JP2003089989A - Method for producing paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new method for producing paper by which a sufficient paper strength can be exhibited in both a dry and a wet states at a low cost with slighter limitations on the range of use than those of a conventional method. SOLUTION: This method for producing the paper comprises using an organic solvent containing a silane-based compound as a fluid medium when vegetable fibers are agglutinated to produce the paper.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing paper by sticking vegetable fibers using an organic solvent in which a silane compound is dissolved as a fluid medium.

[0002]

2. Description of the Related Art In the paper manufacturing process, water is used as a fluid medium for sticking vegetable fibers. The conventional paper produced by such a conventional production method is
The structure usually contains about 4 to 6% water,
This water forms hydrogen bonds with the hydroxyl groups of cellulose in the plant fibers, and plays a strong role in bonding the fibers together.
The strength of the paper is maintained by both the chemical bonding force by the hydrogen bond between the hydroxyl group of cellulose and water and the physical bonding force by the entanglement of the plant fibers.

The above-mentioned hydrogen bond between the hydroxyl groups of cellulose and water is strong, however, water is 100
When heated above ℃, it will evaporate, it will not be possible to maintain such hydrogen bonds, the paper strength will inevitably decrease. On the contrary, even when water permeates the paper, the hydroxyl groups of the cellulose in the plant fiber cannot indirectly bond with each other through the hydrogen bond with water, so that the strength of the paper decreases. . And as a result of these, conventional paper cannot be used as a raw material for products used in high temperature conditions or paper products that are used in contact with water or in a wet condition, and naturally the range of use is limited. Is done.

Therefore, in order to increase the strength of paper, conventionally,
Additives have been added to water, which is a fluid medium. Conventionally added additives include a dry paper strength enhancer that increases the tensile strength (dry paper strength) when the paper is dry, and a tensile strength (wet paper strength) when the paper is wet. There is a wet paper strengthening agent that enhances.

As the dry paper strength enhancer, polyacrylamide type polymer compounds, cationized starch, dialdehyde starch, vegetable gum and the like are used.
In these, the amide group and the hydroxyl group in each compound are hydrogen-bonded to the hydroxyl group of the cellulose in the fiber, and the interpolymer cohesive force is exerted to enhance the dry paper strength. On the other hand, a polyamide polyamine epichlorohydrin resin is used as the wet strength agent. Polyamide polyamine epichlorohydrin resin is
It is cationic and self-fixes to the fiber to crosslink with cellulose to form a three-dimensional network structure, and blocks hydrophilic groups while preventing water from penetrating to enhance wet paper strength.

[0006]

As described above, conventionally, in the production of paper, it is necessary to use an additive such as a wet strength agent or a dry strength agent while using water as a fluid medium. Is currently compensating for the problems of paper.

[0007] However, a paper having an increased dry strength using a dry strength agent has a serious problem in a wet state. That is, when the paper comes into contact with water and the water penetrates into the water, the hydrogen bond formed between the amide group or hydroxyl group in the dry paper strengthening agent and the hydroxyl group of cellulose in the fiber constituting the paper is There is a problem that the paper strength and paper strength are greatly reduced. Therefore, the paper produced using the dry strength agent cannot be used as a raw material for producing a paper product which comes into contact with water unless the surface is coated with an appropriate material.

[0008] Further, in the paper in which the wet strength is strengthened by using the wet strength agent, the paper itself cross-links with the cellulose in the plant fiber to form a three-dimensional network structure, and within the network structure. In order to enhance the wet paper strength by blocking the hydrophilic group,
Although it exhibits high resistance to water infiltration in a wet state, there is still room for improvement in maintaining paper strength in a dry state.

The most serious problem in the conventional paper manufacturing method is to use the dry paper strength enhancer and the wet paper strength enhancer at the same time to enhance the paper strength against both dryness and wetness. Could not be manufactured.

The applicant of the present application has previously proposed a coated paper having a glassy coating film formed on its surface (for example, Japanese Patent Application No. 2000-242269). The coated paper previously proposed by the applicant of the present application has dramatically improved mechanical strength such as tensile strength as compared with ordinary paper, and also has improved heat resistance of the paper. However, although this coated paper can exhibit practically sufficient dry paper strength and wet paper strength, the additional work of coating the glass surface with a glassy material is essential, which naturally increases the manufacturing cost. Had a problem.

Therefore, an object of the present invention is to provide a novel paper which can exert a sufficient paper strength in both a dry state and a wet state and has a low use cost and a limited range of use as compared with a conventional paper. It is to provide a manufacturing method of.

[0012]

Means for Solving the Problems The present inventor has made an earnest study to achieve the above-mentioned object, and pays attention to a fluid medium when a paper is produced by sticking plant fibers or the like to the present invention. It came to completion. The invention of claim 1, which is a novel method for producing paper, capable of maintaining sufficient paper strength in both a dry state and a wet state, and at a low cost. In the production of, as a fluid medium thereof, an organic solvent containing a silane compound is used,
It is a method of manufacturing paper.

The invention according to claim 2 of the present application relates to the invention according to claim 1, characterized in that the silane compound is a compound containing a compound represented by the formula 1 as a main component.

[Formula 1] (In Formula 1, R₁, R_Two, R_ThreeAnd R_FourIs that
Which may be the same or different, hydrogen, an alkyl group or
R is a monomer consisting of an alkenyl group₁O, R _TwoO,
R_ThreeO and R_FourThe bond between O and Si is a siloxane bond.
Is a condensate)

A third aspect of the present invention relates to the first aspect of the present invention, wherein the silane compound is represented by the formula 2
A main component is a compound having one hydrolyzable substituent and one non-hydrolyzable substituent.

[Formula 2] (In the formula 2, R ₅ , R ₆ and R ₇ may be the same or different and each is a monomer consisting of hydrogen, an alkyl group or an alkenyl group, and R ₅ O, R ₆ O and R ₇
The bond between O and Si is a condensate composed of a siloxane bond, and R ₈ is an alkyl group, an alkenyl group or a phenyl group which may contain an epoxy group or a glycidyl group in its molecule.)

A fourth aspect of the present invention relates to the first aspect of the present invention, wherein the silane-based compound has two hydrolyzable substituents and two non-hydrolyzable substituents represented by Formula 3. It is characterized in that a compound having a different substituent is contained as a main component.

[Formula 3] (In Formula 3, R ₉ and R ₁₁ may be the same or different and each is a monomer composed of hydrogen, an alkyl group or an alkenyl group, and the bond between R ₉ O and R ₁₁ O and Si is a roxane bond. R ₁₀ and R ₁₂ are alkyl groups, alkenyl groups or phenyl groups, which may contain an epoxy group or a glycidyl group in their molecule)

The invention according to claim 5 of the present application relates to the invention according to claim 1, wherein the silane compound is represented by formula 1, formula 2 and formula 3.
The compound is characterized by containing at least two kinds of the compounds represented by.

[Formula 1] (In Formula 1, R₁, R_Two, R_ThreeAnd R_FourIs that
Which may be the same or different, hydrogen, an alkyl group or
R is a monomer consisting of an alkenyl group₁O, R _TwoO,
R_ThreeO and R_FourThe bond between O and Si is a siloxane bond.
Is a condensate)

[Formula 2] (In the formula 2, R ₅ , R ₆ and R ₇ may be the same or different and each is a monomer consisting of hydrogen, an alkyl group or an alkenyl group, and R ₅ O, R ₆ O and R ₇
The bond between O and Si is a condensate composed of a siloxane bond, and R ₈ is an alkyl group, an alkenyl group or a phenyl group which may contain an epoxy group or a glycidyl group in its molecule.)

[Formula 3] (In Formula 3, R ₉ and R ₁₁ may be the same or different and each is a monomer composed of hydrogen, an alkyl group or an alkenyl group, and the bond between R ₉ O and R ₁₁ O and Si is a roxane bond. R ₁₀ and R ₁₂ are alkyl groups, alkenyl groups or phenyl groups, which may contain an epoxy group or a glycidyl group in their molecule)

The invention according to claim 6 of the present application relates to the invention according to claim 1, wherein the silane compound is represented by formula 1, formula 2 and formula 3.
It is characterized in that all three kinds of compounds represented by are simultaneously contained.

[Formula 1] (In Formula 1, R₁, R_Two, R_ThreeAnd R_FourIs that
Which may be the same or different, hydrogen, an alkyl group or
R is a monomer consisting of an alkenyl group₁O, R _TwoO,
R_ThreeO and R_FourThe bond between O and Si is a siloxane bond.
Is a condensate)

[Formula 2] (In the formula 2, R ₅ , R ₆ and R ₇ may be the same or different and each is a monomer consisting of hydrogen, an alkyl group or an alkenyl group, and R ₅ O, R ₆ O and R ₇
The bond between O and Si is a condensate composed of a siloxane bond, and R ₈ is an alkyl group, an alkenyl group or a phenyl group which may contain an epoxy group or a glycidyl group in its molecule.)

[Formula 3] (In Formula 3, R ₉ and R ₁₁ may be the same or different and each is a monomer composed of hydrogen, an alkyl group or an alkenyl group, and the bond between R ₉ O and R ₁₁ O and Si is a roxane bond. R ₁₀ and R ₁₂ are alkyl groups, alkenyl groups or phenyl groups, which may contain an epoxy group or a glycidyl group in their molecule)

The invention of claim 7 relates to the invention of claim 1 and is characterized in that the silane compound is cured by using a hydrolyzable organometallic compound as a catalyst. The invention of claim 8 of the present application relates to the invention of claim 7, wherein the hydrolyzable organometallic compound is at least one organometallic compound selected from the group consisting of titanium, zircon, aluminum and tin. Is characterized by.
Hereinafter, the present invention will be described in detail.

As described above, the paper is characterized by being produced by using water as a fluid medium for sticking the plant fiber. The amount of water contained in the paper drops sharply as it goes through the paper manufacturing process.
To 6%. Then, as described above, this water, which is the fluid medium contained in the paper, forms hydrogen bonds with the hydroxyl groups of cellulose in the plant fibers, and indirectly and strongly bonds the fibers. On the other hand, the present invention is characterized by using an organic solvent containing a silane compound instead of water as the fluid medium.

The silane compound used in the present invention is an alkoxysilane compound. The alkoxysilane compound is hydrolyzed and polymerized to form a network, and functions as a binder for binding plant fibers. That is, after mixing with plant fiber, silanol is produced when the alkoxysilane compound is hydrolyzed by the action of a catalyst or the like, but the produced silanol is
It is chemically bonded to the hydroxyl groups of cellulose in plant fibers.
Here, the bond between silanol and cellulose is a direct bond and is strong. Therefore, the paper manufactured according to the present invention has enhanced mechanical strength such as tensile strength as compared with the conventional paper manufactured using water as a fluid medium.

[0021] The state of the binding reaction between the alkoxysilane compound and cellulose can be shown as a schematic diagram, as shown in reaction formula (1). In reaction formula 1, the alkoxysilane compound is expressed as HO—Si—OH for convenience, but it goes without saying that an alkoxysilane compound in which the HO— group is a RO— group is also included in this.

[Reaction formula 1]

Generally, when an alkoxysilane compound is hydrolyzed, a siloxane bond (≡Si-O-Si≡) is formed through the reactions shown in the following reaction formulas (2) to (4),
The siloxane bond network expands. And in this case, unlike the chemical bond between the silanol and the hydroxyl group of cellulose, the network itself is entangled with the plant fiber, and as a result, the siloxane (polysiloxane) forming the network with the plant fiber is formed. The bond strength between them increases. Therefore, in addition to the above-mentioned chemical bond with cellulose, the network formed by this siloxane also makes the paper produced according to the present invention, as compared with the conventional paper produced using water as the fluid medium. The mechanical strength such as tensile strength is increased.

[Reaction formula 2]

[Reaction formula 3]

[Reaction formula 4]

The bond energy of ≡Si—O in the siloxane bond is 106 kcal / mol, whereas the bond energy of the C—C bond, which is a typical bond of organic compounds, is 82.6 kcal / mol. . The paper produced by the production method of the present invention has a siloxane bond formed by hydrolysis of a silane-based compound, and therefore is much more thermally stable than an organic compound. Due to having such a thermally stable bond,
The paper produced according to the present invention is also excellent in physical properties such as heat resistance and abrasion resistance.

The silane compound used in the present invention is
There is no particular limitation as long as it is a general alkoxysilane compound. Specifically, the compound represented by the formula 1 can be exemplified.

[Formula 1]

In equation 1, R₁, R_Two, R_ThreeAnd R_Four
May be the same or different, and hydrogen,
R is a monomer having a kill group or an alkenyl group, and R
₁O, R _TwoO, R_ThreeO and R_FourThe bond between O and Si is white
It is a condensate composed of xane bonds. Also, for example, in Equation 1
One of the indicated compounds may be used alone or 2
You may use it in mixture of 2 or more types. In addition,
The compound may be a monomer, or one or more of them may be used.
Although it may be a condensate of the compound of, when a monomer is used,
Generally, monomers take time to polymerize, so
Difficult to produce paper with sufficient strength in a short time
Could be. Therefore, in the present invention, the formula
It is preferable to use a condensate of a compound represented by 1.
Yes. However, when a condensate is used, the degree of condensation is
If it is too large, the
Insufficient number of coxy groups to produce paper with sufficient strength
Since it may be difficult to
Preference is given to using 10, especially 3 to 8 condensates
Yes. In general, when synthesizing a condensate from a monomer,
It is extremely difficult to control the degree of condensation accurately
Therefore, the reaction was controlled so that the condensation degree was 2 to 10.
However, in reality, it includes a condensate having a degree of condensation of 11 or more.
It is common to Also in the present invention, the degree of condensation is
Strict control is not essential, for example a condensation degree of 1
No problem even if more than one compound is included
There is no.

Among the silane compounds used in the present invention, the compound represented by the formula 1 is specifically as follows:
For example, tetramethoxysilane, tetraethoxysilane,
Tetrapropoxysilane, tetrabutoxysilane, dimethoxydiethoxysilane, dimethoxydipropoxysilane, dimethoxydibutoxysilane, diethoxydipropoxysilane, diethoxydibutoxysilane, dipropoxydibutoxysilane, methoxytriethoxysilane, methoxytripropoxysilane , Methoxytributoxysilane, ethoxytrimethoxysilane, ethoxytripropoxysilane, ethoxytributoxysilane, propoxytrimethoxysilane, propoxytriethoxysilane, propoxytributoxysilane, and the like, or condensation products thereof. . As described above, one kind among these may be used alone, or two or more kinds may be mixed and used. Furthermore, these compounds may be monomers or may be condensates of one or more compounds selected from these.

As described above, the siloxane bond is a bond excellent in heat resistance and abrasion resistance, but on the other hand, it is a so-called "hard" bond. This "hardness" makes it possible to impart excellent physical properties such as heat resistance and abrasion resistance to the paper produced by the present invention, however, paper is used as a raw material to produce paper products. In the case of production, not only the physical properties and the like are excellent, but also the flexibility that conventional paper has may be required.

Tetraalkoxysilane (Si (O
R) ₄ ) and the tetraalkoxysilane oligomer represented by the formula 1, when the hydrolysis reaction shown in the above reaction formulas (2) to (4) completely occurs, all four bonds of the silicon atom are It reacts and becomes a binder formed only by a network of hard siloxane bonds. This is as hard as ceramics, but is brittle on the other hand, and is not necessarily suitable for producing flexible paper in the present invention. Therefore, in the present invention, when a flexible paper is produced, as a silane compound,
Of the four substituents on the silicon atom, it is preferable to use one in which one is not hydrolyzed.

As the silane-based compound in which one of the four substituents of the silicon atom is a non-hydrolyzable substituent, the compound represented by the formula 2 can be exemplified.

[Formula 2]

In the formula 2, R ₅ , R ₆ and R ₇ may be the same or different and each is a monomer consisting of hydrogen, an alkyl group or an alkenyl group, and R ₅ O, R ₆
The bond between O and R ₇ O and Si is a condensate composed of a siloxane bond, and R ₈ is an alkyl group, an alkenyl group or a phenyl group which may contain an epoxy group or a glycidyl group in the molecule. In the silane-based compound represented by the formula 2, R ₈ which does not participate in the hydrolysis and condensation reaction with the adjacent silicon atom remains in the form of “dangling”, so that the formed network is flexible. It is possible to produce paper that is imparted with properties and is more flexible than paper produced using only the siloxane compound represented by Formula 1.

Similarly, in the case of producing paper having flexibility, a silane-based compound in which 2 out of 4 substituents of silicon atom are non-hydrolyzable substituents is used as a silane-based compound. It is also preferable to As the silane-based compound in which two of the four substituents of the silicon atom are not hydrolyzed, those represented by Formula 3 can be exemplified.

[Formula 3]

In the formula 3, R ₉ and R ₁₁ may be the same or different and each is a monomer composed of hydrogen, an alkyl group or an alkenyl group, and R ₉ O and R ₁₁ O
The bond between Si and Si is a condensate composed of a roxane bond,
R ₁₀ and R ₁₂ are alkyl groups, alkenyl groups or phenyl groups which may contain an epoxy group or a glycidyl group in their molecule. This silane-based compound represented by the formula 3 is also present in the formed network because R ₁₀ and R ₁₂ that do not participate in the hydrolysis and condensation reaction with the adjacent silicon atom remain in the form of “dangling”. Is imparted with flexibility, and it becomes possible to produce a paper that is more flexible than paper produced using only the siloxane compound represented by Formula 1.

Specific examples of the silane compound represented by the above formula 2 include methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, butyltrimethoxysilane, methyltriethoxysilane and ethyltriethoxysilane. , Propyltriethoxysilane, butyltriethoxysilane, methyltripropoxysilane, ethyltripropoxysilane, propyltripropoxysilane, butyltripropoxysilane,
Vinyltrimethoxysilane, phenyltrimethoxysilane, γ- (methacryloxypropyl) trimethoxysilane, γ-glycidoxypropyltrimethoxysilane, aminopropyltrimethoxysilane, β- (3,4epoxycyclohexyl) ethyltrimethoxysilane , Vinyltriethoxysilane, phenyltriethoxysilane, γ
-(Methacryloxypropyl) triethoxysilane, γ
Examples thereof include monomers such as -glycidoxypropyltriethoxysilane, aminopropyltriethoxysilane, and vinyltris-β-methoxyethoxysilane, and condensates thereof. Then, like the compound represented by the formula 1, also in the compound represented by the formula 2, one kind among them may be used alone, or two or more kinds may be used in combination, and further May be a monomer or a condensate of one or more compounds selected from these. When using a condensate,
For the same reason as above, it is preferable to use a condensate having a condensation degree of 2 to 10, particularly 3 to 8.

Specific examples of the silane compound represented by the above formula 3 include dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane,
Examples thereof include monomers such as diethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, methylvinyldimethoxysilane, and methylvinyldiethoxysilane, and condensates thereof. And equation 1
Similarly to the compound represented by Formula 2 and the compound represented by Formula 2, in the compound represented by Formula 3, one kind among them may be used alone, or two or more kinds may be used in combination, and further, These compounds may be monomers, or may be a condensate of one or more compounds selected from these. When a condensate is used, it is preferable to use a condensate having a condensation degree of 2 to 10, particularly 3 to 8 for the same reason as above.

The silane compound represented by the formula 2 or the formula 3 having one or two substituents which are not hydrolyzed and therefore do not participate in the condensation reaction can be used alone. In the invention, an organic solvent containing at least two kinds of the silane-based compounds represented by Formula 1, Formula 2 and Formula 3 can be used as the fluid medium. Here, each silane-based compound contained in the fluid medium is one kind or a mixture of two or more kinds of the compounds represented by the respective formulas, and further, each compound may be a monomer, It may be a condensate of one or more compounds selected from the compounds represented by the formula. Further, it may be a condensate of three or more compounds represented by each formula. When a condensate is used, it is preferable to use a condensate having a condensation degree of 2 to 10, particularly 3 to 8 for the same reason as above.

Further, in the present invention, the produced paper is made more flexible by using the organic solvent containing the three kinds of compounds represented by the formulas 1, 2 and 3 at the same time as the fluid medium. be able to. Also in this case, each silane-based compound contained in the fluid medium is one kind or a mixture of two or more kinds of the compounds represented by the respective formulas, and further, each compound may be a monomer. , One or two selected from the compounds represented by the formulas
It may be a condensate of more than one kind of compound. And moreover,
It may be a condensate of three or more compounds represented by each formula. When a condensate is used, it is preferable to use a condensate having a condensation degree of 2 to 10, particularly 3 to 8 for the same reason as above.

As described above, the organic solvent containing at least two or more kinds or all three kinds of the silane compounds represented by the formulas 1, 2 and 3 is used as a fluid medium to be produced by the present invention. It is possible to intentionally change the flexibility of the paper used to produce paper that has the same flexibility as the paper produced by the conventional production method, as well as better physical properties such as heat resistance and abrasion resistance. It becomes possible to do. Regarding the ratio of the compound represented by each formula, the type of silane compound actually used, whether it is a monomer or a condensate, and the flexibility required for the paper to be produced,
It is preferable to conduct a preliminary manufacturing test to determine the physical properties such as heat resistance and abrasion resistance. In such a preliminary production test, the compound represented by the formula 1 as a main component and the compound represented by the formula 2 and / or the formula 3 are added to examine the flexibility, heat resistance and abrasion resistance of the produced paper. Are most appropriate in determining the composition of the fluid medium for making the intended paper. According to the knowledge of the inventors of the present application, it is manufactured that the total amount of the compounds represented by the formula 2 and / or the formula 3 is less than 50% with respect to the total amount of the silane compounds in the fluid medium. It is suitable for imparting flexibility while at the same time ensuring sufficient heat resistance and abrasion resistance of the paper.

When a silane-based compound having an organic substituent as the non-hydrolyzable substituents, that is, R ₈ , R ₁₀ and R ₁₂ in the silane-based compounds represented by the formulas 2 and 3, is used, At the same time as giving flexibility to the network formed by hydrolysis and condensation of the silane compound, it becomes possible to impart water repellency to the network. When using a silane-based compound having an organic substituent for such a purpose, the organic substituent generally increases in organicity, that is, water repellency as the carbon number thereof increases, but the carbon number is too large. In that case, it is preferable to adjust the type and amount of the organic substituent by conducting a preliminary experiment in consideration of the fact that steric hindrance causes strain in the network and the strength as a binder may be reduced.

The equations 1, 2 and / described above have been explained.
Alternatively, as a catalyst for promoting hydrolysis and condensation reaction of the silane-based compound represented by Formula 3 to cure and solidify,
A widely used acid catalyst or base catalyst can be used. Specific examples of the acid catalyst include hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid and the like. Specific examples of the base catalyst include ammonia, tetramethylammonium hydroxide, 2-hydroxyethyltrimethylammonium hydroxide, ethanolamine, diethanolamine, triethanolamine and the like. In order to promote the hydrolysis and condensation reaction of the silane-based compound represented by Formula 1, Formula 2 and / or Formula 3 by using these catalysts to cure and solidify, the reaction water is present in the fluid medium. Need to be.

The above reaction water can be provided as a part of the fluid medium by adding water to the fluid medium. However, the fluid medium in which the silane compound, the reaction water and the catalyst coexist is
Since it easily gels and is difficult to store for a long period of time, it is not preferable for carrying out the present invention. Therefore, in the present invention, it is particularly preferable to use, as the fluid medium, an organic solvent containing a hydrolyzable organometallic compound as a catalyst that does not require the reaction water to coexist. This is because the fluid medium in which the hydrolyzable organometallic compound is allowed to coexist as a catalyst has high long-term storage stability.

A catalyst which does not require the coexistence of reaction water,
When the organometallic compound is added to the fluid medium and comes into contact with the plant fiber, it absorbs moisture (humidity) on the plant fiber and / or in the air and hydrolyzes itself, but at the same time, It forms a network with coexisting silane compounds such as alkoxysilanes, and serves as a binder between plant fibers. The reaction at this time will be described, for example, in the case where tetrabutoxy titanate is used as the organometallic compound, as in the following reaction formulas (5) and (6).

[Reaction formula 5]

[Reaction formula 6]

Here, in the above reaction formula, "≡Ti-
By introducing the "O" bond into the network, physical properties such as heat resistance and abrasion resistance are further improved as compared with a binder having only a siloxane bond. Therefore, in the present invention, the use of an organometallic compound as a catalyst not only has the effect of improving the long-term storage stability of the fluid medium by eliminating the coexistence of reaction water,
It is also effective in further improving the heat resistance and abrasion resistance of the paper obtained by the present invention. Specific examples of the hydrolyzable organometallic compound that can be used as a catalyst in the present invention include those containing titanium, zircon, aluminum or tin. More specifically, for example, tetrapropoxy titanate, tetrabutoxy titanate, tetrapropoxy zirconate, tetrabutoxy zirconate, tripropoxyaluminate, aluminum acetylacetonate, dibutyltin diacetate or dibutyltin dilaurate can be exemplified. One of these organometallic compounds may be used, or two or more thereof may be mixed and used.

The silane compound, the catalyst, and the water of reaction that is allowed to coexist as described above are added to an organic solvent for uniformly mixing them and then used as a fluid medium for the production of paper. As the organic solvent in the present invention, for example, alcohols can be used.
Specifically, for example, methanol, ethanol, propanol, isopropanol, butanol, pentanol or hexanol can be exemplified. Since the viscosity of the fluid medium and the drying speed in the process of manufacturing paper vary depending on the type of organic solvent used, it is preferable to determine the organic solvent to be used in consideration of these factors. Examples of the organic solvent having a high viscosity and a high boiling point that can be used in the present invention include, in addition to the alcohols exemplified above, specifically, for example, ethylene glycol, propylene glycol, diethylene glycol, polyethylene glycol, dipropylene glycol. Alternatively, glycols such as polypropylene glycol, or cellosolves such as methoxyethanol, propoxyethanol, butoxyethanol, methoxypropanol, ethoxypropanol, propoxypropanol or butoxypropanol can be exemplified. Furthermore, the viscosity and the like can be adjusted by adding a surfactant to the fluid medium.

When the above-exemplified glycols or cellosolves are used as the organic solvent, they have a hydroxyl group in the molecule, and therefore, when the silane compound is condensed to form a siloxane bond network. In some cases, the organic molecule is introduced into the network formed by reacting with the silane compound, and the flexibility thereof may be further improved. Therefore, in the present invention, the above organic solvent is positively used so that the organic molecule is introduced into the siloxane bond network,
The flexibility of the network may be further improved.

The main raw material for making paper is vegetable fiber. In the present invention as well, paper is produced from vegetable fiber as a raw material. Here, the vegetable fiber can be used without particular limitation as long as it is used in ordinary production of paper. For example, commercially available NDKP
(Chemical name: PV-60, manufactured by Baccay) and the like, a chemical pulp prepared from wood chips conventionally used for producing paper can be used. In the present invention, in addition to the chemical pulp as exemplified above,
It is also possible to use recycled pulp, mechanical pulp, or the like, which is regenerated from a used paper material, as a fiber material. Therefore, the present invention also contributes to the effective utilization of recycled paper resources, which have been actively pointed out in recent years. In the present embodiment,
"Paper" is made by gluing vegetable fibers and other fibers. In a broad sense, in addition to synthetic paper manufactured by using a synthetic polymer as a material, paper including a fibrous inorganic material is also included (JISP0001 (1998) 4
004). In the general papermaking process, the fluid medium is water, but it includes newly developed air and other fluids (Reference 1). Further, conventionally, when producing paper using plant fibers as a raw material, it is sometimes performed to mix other fibers such as glass fibers and carbon fibers with the plant fibers. Also in the present invention, to the plant fiber of the main raw material,
It is also possible to produce paper by mixing fibers other than vegetable fibers such as glass fibers and carbon fibers.

In the paper manufacturing process of the present invention, an organic solvent containing a silane compound represented by the formula 1 or the like is used as the fluid medium instead of water when the plant fiber pulp is strained and stuck. Other than the above, it is possible to carry out by the same process as the conventional paper manufacturing process. The paper manufacturing process in the present invention will be specifically described below with reference to an example.

First, wood pulp is disintegrated and beaten to prepare a raw material. For example, an appropriate amount of wood pulp is torn in an appropriate amount of water, allowed to stand for a predetermined time, gradually added to the circulating water, and refluxed for a predetermined time. Then, the wood pulp thus disintegrated is beaten. The beating can be carried out by a usual method. After the beating is completed, it is dried and used as a raw material for the next step.

The raw material prepared by disintegrating and beating wood pulp as described above is then subjected to a paper making machine to make paper. Of course, it is also possible to strain by hand without using a paper making machine. At this stage, as a fluid medium for suspending the dried raw material, an organic solvent containing a silane compound represented by Formula 1 or the like is used instead of conventional water.

Specifically, the wood pulp disintegrated and beaten as described above is suspended (diluted) in a fluid medium which is an organic solvent containing the silane compound represented by the above formula 1 and the like.
Then, the mixture is thoroughly mixed with the fluid medium by using a perforated plate or the like. After thoroughly mixing the two, pour an appropriate amount of the mixed solution into a container for paper making, remove the excess fluid medium, and dry with a drum dryer, etc. to hydrolyze and condense the silane compound. A reaction occurs and the cellulose in the plant fiber is firmly bound by the network of siloxane bonds. And as a result, not only mechanical strength such as tensile strength, but also excellent physical properties such as heat resistance and abrasion resistance, a paper capable of exhibiting sufficient paper strength in both a dry state and a wet state is produced. It is.

[0050]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, examples of the present invention will be described for the purpose of explaining the present invention in more detail, but these are merely one embodiment of the present invention and do not limit the present invention.

Example 1 Preparation of Fluid Medium 1 As a silane compound, 3200 g of tetraethoxysilane oligomer (trade name ES-40, manufactured by Colcoat Co., condensation degree (n) = 4 to 5) was added to 1800 g of isopropyl alcohol. , 180 g of dibutyltin diacetate as a catalyst was added, and the mixture was thoroughly stirred and mixed,
A fluid medium was obtained for use in the manufacture of paper. Hereinafter, the fluid medium prepared in this example is referred to as fluid medium 1.

Example 2 Preparation of Fluid Medium 2 As a silane compound, 1600 g of tetraethoxysilane oligomer (trade name ES-40, manufactured by Colcoat Co., condensation degree (n) = 4 to 5) was added to 3490 g of isopropyl alcohol. 90 g of dibutyltin diacetate as a catalyst was added, and the mixture was thoroughly stirred and mixed to obtain a fluid medium used for paper production. Hereinafter, the fluid medium prepared in this example is referred to as fluid medium 2.

Example 3 Preparation of Fluid Medium 3 As a silane compound, 800 g of tetraethoxysilane oligomer (trade name ES-40, manufactured by Colcoat Co., Ltd.,
The degree of condensation (n) = 4 to 5) was dissolved in 4330 g of isopropyl alcohol, 45 g of dibutyltin diacetate as a catalyst was added, and the mixture was thoroughly stirred and mixed to obtain a fluid medium used for paper production. Hereinafter, the fluid medium prepared in this example is referred to as fluid medium 3.

Example 4 Preparation of Fluid Medium 4 To a 500 ml three-necked flask, 181 g of methyltrimethoxysilane, 50 g of methanol and 18 g of pure water were added and sufficiently stirred. Add 2 g to these mixed solutions
61% nitric acid was added, and the mixture was heated and refluxed for 3 hours with stirring. After the above reaction was completed, the pressure in the reaction vessel was reduced while heating to remove methanol to prepare a methyltrimethoxysilane oligomer body (hereinafter referred to as MTM). As a result of subjecting the prepared MTM to gas chromatography analysis, it was confirmed that the prepared oligomeric body was mainly composed of 3 to 4 mers. 2320 g of MTM prepared as described above was dissolved in 2500 g of isopropyl alcohol, 180 g of dibutyltin diacetate was added as a catalyst, and the mixture was sufficiently stirred and mixed to obtain a fluid medium used for paper production. . Hereinafter, the fluid medium prepared in this example is referred to as fluid medium 4.

Example 5 Preparation of fluid medium 5 1160 prepared in Example 4 as a silane compound.
g of MTM was dissolved in 3750 g of isopropyl alcohol, and 90 g of dibutyltin diacetate as a catalyst was added, stirred well and mixed to obtain a fluid medium used for paper making. Hereinafter, the fluid medium prepared in this example is referred to as fluid medium 5.

Example 6 Preparation of fluid medium 6 As the silane compound, 2000 prepared in Example 4 was used.
A mixture of g of MTM and 320 g of dimethyldiethoxysilane was dissolved in 1800 g of isopropyl alcohol, 180 g of dibutyltin diacetate was added as a catalyst, and the mixture was thoroughly stirred and mixed to prepare a fluid medium used for paper production. Got Hereinafter, the fluid medium prepared in this example is referred to as the fluid medium 6.

Example 7 Manufacture of Paper and Testing of the Manufactured Paper Using the fluid media shown in Examples 1 to 6 above, paper was made according to the following steps, and then each of the following: The thickness of the produced paper, "density", "air permeability", "tensile strength", "tensile breaking elongation", "folding strength", "water absorption" And "wet paper strength"
Was measured. Further, for comparison, instead of the fluid medium characteristic to the practice of the present invention as shown in Examples 1 to 6, water used as the fluid medium in the conventional paper manufacturing process is used, and the same process is performed. The same test was performed on the paper manufactured by carrying out the above.

First, the JIS standard (JIS P 8221)
-1 (1998)), commercially available wood pulp (N
DKP, trade name PV-60, manufactured by Baccay) was used as a raw material to carry out the following steps to prepare a chemical pulp. (1) Approximately 600 g of the above wood pulp was collected and
It was cut into about 25 mm square in 0 liter of water and left standing in water for about 10 minutes. (2) The wood pulp prepared as in (1) above was gradually added to 13 liters of water which was circulated in a beater, and circulated for 5 minutes to disintegrate. (3) After the disintegration by the circulation of 5 minutes in the above (2), a weight was put on the lever, the lever was stopped, and beating was started. The beating time was 30 minutes. (4) After beating, the weight of the lever was lowered, the lever was stopped and the mixture was swirled for 5 minutes, and then the product was dried to obtain a raw material.

3 g of the raw material prepared as described above
(Freeze dry weight) / 1 liter was sampled, and the freeness was measured according to JIS standard (JIS P 8121 (1998); pulp freeness test method). as a result,
The freeness was 595 cc (CSF).

Next, the JIS standard (JIS P 8222)
According to (1998)), the raw material prepared as described above was strained to produce paper. The target rice tsubo is 60g /
Ten sheets of m ² and 240 mm square size paper were handmade as described below. (1) After diluting the raw material prepared as described above to a predetermined amount with the fluid medium 1 to 6 prepared in Examples 1 to 6 or water, a required amount is collected and poured into a container for quality control,
Subsequently, each fluid medium or water was added up to the baseline of the container. (2) The porous plate agitator was slowly moved up and down 6 times to mix the raw material and the fluid medium. After 10 seconds, the drain valve was fully opened and the fluid medium was discharged from the quality container. (3) After removing the fluid constitution from the wet paper, it was allowed to stand for about 5 seconds, the drain valve of the container for quality was closed, and it was left standing. Then, the absorbent paper was stacked on the wet paper, pressed, and then dried by a drum dryer. At this stage, in the paper strained using the fluid medium produced in Examples 1 to 6, hydrolysis and condensation reaction of the silane-based compound occurs, a network of siloxane bonds is formed, and cellulose in the pulp is bonded. It becomes a binder. (4) The paper manufactured as described above was cut into a 240 mm square size and conditioned.

The thickness of the paper produced as described above was first tested. The test is based on the JIS standard (JIS
P 8118 (1998)), a micrometer in which the pressure between the pressure surfaces is set to 50 kPa is used, a test piece (paper) is placed between the pressure surfaces, and the test piece is held by the pressure surface. After confirming that, the value immediately after the meter became stable was read. The test was conducted at 1 to 2 points for each test piece.

The paper produced as described above was then weighed. The test is based on the JIS standard (JIS
In accordance with P 8124 (1998)), the weight of each test piece (240 mm square size) was measured and calculated by the following formula. In the following formula, G is the basis weight (g / m ² ) of each test piece, m is the weight (g) of each test piece, and A
Is the area (cm ² ) of each test piece. G = m / A × 10000

The paper produced as described above was then tested for its density. The test is based on the JIS standard (JIS
In accordance with P 8118 (1998)), it was calculated by the following formula from the thickness and weight of each test piece tested as described above. In the following formula, D is the density (g / cm
³ ), W is the basis weight (g / m ² ), and T is the thickness (m
m). D = W / (T × 1000)

The paper produced as described above was then tested for air permeability. The test is based on the JIS standard (JIS
P 8117 (1998)). First, cut the manufactured paper into 50 x 50 mm square size,
The test piece was used. Place the tester vertically so that the cylinder is vertical, first pull up the inner cylinder until the top of the inner cylinder is supported by the latch, then tighten the test piece between the clamping plates and gently lower until the cylinder floats. It was Then, when the movement of the cylinder was stable, the time required for the scale from 0 to 100 ml to pass through the edge of the outer cylinder was measured.

The paper produced as described above was then tested for tensile strength. The test is based on the JIS standard (JIS
P 8113 (1998)). First, the manufactured paper was cut into a width of 15 mm to prepare a test piece. Then, using a constant speed extension type tensile tester, the test piece was lightly gripped by the gripping tool, the long sides were aligned so as to be parallel to the direction in which the load was applied, and the gripping tool was tightly tightened. The tensile speed was set to 10 mm / min.

In the above-mentioned tensile strength test, the value indicated by the tester during the test was taken as the value of tensile elongation at break (%).

The paper produced as described above was then tested for folding endurance. The test is based on the JIS standard (JIS
P 8115 (1994)). First, the manufactured paper was cut into a width of 15 mm to prepare a test piece. Then, a load of 4.9 N is applied to the test piece, and 17 minutes per minute.
The test piece was bent at a speed of 5 plus or minus 10 times until the test piece was cut, and the number of times of reciprocal bending was taken as the value of folding endurance.

The paper produced as described above was then tested for water absorption by the Klemm method. The test is JIS
It was carried out according to the standard (JIS P 8141 (1996)). First, the manufactured paper is 15 mm wide and 200 mm long.
The test piece was cut into mm. Distilled water at 20 ° C. plus or minus 1 ° C. was used as water to be placed in the immersion container. First, a marked line was drawn at a position 15 mm from the short side of the test piece, the test piece was fixed to a hanging tool in accordance with the 0 position of the scale plate, and held vertically. Next, the marked line was quickly put into distilled water, and the timer was started. And 10
The average height in the width direction of the water that rose per minute was read in mm.

The wet paper strength was finally tested on the papers produced as described above. The test method is JIS P8
113 (1998), a constant speed extension type tensile tester is used. The test piece was cut into a width of 15 mm, and the central portion of the test piece was immersed in distilled water adjusted to 20 ° C. in advance,
Place the test piece on the blotter paper, put another blotter paper on the test strip, press lightly to remove excess water. Immediately JIS P
A tensile test is performed according to 8113 (1998). The maximum load at which the test piece broke is the wet paper strength.

[0070]

[Table 1]

Table 1 shows the results of the tests carried out as described above on the paper manufactured as described above. As is clear from Table 1, in the paper manufactured according to the present invention, that is, the paper manufactured by using the fluid mediums of Examples 1 to 6, "air permeability", "tensile strength", and "tensile strength" In each of the tests of "elongation at break", "water absorption", and "strength of wet paper", more preferable results are obtained as compared with the paper produced using conventional water as a fluid medium. This means that the manufacturing method of the present invention can exhibit sufficient paper strength in both a dry state and a wet state as compared with a conventional paper manufacturing method. In other words, as compared with a conventional paper, This means that it is effective in producing a paper having a significantly increased physical strength.

In the results of Table 1, the "folding strength" is inferior to the paper manufactured using water as the fluid medium, and the paper manufactured according to the present invention uses conventional water as the fluid medium. It means that it is inferior in flexibility to the paper manufactured as. This is because the silane-based compound is used as a fluid medium in the present invention to produce paper, and the network of siloxane bonds formed by this is a very strong bond. Thus, the papers produced using the fluid media prepared in Examples 1 to 6 still have challenges in flexibility, but as noted above, machines that outperform conventional papers in other respects. It has a specific strength. Further, it is apparent that the problem of poor flexibility can be improved by appropriately using the silane compounds represented by the formulas 2 and 3 as described above.

[0073]

As described above, the above formula 1
In the present invention using an organic solvent containing a silane-based compound as a fluid medium, in the step of molding and drying the strained paper, hydrolysis and condensation of the silane-based compound and sometimes a catalyst that hydrolyzes it. A reaction is caused to chemically bond with the cellulose in the plant fiber, and adjacent silane compounds are condensed to polymerize to form a siloxane bond network. Further, at this time, since the silane-based compound penetrates into the fine portion of the cellulose, the physical binding with the cellulose causes mechanical entanglement and hydrophobic binding between the organic portions. Therefore, according to the present invention, mechanical strength such as tensile strength is enhanced, and further, plant fibers are agglomerated by a thermally stable siloxane bond, so that physical properties such as heat resistance and abrasion resistance are increased. It is possible to provide a paper having excellent characteristics.

As described above, while the mechanical strength such as tensile strength and the physical characteristics such as heat resistance and abrasion resistance are excellent, the paper produced by the present invention is water-resistant in terms of flexibility. It may be inferior to conventional paper manufactured as a fluid medium. However, although the flexibility still has a problem, the improvement of mechanical strength and physical properties overturns the concept of paper, which has been limited in its use range. As described above, such a problem can be appropriately improved by appropriately using a silane compound having one or two non-hydrolyzable substituents, as described above.

Further, since the manufacturing method of the present invention can be carried out without changing the conventional paper manufacturing process itself, it can be carried out by utilizing existing equipment.
Further, since it can be carried out by simply changing the water used as a fluid medium to an organic solvent containing a silane-based compound in the conventional manufacturing process as it is, it does not significantly increase the manufacturing cost of paper. It has industrial advantages.

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Claims (8)

[Claims] 1. A method for producing paper, wherein an organic solvent containing a silane compound is used as a fluid medium for producing paper by sticking plant fibers. 2. The silane compound is represented by Formula 1.
A compound having a compound as a main component,
The method for producing paper according to claim 1. [Formula 1] (In Formula 1, R₁, R_Two, R_ThreeAnd R_FourIs that
Which may be the same or different, hydrogen, an alkyl group or
R is a monomer consisting of an alkenyl group₁O, R _TwoO,
R_ThreeO and R_FourThe bond between O and Si is a siloxane bond.
Is a condensate) 3. The silane-based compound is mainly composed of a compound represented by Formula 2 having three hydrolyzable substituents and one non-hydrolyzable substituent. The method for producing paper according to claim 1, wherein [Formula 2] (In the formula 2, R ₅ , R ₆ and R ₇ may be the same or different and each is a monomer consisting of hydrogen, an alkyl group or an alkenyl group, and R ₅ O, R ₆ O and R ₇
The bond between O and Si is a condensate composed of a siloxane bond, and R ₈ is an alkyl group, an alkenyl group or a phenyl group which may contain an epoxy group or a glycidyl group in its molecule.) 4. The silane-based compound is represented by formula 3:
The method for producing paper according to claim 1, wherein the main component is a compound having two hydrolyzable substituents and two non-hydrolyzable substituents. [Formula 3] (In Formula 3, R ₉ and R ₁₁ may be the same or different and each is a monomer composed of hydrogen, an alkyl group or an alkenyl group, and the bond between R ₉ O and R ₁₁ O and Si is a roxane bond. R ₁₀ and R ₁₂ are alkyl groups, alkenyl groups or phenyl groups, which may contain an epoxy group or a glycidyl group in their molecule) 5. The silane-based compound is represented by Formula 1, Formula 2, and
At least two or more of the compounds represented by formula 3
The method for producing paper according to claim 1, characterized in that
Law. [Formula 1] (In Formula 1, R₁, R_Two, R_ThreeAnd R_FourIs that
Which may be the same or different, hydrogen, an alkyl group or
R is a monomer consisting of an alkenyl group₁O, R _TwoO,
R_ThreeO and R_FourThe bond between O and Si is a siloxane bond.
Is a condensate) [Formula 2] (In Formula 2, R₅, R₆And R₇Are the same
Or may be different, hydrogen, alkyl group or alkene
R is a monomer consisting of a nyl group,₅O, R₆O and R₇
The bond between O and Si is a condensate composed of siloxane bonds.
R₈Has an epoxy group or a glycidyl group in its molecule
Alkyl, alkenyl or phenyl, which may be included
Is the basis) [Formula 3] (In Formula 3, R₉And R₁₁Are the same or different
May be hydrogen, an alkyl group or an alkenyl group
R is a monomer consisting of₉O and R₁₁Between O and Si
The bond is a condensate composed of a roxane bond and R₁₀as well as
R₁₂Is an epoxy group or glycidyl group in their molecule
Optionally containing an alkyl group, an alkenyl group or a phenyl group
It is a ru basis) 6. The silane-based compound is represented by Formula 1, Formula 2, and
Including all three compounds of formula 3 at the same time
The method for producing paper according to claim 1, which is characterized in that. [Formula 1] (In Formula 1, R₁, R_Two, R_ThreeAnd R_FourIs that
Which may be the same or different, hydrogen, an alkyl group or
R is a monomer consisting of an alkenyl group₁O, R _TwoO,
R_ThreeO and R_FourThe bond between O and Si is a siloxane bond.
Is a condensate) [Formula 2] (In Formula 2, R₅, R₆And R₇Are the same
Or may be different, hydrogen, alkyl group or alkene
R is a monomer consisting of a nyl group,₅O, R₆O and R₇
The bond between O and Si is a condensate composed of siloxane bonds.
R₈Has an epoxy group or a glycidyl group in its molecule
Alkyl, alkenyl or phenyl, which may be included
Is the basis) [Formula 3] (In Formula 3, R₉And R₁₁Are the same or different
May be hydrogen, an alkyl group or an alkenyl group
R is a monomer consisting of₉O and R₁₁Between O and Si
The bond is a condensate composed of a roxane bond and R₁₀as well as
R₁₂Is an epoxy group or glycidyl group in their molecule
Optionally containing an alkyl group, an alkenyl group or a phenyl group
It is a ru basis) 7. The method for producing paper according to claim 1, wherein the silane compound is cured by using a hydrolyzable organometallic compound as a catalyst. 8. The hydrolyzable organometallic compound is
The method for producing paper according to claim 7, which is one or more organometallic compounds selected from the group consisting of titanium, zircon, aluminum and tin.