JP2009153701A - Nose protective material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nose protective material having high mechanical strength capable of bending easily, keeping the shape after bending, and surely protecting a nose. <P>SOLUTION: The nose protective material consists of an olefin resin sheet having shape retention property, wherein both the bending return angles θ are 20 degrees or less when it releases after bending an extension polyolefin-based resin sheet at 180 degrees and 90 degrees and holding it for 1 minute, and 5 minutes pass after release. The extension polyolefin-based resin sheet furthermore overlie both surfaces of a low foaming synthetic resin sheet having 1.2-5 foaming magnifications. Moreover, two extension polyolefin-based resin sheets overlie both surfaces of a low foaming synthetic resin sheet having 1.2-5 foaming magnifications in order to cross the extension directions of two extension polyolefin-based resin sheets. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a nasal protection member that can protect a broken nose.

  It is common to break a nose in a traffic accident or an accident during sports, and the only way to recover from a broken nose is to fix the nose and wait for natural healing. If it is done, it will be broken again and recovery will be delayed. Therefore, it is necessary to protect it with a member having a strength that can alleviate or eliminate the external impact.

As a member for protecting the nose, for example, a mask body is provided on a face protection body such as goggles, and the mask body protects the face such as goggles so that the mask body adheres to the respiratory system (mouth, nose) when worn. There has been proposed a face protector (see, for example, Patent Document 1) provided with a mask, characterized in that the body is elastically attached.
Japanese Patent Laid-Open No. 09-251144

  The face protector covers almost the entire face and is not practical due to its large appearance and cost. Therefore, recently, synthetic resin plates such as aluminum plates and vinyl chloride resins have been bent and fixed with adhesive tape or hook-and-loop fasteners applied to the nose. It is commercially available as “Sprint Foam” from Kensha.

  The nose protection member can be suitably used because it is lightweight, can protect only the nose, and can be easily attached. However, it is necessary to bend the aluminum plate or synthetic resin plate into the shape of the nose in order to apply the aluminum plate or synthetic resin plate to the nose, but it is not easy to bend along the nose, and even if it can be bent It may be deformed by rebound resilience or the like. Further, in order to bend easily into the shape of the nose by hand, the aluminum plate or the synthetic resin plate must be thinned. However, if it is thinned, there is a drawback that the mechanical strength is lowered and the protective effect of the nose is lowered.

  In view of the above problems, an object of the present invention is to provide a nasal protection member that can be easily bent, can retain its shape after bending, has high mechanical strength, and can reliably protect the nose.

  The nasal protection member according to claim 1 is bent and held at 180 degrees and 90 degrees and held for 1 minute, and then released, and the folding return angle θ is less than 20 degrees when 5 minutes have passed after the release. It consists of the extending | stretching polyolefin-type resin sheet which has this.

  The stretched polyolefin resin sheet is bent after 180 degrees and 90 degrees and held for 1 minute, then released, and has a shape retaining property in which the folding return angle θ is less than 20 degrees when 5 minutes have passed after release. It is a sheet.

  The above-mentioned stretched polyolefin resin sheet has shape retainability, but the shape retainability is released after folding the stretched polyolefin resin sheet at 180 degrees and 90 degrees and holding it for 1 minute, and 5 minutes have passed since release. The bending return angle θ is 20 degrees or less, preferably the 180-degree bending return angle θ is 20 degrees or less, and the 90-degree bending return angle θ is less than 20 degrees, more preferably 180-degree bending. The return angle θ is 20 degrees or less and the 90-degree bending return angle θ is 15 degrees or less. If one of the bending return angles θ at the time of 180-degree and 90-degree bending, particularly the 90-degree bending return angle θ exceeds 20 degrees, sufficient shape retention may not be obtained.

  As the polyolefin-based resin constituting the stretched polyolefin-based resin sheet, any olefin-based resin having a film forming ability can be used. For example, a high-density polyethylene resin, a medium-density polyethylene resin, a low-density polyethylene resin, a linear low-density Polyethylene resin, polypropylene resin, ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene-pentene-1 copolymer, ethylene-hexene-1 copolymer, ethylene-octene-1 copolymer, ethylene -Vinyl acetate copolymer, ethylene- (meth) acrylic ester copolymer, ethylene-vinyl chloride copolymer, ethylene-propylene-butene copolymer, etc., and high-density polyethylene resin is preferably used .

  When the weight average molecular weight of the polyolefin resin is less than 100,000, the polyolefin resin becomes brittle and the stretchability is lowered, or a stretched polyolefin resin sheet having sufficient mechanical strength or creep resistance is obtained. On the contrary, when it exceeds 500,000, the melt viscosity becomes high, the hot melt molding processability is lowered, and it becomes difficult to obtain a uniform sheet, and therefore 100,000 to 500,000 is preferable. In the present invention, the weight average molecular weight is a value measured by gel permeation chromatography (GPC).

The melt index (hereinafter referred to as MI) of the polyolefin resin is preferably from 0.1 to 20 (g / 10 minutes), more preferably from 0.2 to 10 (g / 10 minutes), which is excellent in film moldability. It is. MI is an index representing the melt viscosity of a thermoplastic resin specified in JIS K 7210. Furthermore, in the case of a high density polyethylene resin, 0.94 g / cm ³ or more is preferable because the mechanical strength does not improve even if the density is reduced even if the density is reduced.

  As the stretched polyolefin resin sheet, a stretched polyolefin resin sheet having a shape-retaining property in which a polyolefin resin sheet having a weight average molecular weight of 100,000 to 500,000 is uniaxially stretched at a stretch ratio of 5 times or more is preferable.

  In this case, the polyolefin resin is preferably a high-density polyethylene resin having an intrinsic viscosity [η] of less than 3.5 dl / g, such as glass fiber, talc, mica, calcium carbonate, magnesium hydroxide, alumina, zinc oxide, magnesium oxide, It is preferable to add inorganic machine fillers such as aluminum hydroxide, silica alumina, titanium oxide, calcium oxide, calcium silicate, basic magnesium carbonate, carbon fiber, and carbon black.

  The thickness of the polyolefin resin sheet before stretching is not particularly limited, but if it is too thick, stretching becomes difficult. Conversely, if it is too thin, the thickness of the polyolefin resin sheet after stretching becomes too thin. Since shape retainability deteriorates, 0.2 to 5.0 mm is desirable.

  The stretching ratio is 5 times or more, and the stretched stretched polyolefin resin sheet only needs to have shape retention, but 10 to 40 times is preferable. The stretching method may be any conventionally known method, such as a method of stretching while heating with a heater or hot air by a uniaxial stretching method such as a roll uniaxial stretching method or a zone uniaxial stretching method. .

  When stretching uniaxially to a high degree of 10 to 40 times, a multistage uniaxial stretching method in which uniaxial stretching is repeated a plurality of times is preferable. When performing multistage uniaxial stretching, the number of stretching is preferably 2 to 20 times, more preferably 3 to 15 times, still more preferably 4 to 10 times.

  When performing multi-stage stretching by a roll uniaxial stretching method, it is desirable to install a feeding pinch roll, a take-up pinch roll, and at least one, preferably a plurality of contact rolls that rotate at a constant speed between these rolls. By installing such a contact roll, uniform stretchability is improved and stable stretch molding can be performed.

  The contact roll performs uniaxial stretching by applying a frictional force to the polyolefin resin sheet without being pinched. Further, the contact roll may be connected to the feeding roll and / or the take-up roll by a connecting member made of a gear, a chain, a pulley, a belt, or a combination thereof.

  The uniaxial stretching temperature cannot be uniformly stretched when it is low, and the sheet melts and cuts when it is high. Therefore, the range of “melting point−60 ° C.” to the melting point of the polyolefin resin of the polyolefin resin sheet to be stretched is more preferable, It is “melting point−50 ° C.” to “melting point−5 ° C.” of the polyolefin resin.

  In order to improve the dimensional stability of the stretched polyolefin resin sheet, the stretched polyolefin resin sheet may be annealed at a temperature between “melting point−60 ° C.” and melting point of the polyolefin resin.

  If the annealing temperature is lowered, the dimensional stability will not improve, warping will occur if used for a long time, and if it is raised, the polyolefin resin will dissolve and the orientation will disappear and the tensile modulus, tensile strength, etc. will decrease. The resin is preferably annealed at a temperature ranging from “melting point−60 ° C.” to the melting point of the resin.

  Annealing is a heat treatment in the production line. When annealing, the stretched polyolefin resin sheet is stretched if a large tension is applied, and it is not stretched or shrinks in a very small state. The length of the stretched polyolefin resin sheet in the stretching direction is preferably kept substantially unchanged, and it is preferable that no pressure is applied to the stretched polyolefin resin sheet. That is, it is preferable that the annealed stretched polyolefin resin sheet is annealed so that the length of the stretched polyolefin resin sheet before annealing is 1.0 or less.

  Accordingly, when the stretched polyolefin resin sheet is continuously annealed while being moved in the heating chamber with a roll such as a pinch roll, the feed rate ratio of the polyolefin resin sheet on the inlet side and the outlet side is 1.0 or less. It is preferable to anneal with setting.

  The heating method at the time of annealing is not particularly limited, and examples thereof include a method of heating with hot air, a heater, a heating plate, hot water or the like. The time for annealing is not particularly limited, and varies depending on the thickness of the stretched polyolefin resin sheet and the annealing temperature, but is generally preferably 10 seconds or more, more preferably 30 seconds to 60 minutes, and still more preferably 1 to 20 Minutes.

  Further, as a different preferred stretched polyolefin resin sheet, a polyolefin resin sheet having a weight average molecular weight of 100,000 to 500,000 was rolled to a rolling ratio of 5 times or more and then uniaxially stretched to a total stretching ratio of 10 to 40 times. A stretched polyolefin resin sheet may be mentioned.

  The thickness of the polyolefin-based resin sheet before rolling is not particularly limited, but if it is too thick, stretching becomes difficult, and in the rolling process, a large pressing force is required to crush the polyolefin-based resin sheet with a rolling roll. Take-up force is required, and uniform rolling in the width direction may be difficult due to bending of the rolling roll. Conversely, when too thin, the thickness of the polyolefin resin sheet after rolling becomes too thin and uniform rolling. Is not only difficult, but the rolling rolls may come into contact with each other to shorten the life of the rolling roll, so 0.2 to 5.0 mm is desirable.

  The polyolefin resin sheet is first rolled to a rolling ratio of 5 times or more. However, the rolling temperature cannot be uniformly rolled when the temperature is lowered, and melted and cut when the temperature is high. The range of “melting point −40 ° C.” to the melting point of the olefin resin of the polyolefin resin sheet is more preferable, and more preferably “melting point −30 ° C.” to “melting point −5 ° C.” of the olefin resin. In the present invention, the melting point refers to the maximum point of the endothermic peak that accompanies melting of the crystal, which is recognized when thermal analysis is performed with a differential scanning calorimeter (DSC).

  If the applied pressure (linear pressure) applied to the polyolefin resin sheet by the rolling roll is too small, it may not be possible to obtain a predetermined rolling magnification, and conversely if it is too large, not only will the bending of the rolling roll occur, Sliding easily occurs between the rolling roll and the raw sheet, and uniform rolling may be difficult. Therefore, the applied pressure is preferably 100 MPa to 3000 MPa, and more preferably 300 MPa to 1000 MPa.

  When the rolling ratio is less than 5 times, the effect of suppressing necking at the time of uniaxial stretching performed later cannot be obtained, high-strength uniaxial stretching cannot be performed, or the uniaxial stretching step Therefore, it is 5 times or more, preferably 7 times or more. There is no particular upper limit to the rolling ratio, but the higher the rolling ratio, the more load is applied to the rolling equipment, so 10 times or less is preferable.

  The rolling magnification is defined as (cross-sectional area of polyolefin resin sheet) / (cross-sectional area of polyolefin resin sheet after rolling), but the width of the polyolefin resin sheet hardly changes before and after rolling. (Thickness of resin sheet) / (thickness of polyolefin resin sheet after rolling).

  The rolled polyolefin resin sheet is then uniaxially stretched at a total stretch ratio of 10 to 40 times. The uniaxial stretching method is not particularly limited, and the above-described uniaxial stretching method may be adopted. Moreover, since the total draw ratio is 10 to 40 times, the uniaxial draw ratio may be determined so that the total draw ratio is within this range in consideration of the rolling ratio. Is not improved, it is preferably 1.3 times or more, more preferably 1.5 times or more, and still more preferably 1.8 times or more. Moreover, although an upper limit is not specifically limited, 4 times or less are preferable, More preferably, it is 3.5 times or less. The total draw ratio is a value obtained by multiplying the rolling ratio and the uniaxial draw ratio.

  In order to improve the dimensional stability of the stretched polyolefin resin sheet, the stretched polyolefin resin sheet may be annealed at a temperature of the melting point of the polyolefin resin from “melting point−60 ° C.” to the melting temperature or lower.

  If the annealing temperature is lowered, the dimensional stability will not improve, warping will occur if used for a long time, and if it is raised, the polyolefin resin will dissolve and the orientation will disappear and the tensile modulus, tensile strength, etc. will decrease. It is preferable that the resin be annealed at a temperature ranging from “melting point −60 ° C.” to the melting point and below the rolling temperature. Other annealing methods are as described above.

  The annealed polyolefin resin sheet may be further aged in a temperature range from 40 ° C. to the melting point of the polyolefin resin. The dimensional stability of the polyolefin resin sheet annealed by aging becomes more excellent.

  Aging is not a continuous treatment in the production line, but it is a relatively long time (minutes, time units) for heat treatment of single-wafers, scrolls, etc., once processed, such as cut winding, of a stretched polyolefin resin sheet. It means to lay down carefully and heat-treat.

  The aging temperature is the same as that left at room temperature when the temperature is low, and when it is high, it is thermally deformed, so the temperature range is from 40 ° C. to the melting point of the polyolefin resin, and the aging time is not effective in a short time and is too long. Even if an effect does not increase, 12 hours-7 days are preferable.

  The thickness of the stretched polyolefin resin sheet is not particularly limited, but it is preferably 0.04 to 2.0 mm because shape retention is reduced when the thickness is reduced, and deformation is difficult when the thickness is increased.

  A second polyolefin resin layer for laminating a plurality of stretched polyolefin resin sheets by heat-sealing may be laminated on the surface of the stretched polyolefin resin sheet. The second polyolefin resin layer may be laminated only on one side of the stretched polyolefin resin sheet or on both sides.

  The polyolefin resin constituting the second polyolefin resin layer is preferably the same type as the polyolefin resin constituting the stretched polyolefin resin sheet because it is laminated on the stretched polyolefin resin sheet. Since it acts as an adhesive when heat-sealing the stretched polyolefin resin sheet, a polyolefin resin having a melting temperature lower than the melting temperature of the polyolefin resin constituting the stretched polyolefin resin sheet is preferable. A density polyethylene resin, an ethylene-vinyl acetate copolymer and the like are preferable.

  The method for laminating the second polyolefin resin layer on the stretched polyolefin resin sheet may be any conventionally known method. For example, the second polyolefin resin layer and the stretched polyolefin resin sheet may be bonded with an adhesive. Examples thereof include a method of bonding, a method of melt-extruding a second polyolefin resin on a stretched polyolefin resin sheet, and laminating.

  Further, the thickness of the second polyolefin resin layer is not particularly limited, but if it becomes too thin, it becomes difficult to adhere, and if it is too thick, the shape-retaining property of the stretched polyolefin resin sheet is lowered. It is -150 micrometers, Preferably it is 20-80 micrometers.

  In addition, also when laminating the second polyolefin resin layer on the stretched polyolefin resin sheet, the laminate sheet was bent at 180 degrees and 90 degrees and held for 1 minute, and then released, and when 5 minutes passed after the release. It is preferable to have shape retentivity in which both bending return angles θ are 20 degrees or less.

  Although the nose protecting member is made of the above-mentioned stretched polyolefin resin sheet, it may be a stretched polyolefin resin sheet, or two or more layers may be laminated. When two or more layers are laminated, the stretch direction of each stretched polyolefin resin sheet may be the same or different.

  In order to laminate a plurality of stretched polyolefin resin sheets, for example, two stretched polyolefin resin sheets are laminated so that the stretch directions are orthogonal to each other. Three stretched polyolefin resin sheets are shifted by 60 degrees each. And a method of laminating four stretched polyolefin resin sheets by shifting the stretching direction by 45 degrees, or combining or repeating these laminates.

  The stretched polyolefin resin sheet has shape retention when bent in a direction orthogonal to the stretching direction, and when two or more stretched polyolefin resin sheets having different stretching directions are bonded, two or more stretched polyolefin resin sheets The shape retention in an arbitrary direction is improved by the stretching direction, and even if the stretching direction and the bending direction of the stretched polyolefin resin sheet are the same, the stretched polyolefin resin sheet is hardly broken.

  As a method of laminating the stretched polyolefin resin sheet, any conventionally known method may be employed, and examples thereof include a method of bonding with an adhesive and a method of heat-sealing. In particular, when the second polyolefin resin layer is laminated on the stretched polyolefin resin sheet, it is preferably heat-sealed.

  The thickness when the stretched polyolefin resin sheet is laminated is not particularly limited. However, when the thickness is reduced, the shape retaining property is lowered. -2.0 mm is preferable.

  The stretched polyolefin resin sheet according to any one of claims 1 to 3 is laminated on both sides of a low foam synthetic resin sheet having a foaming ratio of 1.2 to 5 times. It is characterized by being made.

  The synthetic resin constituting the low-foaming synthetic resin sheet may be any synthetic resin that can be foamed. Examples thereof include polyolefin resins, polyester resins, urethane resins, polyamide resins, and polyimide resins. However, a synthetic resin that does not deteriorate shape retention or become difficult to bend when laminated with the stretched polyolefin resin sheet is preferable, and the same polyolefin resin as the polyolefin resin that constitutes the stretched polyolefin resin sheet is preferable.

  The expansion ratio of the low-foaming synthetic resin sheet is 1.2 to 5 times, preferably 1.3 to 2 times because it becomes hard and difficult to bend when it is small, and shape retention is reduced when it is large. The thickness of the low foam synthetic resin sheet is not particularly limited. However, if the thickness is reduced, the nose protection member cannot be provided with thickness and cushioning properties. 0.5-5 mm is preferable.

  The low foam synthetic resin sheet may be a laminated sheet in which an unfoamed synthetic resin layer is laminated on both sides of a low foam synthetic resin layer. The expansion ratio of the low foamed synthetic resin sheet is 1.2 to 5 times, preferably 1.3 to 2 times as a whole of the low foamed synthetic resin sheet. The thickness of the low foam synthetic resin sheet is preferably 0.5 to 5 mm.

  As the method for producing the low foam synthetic resin sheet, any conventionally known method may be employed. For example, a mixture of a synthetic resin and a foaming agent such as a chemical decomposition foaming agent or a physical foaming agent is extruded and foamed. It is manufactured by doing.

  Also, as the method for producing the laminated sheet, any conventionally known method may be employed. For example, a mixture of a synthetic resin and a foaming agent such as a chemical decomposition foaming agent and a physical foaming agent is extruded and foamed. Manufactured by coextrusion of unfoamed synthetic resin layers on both sides.

  As a method of laminating the stretched polyolefin resin sheet on both surfaces of the low foam synthetic resin sheet, any conventionally known method may be employed, and examples thereof include a method of bonding with an adhesive and a method of heat-sealing. . In particular, when the second polyolefin resin layer is laminated on the stretched polyolefin resin sheet, it is preferably heat-sealed.

  When the stretching direction of the stretched polyolefin resin sheets on both sides is different by 90 degrees, when the nose protection member is bent into the shape of the nose, the stretched polyolefin resin sheet having the same bending direction and stretching direction is liable to break. When the stretched direction of the stretched polyolefin resin sheet is different, the shape-retaining property is lowered. Therefore, the stretched polyolefin resin sheets on both sides are preferably laminated so that the stretch direction is the same direction.

  The stretched polyolefin resin sheet according to any one of claims 1 to 3, wherein the nose protection member is laminated on both surfaces of a low foam synthetic resin sheet having a foaming ratio of 1.2 to 5 times. The shape retaining property of the nose protection member is lower than the shape retaining property of the stretched polyolefin resin sheet according to any one of claims 1 to 3, but is 90 degrees for easy attachment and protection to the nose. It is preferable that the folding return angle θ is 20 degrees or less when it is bent and held for 1 minute and then released, and when 5 minutes have passed since the release.

  The stretchable polyolefin resin sheet according to any one of claims 1 to 3 is provided on both sides of a low foam synthetic resin sheet having a foaming ratio of 1.2 to 5 times. Two sheets are laminated, and the two oriented polyolefin resin sheets are laminated so that the stretching directions intersect each other.

  The low-foaming synthetic resin sheet is the same as the low-foaming synthetic resin sheet according to claim 4, and two stretched polyolefin resin sheets are laminated on both sides of the foaming synthetic resin sheet. The two stretched polyolefin resin sheets are laminated so that the stretching directions intersect each other.

  When two stretched polyolefin resin sheets are bonded, shape retention in any direction is improved, and the stretched polyolefin resin sheet is cracked even if the stretch direction and the bending direction of the stretched polyolefin resin sheet are the same. It won't be easy.

  The two stretched polyolefin resin sheets may be laminated so that the stretching directions intersect, but the intersecting angle is preferably 90 degrees from the viewpoint of shape retention. In addition, the nose protection member is bent in the shape of the nose and needs to have shape retention in the bent state, and therefore it is preferable that at least one of the stretched polyolefin resin sheets on both sides is stretched in the same direction. .

  As a method of laminating the stretched polyolefin resin sheet on both surfaces of the low foam synthetic resin sheet and laminating the stretched polyolefin resin sheets, any conventionally known method may be employed, for example, bonding with an adhesive. And a method of heat-sealing. In particular, when the second polyolefin resin layer is laminated on the stretched polyolefin resin sheet, it is preferably heat-sealed. Needless to say, three or more stretched polyolefin resin sheets may be laminated.

  The stretched polyolefin resin sheet according to any one of claims 1 to 3 is laminated on both sides of a low foam synthetic resin sheet having a foaming ratio of 1.2 to 5 times. The laminated polyolefin resin sheet according to any one of claims 1 to 3, wherein the two polyolefin polyolefin resin sheets are laminated so that the extending directions thereof intersect each other. However, in order to easily attach and protect to the nose, it is released after being bent at 90 degrees and held for 1 minute, and the folding return angle θ when 5 minutes have passed after release is 20 It is preferable that it is below the degree.

  The configuration of the nose protecting member of the present invention is as described above, and can be easily bent in the direction perpendicular to the extending direction of the stretched polyolefin resin sheet constituting the nose protecting member, and has an excellent shape retaining property in the bent shape. And mechanical strength is high. Therefore, it is possible to protect the nose by applying the stretched polyolefin resin sheet constituting the nose protection member so that the stretch direction of the stretched polyolefin resin sheet and the nasal bridge are substantially at right angles, and bending the nose shape and then fixing it with an adhesive tape or the like.

Next, examples of the present invention will be described, but the present invention is not limited to the following examples.
Example 1
A high-density polyethylene resin (manufactured by Nippon Polyethylene Co., Ltd.) having a weight average molecular weight (Mw) of 330,000 and a melting point of 135 ° C. is supplied to the same-direction biaxial kneading extruder (manufactured by Plastic Engineering Laboratory) and melt kneaded at a resin temperature of 200 ° C. After that, the melt-kneaded material was formed into a sheet having a width of 370 mm and a thickness of 2.5 mm using a calender molding machine controlled at a roll temperature of 110 ° C. to obtain a polyethylene resin sheet.

  The obtained polyethylene resin sheet was rolled at a rolling ratio of 9.5 times using a rolling molding machine (manufactured by Sekisui Koki Co., Ltd.) heated to 125 ° C. to obtain a rolled polyethylene resin sheet having a thickness of 0.27 mm. The obtained rolled polyethylene resin sheet was subjected to a multistage drawing of 1.83 times using a hot air heating type multistage drawing apparatus (manufactured by Kyowa Engineering) heated to 110 ° C., a total draw ratio of 17 times, a width of 280 mm, and a thickness of 0 A 19 mm stretched polyethylene resin sheet was obtained.

  The obtained stretched polyethylene resin sheet was supplied with a pinch roll to a hot air heating tank with a line length of 19.25 m set at 125 ° C. at an inlet speed of 2.75 m / min, and an outlet speed of 2.75 m / min. Set to, and then subjected to primary annealing for 7 minutes, followed by secondary annealing in the same manner to obtain an annealed stretched polyethylene resin sheet, which is then fed to a constant temperature bath at 60 ° C. and aged for 24 hours, An aged stretched polyethylene resin sheet was obtained.

  The obtained stretched polyethylene resin sheet was cut into a width of 1 cm and a length of 15 cm, bent at 180 degrees and 90 degrees so as to be orthogonal to the stretching direction of the stretched polyethylene resin sheet, held for 1 minute, and then released. When the bending return angle θ was measured when minutes passed, both were 5 ° to 10 °.

  A linear low density polyethylene resin (melting point 121 ° C.) was extruded on both sides of the obtained stretched polyethylene resin sheet, and a linear low density polyethylene resin layer having a thickness of 30 μm was laminated to obtain a laminated stretched polyethylene resin sheet. The obtained laminated stretched polyethylene resin sheet was punched into the shape shown in FIG. The stretching direction is the left-right direction in the figure.

  The obtained nose protection member is bent at 180 degrees and 90 degrees so as to be orthogonal to the stretching direction of the laminated stretched polyethylene resin sheet, held for 1 minute, and then released, and the folding return angle θ when 5 minutes have passed after the release is set. When measured, both were 5 to 10 degrees.

(Example 2)
A high-density polyethylene resin (manufactured by Nippon Polyethylene Co., Ltd.) having a weight average molecular weight (Mw) of 330,000 and a melting point of 135 ° C. is supplied to the same-direction biaxial kneading extruder (manufactured by Plastic Engineering Laboratory) and melt kneaded at a resin temperature of 200 ° C. After that, the melt-kneaded material was formed into a sheet having a width of 370 mm and a thickness of 2.5 mm using a calender molding machine controlled at a roll temperature of 110 ° C. to obtain a polyethylene resin sheet.

  The obtained polyethylene resin sheet was rolled at a rolling ratio of 9.5 times using a rolling molding machine (manufactured by Sekisui Koki Co., Ltd.) heated to 125 ° C. to obtain a rolled polyethylene resin sheet having a thickness of 0.27 mm. The obtained rolled polyethylene resin sheet was subjected to a multistage stretching of 1.83 times in a hot air heating type multistage stretching apparatus (manufactured by Kyowa Engineering) heated to 110 ° C., a total stretching ratio of 17 times, a width of 280 mm, and a thickness of 0 A 19 mm stretched polyethylene resin sheet was obtained.

  The obtained stretched polyethylene resin sheet was supplied with a pinch roll to a hot air heating tank with a line length of 19.25 m set at 125 ° C. at an inlet speed of 2.75 m / min, and an outlet speed of 2.75 m / min. Set to, and then subjected to primary annealing for 7 minutes, followed by secondary annealing in the same manner to obtain an annealed stretched polyethylene resin sheet, which is then fed to a constant temperature bath at 60 ° C. and aged for 24 hours, An aged stretched polyethylene resin sheet was obtained.

  The obtained stretched polyethylene resin sheet was cut into a width of 1 cm and a length of 15 cm, bent at 180 degrees and 90 degrees so as to be orthogonal to the stretching direction of the stretched polyethylene resin sheet, held for 1 minute, and then released. When the bending return angle θ was measured when minutes passed, both were 5 ° to 10 °.

  A linear low density polyethylene resin (melting point: 121 ° C.) is extruded on both sides of the obtained stretched polyethylene resin sheet, and a linear low density polyethylene resin layer having a thickness of 30 μm is laminated to form a laminate stretched polyethylene resin having a thickness of 0.25 mm. A sheet was obtained. The obtained laminated stretched polyethylene resin sheet was cut into a width of 1 cm and a length of 15 cm, bent at 180 degrees and 90 degrees so as to be orthogonal to the stretching direction of the laminated stretched polyethylene resin sheet, held for 1 minute, and then released. When the bending return angle θ was measured after the elapse of 5 minutes, both were 5 ° to 10 °.

  The obtained laminated stretched polyethylene resin sheet is heat-sealed on both sides of a low foaming polyethylene resin sheet having a foaming ratio of 1.5 times and a thickness of 0.5 mm, and is punched into the shape shown in FIG. 1 to protect the nose. Member 1 was obtained. FIG. 2 is a cross-sectional view of the obtained nose protection member, in which laminated stretched polyethylene resin sheets 3 and 31 are heat-sealed on both surfaces of the low foamed polyethylene resin sheet 2. The stretching directions of the laminated stretched polyethylene resin sheets 3 and 31 are the same in the horizontal direction in the figure.

    The low foam polyethylene resin sheet 2 is obtained by coextrusion of an unfoamed linear low density polyethylene resin layer having a thickness of 0.1 mm on both sides of a high density polyethylene resin layer having a foaming ratio of 2 times and a thickness of 0.3 mm. Laminated, the total expansion ratio was 1.5 times, and the thickness was 0.5 mm.

  The obtained nose protection member was bent at 90 degrees so as to be orthogonal to the extending direction of the laminated stretched polyethylene resin sheets 3 and 31, held for 1 minute and then released, and the folding return angle θ when 5 minutes passed after release was set to When measured, it was 10 to 15 degrees.

(Example 3)
Two layers of the stretched polyethylene resin sheet obtained in Example 2 were heat-sealed on both sides of the low foam polyethylene resin sheet used in Example 2 and punched into the shape shown in FIG. 1 to protect the nose. A member was obtained. FIG. 3 is a cross-sectional view of the obtained nose protecting member. Laminated stretched polyethylene resin sheets 4 and 41 are sequentially heat-sealed from one side of the low foamed polyethylene resin sheet 2 to one surface of the low foamed polyethylene resin sheet 2. The laminated stretched polyethylene resin sheets 5 and 51 are sequentially heat-sealed to the other surface from the low-foamed polyethylene resin sheet 2 side.

  The stretching directions of the laminated stretched polyethylene resin sheets 4 and 5 on the low foamed polyethylene resin sheet 2 side are the same in the front-rear direction in the figure. The stretching directions of the outer laminated stretched polyethylene resin sheets 41 and 51 are the same in the horizontal direction in the drawing. Accordingly, the stretching direction of the laminated stretched polyethylene resin sheets 4 and 5 and the stretching direction of the laminated stretched polyethylene resin sheets 41 and 51 are orthogonal to each other.

  The obtained nose protection member is bent at 90 degrees so as to be orthogonal to the extending direction of the laminated stretched polyethylene resin sheets 41 and 51, held for 1 minute, and then released. When measured, it was 10 to 15 degrees.

It is a top view which shows one example of the nose protection member of this invention. It is sectional drawing which shows the example from which the nose protection member of this invention differs. It is sectional drawing which shows the example from which the nose protection member of this invention differs.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Nose protection member 2 Low-foam polyethylene resin sheet 3 Laminated stretched polyethylene resin sheet 4 Laminated stretched polyethylene resin sheet 5 Laminated stretched polyethylene resin sheet

Claims (5)

  Folded at 180 degrees and 90 degrees, held for 1 minute, then released, and made of a stretched polyolefin resin sheet having shape retention with a folding return angle θ of 20 degrees or less when 5 minutes have passed after release. A nose protecting member.   The nasal protection member according to claim 1, wherein the stretched polyolefin resin sheet is obtained by uniaxially stretching a polyolefin resin sheet having a weight average molecular weight of 100,000 to 500,000 to a stretch ratio of 5 times or more.   The stretched polyolefin resin sheet is characterized in that a polyolefin resin sheet having a weight average molecular weight of 100,000 to 500,000 is rolled to a rolling ratio of 5 times or more and then uniaxially stretched to a total stretching ratio of 10 to 40 times. The nose protecting member according to claim 1.   A stretched polyolefin resin sheet according to any one of claims 1 to 3, wherein the stretched polyolefin resin sheet according to any one of claims 1 to 3 is laminated on both surfaces of a low foam synthetic resin sheet having a foaming ratio of 1.2 to 5 times. Element.   Two stretched polyolefin resin sheets according to any one of claims 1 to 3 are laminated on both surfaces of a low foam synthetic resin sheet having a foaming ratio of 1.2 to 5 times. A nose protecting member, wherein the stretched polyolefin resin sheets are laminated so that the stretching directions intersect each other.

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