JP7268338B2 - Molded body manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a molded product and a paper product. More specifically, the present invention relates to a papermaking product produced using a papermaking method and a method for obtaining a molded product from this papermaking product.

Molded articles obtained from paper products can be imparted with desired properties by selecting the types of fiber fillers and resins used, and have a high degree of freedom in design, and are therefore used in various articles. Here, the term "paper product" is generally used as a technical term indicating the state of a product obtained by using a method of making a fiber material (for example, Patent Documents 1 and 2). As described in Patent Documents 1 and 2, the paper product is a slurry obtained by dispersing raw materials such as fiber fillers and resins in a liquid dispersion medium. Refers to the solid content in the wet state. Here, the solid content in a wet state refers to the solid content in an uncured state before being subjected to drying and heat treatment. The paper product is heat-treated in the mold to dry and remove the remaining liquid dispersion medium, and the resin is cured to form a molded product.

The strength of the paper product and the molded product obtained therefrom is greatly affected by the state of dispersion of the fiber filler contained therein and the fiber density. Since the dispersion state and fiber density of the fiber filler depend on the manufacturing method of the paper product, various proposals have been made for manufacturing conditions such as the type of additives and the mixing order of raw materials. For example, in Patent Document 3, after adding a flocculant to a slurry containing carbon fibers, a hydrophobic binder powder, and water to flocculate the slurry, the slurry is passed through a filter to separate the water. A technique for obtaining a paper product is disclosed. In Patent Document 3, a hydrophobic binder powder is dispersed in water, aggregated with carbon fibers, and then made into a paper sheet, whereby water contained in the resulting paper sheet can be easily removed, and the resulting paper sheet has a stable binder content. It is disclosed that the body can be obtained.

Patent No. 4675276 Patent No. 5426399 JP 2013-87367 A

However, even when a papermaking body is produced using the method disclosed in Patent Document 3, the fiber filler is not sufficiently dispersed, and the content of the fiber filler is low. In some cases, the lower part of the When there is an uneven distribution of the fiber filler in this way, the molded body obtained from such a paper-made body has variations in mechanical strength such as bending strength, and when a load is applied from a specific direction, the molded body may not be molded. Things could be damaged or deformed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a method for obtaining a molded article with reduced variations in strength.

As a result of intensive studies, the present inventors have found that the above problems can be solved by adding a specific additive to the raw material slurry to be subjected to the papermaking process, and have completed the present invention.

According to the invention,
preparing a slurry comprising a thermosetting resin, a fibrous filler, and a poly(meth)acrylate emulsion;
a step of making a paper from the slurry and dehydrating it to obtain a paper product containing a thermosetting resin, a fiber filler and a poly(meth)acrylic acid ester;
A step of heat-molding the papermaking body to obtain a molded body,
The molded product has a bending strength variation of 7.0% or more and 17.0% or less measured using the following variation measurement method,
and a step in which the molded body has a flexural modulus variation of 5.4% or more and 8.2% or less, measured using the following variation measurement method,
The poly(meth)acrylic acid ester emulsion has a cationic degree of 0.02 meq/g or more and 0.1 meq/g or less ;
(Method for Measuring Variation) The slurry is made into paper and dehydrated to prepare a paper product, and 36 test pieces of 10 mm×80 mm are cut out from the obtained paper product and dried at 70° C. for 1 hour. For each test piece, the flexural strength and flexural modulus are measured by a method conforming to ISO 178, and the variation is calculated using the following formula:
Bending strength variation (%) = [(maximum value - minimum value) / average value] x 100
Flexural modulus variation (%) = [(maximum value - minimum value) / average value] x 100
Here, the "maximum value" is the maximum bending strength or bending modulus value among the 36 test pieces, and the "minimum value" is the minimum bending strength or bending modulus value among the 36 test pieces. flexural modulus value, and "mean value" is the average value of flexural strength or flexural modulus of 36 of said test specimens .

Also according to the present invention,
mixing a thermosetting resin, a fibrous filler, and a polyether oxide in a dispersion medium to obtain a first slurry;
A step of mixing a poly(meth)acrylic acid ester emulsion with the first slurry to obtain a second aqueous slurry;
a step of making a paper from the second aqueous slurry and dehydrating it to obtain a paper product containing a thermosetting resin, a fiber filler, a polyether oxide, and a poly(meth)acrylic acid ester;
A step of heat-molding the papermaking body to obtain a molded body,
The molded product has a bending strength variation of 7.0% or more and 17.0% or less measured using the following variation measurement method,
and a step in which the molded body has a flexural modulus variation of 5.4% or more and 8.2% or less, measured using the following variation measurement method,
Provided is a method for producing a molded article, wherein the poly(meth)acrylic acid ester emulsion has a cationic degree of 0.02 meq/g or more and 0.1 meq/g or less;
(Method for Measuring Variation) The second aqueous slurry is made into paper, dehydrated, and made into a paper product. 36 test pieces of 10 mm×80 mm are cut out from the obtained paper product and dried at 70° C. for 1 hour. For each test piece, the flexural strength and flexural modulus are measured by a method conforming to ISO 178, and the variation is calculated using the following formula:
Bending strength variation (%) = [(maximum value - minimum value) / average value] x 100
Flexural modulus variation (%) = [(maximum value - minimum value) / average value] x 100
Here, the "maximum value" is the maximum bending strength or bending modulus value among the 36 test pieces, and the "minimum value" is the minimum bending strength or bending modulus value among the 36 test pieces. flexural modulus value, and "mean value" is the average value of flexural strength or flexural modulus of 36 of said test specimens.

INDUSTRIAL APPLICABILITY According to the present invention, there is provided a method for producing a molded article in which a fiber filler is highly dispersed.

It is a cross-sectional schematic diagram which shows an example of the manufacturing method of the papermaking body which concerns on this embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, in all the drawings, the same constituent elements are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

(Method for manufacturing a compact according to the first embodiment)
A method for manufacturing a molded body according to the first embodiment of the present invention comprises:
preparing a slurry comprising a thermosetting resin, a fibrous filler, and a poly(meth)acrylate emulsion;
a step of making a paper from the slurry and dehydrating it to obtain a paper product containing a thermosetting resin, an organic fiber, an inorganic fiber and a poly(meth)acrylic acid ester;
and a step of heat-molding the papermaking body to obtain a molded body. The poly(meth)acrylic acid ester emulsion used in this embodiment has a cationic degree of 0.02 meq/g or more and 0.1 meq/g or less.

The present inventors added a poly(meth)acrylic acid ester emulsion having a cationic degree of 0.02 meq/g or more and 0.1 meq/g or less to a slurry containing a thermosetting resin fiber filler to make the slurry into paper. It was found that the fibrous filler was highly dispersed in the paper product obtained by the method. In addition, since the fiber filler is highly dispersed in the molded article obtained from such a papermaking article, variation in strength is reduced, and it is said to have excellent strength against loads from any direction. Found it.

The poly(meth)acrylic acid ester emulsion used in this embodiment has a cationic degree of 0.02 meq/g or more and 0.1 meq/g or less. Here, the cation degree of the poly(meth)acrylic acid ester emulsion refers to the cationic colloid equivalent (meq/g) per gram of the poly(meth)acrylic acid ester in the poly(meth)acrylic acid ester emulsion, and polyvinyl It is measured by a colloid titration method using a potassium sulfate solution.

In this embodiment, by using the poly(meth)acrylic acid ester emulsion having the above cationic degree, a slurry in which the fiber filler is highly dispersed can be obtained. The reason for this is not necessarily clear, but since the surface of the fiber filler and thermosetting resin in the slurry is negatively charged, it interacts strongly with the cationic poly(meth)acrylic acid ester emulsion. This is thought to be due to aggregation. In addition, the poly(meth)acrylic acid ester having a predetermined cationic degree described above aggregates the fiber filler and the thermosetting resin at an appropriate speed, and is highly dispersed in the solvent. is thought to act to form

Examples of the poly(meth)acrylic acid ester emulsion used in the present embodiment include "Hymolock DR-9300" and "Hymofloc DR-7300" manufactured by Hymo Co., Ltd., "Diafloc KM series" manufactured by Mitsubishi Chemical Corporation and Examples include, but are not limited to, "Diaflock KP series", "Aronflock E1600" and "Aronflock E3300" manufactured by MT Aquapolymer Co., Ltd.

Fiber fillers used in the present embodiment include natural fibers such as metal fibers, wood fibers, cotton, hemp, and wool; regenerated fibers such as rayon fibers; semi-synthetic fibers such as cellulose fibers; polyamide fibers, aramid fibers, and polyimide fibers. , synthetic fibers such as polyvinyl alcohol fiber, polyester fiber, acrylic fiber, polyparaphenylene benzoxazole fiber, polyethylene fiber, polypropylene fiber, polyacrylonitrile fiber, ethylene vinyl alcohol fiber; carbon fiber; inorganic fiber such as glass fiber, ceramic fiber, etc. include but are not limited to. A fiber filler may be used individually by 1 type, and may be used in mixture of 2 or more types.

The content of the fiber filler can be 1% by mass or more and 90% by mass or less with respect to the solid content of the slurry, and can be appropriately selected depending on the application of the molded article to be obtained.

The fiber length of the fiber filler is not particularly limited, but it is desirable to use it properly according to the required properties, and for example, it is preferably 500 μm or more and 10 mm or less. By setting the fiber length to 500 μm or more, the properties of the fiber filler, such as mechanical strength and rigidity, can be exhibited. On the other hand, by setting the fiber length to 10 mm or less, moldability can be ensured.

The diameter of the fiber filler is preferably 1 μm or more and 100 μm or less, and particularly preferably 5 μm or more and 80 μm or less. When the thickness is 1 μm or more, the mechanical strength of the resulting molded product can be ensured, and when the thickness is 100 μm or less, moldability can be ensured. The length and diameter of the fibers can be confirmed, for example, by observing the obtained molded article with an electron microscope. Further, the average fiber length and average diameter can be obtained by selecting a total of 100 fiber fillers exposed on the surface of the obtained molded article and calculating the average value thereof.

In one embodiment, it is preferred to use pulp fibers in addition to the fibrous filler. Pulp fibers refer to fibrillated organic fibers. Pulp fibers include, for example, cellulose fibers such as linter pulp and wood pulp, natural fibers such as kenaf, jute and bamboo, para-type wholly aromatic polyamide fibers and their copolymers, aromatic polyester fibers, polybenzazole fibers, Pulp-like fibers obtained by fibrillating organic fibers such as meta-aramid fibers and their copolymers, acrylic fibers, acrylonitrile fibers, polyimide fibers, and polyamide fibers can be mentioned. The pulp fibers may be used singly or in combination of two or more.

The thermosetting resin used in this embodiment is used as a binder resin, and for example, phenol resin, epoxy resin, melamine resin, polyurethane, etc. can be used. As the thermosetting resin, one or a combination of two or more of the above specific examples can be used. As the thermosetting resin, among the above specific examples, it is preferable to use, for example, a phenol resin. Thereby, the strength of the molding can be improved. Therefore, the anisotropy of bending strength can be made smaller. It is also preferable from the viewpoint of further improving the dispersibility of single fibers.

In addition to the above components, the slurry used for the production of the paper product of the present embodiment may optionally contain a paper-making agent, an ion exchange agent, a filler, a flocculant, a conductivity-imparting agent, a flame retardant, and a flame retardant aid. agents, pigments, dyes, lubricants, release agents, compatibilizers, dispersants, crystal nucleating agents, plasticizers, heat stabilizers, antioxidants, anti-coloring agents, UV absorbers, fluidity modifiers, foaming agents , an antibacterial agent, a vibration damping agent, a deodorant, a slidability modifier, an antistatic agent, and the like.

In the present embodiment, the molded product is produced by a step of obtaining a paper-made product using a wet papermaking method and a step of heat-molding the obtained paper-made product to obtain a molded product.

The step of obtaining a paper product includes a step of mixing a thermosetting resin, a fiber filler, and a poly(meth)acrylic acid ester emulsion in a dispersion medium to prepare a slurry; It includes a step of adding the obtained slurry and separating the dispersion medium, and a step of drying the solid content remaining on the mesh and pressing to obtain a paper product.
Details of each step will be described below with reference to FIG.

(Preparation of slurry)
The slurry is prepared by mixing and stirring thermosetting resin A, fiber filler B, and poly(meth)acrylic acid ester emulsion in a dispersion medium, as shown in FIG. 1(a).
Here, the slurry preferably contains pulp fibers in addition to the above materials. By blending the pulp fibers, the fiber filler B can be highly dispersed.
For the step of mixing the above materials in the dispersion medium, for example, a method of stirring in a vessel equipped with a stirrer can be used.

The dispersion medium is not limited, specifically water; alcohols such as ethanol, 1-propanol, 1-butanol and ethylene glycol; ketones such as acetone, methyl ethyl ketone, 2-heptanone and cyclohexanone; ethyl acetate and acetic acid esters such as butyl, methyl acetoacetate and methyl acetoacetate; and ethers such as tetrahydrofuran, isopropyl ether, dioxane and furfural. As the dispersion medium, one or a combination of two or more of the above specific examples can be used. Among these, it is preferable to use water because it is easily available, has a low environmental impact, and is highly safe.

The poly(meth)acrylic acid ester emulsion may be added after mixing the thermosetting resin A, the fiber filler B, optionally pulp fibers, and optionally other components in a dispersion medium and stirring. Alternatively, they may be mixed simultaneously with the above components. In order to disperse each component to a higher degree, the poly(meth)acrylic acid ester emulsion is preferably added after mixing and stirring the above components in the dispersion medium.

(Separation process)
In the separation step, the slurry is placed in a container having a mesh 60 on the bottom as shown in FIG. 1(b), and the dispersion medium and the solid content are separated. As a result, sheet-like aggregates remain on the mesh of FIG. 1(c). In addition, an aggregate contains the raw material component of a slurry, for example.

In the present embodiment, by appropriately selecting the shape of the mesh 60, the shape of the resulting paper product 10 can be adjusted. For example, when a flat sheet-shaped mesh 60 is used, the paper product 10 having a sheet-like shape is obtained. Further, for example, when a mesh 60 having a three-dimensional shape such as corrugation or unevenness is used, the paper product 10 having a three-dimensional shape is obtained. The shape of the papermaking product 10 can be appropriately selected according to the shape of the molded product 20 obtained by curing and molding it, the shape of the mold, and the like. Moreover, the thickness of the papermaking body 10 can be adjusted by adjusting the amount of each material in the material slurry, or by preparing the slurry again and performing the separation step.

Next, the aggregate is dehydrated and pressed to produce a paper product.
Conditions for the dehydration press can be, for example, a temperature of 20° C. or higher and 30° C. or lower and a pressure of 1 kgf/cm ² or higher and 50 kgf/cm ^{2 or} lower.
Here, the dehydration press is preferably performed so that the dehydration rate of the paper product is 20% or less, for example. Note that the dehydration rate according to the present embodiment is the amount of the dispersion medium contained in the aggregate (paper product) after dehydration, assuming that the mass of the dispersion medium contained in the aggregate before dehydration is 100%. Indicates mass.

(Manufacturing method of molding)
Next, a method for manufacturing a molded article will be described.
The method for producing a molded product according to the present embodiment includes, for example, a drying step of heat-treating a paper-made product, and a molding step of molding the paper-made product with a mold under heat and pressure to produce a molded product.
Details will be described below.

(Drying process)
In the drying step, the paper product is heat-treated as shown in FIG. 1(d). This further removes the dispersion medium from the paper product.
The drying method is not limited, and for example, an oven 70 or the like can be used as shown in FIG. 1(d).
Here, the drying temperature can be above the melting point of the thermosetting resin and below the reaction temperature. The reaction temperature is the temperature at which the calculated reaction rate first exceeds 0% in the heating process in differential scanning calorimetry (DSC) measurement. Here, the reaction rate is calculated as follows. First, a temperature profile is measured by DSC measurement for a paper product that has not undergone a curing reaction. Let A [mJ/mg] be the amount of heat generated per unit mass at the exothermic peak of the curing reaction, which is calculated from the temperature profile of the curing reaction thus obtained. Next, for the paper product for which the reaction rate is to be calculated, similarly, the calorific value B [mJ/mg] converted per unit mass of the exothermic peak of the curing reaction is calculated. Using the above A and B, the reaction rate is obtained from the following formula.
(Formula) (reaction rate) = B/A x 100 [%]

(Molding process)
In the molding step, the paper product is die-molded under heat and pressure to produce a molding.
The molded product according to the present embodiment is obtained by subjecting the paper product to mold molding under heat and pressure. The molded product 20 can be produced by heating and pressurizing the sheet-like or three-dimensional papermaking product 10 using a mold having a desired shape. Examples of molding methods include press molding. As shown in FIG. 2(e), the press plate 71 presses the paper product 10, and a hot plate 72 is arranged on the outer peripheral side of the press plate 71 to heat it. Thereby, the molded body 20 can be obtained.

The cured state of the molding according to the present embodiment is the B-stage cured state.
Here, when the heating temperature in the molding process is above the melting point of the thermosetting resin and below the reaction temperature, the molded product can be in a B-stage cured state.

The molded product according to the present embodiment may be further heat-treated at a temperature higher than the reaction temperature to obtain a cured product (molded product) in a C-stage cured state. Here, the heat treatment at a temperature higher than the reaction temperature may be performed simultaneously with the molding step, for example.

(Method for manufacturing a compact according to the second embodiment)
A method for manufacturing a molded body according to the second embodiment of the present invention comprises:
mixing a thermosetting resin, a fibrous filler, and a polyether oxide in a dispersion medium to obtain a first slurry;
A step of mixing a poly(meth)acrylic acid ester emulsion with the first mixed aqueous slurry to obtain a second slurry;
a step of making a paper from the second slurry and dehydrating it to obtain a paper made body containing a thermosetting resin, a fiber filler, a polyether oxide, and a poly(meth)acrylic acid ester;
and a step of heat-molding the papermaking body to obtain a molded body. The poly(meth)acrylic acid ester emulsion used in this embodiment has a cationic degree of 0.02 meq/g or more and 0.1 meq/g or less.

The method for producing a molded article of the second embodiment includes the step of mixing a thermosetting resin, a fiber filler, and a polyether oxide in a dispersion medium to obtain a first slurry. It is different from the manufacturing method of the molded body of the embodiment. In this embodiment, by using polyether oxide, a slurry in which the fiber filler is highly dispersed can be obtained. Similar to the method in the first embodiment, the first slurry may be blended with pulp fibers.

In this embodiment, a poly(meth)acrylate emulsion is added to the first slurry obtained as described above. The poly(meth)acrylate emulsion used is the same as described above.

In a preferred embodiment, the step of obtaining a slurry includes mixing pulp fibers and polyether oxide in a dispersion medium to obtain a mixed slurry, then adding a fiber filler B to the mixed slurry thus obtained, stirring and mixing, and then A step of adding a thermosetting resin and stirring and mixing to obtain a first slurry, and a step of adding a poly(meth)acrylic acid ester emulsion to the first slurry and stirring and mixing to obtain a second slurry are used. is preferred. By using the above method, a slurry in which the fiber filler B is highly dispersed can be obtained.

The steps of producing a papermaking product and a molded product in the second embodiment can be carried out in the same manner as the method in the above-described first embodiment.

(paper product)
The paper product obtained by the method described in the above embodiments contains the thermosetting resin A, the fiber filler B and the poly(meth)acrylic acid ester, and the fiber filler B is evenly distributed. Therefore, the weight variation is 26% or less with respect to the predetermined weight.
Here, in the present embodiment, "weight variation" is defined by the following formula.
Weight variation (%) = [(maximum value - minimum value) / average value] x 100
The weight variation is measured by cutting out a 10 mm×80 mm test piece from a 300 mm×300 mm size paper product, drying it at 70° C. for 1 hour, and then measuring the weight. The "average value" in the above formula is the average weight of each test piece, the "maximum value" is the maximum value among the test pieces, and the minimum value is the minimum value among the test pieces. is.
The smaller the value of the weight variation, the smaller the weight difference in an arbitrary portion of the paper product, indicating that the weight of the paper product is uniform. That is, the smaller the weight variation value, the more uniformly the thermosetting resin A and the fiber filler B contained in the paper product are dispersed.
The weight variation of the paper product is 26% or less, preferably 24% or less. If the weight variation is the above value, the molded product obtained by curing the paper product has excellent strength against loads from any direction.

Since the fiber filler B is highly dispersed in the molded article obtained by curing the papermaking article with such reduced weight variation, the variation in strength is also reduced, and it can withstand loads from any direction. It has excellent strength against

Although the embodiments of the present invention have been described above, these are examples of the present invention, and various configurations other than those described above can also be adopted.
Examples of embodiments will be added below.
1. preparing a slurry comprising a thermosetting resin, a fibrous filler, and a poly(meth)acrylate emulsion;
a step of making a paper from the slurry and dehydrating it to obtain a paper product containing a thermosetting resin, a fiber filler and a poly(meth)acrylic acid ester;
a step of heat-molding the papermaking body to obtain a molded body,
A method for producing a molded article, wherein the poly(meth)acrylic acid ester emulsion has a cationic degree of 0.02 meq/g or more and 0.1 meq/g or less.
2. The step of preparing a slurry includes
mixing the thermosetting resin and the fiber filler in a dispersion medium to obtain a mixed liquid;
1. A step of mixing the poly(meth)acrylic acid ester emulsion with the mixed liquid to obtain a slurry; 3. A method for producing a molded article according to .
3. A paper product containing a thermosetting resin, a fiber filler, and a poly(meth)acrylic acid ester,
A paper product having a weight variation of 26% or less with respect to a predetermined weight.
4. mixing a thermosetting resin, a fibrous filler, and a polyether oxide in a dispersion medium to obtain a first slurry;
A step of mixing a poly(meth)acrylic acid ester emulsion with the first mixed aqueous slurry to obtain a second aqueous slurry;
a step of making a paper from the second slurry and dehydrating it to obtain a paper made body containing a thermosetting resin, a fiber filler, a polyether oxide, and a poly(meth)acrylic acid ester;
a step of heat-molding the papermaking body to obtain a molded body,
A method for producing a molded article, wherein the poly(meth)acrylic acid ester emulsion has a cationic degree of 0.02 meq/g or more and 0.1 meq/g or less.

EXAMPLES The present invention will be described below with reference to Examples and Comparative Examples, but the present invention is not limited to these.

The following materials were used in the amounts shown in Table 1 for the preparation of the papermaking bodies.
(Thermosetting resin)
・ Thermosetting resin 1: resol type phenolic resin ("PR51723" manufactured by Sumitomo Bakelite Co., Ltd.
(fiber filler)
・ Fiber filler 1: PAN-based carbon fiber (fiber length 6 mm to 9 mm)
(pulp fiber)
・ Pulp fiber 1: Aramid microfiber ("Tiara KY-400S" manufactured by Daicel Finechem Co., Ltd.)
・ Pulp fiber 2: Aramid microfiber ("Twaron 1094" manufactured by Teijin Limited)
(Additive)
・ Additive 1: Poly (meth) acrylic acid ester emulsion ("Himolo DR-9300" manufactured by Hymo Co., cation degree 0.04 meq / g)
・ Additive 2: Poly (meth) acrylic acid ester emulsion ("Himolo DR-7300" manufactured by Hymo Co., cation degree 0.034 meq / g)
・ Additive 3: Poly (meth) acrylic acid ester emulsion ("Himolo DR-7300" manufactured by Hymo Co., cation degree 0.017 meq / g)
・ Additive 4: polyethylene oxide (“PEO-18” manufactured by Sumitomo Seika Co., Ltd.)

(Example 1)
(Preparation of paper product)
A thermosetting resin, a fiber filler, and pulp fibers were added to water as a dispersion medium, and the mixture was stirred for 20 minutes to obtain a slurry with a solid concentration of 0.15% by mass. An aqueous solution of Additive 1 prepared in advance was added to the obtained slurry so that the solid content in the slurry was 300 ppm, and the solid content in the slurry was aggregated. Next, the slurry containing the aggregates was filtered through a 30-mesh metal net (screen), and the sheet-like aggregates remaining on the screen were dewatered by pressing at a pressure of 3 MPa. The dehydrated aggregate was dried at 70° C. for 3 hours to obtain a sheet-like preform (paper product).

(Preparation of compact)
The sheet-shaped paper product obtained above was cut into 10 mm×80 mm pieces, and the weight thereof was measured. The cut pieces were laminated so as to have a thickness of 4 mm after molding, and were heat-treated for 10 minutes at a pressure of 650 kg/cm ² and a temperature of 180° C. to obtain a molded body of 10 mm×80 mm×4 mm.

(Example 2)
A paper product and a molded product were produced in the same manner as in Example 1, except that additive 2 was used instead of additive 1.

(Comparative example 1)
A paper product and a molded product were produced in the same manner as in Example 1, except that additive 3 was used instead of additive 1.

(Example 3)
(Preparation of paper product)
Thermosetting resin, fiber filler, and pulp fiber are added to water as a dispersion medium, and an aqueous solution of additive 4 prepared in advance is added so that the solid content is 1000 ppm, and stirred for 20 minutes. , to obtain a dispersion having a solid concentration of 0.15% by mass. An aqueous solution of Additive 1 prepared in advance was added to the obtained dispersion so that the solid content in the dispersion liquid was 300 ppm, and the solid content in the slurry was aggregated. Next, the slurry containing the aggregates was filtered through a 30-mesh metal mesh (screen) at a flow rate of 20 L/min, and the sheet-like aggregates remaining on the screen were dehydrated by pressing at a pressure of 3 MPa. The dehydrated aggregate was dried at 70° C. for 3 hours to obtain a sheet-like preform (paper product).

(Preparation of compact)
The sheet-shaped paper product obtained above was cut into 10 mm×80 mm pieces, and the weight thereof was measured. The cut pieces were laminated so as to have a thickness of 4 mm after molding, and were heat-treated for 10 minutes at a pressure of 650 kg/cm ² and a temperature of 180° C. to obtain a molded body of 10 mm×80 mm×4 mm.

(Comparative example 2)
A paper product and a molded product were produced in the same manner as in Example 3, except that additive 3 was used instead of additive 1.

(Example 4)
A paper product and a molded product were produced in the same manner as in Example 3, except that additive 2 was used instead of additive 1.

(Comparative Example 3)
A paper product and a molded product were produced in the same manner as in Example 3, except that additive 3 was used instead of additive 1.

(Measurement of weight variation of paper product)
The variation in weight of the paper product obtained as described above was measured by the following method. The variation in the weight of the paper product was used as an indicator of the dispersibility of the fiber filler contained in the paper product.
First, 36 test pieces of 10 mm×80 mm were cut out from the obtained sheet-like paper product. The weight of each test piece was measured and the average value was obtained. Then, the weight variation (%) was obtained from the following formula.
Weight variation (%) = [(maximum value - minimum value) / average value] x 100
Here, the "maximum value" is the maximum weight value among the above 36 test pieces, the "minimum value" is the minimum weight value among the 36 test pieces, and the "average value" is , is the average of the weights of 36 specimens.

(Measurement of flexural strength variation and flexural modulus variation of compact)
The flexural strength variation and the flexural modulus variation of the molded article obtained as described above were measured. Specifically, the flexural strength and flexural modulus of 36 test pieces each having a size of 10 mm×80 mm cut out from the sheet-like paper product obtained above were measured by a method conforming to ISO178. Next, the flexural strength variation (%) and the flexural modulus variation (%) were obtained from the following equations. The results are shown in Table 2 below.
Bending strength variation (%) = [(maximum value - minimum value) / average value] x 100
Flexural modulus variation (%) = [(maximum value - minimum value) / average value] x 100
Here, the “maximum value” is the maximum bending strength or bending elastic modulus value among the 36 test pieces, and the “minimum value” is the minimum bending strength or bending elastic modulus value among the 36 test pieces. modulus value, and "mean value" is the average value of the flexural strength or flexural modulus of 36 specimens.

The paper products of Examples have small variations in weight, and molded products obtained by curing such paper products have relatively small variations in flexural strength and flexural elasticity. Therefore, the molded articles of Examples have highly dispersed fiber fillers and have excellent strength against loads from arbitrary directions.

Claims (4)

preparing a slurry comprising a thermosetting resin, a fibrous filler, and a poly(meth)acrylate emulsion;
a step of making a paper from the slurry and dehydrating it to obtain a paper product containing a thermosetting resin, a fiber filler and a poly(meth)acrylic acid ester;
A step of heat-molding the papermaking body to obtain a molded body,
The molded product has a bending strength variation of 7.0% or more and 17.0% or less measured using the following variation measurement method,
and a step in which the molded body has a flexural modulus variation of 5.4% or more and 8.2% or less, measured using the following variation measurement method,
A method for producing a molded article, wherein the poly(meth)acrylic acid ester emulsion has a cationic degree of 0.02 meq/g or more and 0.1 meq/g or less;
(Method for Measuring Variation) The slurry is made into paper and dehydrated to prepare a paper product, and 36 test pieces of 10 mm×80 mm are cut out from the obtained paper product and dried at 70° C. for 1 hour. For each test piece, the flexural strength and flexural modulus are measured by a method conforming to ISO 178, and the variation is calculated using the following formula:
Bending strength variation (%) = [(maximum value - minimum value) / average value] x 100
Flexural modulus variation (%) = [(maximum value - minimum value) / average value] x 100
Here, the "maximum value" is the maximum bending strength or bending modulus value among the 36 test pieces, and the "minimum value" is the minimum bending strength or bending modulus value among the 36 test pieces. flexural modulus value, and "mean value" is the average value of flexural strength or flexural modulus of 36 of said test specimens. The step of preparing a slurry includes
mixing the thermosetting resin and the fiber filler in a dispersion medium to obtain a mixed liquid;
2. The method for producing a molded article according to claim 1, further comprising the step of mixing the poly(meth)acrylic acid ester emulsion with the mixed liquid to obtain a slurry. 3. The method for producing a molded article according to claim 1 or 2, wherein the papermaking article has a weight variation of 26% or less as measured by the following weight variation measuring method;
(Method for measuring weight variation) The slurry was made into paper, dehydrated, and made into a paper product. 36 test pieces of 10 mm x 80 mm were cut out from the obtained paper product, dried at 70°C for 1 hour, and subjected to each test. Weigh the pieces and calculate the weight variation using the following formula:
Weight variation (%) = [(maximum value - minimum value) / average value] x 100
Here, the "maximum value" is the maximum weight value among the 36 test pieces, the "minimum value" is the minimum weight value among the 36 test pieces, and the "average value" is , is the mean value of the weights of 36 such specimens. mixing a thermosetting resin, a fibrous filler, and a polyether oxide in a dispersion medium to obtain a first slurry;
A step of mixing a poly(meth)acrylic acid ester emulsion with the first slurry to obtain a second aqueous slurry;
a step of making a paper from the second aqueous slurry and dehydrating it to obtain a paper product containing a thermosetting resin, a fiber filler, a polyether oxide, and a poly(meth)acrylic acid ester;
A step of heat-molding the papermaking body to obtain a molded body,
The molded product has a bending strength variation of 7.0% or more and 17.0% or less measured using the following variation measurement method,
and a step in which the molded body has a flexural modulus variation of 5.4% or more and 8.2% or less, measured using the following variation measurement method,
A method for producing a molded article, wherein the poly(meth)acrylic acid ester emulsion has a cationic degree of 0.02 meq/g or more and 0.1 meq/g or less;
(Method for Measuring Variation) The second aqueous slurry is made into paper, dehydrated, and made into a paper product. 36 test pieces of 10 mm×80 mm are cut out from the obtained paper product and dried at 70° C. for 1 hour. For each test piece, the flexural strength and flexural modulus are measured by a method conforming to ISO 178, and the variation is calculated using the following formula:
Bending strength variation (%) = [(maximum value - minimum value) / average value] x 100
Flexural modulus variation (%) = [(maximum value - minimum value) / average value] x 100
Here, the "maximum value" is the maximum bending strength or bending modulus value among the 36 test pieces, and the "minimum value" is the minimum bending strength or bending modulus value among the 36 test pieces. flexural modulus value, and "mean value" is the average value of flexural strength or flexural modulus of 36 of said test specimens.

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