency (difficult to get wet). When there were heat seal layers on both sides, the average value on both sides was used.

(4) Oil repellency The oil repellency of the surface of the heat seal layer was evaluated according to TAPPI T-559 cm-02 (kit method). The higher the value (kit value), the higher the oil repellency. When there were heat seal layers on both sides, the average value on both sides was used.

(5) Oil resistance of the bent part The wrapping paper obtained is cut into a size of 5 cm in width and 10 cm in length, folded in half on the heat seal layer side, and a 5 kg metal roll is placed on the fold. I let it pass back and forth. The folds were made so that the MD direction (Machine Direction; the direction of travel of the paper machine) of the paper making was the crease. The folded portion is opened, and a test solution having a kit value of 8 according to TAPPI T-559 cm-02 (kit method) is dropped onto the folded portion on the heat seal layer side. The test solution was wiped off after 15 seconds of dropping, and the permeation of the test solution into the paper substrate was evaluated.
◎: Practical level without penetration.
〇: Slightly penetrated, but practical level.
Δ: Permeated and impractical level.
X: The penetrant has escaped to the back surface, which is a level that is not practical.

As is clear from Table 1, since the wrapping paper according to Examples 1 to 10 contains an underlayer containing at least a pigment and a binder as compared with Comparative Example 1, it has heat-sealing property, moisture resistance, water repellency, and oil repellency. , Excellent oil resistance of bent parts. As the experimental results show, according to the present invention, the amount of the heat seal layer used is significantly reduced as compared with the conventional amount of polyethylene laminate, which contributes to the reduction of plastic dust, and has barrier properties, water repellency and water repellency. It is possible to provide a wrapping paper having excellent oiliness.

Claims (7)

A wrapping paper having at least one heat-sealing layer on at least one surface of a paper base material, the heat-sealing layer containing an ionomer, and the dry coating amount of the heat-sealing layer is 0.1 to 1 in all layers. The wrapping paper which is 10 g / m ² and has at least one or more underlayers containing at least a pigment and a binder between the heat seal layer and the paper base material. The wrapping paper according to claim 1, wherein the content of the binder contained in the under layer is in the range of 50 to 200 parts by mass with respect to 100 parts by mass of the pigment. Permeability The wrapping paper according to claim 1 or 2, wherein 40 to 100% by mass of the pigment contained in the underlayer is kaolin clay. The wrapping paper according to any one of claims 1 to 3, wherein the binder is selected from an acrylic resin, polyvinyl alcohol, and a styrene-butadiene copolymer. The wrapping paper according to any one of claims 1 to 4, wherein the binder is a styrene-butadiene copolymer. The wrapping paper according to any one of claims 1 to 5, wherein the dry coating amount of the under layer ^{is 2 to 30 g / m 2 in all layers.} A step of preparing a coating liquid for a heat seal layer containing an ionomer emulsion, a step of preparing a coating liquid for an under layer containing a pigment and a binder, and a step of preparing a coating liquid for an under layer containing a pigment and a binder, and for the under layer on at least one surface of a paper substrate. A method for producing a wrapping paper, which comprises a step of applying a coating liquid and a step of coating the coating liquid for a heat seal layer in ^{the range of 0.1 to 10 g / m 2 in terms of solid content.}