WO2018181138A1 - Wadding - Google Patents

Abstract

The present invention provides wadding that is suitable for clothing and bedding, that is light and bulky, that exhibits a high heat-retaining property, and that has suppleness capable of assuming the contour of a user's body in motion. This wadding is characterized by being obtained by entwining and mixing a hollow polyester fiber (B) with a side-by-side-type conjugate fiber (A) comprising: a side-by-side-type central part composed of two types of acrylonitrile-based polymers having different acrylonitrile content percentages; and a surface part having a cross-linked structure and a Na salt-type or K salt-type carboxyl group, and further by forming the resultant mixture into a granular cotton-like shape.

Description

Batting

The present invention relates to a padding that can be used as a substitute for feathers, is light and bulky, is flexible, and easily follows the body. The batting of this invention can be used suitably for the batting of clothes, such as a bedclothing bedding and a down jacket.

Cloths for bedding and garments for clothing are light and bulky, have high heat retention, and require a soft texture that follows the movement of the body. For such applications, animal fibers such as feathers and cotton and synthetic fibers such as polyester have been used. Among these, feathers are particularly lightweight, excellent in compression recovery, and do not entangle with each other. In addition, since feathers are excellent in heat retention and flexibility, they have been widely used exclusively as batting for bedding and clothing.

However, due to the recent decline in feather production, the price of feathers has soared and it has become difficult to provide them as a material for these batting. For this reason, there is a strong demand to develop a high-performance alternative batting having the above performance of feathers.

For improving heat retention, a batting made by mixing other synthetic fibers with hygroscopic exothermic fibers excluding animal fibers has been proposed (see Patent Document 1). However, when the hygroscopic exothermic fiber is used in a normal form as used in Patent Document 1, it is extremely difficult to maintain both the hygroscopic exothermic property and bulkiness at a high level, and as a result, the heat retaining property. There is a problem that it cannot be maintained for a long time.

JP 2003-286638 A

The present invention was devised in view of the current state of the prior art, and its purpose is suitable for bedding and clothing having light weight, bulkiness, high heat retention, and flexibility that easily follows the movement of the body. To provide batting.

In order to achieve such an object, the present inventor has intensively studied the configuration of the hygroscopic exothermic fiber used in the batting and the synthetic fiber used in combination, and as a result, the hygroscopic exothermic fiber has a specific center and surface layer. By using a composite fiber with a side-by-side structure, and further using hollow polyester fibers and processing them into a fluffy shape, a batting that has achieved a high level of lightness, bulkiness, heat retention and flexibility I found out that it can be provided.

Specifically, as a hygroscopic exothermic fiber, a central part of a side-by-side structure composed of two types of acrylonitrile-based polymers having different acrylonitrile content ratios contributing to bulkiness, a crosslinked structure and Na salt type contributing to hygroscopic exothermic characteristics Alternatively, by using a specific side-by-side type composite fiber composed of a surface layer portion having a K salt-type carboxyl group, and using a hollow polyester fiber that is light and excellent in bulkiness, and processing them into a fluffy form It has been found that it is possible to provide batting having 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 type composite fiber comprising a center part of a side-by-side type structure composed of two types of acrylonitrile-based polymers having different acrylonitrile contents, and a surface layer part having a crosslinked structure and a Na salt type or K salt type carboxyl group A batting characterized by using (A) and a hollow polyester fiber (B) entangled and mixed to form a crushed cotton.
(2) The batting according to (1), wherein the weight ratio of the contained side-by-side type composite fiber (A) to the hollow polyester fiber (B) is 10:90 to 60:40.
(3) The batting according to (1) or (2), wherein the amount of total carboxyl groups in the side-by-side type composite fiber (A) is 3.5 to 10 mmol / g.
(4) The side-by-side type composite fiber (A) has an Na salt type or K salt type carboxyl group content of 3.0 to 10 mmol / g, according to any one of (1) to (3) 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.

The batting of the present invention uses a crosslinked polyacrylate fiber having a Na salt type or a K salt type carboxyl group as a moisture absorption exothermic fiber, so that it shows a high temperature rise immediately after moisture absorption and a specific composite Since the structure is adopted, there is little influence of the sag of the fiber at the time of moisture absorption, high bulkiness can be brought about, and as a result, high heat retention can be obtained. In addition, lightweight and bulky hollow polyester fibers are used in combination, and these are mixed with the hygroscopic exothermic fibers described above and processed into a cotton-like shape, so they have high bulkiness, lightness, flexibility, and heat retention. Can do.

It is a graph which shows transition of the temperature for every elapsed time of the bridge | crosslinking polyacrylate type fiber which has a Na salt type or Mg salt type carboxyl group measured based on the measuring method and conditions 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) consisting of a specific center portion and a surface layer portion and a hollow polyester fiber (B) are entangled and mixed to form a crushed shape. And With such a feature, moisture absorption exothermic property that rapidly absorbs moisture and exhibits exothermic properties, bulkiness that provides sustained heat retention, light weight, and flexibility can be provided at a high level.

The side-by-side type composite fiber (A) used in the present invention needs to be a crosslinked polyacrylate fiber having a monovalent metal Na salt type or K salt type carboxyl group. Mg salt type or Ca salt type divalent metal salt type has hygroscopic exothermic property, but the initial rising temperature at the time of hygroscopic exotherm is low, so if you want to feel warmth and heat retention early There's a problem. In addition, other divalent metal salt types such as a Zn salt type are not preferable because they are inferior in hygroscopic heat generation and a comfortable environment cannot be obtained. The monovalent metal salt type of the Na salt type or the K salt type has a high initial temperature rise during the hygroscopic heat generation, and thus can feel warmth at an early stage. However, the cross-linked polyacrylate fiber having a Na salt type or K salt type carboxyl group has a bulky property in a normal fiber form and cannot maintain heat retention. Take the structure.

The side-by-side type composite fiber (A) used in the present invention has a central part of a side-by-side type structure composed of two kinds 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 consisting of a surface layer part. The side-by-side type composite fiber (A) of the present invention has a composite structure composed of a central portion and a surrounding surface layer portion, and contributes to improvement in bulkiness by forming a hard structure in the central portion, and the surface layer portion. The present invention is characterized in that it plays a role of high moisture absorption exothermicity by the presence of a cross-linked structure and a Na salt type or K salt type carboxyl group. The side-by-side type composite fiber (A) preferably has a total carboxyl group amount of 3.5 mmol / g or more, and can be up to about 10 mmol / g, preferably up to 6.5 mmol / g. Actually, 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 group amount of the side-by-side type composite fiber is Na salt type or K salt type carboxyl group. 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, and is about 10 mmol / g at maximum, preferably 6.5 mmol at maximum. / G.

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

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

A cross-linked structure is introduced into the surface layer of the fiber having a composite structure as described above. For the introduction of the crosslinked structure, a conventionally known crosslinking agent may be used, but it is preferable to use a nitrogen-containing compound from the viewpoint of the introduction efficiency of the crosslinked structure. As the nitrogen-containing compound, it is preferable to use an amino compound or a hydrazine compound having two or more primary amino groups. Examples of amino compounds having two or more primary amino groups include diamine compounds such as ethylenediamine and hexamethylenediamine, diethylenetriamine, 3,3′-iminobis (propylamine), N-methyl-3,3′-iminobis ( Triamine compounds such as propylamine), triethylenetetramine, N, N′-bis (3-aminopropyl) -1,3-propylenediamine, N, N′-bis (3-aminopropyl) -1,4- Examples include tetramine compounds such as butylenediamine, polyvinylamine, polyallylamine, and the like, and polyamine compounds having two or more primary amino groups. Examples of the hydrazine compound include hydrazine hydrate, hydrazine sulfate, hydrazine hydrochloride, hydrazine hydrobromide, hydrazine carbonate, and the like. 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-linked structure into the fiber. The conditions for introducing the cross-linked structure are not particularly limited, and can be appropriately selected in consideration of the reactivity between the cross-linking agent employed and the acrylonitrile fiber, the amount of the cross-linked structure, and the like. For example, when a hydrazine compound is used as the cross-linking agent, the acrylonitrile fiber described above is immersed in an aqueous solution to which the hydrazine compound is added so that the hydrazine concentration is 0.1 to 10% by weight. And a method of treating at 2 ° C. for 2 to 10 hours.

After the cross-linked structure is introduced, hydrolysis treatment with an alkaline metal compound is performed, and nitrile groups present in the surface layer of the fiber are hydrolyzed to form carboxyl groups. Specific treatment conditions may be set as appropriate in consideration of the amount of carboxyl groups described above, and the like, and various conditions such as the concentration of the treatment agent, reaction temperature, reaction time, etc. are preferably set, but preferably 0.5 to 10% by weight, More preferably, a means for treating in a 1 to 5% by weight treatment chemical aqueous solution at a temperature of 80 to 150 ° C. for 2 to 10 hours is preferred from the industrial and fiber viewpoints. In the present invention, it is preferable that the above-described cross-linking introduction treatment and hydrolysis treatment are collectively performed simultaneously using an aqueous solution in which the respective treatment chemicals are mixed, rather than sequentially performing as described above. Further, in the present invention, it is preferable that the simultaneous treatment is performed under a milder condition of an alkali metal compound having a lower concentration than before, and the subsequent acid treatment is performed under severer conditions at a higher temperature than in the past. By doing in this way, 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 than before and a relatively hard acrylonitrile polymer is preserved in the center portion. Can do.

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, in order to obtain a high moisture absorption rate, the H-type carboxyl group is converted into a salt-type carboxyl group, and about 90% or more, preferably about 95% or more, more preferably substantially all the carboxyl groups are converted into the salt type. It is desirable to use a carboxyl group. The cation constituting the salt-type carboxyl group is sodium or potassium alkali metal. When a polyvalent metal ion such as magnesium, calcium, or zinc is employed, the bulkiness is high, but the initial temperature rise due to moisture absorption is low, which is not preferable. For example, the side-by-side type composite fiber (A) of the present invention has a specific condition as described above for an acrylonitrile-based fiber in which two types of acrylonitrile-based polymers having different acrylonitrile contents are bonded side-by-side. It can be obtained by introducing a bridge and hydrolyzing to form a carboxyl group and selecting sodium or potassium as the counter ion.

Methods for converting H-type carboxyl groups to salt-type carboxyl groups include ion exchange treatment with metal salts such as nitrates, sulfates, hydrochlorides, acid treatments with nitric acid, sulfuric acid, hydrochloric acid, formic acid, etc., or alkaline metal compounds, etc. The method of performing the pH adjustment process by etc. is mentioned.

In the side-by-side type composite fiber (A), the area occupied by the surface layer part in the cross section is preferably 5% to 35%, more preferably 10% to 30%, and still more preferably 10% to 20%. When the area of the surface layer portion is less than the above range, the carboxyl group cannot be sufficiently present in the fiber, and there is a possibility that high moisture absorption exothermic property cannot be exhibited. On the other hand, if the above range is exceeded, the fibers tend to sag 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 reducing the bulkiness of the fiber due to moisture absorption due to the presence of many central parts that are substantially free of carboxyl groups. can do. Further, as shown in FIG. 1, the crosslinked polyacrylate fiber having a Na salt type or K salt type carboxyl group has a higher hygroscopic exothermic property (especially the initial rising temperature) than a divalent metal salt such as an Mg salt type. ) And can be enjoyed as it is in the present invention.

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

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

The hollow polyester fiber (B) used in the present invention is a polyester fiber having cavities or voids therein, and is produced using a conventionally known polyester fiber suitable for filling cotton as long as a hollow portion exists 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 a homopolymer but also a copolymer fiber composed of a plurality of types of polymer blends can be used. The hollow form of the polyester fiber can be suitably obtained by a conventionally known method. For example, a polyester resin pellet is melted, discharged from a C-type nozzle at a high temperature, and wound by a winding roller to form an undrawn yarn. Then, it can be obtained by stretching at a suitable stretching ratio at a temperature of 60 to 90 ° C. or by performing a relaxation heat treatment. The hollow ratio of the hollow polyester fiber (B) is not particularly limited, but is preferably 10% to 60% in view 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. In addition, 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 properties may not be obtained, and if it exceeds the above range, the texture becomes hard and may not be suitable as a batting for bedding. In addition, when the fiber length deviates from the above range, it may be difficult to mix the fibers and process them into a crushed 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, Polyolefin fiber, polyphenylene sulfide fiber, etc.) can be mixed and used. The weight ratio of the side-by-side 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, there is a possibility that sufficient hygroscopic exothermic property cannot be exhibited. If the side by side composite fiber (A) exceeds the above range, the cost increases and the flexibility may also 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 entangled and mixed as essential components and processed into a crushed form. Conventionally known methods can be adopted as a method for processing into a smashed form, for example, a method of stirring each used fiber under a high-speed air current, a method of mixing and stirring each used fiber in a stirrer, It is possible to adopt a method in which a plurality of fibers used are aligned and subjected to a bundling process and then cut, and then heat-treated at a temperature lower than the melting point of the fibers to develop crimps to form fiber balls. Each of the fillings constituting the filling of the present invention is substantially spherical, and the diameter of one filling 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, hemp, wool, nylon, rayon, polyester, acrylic and the like. As described above, the batting of the present invention is lightweight and bulky, and has heat retention and flexibility, so that it can be used as a padding for bedding (bedding, mattress, pillow, etc.) or outer clothing for autumn and winter. It is extremely suitable as a batting.

The present invention will be specifically described with reference to the following examples, but the present invention is not limited thereto. In addition, the ratio in an Example is shown on a weight basis unless there is a notice. The evaluation method of characteristics in the examples is as follows.

(1) Amount of carboxyl groups in side-by-side type composite fiber (A) (i) Total amount of carboxyl groups About 1 g of fiber sample is immersed in 50 ml of 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. When it is confirmed that the bath pH is 4 or more after 15 minutes, the bath is dried (if the bath pH is less than 4, it is washed 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 add phenolphthalein and stir. After 15 minutes, the sample fibers and filtrate are separated by filtration, and the sample fibers are subsequently washed with water until there is no coloration of phenolphthalein. The combined washing water and filtrate at this time are titrated with 0.1 mol / l hydrochloric acid aqueous solution until the phenolphthalein is no longer colored, and the aqueous hydrochloric acid consumption (V1 [ml]) is determined. From the obtained measured value, the total carboxyl group amount is calculated by the following formula.
Total carboxyl group amount [mmol / g] = (0.1 × 15−0.1 × V1) / W1
(Ii) Amount of salt-type carboxyl groups In the above-described method for measuring the total amount of carboxyl groups, the amount of H-type carboxyl groups was calculated in the same manner except that the first immersion in 1 mol / l hydrochloric acid aqueous solution and subsequent water washing were not performed. To do. The amount of salt-type carboxyl groups is calculated by subtracting the amount of H-type carboxyl groups from the total amount of carboxyl groups.

(2) 20 ° C. × 65% RH Hygroscopicity of Side-by-Side Type Composite Fiber (A) About 2.5 g of a fiber sample is dried with a hot air dryer at 105 ° C. for 16 hours and weighed (W2 [g]). Next, the fiber sample is placed in a thermo-hygrostat adjusted to a temperature of 20 ° C. and 65% RH for 5 minutes. The weight of the fiber sample thus absorbed is measured (W3 [g]). From these measurement results, a 20 ° C. × 65% RH moisture absorption rate is calculated by the following equation.
20 ° C. × 65% RH moisture absorption [%] = (W3−W2) / W2 × 100

(3) Specific volume of side-by-side type composite fiber (A) 50 g of the fiber sample is lightly opened, then opened by a card machine and laminated. Six test specimens are cut out so as to have a size of 10 cm × 10 cm, put into a bat and left in a thermo-hygrostat for 24 hours or more. Take out from the thermo-hygrostat, stack it so that the mass is 10.0g to 10.5g, and accurately weigh the test piece made. A 10 cm × 10 cm acrylic plate is placed on the test piece, a weight of 500 g is placed for 30 seconds, then the weight is removed and left for 30 seconds. This operation is repeated three times. After leaving the weight of 500 g and leaving for 30 seconds, the height of the four corners is measured to obtain an average value, and the specific volume is calculated by the following formula.
Specific volume (cm ³ / g) = 10 × 10 × measured average value of height of four corners of sample (mm) / 10 / mass of test piece (g)

(4) Rise temperature of side-by-side type composite fiber (A) The rise temperature of the sample fiber was measured based on ISO18782: 2015.

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

(6) Rising temperature of batting The rising temperature of the batting sample was measured in accordance with ISO18782: 2015.

(7) Stretching along the skin of filling The mini-futon is prepared by uniformly packing 150 g of a filling sample into a cloth on the duvet side that is sewn to 30 cm × 30 cm. Next, a wooden stick having a diameter of 5 cm and a length of 30 cm is prepared and laid on a table. A mini duvet packed with a batting sample is dropped from a height of 10 cm onto a wooden stick. Measure the distance from the ground contact point of the wooden bar to the mini futon contact point. If the distance between the contact points is short, the along-skin property is good.

(8) Lightness of batting Fill the batting sample into a 1000 ml measuring cylinder. Next, 5 g of an acrylic resin top plate is placed and it is confirmed that the volume is 1000 ml. The batting sample weight at that time is measured.

Preparation of side-by-side type composite fiber (A1) 90% by weight of acrylonitrile, 10% by weight of acrylic acid methyl ester, acrylonitrile polymer Ap (Intrinsic viscosity [η] = 1.5 in dimethylformamide at 30 ° C.), 88% by weight of acrylonitrile Then, 12% by weight of vinyl acetate acrylonitrile polymer Bp ([η] = 1.5) was dissolved in a 48% by weight aqueous solution of rhodium soda to prepare a spinning dope. Each spinning undiluted solution is introduced into a compound spinning device according to Japanese Patent Publication No. 39-24301 so that the composite ratio (weight ratio) of Ap / Bp is 50/50, and spinning, washing, drawing, crimping and heat treatment are carried out according to conventional methods. Thus, a side-by-side raw material fiber in which the polymers Ap and Bp having a single fiber fineness of 3.3 dtex were combined was obtained.

The raw fiber was subjected to crosslinking introduction treatment and hydrolysis treatment simultaneously in an aqueous solution containing 0.5% by weight of hydrazine hydrate and 1.6% by weight of sodium hydroxide at 100 ° C. for 2 hours. The solution was treated with an aqueous solution at 120 ° C. for 3 hours and washed with water. The obtained fiber is immersed in water, adjusted to pH 9 by adding sodium hydroxide, washed with water, and dried to form a Na salt type crosslinked polyacrylate 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 such a fiber, absorption is in the vicinity of 2250 cm ⁻¹ derived from the nitrile group, and the hydrolysis of the nitrile group proceeds in the fiber surface layer portion, but the nitrile group is present in the fiber center portion. It was confirmed that it remained.

Preparation of side-by-side type composite fiber (A2) K salt type in the same manner except that potassium hydroxide was used instead of sodium hydroxide added to adjust to pH 9 in the preparation of side-by-side type composite fiber (A1). A cross-linked polyacrylate fiber (surface layer area 18%, K salt type carboxyl group amount 3.9 mmol / g) was obtained.

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

Preparation of side-by-side type composite fiber (A4) Same as 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 wt% to 1.8 wt%. By the method, Na salt type cross-linked polyacrylate fiber was obtained (surface layer area 23%, Na salt type carboxyl group amount 4.9 mmol / g).

Preparation of side-by-side type composite fiber (A5) Acrylonitrile 90% by weight, acrylic acid methyl ester 10% by weight acrylonitrile polymer Ap (Intrinsic viscosity [η] = 1.5 in dimethylformamide at 30 ° C.), acrylonitrile 88% by weight Then, 12% by weight of vinyl acetate acrylonitrile polymer Bp ([η] = 1.5) was dissolved in a 48% by weight aqueous solution of rhodium soda to prepare a spinning dope. Each spinning dope is introduced into a compound spinning device according to Japanese Examined Patent Publication No. 39-24301 so that the composite ratio of Ap / Bp is 50/50, followed by spinning, washing, drawing, crimping, and heat treatment according to conventional methods. A side-by-side raw material fiber in which the polymers Ap and Bp having a fiber fineness of 3.3 dtex were combined was obtained.

The raw fiber was subjected to crosslinking introduction treatment and hydrolysis treatment simultaneously in an aqueous solution containing 0.5% by weight of hydrazine hydrate and 1.6% by weight of sodium hydroxide at 100 ° C. for 2 hours. The solution was treated with an aqueous solution at 120 ° C. for 3 hours and washed with water. The obtained fiber is immersed in water, adjusted to pH 9 by adding sodium hydroxide, and then immersed in an aqueous solution in which magnesium nitrate corresponding to twice the amount of carboxyl groups contained in the fiber is dissolved at 50 ° C. for 1 hour. By carrying out the ion exchange treatment, washing with water and drying, the Mg salt-type crosslinked polyacrylate fiber having an Mg salt-type carboxyl group (surface area 18%, Mg salt-type carboxyl group amount 3.8 mmol / g) Got.

Preparation of side-by-side type composite fiber (A6) 90% by weight of acrylonitrile, 10% by weight of acrylonitrile methyl ester Ap (Intrinsic viscosity [η] = 1.5 in dimethylformamide at 30 ° C.), 88% by weight of acrylonitrile Then, 12% by weight of vinyl acetate acrylonitrile polymer Bp ([η] = 1.5) was dissolved in a 48% by weight aqueous solution of rhodium soda to prepare a spinning dope. Each spinning dope is introduced into a compound spinning device according to Japanese Examined Patent Publication No. 39-24301 so that the composite ratio of Ap / Bp is 50/50, followed by spinning, washing, drawing, crimping, and heat treatment according to conventional methods. A side-by-side raw material fiber in which the polymers Ap and Bp having a fiber fineness of 3.3 dtex were combined was obtained.

The raw fiber was subjected to crosslinking introduction treatment and hydrolysis treatment simultaneously in an aqueous solution containing 0.5% by weight of hydrazine hydrate and 1.6% by weight of sodium hydroxide at 100 ° C. for 2 hours. The solution was treated with an aqueous solution at 120 ° C. for 3 hours and washed with water. The obtained fiber is immersed in water, adjusted to pH 9 by adding sodium hydroxide, and then immersed in an aqueous solution in which calcium nitrate corresponding to twice the amount of carboxyl groups contained in the fiber is dissolved at 50 ° C. for 1 hour. By carrying out the ion exchange treatment, washing with water and drying, the Ca salt type cross-linked polyacrylate fiber having a Ca salt type carboxyl group (surface area 18%, Ca salt type carboxyl group amount 3.9 mmol / g) Got.

Preparation of hygroscopic exothermic fiber (A7) having no side-by-side structure Acrylonitrile polymer Ap of 90% by weight of acrylonitrile and 10% by weight of acrylic acid methyl ester (Intrinsic viscosity [η] = 1.5 in 30 ° C. dimethylformamide) Was dissolved in a 48% by weight aqueous Rhodan soda solution to prepare a spinning dope. The spinning solution was introduced into a spinning device, and spinning, washing, drawing, crimping, and heat treatment were carried out in accordance with conventional methods to obtain raw material fibers having a single fiber fineness of 6.6 dtex and having no side-by-side structure.

The raw fiber was subjected to crosslinking introduction treatment and hydrolysis treatment simultaneously in an aqueous solution containing 0.5% by weight of hydrazine hydrate and 1.6% by weight of sodium hydroxide at 100 ° C. for 2 hours. The solution was treated with an aqueous solution at 120 ° C. for 3 hours and washed with water. The obtained fiber was immersed in water, adjusted to pH 9 by adding sodium hydroxide, washed with water and dried to obtain a Na salt type crosslinked polyacrylate fiber having a Na salt type carboxyl group.

Production of hollow polyester fiber (B1) A shrepe made by Toyobo Co., Ltd. was used. The thickness of this product is 2.0 dtex, the fiber length is 20 mm, and the hollowness is 30%.

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

Preparation of batting Mixing each hygroscopic exothermic fiber and polyester fiber in accordance with the materials and usage ratios listed in Table 1, with a card provided with a plurality of rollers with a garnet wire provided on the surface, sufficiently opening the fiber, An apparatus in which fibers are blown into a room provided with a rotating body that rotates with a plurality of fins in a cylindrical space where air turbulence is likely to occur. Fillings of 1 to 12 and Comparative Examples 1 to 5 were obtained. All of the obtained cotton fillings were substantially spherical cotton, and the diameter of one cotton was about 30 mm.

Table 1 shows 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 batting of Examples 1 to 12 belonging to the scope of the present invention showed excellent results in all evaluation items, whereas the side-by-side type composite fibers (A) Comparisons using Mg salt type and Ca salt type comparative examples 1 and 2, comparative example 3 without smashing processing, comparative example 4 not using hollow polyester fibers, and hygroscopic exothermic fibers without side-by-side structure Example 5 showed clearly inferior results for any of the evaluation items.

According to the present invention, it is possible to provide a filling suitable for bedding and clothing that is lightweight and 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 type composite fiber (A) comprising a center part of a side-by-side type structure composed of two types of acrylonitrile-based polymers having different acrylonitrile contents, and a surface layer part having a crosslinked structure and a Na salt type or K salt type carboxyl group And a hollow polyester fiber (B) entangled and mixed to form a crushed cotton. The batting according to claim 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. The batting according to claim 1 or 2, wherein the total carboxyl group content of the side-by-side type composite fiber (A) is 3.5 to 10 mmol / g. The batting according to any one of claims 1 to 3, wherein the amount of carboxyl group of the Na salt type or K salt type 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. 6. 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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