JP4650890B2 - Paper manufacturing method - Google Patents

Description

  The present invention relates to a method for producing bulky paper using pulp as a raw material and a pulp treating agent for obtaining bulky paper.

  Conventionally, a bulking agent for imparting excellent printing suitability and volume feeling to paper made of pulp (hereinafter also simply referred to as paper) has been reported (for example, Patent Document 1).

On the other hand, specific alkoxysilanes are treated on paper to give paper various functions (Patent Document 2), or pulp slurry is treated to improve the water resistance, dimensional stability and friction resistance of paper. (Patent Document 3) has been attempted.
International Publication No. 98/03730 Pamphlet JP 2003-319721 A JP 2001-181599 A

  In order to improve the surface properties of paper, the paper after drying is often further calendered.

  Even if the pulp or paper is treated with the agent specifically disclosed in Patent Documents 1 to 3 and the desired properties are imparted to the paper, the properties imparted are greatly increased when calendered. It may be damaged.

  The present invention is superior in paper properties (tightness, whiteness, opacity), including initial properties of paper, in particular, a static friction coefficient, a dynamic friction coefficient, and bulkiness, to a tension level even when calendered. It is an object to provide a pulp treating agent that is not significantly impaired (hereinafter also referred to as having excellent calendar resistance) and a suitable paper manufacturing method using the pulp treating agent.

  As a result of examining the alkoxysilane-based treatment agent in more detail, the present inventors have found that the initial properties of the paper, in particular, the paper quality including the static friction coefficient, the dynamic friction coefficient, and the bulkiness are superior to conventional treatment agents, and A pulp treating agent excellent in calendar resistance and a suitable method for producing paper using the agent were found, and the present invention was completed.

In the present invention, a pulp treatment agent (hereinafter referred to as a first pulp treatment agent) comprising an alkoxysilane (a) represented by the general formula (1), an organic acid (b), and water is contacted with pulp fibers. A method for producing a paper having a step (I), wherein 50% by weight or more in alkoxysilane (a) is represented by trialkoxysilane (a1) represented by general formula (2) and general formula (3). At least one selected from the dialkoxysilane (a2), the blending amount of water is 3 times mol or more of the blending amount of the alkoxysilane (a), and the pH of the pulp treating agent at 20 ° C. is 2 to 5 Is a paper manufacturing method (hereinafter referred to as a first paper manufacturing method).
R ¹ _p Si (OR ² ) _4-p (1)
R ¹ Si (OR ² ) ₃ (2)
R ¹ ₂ Si (OR ² ) ₂ (3)
Wherein, R ¹ represents a linear or branched alkyl group having 1 to 6 carbon atoms, a straight-chain or branched alkenyl group having a phenyl group, or 2 to 6 carbon atoms, R ² is 1 to the number of carbon atoms 6 linear or branched alkyl groups, p R ¹ and (4-p) R ² may be the same or different. p shows the integer of 1-3. ]

  In the present invention, a pulp treatment agent (hereinafter referred to as a second pulp treatment agent) comprising alkoxysilane (a ′), an organic acid (b), and water is blended, and the moisture content of the pulp is 50 to 1000% by weight. A method for producing a paper having a step (I ′) of contacting with a pulp web of the alkoxysilane (a ′), wherein 50% by weight or more in the alkoxysilane (a ′) is the alkoxysilane (a) represented by the general formula (1). Yes, a method for producing paper (hereinafter referred to as second paper production method) wherein the amount of water is 3 times mol or more of the amount of alkoxysilane (a ′) and the pH of the treatment agent at 20 ° C. is 2 to 5 About).

  Moreover, this invention is a pulp processing agent formed by mix | blending the alkoxysilane (a) represented by the said General formula (1), organic acid (b), and water, Comprising: 50 in alkoxysilane (a) % By weight or more is at least one selected from trialkoxysilane (a1) represented by general formula (2) and dialkoxysilane (a2) represented by general formula (3), The present invention relates to a pulp treating agent that is at least 3 times the mole of the alkoxysilane (a) and has a pH of 2 to 5 at 20 ° C., that is, a first pulp treating agent.

  Moreover, this invention is a pulp processing kit for obtaining the said 1st pulp processing agent, Comprising: The alkoxysilane (a) represented by the said General formula (1) is contained, Organic acid (b) and water are included. It is composed of a first agent that does not contain, and a second agent that contains the organic acid (b) and water, and does not contain the alkoxysilane (a), and the amount of water used is 3 of the amount of alkoxysilane (a). A pulp treatment kit (more than 50% by weight in the alkoxysilane (a) is the above general formula (2) mixed so that the pH of the pulp treatment agent at 20 ° C. is 2 to 5 or more. The trialkoxysilane (a1) represented and the dialkoxysilane (a2) represented by the general formula (3).

  Moreover, this invention is a pulp processing kit for obtaining the said 2nd pulp processing agent, Comprising: The 1st agent which contains alkoxysilane (a '), does not contain organic acid (b) and water, and organic acid (B) and a second agent that contains water and does not contain alkoxysilane (a ′), and the amount of water used is at least 3 times the amount of alkoxysilane (a ′) in use, 20 Pulp treatment kit mixed so that the pH of the pulp treatment agent at 2 ° C. is 2 to 5 (provided that 50% by weight or more in alkoxysilane (a ′) is an alkoxysilane represented by the above general formula (1) ( a)).

  According to the present invention, a paper production method is superior in paper properties (tightness, whiteness, opacity) including initial characteristics of paper, in particular, a static friction coefficient, a dynamic friction coefficient, and bulkiness, and superior in calendar resistance. As well as a pulp treating agent for obtaining such paper.

[Alkoxysilane (a)]
The alkoxysilane (a) used in the present invention is 50% by weight or more, preferably 60% by weight or more, more preferably 80% by weight or more, and still more preferably 100% by weight from the viewpoint of bulkiness, particularly calendar resistance. Is at least one selected from trialkoxysilane (a1) and dialkoxysilane (a2).

In the alkoxysilane (a), trialkoxysilane (a1), dialkoxysilane (a2), the alkyl groups represented by R ¹ and R ² are methyl, ethyl, propyl, butyl, isopropyl, isobutyl. Group, t-butyl group and the like. Examples of the alkenyl group represented by R ¹ include a vinyl group and allyl group, and examples of R ¹ include a phenyl group. R ¹ is preferably an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and still more preferably an alkyl group having 1 to 2 carbon atoms from the viewpoint of penetrability into the pulp fiber. . R ² is preferably an alkyl group having 1 to 4 carbon atoms, more preferably an alkyl group having 1 to 2 carbon atoms, from the viewpoints of safety of by-products generated by hydrolysis, reactivity of the hydrolysis reaction, and the like. As for p, 1-2 are preferable.

  As the trialkoxysilane (a1), alkyl (C1-6) trimethoxysilane and alkyl (C1-6) triethoxysilane are preferable, and methyltrimethoxysilane, ethyltriethoxysilane, and propyltriethoxysilane are preferable. More preferred. As the dialkoxysilane (a2), dialkyl (C1-6) dimethoxysilane, dialkyl (C1-6) diethoxysilane and the like are preferable, and dimethyldimethoxysilane and diethyldiethoxysilane are more preferable.

  The weight ratio of the trialkoxysilane (a1) to the dialkoxysilane (a2) in the alkoxysilane (a) is preferably 10/0 to 1/9 from the viewpoint of bulkiness, particularly calendar resistance. 5/5 is more preferable, 10/0 to 7/3 is more preferable, and when a surfactant is added to the pulp treating agent, a pulp slurry of a trialkoxysilane (a1) and a dialkoxysilane (a2), a pulp sheet Or it is especially preferable when the processing amount to a pulp web is large.

[Alkoxysilane (a ′)]
The alkoxysilane (a ′) used in the present invention is 50% by weight or more, preferably 60% by weight or more, more preferably 80% by weight or more, and still more preferably 100% by weight from the viewpoint of bulkiness, particularly calendar resistance. % Is alkoxysilane (a) represented by the above general formula (1).
In addition, the compound etc. which are represented by General formula (4) can be preferably used as things other than alkoxysilane (a) in alkoxysilane (a ').

[Wherein, R ³ , R ⁴ , R ⁵ , R ⁶ each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and n represents a number of 2 to 8. . ]

  The alkoxysilane (a ′) further preferably contains at least one selected from trialkoxysilane (a1) and dialkoxysilane (a2). The weight ratio of the trialkoxysilane (a1) to the dialkoxysilane (a2) in the alkoxysilane (a ′) is preferably 10/0 to 1/9 from the viewpoint of bulkiness, particularly calendar resistance. -5/5 is more preferable, and 10 / 0-7 / 3 is further preferable.

[Organic acid (b)]
Examples of the organic acid (b) used in the present invention include oxalic acid (pKa = 1.04, 3.82), maleic acid (pKa = 1.75, 5.83), tartaric acid (pKa = 2.82, 3 .96), fumaric acid (pKa = 2.85, 4.10), citric acid (pKa = 2.90, 4.34), malic acid (pKa = 3.24, 4.71), succinic acid (pKa = 4.00, 5.24), formic acid (pKa = 3.55), lactic acid (pKa = 3.66), adipic acid (pKa = 4.26, 5.03), acetic acid (pKa = 4.56) And propionic acid (pKa = 4.67) and the like. From the viewpoint of easy pH adjustment, an organic acid having a pKa in the range of 2.9 to 5.0 is preferable, and 3.5 to 5 is preferable. More preferred are organic acids in the range of 0.0. Among these, adipic acid, malic acid, acetic acid and propionic acid, which can easily control the hydrolysis reaction and polymerization reaction of alkoxysilane (a), are preferred, and adipic acid having a low odor is particularly preferred.
The dissociation constant pKa is based on “Revised 4th edition, Chemical Handbook II” 10.2.3. Dissociation constant of organic compounds in aqueous solution (P317).

[Pulp treatment agent]
The 1st pulp processing agent used for this invention mix | blends alkoxysilane (a), organic acid (b), and water. Moreover, the 2nd pulp processing agent used for this invention mix | blends alkoxysilane (a '), organic acid (b), and water.
Further, when the pulp treatment agent of the present invention is produced by a two-component kit (hereinafter also referred to as a pulp treatment kit), it contains an alkoxysilane (a) or (a ′), an organic acid (b) and water. And a second agent containing an organic acid (b) and water and not containing alkoxysilanes (a) and (a ′).

  In the pulp treating agent of the present invention, the compounding amount of alkoxysilane (a) or (a ′) is the total amount of the treating agent of the present invention (in the case of a two-component system, the total composition of the first agent and the second agent combined). Medium; the same shall apply hereinafter) 0.1% by weight or more, more preferably 1% by weight or more, particularly preferably 2% by weight or more, 85% by weight or less, further 60% by weight or less, further 50% by weight or less, particularly 25% by weight or less preferable. Further, the content of the alkoxysilane (a) or (a ′) in the first agent is 70 to 100% by weight, more preferably 80 to 100% by weight, particularly 90 to 100% by weight from the viewpoint of storage stability. preferable.

  The blending amount of the organic acid (b) in the pulp treating agent of the present invention is preferably 0.001 to 5% by weight from the viewpoint of suppressing the polymerization reaction of the hydrolyzate of alkoxysilane (a) or (a ′). 0.001 to 1% by weight is more preferable. When the pulp treatment agent of the present invention is produced by a two-component pulp treatment kit, the organic acid (b) is separately from the alkoxysilane (a) or (a ′) compounded in the first agent. It is preferable to mix | blend with a 2nd agent from the point of solubility and storage stability.

  The blending amount of water in the pulp treating agent of the present invention is a silanol compound represented by the following formula (5) (hereinafter referred to as a silanol compound (hereinafter referred to as “silanol compound”)) that swells the pulp fiber sufficiently and is generated by hydrolysis of the alkoxysilane (a). 5)) is preferably 30% by weight or more, more preferably 50% by weight or more, and particularly preferably 70% by weight or more from the viewpoint of sufficiently contacting the pulp fiber. The upper limit is preferably 99.9% by weight or less, more preferably 98% by weight or less, and particularly preferably 90% by weight or less.

[Wherein, X represents a group represented by R ¹ , OR ² or OH, t represents an integer of 0 to 2, and (2t + 4) X may be the same or different, and at least one of these is OH. R ¹ and R ² have the above meanings. ]

  Moreover, the ratio of the alkoxysilane (a) or (a ′) and water in the pulp treating agent of the present invention is sufficient to bring the silanol compound (5) produced by hydrolysis of the alkoxysilane (a) into sufficient contact with the pulp fiber. Therefore, it is at least 3 times the compounding amount of alkoxysilane (a) or (a ′), preferably 10 to 1000 times mol, more preferably 25 to 980 times mol.

  In the pulp treatment agent of the present invention, water is separately from the alkoxysilane (a) or (a ′) blended in the first agent in the case of the two-component pulp treatment kit of the present invention. It is blended in the agent.

  In the pulp treating agent of the present invention, water is preferably ion-exchanged water from the viewpoint of bulkiness, particularly calendar resistance, but from the viewpoint of production efficiency, industrial water usually used in the paper industry can be preferably used.

The pulp treating agent of the present invention improves the dispersion of alkoxysilane (a) or (a ′) in the aqueous phase and promotes the hydrolysis reaction, and in particular, the amount of the trialkoxysilane (a1) is large. It is preferable to add the surfactant (c) from the viewpoint of high bulkiness, particularly calendar resistance, when the amount of processing to the slurry, pulp sheet or pulp web is small.
When the surfactant (c) is blended, the blending amount of the surfactant (c) in the pulp treating agent of the present invention is 0.1 to 20% by weight from the viewpoint of emulsification during mixing and acceleration of hydrolysis. Is preferable, 0.1 to 15% by weight is more preferable, and 0.1 to 5% by weight is further preferable.

  As the surfactant (c), any of a nonionic surfactant, an anionic surfactant, a cationic surfactant, and an amphoteric surfactant can be used, and two or more types can be used in combination. .

  Nonionic surfactants include polyoxyalkylene alkyl ether, polyoxyalkylene alkenyl ether, higher fatty acid sucrose ester, polyglycerin fatty acid ester, higher fatty acid mono- or diethanolamide, polyoxyethylene hydrogenated castor oil, polyoxyethylene sorbitan fatty acid Examples thereof include esters, polyoxyethylene sorbite fatty acid esters, alkyl saccharide surfactants, alkyl amine oxides, and alkyl amido amine oxides. Of these, polyoxyalkylene alkyl ether and polyoxyethylene hydrogenated castor oil are preferable, and polyoxyethylene alkyl ether is particularly preferable.

  Anionic surfactants include alkyl benzene sulfonates, alkyl or alkenyl ether sulfates, alkyl or alkenyl sulfates, olefin sulfonates, alkane sulfonates, saturated or unsaturated fatty acid salts, alkyl or alkenyl ether carboxylates, Examples include α-sulfone fatty acid salts, N-acyl amino acid type surfactants, phosphate mono- or diester type surfactants, and sulfosuccinate esters. As counter ions of the anionic surfactant, alkali metal ions such as sodium ion and potassium ion; alkaline earth metal ions such as calcium ion and magnesium ion; ammonium ion; 1 to 3 alkanol groups having 2 or 3 carbon atoms Examples thereof include alkanolamines such as monoethanolamine, diethanolamine, triethanolamine, and triisopropanolamine.

  Examples of the cationic surfactant include a quaternary ammonium salt represented by the general formula (6).

[In the formula, R ⁷ and R ⁸ each independently represent a hydrogen atom, an alkyl group having 1 to 28 carbon atoms or a benzyl group, and simultaneously become a hydrogen atom or a benzyl group; Except when it becomes an alkyl group. An ⁻ represents an anion. ]

In the general formula (6), one of R ⁷ and R ⁸ is preferably an alkyl group having 16 to 24 carbon atoms, more preferably 22 alkyl groups, particularly a linear alkyl group, and the other one having 1 to 3 carbon atoms. A lower alkyl group, particularly a methyl group is preferred. Examples of the anion An ⁻ include halide ions such as chloride ion, bromide ion and iodide ion; organic anions such as methyl sulfate ion, ethyl sulfate ion, methyl carbonate ion and saccharinate ion. In particular, chloride ions are preferred.

  As the cationic surfactant, mono long-chain alkyl quaternary ammonium salts are preferable, and specific examples include cetyltrimethylammonium chloride, stearyltrimethylammonium chloride, aralkyltrimethylammonium chloride, and behenyltrimethylammonium chloride. Stearyl trimethyl ammonium and behenyl trimethyl ammonium chloride are preferable.

  Examples of amphoteric surfactants include imidazoline series, carbobetaine series, amide betaine series, sulfobetaine series, hydroxysulfobetaine series, and amide sulfobetaine series.

  Among these surfactants (c), from the viewpoint of emulsifying ability (miscibility of alkoxysilane (a) or (a ′), organic acid (b), water and surfactant (c)), HLB 9 to 15 In particular, 11 to 14 nonionic surfactants are preferred. In addition, HLB here shows the calculated value by the Griffin method.

  In the pulp treating agent of the present invention, for the purpose of dissolving the silanol compound (5) produced by hydrolysis of the alkoxysilane (a), lower monohydric alcohols having 1 to 3 carbon atoms such as methanol and ethanol, glycerin, etc. These water-soluble organic solvents can also be blended.

  In addition, the pulp treatment agent of the present invention is intended for pH adjusters, oil agents, silicone derivatives, cationic polymers, humectants, viscosity modifiers, fragrances, dyes, ultraviolet absorbers, antioxidants, antibacterial agents, etc. It can mix | blend suitably according to it.

In the case of using the water-soluble organic solvent in the pulp treating agent of the present invention, the blending amount is 35% by weight or less from the viewpoint of sufficiently swelling the pulp fiber and sufficiently bringing the silanol compound (5) into contact with the pulp fiber. Further, it is preferably 20% by weight or less. In addition to this, the pulp treatment agent after hydrolysis of the alkoxysilane (a) contains R ² OH as a by-product (R ² has the above meaning).

  The pulp treating agent of the present invention hydrolyzes the alkoxysilane (a) to form the silanol compound (5), and the pH at 20 ° C. is 2 in order to bring the silanol compound (5) into sufficient contact with the pulp fiber. -5, preferably 2-4. In the case of a two-component pulp treatment kit, the pH of the second agent at 20 ° C. is adjusted to the above range.

  The pulp treating agent of the present invention contains an alkoxysilane (a) or (a ′), an organic acid (b), and water, if necessary, a surfactant (c), or other optional components immediately before use. It may be prepared by adjusting the pH at 2 to 5.

  The 1st pulp processing agent of this invention contains alkoxysilane (a) from the point which ensures long-term stability, and 50 weight% or more in alkoxysilane (a) is trialkoxysilane (a1) and Two-component system comprising a first agent that is at least one selected from dialkoxysilane (a2), an organic acid (b) and water, and a second agent having a pH of 2 to 5 at 20 ° C. It is preferable that the pulp processing kit is mixed.

  The 2nd pulp processing agent of this invention contains alkoxysilane (a ') from the point which ensures long-term stability, and 50 weight% or more in alkoxysilane (a') is alkoxysilane (a). It is manufactured by blending a two-component pulp treatment kit comprising a first agent that is an organic acid (b) and water and a second agent having a pH of 2 to 5 at 20 ° C. Is preferred.

  In the two-component pulp treatment kit of the present invention, the surfactant (c) is preferably contained in the second agent, but can also be contained in the first agent when the first agent does not contain moisture. Moreover, although it is preferable to contain other arbitrary components in the 2nd agent, if it is a non-aqueous liquid component and a solid component, it can also mix | blend in a 1st agent.

  The pulp treating agent of the present invention is prepared by mixing the alkoxysilane (a) or (a ′), the organic acid (b), and water, if necessary, the surfactant (c), or other optional components immediately before use. In this case, the order of mixing is not particularly limited, but the silanol compound (5) generated by hydrolysis of the alkoxysilane (a) is sufficiently brought into contact with the pulp fiber. It is preferable to mix alkoxysilane (a) or (a ′) after mixing activator (c).

  Further, when both trialkoxysilane (a1) and dialkoxysilane (a2) are used as alkoxysilane (a) or (a ′), first, trialkoxysilane (a1), organic acid (b), and water are added. It is more preferable to mix the dialkoxysilane (a2) after mixing. It is preferable that at least a part of the trialkoxysilane (a1) is hydrolyzed after mixing the trialkoxysilane (a1), the organic acid (b), and water. The progress of hydrolysis can be judged by the increase in the transparency of the liquid.

[Paper manufacturing method]
In the present invention, the first paper manufacturing method is a method including the step (I) of bringing a first pulp treating agent into contact with pulp fibers.

In the step (I), examples of the method for bringing the first pulp treating agent into contact with the pulp fiber include the following methods (i) to (iii).
(I) A method of bringing the first pulp treating agent into contact with pulp fibers in the pulp slurry.
(Ii) A method of bringing the first pulp treating agent into contact with the pulp web.
(Iii) A method of bringing the first pulp treating agent into contact with the pulp sheet.

  In the method (i), the pulp slurry is preferably a pulp dispersion having a pulp fiber weight of 0.1 to 10% by weight and a pulp treating agent or a diluted solution thereof as a medium. Specifically, before the papermaking process in which a dilute liquid of pulp raw material is filtered through the wire mesh to form a paper layer, a pulper, refiner, or other disintegrator or beater, machine chest, head box, or white water tank The first pulp treatment agent may be added to a tank such as a tank or a pipe connected to these facilities, but the first pulp treatment agent may be added uniformly by a refiner, a machine chest, or a head box. A place where it can be blended with pulp raw materials is desirable.

  In order to fully infiltrate the pulp treating agent into the pulp, pulp sheet or pulp web, the time for contacting them is preferably 5 to 90 minutes, particularly preferably 20 to 60 minutes. It is considered that the hydrolyzate of alkoxysilane penetrates into the pulp by leaving it for a certain time after contact.

  In the method (ii), the pulp web refers to a sheet in which pulp fibers are intertwined in a state where they are not bonded by hydrogen bonds or binders. The moisture content of the pulp web with respect to the pulp is preferably 50 to 1000% by weight, more preferably 50 to 800% by weight, still more preferably 50 to 500% by weight, particularly preferably 100 to 500% by weight, and most preferably 150 to 500%. % By weight.

  In the method of (ii), the pulp production process uses a pulp web after the dehydration process after washing in the deinking process, and the paper production process uses a pulp web after the papermaking press process and before the drying process. It is preferable to spray the treatment agent, and the latter is more preferable.

  In the method (iii), examples of the method for bringing the first pulp treating agent into contact with the pulp sheet include a method of immersing the pulp sheet in the first pulp treating agent or spraying the first pulp treating agent. .

  The pulp sheet used in the method (iii) preferably has a moisture content with respect to the pulp sheet of less than 50% by weight. In addition, a pulp sheet means the pulp fiber aggregate | assembly formed into a sheet form by combining pulp fibers with a hydrogen bond or a binder.

  In the method of (iii), in the pulp manufacturing process, the first pulp treatment agent is preferably sprayed, coated and / or immersed in the pulp sheet after the drying process, preferably before winding. Is more preferable.

  When treating the pulp using the pulp treating agent of the present invention, after mixing the alkoxysilane, organic acid, water and surfactant, and other optional components before use, stirring and mixing by means such as shaking, After confirming that the transparency of the mixed solution has been increased visually, it is preferable to bring the pulp, pulp sheet or pulp web into contact with the obtained pulp treating agent.

  The obtained pulp treating agent is preferably brought into contact with the pulp, the pulp sheet or the pulp web within 30 minutes and further within 15 minutes.

  You may heat the pulp, pulp sheet, or pulp web which contacted the pulp processing agent to 40-120 degreeC, Preferably it is 60-120 degreeC, More preferably, it is 90-120 degreeC. Specifically, it is preferable to warm by hot air drying, dryer drying or press heating. Further, the polymerization can be promoted by adjusting the pH of the liquid to 5 to 8 without drying the fibers. The pH can be adjusted with an acid or base after the fibers are immersed in the liquid or after the excess liquid is removed.

  In the step (I), from the viewpoint of bulkiness and calendar resistance, the above methods (ii) and (iii) are preferable, and in particular, before pressing, the moisture content with respect to pulp is preferably 100 to 1000% by weight, More preferably 100 to 500% by weight, still more preferably 100 to 300% by weight, and moisture content after pressing is preferably 50 to 300% by weight, more preferably 50 to 200% by weight, still more preferably 50 to 150%. It is desirable to use the first pulp treating agent of the present invention as water in the weight percent pulp web.

  In the present invention, the second paper manufacturing method is a paper manufacturing method including a step (I ′) of bringing a second pulp treating agent into contact with a pulp web having a moisture content of 50 to 1000% by weight.

  In the step (I ′), examples of the method for bringing the second pulp treating agent into contact with the pulp web include the method (ii) above.

  In the step (I ′), from the viewpoint of bulkiness and calendar resistance, the moisture content with respect to pulp is preferably 100 to 1000% by weight, more preferably 100 to 500% by weight, and still more preferably, before pressing. 100% to 300% by weight, after pressing, the water content in the pulp web is preferably 50 to 300% by weight, more preferably 50 to 200% by weight, and still more preferably 50 to 150% by weight. It is desirable to use a second pulp treating agent.

  The paper making method using the pulp treating agent of the present invention may be a general paper machine. Examples of the paper machine include a long net type, a circular net type, a short net type, a twin wire type, and an inclined wire type paper machine. can give. In particular, the twin wire type is preferable from the viewpoint of reducing the difference between the front and the back of the paper. The paper making speed is preferably 200 m / min or more, more preferably 300 m / min or more, and particularly preferably 500 m / min or more from the standpoint of remarkable effects of improving bulk, whiteness and opacity.

  In addition, a sizing agent, a filler, a yield improver, a drainage improver, a paper strength improver, etc. may be added during papermaking. In particular, in order for the pulp treating agent of the present invention to exhibit its function, it is important to fix to the pulp fiber, and therefore, an agent that promotes fixing (hereinafter referred to as a fixing accelerator) is preferably added. . Examples of the fixing accelerator include aluminum sulfate, a compound having an acrylamide group, and polyethyleneimine. The addition amount of the fixing accelerator is preferably 0.01 to 5 parts by weight with respect to 100 parts by weight of the pulp raw material. The addition amount of the fixing accelerator in the pulp treating agent of the present invention is preferably 0.1 to 100 parts by weight with respect to 100 parts by weight of the alkoxysilane (a) or (a ′). Further, a fixing accelerator may be included in the pulp treating agent of the present invention.

  The processing amount of the pulp treating agent of the present invention is preferably 0.01 to 50 parts by weight, more preferably 0.1 to 50 parts by weight, and more preferably 0.1 to 25 parts by weight as a solid content with respect to 100 parts by weight of the pulp fiber raw material. Part by weight is more preferred, 0.5 to 20 parts by weight is particularly preferred, and 1 to 20 parts by weight is most preferred.

In the paper manufacturing method of the present invention, if necessary, it may have a calendering process for calendering the pulp sheet after the step (I) or (I ′). The method is particularly effective for imparting calendar resistance to the pulp sheet during calendering.
In calendar processing, a calendar device such as a super calendar, a soft calendar, a machine calendar, or a gloss calendar can be used, and these may be used in combination. When the paper of the present invention is used as a base paper for coated paper, a super calendar is preferable. The surface temperature of the calendar is not particularly limited, but it is preferably performed at 50 ° C. or higher.

Process for manufacturing paper of the present invention, basis weight, preferably 30~1000g / m ^2, more preferably 30~700g / m ^2, more preferably 30~300g / m ^2, even more preferably 30 to 200 g / When the paper of m ² is produced, paper quality (tightness, whiteness, opacity) including the initial characteristics of the paper, in particular, the static friction coefficient, the dynamic friction coefficient, and the bulkiness is effectively expressed.

  The paper manufacturing method of the present invention can be applied to various types of paper. For example, non-coated paper and fine coated paper used for book paper and magazines, printing paper such as coated paper used for catalogs and posters, and these base papers, or inkjet paper, PPC paper, foam paper, thermal paper , Information paper such as pressure-sensitive paper and its base paper, or newsprint paper, packaging paper, paperboard such as white paperboard or colored paperboard, etc. It is suitably used for the base paper.

  More specifically, for example, high-quality paper, book paper, medium-quality paper, top-up paper, back-up paper, book thin paper, Kent paper, color high-quality paper, cast coated paper, A0 art paper, A1 art paper, A2 coated paper, A3 coated paper, lightweight coated paper, medium coated paper, gravure paper, pure white roll paper, single gloss bleached kraft paper, pure white wrapping paper, bifurcated kraft paper, bleached kraft paper, colored kraft paper, lined kraft paper, single gloss Kraft paper, thin imitation paper, imitation paper, India paper, copy paper, type paper, tracing paper, copy paper, glassine paper, other processed paper and industrial hybrid paper, fine coated paper, sanitary paper, corrugated paper, household It is suitable for the production of hybrid paper.

  In the following examples,% is% by weight.

Production Example 1
Methyltriethoxysilane (LS-1890, manufactured by Shin-Etsu Chemical Co., Ltd.) was added to a solution in which adipic acid, water, and, if necessary, polyoxyethylene lauryl ether (Emalgen 108, manufactured by Kao Corporation) were mixed, and the cloudy suspension was added. The suspension was stirred until the turbid liquid became transparent to obtain pulp treating agents 1, 3, 5, 7 and 9 having the composition shown in Table 1 (composition before hydrolysis).

Production Example 2
Methyltriethoxysilane (LS-1890, manufactured by Shin-Etsu Chemical Co., Ltd.) was added to a solution in which adipic acid, water, and, if necessary, polyoxyethylene lauryl ether (Emalgen 108, manufactured by Kao Corporation) were mixed, and the cloudy suspension was added. Stir until the suspension is clear. Further, dimethyldiethoxysilane (LS-1370 manufactured by Shin-Etsu Chemical Co., Ltd.) was added and stirred again until the suspension became transparent, and the pulp treatment agent 2 having the composition shown in Table 1 (composition before hydrolysis) was obtained. 4, 8, 10 were obtained.

Examples 1 to 10, Comparative Example 1
Using the pulp raw material shown below, a pulp sheet having a water content of 10% by weight obtained by the following method was treated with the pulp treating agents 1 to 10 prepared immediately in the production examples by the following method to produce paper. Moreover, the paper which does not process a pulp processing agent as a comparison was manufactured.

<Manufacturing method of pulp sheet and processing method of pulp treating agent>
Chemical pulp LBKP (hardwood bleached pulp) was used as a pulp raw material, and it was disaggregated and beaten with a beating machine at 25 ° C. to obtain 2.2% LBKP slurry. The Canadian standard freeness (JIS P 8121) of this product was 420 ml.

LBKP slurry was weighed so that the basis weight of the sheet after paper making was about 80 g / m ² , then diluted with water so that the pulp concentration was 0.5%, and after stirring, using a square tapi paper machine Paper was made with a 150 mesh wire to obtain a wet sheet. The wet sheet after paper making was pressed with a press at 3.5 kg / cm ² for 5 minutes and dried at 105 ° C. for 2 minutes using a drum dryer to obtain a pulp sheet.
This pulp sheet was immersed in a pulp treating agent, immediately pulled up, and left at room temperature for 5 minutes. Thereafter, it was dried at 105 ° C. for 2 minutes using a drum dryer to obtain paper.

Examples 11-18
Using the same pulp raw material as in Example 1, paper was made in the same manner as in Example 1 to obtain a wet sheet. This wet sheet was pressed with a press at 3.5 kg / cm ² for 5 minutes to obtain a pulp web having a moisture content of 150% to the pulp. -4, 7-10 were sprayed in the amount shown in Table 2 and sealed. Thereafter, the mixture was allowed to stand at room temperature for 30 minutes, then opened, and further left for 5 minutes. Thereafter, it was dried at 105 ° C. for 2 minutes using a drum dryer to obtain paper.

Example 19
The same LBKP slurry as in Example 1 was weighed so that the basis weight of the sheet after papermaking was about 80 g / m ^2, and the pulp treatment agent 7 immediately after preparation prepared in the production example was 20% by weight with respect to the pulp ( After adding and stirring for 40 minutes, it is diluted with water so that the pulp concentration is 0.5%, and after stirring, the paper is made with a 150-mesh wire using a square tappi paper machine to obtain wet paper It was. The wet sheet after paper making was pressed with a press at 3.5 kg / cm ² for 5 minutes and dried at 105 ° C. for 2 minutes using a drum dryer to obtain a pulp sheet.

  About the paper obtained in the said Examples 1-19 and the comparative example 1, after performing humidity control for 5 hours or more on conditions of 23 degreeC and 50% of humidity, various paper physical properties were measured with the following method. Further, the tension of the paper obtained by calendering the paper by the following method was measured by the following method. In addition, in the measurement of the intensity | strength after a calendar process, humidity control was not performed but it measured immediately after the calendar process. These results are shown in Table 2.

<Calendar processing>
The conditioned paper was calendered (processing speed: 10 m / min, roll temperature: 50 ° C., processing frequency: 2 times) using a lab calendar device (30FC-200E super calendar manufactured by Kumagai Riki Kogyo Co., Ltd.). In the examples, the treatment of 300 kg / cm was performed on the same paper after increasing the linear pressure after treating at 100 kg / cm.

<Measurement method of basis weight>
The conditioned paper is cut into 150 mm × 150 mm, the weight of the paper is measured, and the basis weight (g / m ² ) is obtained by the following formula (6).

Basis weight (g / m ² ) = paper weight / 0.0225 (6)

<Measurement of strain>
The thickness of the conditioned paper is measured using a paper micrometer at a pressure of 53.9 ± 4.9 kPa at five or more locations, and the average value obtained is defined as the paper thickness (mm).
From the basis weight (g / m ² ) and thickness (mm) of the conditioned paper, the tightness (g / cm ³ ) is obtained by the following formula (7).

Tension = (basis weight) / (thickness) × 0.001 (7)
The smaller the tension is, the higher the bulk is, and the difference of 0.02 in the tension is sufficiently recognized as a significant difference.

<Measurement method of whiteness>
Measured by JIS P 8123 Hunter whiteness (measurement of whiteness B). A difference of 0.5 points in whiteness is sufficiently recognized as a significant difference.

<Measurement method of opacity>
Measured by JIS P 8138A method (measurement of opacity P). A difference of 0.5 point in opacity is fully recognized as a significant difference.

<Measuring method of friction coefficient>
Measured according to JIS P8147 method.

Claims (10)

After the step (I), the pulp treatment agent comprising the alkoxysilane (a) represented by the general formula (1), the organic acid (b), and water is brought into contact with the pulp fiber, and after the step (I). And a calendering process for calendering a pulp sheet, a method for producing a paper selected from printing paper and its base paper, wherein 50% by weight or more in the alkoxysilane (a) is represented by the general formula (2) It is at least one selected from trialkoxysilane (a1) and dialkoxysilane (a2) represented by the general formula (3), and the amount of water is at least 3 times the amount of alkoxysilane (a). Yes, the manufacturing method of the paper whose pH of a pulp processing agent in 20 degreeC is 2-5.
R ¹ _p Si (OR ² ) _4-p (1)
R ¹ Si (OR ² ) ₃ (2)
R ¹ ₂ Si (OR ² ) ₂ (3)
Wherein, R ¹ represents a linear or branched alkyl group having 1 to 6 carbon atoms, a straight-chain or branched alkenyl group having a phenyl group, or 2 to 6 carbon atoms, R ² is 1 to the number of carbon atoms 6 linear or branched alkyl groups, p R ¹ and (4-p) R ² may be the same or different. p shows the integer of 1-3. ]   The method for producing paper according to claim 1, wherein in the step (I), the pulp treating agent is contacted in a pulp slurry having a pulp fiber weight of 0.1 to 10% by weight.   The method for producing paper according to claim 1, wherein in step (I), the pulp treating agent is brought into contact with a pulp sheet having a moisture content with respect to the pulp sheet of less than 50% by weight. Alkoxysilane (a '), an organic acid (b), and the step of pulp processing agent obtained by blending a water volume to pulp moisture into contact with the 50 to 1000 weight% of the pulp web (I'), the step (I ' ), And a calendering process for calendering the pulp sheet, a method for producing a paper selected from printing paper and its base paper, wherein 50% by weight or more in alkoxysilane (a ′) The amount of water is 3 times the molar amount of the alkoxysilane (a ′), and the pH of the treating agent at 20 ° C. is 2 to 2. 5 is a method for producing paper.   The alkoxysilane (a ′) is at least one selected from trialkoxysilane (a1) represented by the general formula (2) according to claim 1 and dialkoxysilane (a2) represented by the general formula (3). The method for producing paper according to claim 4, comprising:   The method for producing paper according to any one of claims 1 to 5, wherein the pulp treating agent further comprises a surfactant (c).   The pulp treatment agent is obtained by mixing trialkoxysilane (a1), organic acid (b), and water and then dialkoxysilane (a2). The manufacturing method of the paper of description.   A pulp treatment agent comprising the alkoxysilane (a) represented by the general formula (1) according to claim 1, an organic acid (b), and water, wherein the pulp treatment agent is 50% by weight in the alkoxysilane (a). The above is at least one selected from trialkoxysilane (a1) represented by general formula (2) and dialkoxysilane (a2) represented by general formula (3) according to claim 1, The pulp processing agent whose quantity is 3 times mol or more of the compounding quantity of alkoxysilane (a), and pH in 20 degreeC is 2-5.   It is a pulp processing kit for obtaining the pulp processing agent in any one of Claims 1-3, 6-8, Comprising: The alkoxysilane (a) represented by General formula (1) of Claim 1 is contained. , A first agent that does not contain organic acid (b) and water, and a second agent that contains organic acid (b) and water, and does not contain alkoxysilane (a). Pulp treatment kit (but 50% by weight in alkoxysilane (a)) that is 3 times mol or more of the amount of silane (a) and mixed so that the pH of the pulp treatment agent at 20 ° C. is 2 to 5 The above is at least one selected from trialkoxysilane (a1) represented by general formula (2) and dialkoxysilane (a2) represented by general formula (3).   A pulp treatment kit for obtaining the pulp treating agent according to any one of claims 4 to 7, comprising an alkoxysilane (a '), a first agent not containing an organic acid (b) and water, and organic It is composed of a second agent containing acid (b) and water and not containing alkoxysilane (a ′), and the amount of water used is at least 3 times the amount of alkoxysilane (a ′) in use, A pulp treatment kit mixed so that the pH of the pulp treating agent at 20 ° C. is 2 to 5 (provided that 50% by weight or more in alkoxysilane (a ′) is represented by the general formula (1) according to claim 1. Alkoxysilane (a).