JP2006283235A - Converting paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a converting paper having sufficient rigidity such as stiffness and toughness of paper in spite of decreased amount of surface coating agent applied to the base paper, generating little troubles such as wrinkling, shifting, printing defect, die cut defect and misalignment of paper in the case of printing, narrow slitting, die cutting (punching) of an adhesive label sheet produced by using a release paper and usable e.g. as a base paper of the release paper. <P>SOLUTION: At least one kind of starch selected from cationized starch, amphoteric starch and cationized and crosslinked starch produced from raw starch is applied as a paper coating agent to at least one surface of a base paper at a coating rate of 0.1-2.0 g/m<SP>2</SP>. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a processed base paper in which starch is applied to the base paper, and particularly to a processed base paper having improved rigidity such as paper crease and waist.

  If the paper for processing paper such as release paper is insufficient, paper wrinkles and misalignment will occur when printing on adhesive label sheets that are adhesive processed using release paper, slitting narrowly, die cutting (punching), etc. It becomes easy to cause printing defects, die cutting defects, uneven widths, and the like. Conventionally, with the aim of improving paper wrinkle, it has been possible to apply double-sided starch and PVA with a size press or gate roll coater in the paper machine process, but sufficient effects have not been obtained.

  There are two methods for increasing the rigidity of the processing base paper with the papermaking chemicals: a method of internally adding chemicals and an external addition method of coating the chemicals on the surface of the papermaking base paper. In general, it is known that when a paper strength enhancer such as polyacrylamide or starch is internally added, the rigidity of the paper is improved. However, in order to obtain a sufficient rigidity improvement effect, an amount more than usual is required, which tends to cause deterioration of the paper formation, and the rigidity may be lowered. In addition, it is considered that adding these chemicals having cohesiveness and adhesiveness to the papermaking process may cause unstable operation, and that adding chemicals is difficult from the viewpoint of cost.

  In addition, as a paper surface coating agent for the purpose of improving rigidity, for example, the following are well known. A method of blending a specific amount of water glass and a polymer emulsion or latex (see Patent Document 1), a method of irradiating a paper sized with a polyvinyl alcohol resin (see Patent Document 2), a polyvinyl alcohol heavy A method of mixing a polymer component and a polyacrylamide polymer component (see Patent Document 3), a method using a polymer obtained by radical polymerization of an acrylamide monomer at a specific polymerization ratio in the presence of a polyvinyl alcohol polymer (Patent Document 4) A method using an aqueous solution containing an acetoacetate group-containing polyvinyl alcohol resin and a zirconium salt (see Patent Document 5), a block copolymer composed of a polyvinyl alcohol component and a polyacrylamide component (see Patent Document 6), (Metal) ) Acrylamide and α, β-unsaturated carboxylic acid or its salt and N, N-dimethyla A method using a water-soluble copolymer containing 0.3 to 1 mole of ethylene urea as a polymerization component per mole of rilamide, N-methylol (meth) acrylamide and N-methylol (meth) acrylamide (see Patent Document 7), (meth) Polymerization component of 0.3 to 1 mol of dicyandiamide per mol of acrylamide and α, β-unsaturated carboxylic acid or salt thereof, N, N-dimethylacrylamide, N-methylol (meth) acrylamide and N-methylol (meth) acrylamide Water-soluble copolymer method (see Patent Document 8), alkyl vinyl ether and maleic anhydride copolymer method (see Patent Document 9), polyamide epichlorohydrin resin, glyoxal or melanin formalin resin Agent and polyvinyl alcohol, starch, polyacrylamide resin or cal A method of applying a water-soluble polymer such as boxymethylcellulose (see Patent Document 10), alkali metal acetate is 2% by weight or less, acetic acid is 5% by weight or less, and the weight ratio of alkali metal acetate / acetic acid is A method of applying a paper coating agent characterized by comprising, as a main component, an alkali metal acetate and an acetoacetate group-containing polyvinyl alcohol resin containing acetic acid at a ratio of 0.01 to 100 (see Patent Document 11) A copolymer comprising a pigment and hollow polymer particles and an adhesive composed of a copolymer latex and starch, the copolymer latex having a number average particle size of 0.06 to 0.2 μm, and constituting the copolymer latex The glass transition temperature of the copolymer is −50 to 45 ° C., and the weight ratio of the copolymer latex / the starch is 80/20 to 5/95 in terms of solid content. Industrial paper composition (Patent Literature 12), a stiffening agent composition for paper (see Patent Document 13) characterized in that it contains an ultrafine particle dispersion of titanium oxide or hydroxide and a paper strength enhancer such as polyacrylamide or polyvinyl alcohol. It is disclosed.

  However, these methods have problems in productivity and cost, are not suitable for high-speed printing due to deterioration of surface tackiness, and have problems in disaggregation when used as waste paper. Therefore, a paper coating agent suitable for lightweight, thin and bulky paper is desired.

JP 59-130398 JP-A-60-155799 JP-A-60-151800 JP-A-1-156597 Japanese Patent Publication No. 3-23678 JP-A-6-65893 JP-A-6-65894 JP 7-238490 A JP-A-8-100388 JP-A-9-3797 JP 2000-110094 A JP 2001-123393 A

  The problem of the present invention is that it has sufficient rigidity despite the small amount of surface coating agent applied to the processed base paper, printed on an adhesive label sheet that has been adhesively processed using a release paper, and has a narrow slit, Provided is a processed base paper that is used as a base paper of the release paper, which is less likely to cause paper wrinkles and misalignment when die cutting (punching) or the like, and hardly causes printing failure, die cutting failure, and uneven width.

Using raw starch as a raw material, at least one starch selected from the group consisting of cationized starch, amphoteric starch, and cationized cross-linked starch is used as a paper coating agent, and 0.1 to 2.0 g / m ² is applied to at least one side of the base paper. By using the processed base paper, the rigidity of the processed base paper can be remarkably improved.

  In general, it is known that when paper is coated with oxidized starch or hydroxyethylated starch, the stiffness of the paper is improved. However, in order to obtain the required rigidity, it is necessary to increase the coating amount of starch, and the surface tackiness increases, so that a phenomenon may occur in which the paper is taken on the blanket of the printing press during offset printing. Therefore, there is a limit to increasing the coating amount, and sufficient rigidity cannot be obtained. However, when raw starch is used as a raw material, at least one starch selected from the group of cationized starch, amphoteric starch, and cationized cross-linked starch is coated on the surface of the base paper as a paper coating agent. The starch has a cationic group in the molecule with respect to the surface of the base paper exhibiting high anionicity, and as a result, the penetration of the starch into the paper is suppressed. Stiffness is remarkably improved. Since the processed base paper of the present invention has a small starch coating amount, there is no problem of surface tackiness.

  The cationized starch, amphoteric starch or cationized cross-linked starch used in the present invention are all produced by a known method. Examples of raw starch (raw starch) used as a raw material include corn starch, tapioca starch, potato starch, sweet potato starch, wheat starch, and rice starch. These may be used alone or as a mixture of two or more kinds. Examples of a method for introducing a cationic group, a method for introducing an anionic group, and a crosslinking reaction method will be described below, but the method is not limited to these methods.

  As a cationizing agent used in the production of cationized starch, amphoteric starch, and cationized cross-linked starch, tertiary amine introduction agents such as diethylaminoethyl chloride hydrochloride, 3-chloro-2-hydroxypropyltrimethylammonium chloride hydrochloride And a quaternary ammonium salt introducing agent such as 2,3-epoxypropyltrimethylammonium chloride hydrochloride. These cationizing agents can be used alone or in combination of two or more.

  Examples of the anionizing agent used in the production of the amphoteric starch include sodium tripolyphosphate, a combination of urea and monosodium phosphate, and disodium phosphate. These anionizing agents can be used alone or in combination of two or more.

  Examples of the crosslinking agent used for the crosslinking reaction of the cationized crosslinked starch include phosphorus oxychloride, trimetaphosphoric acid, acrolein, and epichlorohydrin. These crosslinking agents can be used alone or in combination of two or more.

  The degree of cationization of the cationized starch, amphoteric starch, and cationized cross-linked starch is not particularly limited, but is usually in the range of 0.005 to 0.05, preferably 0.01 to 0.05, more preferably 0.01 to 0.04. It is.

The coating amount on the base paper of at least one starch having a cationic group selected from the group consisting of cationized starch, amphoteric starch and cationized cross-linked starch must be at least 0.1 to 2.0 g / m ^{2 on} one side. It is. Further, in the case of double-sided coating, the coating amount is required to be 0.1 to 2.0 g / m ^2. When the coating amount is less than 0.1 g / m ² , sufficient rigidity cannot be obtained. On the other hand, in order to secure a coating amount exceeding 2.0 g / m ² , it is necessary to increase the starch concentration in the coating solution, and as a result, the viscosity of the coating solution becomes high and coating becomes difficult.

  In the present invention, when at least one starch having a cationic group selected from the group consisting of cationized starch, amphoteric starch, and cationized cross-linked starch is applied to the base paper, it is within the range where the rigidity of the paper does not deteriorate. The surface coating agent may be used in combination. Examples of other surface coating agents include various modified starches such as starch, oxidized modified starch, enzyme-modified starch, and urea phosphate esterified starch, polyacrylamide, polyvinyl alcohol, and various surface sizing agents.

  There is no particular limitation on the apparatus for applying the coating liquid to the surface of the base paper, and apparatuses such as a two-roll size press, a metering size press, and a gate roll coater can be used. However, since the stiffness of the paper increases as the coating agent stays on the paper surface, a metering size press and a gate roll coater are preferred.

  The paper applied in the present invention can be used for high-quality base paper of polyethylene laminate type, such as silicone resin direct coating type glassine paper, semi-glassine paper, clay coat paper, clear coat paper and the like used as release paper.

  The base paper for coating the coating solution containing at least one kind of starch having a cationic group selected from the group of cationized starch, amphoteric starch and cationized crosslinked starch is produced by the above-mentioned acidic papermaking method. However, it may be produced by a neutral papermaking method.

  The raw material pulp may be any pulp that is usually used, and is not particularly limited. Chemical pulp (CP), groundwood pulp (GP), chemiground pulp (CGP), refiner ground pulp (RGP), thermomechanical Pulp of various production methods such as pulp (TMP), chemi-thermomechanical pulp (CTMP), semi-chemical pulp (SCP), and these softwood, hardwood pulp, bleached, unbleached pulp, and deinked pulp (DIP) Etc. are appropriately blended according to the type of paper.

  For base paper produced by the acid papermaking method, if necessary depending on the type of paper, known internal sizing agents for acidic papermaking such as rosin sizing agent, reinforced rosin sizing agent, and synthetic sizing agent can be used. Fillers that are stable even in the acidic region can be used. Specifically, inorganic fillers such as clay, calcined kaolin, deramikaolin, titanium dioxide, zinc oxide, silicon oxide, amorphous silica, urea-holimarin resin, polystyrene resin Organic fillers such as phenol resin and fine hollow particles can be used alone or in combination of two or more.

  In the base paper manufactured by the neutral papermaking method, if necessary depending on the type of paper, a known internally added neutral sizing agent, alkyl ketene dimer (AKD) type sizing agent, alkenyl succinic anhydride (ASA) type Sizing agent, neutral rosin sizing agent can be used, and fillers include calcium carbonate, magnesium carbonate, barium carbonate, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide, clay, calcined kaolin, deramikaolin, titanium dioxide Inorganic fillers such as zinc oxide, silicon oxide, and amorphous silica, urea-holimarin resin, polystyrene resin, phenol resin, and fine hollow particles can be used.

  When making base paper, various nonionic, cationic retention agents, freeness improvers, paper strength improvers, and other internally used auxiliary additives for papermaking are appropriately selected and used as necessary. Is done. Further, for example, sulfuric acid bands, aluminum chloride, sodium aluminate, basic aluminum compounds such as basic aluminum chloride and basic polyaluminum hydroxide, water-soluble aluminum compounds such as water-degradable alumina sol, sulfuric acid A polyvalent metal compound such as ferrous sulfate or ferric sulfate, silica sol, or the like may be internally added. Other starches for papermaking, various starches, polyacrylamide, urea resin, melamine resin, epoxy resin, polyamide resin, polyamide, polyamine resin, polyamine, polyethyleneimine, vegetable gum, polyvinyl alcohol, latex, polyethylene oxide, hydrophilic cross-linked polymer Various compounds such as particle dispersions and derivatives or modified products thereof can be used. Furthermore, internal additives for papermaking such as dyes, fluorescent brighteners, pH adjusters, antifoaming agents, pitch control agents, slime control agents and the like can be appropriately added depending on the intended use.

  The type of the paper machine for making the base paper is not particularly limited, and can be appropriately made with a long net paper machine, a twin wire machine, a Yankee paper machine, or the like. The press line pressure is used within the normal operating range. The calendar may be bypassed or processed within the normal operating range.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to these examples. In addition, all% in an example shows solid content weight%.

The physical properties and paper Clark stiffness in the following examples and comparative examples were measured.
-Clark stiffness: Measured according to JIS P 8143.

[Example 1]
The paste solution of cationized starch (trade name: CATO302, manufactured by Nippon NSC Co., Ltd.) is adjusted to a solid content concentration of 2.0% by weight, and the base paper for processed base paper (manufactured by Nippon Paper Industries Co., Ltd.) with a basis weight of 75 g / m ² is gated. Coating was performed with a roll coater at a speed of 300 m / min. To obtain a processed base paper. The starch coating amount was 1.0 g / m ^{2 on} both sides. The measured values of Clark stiffness are shown in Table 1.

[Example 2]
A processed base paper was obtained in the same manner as in Example 1 except that the paste solution of cationized starch was adjusted to a solid concentration of 3.5% by weight. The amount of starch applied was 1.9 g / m ^{2 on} both sides. The measured values of Clark stiffness are shown in Table 1.

[Example 3]
The paste solution of cationized starch (trade name: CATO304, manufactured by Nippon NSC Co., Ltd.) is adjusted to a solid content of 2.0% by weight, and the base paper for processed base paper (manufactured by Nippon Paper Industries Co., Ltd.) with a basis weight of 75 g / m ² is gated. Coating was performed with a roll coater at a speed of 300 m / min. To obtain a processed base paper. The starch coating amount was 1.1 g / m ^{2 on} both sides. The measured values of Clark stiffness are shown in Table 1.

[Example 4]
A processed base paper was obtained in the same manner as in Example 3 except that the paste solution of cationized starch was adjusted to a solid content concentration of 3.5% by weight. The amount of starch applied was 1.9 g / m ^{2 on} both sides. The measured values of Clark stiffness are shown in Table 1.

[Example 5]
Amphoteric starch (trade name: CATO3210, Nippon NSC Ltd.) sizing solution was adjusted to a solid concentration of 2.0 wt%, the gate to the base paper (manufactured by Nippon Paper Industries Co., Ltd.) for processing base paper having a basis weight of 75 g / m ² Coating was performed with a roll coater at a speed of 300 m / min. To obtain a processed base paper. The amount of starch applied was 0.9 g / m ^{2 on} both sides. The measured values of Clark stiffness are shown in Table 1.

[Example 6]
A processed base paper was obtained in the same manner as in Example 5 except that the paste solution of amphoteric starch was adjusted to a solid content concentration of 3.5% by weight. The starch coating amount was 1.90 g / m ^{2 on} both sides. The measured values of Clark stiffness are shown in Table 1.

[Example 7]
Amphoteric starch (trade name: CATO315, Nippon NSC Ltd.) sizing solution was adjusted to a solid concentration of 2.0 wt%, the gate to the base paper (manufactured by Nippon Paper Industries Co., Ltd.) for processing base paper having a basis weight of 75 g / m ² Coating was performed with a roll coater at a speed of 300 m / min. To obtain a processed base paper. The starch coating amount was 1.0 g / m ^{2 on} both sides. The measured values of Clark stiffness are shown in Table 1.

[Example 8]
A processed base paper was obtained in the same manner as in Example 7 except that the paste solution of amphoteric starch was adjusted to a solid concentration of 3.5% by weight. The starch coating amount was 1.8 g / m ^{2 on} both sides. The measured values of Clark stiffness are shown in Table 1.

[Example 9]
The paste solution of cationized cross-linked starch (trade name: Microcat330, manufactured by NSC Japan Co., Ltd.) is adjusted to a solid content concentration of 2.0% by weight and used as a base paper for processing base paper (manufactured by Nippon Paper Industries Co., Ltd.) with a basis weight of 75 g / m ^2. Coating was performed at a speed of 300 m / min with a gate roll coater to obtain a processed base paper. The amount of starch applied was 0.9 g / m ^{2 on} both sides. The measured values of Clark stiffness are shown in Table 1.

[Example 10]
A processed base paper was obtained in the same manner as in Example 9 except that the paste solution of cationized crosslinked starch was adjusted to a solid content concentration of 3.5% by weight. The amount of starch applied was 1.9 g / m ^{2 on} both sides. The measured values of Clark stiffness are shown in Table 1.

[Comparative Example 1]
The paste solution of oxidized starch (trade name: SK-20, manufactured by Nippon Corn Starch Co., Ltd.) is adjusted to a solid content concentration of 2.6% by weight and used as a base paper for processed base paper (manufactured by Nippon Paper Industries Co., Ltd.) with a basis weight of 75 g / m ^2. Coating was performed at a speed of 300 m / min with a gate roll coater to obtain a processed base paper. The starch coating amount was 1.1 g / m ^{2 on} both sides. SK-20 is a typical one that has been conventionally used as a paper surface coating agent. The measured values of Clark stiffness are shown in Table 1.

[Comparative Example 2]
A processed base paper was obtained in the same manner as in Comparative Example 1 except that the paste solution of oxidized starch was adjusted to a solid content concentration of 4.5% by weight. The starch coating amount was 2.0 g / m ^{2 on} both sides. The measured values of Clark stiffness are shown in Table 1.

実施例１、３、５、７、９と比較例１との比較、及び実施例２、４、６、８、１０と比較例２との比較から、未加工デンプンを原料としたカチオン化デンプンや両性化デンプン、カチオン化架橋デンプンを塗工した実施例１〜１０の加工原紙は、従来用いられている表面塗工用の酸化デンプンを塗工した比較例１、２の上質紙よりも、剛度が大幅に向上した。

From the comparison between Examples 1, 3, 5, 7, and 9 and Comparative Example 1 and the comparison between Examples 2, 4, 6, 8, 10 and Comparative Example 2, cationized starch using raw starch as a raw material The processed base papers of Examples 1 to 10 coated with or amphoteric starch and cationized cross-linked starch are higher than the high quality papers of Comparative Examples 1 and 2 coated with oxidized starch for surface coating that has been conventionally used. Stiffness has been greatly improved.

Claims (2)

Using raw starch as a raw material, at least one starch selected from the group consisting of cationized starch, amphoteric starch and cationized cross-linked starch is used as a paper coating agent. Processed base paper characterized by m ² coating. Raw paper is used as a raw material, and at least one starch selected from the group consisting of cationized starch, amphoteric starch, and cationized cross-linked starch having a cationic group substitution degree of 0.005 to 0.05 is used as a paper coating agent. The processed base paper according to claim 1.