JP2007215703A - Dental floss yarn and dental floss - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide dental floss which shows excellent flossing effects and gives excellent use feeling. <P>SOLUTION: A dental floss yarn is made of atypical fine fiber multi-filaments which have single yarn fineness of 2 dtex or less and have the shape of the fiber cross-section with edges and is preferred to be plied yarn formed by plying by doubling a plurality of textured yarn. Especially, the textured yarn is preferred to be false twist textured yarn. Preferably, the fine fiber multi-filaments comprise a radial shape segment A with a radial fiber cross-section and complementary segments B for complementing the radial shape segment A. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a dental floss yarn and a dental floss.

Between the teeth, plaque (plaque) is likely to stick, and it is a site that tends to cause tooth decay and periodontal disease. Plaque is made of water and organic matter, and most of the organic matter is bacteria (ordinary oral bacteria) and their metabolites. The bacteria change depending on the oral hygiene, causing bad breath and periodontal disease.
In general, toothbrushing is effective for maintaining good dental hygiene, but it is difficult for the toothbrush to reach the gap between the teeth, and the use of dental floss is effective for removing plaque more effectively. is there.

  As such a dental floss, a bundle of nylon fibers having a round cross section or a tape-like one using a polytetrafluoroethylene (PTFE) monofilament yarn is generally used. The former is thick, so it is difficult to insert between the teeth, and it does not reach the narrow space between the teeth, and the plaque 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 the plaque between the teeth is not sufficiently cleaned.

Further, Patent Document 1 discloses a dental floss comprising 50 to 5000 filaments having a thickness of 1 to 50 μm and binding these filaments by heat fusion or the like at intervals of 3 to 30 mm in order to increase the plaque removal efficiency. Are listed.
JP-A-8-117252

Patent Document 2 describes a dental floss in which a nylon filament is textured and a chemotherapeutic preparation is contained in a large number of yarns using the properties of the processed yarn.
Japanese Patent No. 3675822

Patent Document 3 describes that a woven or knitted fabric made of a twisted yarn in which a very fine fiber yarn and a yarn arranged along with the yarn are wound around a core is used for dental floss.
JP-A-2005-240190

  However, Patent Document 1 has to adopt a method of heat fusion, melt fusion, and adhesive bonding as a method for binding filaments. In these methods, the binding portion is cured, and dental floss is inserted between teeth. Sometimes the user feels uncomfortable. Moreover, since this thing does not have constant contact with teeth or gums when flossing, the wiping effect and the feeling of use are also poor.

  Moreover, patent document 2 uses the nylon filament of a normal round cross section, and when using it for daily flossing, the hit | interval between teeth is strong at the time of insertion, and it does not reach to the narrow space between a tooth, a tooth, and a gum, There is no satisfaction that the plaque is removed for the user, and the feeling of use is inferior.

Further, Patent Document 3 describes that a woven or knitted fabric made from a very fine fiber yarn and a twisted yarn having a wound yarn around the core is used for dental floss as one of its applications. However, it is not specifically assumed, and the dental floss in which the thick yarn is part of the core and the yarn wound around the coil in a coiled shape is further woven or knitted, has a large peripheral diameter, It is not suitable for dental floss.

  Therefore, the objective of this invention is providing the thread | yarn for dental floss and the dental floss whose wiping feeling and the wiping effect are favorable compared with the past. Another object of the present invention is to provide a dental floss thread and a dental floss that are soft against the teeth and gums and have a good feeling during flossing.

In order to solve the above-mentioned problems, the gist of the present invention is a dental floss yarn comprising ultrafine fiber multifilaments having a single yarn fineness of 2 dtex or less and an atypical fiber cross-sectional shape having edges.
Among them, a dental floss yarn made of a twisted yarn obtained by aligning and twisting a plurality of processed yarns is preferable, and the processed yarn is preferably a false twisted yarn.
The ultrafine fiber multifilament is preferably a split fiber obtained by splitting a composite fiber multifilament made of at least two kinds of fiber-forming polymers having different official moisture contents with stress.
The fiber cross-sectional shape of the composite fiber multifilament is more preferably a radial segment and a complementary segment that complements the radial segment, and one of the radial segment and the complementary segment is polyamide and the other. More preferably, is made of polyester.
The above-mentioned twisted yarn is preferably one in which a plurality of split fiber yarns are aligned and twisted at a twist number of 20 to 200 T / m.
In the present invention, these dental floss yarns are used as a dental floss by tying them into a yarn bundle, knitted fabric or woven fabric.

  According to the present invention, the yarn for flossing made of ultrafine fiber multifilament having a single yarn fineness of 2 dtex or less and a cross-sectional shape of the fiber having an edge is superior in the wiping effect and has a wiping feeling. Good dental floss can be obtained.

  In addition, if it is a dental floss yarn made of a twisted yarn that has been twisted by twisting multiple processed yarns, the area around the teeth and gums is soft, and the yarn is fused at a fixed interval to bind the yarn. Compared with flossing, there is no sense of incongruity and the feeling of use is good. If this processed yarn is false twisted yarn, the contact with the teeth and gums is soft, and the usability is more excellent.

In addition, when the above-mentioned ultrafine fiber multifilament is a split fiber obtained by splitting a composite fiber multifilament made of at least two types of fiber-forming polymers having different official moisture contents with stress, during flossing, teeth and teeth When dental floss is inserted between the fibers, moisture is contained, and the constituent fibers have a difference in yarn length, the distance between the fibers is easily maintained, and the scraped plaque is easily held between the fibers. For this reason, the plaque once scraped is less likely to reattach to the teeth and gums, and the wiping feeling becomes more excellent.
In addition, if the fiber is split with stress, it can be used as a dental floss without going through a process such as weaving and knitting even though the single yarn as described above is a thin yarn. Since it can suppress that the extra component in a manufacturing process adheres, it becomes a thing suitable for using in an oral cavity.

And if the fiber cross-sectional shape of this composite fiber multifilament is a radial segment and a complementary segment that complements this radial segment, the edge of the segment will easily fit the tooth irregularities, and the plaque can be more reliably captured . With this cross-sectional shape, it is easy to store and hold the scraped plaque in the gaps between the radial segments, so that it is difficult for the plaque to reattach and the wiping feeling is more excellent. Moreover, if it is twisted together, the edge part is likely to appear on the surface layer of the yarn at random, and a good scraping effect is easily obtained.
In addition, if either the radial segment or the complementary segment is made of polyamide and the other is made of polyester, the polyester part which is the harder polymer promotes the scraping effect, and the polyamide which is the softer polymer. Since the contact with the teeth and gums is softened, the scraping effect and the feeling of use are more preferable.

  As long as the above-mentioned twisted yarns are obtained by aligning a plurality of split fiber yarns and twisting them at a twist number of 20 to 200 T / m, the efficiently twisted yarns can be efficiently obtained without binding by heat fusion or the like at regular intervals. The dental floss yarn can be obtained, and the appearance of the yarn becomes round and beautiful.

  In the present invention, these dental floss yarns can be used as a dental floss by tying them into a yarn bundle, knitted fabric or woven fabric. As the dental floss, if the yarn itself is used, it is easy to provide at a low cost and the manufacturing process becomes easy, so that there is less possibility of extraneous matter adhering.

The dental floss yarn and dental floss of the present invention will be described in detail below.
First, the dental floss of this invention is comprised from the yarn for dental floss which consists of an ultrafine fiber multifilament.

  In the dental floss of the present invention, the dental floss yarn may be used as it is, or the dental floss yarn may be knitted or woven to be used as a knitted fabric or a woven fabric. Among them, the thread for dental floss is simple because the manufacturing process is simple, the extra components required during the manufacturing process are reduced, and it can be suitably used for intraoral use, and it is easy to provide inexpensively. It is preferable not to use a woven or knitted fabric but to use it as a yarn bundle for dental floss as it is.

  The elongation rate of the dental floss is preferably 20 to 40%, and the expansion / contraction recovery rate is preferably 20 to 40%. The elongation is measured with a constant-speed tension type tester at a grip interval of 30 cm and a tensile speed of 30 + -3 cm / min according to JIS L1013 8.5.1 Tensile Strength and Elongation Measurement Method. The growth rate. The expansion / contraction recovery rate is a value measured according to JIS L1013 8.12.

The fiber cross-sectional shape of the yarn constituting the dental floss yarn is a variant having an edge.
Note that the “edge” refers to a protruding portion formed by a corner portion of the fiber having a curved cross-sectional shape that is not a gentle arc shape but a bent corner shape. And although the angle of the said corner | angular part may be an obtuse angle, the sharper angle exhibits the wiping performance more excellent. However, in the outline of the fiber cross section, the two sides having the corners do not necessarily have to be straight lines, and may have an arc shape. The edge may be an obtuse angle, a right angle, or an acute angle, but is preferably a right angle or an acute angle, particularly an acute angle, from the viewpoint of efficiently obtaining a plaque scraping effect.
The edge is preferably exposed on the surface of the dental floss yarn. For example, as shown in FIG. 4, the edge is randomly exposed on the surface of the yarn. It is preferable from the point of wiping feeling.

The fiber cross-sectional shape of the thread | yarn which comprises the said thread | yarn for dental floss is illustrated.
For example, as shown in FIG. 1, it consists of a radial segment A and a complementary segment B that complements the radial segment A. Each segment A, B is formed with a large number of edges along the longitudinal direction of the fiber (the portion indicated by P in FIG. 1 and the portion having the same shape is omitted), so that the plaque is scraped efficiently and the plaque is reattached. Is 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.

Such a dental floss yarn can be obtained by splitting a composite fiber multifilament. For example, what consists of a radial segment and a complementary segment mentioned above can be obtained by splitting FIG. 2 (a), (b).
Other examples of the fiber cross-sectional shape of the composite fiber multifilament include FIGS. 2 (c) to 2 (h). In the case of FIG. 2 (g), an ultrafine fiber multifilament composed only of an inner component (D: consisting of 12 segments) can be obtained by dissolving and removing the outer portion (C) of the composite fiber. Moreover, the thing of FIG.2 (h) can melt | dissolve and remove the easily meltable component C, and can obtain the ultrafine fiber multifilament which consists only of the fiber-forming component of D. FIG.

  The splitting of the composite fiber 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 wiping effect of dental floss 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 dental floss can be given volume and elasticity, 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 total fineness of the floss for dental floss is preferably 500 to 1500 dtex from the viewpoint of usability and wiping effect when the yarn itself is used as a floss. More preferably, it is 700-1200 dtex. In the case of a knitted fabric, 500 to 1000 dtex is preferable.

The dental floss yarn is composed of an ultrafine fiber multifilament having a single yarn fineness of 2 dtex or less. Here, the single yarn fineness indicates the segment fineness of each segment after splitting in the case of splitting a composite fiber multifilament (split yarn).
That is, when the single yarn fineness is too thick, the unit fiber surface area of the dental floss is reduced, and unless the dental floss itself is thickened, it is difficult to obtain a sufficient wiping property, and an attempt is made to obtain a sufficient wiping effect. In this case, the dental floss itself becomes thick, and it is difficult to insert between the teeth. In addition, once a plaque or food piece is scraped off, it cannot be taken up between the fiber segments, and the plaque again adheres to the oral cavity such as teeth and gums. On the other hand, if the fine fiber has a single yarn fineness of 2 dtex or less, the plaque is scraped so as to be scraped off by a large number of thin fibers, and pushed up into the fiber group to be captured. The captured plaque is stored in a large amount in a large number of narrow spaces between the fibers to prevent reattachment, and a good scraping effect that cannot be obtained with a normal floss using a multifilament is obtained.
Further, when inserting between teeth, the volume of the portion inserted between the narrow teeth is reduced due to the aggregate of ultrafine fibers. The present invention makes it very easy to insert floss between teeth even when the dental floss has a bulky appearance.
In the case of dental floss having a thick appearance, a wax coding process or the like is usually performed in order to obtain easy insertion between teeth. In the present invention, even if the dental floss has a large appearance, it can be smoothly inserted between the teeth without applying a wax coating. Of course, the dental floss of the present invention may be wax-coated.

  The single yarn fineness is preferably 1.1 dtex or less, and more preferably 0.75 dtex or less. If the fiber is too thin, the lower limit of the single yarn fineness of each segment is preferably about 0.05 dtex, considering that the fiber is likely to be broken by flossing.

  In the dental floss yarn of the present invention, these ultrafine fiber multifilaments are preferably used at least in part, and in particular, 80% by weight or more, particularly about 100% by weight of the dental floss yarn is preferably used.

  The average single yarn fineness of the dental floss yarn of the present invention is preferably 2 dtex or less from the viewpoint of obtaining a good feeling of use and a wiping effect. 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 dental floss yarn of the present invention include 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.

The yarn for dental floss of the present invention is preferably obtained by splitting the above-mentioned composite fiber multifilament composed of at least two kinds of polymers having different official moisture content (standard moisture content at 20 ° C. and 65% RH). In this case, when dental floss is placed in the mouth and wiped between the teeth, the dental floss contains water, and the segment made of a polymer with a high official moisture content swells more, and consists of a polymer with a low official moisture content. There is a difference in yarn length between the segments, the space between the fibers spreads, and the spacing is kept moderate. For this reason, it is easier for plaque to enter between the gaps of each segment than those consisting of a single component, and the plaque is less likely to reattach to the teeth and gums. Is obtained.
The difference in the official moisture content of each of the above polymers is preferably 2% or more, more preferably 3% or more. The upper limit is preferably about 5%.
Preferable examples of the combination of polymers having different official moisture percentages include polyester and polyamide, polypropylene and polyamide, and polyethylene and polyamide. Normally, the official moisture content of nylon is 4.5%, the official moisture content of polyester is 0.4%, and polyolefins such as polyethylene and polybutylene are 0%.
In particular, polyester and polyamide are preferable from the viewpoint of versatility, cost, wiping feeling, and feeling of use, and a combination of polyethylene terephthalate and nylon 6 is preferable from the viewpoint of general-purpose and low-cost availability.

By using these two types of ingredients with different official moisture content, the teeth and gums are softer than those using single-component fibers, and plaques are formed in the gaps between the segments. It is easier to enter, makes it difficult for the plaque to re-adhere, and has an excellent wiping effect and usability.

  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.

  In addition, as a particularly preferably used combination, one of the radial segment A and the complementary segment B is a polyester, and the other is a polyamide. That is, when used as dental floss, the polyamide with a high thermal shrinkage rate of the polymer greatly shrinks, and the polyester does not shrink so much.Therefore, a gap is formed between the two, and the scraped plaque enters into the gap and cleans it. The wiping effect is excellent. Further, splitting by stress is facilitated, the degree of deformation of the fiber cross-sectional shape is low, the shape of the edge portion of the segment is easily maintained, and dental floss having a high wiping effect can be obtained.

  Above all, if the radial segment is polyamide and the complementary segment is polyester, the polyamide part is soft, the radial segment softens the teeth and gums, and the hard complementary polyester part scrapes the plaque. Since it plays a role, it is further excellent in the wiping effect, and a wiping feeling and a feeling of use can be obtained.

The dental floss yarn of the present invention is preferably a processed yarn from the viewpoint of softening the contact with the teeth and gums and efficient removal of plaque.
As the processed yarn, usually, a yarn imparted with bulkiness using thermoplasticity such as synthetic fiber is shown, and as processing methods, for example, twisting, heat fixing, untwisting method, false twisting method, rubbing method, Examples thereof include an indentation method, a molding method, an air injection method, and a composite crimping method. As the processed yarn of the present invention, a false twisted yarn obtained by a false twisting method is preferable.

The dental floss yarn of the present invention is preferably a twisted twisted yarn. The twisted yarn has a beautiful appearance, can be easily inserted into teeth, and can be easily used without fouling during flossing.
As a suitable example of the above-mentioned twisted yarn, a plurality of the above-mentioned composite fiber multifilaments are combined and subjected to false twisting, etc., and after splitting the stress, a plurality of split yarns that have been split are drawn together and combined. Examples include twisted twisted yarn. In this case, by setting the conditions for false twisting and twisting as appropriate, even when the floss is made of a yarn itself, that is, a dental floss consisting of a yarn bundle itself, the round appearance is beautiful. Can be dental floss.

Next, the case where a plurality of the composite fiber multifilaments are false twisted and then twisted will be described in more detail.
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. When the multifilaments split in this way are twisted and twisted, the yarn has conjugation and convergence, and the yarns are easy to handle without being twisted despite the thin yarn. Moreover, the plaque can be reliably captured between the crimped fibers, and the dental floss excellent in usability and wiping effect is obtained.

The dental floss yarn is heat set in a twisted state as a false twisted yarn, and when the twist is released, the filament is crimped to give volume and stretchability. It has softness around the teeth and gums and ease of insertion between narrow teeth. Moreover, by twisting, the edge part of each segment is randomly and obliquely arranged on the surface of the yarn, and exhibits a high wiping effect on the teeth. FIG. 4 is a photomicrograph of an example of the dental floss yarn of the present invention as seen from the longitudinal direction, and the state where the edge portions of each segment are randomly and randomly arranged on the surface of the yarn appears. .

  The false twisting conditions and the twisting conditions are appropriately set according to the polymer of the yarn, the thickness of the yarn, the desired appearance, and the like. For example, when using a composite multifilament composed of a radial segment of polyamide and a complementary segment of polyester, false twisting is performed by performing false twisting at a false twist number of 2700-3700 T / M at about 150-185 ° C. A plurality of processed yarns are aligned and twisted at a twist number of 20 to 200 T / M, preferably 40 to 150 T / M. Under such conditions, it is easy to insert the dental floss into the teeth, the flossing is smooth, and even when the yarn itself is used as the dental floss, the floss has a more rounded appearance and is particularly preferable.

  Fig. 3 shows splitting of a composite fiber multifilament whose fiber cross-sectional shape is composed of a radial segment and a complementary segment by applying false twisting. It is an example of the microscope picture of the fiber cross section of the thread for dental floss obtained by doing. If this is treated with normal treatment to obtain dental floss, the plaque is captured in the gap between the radial segment and the complementary segment, and once it is captured, it is efficient that the plaque reattaches to the teeth and gums. Can prevent well.

The dental floss yarn preferably has an elongation of 20 to 40% and an expansion / contraction recovery rate of 20 to 40%. Within this range, the yarn has conjugation properties, the combined yarn does not fall apart, and there is no inconvenience such as a portion of the yarn being caught on the repaired portion of the tooth, so it can be used directly as dental floss. It is suitable for. Moreover, since it has moderate elasticity, it has a characteristic that the contact with the teeth and gums is soft when the teeth are wiped, and is suitable as a dental floss. In addition, as for the elongation rate of the split fiber obtained by the said false twist split fiber, what has an elongation rate of 20 to 40% and an expansion-contraction restoration rate of 20 to 40% is preferable.
In addition, elongation rate is the elongation rate measured with the constant-speed tension type | mold tester with the holding | grip space | interval of 30 cm and the tensile speed of 30 + -3 cm / min of JIS L1013 8.5.1 standard time test. The expansion / contraction recovery rate is a value measured according to JIS L1013 8.12.

An example of the suitable manufacturing method of the dental floss of this invention is shown.
First, a composite fiber multifilament composed of a modified cross-section segment having a polymer composition as described above is prepared. The multifilament is subjected to false twisting at a twist number of 2700 to 3700 T / m at 150 to 185 ° C., for example, and divided into segments. Then, 5 to 15 obtained processed yarns are aligned and twisted at a twist number of 20 to 200 T / M, more preferably 40 to 150 T / m. The resultant twisted yarn is used as it is as a yarn bundle, as a dental floss yarn, subjected to ordinary treatment, and used as a dental floss.
In this case, false twist splitting was used, but stress splitting such as knit denit as described above may be used. Moreover, in the case of a twisted yarn in which a plurality of false twisted yarns are twisted together, the false twisting direction and the twisting direction may be the same or opposite. The dental floss yarn may be used as a dental floss by attaching mint or the like.

Example 1
84dtex / 28f split type composite fiber multifilament having a cross-sectional shape of FIG. 2 (a) (radial A component: polyamide, single yarn fineness 0.75 dtex, 4 complementary B components (fan shape): single polyester Yarn fineness 0.56 dtex) (Berryma (registered trademark) manufactured by KB Seiren) was prepared. The official moisture content of the A component is 4.5%, the official moisture content of the B component is 0.4%, and the difference is 4.1%.
This filament is fed at an overfeed rate of 2%, and the spindle rotation speed is 400,000 rp.
m, false twist number 3600T / M, set temperature 175 ° C, false twist in the S direction, false twisted yarn (stretch rate is 35.0%, stretch recovery rate is 33.2%) Obtained. Next, ten false twisted yarns obtained were aligned and twisted by applying 50 T / M twist in the Z direction to obtain a 840 dtex / 280 f twisted yarn. Thereafter, dental floss (component A: 0.75 dtex) was obtained. B component: 0.56 dtex, average single yarn fineness: 0.6 dtex). This dental floss had a stretching rate of 29.3% and a stretching / restoring rate of 33.2%. Moreover, the micrograph of the fiber cross-sectional view of the obtained dental floss is shown in FIG. 3, and the micrograph taken from the longitudinal direction of the fiber is shown in FIG.
The resulting dental floss had a slightly thicker and softer round appearance than the conventional one, and the threads looked neatly arranged. When this dental floss was used, it was easy to insert between the teeth, and the area around the teeth and gums was very soft. Moreover, the dental floss was widely applied between the teeth, and the wiping feeling was excellent, so that it could be wiped off firmly.

(Example 2)
A dental floss was obtained in the same manner as in Example 1 except that a twist of 120 T / M was applied in the Z direction. The obtained dental floss had a finer appearance than that of Example 1, but the round shape seemed to be soft and the yarn seemed to be neatly arranged. When this dental floss was used, it was easy to insert between the teeth, and the area around the teeth and gums was very soft. Moreover, the dental floss was widely applied between the teeth, and the wiping feeling was excellent, so that it could be wiped off firmly.

(Example 3)
Dental floss was obtained in the same manner as in Example 1 except that the number of twists during the twisting was changed to 35 T / M, 80 T / M, 120 T / M, and 160 T / M. All of them were excellent in wiping feeling and excellent in wiping effect and feeling of use. About the wiping effect, the thing of 80 T / M and 120 T / M was especially excellent. The apparent thickness became thinner as the number of twists increased. Everything was in order. The one with 160 T / M was slightly harder than the other ones, and it was harder to insert between the teeth than the other ones. All of them were soft when flossing and were excellent in wiping feeling, wiping effect and feeling of use. In particular, 35T / M, 80T / M, and 120T / M were soft on the teeth and gums. 80T / M and 120T / M were particularly excellent in terms of easy insertion of teeth into dental floss, softness during flossing, wiping feeling, and wiping effect.

Example 4
Examples except that the number of twisted false twisted yarns is 5, 8, 13, 16, and the fineness of the twisted yarn is 420 dtex / 140f, 672 dtex / 224f, 1092 dtex / 364f, 1344 dtex / 448f Dental floss was obtained as in 1.
All of them were excellent in wiping feeling, wiping effect and feeling when used as dental floss. The five items felt unsatisfactory when flossing compared to the others. The 16 items were inferior to the others in terms of ease of insertion. Therefore, 8 and 13 were particularly excellent in wiping feeling and usability.

(Example 5)
FIG. 2 (b) 110 dtex / 50 f split-type composite fiber multifilament (radial A component: polyamide, single yarn fineness 2 dtex, 8 complementary B components (fan shape): polyester single yarn fineness Except for preparing 0.2 dtex), a dental floss (A component: 2 dtex, B component: 0.2 dtex, average single yarn fineness: 0.4 dtex) was obtained in the same manner as in Example 1.
The resulting dental floss looked a little thicker and softer than the conventional one, and the yarn seemed to be neatly arranged. When this dental floss was used, it was easy to insert between the teeth, and the area around the teeth and gums was very soft. Moreover, the dental floss was widely applied between the teeth, and the wiping feeling was excellent, so that it could be wiped off firmly.

(Example 6)
After aligning false twisted yarn, instead of twisting, it is the same as in Example 1 except that interlacing is performed at an air pressure of 0.29 MPa and interlaced at 1.5 cm intervals. Thus, dental floss (stretch rate: 35.0%, stretch recovery rate: 33.2%) was obtained.
The resulting dental floss had a thick appearance and a narrow appearance. When this dental floss was used, although it was inferior to those of Examples 1 to 5, it was easier to insert between the teeth than those of Comparative Examples 1 to 4 described later, and the teeth and gums were soft. Moreover, although it was inferior to Examples 1-6, compared with the thing of Comparative Examples 1-4, dental floss hits widely between teeth and the wiping feeling and the wiping effect were also favorable.

(Comparative Example 1)
A 78 dtex / 24f nylon filament with a round cross section was prepared. This filament was twisted in the S direction at 3600 T / M and a set temperature of 175 ° C. to obtain a false twisted yarn.
Next, ten false twisted yarns obtained were aligned, heat-sealed at 30 mm intervals, combined, and used as dental floss. When inserted between the teeth, the heat-sealed part was hard and the gap between the teeth As compared with the dental floss obtained in Examples 1 to 6, the insertion was very difficult to perform. Further, when flossing, the yarn did not reach the narrow space between the teeth, and the wiping degree was inferior. Moreover, compared with the thing of Examples 1-6, the circumference | surroundings to a tooth | gear and a gum were felt hard, and it was inferior to a usability | use_condition.

(Comparative Example 2)
A 78 dtex / 24f nylon filament with a round cross section was prepared. This filament was twisted in the S direction at 3600 T / M and a set temperature of 175 ° C. to obtain a false twisted yarn. Subsequently, ten false twisted yarns obtained were aligned and twisted in a twisting direction Z of 50 T / M to obtain a 780 dtex / 240 f twisted yarn, which was used as dental floss.
When the obtained dental floss was used, it was difficult to insert between the teeth, and it was hard to hit the teeth and gums. It was also painful when using floss. The wiping feeling was not satisfactory, and the wiping effect was inferior to that of Examples 1-6.

(Comparative Example 3)
When a dental floss tape made of commercially available PTFE was prepared and used as a dental floss, it had a flat surface and felt well against the teeth, but the feeling of hitting the teeth was inferior compared to those of Examples 1-6. I felt it. Moreover, the feeling of wiping was not obtained and sufficient wiping effect was not obtained.

(Comparative Example 4)
A dental floss made of a commercially available nylon filament was prepared (single yarn fineness: 3 dtex, 272 filaments, round cross section). When this was used as a dental floss, it was difficult to reach the fine areas between the teeth, and the teeth and gums were felt hard. Moreover, there was little feeling of fit even if it inserted, and the wiping feeling and the wiping effect were also inferior.

(Example 7)
The composite fiber multifilament (C is alkali-soluble polyester, D is polyethylene terephthalate, C: D (area ratio) is 1: 3) shown in FIG. 2 (h) is 3600T / M, false twisting is performed in the S direction at a set temperature of 205 ° C., and seven of the obtained false twisted yarns are aligned, twisted 50 times T / m in the Z direction and twisted, 70 ° C., A 20-minute twist set was applied to obtain a 1169 dtex / 350 f double twisted yarn. The obtained twisted yarn was scraped and subjected to 25% alkali weight loss, and the alkali-soluble polyester was removed to obtain a dental floss yarn (average single yarn fineness: 0.28 dtex), which was designated as dental floss.
The obtained dental floss was superior in cleaning effect and usability compared to Comparative Examples 1 to 4, but inferior in softness, wiping feeling and wiping effect as compared with those in Examples 1 to 5. It was.

(Example 8)
Six false twisted yarns obtained in Example 1 were combined and knitted with chain knitting using crochet No. 2 to obtain dental floss.
When the obtained dental floss was used, both the wiping feeling and the wiping effect were better than those of Comparative Examples 1 to 4. Moreover, it was easier to insert between the teeth than in Comparative Examples 1, 2, and 4. Examples 1-5 were softer on the teeth and gums.

Example 9
Six false twisted yarns obtained in Example 1 and four regular polyesters of 84 dtex / 36f were aligned and twisted under the same conditions as in Example 1 to obtain a twisted yarn (total fineness: 840 dtex, The ultrafine fiber multifilament was obtained as a dental floss.
Compared with the dental floss of Comparative Examples 1-4, the wiping feeling and the wiping effect were favorable. Compared with Comparative Examples 1, 2, and 4, it was easy to insert between the teeth, and the teeth and gums were softer, but the dental floss of Examples 1 to 5 was softer to the gums, and a feeling of wiping, Excellent wiping effect and usability.

(Example 10)
Composite fiber multifilament with 84 dtex / 28f, fiber cross-sectional shape as shown in FIG. 2 (f) and 11 divisions (polymer is composed of 11 polyethylene terephthalates and 11 nylons alternately side by side) A twisted yarn was obtained in the same manner as in Example 1 except that the prepared yarn was prepared. The twisted yarn was 840 dtex / 280 f, the single yarn fineness was 0.2 to 0.3 dtex, and the average single yarn fineness was 0.25 dtex. This twisted yarn was made into dental floss in the same manner as in Example 1.
The resulting dental floss looked round and shaped and the threads were neatly arranged. The thing of Example 1 was thicker in appearance and richer in bulkiness. When using this dental floss, compared with Comparative Examples 1 to 4, it was easy to insert between the teeth, the area around the teeth and gums was soft, the wiping feeling was good, and the wiping was also good, The one of Example 1 was superior in ease of insertion, softness to teeth and gums, wiping feeling, and wiping effect.

It is a figure explaining the fiber cross-sectional shape of the split fiber which split the composite fiber multifilament of this invention. It is an example of the fiber cross-sectional shape of the composite fiber multifilament before splitting of this invention. An example of the electron micrograph of the fiber cross-sectional view of the thread | yarn for dental floss of this invention is shown. It is an example of the electron micrograph which shows that the dental floss thread | yarn of this invention becomes a spiral shape in the longitudinal direction, and the edge part of a radial segment and a complementary segment is expressing on the fiber surface at random.

Explanation of symbols

A Radial segment B Complementary segment

Claims (8)

A floss for dental floss composed of an ultrafine fiber multifilament having a single yarn fineness of 2 dtex or less and a fiber cross-sectional shape having an edge. The dental floss yarn according to claim 1, wherein the dental floss yarn is a twisted yarn obtained by aligning and twisting a plurality of processed yarns. The dental floss yarn according to claim 3, wherein the processed yarn is a false twisted yarn. 4. The split fiber according to claim 1, wherein the ultrafine fiber multifilament is a split fiber obtained by splitting a composite fiber multifilament composed of at least two types of fiber-forming polymers having different official moisture percentages with stress. For dental floss. The dental floss yarn according to any one of claims 1 to 4, wherein the ultrafine fiber multifilament includes a radial segment and a complementary segment that complements the radial segment. The dental floss yarn according to claim 5, wherein one of the radial segment and the complementary segment is polyamide and the other is polyester. The dental floss yarn according to any one of claims 2 to 6, wherein a plurality of split yarns are aligned and twisted at a twist number of 20 to 200 T / m. A dental floss which is made into a yarn bundle, a knitted fabric or a woven fabric using the dental floss yarn according to any one of claims 1 to 7.