JP5992700B2 - Interdental floss thread - Google Patents

Description

  The present invention relates to an interdental floss thread.

In recent years, research on the relationship between bacteria in the oral cavity and systemic diseases has progressed, and it has become clear that the environment in the oral cavity has a major impact on general health and overall life. Along with this, daily oral care is becoming more and more important and has been widely practiced not only in medical and nursing care.
In particular, it is a site where an oral biofilm (synonymous with plaque or plaque) is easily attached between teeth, and tooth decay and periodontal disease are likely to occur. Oral biofilms are composed of water and organic substances, and most of the organic substances are bacteria (ordinary oral bacteria) and their metabolites. The bacteria change depending on the hygiene of the oral cavity, causing bad breath and periodontal diseases. It becomes.
In general, toothbrushing is effective to maintain good dental hygiene. However, it is difficult for the toothbrush to reach the gap between the teeth. Use is effective.

  As such interdental floss, usually a bundle of nylon filament raw yarns having a round cross section with a single yarn diameter of around 30 μm (single yarn fineness of 4 to 12 dtex), or a tape using polytetrafluoroethylene (PTFE) monofilament yarn Many are used. Since the former is thick, it is difficult to insert between the teeth because the thread is thick, and it cannot reach the narrow space between the teeth, and the oral biofilm cannot be sufficiently wiped off. In the latter, it is easy to insert between the teeth, but it is difficult to fit the delicate unevenness of the teeth, and this also does not sufficiently wipe the oral biofilm between the teeth.

  Patent Document 1 describes a dental floss composed of 144 filaments having a thickness of 1 to 50 μm in a multilobal cross section in order to increase the removal efficiency of an intraoral biofilm.

  Patent Document 2 describes a dental floss in which a nylon filament is textured and a chemotherapeutic preparation is contained in a number of yarns using the properties of the processed yarn.

Japanese National Patent Publication No. 11-506672 Japanese Patent No. 3675822

However, in the floss described in Patent Document 1, a fiber cross section having three leaves is shown for improving the comfort and cleaning characteristics. However, each leaf portion is elongated, and thin teeth and teeth like a flossing are shown. When a thread passes between them, the adjacent two leaves overlap with each other due to the pressure, and it becomes as if it was a single, vertically long, flat thread, and it is not effective for scraping the oral biofilm just by stroking the tooth surface.
Patent Document 1 only describes an example of a floss having 144 filaments, and the total fineness suitable for the floss is 500 to 700 D (556 to 778 dtex). From these, the single yarn fineness of the filament is also 3.9 to 5.4 dtex, and the floss that converges them is difficult to enter between the interdental and gingival borders, and the oral biofilm on the tooth surface unevenness Inappropriate for removal of the teeth, it may be thick and difficult to insert during interdental insertion.

  Patent Document 2 uses a normal round cross-section nylon filament, and when used for everyday flossing, the contact between teeth is strong at the time of insertion, and it reaches a narrow space between the teeth and the teeth and gums. Therefore, there is no satisfaction that the oral biofilm is taken for the user, and it is inferior to the feeling of use.

  Accordingly, an object of the present invention is to provide a floss for interdental floss that has a better efficiency of removing intraoral biofilm and a better wiping effect than conventional products. It is another object of the present invention to provide an interdental floss thread that is soft to the teeth and gums during actual flossing and is optimal for actual use.

The object of the present invention is an interdental floss yarn composed of a modified multifilament having a multi-leaf shape having a cross-sectional shape of 3 to 6 leaves, and the single yarn fineness of the modified cross-section multifilament is 0.5 to 4 dtex, the total fineness is 400 to 1100 dtex , the length of the maximum width of the leaf part is the same as the length of the line connecting the most concave adjacent parts of the filament surface, and the most concave of the filament surface The ratio of the length (a) in the longitudinal direction of the leaf part, which is the length from the center of the line connecting adjacent points to the tip of the leaf including the line, and the length (b) of the maximum width (a / B) is achieved with an interdental floss thread characterized in that it is between 0.5 and 1.5.

Moreover, it is suitable that the modified cross-section multifilament is a false twisted yarn.
Moreover, it is suitable that the irregular-shaped multifilament is a twisted yarn twisted together with a twist number of 50 to 250 t / m.
Moreover, you may combine the ultra fine multifilament whose single yarn fineness is 2 dtex or less.

When the interdental floss yarn of the present invention is an interdental floss, the biofilm removal efficiency in the oral cavity is better than the conventional one, and the wiping effect is good. Is soft and has a good feeling of use.
In addition, the ratio of leaf-shaped leaves (a / b) is small, and there is little deformation even when passing through a narrow gap (contact) between teeth. It can be cut gently and scraped firmly, and also keeps a lot of gaps between filaments, so by removing the scraped oral biofilm into the gap and not releasing it, it is easy to wipe between teeth It becomes a floss.
When used in the oral cavity, moisture such as saliva can easily enter into the gaps between the filaments by capillary action, and comfort during use is also improved.
In addition, filaments with small single yarn fineness penetrate well into the interdental and gingival borders, reach the oral biofilm in the corner, and oral biofilms in places that could not be removed before It can be effectively scraped off.

It is explanatory drawing which shows an example of the fiber cross-sectional shape of the thread | yarn for interdental floss of this invention. It is an electron micrograph of the fiber cross section of an example of the thread for interdental floss of this invention. It is an electron micrograph which shows a mode that the thread for interdental floss of this invention shown in FIG. 2 becomes a spiral shape in a longitudinal direction. It is explanatory drawing which shows an example of the fiber cross-sectional shape of the other thread | yarn used according to the thread | yarn for interdental floss of this invention. It is explanatory drawing which shows the outline of the apparatus used in order to evaluate the removal efficiency of the intraoral biofilm of this invention Example.

  Hereinafter, the present invention will be described in detail.

The present invention relates to a floss for interdental floss comprising a multi-filament having a multi-leaf shape having a cross-sectional shape of 3 to 6 leaves, and the single-fiber fineness of the multi-filament having a cross-section is 0.5 to 4 dtex, the total fineness 400 to 1100 dtex , the maximum width of the leaf portion is the same as the length of the line connecting the most concave adjacent portions on the filament surface, and the adjacent concave portion on the filament surface The ratio (a / b) of the length (a) in the longitudinal direction of the leaf portion, which is the length from the center of the line connecting the lines to the tip of the leaf including the line, and the length (b) of the maximum width is It is a thread for interdental floss characterized by being 0.5-1.5.

  The single yarn fineness of the modified multifilament according to the present invention needs to be 0.5 to 4 dtex, preferably 0.6 to 3.7 dtex, more preferably 1 to 2 dtex.

If the single yarn fineness is too large, the surface area of the unit fibers when using interdental floss will be small, and if the interdental floss itself is not thickened, it will be difficult to obtain sufficient wiping properties, and a sufficient wiping effect will be obtained. If it does so, interdental floss itself will become thick, and it will be difficult to insert between teeth. Moreover, once the oral biofilm or food piece is scraped, it cannot be taken in between the filament segments, and the oral biofilm adheres again to the oral cavity such as teeth and gums. On the other hand, if the filament has a single fiber fineness of 4 dtex or less, the biofilm in the oral cavity is scraped so as to be scraped off with a large number of thin filaments, and pushed up into the filament group to be captured. The captured biofilm in the oral cavity is stored in a large amount in a large number of narrow spaces between the filaments, preventing reattachment, and has a good scraping effect that cannot be obtained with an interdental floss using ordinary multifilaments. can get.
Further, when inserted between the teeth, the volume of the portion inserted between the narrow teeth and the teeth (contacts) is reduced due to the aggregate of fine filaments. According to the present invention, insertion between the teeth is very easy even when the interdental floss has a bulky appearance.
Further, in the case of an interdental floss having a large appearance, a wax coating treatment or the like is usually performed in order to obtain easy insertion between teeth. In this invention, even if it is a case where it is a case where it is set as the interdental floss whose appearance is comparatively thick, it can insert smoothly between teeth, without giving a wax coating.
Note that the interdental floss yarn of the present invention may be wax-coated depending on the purpose when flossing.

  In addition, the total fineness of the modified cross-section multifilament according to the present invention is required to be 400 to 1100 dtex from the viewpoint of easy entry between teeth, preferably 500 to 1000 dtex, more preferably 600 to 900 dtex. is there.

Moreover, the cross-sectional shape of the irregular cross-section multifilament which concerns on this invention is a multi-leaf shape of 3-6 leaves, for example, the cross-section multifilament 1 of a cross-section as shown in FIG. 1 is mentioned.
Further, as shown in FIG. 1, the ratio (a) / (b) of the length (a) in the longitudinal direction of the leaf portion to the length (b) of the maximum width is 0.5 to 1.5. is necessary. In FIG. 1, auxiliary lines indicated by dotted lines connect adjacent locations on the filament surface that are the most concave.
In the present invention, the length (b) of the maximum width of the leaf portion is the same as the length of the line connecting the most concave adjacent portions on the filament surface.
The length (a) in the longitudinal direction of the leaf portion refers to the length from the center of the line connecting the most concave adjacent portions on the filament surface to the tip of the leaf including the line.
Also,
If the ratio (a / b) of the multilobal leaf portion is within the above range, the deformation of the filament is small even if it passes through a narrow gap (contact) between the teeth, so that the oral bio Can be effectively cut into the film mass and scraped firmly,
Since many gaps between the filaments can be maintained, the interdental floss with good wiping efficiency is obtained by taking the intraoral biofilm that has been scraped off into the gap and not releasing it.
FIG. 2 is an electron micrograph showing a fiber cross-sectional shape of an example of an interdental floss yarn of the present invention.
Further, the ratio (a / b) of the leaf portions in one filament may be the same or different.

  Examples of the modified cross-section multifilament polymer used in the interdental floss yarn of the present invention include, for example, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon 6 and nylon 66, and polyolefins such as polypropylene and polyethylene. Is mentioned.

The interdental floss yarn of the present invention is preferably a processed yarn from the viewpoint of softening the contact with the teeth and gums and efficiently scraping off the oral biofilm.
As the processed yarn, usually, a yarn imparted with bulkiness using thermoplasticity such as synthetic fiber is shown, and as the processing method, for example, twisting, heat fixing, untwisting method, false twisting method, rubbing method, indentation Method, molding method, air injection method, composite crimping method and the like. As the processed yarn used in the present invention, a false twisted yarn obtained by a false twisting method is preferable.

  Interdental floss yarn is heat-set in a twisted state as false twisted yarn, and when the twist is released, the filament is crimped, and volume and stretchability are added. Therefore, it has softness around the teeth and gums and ease of insertion between narrow teeth. In addition, since the irregular cross-sectional shape is fixed and the shape is clear, the edge of the filament becomes clear.

  Moreover, it is suitable for the interdental floss yarn of the present invention to be a twisted twisted yarn, whether raw yarn or false twisted yarn is used. The twisted yarn has a beautiful appearance, can be easily inserted into teeth, and can be easily used without fouling during flossing. In addition, a gentle spiral edge on the side of the yarn can be effectively cut into the mass of the oral biofilm and scraped off firmly.

When twisting together, the number of twists is preferably 50 to 250 t / m, more preferably 75 to 200 t / m, and still more preferably 80 to 150 t / m.
Under such conditions, the contact with the gums does not become too strong, the interdental floss is easy to insert into the teeth, the flossing is smooth, and even when the thread itself is used as the interdental floss, it is more round and clean It becomes an interdental floss of appearance and is particularly preferable.

As a suitable example of the above-mentioned twisted yarn, a twisted yarn obtained by twisting and twisting a plurality of deformed cross-section multifilaments subjected to false twisting may be mentioned. In this case, by appropriately setting the conditions of false twisting and double twisting, even in the case of an interdental floss consisting of the yarn itself, that is, the yarn bundle itself, the space is held together, and each filament is not flat, Interdental floss with a beautiful appearance can be obtained.
The twisting direction may be false twisted in one direction and then a plurality of twisted lines may be twisted in the same direction, or may be twisted in one direction and then twisted in the opposite direction.

  The above-mentioned twisted yarn is obtained by, for example, subjecting a deformed cross-section multifilament to false twisting at a false twist number of 2700 to 3700 t / m at about 150 to 185 ° C., and drawing a plurality of obtained false twisted yarns. It is obtained by aligning and twisting with the number of twists.

  When the multifilaments are twisted in this way, the yarns are more conjugative and convergent, and the yarns involved in the thin yarns are easy to handle without twisting. In addition, the oral biofilm can be reliably supplemented between the crimped filaments, and the interdental floss is excellent in usability and wiping effect.

  FIG. 3 is a micrograph of an example of the interdental floss yarn of the present invention as seen from the longitudinal direction. The side surface is gently twisted. The inner biofilm can be scraped off like a knife.

The interdental floss yarn preferably has an elongation rate of 10 to 40% and an expansion / contraction restoration rate of 5 to 40%. Within this range, the yarn has conjugation properties, the combined yarn does not fall apart, and there is no inconvenience such as part of the yarn being caught on the repaired part of the tooth, so it can be used as a floss as it is. It is suitable for. Moreover, since it has moderate elasticity, it has the characteristic that the contact with a tooth | gum and a gum | gum is soft at the time of the wiping of a tooth, and it is suitable as an interdental floss.
In addition, elongation rate is the elongation rate measured by the constant-speed tension type | mold tester of the holding | grip space | interval 30cm and the tensile speed of 30 +/- 3cm / min of a JIS L1013 8.5.1 standard time test. The expansion / contraction recovery rate is a value measured according to JIS L1013 8.12.

  The interdental floss yarn of the present invention may be composed only of a modified cross-section multifilament, but depending on the purpose, other than a multi-filament formed from a round cross-section yarn, a split composite yarn, etc. May be combined.

In the present invention, ultrafine multifilaments may be used in combination with the irregular shaped multifilament. When obtaining softness and good usability as the interdental floss, when scraping to a finer location, it is preferable to use an ultrafine multifilament in combination.
The cross-sectional shape of the fiber of the ultrafine multifilament is, for example, as shown in FIG. 4, and the radial segment A of the single filament 2 of the ultrafine multifilament split from the split composite multifilament, and the radial segment What consists of the complementary segment B to complement is suitable. Each segment A, B is formed with a number of sharp edges along the longitudinal direction of the filament (the portion indicated by S in FIG. 4 and the portion having the same shape is omitted), so that the oral biofilm is efficiently scraped, The reattachment of the oral biofilm is also prevented, and an excellent wiping effect can be obtained.
In the case of such a radial segment A and a complementary segment B, it is preferable that the radial segment A is obtained by dividing the complementary segment B into three or more. The upper limit is preferably about 16. Particularly preferably, it is divided into 4 to 8 pieces.

  Splitting of the split composite multifilament can be performed by removing one component by dissolution or decomposition, swelling with a swelling agent, or shrinking with a shrinking agent. Further, it is possible to perform stress splitting in which a plurality of components are physically divided by friction or impact. In the present invention, stress splitting is preferred. More specifically, for example, splitting by hitting or stroking, splitting by washing with water, splitting by deflaming in the dyeing process, gear crimp, Examples thereof include a split fiber method by performing processing such as knitted knitting and false twisting. Of these, split fiber by false twisting is preferable.

  When stress splitting is performed by false twisting, the degree of shape loss of each segment is low and it is easy to maintain the atypical degree of the fiber cross section, and the interdental floss wiping effect can be further enhanced. Moreover, in the false twisting, heat setting is performed in a state where twist is applied, and the twist is released, so that the filament can be crimped. As a result, the interdental floss can be given volume and stretchability, so that the contact with the teeth and gums becomes soft, and insertion between narrow teeth becomes easy and the feeling of use is excellent. Furthermore, since it can be easily obtained without complicated processes, it is possible to reduce the use of extra drugs and the like.

  The average single yarn fineness of the ultrafine multifilament after splitting the split composite multifilament is preferably 2 dtex or less from the viewpoint of obtaining a good feeling of use and a wiping effect. More preferably, it is 1.1 dtex or less, More preferably, it is 0.75 dtex or less. The lower limit is preferably 0.1 dtex.

  Examples of the polymer used for the split composite multifilament include, for example, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon 6 and nylon 66, and polyolefins such as polypropylene and polyethylene. In the case of splitting the stress, a combination of polymers such as polyester and polyamide, polypropylene and polyamide, polyethylene and polyamide is preferably used.

  Moreover, the combination of these polymers has a constant difference in heat shrinkage (JISL1013 8.18.1 hot water shrinkage (b) by filament shrinkage method (b method)) when each polymer is a single yarn. A polymer in the range (eg 2 to 10%) is preferred.

  As a particularly preferred combination, when the radial segment is polyamide and the complementary segment is polyester, the polyamide portion is soft, and the radial segment softens the teeth and gums and hard complementary shape. Since the polyester part plays a role of scraping off the oral biofilm, the wiping effect is further improved, and a wiping feeling and a feeling of use can be obtained.

The mixing ratio of the irregular shaped multifilament and the ultrafine multifilament is preferably 1: 1 to 3: 1 (fineness ratio).
By aligning and twisting the odd-shaped cross-section multifilament and the ultrafine multifilament, it is possible to obtain an interdental floss yarn.

In the interdental floss according to the present invention, the interdental floss yarn may be used as it is or may be in a pick form. Further, the interdental floss yarn may be knitted and woven to be used as a knitted fabric or a woven fabric. Especially, the manufacturing process is simple, the extra components necessary during the manufacturing process are reduced, it can be suitably used for oral cavity, and it is easy to provide at low cost. It is preferable not to use the knitted or knitted fabric, but to use it for the interdental floss as it is as a yarn bundle.
When the yarn bundle is used as it is, the yarn bundle may be wound around a finger, used in a floss holder, or used as a pick floss.

Example 1
84 dtex / 72f polyester multifilament (Soarion (registered trademark) Y manufactured by KB Seiren Co., Ltd.) having the cross-sectional shape of FIG. 1 was prepared. This filament was twisted in the Z direction at a spindle rotation speed of 300,000 rpm, a false twist number of 3,000 t / m, and a set temperature of 180 ° C. to obtain a false twisted yarn. Next, eight false twisted yarns obtained were aligned, twisted at 120 t / m in the S direction, and heat set at 60 ° C. for 40 minutes to obtain a 686 dtex / 576 f double twisted yarn, which was directly interdental Floss (test yarn) was used.
When the cross section of the above-mentioned twisted yarn was calculated from a photograph taken with an electron microscope, the leaf part ratio (a / b) was in the range of 1.1 to 1.4. In addition, the elongation rate was 29.4%, and the expansion / contraction restoration rate was 15.8%.
The appearance of the obtained interdental floss seemed to have a finer thread than the conventional one. In addition, the interdental floss was widely applied between the teeth, the wiping feeling was excellent, and it was wiped off firmly.
Moreover, the removal efficiency and usability | use_condition of the following intraoral biofilm were evaluated.

(Example 2)
84 dtex / 28 f split-type composite fiber filament (radial A component: polyamide (nylon 6), single yarn fineness 0.75 dtex, four complementary B components: polyester (polyethylene terephthalate) ), Single yarn fineness 0.56 dtex) (Berima (registered trademark) manufactured by KB Seiren). This filament was twisted in the S direction at 3,600 t / m and a set temperature of 175 ° C. to obtain a false twisted yarn.
Two false twisted yarns made of this split type composite fiber and 6 false twisted yarns obtained in Example 1 are aligned, twisted in the S direction at 120 t / m, and heat set at 60 ° C. for 40 minutes. And a 686 dtex / 712f intertwisted yarn was obtained as an interdental floss (test yarn). The weight ratio of both was 1: 3.
The extension rate of the interdental floss was 30.1%, and the expansion / contraction restoration rate was 15.5%.
When the obtained interdental floss was used, it was easy to insert between the teeth, and the contact with the teeth and gums was very soft. The interdental floss was widely applied between the teeth, and the wiping feeling was excellent, and it was wiped down to a fine location.
Moreover, the removal efficiency and usability | use_condition of the following intraoral biofilm were evaluated.

(Comparative Example 1)
An interdental floss made of commercially available 66 nylon filaments was prepared (270 filaments, round cross section).
This interdental floss was immersed in hot water at 60 ° C. for 5 minutes, and after removing the paste, the single yarn fineness was 3 dtex and the elongation was 12.0%.
Moreover, the removal efficiency and usability | use_condition of the following intraoral biofilm were evaluated.

The removal efficiency of the oral biofilm was evaluated by the following scrub removal evaluation system (according to an experiment by Professor Yoshiyoshi Koseki, Department of Preventive Dentistry, Graduate School of Dentistry, Tohoku University).

[Abrasion removal evaluation system]
As shown in FIG. 5, the scrub removal evaluation system fixes one end of the test yarn 3, passes a pulley (the shaft is fixed), applies a tension T to the other end, and samples 4 (intraoral biofilm). Or a base material in a state where cleaning is performed) is brought into contact with the test yarn 3 with a constant contact force P, and the test yarn 3 is moved vertically along the pulley at a constant speed. The removal of the sample 4 is attempted by moving the sample 4 while maintaining the movement or contact force P, and the removal amount is evaluated.

[Oral biofilm removal efficiency]
By generating and collecting an intraoral biofilm, using a sample in which the intraoral biofilm is adhered to the surface of the base material, and moving the pulley together with the scrub removal evaluation system under the conditions shown in Table 1, 1 The oral biofilm remaining on the surface was stained and washed with plaque revealing solution, photographed, and the presence / absence and shade of the color was measured to calculate the removal efficiency.
The results are shown in Table 1.

  The test of Example 1 and Example 2 was compared when the removal efficiency was compared when the force (contact force P) for pressing the test yarn against the substrate to which the intraoral biofilm was adhered was 0.20 N or 0.49 N Both yarns showed higher removal efficiency than the test yarn of Comparative Example 1.

[Dental contact part passage resistance]
In addition, two hydroxyapatite disks (13 mm × 2 mm) were brought into contact with each other with a force of 3.92 N to form a model of a narrow part (contact) between teeth. The test yarn was passed through this contact, and the resistance force at the time of passing was measured.
The results are shown in Table 2.

  Comparing the interdental contact partial passage resistance of each test yarn, the resistance of the test yarns of Example 1 and Example 2 was significantly lower than that of the test yarn of Comparative Example 1. From this, it was found that the test yarns of Examples 1 and 2 can pass between the teeth with less force and are easy to use. From the above, it can be said that the smaller the single yarn fineness, the easier to pass between the teeth and the easier to use.

[Comparison of feeling of use]
An experimental collaborator who obtained informed consent (39 hygienist school students) removed the oral biofilm with the test yarn supported by hand, and conducted a questionnaire survey on the feeling of use / removability. At the same time, it was confirmed by oral examination that there was no injury to the gums.
The results are shown in Table 3.

As a result, many respondents answered that Example 1 and Example 2 were easier to pass than Comparative Example 1 in response to the question "How is the thread of the interdental contact?" On the other hand, Comparative Example 1 had the largest number of responses that were difficult to pass, and in particular, there were 0 in Examples 1 and 2, but 5 in Comparative Example 1 that were “very difficult to pass”.
In response to the question “How easy is it to remove dirt?”, It was answered that Example 1 and Example 2 could be significantly removed compared to Comparative Example 1. On the other hand, many respondents said that Comparative Example 1 was more difficult to remove than Example 1 and Example 2.
In response to the question “Did you feel pain in your gums?” Compared to Examples 1 and 2, Comparative Example 1 was “very painful”, “feels pain”, “looks painful” There were many answers that felt the same. On the other hand, there were many answers in Example 1 and Example 2 that “gingiva is not painful at all”.
In response to the question “How is it easy to handle?”, There were many responses that Example 1 was significantly easier to handle than Example 2 and Comparative Example 1.
Moreover, although not described in Table 3, many respondents said that they wanted to use in order of Example 1, Example 2, and Comparative Example 1 in response to the question “Which thread do you want to use most in the future?” .

(Example 3)
84 dtex / 48f polyester multifilament) Soarion (registered trademark) Y) manufactured by KB Seiren was prepared. Eight of these filaments were aligned, twisted at 160 t / m in the S direction, and heat set at 60 ° C. for 40 minutes to obtain a 661 dtex / 384 f twisted yarn, which was used as an interdental floss.

Example 4
A 56 dtex / 36 f polyester multifilament (Soarion (registered trademark) Y manufactured by KB Seiren Co., Ltd.) having the cross-sectional shape of FIG. 1 was prepared. This filament was twisted in the Z direction at a spindle rotation speed of 300,000 rpm, a false twist number of 3,000 t / m, and a set temperature of 180 ° C. to obtain a false twisted yarn. Subsequently, twelve false twisted yarns obtained were aligned, twisted at 120 t / m in the S direction, and heat set at 60 ° C. for 40 minutes to obtain a 726 dtex / 432 f intertwisted yarn, which was used as an interdental floss.

(Comparative Example 2)
A 84 dtex / 48f polyester multifilament (KB Selen Co., Ltd.) having a round cross-sectional shape was prepared. Eight of these filaments were aligned, twisted at 160 t / m in the S direction, and heat set at 60 ° C. for 40 minutes to obtain a 653 dtex / 384 f twisted yarn, which was used as an interdental floss.
The single yarn fineness of the interdental flosses of Examples 3 and 4 and Comparative Example 2 was about 1.7 dtex, respectively.
The interdental floss of Example 3 and 4 and Comparative Example 2 was set in a floss folders, the removal efficiency of the pseudo plaque coated on a glass piece was measured using the above abrasion removal evaluation system of Example 4 The interdental floss has a higher removal rate than the interdental floss of Example 3, and the interdental floss of Example 3 and the interdental floss of Comparative Example 2 have a higher removal efficiency than the interdental floss of Example 3. Was high.

1 Modified multifilament 2 Ultrafine multifilament 3 Test yarn 4 Sample

Claims (4)

An interdental floss yarn comprising a multi-filament having a multi-leaf shape having a multi-leaf shape with a cross-sectional shape of 3-6 leaves, and the single-fiber fineness of the multi-filament of a cross-section is 0.5-4 dtex, and the total fineness is 400-1100 dtex. The maximum width of the leaf part is the same as the length of the line connecting the most concave adjacent parts of the filament surface, and the line connecting the adjacent concave part of the filament surface. The ratio (a / b) of the length (a) in the longitudinal direction of the leaf portion, which is the length from the center of the leaf to the tip of the leaf including the line, and the length (b) of the maximum width is 0.5 to An interdental floss thread characterized by being 1.5.   2. The interdental floss yarn according to claim 1, wherein the modified multifilament is a false twisted yarn.   The interdental floss yarn according to claim 1 or 2, wherein the irregularly shaped multifilament is a twisted yarn twisted together with a twist number of 50 to 250 t / m.   The interdental floss yarn according to any one of claims 1 to 3, wherein ultrafine multifilaments having a single yarn fineness of 2 dtex or less are combined.