JP7061292B2 - Batting - Google Patents

Description

The present invention relates to a batting that is lightweight, bulky, flexible, easy to follow the body, and can be used as a substitute for feathers. The batting of the present invention can be suitably used for the batting of bedding, the batting of clothing such as down jackets, and the like.

Bedding batting and clothing batting are required to be lightweight, bulky, have high heat retention, and have a soft texture that follows the movement of the body. Animal fibers such as feathers and cotton and synthetic fibers such as polyester have been used for such applications. Of these, feathers are particularly lightweight and have excellent compression stability, and since feathers do not entangle with each other, they have the characteristics of being able to maintain extremely excellent bulkiness for a long period of time. In addition, feathers are often used as batting for bedding and clothing because they have excellent heat retention and flexibility.

However, due to the decrease in the production of feathers in recent years, the price of feathers has risen, and it has become difficult to provide them as a material for batting at an affordable price. Therefore, it is strongly desired to develop a highly functional alternative batting having the above-mentioned performance of feathers.

Regarding the improvement of heat retention, a batting in which other synthetic fibers are mixed with moisture-absorbing heat-generating fibers excluding animal fibers to form a cotton-like batting has been proposed (see Patent Document 1). However, when the hygroscopic heat-generating fiber is used in a normal form as used in Patent Document 1, it is extremely difficult to maintain both the hygroscopic heat-generating property and the bulkiness at a high level, and as a result, the heat retention property is maintained. There was a problem that it could not be maintained for a long period of time.

Japanese Patent Application Laid-Open No. 2003-286638

The present invention was invented in view of the current state of the prior art, and an object thereof is suitable for bedding and clothing which are lightweight, bulky, have high heat retention, and have flexibility that easily follows the movement of the body. To provide batting.

As a result of diligent studies on the constitutional form of the hygroscopic heat-generating fiber used for the batting and the synthetic fiber used in combination with the moisture-absorbing heat-generating fiber in order to achieve the above object, the present inventor has determined from a specific central portion and surface layer portion as the hygroscopic heat-generating fiber. By using composite fibers with a side-by-side structure and hollow polyester fibers, which are processed into a cotton-like shape, the batting that achieves a high level of lightness, bulkiness, heat retention, and flexibility is achieved. I found that I could provide it.

Specifically, as the hygroscopic heat-generating fiber, the central part of the side-by-side structure composed of two types of acrylonitrile-based polymers having different acrylonitrile contents that contribute to bulkiness, and the crosslinked structure and Na salt type that contribute to the hygroscopic heat generation. Alternatively, by using a specific side-by-side type composite fiber consisting of a surface layer portion having a K-salt type carboxyl group, and by using a hollow polyester fiber that is lightweight and has excellent bulkiness, and processing these into a cotton-like form. , Found that it is possible to provide batting that also has the performance of feathers.

The present invention has been completed based on such findings, and has the following configurations (1) to (6).
(1) Side-by-side composite fiber composed of a central portion of a side-by-side structure composed of two types of acrylonitrile-based polymers having different acrylonitrile contents, a crosslinked structure, and a surface layer portion having a Na salt type or K salt type carboxyl group. (A) and hollow polyester fiber (B) were entwined and mixed to form a cotton-like material , and the area occupied by the surface layer portion in the cross section of the side-by-side type composite fiber (A) was 5% or more. Batting characterized by 35% or less .
(2) The batting according to (1), wherein the weight ratio of the side-by-side type composite fiber (A) and the hollow polyester fiber (B) contained is 10:90 to 60:40.
(3) The batting according to (1) or (2), wherein the side-by-side type composite fiber (A) has a total carboxyl group amount of 3.5 to 10 mmol / g.
(4) The description according to any one of (1) to (3), wherein the side-by-side type composite fiber (A) has a Na salt type or K salt type carboxyl group amount of 3.0 to 10 mmol / g. Batting.
(5) The batting according to any one of (1) to (4), wherein the side-by-side type composite fiber (A) has a single fiber fineness of 1 to 15 dtex and a fiber length of 10 to 50 mm.
(6) The batting according to any one of (1) to (5), wherein the hollow polyester fiber (B) has a single fiber fineness of 0.5 to 10 dtex and a fiber length of 5 to 70 mm.

Since the batting of the present invention uses a crosslinked polyacrylate fiber having a Na salt type or K salt type carboxyl group as the hygroscopic heat-generating fiber, it exhibits a high temperature rise immediately after moisture absorption and is a specific composite. Since the structure is adopted, the influence of the sagging of the fiber at the time of moisture absorption is small, a high bulkiness can be brought about, and as a result, a high heat retention sustainability can be obtained. In addition, lightweight and bulky hollow polyester fiber is used together, and this is mixed with the above-mentioned hygroscopic heat-generating fiber and processed into a fluffy shape, so it has high bulkiness, light weight, flexibility, and heat retention durability. Can be done.

It is a graph which shows the transition of the temperature with respect to the elapsed time of the crosslinked polyacrylate fiber having a carboxyl group of Na salt type or Mg salt type measured according to the measurement method and condition of ISO18782: 2015.

Hereinafter, the batting of the present invention will be described in detail.

The batting of the present invention is characterized in that a side-by-side type composite fiber (A) composed of a specific central portion and a surface layer portion and a hollow polyester fiber (B) are entwined and mixed to form a cotton-like material. And. With such a feature, it is possible to provide a high level of hygroscopic heat generation that rapidly absorbs moisture and exhibits heat generation, bulkiness that provides continuous heat retention, light weight, and flexibility.

The side-by-side type composite fiber (A) used in the present invention needs to be a crosslinked polyacrylate-based fiber having a Na salt type or K salt type carboxyl group of a monovalent metal. The Mg salt type or Ca salt type divalent metal salt type has hygroscopic heat generation, but since the initial rising temperature at the time of hygroscopic heat generation is low, if you want to feel warmth and heat retention at an early stage, There's a problem. Further, other divalent metal salt types such as Zn salt type are not preferable because they are inferior in hygroscopic heat generation and a comfortable environment cannot be obtained. The Na salt type or the K salt type monovalent metal salt type has a high initial temperature rise at the time of heat absorption and heat generation, so that the warmth can be felt at an early stage. However, the crosslinked polyacrylate fiber having a Na salt type or K salt type carboxyl group lacks bulkiness in a normal fiber form and cannot maintain heat retention. Therefore, a special composite as described later in the present invention. Take the structure.

The side-by-side composite fiber (A) used in the present invention has a central portion of a side-by-side structure composed of two types of acrylonitrile-based polymers having different acrylonitrile contents, a crosslinked structure, and a Na-salt-type or K-salt-type carboxyl group. It is a composite fiber composed of a surface layer portion having. The side-by-side type composite fiber (A) of the present invention has a composite structure consisting of a central portion and a surface layer portion around the central portion, and by forming a hard structure at the central portion, it contributes to improvement of bulkiness and the surface layer portion. It is characterized by having a crosslinked structure and the presence of Na-salt-type or K-salt-type carboxyl groups to play a role of high hygroscopic heat generation. The side-by-side type composite fiber (A) preferably has a total carboxyl group amount of 3.5 mmol / g or more, and can have a maximum of about 10 mmol / g, preferably a maximum of 6.5 mmol / g. In reality, substantially the entire amount of this carboxyl group is present in the surface layer portion. Further, it is preferable that about 90% or more, preferably about 95% or more, more preferably substantially all of the total carboxyl groups of the side-by-side type composite fiber are Na salt type or K salt type carboxyl groups. Specifically, the side-by-side type composite fiber (A) preferably has a Na salt type or K salt type carboxyl group amount of 3.0 mmol / g or more, preferably about 10 mmol / g, and preferably a maximum of 6.5 mmol. / G.

The side-by-side type composite fiber (A) uses an acrylonitrile-based fiber as a raw material fiber, and the acrylonitrile-based fiber can be produced from an acrylonitrile-based polymer by a known method. The acrylonitrile-based polymer preferably contains 50% by weight or more of acrylonitrile, and more preferably 80% by weight or more. When the content of acrylonitrile is low, the crosslinked structure is reduced, and the physical characteristics of the fiber may be deteriorated. The crosslinked structure can be introduced into the fiber by reacting the nitrile group of the acrylonitrile-based polymer with a nitrogen-containing compound such as a hydrazine-based compound.

The side-by-side type composite fiber (A) has a composite structure in which two types of acrylonitrile-based polymers having different acrylonitrile contents are bonded side-by-side. By arranging the two types of acrylonitrile polymers having different acrylonitrile contents side by side in this way, a difference in the degree of shrinkage during the hydrolysis treatment can occur, and crimping can be expressed, resulting in crimping. As a result, it can contribute to the improvement of bulkiness. In order to sufficiently improve the bulkiness, the difference in the acrylonitrile content between the two types of acrylonitrile-based polymers is preferably 1 to 8% by weight, more preferably 1 to 5% by weight, and the two types. The composite ratio (weight ratio) of the acrylonitrile-based polymer is preferably 20/80 to 80/20, more preferably 30/70 to 70/30.

A crosslinked structure is introduced into the surface layer portion of the fiber having the composite structure as described above. A conventionally known cross-linking agent may be used for introducing the cross-linked structure, but it is preferable to use a nitrogen-containing compound from the viewpoint of the introduction efficiency of the cross-linked structure. As the nitrogen-containing compound, it is preferable to use an amino compound having two or more primary amino groups or a hydrazine-based compound. Examples of the amino compound having two or more primary amino groups include diamine compounds such as ethylenediamine and hexamethylenediamine, diethylenetriamine, 3,3'-iminobis (propylamine), and N-methyl-3,3'-iminobis ( Triamine compounds such as propylamine), triethylenetetramine, N, N'-bis (3-aminopropyl) -1,3-propylene diamine, N, N'-bis (3-aminopropyl) -1,4- Examples thereof include tetramine-based compounds such as butylene diamine, polyamine-based compounds having two or more primary amino groups such as polyvinylamine and polyallylamine. Examples of the hydrazine-based compound include hydrated hydrazine, hydrazine sulfate, hydrazine hydrochloride, hydrazine hydrobromide, and hydrazine carbonate. The upper limit of the number of nitrogen atoms in one molecule is not particularly limited, but is preferably 12 or less, more preferably 6 or less, and particularly preferably 4 or less. When the number of nitrogen atoms in one molecule exceeds the above upper limit, the cross-linking agent molecule becomes large, and it may be difficult to introduce a cross-linking structure into the fiber. The conditions for introducing the crosslinked structure are not particularly limited, and can be appropriately selected in consideration of the reactivity between the crosslinked agent to be adopted and the acrylonitrile-based fiber, the amount of the crosslinked structure, and the like. For example, when a hydrazine-based compound is used as a cross-linking agent, the above-mentioned acrylonitrile-based fiber is immersed in an aqueous solution to which the above-mentioned hydrazine-based compound is added so that the hydrazine concentration is 0.1 to 10% by weight, and 80 to 150 is used. Examples thereof include a method of processing at ° C. for 2 to 10 hours.

After the crosslinked structure is introduced, a hydrolysis treatment with an alkaline metal compound is performed, and the nitrile group existing on the surface layer portion of the fiber is hydrolyzed to form a carboxyl group. As specific treatment conditions, various conditions such as the concentration of the treatment agent, the reaction temperature, and the reaction time may be appropriately set in consideration of the above-mentioned amount of carboxyl group and the like, but preferably 0.5 to 10% by weight. More preferably, a means for treating at a temperature of 80 to 150 ° C. for 2 to 10 hours in a 1 to 5% by weight aqueous solution of a treatment agent is industrially and fibrous. In the present invention, it is preferable that the above-mentioned cross-linking introduction treatment and hydrolysis treatment are collectively and simultaneously treated using an aqueous solution in which each treatment agent is mixed, rather than being carried out in order as described above. Further, in the present invention, it is preferable to carry out this simultaneous treatment under mild conditions of the alkali metal compound having a lower concentration than before, and then to carry out the acid treatment under severe conditions at a higher temperature than before. By doing so, the side-by-side type composite fiber (A) of the present invention has a structure in which more carboxyl groups are present in the surface layer portion and a relatively hard acrylonitrile-based polymer is preserved in the central portion. Can be done.

The formed carboxyl group includes a salt-type carboxyl group whose counter ion is a cation other than a hydrogen ion and an H-type carboxyl group whose counter ion is a hydrogen ion. In the present invention, the H-type carboxyl group is converted into a salt-type carboxyl group in order to obtain a high hygroscopicity, and about 90% or more, preferably about 95% or more, more preferably substantially all the carboxyl groups are salt-type. It is desirable to use a carboxyl group. The cations constituting the salt-type carboxyl group are alkali metals of sodium or potassium. When magnesium, calcium, zinc or the like, which are polyvalent metal ions, are used, they are bulky, but they are not preferable because the initial temperature rise due to moisture absorption is low. For example, the side-by-side composite fiber (A) of the present invention is a side-by-side bonded acrylonitrile-based polymer having two types of acrylonitrile-based polymers having different acrylonitrile contents under the specific conditions as described above. It is obtained by cross-linking introduction and hydrolysis to form a carboxyl group and selecting sodium or potassium as the counter ion.

As a method for converting an H-type carboxyl group into a salt-type carboxyl group, ion exchange treatment with a metal salt such as nitrate, sulfate or hydrochloride, acid treatment with nitric acid, sulfate, hydrochloric acid, formic acid or the like, or an alkaline metal compound or the like, etc. A method of performing a pH adjustment treatment or the like according to the above can be mentioned.

The area occupied by the surface layer portion in the cross section of the side-by-side type composite fiber (A) is preferably 5% or more and 35% or less, more preferably 10% or more and 30% or less, and further preferably 10% or more and 20% or less. If the area of the surface layer portion is less than the above range, the carboxyl group cannot be sufficiently present in the fiber, and it may not be possible to exhibit high hygroscopic heat generation. On the other hand, if it exceeds the above range, the fibers tend to be worn out due to moisture absorption, which may cause a problem in bulkiness. The side-by-side type composite fiber (A) of the present invention achieves high bulkiness by allowing a large number of central portions in which carboxyl groups are substantially absent, so that the influence of the decrease in bulkiness due to the sagging of the fiber due to moisture absorption is small. can do. Further, as shown in FIG. 1, the crosslinked polyacrylate fiber having a Na salt type or K salt type carboxyl group has higher hygroscopic heat generation (particularly the initial rising temperature) than the divalent metal salt such as the Mg salt type. ), And in the present invention, the characteristics can be enjoyed as they are.

Since the side-by-side type composite fiber (A) of the present invention is a crosslinked polyacrylate-based fiber having a Na salt type or K salt type carboxyl group having the above-mentioned special composite structure, it is in an environment of 20 ° C. × 65% RH. Moisture absorption in the range of 6.0-40% can be easily achieved within 5 minutes. In particular, the hygroscopic heat-generating fiber of the present invention can realize a high hygroscopic heat-generating effect (high rising temperature) within the first 5 minutes when it comes into contact with human skin.

Further, the side-by-side type composite fiber (A) of the present invention is composed of a crosslinked polyacrylate-based fiber having a Na salt type or K salt type carboxyl group having the above-mentioned special composite structure, and therefore has a range of 10 to 100 cm ³ / g. Specific volume can be achieved. Such high bulkiness is brought about by the high bulkiness of the crosslinked polyacrylate-based fiber having a Na salt type or K salt type carboxyl group having a special composite structure. If the specific volume is less than the above range, the heat retention may be insufficient because sufficient air is not taken in. If the specific volume exceeds the above range, the shape may be easily lost even if a small amount of force is applied, and the shape retention may be insufficient.

The hollow polyester fiber (B) used in the present invention is a polyester fiber having a cavity or a void inside, and is manufactured by using a conventionally known polyester fiber suitable for cotton padding as long as a hollow portion is present in the cross section. Can be done. Examples of the polyester fiber include polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate and the like, and not only homopolymers but also copolymer fibers composed of a plurality of polymer blends can be used. The hollow polyester fiber can be appropriately obtained by a conventionally known method. For example, the undrawn yarn is obtained by melting the polyester resin pellet, discharging it from a C-shaped nozzle at a high temperature, and winding it with a take-up roller. It can be obtained by stretching at a temperature of 60 to 90 ° C. at an appropriate stretching ratio, or by subjecting it to a relaxation heat treatment. The hollow ratio of the hollow polyester fiber (B) is not particularly limited, but is preferably 10% to 60% in consideration of lightness, bulkiness, heat retention and the like.

The single fiber fineness of the side-by-side type composite fiber (A) used in the present invention is preferably 1 to 15 dtex, and the fiber length is preferably 10 to 50 mm. Further, the single fiber fineness of the hollow polyester fiber (B) used in the present invention is preferably 0.5 to 10 dtex, and the fiber length is preferably 5 to 70 mm. If the single fiber fineness is less than the above range, high bulkiness and compression recovery may not be obtained, and if it exceeds the above range, the texture becomes hard and may not be suitable as batting for bedding or the like. Further, if the fiber length deviates from the above range, it may be difficult to mix the fibers and process them into a cotton-like shape.

In the batting of the present invention, in addition to the side-by-side type composite fiber (A) and the hollow polyester fiber (B), other conventionally known synthetic fibers (non-hollow polyester fiber, polyamide fiber, etc.) at a ratio of 30% by weight or less of the total weight of the batting. Polyester fiber, polyphenylene sulfide fiber, etc.) can be mixed and used. The weight ratio of the side-by-side type composite fiber (A) and the hollow polyester fiber (B) contained in the batting of the present invention is preferably 10:90 to 60:40, more preferably 15:85 to 50:50. If the side-by-side type composite fiber (A) is less than the above range, sufficient hygroscopic heat generation may not be exhibited, and if it exceeds the above range, the cost may increase and the flexibility may decrease.

The batting of the present invention is characterized in that the above-mentioned side-by-side type composite fiber (A) and hollow polyester fiber (B) are entwined and mixed as essential components, and the batting is processed into a cotton-like shape. As a method for processing into a cotton-like shape, a conventionally known method can be adopted. For example, a method of stirring each used fiber under a high-speed air flow, a method of putting each used fiber in a stirrer, mixing and stirring, and each method. It is possible to adopt a method in which a plurality of fibers to be used are aligned, subjected to a focusing treatment, then cut, and then heat-treated at a temperature lower than the melting point of the fibers to develop crimping and form a fiber ball. Each of the crushed cottons constituting the batting of the present invention is substantially spherical, and the diameter of one crushed cotton can be, for example, about 5 to 50 mm.

The batting of the present invention can be used not only alone but also with conventionally used fibers such as feather, cotton, linen, wool, nylon, rayon, polyester and acrylic. As described above, the batting of the present invention is lightweight, bulky, heat-retaining, and flexible, so that it can be used as a batting for bedding (comforters, mattresses, pillows, etc.) or as a padding for outer clothing for autumn and winter. Very suitable as batting.

The present invention will be specifically described with reference to the following examples, but the present invention is not limited thereto. The ratios in the examples are shown on a weight basis unless otherwise specified. The method for evaluating the characteristics in the examples is as follows.

(1) Carboxyl group amount of side-by-side type composite fiber (A) (i) Total carboxyl group amount About 1 g of the fiber sample is immersed in 50 ml of a 1 mol / l hydrochloric acid aqueous solution for 30 minutes. The fiber sample is then immersed in water at a bath ratio of 1: 500. After 15 minutes, when it is confirmed that the bath pH is 4 or more, it is dried (if the bath pH is less than 4, wash again with water). Next, about 0.2 g of a sufficiently dried fiber sample is precisely weighed (W1 [g]), 100 ml of water is added, and 15 ml of a 0.1 mol / l sodium hydroxide aqueous solution and 0.4 g of sodium chloride are added. And phenolphthalein are added and stirred. After 15 minutes, the sample fibers and the filtrate are separated by filtration, and the sample fibers are subsequently washed with water until the coloration of phenolphthalein disappears. The sum of the water-washed water and the filtrate at this time is titrated with a 0.1 mol / l hydrochloric acid aqueous solution until the coloration of phenolphthalein disappears, and the hydrochloric acid aqueous solution consumption (V1 [ml]) is determined. From the obtained measured values, the total amount of carboxyl groups is calculated by the following formula.
Total carboxyl group amount [mmol / g] = (0.1 × 15-0.1 × V1) / W1
(Ii) Salt-type carboxyl group amount In the above-mentioned method for measuring the total carboxyl group amount, the H-type carboxyl group amount is calculated in the same manner except that the first immersion in a 1 mol / l hydrochloric acid aqueous solution and the subsequent washing with water are not performed. do. The salt-type carboxyl group amount is calculated by subtracting the H-type carboxyl group amount from the total carboxyl group amount described above.

(2) 20 ° C. × 65% RH moisture absorption rate of the side-by-side type composite fiber (A) About 2.5 g of the fiber sample is dried at 105 ° C. for 16 hours in a hot air dryer and weighed (W2 [g]). Next, the fiber sample is placed in a constant temperature and humidity chamber adjusted to a temperature of 20 ° C. and 65% RH for 5 minutes. The weight of the fiber sample absorbed in this way is measured (W3 [g]). From these measurement results, the 20 ° C. × 65% RH hygroscopicity is calculated by the following formula.
20 ° C x 65% RH hygroscopicity [%] = (W3-W2) / W2 x 100

(3) Specific volume of side-by-side type composite fiber (A) 50 g of fiber sample is lightly opened, then opened with a card machine and laminated. Cut out 6 test pieces to a size of 10 cm × 10 cm, put them in a vat, and leave them in a constant temperature and humidity chamber for 24 hours or more. Take out from a constant temperature and humidity chamber, stack them so that the mass is 10.0 g to 10.5 g, and weigh the prepared test pieces accurately. A 10 cm × 10 cm acrylic plate is placed on the test piece, a weight of 500 g is placed on the test piece for 30 seconds, then the weight is removed and the weight is left for 30 seconds. This operation is repeated 3 times, and after leaving it for 30 seconds excluding the weight of 500 g, the height of the four corners is measured to obtain the average value, and the specific volume is calculated by the following formula.
Specific volume (cm ³ / g) = 10 × 10 × Measured average value of the height of the four corners of the sample (mm) / 10 / Mass of the test piece (g)

(4) Increased temperature of side-by-side type composite fiber (A) The increased temperature of the sample fiber was measured according to ISO18782: 2015.

(5) Specific volume of batting The specific volume of batting is calculated by the same method as the specific volume of (3) side-by-side type composite fiber (A) described above.

(6) Ascending temperature of batting The ascending temperature of the batting sample was measured according to ISO18782: 2015.

(7) Skin-friendly batting A mini futon is prepared by uniformly packing 150 g of a batting sample into a futon-side fabric sewn to a size of 30 cm × 30 cm. Next, prepare a wooden stick with a diameter of 5 cm and a length of 30 cm and lay it on a table. Drop a mini duvet filled with batting samples from a height of 10 cm onto a wooden stick. Measure the distance from the grounding point of the wooden rod to the grounding point of the mini futon. The shorter the distance between the grounding points, the better the skin-likeness.

(8) Lightness of batting Fill a 1000 ml graduated cylinder with a batting sample. Next, place 5 g of the acrylic resin top plate and check if the volume is 1000 ml. The weight of the batting sample at that time is measured.

Preparation of side-by-side composite fiber (A1) 90% by weight of acrylonitrile, 10% by weight of acrylic acid methyl ester Acrylonitrile-based polymer Ap (extreme viscosity in dimethylformamide at 30 ° C. [η] = 1.5), 88% by weight of acrylonitrile , 12% by weight of vinyl acetate, acrylonitrile-based polymer Bp ([η] = 1.5) was dissolved in 48% by weight of Rodin soda aqueous solution to prepare a spinning stock solution. Each spinning stock solution is guided to the composite spinning apparatus according to Tokusho No. 39-24301 so that the composite ratio (weight ratio) of Ap / Bp is 50/50, and spinning, washing with water, stretching, crimping, and heat treatment are performed according to a conventional method. Then, a side-by-side type raw material fiber in which a polymer Ap and Bp having a single fiber fineness of 3.3 dtex was combined was obtained.

In an aqueous solution containing 0.5% by weight of hydrated hydrazine and 1.6% by weight of sodium hydroxide in the raw material fiber, cross-linking introduction treatment and hydrolysis treatment were simultaneously carried out at 100 ° C. for 2 hours to obtain 8% by weight nitric acid. It was treated with an aqueous solution at 120 ° C. for 3 hours and washed with water. The obtained fiber is immersed in water, sodium hydroxide is added to adjust the pH to 9, washed with water, and dried to obtain a Na salt-type crosslinked polyacrylate-based fiber having a Na-salt-type carboxyl group (surface layer area: 18%). , Na salt type carboxyl group amount 3.8 mmol / g) was obtained. In the infrared absorption measurement of the fiber, there was absorption near 2250 cm ^-1 derived from the nitrile group, and the hydrolysis of the nitrile group was progressing in the fiber surface layer portion, but the nitrile group was present in the fiber center portion. It was confirmed that it remained.

Preparation of side-by-side type composite fiber (A2) K-salt type by the same method except that potassium hydroxide was used instead of sodium hydroxide added to adjust the pH in the above-mentioned preparation of side-by-side type composite fiber (A1). Crosslinked polyacrylate fibers (surface layer area 18%, K-salt type carboxyl group amount 3.9 mmol / g) were obtained.

Preparation of Side-by-Side Composite Fiber (A3) Na salt-type crosslinked polyacrylate fiber was prepared by the same method except that the composition of the acrylonitrile polymer Ap was changed to 92% by weight of acrylonitrile and 8% by weight of acrylate methyl ester in Example 1. Obtained (Na salt type carboxyl group amount 3.8 mmol / g).

Preparation of Side-by-Side Composite Fiber (A4) Same as in Example 1 except that the content of sodium hydroxide in the aqueous solution used for the cross-linking introduction treatment and the hydrolysis treatment was changed from 1.6% by weight to 1.8% by weight. A Na salt-type crosslinked polyacrylate fiber was obtained by the method (surface layer area 23%, Na salt type carboxyl group amount 4.9 mmol / g).

Preparation of side-by-side composite fiber (A5) Acrylonitrile 90% by weight, acrylonitrile methyl ester 10% by weight acrylonitrile polymer Ap (extreme viscosity in dimethylformamide at 30 ° C. [η] = 1.5), acrylonitrile 88% by weight , 12% by weight of vinyl acetate, acrylonitrile-based polymer Bp ([η] = 1.5) was dissolved in 48% by weight of Rodin soda aqueous solution to prepare a spinning stock solution. Each spinning stock solution is guided to the composite spinning apparatus according to Tokusho No. 39-24301 so that the composite ratio of Ap / Bp is 50/50, and spinning, washing with water, stretching, crimping, and heat treatment are performed according to a conventional method. A side-by-side type raw material fiber obtained by combining a polymer Ap and Bp having a fiber fineness of 3.3 dtex was obtained.

In an aqueous solution containing 0.5% by weight of hydrated hydrazine and 1.6% by weight of sodium hydroxide in the raw material fiber, cross-linking introduction treatment and hydrolysis treatment were simultaneously carried out at 100 ° C. for 2 hours to obtain 8% by weight nitric acid. It was treated with an aqueous solution at 120 ° C. for 3 hours and washed with water. The obtained fiber is immersed in water, sodium hydroxide is added to adjust the pH to 9, and then the solution is immersed in an aqueous solution containing magnesium nitrate, which is twice the amount of the carboxyl group contained in the fiber, at 50 ° C. for 1 hour. After performing ion exchange treatment, washing with water and drying, the Mg salt-type crosslinked polyacrylate-based fiber having an Mg-salt-type carboxyl group (surface layer area 18%, Mg salt-type carboxyl group amount 3.8 mmol / g) Got

Preparation of side-by-side composite fiber (A6) 90% by weight of acrylonitrile, 10% by weight of acrylic acid methyl ester Acrylonitrile-based polymer Ap (extreme viscosity in dimethylformamide at 30 ° C. [η] = 1.5), 88% by weight of acrylonitrile , 12% by weight of vinyl acetate, acrylonitrile-based polymer Bp ([η] = 1.5) was dissolved in 48% by weight of Rodin soda aqueous solution to prepare a spinning stock solution. Each spinning stock solution is guided to the composite spinning apparatus according to Tokusho No. 39-24301 so that the composite ratio of Ap / Bp is 50/50, and spinning, washing with water, stretching, crimping, and heat treatment are performed according to a conventional method. A side-by-side type raw material fiber obtained by combining a polymer Ap and Bp having a fiber fineness of 3.3 dtex was obtained.

In an aqueous solution containing 0.5% by weight of hydrated hydrazine and 1.6% by weight of sodium hydroxide in the raw material fiber, cross-linking introduction treatment and hydrolysis treatment were simultaneously carried out at 100 ° C. for 2 hours to obtain 8% by weight nitric acid. It was treated with an aqueous solution at 120 ° C. for 3 hours and washed with water. The obtained fiber is immersed in water, sodium hydroxide is added to adjust the pH to 9, and then the solution is immersed in an aqueous solution containing calcium nitrate, which is twice the amount of the carboxyl group contained in the fiber, at 50 ° C. for 1 hour. After performing ion exchange treatment, washing with water and drying, Ca salt-type crosslinked polyacrylate fiber having Ca salt-type carboxyl group (surface layer area 18%, Ca salt-type carboxyl group amount 3.9 mmol / g) Got

Preparation of moisture-absorbing heat-generating fiber (A7) having no side-by-side structure Acrylonitrile-based polymer Ap of 90% by weight of acrylonitrile and 10% by weight of acrylate methyl ester Ap (extreme viscosity in dimethylformamide at 30 ° C. [η] = 1.5) Was dissolved in a 48 wt% rodane soda aqueous solution to prepare a spinning stock solution. The undiluted spinning solution was guided to a spinning apparatus and subjected to spinning, washing with water, stretching, crimping, and heat treatment according to a conventional method to obtain a raw material fiber having a single fiber fineness of 6.6 dtex and having no side-by-side structure.

In an aqueous solution containing 0.5% by weight of hydrated hydrazine and 1.6% by weight of sodium hydroxide in the raw material fiber, cross-linking introduction treatment and hydrolysis treatment were simultaneously carried out at 100 ° C. for 2 hours to obtain 8% by weight nitric acid. It was treated with an aqueous solution at 120 ° C. for 3 hours and washed with water. The obtained fiber was immersed in water, sodium hydroxide was added to adjust the pH to 9, washed with water, and dried to obtain a Na-salt-type crosslinked polyacrylate-based fiber having a Na-salt-type carboxyl group.

Preparation of hollow polyester fiber (B1) A shrape manufactured by Toyobo Co., Ltd. was used. The thickness of this product is 2.0 dtex, the fiber length is 20 mm, and the hollow ratio is 30%.

Preparation of non-hollow polyester fiber (B2) After melt-kneading polyethylene terephthalate pellets and 3% by weight of calcium carbonate particles with an average particle diameter of 0.4 μm, spinning and stretching to 2.0 dtex to make the fiber length 20 mm. A cut non-hollow polyester fiber (hollow ratio is 0%) was prepared.

Preparation of batting Mix each moisture-absorbing heat-generating fiber and polyester fiber according to the materials and usage ratios shown in Table 1, and sufficiently open the fibers with a card provided with multiple rollers provided with garnet wire on the surface. Example: An apparatus in which fibers are blown into a room provided with a rotating body in which a plurality of fins are attached and rotated in a cylindrical space where turbulent air flow is likely to occur, and the fibers can be taken out after turbulent flow stirring for a predetermined time. The batting of 1 to 12 and Comparative Examples 1 to 5 was obtained. All of the obtained batting were substantially spherical crushed cotton, and the diameter of one crushed cotton was about 30 mm.

Table 1 shows the details and evaluation results of each material and manufacturing conditions used for the batting of Examples 1 to 12 and Comparative Examples 1 to 5.

As is clear from the results in Table 1, the battings of Examples 1 to 12 belonging to the scope of the present invention show excellent results in all the evaluation items, whereas the side-by-side type composite fiber (A) shows excellent results. Comparative Examples 1 and 2 of Mg salt type and Ca salt type, Comparative Example 3 not crushed, Comparative Example 4 not using hollow polyester fiber, and comparison using moisture-absorbing heat-generating fiber that does not have a side-by-side structure. Example 5 showed clearly inferior results in any of the endpoints.

According to the present invention, it is possible to provide a padding suitable for bedding and clothing which is lightweight, bulky, has high heat retention, and has flexibility that easily follows the movement of the body, and contributes particularly to feather replacement applications. Is big.

Claims (6)

Side-by-side composite fiber (A) consisting of a central portion of a side-by-side structure composed of two types of acrylonitrile-based polymers having different acrylonitrile contents, a crosslinked structure, and a surface layer portion having a Na salt type or K salt type carboxyl group. And the hollow polyester fiber (B) were entwined and mixed to form a cotton-like material , and the area occupied by the surface layer portion in the cross section of the side-by-side type composite fiber (A) was 5% or more and 35% or less. Batting characterized by being . The batting according to claim 1, wherein the weight ratio of the side-by-side type composite fiber (A) to the hollow polyester fiber (B) contained is 10:90 to 60:40. The batting according to claim 1 or 2, wherein the side-by-side type composite fiber (A) has a total carboxyl group amount of 3.5 to 10 mmol / g. The batting according to any one of claims 1 to 3, wherein the Na salt type or K salt type carboxyl group amount of the side-by-side type composite fiber (A) is 3.0 to 10 mmol / g. The batting according to any one of claims 1 to 4, wherein the side-by-side type composite fiber (A) has a single fiber fineness of 1 to 15 dtex and a fiber length of 10 to 50 mm. The batting according to any one of claims 1 to 5, wherein the hollow polyester fiber (B) has a single fiber fineness of 0.5 to 10 dtex and a fiber length of 5 to 70 mm.

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