JP2003055893A - Coated paper for offset printing and coated raw paper for the same, and method for producing the coated raw paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide coated raw paper which is used for coated paper for offset printing and can be produced in excellent productivity due to the reduction in stains in a paper-making system and simultaneously due to the improvement in the control of a raw paper-sizing property from the viewpoints of resource saving and the high degree closing of the paper-making system, to provide a method for producing the coated raw paper having excellent productivity and excellent quality balance and used for the coated paper for offset printing, and simultaneously to provide the coated paper which is used for offset printing and has excellent ink adhesiveness, because the coated raw paper for the coated paper has a specific 10 second Cobb value. SOLUTION: This coated raw paper for coated paper for offset printing is characterized by using a styrene-acrylic copolymer sizing agent to be added only by an outer addition method without containing a sizing agent having been added by an inner addition method in a paper-making process. The method for producing the coated raw paper for the coated paper for offset printing coating raw paper with a prescribed amount of a sizing agent to be added by an outer addition method by the use of a film transfer style sizing press device. The coated paper for offset printing is used with raw paper having a specific 10 second Cobb value and using only a sizing agent to be added by an outer addition method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coated paper for offset printing, a coated base paper therefor, and a method for producing the coated base paper. More specifically, from the viewpoint of highly closed inside the papermaking system and resource saving. Since it does not contain the internally added sizing agent that has been conventionally used in papermaking, and only the externally added sizing agent is used, stains in the papermaking system can be reduced and at the same time control of the sizing property is easy and excellent in productivity. Offset printing coated paper for offset printing, which has an excellent balance between productivity and quality by applying a prescribed amount of size press liquid using a film transfer type size press device. Manufacturing method of coated base paper in
Further, the present invention relates to a coated paper for offset printing which has excellent printability by providing a coating layer on a coated base paper having a specific 10 second Cobb value using only an externally added sizing agent.

[0002]

2. Description of the Related Art In a papermaking process that uses a huge amount of industrial water, it cannot be realized without recycling papermaking white water because of limited water resources. In recent years, from the viewpoint of increasing environmental awareness and saving water, it is said that the amount of circulating water in the system will be increased in order to reduce the amount of papermaking white water discharged to the outside of the papermaking system, and the amount of newly added industrial water used will be kept low. The so-called papermaking process is being closed.

In the papermaking process, a white water recovery device such as a polydisk filter and a saver is used for the circulation and reuse of the white water, and the recovered pulp component and the recovered fresh orange water are separated by these white water recovery devices. The pulp content is reused as a recovered pulp slurry only inside the papermaking system, and the collected fresh orange water is reused inside and outside the papermaking system. However, chemicals such as the internally added sizing agent used in the papermaking system circulate in the system if they do not settle on the paper and accumulate, producing hydrolysates and becoming a nutrient source for various bacteria. There is a problem that slime is generated and the inside of the papermaking system is contaminated.

However, in recent years, there has been a movement to reconsider the effect of so-called external sizing agents used in the size pressing process, which has been used as an auxiliary means for the sizing property of paper. For speeding up the paper machine and making newsprint with severe productivity, the method of replacing the internal sizing agent with the external sizing agent has already begun to be used, but high sizing is required. This method has not been applied to the general paper used.

Further, in the production of coated base paper for coated paper for offset printing, some on-machine coating type paper machines do not contain an internally added sizing agent and do not use an externally added sizing agent. So-called coated paper using so-called unsized base paper has been produced, but it is difficult to control the permeation of the coating liquid into the base paper with unsized paper, which only increases the burden on the coating liquid. However, it was difficult to obtain the desired quality and operability.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to reduce stains in a papermaking system when only an externally added sizing agent is used without containing an internally added sizing agent that has been conventionally used in papermaking. At the same time, we provide coated base paper for offset printing coated paper with excellent productivity by improving the controllability of the base paper size.In addition, the externally added sizing agent is specified using a film transfer type size press device. It is intended to provide a method for producing a base paper for coating in offset printing which has an excellent balance between productivity and quality by quantity coating. Further, by using an externally added size coated base paper having a specific 10-second Cobb value using only an externally added size agent, an offset printing coated paper having excellent printability is provided.

[0007]

DISCLOSURE OF THE INVENTION As a result of intensive studies in view of the above, the present inventor has invented a coated base paper in a coated paper for offset printing of the present invention, a method for producing the same, and a coated paper for offset printing. Came to.

That is, the coated base paper in the coated paper for offset printing of the present invention is the coated base paper of the coated paper for offset printing in which at least one coating layer is provided on one side or both sides. It is characterized in that only the externally added sizing agent is used without containing the internally added sizing agent.

In the present invention, the externally added sizing agent is
It is preferably a styrene-acrylic copolymer.

In the present invention, it is preferable to use waste paper pulp as the pulp raw material.

Further, the method for producing a coated base paper in an offset printing coated paper according to the present invention is a coated base paper in an offset printing coated paper in which at least one coating layer is provided on one side or both sides. B at ° C / 60 rpm
A size press liquid mainly composed of a water-soluble binder containing an externally added sizing agent having a lookfield viscosity of 50 mPa · s or less is prepared, and the size press liquid is treated with a film transfer type size pressing device to remove the internally added sizing agent. It is characterized in that 0.01 to 0.05 g / m ² (dry solid content) of an externally added sizing agent is applied onto a size-free base paper without internal addition.

Furthermore, the coated paper for offset printing of the present invention is the coated base paper in the coated paper for offset printing described above, and has a contact time with water of 10 based on the water absorption test method defined in JIS P8140. A coating layer is provided on the coated base paper having a water absorption per second (Cobb value for 10 seconds) of 30 to 80 g / m ² .

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The coated base paper in the coated paper for offset printing of the present invention, the method for producing the same, and the coated paper for offset printing will be described in detail below.

The inventor of the present invention firstly describes the degree of stains in the papermaking system when an internally added sizing agent and an externally added sizing agent are used for the coated base paper in the offset printing coated paper of the present invention. At the same time, the relationship of productivity by improving the controllability of the sizing of base paper was examined.

Further, in the present invention, in order to avoid confusion, a paper obtained by mixing paper pulp with a paper-making chemical and not making a size press treatment is referred to as a "paper-making base paper" (hereinafter referred to as "paper-making base paper").
It may also be referred to simply as base paper. ), And a papermaking paper made without adding an internally added sizing agent in the papermaking paper is referred to as a “paper without internal size”.

Generally, in order to give the sizing property to the base paper in the papermaking process, an internally added sizing agent and an externally added sizing agent are used in combination, but the papermaking speed is increased, and the dehydration condition on the wire becomes strict. If the share added to the slurry for the purpose of improving the dispersion of the pulp slurry is increased, the internally added sizing agent is not bound to the pulp fiber by a chemical reaction, and thus is easily desorbed. The desorbed internally added sizing agent flows into the white water without exhibiting the original sizing property, and since the white water is recirculated as dilution water of the pulp slurry, it is circulated in the papermaking system and Will be accumulated. The unfixed internally added sizing agent thus accumulated undergoes hydrolysis or other unfixed substances or self-aggregation, and is discharged out of the system in the form of dirt.

Further, the dirt accumulated in the stagnation in the system becomes a suitable medium for aerobic and anaerobic fungi, and induces the generation of new dirt called slime. Bactericides and growth inhibitors are used for these fungi, but basically it is only necessary to add substances that cause stains to the system. From the viewpoint of preventing stains in the papermaking system, it is preferable not to add it if it can be ensured.

Generally, the size of the coated base paper in the offset printing coated paper in which at least one coating layer is provided on one side or both sides is used when the coated base paper is manufactured. A method of controlling the amount of the internally added sizing agent or a method of coating the externally added sizing agent on the paper making surface of the coated paper for offset printing may be used alone or in combination. In the present invention, the internally added sizing agent does not contain the sizing agent because it deteriorates the stain in the papermaking system, and the sizing property is controlled only by the externally added sizing agent. J
According to the terms of paperboard / paper / pulp of ISP0001,
The sizing agent applied to the surface of the paper is generally called a surface sizing agent, but in the present invention, the surface sizing agent is referred to as an “external addition sizing agent” in order to make a distinction from the internally sizing agent. It is written as ".

On the other hand, the externally added sizing agent is generally applied with a water-soluble binder in a size pressing device installed after the pre-dryer, separately from the paper making system, and applied to the paper. It has been coated by using a known method such as a size press method, a spray method, or a calendar sizing method, which is dried by an after-dryer and expresses size properties. As described above, the externally added sizing agent has been playing an auxiliary role of the internally added sizing agent so far. In the present invention, however, the sizing characteristics of the externally added sizing agent that can be imparted to the papermaking paper have been noted. That is, the sizing property imparted by the externally added sizing agent is different from the internally added sizing agent in that the yield is always high regardless of the condition of the preparation system, and the productivity and controllability are excellent. Further, in the present invention, as a method capable of sufficiently imparting effective sizing property to the unsized internal raw paper,
It is preferable to use a size press device.

In the present invention, the water-soluble binder used in the above size press is, for example, polyvinyl alcohol, silanol-modified polyvinyl alcohol, vinyl acetate, oxidized starch, phosphate esterified starch, etherified starch, carboxymethyl cellulose, hydroxy. Cellulose derivatives such as ethyl cellulose, casein, gelatin, soybean protein, silyl-modified polyvinyl alcohol, etc .;
Maleic anhydride resin, styrene-butadiene copolymer,
Conjugated diene-based copolymer latex such as methyl methacrylate-butadiene copolymer; vinyl-based polymer latex such as ethylene-vinyl acetate copolymer; or functional group-containing monomer such as carboxyl group of these various polymers Group-modified polymer latex; water-based adhesive such as thermosetting synthetic resin system such as melamine resin, urea resin; polymethylmethacrylate, polyurethane resin, unsaturated polyester resin, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, alkyd resin, etc. One or more synthetic resin adhesives can be used. In addition, the use of known natural or synthetic resin adhesives is not particularly limited.

As the externally added sizing agent, generally, a styrene-maleic acid copolymer, a vinyl acetate-maleic acid copolymer, an alkyl ketene dimer, a styrene-
Acrylic copolymer, composite material of anionic copolymer and cationic copolymer called ion complex,
Also known are olefin-maleic acid copolymers and the like.

The present inventor, while examining means for controlling these sizing properties with an externally added sizing agent, shows that alkyl ketene dimer exhibits the most excellent properties if only sizing properties are evaluated. There are many operational problems such as slip characteristics of winding at the time of winder due to reduction of friction coefficient and generation of stains on size press equipment due to inadequate management of size press liquid temperature, satisfying both operability and size at the same time. It has been found that a styrene-acrylic copolymer is the most preferable externally added sizing agent.

The externally added sizing agent of the styrene-acrylic copolymer referred to herein is an anionic unsaturated carboxylic acid such as acrylic acid or methacrylic acid (both are referred to as (meth) acrylic acid), or These ammonium salts or alkali metal salts, an acrylic acid ester or a methacrylic acid ester (both are referred to as (meth) acrylic acid ester), or a nonionic unsaturated monomer such as (meth) acrylamide or (meth) acrylonitrile. And monomers such as N, N-dialkylaminoalkyl (meth) acrylate, N, N-dialkylaminoalkyl (meth) acrylamide, mineral acid salts thereof and quaternary compounds thereof, and styrene, α-methyl Styrenes such as styrene, and the aromatic rings of these styrenes have alkyl groups of 1 to 4 carbon atoms. A copolymer of styrene monomer styrene compound having a group.

Specific examples of the anionic copolymer include styrene- (meth) acrylic acid type copolymers, and specific examples of the cationic copolymer include styrene-
Examples thereof include N, N-dialkylaminoalkyl (meth) acrylate-based copolymers and styrene-N, Ndialkyl (meth) acrylamide-based copolymers. Specific examples of the amphoteric copolymer include styrene- (meth) acrylic acid-
Examples thereof include N, N dialkylaminoalkyl (meth) acrylamide copolymers.

As the method for producing the above-mentioned copolymer, various known methods such as solution polymerization, emulsion polymerization and suspension polymerization can be employed as they are.

Further, the size press liquid contains, as other additives, a pH adjusting agent, a thickening agent, a fluidity improving agent, a defoaming agent, a foam suppressing agent, a release agent, a foaming agent, a penetrating agent, a coloring dye. Of course, it is also possible to appropriately mix a color pigment, a fluorescent whitening agent, an ultraviolet absorber, a preservative, a fungicide, an antioxidant, an inorganic conductive agent such as sodium chloride and potassium chloride, an organic conductive agent, and the like. .

In the present invention, NBKP and LBK are used as the wood pulp used for making the paper.
In addition to P, NBSP, LBSP, GP, TMP, etc., waste paper pulp can be mentioned. In use, several kinds of them are mixed and used at a ratio according to the purpose.

The raw materials for the used paper pulp referred to in the present invention include top white, ruled white, cream white, card,
Special white, medium white, imitation, fair white, Kent, white art, special cut,
Examples include separate papers, newspapers, and magazines. Further specific examples include non-coated computer recording paper, which is information-related recording paper, printer recording paper such as thermal paper and pressure-sensitive paper, and OA waste paper such as PPC recording paper, art paper, coated paper, and slightly coated paper, Coated paper such as matte paper, high-quality paper, high-quality paper, notebook, notepaper, wrapping paper, fancy paper, medium-quality paper, newsprint, waste paper, super hanging paper, imitation paper, pure white roll paper, milk carton, etc. Paper such as non-coated paper and waste paper such as paperboard such as chemical pulp paper and high-yield pulp-containing paper are used, but are not particularly limited to printing, copying, printing and non-printing.

Waste paper pulp has a high content of fine fibers,
Since the fiber surface is keratinized, the internally added sizing agent is unlikely to yield, the fixing rate on the paper surface that contributes to the sizing property decreases, and the outflow rate into white water tends to increase. Therefore,
It is preferable to add sizing property to the waste paper-containing paper by an externally added sizing agent. The mixing ratio of the waste paper pulp depends on the required quality of the offset coated paper, but is preferably about 40% in the present invention.

The filler used for making the base paper of the present invention is not particularly limited, and known calcium carbonate such as heavy calcium carbonate and light calcium carbonate, inorganic filler such as talc, clay and kaolin, and organic filler. Fillers can be used. Of course, it is also possible to use several kinds of calcium carbonate and various fillers in combination.

The internally added sizing agent used for making the base paper of the present invention is not particularly limited, and is a rosin-based sizing agent, alkenyl succinic anhydride, alkyl ketene dimer, neutral rosin sizing agent, petroleum resin-based agent. Sizes can be used.

In addition to the above, various anionic, nonionic, cationic, or amphoteric paper strength improvers that have been conventionally used, etc., may be added to the paper stock as long as the desired effects of the present invention are not impaired. The above-mentioned internal additive for papermaking is appropriately selected and used as necessary. For example, one or more of various starches and polyacrylamide, polyethyleneimine, polyamine, polyamide / polyamine, urea formalin resin, melamine formalin resin, vegetable gum, polyvinyl alcohol, latex, polyethylene oxide, polyamide resin are suitable. Used in combination.

It should be noted that it is possible to appropriately add a papermaking internal additive such as a dye, a pH adjusting agent, an antifoaming agent, a pitch control agent, and a slime control agent to the paper stock according to the purpose.

In the method for making a base paper according to the present invention, the paper machine includes a fourdrinier paper machine, a twin wire paper machine, an on-top paper machine, a combination paper machine, a round net paper machine, a Yankee paper machine and the like known in the paper manufacturing industry. Machine can be used as appropriate.

Further, in the present invention, in order to avoid confusion, a paper obtained by size-pressing a "papermaking base paper" (hereinafter also simply referred to as a base paper) is referred to as a "coated base paper", Among these, the base paper treated with the liquid in which the externally added sizing agent was not added to the size press liquid was treated with "the externally added size-free coated base paper" and the liquid with the externally added sizing agent added. The base paper will be referred to as "external size coated base paper".

Next, the inventor of the present invention examined a method for producing a base coating paper for a coated paper for offset printing.

In examining the means for applying a liquid mainly composed of the water-soluble binder containing the externally added sizing agent, conventional size press, film transfer type size press (gate roll) It was confirmed that a size coater), a rod coater, a bill blade, a short dwell coater or the like can be used. In this patent, among these coating devices, it is preferable to use a film transfer type size press device which is excellent in productivity, has less penetration of the size press liquid into the inside of the base paper layer, and is excellent in controllability of size property. I found it.

Further, in a film transfer type size press, a specified amount of a size press liquid mainly composed of a water-soluble binder containing an externally added sizing agent having a Brookfield viscosity at 60 ° C. at 60 rpm of 50 mPa · s or less is applied. By doing so, it becomes possible to provide a base paper for coating in offset printing which is excellent in size and coating suitability.

Although there are various methods for defining the liquid viscosity, a Brookfield at 60 ° C. and 60 rpm is used.
The d-viscosity expresses the viscosity in a low shear state, and is an effective regulation method for controlling the coating amount and the transfer amount in a film transfer type size press device.

In the present invention, by using a size press liquid mainly composed of a water-soluble binder containing an externally added sizing agent having a Brookfield viscosity of 50 mPa · s or less at 60 rpm at 60 ° C., the target coating amount control,
We also found that the transfer amount can be controlled. Bro
When the okfield viscosity is 50 mPa · s or more, the amount of the liquid adhered by the size press increases, so that the penetration of the coating liquid is suppressed and, as a result, the controllability of the loading angle of the blade for controlling the coating amount is likely to deteriorate.

The coating amount in the film transfer type size press in the present invention is preferably 0.01 to 0.05 g / m ² as the solid content of the externally added sizing agent. When the coating amount is less than 0.01 g / m ^2, it is not preferable because sufficient sizeability and coating suitability cannot be obtained. On the other hand, when the coating amount exceeds 0.05 g / m ² , the sizing property becomes high. It is not preferable because it is too much and the permeability of the coating liquid is deteriorated and the suitability for coating is deteriorated.

After coating, it is possible to finish using a calender device such as a machine calender, a thermal calender, a super calender and a soft calender, if necessary.

Further, the present inventor studied the offset printing coated paper having the optimum offset printing suitability of the present invention.

Among these, the following conditions were found as a result of examining the relationship between the size property of the coated base paper, the coating suitability of the pigment coating liquid in the coating device, and the offset printing characteristics of the coated paper.

There are various liquid supply systems in the coating apparatus,
During the period from the time when the pigment coating liquid is applied to the coating base paper of offset printing coated paper until the coating amount is adjusted, the pigment coating liquid penetrates the coating base paper with the water-based part of the composition. However, the so-called immobilization state of the coating layer is generally reached until the drying step is started. In this case, controlling the permeation into the coated base paper is a necessary characteristic for maintaining the operability of the coating apparatus and for designing the offset printability of the coated paper as a product. Therefore, as a result of a comparative examination of the Cobb sizing degree of the coated base paper, the offset printing characteristics of the coated paper, and the operability of the coating apparatus, the 10 second Cobb sizing degree and the offset printing characteristics of the coated base paper, especially during printing There was a good correlation with the ink receptivity of the ink. Then, it was found that when the 10-second Cobb value of the coated base paper in the coated paper for offset printing is 30 to 80 g / m ² , the ink receptivity when offset printed on the coated paper is good.

In order to improve only the early formation of the immobilization layer due to the excessive penetration of the pigment coating liquid into the coating base paper, it is sufficient to set the size of the coating base paper to be low, and if the 10 second Cobb size degree is large. The bigger the better, the better. But,
From the operability side of the coating device, the immobilization layer forming speed is improved if the size of the coating base paper in the offset printing coated paper is excessively reduced, but conversely when adjusting the coating amount in the coating device. The fluidity of the coating liquid deteriorates, causing problems in operability. Therefore, considering the printing characteristics of the coated base paper and the operability during coating in the coated paper for offset printing, it was found that the 10 second Cobb value is preferably 30 to 80 g / m ² , and The inventors have invented a coated base paper for coated paper for offset printing.

When the 10 second Cobb value is 30 g / m ² or less,
Penetration of the pigment coating liquid into the coating base paper is too small, which tends to cause binder migration in the drying process,
When offset printing is performed on coated paper, the ink setting properties and ink receptivity deteriorate. Also, the 10 second Cobb value is 8
When it exceeds 0 g / m ² , the fluidity of the coating liquid is deteriorated when the coating amount is adjusted by a coating device, and problems such as streak and increase in loading angle occur in operability.

[0048]

EXAMPLES The effects of the present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. In addition,% in an Example shows the mass%.

Examples 1 to 8 and Comparative Examples 1 to 3 First, for the purpose of clarifying the first invention, base papers 1 to 9 were prepared according to the following formulations. In the present invention, the base paper composition means a papermaking base paper composition.

[0050] <Base paper formulation 1> Base paper formulation; LBKP (freeness; 450 ml, cf) 100 parts 10 parts of calcium carbonate (Okutama Kogyo; TP-121) Aluminum sulfate 0.8 parts Amphoteric starch (manufactured by Japan NSC Co .; Cato3210) 1 part Yield improver (manufactured by Hymo Co .; NR-11LS) 0.02 part

[0051] <Base paper formulation 2> Base paper formulation; LBKP (freeness; 450 ml, cf) 100 parts Talc (Hyogo Clay Co .; Hyogo Talc) 10 copies Aluminum sulfate 2.5 parts Synthetic paper strength agent (manufactured by Seikou Kagaku Kogyo; Stargum A-15) 0.8 part Yield improver (manufactured by Hymo Co .; NR-11LS) 0.02 part

[0052] <Base paper formulation 3> Base paper formulation; LBKP (freeness; 450 ml, cf) 100 parts 10 parts of calcium carbonate (Okutama Kogyo; TP-121) AKD size agent (Arakawa Chemical Co .; SPK-903) 0.02 parts Aluminum sulfate 0.6 part Amphoteric starch (manufactured by Japan NSC Co .; Cato3210) 1 part Yield improver (manufactured by Hymo Co .; NR-11LS) 0.02 part

[0053] <Base paper formulation 4> Base paper formulation; LBKP (freeness; 450 ml, cf) 100 parts Indonesia Clay (P.T. ALTER ABADI; BRU-30) 10 parts Rosin sizing agent (Arakawa Chemical Industry Co., Ltd .; Size Pine N-705) 0.35 parts Aluminum sulfate 3 parts Synthetic paper strength agent (manufactured by Seikou Kagaku Kogyo; Stargum A-15) 0.8 part Yield improver (manufactured by Hymo Co .; NR-11LS) 0.02 part

[0054] <Base paper formulation 5> Base paper formulation; LBKP (freeness; 450 ml, cf) 100 parts 10 parts of calcium carbonate (Okutama Kogyo; TP-121) Neutral rosin sizing agent (Harima Kasei; NeuSize M-10-45) 0.3 parts Aluminum sulfate 1.2 parts Amphoteric starch (manufactured by Japan NSC Co .; Cato3210) 1 part Yield improver (manufactured by Hymo; NR-11LS) 0.03 part

[0055] <Base paper formulation 6> Base paper formulation; LBKP (freeness; 450 ml, cf) 60 parts           Imitation waste paper pulp (freeness; 200 ml, cf) 40 parts Calcium carbonate (Okutama Kogyo Co., Ltd .; TP-121) 9 parts Aluminum sulfate 0.8 parts Amphoteric starch (manufactured by Japan NSC Co .; Cato3210) 1 part Yield improver (manufactured by Hymo Co .; NR-11LS) 0.02 part

[0056] <Base paper formulation 7> Base paper formulation; LBKP (freeness; 450 ml, cf) 60 parts           Imitation waste paper pulp (freeness; 200 ml, cf) 40 parts Talc (Hyogo Clay Co .; Hyogo Talc) 9 copies Aluminum sulfate 2.5 parts Synthetic paper strength agent (manufactured by Seikou Kagaku Kogyo; Stargum A-15) 0.8 part Yield improver (manufactured by Hymo Co .; NR-11LS) 0.02 part

A 0.3% slurry of each of the above base papers was made into a base paper having a paper width of 1,300 mm, a paper making speed of 150 m / min and a basis weight of 62.7 g / m ² and a water content of 5.0% by a Fourdrinier paper machine. This was used as a papermaking base paper.

Next, according to the following method, Examples 1 to 1
8 and the coated base papers of the offset printing coated papers of Comparative Examples 1 to 3 were produced.

Example 1 The base paper 1 produced as described above was subjected to a film transfer type size press with a blend of the size press liquid 3, and an external additive size coating with an external additive sizing agent solid content adhesion amount of 0.03 g / m ² was applied. A base paper was obtained and used as a base paper for coating in the coated paper for offset printing of Example 1. The ash content of the base paper 8 was 7.6%.

Example 2 The base paper 2 produced as described above was subjected to a film transfer type size press with a blend of the size press liquid 3, and an external additive size coating with an external additive sizing agent solid content of 0.03 g / m ² was applied. A base paper was obtained and used as a base paper for coating in the coated paper for offset printing of Example 2. The ash content of the base paper 2 was 7.7%.

Example 3 The base paper 6 produced above was subjected to a film transfer type size press with the following composition to obtain an externally added size coated base paper having a solid content adhesion amount of 0.03 g / m ^2. The coated base paper of the offset coated paper. The ash content of the base paper 6 was 7.6%. <Composition of size press liquid 3> Oxidized starch (manufactured by Japan Food Processing Co .; MS-3800) 17 parts Externally added sizing agent (manufactured by Arakawa Chemical Co., Ltd .; styrene-acrylic copolymer; MA-3) 0.34 parts Water 82 .66 parts

Example 4 The base paper 7 produced as described above was subjected to a film transfer type size press with a blend of the size press liquid 3, and an external additive size coating with a solid content of the external additive sizing agent of 0.03 g / m ² was applied. A base paper was obtained and used as a base paper for coating in the offset printing coated paper of Example 4. The ash content of the base paper 7 was 7.4%.

Example 5 The base paper 1 prepared above was subjected to a film transfer type size press with the following composition to obtain an externally added size coated base paper with a solid content adhesion amount of 0.015 g / m ^2.
The coated base paper of the offset coated paper. <Composition of size press liquid 4> Oxidized starch (manufactured by Japan Food Processing Co .; MS-3800) 17 parts Externally added sizing agent (manufactured by Arakawa Chemical Co., Ltd .; AKD system;) 0.15 parts Water 82.85 parts

Example 6 A film transfer type size press having the following composition was applied to the base paper 1 prepared above to obtain an externally added size coated base paper having a solid content adhesion amount of 0.03 g / m ^2. The coated base paper of the offset coated paper. <Composition of 5 size press liquids> Oxidized starch (manufactured by Japan Food Processing Co., Ltd .; MS-3800) 17 parts Externally added sizing agent (manufactured by Arakawa Chemical Co., Ltd .; Olefin system; Polimaron 477) 0.34 parts Water 82.66 parts

Example 7 The base paper 1 produced as described above was subjected to a film transfer type size press with the following composition to obtain an externally added size coated base paper having a solid content adhesion amount of 0.03 g / m ^2. The coated base paper of the offset coated paper. <Six Press Size Mixture> Oxidized starch (manufactured by Japan Food Processing Co., Ltd .; MS-3800) 17 parts Externally added sizing agent (manufactured by Marima Kasei Co., Ltd .; Ion Complex Flex; G-7015) 0.34 parts Water 82.66 parts

Example 8 The base paper 1 produced above was subjected to a film transfer type size press with the following composition to obtain an externally added size coated base paper having a solid content adhesion amount of 0.03 g / m ^2. The coated base paper of the offset coated paper. <Composition of Size Press Liquid 7> Oxidized starch (manufactured by Japan Food Processing Co .; MS-3800) 17 parts Externally added sizing agent (manufactured by Harima Chemicals; wax emulsion system; C-300) 0.34 parts water 82.66 parts

Comparative Example 1 The base paper 3 prepared above was size-pressed by the film transfer method with the following composition to obtain a size-pressed liquid-free coated base paper having a solid content of 1.5 g / m ^2. The coated base paper in the coated paper for offset printing of Comparative Example 1 was used. The ash content of the base paper 3 was 7.8%. <Composition of size press liquid 2> Oxidized starch (manufactured by Japan Food Processing Co .; MS-3800) 17 parts Water 83 parts

Comparative Example 2 The base paper 4 produced above was size-pressed by the film transfer method with the blending of the size-press liquid 2, and the size-press liquid with a solid content of 1.5 g / m ² was applied without external coating. A base paper was obtained and was used as a coated base paper in the coated paper for offset printing of Comparative Example 2. The ash content of the base paper 4 was 7.7%.

Comparative Example 3 The base paper 5 produced as described above was subjected to a film transfer type size press with the composition of the size press liquid 1, and the external press-applied size coated base paper with a solid content of the size press liquid of 1.5 g / m ² was applied. To obtain a coated base paper in the coated paper for offset printing of Comparative Example 3. The ash content of the base paper 5 was 7.8%.

With respect to the coated base papers of the coated papers for offset printing of Examples 1 to 8 and Comparative Examples 1 to 3 produced as described above, the stain and size property of the papermaking system were measured. The results are shown in Table 1.

1) <Dirt> Paper making was carried out for 72 hours or more with the above-mentioned stock material, and the state of foreign matter adhering to the felt suction lip of the paper machine was judged. In the present invention, a state of O or higher is preferable. ◎: Excellent ○: Good △: Slightly inferior ×: A lot of dirt

1) Steckigt sizing degree: JIS P81
According to the Steckigt sizing degree test method defined in No. 22, the sizing property of the base paper was measured. In the present invention, 0.3 to 1
0 seconds is preferred.

2) <Static friction coefficient> The static friction coefficient was measured according to JIS P-8112. In this evaluation, front and back, MD (flow direction of base paper) and MD were used as the combination of base papers. A static friction coefficient of 0.4 or more is preferable for the slip suitability of winding at the time of winder.

[0074]

[Table 1]

Evaluation results: As described above, according to Table 1, the externally added size-coated base papers of Examples 1 and 2 in which the internally added size was not contained but the externally added size was applied, the papermaking system was used. It can be seen that the internal stains are improved and the size represented by the water absorption can be controlled. On the other hand, when it is attempted to control the sizing property by adding the internally added sizing agent and without using the externally added sizing agent, as shown in Comparative Examples 1 and 2, stains in the papermaking system due to the internally added sizing agent deteriorate. Resulting in. In Comparative Example 3, the internal addition method and the external addition sizing agent are used in combination, but it is difficult to control the sizing property, and although the stain in the papermaking system is improved to some extent, the sizing property may become extremely high. Recognize.

In the system in which the externally added sizing agent was applied without containing the internally added sizing agent, the styrene-acrylic copolymers of Examples 1 to 4 were used as the offset coating base papers. It is understood that the static friction coefficient value is improved and the sizing property represented by the Steckigt sizing degree can be controlled. On the other hand, in the offset coating base paper to which the AKD-based externally added sizing agent of Example 5 is applied, the Steckigt sizing degree increases, but the static friction coefficient value decreases. Furthermore, it is also found that the static friction coefficient and the sizing degree cannot be balanced even when the olefin-based sizing agent of Example 6, the ion complex-based agent of Example 7, and the wax emulsion-based sizing agent of Example 8 are used. On the other hand, in Examples 3 to 4, the waste paper pulp is blended in the base paper, but it is understood that there is no problem in the balance between the static friction coefficient and the size degree of the base paper for offset coating.

Examples 9 to 15 Next, the coated base papers for the offset printing coated papers of Examples 9 to 15 were prepared by the following method.

Example 9 The base paper 1 produced above was size-pressed using a film transfer type Simsizer with the following composition to give an external addition size of 0.03 g / m ^{2 as} an external addition size. A coated base paper was obtained and was used as the coated base paper in the coated paper for offset printing of Example 9. The ash content of the base paper 1 was 7.6%. <Compound of size press liquid 1> Oxidized starch (manufactured by Japan Food Processing Co .; MS-3800) 17 parts External sizing agent (manufactured by Harima Kasei; prototype 3 of styrene-acrylic copolymer) 0.34 parts water 82 .66 parts

Example 10 The size press of Example 9 prepared above was used in the same manner except that a film transfer type gate roll coater (abbreviated as GRC) was used. A coated base paper of the offset printing coated paper of Example 10 having a thickness of / m ² was manufactured.

Example 11 The size press liquid 1 formulation of Example 10 prepared above was
A coated base paper was prepared in the same manner as in the coated paper for offset printing of Example 11 in which the solid content of the externally added sizing agent was 0.012 g / m ² except that the size press liquid 8 was added. <Composition of 8 size press liquids> Oxidized starch (manufactured by Japan Food Processing Co., Ltd .; MS-3800) 17 parts External sizing agent (manufactured by Harima Kasei Co .; prototype 3 of styrene-acrylic copolymer) 0.15 parts water 82 .85 parts

Example 12 8 parts of the size press liquid of Example 11 prepared above was mixed with
A coated base paper for the offset printing coated paper of Example 12 having an externally added sizing agent solids content of 0.05 g / m ² was produced in the same manner except that the size press liquid 9 was added. <9 blends of size press liquid> Oxidized starch (manufactured by Japan Food Processing Co .; MS-3800) 17 parts Externally added sizing agent (manufactured by Harima Kasei; prototype 3 of styrene-acrylic copolymer) 0.51 part Water 82 .49 copies

Example 13 The size press liquid 1 formulation of Example 10 prepared above was
A coated base paper was prepared in the same manner as the coated paper for offset printing of Example 13 in which the solid content of the externally added sizing agent was 0.18 g / m ² except that the size press liquid 10 was added. <Composition of size press liquid 10> Oxidized starch (manufactured by Japan Food Processing Co., Ltd .; MS-3800) 19 parts Externally added sizing agent (manufactured by Harima Kasei Co .; prototype 3 of styrene-acrylic copolymer) 0.62 parts Water 80 .38 copies

Example 14 The size press liquid 1 formulation of Example 10 prepared above was
A coated base paper was prepared in the same manner as in the coated paper for offset printing of Example 14 having an externally added sizing agent solids content of 0.06 g / m ² except that the size press liquid 11 was added. <Compound of size press liquid 11> Oxidized starch (manufactured by Japan Food Processing Co., Ltd .; MS-3800) 18 parts Externally added sizing agent (manufactured by Harima Kasei Co .; prototype 3 of styrene-acrylic copolymer) 0.34 parts water 81 .66 copies

Example 15 The size press of Example 9 prepared above was changed from GRC to the conventional size press system, and the same composition was used except that 1 size press liquid was mixed with 12 size press liquid. Sizing agent solid content deposition amount 0.03 g / m ²
The coated base paper in the coated paper for offset printing of Example 15 was manufactured. <Composition of size press liquid 12> Oxidized starch (manufactured by Japan Food Processing Co .; MS-3800) 6 parts Externally added sizing agent (manufactured by Harima Kasei Co .; prototype 3 of styrene-acrylic copolymer) 0.68 parts water 93 .32 copies

Further, with respect to the coating base paper in the coated paper for offset printing produced in Examples 9 to 15, 65% by mass of the coating liquid having the following composition was used to coat 12 g / m ² on one side using a blade coater. Double-sided coating was performed at a coating amount of 1,200 m / min. <Pigment coating liquid 1 formulation> Commercial primary kaolin clay 50 parts Commercial heavy calcium carbonate 50 parts Commercial polyacrylic acid-based dispersant 0.1 part Latex binder 12 parts Commercial phosphate ester starch 3 parts Commercial carboxymethylcellulose-based thickener (CMC ) 0.1 part sodium hydroxide adjusted to pH 9.6

The size of the coated base paper in the coated paper for offset printing of Examples 9 to 15 produced as described above was evaluated, and the suitability for coating was evaluated. The results are shown in Table 2.

1) <Steckigt sizing degree> The sizing property of the base paper was measured according to the Steckigt sizing degree test method defined in JIS P8122. In the present invention, 0.3 to 10 seconds is preferable.

1) <Blade coater coating suitability> The blade coater coating suitability was determined by using the coating base paper in the offset printing coated paper prototyped in the examples and using the above 65% by mass of <pigment coating liquid 1 formulation>. Coating amount using one side 12g /
Double-sided coating with a blade coater at m ² , coating speed of 1,200 m / min, occurrence of coating defects such as streaks, and blade loading angle control required to coat the target coating amount The suitability for coating was evaluated. In the present invention, a state of Δ or higher is preferable. ⊚: Excellent ○: Good Δ: Slightly inferior, but at practical lower limit level ×: Poor

[0089]

[Table 2]

Evaluation results: As described above, according to Table 3, the styrene-acrylic copolymers of Examples 9 to 12 were used in a system in which the internally added sizing agent was not contained but the externally added sizing agent was applied. In addition to the sizing degree, the blade coater coating suitability of the pigment coating liquid is good not only for the coating base paper in the offset printing coated paper that was size-pressed with the film transfer type size press device You can see that On the other hand, the base paper coated with the conventional size press machine of Example 15 is apt to be penetrated by the pigment coating liquid, and therefore, it is considered that the streak tends to be strong relative to the size. Furthermore, Examples 13-1
In No. 4, the viscosity of the size press liquid exceeds 50 mPa · s, but in such a case, the amount of the liquid adhered by the size press increases, so that the penetration of the coating liquid is suppressed.
It can be seen that the controllability of the blade loading angle for controlling the coating amount deteriorates.

Examples 16 to 18 and Comparative Examples 4 to 5 Example 18 The base paper 1 produced above was size-pressed using a film transfer type GRC with the following composition,
Externally added size agent An externally added size coated base paper having a solid content adhesion amount of 0.032 g / m ² was obtained and used as a coated base paper in the offset printing coated paper of Example 16. <Composition of Size Press Liquid 13> Oxidized starch (manufactured by Japan Food Processing Co .; MS-3800) 17 parts External sizing agent (manufactured by Arakawa Chemical Co., Ltd .; styrene-acrylic copolymer; MA-8 modified) 0.34 parts water 82.66 parts

Example 17 The base paper 1 prepared above was size-pressed using a film transfer type GRC with the following composition,
Externally added sizing agent An externally added sized coated base paper having a solid content adhesion amount of 0.016 g / m ² was obtained and used as the coated base paper in the offset printing coated paper of Example 17. <Composition of size press liquid 14> Oxidized starch (manufactured by Japan Food Processing Co .; MS-3800) 17 parts Externally added sizing agent (manufactured by Harima Kasei Co .; styrene-acrylic copolymer; KN-500) 0.17 parts water 82 .83 parts

Example 18 The base paper 1 produced above was size-pressed using a film transfer type GRC with the following composition,
Externally added sizing agent An externally added sized coated base paper having a solid content deposition amount of 0.016 g / m ² was obtained and used as the coated base paper in the offset printing coated paper of Example 18. <15 blends of size press liquid> Oxidized starch (manufactured by Japan Food Processing Co .; MS-3800) 17 parts Externally added sizing agent (manufactured by Arakawa Chemical Co., Ltd .; styrene-acrylic copolymer; modified MA-3) 0.16 parts water 82.64 copies

Comparative Example 4 The base paper 1 produced as described above was size-pressed using a film transfer type GRC with the size press liquid formulation 4 to obtain an externally added size coated base paper, and the offset printing coating of Comparative Example 4 was obtained. It was used as the coated base paper for engineering paper.

Comparative Example 5 A base paper produced in the same manner except that the amount of AKD sizing agent added to the base paper 3 produced above was 0.035 parts.
A size press was performed using a film transfer type GRC with the following composition to obtain an externally added size coated base paper,
The coated base paper in the coated paper for offset printing of Comparative Example 5 was used. <Composition of 15 size press liquids> Self-modified starch (thermochemical modification treatment) 8 parts Water 92 parts

Furthermore, a coating solution having a coating solution concentration of 65% by mass was applied to the coating base paper in the coated paper for offset printing of Examples 16 to 18 and Comparative Examples 4 to 5 using a blade coater. Coating amount: 12 g / m ^{2 on} one side, coating speed:
Both sides were coated at 1,200 m / min. <Pigment coating liquid 1 formulation> Commercial primary kaolin clay 60 parts Commercial heavy calcium carbonate 40 parts Commercial polyacrylic acid-based dispersant 0.1 part Latex binder 12 parts Commercial phosphate ester starch 3 parts Commercial carboxymethylcellulose-based thickener (CMC ) 0.1 part sodium hydroxide adjusted to pH 9.6

Further, Examples 16 to 18 and Comparative Example 4
In Nos. 5 to 5, the obtained double-sided coated paper was offline with a super calender finishing device (number of steps: 10 steps, rigid roll: chilled roll with an outer diameter of 400 mm, elastic roll: cotton roll with an outer diameter of 400 mm, linear pressure: 220k
(g / cm) was used for calendering to produce a coated paper for offset printing.

Regarding the coated base paper in the coated paper for offset printing of Examples 16 to 18 and Comparative Examples 4 to 5 prepared as described above, the water absorbency of the base paper, the coating suitability at the time of coating, and the offset printing The printability of the coated paper was evaluated. The results are shown in Table 3.

1) <Water absorption of base paper (10 second Cobb value)>:
According to the water absorption test method specified in JIS P8140, the water absorption (Cobb value) at which the contact time with water was 10 seconds was used as the water absorption of the base paper. In the present invention, a water absorption of 30 to 80 g / m ² is preferable.

2) <Ink inking property> Using a RI printing aptitude tester, linseed oil was transferred and indigo solid printing was performed, and then the print density and print unevenness were visually determined, and ◎ ( It was evaluated in four grades: very good) (good) Δ (normal) × (poor). However, in the present invention, ◯ or more is desirable.

3) <Ink setting property> After performing solid red printing using an RI printability tester,
A blank coated paper is pressure-bonded to the printed surface, and the density of the ink transferred to the coated paper is visually determined, and is classified into four stages: ◎ (very good) ○ (good) △ (normal) × (poor) evaluated. However, in the present invention, ◯ or more is desirable.

4) Printing Gloss After performing heavy solid printing of indigo, crimson and yellow (ink amount 0.2 cc each) using an RI printability tester, gloss was measured at 60 ° -60 ° with a gloss meter. ° The reflectance was evaluated.
In the present invention, 65% or more is desirable.

[0103]

[Table 3]

Evaluation results: As described above, according to Table 3, the styrene-acrylic copolymers of Examples 16 to 18 were used in the system in which the externally added sizing agent was applied without containing the internally added sizing agent. Was used as an externally added sizing agent and subjected to size pressing with a film transfer type size press device, and the coated base paper in the offset printing coated paper having a 10 second Cobb value in the range of 30 to 80 g / m ² It can be seen that not only the suitability of the liquid for coating with the blade coater but also the suitability for offset printing of the coated paper are improved. On the other hand, the coating base paper of Comparative Example 4 in which neither the internal sizing agent nor the external sizing agent is used easily penetrates the pigment coating liquid, so that the pigment coating liquid easily penetrates into the coating raw paper and the streak tends to occur strongly. In addition, it is considered that the printing gloss of coated paper is difficult to obtain. Furthermore, Comparative Example 5
Since the internally added sizing agent works very well, the 10-second Cobb value becomes 20 g / m ² and the pigment coating liquid does not easily penetrate into the coating base paper, so binder migration occurs during drying and coating It can be seen that the ink inking of the paper and the ink setting property deteriorate.

[0105]

The coated base paper in the offset printing coated paper according to the present invention is characterized in that it does not contain the internally added sizing agent used in papermaking, but uses only the externally added sizing agent. From the viewpoints of highly closed inside the papermaking system and resource saving, it is possible to reduce stains inside the papermaking system, at the same time easy to control the size property, and it is excellent in productivity. In addition, by applying a specified amount of a size press liquid of a specific viscosity containing an externally added sizing agent using a film transfer type size press device, it is possible to coat offset printing coated paper with an excellent balance of productivity and quality. A method for manufacturing engineering base paper can be provided. Furthermore, using only the externally added sizing agent 1
By providing a coating layer on a coated base paper having a specific 0 second Cobb value, a coated paper for offset printing having excellent productivity and printability can be obtained.

Claims (5)

[Claims] 1. A coated base paper for offset printing coated paper having at least one coating layer on one or both sides, wherein a sizing agent (hereinafter
It is called internal sizing agent. And a sizing agent according to the external addition method (hereinafter, referred to as an externally added sizing agent) is not used, and the coated base paper in the coated paper for offset printing is characterized. 2. The coated base paper in the coated paper for offset printing according to claim 1, wherein the externally added sizing agent is a styrene-acrylic copolymer. 3. The coated base paper in the coated paper for offset printing according to claim 1 or 2, wherein the coated base paper is made of waste paper pulp as a pulp raw material. 4. A method for producing a coated base paper for coated paper for offset printing, comprising: Bro at 60 ° C./60 rpm.
The size press liquid mainly composed of a water-soluble binder containing an externally added sizing agent having an okfield viscosity of 50 mPa · s or less is prepared, and the size press liquid is added to the internally added sizing agent using a film transfer type size press device. 0.01 to 0.05 g / size of an externally added sizing agent is applied to a base paper that is made without using it (hereinafter referred to as a size-free base paper without internal addition).
m ² (dry solid content) is applied, a method for producing a base paper for coating in offset printing. 5. The coated base paper in the coated paper for offset printing according to claim 1, and J
At least one or both sides of the coated base paper having a water absorption (10 seconds Cobb value) of 30 to 80 g / m ² in which the contact time with water is 10 seconds according to the water absorption test method specified in ISP8140 A coated paper for offset printing, comprising one or more coating layers.