JP3496729B2 - Elastic yarn wound body for disposable diapers - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wound body (cheese) of elastic yarn for a paper diaper, which has an unwinding resistance from cheese in an appropriate range and has good process passability in a processing step.

[0002]

2. Description of the Related Art Elastic yarns, particularly elastic yarns made of polyurethaneurea, have been applied to various fiber fields due to their unique extensibility. In recent years, many disposable diapers have been used as hygiene products. When producing these products, elastic thread wound body (cheese)
Are arranged in parallel, the elastic yarn is unwound in parallel from the wound body (cheese) of the elastic yarn, and the elastic yarn is supplied to the forming portion of the product.

[0003]

When the elastic yarn is unwound from cheese in the process for producing a disposable diaper, the surface of the cheese is disturbed, and it is difficult to unwind it from the cheese, resulting in a decrease in process passability. In addition, it becomes difficult to unwind the elastic yarn in the inner layer of cheese, and the process passability decreases.
An object of the present invention is to improve the processability of elastic yarns in the manufacturing process of disposable diapers.

[0004]

[Means for Solving the Problems] That is, the present invention provides a wound body (cheese) of an elastic yarn made of polyurethaneurea, in which the amount of the attached oil agent on the surface of the elastic yarn is 0.1 to 0.8% by weight. , An elastic yarn wound body for a paper diaper having an unfolding elongation rate of the cheese inner layer of 40 to 100% and a hardness of the cheese surface of 30 to 50 degrees. Methylene ether glycol, diphenylmethane diisocyanate,
The elastic thread wound body for a paper diaper is obtained by polymerizing from an aliphatic diamine. The elastic yarn cheese having a wound amount of 0.2 kg or more, preferably 3.0 kg or more is a preferred embodiment of the present invention.

The polyurethane urea constituting the yarn is obtained by reacting a polyether glycol or polyester glycol having a number average molecular weight of 1,000 to 5,000 with an excess molar amount of an organic diisocyanate compound to obtain an intermediate polymer having an isocyanate group as an end group. It is obtained by dissolving the intermediate polymer in an inert solvent and then adding an organic diamine and reacting. If necessary, an antioxidant, a delusterant such as titanium oxide, a tertiary amine, etc. are added to the polymer solution thus obtained, and spinning is performed to obtain an elastic yarn. In order to achieve the object of the present invention, the following is carried out in the spinning process. The segmented polyurethane solution is made into elastic yarn by a conventional dry spinning method. That is, the polymer solution is extruded into the hot air through the pores, dried, passes through the spinning tube, passes over the roller below the spinning tube, and is wound up by the winding machine to obtain cheese. The roller surface speed and the winding speed are selected so that the overfeed rate represented by the following formula is a value between -15 and 0. Overfeed rate = ((W−G) / G) × 100 where W is the winding speed (meter / minute) G is the surface speed of the roller under the spinning cylinder (meter / minute). Further, the elastic yarn is treated with a finishing oil agent before being wound up on cheese. The amount of the finish oil adhering at this time is 0.1 to 0.8% (% by weight, and the same applies hereinafter). If the amount of the finish oil adhering is 0.1% or less, the ears of the cheese are larger than the central part, and cheese having a normal shape cannot be obtained. Then, the elongation rate of the inner cheese layer when released exceeds 00%, and the process passability in the process for producing a disposable diaper decreases. Also, 0.8
%, The hardness of the cheese surface decreases, and cheese surface disorder occurs in the paper diaper manufacturing process. Furthermore, 0.8
If it is more than 100%, the adhesiveness between the adhesive used in the paper diaper manufacturing process and the elastic yarn is lowered and the defective rate of the product is increased.

In order to suppress the cheese surface disorder, the surface hardness of the cheese must be 30 to 50 degrees. Below 30 degrees, when the cheese surface is set on the feeding roller, the surface is disturbed as the roller rotates, and the elastic yarn is seen to break. Further, if it exceeds 50 degrees, the unwinding of the elastic yarn from the surface of the cheese may not proceed smoothly and the cheese may be wound up on the cheese side. The adhesion of the oil agent was adjusted to 0.1 to 0.8%, and the hardness of the cheese surface was 30 to 5 by winding the overfeed rate between -15 and 0.
An elastic yarn cheese having an unwinding elongation of the inner layer of 40 to 100% is obtained, and this cheese has no problem in process passability in a paper diaper manufacturing process and has good adhesiveness. It is also possible to set the amount of cheese rolled up to 3 kg or more. In the paper diaper manufacturing process, the elastic yarn cheese winding amount of 2.5 kg or more, preferably 3 kg or more is desirable in view of the operation rate of the process. According to the present invention, since the cheese rolling amount can be increased, it is possible to increase the operating rate.

Examples of the polyether glycol used in the present invention include polytetramethylene ether glycol and polypropylene ether glycol. Polyester glycols include those obtained by polycondensing organic dibasic fatty acids such as succinic acid and adipic acid with organic glycols such as ethylene glycol, propylene glycol, butanediol or hexanediol.
Polytetramethylene ether glycol having a number average molecular weight of 1000 to 3000 is preferably used. As the organic diisocyanate compound used in the present invention,
p, p'-diphenylmethane diisocyanate, 2,4
-Toluene diisocyanate, 1,4-phenylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate and the like can be mentioned. Particularly, p, p'-diphenylmethane diisocyanate is preferable. Furthermore, the polyether glycol or polyester glycol and the organic diisocyanate compound are used in a ratio of isocyanate groups to hydroxyl groups of between 1.4 and 2.7. More preferably, this ratio is between 1.5 and 2.2.

As the organic diamine, hydrazine, ethylenediamine, 1,2-propylenediamine, 1,4-
Butylene diamine, 1,6-hexamethylene diamine,
1,3-cyclohexyldiamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodicyclohexylmethane, m-xylylenediamine and hydrogenated products thereof,
Examples thereof include diamines such as p-xylylenediamine and hydrogenated products thereof, or a mixture thereof. Among these diamines, ethylenediamine, 1,2-diaminopropane, or a mixture thereof is preferable as one giving good physical properties.

As the inert solvent used in the polymerization reaction, N, N-dimethylformamide, N, N-dimethylacetamide, N, N, N ', N'-tetramethylurea and N-methylpyrrolidone are used. And a polar solvent such as dimethyl sulfoxide. If necessary, the segmented polyurethaneurea solution obtained from these may be added with an antioxidant such as hindered phenol, an ultraviolet absorber, a pigment, a tertiary amino compound, or the like. The oil agent adhesion amount is measured as follows. About 2 g of a sample (elastic thread) is accurately weighed and placed in a 200 ml Erlenmeyer flask with a stopper. Add 100 ml petroleum ether and allow to soak for 10 minutes at room temperature with vigorous stirring. The sample is taken out, the same operation is repeated again using a new petroleum ether having the same temperature and the same volume, followed by air-drying and leaving it in a dryer at 105 ± 2 ° C. for 1 hour to dry it. This petroleum ether oil content is defined as the amount of oil agent attached.

Petroleum ether oil output (%) = (1- (W '
/ W) × 100 where W: weight at the time of sampling (gram) W ′: dry weight of the sample after treatment (gram) The surface hardness of cheese is measured according to the method of JIS K63015. Place the spring hardness tester C type on the surface of cheese vertically, press it with a force of 5 kg and read the scale. Hardness is expressed in degrees. In the present invention, the unwound elongation of the cheese inner layer is the unwound elongation of the elastic yarn from one half or less of the cheese winding thickness to a thickness at which the cheese winding thickness of the elastic yarn becomes almost 0. Is. The elongation of the elastic yarn from cheese during unwinding is measured as follows.
The cheese is set on a satin-finished roller having a diameter of 10 cm and prepared so that the surface speed of the roller is 50 meters per minute. On one side, a winding bobbin is set on a satin-finished roller having the same diameter of 10 cm, and the elastic yarn sent out at 50 meters per minute is wound on one winding bobbin. At that time, the elastic yarn fed out prepares the winding roller at the lowest speed at which the elastic yarn cannot be pulled up in the rotating direction of the cheese. The surface speed of the lowest roller is measured, and the elongation rate at unrolling is expressed as follows.

Elongation rate during unwinding (%) = (S−S ₀ ) / S ₀ × 100 where S ₀ is the delivery speed of the elastic yarn (50 meters /
Min) S is the lowest winding speed (m / min) of the elastic yarn. The elongation rate when unwound is 100% or less, preferably 40 to 10
It is an object of the present invention to obtain 0% elastic yarn cheese. The elastic yarn is normally supplied to the diaper process at a stretch ratio of 1.3 to 2.0. Therefore, the elongation rate when unwound is 10
If it exceeds 0%, the supply from elastic yarn cheese will not be smooth. When the content is 40% or less, the shape of the cheese is distorted. The cheese of the elastic yarn having a specific unwound elongation of the present invention is directly related to the improvement of the processability of the elastic yarn in the process for producing a disposable diaper, which is the object of the present invention.

The invention is illustrated in the examples below.
It should be noted that these examples illustrate the present invention and are not limited thereto. In the examples, parts are by weight.

【Example】

Example 1 975 parts of polytetramethylene ether glycol having a number average molecular weight of 1950 and 250 parts of p, p′-diphenylmethane diisocyanate were placed in a polymerization flask and heated to 70 ° C. on an oil bath while stirring. After heating for 1 hour, the oil bath was removed and N, N-dimethylformamide 24
50 parts was added and the reaction mixture was dissolved while cooling on an ice-water bath. When the internal temperature reached 8 ° C, 35.15 parts of 1,2-diaminopropane and 1.73 parts of N, N-diethylamine were added to N.V. A solution dissolved in 500 parts of N-dimethylformamide was gradually added dropwise with stirring. About 400
After adding 1 part, the ice-water bath was removed, and the amine solution was added dropwise. After adding a total of 500 parts of amine container, a solution of 6.8 parts of N, N-diethylamine and 30 parts of N, N-dimethylformamide was added. 50 parts of titanium oxide, 1,3,5-tris (4
13 parts of -t-butyl-3-hydroxy-2,6-dimethyl-benzyl) isocyanuric acid, 25 parts of a 50% by weight N, N-dimethylformamide solution of poly (N, N-diethylaminoethyl) methacrylate, and further N, N-dimethylformamide was added to adjust the solid content concentration to 30% by weight.

The polymer solution thus obtained was supplied at a rate of 62.2 g / min to a spinneret having 40 pores, and extruded from the pores into hot air to evaporate the solvent. The dried yarn was passed through a false twisting machine which generates a swirling air flow, and after passing false twist, passed over a roller set to a surface speed of 445 m / min and brought into contact with an oiling roller. A mixed oil agent of dimethylsiloxane having a viscosity of 10 cst, polyether modified silicone, and mineral oil was supplied to the oiling roller, and the roller surface speed was adjusted so that the amount of the oil agent attached was 0.4%. The elastic yarn is 400 m / min on the winder and has a length of 114
A bobbin having an outer diameter of 82 mm and an outer diameter of 82 mm was wound up to obtain an elastic yarn cheese having a weight of 3 kg. The elastic yarn thus obtained had a denier of 420 and the amount of deposited oil agent was 0.36% by weight. And, the unwound elongation of the inner layer is 83%, and the hardness of the cheese surface is 37.7.
It was degree.

The cheese thus obtained is set on two rollers rotating at a surface speed of 60 m / min,
While unwinding the elastic yarn from the cheese at 120 m / min,
The disordered state of the cheese surface was visually observed, but the disordered surface of the cheese was not observed. Furthermore, after removing 2.4 kg of elastic yarn from the cheese, it was set on a roller in the same manner as above and the disordered state of the cheese surface was visually observed, but the elastic yarn was taken up on the cheese surface and it was wound up. I couldn't do it.

Comparative Example 1 A polymer solution obtained in the same manner as in Example 1 was used.
It was spun in the same manner as in. At that time, after false twisting was applied, it was passed over a roller set at a surface speed of 380 m / min and brought into contact with an oiling roller. The surface speed of the oiling roller was adjusted so that the amount of the applied oil agent was 0.4%, the winding machine was 400 m / min, and the length was 114 mm.
It was wound on a bobbin having an outer diameter of 82 mm to obtain elastic-thread cheese having a weight of 3 kg. The elastic yarn obtained had a denier of 420 and the amount of deposited oil agent was 0.41% by weight. The elongation rate of the inner layer when unwound was 116%, and the hardness of the cheese surface was 44.4 degrees. The cheese thus obtained is set on two rollers that rotate at a surface speed of 60 m / min, and the turbulent state of the cheese surface is visually observed while unwinding the elastic yarn from the cheese at 120 m / min. The cheese surface was not observed to be disturbed when observed. Furthermore, about 2.
After removing 4 kg, it was set on a roller in the same manner as above and the disordered state of the cheese surface was visually observed, but it was found that elastic yarn was taken up in the direction of rotation of the cheese and rolled up. Although it was not enough to cut the elastic yarn, there was a problem with processability.

Comparative Example 2 The polymer solution obtained in the same manner as in Example 1 was used as Example 1.
It was spun in the same manner as in. At that time, after applying false twist, it passed over a roller set to a surface speed of 445 m / min and brought into contact with an oiling roller. The surface speed of the oiling roller was adjusted so that the amount of the applied oil was 1.0%, and the winding machine was 400 m / min and the length was 114 mm.
It was wound on a bobbin having an outer diameter of 82 mm to obtain elastic-thread cheese having a weight of 3 kg. The elastic yarn obtained had a denier of 420 and the amount of the attached oil agent was 1.08% by weight. And, the unwound elongation of the inner layer was 60%, and the hardness of the cheese surface was 27.4 degrees. The cheese thus obtained is set on two rollers that rotate at a surface speed of 60 m / min, and the turbulent state of the cheese surface is visually observed while unwinding the elastic yarn from the cheese at 120 m / min. Observed, the disturbance of the cheese surface occurred along with the unwinding of the elastic yarn, and the elastic yarn pulled out from the cheese came off from the cheese surface and the elastic yarn was cut. Furthermore, after removing about 2.4 kg of elastic yarn from the cheese, it was set on a roller as above, and the disordered state of the cheese surface was visually observed, but in the inner layer, the elastic yarn was taken on the cheese surface and rolled up. I couldn't see it.

Example 2 A polymer solution obtained in the same manner as in Example 1 was used as Example 1.
It was spun in the same manner as in. The polymer solution thus obtained was spun in the same manner. At that time, the overfeed rate was -11.1%. Further, the amount of the oil agent attached was set to 0.5%. Then, an elastic thread cheese having a weight of 3 kg was obtained. The elastic yarn thus obtained had a denier of 420, and the amount of deposited oil was 0.52% by weight. Then, the unwound elongation of the inner layer was 72%, and the hardness of the cheese surface was 34.3 degrees. Then, the obtained cheese is placed in a steam bath at a temperature of 90 ° C for 3 times.
Heat treated for hours. By doing so, the unwound elongation of the inner layer was 91% and the hardness of the cheese surface was 43.0 degrees.

The cheese thus obtained is set on two rollers rotating at a surface speed of 60 m / min,
While unwinding the elastic yarn from the cheese at 120 m / min,
When the appearance of the cheese surface was visually observed, only the cheese surface was not sagging, and it appeared to be more stable than in Example 1. Furthermore, after removing about 2.4 kg of elastic yarn from the cheese, it was set on a roller in the same manner as above and the disordered state of the cheese surface was observed, but it was not observed that the elastic yarn was taken up on the cheese surface and rolled up. It was

[0019]

EFFECT OF THE INVENTION A wound body (cheese) of an elastic yarn made of polyurethaneurea according to the present invention, wherein the amount of the oil agent adhered to the surface of the elastic yarn is 0.1 to 0.8%, and the inner layer of the cheese is unwound. Time elongation rate is 40 to 100%, cheese surface hardness is 30 to 50
The elastic thread wound body for a paper diaper, which has a certain degree, has an excellent unwinding property from the beginning to the end in the thickness direction of the wound body, and has consistently excellent passability in the process for producing a paper diaper.

Claims (2)

(57) [Claims] 1. A wound body (cheese) of elastic yarn made of polyurethaneurea, wherein the amount of the attached oil agent on the surface of the elastic yarn is 0.1 to 0.8% by weight, and the elongation rate of the inner layer of cheese when unwound is unwound. Is 40 to 100%, and the hardness of the cheese surface is 30 to 50 degrees. 2. The elastic yarn wound body for a paper diaper according to claim 1, wherein the polyurethane urea is obtained by polymerizing at least a polytetramethylene ether glycol having a number average molecular weight of 1,000 to 3,000, diphenylmethane diisocyanate, and an aliphatic diamine.