JPH0639742B2 - Method of manufacturing a rigid sheet having moldability - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a method for producing a rigid sheet having moldability. More specifically, the present invention relates to a method for manufacturing a rigid sheet used for manufacturing core materials such as shoes and bags or various cases by molding.

<Prior Art> Currently, pulp boards and film boards are used as materials for core materials such as shoes and bags and various cases. As a board used for these purposes, it has high rigidity to ensure shape retention when it is made into a product, has heat resistance, has no delamination when wet, and has some hygroscopicity. Furthermore, it is desirable to have a light and beautiful appearance. Further, when a product is formed by molding, moldability, especially large deformability, is required. From this point of view, the above-mentioned conditions are not sufficiently satisfied by a conventional pulp board formed by solidifying a pulp with a resin and a plastic board which is a plastic thick film containing a large amount of filler. That is, the pulp board has high rigidity when dried, and has heat resistance and hygroscopicity, but when wet, the rigidity is reduced and delamination is likely to occur, it is weak against bending, and the moldability of large deformation is poor. On the other hand, the plastic board has the characteristics of high moldability and high strength, but has the drawback that it is heavy, has no hygroscopicity, and has poor tactile sensation.

Various proposals have been made to provide a board which eliminates the drawbacks of the pulp board and the plastic board. For example, in JP-A-58-46183, a non-woven fabric is coated or impregnated with a polymer foam which is foamed 1.1 to 10 times at a solid content weight ratio of 1: 0.3 to 10. , A core material composed of an integrally obtained sheet is disclosed. Although this core material has water resistance and a certain degree of moldability, it has a resin plate-like feel because the resin floats on the surface, tends to show chalk marks, and has a low elongation as a sheet, which causes a large deformation. There is a problem that it is not moldable and is considerably heavy.

On the other hand, a non-woven fabric having excellent thermoformability, that is, a large deformation formability, was filed by the same applicant as the applicant of the present invention under the name "nonwoven fabric having high elongation without heat shrinkage" (special No. 59-50185).
Although this non-woven fabric is excellent in thermoformability, it cannot be used for the above-mentioned applications because of its low rigidity.

<Problems to be Solved by the Invention> As is clear from the above, in the case of conventionally known boards or sheets, the conditions are comprehensively satisfied when manufacturing core materials such as shoes or bags or various cases by molding. There is a problem that it cannot be done. The present invention solves such problems and has rigidity, water resistance, folding resistance and lightness,
Moreover, it is an object of the present invention to provide a method for producing a rigid sheet that does not easily generate chalk marks and can be subjected to large deformation molding under heating without using a resin.

<Means for Solving Problems> As a result of earnest research to solve the above-mentioned problems, the inventors of the present invention produced a non-woven sheet using polyester filaments having a specific performance, and made the non-woven sheet. It was found that a rigid sheet capable of comprehensively satisfying the conditions as the above-mentioned board or sheet can be produced by carrying out the two-step heat treatment of 1.

That is, an object of the present invention is to provide a breaking elongation of 100% or more, a boiling water shrinkage of 5% or more, a fiber cross section having a circular cross section with a radius R, and an average refractive index at the center thereof is n | (0), 0 from the center. When the average refractive index in a portion of the distance .8R and n‖ (0.8), n‖ (0 ) ≦ 1.64 in and {n‖ (0.8) -n‖ (0 )} ≧ 5 × 10 - ³ Producing a non-woven web using substantially 100% of filled polyethylene terephthalate filaments; a temperature of 70-130 ° C., a linear pressure of 5-5 between the first roll pair of which at least one is an embossing roll. Applying a plurality of partial thermocompression bonding parts to the nonwoven web by passing it under the condition of 90 kg / cm; and optionally arranging with a gap at least narrower than the thickness of the nonwoven web having the partial thermocompression bonding parts. A first roll between a second roll pair having the following surface states: Passing a nonwoven fabric web having the partial thermocompression bonding portion under a temperature condition of at least higher than the pairwise treatment temperature to form a fiber-welded layer on the surface of the nonwoven fabric web. This is achieved by a method of manufacturing a rigid sheet having moldability.

Hereinafter, the present invention will be specifically described with reference to the accompanying drawings showing an example of a rigid sheet having moldability obtained by carrying out the present invention.

FIG. 1 is a perspective view showing an example of a rigid sheet having moldability (hereinafter simply referred to as a rigid sheet) obtained by carrying out the present invention. As shown in FIG. 1, the rigid sheet 1
Consists of a non-woven fabric formed from a plurality of polyester filaments 7. A plurality of recesses 2 are provided on one surface of the rigid sheet 1, and in the bottom region 3 of the countless recesses, polyester filaments constituting the non-woven fabric are resinified and integrated to form a hard portion. On the other hand, inside the portion 4 in which the concave portion is not provided, the polyester filaments constituting the non-woven fabric substantially maintain the fiber state, and as a result, the volume of the rigid sheet is maintained and the cushioning property is imparted. Then, as better shown in the cross-sectional view of FIG. 3, the polyester filaments are fused to each other on both side surfaces 5 and 6 of the rigid sheet 1 to form film-like surface layers 53 and 54, and therefore The surface is smooth and no fluff is generated.

The resinized bottom region 3 and the film-like surface layers 53, 54
By providing the rigid sheet 1, the rigid sheet 1 has rigidity exceeding that of a conventionally known board. Further, since the rigid sheet 1 is made of a non-woven sheet made of polyester filaments, and the film upper surface layers 53 and 54 are formed, it has water resistance. Further, since the resin-formed bottom region 3 and the film-like surface layers 53 and 54 are present and the portion 4 that substantially supports the film-like surface layers 53 and 54 from inside is maintained in a fibrous state, folding endurance is improved. Excel. Further, since most of both ends of the polyester filament 7 in the portion 4 in which the fiber state is substantially maintained are restrained by the bottom region 3, the rigid sheet 1 manufactured by the method of the present invention.
Does not cause delamination. Further, since the rigid sheet 1 manufactured by the method of the present invention does not use a resin in its manufacturing, the manufactured rigid sheet does not have a resinous feel and does not generate a choke mark. Further, as the polyester filaments used in the production of the rigid sheet, a specific fiber having a property of being easily stretched under heating as described later is used, and the fiber state is substantially maintained.
By having, it has a large deformability.

The shape and arrangement of the recesses in the rigid sheet 1 are not limited to those shown in FIGS. 1 and 3, and may be freely selected. That is, the cross-sectional shape of the recess may be any shape such as square, rectangle, and circle, and the arrangement thereof may be staggered or lattice-shaped. However, it is more preferable that the recesses having the above-described shape are regularly arranged. The concave portions may be continuously arranged in a line. The size of the recess is usually about 0.1 to ²⁰ mm ² , and the area ratio of the portion provided with the recess to the entire surface of the rigid sheet 1 is in the range of 5% to 75%. You can select it.

The bottom region 3 in the rigid sheet 1 is not limited to being provided in contact with the surface layer 54 side as shown in FIG. That is, other than that, as shown in FIG.
It may be provided at a substantially intermediate portion between 3, 54.

In carrying out the present invention, as a polyester filament having the above-mentioned specific performance, a breaking elongation of 100% or more,
The shrinkage rate of boiling water is 5% or more, the fiber cross section has a circular cross section with a radius R, and the average refractive index of the central portion is n ∥ (0), and 0.
Assuming that the average refractive index at the distance of 8R is n || (0.8), n | (0) ≤1.64 and {n | (0.8) -n ||
Which comprises using a ³ Polyethylene terephthalate filament satisfying - (0)} ≧ 5 × 10. A non-woven sheet made of such long fibers (hereinafter simply referred to as “polyester shrinkable non-woven sheet”) will be referred to by the applicant of the present invention under the name of “non-woven sheet having high elongation with improved thermal deterioration”. Japanese Patent Application No. 59-50184 filed on March 17, 59
Are disclosed in the specification.

In carrying out the present invention, the polyester shrinkable non-woven sheet is used as an intermediate non-woven sheet, that is, a non-woven sheet after the completion of the first step in the method for manufacturing a rigid sheet described below.

The polyester shrinkable non-woven sheet is obtained by melt spinning polyethylene terephthalate, and by rapidly stretching it under cooling immediately after spinning, the outer layer portion is rapidly cooled and the crystallinity and molecular orientation become larger than the center and the average refractive index increases. It is made by using polyethylene terephthalate continuous fibers having a two-layer structure that satisfies the above-mentioned conditions shown by the ratio.

By using the polyester filaments having the specific performance, the rigid sheet produced by the production method of the present invention has a high elongation at break, a low softening point, and the property of being easily flattened by heat. It has a structure as illustrated in the drawings and FIG. 4 and has excellent performance as described above, and can be used for large deformation molding.

If a rigid sheet is to be made using polyester filaments having a higher degree of crystallinity than the above range, it is necessary to perform heat treatment near the melting point, and as a result, the film-like surface layer is hard and the rigid sheet It is also brittle and can only make things that break easily.

On the other hand, when a rigid sheet is made using polyester long fibers having a performance depending on the crystallinity lower than the above range, the heat resistance is poor due to the low degree of crystallinity / orientation, and as a result, the film-like surface layer When forming 53 and 54, the fibers become fragile and brittle due to heat, while in the part 4 where the recess is not provided, the fibers are thermally bonded to each other, and as a result, the tear strength of the rigid sheet is reduced and the elongation disappears. As a result, it becomes impossible to perform a large deformation molding process.

Acrylic or PVA for coloring the rigid sheet
The non-woven fabric sheet may be provided with a pigment mixed with a resin. At that time, it is preferable that the adhesion amount is 30% or less.

Next, a method of manufacturing the rigid sheet having moldability of the present invention will be described.

The manufacturing method of the present invention comprises the steps of forming a web of polyester filaments having the above-mentioned specific properties, and forming a plurality of recesses, that is, partial thermocompression-bonded parts by hot embossing on the web to form the intermediate nonwoven sheet. It comprises a first heat treatment step and a second heat treatment step in which the surface of the intermediate non-woven sheet is thermocompression-bonded by a pair of rollers provided with a preset gap to form a rigid sheet having moldability.

As a method for producing a web from long fibers, various conventionally known methods can be used. However, it is more preferable to form the web by using a so-called spunbond method, in which each single fiber is opened and laminated immediately after spinning the long fibers to form a web.

In the first heat treatment step, a roll temperature of 70 to 130 ° C., preferably 90 ° C. to 120 ° C. is used for the web using a pair of embossing rolls having protrusions on at least one surface thereof.
Linear pressure at the temperature of 5 to 90 kg / cm, preferably 20 to 70
This is a process of thermocompression bonding under kg / cm. The processing speed in this case is in the range of 3 to 50 m / min, more preferably 5 to 30
It is recommended to select in the range of m / min. Thus, the above-mentioned intermediate nonwoven sheet is obtained. This intermediate non-woven sheet 1'is the second
As shown in the figure, the polyester filaments 7 constituting the non-woven sheet 1'are constrained by the bottoms 3 of the plurality of recesses, but the filaments on the surfaces 51 and 52 of the non-woven sheet 1'are not welded. However, as shown in an exaggerated manner in FIG. 2, a part 71 of the long fibers is exposed on the surface in a fluffy shape, and the stretchable nonwoven sheet 1'is formed.
It itself is flexible and does not have rigidity.

The intermediate non-woven sheet 1'in this state is the above-mentioned Japanese Patent Application No. 59-59.
Substantially the same as the nonwoven sheet with improved high elongation of thermal degradation disclosed in -50184.

As a pair of rollers for forming the concave portion of the non-woven sheet 1 ', an embossing roller is usually used in the upper part and a smoothing roller is used in the lower part. However, by using embossing rollers for both the upper roller and the lower roller and arranging the convex portions correspondingly, the bottom region 3 of the concave portion may be provided at the substantially central portion of the pressure of the non-woven sheet 1 '(first (See Fig. 4).

The shape and arrangement of the convex portion of the embossing roller may be arbitrarily selected and used according to the application of the manufactured rigid sheet. That is, the cross-sectional shape of the convex portion can be an arbitrary shape such as a square, a rectangle, and a circle, and the arrangement thereof can be an arbitrary arrangement such as a zigzag pattern or a lattice pattern. In addition, an embossing roller having a convex portion that satisfies the conditions described in the above description of the concave portion of the rigid sheet can be used.

In the second heat treatment step, a pair of rollers arranged such that the gap between the rollers of the intermediate nonwoven sheet 1'is set to 80% or less, preferably 70% or less of the thickness of the intermediate nonwoven sheet 1 '. Roll between 130 ° and 210
℃, preferably 150-180 ℃, speed 3-50m / mi
In this step, the surface of the intermediate nonwoven sheet 1'is smoothed by thermocompression bonding under n, preferably 5 to 30 m / min to form film-like surface layers 53 and 54 as illustrated in FIG. The surface of the roller may be smooth, or may have a satin pattern, a silk pattern, or the like. In the case of Tashishi satin pattern, the depth of the groove is preferably 100 μm or less.

Thus, the rigid sheet having moldability obtained by the manufacturing method of the present invention is a sheet that can satisfy the performance required as a board such as rigidity comprehensively and can be molded with large deformation. Therefore, it is used for the insole material 21 of the sports shoe 20 shown in FIG. 7a (the insole material 21 is molded so as to be curved at the portion 22 as shown in FIG. 7b) and the core material of the bag shown in FIG. And exhibit excellent performance. Further, it can be used for manufacturing a molded case or the like by performing so-called deep drawing by utilizing the fact that large deformation can be molded.

Next, the definitions and / or measuring methods of the properties described in various places in the present specification will be collectively described below.

◎ Circular cross section of fiber The cross section of the constituent fiber in the present specification may be a perfect circle, a flat circle within a range not impairing the object of the present invention, or a shape having star-shaped irregularities. Here, the circular cross section in the present invention means that the circumscribed circle and the inscribed circle have radii R ₁ and R ₂ with respect to the cross-sectional shape (R ₁ = R _{2 in} the case of a perfect circle),
The value of the ratio is 1.0 to 1.1, and the radius R is represented by (R ₁ + R ₂ ) / 2, and the center is the straight line connecting the center of the circumscribed circle and the center of the inscribed circle. Say a point.

◎ Observed from the side of the fiber by the interference fringe method, using an average bending ratio (n ∥, n ⊥) and an average birefringence transmission quantitative interference microscope (for example, Interferco, an interference microscope manufactured by Carl Zeiss Jena of East Germany). The average refractive index distribution can be measured. This method applies to fibers having a circular cross section.

The index of refraction of a fiber is characterized by the index of refraction n‖ for polarized light having an electric field vector parallel to the fiber axis and the index of refraction n⊥ for polarized light having an electric field vector perpendicular to the fiber axis.

The measurements described here are all green light (wavelength λ = 549 m
μ) is used.

The fiber uses an optically flat slide glass and cover glass, has a refractive index (N) that gives a shift of interference fringes within the range of 0.2 to 2 wavelengths, and is an inactive encapsulation for the fiber. It is immersed in the agent. A few fibers are dipped in this encapsulant so that the single yarns do not come into contact with each other. Furthermore, the fibers should have their fiber axes perpendicular to the optical axis of the interference microscope and the interference fringes. This interference fringe pattern is photographed and magnified about 1500 times for analysis.

The refractive index of the fiber encapsulant is N, and the point S'- on the outer circumference of the fiber
Refractive index n ‖ (or n ⊥) between S ″, thickness t between S ′ and S ″, wavelength of used light beam is λ, background parallel fringe spacing (corresponding to 1 λ) is D, and fiber interference fringes The optical path Γ is represented by Γ = d / Dλ = (n‖ (or n⊥) -N) t, where d is the deviation of

Assuming that the radius of the fiber is R, the optical path difference at each position from the center R _{0 of} the fiber to the outer circumference R indicates the refractive index of the fiber at each position n
The distribution of (or n⊥) can be obtained. When r is the distance from the center of the fiber to each position, X = r / R = 0,
That is, the refractive index at the center of the fiber is defined as the average refractive index (n / |
₍₀₎ or n⊥ ₍₀₎ ). X has a value of 1 on the outer circumference and a value in the range of 0 to 1 at other portions. For example, the refractive index at the point of X = 0.8 is n ∥ _(0.8) (or,
n⊥ _(0.8) ). The difference between the inner and outer layers of the average refractive index (n || _{) of the} fiber is expressed as n | _{( 0.8)} -n | ₍₀₎ . Further, the average birefringence (Δn) is Δ from the average refraction index n ∥ _(n) and n ⊥ _(0).
It is represented by n = n / ₍₀₎ -n / ₍₀₎ .

◎ Boiling water shrinkage ratio If the sample length under a load of 0.1 g / d is set to L ₀ , the load is removed and the sample is treated for 30 minutes in boiling water, and again the sample length measured under the same load is set to L, boiling water Shrinkage is It is represented by.

◎ Matching weight Take a test piece of 20 cm x 20 cm, weigh it, and convert it into a weight.

◎ Thickness Measure at least 3 points using a dial gauge with a load of 100 g / m ² and express the average value.

◎ Fracture strength and elongation Measured with an Auto Graph DSS-2000 type universal tensile tester manufactured by Shimadzu Corporation at a gripping length of 10 cm and a tensile speed of 20 cm / min.

◎ Tear strength (Pendulum method) A 6.5 cm x 10 cm test piece is placed in the vertical and horizontal directions, 3 each
The maximum load shown when tearing was done using an Elmendorf tear strength tester after taking more than one sheet and being torn is represented by the average value in each of the vertical and horizontal directions.

◎ Abrasion resistance A test piece measuring 20 cm in length and 3 cm in width was rubbed 100 times with a friction tester type II (Gakushin type) under a load of 500 g, and then the appearance change of the test piece was checked according to the following criteria. It was judged and used as a guide for wear resistance.

(Judgment Criteria) Class A: No fuzz at all.

Class B: Some feathering, but not noticeable.

Class C: Conspicuous fuzz.

◎ Softening temperature The softening temperature is indicated by the temperature when the wear resistance is class A by thermocompression bonding between a pair of smooth rolls at a linear pressure of 20 kg / cm ² .

◎ HR-1 (Heat deterioration by exposure to high temperature for a long time) 10 fibers in the web are cut into a length of 30 cm, and treated in a hot air dryer at 160 ° C for 5 minutes without tension. A tensile test is performed on the five fibers that have been subjected to this heat treatment, and the average value of the breaking elongations is determined and is designated as L ₁ . Next, the remaining 5 fibers are left in the same hot air dryer at 150 ° C. for 300 hours, and then similarly subjected to a tensile test to obtain an average value of elongation at break, which is L ₂ . The elongation retention rate L ₂ / L ₁ × 100 at this time was used as a measure of thermal deterioration.

◎ Flex resistance A 4 cm x 10 cm sample is prepared, and this sample is folded in two and repeated 10 times to determine the appearance.

(Judgment Criteria) Class A: The appearance quality does not change Class B: Bending wrinkles are slightly visible but inconspicuous C Class: Bending wrinkles are conspicuous and the structure is partially destroyed ◎ Stiffness (bending anti-friction) JIS-L-1096 Bending repulsiveness A method (Gurley method)
Judge by That is, a 4.5 cm × 10 cm sample is made vertically and horizontally and measured using the Gurley test.

The bending resistance after water impregnation is obtained from the measured value after the sample is immersed in water for 24 hours.

◎ Moldability The moldability of the sample is evaluated using the equipment shown in Fig. 5.
That is, a mold 11 having a hemispherical concave portion corresponding to a plug 11 having a hemispherical tip and a tip is prepared, and a sample 10 is attached to the frame 1
It is fixed on the die 12 by 3. The plug 11 and the mold 12 have been heated to 150 ° C., and in this state, the plug 11 is pressed into the concave portion of the mold to be pressed into a hemispherical shape. After that, the hemispherical shape is given to the sample by removing the sample 10 from the mold 12 and leaving it. The height (h) of the hemispherical portion of the shaped sample shown in FIG. 6 is measured, and the moldability is evaluated by setting the ratio of the value and the depth (h ₀ ) of the concave portion of the mold to the molding set rate. I used it as a guide.

Molding set rate = h / h ₀ × 100 Measuring condition h ₀ : 30 mm Temperature: 150 ° C Pressure: 50 kg / cm ² hours: 30 sec The higher the molding set rate, the better the moldability, and the molding set rate 0 In the case of, the sample cannot be molded at all.

<Examples> Examples of the production method according to the present invention and physical properties of a rigid sheet having moldability produced by the production method will be described below in comparison with those of various conventionally known boards.

Examples 1 to 3 and Comparative Examples 4 and 5 First, the performance of polyester filaments used in carrying out the production method of the present invention is shown by changing the production method of the fibers.

Using a rectangular spinneret with a hole diameter of 0.25 mm and 1000 holes, polyethylene terephthalate with an inherent viscosity of 0.75 at a discharge rate of 850 g / min was spun at a melting temperature of 290 ° C., from the spinneret to the air sucker for traction. The distance (HD) and the spinning speed were changed, and the web was collected on a wire net to take out a uniform web.

In this case, at a position 300 mm directly below the spinneret, the temperature was 13 ° C from the cold air chambers placed on both sides of the filament group.
Of cold air, blowing zone length (l) 70 mm, blowing angle
Under the condition of (θ) 35 °, it was sprayed uniformly at a cold air velocity of 0.8 m / sec.

Table 1 shows the relationship between the microstructural features and the physical properties of the fibers constituting the obtained web. Examples 1 to 3 in the table are fibers of the present invention, and Comparative Examples 4 and 5 are fibers outside the scope of the present invention.
That is, in Comparative Examples 4 and 5, HD was used without using cold air.
And a fiber when a web having a predetermined spinning speed is obtained by appropriately changing the air-sucker pressure-bonding amount. The results obtained are shown in Table 1.

From Table 1, it can be seen that the fibers used in the present invention of Examples 1 to 3 have sufficient breaking elongation, refractive index, thermal characteristics, and thermal deterioration. On the other hand, it is understood that the fibers of Comparative Examples 4 and 5 outside the condition of the fiber used in the present invention are insufficient in any of the above-mentioned characteristics.

Examples 6 to 8, Comparative Examples 9 and 10 Using the polyester fibers of Examples 1 to 3 and Comparative Examples 4 and 5, a nonwoven sheet web having a basis weight of about 250 g was uniformly arranged as the first heat treatment step. Upper embossing roll having convex portions (upper surface area of convex portions 0.2 mm ² , height of convex portions 0.
7 mm) and a lower roll having a smooth surface.
In this case, the ratio of the thermocompression bonding portion was 12%, the temperature of the upper and lower rolls was 110 ° C., and the linear pressure was 20 kg / cm. However, only Comparative Example 10 was performed at an upper and lower roll temperature of 235 ° C.

The obtained intermediate nonwoven sheet was subjected to a second heat treatment step by using upper and lower rolls having a smooth surface and a temperature of the upper and lower rolls of 190.
℃, the gap between the upper and lower rolls to the intermediate nonwoven sheet thickness 70
%, And the surface was thermocompression bonded. Taishi Comparative Example 10
The temperature of the upper and lower rolls was 235 ° C. Comparative Example 9 was the second heat treatment step and could not be taken out as a sheet because the heat resistance was significantly deteriorated. Table 2 shows the physical properties of the non-woven sheets obtained in the actual examples and the comparative examples.

From Table 2, the non-woven sheets of Examples 6 to 8, that is, the rigid sheets produced by the method for producing a rigid sheet having moldability according to the present invention, have high breaking elongation and tear strength, and have excellent flex resistance and wear resistance. It turned out to be excellent in sex. In particular, the most important physical properties as a rigid sheet, that is, rigidity (bending half-plyness) and moldability, are markedly superior to the comparative examples.

Examples 11 to 16 and Comparative Example 17 Next, under the manufacturing conditions of Example 6, the shape and arrangement of the protrusions of the upper roll in the first heat treatment step were changed as shown in Table 3, and the second heat treatment was further performed. Change the surface condition of the upper roll and the gap between the upper and lower rolls in the process as shown in Table 4,
The rigid sheets of Examples 11 to 16 were manufactured by combining them in various ways. On the other hand, Comparative Example 17 is a non-woven sheet obtained by subjecting the fibers of Example 1 shown in Table 1 above to needle punching and then passing them through a second heat treatment step. The needle punch condition in this case was to use a # 40 needle with a protrusion depth of 13
mm, and the number of punches is 200 times / cm ² . The physical properties of the non-woven sheets obtained in Examples and Comparative Examples were evaluated, and the results are shown in Table 5.

From Table 5, it can be seen that changing the conditions for the rolls as shown in Tables 3 and 4 does not change the physical properties of the rigid sheet so much.

This indicates that when the rigid sheet is manufactured, the appearance of the rigid sheet can be arbitrarily changed according to the end use.
On the other hand, in Comparative Example 17 in which the needle punch was used instead of the first step, it was found that the rigidity (bending repulsion) was inferior.
This is because Comparative Example 17 does not have the partial thermocompression bonding portion (bottom region 3 shown in FIG. 1).

Performance comparison with a known board (Example 12, Comparative Example 18-
20) Next, regarding each physical property required as a rigid sheet, the rigid sheet of Example 12 described above and various commercially available boards,
That is, a short fiber non-woven fabric processed by resin (Comparative Example 1
8), valve board (Comparative Example 19), and PVC film (Comparative Example 20). The results obtained are shown in Table 6.

From Table 6, the rigid sheet made by the manufacturing method of the present invention has a lighter weight per thickness than various commercially available boards,
It is clear that it has high rigidity, is excellent in bending resistance and water resistance, and is excellent in terms of moldability and generation of choke marks.

<Effects of the Invention> Since the method for producing a rigid sheet having moldability of the present invention is configured as described above, the rigid sheet produced by this production method has sufficient rigidity and is
It is fold-resistant and light, and because no resin is used as a binder between fibers, it does not generate chalk marks, has no resinous feel, and has moldability that cannot be achieved with conventional boards. Therefore, the rigid sheet produced by the production method of the present invention exhibits excellent performance when used in shoes, bags, etc., and also in molded products with large deformations that cannot be achieved using conventional boards. Can be used.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a rigid sheet having moldability obtained by the manufacturing method of the present invention. FIG. 2 is a cross-sectional view of the nonwoven sheet after the first heat treatment step in the manufacturing method of the present invention is applied. FIG. 3 is a sectional view of the rigid sheet taken along the line III-III in FIG. FIG. 4 is a sectional view similar to FIG. 3, showing another embodiment of the rigid sheet having moldability obtained by the manufacturing method of the present invention. 5 and 6 are schematic diagrams for explaining the moldability test method, and FIG. 5 shows an instrument used for the moldability test,
FIG. 6 shows the shape of the molded board. FIG. 7a, FIG. 7b and FIG. 8 are views showing a product using a rigid sheet having moldability obtained by the manufacturing method of the present invention, and FIG. 7a shows that the rigid sheet is used as an insole. FIG. 7 is a perspective view of the sports shoe shown in FIG.
FIG. b is a perspective view of the molded insole member, and FIG. 8 is a perspective view of a bag using a rigid sheet as a core member. 1 ... Rigid sheet having moldability, 2 ... Recessed portion, 3 ... Bottom region (partial thermocompression bonding portion), 4 ... Portion not provided with recessed portion, 5, 6 ... Surface of rigid sheet, 7 ... ... Polyester long fibers, 53,54 ... film-like surface layer.

Claims (1)

[Claims] 1. A breaking elongation of 100% or more, a boiling water shrinkage of 5% or more, a fiber cross section having a circular cross section with a radius R, and an average refractive index at the center thereof is n.parallel. (0), 0.8R from the center. Assuming that the average refractive index in the part of distance is n ‖ (0.8), n ‖ (0) ≤
Substantially ten polyethylene terephthalate continuous fibers satisfying 1.64 and satisfying {n / (0.8) -n / (0)} ≧ 5 × 10 ⁻³
0% to produce a nonwoven web; a temperature of 70 to 130 ° C. and a linear pressure of 5 to 90 kg between a first pair of rolls, at least one of which is an embossing roll.
A plurality of partial thermocompression bonding portions to the non-woven web by passing the non-woven web under a condition of / cm / cm; The nonwoven fabric web having the partial thermocompression bonding portion is passed between the second roll pair having the surface condition under a temperature condition at least higher than the treatment temperature of the first roll pair, and the fiber welding layer is formed on the surface of the nonwoven fabric web. And a step of forming a rigid sheet having moldability.