JP2023136165A - Shape holding material and method for producing the same - Google Patents

Abstract

To provide a shape holding material which is formed of an olefin-based resin composition containing a biomass-derived polyolefin-based resin, and has large mechanical strength, especially, rigidity (tensile elastic modulus), and is excellent in shape retention property.SOLUTION: There are provided: a shape holding material that is a stretched molding formed of an olefin-based resin composition containing a biomass-derived polyolefin-based resin, which has shape retention property; and a method for producing a shape holding material which includes rolling and stretching a molding formed of an olefin-based resin composition containing a biomass-derived polyolefin-based resin, and then uniaxially stretching the molding by the total stretching ratio of 10 to 40 times.SELECTED DRAWING: Figure 1

Description

The present invention relates to a shape-retaining material made of a polyolefin resin including an environmentally friendly biomass-derived polyolefin resin, and a method for producing the same.

Conventionally, shape-retaining materials obtained by stretching thermoplastic resin sheets have been used as a binding alternative to metal wires because they can maintain the bent shape without returning to the original shape when the material is bent. It is used as a shape-retaining material for sheets, hat brim materials, masks, aprons, bags, etc.

The above-mentioned shape-retaining material is, for example, made by melting general-purpose polyethylene with an intrinsic viscosity of less than 3.5 dl/g and extruding it into a raw thread or raw belt shape, so that the maximum thickness of the polyethylene melt-solidified product is 1 mm. Formed into the above yarn or original belt, bent the stretched product 180 degrees at a temperature of 60°C or higher and lower than the melting point of polyethylene, and after 10 minutes the return angle is 20 degrees or less, and 90 degrees A method for producing a filament-like or band-like plastically deformable polyethylene material, which comprises stretching the material until the return angle is 15 degrees or less 10 minutes after bending." (For example, see Patent Document 1.) is 950 kg/m3 or ^more , weight average molecular weight (Mw)/number average molecular weight (Mn) is 5 to 15, and the content of α-olefin having 3 to 6 carbon atoms is less than 2% by weight.Ethylene homopolymer or ethylene-α - A shape-retaining material that is a stretched product made of an olefin copolymer and has a stretching ratio of 7 to 20 times, is a fibrous or band-like molded product, and has a return angle of 12 degrees or less when bent at 90 degrees. (for example, see Patent Document 2), etc., and ``shape-retaining material using polyethylene resin or ethylene-α-olefin copolymer'' is exemplified.

However, in recent years, with increasing calls for building a recycling-oriented society, the use of olefin resins such as polyethylene resin and polypropylene resin produced from fossil fuels, in other words, olefin resins derived from petroleum, has been avoided. It's here.

In addition, ``5 to 300 parts by weight of a flexible resin group made of at least one biodegradable polyester resin is mixed with 100 parts by weight of a fragile resin group made of at least one biodegradable polyester resin. extrusion molding a resin mixture in which the elongation of the tensile properties of the resin of the brittle resin group is 1 to 30% and the elongation of the tensile properties of the resin of the flexible resin group is 50 to 1000%. ``A method for improving the deformation retention of plastic materials, which is characterized by heat-treating at 30 to 150°C after cooling to room temperature'' (see, for example, Patent Document 3), and ``A method for improving shape retention using polylactic acid.'' "Materials" are exemplified.

Biodegradable polyester resins such as polylactic acid are biodegradable unlike olefin resins and the like, so they are preferable materials for protecting the global environment. However, biodegradable polyester resins such as polylactic acid are difficult to mold, and even if they can be molded, their mechanical strength is low and it is difficult to impart shape retention properties, making them unsuitable as shape retention materials.

Patent No. 5862055 Patent No. 6764754 Japanese Patent Application Publication No. 2006-117749

In view of the above problems, an object of the present invention is to provide an olefin resin composition containing a biomass-derived polyolefin resin, which has high mechanical strength, particularly rigidity (tensile modulus), and excellent shape retention. The purpose of this invention is to provide materials and methods for producing the same.

That is, the present invention
[1] A shape-retaining material that is a stretched molded article made of an olefin-based resin composition containing a biomass-derived olefin-based resin, and is characterized by having shape-retaining properties;
[2] The shape-retaining material according to [1] above, wherein the olefin resin composition consists of 5 to 100% by weight of a biomass-derived olefin resin and 95 to 0% by weight of a petroleum-derived olefin resin;
[3] The shape-retaining material according to [1] or [2] above, wherein the biomass-derived olefin resin is a biomass-derived high-density polyethylene resin;
[4] The shape-retaining material according to [2] or [3] above, wherein the petroleum-derived olefin resin is a petroleum-derived high-density polyethylene resin;
[5] Shape retention is determined by bending at 180 degrees in the direction (TD direction) perpendicular to the stretching direction (MD direction), holding it for 1 minute, releasing it, and returning the bending angle to 25% when 5 minutes have passed after release. The shape-retaining material according to any one of [1] to [4] above, characterized in that the shape-retaining material has a
[6] Shape retention is determined by bending at 90 degrees in a direction (TD direction) perpendicular to the stretching direction (MD direction), holding it for 1 minute, releasing it, and returning the bending angle to 15 5 minutes after release. The shape-retaining material according to any one of [1] to [5] above, characterized in that the shape-retaining material has a
[7] The shape-retaining material according to any one of [1] to [6] above, wherein the stretched molded product is linear, band-shaped, or sheet-shaped;
[8] Any one of the above [1] to [7], characterized in that a molded article made of an olefin resin composition containing a biomass-derived olefin resin is rolled and stretched at a rolling stretching ratio of 5 times or more. A method for manufacturing the shape-retaining material described above,
[9] According to any one of [1] to [7] above, the molded article made of an olefin resin composition containing a biomass-derived olefin resin is uniaxially stretched at a stretching ratio of 5 times or more. A method for producing a shape-retaining material,
[10] The above-mentioned [1] to [7] characterized in that a molded body made of an olefin resin composition containing a biomass-derived olefin resin is rolled and stretched, and then uniaxially stretched at a total stretching ratio of 10 to 40 times. A method for producing a shape-retaining material according to any one of
[11] The method for producing a shape-retaining material according to [10] above, characterized in that the rolling draw ratio is 5 times or more, and
[12] The method for producing a shape-retaining material according to [10] or [11] above, wherein the uniaxial stretching ratio is 1.1 times or more.

The configuration of the shape-retaining material and the method for producing the same of the present invention is as described above. A shape-retaining material with excellent retentivity can be provided.

(A) is a plan view showing an example of the shape-retaining material of the present invention, and (B) and (C) are side views showing a method for measuring the bending return angle (TD direction bending).

The shape-retaining material of the present invention is a stretched molded article made of an olefin-based resin composition containing a biomass-derived olefin-based resin, and is characterized by having shape-retaining properties.

The above-mentioned olefin resin composition is an olefin resin composition containing an olefin resin derived from biomass. That is, it is an olefin resin composition made of a biomass-derived polyolefin resin or an olefin resin composition made of a biomass-derived polyolefin resin and a petroleum-derived polyolefin resin.

If the amount of biomass-derived polyolefin resin added to the above olefin resin composition increases, the moldability may decrease or become brittle, resulting in a decrease in the mechanical strength of the molded product. In the case of a molded article, it is preferable to reduce the amount of biomass-derived polyolefin resin added. Therefore, the proportion of biomass-derived polyolefin resin in the olefin resin composition is preferably 5 to 100% by weight, and the proportion of petroleum-derived olefin resin is preferably 95 to 0 weight%.

If the ratio of biomass-derived polyolefin resin in the above olefin resin composition decreases, the ratio of petroleum-derived olefin resin will increase, and the effect of contributing to the creation of a recycling-oriented society will decrease. The biomass degree of is preferably higher, preferably 10% or more, and more preferably 30% or more.

The above-mentioned biomass-derived polyolefin resin is a polymer obtained by polymerizing olefin that has been chemically purified by reaction using ethanol produced from renewable natural raw materials (for example, corn, sugar cane, beets, manioc, etc.) as a raw material.

Examples of the biomass-derived polyolefin resin include polyethylene homopolymers such as high-density polyethylene resin, medium-density polyethylene resin, and low-density polyethylene resin; Copolymers with α-olefins such as hexene, 1-pentene and 1-heptene, polypropylene homopolymers such as homopolypropylene resins and random polypropylene resins, mainly consisting of propylene, ethylene, 1-butene, 1-hexene, -Copolymers with α-olefins such as pentene and 1-heptene, homopolymers of α-olefins such as 1-butene, 1-hexene, 1-pentene, and 1-heptene, and copolymers thereof, etc. , high density polyethylene resin, low density polyethylene resin and linear low density polyethylene resin are preferred. Note that these polyolefin resins may be used alone, or two or more types of polyolefin resins may be used in combination.

When the biomass content of the above-mentioned biomass-derived polyolefin resin decreases, the ratio of biomass olefin monomer in the biomass-derived polyolefin resin decreases, and the ratio of petroleum-derived olefin monomer increases, contributing to the creation of a recycling-oriented society. Since the effect decreases, the biomass degree of the olefin resin is preferably higher, preferably 50% or more, more preferably 90% or more, and even more preferably 95%.

The above-mentioned petroleum-derived polyolefin resins are polymers polymerized using conventionally used olefin monomers refined from petroleum as main raw materials, such as high-density polyethylene resin, medium-density polyethylene resin, low-density polyethylene resin, etc. Polyethylene homopolymers, copolymers mainly composed of ethylene and α-olefins such as propylene, 1-butene, 1-pentene, 1-hexene, 1-pentene, 1-heptene, homopolypropylene resins, random polypropylene resins Polypropylene homopolymers such as propylene, copolymers with α-olefins such as ethylene, 1-butene, 1-hexene, 1-pentene, 1-heptene, 1-butene, 1-hexene, 1- Examples include homopolymers of α-olefins such as pentene and 1-heptene, and copolymers thereof, and high-density polyethylene resins, low-density polyethylene resins, and linear low-density polyethylene resins are preferred. Note that these polyolefin resins may be used alone, or two or more types of polyolefin resins may be used in combination.

As the biomass-derived polyolefin resin and the petroleum-derived polyolefin resin, high-density polyethylene resin is particularly preferred.

The above-mentioned high-density polyethylene resin is polymerized by a medium-low pressure method and has a density of 0.945 to 0.960 g/cm ³ , and contains trace amounts of propylene, butene-1, pentene-1, hexene-1, α-olefin such as octene-1 may be copolymerized.

If the weight average molecular weight of the high density polyethylene resin is less than 100,000, it will become brittle, its stretchability will decrease, and a stretched molded product with sufficient mechanical strength or creep resistance will not be obtained. On the other hand, if it exceeds 500,000, the melt viscosity will increase, the hot-melt molding processability will decrease, and it will be difficult to obtain a uniform stretched molded product, so 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).

Further, the melt mass flow rate (hereinafter referred to as "MFR") of the high density polyethylene resin is preferably 0.1 to 20 g/10 min, more preferably 0.20 to 0.60 g/10 min, which provides excellent film formability. minutes, more preferably 0.30 to 0.45 g/10 minutes. Note that MFR is an index representing the melt viscosity of a thermoplastic resin as defined in JIS K 7210.

The density of the above-mentioned high-density polyethylene resin is 0.945 to 0.945 to 0.0.0. It is preferably 960 g/cm ³ , more preferably 0.950 to 0.960 g/cm ³ .

In addition, the polyolefin resin composition may contain, as required, within a shape-retentive range, materials commonly used in the molding of polyolefin resins, such as calcium carbonate, magnesium carbonate, and aluminum oxide. , inorganic fillers such as magnesium oxide, titanium oxide, magnesium hydroxide, talc, mica, and clay, heat stabilizers, heat resistance improvers, light stabilizers, ultraviolet absorbers, antioxidants, impact modifiers, antifogging agents, Additives such as antistatic agents, flame retardants, colorants, and pigments may be added as necessary.

The stretched molded product is a molded product that has shape retention properties and is obtained by stretching a molded product made of an olefin resin composition containing the biomass-derived olefin resin. The shape of the molded product is not particularly limited, but since it is a shape-retaining material, it is preferably fibrous, band-like, sheet-like, or the like.

The method for producing a fibrous, band-like, sheet-like, etc. molded article before stretching is not particularly limited, and any conventionally known production method may be adopted, such as extrusion method, inflation method, casting method, T-die method, etc. method, calendar method, etc.

A stretched molded article in the form of a fiber, a belt, a sheet, etc. is obtained by stretching the molded article in the form of a fiber, a belt, a sheet, etc., and shape retention is imparted by stretching. The stretching ratio of the stretched molded product is not particularly limited, as long as the stretched molded product has shape retention properties, and is generally 5 times or more, preferably 10 to 40 times.

The above-mentioned shape-retaining material has shape-retaining property, and shape-retaining property is the ability of the shape-retaining material to maintain the deformed shape as it is, and in the present invention, the shape-retaining material is ) is bent at 180 degrees in the direction perpendicular to the direction (TD direction) and held for 1 minute, then released, and the bending return angle (hereinafter referred to as "180 degree bending return angle") and the stretching direction ( Bend it at 90 degrees perpendicular to the MD direction (TD direction), hold it for 1 minute, release it, and evaluate it by the bending return angle (hereinafter referred to as "90 degree bending return angle") 5 minutes after release. did.

Shape retention is the property of retaining a deformed shape as it is, so the smaller the return angle, the better the shape retention.The "180 degree return angle" is preferably 25 degrees or less, and more Preferably it is 22 degrees or less. Further, the "90 degree bending return angle" is preferably 15 degrees or less, more preferably 12 degrees or less.

Next, a method for measuring the "180 degree bending return angle" will be explained with reference to the drawings. FIG. 1(A) is a plan view showing an example of the shape-retaining material of the present invention, and FIGS. 1(B) and 1(C) are side views showing a method for measuring the bending return angle. In the figure, numeral 1 is a shape-retaining material, which is stretched in the direction of the arrow X. That is, the X direction is the stretching direction and the MD direction. The arrow Y direction is perpendicular to the stretching direction (MD direction) (TD direction).

To measure the "180 degree bending return angle", first, the flat shape-retaining material 1 shown in FIG. Fold it in half and stack it in two layers (folded at 180 degrees) as shown in Figure 1(B). When they are stacked and released after holding their shape for 1 minute, the stacked shape-retaining materials act to return to their original shape, as shown in Figure 1 (C), so 5 minutes have passed after release. When this is done, the angle θ formed by the two layers (the angle at which the molded product returned to its original shape after being bent by 180 degrees) is measured. This angle θ is the "180 degree bending return angle".

The method for measuring the "90 degree bending return angle" is the same as the "measuring method for the 180 degree return angle" except that the bending angle is 90 degrees. In other words, the method for measuring the "90 degree bend return angle" is to bend a flat shape-retaining material to 90 degrees in a direction (TD direction) perpendicular to the drawing direction (MD direction), hold that shape for 1 minute, and then release it. Then, since the shape-retaining material acts to return to its original shape, the angle formed by the bent shape-retaining material is measured 5 minutes after release. The angle obtained by subtracting 90 degrees from the measured angle (the angle at which the shape-retaining material bent to 90 degrees returns to its original shape) is the "90 degree bending return angle."

A linear, band-shaped or sheet-shaped stretched molded body is produced by stretching the above-mentioned linear, band-shaped or sheet-shaped molded body. Any conventionally known stretching method may be used as the stretching method, and examples thereof include rolling stretching, uniaxial stretching, and a combination of rolling stretching and uniaxial stretching.

That is, the method for producing a shape-retaining material of the present invention involves rolling and stretching a linear, band-shaped, sheet-shaped, etc. shaped body made of an olefin resin composition containing a biomass-derived olefin resin at a rolling ratio of 5 times or more. It is characterized by

The thickness or thickness of the linear, band-shaped, sheet-like, etc. molded object before rolling and stretching is not particularly limited, but if it is too thick or thick, a large pressure will be applied to crush the molded object with the rolling rolls. It may be difficult to roll uniformly in the width direction due to deflection of the rolling rolls, etc. On the other hand, if it is too thin, the thickness of the formed product after rolling and stretching may become too thin or the thickness may become too thin. The thickness is preferably 0.2 to 15.0 mm because not only will it become too thin, making uniform rolling and stretching difficult, but also the rolling rolls may come into contact with each other, shortening the life of the rolling rolls.

If the rolling temperature is too low, it will not be possible to roll and stretch uniformly, and if it is too high, melting will occur. The range is preferably from "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 an endothermic peak associated with melting of a crystal, which is observed when performing thermal analysis with a differential scanning calorimeter (DSC).

If the pressing force (linear pressure) applied to the compact by the rolling rolls is too small, it may not be possible to obtain the desired rolling ratio; on the other hand, if it is too large, not only will the rolling rolls become deflected, but the rolling The pressing force is preferably 100 MPa to 3000 MPa, more preferably 300 MPa to 1000 MPa, since slipping may easily occur between the molded body and the molded body, making uniform rolling and stretching difficult.

The rolling draw ratio is 5 times or more, preferably 7 times or more, and more preferably 9 times or more, since sufficient shape retention cannot be imparted if the rolling draw ratio is less than 5 times. Although there is no upper limit to the rolling/stretching ratio, it is preferably 40 times or less because the higher the rolling/stretching ratio is, the more load is placed on the rolling equipment. The rolling draw ratio is defined as (cross-sectional area of the compact before rolling)/(cross-sectional area of the compact after rolling), but since the width of the compact does not change much before and after rolling, The ratio may be (thickness of the previous molded body)/(thickness of the molded body after rolling and stretching).

A different method for producing a shape-retaining material of the present invention involves uniaxially stretching a linear, band-shaped, sheet-shaped, etc. molded body made of an olefin resin composition containing a biomass-derived olefin resin to a stretching ratio of 5 times or more. Features.

The above-mentioned uniaxial 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 highly stretched, a multi-stage uniaxial stretching method in which uniaxial stretching is repeated multiple times is preferred. When carrying out multi-stage uniaxial stretching, the number of stretching is preferably from 2 to 20 times, more preferably from 3 to 15 times, still more preferably from 4 to 10 times.

Further, when multi-stage stretching is performed by a roll uniaxial stretching method, it is desirable to install a feed-out pinch roll, a take-up pinch roll, and at least one, preferably a plurality of contact rolls rotating at a constant speed between these rolls. By installing such a contact roll, uniform stretchability is improved and stable stretch forming can be performed.

The contact rolls perform uniaxial stretching by applying frictional force to the molded body without being pinched. Further, the contact roll may be connected to the feeding roll and/or the take-up roll by a connecting member consisting of a gear, a chain, a pulley, a belt, or a combination thereof.

If the uniaxial stretching temperature is too low, uniform stretching will not be possible, and if it is too high, the molded product will melt and break. The melting point of the resin is -50°C to -5°C.

The thickness or thickness of the linear, band-shaped, or sheet-shaped molded product before stretching is not particularly limited, but if it is too thick or thick, it will be difficult to stretch, and conversely, if it is too thin or If it is too large, the thickness of the stretched molded product will be too thin or too thin, resulting in poor shape retention, so it is preferably 0.2 to 15.0 mm.

The above stretching ratio is 5 times or more, preferably 7 times or more, and more preferably 9 times or more, since sufficient shape retention may not be imparted if the stretching ratio is less than 5 times. . Although there is no upper limit to the stretching ratio, the higher the stretching ratio, the lower the manufacturing efficiency, so it is preferably 40 times or less. Note that the stretching ratio is defined as (cross-sectional area of the molded body before stretching)/(cross-sectional area of the molded body after stretching).

A further different method for producing a shape-retaining material of the present invention is to roll and stretch a linear, band-shaped, sheet-shaped, etc. molded body made of an olefin resin composition containing a biomass-derived olefin resin, and then to apply a total stretching ratio of 10 to 10. It is characterized by being uniaxially stretched 40 times.

The thickness or thickness of the linear, band-shaped, sheet-shaped, etc. shaped product to be stretched before rolling is not particularly limited, but if it is too thick or thick, rolling stretching and uniaxial stretching will become difficult, and vice versa. On the other hand, if it is too thin or too thin, the thickness of the molded product after rolling and stretching and uniaxial stretching will be too thin and the shape retention will be reduced, so it is preferably 0.2 to 15.0 mm.

In the method for manufacturing the shape-retaining material described above, a linear, band-shaped, sheet-shaped, etc. shaped body is rolled and stretched, and then uniaxially stretched at a total stretching ratio of 10 to 40 times. As mentioned above.

If the rolling ratio is less than 5 times, the effect of suppressing necking during uniaxial stretching performed later may not be obtained, high-magnification uniaxial stretching may not be possible, or the uniaxial stretching process may not be possible. Since this places a burden on the operator, it is preferably 5 times or more, more preferably 7 times or more. Although there is no upper limit to the rolling ratio, it is preferably 11 times or less because the higher the rolling ratio is, the more load is placed on the rolling equipment.

The stretching ratio for the above uniaxial stretching is 10 to 40 times the total stretching ratio, so it is sufficient to consider the rolling ratio and determine the total stretching ratio within this range. However, if the uniaxial stretching is small, the mechanical Since the strength does not improve, it is preferably 1.1 times or more, more preferably 1.3 times or more. The upper limit is not particularly limited, but is preferably 4 times or less, more preferably 3.0 times or less. Incidentally, the total stretching ratio is a value obtained by multiplying the rolling ratio by the uniaxial stretching ratio.

In order to improve the dimensional stability of the shape-retaining material obtained by the above production method, it may be annealed at a temperature between "melting point -60° C." and the melting point of the polyolefin resin. If the annealing temperature is low, the dimensional stability will not improve and warping will occur if used for a long time, and if the annealing temperature is high, the polyolefin resin will dissolve and the orientation will disappear, reducing the tensile modulus, tensile strength, etc. It is preferable to anneal at a temperature between "melting point -60° C." and the melting point of the resin.

Annealing is heat treatment carried out on the production line. During annealing, if the shape-retaining material is under high tension, it will be stretched, and if no tension or very little tension is applied, it will shrink, so it will retain its shape. It is preferable that the length of the shape-retaining material in the stretching direction is not substantially changed, and it is also preferable that no pressure is applied to the shape-retaining material. That is, it is preferable to perform annealing so that the length of the annealed shape-retaining material is 1.0 or less of the length of the shape-retaining material before annealing.

Therefore, when continuously annealing the shape-retaining material while moving it inside the heating chamber with rolls such as pinch rolls, the feed speed ratio of the shape-retaining material on the inlet and outlet sides should be set to 1.0 or less. It is preferable to perform annealing.

The heating method used for annealing is not particularly limited, and examples thereof include methods of heating with hot air, a heater, a heating plate, hot water, and the like. The annealing time is not particularly limited and varies depending on the thickness and annealing temperature of the stretched shape-retaining material, but is generally preferably 10 seconds or more, more preferably 30 seconds to 60 minutes, and even more preferably 1 ~20 minutes.

The annealed shape-retaining material may be further aged at a temperature ranging from 40° C. to the melting point of the polyolefin resin. By aging, the dimensional stability of the annealed shape-retaining material becomes better.

Aging is not a process that is carried out continuously on a production line, but rather a heat treatment process of shape-retaining materials that have been processed once, such as sheets, rolls, etc., by allowing them to rest for a relatively long time (in minutes or hours). means. If the aging temperature is low, it will be the same as leaving it at room temperature, and if it is high, it will be thermally deformed, so it should be in the temperature range from 40℃ to the melting point of polyolefin resin. The period of 12 hours to 7 days is preferable since the effect will not increase even if the treatment is carried out.

The thickness and thickness of the shape-retaining material are not particularly limited, but are preferably from 0.04 to 2 mm because shape-retaining properties decrease when the material becomes thin or thin.

Next, the present invention will be explained, but the present invention is not limited to the examples.

The olefin resins used are as follows.
(1) Biomass-derived polyethylene resin/Bio-HDPE High density polyethylene resin (manufactured by Braskem, MFR (190°C/2.16Kg) 0.33g/10min, melting point approximately 140°C, density 0.952g/cm ³ , Biomass degree 96%)
・Bio-LLDPE linear low density polyethylene resin (manufactured by Braskem, MFR (190°C/2.16Kg) 1.0g/10min, melting point approximately 130°C, density 0.916g/cm ³ , biomass degree 84%)

(2) Petroleum-derived polyethylene resin/p-HDPE High-density polyethylene resin (manufactured by Japan Polyethylene Co., Ltd., MFR (190℃/
2.16Kg) 0.4g/10min, melting point 133℃, density 0.956g/ ^cm3 )
・p-LDPE low density polyethylene resin (manufactured by Sumitomo Chemical Co., Ltd., MFR (190℃/2.16
Kg) 0.3g/10min, melting point 108℃, density 0.922g/ ^cm3 )

(Example 1, Comparative Example 1)
The predetermined amounts of the olefin resin composition shown in Tables 1 and 2, consisting of Bio-HDPE and p-HDPE, were supplied to a single screw extruder with a screw diameter of 70 mm, and after melt-kneading at 200°C, the melt-kneaded product was was molded into a sheet using a calendar molding machine with a roll temperature controlled at 110° C. to obtain a sheet-like molded product. The biomass degree of the olefin resin composition was measured and is also listed in Tables 1 and 2.

The obtained molded body was rolled and stretched to the rolling ratio shown in Tables 1 and 2 using a rolling molding machine (manufactured by Sekisui Koki Seisakusho) heated to 125° C. to obtain a stretched molded body. The obtained stretched molded product was supplied to a hot air heating tank with a line length of 19.25 m, which was equipped with pinch rolls and set at 125°C, at an inlet speed of 2.75 m/min, and an outlet speed of 2.75 m/min. First annealing was performed for 7 minutes, followed by second annealing in the same manner to obtain an annealed stretched molded product, which was then supplied to a constant temperature bath at 60°C and aged for 24 hours to maintain shape. I got the material.

The obtained shape-retaining material was cut to a width of 10 mm and a length of 15 cm, and was fed to a Tensilon universal testing machine ("RTC-1250A type" manufactured by Orientec), and was tested in the stretching direction (MD direction) and the direction perpendicular to the stretching direction. A tensile test was performed in the TD direction at a speed of 100 mm/min until breaking, and the tensile modulus, maximum tensile strength, and elongation at break were measured. The results are shown in Tables 1 and 2.

In addition, the obtained shape-retaining material was cut into pieces of 10 mm in width and 15 cm in length, bent at 90 degrees and 180 degrees in the direction perpendicular to the stretching direction (TD direction), held for 1 minute, and then released. The bending return angles ("90 degree bending return angle" and "180 degree bending return angle") after minutes were measured, and the results are shown in Tables 1 and 2.

(Examples 2 to 7, Comparative Examples 2 and 3)
The predetermined amounts of the olefin resin compositions shown in Tables 1 and 2, consisting of Bio-HDPE, Bio-LLDPE, p-HDPE, and p-LDPE, were supplied to a single screw extruder with a screw diameter of 70 mm, and melted and mixed at 200°C. After kneading, the melted and kneaded product was formed into a sheet using a calendar background air controlled at a roll temperature of 110° C. to obtain a sheet-like molded product. The biomass degree of the olefin resin composition was measured and is also listed in Tables 1 and 2.

The obtained molded body was rolled to the rolling ratio shown in Tables 1 and 2 using a rolling machine heated to 125° C. (manufactured by Sekisui Koki Seisakusho) to obtain a stretched molded body. The obtained stretched product was subjected to uniaxial multistage stretching to the stretching ratios shown in Tables 1 and 2 using a hot air heating type multistage stretching device (manufactured by Kyowa Engineering) heated to 110°C. A stretched molded article having a total stretching ratio was obtained.

The obtained stretched molded product was supplied to a hot air heating tank with a line length of 19.25 m, which was equipped with pinch rolls and set at 125°C, at an inlet speed of 2.75 m/min, and an outlet speed of 2.75 m/min. First annealing was performed for 7 minutes, followed by second annealing in the same manner to obtain an annealed stretched molded product, which was then supplied to a constant temperature bath at 60°C and aged for 24 hours to maintain shape. I got the material.

The obtained shape-retaining material was cut to a width of 10 mm and a length of 15 cm, and was fed to a Tensilon universal testing machine ("RTC-1250A type" manufactured by Orientec), and was tested in the stretching direction (MD direction) and the direction perpendicular to the stretching direction. A tensile test was performed in the TD direction at a speed of 100 mm/min until breaking, and the tensile modulus, maximum tensile strength, and elongation at break were measured. The results are shown in Tables 1 and 2.

In addition, the obtained shape-retaining material was cut into pieces of 10 mm in width and 15 cm in length, bent at 90 degrees and 180 degrees in the direction perpendicular to the stretching direction (TD direction), held for 1 minute, and then released. The bending return angles ("90 degree bending return angle" and "180 degree bending return angle") after minutes were measured, and the results are shown in Tables 1 and 2.

The shape-retaining material of the present invention is as described above, and is made of an olefin resin composition containing a biomass-derived polyolefin resin, is environmentally friendly, has excellent mechanical strength such as tensile modulus and tensile strength, and retains its shape. Due to its excellent properties, it is suitable as a binding material to replace metal wire, core material for the brim of hats, shape-retaining core material for masks, aprons, bags, etc., lid material for containers such as cup ramen noodles, and cutting blades for saran wrap. Can be used. Further, it can be suitably used as a laminated sheet laminated with paper, synthetic resin film, etc., or a composite body laminated with a molded article.

1 Shape-retaining material X MD direction (stretching direction)
Y TD direction (direction perpendicular to the stretching direction)
θ Bending return angle

Claims (12)

A shape-retaining material that is a stretched molded article made of an olefin-based resin composition containing a biomass-derived olefin-based resin, and is characterized by having shape-retaining properties. The shape-retaining material according to claim 1, wherein the olefin resin composition comprises 5 to 100% by weight of a biomass-derived olefin resin and 95 to 0 weight% of a petroleum-derived olefin resin. The shape-retaining material according to claim 1 or 2, wherein the biomass-derived olefin resin is a biomass-derived high-density polyethylene resin. The shape-retaining material according to claim 2 or 3, wherein the petroleum-derived olefin resin is a petroleum-derived high-density polyethylene resin. Shape retention is determined by bending at 180 degrees in the direction (TD direction) perpendicular to the stretching direction (MD direction), holding it for 1 minute, releasing it, and returning the bending angle to 25 degrees or less 5 minutes after release. Shape-retaining material according to any one of claims 1 to 4, characterized in that: Shape retention is determined by bending at 90 degrees in the direction (TD direction) perpendicular to the stretching direction (MD direction), holding it for 1 minute, releasing it, and returning the bending angle to 15 degrees or less 5 minutes after release. Shape-retaining material according to any one of claims 1 to 5, characterized in that: The shape-retaining material according to any one of claims 1 to 6, wherein the stretched molded body is linear, band-shaped, or sheet-shaped. The shape-retaining material according to any one of claims 1 to 7, characterized in that a molded body made of an olefin resin composition containing a biomass-derived olefin resin is rolled and stretched at a rolling stretching ratio of 5 times or more. Production method. Production of the shape-retaining material according to any one of claims 1 to 7, characterized in that a molded body made of an olefin resin composition containing a biomass-derived olefin resin is uniaxially stretched at a stretching ratio of 5 times or more. Method. According to any one of claims 1 to 7, the molded body made of an olefin resin composition containing a biomass-derived olefin resin is rolled and stretched, and then uniaxially stretched at a total stretching ratio of 10 to 40 times. A method of manufacturing the shape-retaining material described. 11. The method for producing a shape-retaining material according to claim 10, wherein the rolling draw ratio is 5 times or more. The method for producing a shape-retaining material according to claim 10 or 11, wherein the uniaxial stretching ratio is 1.1 times or more.

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