HK1114885B - Fiber used as doll's hair, made from vinylidene chloride resin - Google Patents

Description

Fibers for doll hair made of vinylidene chloride resin

Technical Field

The present invention relates to fibers for doll hair made of vinylidene chloride resin which are excellent in fiber processability and the like.

Background

Doll hair, which may be implanted into a doll head, generally requires a similar look and feel to human hair. As such fibers for doll hair, synthetic linear polyamide, acrylic resin, or the like is known to be used as a material. In particular, doll hair made of vinylidene chloride resin has become mainstream in view of excellent appearance and texture of hair (for example, see patent documents 1 and 2).

However, since vinylidene chloride resins have low thermal stability, yarn breakage or the like due to thermal decomposition products often occurs in the melt spinning step. In addition, in the case of hollow fibers which are widely preferred from the viewpoint of weight reduction or the like (for example, see patent document 3), thermal decomposition is promoted due to a pressure rise in the spinneret part. Therefore, the frequency of orifice replacement becomes high. For this reason, it is difficult to produce fibers stably in practice, and the productivity has to be lowered.

In order to improve the thermal stability of the vinylidene chloride resin, it is also considered to use a large amount of various stabilizers, plasticizers, and the like. However, if a large amount of this stabilizer is used in doll hair, the excessive stabilizer or plasticizer migrates to the fiber surface due to crystallization of the vinylidene chloride resin after spinning, and the fiber surface becomes sticky. This results in only fibers with poor hand and appearance. Further, when the fibers are used as doll hair and subjected to a curling process, clogging and the like may occur.

Therefore, there is a need for fibers that maintain the excellent appearance and feel of doll hair made of vinylidene chloride resin, while minimizing the use of stabilizers and plasticizers.

Patent document 1: japanese patent laid-open publication No. Sho 61-113814

Patent document 2: japanese patent laid-open No. 2000-226726

Patent document 3: japanese laid-open patent publication No. 6-220712

Disclosure of Invention

The invention provides doll hair made of vinylidene chloride resin, which has excellent productivity and maintains excellent appearance, hand feeling and the like.

The invention relates to a fiber for doll hair, which is characterized in thatCharacterized in that it contains a weight average molecular weight of 5X 10⁴～8×10⁴And the vinylidene chloride resin of (1) and (2) contains 3 to 10% of a vinylidene chloride resin having a molecular weight of 1X 10⁴The following low molecular weight components. Here, the doll hair fibers preferably contain 90% by weight or more of the vinylidene chloride resin. The vinylidene chloride resin preferably has a ratio (Mw/Mn) of a weight average molecular weight (Mw) to a number average molecular weight (Mn) of 2 to 5. The doll hair fibers are preferably hollow filaments having a hollow ratio of 3 to 30%, and the average outer diameter of the fiber surface is preferably 0.01 to 0.2 mm.

Effects of the invention

The fibers for doll hair of the present invention are excellent in productivity. Specifically, the spinning processability is excellent, and the frequency of yarn breakage and spinneret hole replacement during spinning is low. The doll hair fibers of the present invention are excellent in touch and appearance. This is because the amount of the stabilizer and the plasticizer used can be kept at a minimum and the fibers are not sticky on the surface.

Drawings

FIG. 1 is a conceptual diagram showing a typical molecular weight distribution example of a vinylidene chloride resin.

Fig. 2 is a schematic diagram showing an example of a schematic configuration of the crimping apparatus.

Fig. 3 is a schematic view showing a schematic configuration of the tufting sewing machine.

Description of the reference symbols

1 resin bag

2 crimped fibers

3 core rod

4 heater

5 machine head

6 tubular yarn guide rod

7 bobbin

8 flocking sewing machine body

9 doll head

10 Sewing needle

11 rotating tubular yarn guide bar (yarn guide)

12 doll hair

13 bobbin

14 fiber

Detailed Description

The present invention will be described in detail below centering on a particularly preferred embodiment.

The fibers for doll hair according to the present invention are characterized by containing a specific vinylidene chloride resin described below.

Vinylidene chloride resin has a weight average molecular weight of 5X 10⁴～8×10⁴. Preferably 5.5X 10⁴Above, 7.5 × 10⁴Hereinafter, more preferably 6 × 10⁴Above, 7 × 10⁴The following. This range is low for the weight average molecular weight of the vinylidene chloride resin generally used. However, if the amount is within this range, productivity can be improved while maintaining the strength necessary for doll hair. From the strength point of view, it is 5X 10⁴The above. When the amount is within this range, the ability to be implanted and the resistance to plucking during combing can be obtained when the head of a doll is implanted with hairs well. And, from the viewpoint of productivity, 8X 10⁴The following. Although the reason is not clear, if the amount is within this range, thermal decomposition and clogging of the spinneret holes are unlikely to occur in the extruder during spinning, and the time during which the spinneret holes can be continuously used without replacement becomes long.

The replacement of the spinneret hole as referred to herein means the replacement of the spinning operation with another spinneret hole after the spinning operation is stopped. Since the spinneret holes require time for precise cleaning, the cleaned spinneret holes are prepared in advance. When generation of bubbles (hydrochloric acid gas) and clogging of the spinneret orifice are caused by thermal decomposition of the vinylidene chloride resin, replacement is performed while purging the inside of the extruder is performed. The frequency of orifice replacement has a great influence on productivity, and therefore, a long continuous use time of the orifices (a time during which continuous spinning is possible without replacing the orifices from the start to the stop of spinning) is important.

In order to adjust the weight average molecular weight of the vinylidene chloride resin to the above range, a method of using a larger amount of the polymerization initiator than before, setting the polymerization temperature to a higher temperature than before, or using both of them may be used.

Vinylidene chloride resin having a molecular weight of 1X 10⁴The following low molecular weight components are in the range of 3% to 10% of the total amount of the vinylidene chloride resin. The molecular weight here is 1X 10⁴The following low molecular weight components are represented by the following formula in which GPC charts are obtained by gel permeation chromatography.

(molecular weight 1X 10)⁴The following ratio of low molecular weight components) ═ by (molecular weight 1 × 10)⁴The following area occupied by the low-molecular weight component)/(total area of peaks) × 100

FIG. 1 shows 1 example of the molecular weight distribution. In FIG. 1, the area of the range indicated by oblique lines means that the molecular weight is 1X 10⁴The area occupied by the following low-molecular-weight components. The area enclosed by the curve on the GPC chart and the horizontal axis is the total area of the peaks.

Vinylidene chloride resin having a molecular weight of 1X 10⁴The low molecular weight component is 3% or more. Although the reason is not clear, in this range, bubbles (hydrochloric acid gas) and clogging of the spinneret holes are less likely to occur during spinning, and the continuous use time of the spinneret holes becomes longer. And has a molecular weight of 1X 10⁴The following low molecular weight components show the effect of replacing various additivesAnd (5) fruit. In order to exert this effect, it is necessary that the low molecular weight component be 3% or more. The strength is 10% or less. When the amount is within this range, the strength necessary for doll hair can be secured, and the hair-setting workability in hair setting to the doll head and the hair removal resistance in hair combing can be improved. Preferably 3% or more and 9% or less, more preferably 4% or more and 8% or less, and further preferably 5% or more and 7% or less.

In order to obtain a vinylidene chloride resin having a molecular weight of 1X 10⁴The content of the low-molecular-weight component described below is adjusted to the above range, and the polymerization ratio can be appropriately set. This is because a large amount of high-molecular-weight polymer is produced from the initial stage to the middle stage of polymerization, that is, at a stage where the polymerization rate is low, and a large amount of low-molecular-weight polymer is produced at the end stage of polymerization, that is, at a stage where the polymerization rate is high. The polymerization ratio herein means a weight ratio of a polymer produced by a polymerization reaction to the whole polymer used for polymerization. Further, a larger amount of the polymerization initiator may be used, and the kind of the polymerization initiator may be changed. In addition, they may be used in combination.

When the kind of the polymerization initiator is changed, a specific polymerization initiator such as diisopropyl peroxydicarbonate, dilauroyl peroxide, tert-butyl peroxypivalate, or the like can be used.

The molecular weight distribution of the vinylidene chloride resin may be a monomodal distribution, a bimodal distribution of a component having a lower molecular weight and a component having a higher molecular weight, or a multimodal collection, as long as the above conditions are satisfied. The single peak is preferable from the viewpoint of ease of production. The degree of dispersion (Mw/Mn) as the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the vinylidene chloride resin is preferably in the range of 2 to 5, more preferably in the range of 2.1 to 4, and even more preferably in the range of 2.2 to 3. The molecular weight distribution shown in FIG. 1 is a preferred example.

The vinylidene chloride resin can be obtained by polymerizing vinylidene chloride alone. In order to further improve the physical properties of the fibers, a copolymer of vinylidene chloride and at least one ethylene derivative copolymerizable with vinylidene chloride may be used. The vinylidene chloride unit is preferably 50% by weight or more in the copolymer.

As the ethylene derivative, there can be mentioned:

nitrile having ethylenic unsaturation: acrylonitrile or methacrylonitrile, etc.;

alkyl esters of acrylic or methacrylic acid: methacrylic acid esters or methyl methacrylate, etc.;

hydroxyalkyl ester: hydroxypropyl acrylate, hydroxyethyl acrylate, hydroxybutyl acrylate, and the like;

ethylene ester of saturated carbonic acid: vinyl acetate and the like;

amide having an ethylenically unsaturated group: acrylamide and the like;

carbonic acid having ethylenic unsaturated group: acrylic acid and the like;

ethylenically unsaturated alcohol: aryl alcohols and the like;

vinyl halide: vinyl chloride, and the like.

Among them, methacrylic acid esters and vinyl chloride are preferable, and vinyl chloride is more preferable, from the viewpoint of good thermal stability.

The preferred weight ratio of vinylidene chloride units and ethylene derivative units in the copolymer will vary depending on the ethylene derivative used. For example, when the ethylene derivative is vinyl chloride, the preferable weight ratio of vinylidene chloride unit/vinyl chloride unit is 65/35 to 98/2. When the vinyl chloride unit is 35% by weight or less based on 100% by weight of the total of the two components, the transparency of the resulting vinylidene chloride resin can be maintained. In addition, since the vinyl chloride unit is 2 wt% or more, the melt viscosity of the vinylidene chloride resin can be maintained low, and melt extrusion becomes easier. More preferably, the weight ratio of vinylidene chloride units/vinyl chloride units is from 80/20 to 95/5. When the ethylene derivative is a methacrylate, for example, the weight ratio of vinylidene chloride units/methacrylate units is preferably in the range of 80/20 to 99/1.

In order to obtain a vinylidene chloride resin, the above monomers as raw materials are first put into a reaction vessel having a stirring blade and polymerized while stirring by a known method such as suspension polymerization or emulsion polymerization. Dehydration, drying and the like after polymerization can be carried out according to a known method. Thus, a weight average molecular weight of 5X 10 was obtained⁴～8×10⁴And a vinylidene chloride resin containing a certain amount of low-molecular weight components.

The fibers for doll hair may contain, in addition to the above vinylidene chloride resin, other components such as a plasticizer and a heat stabilizer, if necessary, in a range not to impair the effects of the present invention. Examples of the other components include resins other than vinylidene chloride resins, plasticizers, heat stabilizers, surfactants, lubricants, antistatic agents, antioxidants, light stabilizers, and pigments. The content of the vinylidene chloride resin in the fibers for doll hair is preferably 90% by weight or more, more preferably 92% by weight or more, and still more preferably 95% by weight or more, from the viewpoint of adaptation to the feel of doll hair.

Examples of the plasticizer include diisobutyl adipate, dibutyl adipate, acetyl tributyl citrate, dibutyl sebacate, dioctyl adipate, and dioctyl phthalate. From the viewpoint of hand feeling, diisobutyl adipate, dibutyl adipate and acetyl tributyl citrate are preferable, and diisobutyl adipate or dibutyl adipate is more preferable. By using the plasticizer, the melt extrusion processability can be improved, and the productivity of the fiber can be further improved. On the other hand, however, the fiber surface is easily sticky, and the hand feeling is deteriorated when it is used as doll hair. The amount of the plasticizer is preferably 5% by weight or less, more preferably 2% by weight or more and 5% by weight or less in the resin composition.

Examples of the heat stabilizer include epoxidized linseed oil, epoxidized soybean oil, bisphenol a diglycidyl ether, pentaerythritol tetrakis [3- (3, 5-di-t-butyl-4-hydroxyphenyl) propionate ], butyl epoxy stearate, octyl epoxy stearate, magnesium oxide, magnesium hydroxide, and paraffin. Preferably epoxidized linseed oil, epoxidized soybean oil, epoxidized butyl stearate, and epoxidized octyl stearate, and most preferably epoxidized linseed oil. Since the heat stabilizer is used, thermal decomposition of the vinylidene chloride resin can be reduced. On the other hand, like the plasticizer, the fiber surface tends to become sticky, and the hand is deteriorated. The heat stabilizer is preferably 5% by weight or less, more preferably 1% by weight or more and 4% by weight or less in the resin composition.

Both the plasticizer and the heat stabilizer increase the sticky feeling on the surface of the fiber and deteriorate the hand feeling. Therefore, the total content of the plasticizer and the heat stabilizer is preferably 10% by weight or less, and more preferably 8% by weight or less, in the resin composition.

Doll hair fibers were produced as follows. First, a raw material containing the above vinylidene chloride resin was supplied to an extruder to be melted, and the melt was spun out from a spinneret and cooled in a cold water tank. Then, the resultant is stretched at a stretching temperature according to the purpose and then wound on a bobbin or the like. The temperature of the cold water tank is preferably 30 ℃ or lower, and more preferably 20 ℃ or lower. The stretching ratio is preferably in the range of 2 to 6 times, and more preferably 3 to 5 times. Within this range, the strength and stretch necessary to be doll hair may be maintained.

The cross-sectional structure of the doll hair fibers may be any of a uniform structure, a hollow structure, a multilayer structure, and the like, depending on the intended use and purpose. The cross-sectional shape may be a generally circular shape, or may be a special-shaped shape such as a triangle, polygon, Y-shape, star-shape, or flat shape. A round shape with a hollow configuration is particularly preferred from the standpoint of the light and slippery feel desired for a doll. Additionally, the doll hair fibers may be multifilament yarns of combinations of monofilaments of various configurations and shapes. When used as multifilament, fibers other than the doll hair fibers of the present invention may be blended.

When the fiber is a hollow fiber, the hollow ratio of the fiber is preferably 3 to 30%. The hollow ratio herein means a ratio of an area drawn by the outer periphery of the hollow of the fiber to an area drawn by the outer periphery of the fiber when a cross-sectional shape of a plane perpendicular to the longitudinal direction of the fiber is observed under a microscope. From the viewpoint of light touch and volume required for doll hair, the amount of the hair is 3% or more. From the viewpoint of the strength required for doll hair, the content is 30% or less. In this range, for example, breakage (breakage of hollow fibers in the wale direction) is less likely to occur, and when hair is implanted into the doll head, the hair implantation processability and the hair removal resistance during combing are also improved.

The average outer diameter of the fibers is preferably 0.01 to 0.2 mm. The average outer diameter is a value obtained by obtaining the outer diameter of a fiber cross section (a simple average of the major axis and the minor axis) for a plurality of cross sections and averaging these numbers as the average outer diameter, which is obtained by observing the cross section shape of a plane perpendicular to the longitudinal direction of the fiber with a microscope. From the viewpoint of the strength necessary for doll hair, the average outer diameter is preferably 0.01mm or more. From the viewpoint of soft hand feeling similar to natural hair, 0.2mm or less is preferable.

The fibers for doll hair may be subjected to a shaping treatment such as crimping treatment if necessary. Fig. 2 is a schematic diagram showing an example of a crimping apparatus for crimping fibers. The fibers are taken out from one or more bobbins 7 around which the spun fibers are wound, and fed in a bundle state to the machine head 5 via a tubular yarn guide (yarn guide) 6. The inside of the machine head 5 and the tubular yarn guide 6 rotate about the core rod 3. The fiber fed out from the mandrel 3 is sequentially moved to the left side of the drawing while being wound around the mandrel 3, and is heated by the heater 4 provided around the mandrel 3 to fix the fiber shape in the wound state. The fibers passed through the heater 4 are separated from the mandrel 3 at the end portion (left end portion in the drawing) of the mandrel 3, and are contained in the resin bag 1 in a curled shape. Thus, the curling process is completed.

Fig. 3 is a schematic diagram showing an example of a schematic configuration of a hair-setting sewing machine for setting doll hair fibers in a doll head. The fiber 14 drawn from the bobbin 13 for winding the fiber is introduced onto the doll head 9 through a rotating tubular yarn guide 11 provided in the sewing machine 8. The sewing needle 10 penetrates the doll head 9 from the inner side of the doll head 9 upward, and the hanging fiber 14 penetrates the inner side of the doll head 9 to be flocked. The necessary portion of the doll head 9 is integrally flocked by relatively moving the position of the doll head 9 and the outlet of the rotating tubular yarn guide 11.

Examples

The present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to the specific embodiments of the following examples.

1. Method for evaluating various physical properties

(weight average molecular weight (Mw), number average molecular weight (Mn), degree of dispersion (Mw/Mn))

The measurement was carried out by gel permeation chromatography under the following conditions according to a known method.

A measuring device: liquid chromatograph (model: LC-10AD (manufactured by Shimadzu corporation))

Column: (trade names: シヨウデツクス, アサヒパツク GS-3107E (Showa Denko K.K.)) 2 cells were connected in series

Carrier: tetrahydrofuran (THF)

External standard: polyethylene Standard specimen (ジ - エルサイエンス Co., Ltd.)

(ratio of Low molecular weight component having a molecular weight of 1X 104 or less)

In a GPC chart obtained by measuring the weight average molecular weight or the like, the low molecular weight component having a molecular weight of 1 × 104 or less is obtained from the ratio of the area occupied by the entire area occupied by the peak (the following formula). In FIG. 1, the area of the range indicated by oblique lines means that the molecular weight is 1X 10⁴The area occupied by the following low-molecular-weight components. The total area of peaks is the area enclosed by the curve and the horizontal axis on the GPC chartAnd (4) accumulating.

(molecular weight 1X 10)⁴The following ratio of low molecular weight components) ═ by (molecular weight 1 × 10)⁴The following area occupied by the low-molecular weight component)/(total area of peaks) × 100

(average outer diameter, hollow ratio)

(i) 10 hollow monofilaments were arranged in parallel and fixed with epoxy resin.

(ii) The cross section was cut perpendicular to the longitudinal direction and observed with a microscope.

(iii) The longest diameter and the shortest diameter of the outer periphery of each filament cross section were measured and simply averaged to obtain the filament outer diameter.

(iv) The longest diameter and the shortest diameter of the inner circumference (outer circumference of the hollow portion) of each filament cross section were measured and simply averaged to obtain the filament inner diameter.

(v) The outer diameter area and the inner diameter area of each monofilament are calculated from the outer diameter and the inner diameter of the monofilament.

From these, the ratio of the hollow portion was determined by the following equation.

Ratio of hollow portion (inner diameter area/outer diameter area × 100)

(vi) The average of the ratios of the outer diameter and the hollow portion of 10 filaments was obtained as the average outer diameter and the hollow ratio.

(evaluation of spinning Productivity)

In the melt spinning step, the spinning productivity was evaluated by the length of the continuous use time of the spinneret from the start to the stop of spinning.

The definition of terms is as follows.

Spinneret orifice continuous service time: spinning is continuously operated for 5 times, and the simple average of each spinning continuous operation time

Spinning continuous running time: time during which spinning can be continuously carried out from start to stop of spinning operation

Stopping of spinning operation: when multiple wire breaks occur

The occurrence of broken wires is more: 3 interruptions of spinning between 30 minutes of operation

And (3) interrupting spinning: at least one of the filaments extruded from the spinneret holes is broken

The longer the spinneret hole was continuously used, the higher the spinning productivity was evaluated. The evaluation criteria for spinning productivity are as follows.

Very good: the continuous service time of the spinneret orifice is more than 15 hours

O: the continuous service time of the spinneret orifice is more than 10 hours and less than 15 hours

And (delta): the continuous service time of the spinneret orifice is more than 6 hours and less than 10 hours

X: the continuous service time of the spinneret orifice is less than 6 hours

(Hair sticky)

Sample preparation: a strand of 200mm in length was flocculent. The total wire count was about 20 g.

Environmental conditions: storing in a thermostatic bath at 54 deg.C for 3 days

After the above samples were stored under the above-mentioned environmental conditions, the stickiness on the fiber surface was evaluated organoleptically. The number of the monitored people is 20. Evaluation criteria in each monitoring are as follows.

And 4, dividing: dry and comfortable feeling

And 3, dividing: slightly felt to have tackiness

And 2, dividing: feel sticky

1 minute: a slimy hand feeling similar to that of oil was felt.

Then, the scores given by the monitoring of 20 persons were simply averaged to obtain an evaluation score, and the following criteria were used as the evaluation of tackiness.

4.0 points below and 3.5 points above: very good

Less than 3.5 points and more than 3.0 points: o-

Less than 3.0 points and more than 2.0 points: delta

Less than 2.0 points and more than 1.0 point: is prepared from

(crimping processability)

A processing device: crimping apparatus (same as shown in FIG. 2)

Rotation speed: 4000rpm

Heating the temperature of the heating tank: 180 +/-5 DEG C

Sample line testing: 500d/10f (bundle of 10 monofilaments) (d: denier, f: filament number) taken out from a 4kg winding bobbin, 2

Curled shape: 13mm phi

The curling was performed under the above conditions, and the number of occurrences of abnormal running of the sample wire (clogging, winding of the wire harness) was measured on the mandrel bar 3 of fig. 2 (the number of occurrences per bobbin). The evaluation criteria are as follows.

Very good: less than 1 time

O: more than 1 time and less than 3 times

And (delta): more than 3 times and less than 5 times

X: more than 5 times

(Hair-planting processability)

(1) Hair-planted doll head manufacturing method

The synthetic fibers for doll hair obtained in examples and comparative examples were flocked under the following conditions.

Doll head: spherical shape having a diameter of 2.5cm formed from a vinyl chloride sheet (thickness 1mm)

Doll flocking sewing machine (same as shown in fig. 3): ltd company, model number: TUNF-28B

The hair planting speed is as follows: 1000RPM

Fiber cut length: 20cm

A hair planting part: from the head top (horizontal part) to the head back (vertical part) and head side (vertical part)

The hair planting area is as follows: about 7cm²

The weight of the planted hair is as follows: about 20g

(2) Evaluation of Hair-planting workability

The number of times of thread breakage occurred during hair attachment of 100 doll heads was defined as "incidence (%) of thread breakage". The lower the incidence, the more excellent the hair-planting workability. The evaluation criteria are as follows.

Very good: less than 1 percent

O: more than 1 percent and less than 5 percent

And (delta): more than 5 percent and less than 10 percent

X: over 10 percent

(dehairing resistance after combing)

Doll head: the doll heads produced by evaluation of hair-planting workability were fixed to the top of a fixture, and combed under the following conditions.

Doll head fixture: environmental conditions of a fixed bar of 30cm length standing from the ground: room temperature 23 ℃ and humidity 80% RH

Comb: commercially available needle comb for cat and dog pets

Combing: vertically downward, 20 times.

Thereafter, the weight of the depilated hair was measured. The depilation ratio is determined by the following equation.

The depilation ratio (% by weight) — (weight of depilated hair)/(weight of planted hair) × 100

The evaluation criteria are as follows.

Very good: the depilation ratio is less than 1% by weight

O: the depilation ratio is 1 wt% or more and less than 3 wt%

And (delta): the depilation ratio is more than 3 wt% and less than 5 wt%

X: the depilation ratio is 5 wt% or more

2. Raw material

The raw materials used are as follows.

(i) Using resins

Resin A: a vinylidene chloride-vinyl chloride copolymer resin obtained by free-polymerizing a monomer mixture consisting of 87 parts by weight of vinylidene chloride, 13 parts by weight of vinyl chloride and 0.5 part by weight of lauryl peroxide as a polymerization initiator at a polymerization temperature of 65 DEG C

B, resin: the same as the resin A except that the polymerization initiator was used in an amount of 0.4 part by weight

C, resin: the same as the resin A except that the polymerization initiator was used in an amount of 0.3 part by weight

D-I resin: the same as for the resin A except that the amount of the polymerization initiator, the polymerization temperature and the polymerization rate were adjusted, respectively

Physical Properties (weight average molecular weight (Mw) and molecular weight of 1X 10) of each resin⁴The proportions and dispersity (Mw/Mn)) of the low-molecular-weight components are shown in Table 1.

(ii) Plasticizer

Diisobutyl adipate: manufactured by Tiangang chemical industries Co Ltd

Acetyl tributyl citrate: manufactured by Senmura Kyowa Kabushiki Kaisha

(iii) Heat stabilizer

Epoxidized linseed oil: ダイセル chemical Co

3. Examples of the embodiments

Example 1

(1) Using raw materials

Resin A, and plasticizers and heat stabilizers shown in Table 1

(2) Manufacture of fibers for doll hair

The above raw materials were melt-spun from a spinneret hole for a hollow fiber in a single-shaft extruder described below. After quenching in a cold water bath at 15 ℃, the resultant was drawn to obtain the following multifilament.

(Specification and conditions of Single-shaft extruder)

The diameter of the screw is as follows: 50mm phi in size

Extrusion amount: 25kg/hr

Extrusion temperature: 180 deg.C

(stretching conditions)

Stretching 4 times with differential roller

(obtained multifilament)

Coarseness: 500d/10f

Average outer diameter of monofilament: 0.07mm

Hollow ratio of monofilament: 15 percent of

The fibers were evaluated for spinning productivity, tackiness, crimping processability, flocking processability, and plucking resistance. The results are shown in Table 1. It was confirmed that the spinning productivity was high, and that the hair for doll had good flocking processability and curling processability, had a dry touch, and had excellent performance.

Example 2

Doll hair fibers were produced and evaluated in the same manner as in example 1, except that the resin B was used instead of the resin a. The obtained monofilaments had the same hollow ratio and average outer diameter as those of example 1. The evaluation results are shown in table 1. All the evaluation items were referred to, and good results were obtained.

Example 3

Doll hair fibers were produced and evaluated in the same manner as in example 1, except that the resin C was used instead of the resin a. The obtained monofilaments had the same hollow ratio and average outer diameter as those of example 1. The evaluation results are shown in table 1.

Comparative examples 1 to 3

Doll hair fibers were produced and evaluated in the same manner as in example 1 using the resins, plasticizers and heat stabilizers shown in table 2. The evaluation results are shown in table 2. The yarn breakage is easy to occur during spinning, the spinneret orifice needs to be replaced in a short time, and the productivity is low.

Comparative examples 4 to 6

Doll hair fibers were produced and evaluated in the same manner as in example 1 using the resins, plasticizers and heat stabilizers shown in table 2. The results are shown in Table 2. Although the productivity of the obtained fiber was improved as compared with comparative examples 1 to 3, the problem of yarn entanglement occurred during crimping. Furthermore, the hair is sticky and has a poor touch feeling, and is not preferable as doll hair.

Comparative examples 7 to 9

Doll hair fibers were produced and evaluated in the same manner as in example 1 using the resins, plasticizers and heat stabilizers shown in table 2. The results are shown in Table 2. The obtained fibers have many broken threads during hair-setting and many unhairing during hair combing, and thus have problems in practical use as doll hair.

Claims (5)

1. A fiber for doll hair, characterized by containing a fiber having a weight average molecular weight of 6 x 10⁴～8×10⁴The vinylidene chloride resin of (1), wherein the vinylidene chloride resin contains 3% to 10% of a molecular weight of 1X 10 as measured by gel permeation chromatography⁴The following low molecular weight components.

2. The fiber for doll hair according to claim 1, characterized in that it contains 90% by weight or more of the vinylidene chloride resin.

3. The fiber for doll hair according to claim 1, wherein the vinylidene chloride resin has a ratio of a weight average molecular weight Mw to a number average molecular weight Mn, Mw/Mn, of 2 or more and 5 or less.

4. The doll hair fiber according to any one of claims 1 to 3, which is a hollow filament having a hollow rate of 3 to 30% and an average outer diameter of 0.01 to 0.2 mm.

5. A method for producing a fiber for doll hair, characterized in that a raw material is melted, the melt is spun from a spinneret, the spun product is cooled in a cold water tank at a temperature of 30 ℃ or lower, and then stretched 2 to 6 times and wound, wherein the raw material contains a fiber having a weight average molecular weight of 5 x 10⁴～8×10⁴The vinylidene chloride resin of (1), wherein the vinylidene chloride resin contains 3% to 10% of a molecular weight of 1X 10 as measured by gel permeation chromatography⁴The following low molecular weight components.