JP7032863B2 - Cellulose cloth paper impregnation composition, impregnated product and molded product using this - Google Patents

Description

The present invention relates to a composition for impregnating cellulose cloth paper, an impregnated product using the same, and a molded product.

Conventionally, in the production of various molded products such as laminated plates such as semiconductor substrates, decorative plates, oil filters, and sliding members, impregnated products obtained by impregnating cellulose cloth such as paper with a thermosetting material have been used. The cured product obtained by curing such an impregnated material is superior in strength to the cellulose cloth paper. As the thermosetting material, a resol type phenol-formaldehyde resin is generally used. The phenol-formaldehyde resin is often used in the form of an alcohol varnish.

However, since the phenol-formaldehyde resin uses formaldehyde as a raw material, formaldehyde is emitted from an impregnated product or a molded product using the same. Furthermore, when used in the form of alcohol varnish, alcohol is volatilized during the production of impregnated products and molded products, so it is treated as a dangerous substance. Therefore, it is not preferable from the viewpoint of environment and safety.

As a solvent-free resin composition for a decorative board that does not contain formaldehyde or phenol, a resin composition containing a curable, solid crystalline oligomer at room temperature and an unsaturated polyester has been proposed (Patent Document 1).

On the other hand, the following are proposed as formaldehyde-free binders that bind fibers, especially inorganic fibers.
(1) Substantially containing a specific amount of a reduced sugar, an acid precursor selected from the group consisting of ammonium sulfate, ammonium phosphate, ammonium nitrate and ammonium carbonate, a source of nitrogen, and water. Formaldehyde-free binder solution (Patent Document 2).
(2) A thermosetting binder composition containing a sugar or a first component which is a mixture of sugars and phenols, an ammonium salt, and a surfactant (Patent Document 3).

Japanese Unexamined Patent Publication No. 2008-23129 Japanese Patent No. 5704751 Japanese Unexamined Patent Publication No. 2016-60913

The resin composition for decorative boards of Patent Document 1 does not use formaldehyde or a solvent, but it is necessary to use other harmful chemical substances (urethane acrylate, diallyl phthalate, etc.). Further, when manufacturing a decorative board, it is necessary to separately apply a curing agent solution, and there is a problem that the number of steps increases as compared with the conventional case (when a phenol / formaldehyde resin is used).
In Patent Documents 2 and 3, the effect on cellulose cloth has not been confirmed. According to the studies by the present inventors, the binder of Patent Document 2 has a low reinforcing effect on the cellulose cloth, and has a problem that the strength when the binder is impregnated into the cellulose cloth and cured is inferior to the conventional one. The binder of Patent Document 3 may also have the same problems as described above, or may cause damage to the cellulose cloth.

The present invention provides a composition for impregnating cellulose cloth paper, which can obtain excellent strength when impregnated with cellulose cloth paper and cured without using formaldehyde as a raw material, and an impregnated product and a molded product using the same. The purpose is.

As a result of diligent studies, the present inventors have made a combination of a sugar or a mixture of sugars and phenols with an organic acid ammonium salt, as compared with the case where the ammonium salt is an inorganic acid ammonium salt. We have found that the strength when impregnated into cloth and cured is excellent, and completed the present invention.

The present invention has the following aspects.
[1] A composition for impregnating cellulose cloth, which comprises a first component which is a sugar or a mixture of sugar and phenols, and an organic acid ammonium salt.
[2] The composition for impregnating cellulose cloth according to [1], which is substantially free of formaldehyde.
[3] The sugar contains a fructose source and contains.
The composition for impregnating cellulose cloth according to [1] or [2], wherein the content of the fructose source in terms of fructose is 40% by mass or more with respect to the total mass of the sugar.
[4] The composition for impregnating cellulose cloth according to any one of [1] to [3], wherein the organic acid ammonium salt contains an ammonium carboxylate salt.
[5] The first component is a mixture of sugar and phenols.
The composition for impregnating cellulose cloth according to any one of [1] to [4], wherein the phenols are water-soluble phenols.
[6] The cellulose cloth according to [5], wherein the water-soluble phenols contain at least one selected from the group consisting of resorcinol, tannin, phenol, cresol, aminophenol, catechol, hydroquinone, pyrogallol and phloroglucinol. Composition for impregnation.
[7] The composition for impregnating cellulose cloth according to any one of [1] to [6], wherein the mass ratio of the organic acid ammonium salt to the first component is 0.02 to 1.0.
[8] The first component is a mixture of sugar and phenols.
The composition for impregnating cellulose cloth according to any one of [1] to [7], wherein the ratio of the phenols to the sugar is 1 to 50% by mass.
[9] The composition for impregnating cellulose cloth according to any one of [1] to [8], which further contains water.
[10] An impregnated product obtained by impregnating a cellulose cloth with the composition for impregnating the cellulose cloth according to any one of the above [1] to [9].
[11] A molded product made of a cured product of the impregnated product of the above [10].

According to the present invention, a composition for impregnating a cellulose cloth paper and an impregnated product or a molded product using the same can obtain excellent strength when the cellulose cloth is impregnated and cured without using formaldehyde as a raw material. Can be provided.

It is a graph which shows the result of Example 2, 10-14, 16 and the Example which changed only the heat treatment condition from these Examples. 3 is a graph showing the results of Comparative Example 3, Examples 2, 6 to 7, and 26 to 31.

[Composition for impregnating cellulose cloth]
The cellulose cloth paper impregnating composition of the present invention (hereinafter, also referred to as “the present impregnating composition”) contains a first component and an organoacid ammonium salt.
The first component is sugar or a mixture of sugar and phenols.
If necessary, the composition for impregnation may further contain components other than sugars, phenols and ammonium organic acid salts as long as the effects of the present invention are not impaired.

<First ingredient>
The sugar constituting the first component may be one kind or two or more kinds.
When the first component is a mixture of sugar and phenols, the phenols constituting the first component may be one kind or two or more kinds.

As the first component, a mixture of sugar and phenols is preferable because it has a more excellent reinforcing effect on cellulose cloth.
When the first component is a mixture of sugar and phenol, the ratio of phenol to sugar (100% by mass) is preferably 1 to 50% by mass, preferably 2 to 30% by mass. It is more preferably 5 to 25% by mass, and particularly preferably 5 to 25% by mass. When the proportion of phenols is not less than the lower limit of the above range, the reinforcing effect on the cellulose cloth is more excellent, and the strength of the cured product (molded product) of the impregnated material is more excellent. When the proportion of phenols is not more than the upper limit of the above range, the reinforcing effect can be enhanced at a more economical cost.

The first component is preferably water-soluble. That is, when the first component is composed of sugar, it is preferable that the sugar is water-soluble, and when the first component is composed of a mixture of sugar and phenols, it is preferable that the sugar and the phenols are each water-soluble. ..
"Water-soluble" means that the solubility in water at 20 ° C. is 2 g / 100 mL or more.
When the present impregnation composition is impregnated into cellulose cloth, it is usually in the state of a solution in which the first component and the like are dissolved in a liquid medium. If the first component is water-soluble, the impregnating composition can be in the state of a solution even if only water is used as the liquid medium. If the solution does not contain an organic solvent such as alcohol, vapor of the organic solvent is not generated when the solution is impregnated into cellulose cloth and then dried, which is preferable in terms of environment and safety.

(Sugar)
Examples of sugars include monosaccharides, oligosaccharides, dextrins, fructans, and derivatives thereof.
In the present invention, the "oligosaccharide" is assumed to be a combination of 2 or more and 10 or less monosaccharides. "Dextrin" also includes the general concept of maltodextrin and refers to a sugar composition having a DE of 20 or less. "Fructan" is assumed to be a combination of 11 or more monosaccharides.

Examples of the monosaccharide include glucose, fructose, mannose, galactose, ribose, xylose and the like.
Examples of oligosaccharides include disaccharides such as sucrose, maltos, lactose, trehalose, and isomaltose; trisaccharides such as maltotriose and raffinose; malto-oligosaccharides; isomalto-oligosaccharides; fructooligosaccharides; manno-oligosaccharides; galactooligosaccharides. And so on.

Any one of these sugars may be used alone or in combination of two or more.
The sugar may be a reducing sugar or a non-reducing sugar, and a reducing sugar is preferable.
As the sugar, a water-soluble sugar is preferable. Examples of the water-soluble sugar include monosaccharides, disaccharides, oligosaccharides, dextrins and the like, and monosaccharides or disaccharides are preferable, and monosaccharides are more preferable.

The sugar preferably contains a fructose source. The inclusion of a fructose source increases the curing rate of the impregnating composition. For example, when cured under the same curing conditions, a cured product having a higher degree of curing and higher strength can be obtained as compared with the case where the fructose source is not contained.
The fructose source refers to fructose alone or a sugar capable of producing fructose by hydrolysis or the like. Examples of the sugar capable of producing fructose include oligosaccharides containing fructose units, polysaccharides containing fructose units, derivatives thereof and the like, and specific examples thereof include sucrose, raffinose, fructooligosaccharides and fructans. Any one of these fructose sources may be used alone or in combination of two or more.
As the fructose source, at least one selected from the group consisting of fructose, sucrose, raffinose, and fructooligosaccharide is preferable.
When the sugar contains a fructose source, the sugar may consist only of the fructose source or may further contain other sugars other than the fructose source.
The fructose-equivalent content of the fructose source is preferably 40% by mass or more, more preferably 45% by mass or more, and particularly preferably 50% by mass or more, based on the total mass (100% by mass) of the sugar. The upper limit of the content is not particularly limited and may be 100% by mass.

(Phenols)
Examples of the phenols include plant-derived phenols and fossil fuel-based phenols.
Examples of plant-derived phenols include flavonoid-based tannins, catechins, anthocyanins, rutins, isoflavones, phenolic acid-based chlorogenic acids, ellagic acids, lignans, curcumins, coumarins, lignins and other polyphenols, cardanol, cashew nut shell liquids and the like. Can be mentioned.
Examples of fossil fuel-based phenols include phenol, cresol, aminophenol, xylenol, trimethylphenol, ethylphenol, propylphenol, butylphenol, butylcresol, phenylphenol, cumylphenol, methoxyphenol, bromophenol, bisphenol A, and bisphenol F. , Bisphenol S, catechol, resorcinol, hydroquinone, pyrogallol, fluoroglucolcinol and the like.
Any one of these phenols may be used alone or in combination of two or more.

As the phenols, water-soluble phenols are preferable. The definition of water solubility is as described above. That is, the water-soluble phenols are phenols having a solubility in water at 20 ° C. of 2 g / 100 mL or more.
Examples of water-soluble phenols include resorcinol, tannin, phenol, cresol, aminophenol, catechol, hydroquinone, pyrogallol, phloroglucinol and the like.

As the phenols, polyhydric phenols (phenols having two or more hydroxyl groups) are preferable, and water-soluble polyhydric phenols are more preferable, because the effect of the present invention is excellent.
As the polyhydric phenols, at least one selected from the group consisting of resorcinol, tannin, catechol, hydroquinone, pyrogallol, phloroglucinol and lignin is preferable, and either one or both of resorcinol and tannin is particularly preferable.

<Ammonium organic acid salt>
The ammonium organic acid salt functions as a source of ammonia that reacts with sugar in the curing reaction of the present impregnating composition and as a source of an acidic substance that functions as a catalyst in the subsequent reaction.
Examples of the organic acid ammonium salt include diammonium citrate, triammonium citrate, ammonium acetate, ammonium formate, ammonium lactate, ammonium oxalate, ammonium tartrate, ammonium malate, ammonium succinate, ammonium phthalate, and ammonium benzoate. Ammonium carboxylic acid salts such as ammonium phenol sulfonate; ammonium aromatic sulfonates such as ammonium phenol sulfonate, ammonium paratoluene sulfonate, ammonium xylene sulfonate; amino acid ammonium salts such as ammonium glutamate and the like. Any one of these organoacid ammonium salts may be used alone or in combination of two or more.

As the ammonium organic acid salt, the ammonium carboxylate salt is preferable because it has a more excellent effect of accelerating the curing reaction and does not easily damage the cellulose cloth. Among them, at least one selected from the group consisting of diammonium citrate, triammonium citrate, ammonium acetate, ammonium formate, ammonium lactate, and ammonium oxalate is particularly preferable because of its high reinforcing effect and easy availability.

<Other ingredients>
The other components are not particularly limited, and can be appropriately selected and used from known components that can be blended in the composition for impregnating cellulose cloth. For example, water, organic solvents, inorganic acid ammonium salts, additives (surfactants, water repellents, defoamers, flame retardants, preservatives, fungicides, plasticizers, colorants, thickeners, bulking agents, etc. ) Etc. can be mentioned. Examples of the organic solvent include methanol, ethanol, isopropyl alcohol and the like. As the inorganic acid ammonium salt, known ones can be appropriately used as long as they do not damage the cellulose cloth, and examples thereof include ammonium sulfate, ammonium phosphate, ammonium hydrogenphosphate, ammonium borate, ammonium carbonate and ammonium hydrogencarbonate. Be done. Any one of these may be used alone or two or more thereof may be used in combination.

The composition for impregnation typically further contains water due to its impregnation property on cellulose cloth.
The impregnating composition may be a liquid composition in which the first component and the ammonium organic acid salt are dissolved or dispersed in water.

<Composition of the composition for impregnation>
In the present impregnation composition, the content of the first component is preferably 50 to 99% by mass, more preferably 60 to 95% by mass, when the total solid content of the main impregnation composition is 100% by mass. 70 to 90% by mass is particularly preferable. The first component is a component that forms the skeleton of the cured product of the present impregnating composition. When the content of the first component is not more than the lower limit of the above range, the reinforcing effect on the cellulose cloth is efficiently exhibited, and the strength of the cured product of the impregnated material is more excellent. When the content of the first component is not more than the upper limit of the above range, the effect of other components such as the ammonium organic acid salt is fully exhibited.

In the present impregnation composition, the content of sugar and the content of phenols are the solid content, respectively. Therefore, the content of the first component is also the solid content.
The solid content of phenols is non-volatile. The non-volatile component refers to the residue after heating 1.5 g of the sample at 135 ° C. for 1 hour.

In the present impregnation composition, the mass ratio of the organic acid ammonium salt to the first component (organic acid ammonium salt / first component) is preferably 0.02 to 1.00, and is preferably 0.05 to 0.60. Is more preferable. When the mass ratio is at least the lower limit of the above range, the reinforcing effect on the cellulose cloth is more excellent. Further, when the impregnated material obtained by impregnating the cellulose cloth paper with the present impregnating composition is cured, it is easy to complete the curing within predetermined molding conditions (temperature, time). When the mass ratio of the organic acid ammonium salt / first component is not more than the upper limit of the above range, an excellent reinforcing effect can be obtained at a more economical cost.

In the present impregnation composition, the total content of the first component and the organic acid ammonium salt is preferably 80% by mass or more, preferably 90% by mass or more, when the total solid content of the main impregnation composition is 100% by mass. More preferably, 95% by mass or more is particularly preferable. The upper limit of the total content is not particularly limited and may be 100% by mass.

When the present impregnation composition contains water, the water content can be appropriately set in consideration of the impregnation property of the present impregnation composition with respect to the cellulose cloth, and is not particularly limited, but is, for example, the total of the present impregnation composition. It can be 5 to 95% by mass with respect to the mass.

The content of the organic solvent in the impregnating composition may be appropriately adjusted according to the production conditions of the molded product, but it is preferable that the content is not large in terms of environment and safety. Specifically, when an organic solvent is used, it is preferably 50% by mass or less, more preferably 30% by mass or less, still more preferably 10% by mass or less, when the whole composition for impregnation is 100% by mass. It is particularly preferably 5% or less, and most preferably it contains substantially no organic solvent. Here, "substantially free of organic solvent" means that no organic solvent is blended in the preparation of the present impregnating composition.

The composition for impregnation preferably does not contain an inorganic acid ammonium salt. By not containing the inorganic acid ammonium salt, that is, containing only the organic acid ammonium salt as the ammonium salt, the curability of the present impregnating composition and the strength of the cured product are more excellent.

The impregnating composition can exert an excellent reinforcing effect on cellulose cloth without using formaldehyde. Therefore, it is preferable that the composition for impregnation is substantially free of formaldehyde.
Here, "substantially free of formaldehyde" means that formaldehyde or a raw material containing formaldehyde (for example, phenol / formaldehyde resin obtained by the reaction of phenols with formaldehyde) is blended in the preparation of the present impregnating composition. Indicates that there is no.

The solid content concentration of the impregnating composition is preferably 5 to 80% by mass, more preferably 10 to 50% by mass. When the solid content concentration is within the above range, the balance between the impregnation property and the reinforcing effect is good.

When the impregnating composition is liquid, the viscosity of the impregnating composition is preferably 500 mPa · s or less, more preferably 300 mPa · s or less. The viscosity is a value measured by an E-type viscometer (for example, TVE-25 manufactured by Toki Sangyo Co., Ltd.) at 25 ° C. When the viscosity is within the above range, the impregnation property is good.

The composition for impregnation can be prepared by mixing a first component (carbohydrate or sugar and phenols), an ammonium salt of an organic acid, and other components as necessary.
When two or more kinds of sugars are used in combination, each sugar may be blended in the preparation of the present impregnation composition, or a raw material containing two or more kinds of sugars may be used. Examples of the raw material containing two or more kinds of sugars include isomerized sugar (containing glucose, fructose, etc.), starch syrup (containing glucose, maltose, etc.) and the like.
When the present impregnating composition contains water, a raw material (liquid sugar raw material) containing water and sugar and in a liquid state may be used when preparing the present impregnating composition. The water in the present impregnation composition may be derived from a liquid sugar raw material, may be separately blended at the time of preparation of the present impregnation composition, or may be both of them. good.

<Action effect>
The present impregnating composition is impregnated with cellulose cloth to obtain an impregnated product. The composition for impregnation has a thermosetting property that is cured by heating. Therefore, the impregnated material also has thermosetting property.
When the impregnated material using the present impregnating composition is cured, excellent strength can be obtained without using formaldehyde as a raw material. Its strength is comparable to that of the conventionally used phenol / formaldehyde resin.
Although it is not clear why the excellent strength can be obtained, the reinforcing effect of the impregnating composition on the cellulose cloth is excellent, the curability of the impregnating composition is high, and the impregnating composition is the cellulose cloth. It is conceivable that it is difficult to damage the product.
Further, in the present impregnation composition, water can be used as a solvent for dissolving the first component, an organic acid ammonium salt and the like. Therefore, the composition can be a composition that does not contain an organic solvent or has a low content of the organic solvent.

As the thermosetting mechanism of the present impregnating composition, a mechanism similar to caramelization can be considered. When the composition for impregnation is heated, the sugar having a 5- or 6-membered ring structure first reacts with ammonia derived from an ammonium organic acid salt to form glucosylamine, and then 1-amino-1 with ring opening. -Deoxy-2-Ketose is formed. This is commonly referred to as the Amadori rearrangement. Subsequently, due to the influence of the acidic substance derived from the ammonium organic acid salt and heating, the ring is closed with dehydration to produce hydroxymethylfurfural (hereinafter referred to as HMF). HMF is a thermally unstable compound, and the produced HMF reacts with other HMFs and premixed phenols under continuous heating with further dehydration. As the reaction progresses, curing progresses, and eventually it is completed. It is presumed that the resulting cured product has a caramel-like structure or a structure in which a phenolic skeleton is introduced into a part thereof.
It is considered that water is the only by-product of the above reaction. Therefore, when the impregnating composition does not substantially contain an organic solvent and formaldehyde, it is considered that the gas generated when the impregnated product is cured is generally only water vapor, which is excellent in terms of environment and safety.

[Impregnated material]
The impregnated product of the present invention (hereinafter, also referred to as “the impregnated material”) is a cellulose cloth paper impregnated with the present impregnated composition.
The composition for impregnation may be impregnated in the entire cellulose cloth paper, or may be impregnated only in a part of the cellulose cloth paper, for example, in the vicinity of the surface layer.

Cellulose cloth paper refers to cloth paper containing cellulose fibers as a main component, and cloth paper is a general term for paper and cloth. Examples of the cloth include non-woven fabric, woven cloth, felt and the like.
The cellulose cloth is not particularly limited and may be appropriately selected depending on the intended use of the impregnated material.
Paper is preferable as the cellulose cloth paper. Examples of the paper include filter paper, kraft paper, and processed base paper.
The basis weight of the cellulose cloth is preferably 30 to 500 g / m ² , more preferably 50 to 300 g / m ² .

The impregnated product can be produced by impregnating a cellulose cloth with the composition for impregnating the present impregnation.
The impregnation method of the present impregnation composition is not particularly limited, and a known method can be used. For example, a method of immersing a cellulose cloth in a diluted composition of the present impregnating composition or the present impregnating composition with water or the like, or a diluted product of the present impregnating composition or the present impregnating composition diluted with water or the like is cellulose. Examples thereof include a method of applying to cloth paper. The impregnation amount of the present impregnation composition can be appropriately adjusted depending on the intended use and molding conditions.
Further, the prepreg may be obtained by impregnating the cellulose cloth paper with the present impregnating composition and then drying it.
Drying is performed to remove a solvent such as water and to adjust the curing conditions. Drying can be performed by a known method. The drying conditions can be appropriately set as long as the impregnating composition is not completely cured.

<Action effect>
Since the present impregnated material uses the present impregnated composition, it has thermosetting property. When the impregnated material is cured, excellent strength can be obtained without using formaldehyde as a raw material, as described above. Further, the present impregnated product can be produced without using an organic solvent or by reducing the amount of the organic solvent used as compared with the amount used for the conventional impregnated material.

<Use>
The application of this impregnated material is not particularly limited, and can be used, for example, in the production of various molded products such as laminated plates such as semiconductor substrates, decorative plates, oil filters, sliding members, core materials, core materials, and rollers.

[Molded product]
The molded product of the present invention (hereinafter, also referred to as “main molded product”) is made of a cured product of the present impregnated product.
The present molded product is obtained by curing the present impregnated product. An example of the manufacturing method of this molded product is shown below. A prepreg (impregnated material) is obtained by impregnating kraft paper with the present impregnating composition and drying it. Several to dozens of these prepregs are stacked and cured by a hot press. As a result, a laminated plate (molded product) can be obtained.
Examples of the heat treatment conditions for curing the impregnated material include conditions of 3 to 30 minutes at 150 to 200 ° C. Annealing may be performed if necessary.

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the examples. In each of the following examples, "part" and "%" indicate "parts by mass" and "% by mass", respectively, unless otherwise specified. Examples 1, 3 to 5, 8, 9, and 17 are reference examples.
The materials used in each example are shown below.

<Material>
(Sugar)
75FG: High fructose corn syrup (containing glucose, fructose, etc.), solid content concentration 75.5%, glucose 50.9%, fructose 43.7%, and other sugars 5.4 with respect to the total solid content. % Content, manufactured by Gun Ei Chemical Industry Co., Ltd.
Glucose: Made by Sanei Saccharification Co., Ltd.
Fructose: Reagent, manufactured by Wako Pure Chemical Industries, Ltd.
Sucrose (sucrose): Reagent, manufactured by Wako Pure Chemical Industries, Ltd.
Maltose: Reagent, manufactured by Wako Pure Chemical Industries, Ltd.
Xylose: Reagent, manufactured by Wako Pure Chemical Industries, Ltd.
Galactose: Reagent, manufactured by Wako Pure Chemical Industries, Ltd.
KM-55: starch syrup (containing glucose, maltose, maltotriose, etc.), solid content concentration 75.8%, glucose 2.0%, maltose 55.3%, maltotriose with respect to the total solid content Contains 20.0% and 22.7% of other sugars, manufactured by Gunei Chemical Industry Co., Ltd.
The solid content concentration in 75FG and KM-55 is a value calculated by 100-moisture (%). Moreover, the solid content is a sugar.

(Phenols)
Resorcinol: manufactured by Sumitomo Chemical Co., Ltd.
Phenol: Made by Mitsui Chemicals, Inc.
Catechol: Reagent, manufactured by Wako Pure Chemical Industries, Ltd.
Hydroquinone: Reagent, manufactured by Wako Pure Chemical Industries, Ltd.
Pyrogallol: Reagent, manufactured by Wako Pure Chemical Industries, Ltd.
Mimosa powder: A type of tannin, from Tanzania.
Kebracho Tannin: A type of tannin from Argentina.
Chestnut tannin: A type of tannin, from Italy.

(Ammonium salt)
Diammonium citrate: Reagent, manufactured by Wako Pure Chemical Industries, Ltd.
Triammonium citrate: Reagent, manufactured by Wako Pure Chemical Industries, Ltd.
Ammonium acetate: Reagent, manufactured by Wako Pure Chemical Industries, Ltd.
Ammonium formate: Adjusted with formic acid (reagent, Wako Pure Chemical Industries) and ammonia water (reagent, Wako Pure Chemical Industries).
Ammonium lactate: Adjusted with lactic acid (reagent, Wako Pure Chemical Industries) and ammonia water (reagent, Wako Pure Chemical Industries).
Ammonium carbonate: Reagent, manufactured by Wako Pure Chemical Industries, Ltd.
Ammonium hydrogen carbonate: Reagent, manufactured by Wako Pure Chemical Industries, Ltd.
Ammonium sulfate: Made by Ube Chemical Co., Ltd.
Ammonium phosphate: Reagent, manufactured by Wako Pure Chemical Industries, Ltd.

<Comparative Example 1>
(Preparation of composition for impregnating cellulose cloth paper)
PL-3225 (methanol-soluble phenol / formaldehyde resin) manufactured by Gun Ei Chemical Industry Co., Ltd. was diluted with methanol so as to have a non-volatile content of 30% to prepare a composition for impregnating cellulose cloth.

(Making impregnated material)
The obtained cellulose cloth paper impregnating composition was impregnated into a filter paper having a basis weight of 100 g / m ² and dried in an oven at 70 ° C. for 30 minutes to obtain an impregnated product (prepreg). The impregnation amount of the composition for impregnating the cellulose cloth paper was adjusted so that the basis weight of the reinforcing filter paper obtained by subsequently performing a curing treatment on the impregnated material was about 220 g / m ² .

(Case-hardening / evaluation)
The obtained impregnated material was cured under the heat treatment conditions shown in Table 1 to obtain a reinforcing filter paper (molded product) having a basis weight of about 220 g / m ² (within the range of 220 g / m ² ± 2.5%). rice field.
The obtained reinforcing filter paper was evaluated as follows. The results are shown in Table 1.

"Evaluation of strength (measurement of breaking stress)"
A strip-shaped test piece of 10 cm × 2 cm was cut out from the obtained reinforcing filter paper and subjected to a tensile test. In the tensile test, the breaking stress (N) was measured with a Strograph V10-C manufactured by Toyo Seiki under the conditions of a span of 40 mm and a crosshead speed of 3 mm / min.
The breaking stress value B (N) is divided by the basis weight A (g / m ² ) of the filter paper after heat treatment to calculate the breaking stress (B / A) (N / (g / m ² )) per basis weight. did.

<Comparative Example 2>
The same filter paper having a basis weight of 100 g / m ² used in Comparative Example 1 was cured under the heat treatment conditions shown in Table 1 without impregnating the cellulose cloth paper impregnating composition. The strength of the cured filter paper was evaluated in the same manner as in Comparative Example 1. The results are shown in Table 1.

<Examples 1 to 31, comparative examples 3 to 7>
(Preparation of composition for impregnating cellulose cloth paper)
Carbohydrates, ammonium salts, and phenols were dissolved in water so as to have the compositions shown in Tables 2 to 9, respectively, to prepare a liquid cellulose cloth impregnating composition.

(Making impregnated material)
The obtained cellulose cloth paper impregnating composition is impregnated into a filter paper having the same basis weight of 100 g / m ² as that used in Comparative Example 1, and dried in an oven at 90 ° C. for 30 minutes to obtain an impregnated product (prepreg). Obtained. The impregnation amount of the composition for impregnating the cellulose cloth paper was adjusted so that the basis weight of the reinforcing filter paper obtained by subsequently performing a curing treatment on the impregnated material was about 220 g / m ² .

(Case-hardening / evaluation)
The obtained impregnated material was cured under the heat treatment conditions shown in Tables 2 to 9 to obtain a reinforcing filter paper having a basis weight of about 220 g / m ² (within the range of 220 g / m ² ± 2.5%).
The strength of the obtained reinforced filter paper was evaluated in the same manner as in Comparative Example 1. The results are shown in Tables 2-9. In addition, the degree of curing of the reinforcing filter papers of Examples 1 to 25 (excluding Examples 13-2, 13-3, 16-2, 16-3) and Comparative Examples 3 to 7 was evaluated by the following procedure. The results are shown in Tables 2-6.

"Evaluation of degree of hardening"
A test piece was cut out from the obtained reinforcing filter paper, and the test piece was immersed in about 100 mass times the amount of ion-exchanged water at room temperature for 24 hours to extract the water-soluble component in the test piece. Then, the test piece was removed from the ion-exchanged water to obtain extracted water. The non-volatile content of this extracted water (residue after heat treatment at 135 ° C. for 1 hour) was determined. The non-volatile content corresponds to a composition for impregnating cellulose cloth that has not been cured. From the non-volatile content, the degree of curing (%) was calculated by the following formula.
Curing degree = (CD) / C × 100
Here, C indicates the difference (g) obtained by subtracting the mass of the filter paper before impregnation from the mass of the test piece after curing, and D indicates the non-volatile content (g) extracted from the test piece.

In Tables 1 to 9, the blending amounts of sugars, ammonium salts, and phenols are the values in terms of solid content.
The example with a branch number is an example in which only the heat treatment conditions are changed with respect to the example without the branch number (for example, in the case of Examples 2-2 and 2-3, with respect to Example 2).

Examples 2, 10 to 14, 16 and Examples in which only the heat treatment conditions are changed from these Examples (Examples 2-2, 10-2 to 14-2, 16-2, 2-3, 10-3 to 14) From the results of -3 and 16-3), a graph showing the relationship between the heat treatment conditions and the breaking stress (N) was created for each type of sugar. This graph is shown in FIG.
From the results of Comparative Example 3, Examples 2, 6 to 7, and 26 to 31, a graph was created in which the mass ratio of the ammonium organic acid salt to the first component was taken on the horizontal axis and the breaking stress per basis weight was taken on the vertical axis. did. This graph is shown in FIG.

In Examples 1 to 31, the breaking stress per basis weight of the reinforcing filter paper was higher and the strength was excellent as compared with Comparative Example 2 in which the filter paper was not impregnated with the cellulose cloth paper impregnating composition and only heat-treated. In addition, the strength in Examples 1 to 31 was as excellent as that in Comparative Example 1 in which an alcohol varnish of a general phenol / formaldehyde resin was used as the composition for impregnating cellulose cloth.

In Comparative Example 3 in which the composition for impregnating the cellulose cloth paper did not contain an ammonium salt, the breaking stress per basis weight of the reinforcing filter paper was lower than that in Comparative Example 2, and the reinforcing effect could not be obtained. Moreover, the degree of curing was low.
In Comparative Examples 4 to 5 in which ammonium sulfate and ammonium phosphate were used as the ammonium salts, the degree of curing was high, but the strength was further inferior to that of Comparative Example 3. It is considered that this is because the ammonium salt damaged the filter paper.
In Comparative Examples 6 to 7 using ammonium carbonate and ammonium hydrogencarbonate as the ammonium salt, the strength was inferior to that of Examples 1 to 7 in which only the type of ammonium salt was different. In Comparative Examples 6 to 7, the degree of curing is low, which is considered to be one of the reasons for the inferior strength.

From FIG. 1, when the heat treatment conditions are the same, the reinforcing effect on the cellulose cloth can be obtained even if the sugars are different, and when a fructose source (fructose or 75FG) is used as the sugar, the strength of the reinforcing filter paper is increased. It was confirmed that it was particularly excellent.
In the case of xylose, unlike other sugars, the strength tended to decrease as the heat treatment temperature increased. This is thought to be due to the fact that xylose is a pentose and therefore has a different curing mechanism from other sugars. As described above, the present impregnating composition is considered to undergo a highly reactive intermediate called HMF in the curing process, but since xylose is a pentose, it is considered to be cured via furfural. Furfural is less reactive than HMF and has a boiling point as low as about 160 ° C., so that it easily volatilizes under high-temperature curing conditions. Therefore, unlike other sugars, it is considered that the strength tends to decrease as the heat treatment temperature increases.

From FIG. 2, the strength is greatly improved by adding a small amount of the organic acid ammonium salt, for example, the addition of the ammonium salt / first component (mass ratio) is about 0.02, and the ammonium salt / first component (mass ratio) is 0. It was confirmed that the strength was maximized near .2.

Claims (8)

It contains the first component, which is a mixture of sugars and phenols, and an ammonium organic acid salt.
The phenols are water-soluble polyhydric phenols, and are
The organic acid ammonium salt is triammonium citrate ,
A composition for impregnating cellulose cloth with a mass ratio of the organic acid ammonium salt to the first component of 0.02 to 1.0 . The composition for impregnating cellulose cloth according to claim 1, which is substantially free of formaldehyde. The sugar contains a fructose source and
The composition for impregnating cellulose cloth according to claim 1 or 2, wherein the content of the fructose source in terms of fructose is 40% by mass or more with respect to the total mass of the sugar. The composition for impregnating cellulose cloth according to any one of claims 1 to 3, wherein the phenols include at least one selected from the group consisting of resorcinol, tannin, catechol, hydroquinone, pyrogallol and phloroglucinol. The composition for impregnating cellulose cloth according to any one of claims 1 to 4 , wherein the ratio of the phenols to the sugar is 1 to 50% by mass. The composition for impregnating cellulose cloth according to any one of claims 1 to 5 , further comprising water. An impregnated product obtained by impregnating a cellulose cloth with the composition for impregnating a cellulose cloth according to any one of claims 1 to 6 . A molded product made of a cured product of the impregnated product according to claim 7 .

Images