JP5504518B2 - Interdental brush - Google Patents

Description

  The present invention includes a brush portion formed by twisting brush hairs with a metal wire, a wire portion formed with the twisted straight metal wire, and a grip portion for inserting a part of the straight metal wire. Specifically, the present invention relates to an interdental brush in which the wire portion does not easily come out of the gripping portion and the gripping portion has excellent antibacterial properties.

  The conventional interdental brush uses a soft thermoplastic synthetic resin such as soft polyethylene such as low-density polyethylene (LDPE) or polypropylene (PP) as the gripping part, so a metal wire made of stainless steel or the like is twisted. It is manufactured by press-fitting a straight metal wire into a plastic gripping part, but the gripping part into which the straight metal wire is inserted is simply inserted by twisting the straight metal wire. As it is used for a period, there is a problem that a gap is generated between the gripping part and the straight metal wire, and the brush part is easily pulled out. For this purpose, the brush portion is prevented from coming out of the handle member by bending it into a U-shape or a U-shape and embedding a predetermined length in the handle member. The process of bending this straight metal wire into a U-shape or U-shape is a cumbersome and difficult operation, and it requires a work process and requires time and money, so there is a demand to omit it. At the same time, there was a demand to have antibacterial properties in the gripping part.

The interdental brush handle member described in Patent Document 1 shown below is known as an interdental brush that does not require the work of bending the linear metal wire and has an excellent antibacterial property. .
In Patent Document 1, a thermoplastic synthetic resin constituting a handle member (corresponding to a “gripping part”) of an interdental brush is made of at least a metal-adhesive polyolefin, and a metal wire embedded in the handle member is twisted. Since a part of the straight metal wire is bonded by the metal-adhesive polyolefin, it is fine, troublesome and difficult to fold a part of the straight metal wire into a U shape or a U shape. It is described that there is no need to work, and the bending process can be omitted, and the polymer blend in which the thermoplastic synthetic resin is composed of at least a metal-adhesive polyolefin includes metal-adhesive polyolefin, EVA (ethylene・ Combination of vinyl acetate copolymer resin and soft polyolefin provides sufficient adhesion to metal wires, and release agent Molding is possible without using it, and it is preferable because molding processability is good and appropriate flexibility can be obtained for the pattern member. The most preferable blending ratio is 30 parts by weight of metal-adhesive polyolefin. And 45 parts by weight of EVA and 25 parts by weight of soft polyethylene.

  Furthermore, in Patent Document 1, for example, the handle member of No. 5, which is an example relating to the handle member of the interdental brush, contains 0.5% by weight of antibacterial zeolite in low density polyethylene, and No. 6 No. 5 detects the number of surviving bacteria in the antibacterial test of Staphylococcus aureus and Escherichia coli on the brush hair. It is described that there is no detection and that Example No. 6 also has no detection (see Patent Document 1).

Japanese Patent No. 4097311

  The handle member of the interdental brush described in Patent Document 1 is a metal-adhesive polyolefin, EVA, which is not a general-purpose resin, so its price is expensive, and metal adhesive polyolefin 30 parts by weight, EVA 45 parts by weight, soft polyethylene To form pellets by blending 25 parts by weight, it takes time and money to manage the manufacturing process, and it is difficult to control temperature, time, etc. to injection-mold the gripping part of the interdental brush, and There is a problem that the cost of the interdental brush is high. Furthermore, since the silver antibacterial agent has a high price per weight and is easily colored by increasing the blending, there is a strong demand to reduce the blending ratio.

  Therefore, the problem of the present invention was devised as a result of intensive research in view of the above circumstances, and even if the gripping part is molded using a general-purpose resin as the gripping part resin of the interdental brush, the above metal It does not easily come out of the grip part where a part of the wire is inserted, and the content rate of the silver antibacterial agent contained in the general-purpose resin is higher than the content rate of the silver antibacterial agent contained in the conventional grip part. Even if it is small, it is providing the interdental brush provided with the holding part which exhibits the effect equivalent to or more than the antibacterial effect which the said conventional holding part has.

The inventor has completed the interdental brush of the present invention as a result of diligent research to solve the above problems.
That is, in order to solve the above-mentioned problem, the interdental brush according to the first aspect of the present invention is a linear metal formed of a brush portion in which brush hairs are twisted into a metal wire and the twisted metal wire. An interdental brush comprising a linear wire portion made of wire and a thermoplastic resin gripping portion in which the end of a predetermined length of the linear wire portion is embedded, wherein the thermoplastic resin of the gripping portion is a polyethylene resin Polypropylene resin or nylon resin, characterized in that a spherical glass powder having an average particle size of 10 to 40 μm is contained in the resin in a range of 40 to 70% by weight of glass.
Similarly, the interdental brush of the invention according to claim 2 is characterized in that the spherical glass powder is E glass or silica glass.
The interdental brush of the invention according to claim 3 is characterized in that the shape of the gripping portion of the interdental brush is a linear shape or a bent shape.
The interdental brush of the invention according to claim 4 is a brush portion in which brush hairs are twisted into a metal wire, and a straight wire portion made of a straight metal wire formed from the twisted metal wire, An interdental brush composed of a thermoplastic resin gripping part in which the end of a predetermined length of the linear wire part is embedded, and the thermoplastic resin of the gripping part is a polyethylene resin, a polypropylene resin or a nylon resin, and these A spherical glass powder having an average particle size of 10 to 40 μm is contained in the resin in a range of 40 to 70% by weight of glass, and a silver antibacterial agent is contained in a range of 0.05 to 0.10% by weight. It is characterized by being.
The interdental brush of the invention according to claim 5 is the survival of the gripping part in which the gripping part contains a silver antibacterial agent in a range of 0.50 to 1.00% by weight in a thermoplastic resin containing no spherical glass powder. It is a value equal to or smaller than the logarithm of the number of bacteria.
In the interdental brush of the invention according to claim 6, the gripping portion containing at least 0.05% by weight of the silver-based antibacterial agent contains 0 silver-based antibacterial agent in the gripping portion of the thermoplastic resin not containing the spherical glass powder. It is a value smaller than the logarithm of the number of surviving bacteria of the gripping part containing 5% by weight.
The interdental brush of the invention according to claim 7 is characterized in that the gripping part containing 0.1% by weight of the silver antibacterial agent contains a silver antibacterial agent in the gripping part of the thermoplastic resin not containing the spherical glass powder. It is a value equivalent to the logarithm of the number of surviving bacteria in the gripping part containing 0% by weight.
An interdental brush according to an eighth aspect of the present invention includes a sleeve that can cover a brush portion of the interdental brush.
The interdental brush of the invention according to claim 9 is characterized in that the spherical glass powder is E glass or silica glass.
The interdental brush of the invention according to claim 10 is characterized in that the silver antibacterial agent is silver zeolite, silver glass, or silver zirconium phosphate.
The interdental brush of the invention according to claim 11 is characterized in that the shape of the gripping portion of the interdental brush is a linear shape or a bent shape.

The interdental brush of the present invention contains 40 to 70% by weight of spherical glass powder in a general-purpose resin so that the linear metal wire does not come out of the gripping part without using metal adhesive polyolefin. Can be obtained.
Further, the interdental brush of the present invention contains 40 to 70% by weight of spherical glass powder in the resin, so that the blending ratio of the silver-based antibacterial agent contained in the conventional gripping part is 1/10. In addition, it has a special effect that a gripping part of an interdental brush excellent in antibacterial properties can be obtained.

It is a top view which shows an example of an interdental brush. It is a longitudinal cross-sectional view of one extruder used for shaping | molding of the pellet which contains spherical glass powder and silver glass in the thermoplastic resin which is the raw material of the holding part of this invention. It is a distribution map which shows distribution of the average particle diameter of spherical glass powder. It is an electron micrograph of 1000 times the spherical glass powder. It is the electron micrograph which expanded the cut part which cut | disconnected the pellet obtained by mix | blending 50 weight% of spherical glass powders with PP perpendicularly | vertically from the side surface 50 times. It is the electron micrograph which image | photographed the surface of the injection molding body of PP with a glass compounding ratio of 50 weight% enlarged 200 times from the front. It is the electron micrograph which image | photographed the surface of the injection molding body of PP with a glass compounding ratio of 50 weight% enlarged 200 times from the angle of 45 degreeC. It is the electron micrograph which image | photographed the cross section of the injection molding body of PP with a glass compounding ratio of 50 weight% enlarged 200 times. It is a graph of Staphylococcus aureus showing the relationship between the silver zeolite blending ratio blended in the LDPE shown in Table 3 and the survival cell count Log (CFU / ml) of Staphylococcus aureus. 4 is a graph of Escherichia coli showing the relationship between the proportion of silver zeolite blended in the LDPE shown in Table 3 and the number of surviving bacteria Log (CFU / ml). 5 is a graph of Staphylococcus aureus showing the relationship between the ratio of silver zeolite blended in PP shown in Table 4 and the survival cell count Log (CFU / ml) of Staphylococcus aureus. 5 is a graph of E. coli showing the relationship between the proportion of silver zeolite blended in PP shown in Table 4 and the number of surviving bacteria of E. coli Log (CFU / ml). It is a graph of Staphylococcus aureus showing the relationship between the silver glass blending ratio blended in Ny shown in Table 5 and the survival cell count Log (CFU / ml) of Staphylococcus aureus. 6 is a graph of Escherichia coli showing the relationship between the silver glass blending ratio blended in Ny shown in Table 5 and the survival cell count Log (CFU / ml) of Escherichia coli.

The best mode for carrying out the present invention will be described below. The present invention is not limited to the following best mode.
FIG. 1 is a plan view showing an example of an interdental brush according to the present invention.
The interdental brush 1 includes a brush portion 2 formed by twisting brush hairs 5 with a metal wire, a linear wire portion 3 formed with a straight metal wire of the twisted metal wire, and a linear shape thereof. The grip portion 4 is configured to insert a part of the wire portion 3.

  The end of the predetermined length of the linear wire part 3 is embedded in the thermoplastic resin containing the spherical glass powder or the spherical glass powder and the silver-based antibacterial agent. A cylindrical portion 6 that wraps the linear wire portion 3 protrudes from the conical head portion 4a of the grip portion 4, and a curved shape that is easy to pinch with a finger between the trunk portion 4b and the tail portion 4c. A shaped knob 7 is provided. The outer diameter of the trunk | drum 4b and the tail part 4c is the same, The brush part 2 can be covered by inserting and connecting to the sleeve which is not shown in figure as needed. Therefore, the interdental brush 1 can be stored by inserting it into the sleeve from the direction of the brush part 2 and fitting the body part 4b, and extending from the sleeve by fitting the tail part 4c to the sleeve. The interdental brush can be used in the state.

(Extruder for pellets for gripping part)
Next, the manufacturing method of the pellet which contains the spherical glass powder and silver glass in the thermoplastic resin which is a raw material of the holding part of this invention is demonstrated. Since the manufacturing method of the pellet which contains only spherical glass powder in a thermoplastic resin can also be manufactured by said same method, the manufacturing method of the pellet which contains only spherical glass powder is abbreviate | omitted.
The said pellet is manufactured using the extruder provided with two types of hoppers shown in FIG.

  Reference numeral 20 is an extruder, reference numeral 21 is a motor, reference numeral 22 is a speed reducer, reference numeral 23 is a screw, reference numeral 24 is a heater / blower, reference numeral 25 is a screw thread, reference numeral 26 is a breaker plate, reference numeral 27 is a nozzle die, reference numeral 28 is a first Reference numeral 28 'represents pellets, reference numeral 29 represents a second hopper, and reference numeral 29' represents spherical glass powder and silver glass.

  The extruder 20 is provided with two hoppers into which thermoplastic resin pellets 28 'as feed materials and spherical glass powder and silver glass 29' are charged. The hoppers of the extruder 1 shown in FIG. 2 are referred to as a first hopper 28 and a second hopper 29 in order from the left side, and thermoplastic resin pellets 28 'are introduced into the first hopper 28 and provided near the middle part of the extruder. The second hopper 29 is charged with spherical glass powder and silver glass 29 '. The position where the second hopper 29 is arranged is provided in a region where the pellets 28 ′ supplied from the first hopper 28 into the screw barrel are in a molten state as the screw 23 is kneaded and conveyed.

  By the way, the present inventor can form a pellet (glass-containing molding pellet) by blending a spherical glass powder of 40% by weight or more into a general-purpose thermoplastic resin and kneading and extruding it with an extruder before filing this application. As a result of diligent research, we have completed a glass-containing molding pellet that can contain solid spherical glass powder in a general-purpose thermoplastic resin in an amount of 40 to 70% by weight. PCT / JP2008 / 68093 ( (Japanese Patent Application No. 2009-504515) (name of invention “Pellet for glass-containing molding and method for producing the same”, priority claim date: H19.10.4, (International Publication No. WO2009 / 044884). Conventionally, the reason why only the solid spherical glass powder can be contained in a general-purpose thermoplastic resin up to 35% by weight is the international publication number WO200. Although described in detail in U.S. Pat. No. 4,048,84, in short, when a spherical glass powder containing 35% by weight or more is mixed and extruded in a general-purpose thermoplastic resin, a molten resin containing a spherical glass powder is obtained. This is because the fluidity of the abruptly decreases and it becomes difficult to extrude.

(Thermoplastic resin)
The international publication number WO2009 / 044884 describes in detail a method for molding glass-containing molding pellets of nine types of resins including a method for producing spherical glass powder. Although known before the application, the gripping portion of the interdental brush is referred to as a polyethylene resin (hereinafter referred to as “PE”), a polypropylene resin (hereinafter referred to as “PP”) or a nylon resin (hereinafter referred to as “Ny”). It has been conventionally performed to use a soft thermoplastic synthetic resin such as), and these resins are well known as crystalline polymers. A method for forming a molding pellet by blending spherical glass powder with these resins will be described below.

(Spherical glass powder)
The glassy material of the spherical glass powder of the present invention includes alkali glass, soluble glass, non-alkali glass, silica glass, etc. having one or more of SiO ₂ , B ₂ O ₃ , and P ₂ O ₃ as skeleton components. Can be mentioned. And in order to make the shape spherical, the distribution of the average particle diameter can be sharpened by using a method of pulverizing glass fibers. When the spherical glass powder has a large alkali content, the thermoplastic resin is likely to be embrittled, and therefore, E glass or silica glass which is non-alkali glass is preferable.

  As the spherical glass powder, glass fiber having a diameter of 20 μm is used as a material. Since the diameter of the glass fiber is constant, a pulverized product having a diameter of 20 μm and a length of 10 to 30 μm is obtained by pulverizing the glass fiber so that the length of the glass fiber does not vary from the diameter of 20 μm. This pulverized product is sprayed into a 2500 to 3000 ° C. flame by an oxygen burner provided inside the furnace to be spheroidized, and the sprayed sphere is sprayed with γ-glycidyloxypropylmethyldibenzene from a water injection device provided at the bottom of the furnace. Water containing 0.1% by weight of ethoxysilane was sprayed, silanized in a sprayed state, and collected with a bag filter. The collected glass powder is a spherical glass powder having a spherical average particle diameter of 10 to 40 μm. Thus, the spherical glass powder with an average particle diameter of 10-40 micrometers was obtained by using as a material the diameter of the said glass fiber 20 micrometers. The obtained spherical glass powder was solid. Hereinafter, the method of performing the silanization treatment performed in the spray state is referred to as “spray method”.

The spherical glass powder is obtained by silanizing the above spherical glass powder with the spraying method. In other words, the spherical glass powder is characterized in that its surface is entirely covered with a silane compound.
Examples of the silane compound include those represented by the following formula.
R _4-n -Si- (OR ') _n
(In the formula, R represents an organic group, R ′ represents a methyl group, an ethyl group or a propyl group, and n represents an integer selected from 1 to 3).

  Such silane compounds include vinyltriethoxysilane, vinyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ Silane coupling agents having an epoxy group such as glycidyloxypropylmethyldiethoxysilane, silane coupling agents having a mercapto group such as γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β (amino Examples include silane coupling agents having an amino group such as ethyl) γ-aminopropyltrimethoxysilane, N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane.

  FIG. 3 is a graph showing the frequency of distribution of the average particle diameter of the spherical glass powder obtained by the method for producing the spherical glass powder described above. The horizontal axis of this graph represents the particle size (μm) of the spherical glass powder, and the vertical axis represents the distribution frequency (%). The spherical E glass shows the highest distribution frequency at a particle size of 25 μm, and is distributed in a range of 10 to 40 μm on the normal distribution curve centering on the particle size of 25 μm. I understand that it is expensive.

FIG. 4 is a 1000 × electron micrograph of the spherical glass powder. From this photograph, it can be observed that the spherical glass powder has a spherical shape and a solid shape, and has various particle sizes.
From the graph in FIG. 3 and the photograph in FIG. 4, the spherical glass powder in the thermoplastic resin is a perfect sphere, and there are various sizes of particles, but the average particle size is It is shown to be 10-40 μm.

  By the way, when the spherical glass powder is put into the molten thermoplastic resin and kneaded, if the particle size becomes 10 μm or less, the proportion of fine particles increases, and the amount of heat from the resin increases as the specific surface area increases. As a result, the melt temperature rises due to a sudden drop in the temperature of the resin, and the resin temperature during kneading rises extremely due to shearing heat generation, making it difficult to adjust the determined blending ratio of both materials. become. In addition, by adding spherical glass powder to the thermoplastic resin, generally, the dimensional stability, mechanical strength (impact strength, bending strength, etc.), warpage, and transmission barrier properties of the molded product can be improved.

  When the particle size is 40 μm or more, the proportion of large particles increases, and the increase in melt viscosity during kneading is small, but when cutting the glass-containing composition into pellets of a certain size, wear of the cutting blade becomes severe, It becomes difficult to continuously produce a large amount of the glass-containing composition, resulting in production problems. Further, when the particle size is 40 μm or more, the impact strength is particularly lowered, which is not preferable. Therefore, the average particle size is preferably in the range of 10 to 40 μm.

  By blending and kneading a maximum of 70% by weight of spherical glass powder into the molten thermoplastic resin, it is extruded into a 3 mm diameter rod from a nozzle die provided at the discharge port of the extruder and cooled with water. A glass-containing molding pellet in which spherical glass powder is independently dispersed in the thermoplastic resin is obtained by cutting to a length of about 4 mm with a cutter, but the diameter and length are not limited thereto.

FIG. 5 is an electron micrograph obtained by enlarging a pellet obtained by blending 50% by weight of spherical glass powder with PP into a 50-fold magnified section cut vertically from the side.
From the photograph of the cut part of the pellets in FIG. 5, it is observed that the pellets are blended in a state where the individual spherical glass powders are dispersed independently without aggregation in PP.

From this, the spherical glass powder is entirely coated with a silane compound by a spraying method, and the pellets formed by kneading and extruding in an extruder are aggregated in the resin. It was found that they were blended in an independently dispersed state.
And draw a circle from the middle point of the photograph of FIG. 5 to the position of the upper and lower ends, divide the circle equally into 16 and visually count the number of spherical glass powder blended in each of the 16 sections, The counted results are shown in Table 1.
In addition, when spherical glass powder was present on the 16 dividing line, the number of spherical glass powders was calculated as 1/2.
From the measurement results in Table 1, the number of spherical glass powders in each section is in the range of 140 ± 1, indicating that the spherical glass powder is uniformly dispersed in the pellets.

  From the above, the glass-containing molding pellets for the gripping part of the present invention obtained by kneading and extruding spherical glass powder and thermoplastic resin pellets with an extruder are solid in a spherical shape. It has an average particle diameter of 10 to 40 μm, its surface is entirely covered with a silane compound, and is dispersed uniformly and uniformly in a thermoplastic resin at a glass blending ratio in the range of 40 to 70% by weight. It has been found that it is contained in the state where it has been.

(Skin layer)
When manufacturing an injection molded product with a fine shape and shape using resin pellets using an injection molding device, when the molten resin is injected into the injection mold, the molten resin is rapidly cooled on the wall surface of the mold that forms the cavity. It is well known that a layer (hereinafter referred to as “skin layer”) in which resin is solidified is formed on the wall surface.
The inventor photographed the surface of the PP injection-molded body having a glass blending ratio of 50% by weight at a magnification of 200 times using an electron microscope. FIG. 6 is an electron micrograph taken by enlarging the surface of a PP injection molded body with a glass blending ratio of 50% by weight 200 times from the front. FIG. 7 is an electron micrograph taken by enlarging the surface of a PP injection molded body with a glass blending ratio of 50% by weight from a 45 ° C. angle by 200 times. The photographs in FIGS. 6 and 7 show that large and small spherical convex portions exist in a dispersed state as a characteristic shape of the surface of the injection molded body.

  The large and small spherical convex portions are formed by contact of molten PP containing spherical glass powder with the mold surface. As described above, a skin layer is formed on the surface of an injection-molded body made of 100% resin. However, considering the scale of 100 μm in the photograph, the skin layer is formed on the spherical convex portion in FIGS. This indicates that a large number of spherical glass powders exist on the surface, and therefore it is presumed that no skin layer is formed on the surface of the glass-containing resin molded body.

  Therefore, by photographing with an electron microscope whether or not a skin layer is formed on the surface of the injection-molded body, and examining the surface structure, the PP injection-molded body with a glass blending ratio of 50% by weight was cut. The cut surface was photographed with an electron microscope. FIG. 8 is an electron micrograph taken by magnifying the cross section of the PP injection molded body having a glass blending ratio of 50% by weight at 200 times. The black part above the photo is an acrylic resin sandwiched to cut the injection molded body, the white spherical part is a spherical glass powder, and the part containing the spherical glass powder is an injection molded part including the surface. is there. A skin layer is formed on the surface (in the range from 0 to at least 150 μm) of an injection-molded body made of 100% resin. From the scale of 100 μm in the photograph, many spherical glass powders are formed on the surface on which the skin layer is formed. It can be seen that is distributed. Therefore, the cross-sectional photograph of the injection-molded body in FIG. 8 shows that when the surface of the glass-containing resin molded body has a glass blending ratio of 50% by weight, a skin layer is not formed and spherical glass powder is present.

(Manufacturing method of gripping part pellets)
Although the manufacturing method of the pellet for holding | grip parts described below demonstrates the manufacturing method containing a silver type antibacterial agent, when not containing a silver type antibacterial agent, what is necessary is just to exclude a silver type antibacterial agent.
LDPE, PP or Ny can be used as the thermoplastic resin used for the grip portion 4. The spherical glass powder to be blended in the gripping part 4 preferably contains E glass or silica glass having a large thermal conductivity and an average particle diameter of 10 to 40 μm in a proportion of 40 to 70% by weight, and contains an antibacterial agent. In this case, the silver antibacterial agent preferably contains silver zeolite, silver glass or silver zirconium phosphate, and preferably contains at least 0.05% by weight of the silver antibacterial agent in one of the thermoplastic resins. .
When an injection molding device is used to manufacture an injection molded body having a fine shape and shape that is molded by an injection molding machine using resin pellets, the mold wall surface that forms a cavity when molten resin is injected into the injection mold It is well known that the molten resin is rapidly cooled and a layer in which the resin is solidified, that is, a so-called skin layer is formed on the wall surface. If the spherical glass powder is less than 40% by weight in the thermoplastic resin, a skin layer is formed on the surface of the grip portion 4, so that distortion such as sink marks and warpage occurs, and the antibacterial effect is impaired.

  The weight of the pellets 28 ′ fed according to the determined blending ratio is weighed and put into the first hopper 28, and the pellets 28 ′ sent by kneading and conveying by the screw 23 are in a molten state by the heater, that is, At the position where the second hopper 29 is disposed, the weight of the spherical glass powder and silver antibacterial agent 29 ′ supplied according to the determined blending ratio is weighed and put into the second hopper 29. The spherical glass powder and the silver-based antibacterial agent 29 'charged into the molten resin are extruded while being kneaded to form a resin composition containing the spherical glass powder and the silver-based antibacterial agent 29', and then cut. Thus, pellets containing spherical glass powder and silver antibacterial agent 29 'are obtained. The temperature of the heater is determined according to the melting point of the thermoplastic resin used. 2 is the same as the conventional extruder except for the structure of the hopper except for the structure of the extruder, so that the description of the structure of the extruder of FIG. 2 is omitted.

(Manufacturing method of grip part)
Pellet containing spherical glass powder and silver antibacterial agent is put into a hopper of an injection molding machine, and the pellet is melted at the melting temperature set according to the resin at the front, middle and rear of the heater / blower, A grasping part was formed by injection into a mold in which parts of an interdental brush composed of a brush part and a linear wire part were inserted.

(Pull-out test of straight wire part)
The gripping part of the brush part was molded by the above molding method, and a pulling test between the linear wire part and the gripping part was performed and evaluated using a tensile tester AGS-100G (Shimadzu Corporation). The results of the pull-out test are shown in Table 2.
In Example 10, when a pulling test of a gripping part containing 50% by weight of LDPE and 49.9% by weight of E glass powder and 0.1% by weight of silver glass and a straight wire part was performed, the linear wire part was It was cut without coming out. On the other hand, the comparative example 10 which does not contain E glass powder has slipped out at 50 N / mm ² .

(Antimicrobial test piece)
100% resin pellets from the first hopper of the injection molding machine, 40% and 50% by weight pellets and filler from the second hopper (except in the case of the 40% and 50% glass blending ratio of the comparative example). The pellet injection part temperature of the injection molding machine is 230 ° C., the screw central part temperature is 240 ° C., the extrusion part temperature is 245 ° C., and the pressure is 50 kg / cm ² . Antibacterial test pieces were molded.

(Antimicrobial test)
The antibacterial test was performed by performing an antibacterial test on the above test plate based on JIS Z2801. As a strain, S. aureus (NBRC 12732) and E. coli (NBRC 3301) were inoculated at 2.5 × 10 ⁵ cells / ml, cultured at 35 ° C. for 24 hours, washed, and washed 24 hours after the untreated specimen. The number of viable bacteria (CFU / ml) and the number of surviving bacteria (CFU / ml) 24 hours after Example were measured.

The manufacturing method of the above-mentioned three kinds of pellets containing spherical E glass as a spherical glass powder and silver-based antibacterial agent, using LDPE as a thermoplastic resin as Example 1, PP as Example 2 and Ny as Example 3. First, then, a manufacturing method for forming the grip portion of the interdental brush using the above three types of pellets, and a manufacturing method for forming a test piece for measuring the antibacterial effect of each resin will be described. .
Example 1
(LDPE glass-containing molding pellets)
Two types of glass-containing molding pellets having a weight ratio of 40:60 and 50:50 of spherical E glass silanized by a spray method and LDPE were prepared using LDPE as a thermoplastic resin.
While weighing 60% by weight of Sumikasen G801 (trade name: Sumitomo Chemical Co., Ltd.) as LDPE from the first hopper of the above-described extruder, and putting it in a molten state at 230 ° C., from the second hopper A spherical E glass is weighed and 40% by weight preheated to a temperature equal to or close to the melting temperature of 230 ° C. is added and kneaded at 230 ° C. with a screw speed of 200 times / min. Then, it was cooled with water and cut to a length of 4 mm to obtain pellets of the first level in Example 1.

  In the same manner, a second level pellet of 50% by weight of Sumikasen G801 and 50% by weight of spherical E glass was obtained. In addition, the silver zeolite which is a silver type antibacterial agent uses AJ10N (trade name: Sinanen Zeomics Co., Ltd. product), and is charged into the molding pellets with the spherical E glass from the second hopper. However, when silver zeolite is charged, it is charged from the first hopper at a ratio obtained by subtracting the weight percentage from the resin. Since the silver antibacterial agent is blended in the same manner in Examples 2 and 3 described below, they are omitted in Examples 2 and 3 described below.

(LDPE gripping part)
A method for forming the LDPE gripping portion will be described. EPE and LDPE pellets containing silver antibacterial agent are put into a hopper of an injection molding machine, the heater blower is 235 ° C in the front, 245 ° C in the middle and 220 ° C in the rear at the melting temperature. It was melted and injected into a 40 ° C. mold into which an interdental brush part consisting of a brush part and a linear wire part was inserted, and a grip part was formed.

(Example 2)
(PP glass-containing molding pellets)
Using PP as a thermoplastic resin, two types of glass-containing molding pellets having a weight blending ratio of 40:60 and 50:50 of spherical E glass silanized by a spray method and PP were prepared.
Weighed Novatec MH3 (trade name: Nippon Polypro Co., Ltd. product) as PP from the first hopper of the above-mentioned extruder and charged 60% by weight. Weigh the spherical E glass and add 40% by weight preheated to a temperature similar to or close to the melting temperature of 220 ° C, knead at 220 ° C and a screw speed of 200 rotations / minute, and form a 3mm rod Then, it was cooled with water and cut to a length of 4 mm to form a pellet to obtain a molding pellet having a glass blending ratio of 40% by weight.
Similarly, two types of molding pellets having 50% by weight of Novatec MH3, 50% by weight of spherical E glass and 50% by weight of glass were obtained. As silver zeolite, AJ10N (trade name: Sinanen Zeomics Co., Ltd. product) was used.

(PP gripping part)
A method for forming the PP gripping portion will be described. P pellets containing E glass and silver antibacterial agent are put into the hopper of an injection molding machine, and the above pellets are heated at a melting temperature of 245 ° C at the front of the heater and the lower part, 250 ° C at the middle and 230 ° C at the rear. It was melted and injected into a 40 ° C. mold into which an interdental brush part consisting of a brush part and a linear wire part was inserted, and a grip part was formed.

(Example 3)
(Ny glass-containing molding pellets)
Nylon 6 (hereinafter referred to as “Ny6”) is used as the thermoplastic resin, and two types of glass-containing moldings are used in which the weight ratio of the spherical E glass silanized by spraying and Ny6 is 40:60 and 50:50. Pellets were prepared.
The weight of Amilan CM1007 (trade name: product of Toray Industries, Inc.) as Ny6 was weighed from the first hopper of the above-mentioned extruder, and 60% by weight was put into a molten state at 230 ° C. E glass is weighed and 40% by weight preheated to a melting temperature of 230 ° C. or similar to that is added, and kneaded at 230 ° C. with a screw speed of 200 times / min. Extrusion, water cooling, cutting to a length of 4 mm to form a pellet, the first level molding pellet of Example 3 was obtained. The preheating temperature is most preferably the same as the melting temperature of 230 ° C., and (230 ° C. ± 10% temperature) is preferred.
In the same manner, a second level molding pellet of 50% by weight of Amilan CM1007 and a second level molding pellet of 50% by weight of spherical E glass was obtained. As the silver glass, 721ST (trade name: Koa Glass Co., Ltd. product) was used.

(Ny6 gripping part)
A method for forming the grip portion of Ny6 will be described. Ny6 pellets containing E glass and silver antibacterial agent are put into a hopper of an injection molding machine, and the above pellets are heated at a melting point of 255 ° C at the front of the heater and blower, 265 ° C at the middle and 245 ° C at the rear. It was melted and injected into a 50 ° C. mold into which an interdental brush part consisting of a brush part and a linear wire part was inserted, and a grip part was formed.

(Result of antibacterial test of Example 1)
Table 3 is a table showing the results of antibacterial tests of Example 1 and Comparative Example 1 of LDPE.
The first column of Table 3 shows the types of Examples and Comparative Examples, the second column shows the E glass blending ratio, the third column shows the silver antibacterial blending ratio, the fourth and sixth columns are The result of the number of residual bacteria measured by the antibacterial test of various bacteria is shown, the fourth column shows the result against S. aureus, and the sixth column shows the result against E. coli. The fifth column and the seventh column show the result of the number of surviving bacteria in logarithm.

(Antimicrobial test result of Example 2)
Table 4 is a table showing the antibacterial test results of PP Example 2 and Comparative Example 2.

(Antimicrobial test results of Example 3)
Table 5 is a table showing the antibacterial test results of Ny Example 3 and Comparative Example 3.

FIG. 9 is a graph of Staphylococcus aureus showing the relationship between the proportion of silver zeolite blended in the LDPE shown in Table 3 and the number of remaining Staphylococcus aureus logs (CFU / ml). 4 is a graph of Escherichia coli showing the relationship between the proportion of silver zeolite blended in the LDPE shown in Table 3 and the number of surviving bacteria Log (CFU / ml). In the graph, Δ marks indicate Comparative Example 1, ◇ marks indicate Example 1-1, and □ marks indicate Example 1-2. And the linear equation described on the right side of each graph is an approximate linear equation calculated from three points, showing Comparative Example 1, Example 1-1, and Example 1-2 from the top.
FIG. 11 is a graph of Staphylococcus aureus showing the relationship between the proportion of silver zeolite blended in PP shown in Table 4 and the number of surviving bacteria Log (CFU / ml) of Staphylococcus aureus. 5 is a graph of E. coli showing the relationship between the proportion of silver zeolite blended in PP shown in Table 4 and the number of surviving bacteria of E. coli Log (CFU / ml). In the graph, Δ marks indicate Comparative Example 2, ◇ marks indicate Example 2-1, and □ marks indicate Example 2-2. The linear equation described on the right side of each graph is an approximate linear equation calculated from three points, showing Comparative Example 2, Example 2-1 and Example 2-2 from the top.

  FIG. 13 is a graph of Staphylococcus aureus showing the relationship between the silver glass blending ratio blended with Ny shown in Table 5 and the number of surviving bacteria Log (CFU / ml) of Staphylococcus aureus. 6 is a graph of Escherichia coli showing the relationship between the silver glass blending ratio blended in Ny shown in Table 5 and the survival cell count Log (CFU / ml) of Escherichia coli. In the graph, Δ marks indicate Comparative Example 3, ◇ marks indicate Example 3-1, and □ marks indicate Example 3-2. The linear equation described on the right side of each graph is an approximate linear equation calculated from three points, showing Comparative Example 3 from the top, Example 3-1 and Example 3-2.

  Looking at the whole graphs of FIGS. 9 to 14 and Tables 3 to 5, each of the three types of graphs of Comparative Examples 1 to 3 shows a linear equation having substantially the same gradient and contact points, and the gradient is about 4 The three types of graphs of Examples 1 to 3 show linear equations with substantially the same slope and contact point, and the slope is about 47 (10 in Comparative Examples 1 to 3). 2) is different from Comparative Examples 1 to 3. And Examples 1-2, 2-2, and 3-2 which contained 50 weight% of spherical glass powders in a thermoplastic resin are spherical glass powders irrespective of the kind of silver type antibacterial agent of silver glass or silver zeolite. From Examples 1-1, 2-1 and 3-1 containing 40% by weight, the logarithm of the number of surviving bacteria tends to be small. In addition, the logarithm of the number of surviving bacteria in Examples 1 to 3, in which 40 or 50% by weight of spherical glass powder is blended in the thermoplastic resin and 0.10% by weight of the silver antibacterial agent is contained, the silver antibacterial agent is 1 The value of 1.0 which is the same as the logarithm of the survival cell count of Comparative Examples 1 to 3 containing 0.000% by weight is shown. Furthermore, the logarithm of the number of surviving bacteria in Examples 1 to 3 containing 40% by weight or 50% by weight of spherical glass powder in the thermoplastic resin and 0.05% by weight of silver antibacterial agent is The value is smaller than the logarithm of the survival cell count of Comparative Examples 1 to 3 containing 0.50% by weight of the antibacterial agent.

  From the antibacterial measurement results of Examples 1 to 3 described above, the gripping part of the interdental brush of the present invention contains the above spherical glass powder in a thermoplastic resin in a glass blending ratio of 40 to 70% by weight, By containing silver antibacterial agent in the range of 0.05 to 0.10% by weight, the silver antibacterial agent is contained in the range of 0.50 to 1.00% by weight in the thermoplastic resin not containing spherical glass powder. It has been found that the logarithm value of the number of surviving bacteria is smaller than or equal to that of the conventional gripping part. This means that the grasping part of the interdental brush of the present invention is 1/10 of the mixing ratio of the silver antibacterial agent contained in the conventional grasping part, and the logarithm value of the number of surviving bacteria is equal or smaller than that. Therefore, the gripping part of the interdental brush of the present invention has excellent antibacterial properties even if the compounding ratio of the silver antibacterial agent is small.

  By the way, as described above, the electron micrograph of FIG. 8 shows that if 50% by weight of spherical glass is blended in the resin, there is no formation of a skin layer in the resin covering it. 3 to 5, the gripping portions of Examples 1-1, 2-1 and 3-1 were compounded with 40% by weight of spherical glass powder in resin and 0.05 or 0.10% by weight of silver-based antibacterial agent. It has been shown that the antibacterial property can be obtained by blending, so that the skin layer is not formed. This means that the conventional gripping portion prevents the surface of the silver-based antibacterial agent from bleeding out to the surface due to the formation of a skin layer, while the blending ratio of the spherical glass powder is 40% by weight, 50% by weight gripping part has no skin layer formation, so the presence of spherical glass powder and silver antibacterial agent on the surface proves that silver ions of silver antibacterial agent can penetrate into the surface To do.

  By the way, although the Example which contains a silver type antibacterial agent in the thermoplastic synthetic resin of a holding part was demonstrated, it is also possible to contain not only the holding part 4 but the resin of the sleeve of an interdental brush. And as an Example, although the said grip part 4 demonstrated the thing of a linear shape, it is not necessary to limit to a linear shape, The thing of the shape bent arbitrarily may be sufficient, and the interdental brush of this invention is a grip. The shape of the part includes a straight shape and a bent shape.

DESCRIPTION OF SYMBOLS 1 Interdental brush 2 Brush part 3 Straight wire part 4 Gripping part 5 Brush hair 20 Extruder 28 1st hopper 29 2nd hopper

Claims (11)

A brush portion in which brush hairs are twisted into a metal wire, a straight wire portion made of a straight metal wire formed with the twisted metal wire, and a predetermined length of the end of the straight wire portion are embedded An interdental brush comprising a thermoplastic resin gripping part,
The thermoplastic resin of the gripping part is a polyethylene resin, a polypropylene resin or a nylon resin, and a spherical glass powder having an average particle size of 10 to 40 μm is contained in the resin in a range of 40 to 70% by weight of glass. Interdental brush characterized.   The interdental brush according to claim 1, wherein the spherical glass powder is E glass or silica glass.   The interdental brush according to claim 2, wherein the shape of the gripping portion of the interdental brush is a linear shape or a bent shape. A brush portion in which brush hairs are twisted into a metal wire, a straight wire portion made of a straight metal wire formed with the twisted metal wire, and a predetermined length of the end of the straight wire portion are embedded An interdental brush comprising a thermoplastic resin gripping part,
The thermoplastic resin of the gripping part is a polyethylene resin, a polypropylene resin or a nylon resin, and a spherical glass powder having an average particle diameter of 10 to 40 μm is contained in these resins in a range of 40 to 70% by weight of glass, An interdental brush characterized by containing a silver antibacterial agent in a range of 0.05 to 0.10% by weight.   The logarithm of the number of surviving bacteria of the gripping part is a logarithm of the number of surviving bacteria of the gripping part containing a silver antibacterial agent in a range of 0.50 to 1.00% by weight in a thermoplastic resin containing no spherical glass powder. The interdental brush according to claim 4, wherein the interdental brush has an equivalent or smaller value.   The logarithm of the survival cell count of the gripping part containing at least 0.05% by weight of the silver antibacterial agent is 0.5% by weight of silver antibacterial agent in the gripping part of the thermoplastic resin not containing the spherical glass powder. The interdental brush according to claim 5, wherein the interdental brush has a value smaller than the logarithm of the number of surviving bacteria of the gripping part.   The logarithm of the survival cell count of the gripping part containing 0.1% by weight of the silver antibacterial agent contains 1.0% by weight of silver antibacterial agent in the gripping part of the thermoplastic resin not containing the spherical glass powder. The interdental brush according to claim 5, wherein the interdental brush has a value equivalent to the logarithm of the number of surviving bacteria in the gripping part.   The interdental brush according to claim 5, further comprising a sleeve that can cover a brush portion of the interdental brush.   The interdental brush according to claim 5, wherein the spherical glass powder is E glass or silica glass.   The antibacterial brush hair according to claim 9, wherein the silver-based antibacterial agent is silver zeolite, silver glass, or silver zirconium phosphate.   The interdental brush according to claim 10, wherein the shape of the gripping portion of the interdental brush is a linear shape or a bent shape.