JPH01239107A - Modified cross-section yarn for brush - Google Patents

Abstract

PURPOSE:To obtain the subject yarn having a specific cross-section and capable of cleaning an object in high efficiency without damaging the object, by using a resin composition composed of a high-pressure polyethylene and a low-pressure polyethylene each having specific respective physical properties. CONSTITUTION:The objective yarn having a cross-section composed of >=3 main branches each having protrusions 2 can be produced by using a resin composition produced by compounding (A) 10-90wt.% of a high-pressure polyethylene resin having a density of <=0.93 and a melt index of 0.4-4g/10min and (B) 10-90wt.% of a low-pressure polyethylene resin having a density of <=0.93 and a melt index of 0.5-4g/10min. Preferably, the main branches 1 are radially extended from the center 4 interposing equal angles therebetween. The number of the protrusions 2 is preferably two or more.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Field of Application> The present invention relates to a thread of irregular cross section for a brush used for cleaning instruments and articles.

<Conventional technology and problems to be solved by the invention> Conventionally, threads for brushes have been used for various purposes, such as threads with the tips split at the ends, and threads with irregular cross-sections in various shapes. In the case of automobiles, in order to minimize damage caused by brushing during washing, threads that come into contact with the object being washed softly and have good cleaning efficiency are desired.
Cross- and star-shaped threads with improved cross-sectional shapes have been developed and used as car wash brushes using high-pressure low-density polyethylene resin. However, problems such as damage to the car body, cracked threads, and rapid wear and tear due to the tip being torn off remain unresolved.

Furthermore, since the amount of water used during washing is large, there is a demand for a brush that can reduce the amount of water used. However, such brush thread has not yet been produced.

Brush thread materials include nylon, polyester,
Polyolefin resins and the like are used, but these are appropriately selected depending on the items to be cleaned.

Low-density polyethylene resin is often used in applications where scratches are extremely sensitive, such as automobiles, due to its flexibility.
The reason for this is that the thread is made thick to prevent it from getting tangled in protrusions such as rearview mirrors, but the thread can still get caught in the gap K between the vehicle body and parts, and in such cases, the thread may get caught in the gap K between the vehicle body and parts. The strength of the thread is weak so that the tip does not break and damage car parts. Further, for the purpose of increasing car washing efficiency, cross-shaped threads as shown in FIG. 2 have been made of high-pressure low-density polyethylene resin (monofilament of approximately 4,000 to 6,000 deniers) and have been used.

However, the above-mentioned problems have not yet been solved.

<Means for Solving the Problem> As a result of various studies to solve this problem, the present inventors have found that the invention described below provides a method that prevents damage to the object to be cleaned.
It was also discovered that cleaning can be done efficiently.

The present invention has the following features: (1) Density is 0.930 or less and melt index is 0.
．． 4-4, Og/lo minute high-pressure polyethylene resin 10
~90 weight trowel and density 0.930 or less and melt index 0.5-4. Consisting of a resin composition blended with 10 to 90% by weight of low-pressure polyethylene resin of og/lo minute,
The cross-sectional shape has three or more main stems, and the main stem has at least one
The thread having an irregular cross section (2) has a main stem and a cross-sectional shape that forms a space surrounded by the protrusions provided from the V center to the tip in the length direction of the main stem. (3) The irregular cross-section yarn for brushes according to paragraph (1) or (2), wherein the thread thickness is in the range of 1,000 to 10,000 deniers (4) ) During spinning, the above-mentioned (
11. To provide a thread of irregular cross-section for a brush according to item (21 or (3)).

Hereinafter, the present invention will be explained in more detail, including its effects.

The high-pressure polyethylene resin mentioned here has a structure such as ``Santic, F1920 (trade name)'' manufactured by Polymer Co., Ltd. In addition, low-pressure polyethylene resins are made at a pressure of about 2oom/α2 or less during polymerization and basically have a linear structure.For example, rNUC polyethylene LL and NUCG5 from Nippon Unicar Co., Ltd.
211 (product name)".

The cross-sectional shape of the thread of the present invention is such that one or more, preferably a plurality of protrusions are provided at the tip of a plurality of preferably radially extending main stems. The protrusions increase the contact surface of the thread to the object to be cleaned and preferably form an enclosed space between each main stem and the protrusion. More preferably, there is a protrusion at the center or tip of the main stem. This space has the effect of retaining water during cleaning and allows the water to spread well over the surface of the object to be cleaned, thereby greatly increasing the cleaning effect. In addition, since water is more likely to be present on the surface of the object to be cleaned, a complementary effect is obtained in that the surface is prevented from being damaged.

However, although such wonderful effects can be obtained,
Because the protrusions are attached to the main shaft, cracks are likely to occur near the intersection of the main transfer parts due to repeated impact during cleaning and bending fatigue, and cracks also occur at the tips of the threads and the attached roots. In severe cases, the threads may break into fine fibers that become tangled with each other, or even get tangled with the object to be cleaned, causing damage to the object.

Conventionally, thread for car wash brushes has been made of high-pressure low-density polyethylene resin, which has been processed into threads with irregular cross-sections, such as a cross (Figure 2).

In this case, if the main part of the thread is provided with a protrusion, the thread becomes more likely to break, resulting in frequent cracking of the thread, making it unsuitable for practical use.

Therefore, as a result of intensive studies to improve this point, we found that the density was 0.930 or less and the melt index was 0.4.
~4.0.9/lo minute (measured according to JIS K6760) high pressure polyethylene resin 10 to 90% by weight, density of 0.930 or less, and melt index of 0.5 to 4-0
．． A resin composition obtained by spinning a resin composition consisting of 10 to 90% by weight of a low-pressure polyethylene resin of 9/lo, has a cross-sectional shape of three or more pieces, preferably extending radially, and more preferably forming angles with each other at their intersections. have substantially equal main stems, and on said main stems at least one, preferably a plurality of
We have found that this problem can be solved by creating a thread with an irregular cross-section for brushes that has protrusions large enough to achieve the object of the present invention, and have completed the present invention.

In the case of a yarn with a special shape like the one of the present invention, the tensile strength of the yarn, the bulkiness (strength) of the yarn, the degree to which the yarn curls during use, and the spinning Although it is possible to produce yarn relatively easily by appropriately selecting the spinning conditions during spinning, it has not been possible to obtain properties such as properties that are practically satisfactory in terms of yarn cracking.

Excellent performance against yarn cracking, as it turned out that it is impossible to set conditions that satisfy each of the processing conditions that are contradictory to yarn cracking, bulk, and curling properties. With low-density polyethylene resin made using a low-pressure method, the cracking of the yarn is greatly improved, but the bulk of the yarn is low (too stiff).

While being used as a brush, the threads are forced into strong contact with the object to be cleaned and are squeezed, causing the threads to partially stretch and curl, and eventually become entangled in the protrusions of the object and cause parts to be damaged. It will damage it.

As a countermeasure to this problem, in order to improve the bulkiness of the yarn and reduce the occurrence of curling, it is generally done to increase the drawing ratio during spinning, but in this case, the degree of orientation of the yarn increases and the bulkiness and occurrence of curling are improved. On the other hand, if the strength of the thread becomes too high, it becomes difficult to cut the time series caught in gaps etc., increasing the possibility of tearing parts, and the thread becomes easier to avoid in the warp. That is difficult.

As a result of intensive research to solve this problem, we have found that this problem can be solved by using specific resins and mixing them in specific proportions.

The high pressure polyethylene resin used in the present invention has a density of 0.9
30 or less, low pressure polyethylene resin has a density of 0.930
The reason for this is as follows: If the density exceeds this, the yarn becomes less flexible and hard, and the strength (tensile strength) of the yarn becomes too strong (it becomes difficult to break), and the yarn is more likely to tear vertically. The yarn will not be able to withstand practical use.

Melt index is 0.4 for high pressure polyethylene
-4.0, and 0.5 to 4.0 for low-pressure polyethylene, but this means that if the melt index is smaller than this, the load on the extruder during extrusion will be large, and the pressure of the resin on the spinneret will increase. However, melt fractures may occur on the surface of the molten material flowing out from the spinneret, and it may be difficult to create a draft to make yarn, resulting in uneven thickness of the yarn due to draft irregularities, or draft breakage. etc. occur frequently, making it extremely difficult to make thread. Furthermore, in the drawing process, if the drawing ratio is increased, thread breakage occurs and the necessary drawing cannot be applied, resulting in insufficient orientation, resulting in bulky and easily curled threads.

Conversely, when the melt index is higher than this range,
The threads tend to crack in the warp (the threads become weaker and the ends of the threads break off, causing faster wear).

When low-density polyethylene resins made by high-pressure method and low-pressure method are blended, the resulting threads will have different properties depending on the characteristics of each resin, but if you use one with a density and melt index within the above range, it will be practical. Although threads with no problems can be made, the proportion of each resin in the blend is 10 to 90% by weight.
If it is out of this range, if there is too much high-pressure polyethylene, the yarn will break, and if too much low-pressure polyethylene is used, problems will occur, such as curling of the yarn, weakening of the yarn, and a reduction in the bulk of the brush. In addition, the ratio of each component is preferably 20 to 80% by weight.

Further, a typical shape of the irregular cross-section thread is shown in FIG.

Further, in FIGS. 4 to 23, except for FIGS. 1-7 and 22-23, only the skeleton in the form of irregular cross-section threads is shown in the form of schematic diagrams. These are merely examples and do not limit the invention in any way. Next, the irregular cross-section yarn of the present invention will be explained in more detail using FIG. 1 as a representative of these yarns. It will be done.

Preferably, it has a shape with a space 3 surrounded by a main stem and a protrusion. The size of the protrusion is preferably sufficient to form the space.

Further, it is preferable that the protrusion is provided in the length direction of the main body, from approximately the center to the tip. 4 indicates the main trunk intersection. The thickness of the thread is preferably in the range of 1,000 to 10,000 deniers. If the thread is less than 1,000 denier, the thread will have a weak stiffness, and in the case of a rotating brush, it will seem to wrap around the shaft of the brush, and it will not be able to function as a brush. On the other hand, 00 to l
This is because if the denier exceeds 0, the object to be cleaned will be strongly damaged and damaged, and the number of threads per weight of thread will be small, resulting in lower cleaning efficiency. From this point of view, a yarn of 2,000 to 7,000 deniers is preferable, and it is further preferable that the irregular cross-section yarn is stretched, and the appropriate stretching magnification is 3 to 8 times, and at a magnification lower than 3 times, the yarn is almost oriented. Because it is not stiff, it has a weak waist and curls easily, and the thread strength is insufficient, making it impractical. Furthermore, if the stretching is higher than 8 times, the orientation will be too high and the yarn will easily break, and the strength of the needle thread will become excessive and if it wraps around the object to be cleaned, the object to be cleaned may be damaged.

The relationship between the length and width of each main stem and protrusion, and the relationship between the sizes of the main stem and the protrusion are set for each irregular cross-section thread so as to meet the above conditions.

<Example> Example 1 60% by weight of a high-pressure polyethylene resin with a density of 0.923 and a melt index of 3.0 and 40% by weight of a low-pressure polyethylene resin with a density of 0.920 and a melt index of 2.0,
Blended in pellet form using a tumbler blender, L/D 224, compression ratio 3.0, screw diameter 50 yen.
A spinneret with 12 holes shaped as shown in Fig. 3 was attached to a φ monofilament spinning machine, and the temperature of the molten resin was 190°C.
After extrusion at 85°C and cooling with water, the yarn was placed in a drawing bath containing hot water at 85°C, and the resulting yarn was drawn 5 times and spun.

The thickness of the thread was 4,500 denier, and the cross-sectional shape of the thread was as shown in Figure 1. The obtained yarn was processed into a brush in an automobile car wash machine, and the brush was actually washed in the equivalent of 2,000 passenger cars to evaluate the degree of damage to the yarn. This result is T in Table-1.
As shown in e5tNl 1, the yarn was slightly damaged, but it was of a level that caused no practical problems. Also, the bristles of the attached brush were bulky and visually appealing.

Example 2 Same as Example I except that 60% by weight of a high-pressure polyethylene resin with a density of 0.921 and a melt index of 0.6 and 40% by weight of a low-pressure polyethylene resin with a density of 0.920 and a melt index of 2.0 were used ( C-spun.The obtained yarn had almost no defects such as cracks in the yarn, breakage at the tip end, curling, etc. as shown in Te5tNIL2 in Table 1, and the brush had a high bulk and was excellent.

Example 3 Same as Example 1 except that 60% by weight of high-pressure polyethylene resin with a density of 0.928 and melt index of 0.5 and 40% by weight of low-pressure polyethylene resin with a density of 0.925 and melt index of 0.5 were used. As a result of evaluating this yarn, some damage was observed, probably because the yarn was easily broken, such as N-1 Te5tNl.

However, it was sufficiently durable for practical use.

Example 4 Same as Example 1 except that 85% by weight of high-pressure polyethylene resin with density 0.921 and melt index 0.6 and 15% by weight of low-pressure polyethylene resin with density 0.920 and melt index 2.0 were used. The results of evaluating the yarn obtained after spinning were as shown in Teatf@4 in Table 1. The yarn was somewhat brittle and damaged, but no curling occurred and the bulk of the yarn was high and visible. It was something.

Example 5 Same as Example 1 except that 15% by weight of high pressure polyethylene resin with density 0.921 melt index Q, 6 and 85% by weight low pressure polyethylene resin with density 0.920 melt index 2.0 were used. It was spun in the same manner. The evaluation results of the obtained yarn are Te5tl@50 in Table-1.
There was no problem with the yarn cracking, but the yarn was slightly curled, and the bulk of the yarn was slightly lower, but it was sufficient for practical use.

Comparative Example 1 Spinning was carried out in the same manner as in the example except that only a high-pressure polyethylene resin having a density of 0.921 and a melt index of 0.6 was used. The evaluation results for this yarn are shown in Table 1, Te5t+c6. The yarn was cracked and partially turned into fine fibers. The tip of the yarn was also partially cut and shortened. However, there was no curling, and the yarn was short. The bulk looked good when it was installed, but after the test, the threads broke, it became fluffy, and the bulk was low (in a very poor-looking condition).

Comparative Example 2 The yarn obtained by spinning was evaluated in the same manner as in Example 1, except that a low-pressure polyethylene resin having a density of 0.920 and a melt index of 20 was used. This result is Te5t in Table-1.
As with Nl, there was no visible cracking in the threads, but curling occurred and it started to get tangled in the rearview mirror. The volume of the upper thread was low and looked depressing.

Comparative Example 3 Except for using 60% by weight of a high-pressure polyethylene resin with a density of 0.921 and a melt index of 4.0 and a low-pressure polyethylene resin with a density of 0.925 and a melt index of 5.0,
Spinning was carried out in the same manner as in Example 1.

The results of evaluation of the obtained yarn were as shown in Table 1 for Te5tN18. Although the yarn was easily broken and could not be put to practical use, it did not curl and was a bulky brush.

Comparative Example 4 Example 1 except that a mixture of 60% by weight of a high-pressure polyethylene resin with a density of 0.940 and a melt index of 0.8 and 40% by weight of a low-pressure polyethylene resin with a density of 0.935 and a melt index of 3.0 was used. It was spun in the same manner.

The evaluation results of the obtained yarn were as shown in Table 1 for Te5tNu9, which showed that the yarn cracked frequently and was not very usable.However, there was no occurrence of curling, and the yarn had a high bulk.

Comparative Example 5 Same as Example 1 except that 60% by weight of a high-pressure polyethylene resin with a density of 0.917 and a melt index of 0.3 and 40% by weight of a low-pressure polyethylene resin with a density of 0.922 and a melt index of 0.3 were used. The obtained yarn, which was spun in the same manner as Te5tNl 10 in Table 1, had few yarn cracks, but it was difficult to draw and the yarn broke frequently, making it difficult to spin, and the yarn curled and the bulk of the yarn was low. It was inferior.

The following margin <Effects of the invention> Density is 0.930 or less, melt index is 0.4 ~
4. High pressure polyethylene resin of og/lo minute 10-90
% by weight, preferably 20-80% by weight, and 10-90% by weight of low-pressure polyethylene resin having a density of 0.930 or less and a melt index of 0.5-4.0, preferably 20-80% by weight.
The cross-sectional shape spun from a resin composition consisting of M amount% is 3
By using a brush thread that has a main stem that extends radially and has a plurality of protrusions at the tip of the main stem, the thread of the present invention has good water retention properties, and the water can spread well to the surface of the object to be cleaned. It is highly effective, and the water covers the surface, making it difficult to get scratches, and the special shape of the upper thread gives it a firmer look. Despite having a structure that is prone to breakage, this is the ideal thread for cleaning brushes that can eliminate many problems such as cracking of the thread, breakage of the tip end, and curling of the thread. I was able to obtain.

The yarn of the present invention is not limited to the car wash brush used as an example to explain the present invention, but can be used for cleaning a wide variety of general objects. In particular, it can exhibit excellent performance in cleaning items that are easily damaged and in applications where it is necessary to increase the cleaning efficiency when washing with water.

[Brief explanation of the drawing]

Figures 1.17 and 22.23 are cross-sectional views of the yarn of the present invention;
16. Figures 18 to 21 are schematic diagrams of the cross-sectional shape of the yarn of the present invention, 1 is the main stem, 2 is the protrusion, 3 is the space, 4 is the intersection of the main stems, and Figure 2 is the cross section of the conventional yarn. FIG. 3 is a plan view of a spinneret for the yarn of FIG. 1 according to the invention. Asahi Kasei Kogyo Co., Ltd.Figure 1Figure 2Figure 3Figure 4Figure 5Figure 6Figure 7Figure 8Figure 9Figure 10Figure 11Figure 12Figure 13Figure 14 Figure Figure 15 Figure 16 Figure 17 Figure 18 Figure 19 Figure 20 Figure 21 Figure 22 Figure 23

Claims (2)

[Claims] (1) Density is 0.930 or less, melt index is 0
．． 4-4.0g/10min high pressure polyethylene resin 10
~90% by weight and 10 to 90% by weight of a low-pressure polyethylene resin with a density of 0.930 or less and a melt index of 0.5 to 4.0 g/10 minutes, with a cross-sectional shape of 3 irregular cross-section yarn for brushes having at least one main stem and at least one protrusion on the main stem (2) The brush according to item (1) above, which has a cross-sectional shape that forms a space surrounded by the main stem and the protrusions provided from approximately the center to the tip in the length direction of the main stem. irregular cross section thread