TW202006200A - Manufacturing method of flake - Google Patents

Abstract

The present invention provides a method of manufacturing a sheet article by an environmentally-conscience manufacturing process, the sheet article having an elegant appearance, a soft feel, and good wear resistance even when a polyvinyl alcohol aqueous solution which has a low degree of polymerization and low viscosity and traditionally has high solubility to water is used. In this method for manufacturing a sheet article, the following steps 1 to 4 are performed in order. 1. A polyvinyl alcohol applying step of applying a polyvinyl alcohol aqueous solution to a fibrous substrate that is mainly composed of microfiber expression type fiber, the polyvinyl alcohol aqueous solution being an aqueous solution of polyvinyl alcohol having a saponification degree of 90% or more and an rrr composition abundance ratio in a tacticity evaluation measured by 13C-NMR in a heavy water solvent of 14.5% or more, to thereby apply 0.1 to 50 mass% of the polyvinyl alcohol to fiber mass contained in the fibrous substrate. 2. A microfiber expression step. 3. A polyurethane applying step. 4. A polyvinyl alcohol removing step.

Description

Manufacturing method of flake

The invention relates to a method for manufacturing a sheet, which uses water-dispersible polyurethane in the binder resin, thereby reducing the amount of organic solvent used in the manufacturing step, and considering the environment in the sheet, Both good flexibility and high-grade appearance quality are considered, and it has good wear resistance.

Sheets mainly composed of fibrous base material and polyurethane have excellent characteristics not found in natural leather, and are widely used in various applications. In particular, a leather-like sheet material using a polyester-based fibrous base material is excellent in light resistance, and its use is expanding year by year in applications such as clothing, chair covers, and automotive interior materials.

When manufacturing such a sheet, it is generally used to impregnate the fibrous substrate with an organic solvent solution of polyurethane, and then impregnate the resulting fibrous substrate with non-solvent water or organic solvent of polyurethane / Wet coagulation of polyurethane in the mixed solution of water. As an organic solvent for such a polyurethane solvent, a water-miscible organic solvent such as N,N-dimethylformamide (hereinafter referred to as "DMF") is used. For example, it is proposed to impregnate nonwoven fabric with polyethylene Alcohol solution to obtain fibrous flakes, the fibrous flakes were immersed in polyurethane impregnating solution, and the polyurethane was wet coagulated in a 45% DMF aqueous solution at 20°C, then at 85°C The hot water removes DMF and polyvinyl alcohol, and a method of manufacturing a sheet (refer to Patent Document 1).

Furthermore, in recent years, in the manufacture of sheets, due to considerations of the health status, safety, and surrounding environment of the operator, a technology that reduces the use of organic solvents has attracted much attention.

As a specific solution, for example, there is a method of using a water-dispersible polyurethane in which polyurethane has been dispersed in water instead of polyurethane that has been dissolved in an organic solvent in the past. In addition, in the same way as in the conventional manufacturing process that uses a polyurethane that dissolves in an organic solvent, in order to form a gap between the fiber and the polyurethane, it is proposed to provide polyvinyl alcohol to the fibrous base material in advance. Then, a method of giving polyurethane and then removing polyvinyl alcohol (refer to Patent Document 2).

[Prior Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 2002-30579

Patent Literature 2: International Publication No. 2014/084253

In the past, the fibrous base material was impregnated with water-dispersible polyurethane, and the sheet material provided with the polyurethane was due to the strong adhesion of the polyurethane to the fiber of the fibrous base material. There is a problem of hard texture.

As disclosed in Patent Document 2, in the method of preliminarily imparting polyvinyl alcohol to the fibrous substrate, then imparting polyurethane to the substrate, and then removing the polyvinyl alcohol, the polyvinyl alcohol is water-soluble, while the fibrous When the base material is provided with polyvinyl alcohol and then wetted with water, the polyvinyl alcohol may dissolve and fall off. Therefore, for example, in Patent Document 2, an attempt is made to suppress the shedding of polyvinyl alcohol into water by using a polyvinyl alcohol aqueous solution having a saponification degree of 98% or more, a polymerization degree of 800 to 3500, and few impurities.

However, since polyvinyl alcohol having a high degree of polymerization is used, the viscosity of the polyvinyl alcohol aqueous solution becomes high, and there is a problem that the impregnability to the fibrous base material or the handleability of the polyvinyl alcohol aqueous solution decreases.

Therefore, the present invention aims to provide a sheet-like object, which reduces the use of organic solvents in the manufacturing process and considers the environment. Even when using a polyvinyl alcohol aqueous solution with a low degree of polymerization and a low viscosity, it also has the beauty of having fluff The appearance and soft texture, and has good wear resistance.

In order to achieve the above object, the present inventors have repeatedly reviewed the results and found that using polyvinyl alcohol with a high degree of saponification, after the polyvinyl alcohol is imparted, the polyurethane is imparted, whereby an excellent flexibility can be obtained The sheet-like material can effectively reduce the solubility of polyvinyl alcohol in water by making the three-dimensional regularity of polyvinyl alcohol a structure with higher reciprocity.

That is, in order to solve the above problems, the present invention is a method for producing a sheet-like article of the present invention, which is a method for producing a sheet-like article containing a fibrous base material containing ultra-fine fibers and a polyurethane, including the following (1 ) ~ (4) steps.

(1) The polyvinyl alcohol imparting step is to impart an aqueous solution of polyvinyl alcohol to a fibrous base material having ultra-fine fiber-exposed fibers as a main constituent component, thereby imparting a fiber mass of 0.1 to 0.1% relative to the fibrous base material. 50% by mass of the aforementioned polyvinyl alcohol, and the aqueous solution of the polyvinyl alcohol has the following characteristics,

(Polyvinyl alcohol: the degree of saponification is 90% or more, and in the evaluation of stereoregularity measured by ¹³ C-NMR in a heavy water solvent, the rrr composition existence ratio is 14.5% or more);

(2) The ultrafine fiber development step is to make the ultrafine fiber development fibers of the fibrous base material into ultrafine fibers with an average single fiber diameter of 0.1 μm to 10 μm after the foregoing steps;

(3) The step of imparting a polyurethane is to impart a water-dispersible polyurethane to the fibrous base material to which the polyvinyl alcohol is imparted after the aforementioned step;

(4) The polyvinyl alcohol removal step is to remove the polyvinyl alcohol from the fibrous base material provided with the water-dispersible polyurethane after the foregoing step.

According to a preferred aspect of the manufacturing method of the present invention, the degree of polymerization of the aforementioned polyvinyl alcohol is 200-3500.

According to a preferred aspect of the method for manufacturing a sheet-like object of the present invention, in the aforementioned ultrafine fiber development step, a fibrous base material containing the aforementioned ultrafine fiber development type fiber as a main component is treated with an alkaline aqueous solution.

According to a preferred aspect of the manufacturing method of the present invention, in the polyvinyl alcohol imparting step, after the polyvinyl alcohol is imparted, it is heated at 80 to 190°C.

According to a preferred aspect of the manufacturing method of the present invention, in the aforementioned polyvinyl alcohol imparting step, the fibrous base material having the aforementioned ultra-fine fiber-exposed fibers as the main constituent component is made of fibers and woven fabrics and/or knitted fabrics. Tangled integrators.

According to the present invention, there can be obtained a sheet-like material which, by considering the environmentally friendly manufacturing steps, achieves a beautiful appearance even when using a polyvinyl alcohol aqueous solution having a low degree of polymerization and a low viscosity, which is highly soluble in water. And soft texture, and has good wear resistance.

[Form for carrying out the invention]

The manufacturing method of the sheet-like object of the present invention is to perform the following steps (1) to (4).

(1) The polyvinyl alcohol imparting step is to impart an aqueous solution of polyvinyl alcohol to a fibrous base material having ultra-fine fiber-exposed fibers as a main constituent component, thereby imparting a fiber mass of 0.1 to 0.1% relative to the fibrous base material. 50% by mass of the aforementioned polyvinyl alcohol, and the aqueous solution of the polyvinyl alcohol has the following characteristics,

(Polyvinyl alcohol: the degree of saponification is 90% or more, and in the evaluation of stereoregularity measured by ¹³ C-NMR in a heavy water solvent, the rrr composition existence ratio is 14.5% or more);

(2) The ultrafine fiber development step is to make the ultrafine fiber development fibers of the fibrous base material into ultrafine fibers with an average single fiber diameter of 0.1 μm to 10 μm after the foregoing steps;

(3) The step of imparting a polyurethane is to impart a water-dispersible polyurethane to the fibrous base material to which the polyvinyl alcohol is imparted after the aforementioned step;

(4) The polyvinyl alcohol removal step is to remove the polyvinyl alcohol from the fibrous base material provided with the water-dispersible polyurethane after the foregoing step.

Hereinafter, its constituent elements will be described in detail, but the present invention is not limited at all by the scope described below as long as it does not exceed its gist.

(Manufacturing method of flakes)

In the manufacturing method of the sheet of the present invention, the steps (1) to (4) above are performed in sequence. After the aforementioned polyvinyl alcohol aqueous solution is applied to the fibrous base material having the ultrafine fiber exhibiting fibers as the main constituent components, the ultrafine fiber exhibiting fibers (such as island-in-the-sea fibers) are subjected to the step of exhibiting ultrafine fibers (such as the sea-removal step) Then, to the fibrous base material to which polyvinyl alcohol is added, the ultrafine fiber as the main component, a water-dispersible polyurethane liquid is added, and the polyvinyl alcohol is further removed from the fibrous base material. Between the fiber and the polyurethane, a large gap is generated from the removed polyvinyl alcohol and the removed sea component. Furthermore, the ultrafine fibers can be partially directly controlled by the polyurethane, and while exhibiting a beautiful appearance and soft texture, it also exhibits good wear resistance.

In addition, when a polyvinyl alcohol aqueous solution is applied to the fibrous base material and heated and dried, the polyvinyl alcohol in the water is drawn by the movement of water during drying and is concentratedly attached to the surface layer of the fibrous base material. Migration phenomenon. As a result, the polyvinyl alcohol tends to adhere to the surface layer of the fibrous base material and its vicinity, but not to the inside. In this state, the water-dispersed polyurethane provided after that will mainly adhere to the inside of the fibrous base material. Then, if the polyvinyl alcohol is removed, there will be a large gap between the fiber and the polyurethane on the surface layer of the fibrous base material to which the polyvinyl alcohol adheres and its vicinity, and the flakes obtained if the raising step is performed The appearance of the surface of the object is difficult to bunch up, and the beautiful appearance of the hair is evenly divided.

On the other hand, if the sea-removal treatment is performed after the polyvinyl alcohol is removed, voids due to the removal of polyvinyl alcohol and voids due to the sea component that is removed from the sea are generated between the polyurethane and the ultrafine fibers Both, so the area where the polyurethane directly controls the surface of the ultrafine fibers changes little. The texture of the flakes becomes soft, but the characteristics such as wear resistance tend to deteriorate.

The details of each step are shown below.

[Polyvinyl alcohol application step]

First, the polyvinyl alcohol imparting step of the first step will be described, which is to impart a polyvinyl alcohol aqueous solution to a fibrous base material having ultrafine fiber-exposed fibers as a main constituent component, thereby imparting to the fibrous base material The fiber mass is 0.1-50% by mass of the polyvinyl alcohol, and the aqueous solution of the polyvinyl alcohol has the following characteristics. The saponification degree of the polyvinyl alcohol system used here is 90% or more, and the rrr composition existence ratio is 14.5% or more.

In the present invention, the polyvinyl alcohol imparted to the fibrous base material preferably uses polyvinyl acetate as a raw material. Moreover, it is also preferable to use poly(trifluorovinyl acetate) as a raw material. The degree of saponification of the polyvinyl alcohol system is 90% or more, preferably 95% or more, and more preferably 98% or more. By setting the degree of saponification of polyvinyl alcohol to a certain value or more, when polyvinyl alcohol is added to the fibrous base material, when water-dispersible polyurethane is added, the polyvinyl alcohol can be prevented from dissolving in the water-dispersible type In polyurethane liquid. On the other hand, if the degree of saponification is low, when the water-dispersible polyurethane solution is applied to the fibrous substrate, the polyvinyl alcohol is dissolved in the water-dispersible polyurethane solution, and the polyvinyl alcohol is collected. Into the interior of polyurethane, it will become difficult to remove polyvinyl alcohol later. Therefore, the bonding state of the polyurethane and the fiber cannot be controlled stably, and the texture becomes hard.

In addition, in the present invention, the saponification degree of polyvinyl alcohol is described in 3.5 "Saponification Degree" of JIS K6726: 1994 "Polyvinyl Alcohol Test Method", and can be calculated as follows.

(1) Weigh the polyvinyl alcohol, put it into an Erlenmeyer flask, add water and phenolphthalein solution, and completely dissolve it at a temperature above 90°C.

(2) After leaving to cool to room temperature, add a sodium hydroxide aqueous solution with a burette, shake and mix well, and keep at room temperature for 2 hours or more. Here, when the degree of saponification is less than 97%, a 0.5 mol/L sodium hydroxide aqueous solution is used, and when it is 97% or more, a 0.1 mol/L sodium hydroxide aqueous solution is used.

(3) Using a burette with the same amount as the aqueous sodium hydroxide solution, add sulfuric acid or hydrochloric acid at the same molar concentration (unit mol/L) as the aqueous sodium hydroxide solution, and mix thoroughly by shaking.

(4) Titrate with aqueous sodium hydroxide until it turns reddish.

(5) Carry out a blank test without adding polyvinyl alcohol.

(6) The degree of saponification H is calculated by the following formula.

H =100- X ₂

Here,

X ₁ : the amount of acetic acid equivalent to the remaining acetic acid groups (%)

X ₂ : residual acetic acid group (mol%)

H: degree of saponification (mol%)

a: (4) the amount of sodium hydroxide aqueous solution used (mL)

b: (5) The amount of sodium hydroxide aqueous solution used in the blank test (mL)

f: factor of aqueous solution of sodium hydroxide

D: concentration of aqueous sodium hydroxide solution (mol/L)

S: The amount of polyvinyl alcohol collected (g)

P: Purity (%) of polyvinyl alcohol.

In addition, when the raw material before saponification is a vinyl carboxylate polymer other than polyvinyl acetate, the above formula can be rewritten as follows.

X ₁ : the amount of carboxylic acid equivalent to the remaining carboxylic acid group (%)

X ₂ : residual carboxylic acid group (mol%)

The molecular weight of the carboxylic acid constituting the vinyl carboxylate is used instead of 60.05 (molecular weight of acetic acid) where X ₂ is required.

In addition, in the present invention, the polyvinyl alcohol imparted to the fibrous substrate is based on the evaluation of stereoregularity measured by ¹³ C-NMR in a heavy water solvent, and the ratio of the rrr composition is 14.5% or more.

In the repeating structure of the vinyl alcohol unit, adjacent hydroxyl groups become "r" (racemo) repeating in different directions from each other, and partly become a counter-row structure. For the row structure relative to the plane formed by the carbon chain in the polymer, the hydroxyl groups are alternately arranged up and down, so it becomes easy to form many hydrogen bonds due to the hydroxyl groups of the molecules of the polyvinyl alcohol molecules located in the row structure structure. As a result, the hydroxyl groups contributing to the formation of hydrogen bonds with water molecules are reduced, the solubility in water is reduced, and the solubility in warm water is also reduced.

In the ¹³ C-NMR measurement in the heavy water solvent, the adjacent hydroxyl groups of the vinyl alcohol unit will become "m" in the same direction and "r" in different directions will be due to the arrangement from the polyvinyl alcohol skeleton The peak of methylene carbon will be split into 5, and it can be evaluated as the arrangement of m and r of the 4 unit part of vinyl alcohol. It is known that these arrangements start from the peak on the high magnetic field side and become "mmm", "mmr", "mrr", "rmr", "rrr". The total value of these absorption points is regarded as 100%, and the existence ratio of each arrangement is expressed as a percentage. Polyvinyl alcohol systems with the highest repellency rrr structure in the existing ratio of 14.5% or more can effectively reduce the solubility in water. The existence ratio of the rrr structure is preferably 14.7% or more, and more preferably 15.0% or more. The higher the existence ratio of the rrr structure is the higher the ratio of the row structure, which can further reduce the solubility of water. When the existing ratio of the rrr structure is less than 14.5%, the hydrogen bond formation between polyvinyl alcohols becomes less, and the polyvinyl alcohol in water dissolves and falls off during the sea-removal step, etc., directly holding the polyurethane fibers Part of the system is increased, and the softness or surface appearance of the sheet is low.

From the viewpoint of reducing the solubility of polyvinyl alcohol in water, in addition to the rrr structure, the presence ratio of the mrr structure is preferably 25% or more, more preferably 25.5% or more, and still more preferably 26% or more. In addition, the total of the existing ratio of the rrr structure and the existing ratio of the mrr structure is preferably 39.5% or more, more preferably 40% or more, and still more preferably 40.5% or more. On the other hand, the sum of the existence ratio of the mmm structure and the existence ratio of the mmr structure is preferably 50% or less, more preferably 48% or less, and still more preferably 45% or less.

The preferred upper limit of the rrr structure is not specified, but from the viewpoint of ease of acquisition or production, it is preferably 28.0% or less, and further preferably 20.0% or less.

In addition, the existence ratio of the rrr composition of polyvinyl alcohol was measured as follows, and the calculated value was used.

First, polyvinyl alcohol was dissolved in a heavy water solvent at a temperature of 80°C, and ¹³ C-NMR measurement at a resonance frequency of 100 MHz was performed at a measurement temperature of 80°C. Among the two peak groups corresponding to the carbon atoms of polyvinyl alcohol, the peak group observed at 45 to 49 ppm corresponds to the peak group of methylene carbon in the polyvinyl alcohol skeleton. In addition, the peak group on the low magnetic field side is a methine carbon peak group bonded to the hydroxyl group in the polyvinyl alcohol skeleton. Regarding the carbon peak group constituting the methylene group, regarding the five peaks detected, when the peaks overlap, vertical division is performed in the valley of the peaks, the integral value is calculated, and the existence ratio of each arrangement is calculated as a percentage. Furthermore, the peaks of the rrr structure are among the peak groups and are observed on the side of the lowest magnetic field.

The existence ratio of the rrr structure can be adjusted by appropriately changing the polymerization conditions or polymerization catalyst of polyvinyl alcohol or polyvinyl acetate that can be used as a raw material.

In addition, according to the degree of polymerization of the polyvinyl alcohol system, the solubility in water and the viscosity of the polyvinyl alcohol aqueous solution will change. The polyvinyl alcohol having a low degree of polymerization means that the viscosity of the polyvinyl alcohol aqueous solution is low, and the impregnability of the aqueous solution to the fibrous base material and the operability of the aqueous solution are excellent. On the other hand, the greater the degree of polymerization of polyvinyl alcohol, the lower the solubility in water. When the water-dispersible polyurethane is added, the dissolution of polyvinyl alcohol in the water-dispersible polyurethane solution can be further suppressed. As described above, the polyvinyl alcohol of the present invention has a high ratio of the rrr composition, so even when the degree of polymerization of the polyvinyl alcohol is low, the dissolution of the polyvinyl alcohol in the water-dispersed polyurethane solution can be effectively suppressed . Therefore, the average degree of polymerization of polyvinyl alcohol is preferably 200 or more, more preferably 300 or more, and still more preferably 400 or more. By setting the polymerization degree of polyvinyl alcohol to 200 or more, the dissolution of polyvinyl alcohol into water can be suppressed. The average degree of polymerization of polyvinyl alcohol is preferably 3500 or less, more preferably 2500 or less, still more preferably 1500 or less, and particularly preferably 1000 or less. By setting the degree of polymerization of polyvinyl alcohol to 3500 or less, the viscosity of the polyvinyl alcohol aqueous solution can be suppressed from becoming too high, and the impregnability to the fibrous base material and the handling of the polyvinyl alcohol aqueous solution can be improved.

In addition, in the present invention, the average degree of polymerization of polyvinyl alcohol is in accordance with 3.7 "Average degree of polymerization" of JIS K6726: 1994 "Test Method for Polyvinyl Alcohol", as measured in the following (1) to (7), (8 ) Specifies the average degree of polymerization calculated in the present invention.

(1) Put polyvinyl alcohol in an Erlenmeyer flask, add methanol, add an aqueous solution of sodium hydroxide, and mix with stirring.

(2) Heat in a water bath at 40±2°C for 1 hour to completely saponify the remaining carboxylic acid groups.

(3) Wash with methanol, remove sodium hydroxide and sodium carboxylate, and dry at 105±2℃ for 1 hour.

(4) Measure the sample obtained in (3), add water, heat to dissolve, leave to cool to room temperature, and filter.

(5) Using the Oswald viscometer, find the relative viscosity of the filtrate of (4) at 30.0±0.1°C with respect to water at the same temperature.

(6) Dry at 105±2°C for more than 4 hours to determine the concentration of the filtrate whose viscosity has been measured.

(7) The average degree of polymerization P _{A is} calculated by the following formula.

C: Concentration of test solution (g/L)

W ₂ : mass of dried sample and evaporating dish (g)

W ₃ : Mass of evaporating dish (g)

V: volume of filtrate (mL)

P _A : average degree of polymerization

[η]: Ultimate viscosity

η _rel : relative viscosity

t ₀ : seconds of water falling (s)

t ₁ : seconds for the test solution to fall (s)

(8) The decimal point of the obtained average polymerization degree is simplified to an integer. The value is expressed as n+50*m. n is an integer from 0 to 49. m is an integer above zero. When n is 0~24, the average polymerization degree is regarded as 50*m. When n is 25~49, the average polymerization degree is regarded as 50*(m+1).

Furthermore, when the value of the average degree of polymerization PA calculated in (7) above is outside the range defined by the present invention, it is regarded as polyvinyl alcohol that is not defined by the present invention as the average degree of polymerization.

In the present invention, the viscosity of the polyvinyl alcohol aqueous solution is a polyvinyl alcohol aqueous solution with a concentration of 4% by mass as measured in JIS K6726: 1994 "Polyvinyl Alcohol Test Method" 3.11.1 "Rotating Viscometer Method" as follows Viscosity at 20°C.

(1) Weigh the polyvinyl alcohol and put it into an Erlenmeyer flask. Prepare these three.

(2) Add water separately so that the concentration becomes 3.8% by mass, 4.0% by mass, and 4.2% by mass, completely heat and dissolve, leave to cool to a temperature of 20°C, and completely defoam.

(3) Using a rotary viscometer, measure the viscosity at a temperature of 20.0±0.1℃.

(4) Measure the concentration (mass%) of the liquid used for the measurement, make a graph with the viscosity taken on the vertical axis and the concentration taken on the horizontal axis, and find the viscosity (mPa‧s) at a concentration of 4% by mass.

In the present invention, the polyvinyl alcohol is preferably a 4 mass% aqueous solution of the polyvinyl alcohol. The viscosity at 20° C. becomes 2 to 70 mPa‧s. Since the viscosity of polyvinyl alcohol is in this range, a moderate migration structure within the fibrous base material can be obtained during drying, and a balance between the softness of the sheet and the physical properties such as surface appearance and wear resistance can be obtained. By setting the viscosity to 2 mPa‧s or more, preferably 3 mPa‧s or more, and more preferably 4 mPa‧s or more, the extreme migration structure can be suppressed. On the other hand, by setting the viscosity to 70 mPa‧s or less, preferably 50 mPa‧s or less, and more preferably 40 mPa‧s or less, the fibrous base material can be easily impregnated with polyvinyl alcohol.

In the present invention, the glass transition temperature (Tg) of polyvinyl alcohol is preferably 70 to 100°C or lower. By setting the glass transition temperature of the polyvinyl alcohol to 70° C. or higher, preferably 75° C. or higher, the softening in the drying step can be prevented, the size stability of the fibrous substrate can be obtained, and the surface of the sheet can be suppressed The appearance has deteriorated. In addition, by setting the glass transition temperature to 100° C. or lower, preferably 95° C. or lower, it is possible to prevent the deterioration of the handleability due to the excessive rigidity of the fibrous base material.

In the present invention, the melting point of polyvinyl alcohol is preferably 200 to 250°C. Since the melting point of polyvinyl alcohol is set to 200° C. or higher, preferably 210° C. or higher, it can prevent softening in the drying step, obtain dimensional stability of the fibrous base material, and suppress the change in surface appearance of the sheet difference. In addition, since the melting point of polyvinyl alcohol is set to 250° C. or lower, more preferably 240° C. or lower, it is possible to prevent deterioration of the handleability due to the excessive rigidity of the fibrous base material.

Furthermore, in the present invention, the glass transition point and melting point of polyvinyl alcohol are the glass transition temperature measured in differential scanning calorimetry (DSC) in JIS K7121: 1987 "Method for Measuring the Transition Temperature of Plastics", Melting temperature.

(1) Weigh the polyvinyl alcohol and put it in an aluminum container.

(2) A DSC curve is obtained at a glass transition temperature of 20°C/min and a melting temperature of 10°C/min, and the respective temperatures are read from the DSC curve.

Next, a description will be given of a polyvinyl alcohol imparting step which imparts an aqueous solution of polyvinyl alcohol to a fibrous base material having ultrafine fiber-exposed fibers as a main constituent component, thereby imparting a mass of 0.1 fiber to the fibrous base material ~50% by mass of this polyvinyl alcohol.

The fibrous base material of the present invention is composed of ultra-fine fiber-exposed fibers as the main component. The ultra-fine fiber-exposed fiber in the fibrous machine material is preferably 50 to 100% by mass. From the viewpoint of obtaining a beautiful surface appearance of the sheet-like material, the ultrafine fiber-exposed fiber in the fibrous base material is more preferably 60% by mass or more, and further preferably 70% by mass or more. By using ultra-fine fiber development type fibers, the fibers can be ultra-fine because of the subsequent ultra-fine fiber step, and a beautiful surface appearance can be obtained.

As the aforementioned ultrafine fiber-exposed fiber, (a) a thermoplastic resin having two components with different solvent solubility can be used as the sea component and the island component, and the sea component can be dissolved and removed using a solvent or the like, thereby making the island component into an ultrafine fiber The "island type fiber". In addition, (b) "removable composite fibers" in which two-component thermoplastic resins are alternately arranged in a radial or multi-layer shape in a fiber cross-section, and each component is peeled off and split into extremely fine fibers, etc. . Among them, due to the removal of the sea component, the island-in-the-sea fiber can give a moderate gap between the island components, that is, between the very fine fibers, so it is also more suitable to use from the viewpoint of the softness or texture of the sheet .

The island-in-the-sea fibers include, for example, island-in-the-sea composite fibers spun using an island-in-sea composite spinneret and alternately arranging two components of the sea component and the island component; or a mixture of the sea component and the island component and spinning Mixed spinning fiber, etc. From the point that extremely fine fibers of uniform fineness can be obtained, and also that extremely fine fibers of sufficient length can be obtained and also contribute to the strength of the resulting sheet-like material, the former island-in-the-sea composite fibers are more suitable.

The island component of the sea-island type fiber is not particularly limited, and the following can be exemplified.

Polyesters such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate and polylactic acid.

Polyamide 6 such as polyamide 6 or polyamide 66; acrylic; polyethylene; polypropylene. And, thermoplastic resins such as thermoplastic cellulose that can be melt-spun.

Among them, from the viewpoint of strength, dimensional stability, and light resistance, polyester fibers are preferably used. In addition, from the viewpoint of environmental considerations, fibers obtained from recycled raw materials and plant-derived raw materials are preferred. Furthermore, the fibrous base material can also be composed of fibers of different materials.

The sea component of the island-in-the-sea fiber is not particularly limited, and the following can be exemplified.

Hydrocarbon addition polymers such as polyethylene, polypropylene, polystyrene, etc.

Copolymerized with copolymerized polyesters such as sodium sulfoisophthalate or polyethylene glycol. Polylactic acid. Polyvinyl alcohol.

Among them, from an environmental point of view, it is preferable not to use an organic solvent, preferably a decomposable alkali-decomposable copolymerization copolymerized polyester or polylactic acid such as sodium sulfoisophthalate or polyethylene glycol, Hot water soluble polyvinyl alcohol.

The cross-sectional shape of the fibers constituting the fibrous base material is not particularly limited, and it may be a circular cross-section, or a polygonal shape such as an ellipse, a flat shape, a triangular shape, or a special-shaped section such as a fan shape and a cross shape.

For the morphology of the fibrous base material of the present invention, woven fabrics, knitted fabrics, non-woven fabrics, etc. can be used. Among them, the nonwoven fabric is more preferable because the surface appearance of the sheet-shaped object during surface raising treatment is good.

The nonwoven fabric may be any of short fiber nonwoven fabric and long fiber nonwoven fabric. However, long-fiber non-woven fabrics have less fiber than the short-fiber non-woven fabrics when the flakes that become fluff when they are fluffed toward the thickness side, the denseness of the fluff becomes lower, and the surface appearance tends to deteriorate, so it is better to use short-fiber non-woven fabrics .

The fiber length of the short fiber in the short fiber non-woven fabric is preferably 25 to 90 mm. By setting the fiber length to 25 mm or more, preferably 30 mm or more, a sheet having excellent abrasion resistance can be obtained by entanglement. In addition, by setting the fiber length to 90 mm or less, preferably to 80 mm or less, a sheet-like article having excellent texture or quality can be obtained.

As a method of entanglement of fibers or fiber bundles of the nonwoven fabric, needle piercing or water jet piercing may be used.

In the present invention, when the fibrous substrate including the ultrafine fiber exhibiting fibers is a nonwoven fabric, the nonwoven fabric is preferably an ultrafine fiber exhibiting fibers that are pre-entangled with each other. In this way, the fibrous base material containing the ultra-fine fibers becomes a structure in which bundles of the ultra-fine fibers have been entangled, and the ultra-fine fibers are entangled in a bundle state, and the strength of the sheet is increased.

When the fibrous base material with the ultrafine fiber display type fiber as the main component is a non-woven fabric, it may be more entangled and integrated with the woven fabric or knitted fabric for the purpose of improving the strength inside. For example, in the case of woven fabrics, plain weave, twill weave, and satin weave can be cited. From a cost perspective, plain weave is more suitable. In the case of knitted fabrics, circular knitting, tricot knitting, russell knitting, etc. may be mentioned. The average single fiber diameter of the fibers constituting the woven fabric or knitted fabric is preferably 0.3 to 20 μm.

In the fibrous substrate with the ultra-fine fiber display type fiber as the main component, the fiber is entangled and integrated with the woven fabric and/or knitted fabric, before the water-dispersible polyurethane is imparted, the poly Vinyl alcohol, water-dispersed polyurethane directly controls the area of the woven fabric or knitted fabric, and the texture of the sheet is not easy to harden. In particular, when the woven fabric and/or knitted fabric used is composed of fibers of non-ultrafine fiber-exposed fibers, a sheet material with significantly excellent flexibility can be obtained.

The amount of polyvinyl alcohol added to the fibrous substrate is 0.1 to 50% by mass relative to the fiber mass of the fibrous substrate. By setting the amount of polyvinyl alcohol applied to 0.1% by mass or more, preferably 1% by mass or more, a sheet having good flexibility and texture can be obtained, and the amount of polyvinyl alcohol applied to 50 The mass% or less, preferably 45 mass% or less, and a sheet having good physical properties such as good processability and abrasion resistance can be obtained.

In the present invention, the method of imparting polyvinyl alcohol to the fibrous substrate is not particularly limited, and various methods generally used in the art can be used. Among them, the method of dissolving polyvinyl alcohol in water, impregnating the fibrous base material, and heating and drying is preferred from the viewpoint of uniform application. If the drying temperature is too low, a long drying time is required, and if the temperature is too high, the polyvinyl alcohol will be insoluble and subsequent dissolution and removal will become difficult. Therefore, the drying temperature is preferably 80 to 140°C, and the drying temperature is more preferably 110 to 130°C. The drying time is usually 1 to 20 minutes, and from the viewpoint of processability, it is preferably 1 to 10 minutes, and more preferably 1 to 5 minutes. In addition, in order to make polyvinyl alcohol insoluble, heat treatment may be performed after drying. The preferred temperature for heat treatment is 80~190℃. For heat treatment, the insolubilization of polyvinyl alcohol and the thermal degradation of polyvinyl alcohol are carried out simultaneously. A more preferable temperature is 90 to 170°C.

[Extra-fine fiber display steps]

Next, a description will be given of the ultrafine fiber development step of the second step, which is to exhibit ultrafine fibers with an average single fiber diameter of 0.1 to 10 μm from a fibrous base material containing ultrafine fiber development type fibers.

As described above, the ultrafine fiber-exposing fiber is preferably a sea-island fiber. The ultra-fine fibers of the fibrous base material with such fibers as the main constituents are treated by sea removal. It can be performed by immersing the fibrous base material in a solvent, dissolving the sea component in the solvent, and squeezing the fibrous base material. When the ultrafine fiber-exposed fiber is a sea-island fiber, as a solvent, when the sea component is polyethylene, polypropylene or polystyrene, an organic solvent such as toluene or trichloroethylene can be used, and when the sea component is a copolymerized polyester Or polylactic acid, an alkaline aqueous solution such as sodium hydroxide can be used. In addition, when the sea component is polyvinyl alcohol, hot water can be used. From the point of view of consideration of the environment in the step, desalination treatment with an alkaline aqueous solution such as sodium hydroxide or hot water is preferred.

In a preferred aspect of the present invention, the average single fiber diameter of the ultra-fine fibers obtained from the ultra-fine fiber-exposing fibers through the ultra-fine fiber step is 0.1-10 μm. By setting the average single fiber diameter to 10 μm or less, preferably to 7 μm or less, and more preferably to 5 μm or less, a sheet having excellent flexibility or fluff quality can be obtained. On the other hand, by setting the average single fiber diameter to 0.1 μm or more, preferably 0.3 μm or more, and more preferably 0.7 μm or more, the color rendering after dyeing or lapping by sanding, etc. The bundle-like fibers at the time of treatment are excellent in dispersibility, and are also easy to split.

Furthermore, in the present invention, the average single fiber diameter is a value obtained by the following procedure.

(1) From the fibrous base material, off-sea sheet, and sheet-like material, cut out the part to be a sample.

(2) For the sample, use a scanning electron microscope (SEM) to observe three cross-sections perpendicular to the thickness direction containing the fiber at 3000 times. For each cross-section, measure in μm units in a field of view of 30 μm×30 μm. The single fiber diameter of the 50 ultra-fine fibers is up to the first decimal place.

(3) The diameter of a total of 150 single fibers with three cross sections is measured, and the average value is calculated to the first decimal place.

(4) However, when fibers with a fiber diameter of more than 50 μm are mixed, the fiber system is deemed to be inconsistent with extremely fine fibers and excluded from the measurement object of the average fiber diameter. In addition, when the ultrafine fiber has a profile cross section, first, the cross-sectional area (S) of the single fiber is measured, and the diameter of the single fiber is obtained by calculating the diameter (D) of a circle corresponding to the cross-sectional area as follows. Calculate the average value of the parent group as the average single fiber diameter.

S=π D ² /4.

[Polyurethane imparting step]

Next, the polyurethane applying step of the third step will be described, which is to give a water-dispersible polyurethane to a fibrous base material having ultrafine fibers as a main constituent component to which polyvinyl alcohol is added.

The water-dispersed polyurethanes are classified as: (I) Forced emulsified polyurethanes stabilized in water by using surfactants, and (II) Polyurethanes in (II) The ester molecular structure has a hydrophilic structure, and even if the surfactant is not present, it can disperse and stabilize the self-emulsifying polyurethane in water, but any one can be used in the present invention.

The method of imparting the water-dispersible polyurethane to the fibrous base material is not particularly limited. The method of impregnating ‧ water-dispersible polyurethane solution onto a fibrous substrate and heating and drying after solidification is preferable because it can be evenly applied.

From the viewpoint of storage stability of the water-dispersible polyurethane solution, the concentration of the polyurethane is preferably 10 to 50% by mass in the water-dispersible polyurethane solution, and more preferably 15 ~40% by mass.

In addition, the water-dispersible polyurethane liquid used in the present invention may contain a water-soluble organic solvent of 40% by mass or less relative to the polyurethane liquid in order to improve storage stability or film-forming properties. From the viewpoint of preservation of the film-forming environment and the like, the content of the organic solvent is preferably 1% by mass or less.

In addition, as the water-dispersible polyurethane liquid used in the present invention, it is preferable to have thermal coagulability. By using a heat-dispersible water-dispersible polyurethane liquid, the polyurethane can be uniformly provided in the thickness direction of the fibrous base material.

In the present invention, the so-called thermosetting property refers to the property that when the polyurethane liquid is heated, if it reaches a certain temperature, the fluidity of the polyurethane liquid decreases and the solidification occurs. This temperature is called the heat-sensitive solidification temperature. In the manufacture of sheet material with polyurethane, after the polyurethane liquid is applied to the fibrous base material, it is made by dry coagulation, wet heat coagulation, wet coagulation, or a combination of these It is solidified and dried to impart polyurethane to the fibrous substrate. As a method of coagulating a water-dispersible polyurethane liquid that does not exhibit thermal coagulability, dry coagulation is practical in industrial production. At that time, a migration phenomenon in which polyurethane was concentrated on the surface layer of the fibrous substrate occurred, and the texture of the sheet attached with polyurethane tended to harden. At that time, by adjusting the viscosity of the water-dispersed polyurethane liquid with a thickener, migration can be prevented. In addition, in the case of a water-dispersible polyurethane liquid exhibiting thermal coagulation, a thickener may be added to perform dry coagulation to prevent migration.

The thermal coagulation temperature of the water-dispersible polyurethane liquid is preferably 40 to 90°C. By setting the heat-sensitive coagulation temperature to 40° C. or higher, the stability of the polyurethane liquid during storage becomes good, and it is possible to suppress the adhesion of the polyurethane to the machine during operation. In addition, by setting the thermal coagulation temperature to 90° C. or lower, the migration of polyurethane to the surface layer of the fibrous base material can be suppressed.

In one aspect of the present invention, in order to make the heat-sensitive coagulation temperature as described above, a heat-sensitive coagulant may be appropriately added. Examples of the heat-sensitive coagulant include inorganic salts such as sodium chloride, potassium chloride, sodium sulfate, magnesium sulfate, calcium sulfate, and calcium chloride; sodium persulfate, potassium persulfate, ammonium persulfate, and azobisiso Free radical reaction initiators such as butyronitrile and benzoyl peroxide.

In a preferred aspect of the present invention, the polyurethane solution can be impregnated and coated on a fibrous substrate, etc., by dry coagulation, wet heat coagulation, wet coagulation, or a combination of these, the polyurethane Ester solidifies.

The temperature of the aforementioned wet heat coagulation is preferably set to be higher than the heat-sensitive coagulation temperature of the polyurethane, more preferably 40 to 200°C. By setting the temperature of moist heat coagulation to 40°C or higher, preferably 80°C or higher, the time from polyurethane to coagulation can be shortened to further suppress migration. On the other hand, it is possible to prevent the thermal degradation of polyurethane or polyvinyl alcohol by setting the temperature of humid heat coagulation to 200°C or lower, preferably 160°C or lower.

The temperature of the aforementioned wet coagulation is set to be higher than the heat-sensitive coagulation temperature of the polyurethane, preferably 40 to 100°C. By setting the temperature of wet coagulation in hot water to 40°C or higher, preferably 80°C or higher, the time from polyurethane to coagulation can be shortened to further suppress migration.

The temperature and drying temperature of the aforementioned dry coagulation are preferably 80 to 140°C. By setting the dry coagulation temperature and the drying temperature to 80° C. or higher, preferably 90° C. or higher, the productivity is excellent. On the other hand, by setting the dry coagulation temperature and the drying temperature to 140° C. or lower, preferably 130° C. or lower, thermal degradation of polyurethane or polyvinyl alcohol can be prevented.

In the present invention, after the polyurethane is solidified, heat treatment may be performed. By performing heat treatment, the interface between the polyurethane molecules is reduced, and it becomes a stronger polyurethane. After removing the polyvinyl alcohol from the sheet provided with the water-dispersible polyurethane, heat treatment is also preferred. The temperature of the heat treatment is preferably set to 80 to 170°C.

The polyurethane used in the present invention is preferably obtained by the reaction of a polymer diol, an organic diisocyanate and a chain extender.

The polymer diol is not particularly limited, and for example, polycarbonate-based, polyester-based, polyether-based, polysiloxane-based, and fluorine-based diols can be used, and copolymers in combination with these can also be used . From the viewpoint of hydrolysis resistance, polycarbonate-based and polyether-based diols are preferably used. In addition, from the viewpoint of light resistance and heat resistance, polycarbonate and polyester systems are preferably used. Furthermore, from the viewpoint of the balance of hydrolysis resistance, heat resistance and light resistance, polycarbonate-based and polyester-based diols are more preferred, and polycarbonate-based diols are particularly preferred.

The aforementioned polycarbonate diols can be produced by the transesterification reaction of alkanediol and carbonate, or the reaction of phosgene or chloroformate with alkanediol.

The alkanediol is not particularly limited, and examples thereof include the following.

Examples of linear alkanediols include ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, and 1, 10-decanediol, etc.

As the branched alkylene glycol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-methyl-1, 8-octanediol, etc.

In addition, alicyclic diols such as 1,4-cyclohexanediol, aromatic diols such as bisphenol A, glycerin, trimethylolpropane, pentaerythritol and the like can be mentioned.

It may be a polycarbonate diol obtained from each individual alkanediol, or any one of copolymerized polycarbonate diols obtained from two or more kinds of alkanediols.

Examples of the polyester diols include polyester diols obtained by condensing various low molecular weight polyols and polybasic acids.

The low-molecular-weight polyol is not particularly limited, and examples thereof include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and 2 ,2-dimethyl-1,3-propanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,8-octanediol, diethylene glycol, triethylene glycol One or more selected from alcohol, dipropylene glycol, tripropylene glycol, cyclohexane-1,4-diol and cyclohexane-1,4-dimethanol. In addition, an adduct obtained by adding various alkylene oxides to bisphenol A can also be used.

In addition, the polybasic acid is not particularly limited, and examples thereof include succinic acid, maleic acid, adipic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and ten. One or more selected from dioxane dicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid and hexahydroisophthalic acid.

The polyether-based diol is not particularly limited, and examples thereof include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and copolymerized diols combining these.

The number average molecular weight of the polymer diol used in the present invention is preferably 500-4000. It is possible to prevent the texture from becoming hard by setting the number average molecular weight to 500 or more, preferably 1500 or more. In addition, the strength as a polyurethane can be maintained by setting the number average molecular weight to 4000 or less, preferably 3000 or less.

The organic diisocyanate is not particularly limited, and examples thereof include aliphatic diisocyanates such as hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, and xylylene diisocyanate. , Or aromatic diisocyanates such as diphenylmethane diisocyanate, toluene diisocyanate, etc., and these can also be used in combination. Among them, aliphatic diisocyanates such as hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, etc. are more preferably used from the viewpoint of light resistance.

The chain extender is not particularly limited, and amine-based chain extenders such as ethylenediamine and methylenebisaniline, and glycol-based chain extenders such as ethylene glycol can be used. In addition, a polyamine obtained by reacting polyisocyanate with water may be used as a chain extender.

In polyurethane, for the purpose of improving water resistance, abrasion resistance and hydrolysis resistance, etc., a crosslinking agent may be used together. The cross-linking agent may be an external cross-linking agent added as a third component to the polyurethane, or an internal cross-linking agent that has previously introduced a reaction point that becomes a cross-linked structure into the molecular structure of the polyurethane. In the present invention, from the point that the cross-linking points can be formed more uniformly within the polyurethane molecular structure, and the reduction in softness can be reduced, it is preferable to use an internal cross-linking agent.

唑啉基、碳二亞胺基、環氧基、三聚氰胺樹脂及矽醇基等之化合物。惟，若交聯係過剩地進行，則有聚胺甲酸酯硬化而片狀物的質感變硬之傾向，故在反應性與柔軟性的平衡之點上，較宜使用具有矽醇基者。 As the aforementioned crosslinking agent, an isocyanate group,

Compounds such as oxazoline, carbodiimide, epoxy, melamine resin and silanol. However, if the cross-linking is carried out excessively, the polyurethane tends to harden and the texture of the flakes becomes hard, so it is preferable to use a silanol group at the point of balance between reactivity and flexibility.

In addition, the polyurethane used in the present invention preferably has a hydrophilic group in the molecular structure. By having a hydrophilic group in the molecular structure, the dispersion and stability of the water-dispersible polyurethane can be improved.

As the hydrophilic group, for example, cationic systems such as quaternary amine salts, anionic systems such as sulfonates or carboxylates, nonionic systems such as polyethylene glycol, a combination of cationic systems and nonionic systems, And any hydrophilic group in combination of anionic and nonionic systems. Among them, particularly preferred is the use of a nonionic hydrophilic group free of concerns about yellowing caused by light or defects caused by neutralizing agents.

Moreover, in the case of an anionic hydrophilic group, a neutralizing agent is required, for example, when the aforementioned neutralizing agent is a tertiary amine such as ammonia, triethylamine, triethanolamine, triisopropanolamine, trimethylamine and dimethylethanolamine, etc. At the time, the amine produced ‧ volatilization due to the heat during film formation or drying, and was released outside the system. Therefore, in order to suppress atmospheric emission or deterioration of the working environment, it is necessary to introduce a device capable of recovering the volatilized amine. In addition, when the amine does not evaporate due to heating and remains in the sheet of the final product, it is also considered to be discharged into the environment when the product is incinerated. On the other hand, in the case of a nonionic hydrophilic group, since a neutralizing agent is not used, it is not necessary to introduce an amine recovery device, and since there is no concern that the amine remains in the sheet, it can be used more preferably.

In addition, when the neutralizing agent of the anionic hydrophilic group is an alkali metal such as sodium hydroxide, potassium hydroxide and calcium hydroxide, or a hydroxide of an alkaline earth metal, etc., if the polyurethane part is covered with water When wet, it shows basicity, but since the nonionic hydrophilic group does not use a neutralizing agent, there is no need to worry about the deterioration caused by the hydrolysis of polyurethane.

The water-dispersible polyurethane used in the present invention can contain various additives as needed, such as pigments such as carbon black, phosphorus-based, halogen-based, polysiloxane-based and inorganic flame retardants, phenol-based , Sulfur-based and phosphorus-based antioxidants, benzotriazole-based, diphenyl ketone-based, salicylate-based, cyanoacrylate-based and oxanilide-based UV absorbers, hindered amine-based or benzene Light stabilizers such as formates, hydrolytic stabilizers such as polycarbodiimide, plasticizers, antistatic agents, surfactants, softeners, water repellents, coagulation regulators, viscosity regulators, dyes, Fillers such as preservatives, antibacterial agents, deodorants, cellulose particles, microspheres, and inorganic particles such as silica or titanium oxide. In addition, in order to further increase the gap between the fiber and the polyurethane, an inorganic system such as sodium bicarbonate, 2,2'-azobis[2-methyl-N-(2-hydroxyethyl ) Acrylate] and other organic foaming agents.

The content ratio of the polyurethane is preferably 1 to 80% by mass relative to the fibrous base material of the present invention, which contains ultrafine fibers as the main constituent component. By setting the ratio of the polyurethane to 1% by mass or more, preferably 5% by mass or more, it is possible to prevent the fibers from falling off while obtaining sheet strength. In addition, by setting the blending ratio of the polyurethane to 80% by mass or less, preferably 70% by mass or less, the texture can be prevented from becoming hard, and good pile quality can be obtained.

[Polyvinyl alcohol removal step]

Next, the step of removing polyvinyl alcohol from the fibrous base material containing ultrafine fibers to which polyvinyl alcohol and water-dispersed polyurethane are added in the fourth step will be described.

In a preferred aspect of the present invention, by removing polyvinyl alcohol from the fibrous base material after the polyurethane has been applied, a soft sheet is obtained. The method for removing polyvinyl alcohol is not particularly limited. For example, the preferred form is to immerse the sheet in hot water at 60 to 100°C, and if necessary, squeeze the liquid by a rolling mill or the like to dissolve and remove it.

In the manufacturing method of the sheet-like object of the present invention, after the water-dispersible polyurethane is applied to the fibrous base material to which at least polyvinyl alcohol is applied, a step of cutting in half in the thickness direction may also be included. In the step of imparting polyvinyl alcohol, polyvinyl alcohol tends to adhere to the surface layer of the fibrous base material due to migration, and the amount of polyvinyl alcohol attached to the inner layer is small. Then, by giving the water-dispersible polyurethane after cutting in half in the thickness direction, it is possible to obtain that the water-dispersible polyurethane has less adhesion on the side where the amount of polyvinyl alcohol adhesion is large, and adhesion on the polyvinyl alcohol A sheet with a small amount of water-dispersible polyurethane attached to the structure. When the surface on which the polyvinyl alcohol adheres more, in other words, the surface on which the water-dispersible polyurethane adheres less, is used as the fluff surface of the sheet, the following effects can be obtained. By giving polyvinyl alcohol, a large gap is created between the polyurethane and the ultrafine fibers constituting the fluff. By this, the fibers constituting the fluff are given a degree of freedom, the texture of the surface becomes soft, and good appearance quality and soft touch can be obtained.

Conversely, when the surface on which polyvinyl alcohol adheres less, that is, the surface on which water-dispersible polyurethane adheres more, is used as the fluff surface of the sheet, the following effects can be obtained. The fiber system constituting the fluff is strongly controlled by polyurethane. Therefore, the pile length is short, but a good appearance quality with a dense feeling is obtained, and the change in abrasion resistance is good. Furthermore, by including the step of cutting in half in the thickness direction of the sheet, the production efficiency can be improved.

In the present invention, at least one side of the sheet may be fluffed to form fluff on the surface. The method of forming fluff is not particularly limited, and various methods commonly performed in the art by sanding with sandpaper or the like can be used. If the fluff length is too short, it is difficult to obtain a beautiful appearance, and if it is too long, there is a tendency for pilling to occur easily, so the fluff length is preferably 0.2 to 1 mm.

Furthermore, in one aspect of the present invention, before the fluffing treatment, polysiloxane or the like as a slip agent may be added to the sheet. By imparting a slip agent, it can be easily fluffed by surface grinding, and the surface quality becomes very good and suitable. In addition, an antistatic agent may be added before the fuzzing process. By the application of the antistatic agent, the grinding powder generated from the sheet due to grinding becomes less likely to accumulate on the sandpaper, which is preferred.

In one aspect of the invention, the flakes can be dyed. As the dyeing method, various methods commonly used in this field can be used, but from the viewpoint of imparting a kneading effect while dyeing the sheet, and softening the sheet, a method using a flow dyeing machine is preferred .

The dyeing temperature also depends on the type of fiber, but it is preferably 80 to 150°C. By setting the dyeing temperature to 80° C. or higher, preferably 110° C. or higher, the fiber can be dyed efficiently. On the other hand, the deterioration of the polyurethane can be prevented by setting the dyeing temperature to 150°C or lower, preferably 130°C or lower.

The dye used in the present invention is not particularly limited as long as it is selected according to the type of fiber constituting the fibrous base material. For example, if it is a polyester fiber, a disperse dye can be used, and if it is a polyamide fiber, Acid dyes or gold-containing dyes can be used, or a combination of these can be used. When dyeing with disperse dyes, reduction washing can be carried out after dyeing.

In addition, the use of dyeing aids in dyeing is also a preferred aspect. By using dyeing aids, the uniformity or reproducibility of dyeing can be improved. In addition, after dyeing in the same bath or after dyeing, a finishing agent using a softener such as polysiloxane, an antistatic agent, a water repellent agent, a flame retardant, a light-resistant agent, an antibacterial agent, etc. may be applied.

(Flakes)

The sheet obtained by the aforementioned manufacturing method achieves a beautiful appearance and soft texture, and has good wear resistance.

In the present invention, the surface appearance of the sheet-like object is evaluated by the following method.

The surface appearance of the sheet is 10 adult males and 2 females in good health, and a total of 20 are regarded as evaluators. By visual and sensory evaluations, a 5-level evaluation is performed as follows, and the most evaluations are regarded as The surface appearance of the sheet. In addition, the appearance of the surface is regarded as good from grade 3 to grade 5.

Level 5: Uniform fiber fluff, good dispersion of fibers, good appearance.

Level 4: Evaluation between Level 5 and Level 3.

Grade 3: Although there is a slight defect in the dispersion state of the fiber, there is fluff of the fiber, and the appearance is fairly good.

Level 2: Evaluation between level 3 and level 1.

Level 1: The dispersion state of the fiber is very poor overall, or the fluff of the fiber is long and the appearance is poor.

In the present invention, the softness of the sheet is based on the "A method (45° cantilever method)" described in 8.21 "Stiffness" and 8.21.1 of JIS L1096: 2010 "Test method for grey fabrics of woven fabrics and knitted fabrics" , By evaluating the size of the stiffness (mm) measured as follows.

(1) Make a pair of test pieces of 2 cm × 15 cm in longitudinal and lateral directions respectively.

(2) Place on a water platform with a slope of 45°.

(3) Slide the test piece, and read the position of the other end when the center point of one end of the test piece comes into contact with the inclined surface by a ruler.

(4) The moving length of the test piece at this time is expressed in (mm), and the average value of the moving lengths of the five test pieces is determined as the stiffness (mm).

In the present invention, the stiffness of the sheet is preferably 20 to 45 mm, and more preferably 25 mm or more. In addition, when the stiffness is high, it is preferably 40 mm or less.

In the present invention, the wear resistance is evaluated by the degree of reduction of the wear loss (mg) measured by the following method.

(1) A circular sample (diameter 45 mm) of the sheet-like material was cut out, and the mass was measured.

(2) Cut the polyamide fiber with a diameter of 0.4mm containing polyamide 6 into a length of 11mm perpendicular to the length of the fiber, and use 100 parallel wires to form a bundle. Use 97 concentric bundles with 6-fold concentricity The circle is arranged in a circle with a diameter of 110 mm (1 at the center, 6 at a circle with a diameter of 17 mm, 13 at a circle with a diameter of 37 mm, 19 at a circle with a diameter of 55 mm, and 26 at a circle with a diameter of 74 mm. There are 32 round brushes (9700 nylon yarns) in a circle with a diameter of 90 mm and a middle interval in each circle. Under the conditions of a load of 8 pounds (about 3629 g), a rotation speed of 65 rpm, and a number of rotations of 50 times, Abrasive the surface of the round sample (45mm diameter) of the flakes.

(3) Measure the mass of the sample after wear, and calculate the mass change of the sample before and after wear.

(4) The wear loss (mg) of the average value of the mass change of 5 samples is taken as the abrasion resistance.

In the present invention, the amount of wear reduction of the flakes is preferably 30 mg or less, and more preferably 25 mg or less.

In addition, the density of the sheet obtained by the aforementioned manufacturing method is preferably 0.2 to 0.7 g/cm ³ . By setting the density to 0.2 g/cm ³ or more, preferably 0.3 g/cm ³ or more, the surface appearance becomes dense, and high-quality quality can be exhibited. On the other hand, by setting the density to 0.7 g/cm ³ or less, preferably 0.6 g/cm ³ or less, the texture of the sheet-like material can be prevented from becoming hard.

[Example]

Next, the method for manufacturing the sheet of the present invention will be described in more detail by way of examples, but the present invention is not limited by these examples, and those with ordinary knowledge in the art within the technical idea of the present invention The system can undergo many deformations.

[Evaluation method]

The evaluation method will be described in detail below, but unless there is no particular description in the measurement of each physical property, the measurement is performed according to the method described above.

(1) Three-dimensional regularity of polyvinyl alcohol

In a straight tube, put a sample in which 10 mg of polyvinyl alcohol was dissolved in 1 mL of heavy water (D ₂ O) at a temperature of 80° C. to measure the temperature at 80° C., the resonance frequency of 100 MHz, and the cumulative number of times 20,000 times As above, ¹³ C-NMR measurement was performed. For the measurement, ECA400 manufactured by JEOL RESONANCE was used.

(2) Average single fiber diameter

As a scanning electron microscope, VE-7800 model manufactured by KEYENCE Corporation was used.

[Example 1] (Non-woven fabric forming step for fibrous substrate)

Polyethylene terephthalate copolymerized with 8 mol% of 5-sulfoisophthalic acid sodium was prepared as the sea component, and polyethylene terephthalate was prepared as the island component. A sea-island composite fiber with a number of islands of 36 islands/1 filament and an average single fiber diameter of 17 μm was obtained at a composite ratio of 45% by mass of sea component and 55% by mass of island component. The obtained sea-island composite fiber was cut into a fiber length of 51 mm to become a short fiber. It is formed into a fiber web by a carding machine and a cross-laying machine, and becomes a non-woven fabric by needle punching. The nonwoven fabric thus obtained was immersed in hot water at a temperature of 98°C for 2 minutes to shrink it, and dried at a temperature of 100°C for 5 minutes to form a nonwoven fabric for a fibrous base material.

(Procedure for preparing polyvinyl alcohol aqueous solution)

Polyvinyl alcohol having a saponification degree of 98%, a rrr composition ratio of 15.5% and a polymerization degree of 450 obtained from polyvinyl acetate was prepared. This was added to water at 25°C, and after raising the temperature to 90°C, it was kept at 90°C while stirring for 2 hours to prepare an aqueous solution with a solid content of 10% by mass to obtain an aqueous solution of polyvinyl alcohol.

(Polyvinyl alcohol imparting step)

The fibrous base material non-woven fabric was impregnated with the polyvinyl alcohol aqueous solution, heated and dried at a temperature of 140°C for 10 minutes, and then subjected to a heat treatment at a temperature of 160°C for 5 minutes. A polyvinyl alcohol-imparting sheet having an adhesion amount of polyvinyl alcohol of 30% by mass relative to the fiber mass of the nonwoven fabric for fibrous base materials was obtained.

(Extra-fine fiber display steps)

The polyvinyl alcohol-imparting sheet was immersed in an aqueous solution of sodium hydroxide having a concentration of 10 g/L heated to a temperature of 60° C. and treated for 30 minutes to obtain a sea-removing sheet after removing the sea component of the sea-island composite fiber. The average single-fiber diameter of the off-sea section is 3 μm.

(Polyurethane solution preparation step)

For 100 parts by mass of the solid content of polycarbonate-based self-emulsifying polyurethane liquid using polyhexamethylene carbonate as the polyol and dicyclohexylmethane diisocyanate as the isocyanate, add 1 part by mass of sulfuric acid Magnesium is used as a heat-sensitive coagulant, and the whole is prepared to 20% by mass of solid content with water to obtain a water-dispersible polyurethane liquid. The sensible heat setting temperature is 65°C.

(Polyurethane imparting step)

The above-mentioned polycarbonate-based polyurethane liquid is impregnated with the above-mentioned demineralized sheet provided with polyvinyl alcohol. It is treated in a dry heat environment at a temperature of 120°C for 10 minutes and dried, and further subjected to a dry heat treatment at a temperature of 150°C for 2 minutes. A sheet having an adhesion amount of polyurethane of 30% by mass relative to the fiber mass of the nonwoven fabric was obtained.

(Polyvinyl alcohol removal step)

The above-mentioned polyurethane-attached sheet was immersed in water heated to 95° C. for 10 minutes to obtain a sheet obtained by removing the provided polyvinyl alcohol.

(Half cut, fluff, dye, restore washing steps)

The above-mentioned polyvinyl alcohol-removed sheet was cut in half in the thickness direction. By grinding with 240-mesh ring sandpaper, the surface opposite to the half-cut surface is raised. Then, using a circulating flow dyeing machine, dyeing with disperse dyes, reduction washing is performed to obtain sheets.

The surface of the obtained sheet-like object is good, and has a soft texture.

[Example 2] (Non-woven fabric forming step for fibrous substrate)

Polyethylene terephthalate copolymerized with 8 mol% of 5-sulfoisophthalic acid sodium was prepared as the sea component, and polyethylene terephthalate was prepared as the island component. A sea-island composite fiber with a number of islands of 16 islands per filament and an average single fiber diameter of 12 μm was obtained at a composite ratio of 45% by mass of sea component and 55% by mass of island component. The obtained sea-island composite fiber was cut into a fiber length of 51 mm to become a short fiber. It is formed into a fiber web by a carding machine and a cross-laying machine, and is subjected to a needle punching treatment to become a non-woven fabric. The nonwoven fabric thus obtained was immersed in hot water at a temperature of 98°C for 2 minutes to shrink it, and dried at a temperature of 100°C for 5 minutes to form a nonwoven fabric for a fibrous base material.

(Procedure for preparing polyvinyl alcohol aqueous solution)

In the same manner as in Example 1, a polyvinyl alcohol aqueous solution was obtained.

(Polyvinyl alcohol imparting step)

Using the same polyvinyl alcohol aqueous solution as in Example 1, a polyvinyl alcohol-imparting sheet having a polyvinyl alcohol adhesion amount of 30% by mass relative to the fiber mass of the nonwoven fabric for fibrous substrates was obtained.

(Extra-fine fiber display steps)

The nonwoven fabric for the fibrous base material was treated in the same manner as in Example 1 to obtain a sea-removed sheet after removing the sea component of the sea-island composite fiber. The average single-fiber diameter of the off-sea sheet profile is 2 μm.

(Polyurethane solution preparation step)

In the same manner as in Example 1, a water-dispersed polyurethane liquid was obtained.

(Polyurethane imparting step)

In the same manner as in Example 1, a polyurethane-imparting sheet was obtained.

(Polyvinyl alcohol removal step)

In the same manner as in Example 1, a polyvinyl alcohol removal sheet was obtained.

(Cutting half, raising, dyeing, restoring and washing)

In the same manner as in Example 1, a sheet was obtained.

The surface of the obtained sheet-like object is good, has a soft texture, and has good abrasion resistance.

[Example 3] (Non-woven fabric forming step for fibrous substrate)

Polyethylene terephthalate copolymerized with 8 mol% of 5-sulfoisophthalic acid sodium was prepared as the sea component, and polyethylene terephthalate was prepared as the island component. A sea-island composite fiber with a number of islands of 16 islands/1 filaments and an average single fiber diameter of 20 μm was obtained at a composite ratio of 20% by mass of sea component and 80% by mass of island component. The obtained sea-island composite fiber was cut into a fiber length of 51 mm to become a short fiber. It is formed into a fiber web by a carding machine and a cross-laying machine, and is subjected to a needle punching treatment to become a non-woven fabric. The nonwoven fabric thus obtained was immersed in hot water at a temperature of 98°C for 2 minutes to shrink it, and dried at a temperature of 100°C for 5 minutes to form a nonwoven fabric for fibrous substrates.

(Procedure for preparing polyvinyl alcohol aqueous solution)

In the same manner as in Example 1, a polyvinyl alcohol aqueous solution was obtained.

(Polyvinyl alcohol imparting step)

Using the same polyvinyl alcohol aqueous solution as in Example 1, a polyvinyl alcohol-imparting sheet having a polyvinyl alcohol adhesion amount of 30% by mass relative to the fiber mass of the nonwoven fabric for fibrous substrates was obtained.

(Extra-fine fiber display steps)

The nonwoven fabric for the fibrous base material was treated in the same manner as in Example 1 to obtain a sea-removed sheet after removing the sea component of the sea-island composite fiber. The average single fiber diameter in the profile of the off-sea sheet is 4.4 μm.

(Polyurethane solution preparation step)

In the same manner as in Example 1, a water-dispersed polyurethane liquid was obtained.

(Polyurethane imparting step)

In the same manner as in Example 1, a polyurethane-imparting sheet was obtained.

(Polyvinyl alcohol removal step)

In the same manner as in Example 1, a polyvinyl alcohol removal sheet was obtained.

(Half cut, fluff, dye, restore washing steps)

In the same manner as in Example 1, a sheet was obtained.

The surface of the obtained sheet-like object is good, has a soft texture, and has good abrasion resistance.

[Example 4] (Non-woven fabric forming step for fibrous substrate)

Polyethylene terephthalate copolymerized with 8 mol% of 5-sulfoisophthalic acid sodium was prepared as the sea component, and polyethylene terephthalate was prepared as the island component. A sea-island composite fiber with a number of islands of 16 islands/1 filaments and an average single fiber diameter of 24 μm was obtained at a composite ratio of 10% by mass of sea component and 90% by mass of island component. The obtained sea-island composite fiber was cut into a fiber length of 51 mm to become a short fiber. It is formed into a fiber web by a carding machine and a cross-laying machine, and is subjected to a needle punching treatment to become a non-woven fabric. The nonwoven fabric thus obtained was immersed in hot water at a temperature of 98°C for 2 minutes to shrink it, and dried at a temperature of 100°C for 5 minutes to form a nonwoven fabric for a fibrous base material.

(Procedure for preparing polyvinyl alcohol aqueous solution)

In the same manner as in Example 1, a polyvinyl alcohol aqueous solution was obtained.

(Polyvinyl alcohol imparting step)

Using the same polyvinyl alcohol aqueous solution as in Example 1, a polyvinyl alcohol-imparting sheet having a polyvinyl alcohol adhesion amount of 30% by mass relative to the fiber mass of the nonwoven fabric for fibrous substrates was obtained.

(Extra-fine fiber display steps)

The nonwoven fabric for the fibrous base material was treated in the same manner as in Example 1 to obtain a sea-removed sheet after removing the sea component of the sea-island composite fiber. The average single fiber diameter in the profile of the off-sea sheet is 5.5 μm.

(Polyurethane solution preparation step)

The same water-dispersed polyurethane liquid as in Example 1 was used.

(Polyurethane imparting step)

In the same manner as in Example 1, a polyurethane-imparting sheet was obtained.

(Polyvinyl alcohol removal step)

In the same manner as in Example 1, a polyvinyl alcohol removal sheet was obtained.

(Half cut, fluff, dye, restore washing steps)

In the same manner as in Example 1, a sheet was obtained. The surface of the obtained sheet-like object is good, has a soft texture, and has good abrasion resistance.

[0160] [Example 5] (Nonwoven fabric for fibrous substrate)

The same nonwoven fabric as the fibrous base material used in Example 1 was used.

(Preparation of aqueous solution of polyvinyl alcohol)

In the same manner as in Example 1, a polyvinyl alcohol aqueous solution was obtained.

(Conferred by Polyvinyl Alcohol)

Using the same polyvinyl alcohol aqueous solution as in Example 1, a polyvinyl alcohol-imparting sheet was obtained in the same manner as in Example 1, except that the pressure after impregnation was adjusted to change the adhesion amount of polyvinyl alcohol. This sheet system has an adhesion amount of polyvinyl alcohol of 20% by mass with respect to the fiber mass of the nonwoven fabric for fibrous substrates.

(Extra-fine fiber display steps)

In the same manner as in Example 1, a sea-off sheet was obtained from the nonwoven fabric for the fibrous base material.

(Polyurethane solution preparation step)

The same water-dispersed polyurethane liquid as in Example 1 was used.

(Polyurethane imparting step)

In the same manner as in Example 1, a polyurethane-imparting sheet was obtained.

(Polyvinyl alcohol removal step)

In the same manner as in Example 1, a polyvinyl alcohol removal sheet was obtained.

(Half cut, fluff, dye, restore washing steps)

In the same manner as in Example 1, a sheet was obtained.

The surface of the obtained sheet-like object is good, has a soft texture, and has good abrasion resistance.

[Example 6] (Non-woven fabric forming step for fibrous substrate)

Polyethylene terephthalate copolymerized with 8 mol% of 5-sulfoisophthalic acid sodium was prepared as the sea component, and polyethylene terephthalate was prepared as the island component. A sea-island composite fiber with a number of islands of 16 islands/1 filaments and an average single fiber diameter of 20 μm was obtained at a composite ratio of 20% by mass of sea component and 80% by mass of island component. The obtained sea-island composite fiber was cut into a fiber length of 51 mm to become a short fiber. It is passed through a carding machine and a cross-laying machine to form a fiber web. On both sides of the net, a flat fabric of 84dtex-72 filament of polyethylene terephthalate (PET) and a strong twisted yarn with a twist number of 2000T/m was laminated and subjected to needle-punching treatment to become a nonwoven fabric. The nonwoven fabric thus obtained was immersed in hot water at a temperature of 98°C for 2 minutes to shrink it, and dried at a temperature of 100°C for 5 minutes to form a nonwoven fabric for a fibrous base material.

(Procedure for preparing polyvinyl alcohol aqueous solution)

In the same manner as in Example 1, a polyvinyl alcohol aqueous solution was obtained.

(Polyvinyl alcohol imparting step)

Using the same polyvinyl alcohol aqueous solution as in Example 1, a polyvinyl alcohol-imparting sheet was obtained in the same manner as in Example 1, except that the pressure after impregnation was adjusted to change the adhesion amount of polyvinyl alcohol. This sheet system has an adhesion amount of polyvinyl alcohol of 15% by mass relative to the fiber mass of the nonwoven fabric for fibrous substrates.

(Extra-fine fiber display steps)

The nonwoven fabric for the fibrous base material was treated in the same manner as in Example 1 to obtain a sea-removed sheet after removing the sea component of the sea-island composite fiber. The average single fiber diameter in the profile of the off-sea sheet is 4.4 μm.

(Polyurethane solution preparation step)

The same water-dispersed polyurethane liquid as in Example 1 was used.

(Polyurethane imparting step)

In the same manner as in Example 1, a polyurethane-imparting sheet was obtained.

(Polyvinyl alcohol removal step)

In the same manner as in Example 1, a polyvinyl alcohol removal sheet was obtained.

(Cutting half, raising, dyeing, restoring and washing)

A sheet-like object was obtained in the same manner as in Example 1, except that the half surface was cut and fluffed.

The surface of the obtained sheet-like object is good, has a soft texture, and has good abrasion resistance.

[Example 7] (Non-woven fabric forming step for fibrous substrate)

The same nonwoven fabric as the fibrous base material used in Example 1 was used.

(Procedure for preparing polyvinyl alcohol aqueous solution)

A polyvinyl alcohol having a degree of saponification of 98%, a rrr composition ratio of 15.2%, and a degree of polymerization of 1,000 obtained from polyvinyl acetate was prepared. This was added to water at 25° C., and after the temperature was raised to 90° C., the temperature was kept at 90° C. while stirring for 2 hours, and a polyvinyl alcohol aqueous solution with a solid content of 10% by mass was obtained.

(Polyvinyl alcohol imparting step)

A polyvinyl alcohol-imparting sheet having an adhesion amount of polyvinyl alcohol of 30% by mass relative to the fiber mass of the nonwoven fabric for fibrous substrates was obtained in the same manner as in Example 1 except that the above-mentioned polyvinyl alcohol aqueous solution was used.

(Extra-fine fiber display steps)

In the same manner as in Example 1, a sea-off sheet was obtained from the nonwoven fabric for the fibrous base material.

(Polyurethane solution preparation step)

The same water-dispersed polyurethane liquid as in Example 1 was used.

(Polyurethane imparting step)

In the same manner as in Example 1, a polyurethane-imparting sheet was obtained.

(Polyvinyl alcohol removal step)

In the same manner as in Example 1, a polyvinyl alcohol removal sheet was obtained.

(Half cut, fluff, dye, restore washing steps)

In the same manner as in Example 1, a sheet was obtained.

The surface of the obtained sheet-like object is good, has a soft texture, and has good abrasion resistance.

[Example 8] (Non-woven fabric forming step for fibrous substrate)

In the same manner as in Example 6, a nonwoven fabric for fibrous base materials was obtained.

(Procedure for preparing polyvinyl alcohol aqueous solution)

In the same manner as in Example 7, a polyvinyl alcohol aqueous solution was obtained.

(Polyvinyl alcohol imparting step)

Except for using the polyvinyl alcohol aqueous solution of Example 7, in the same manner as in Example 6, a polyvinyl alcohol-imparting sheet having a polyvinyl alcohol adhesion amount of 15% by mass relative to the fiber mass of the nonwoven fabric for fibrous substrates was obtained.

(Extra-fine fiber display steps)

In the same manner as in Example 1, off-sea slices were obtained.

(Polyurethane solution preparation step)

The same water-dispersed polyurethane liquid as in Example 1 was used.

(Polyurethane imparting step)

In the same manner as in Example 1, a polyurethane-imparting sheet was obtained.

(Polyvinyl alcohol removal step)

In the same manner as in Example 1, a polyvinyl alcohol removal sheet was obtained.

(Half cut, fluff, dye, restore washing steps)

In the same manner as in Example 6, a sheet was obtained.

The surface of the obtained sheet-like object is good, has a soft texture, and has good abrasion resistance.

[Comparative Example 1] (Non-woven fabric forming step for fibrous substrate)

The same nonwoven fabric as the fibrous base material used in Example 1 was used.

(Procedure for preparing polyvinyl alcohol aqueous solution)

Polyvinyl alcohol having a saponification degree of 98% obtained from polyvinyl acetate, a rrr composition ratio of 14.1%, and a polymerization degree of 400 was prepared. This was added to water at 25°C, and after raising the temperature to 90°C, it was kept at 90°C while stirring for 2 hours to prepare an aqueous solution with a solid content of 10% by mass to obtain an aqueous solution of polyvinyl alcohol.

(Polyvinyl alcohol imparting step)

Except for using the above-mentioned polyvinyl alcohol aqueous solution, in the same manner as in Example 1, a polyvinyl alcohol-imparting sheet having a polyvinyl alcohol adhesion amount of 30% by mass relative to the fiber mass of the nonwoven fabric for fibrous base materials was obtained.

(Extra-fine fiber display steps)

In the same manner as in Example 1, a sea-off sheet was obtained from the nonwoven fabric for the fibrous base material.

(Polyurethane solution preparation step)

The same water-dispersed polyurethane liquid as in Example 1 was used.

(Polyurethane imparting step)

In the same manner as in Example 1, a polyurethane-imparting sheet was obtained.

(Polyvinyl alcohol removal step)

In the same manner as in Example 1, a polyvinyl alcohol removal sheet was obtained.

(Half cut, fluff, dye, restore washing steps)

In the same manner as in Example 1, a sheet was obtained.

The obtained sheet-like material is partially dissolved in an alkali aqueous solution or a water-dispersed polyurethane solution, and does not become a uniformly imparted state, and the surface appearance system is poorly dispersed in fibers, and there is no dense feeling of fluff And bad, hard texture.

[Comparative Example 2] (Nonwoven fabric for fibrous substrate)

In the same manner as in Example 6, a nonwoven fabric for fibrous base materials was obtained.

(Preparation of polyvinyl alcohol aqueous solution)

In the same manner as in Comparative Example 1, a polyvinyl alcohol aqueous solution was obtained.

(Given by polyvinyl alcohol)

Except for using the polyvinyl alcohol aqueous solution of Comparative Example 1, in the same manner as in Example 6, a polyvinyl alcohol-imparting sheet having a polyvinyl alcohol adhesion amount of 15% by mass relative to the fiber mass of the nonwoven fabric for fibrous substrates was obtained.

(Extra-fine fiber display steps)

In the same manner as in Example 1, off-sea slices were obtained.

(Polyurethane solution preparation step)

The same water-dispersed polyurethane liquid as in Example 1 was used.

(Polyurethane imparting step)

In the same manner as in Example 1, a polyurethane-imparting sheet was obtained.

(Polyvinyl alcohol removal step)

In the same manner as in Example 1, a polyvinyl alcohol removal sheet was obtained.

(Half cut, fluff, dye, restore washing steps)

In the same manner as in Example 6, a sheet was obtained.

The obtained sheet-like material is partially dissolved in an alkali aqueous solution or a water-dispersed polyurethane solution, and does not become a uniformly imparted state, and the surface appearance system is poorly dispersed in fibers, and there is no dense feeling of fluff And bad, hard texture.

[Comparative Example 3]

(Non-woven fabric forming step for fibrous substrate)

The same nonwoven fabric as the fibrous base material used in Example 1 was used.

(Procedure for preparing polyvinyl alcohol aqueous solution)

A polyvinyl alcohol having a saponification degree of 98% obtained from polyvinyl acetate, a rrr composition existence ratio of 13.9%, and a polymerization degree of 500 was prepared. This was added to water at 25° C., and the temperature was raised to 90° C. After stirring for 2 hours, the temperature was kept at 90° C. A solid content of 10% by mass aqueous solution was prepared to obtain a polyvinyl alcohol aqueous solution.

(Polyvinyl alcohol imparting step)

Except for using the above-mentioned polyvinyl alcohol aqueous solution, in the same manner as in Example 1, a polyvinyl alcohol-imparting sheet having a polyvinyl alcohol adhesion amount of 30% by mass relative to the fiber mass of the nonwoven fabric for fibrous substrates was obtained.

(Extra-fine fiber display steps)

In the same manner as in Example 1, a sea-off sheet was obtained from the nonwoven fabric for the fibrous base material.

(Polyurethane solution preparation step)

The same water-dispersed polyurethane liquid as in Example 1 was used.

(Polyurethane imparting step)

In the same manner as in Example 1, a polyurethane-imparting sheet was obtained.

(Polyvinyl alcohol removal step)

In the same manner as in Example 1, a polyvinyl alcohol removal sheet was obtained.

(Half cut, fluff, dye, restore washing steps)

In the same manner as in Example 1, a sheet was obtained.

The obtained sheet-like material is partially dissolved in an alkali aqueous solution or a water-dispersed polyurethane solution, and does not become a uniformly imparted state, and the surface appearance system is poorly dispersed in fibers, and there is no dense feeling of fluff And bad, hard texture.

【0223】 [Comparative Example 4] (Non-woven fabric forming step for fibrous substrate)

The same nonwoven fabric as the fibrous base material used in Example 1 was used.

(Procedure for preparing polyvinyl alcohol aqueous solution)

Polyvinyl alcohol having a saponification degree of 99%, a rrr composition existing ratio of 14.4%, and a polymerization degree of 500 obtained from polyvinyl acetate was prepared. This was added to water at 25°C, and after raising the temperature to 90°C, it was kept at 90°C while stirring for 2 hours to prepare an aqueous solution with a solid content of 10% by mass to obtain an aqueous solution of polyvinyl alcohol.

(Polyvinyl alcohol imparting step)

Except for using the above-mentioned polyvinyl alcohol aqueous solution, in the same manner as in Example 1, a polyvinyl alcohol-imparting sheet having a polyvinyl alcohol adhesion amount of 30% by mass relative to the fiber mass of the nonwoven fabric for fibrous base materials was obtained.

(Extra-fine fiber display steps)

In the same manner as in Example 1, a sea-off sheet was obtained from the nonwoven fabric for the fibrous base material.

(Polyurethane solution preparation step)

The same water-dispersed polyurethane liquid as in Example 1 was used.

(Polyurethane imparting step)

In the same manner as in Example 1, a polyurethane-imparting sheet was obtained.

(Polyvinyl alcohol removal step)

In the same manner as in Example 1, a polyvinyl alcohol removal sheet was obtained.

(Half cut, fluff, dye, restore washing steps)

In the same manner as in Example 1, a sheet was obtained.

The obtained sheet-like material is partially dissolved in an alkali aqueous solution or a water-dispersible polyurethane solution, and does not become a uniformly imparted state. The surface appearance is poor in the dispersion state of the fibers, and there is no dense feeling of fluff. And bad, hard texture.

[Comparative Example 5] (Non-woven fabric forming step for fibrous substrate)

The same nonwoven fabric as the fibrous base material used in Example 1 was used.

(Procedure for preparing polyvinyl alcohol aqueous solution)

Polyvinyl alcohol having a saponification degree of 88% obtained from polyvinyl acetate, a rrr composition ratio of 14.2%, and a polymerization degree of 500 was prepared. This was added to water at 25°C, and after raising the temperature to 90°C, it was kept at 90°C while stirring for 2 hours to prepare an aqueous solution with a solid content of 10% by mass to obtain an aqueous solution of polyvinyl alcohol.

(Polyvinyl alcohol imparting step)

Except for using the above-mentioned polyvinyl alcohol aqueous solution, in the same manner as in Example 1, a polyvinyl alcohol-imparting sheet having a polyvinyl alcohol adhesion amount of 30% by mass relative to the fiber mass of the nonwoven fabric for fibrous base materials was obtained.

(Extra-fine fiber display steps)

In the same manner as in Example 1, a sea-off sheet was obtained from the nonwoven fabric for the fibrous base material.

(Polyurethane solution preparation step)

The same water-dispersed polyurethane liquid as in Example 1 was used.

(Polyurethane imparting step)

In the same manner as in Example 1, a polyurethane-imparting sheet was obtained.

(Polyvinyl alcohol removal step)

In the same manner as in Example 1, a polyvinyl alcohol removal sheet was obtained.

(Half cut, fluff, dye, restore washing steps)

In the same manner as in Example 1, a sheet was obtained.

The obtained sheet-like material is partially dissolved in an alkali aqueous solution or a water-dispersed polyurethane solution, and does not become a uniformly imparted state, and the surface appearance system is poorly dispersed in fibers, and there is no dense feeling of fluff And bad, hard texture.

[Comparative Example 6] (Non-woven fabric forming step for fibrous substrate)

The same nonwoven fabric as the fibrous base material used in Example 1 was used.

(Procedure for preparing polyvinyl alcohol aqueous solution)

In the same manner as in Example 1, a polyvinyl alcohol aqueous solution was obtained.

(Extra-fine fiber display steps)

The fibrous base material obtained above was immersed in a non-woven fabric in an aqueous solution of sodium hydroxide with a concentration of 10 g/liter heated to a temperature of 95° C. and treated for 10 minutes to obtain a sea-removal sheet after removing the sea component of the sea-island composite fiber . The average single fiber diameter in the cross-section of the off-sea sheet is 3 μm.

(Polyvinyl alcohol imparting step)

The polyvinyl alcohol aqueous solution obtained in Example 1 was impregnated with the above-mentioned sea-removing piece. This was heated and dried at a temperature of 140° C. for 10 minutes to obtain a polyvinyl alcohol-imparting sheet in which the adhesion amount of polyvinyl alcohol to the sea-removing sheet was 30% by mass.

(Polyurethane solution preparation step)

The same water-dispersed polyurethane liquid as in Example 1 was used.

(Polyurethane imparting step)

In the same manner as in Example 1, a polyurethane-imparting sheet was obtained.

(Polyvinyl alcohol removal step)

In the same manner as in Example 1, a polyvinyl alcohol removal sheet was obtained.

(Half cut, fluff, dye, restore washing steps)

In the same manner as in Example 1, a sheet was obtained.

The surface of the obtained sheet-like object has a good appearance and has a soft texture, but the amount of wear reduction is large.

[Comparative Example 7] (Non-woven fabric forming step for fibrous substrate)

The same nonwoven fabric as the fibrous base material used in Example 1 was used.

(Procedure for preparing polyvinyl alcohol aqueous solution)

In the same manner as in Example 1, a polyvinyl alcohol aqueous solution was obtained.

(Polyvinyl alcohol imparting step)

The same polyvinyl alcohol aqueous solution as in Example 1 was used, and the quality of the fiber relative to the nonwoven fabric for the fibrous base material was obtained in the same manner as in Example 1, except that the pressure after impregnation was adjusted to change the adhesion amount of polyvinyl alcohol. A polyvinyl alcohol-imparting sheet having a polyvinyl alcohol adhesion amount of 55% by mass.

(Extra-fine fiber display steps)

In the same manner as in Example 1, a sea-off sheet was obtained from the nonwoven fabric for the fibrous base material.

(Polyurethane solution preparation step)

The same water-dispersed polyurethane liquid as in Example 1 was used.

(Polyurethane imparting step)

In the same manner as in Example 1, a polyurethane-imparting sheet was obtained.

(Polyvinyl alcohol removal step)

In the same manner as in Example 1, a polyvinyl alcohol removal sheet was obtained.

(Half cut, fluff, dye, restore washing steps)

In the same manner as in Example 1, a sheet was obtained. Although the obtained sheet-like material has a soft texture, due to the excessive amount of polyvinyl alcohol, the polyurethane has insufficient gripping system for the fiber, the surface appearance is too long and poor, and the wear resistance is poor.

Table 1 shows the test conditions of each example and comparative example and the evaluation results of the sheet.

[Table 1]

The flakes obtained in Examples 1 to 8 are inhibited from dissolving or falling off of water in the polyvinyl alcohol in the sea-removal step or the water-dispersible polyurethane-imparting step, and the fiber and polyurethane There is a moderate gap between them and it can be controlled, so all of them have good surface appearance, soft texture, and good wear resistance. On the other hand, the sheets obtained in Comparative Examples 1 to 5 had dissolution or shedding of the polyvinyl alcohol in the sea-removal step or the water-dispersed polyurethane-imparting step, and the fibers and polyurethane The direct control of the acid ester becomes more, so the texture becomes harder. In addition, the appearance of the surface is also poor in the dispersion state of the fibers, and there is no sense of compactness and defects. The sheet-like materials obtained in Comparative Examples 6 and 7 consisted of many fibers and polyvinyl alcohol in the process of production. Since the fibers and the polyurethane were weakened, the abrasion resistance deteriorated.

[Possibility of industrial use]

The sheet-like material obtained by the present invention can be applied as a skin material for furniture, chairs and wall materials, or seats, ceilings, and interior decorations in the interior of vehicles such as automobiles, trams, and aircrafts, and as an interior decoration with a very beautiful appearance Materials, shirts, jackets, casual shoes, sports shoes, gentlemen's shoes, women's shoes, etc. shoe uppers, decorations, etc., leather bags, belts, wallets, etc., as well as the materials used for clothing, wipes, Industrial materials such as abrasive cloth and CD jacket.

Claims (5)

A method for manufacturing a sheet-like object, which is a method for manufacturing a sheet-like object containing a fibrous base material containing ultra-fine fibers and polyurethane, and includes the following steps (1) to (4); (1) The polyvinyl alcohol imparting step is to impart an aqueous solution of polyvinyl alcohol to a fibrous base material having ultra-fine fiber-exposed fibers as a main constituent component, thereby imparting a fiber mass of 0.1 to 0.1% relative to the fibrous base material. 50% by mass of the polyvinyl alcohol, and the aqueous solution of the polyvinyl alcohol has the following characteristics, (Polyvinyl alcohol: the degree of saponification is 90% or more, and in the evaluation of stereoregularity measured by ¹³ C-NMR in a heavy water solvent, the rrr composition existence ratio is 14.5% or more); (2) The ultrafine fiber development step is to make the ultrafine fiber development type fibers of the fibrous base material into ultrafine fibers with an average single fiber diameter of 0.1 μm to 10 μm after the foregoing steps; (3) Polyurethane-imparting step is to impart water-dispersible polyurethane to the fibrous base material imparted with the polyvinyl alcohol after the aforementioned steps; (4) The polyvinyl alcohol removal step is to remove the polyvinyl alcohol from the fibrous base material provided with the water-dispersible polyurethane after the aforementioned step. The method for manufacturing a sheet-like object according to claim 1, wherein the degree of polymerization of the polyvinyl alcohol is 200-3500. The method for manufacturing a sheet-like object according to claim 1 or 2, wherein in the ultrafine fiber development step, a fibrous substrate having the ultrafine fiber development type fiber as a main constituent component is treated with an alkaline aqueous solution. The method for producing a sheet-like article according to any one of claims 1 to 3, wherein in the polyvinyl alcohol imparting step, after the polyvinyl alcohol aqueous solution is imparted, it is heated at 80 to 190°C. The method for manufacturing a sheet-like article according to any one of claims 1 to 4, wherein in the polyvinyl alcohol imparting step, the fibrous base material is a fiber and a woven fabric and/or knitted fabric are entangled and integrated.