JP2726206B2 - Molded article made of acrylic synthetic fiber and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded article made of a novel material (a sheet composed of acrylic synthetic fibers having a special structure) and a method for producing the same, particularly to various containers, food trays, and sheet-like articles. Packaging materials such as cushioning materials,
The present invention relates to a molded article suitable as a shoulder pad and an interlining for clothing and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, packaging products such as various containers, food trays, and sheet-like cushioning materials, and shoulder pads and interlining for clothing have been produced by compression molding, extrusion molding, or the like of synthetic resin.
It is formed by foam molding or the like.

[0003]

Among such molded articles, packaging articles such as various containers, food trays, and sheet-shaped cushioning materials are made of synthetic resin and therefore have no freshness in appearance. As a packaging material for expensive commodities, it lacked a sense of quality. In recent years, consumers have been demanding packaging materials suitable for expensive commodities from the viewpoint of luxury goods, but the conventional production method could not meet such demands.

[0004] In addition, shoulder pads and interlining for clothing, etc.
A synthetic resin product is excellent in shape retention, but has a disadvantage of being too hard. The present invention is intended to solve such a problem. By providing a molded article made of acrylic synthetic fibers having a special structure instead of a synthetic resin, a packaging material such as a tray for food can be provided with a high quality feeling. It is also an object of the present invention to provide appropriate hardness and flexibility such that the shoulder pads and interlining for clothing do not lose their shape.

[0005]

In order to achieve the above-mentioned object, a first aspect of the present invention is to form a plurality of elongated voids made of an acrylic polymer having an acrylonitrile unit of 50% by weight or more and extending along a length direction. Inside, it is composed of acrylic synthetic fibers formed in a structure in which the cross-sectional shape of the void is unspecified, and a part of the fibers is divided into a number of finer fine filaments. Are dispersed and spread in one part, and in another part they are gathered together in a bundle, and the fibers are three-dimensionally formed by a sheet in which the fibers are integrated by entanglement. On at least one of the side surfaces, the fused portion of the fiber is present, and inside the thickness direction, there are many elongated voids of the fiber and many spaces between the fibers. acrylic Elasticity and shape retention of synthetic fibers
Provided is a molded article having properties .

[0006] Claim 2 is that the acrylonitrile unit is 50
% By weight or more of an acrylic polymer, having a plurality of elongated voids extending along the length direction therein, and having a structure in which the cross-sectional shape of the voids is unspecified. A part of the fiber is divided into a number of finer finer filaments, and the fine filaments are dispersed and spread in a certain portion, and are gathered in a bundle in another portion. The sheets integrated by entanglement with each other are heated at a temperature of 150 to 200 ° C. and a pressure of 1 to 10 kg.
The present invention provides a method for producing a molded article made of an acrylic synthetic fiber, which is three-dimensionally molded at a molding time of 1/60 seconds / cm ² .

[0007] Claim 3 is that the acrylonitrile unit is 50
% By weight or more of an acrylic polymer, having a plurality of elongated voids extending along the length direction therein, and having a structure in which the cross-sectional shape of the voids is unspecified. A part of the fiber is divided into a number of finer finer filaments, and the fine filaments are dispersed and spread in a certain portion, and are gathered in a bundle in another portion. It is formed into a plate shape by a sheet that is integrated by entanglement with each other, and at least one of the front and back surfaces of the plate-like material has an intimate contact portion of the fiber. The elasticity and shape retention of acrylic synthetic fiber, characterized by many voids and many spaces between fibers
A molded article having the same is provided.

[0008] Claim 4 is that the acrylonitrile unit is 50
% By weight or more of an acrylic polymer, having a plurality of elongated voids extending along the length direction therein, and having a structure in which the cross-sectional shape of the voids is unspecified. A part of the fiber is divided into a number of finer finer filaments, and the fine filaments are dispersed and spread in a certain portion, and are gathered in a bundle in another portion. The sheets integrated by entanglement with each other are subjected to a temperature of 90 to 150 ° C. and a linear pressure of 0.5 to 100.
A method for producing a molded article made of acrylic synthetic fiber, characterized in that the molded article is formed into a plate by rolling with a metal roll at kg / cm .

[0009] Here, the acrylic synthetic fiber is partially divided into a number of finer filaments, and there are naturally undivided portions. for that reason,
The fibers that are entangled in the sheet, and the fibers that form the fused portion on the surface of the molded body,
It contains both divided parts (fine filaments) and undivided parts of fibers.

That is, the molded article according to claims 1 and 3 is:
The sheet made of the acrylic synthetic fiber having the special structure described above is formed into a predetermined shape. FIG. 1 shows an electron micrograph (× 4,000) of a cross section of the acrylic synthetic fiber, and FIG. 2 shows an electron micrograph (× 4,000) of a vertical cross section. In FIG. 1, a black portion a is a cross section of the gap, and the shape is various, such as a substantially circular shape, a flat shape, a shape in which the edge is repeatedly bent, and a large cross-sectional area. It can be seen that a large number of elongated voids having an irregular cross section, which are not constant and small, are irregularly present in the fiber.

In FIG. 2, similarly, it can be seen that the black portions b are the voids, and each void extends substantially in parallel along the length direction of the fiber. In the present invention, such a fiber constitutes a sheet, and in this sheet, a part of the fiber is divided into many finer filaments. Such fine filaments are partly divided by applying an external force to the fibers, and in order to facilitate this division, the length of the above-mentioned elongated voids is 60 μm or more. Is preferred.

Further, in the elongated void, adjacent ones thereof may be partially connected by a void. Further, it is preferable that the number of the elongated voids in one cross section of the fiber is 100 or more in order to easily divide into fine filaments by the external force as described above. Such an acrylic synthetic fiber is produced from an acrylic polymer as follows.

[0013] As the acrylic polymer, 50% by weight
(Hereinafter, "%" indicates "% by weight" unless otherwise specified.)
There is a polymer of the above acrylonitrile unit (hereinafter abbreviated as "AN") and another monomer copolymerizable with AN, or a mixed polymer obtained by mixing these polymers. When the AN is less than 50%, the non-melting and thermoplastic properties inherent in the acrylic polymer are lost, and it is difficult to maintain the shape during compression molding of the molded article. There is no upper limit for the content of AN and it is 100% of AN
It may be a polymer. Also, when the acrylic polymer is a mixture, the content of AN must be 50% or more based on the weight of the mixed polymer.

Examples of monomers copolymerizable with AN include conventionally known monomers such as acrylic acid, methacrylic acid and esters thereof (methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, etc.), vinyl acetate , Vinyl chloride, vinylidene chloride, acrylamide, methacrylamide, methacrylonitrile, allylsulfonic acid, methallylsulfonic acid, styrenesulfonic acid, vinylpyridine, N, N-dimethylaminoethyl methacrylate and the like.

The acrylic polymer and the polyalkylene glycol are converted into a conventionally known solvent for the acrylic polymer, for example, a concentrated aqueous solution of dimethylformamide, dimethylacetamide, dimethylsulfoxide, and rhodane salt;
It is dissolved in a solvent such as a concentrated aqueous solution of zinc chloride or an aqueous solution of nitric acid to prepare a spinning stock solution. The optimum concentration of the acrylic polymer in the spinning dope differs depending on the solvent, but is generally 10 to 3%.
0% is preferred.

The addition of the polyalkylene glycol
This is an important requirement for forming the aforementioned elongated voids in the acrylic synthetic fiber. This polyalkylene glycol has ethylene oxide and propylene oxide,
It is a random copolymer or a block copolymer copolymerized in a weight ratio of 80:20 to 20:80, and has a number average molecular weight of 5,000 to 50,000, preferably 6, 000 to 20,000.

If the number average molecular weight is smaller than 5,000, no elongated voids extending continuously in the longitudinal direction of the fiber are formed, and the porous fiber has extremely fine, almost spherical voids. On the other hand, when the number average molecular weight exceeds 50,000, the fiber becomes a fiber having a huge streak-like cavity, and moreover, a fiber having at most several tens of cavities in the cross section of the fiber. With such a fiber, it is difficult to divide the fiber into fine filaments by an external force, which is not suitable for the fiber for a molded article of the present invention. In order to obtain a fiber having elongated voids extending along the length direction of the fiber and having an unspecified cross-sectional shape in a cross section, the number average molecular weight is 10,000 to
Those of 20,000 are particularly preferred.

Further, the spinning dope prepared by dissolving the polyalkylene glycol is aged for at least 4 hours. This is a necessary condition for obtaining an acrylic synthetic fiber having a large number of continuous elongated voids along the fiber length direction. Here, aging means that the spinning solution prepared by dissolving the acrylic polymer and the polyalkylene glycol is, for example, allowed to stand still or gently without vibrating or vibrating. Liquid.

It is not clear why the above-mentioned elongated voids are formed by aging the spinning solution to which the polyalkylene glycol has been added, but it is presumed as follows. That is, the aging of the spinning solution causes aggregation of the polyalkylene glycol, and when the spinning solution is spun from the pores of the spinneret into the coagulation medium through a tube, a shear force acts on the spinning solution. Fine streaks of polyalkylene glycol are formed. Then, the acrylic polymer solidifies, and due to the difference in solidification characteristics between the two that the polyalkylene glycol does not solidify,
It is considered that voids having a complicated shape as described above are generated by the phase separation of both polymers. This aging time is 4
A longer time may be used as long as the time is longer than 4 hours.
Preferably, it is 10 hours.

The amount of the polyalkylene glycol to be added is 5 to 20%, preferably 10 to 20% based on the acrylic polymer.
To 15%. If the added amount is less than 5%, the above-mentioned elongated voids are reduced, and if it is more than 20%, the number is too large, and the fibers are divided into finer fine filaments in the fiber production process, or the stable spinning is performed. And other problems occur. When the addition amount is 10 to 15%,
It is preferable because the number of the elongated voids and the spinning stability can be most balanced.

The spinning solution is extruded through a spinneret into a coagulating medium of the spinning solution, and the coagulated yarn is subjected to various treatments such as washing, drawing, drying, and heat treatment, so that a large number of elongated voids extending in the length direction are obtained. The acrylic synthetic fiber which has inside is formed. At this time, the polyalkylene glycol added to the spinning solution is eluted from the coagulated filament in the process of coagulation, washing with water, stretching and the like.

The spinning method employed here is wet spinning,
Any method such as dry spinning or dry-wet spinning may be used,
After spinning, in order to elute the polyalkylene glycol from the coagulated filament, it is preferable to stretch and wash in an aqueous medium. In the molded article of the present invention, a part of such an acrylic synthetic fiber is divided into many finer fine filaments, and the fine filaments are dispersed and spread in a certain portion, and are bundled in another portion. And formed into a sheet in which the fibers are integrated by entanglement with each other.

The above-mentioned acrylic synthetic fibers are easily divided into fine filaments by receiving an external force, and the divided fine filaments, the undivided acrylic synthetic fibers, and the divided Entanglement between the fine fibers and the undivided acrylic synthetic fibers occurs. That is, by applying an external force to the acrylic synthetic fiber, division into fine filaments and entanglement of the fibers and filaments can be performed simultaneously and easily.

Therefore, the sheet in the present invention can be obtained by converting the acrylic synthetic fiber into a nonwoven fabric by, for example, a conventionally known columnar flow punching treatment using high-pressure water. By this columnar flow punching process,
Most of the acrylic synthetic fibers present on the surface of the non-woven fabric are divided into a number of finer filaments, which are dispersed and spread randomly in one part and bundled in another part. They assemble and these fibers are entangled with each other. In addition, undivided acrylic synthetic fibers exist inside the nonwoven fabric.

The division of the acrylic synthetic fiber is as follows.
The degree can be adjusted by changing the magnitude of the external force applied to the fibers, and the dispersion state of the obtained fine filaments and the degree of entanglement between the fibers can also be adjusted by the magnitude of the external force. it can. There is no particular limitation on the length of the fibers constituting the sheet, and both long fibers and short fibers can be used.
Is preferably used, and more preferably 10 to 60 mm.

The basis weight of the nonwoven fabric can be appropriately changed according to the properties of the desired molded product, but is usually 50 to 1000 g / m ² , preferably 100 to 50 g / m ^2.
0 g / m ² . The nozzle diameter used for high-pressure column-shaped flow punching is 0.05-1 mm, preferably 0.1-0.
5mm, the pressure of the injection water is 20-100kg / c
m ² , preferably 40 to 80 kg / cm ² , and the web is sprayed with such a jet of water to entangle the fibers, whereby the division of the acrylic synthetic fibers into fine filaments and the entanglement of the fibers proceed almost simultaneously. Then, a sheet for a molded article according to the present invention can be formed.

The molded article of the first aspect is formed three-dimensionally from such a sheet, and a part of the fibers forming at least one of the inner surface and the outer surface thereof is fused, and the thickness of the fiber in the thickness direction is increased. Inside, there are many elongated voids of the fibers and many spaces between the fibers. That is, the molded article is obtained by placing a sheet made of the above-mentioned acrylic synthetic fiber in a mold having a predetermined shape and molding the sheet under a predetermined temperature and pressure. At the time of molding, the temperature of the mold is set to 150 to 200 ° C., and the pressure is set to 1
To 10 kg / cm ^2, the molding time to 60 seconds, preferably 2 to 10 seconds.

If the molding temperature exceeds 250 ° C., the acrylic synthetic fibers will be denatured or decomposed, making molding difficult.
If the pressure exceeds 30 kg / cm ² , the fusion of the fibers on each side of the sheet becomes severe and molding becomes difficult. When the molding temperature is less than 100 ° C. and the pressure is 0.5 kg / cm
^If it is less than ² , it is not possible to form a fused portion of the fiber on each side of the sheet.

By appropriately adjusting these conditions within the above ranges, molded articles having various characteristics can be produced. The design of the mold to be used can be changed as appropriate in accordance with the shape of the target molded body and the like. The molded article according to claim 3 is formed into a plate shape from the above-mentioned sheet, and is obtained by rolling the sheet between metal rolls. At this time, the temperature of the metal roll, 9 0
The temperature is 150 ° C., and the linear pressure is 0.5 to 100 kg / cm, preferably 1 to 10 kg / cm. By appropriately adjusting these conditions, molded articles having various characteristics can be produced.

As the metal roll, various rolls such as a roll having a smooth surface and a roll having an uneven surface can be used according to the purpose. In other words, if a roll having irregularities on the surface is used, a concavo-convex pattern is drawn on the surface of the molded article, so that a molded article having a design property can be obtained. FIG.
FIG. 4 is an electron micrograph (magnification: 235) showing the inner surface of a tray which is an example of the molded product of FIG.

Most of the acrylic synthetic fibers present on the inner surface and the outer surface of the molded product are divided into fine filaments, and the fine filaments are dispersed and spread in one part and bundled in another part. The filaments are converged in a shape, indicating that these filaments are entangled with each other. These fine filaments present on the inner surface and the outer surface of the molded body are in close contact with each other, and are partially fused and bonded by heat and pressure (see FIGS. 3 and 4). , Blackened portion c). In the portion where the fine filaments are fused, there are some places where the fibers are converted into resin.

FIG. 5 is an electron micrograph (magnification: 177) showing the cross-sectional form of the molded product (tray) shown in FIGS. In FIG. 5, the upper surface corresponds to the inner surface of the molded body, and the lower surface corresponds to the outer surface. As can be seen from this photograph, on the inner surface and outer surface of the molded body,
The fine filaments obtained by dividing the acrylic synthetic fibers are heated and pressed at the time of molding and are fused to form a resinized thin layer (white opaque portion d).

As can be seen from FIG. 5, undivided acrylic synthetic fibers also exist inside the molded sheet in the thickness direction, and these uninterrupted acrylic synthetic fibers are entangled with each other. It is entangled with the divided fine filaments. The undivided fibers and the divided fine filaments existing inside these thickness directions are not fused together because the fibers are in close contact with each other and are simply and strongly pressed. In other words, even after being formed into a molded article, the inside of the sheet in the thickness direction of the sheet forming the same has a structure (having a large number of elongated voids extending in the length direction) which is almost the same as before the molding. Synthetic fibers are present. Furthermore, many spaces (for example, e) are included between the fibers.

On the other hand, FIG. 6 is an electron microscope photograph (magnification: 590) showing the front surface of a plate-like material which is an example of the molded article according to claim 3, FIG. It is an electron micrograph (630 times) which shows the cross section state of the surface side of an object. 6 and 7, an elongated white portion (for example, f) is a fiber, and a black portion (for example, g) is a space surrounded by the fiber. As can be seen from FIG. 8, the surface portion is mainly composed of divided fine filaments (for example, f), and the middle portion in the thickness direction is mainly a divided fine filament which is thicker than the surface portion ( For example, h) and undivided acrylic synthetic fibers (for example, i). Further, the inside of the plate-shaped object in the thickness direction includes many spaces (for example, j) between the fibers.

That is, most of the acrylic synthetic fibers present on the front surface and the back surface of the plate-like material are divided into fine filaments, and the fine filaments are dispersed and spread in one portion and spread in another portion. The bundles are bundled and converged, and it can be seen that these filaments are entangled with each other. In addition, it can be seen that these filaments are not fused but are closely adhered.

When a nonwoven fabric made of the above-mentioned acrylic synthetic fiber is produced as the sheet in the present invention,
Other fibers, for example, synthetic fibers and natural fibers can be appropriately mixed in a range of 50% or less.

[0037]

According to a first aspect of the present invention, there is provided a molded article comprising an acrylic synthetic fiber having therein a plurality of elongated voids extending along a length direction, wherein the transverse cross-sectional shape of the void is unspecified.
Some of the fibers are divided into a number of finer filaments,
The fine filaments are dispersed and spread in a certain portion, and are gathered in a bundle in another portion, and are three-dimensionally formed by a sheet in which the fibers are integrated by entanglement with each other.

When a conventional non-woven fabric made of fibers is put into a mold and a three-dimensional molded body is to be manufactured under heating and pressure, the non-woven fabric cannot be sufficiently coped with the stretching force applied during molding. It has been difficult to obtain a uniform molded body due to partial stretching or cutting. However, in the molded article according to claim 1, in addition to the special structure of the acrylic synthetic fiber and the special structure of a sheet made of the fiber, the acrylic synthetic fiber is non-melting but thermoplastic. Due to the inherent thermal properties of the sheet, it is possible to significantly improve the physical properties such as the tensile strength of the sheet, so that the sheet can sufficiently cope with the stretching force acting at the time of molding using a mold. It is presumed.

Further, the molded article according to claim 1 is formed into a predetermined shape by the sheet, and at least one of an inner surface and an outer surface has a fused portion of the fiber, and Inside the direction there are many elongated voids of said fibers and there are many spaces between the fibers.
Here, by the manufacturing method according to claim 2, the sheet is heated at a temperature of 150 to 200 ° C., a pressure of 1 to 10 kg / cm ² ,
If molding is performed for a molding time of 1 to 60 seconds , a large number of elongated voids of the fiber are present inside the thickness direction (ie,
The fibers are left undivided or the degree of division is low), and the fibers are fused to at least one of the inner side surface and the outer side surface of the molded body while a large amount of space exists between the fibers. Parts can be formed.

The fused portion greatly contributes to the shape retention of the three-dimensional molded body. As described above, undivided acrylic synthetic fibers are formed inside the cross section of the sheet formed into a predetermined shape. Although it exists and contains a lot of spaces between fibers, it is a major factor in firmly maintaining the shape of the molded body. On the other hand, the molded body according to claim 3 is formed into a plate shape by the sheet, and at least one of the front and back surfaces has a portion where the fibers are in close contact with each other. Has many elongated voids of the fibers and many spaces between the fibers. And the entanglement of fibers on the surface of the plate-like material and the close contact state thereof, as described above, greatly contribute to the shape retention of the plate-like material, appropriate hardness, flexibility, and flexibility,
The space existing inside the thickness direction and the undivided acrylic synthetic fibers give the plate-like material elasticity. Such a plate-like object can be easily obtained by the method according to claim 4. That is, according to the manufacturing method of claim 4,
The sheet is heated at a temperature of 90 to 150 ° C. and a linear pressure of 0.5 to 100.
If rolled by a metal roll at kg / cm , inside the thickness direction, many elongated voids of the fiber exist (that is, the fiber is left undivided or the degree of division is low), and the space between the fibers is large. While the above-mentioned space exists, a contact portion of the fiber can be formed on at least one of the front and back surfaces of the plate-like object.

[0041]

The present invention will be described below in more detail with reference to examples. First, an acrylic synthetic fiber constituting a sheet for a molded article was produced as follows. In dimethylformamide, the composition is AN5.0%, methyl acrylate4.
5% and 0.5% sodium methallylsulfonate copolymer and polyethylene oxide-polypropylene oxide-polyethylene oxide block type polyether (number average molecular weight 10,000, polymerization ratio polyethylene oxide: polyethylene oxide = 70:30), and allowed to stand for 6 hours,
23% of the copolymer and 2.% of the block type polyether.
A spinning dope containing 3% was prepared.

The undiluted spinning solution is extruded through a spinneret having pores having a diameter of 0.08 mm into an aqueous coagulation bath containing 35% dimethylformamide at a temperature of 35 ° C., and after washing the coagulated filaments in boiling water, 80 after stretching 10 times
℃ hot air, then crimped, and further
m was processed into fibers by cutting. The single fiber fineness of the obtained fiber was 2d, the tensile strength was 3.2 g / d, and the tensile elongation was 32%.

FIGS. 1 and 2 (at a magnification of 4,000) show electron micrographs showing the state of the cross section and the vertical section of the fiber. As can be seen from these figures, the fiber had a very large number of elongated voids extending along its length. The fibers are formed into two webs having a basis weight of 120 and 200 g / m ² using a carding machine. The webs are placed on a wire mesh and moved at a speed of 4 m / min. The high pressure water of 60 kg / cm < ² > was sprayed toward the said web from the apparatus which has the nozzle which has a line at 0.8 mm intervals. After repeating this treatment 10 times, the obtained nonwoven fabric was dried in hot air at 80 ° C.

In the sheet thus obtained, a part of the acrylic synthetic fiber is divided into a number of finer fine filaments, and the fine filaments are dispersed in a random direction in one portion and are dispersed in another portion. In this example, the fine fibers and undivided fibers were entangled with each other, and the entire fibers were integrated by entanglement as a whole. Various molded articles were formed from the two types of sheets thus obtained. <Example 1> A sheet having a basis weight of 200 g / m ² was put into a tray manufacturing mold, and the temperature was 180 ° C and the pressure was 2 kg / cm ^2.
For 6 seconds to produce a tray.

An electron micrograph showing the inner surface, outer surface, and cross-section of the obtained tray is shown in FIG.
These are shown in FIG. 4 (234 times) and FIG. 5 (177 times), respectively. Most of the acrylic synthetic fibers present on the inner and outer surfaces of the tray are divided into fine filaments, which are dispersed and spread in one part and bundled in another part. It is converging and it can be seen that these filaments are entangled with each other. These fine filaments present on the inner surface and the outer surface of the molded body are in close contact with each other, and are partially fused and bonded by heat and pressure (see FIGS. 3 and 4). , Blackened portion c). In the portion where the fine filaments are fused, there are some places where the fibers are converted into resin.

In FIG. 5, the upper surface corresponds to the inner surface of the tray, and the lower surface corresponds to the outer surface. As can be seen from this photograph, on the inner surface and the outer surface of the molded article, the fine filaments obtained by dividing the acrylic synthetic fiber are heated and pressed at the time of molding to fuse and form a resinized thin layer. The part (white opaque part d) is recognized. Also,
As can be seen from FIG. 5, undivided acrylic synthetic fibers also exist inside the sheet in the thickness direction of the molded article, and these are fine fibers which are entangled or divided by the undivided ones. Entangled with the article. The undivided fibers and the divided fine filaments existing inside these thickness directions are not fused together because the fibers are in close contact with each other and are simply and strongly pressed. In other words, even after being formed into a molded article, the inside of the sheet in the thickness direction of the sheet forming the same has a structure (having a large number of elongated voids extending in the length direction) which is almost the same as before the molding. Synthetic fibers are present. Furthermore, many spaces (for example, e) are included between the fibers.

As described above, on the inner and outer surfaces of the obtained tray, opaque portions resinified by the fusion of the fibers are recognized, and the fibers in the interior are fused but bonded. No part was found. No abnormalities such as deformation and breakage of the sheet were observed during molding, and the moldability was extremely good. Furthermore, unlike the tray made of synthetic resin, the obtained tray had a fabric-like texture. <Example 2> Except that the molding pressure was 5 kg / cm ² ,
A tray was manufactured in the same manner as in Example 1.

The obtained tray had no difference in appearance from the tray of Example 1 except that the fibers were fused on the inner and outer surfaces and a resin-translucent portion was clearly observed. . No abnormalities such as deformation and breakage of the sheet were observed during molding, and the moldability was extremely good. Furthermore, unlike the tray made of synthetic resin, the obtained tray had a fabric-like texture. Example 3 A tray was manufactured by molding a sheet having a basis weight of 120 g / m ² under the same conditions as in Example 1.

On the inner and outer surfaces of the obtained tray,
An opaque part resinified by fusion of the fibers is recognized,
The fibers inside were crimped but no fused parts were found. No abnormalities such as deformation and breakage of the sheet were observed during molding, and the moldability was extremely good. The inner surface, outer surface, and cross-sectional state of the obtained tray were almost the same as those in Example 1. Furthermore, unlike the tray made of synthetic resin, the obtained tray had a fabric-like texture. <Example 4> A sheet having a basis weight of 200 g / m ² was applied to a rolling mill (a linear speed of 4 m / min, consisting of two rolls having a smooth surface, and a surface temperature of 90 ° C) to be formed at a linear pressure of 60 kg / cm. To produce a calendered plate.

An electron micrograph showing the state of the inner side surface, outer side surface, and cross section of the obtained plate-like object is shown in FIG.
These are shown in FIG. 7 (590-fold) and FIG. 8 (630-fold), respectively. 6 and 7, the elongated white portion (eg, f) is a fiber, and the black portion (eg, g) is
It is a space surrounded by these fibers. As can be seen from FIG. 8, the surface portion is mainly made of divided fine filaments (for example, f), and the middle portion in the thickness direction is mainly
It is composed of divided fine filaments that are thicker than the surface (for example, h) and undivided acrylic synthetic fibers (for example, i). Further, the inside of the plate-shaped object in the thickness direction includes many spaces (for example, j) between the fibers.

That is, most of the acrylic synthetic fibers present on the front and back surfaces of the plate-like material are divided into fine filaments, and the fine filaments are dispersed and spread in one part and spread in another part. The bundles are bundled and converged, and it can be seen that these filaments are entangled with each other. In addition, it can be seen that these filaments are not fused but are closely adhered.

The shape retention, hardness, flexibility,
And the flexibility was sufficient as a packaging material for commodities. <Example 5> A sheet having a basis weight of 200 g / m ² was rolled into a rolling mill (linear velocity: 4 m / min, surface width: 0.4 mm, length: 2.6 m).
m, two embossing rolls having a height of 0.60 mm and arranged in a staggered manner, and subjected to a surface temperature of 90 ° C.) and molded at a linear pressure of 60 kg / cm to produce an embossed plate-like material. .

Electron micrographs showing the state of the protruding portions on the front surface, the back surface, and the cross section of the obtained plate-like material are shown in FIG.
FIG. 9 (590 ×), FIG. 10 (580 ×), and FIG.
12 (590), FIG. 13 (580), and FIG. 14 (370) show electron micrographs showing the state of the recessed portion at (226 times). Regarding the raised portion, in FIGS. 9 and 10, the elongated white portion (for example, f) is a fiber and the black portion (for example, g).
Is a space surrounded by these fibers. FIG.
As can be seen from FIG. 1, the surface portion is mainly composed of divided fine filaments (for example, f), and the middle portion in the thickness direction is mainly a divided fine filament that is thicker than the surface portion (for example, h). And undivided acrylic synthetic fibers (for example, i). Further, a very small space (for example, g) exists between the fibers in the surface portion of the plate-like material, and a large space (for example, j) exists between the fibers in the thickness direction inside.

That is, most of the acrylic synthetic fibers present on the front and back surfaces of the plate-like material are divided into fine filaments, and the fine filaments are dispersed and spread in one portion, and spread in another portion. The bundles are bundled and converged, and it can be seen that these filaments are entangled with each other. In addition, it can be seen that these filaments are not fused but are closely adhered.

As can be seen from FIGS. 12 and 13, the acrylic synthetic fibers present on the front and back surfaces of the plate-like material are mostly divided into fine filaments. Some parts are dispersed and spread, while others are bundled and converged.These filaments are entangled with each other, and the front and back surfaces of the plate-like material are pressed by the action of heat and pressure. Therefore, many portions where the fibers are fused (for example, k) are observed. FIG.
As can be seen from FIG. 4, in the thickness direction, the fibers are extremely tightly packed due to a high degree of compression, but there is a space (for example, 1) between the fibers.

This plate-like material was more flexible than that of Example 4, but was superior in shape retention.

[0057]

As described above, the molded article according to claim 1 is three-dimensionally formed by a sheet having a special structure formed of an acrylic synthetic fiber having a special structure. Since the fused portion of the fibers is present on at least one of the side surfaces, the shape retention is good. Further, inside the thickness direction, an elongated space of the fiber is formed.
There are many gaps and many spaces between fibers
Therefore, it has elasticity. Thereby, it is possible to provide a high-quality tray having a cloth texture unlike a synthetic resin product, a shoulder pad having an appropriate hardness that does not lose its shape, and the like. The method according to claim 2 comprises:
It is suitable as a method for producing the molded article according to claim 1.
You.

According to the third aspect of the present invention , the molded article is formed into a plate shape having a special cross-sectional structure by the sheet.
Since a plate having appropriate hardness, flexibility, and flexibility can be provided, it is useful as a packaging material such as a sheet-like cushion material or an interlining for clothing. Claim 4
Is a method for producing a molded article according to claim 3.
It is suitable.

[Brief description of the drawings]

FIG. 1 is an electron micrograph (× 4,000) showing a fiber shape in a cross section of an acrylic synthetic fiber constituting a molded article of the present invention.

FIG. 2 is an electron micrograph (× 4,000) showing a fiber shape in a longitudinal section of an acrylic synthetic fiber constituting a molded article of the present invention.

FIG. 3 is an electron micrograph (magnification: 235) showing the shape of a fiber on the inner surface of the molded article according to claim 1.

FIG. 4 is an electron micrograph (× 234) showing the shape of a fiber on the outer surface of the molded article according to claim 1;

FIG. 5 is an electron micrograph (177 times) showing a fiber shape in a cross section of the molded article according to claim 1;

FIG. 6 is an electron micrograph (590 ×) showing a fiber shape on the surface of a molded article according to claim 3 (Example 4).

FIG. 7 is an electron micrograph (590 ×) showing a fiber shape on the back surface of a molded article according to claim 3 (Example 4).

FIG. 8 is an electron microscope photograph (magnification: 630) showing a fiber shape in a cross section of a molded article according to claim 3 (Example 4).

FIG. 9 is an electron micrograph (590 times) showing the shape of a fiber on the surface of a molded article according to claim 3 (embossed portion of Example 5).

FIG. 10 is an electron microscope photograph (magnification: 580) showing a fiber shape on the back surface of the molded article according to claim 3 (embossed portion of Example 5).

FIG. 11 is an electron micrograph (× 226) showing a fiber shape in a cross section of a molded article according to claim 3 (embossed portion of Example 5).

FIG. 12 is an electron micrograph (590 times) showing the shape of a fiber on the surface of a molded article according to claim 3 (the concave portion of Example 5).

FIG. 13 is an electron microscope photograph (magnification: 580) showing the fiber shape on the back surface of the molded product according to claim 3 (the concave portion of Example 5).

FIG. 14 is an electron micrograph (magnification: 370) showing a fiber shape in a cross section of a molded article according to claim 3 (a concave portion in Example 5).

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Claims (4)

(57) [Claims] 1. A structure comprising an acrylic polymer containing 50% by weight or more of acrylonitrile units and having therein a plurality of elongated voids extending along the length direction, wherein the cross-sectional shape of the voids is unspecified. Is composed of acrylic synthetic fibers formed into a plurality of fine filaments, which are divided into a number of finer filaments, which are dispersed and spread in one part and bundled in another part. While the fibers are formed three-dimensionally by a sheet in which the fibers are integrated by entanglement with each other, the fused portion of the fibers is formed on at least one of the inner surface and the outer surface of the molded body. The elasticity and shape retention of acrylic synthetic fibers, characterized in that there are many elongated voids in the fibers and many spaces between the fibers inside the thickness direction .
A molded article having : 2. A structure comprising an acrylic polymer containing 50% by weight or more of acrylonitrile units, having therein a plurality of elongated voids extending along the length direction, wherein the cross-sectional shape of the voids is unspecified. Is composed of acrylic synthetic fibers formed into a plurality of fine filaments, which are divided into a number of finer filaments, which are dispersed and spread in one part and bundled in another part. And a sheet in which the fibers are integrated by entanglement with each other at a temperature of 150 to 200 ° C. and a pressure of 1 to 10 kg / c.
A method for producing a molded article made of acrylic synthetic fiber, characterized in that the molded article is formed three-dimensionally with m ² and a molding time of 1 to 60 seconds . 3. A structure comprising an acrylic polymer containing 50% by weight or more of acrylonitrile units, having therein a plurality of elongated voids extending along the length direction, wherein the cross-sectional shape of the voids is unspecified. Is composed of acrylic synthetic fibers formed into a plurality of fine filaments, which are divided into a number of finer filaments, which are dispersed and spread in one part and bundled in another part. While the fibers are formed into a plate by a sheet in which the fibers are integrated by entanglement with each other, at least one of the front and back surfaces of the plate-like material has a close contact portion of the fibers, and has a thickness. A molded article having elasticity and shape retention made of an acrylic synthetic fiber, characterized in that there are many elongated voids in the fiber inside the direction and many spaces between the fibers. 4. A structure comprising an acrylic polymer containing 50% by weight or more of acrylonitrile units and having therein a plurality of elongated voids extending along the length direction, wherein the cross-sectional shape of the voids is unspecified. Is composed of acrylic synthetic fibers formed into a plurality of fine filaments, which are divided into a number of finer filaments, which are dispersed and spread in one part and bundled in another part. And a sheet in which the fibers are integrated by entanglement with each other at a temperature of 90 to 150 ° C. and a linear pressure of 0.5 to 100 kg / c.
A method for producing a molded article made of acrylic synthetic fiber, characterized in that the molded article is formed into a plate by rolling with a metal roll at m .