JPH0724094Y2 - Interdental cleaning tool - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to an interdental cleaning tool, and more particularly to an interdental cleaning tool excellent in portability and usability.

Technical background of the invention Filamentous dental floss is known as a device for removing food residues and the like sandwiched between teeth. Dental floss is used to remove food residues and the like in the interdental part by inserting it into the interdental part and stretching it tightly with fingers to pass between the teeth.

Such a dental floss is cut to an appropriate length, and the dental floss alone can be used as an interdental cleaning tool, but it is stretched between a pair of protruding portions formed on the handle portion, which is excellent in portability. It is also used as an interdental cleaning tool.

However, in the conventional interdental cleaning tool in which the dental floss is stretched between the pair of protrusions formed on the handle in this manner, the direction in which the dental floss is stretched and the handle to be held by the hand Since the longitudinal direction of the part is fixed in parallel, the front teeth are easy to clean, but the back teeth are difficult to clean.

Further, as the dental floss used in the conventional interdental cleaning tool, a nylon crimp type multifilament is used. However, because nylon dental floss has poor tensile strength or impact resistance, it is often cut during use, and it is not possible to clean all interdental parts in the mouth with a single dental floss. Since it is poor in self-lubricating property, it has a problem that it tends to be caught on the teeth and the feeling during use is bad.

Therefore, it has been desired to develop a dental floss having excellent tensile strength, impact resistance, creep resistance, and usability.

It is already known that a molecular oriented molded product having a high elastic modulus and a high tensile strength can be obtained by molding ultra-high molecular weight polyethylene into a fiber, a tape or the like and stretching it. For example, JP-A-56-15408 describes that a dilute solution of ultrahigh molecular weight polyethylene is spun and the resulting filament is drawn. In addition,
JP-A-59-130313 describes that an ultrahigh molecular weight polyethylene and a wax are melt-kneaded, and this kneaded product is extruded, cooled and solidified, and then stretched. It is described that the kneaded product is extruded, drafted, cooled and solidified, and then stretched.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and provides an interdental cleaning tool that is excellent in portability and that can easily clean not only the front teeth but also the back teeth during use. Is the first purpose.

In addition, the present invention further provides an easy-to-use interdental cleaning tool having stretched dental floss excellent in tensile strength and impact resistance, creep resistance, water resistance and self-lubrication. It has two purposes.

SUMMARY OF THE INVENTION In order to achieve the first object, an interdental cleaning tool according to the present invention has a pair of protrusions formed on a handle portion at a predetermined distance from each other, and an intrinsic viscosity between the protrusions. Multiple ultra high molecular weight olefins with [η] of at least 5 dl / g (co)
A dental floss made of a stretched filament of a polymer is stretched, and the handle portion is composed of a first handle portion, a second handle portion, and a hinge portion for varying a crossing angle of these first and second handle portions. The dental floss is rotatably movable with respect to one of the first and second handle portions in the tensioning direction.

According to such an interdental cleaning tool, the tensioning direction of the dental floss can be freely changed with respect to any one of the handle parts by changing the crossing angle of the first and second handle parts.
Both front and back teeth can be easily cleaned.

In addition, dental floss has an intrinsic viscosity [η] of at least
Since it is composed of dental floss consisting of stretched filaments of multiple ultra-high molecular weight olefin (co) polymers of 5 dl / g, this filament has excellent tensile strength and impact resistance, as well as creep resistance and water resistance. It is possible to stretch this dental floss strongly between the protruding parts of the interdental cleaning tool due to its excellent properties and self-lubricating property. The dental floss is not cut even if it is passed. Further, as an intrinsic property of the ultrahigh molecular weight olefin (co) polymer, it is rich in self-lubricating property and has an excellent feeling during use.

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, an interdental cleaning tool according to the present invention will be specifically described with reference to the drawings.

FIG. 1 is a side view of an interdental cleaning tool according to an embodiment of the present invention,
2 is a view taken along the line II-II shown in FIG. 1, and FIG. 3 is a perspective view of the interdental cleaning tool.

As shown in FIG. 1, the interdental cleaning tool 2 according to the present invention has a rod-shaped handle portion 8 and rod-shaped protruding portions 4a, 4b protruding substantially at right angles to the handle portion 8. In addition, the protrusion 4
The angle between a and 4b and the handle portion 8 can be changed in detail depending on the use site and the like. One of the protrusions 4a is formed on the tip side of the handle portion 8, and the other of the protrusions 4b is formed apart from the one protrusion 4a by a predetermined distance. The spacing between the protrusions 4a and 4b needs to be wider than the thickness of the teeth of an ordinary person, and is preferably 10 to 30 mm.
It is preferable that the protrusions 4a and 4b and the handle 8 are integrally formed of synthetic resin or the like.

A dental floss 6 is stretched between the protrusions. As a means for stretching the dental floss 6 and fixing it to each of the protrusions 4a, 4b, known means such as adhesion and engagement can be adopted, but preferably, it can also be removable. This is because it becomes easy to replace the dental floss 6.
In addition, the tip of the handle portion 8 is sharpened so that the needle-like tip portion 10
It is preferable that the toothpick has a function as a toothpick. However, it is preferable to form the enlarged portion 12 on the needle-like tip portion 10. By providing the enlarged portion 12, the needle-like tip 10
This is to prevent the person from touching the user's body and feeling pain when carrying or using it.

The shape of the enlarged portion 12 is preferably a disc shape as shown in the figure, but is not limited to this, and may be a spherical shape, a hemispherical shape, a dice shape, a round bar shape, or any other shape. Also, the enlarged part
The size of 12 is not particularly limited as long as it has an outer shape larger than that of the needle-shaped tip portion 6. A disk shape is preferable as the shape of the enlarged portion 12 because it is convenient for massaging the tooth surface and the gingival portion with the enlarged portion 12.

It is preferable that such an enlarged portion 12 is formed integrally with the handle portion 8 by using wood or synthetic resin. The material of the handle portion 4 and the enlarged portion 12 is not particularly limited, and is a material that does not cut when bent several times with the hinge portion, and the enlarged portion 12 from the needle-like tip portion 8 to fingers, teeth, scissors, knife, etc. Any material can be used as long as it can be easily removed by using.

In the present invention, the handle portion 8 as described above is replaced with the first handle portion 8a.
And the second handle part 8b, and these first and second handle parts
8a, 8b are integrally formed with a molded hinge part 8c that is continuous,
The crossing angle of the first and second handle portions 8a and 8b is variable.

In the illustrated example, the hinge portion 8c is formed by providing a constricted portion on a part of the handle portion 8, but the hinge portion 8c may be formed by other means. Further, in the illustrated example, the projecting portions 4a and 4b are formed on the second handle portion 8a side, but they may be formed on the second handle portion 8b side. Further, the position where the hinge portion 8c is formed is not particularly limited, but it should be formed at a position where the dental floss 6 does not sag too much when the crossing angle of the first and second handle portions 4a, 4b is changed. Is preferred. In the example shown in FIG. 1, it is preferable to form the hinge portion 8c at a position within the range A in the drawing.

By providing the hinge portion 8c, as shown in FIG.
The stretching direction of the dental floss 6 can be pivotally moved with respect to the one first handle portion 8a. Therefore, if the first handle portion 8a is pressed with a finger, the second handle portion 8b side is put into the mouth, and the teeth and the crossing angle of the first and second handle portions 8a and 8b are changed, even the front teeth Even the back teeth can be easily cleaned.

In the present invention, the material of the dental floss 12 is drawn filament of ultra high molecular weight olefin (co) polymer, and more specifically, drawn filament of ultra high molecular weight polyolefin and / or ultra high molecular weight ethylene / α-olefin. It is a stretched filament of a copolymer.

As the ultrahigh molecular weight polyolefin constituting the stretched filament, specifically, ultrahigh molecular weight polyethylene, ultrahigh molecular weight polypropylene, ultrahigh molecular weight poly-1-butene, and ultrahigh molecular weight copolymer of two or more kinds of α-olefins and the like. Can be illustrated. The drawn filament of this ultra-high molecular weight polyolefin has excellent tensile strength and impact resistance, as well as excellent creep resistance and water resistance.

The ultrahigh molecular weight ethylene / α-olefin copolymer constituting the stretched filament includes ultrahigh molecular weight ethylene / propylene copolymer, ultrahigh molecular weight ethylene / 1-butene copolymer, and ultrahigh molecular weight ethylene / 4-. Methyl-1-
Pentene copolymer, ultra high molecular weight ethylene / 1-hexene copolymer, ultra high molecular weight ethylene / 1-octene copolymer, ultra high molecular weight ethylene / 1-decene copolymer, etc. 20, preferably 4-10 α-
An ultra high molecular weight ethylene / α-olefin copolymer with an olefin can be exemplified. In this ultra high molecular weight ethylene / α-olefin copolymer, α-C3 or more
The olefin is contained in an amount of 0.1 to 20, preferably 0.5 to 10, more preferably 1 to 7 per 1000 carbon atoms of the polymer.

The drawn filament obtained from such an ultrahigh molecular weight ethylene / α-olefin copolymer is particularly excellent in impact resistance and creep resistance as compared with the drawn filament obtained from an ultrahigh molecular weight polyethylene.

The ultrahigh molecular weight polyolefin or ultrahigh molecular weight ethylene / α-olefin copolymer constituting the stretched filament has an intrinsic viscosity [η] of 5 dl / g or more, preferably 7 to 30 d.
It is in the range of 1 / g, and the drawn filament obtained from this copolymer has excellent mechanical properties or heat resistance. That is, the molecular terminals do not contribute to the fiber strength, and the number of the molecular terminals is the reciprocal of the molecular weight (viscosity). Therefore, the one having a large intrinsic viscosity [η] gives a high strength.

The density of the drawn filament is 0.940 to 0.990 g / cm ^3, preferably 0.960 to 0.985 g / cm ³ . Here, the density is the conventional method (A
According to STM D 1505), it was measured by the density gradient tube method. The density gradient tube at this time was prepared by using carbon tetrachloride and toluene, and the measurement was performed at room temperature (23 ° C).

The dielectric constant (1KHz, 23 ℃) of the drawn filament is 1.4 to 3.0
Preferably 1.8 to 2.4, positive tangent (1KHz, 80 ℃)
Is 0.05 to 0.008%, preferably 0.040 to 0.010%.
Here, the dielectric constant and the tangent tangent were measured by ASTM D 150 using a film-shaped sample prepared by densely aligning fiber- and tape-shaped molecular orientation bodies in one direction.

The draw ratio of the drawn filament is 5 to 80 times, preferably 10
~ 50 times.

The degree of molecular orientation in the drawn filament can be known by an X-ray diffraction method, a birefringence method, a fluorescence polarization method or the like. For example, Yukichi Kure and Teruichiro Kubo: Orientation degree by half width described in detail in Journal of Industrial Chemistry, Vol. 39, p. 992 (1939),
Ie the formula (In the formula, H ° is the half-value width (°) of the intensity distribution curve along the Debye ring of the strongest paratropic plane on the equator.) The degree of orientation (F) defined by is 0.90 or more, especially 0.95 or more. It is desirable from the viewpoint of mechanical properties that the molecules are oriented so that

Furthermore, the drawn filament has excellent mechanical properties, and has an elastic modulus of 20 GPa or more, particularly 30 GPa or more, and a tensile strength of 1.2 GPa or more, particularly 1.5 GPa or more.

Impulse voltage breakdown value of drawn filament is 110-250
KV / mm It is preferably 150 to 220 KV / mm. The impulse voltage breakdown value was measured by using a sample similar to the case of the dielectric constant, pressurizing it while applying a negative polarity impulse in 2 KV / 3 times steps with a JIS type electrode of brass (25 mmφ) on a copper plate.

When the drawn filament is an ultrahigh molecular weight ethylene / α-olefin copolymer drawn filament, the drawn filament is characterized in that impact resistance, breaking energy and creep resistance are remarkably excellent.
The characteristics of the drawn filaments of these ultra-high molecular weight ethylene / α-olefin copolymers are represented by the following physical properties.

The breaking energy of the drawn filament of the ultrahigh molecular weight ethylene / α-olefin copolymer is 8 kg · m / g or more, preferably 10 kg · m / g or more.

In addition, the drawn filament of the ultrahigh molecular weight ethylene / α-olefin copolymer has excellent creep resistance. In particular, it is outstandingly excellent in creep resistance at high temperatures, which is equivalent to the accelerated condition of room temperature creep property. The load is 30% breaking load, the ambient temperature is 70 ° C, and the elongation after 90 seconds (%)
The creep obtained as is less than 7%, especially less than 5%, and the creep speed (ε, se after 90 to 180 seconds)
c ^-1 ) is 4 × 10 ^-4 sec ^-1 or less, especially 5 × 10 ^-5 sec ^-1 or less.

Among the drawn filaments, ultra high molecular weight ethylene / α-
The stretched filament of the olefin copolymer has the above-mentioned room temperature physical properties, but in addition to these room temperature physical properties, if it also has the following thermal properties, the above room temperature physical properties are further improved, It is also preferable because it has excellent heat resistance.

A drawn filament of an ultra-high molecular weight ethylene / α-olefin copolymer has a heat of fusion based on at least one crystal melting peak (Tp) at a temperature that is at least 20 ° C higher than the crystal melting temperature (Tm) of the copolymer. Is 15% or more, preferably
20% or more, especially 30% or more.

Original crystal melting temperature (Tm) of ultra high molecular weight ethylene copolymer
Can be determined by a method in which the drawn filament is completely melted and then cooled, the molecular orientation in the drawn filament is relaxed, and then the temperature is raised again, that is, a second run in a so-called differential scanning calorimeter.

To further explain, in the drawn filament, the crystal melting peak does not exist at all in the original crystal melting temperature range of the above-mentioned copolymer, or if it exists, it slightly exists as tailing. The crystal melting peak (Tp) is generally in the temperature range Tm + 20 ° C to Tm + 50 ° C, especially Tm + 20 ° C to Tm
It is usually represented in the region of + 100 ° C, and this peak (Tp) is often represented as a plurality of peaks within the above temperature range. That is, this crystal melting peak (Tp)
Is often separated into two parts, a high temperature side melting peak (Tp ₁ ) in the temperature range Tm + 35 ° C. to Tm 100 ° C. and a low temperature side melting peak (Tp ₂ ) in the temperature range Tm + 20 ° C. to Tm + 35 ° C. Depending on the manufacturing conditions of the drawn filament,
Tp ₁ and Tp ₂ may consist of multiple peaks.

These high crystal melting peaks (Tp ₁ , Tp ₂ ) significantly improve the heat resistance of the drawn filaments of ultra-high molecular weight ethylene / α-olefin copolymers, and the strength retention or elasticity after high temperature heat history. It seems to contribute to the retention rate.

The total amount of heat of fusion based on the high temperature side melting peak (Tp ₁ ) in the temperature range Tm + 35 ° C to Tm + 100 ° C is
It is preferably 1.5% or more, particularly 3.0% or more.

As long as the total heat of fusion based on the high-temperature side melting peak (Tp ₁ ) satisfies the above value, if the high-temperature side melting peak (Tp ₁ ) does not appear as a major peak, that is, the small peak Even if it has an aggregate or a broad peak, the heat resistance may be slightly lost, but the creep resistance is excellent.

The melting point and the heat of crystal fusion were measured by the following methods.

The melting point was measured by a differential scanning calorimeter as follows. As the differential scanning calorimeter, DSCII type (manufactured by Perkin Elmer) was used. The sample was constrained in the orientation direction by winding about 3 mg around an aluminum plate having a thickness of 4 mm × 4 mm and a thickness of 0.2 mm. Then, the sample wound around the aluminum plate was enclosed in an aluminum pan to obtain a measurement sample. In addition, the same aluminum plate as that used for the sample was normally enclosed in an empty aluminum pan to be put in the reference holder to balance the heat. First, the sample is about 1 at 30 ℃
The temperature was maintained for 10 minutes, and then the temperature was raised to 250 ° C. at a temperature rising rate of 10 ° C./minute to complete the first melting point measurement at the time of heating. Continue
The sample was held at 250 ° C. for 10 minutes, then cooled at a cooling rate of 20 ° C./min, and further held at 30 ° C. for 10 minutes. Next, the second heating was carried out at a heating rate of 10 ° C./min to 250 ° C., and the melting point measurement at the second heating (second run) was completed. At this time, the maximum value of the melting peak was taken as the melting point. When it appears as a shoulder, a tangent line was drawn between the inflection point on the low temperature side and the inflection point on the high temperature side of the shoulder, and the intersection was taken as the melting point.

Also, from the melting point (Tm) of the original crystal melting point (Tm) of the ultra-high molecular weight ethylene copolymer, which is obtained by connecting the points of 60 ° C and 240 ° C of the endothermic curve to the straight line (baseline) and the main melting peak at the second heating A perpendicular line is drawn at a point higher by ℃, the low temperature side surrounded by these is based on the original crystal melting (Tm) of the ultra high molecular weight ethylene copolymer, and the high temperature side expresses the function of the drawn filament. Based on the crystal melting (Tp), the heat of fusion of each crystal was calculated from these areas. Also, the heat of fusion based on the melting of Tp ₁ and Tp ₂ was measured according to the method described above, and the perpendicular line from Tm + 20 ℃ and Tm
A portion surrounded by a vertical line from + 35 ° C. was taken as the amount of heat of fusion based on the melting of Tp ₂ , and a high temperature side portion was similarly calculated as the amount of heat of fusion based on the melting of Tp ₁ .

The drawn filament of ultra-high molecular weight ethylene / α-olefin copolymer has a strength retention of 95% or more and an elastic modulus retention of 90% or more, especially 95% after being subjected to a heat history of 170 ° C. for 5 minutes. % Or more, and it has excellent heat resistance that is not found in conventional drawn filaments of polyethylene.

Method for producing molecularly oriented molded body of ultra-high molecular weight polyolefin As a method for obtaining the above-mentioned stretched ultra-high molecular weight polyolefin having high elasticity and high tensile strength, for example, JP-A-56
-15408, JP-A-58-5228, JP-A-59-1
As described in detail in JP 30313, JP-A-59-187614, etc., an ultrahigh molecular weight polyolefin is made into a dilute solution, or a low molecular weight compound such as paraffin wax is added to the ultrahigh molecular weight polyolefin. A method of improving the stretchability of the ultrahigh molecular weight polyolefin and stretching it at a high ratio can be exemplified.

Method for Producing Molecularly Oriented Molded Body of Ultra High Molecular Weight Ethylene / α-Olefin Copolymer Raw materials and production method will be described below in this order.

The raw material ultrahigh molecular weight ethylene / α-olefin copolymer is obtained by slurry-polymerizing ethylene and an α-olefin having 3 or more carbon atoms in, for example, an organic solvent using a Ziegler catalyst.

As the α-olefin having 3 or more carbon atoms, propylene,
Butene-1, pentene-1,4-methylpentene-1, hexene-1, heptene-1, octene-1 and the like are used, but among them, butene-1, 4-methylpentene-1, hexene-1, Octene-1 and the like are preferable. Such an α-olefin has a carbon number of the obtained copolymer.
Copolymerized with ethylene so that it is present in the above amounts per 1000 pieces. Further, the ultrahigh molecular weight ethylene / α-olefin copolymer used as a base for producing the molecular oriented material should have a molecular weight corresponding to the above-mentioned intrinsic viscosity [η].

Α- in Ultra High Molecular Weight Ethylene / α-Olefin Copolymer
The quantification of the olefin component is performed by an infrared spectrophotometer (manufactured by JASCO Corporation). Specifically, the absorbance at 1378 cm ^-1 , which represents the bending vibration of the methyl group of the α-olefin incorporated in the ethylene chain, was measured by an infrared spectrophotometer, and this value was measured in advance in the ¹³ C nuclear magnetic field. In the resonance device,
The amount of α-olefin in the ultrahigh molecular weight ethylene / α-olefin copolymer is quantified by converting it into the number of methyl branches per 1000 carbon atoms using a calibration curve prepared using a model compound.

Manufacturing Method When manufacturing a molecular oriented body from the above ultrahigh molecular weight ethylene / α-olefin copolymer, a diluent is added to the copolymer. As such a diluent, for example, various wax-like substances having compatibility with the ultra high molecular weight ethylene copolymer are used.

As the wax as the diluent, specifically, an aliphatic hydrocarbon compound or a derivative thereof is used.

As such an aliphatic hydrocarbon compound, a compound mainly composed of a saturated aliphatic hydrocarbon compound and usually having a molecular weight of 2000 or less, preferably 1000 or less, more preferably 800 or less, called a paraffin wax is used.

Specific examples of such an aliphatic hydrocarbon compound include n-alkanes having 22 or more carbon atoms such as docosane, tricosane, tetracosane, and triacontane, or a mixture thereof with a lower n-alkane containing them as a main component, petroleum oil. So-called paraffin wax separated and purified from ethylene, a low molecular weight polymer obtained by copolymerizing ethylene or ethylene with other α-olefins, medium-low pressure polyethylene wax, high-pressure polyethylene wax, ethylene copolymer wax or medium wax -Waxes obtained by reducing the molecular weight of polyethylene such as low-pressure polyethylene and high-pressure polyethylene by thermal degradation, oxides of these waxes, oxidized waxes such as maleic acid-modified waxes, and maleic acid-modified waxes are used.

The aliphatic hydrocarbon compound derivative is, for example, one or more, preferably 1 to 2 at the terminal or inside of the aliphatic hydrocarbon group (alkyl group, alkenyl group).
A compound having a functional group such as a carboxyl group, a hydroxyl group, a carbamoyl group, an ester group, a meltcapto group, and a carbonyl group, and particularly preferably one having 8 or more carbon atoms, preferably 12 to 50 carbon atoms or 130 to 2000 molecular weight. Preferably, 200 to 800 fatty acids, aliphatic alcohols, fatty acid amides, fatty acid esters, aliphatic mercaptans, aliphatic aldehydes and aliphatic ketones are used.

As such an aliphatic hydrocarbon compound derivative, specifically, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, fatty acids such as oleic acid, lauric alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, etc. The fatty acid amides such as aliphatic alcohols, caprinamide, laurinamide, palmitinamide, stearylamide, and fatty acid esters such as stearyl acetic acid ester are used.

The ultra high molecular weight ethylene / α-olefin copolymer and the diluent are different depending on their types, but generally 3:
Used in a weight ratio of 97 to 80:20, in particular 15:85 to 60:40.
When the amount of the diluent is lower than the above range, the melt viscosity becomes too high, which makes melt-kneading and melt-molding difficult, and the resulting molded article is significantly roughened, and stretch breakage is likely to occur. On the other hand, when the amount of the diluent is more than the above range, the melt-kneading becomes difficult and the stretchability of the obtained molded product becomes poor.

Melt kneading is generally carried out at temperatures of 150 to 300 ° C, especially 170 to 270 ° C. If the temperature is lower than the above range, the melt viscosity is too high, which makes melt molding difficult. If the temperature is higher than the above range, ultra high molecular weight ethylene / α due to thermal degradation is generated.
-The molecular weight of the olefin copolymer decreases, and it becomes difficult to obtain a molded product having excellent high elastic modulus and high strength. The blending may be performed by dry blending with a Henschel mixer, a V-type blender, or the like, or using a single-screw extruder or a multi-screw extruder.

Melt molding of a dope (stock solution for spinning) composed of an ultrahigh molecular weight ethylene / α-olefin copolymer and a diluent is generally carried out by melt extrusion molding. Specifically, a filament for drawing is obtained by melt-extruding the dope through a spinneret. At this time, a draft, that is, stretching in a molten state, can be added to the melt extruded from the spinneret. The ratio of the extrusion speed V ₀ of the molten resin in the die orifice and the winding speed V of the unstretched material that has been cooled and solidified can be defined as the draft ratio by the following formula.

Draft ratio = V / V ₀ (2) Such a draft ratio varies depending on the temperature of the mixture, the molecular weight of the ultra high molecular weight ethylene copolymer, and the like, but is usually 3 or more, preferably 6 or more. .

Next, the ultra high molecular weight ethylene / α thus obtained
-Stretching the unstretched molded product of the olefin copolymer. The stretching is performed so that the unstretched molded product obtained from the ultra-high molecular weight ethylene / α-olefin copolymer is effectively imparted with at least uniaxial molecular orientation.

The stretching of an unstretched molded article obtained from an ultrahigh molecular weight ethylene / α-olefin copolymer is generally 40 to 160 ° C, particularly 80
It is carried out at a temperature of ~ 145 ° C. As a heat medium for heating and holding the unstretched molded article at the above temperature, air, steam,
Any liquid medium can be used. However, as a heat medium, a solvent capable of eluting and removing the above-mentioned diluent, and a liquid medium whose boiling point is higher than the melting point of the molded body composition, specifically, decalin, decane,
When the stretching operation is performed using kerosene or the like, it is possible to remove the above-mentioned diluent, and it is possible to achieve a high stretching ratio without causing uneven stretching during stretching.

The means for removing the diluent from the ultrahigh molecular weight ethylene / α-olefin copolymer is not limited to the above method, and a method of stretching the unstretched material after treating it with a solvent such as hexane, heptane, hot ethanol, chloroform, benzene, or the like, A stretched product having a high elastic modulus and high strength can also be obtained by removing the diluent in the molded product by a method of treating the stretched product with a solvent such as hexane, heptane, hot ethanol, chloroform or benzene.

The stretching operation can be carried out generally or in multiple stages of two or more. Although the draw ratio depends on the desired molecular orientation and the effect of improving the melting temperature associated therewith, it generally ranges from 5 to 5.
It is 80 times, preferably 10 to 50 times.

Generally, it is preferable to carry out the stretching operation by multi-stage stretching of two or more stages, and in the first stage, the stretching operation is performed while extracting the diluent in the extrusion-molded product at a relatively low temperature of 80 to 120 ° C, and the second stage. After that, it is preferable to perform the stretching operation of the molded body at a temperature of 120 to 160 ° C. and a temperature higher than the first stage stretching temperature.

In the case of the uniaxial stretching operation, tensile stretching may be performed between rollers having different peripheral speeds.

The drawn filaments thus obtained can be heat treated, if desired, under restraint conditions. This heat treatment is generally 140-180 ℃, preferably at a temperature of 150-175 ℃,
It can be carried out for 1 to 20 minutes, preferably 3 to 10 minutes.
By heat treatment, crystallization of the oriented crystal part further progresses, shift of the crystal melting temperature to a high temperature side, improvement of strength and elastic modulus,
Further, the creep resistance at high temperature is improved.

In the present invention, a plurality of drawn filaments of such ultra-high molecular weight polyolefin or ultra-high molecular weight ethylene / α-olefin copolymer is usually bundled to form a drawn multi-filament, for example, the dental floss shown in FIG. 6 is preferably used. At this time, twisting can be applied in order to prevent the monofilament from coming loose, and wax can be used in order to further improve lubricity after twisting. In addition, fragrances such as mint can be used to further improve the feeling of use.

Effect of the Invention According to such an interdental cleaning tool, the extending direction of the dental floss can be freely changed with respect to any one of the handle parts by changing the crossing angle of the first and second handle parts. For,
Both front and back teeth can be easily cleaned.

In addition, dental floss has an intrinsic viscosity [η] of at least
Since it was composed of a dental floss consisting of drawn filaments (stretched multifilaments) of multiple ultra-high molecular weight olefin (co) polymers of 5 dl / g, when the dental floss consisting of this multifilament was used, Since the filament has excellent tensile strength and impact resistance, as well as excellent creep resistance, water resistance and self-lubricating property, it is possible to strongly stretch this dental floss between the protruding parts of the interdental cleaning tool. It is possible, and even if this dental floss is inserted into the interdental part and passed between the teeth, the dental floss is not cut. Also, ultra high molecular weight olefin (co) polymers, that is, ultra high molecular weight polyolefin and ultra high molecular weight ethylene
As an original property of the α-olefin copolymer, it is rich in self-lubricating property and has an effect of being excellent in feeling during use.

[Brief description of drawings]

FIG. 1 is a side view of an interdental cleaning tool according to an embodiment of the present invention,
2 is a view taken along the line II-II shown in FIG. 1, and FIG. 3 is a perspective view of the interdental cleaning tool. 2 ... Interdental cleaning tool, 4a, 4b ... Projection part, 6 ... Dental floss, 8 ... Handle part, 8a ... 1st handle part, 8b ... 2nd
Handle part, 8c …… Hinge part.

Claims (1)

[Scope of utility model registration request] 1. A pair of protrusions are formed on the handle portion at a predetermined distance from each other, and a plurality of ultra-high molecular weight olefins having an intrinsic viscosity [η] of at least 5 dl / g (co ) Dental floss composed of stretched filaments of a polymer is stretched, and the handle portion includes a first handle portion, a second handle portion, and a first handle portion.
And a hinge portion for changing the crossing angle of the second handle portion, and the dental floss can be rotatably moved with respect to either one of the first and second handle portions. Interdental cleaning tool.