JPS6037230B2 - Artificial leather - Google Patents

Description

[Detailed description of the invention] This invention relates to artificial leather.

More specifically, the present invention relates to artificial leather obtained by filling a rubber-like elastic polymer into a nonwoven fabric structure mainly composed of ultrafine single fibers. The following properties are generally required for a nonwoven fabric structure for artificial leather that resembles natural leather. m. Must have a delicate and uniform fluff and an elegant lighting effect. '2
} It must be flexible and have a certain strength even if it is thin.

Conventionally, an attempt to create such a non-woven fabric structure has been disclosed, for example, in Japanese Patent Publication No. 47-44605.

As shown in Figure 3, this nonwoven fabric basically has a single fiber density of 0.001 to 0.5 denier and a single fiber count of 5 to 20.
Equipped with a base material layer composed of an entangled body made of ultrafine fibers East 2A within the range of 0 and a polymeric elastic body mainly made of polyurethane 4 filled in the fiber gaps of this entangled body,
On the surface of this base material layer, the raised layer 3A of the fiber east was present. However, in such a normal nonwoven structure, although the single fiber grade of the basic constituent fibers of the entangled body constituting the base material layer is limited to a small value, the number of single fibers is 5 to 200 ultrafine fibers. Therefore, the nape layer 3A formed by raising the nape becomes substantially tuft-shaped (east-shaped) as shown in Fig. 3.
In terms of shape, it is similar to collagen fibers of natural leather, but because the density of the fibers is extremely low, it does not have the delicate and uniform fluff of the artificial leather characteristic requirement item {1'. Particularly in the case of products with short fluff, there is a problem in that the polymeric elastic body 4 is directly exposed on the surface of each napped area of the fluff layer 3A, resulting in a coarse leather-like appearance and feel. In addition, since the base material layer is basically composed of an entangled body consisting only of the fiber Togai 2A, even if it has flexibility, it does not meet the requirements for the thinness of the artificial leather property requirements (2). For example, in the case of clothing applications, it is desirable that the thickness of artificial leather be one layer or less from the viewpoint of drapability, but such an entangled body made only of ultrafine fiber East 2A cannot be used. Sufficient strength could not be obtained for thin fabrics.There was a problem in that the areas subject to strong bending, such as seams, were extremely prone to tearing.On the other hand, this non-woven fabric using ultra-fine fiber Higashi also had problems in its manufacturing process. Was.

The nonwoven fabric disclosed in Japanese Patent Publication No. 47-44605 uses sea-island fiber as a raw material, passes it through a guard and a cross wrapper to form a sheet, and then needle-punches this sheet to form an entangled body. , is produced by extracting or decomposing and removing the sea components of this sea-island fiber to form ultra-fine fibers. In addition, a method is disclosed in Japanese Patent Publication No. 41-3759 in which, instead of this sea-island fiber, mixed fibers made of blended paper yarn are used to form an entangled body in the same manner as described above, and one of the components is extracted with a solvent or subjected to decomposition treatment to form ultrafine fibers. However, in either case, a chemical treatment is performed after molding the composite body to transform the fibers of normal thickness into ultra-fine fibers, which has the disadvantage of complicating the manufacturing process. At the same time, in such a manufacturing method, the obtained ultrafine fibers end up having an eastern shape, so that the disadvantages in physical properties of nonwoven fabrics using the above-mentioned eastern shaped ultrafine fibers cannot be avoided. On the other hand, even if there were other methods for producing ultra-fine fibers, if random ultra-fine single fibers with no eastern shape were used from the beginning, they would not pass through the carding machine, and when needle-punched, the fibers would fall off due to burps, making them unsatisfactory. Since an entangled body could not be obtained, a complicated process was adopted in which sea-island fibers or blended fibers of normal grade were initially used, and after the entangled body was formed, they were made into ultra-fine fibers. The use of Toga microfibers in conventional nonwoven fabrics is therefore thought to have arisen as a result of the aforementioned manufacturing process limitations, rather than being based on the positive advantages of Toga morphology, and was originally Therefore, there was a strong demand for the use of random ultrafine fibers. In addition, during the above-mentioned production, the step of integrating the ultrafine single fibers cannot be omitted, and even if a sheet-like material without three-dimensional entanglement due to entangled bodies is filled with a polymeric elastic material, it becomes paper-like and cannot be put to practical use. do not have.

However, the use of a needle punch as the entangling means was not preferred because it could damage the entangled body components and cause insufficient strength. As a result of further studies to solve these problems, the inventors discovered that even a non-straight ultrafine monofilament fiber aggregate can be combined with an appropriate interlining by entangling it with a suitable interlining. By setting the ratio of the interlining weight to a constant value, a three-dimensional entangled body with sufficient strength even though it is thin can be obtained, and this entangled body can be used as a base material layer and filled with a polymeric elastic material. The artificial leather is completely delicate and
It has been found that a uniform fluff layer can be obtained.

This invention relates to a fiber aggregate formed by melt-blown ultrafine single fibers having an average fiber diameter of 0.1 to 5.0 m, which are substantially separated into single fibers and intertwined with each other in three dimensions; It consists of an interlining made of buried bran fabrics, and some of the short fibers of this aggregate intertwine with the fibers that make up this interlining or (and) penetrate through the gaps in the fiber structure of this interlining. , the fibers constituting this interlining are integrated with each other without substantially damaging them, the entanglement strength of this entangled body is at least 50 mm, and the ratio of the basis weight of this aggregate to the basis weight of the interlining of the parentheses. is 1.5 or more, the interstitial spaces of this tangled body are filled with a polymeric elastic material, and at least one surface thereof has a nap layer made of ultrafine fibers constituting this tangled body. It's leather.

The present invention will be specifically illustrated and explained in detail below.

Before being impregnated with the rubbery fiber polymer of the present invention, the nonwoven fabric has a cross-sectional structure as shown in FIG.

In FIG. 1, an ultrafine single fiber aggregate 2 is arranged on both sides of an interlining 1 made of a knitted fabric, and this ultrafine short fiber aggregate is made up of ultrafine fibers 14 intertwined with each other in a three-dimensional manner, and The fibers constituting the above-mentioned aggregate become entangled with the fibers constituting the interlining, or (and) become tightly entangled by inserting or threading through the fiber structure, stitches, interfiber voids, etc. of the interlining. are doing. FIG. 1A is a diagram showing a mode in which the ultrafine short fiber aggregate and interlining are highly entangled,
The mouth is a diagram showing a mode in which the degree of entanglement is low. FIG. 2 shows the cross-sectional structure of the artificial leather of the present invention, and the short fiber aggregate 2, interlining 1, and their intertwined and intertwined states are the same as in FIG. 1.

In FIG. 2, 3 indicates the fluff of the ultrafine single fibers, and 4 indicates the rubber-like elastic polymer filled in the gaps between the fiber structures. Figure 3 shows
This figure shows the cross-sectional structure of a conventional raised nonwoven fabric, and since it is a tangled body of fibers East 2A, its fluff is also East 3A.

In this invention, the average fiber diameter of the ultrafine short fibers is 0.1
~5.0 Buddha skin is required.

Not only can a soft and moist leather-like texture be obtained for the first time under 5.0 mm, but also graceful chalk marks appear even with extremely short fluff (50 r skin or less), regardless of the fluff length. A dense surface condition is achieved with excellent writing effects that could never be obtained with conventional fiber fluff.

As understood from the model structure of natural leather in Figure 4,
The thickness of the constituent fibers and fiber east becomes thinner as it approaches the grain side from the thick fiber east, which is made up of thick fibers on both sides of the meat.

In contrast to rough-textured suede leather with thick fluff 3C obtained by raising the flesh side surface, nubatsu leather with fine fiber east fluff 3B obtained by raising the silver side has a rough texture. It is considered to be a luxury item among leather products. The non-woven fabric structure of the present invention is a highly valuable structure having an ultra-nubuck-like surface whose surface is densely covered with fluff made only of ultrafine monofilament paper with a runout of 5.0 or less. However, if the average fiber density of the ultra-fine single woven fibers is less than 0.1, the surface fuzz tends to break, making it unsuitable as a product.
Any fiber can be used in this invention as long as it has fiber-forming ability.

Examples include polyester, polyamide, polyolefin, polyacrylonitrile, copolymers and blends thereof. The three-dimensionally intertwined ultrafine short fiber aggregate as used in the present invention is a state in which single fibers that are not in the fiber east state are substantially entangled not only in the planar direction of the sheet but also in the thickness direction. To achieve the purpose of this invention, excessive three-dimensional entanglement must be avoided.

The proper entangled state can be indicated by the entangled strength and high density of the ultrafine short fiber aggregate. The tensile strength refers to the tensile strength at a thickness of 0.6 of a three-dimensional intertwined body of ultrafine single stitches forming the outer layer of a nonwoven structure, and in this invention, the following The values measured in the following manner are used.

That is, out of a simple laminated sheet of the ultrafine short fiber aggregate 2 and bran fabric shown in FIG. The tensile strength of this sheet material is measured after it has been subjected to an entanglement treatment by colliding with a high-speed liquid jet flow under the same conditions as those for processing the material. Bulk density is the weight per unit volume, and is measured as follows.

Using Maeda type compressive elastic material, a 6 x 7 sample was made with a diameter of 2.0
Place it on a circular plate, apply a load of 5.0 mm (1.6 mm/ground), measure the thickness, and calculate the volume. It is determined by dividing the sample weight by the volume. In this invention, the entangling strength is 1.0 to 2.4k9/伽, and the high density is 0.12 to 0.24.
Evening/Arc 3.

It is desirable that the total intersection strength is 1.5 to 2.2k.
9/skin, high density 0.15-0.22 m/ground. As excessive three-dimensional entanglement progresses, with entanglement strength of 2.4K9/skin and high density of 0.24K9/Sakaki, compression of the fiber aggregate occurs at the same time as the intercrossing of the constituent fibers, reducing the degree of freedom between the fibers. come. If a rubber-like elastomeric polymer is filled into a nonwoven fabric strip structure with excessive intersections, it will become coarse, hard, and paper-like, and the leather-like material of the present invention cannot be obtained. On the other hand, the entanglement process was insufficient, the entanglement strength was 1.0k9/low, and the high density was 0.1.
If the value is less than 2, the result will be paper-like and will lack the suppleness and elasticity characteristic of high-quality clothing leather. The knitted fabric of the present invention effectively intertwines ultrafine single fibers and plays an important role in stably forming a delicate non-woven structure.

In other words, in order to make short fibers into non-woven fabrics, the conventional method was to fix the fibers to some extent by crimping or using adhesives, and then use that bonding strength as a base to create new bonds using needle punches, etc. was causing it. Since fibers are bound together, the fibers must be free to move in random directions and cannot intertwine. However, too much freedom
This time, strong confounding connections will not occur forever. Therefore, when starting the interlacing process, one end of the short fiber,
Or, some part is supported and fixed by something, and one free end or freely movable part is entangled with the freely movable part of another fiber, and the entanglement occurs one after another in a chain to form a three-dimensional entangled body. It is desirable to form an interlaced nonwoven mechanism. The striped fabrics interposed in the core of the non-woven fabric structure of the present invention act as a support for the short fibers when they begin to intertwine, thereby efficiently interlacing the fibers without causing any slippage of the fibers. is becoming more and more popular.

Short fibers are entangled, inserted, or penetrated into the silk fabric of knitted fabrics, resulting in strong three-dimensional entanglement, and the strength and dimensional stability of the nonwoven fabric structure are significantly increased. Furthermore, knitted fabrics play a major role in facilitating the presence of longitudinally oriented fibers (in the thickness direction of the sheet) inside the three-dimensional entangled structure.

This is because the knitted fabric is interposed inside the fabric, so the intertwined short-time fibers penetrate or insert into the structure of the green fabric, and exist as vertically oriented fibers, which lowers the compression rate and compression recovery rate of the nonwoven structure. Improve. As mentioned above, knitted fabrics not only provide their own strength to non-woven structures, but also help the three-dimensional entanglement of the ultra-fine filaments that make up the non-woven structures, and also The presence of the fibers therein facilitates the presence of these fibers, thereby serving to significantly improve the physical properties of the nonwoven fabric structure of the present invention.

Furthermore, knitted fabrics have the effect of increasing the fluff density and improving the fluff uniformity of the nonwoven fabric farm structure of the present invention. The knitted fabrics used in this invention must have a roughness that allows the ultrafine fibers to penetrate or fill the structure of the knitted fabrics in an entangled state, and have a basis weight in the range of 10 to 100 fibers/pillow. It is desirable that the time is 30 to 70 evenings/day.

When it is less than 10 minutes, the knitted fabric becomes extremely loose, and when it is inserted into the middle part, it cannot be spread evenly and wrinkles occur.

In addition, it may be too thin to fix the fibers in the vertical direction, making it impossible to improve the elasticity of the nonwoven structure. On the other hand, when the basis weight is 100 mm/m or more, the fabric structure becomes dense, fiber penetration and filling are difficult to occur, and short fiber aggregates cannot be entangled with the fibers of the fabric, resulting in a lack of unity. There is a tendency to be unable to build certain structures. From the point of view of flexibility, it is better to select the constituent fibers of the knitted fabric from multi-twill yarns (single-stitch paper is preferred) that does not exceed 7M. Regarding the types of knitted fabrics, there are various types of knitted fabrics such as weft knitting, warp knitting represented by tricot knitting, lace line and various knitted fabrics based on these knitting methods, and flat knitting fabrics based on plain bran, twill weave, satin weave and their spellings. Various types of textiles can be mentioned, but any type can be used as long as it has a textile structure that has surface stitches and textures that allow ultra-fine short fibers to be embedded in the tissue, and also has textile fiber voids inside. There may be.

The fibers constituting the knitted fabrics may be any fibers that can be knitted, such as synthetic fibers such as polyester, polyamide, and polyacrylonitrile, recycled cellulose fibers such as rayon and Kypra, and natural fibers such as cotton. The denier is preferably 3 deniers or less.

A knitted fabric with too large a single yarn denier may make the nonwoven tail structure stiff. “Entanglement strength” of woven and entangled bodies
means the strength of entanglement between the ultrafine short fiber aggregate and green fabrics, and is a measure of the entanglement between the ultrafine fibers and knitted fabrics that make up this aggregate, and is determined as follows. measured.

As shown in Figure 8, take a sample with a length of 20 skins and a width of 1 skin, remove the ultrafine short fiber aggregate 2 and knitted fabric 1 in advance from one end to point C, 10 skins apart, and place the peeled part C at the center. A and B are grasped at 5 skins from C, and a shopper is used to pull A and B in opposite directions, and the maximum force when peeled from C is measured. The entanglement strength is required to be at least 50. The greater the entanglement strength of the nonwoven fabric structure of this invention, the more integrated it becomes and the higher the density.
If it is 50 ta or more, it will give a sufficient sense of unity. However, 50
If the rubber-like elastic polymer is filled with a rubber-like elastic polymer, it will not have a sense of unity and will only have a paper-like texture, and there will be a problem of peeling from the interlining during use. On the other hand, a nonwoven structure useful as artificial leather for clothing requires not only excellent physical properties but also a high degree of flexibility. The most suitable entanglement strength that satisfies these properties is 70 to 200 degrees. A liquid stream ejected at high speed from a nozzle with a particularly narrow orifice is used to entangle the ultra-fine single wires with an average fiber diameter of 5.0 mm or less, and to entangle the knitted fabric in the inner layer region. is valid. When a high-speed fluid jet impinges on the laminated sheet material shown in FIG. 5, the entanglement strength increases, and at the same time, the entanglement strength also increases.

Finally, it becomes impossible to separate the ultrafine staple fiber aggregate from the interlining, and the entanglement strength cannot be measured in such a state. The entanglement of ultrafine single fibers and the entanglement of ultrafine fibers and knitted fabrics in this invention are mainly due to the entanglement of the fibers, and the bonding is not due to thermal fusion or electrical bonding using static electricity.

For example, when melt blowing is performed directly on a knitted fabric as in JP-A-50-12157, some single yarns initially enter the rough texture of the fabric, but the accumulated fibers soon spread out into the rough texture of the fabric. I covered it. Embedding of single yarns into the knitted fabric is eliminated. In particular, when the basis weight of the accumulated web exceeds 30 yen/pillow, the knitted fabric and the accumulated web are completely separated and cannot be integrated. The entanglement strength of such a laminated sheet material is at most 10 degrees/low, which is far from the purpose of this invention and is outside the scope of this invention. In the present invention, the term "there is no substantial damage to the fibers constituting the knitted fabrics" means that the fibers constituting the knitted fabrics do not emerge from the surface of the nonwoven fabric structure, and the above-mentioned jetting fluid is used. can be achieved.

However, it is not preferable to use needle punching, which is a known non-woven fabric forming method, for the ultrafine fibers of the present invention. When needle-punching an ultra-fine fibrous sheet material with a thickness of 5.0 or less that is not shaped like an easterly sheet, the fibers will noticeably slip through or fall off due to damage, resulting in barb holes, and there will be almost no entanglement in the vertical direction. Furthermore, the interlining fabric fibers are cut, the structure is damaged, and in some cases, the constituent fibers come out to the surface of the nonwoven fabric layer, causing the product to lose its value. The total basis weight of the ultrafine short fiber aggregate of the present invention needs to be 1.3 tones or more relative to the basis weight of the interlining. If the basis weight ratio is less than 1.5, the elasticity unique to nonwoven fabrics will be lost, and the interlining will be exposed on the surface. Further, although FIGS. 1 and 2 show an example in which the interlining is located approximately at the center, it does not necessarily have to be located at the center, and may be positioned to such an extent that the interlining fibers are not exposed on the surface of the nonwoven fabric. The three-dimensional entangled body of the ultra-fine single fiber and knitted fabric of this invention has a soft texture and excellent physical properties, and its usefulness is demonstrated not only in the field of artificial leather but also in fields such as filters. .

The three-dimensional entangled body described above can be prepared using polyurethane, NB
When the fibers are bound by filling with a rubber-like elastic polymer such as R, and then the surface is brushed with sandpaper or a wire brush, the fluff of the ultra-fine single fibers with virtually no fiber bundles is created, resulting in a nubuck-like synthetic material. A nonwoven regular structure as shown in FIG. 2 useful as leather is obtained.

It is preferable that the woven longitudinally entangled body of the present invention has a boiling water area shrinkage rate of 5 to 30%.

A nonwoven structure having a shrinkage rate in this range can be filled with a rubber-like elastomeric polymer without significantly reducing the shrinkage rate by using a solvent for the polymer, such as N,N-dimethylformamide, during an impregnation process. can be done. That is, when a nonwoven structure with a boiling water area shrinkage rate of 5 to 30% is impregnated with a rubber-like elastic polymer and then shrunk by 5 to 20%, the elasticity of the restructured nonwoven fabric is significantly improved, and the surface is also raised. When this is done, ultra-fine single-filament, vertical, dense fuzz is generated, and even if the fuzz length is extremely short, the rubber-like elastic polymer portion on the surface is not exposed, and a super nubuck-like leather-like material can be obtained. If the boiling water area shrinkage rate of a nonwoven structure is less than 5%, the elasticity characteristic of natural leather will be inferior, and it will tend to have a cloth-like texture.On the other hand, if it exceeds 30%, the texture will become stiff. There is a mirror direction. Further, the rubber-like elastic polymer is preferably filled in an amount of 20 to 45% by weight based on the weight of the total woven entangled body from the viewpoint of elasticity and flexibility of the obtained restructured nonwoven fabric.

For example, the following method can be used to produce the nonwoven regular structure of the present invention.

A relatively coarse knitted fabric is placed on a random web made of ultrafine short fibers with an average fiber diameter of 0.1 to 5.0 mounds, which is produced by a melt blowing method and has substantially no fiber length, and then The same web as before is placed on top to obtain a laminate sheet having a three-layer structure as shown in FIG.

This laminated sheet material is placed on a permeable screen, and a high-speed liquid stream is impinged on it from above to obtain a nonwoven fabric with a three-dimensional entangled structure. The melt blowing method is disclosed, for example, in Japanese Patent Application Laid-Open No. 50-146972, and an example of the process is shown in FIG.

The thermoplastic polymer is melted in an extruder 5 and expelled through an array of orifices 12. A heated high velocity gas, e.g. air, is injected through slits 13 on either side of the orifice to attenuate the molten thermoplastic polymer, forming a fiber stream 7 of ultra-fine fibers. The fibers generated here are carried by the gas flow (turbulent flow) ejected from the slit outlet and are accumulated on a construction surface such as a moving screen 9 as a web 8 substantially free of fibers. In such a melt blowing method, by selecting conditions such as the mouth temperature, gas temperature, gas pressure, and polymer discharge base, the thermoplastic ultrafine short fibers with an average fiber diameter of 0.1 to 5.0 mm are used in the present invention. Fibers can be produced. For example, in the case of polyethylene terephthalate, the temperature is 320℃.
An ultrafine short fiber web with an average fiber diameter of 2.0 mm was obtained under the following conditions: gas temperature of 365 oC, gas pressure of 3.5 k9/base, and polymer discharge rate of 0.2 mm/side/orifice. The diameter of the fibers produced by the melt blowing method is extremely small (several mm to 1/10 mm), so it is difficult to measure the length of the fibers, but the average length of the fibers is more than 3 m. , usually estimated to be between 100 and 30 Dian Cape.

In this invention, it is necessary that the single fibers constituting the web have a high degree of freedom without being restricted by thermal adhesion or other factors.In particular, from the viewpoint of flexibility, which is important for artificial leather for clothing, heat fusion is required. Care must be taken to prevent this from happening.

Therefore, the distance between the orifice and the screen, that is, the accumulation distance, is 20 to 60 arcs, preferably 25 to 55 arcs. If the weight is less than 20, the resulting fibers will be deposited before solidification is complete, resulting in a lot of adhesion between the fibers, resulting in a hard texture.If it is more than 60, the uniformity of the basis weight will be poor.

In particular, in the present invention, a bran woven fabric may be placed on a screen, and the fibers may be directly blown onto the screen to collect the fibers.

At this time, it is necessary to prevent fusion between the knitted fabric and the ultrafine single fibers from the viewpoint of entanglement and flexibility in the subsequent process. In the melt blowing method described above, the high-speed heated gas flow causes the molten polymer to be drawn into small pieces, and after exiting the slit, it becomes a turbulent flow and disturbs the generated ultra-fine short fibers, so that the web accumulated on the screen is divided into two. It becomes a dimensional random structure.

FIG. 6 shows a cross-sectional micrograph of the melt O-web, and no matter which part of the cross section is sampled, the same fiber condition is shown and there is no substantial fiber formation. Furthermore, the melt-blown web does not have a three-dimensional entangled structure as referred to in the present invention because the fibers are intertwined with each other particularly in the sheet thickness direction (vertical direction). The degree of entanglement can be expressed in terms of tensile strength and bulkiness, but a meltblown web assembled without fusion between single fibers has a tensile strength of 0.1k.
g/, high density is about 0.02-0.05 g/,
In addition, even if this stacked sheet material is pressed at room temperature to prevent fusion between single fibers and the density is increased to 0.2 m/clump, the tensile strength remains extremely low at 0.5 k9/Kitsunefuman. be. Such a low strength indicates that the constituent fibers are not three-dimensionally entangled. Furthermore, even if a rubber-like elastic polymer is filled into a sheet material that does not have such three-dimensional intersection, the material becomes paper-like, and the leather-like material referred to in the present invention cannot be obtained. Next, high-speed liquid flow processing will be explained.

A sheet material (Figure 5) consisting of a sandwich-like stack of melt-blown webs with a knitted fabric as the interlining is placed on a permeable screen, and a liquid stream ejected from above at high speed is directly impinged on the sheet material. . As the high-speed liquid jet flow, it is preferable to use water jetted under high pressure from a narrow orifice. The orifice diameter is 0.05~0.2mm, preferably 0.05~0.15mm.
The pressure to push out water is 10-40k9/preferably 1.5
~35k9/shu is adopted. At 40 k9/min or more, the entangling effect increases, but the density tends to increase too much and the resulting nonwoven fabric becomes somewhat hard.

Further, if the amount is less than 10k9/m, it takes a long time to achieve the desired degree of cross-over. In the high-speed liquid processing of this invention,
It was discovered that it is important to draw a moderate amount of suction from below the screen.

Without suction, a large number of air bubbles will form in the nonwoven sheet material and satisfactory crisscrossing will not occur. On the other hand, if the suction is too strong, the fibers constituting the nonwoven sheet will not be able to move to rearrange themselves, and in this case too, almost no entanglement will occur. Suitable suction conditions are -5 to 50 Hg. (Based on atmospheric pressure) Also, a wire mesh is used for the screen. The finer the wire mesh is, the more preferable it is in terms of the smoothness and uniformity of the surface of the obtained nonwoven fabric square structure. When a high-speed liquid jet is made to collide with the laminated sheet material as shown in FIG. 5,
The ultrafine fibers that make up the melt-blown web are rearranged so that they are inserted into the thickness direction of the sheet material, and become intertwined with neighboring fibers.

By repeating this rearrangement, three-dimensional entanglement of all the ultrafine single fibers is completed. At the same time, the ultrafine monofilament fibers are inserted into, penetrate through, or sew into the tissue voids of the knitted fabric interposed in the core. In addition, the ultrafine fibers should be intertwined with the fibers constituting the striped fabrics to such an extent that the ultrafine fibers will not easily slip through the IJ. Matching.
The impingement of liquid jets is thus an entangling process that involves significant rearrangement of the microfibers that make up the meltblown web.
In order to obtain the nonwoven fabric structure of the present invention, it is difficult to manufacture it from a sheet material having a fiber pattern, and it is necessary that the constituent fibers of the sheet material before the interlacing treatment do not have a fiber pattern.

As in the past, sheet products with fiber length (particularly fiber length of 1)
Even if three-dimensional intersection processing is performed on the fibers (more than the enemy) by means such as needle punching or high-speed fluid flow, the resulting nonwoven fabric will not have all the fibers divided into single fibers. Most of it still exists as Textile East. It is true that the proportion of single fibers increases if needle punching and high-speed fluid flow processing are repeated and repeated, but such processing conditions result in severe fiber cuts, needle punch holes, streaks, etc. Finally, there is a drawback that the strength of the nonwoven fabric material is extremely reduced. The non-woven fabric structure of this invention has a structure in which ultra-fine single fibers are intertwined with each other and sewn with the intervening knitted fabric, which is excellent in flexibility and is made only of conventional fibers. It is possible to obtain artificial leather with physical properties that cannot be achieved with nonwoven fabric.

That is, the strength and flexibility of a nonwoven fabric are closely related to its density, and the higher the density, the greater the strength, but on the other hand, the texture becomes harder and the flexibility becomes worse. In order to simultaneously achieve flexibility and high strength (particularly sewing strength), which are desirable for clothing applications, mere intertwining of ultrafine single fibers is not sufficient. Artificial leather with high flexibility, high sewing strength, and excellent dimensional stability can only be obtained by the intertwining of the microfibers with each other and with the knitted fabrics interposed inside. Another feature of this invention is that
The objective is to obtain artificial leather with uniform surface fluff and high fluff density.

The state of fuzz generation is mostly determined by the entangled structure of the nonwoven fabric. When a conventional nonwoven fabric with a fiber east entangled structure is raised, it appears as a stump-like tuft-like fluff on the fiber east as shown in FIG. Especially when the fluff length of such fibers is shortened, the surface texture becomes rough and brittle. However, since the nonwoven regular structure of the present invention is a three-dimensional intertwined structure of ultrafine single fibers, a major feature is that fluff consisting only of ultrafine single fibers is generated at a high density. In particular, since the fluff is made of ultra-fine single fibers with an average fiber diameter of 0.1 to 5.0, elegant chalk marks will appear even if the average fluff length is shortened to less than 100 degrees or less. It has an excellent lighting effect and a moist surface touch unique to natural leather that could not be produced with conventional fibers, and is a smooth, fine-grained leather-like material.
The present invention will be explained in more detail with reference to Examples below. However, the physical properties shown in Examples and Comparative Examples are the values obtained by the following measurements.

To determine the tensile strength, take a sample with a length of 2 melons and a width of 1 skin, stretch and cut it using an autograph with the gripping length as 1 arc, and find the maximum strength at that time.

To make a strong material, take a sample as shown in Figure 9A and make a cut from one side to the other end up to C.

Next, spread it out as shown in Figure 9, set the grip length at the A and B ends to 5mm, pull the A and B ends in the direction of the arrow, and measure the maximum force when point C is torn using an autograph. This is what I did. To determine the sewing strength, two samples with a length of 10 pieces and a width of 2 pieces are taken, the two samples are overlapped as shown in FIG. 10, and then the overlapped part is sewn into a U-shape. The sewing conditions were a normal sewing machine, needle number 11, sewing thread polyester thread 5 points, sewing stitches 1 role/3.
It was an arc. These two samples were sewn together in the longitudinal direction, and the 5 arcs at both ends were grasped and pulled using an autograph, and the maximum strength (k9) at which breakage occurred at the seam was measured. Sewing strength (k9/arc) is obtained by dividing the maximum strength by the width of the sample (2 skins). Stretching recovery rate is 20 skin length x 1 width
A skin sample is taken, the top 5 skin is grasped, and the sample is suspended from above and fixed.

Next, the lower end 5 skin is grasped, a load of 1.0k9 is suspended, and the elongation is measured. The initial length is L. (kg), 1
The length when a load is applied for a period of time is determined, L, (伽), and then the load is removed and left for another 10 minutes. If the length at this time is L2 (skin), elongation recovery rate=E=EXloo(
%) to find the elongation recovery rate.

The compression rate and compression recovery rate are 10 arc×
Take a sample of 1 woman from a square piece of 10 skins, overlap this 1 woman, place a thin metal plate (50 pieces) of the same width on top of it, leave it for 2 minutes and measure its thickness, then 1
Apply a load of 0k9 evenly over the entire surface and leave it for 30 minutes.

The thickness L is measured after 30 minutes under load, and then the load is removed and the thickness is left for another 30 minutes, and the thickness at that time is determined. t
From o, L, and t2, the compression rate and compression recovery rate are as follows.

Example 1 In the apparatus shown in FIG. 7, polyethylene terephthalate was melt blown under the conditions of spinneret temperature of 32 pm, gas temperature of 365 qo, gas pressure of 4.0 k9/base, and resin discharge rate of 0.2 pm/rib/orifice. , I collected the bottles on a moving wire mesh with a distance of 40 skins and got the web with a weight of 80 nights.

The boiling water area shrinkage rate of this web was 70%, and the average fiber diameter was 2.0 mm as determined by electron microscopy. A rough double-sided knitted fabric (polyethylene terephthalate 4/38 multifilament) with a fabric weight of 40/38 is spread uniformly on top of this web, and then a melt-blown web similar to that shown above is placed on top of it. (with a basis weight of 80 tano) were stacked together to form a sheet with a three-layer structure. This three-layer structure sheet was placed on a wire mesh, and while suction was applied from below at -25 Hg (based on atmospheric pressure), a nozzle with a diameter of 0.10 feet was applied to the entire surface of the sheet for 20 km.
A high-pressure water stream continuously ejected with the pressure of 9/c whiskers was applied once to each side, and then twice to the front and back at a pressure of 30k9/cm. The thus obtained nonwoven fabric regular structure had a cross-sectional structure as shown in FIG. 1A, and was extremely fulfilling. Its physical property values are shown below.

Bulk Altitude: 0.20 m / Ground tensile strength: 7.4 k9 / Skin entanglement strength: 1.9 k9 / Skin entangled strength: 100 m Soaked in polyvinyl alcohol aqueous solution.

The amount of adhesion was 15% of the original weight. It was then soaked in a 10% DMF solution of polyurethane elastomer.
The amount of adhesion was 35% of the original weight. then 30%
The polyurethane was placed in a DMF aqueous solution and allowed to stand for 30 minutes to sufficiently solidify the polyurethane, and when it was further immersed in 7,000 °C warm water, the area shrinkage was 15%. After washing and drying, the surface was brushed with sandpaper, resulting in a Nupac-like artificial leather that was soft, extremely full, and had a fine-grained surface. When the surface of this artificial leather was observed under a microscope, it was found that the average fiber diameter was 21 and the fluff length was 50 to 5.
It was fluff made of single fibers of 0.00 floss. Despite this short fluff, it had an elegant lighting effect, and was so delicate that the polyurethane on the surface was not exposed. The physical properties of this nonwoven fabric structure are shown below. Weight: 250 mm / Thickness: 0.6 Leg tensile strength: 8.7 k9 / Skin tear strength: 3.5 [9 Sewing strength: 7.0 k9 / Skin stretch recovery rate: 90% Compression rate: 25% Compression recovery rate: 86% Examples 2 Among the melt-flowing conditions of Example 1, the gas pressure was set to 2.8 k9/c, and the other conditions were the same, and polyethylene terephthalate was melt-blown to obtain an average fiber diameter of 4.
5 Pu skin, eyesight 100 Yu/I got that web.

A woven fabric made of gauze-like polyethylene terephthalate fibers having a basis weight of 45 f/3/24 f was sandwiched between two of these webs to form a sheet with a three-layer structure.

This three-layer structure sheet was placed on a wire mesh, and while suction was applied from below at -35 Hg (based on atmospheric pressure), a nozzle with a diameter of 0.1 mm was applied continuously over the entire surface of the sheet at a pressure of 20 k9/ground. Apply the jet of high-pressure water to the front and back once, then 3 times.
Apply 0k9/ground pressure twice on the front and back, and then apply 40kg/
I hit it twice on the front and back with ground pressure. Then, when the bond was immersed in boiling water for 1 minute to cause shrinkage, the shrinkage rate was 12% in area shrinkage. When the cross section of the thus obtained nonwoven fabric structure was observed with a scanning electron microscope, no three-layer structure was observed, and it was found to be almost integrated with the fabric and three-dimensionally intertwined, as shown in Figure 1. It had a similar cross-sectional structure. This nonwoven fabric structure was extremely delicate and full of substance, and its physical properties were as follows. Bulk/Degree: 0.22
Poly/ground tensile strength: 7.8k9/cross-entanglement strength: 2.2k9/skin-entanglement strength: unmeasurable After drying, the nonwoven fabric strip structure was immersed in a 5% polyvinyl alcohol aqueous solution.

The amount of adhesion was 15% of the original weight. It was then soaked in a 15% DMF solution of polyurethane elastomer. The amount of adhesion was 38% of the original weight. then 30
% DMF aqueous solution and allowed to stand for 30 minutes to fully solidify the polyurethane. Further, polyvinyl alcohol and DMF were completely removed and dried in warm water at 10 pm. After washing and drying, the surface was brushed with sandpaper, resulting in an excellent artificial leather that was soft, full-bodied, and had a delicate surface.

The physical properties of this nonwoven fabric soaring structure were as follows. eye
Attachment: 280mm/Thickness: 0.7 Rib tensile strength: 9.0k9/c Bow tear strength: 3.8k9 Sewing strength: 7.2kg/gold Elongation recovery rate: 92% Compression rate: 30% Compression recovery rate: 91% Example 3 In the apparatus shown in FIG.
1500, gas temperature 360pm, gas pressure 4.0k9/
Melt blowing was carried out under the conditions of ground and resin discharge rate of 0.1 min/mie/orifice and collection on a moving wire mesh at a collection distance of 50 cm to obtain a web with an average fiber length of 0.3 rm.

A double-sided knitted fabric (nylon 66
, 4/34f multifilament) were uniformly spread and sandwiched to form a three-layer structure.

This three-layer sheet was treated with a high-pressure water stream in the same manner as in Example 1. This nonwoven fabric had the following physical properties and was rich in sense of fulfillment. Bulk height: 0.16 mm / ground tensile strength: 7.2 k9 / cross-entanglement strength: 1.7 k9 / overall skin strength: 180 mm The fabric was impregnated with polyurethane and coagulated in the same manner as in Example 1.

After washing and drying, the surface was brushed with sandpaper, resulting in extremely soft and full-bodied artificial leather with a finely fluffed surface. The physical properties of this nonwoven fabric structure were as follows. Weight: 290mm / Thickness: 0.7 Tensile strength: 8.5k9 / Tear strength: 3.6k9 Sewing strength: 6.8mm / 9mm Elongation recovery rate: Total % Compression rate: 27% Compression recovery rate: 85% Comparative Example 1 Polyethylene terephthalate was melt-blown to obtain a web with an average fiber diameter of 8 mounds and a basis weight of 80 m/m.

Using this web, it was interlaced with a green area in the same manner as in Example 1, and further impregnated with polyurethane and coagulated. The nonwoven fabric fabric obtained by brushing the surface is coarse and hard, and the surface is rough, and when the fluff length is set to less than 500 piles, the elegant lighting effect as in the product of the present invention does not appear. Comparative Example 2 The three-layer structure sheet used in Example 1 was placed on a wire mesh and treated under the same high-pressure water flow conditions as in Example 1 without suction from below.

This non-woven fabric structure had a bulk height of 0.17 m/g, an entanglement strength of 1.0 k9/g, and an entanglement strength of 30 m/g, and lacked a sense of unity. The structure obtained by impregnating this nonwoven fabric with polyurethane and coagulating it in the same manner as in Example 1 was
It was paper-like with no solid feel for leather, and peeling from the interlining was observed during bending. Comparative Example 3 A nonwoven fabric was obtained in exactly the same manner as in Example 1 except that a knitted fabric was inserted.

When the cross section of this nonwoven fabric was observed using an electron microscope, it was found that it had a three-dimensional entangled structure of ultrafine single fiber papers, but the degree of entanglement was considerably lower than that of the restructured nonwoven fabric obtained in Example 1. there were. Moreover, those filled with polyurethane and having a raised surface lacked a sense of fulfillment. The physical properties of this raised nonwoven fabric have a tensile strength of 3.2k.
9/skin, tear strength 1.5k9, sewing strength 3.9kg/gaya, elongation recovery rate 43%, compression rate 8%, and compression recovery rate 67%. Comparative Example 4 Sea-island fibers were obtained by melt spinning using parts by weight of nylon 6,4 as the island component and parts by weight of polystyrene 6 as the sea component.

This sea-island component was crimped using a pressing machine and cut on the 35 side to form staples. This staple is made into a cross-laid web with a fabric weight of 80 mm using a card machine and a crosslayer, and between the two webs,
A woven fabric made of gauze-like polyester fiber III/24f was sandwiched between the two to form a three-layer structure sheet. This sheet material was needle-punched and further treated with a high-pressure water stream of 50k9/ml to form a non-woven fabric, and then treated with chloroform to extract and remove the sea component styrene. The density of this fibrous structure was as low as 0.15 m/s. Furthermore, those impregnated with polyurethane, coagulated, and raised on the surface lacked elasticity, the fluff was made up of fibers, lacked a moist texture, and had a rough surface.

[Brief explanation of the drawing]

FIG. 1 is a sectional view vaguely showing an example of a restructured nonwoven fabric before being impregnated with the rubber-like elastic polymer of the present invention.
The opening indicates the difference in the degree of entanglement between the knitted fabric and the ultrafine short fiber aggregate. FIG. 2 is a cross-sectional view schematically showing the state of the artificial leather of the present invention and the fluff on its surface. FIG. 3 is a cross-sectional view showing a nonwoven fabric structure made of fibers as a comparative example and its surface condition. FIG. 4 is a cross-sectional view schematically showing the structure of natural leather. FIG. 5 is a cross-sectional view schematically showing the three-layer structure of the nonwoven fabric regular structure of the present invention before the entanglement treatment. FIG. 6 is a scanning electron microscope cross-sectional photograph showing an example of a nonwoven web used in the nonwoven fabric-rich structure of the present invention. FIG. 7A is a perspective view showing an example of the process for manufacturing the web shown in FIG. 6;
FIG. 7 is a cross-sectional view of a die used in the same process. FIG. 8 is a side sectional view showing a sample for measuring entanglement strength.
Figure 9A is a plan view showing the sample for tear strength measurement;
The figure is a perspective view showing a measurement state. FIG. 10 is a perspective view of a sample for measuring sewing strength. 1: knitted fabric, 2: ultrafine short fiber aggregate, 2A: ultrafine fiber east, 2B: natural leather fiber east, 3: fluff, 3A: ultrafine fiber east fluff, 3B: natural leather fluff, 4: rubber-like Elastic polymer, 5: Extruder, 6
: Gas introduction pipe, 7: Ultrafine short fiber flow, 8: Web, 9: Collector, 10: Drive roll, 11: Delivery roll,
12: Orifice, 13: Slot, 14: Ultra-fine single fiber. Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 and Figure 8 Figure 9 Figure 0

Claims (1)

[Claims] 1 Consists of a fiber aggregate formed by melt-blown ultrafine fibers with an average fiber diameter of 0.1 to 5.0 μm that are substantially separated into single fibers and intertwined with each other three-dimensionally, and a knitted fabric embedded in this aggregate. Some of the fibers of this aggregate are intertwined with the fibers that make up this interlining or (and)
By penetrating the interlining fiber tissue gap, the fibers constituting the interlining are entangled with each other without substantially damaging them, and the entangled body has an entanglement strength of at least 50%.
g, the ratio of the basis weight of the aggregate to the basis weight of the interlining is 1.5 or more, a rubber-like elastic polymer is interposed in the interstitial spaces of this entangled body, and the surface is covered with ultrafine fibers in the form of downy hairs. Artificial leather characterized by being fluffed.