JP2021118827A - Bristles for brushes - Google Patents

Abstract

To mitigate the increased load of waste on the environment.SOLUTION: Bristles for brushes comprise synthetic fibers that are predominantly composed of polybutylene succinate (PBS) and have a biodegradability of 25 or more after one month in compost.SELECTED DRAWING: Figure 1

Description

The present invention comprises polybutylene succinate (hereinafter, may be abbreviated as PBS) which is an aliphatic polyester biodegradable resin made from 1,4-butanediol and succinic acid and / or a derivative thereof. It relates to bristles for brushes using degradable fibers.

The main raw material of conventional plastics is derived from petroleum, and it is regarded as a problem that the burden on the environment is high, such as the depletion of resources due to the mass consumption of plastic products and the emission of carbon dioxide due to the combustion treatment. Furthermore, the environmental load is on the rise due to the increase in the amount of plastic products used due to the increase in the global population.

For example, it is said that about 3.6 billion toothbrushes (Patent Document 1) that use nylon and polybutylene terephthalate (PBT) as brush bristles are discarded worldwide in one year, and will continue to be used worldwide. As the amount of toothbrushes discarded increases with the increase in population, there are concerns about the depletion of petroleum resources and the increase in environmental load. Further, there are similar problems in paint brushes and makeup brushes.

Japanese Unexamined Patent Publication No. 1997-31252

An object of the present invention is to solve the environmental load in the above-mentioned conventional materials.

That is, an object of the present invention is to provide a brush having a small environmental load.

In order to solve the above problems, the present invention adopts the following configuration.

Brush bristles composed of synthetic fibers containing polybutylene succinate (PBS) as a main component and having a biodegradation degree of 25 or more after 1 month in compost.

In the brush bristles of the present invention, 50% by mass or more of the polybutylene succinate (PBS) is made of a non-petroleum-derived raw material, and the cross-sectional area orthogonal to the fiber axis is 20 μm ^{2 to} 100 mm ^2. preferable.

Further, the brush bristles of the present invention preferably have a tapered shape at at least one end, and are preferably used as a brush using this at least partly.

According to the present invention, it is possible to provide a brush using a biodegradable synthetic fiber made of polybutylene succinate (PBS) having a small environmental load. Therefore, the biodegradable synthetic fiber of the present invention is extremely useful for brush applications such as toothbrushes, paint brushes, and cosmetic brushes, whose usage is increasing as the population increases.

It is a schematic diagram which shows an example of the form of the brush bristles of this invention. It is a schematic diagram which shows an example of the toothbrush using the bristles for a brush. It is a schematic diagram which shows an example of the cross-sectional form of the brush bristles of this invention.

Hereinafter, the present invention will be described in detail.

The bristles for brushes of the present invention are composed of synthetic fibers containing polybutylene succinate (hereinafter, sometimes abbreviated as PBS), which is a kind of aliphatic polyester, as a main component. Polybutylene succinate (PBS) used in the present invention is an aliphatic polyester-based biodegradable resin having a structure obtained by using 1,4-butanediol and succinic acid and / or a derivative thereof as raw materials.

The production method using polybutylene succinate (PBS) as a synthetic fiber is not particularly limited, and dry / wet / solution spinning may be used, but melt spinning is particularly preferable in order to reduce the environmental load.

The form of the synthetic fiber obtained by melt spinning is not particularly limited, such as filaments and staples, but is preferably monofilament. A monofilament is a yarn having an independent morphology with a diameter of 20 μm to 6 mm. The independent form means that the form is not twisted, and the one that is aligned and bundled in parallel is treated as an aggregate of monofilaments.

The synthetic fiber used in the brush of the present invention is made of a synthetic resin containing polybutylene succinate (PBS) as a main component. The synthetic resin containing polybutylene succinate (PBS) as a main component means a synthetic resin in which more than 50% by mass of the components contained in the synthetic resin is the polybutylene succinate (PBS). The ratio of polybutylene succinate (PBS) is more preferably 70% by mass or more, further preferably 90% by mass or more, further preferably 95% by mass or more, and containing 97.5% by mass or more. Is particularly preferred.

The polybutylene succinate (PBS) is preferably composed of 50% or more of a non-petroleum-derived raw material, and the ratio is more preferably 75% or more, further preferably 99% or more.

The bristles for brushes of the present invention are composed of synthetic fibers having a biodegradation degree of 25 or more after one month in compost. The degree of biodegradation after one month in composting is an index of biodegradability, and by satisfying such conditions, an excellent environmental load reduction effect can be obtained. From this point of view, the degree of biodegradation in compost after 1 month is preferably 50 or more, more preferably 100 or more.

The degree of biodegradation after 1 month in compost is 1 g of brush bristles in household compost using a commercially available household compost and compost fungus bed according to the compost used for the decomposition evaluation of biodegradable plastic of ISO14855. It is obtained by measuring (μm) the decrease in the peripheral length of the synthetic fiber after degrading for 1 month.

Further, as another resin that can be used in combination with polybutylene succinate (PBS) used in the present invention as needed, it has moldability, appropriate flexibility and hardness, and is disintegrated by the action of microorganisms. Any resin can be used as long as it is obtained. For example, polyhydroxyalkanoic acid (hereinafter sometimes abbreviated as PHA), a blend of starch and modified polyvinyl alcohol, a blend of starch and a biodegradable synthetic polymer, etc. Examples thereof include natural polymer (starch) -based resins and synthetic resins such as polycaprolactone.

The cross-sectional area of the cross section of the synthetic fiber used for the brush bristles of the present invention orthogonal to the fiber axis is preferably ^{20 μm 2 to} 100 mm ^2. More preferably, it is 5,000 μm ^{2 to 1} mm ² , and most preferably 10,000 μm ^{2 to} 0.25 mm ² . For example, in a toothbrush, by setting a specific cross-sectional area range, it is possible to achieve both invasion into teeth and cleanability after invasion, and an excellent usability can be exhibited.

The cross-sectional shape of the cross section orthogonal to the fiber axis of the synthetic fiber used for the brush bristles of the present invention is not particularly limited, and any shape such as a circular shape, a triangular shape other than a circular shape, a square shape, a star-shaped cross section, or the like. However, it does not matter, and it is possible to take a form in which a plurality of pieces are connected. For example, in a paint brush or a makeup brush, by adopting a specific cross-sectional shape, the desired liquid-containing or powder-containing property is improved, and an excellent usability can be exhibited.

The synthetic fiber used for the brush bristles of the present invention has the desired performance of additives such as pigments, dyes, lightfasteners, ultraviolet absorbers, antioxidants, crystallization inhibitors, and plasticizers. It can be added in the polymerization step, after polymerization or immediately before spinning as long as it does not inhibit, but since the object of the present invention is to biodegrade and reduce the environmental load, it is preferable that the amount of additive is small. , More preferably additive-free.

The method for producing brush bristles of the present invention is not particularly limited, but melt spinning is preferable for reducing the environmental load, rather than dry / wet / solution spinning. There is no problem with either single or compound.

The brush bristles of the present invention preferably have a tapered shape at at least one end. As a preferable tapered shape, the portion 0.5 mm from the tip has a diameter of 90% or less of the cross section of the central portion in the longitudinal direction of the hair material, more preferably 80% or less, and most preferably 50% or less. Is. Further, the processing for forming the tapered shape is not particularly limited, but chemical processing is preferable in order to stabilize the tip shape and obtain the above-mentioned shape.

Further, the brush bristles of the present invention are preferably used as a brush using at least a part of the bristles. At this time, the cross-sectional shape of the hole for implanting the synthetic fiber used for the brush is not only a round cross section, an elliptical shape, an oval shape, and a rectangular shape, but also a rhombus, a bamboo leaf shape, a teardrop shape, and the like. The shape is not restricted, and the depth and number of pores are also not restricted.

Further, the cross-sectional shape of the synthetic fiber planted in the flocked hole is not particularly limited, and not only the same shape but also a hybrid of a plurality of shapes can be obtained.

Further, the method of flocking the hair for the brush may be a method suitable for the application, and generally, there are flat line flocking and non-flat line flocking for the toothbrush application, but any flocking method can be used. However, other methods may be used, and there are no restrictions.

The above conditions may be appropriately determined according to the intended use, usage pattern, usage conditions, required characteristics, and the like.

The brush of the present invention is suitable as a toothbrush, a tongue brush, an interdental brush, a cosmetic brush, and a facial brush because the synthetic fiber for the brush has the above-mentioned characteristics. It is also preferably used in industrial applications such as.

Further, in the brush of the present invention, a range of 1 to 100 mm is exemplified as a preferable range of the brush bristles length (length from the brush root to the bristles), although it depends on the use thereof, and more preferably 5. The range is ~ 35 mm.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a brush bristles 1 according to an embodiment (Embodiment 1) of the present invention, and FIG. 1 (A) shows one end of the bristles 1. As shown in FIG. 1 (B), the brush bristles 1 are formed on one end or both ends of the synthetic fiber 2 made of a synthetic resin containing polybutylene succinate (PBS) as a main component in the longitudinal direction. (FIG. 1 (A) shows only one end of the brush bristles 1), and a tapered portion 3 is formed.

The brush bristles of the present invention preferably have a tapered shape formed by alkali weight reduction processing. As a result, the tapered portion 3 as shown in FIG. 1A is formed, so that the tapered portion 3 is thinner than the brush bristle material on which the tapered portion 3 is not formed, and the penetration into the teeth is improved when scraping dirt. However, it can exert a high cleaning effect and exhibit excellent cleaning performance.

Two types of methods are typically known as methods for transplanting the brush bristles 1 configured as described above to the brush constituent members, but when these two methods are used for a toothbrush. Will be described as an example with reference to FIG.

FIG. 2A shows a toothbrush 13 in which the brush bristles 11 are flocked on the head portion of the toothbrush component 12, and as a method of flocking the brush bristles 11, aa'a'of FIG. 2 (A). There are two types of methods as shown in FIGS. 2 (B) and 2 (C), which are enlarged cross-sectional views along the line. In the method shown in FIG. 2B, the brush bristles 11 folded in half are inserted into the bristles holes 14, and the brush bristles 11 are fixed to the toothbrush component 12 with a fixture called a flat line 15. The finished toothbrush is commonly referred to as a flat line toothbrush. In such a flat-line toothbrush, both ends of the brush bristles 11 prepared in advance serve as the bristles of the brush. In the method shown in FIG. 2C, one end of the brush bristles 11 is inserted into the through hole 16 of the head portion surface side member 12a of the toothbrush component member 12, and the other end of the inserted brush bristles 11 is inserted. A heating device (not shown) is applied to the end to form a lump for preventing or fixing, which is called a hot-bulb 17, and then the back member 12b of the head is joined to hide the hot-bulb 17 and a toothbrush. Complete the product. The finished toothbrush is commonly referred to as a flat line toothbrush. In such a non-flat line toothbrush, one end of the brush bristles 11 prepared in advance serves as the bristles of the brush. Therefore, when the brush bristles 1 according to the present invention are used for a flat line toothbrush, the above-mentioned tapered portions 3 are formed at both ends of the brush bristles 1, and the non-flat line toothbrush When used, the tapered end 4 will be formed on only one end of the brush bristles 1.

The brush bristles of the present invention may take various forms other than the above-described first embodiment. FIG. 4 illustrates various forms in the cross section of the fiber. Various forms such as composite cross sections 21, 31 and irregular cross sections 41, 51, 61, 71 can be adopted.

Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited thereto.

The measurement of each characteristic was performed as follows.

(1) Degree of biodegradation In a compost using a container with a capacity of 30 L manufactured by Ecoclean Co., Ltd., which is a commercially available household compost corresponding to the compost used for decomposition evaluation of biodegradable plastic of ISO14855, and an ecopower chip manufactured by the same company. A test piece was prepared by attaching 1 g of hair to a mount that protrudes more than half of the hair length, and used in the same way as normal compost. The circumference of the cross section of the synthetic fiber before use and 1 month. The difference (μm) in the peripheral length of the cross section of the synthetic fiber after that was taken as the degree of biodegradation.

(2) Cross-sectional area of synthetic fiber for brush The synthetic fiber is fixed, cut with a microtome, the cross section is enlarged to a magnification of 200, and the cross-sectional area is measured.

(3) Perimeter of cross section The synthetic fiber is fixed, cut with a microtome, the cross section is enlarged to a magnification of 200, and the perimeter is measured.

[Examples 1 to 3]
Bio-PBS® (registered trademark) (55% by mass aliphatic polyester made from non-petroleum raw material, manufactured by "PTT MCC Biochem", the same applies hereinafter) is used in a melt spinning apparatus having a uniaxial extruder of Φ60 mm (L / D = 25). It was fed and melted at a spinning temperature of 250 ° C. The molten resin was weighed with a gear pump so that the cross section and the cross-sectional area in the fiber axial direction after stretching were as shown in Table 1, and then spun out from the hole-shaped base holes shown in Table 1. The spun strand was introduced into a cooling bath filled with warm water having a temperature of 25 ° C., passed through the cooling bath for 30 seconds, and then taken up by a first roll rotating at a surface speed of 3 m / min. The unstretched monofilament that has been taken up is continuously stretched one step between the first roll and the second roll at the stretching ratio shown in Table 1 without being wound once, and then subjected to a 1x relaxation treatment between the second roll and the third roll. After that, it was wound on a winder. A hot water bath having a length of 1500 mm and a temperature of 80 ° C. was installed between the first roll and the second roll as a heat source for stretching. The characteristics of the monofilament thus obtained are shown in Table 1.

[Examples 4 to 5]
A resin obtained by mixing Bio-PBS® and GS Alliance starch resin (“GS BP Search” with 80% by mass of non-petroleum-derived raw material) in the ratio shown in Table 1 was mixed into a monofilament in the same manner as in Example 1. Table 1 shows the characteristics of the case.

[Comparative Example 1]
Table 1 shows the characteristics when Trecon (registered trademark) (polybutylene terephthalate of 0% by mass of non-petroleum-derived raw material) is made into a monofilament by the same method as in Example 1.

The present invention can be applied to any brush, and is particularly suitable for toothbrushes, tongue brushes, makeup brushes, facial brushes, application brushes, liquid crystal cleaning brushes, and the like.

1, 11, Brush bristles 2 Synthetic fiber 3 Tapered part 12 Toothbrush component 12a Head part front side member 12b Head part back side member 13 Toothbrush 14 Fleece hole 15 Flat line 16 Through hole 17 Burnt ball 21, 31 Brush hair material (Composite fiber)
41, 51, 61, 71 Brush bristles (deformed cross-section fiber)

Claims (5)

Brush bristles made of synthetic fibers containing polybutylene succinate (PBS) as the main component and having a biodegradability of 25 or more after 1 month in compost. The brush bristles according to claim 1, wherein 50% by mass or more of the polybutylene succinate (PBS) is made of a non-petroleum-derived raw material. The brush bristles according to claim 1 or 2, wherein the cross-sectional area of the cross section orthogonal to the fiber axis of the brush bristles is 20 μm ^{2 to} 100 mm ^2. The brush bristles according to any one of claims 1 to 3, wherein at least one end has a tapered shape. A brush using at least a part of the brush bristles according to any one of claims 1 to 4.

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