JPH02160590A - Production of glossy printed matter and device suitable for the same - Google Patents

Abstract

PURPOSE:To obtain a printed matter with a high degree of gloss and enhance workability and economy by a method wherein a web form printed matter is coated with a coating agent for pressing, and the printed matter in the web- like is brought into intimate contact with a specular-finished surface of a hot roller of a press. CONSTITUTION:A web-like printed matter 2 drawn out from a roll stand 1 is coated with a coating agent for pressing, at a coater 3. The printed matter 2 is made glossy by a press 5. The press 5 consists mainly of a specular-finished hot roller 7 and a pressing roller 8. The web-like printed matter coated with the coating agent is brought into intimate contact with the hot roller 7 at a temperature of 90-150 deg.C by a linear pressure of 60-150kg/cm, whereby a desired gloss is imparted to the printed matter. The web-like printed matter is obtained by printing on a paper with a basis weight of not more than 100g/m<2> or of 100-350g/m<2>. The coating agent for pressing whose main ingredient is an aqueous resin dispersed material with a glass transition temperature Tg of 60-130 deg.C, as a main constituent.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to a method for producing glossy printed matter, and is directed to a web-like printed matter.After applying a coating material for press processing, hot press processing is performed in the web state. It is an object of the present invention to provide a method for manufacturing glossy printed matter, which is characterized by performing the following steps.

<Prior art and its problems> A high degree of gloss and durability are often required due to the desire to make printed matter more beautiful and more luxurious.

For example, if the printed material is used for gift containers or packaging containers that need to convey a high-quality image of the contents (detergent containers, electrical product containers, etc.), poster calendars, book covers, shopping bags, etc. requires high gloss, abrasion resistance, water resistance, or stain resistance.

Conventionally, in order to obtain printed matter with a high degree of gloss, a method has been used that uses paper with excellent smoothness, such as cast coated paper. Cast-coated paper is obtained by applying a large amount of a coating agent containing a large amount of clay to paper manufactured by a paper manufacturer, and then bringing the coated layer into contact with a cast surface such as a chrome-plated drum. This kind of cast paper contains a large amount of clay, etc., which makes it heavy and hard, and it lacks bending resistance.
Since it is designed to be printed after casting, its water resistance and abrasion resistance are insufficient.

Therefore, although printing using cast coated paper is effective in terms of giving gloss, it is not sufficient in terms of the above-mentioned durability of the printed matter, and if you want to obtain a higher degree of durability, post-processing such as varnishing is required. It was what I needed. Therefore, for such purposes, it is not economical because the cost of cast coated paper itself is high and furthermore, the above-mentioned post-processing is required.

Therefore, as usual gloss imparting means, methods have been used such as overcoating printed matter with so-called varnish or coating with vinyl, or laminating a plastic film.

However, although the former method of applying varnish or vinyl coating is effective in improving gloss to a certain extent, it does not satisfy the high market demands for cosmetic decoration and luxury.

In the latter case, although a high level of gloss can be obtained from the plastic film, the unevenness of the adhesive used when bonding the paper to the paper impairs transparency, resulting in a decline in quality, and equipment This was problematic both in terms of performance and cost.

On the other hand, a method is also used in which a resin solution is applied onto a printed matter, and after drying, flat pressure pressing or endless pressing is performed using a mirror plate. In this method, a resin film that has been dried after application is thermally melted and smoothed using a mirror plate, so that a high level of gloss can be obtained.

However, the flat press method had extremely low f% workability, and the endless press method consists of an endless belt made of stainless steel or the like, and printed matter is continuously inserted one sheet at a time. Because of this type, the workability is better than the former, but there are problems such as the belt surface and the printed matter not being peeled off smoothly and having to be peeled off by one person. Even if the paper itself has a certain degree of rigidity, it will not peel off smoothly, so for paper with a weight of 1007/Ln2 or less,
This method was completely inapplicable.

<Problems to be Solved by the Invention> Therefore, the present invention aims to solve the conventional problems, and provides a manufacturing method with excellent workability and economical efficiency to obtain a printed product with higher gloss. It is intended to provide a method.

Further, the present invention provides an apparatus suitable for carrying out the above method for producing glossy printed matter.

Means for Solving Problems> That is, the present invention provides a hot roller of a press machine having at least one mirror-finished hot roller after applying a coating material for press processing to a web-shaped printed matter. A method for producing a glossy printed matter, characterized in that the printed matter is brought into close contact with the surface in a web state (Claim 1)
It is related to. Further, the present invention provides that the web-like printed material has fE It 100? / rr /
A method for producing glossy printed matter (claim 3), which is a printed matter printed on paper with a size of 2.0 m in size, and a coating material for press processing that mainly contains an aqueous resin dispersion having a glass transition temperature (Tg) in the range of 60 to 130°C. A method for producing glossy printed matter (Claim 4)
).

Furthermore, the present invention provides a coating means for applying a coating agent for press processing to printed matter pulled out from a mill roll stand for printed matter printed on web-like paper, a mirror-finished hot roller and a pressure roller, and a coating agent for press processing. Manufacture of glossy printed matter mainly consisting of a press processing means for imparting gloss to the printed matter, and a guide roller for adjusting the contact width of the web-like printed matter coated with a coating agent with the hot roller. Equipment suitable for (M requirement 5)
, a printing means for printing on paper pulled out from a web-like paper mill roll stand, an application means for applying a coating for pressing onto the printed paper, a mirror-finished hot roller and a pressing roller. and a guide roller for adjusting the contact width of the web-shaped printed matter coated with a press coating material with the hot roller, and mainly consists of a press processing means for imparting gloss to the printed matter. Mounting W suitable for producing glossy printed matter
(Claim 6).

Hereinafter, the method for producing a glossy printed matter according to the present invention will be explained in more detail.

First, the printing materials used in carrying out the method of the present invention include papers such as coated cardboard, K liner, jute liner, etc. used for printing on various folding cartons, posters and other printing, art paper, coated paper, etc. This applies to paper such as katatsu and paper.

There are no particular restrictions on the quality or thickness of the paper used here, but in particular paper with a weight of 100% grams/m2 or less has good dimensional stability against heat during press processing, and has a smooth surface. It is desirable to have excellent properties and homogeneity.

The methods for printing on these papers are as follows:
This can be done by any of the conventional methods such as planographic printing, gravure printing, flexographic printing, etc., but it is limited to printing in the form of a web. Note that the printing ink may be any of oil-based, solvent-based, and water-based inks that are suitable for each printing method.

After the printing process is completed, the printed matter printed on the above-mentioned printing material by lithographic printing (rotographic printing), gravure printing, or flexo printing is coated with a coating material for press processing.

Regarding the coating of the press processing coating material, various methods such as roll coating, air knife coating, curtain coating, spray coating, etc. are applied using the press processing coating material shown below on the web-shaped printed matter printed by the above method. It can be coated using different methods.

Furthermore, a gravure printing machine or a flexo printing machine can also be used as a coating means. In this coating process, if it is performed separately from the printing process, it will be dried after coating and then rolled up, but due to the type of printing machine used in the printing process or the attached equipment, etc. For example, if a coating device is connected to the line of a rotary lithographic printing press, or a multicolor gravure or flexo printing press has a surplus printing unit that is not used for printing. By using these as coating machines for press-working coating materials, printing and coating can be performed continuously.

Next, various types of press coating materials conventionally used in press methods using flat pressure presses or elm dress belts can be used as coating materials for press processing to be applied onto the printed matter; Water-based ones are more preferable from the viewpoint of the environment and fire hazards. As a solvent type, a resin solution consisting of vinyl chloride/vinyl acetate resin can be used, and as an aqueous type, the main component is an aqueous resin dispersion with a glass transition temperature (Tg) in the range of 60 to 130°C. A coating composition having the following properties is preferred.

When obtaining an aqueous resin dispersion having a specific glass transition temperature to be used in an aqueous press coating, it is necessary to consider the glass transition temperature of the vinyl monomer homopolymer shown below and use the conventionally known approximate formula. By setting the polymerization ratio of each vinyl monomer to be used based on the following, an aqueous resin dispersion having a desired glass transition temperature can be obtained. On the other hand, a so-called polymer blend, which is a mixture of an aqueous resin dispersion made of a polymer with a relatively high Tg and an aqueous resin dispersion made of a polymer with a relatively low Tg, can also be used to obtain an aqueous resin dispersion with a desired Tg. Examples of vinyl monomers that can be used to produce the aqueous resin dispersion according to the present invention are as follows.

Vinyl monomers from which a homopolymer with a relatively high Tg can be obtained include acrylic vinyl monomers such as acrylic acid, methacrylic acid, methyl methacrylate, and ethyl methacrylate, and styrene vinyl monomers such as styrene and α-methylstyrene. In addition, examples of the relatively low Tg vinyl monomer include acrylic acid or methacrylic acid alkyl esters other than the above-mentioned methyl methacrylate and ethyl methacrylate, such as methyl, ethyl,
Propyl, isopropyl, n-butyl, S-butyl, t
-Butyl, hexyl, 2-ethylhexyl, decyl, lauryl, and other esters having a linear or side chain alkyl group can be exemplified. In addition to the above-mentioned monomers, it is also possible to copolymerize other vinyl monomers, such as unsaturated monocarboxylic acids such as crotonic acid, α- and β-unsaturated dicarboxylic acids such as itaconic acid, fumaric acid, and maleic acid, N
- acrylamide derivatives containing at least one N-substituted methylol group, such as methylol acrylamide, N-butoxymethyl acrylamide, ethylene glycol, diethylene glycol, propylene glycol,
Mono- or diesters of acrylic acid or methacrylic acid of glycols such as dipropylene glycol,
Alternatively, monomers such as glycidyl ether of acrylic acid and methacrylic acid, acrylonitrile, vinyl chloride, vinyl acetate, vinyl propionate, vinylidene chloride, etc. can be exemplified.

Among these exemplified vinyl monomers, those whose main components are acrylic acid, methacrylic acid, or their alkyl esters, and styrene vinyl monomers are preferred.

To obtain an aqueous resin dispersion from these monomers, the aforementioned monomers are emulsion polymerized using a hydrophilic catalyst such as ammonium persulfate, potassium persulfate, hydrogen peroxide, or a redox catalyst using a generally known method to stably disperse the monomers. If necessary, an emulsifier can be added.

As these emulsifiers, it is possible to copolymerize a mixture of vinyl monomers in an emulsified state in the presence of an anionic or nonionic surfactant, but the use of low-molecular surfactants for boat fishing is bad for the water resistance of the resulting coating. Therefore, when water resistance is particularly required, polymeric anionic activators are suitable as emulsifiers.

The aqueous resin dispersion used in the present invention also has excellent performance by using such an emulsifier. Examples of such polymeric emulsifiers include conventional aqueous solutions of alkali-soluble resins such as shellac and (meth)acrylic or maleic acid copolymers having carboxyl groups.

Regarding the coating composition for press processing used in the present invention, it is necessary to use an aqueous resin dispersion having a relatively high glass transition temperature (60 to 130°C). As a dispersant used during polymerization,
Using a relatively large amount of an aqueous solution of an alkali-soluble resin composed of a vinyl monomer that forms a homopolymer with a high glass transition temperature, such as acrylic acid, methacrylic acid, or styrene, other vinyl monomers are emulsion polymerized using a conventional method. It is preferable that

As the alkali used for water-solubilizing the alkali-soluble resin, known ones can be used, such as ammonia, organic amines such as triethanolamine, monoethanolamine, etc. However, from the viewpoint of drying the water-soluble resin, volatile If the resulting water-soluble resin dispersion has a Tg of less than 60°C, the heat resistance will be insufficient, resulting in decreased gloss or blocking, and if the Tg exceeds 130°C. The coating film cannot be sufficiently crushed during press processing, and the desired high gloss (normally, high gloss has a specular gloss of 70 or higher at an incident angle of 60°, and has ultra-gloss). 80 or above) is difficult to obtain.

In addition, the following additives can be added to the composition as necessary, and these additives include water-soluble varnish to assist in adhesion to the printed surface, acrylic resin, An aqueous solution of an alkali-soluble resin such as maleic oxygen resin or shellac can be added.

In addition, waxes such as polyethylene waxes are used to improve scratch resistance, higher fatty acids such as stearic acid, higher alcohols such as cetyl alcohol, and interfaces such as phosphoric acid esters are used to improve peelability during press processing. Activators etc. can be used.

Further, coloring agents such as dyes and pigments or extender pigments can be added as additives, and it is also possible to obtain a colored glossy film if necessary.

The coating agent for press processing consisting of the above-mentioned components is applied to the entire surface or as necessary by using the above-mentioned application means on a web-shaped printed matter printed in a rotary manner using flexo ink, lithographic ink, gravure ink, etc. It can be applied to parts.

The printed web-like material may be coated continuously with the printing process as described above, or the coating process may be performed independently, or the coating process and the press processing process described below may be performed consecutively. It's good to go.

The web-like printed material coated with the coating composition for press processing is dried, if necessary, and then glossed with a hot roller used for press processing.

The temperature of the hot roller is in the range of 90 to 150'C, and the pressure with the pressure roller is 60 to 150K in linear pressure.
g/cm.

As a device for press working, a continuous press machine having at least one pair of mirror-finished hot roller and press roller can be used.

When carrying out the method of the present invention, a press machine in which a hot roller and a press roller are paired may be used, but a type in which 2 to 3 or more pairs of press rolls for glossing are continuous is used. You can also use those. Regarding the press working process, it is possible to perform it continuously with the applying process of the coating material for press working, but it is also possible to perform only the press working process independently.

Although each process has been described above, printed matter having a high degree of gloss can be efficiently produced by performing each process individually, or by performing some or all of the processes in succession.

Next, an apparatus suitable for carrying out the method for producing a glossy printed matter according to the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram showing the main parts of an apparatus suitable for manufacturing glossy printed matter according to the present invention. In FIG. A coating agent is applied onto the web-shaped printed matter 2 in a coating device 3 for applying a coating material for press processing.

FIG. 1 shows a central impression drum type flexo printing machine in which a printing unit that is not used for printing, for example, unit 34 in the figure, is used as a coating device.

4 indicates a dryer installed as necessary. Note that the web-like printed material whose surface is coated with a coating agent is given gloss in a press processing machine 5. The press process 815 mainly consists of a mirror-finished hot roller 7 and a roller 8 for pressing, and the web-like printed matter coated with a coating material is heated at a temperature of 90 to 150'C, and then heated to a temperature of 60 to 60'C. Close contact is made with a linear pressure of 150 Kg/cm to impart the necessary gloss. here,
The guide roller shown is for adjusting the contact width of the web-like printed matter with the hot roller. By changing the contact width with the hot roller depending on the weight of the paper used and the glass transition temperature of the resin used in the coating material for press processing, sufficient melting of the coating material is achieved, resulting in a smooth mirror surface. This is to ensure that the

After the press working, it is wound up by a winding roller 6. After that, punching, box making, bag making, and other processing will be performed.

When using the apparatus shown in Fig. 1, unprinted paper is set on the roll stand, and the printing units 3-1 to 3-3 of the flexo printing machine shown as coating devices perform fluxo printing. By applying the coating material for press processing in step 3-4, printing, coating, and press processing can be performed continuously.

Although not shown in the drawings, when multiple pairs of press rollers are combined in succession, by making the diameter of the press rollers vary in size, it is possible to reduce the speed difference to a greater or lesser extent at the contact portion of each pair of rolls. In other words, slippage occurs, making it possible to impart higher gloss.

<Example> Dispersion Production Example 1 An ammonia aqueous solution of an alkali-soluble resin consisting of 53% by weight of methacrylic acid, 23% by weight of methyl methacrylate, and 24% by weight of styrene was used as a dispersant, and for 66 parts by weight of the resin content of the dispersant, 34 parts by weight of styrene is added and emulsion polymerization is carried out by a conventional method to obtain aqueous resin dispersion A. The resulting dispersion A had a solid content of 37% by weight and a glass transition temperature of 125°C.

Dispersion Production Example 2 Similar to Production PA1, an ammonia aqueous solution of an alkali-soluble resin consisting of 28% by weight of methacrylic acid, 4% by weight of acrylic acid, 7% by weight of methacrylate, and 61% by weight of ethyl acrylate was used as a dispersant. Aqueous resin dispersion B is obtained by emulsion polymerizing 88 parts by weight of styrene with respect to 12 parts by weight of the resin content. The obtained dispersion B had a solid content of 55
% by weight, glass transition temperature, approximately 89°C.

Press processing coating production examples 1 and 2 Using dispersions A and B obtained in dispersion production examples 1 and 2, 80 parts of dispersion, 10 parts of ethanol, 5 parts of butylgarbitol, 1 part of polyethylene wax, phosphoric acid Coating agents 1 and 2 are prepared by mixing 1 part of an ester mold release agent and 3 parts of water.

To Example 1-2 Web-like coated paper (85%?/m2) was used as printing paper.
, manufactured by Tamako Paper Co., Ltd.), and using a Gobden flexo printing machine, using water-based flexo ink for the first color and coating materials 1 and 2 for the second color, the coating material for printing and press processing was applied. Then, using only the press machine part of the apparatus shown in Figure 1, the hot roller temperature was 150.
Pressing was carried out under the conditions of 80-7 minutes at a pressure of 100 Kg/am to impart gloss. The gloss after pressing was measured using a gloss meter at the overlapping area of the printing ink and coating material, and the measured values are shown in Table 1.

Table 1 Examples 3 to 4 The same paper as in Example 1 was used as the printing paper, printed with solvent-based gravure ink, rolled up, printed with offset rotary printing ink, and rolled up as shown in Figure 1. Each was placed on a roll stand, and the coating material 2 was applied with a coating machine, while press working was continuously performed under the same conditions as the PAl used to impart gloss.

Similarly, the gloss was measured and added to Table 1.

Comparative Examples 1 to 2 Using the printed materials that were coated with the press coating materials in Examples 1 and 2 but not pressed, the gloss by applying only the gloss varnish was measured and added to Table 1.

Comparative Example 3 Printing and coating were carried out under the same conditions as in Example 1 except that cast coated paper was used as the printed matter, and the gloss was measured in the same manner and added to Table 1.

Comparison @ 4 The printed material coated with the coating material in Example 1 was cut and pressed using a conventionally used endless press machine made of a stainless steel belt. The speed of the press machine is 25 m/min, the temperature is 120°C, and the pressure is 100 kg.
/c++ was used.

Even though endless press machines have a cooling process after the hot roller, the printed material cannot be separated smoothly, and without manual assistance, it can get caught up in the belt again, causing problems in the production process. The quality was extremely bad. Therefore, this endless press cannot perform efficient press working.

Evaluation Test 1 The prints obtained in Examples 1 to 4 and Comparative Examples 1 to 3 were tested for abrasion resistance, water resistance, and bending resistance, and the results were added to Table 1.

In addition, each evaluation in [Evaluation Test] was performed by the following method.

Friction resistance: Each printed material was tested with a Gakushin type friction resistance tester at a load of 500g.2.
Tested 000 times and selected those with sufficient resistance.
1. Those that were not sufficient were evaluated as ×.

Water resistance: Using the same method as the abrasion resistance test above, using a cloth soaked in water,
The abrasion resistance was similarly examined under a load of 500 g 50 times, and those with sufficient water resistance were evaluated as ◯, those that slightly stained the cloth were rated Δ, and those that stained the cloth were evaluated as ×.

Folding resistance: The printed side was rated as ``×'' if the folding mark appeared on the 91st side with the printed side facing outward, and ``○'' if there was no change.

Examples 5-6 Web-shaped coated cardboard <300
';! / m'', Jute Star manufactured by Daishowa Paper Co., Ltd.), printing and press processing were carried out using Gobden's Flexographic Stamp +F111fi, using water-based flexographic ink for the first color and coating materials 1 and 2 for the second color, respectively. Then, using only the press machine part of the apparatus shown in FIG. 1, press working was carried out at a hot roller temperature of 150° C. and a pressure of 100 g/arm for 80 m and 7 minutes. Gloss was imparted. The gloss after press working was measured using a gloss meter at the overlapping area of the printing ink and coating material, and the measured values are shown in Table 2.

Table 2 Examples 7 to 8 and Comparative Examples 4 to 5 The paper used was given gloss in the same manner as in Examples 3 to 4 and Comparative Examples 1 to 2, except that the coated cardboard of Example @5 was used. Each result was evaluated in the same manner and added to the above-mentioned Cloth-2.

Effect> As explained above, by following the method of the present invention, it is possible to efficiently and economically obtain printed matter with high gloss and durability even when the paper used is light weight, so-called thin paper. It is.

Further, according to the apparatus disclosed in the present invention, the coating process for press working coating and the press working process, including the printing process, can be carried out continuously and efficiently.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the main parts of an apparatus suitable for producing glossy printed matter according to the present invention. Note that the symbols in the figure indicate the following.

Claims (6)

[Claims] (1) After applying a coating material for press processing to a web-shaped printed matter, the printed matter is closely contacted in a web state to the hot roller surface of a press processing machine that has at least one mirror-finished hot roller. A method for producing a glossy printed matter, characterized by: (2) Web-shaped printed matter weighs 100 grams/m^2
The method for producing a glossy printed matter according to claim 1, wherein the printed matter is printed on the following paper. (3) The method for producing a glossy printed matter according to claim 1, wherein the web-like printed matter is a printed matter printed on paper having a weight of 100 to 350 g/m^2. (4) Glass transition temperature (Tg) of coating material for press processing
2. The method for producing glossy printed matter according to claim 1, wherein the main component is an aqueous resin dispersion having a temperature in the range of 60 to 130°C. (5) Coating means for applying a coating material for press processing to printed matter pulled out from a mill roll stand for printed matter printed on web-like paper, a mirror-finished hot roller and a press roller, and a coating material for press processing. It is equipped with a guide roller for adjusting the contact width of the web-like printed matter coated with the hot roller, and is suitable for producing glossy printed matter mainly consisting of a press processing means for imparting gloss to the printed matter. equipment. (6) Printing means for printing on the paper pulled out from the web-like paper mill roll stand, coating means for applying a coating for press processing on the printed paper, mirror-finished hot roller and press It is equipped with a roller and a guide roller for adjusting the contact width of a web-like printed matter coated with a coating material for press processing with the hot roller, and mainly consists of a press processing means for imparting gloss to the printed matter. Equipment suitable for producing glossy printed matter.