JP2942315B2 - Thermochromic polyvinyl alcohol fiber and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a fiber whose reversible color changes with temperature, and is a yarn, cotton, fiber cloth, knitted cloth, pile cloth,
It can be easily processed into non-woven fabric and paper, and it can be used as a basic material in textile processing such as clothing, bedding, interior goods, stationery, toys, and industrial goods. It is about fibers.

<Conventional technology> Recently, a coating material in which a reversible thermochromic material is mixed with wax, rubber, natural resin, synthetic resin, or the like is used for clothing, bedding, interior, stationery, toy, etc. Impregnated and coated on the surface of textile products
No. 179389) is on the market.

However, because of the weak impregnation / coating surface and the presence of the thermochromic material only on the surface layer, the above-mentioned materials have friction in the processing steps of beaters, cards, twisted yarns, looms, etc., and clothing, washing, etc. The thermochromic material is damaged or falls off due to bending, pulling, friction, washing with water, etc. during use. In addition, the fibers and fiber products become harder than they are after application, so that the feeling is impaired.

Further, in order to compensate for the above-mentioned drawbacks, attempts have been made to mix thermochromic materials into fibers. However, known thermochromic materials basically have no chemical resistance to acids and alkalis. .

Accordingly, for example, when wet spinning is performed in a sulfuric acid bath by mixing a thermochromic material with viscose, the resulting fiber has no thermochromic ability because the thermochromic material is decomposed by a strong acid.

In addition, when melt spinning is performed by mixing a thermochromic material with a general thermofusible resin, if the fiber diameter is not at least twice the diameter of the thermochromic material particles, thread breakage frequently occurs. Therefore, there is a disadvantage that the process is not stable and spinning of fine denier cannot be performed. Therefore, particularly when used as a main fiber and a binder fiber for yarn production, a fine fiber is required to obtain a good feeling, but a melt spun fiber that does not meet this application cannot be obtained.

In this way, the thermochromic material is not damaged or dropped off during processing and practical use, does not impair the thermochromic ability and color density, and has a good feeling, especially a fiber material of 5 denier or less. -Textile products have not been obtained to date.

<Problems to be Solved by the Invention> The present invention is a fiber which is extremely excellent as a thermochromic fiber, that is, a thermochromic material is not damaged or dropped off in a processing step, clothing, washing, etc., and has a thermochromic ability and coloring. Without losing concentration,
Another object of the present invention is to provide a fiber and a fiber product having an excellent texture.

<Means for Solving the Problems> The present invention provides a thermochromic polyvinyl alcohol fiber containing a thermochromic material in an amount of 1 to 70% by weight inside a fiber and having a water dissolution temperature of 40 ° C. or higher. The thermochromic polyvinyl alcohol fiber preferably has a fiber diameter dμm of 30 μm or less and a range of r <d ≦ 20r, where the diameter of the thermochromic material particles is r μm. Such a fiber contains a thermochromic material having a particle diameter of 20 μm or less in an amount of 1 to 70% by weight based on polyvinyl alcohol.
A solution obtained by dissolving a polyvinyl alcohol-based resin of No. 9 as a spinning solution is discharged from a nozzle into an aqueous solution of an inorganic salt solution having a pH of 4 to 9 or into an air bath at 100 to 180 ° C. to perform spinning.

The thermochromic material applicable to the present invention may be a conventionally known thermochromic material, and is, for example, a combination with an electron-donating color-forming compound, an electron-accepting color-developing compound, and a color-changing temperature regulator. Specific examples include those described in JP-B-51-44707. Examples of the electron-donating color-forming compound include diarylphthalides, polyarylcarbinols, and leuco auramines. Examples of the color-developing compound include monophenols and polyphenols, and examples of the discoloration temperature regulator include monohydric alcohols and polyalcohols. The coloration at room temperature and at the time of discoloration may be any color as long as it is easy to distinguish, and either one may be decolored. In order to convert these thermochromic materials into pigments, known microencapsulation techniques are applied, and specific examples thereof include an interfacial polymerization method, a curing-in-liquid coating method, a phase separation method, and a melting dispersion cooling method.

Regarding the particle diameter of the pigment, if it exceeds 50 μm, the permeability of the undiluted solution during spinning, such as overcoating and a metal plate, becomes extremely poor, and it becomes difficult to obtain fine denier fibers, so it is more preferably 20 μm or less, and still more preferably Is preferably 10 μm or less. Regarding the form of the pigment, if it is different from a spherical form, it causes aggregation and phase separation, etc., and therefore, it is necessary that the form be a spherical form or a form close to the form in order to obtain a good dispersion state in the spinning dope.

As the polymer constituting the thermochromic polyvinyl alcohol-based fiber of the present invention, polyvinyl alcohol or other copolymer components such as ethylene / vinyl fluoride / vinyl chloride / styrene / methyl methacrylate / vinyl versacate / lauryl vinyl ether -Examples include polyvinyl alcohol-based resins obtained by copolymerizing olefin sulfonic acid and the like, and polymer mixtures obtained by mixing polyvinyl alcohol with other polymers. Among them, substantially only polyvinyl alcohol, that is, the degree of polymerization is 1000 or more, more preferably 1700 or more, and the degree of saponification is 95 mol% or more, more preferably 97 mol% or more, and still more preferably 99.9% or more. Is desirable. This is because completely saponified polyvinyl alcohol has extremely high transparency, so that the thermochromic materials contained inside the fiber are all effectively colored, and are applied and impregnated to the fiber and fiber products and adhered to the surface only. This is because it is possible to obtain thermochromic properties and coloring densities inferior to those of the above.

As a method for incorporating a thermochromic material into polyvinyl alcohol-based fibers, there is a method in which a thermochromic material is mixed with a spinning solution in which polyvinyl alcohol is dissolved, and the mixture is discharged from a nozzle and spun. Regarding the content of the thermochromic material at this time, color development sufficient to determine that the content is less than 1% based on the weight of the fiber cannot be obtained. If it exceeds 70%, coagulation and phase separation will occur in the spinning dope, and it will be difficult to disperse uniformly in the fiber, making it impossible to obtain accurate thermochromic ability and coloring density. The amount is preferably 1 to 70% by weight, more preferably 3 to 40% by weight, and still more preferably 8 to 20% by weight, for example, because the fiber strength is reduced due to the lack of application.

As a spinning method, first, a wet spinning method is used.
In this method, a thermochromic material having a particle diameter of 20 μm or less is uniformly dispersed in 1 to 70% by weight of polyvinyl alcohol and mixed in a 5 to 20% by weight aqueous solution of polyvinyl alcohol to adjust the pH to 4 to 9. Is used as a spinning solution, but boric acid or an auxiliary agent for improving spinning condition may be added. The reason for adjusting the pH is that if the pH is 3 or less or 10 or more, the thermochromic material is decomposed and the thermochromic ability is lost. Next, the spinning dope is discharged from a nozzle into a coagulation bath composed of an aqueous solution of an inorganic salt having a dehydrating ability adjusted to pH 4 to 9, and dewatered and coagulated to obtain a spinning raw yarn. The inorganic salt used is sodium sulfate, ammonium sulfate, or the like, and is generally used at a concentration near saturation. Further, the pH of the coagulation bath needs to be adjusted to 4 to 9 for the same reason as in the case of the spinning solution.

Next, another spinning method includes a dry spinning method.
In this method, first, a thermochromic material having a particle diameter of 20 μm or less is uniformly dispersed in 1 to 70% by weight of polyvinyl alcohol and mixed, and a high-concentration polyvinyl alcohol adjusted to pH 4 to 9 at 20 to 60% by weight is used. An aqueous alcohol solution is used as the spinning solution,
It is extruded from the nozzle into an air bath and fitted to form spun atoms. As the temperature of the air bath, drying is insufficient when the temperature is 100 ° C. or lower, and crystallization of polyvinyl alcohol proceeds excessively when the temperature is 180 ° C. or higher, and the subsequent stretchability decreases. ~ 180 ° C, more preferably 13
The reason for adjusting the pH of the spinning solution, which is 0 to 160 ° C., is the same as in the case of the wet spinning method.

The spinning yarn obtained by the above two spinning methods can be set at a water dissolution temperature of 40 ° C. or higher, and can be appropriately selected depending on the application. For example, when obtaining sufficient morphological stability to process and use yarn, cotton, woven fabric, knitted fabric, pile fabric, nonwoven fabric, paper, etc., usually set at 90 to 110 ° C,
For example, when used as a binder fiber for papermaking, 40
Set to ~ 95 ° C.

In particular, in the wet spinning method, it is possible to obtain a fiber of 5 denier or less, and further, 2 denier or less. Since the particle size of the capsule containing the thermochromic material is several μm or more, such a denier fiber cannot be easily blended with a fiber from another polymer by a melt spinning method, and a fine denier fiber such as paper is used. The fibers according to the invention are most suitable for the required fields.

In order to impart sufficient strength, form stability, and water resistance, stretching and heat treatment can be performed.However, if preferred conditions are shown, the stretching temperature is 200 to 230 ° C. Then, the temperature is more preferably 210 to 220 ° C. The stretching ratio is preferably 7 times or more, particularly 8 times or more and 12 times or less in order to impart sufficient fiber strength. The heat treatment temperature is 220 to 240 ° C., and more preferably 225 to 235 ° C. in consideration of the morphological stability of the fiber.

Regarding the form of the fiber, the thermochromic ability is related to the thickness of the fiber, and the thinner the surface, the larger the surface area becomes sensitive to temperature, and the thicker the fiber, the more gently it can respond, but it is preferably up to 0.5 to 5 denier, Since it can be adjusted freely within this range, it is appropriately selected depending on the use such as paper, clothing use, industrial material use and the like. In particular, it is preferable to produce by a wet spinning method in a range of 0.5 denier or more and by a dry spinning method in a range of 3 denier or more. When the thermochromic material is contained in polyvinyl alcohol, the diameter of the fiber is dμm when the diameter of the thermochromic material particles is rμm.
Is desirably established in the range of r <d ≦ 20r. This relationship is particularly important when obtaining fine denier fibers,
When the fiber diameter is 5 denier or less, that is, about 30 μm or less, when the fiber diameter is out of the above range, the spinning condition tends to be poor, and the quality of the obtained fiber tends to be poor.

Regarding the cross-sectional shape of the fiber, besides the usual fiber form, triangular, pentagonal, octagonal, T-shaped, L-shaped, Y-shaped, star-shaped, dogbone-shaped, horseshoe-shaped, flat, etc., cross-sectional fibers, macaroni, lotus root It may be a hollow fiber having a shape, a sponge shape, a rice shape, or the like. In addition, side-by-side type, skin core type,
It may be a composite fiber such as a matrix type, and in this case, the thermochromic material may be contained in only one fiber component or may be contained in a plurality of fiber components, and different thermochromic materials having different colors are different from each other. It may be contained in a fiber component.

Further, the polyvinyl alcohol-based resin may contain additives other than the thermochromic material, such as an aromatic agent, a pigment of another color, a fluorescent whitening agent, a stabilizer, and an ultraviolet absorber. In particular, when a fragrance is added, performance such as magic, unexpectedness, appeal, and fun is greatly improved as compared with the case of using only the thermochromic material.

The thermochromic polyvinyl alcohol-based fiber obtained by adopting the above method does not impair the thermochromic ability, color density, and feeling, and does not damage or fall off the thermochromic material. A thermochromic fiber excellent in washing resistance and suitable for textile products requiring magic, unexpectedness, appeal, fun, etc. can be obtained.

In the present invention, the term "fiber" generally refers to a filament, a single fiber, or a twisted, processed, or spun yarn of such a filament.

These textiles include clothing and fashion supplies such as shirts, baby clothes, ski wear, swimwear, and gowns and their fabrics, bedding covers, carpets, furoshiki, wallpaper, cushions, and other bedding products, and the like. Fabric,
Decorative items such as embroidery, lace, ribbon, false eyelashes, lamp pseudo, etc., fancy items and their fabrics, stationery items such as notebooks, eraser cases, picture books, bags, brush cases, etc. Hair, Christmas tree cotton, emblems, etc., toys and ideas, and their fabrics, storage temperature sensors for fresh food, temperature sensors for courier materials, temperature sensors for electronic devices, etc. It can be applied to fabrics.

The principles, embodiments and effects of the present invention will be described in more detail with reference to the following examples, but these examples are merely taken as examples, and these examples do not limit the present invention in any way. Absent.

Example 1 Crystal violet lactone / bisphenol A
A thermochromic material composed of cetyl alcohol was microencapsulated by an epoxy resin / amine interfacial polymerization method to obtain a spherical pigment having an average particle diameter of 4 to 10 μm. This pigment was white at 40 ° C. or higher and blue at 40 ° C. or lower.

Next, a 16% by weight aqueous solution of polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 99.9 mol% was prepared, and the thermochromic pigment was mixed with polyvinyl alcohol at 20% by weight and uniformly dispersed. Was adjusted to be a spinning stock solution. This was discharged from a metal plate into a sodium sulfate bath adjusted to pH 5, wet-spun, dried, and then stretched by dry heat at 220 ° C to obtain a fiber having a denier of 2 denier and a water dissolution temperature of 96 ° C.

This fiber exhibited white color at 40 ° C. or higher and blue color at 40 ° C. or lower, and was excellent in thermochromic property and color density.

Example 2 A thermochromic material composed of 3-diethylamino-7,8-benzfluorane / bisphenol A / stearyl alcohol is microencapsulated by an epoxy resin / amine interfacial polymerization method to form a sphere having an average particle diameter of 4 to 10 μm. It was a pigment. This pigment exhibited a white color at 50 ° C or higher and a pink color at 50 ° C or lower.

Next, a 42% by weight aqueous solution of polyvinyl alcohol having a polymerization degree of 1680 and a saponification degree of 99.8 mol% was mixed with the thermochromic pigment in an amount of 10% by weight with respect to the polyvinyl alcohol. did. 170 ° C
And dry-spun at 220 ° C. to obtain a fiber having a denier of 4 denier and a hot water dissolving temperature of 110 ° C.

This fiber exhibited a white color at 50 ° C. or higher and a pink color at 50 ° C. or lower, and was excellent in thermochromic properties and color density.

Example 3 Crystal violet lactone / bisphenol A
A thermochromic material composed of cetyl alcohol was microencapsulated by an epoxy resin / amine interfacial polymerization method to obtain a spherical pigment having an average particle diameter of 4 to 10 μm. This pigment was white at 40 ° C. or higher and blue at 40 ° C. or lower.

Next, a 42 wt% aqueous solution of polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 99.9 mol% was mixed with the thermochromic pigment in an amount of 10 wt% with respect to the polyvinyl alcohol. And

A thermochromic material consisting of 3-diethylamino-7,8-benzfluoran / bisphenol A / stearyl alcohol was microencapsulated by an epoxy resin / amine interfacial polymerization method to obtain a spherical pigment having an average particle diameter of 4 to 10 μm. . This pigment exhibited a white color at 50 ° C or higher and a pink color at 50 ° C or lower.

Next, the same polyvinyl alcohol as in the above was prepared as a 42% by weight aqueous solution, and the thermochromic pigment was mixed with polyvinyl alcohol at 10% by weight and uniformly dispersed to obtain a spinning dope 2 having a pH of 7.

The spinning dope 1 and the spinning dope 2 were each extruded from a side-by-side type metal plate into an air bath at 170 ° C., dry-spun, and stretched by dry heat at 220 ° C. to obtain a fiber having a denier of 5 denier and a water dissolution temperature of 110 ° C. .

This fiber exhibited a purple color at room temperature, a pink color at 40 to 50 ° C, became white at 50 ° C or higher, and was excellent in thermochromic properties and color density.

Example 4 Polyvinyl alcohol having a degree of polymerization of 1700 and a degree of saponification of 99.9 mol% was converted into an aqueous solution of 16% by weight, and the same thermochromic pigment used in Example 1 was used in an amount of 10% by weight based on polyvinyl alcohol and a jasmine fragrance. For polyvinyl alcohol
The mixture was mixed at 10% by weight, uniformly dispersed, and adjusted to pH by adding sulfuric acid to obtain a spinning stock solution. This was discharged from a metal plate into a sodium sulfate bath adjusted to pH 5, wet-spun, dried, and then stretched by dry heat at 220 ° C to obtain a fiber having a denier of 2 denier and a water dissolution temperature of 96 ° C.

This fiber exhibited white color at 40 ° C. or higher and blue color at 40 ° C. or lower, had excellent thermochromic properties and color density, and had a sufficient jasmine scent.

Example 5 Polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 98.9 mol% was converted into a 16% by weight aqueous solution, and the same thermochromic pigment used in Example 2 was mixed with polyvinyl alcohol at 20% by weight and uniformly mixed. And adjusted to pH 6 by adding sulfuric acid to obtain a spinning stock solution. This was discharged from a metal plate into a sodium sulfate bath, wet-spun, and dried to obtain a fiber having a denier of 1 denier and a water dissolution temperature of 70 ° C.

This fiber exhibited a white color at 50 ° C. or higher and a pink color at 50 ° C. or lower, and was excellent in thermochromic property and color density.

Comparative Example 1 Alkaline cellulose was sulfurized, and sodium hydroxide was added to form viscose, and the thermochromic pigment used in Example 1 was mixed with 20% by weight of the raw material cellulose, and the mixture was uniformly dispersed to obtain a spinning dope. And

This was discharged from a metal plate into a coagulation bath of sulfuric acid 136 g / l and zinc sulfate 16 g / l having a pH of 1 or less, subjected to ordinary wet spinning, desulfurized and acid-treated, and dried to obtain a fiber having a denier of 2 denier. .

This fiber is colored blue below 40 ° C, but at 40 ° C
The color did not change and remained blue.

Comparative Example 2 Polyvinyl alcohol having a degree of polymerization of 1700 and a degree of saponification of 99.9 mol% was converted into an aqueous solution of 16% by weight, and the same thermochromic pigment used in Example 1 was mixed with 20% by weight of the polyvinyl alcohol to obtain a uniform mixture. And adjusted to pH 6 to give a spinning stock solution. 15g of sodium hydroxide from a metal plate
l, discharge into a coagulation bath of sodium sulfate 350 g / l with a pH of 14 or more, wet spinning, neutralize, wash and dry, stretch dry at 220 ° C, single denier 1 denier, water dissolution temperature 99 ° C Fiber was obtained.

This fiber is colored blue below 40 ° C, but at 40 ° C
The color did not change and remained blue.

Comparative Example 3 The same thermochromic pigment as used in Example 1 was mixed with a 45% by weight emulsion of an acryl-vinyl acetate copolymer and 5% by weight of an acryl-vinyl acetate copolymer was mixed with 4 denier single fiber. The thermochromic pigment was adjusted to 10% by weight based on polyacrylonitrile, and dried at 100 ° C.

This fiber exhibited white color at 40 ° C. or higher and blue color at 40 ° C. or lower, and was excellent in thermochromic property and color density.

Table 1 shows the results of the physical properties, thermochromic ability, and coloring density of the eight types of thermochromic fibers.

Next, the following test-1 was conducted on eight types of thermochromic fibers.
And Test-2, the thermochromic ability and the color density were examined.

Test-1 (Paper making test) The fibers obtained in Examples 1 to 4 and Comparative examples 1 to 3 were each cut into 3 mm pieces and defibrated by Peter. Similarly, 1 denier vinyl fiber binder for papermaking and 3 mm fiber length (VPB105-2 × 3, manufactured by Kuraray Co., Ltd.) were disintegrated, and the mixing ratio of thermochromic fiber and vinylon binder was 90% by weight: 10% by weight, respectively. Paper was made at an amount of 40 g / m ² . In Example 5, the mixing ratio of 1 denier for papermaking and 3 mm in fiber length (manufactured by Kuraray Co., Ltd., EP103 × 3) to the thermochromic binder of Example 5 was 90% by weight: 10% by weight, and the basis weight was 40 g. and paper in / m ^2.

Test-2 (Washing Test) The fibers obtained in Examples 1 to 4 and Comparative Examples 1 to 3 were spun into a 10th yarn by a usual method, and flattened at 50 yarns / 45 yarns / inch.

A washing test was performed on the obtained woven material. In addition,
Washing test is JIS L0217-103 method, 2g per liter of water at 40 ℃
And a synthetic detergent for clothing is added and dissolved to make a washing liquid.
A sample and, if necessary, a load cloth are put into the washing liquid so that the bath ratio becomes 1:30, and the operation is started. After the treatment for 5 minutes, the operation was stopped, the sample and the load cloth were dehydrated with a dehydrator, then rinsed at the same bath ratio for 2 minutes with fresh water of a washing liquid and then dehydrated, and then dehydrated again for 2 minutes. This is a method of rinsing and air-drying.

 Table 1 summarizes the results of the above two tests.

From the results in Table 1, it is found that the thermochromic fiber of the present invention does not damage or fall off the thermochromic material in the processing step, washing, etc., does not impair the feeling, the thermochromic ability, the coloring density, and has the magic property. -It is clear that the fiber and the fiber product have properties such as unexpectedness, appeal, and fun.

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masaki Okazaki 1-12-39 Umeda, Kita-ku, Osaka-shi, Osaka Kuraray Co., Ltd. (72) Inventor Tsutomu Kito 3-17 Midoricho, Showa-ku, Nagoya-shi, Aichi Ink Co., Ltd. (72) Inventor Kuniyuki Senga 3-17 Midoricho, Showa-ku, Nagoya-shi, Aichi Pilot Ink Co., Ltd. Examiner Tadahiro Manada (56) References JP-A-3-82812 (JP, A) (58) Field surveyed (Int.Cl. ⁶ , DB name) D01F 1 / 04,6 / 14,6 / 50 D21H 13/16

Claims (5)

(57) [Claims] 1. A thermochromic polyvinyl alcohol fiber containing a thermochromic material in an amount of 1 to 70% by weight inside a fiber, having a water dissolution temperature of 40 ° C. or more and a diameter of 30 μm or less. 2. When the diameter of the thermochromic material particles is r μm, the fiber diameter d μm is 30 μm or less, and r <d ≦ 20.
The thermochromic polyvinyl alcohol-based fiber according to claim 1, which is in the range of r. 3. A thermochromic material having a particle diameter of 20 μm or less is contained in an amount of 1 to 70% by weight based on polyvinyl alcohol.
Production of a thermochromic polyvinyl alcohol-based fiber, characterized in that a solution for dissolving polyvinyl alcohol-based resin of No. 9 to No. 9 is used as a spinning dope, and this solution is discharged from a nozzle into an aqueous solution of an inorganic salt having a pH of 4 to 9 and wet-spun. Method. 4. A thermochromic material having a particle size of 20 μm or less is contained in an amount of 1 to 70% by weight based on polyvinyl alcohol.
9. A method for producing thermochromic polyvinyl alcohol-based fibers, characterized in that a solution of the polyvinyl alcohol-based resin of No. 9 is used as a spinning solution, and the solution is discharged from a nozzle into an air bath at 100 to 180 ° C. and dry-spun. 5. A paper containing the thermochromic polyvinyl alcohol-based fiber according to claim 1.