JPH03167395A - Metallized paper - Google Patents

Abstract

PURPOSE:To obtain the subject metallized paper useful for sticker, etc., having excellent metallic luster by applying a coated layer having specific smoothness and air permeability on base paper and making resin layer on the coated layer to cured resin layer with irradiation of electron rays. CONSTITUTION:The aimed metallized paper is composed of base paper and a resin layer and a metallized layer laminated in turn. The base paper is coated paper having a layer containing pigment and adhesive as principal ingredients. The surface of the coated layer has <=35mmHg smoothness measured by Smooster smoothness tester and >=400sec/10cc air permeability measured by high-pressure Gurley air permeability tester and further the resin layer is a layer cured by irradiation of electron rays.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to metallized paper having a beautiful metallic luster and used in the fields of general labels, stickers, wrapping paper, origami, etc. "Conventional technology" Conventionally, in the field of labels, art coated paper, paper made by laminating metal foil such as aluminum foil on art coated paper, etc., have been used.In particular, paper laminated with metal foil has been used. It is widely used because of its excellent product appeal.

However, in recent years, label paper laminated with metal foil is gradually being replaced by metallized paper. For example, when aluminum is used, the amount of aluminum ξ in aluminum vapor-deposited paper is less than 1/100 of that in label paper laminated with aluminum ξ foil.
This is because there are advantages such as resource saving and cost reduction. It also has other advantages such as good printability, cutting workability, and surface gloss. Also, in the field of packaging paper, the use of metallized paper is becoming more widespread to add appeal and fashion. A typical metal-deposited paper is one in which a resin layer mainly composed of synthetic resin and a metal-deposited layer are sequentially provided on a base paper. The base paper used is base paper, coated paper with a coating layer containing pigments and adhesives as main ingredients, and the synthetic resin used for the resin layer is solvent-based, aqueous-based, or non-solvent-based. Generally, solvent-based products are used. Even in such metal-deposited paper, it is difficult to obtain a metal-deposited paper that maintains the luster characteristic of metals, and metal-deposited sheets using a film as a support are currently preferred.

``Problem to be Solved by the Invention'' The present invention is to efficiently provide metallized paper having extremely excellent metallic luster.

"Means for Solving the Problems" The present invention provides a metal-deposited paper in which a resin layer and a metal-deposited layer are laminated on a base paper, in which the base paper has a coating layer mainly containing a pigment and an adhesive. The coating layer is made of a coated paper whose smoothness is 35 smHg or less as measured by a Smooster smoothness meter, and whose air permeability is 400 seconds/10 cc or more as measured by a high-pressure Gurley air permeability meter, and the resin layer is made of electronic paper. This is a metal-deposited paper characterized by a resin layer that is cured by radiation. "Function" The present invention is a metal-deposited paper having the above structure.

When a base paper is used as a base paper, even if a synthetic resin is applied and a metal vapor-deposited layer is provided, unevenness on the surface of the base paper becomes noticeable, so that only a metal-deposited paper with poor metallic luster can be obtained.

In order to improve smoothness, even in the case of coated paper in which a coating layer mainly composed of pigment and adhesive is provided on the side of the base paper that is in contact with the resin layer, the smoothness of the coating layer surface can be measured using the Smoothstar Smoothness Meter. If a value exceeding 351 II mHg is used, a satisfactory metallic luster cannot be obtained even if a metal vapor deposition layer is provided.

In addition, even for coated paper with a coating layer on one side, where the surface smoothness is 35 mmHg or less as measured by the Smooth Star smoothness meter, it is sufficient if the air permeability measured by the high-pressure Ni Gurley air permeability meter is less than 400 seconds/10 cc. A metallic luster cannot be obtained.

This is probably because, when forming the resin layer, the resin penetrates into the coated paper more than necessary, resulting in a decrease in surface smoothness.

Furthermore, by using a layer of electron beam curable resin cured by electron beam irradiation as the resin layer, it has an extremely smooth surface that other resin layers do not have, and also has excellent adhesion between the base paper and the metal vapor deposited layer. There is.

According to the present invention, by using a specific base paper in combination with an electron beam curing resin layer, a metal-deposited paper having extremely excellent metallic luster can be obtained.

The base paper used in the present invention may be general high-quality paper, various types of mechanical pulp paper (BCTMP, CTMP, SGP, RGP), etc.
etc.), DIP, etc., or base paper made from neutral paper is used. Examples of pigments that make up the coating layer include clay kaolin, aluminum hydroxide, precipitated calcium carbonate, heavy calcium carbonate, titanium oxide, barium sulfate, zinc oxide, satin white, calcium sulfate, talc, and plastic pigments. One or more of the usual pigments for coated paper, such as pigments, are selected and used as appropriate. Examples of adhesives include conjugated diene copolymer latexes such as styrene-butadiene copolymer and methyl methacrylate-butadiene copolymer, and acrylics such as polymers or copolymers of acrylic esters and/or methacrylic esters. One or more latexes such as polymer latex, vinyl polymer latex such as ethylene-vinyl acetate copolymer, or modified latex obtained by modifying these various polymer latexes with a monomer containing a functional group such as a carboxyl group. It is selected and used as appropriate.

Among these adhesives, styrene-butadiene copolymer latex and/or modified styrene-butadiene copolymer latex are particularly preferred because they yield a base paper with an extremely smooth surface. When latex is used as an adhesive to shape the coating layer, it is possible to form a smooth coating layer, and even a metal vapor deposited layer.
Latex probably not only contributes to the planar distribution of the coating layer due to the shape of pigments such as kaolin, but also forms a film-like membrane in the voids, exerting a hole-filling effect and increasing the water repellency of the coating layer. It is speculated that this is because the flexibility of this film gives flexibility and barrier properties to the coated layer, and as a result, it has the effect of improving the metallic luster and preventing the occurrence of classic when the metal vapor deposited layer is formed. Ru. The amount of adhesive used in the coating layer is in the range of 10 to 30 parts by weight, preferably 14 to 30 parts by weight, based on the weight of the pigment IOO.
It is preferable to use it in a range of about parts by weight. If the amount of adhesive used is less than 10 parts by weight, it will be difficult to obtain a coated layer with excellent smoothness, and barrier properties will be lacking. Further, it is not preferable to use more than 30 parts by weight because this will result in a decrease in blocking properties.

In addition, as an adhesive, starches such as positive starch and oxidized starch used for ordinary coated paper; cellulose derivatives such as carboxymethyl cellulose and hydroxyethyl cellulose; Synthetic resin adhesive; gelatin,
It is also possible to use proteins such as casein, soybean protein, synthetic protein, etc., but it is necessary to keep it to an extent that does not impair the desired effects of the present invention. Further, various auxiliary agents such as antifoaming agents, colorants, flow modifiers, etc. may be used as appropriate.

The paint for the coating layer prepared in this manner can be applied to a blade coater, air knife coater, roll coater, brush coater, curtain coater, chamber coater, bar coater, gravure coater, or size press, which are commonly used in the manufacture of coated paper. The base paper is coated in one layer or in multiple layers using an on-machine coater or an off-machine coater equipped with a coating device such as a coater.

The coating amount is desirably adjusted within a range of about 10 to 30 g/rrf, preferably within a range of 15 to 25 g/rrf. Incidentally, if the coating amount is less than 10g/rrf, the surface smoothness of the paint layer will be insufficient and it will not be possible to obtain a satisfactory gloss on the metal-deposited surface, and if the coating amount is more than 30g/rrf, the product will deteriorate. This is not preferable because the thickness of the coating becomes too large, which requires lowering the basis weight of the base paper or making significant adjustments to the coating composition.

Thus, it is preferable that the base paper provided with a specific coating layer as described above is further subjected to a smoothing treatment after drying the coating layer.
For example, super calendar, gloss calendar (JP-A-49-132305, published patent publication 63-50018)
8), Soft Calendar (Paper Valp Technology Times, 6)
August 2nd issue. Pages 31-36. PP I, 1987.11
Monthly issue, pages 45-47. WFP, 1985. 22,87
Various types of calendars, which are more powerful than metal rolls, drums, and elastic rolls (pages 3 to 877), are used as appropriate on-machine or off-machine. The surface of the metal roll may be mirror-finished with hard chrome plating, etc., and the surface temperature is 100 to 50.
It is more preferable to maintain the temperature at a high temperature of 0°C. In addition, as the elastic roll, resin rolls such as polyurethane, polyamide, polyimide, etc., or rolls formed by cutting cotton, asbestos, nylon, aramid fibers, etc., are used as appropriate.
A material with high heat resistance, such as an aramid roll, is particularly preferably used.

Various processing conditions when processing with a high-temperature calender are adjusted appropriately depending on the base paper conditions used, properties of the coated layer, coating amount, paper moisture, finishing speed, etc., but the higher the surface temperature of the calender roll, the better the coating will be. It is preferable because it further promotes plasticization of the coating layer, and is generally adjusted within a range of about 150 to 300°C. In addition, the pressure conditions for the calender roll are linear pressure of 1
It is preferable to maintain it at about 00 to 500 kg/cm,
Generally, it is adjusted in the range of about 150 to 350 kg/cm, and the number of pressure nips is usually 2 to 6 nips per drum in the case of a soft calender, but 3 to 11 in the case of a super calender. A nip level is common. The moisture content of the base paper before entering the nip is preferably about 3 to 10%, and the finishing speed of the calendar is 100 to 1300 m/min, although it varies greatly depending on the paper weight, paper type, etc.
A range of is preferred.

The coated paper thus obtained, which has a smoothness of 35 mmllg or less as measured by a smoothness tester and an air permeability of 400 seconds/10 cc or more as measured by a high-pressure Gurley test, is used as a base paper.

In addition, in order to further improve the smoothness of the base paper, an undercoat layer mainly composed of synthetic resin is provided on the surface of the coating layer of the base paper for the purpose of increasing the adhesive strength between the vapor deposition layer and the base paper. You can also do it.

The synthetic resin used for this undercoat layer is
In addition to electron beam curable resins, examples include alkyd resins, acrylic resins, vinyl resins, cellulose resins, urethane resins, and polyester resins, which can be dissolved or dispersed in a solvent or aqueous medium. It is applied by coating. Further, ultraviolet curable resins can also be used.

Of course, it is also possible to provide a coating layer, a heat-sensitive recording layer, a pressure-sensitive recording layer, etc., on the back side of the base paper.

Electron beam curable resin layers are sequentially formed on the base paper thus formed.

Methods for forming the metal vapor deposition layer include (1) direct vapor deposition method and (2) transfer method. (2) The direct vapor deposition method is a method in which an electron beam curable resin is applied onto a base paper, cured by irradiation with an electron beam, and then a metal is vacuum evaporated onto the electron beam curable resin layer. In addition, the transfer method involves performing metal vapor deposition on a plastic film support such as polyester film that has been treated with a release coating, and applying an electron beam curable resin on the vapor deposition layer and/or base paper. After bonding the vapor-deposited layer surface with the base paper and irradiating it with electron beam to harden the resin,
This method involves peeling off the plastic film support to obtain metallized paper. Generally, the surface of the metal vapor deposited layer obtained by the transfer method has excellent smoothness and gloss, and has less curl.

Examples of the vapor-deposited metal of the metal vapor-deposited layer include metals such as aluminum, gold, silver, and zinc, but aluminum is preferable from the viewpoint of cost and appearance. In the case of vapor deposition, the thickness of the vapor deposited layer is preferably about 1,000 mm from the viewpoint of appearance and cost.

The electron beam curable resin used in the present invention is not particularly limited as long as it is a resin that can be cured by electron beams, but it may be made up of, for example, the following prebolimers and monomers.

(1). Examples of the polymers include (a) aliphatic, alicyclic, and araliphatic di- to hexavalent polyhydric alcohols and poly(meth)acrylates of polyalkylene glycols; (b) aliphatic, alicyclic, and araliphatic polyhydric alcohols; , aromatic 2-6
(C) Poly(meth)acryloyloxyalkyl phosphate ester; (d) Polyester poly(meth)acrylate;
e) Eboxy poly(meth)acrylate; (f)
Polyurethane poly(meth)acrylate; (8) Polyamide poly(meth)acrylate; (b) Polysiloxane poly(meth)acrylate: (i) Vinyl or diene having a (meth)acryloyloxy group in the side chain and/or terminal system low polymer; (j) the oligoester described in (a) to (i) above (
meth)acrylate modified products, etc.

(2). The heptanomers include (a) carboxyl group-containing monomers represented by ethylenically unsaturated mono- or polycarboxylic acids, and carboxylic acid group-containing monomers such as their alkali metal salts, ammonium salts, and amine salts; (C) A monomer containing an aliphatic group represented by ethylenically unsaturated (meth)acrylamide or alkyl-substituted (meth)acrylamide, and vinyllactams such as N-vinylpyrrolidone; (C) Aliphatic or aromatic Sulfonic acid group-containing monomers represented by vinyl sulfonic acids and their alkali metal salts, ammonium salts, amine salts, etc.; (d) Hydroxyl groups represented by ethylenically unsaturated ethers, etc. Containing monomer; (e) A ξ group-containing monomer such as dimethylanoethyl (meth)acrylate-2-vinylpyridine; (f)
Quaternary ammonium group-containing monomer; (8) Alkyl ester of ethylenically unsaturated carboxylic acid; (h) Nitrile group-containing monomer such as (meth)acrylonitrile; (i) Styrene; U) Vinyl acetate, acetic acid ( Esters of ethylenically unsaturated alcohols such as meth)allyl; (g) Mono(meth)acrylates of alkylene oxide addition polymers of compounds containing active hydrogen; (1) Diesters of polybasic acids and unsaturated alcohols; Representative bifunctional monomers containing ester groups; (e) Bifunctional monomers consisting of diesters of alkylene oxide addition polymers of active hydrogen-containing compounds and (meth)acrylic acid; (n) N, N -Bisacrylamides such as methylene bisacrylamide: (0) Difunctional monomers such as divinylbenzene, divinylethylene glycol, divinyl sulfone, divinyl ether, and divinyl ketone; (P) A combination of polycarboxylic acid and unsaturated alcohol Ester group-containing polyfunctional monomer represented by polyester; (q) polyfunctional monomer consisting of polyester of alkylene oxide addition polymer of active hydrogen-containing compound and (meth)acrylic acid; (r) trifunctional monomer; Polyfunctional unsaturated monomers such as vinylbenzene.

etc.

When applying the electron beam curable resin onto the base paper or onto the vapor deposited layer of the vapor deposition transfer film, a conventional coating method such as a bar coater, roll coater, air knife coater, or gravure coater is used. Further, the coating amount is preferably 0.1 to 20 g/rrf in terms of dry weight, and more preferably 1-Log/rrf. At this time, the coating amount is 0.
If it is less than 1g/rrf, the surface smoothness will be insufficient and sufficient metallic luster will not be obtained.If it is more than 20g/rrf, it will not only be economically disadvantageous, but depending on the resin used, the label will become too hard and difficult to cut. This poses the problem of poor workability.

The dose of the irradiated electron beam is 0. 1-20 Mrad, preferably 0. A range of approximately 5 to 10 Mrad is desirable.

0. If it is less than I Mrad, the resin component cannot be sufficiently cured, and if it exceeds 20 Mrad, the strength of the base paper may decrease.

Examples of electron beam irradiation methods include scanning method,
A curtain beam method, a broad beam method, etc. can be adopted, and an appropriate acceleration voltage for irradiation is 100 to 300 KV.

The metal oxidation prevention and scratch resistance are applied on the formed metal vapor layer.
A top coat layer may be provided on the metal vapor deposited layer as necessary to impart wear resistance or improve suitability for post-processing such as printing. As the top coat layer, the same synthetic resin or electron beam curing resin as used for the undercoat layer can be used. "Example" The present invention will be described in more detail with reference to Examples below, but of course the scope is not limited thereto. In addition, "parts" and "%" in the examples indicate "parts by weight" and "% by weight," respectively.

Example I A paper was prepared by adding 1.5 parts of rosin size, 5 parts of talc, and 3 parts of sulfuric acid to a pulp composition of 50 parts of NBKP and 50 parts of LBKP. Dry using a type cylinder dryer, weighing 60g/
A rd base paper was obtained.

On the other hand, kaolin (product name: UW-90, manufactured by EMC) 1
00 parts and 0.2 parts of sodium hexametaphosphate were dispersed in water to prepare a pigment slurry with a solid content concentration of 70%, and to this pigment slurry, 3 parts of oxidized starch (trade name: Ace A. manufactured by Oji Cornstarch Co., Ltd.), 25 parts (solid content) of a modified styrene-ptadiene copolymer latex (trade name: JSRO696, manufactured by Nippon Gogo Rubber Co., Ltd.) were added, and water was further added to prepare a coating liquid with a solid content concentration of 60%.

This coating liquid was coated on one side of the base paper using an off-bent blade coater so that the coated amount after drying was 25 g/bo, and then a metal roll having a surface temperature of 150"C and a boria ξ Linear pressure of 250 kg with a 4-nip soft compact calender made of elastic rolls of hard resin.
The surface was finished and a base paper was obtained under the conditions of /cm.

The base paper is coated with an electron beam curable resin (manufactured by Mobil Chemical Company,
77X-187A) was applied to 4 g/bo, and a vapor-deposited film (
A silicone release agent was applied to a polyethylene terephthalate film with a thickness of 25 μm, and aluminum was deposited on it to a thickness of 500 μm using a vacuum deposition device. Then, an electron beam of 3 Mrad was irradiated using an electron beam irradiation device (Electro Curtain CB150i manufactured by ESI). After irradiation, the polyethylene terephthalate film was peeled off to obtain metallized paper with the vapor-deposited layer transferred to the base paper side.

Example 2 On one side of the base paper of Example 1, 80 parts of kaolin and 20 parts of heavy calcium carbonate were added as pigments, and 3 parts of oxidized starch (solid content) and 16 parts of styrene-butadiene latex (per 100 parts of pigment as adhesives) were added. A coating liquid consisting of solid content) was coated to a dry weight of 13 g/rrf and dried to obtain cast coated paper Kawahara paper.

On the other hand, 90 parts of kaolin and 10 parts of light calcium carbonate are used as pigments, and 1 part of casein is used as an adhesive for 100 parts of pigment.
A cast coating liquid was prepared consisting of 0 parts (solid content) and 12 parts (solid content) of acrylic acid/butadiene/methyl methacrylate (ratio: 2/33/65) copolymer latex.

After applying the coating liquid to the pigment-coated surface of the cast-coated paper Kawahara paper so that the dry weight becomes Log/n{, the coating liquid is pressed against a chrome-plated cast drum (surface temperature 90″C), After drying, it was peeled off to obtain a base paper which is a cast coated paper.

Al ξ
A metal-deposited paper in which the nium-deposited layer was transferred to the base paper was obtained.

Comparative Example 1 A metallized paper with an aluminum vapor-deposited layer transferred to the base paper was obtained in the same manner as in Example 1, except that a commercially available coated paper was used as the base paper.

Example 3 4 g of electron beam curable resin (77X-187A, manufactured by Mobilke Rencal) was placed on the same base paper as in Example 1.
r+i coating and irradiation with 3 Mrad electron beam. On this cured resin layer, aluminum was deposited to a thickness of 500 mm using a vacuum deposition apparatus to obtain metal-deposited paper.

Example 4 4 g/% of an electron beam curable resin (EB-A-40, manufactured by Dainippon Ink Co., Ltd.) was applied onto the same base paper as in Example 1, and 3
It was irradiated with Mrad's electron beam. On this cured resin layer,
Aluminum was deposited to a thickness of 500 mm using a vacuum deposition apparatus to obtain metal-deposited paper.

Example 5 A metallized paper with an aluminum vapor-deposited layer having a thickness of 500 mm was obtained in the same manner as in Example 3 except that the cast coated paper of Example 2 was used as the base paper.

Comparative Example 2 A metallized paper with an aluminum vapor-deposited layer of 500 mm thick was obtained in the same manner as in Example 3, except that a commercially available coated paper was used as the base paper.

Comparative Example 3 A metallized paper with an aluminum vapor-deposited layer of 500 mm thick was prepared in the same manner as in Example 3, except that a commercially available coated paper different from that used in Comparative Example 2 was used as the base paper. Obtained.

Comparative Example 4 A metal-deposited paper having a 500-thick aluminum-deposited layer was obtained using the same material as in Example 3, except that a commercially available highly glossy paper was used as the base paper.

Comparative Example 5 After forming a resin layer by applying an acrylic emulsion to a dry weight of 4 g/ryf on the same base paper as in Example 1, 500% of aluminum was applied onto the resin layer using a vacuum evaporation device. The metal-deposited paper was obtained by vapor deposition to a thickness of about 100 ml.

The smoothness (value measured by Smoostar smoothness meter, unit: mn+Hg) and air permeability (value determined by high-pressure Gurley air permeability meter, unit) of the base paper of the IO type metallized paper obtained as above. Table 1 shows the measured values (2 seconds/10 cc) and the evaluation of the metallic luster after forming the metal vapor deposition layer.

Table I [Evaluation] ◎ ・・・ ○ ・・・ △ ・・・ × (Excellent)
(Poor) "Efficacy" As is clear from Table 1, the base paper has a smoothness of 35 mmHg or less as measured by the Smoostar smoothness meter, and an air permeability of 400 seconds/10 cc or more as measured by the high-pressure Gurley air permeability meter. The metal-deposited paper of the present invention, in which a metal-deposited layer was provided through a resin layer cured by electron beam irradiation using a coated paper having a high gloss, had extremely excellent metallic luster.

Claims (1)

[Claims] In metal-deposited paper formed by laminating a resin layer and a metal-deposited layer on a base paper, the base paper has a coating layer mainly composed of pigment and adhesive, and the smoothness of the surface of the coating layer is the Smoother smoothness. It is made of coated paper with a measured value of 35 mmHg or less and an air permeability of 400 seconds/10 cc or more as measured by a high-pressure Gurley air permeability meter, and the resin layer is a resin layer cured by electron beam irradiation. Characteristic metallized paper.