JP2004090608A - Laminated sheet having foldable ruled line and molded article using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated sheet having foldable ruled lines which is excellent in heat resistance and ruled line working properties, and its molded article. <P>SOLUTION: The laminated sheet having the foldable ruled lines, in which the foldable ruled lines are provided to a biodegradable laminated sheet having an un-oriented polylactic acid resin layer and a layer made of biodegradable resins except a polylactic acid resin, is used. <P>COPYRIGHT: (C)2004,JPO

Description

【００８４】
［結果］
表１に示すように、実施例１〜６については何れの罫線加工刃で罫線加工を行ったものでも罫線加工性、罫線部の耐折性、耐熱性に問題なく、良好な折り曲げ罫線入りシート、及び成形加工品が得られた。またポリ乳酸系樹脂以外の生分解性樹脂からなる層の比率が小さいものや、ポリ乳酸系樹脂の結晶化度が低いものについては透明性も良好であった。
一方、比較例１ではポリ乳酸系樹脂以外の生分解性樹脂からなる層が無いために、罫線加工時に数枚程度の割れが発生し、罫線加工時に割れが発生しなかったサンプルでも罫線部の耐折性評価で全てが何れの罫線刃で罫線を行った場合でも１〜２回の操作で罫線部に割れが発生した。
また比較例１のシートでは耐熱性試験においてシート同士のブロッキングが見られ、またシートも変形していた。
比較例２では耐熱性に問題はなかったが、罫線加工性、及び罫線部の耐折性については比較例１とほぼ同様な結果であった。
比較例３においては罫線加工性、罫線部の耐折性、及び耐熱性何れの試験においても比較例１とほぼ同様な結果であった。
【００８５】
【発明の効果】
以上のように本発明ではポリ乳酸系樹脂とポリ乳酸系樹脂以外の生分解性樹脂の積層シートを用いることで耐熱性、罫線加工性に優れた折り曲げ罫線入り積層シート、及びその成形加工品を提供することが出来る。
【図面の簡単な説明】
【図１】折り曲げ罫線を設けたシートの例を示す斜視図
【図２】折り曲げ罫線を設けたシートの他の例を示す斜視図
【図３】折り曲げ罫線を設けたシートの他の例を示す斜視図
【図４】（ａ）折り曲げ罫線を設けたシートの他の例を示す斜視図
（ｂ）（ａ）のＡ−Ａ断面図
【図５】（ａ）折り曲げ罫線を設けたシートの他の例を示す斜視図
（ｂ）（ａ）のＥ−Ｅ断面図
【図６】（ａ）折り曲げ罫線を設けたシートの他の例を示す斜視図
（ｂ）（ａ）のＢ−Ｂ断面図
【図７】（ａ）折り曲げ罫線を設けたシートの他の例を示す斜視図
（ｂ）（ａ）のＣ−Ｃ断面図
（ｃ）（ａ）のＤ−Ｄ断面図
【図８】罫線刃の例を示す斜視図
【図９】罫線刃の他の例を示す斜視図
【図１０】罫線刃の他の例を示す斜視図
【図１１】罫線刃の他の例を示す斜視図
【図１２】罫線刃の他の例を示す斜視図
【図１３】罫線刃の他の例を示す斜視図
【図１４】（ａ）罫線刃の他の例を示す斜視図
（ｂ）（ａ）の正面図
（ｃ）（ａ）の側面図
【符号の説明】
１　シート
２ａ、２ｂ、２ｃ、２ｄ、２ｅ、２ｆ　凹溝
３ａ　凸部
３ｂ　円弧状凸部
４　深溝
５　断続孔
６　深溝部
７　延伸部
１１ａ、１１ｂ、１１ｃ、１１ｄ、１１ｅ、１１ｆ、１１ｇ　罫線刃
１２ａ、１２ｂ、１２ｃ、１２ｄ、１２ｅ、１２ｆ、１２ｇ　刃先
１３　突状部
１４ａ　凹部
１４ｂ　円弧状凹部
１５　突状部
１６　突起部
１７　凸部[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a laminated sheet with a folded crease, and a molded product using the laminated sheet with a folded crease.
More specifically, a laminated sheet with a folded ruled line using a polylactic acid-based resin that is excellent in heat resistance and crease processability and decomposes in a natural environment, and a plastic folded and assembled along the folded ruled line of the laminated sheet with a folded ruled line The present invention relates to a molded product such as a case, a calendar storage case, an advertising panel, and various bent plates.
[0002]
[Prior art]
A plastic case for storing cosmetics, fragrances, stationery, miscellaneous goods, etc., a case for storing a desktop calendar, advertising panels used in vending machines and stores, and various folding plates, etc. Processed products that are bent along the ruled lines and assembled have been used in many cases. As such materials, polypropylene, polyvinyl chloride, polystyrene, polyethylene terephthalate and the like have been conventionally used. These plastic products are generally disposable, and when disposed after use, disposal such as incineration or landfill is a problem. Resins such as polypropylene and polystyrene generate a large amount of heat during combustion and may damage the incinerator during the burning process. Polyvinyl chloride generates harmful gases during incineration.
[0003]
On the other hand, even in landfills, these plastic products have high chemical stability, are hardly decomposed in the natural environment, and remain semi-permanently in the soil, saturating the capacity of the land for garbage disposal in a short period of time. In addition, when dumped into the natural environment, the landscape is impaired or the living environment such as marine life is destroyed.
[0004]
Therefore, from the viewpoint of environmental protection, research and development of biodegradable materials have been actively performed in recent years. Polylactic acid is one of the biodegradable materials that has attracted attention. Since polylactic acid-based resin is biodegradable, hydrolysis proceeds spontaneously in soil or water, and becomes a harmless degradation product by microorganisms. Further, since the combustion heat is small, even if incineration is performed, the furnace is not damaged.
Furthermore, since the starting material is derived from a plant, it has such features that it can escape from depleting petroleum resources.
[0005]
[Problems to be solved by the invention]
However, polylactic acid-based resin is hard and brittle, is a material that is weak to impact, and has only a few percent elongation at break. Therefore, when a folding ruled line is to be provided on such a sheet, the sheet may be broken. In addition, even if the sheet does not crack when the folding ruled line is provided, the sheet may be broken at the time of folding.
[0006]
In addition, polylactic acid-based resin has low heat resistance, and when storing or transporting polylactic acid-based resin sheets and molded products, the inside of storage, trucks and ships, and ships may reach high temperatures in the summer, etc. Since the number is not small, problems such as deformation and fusion may occur.
[0007]
Therefore, an object of the present invention is to provide a folded creased laminated sheet having excellent heat resistance and crease workability, and a molded product thereof.
[0008]
[Means for Solving the Problems]
As a result of intensive studies to solve the above-described problems, a sheet excellent in heat resistance and crease line processing by laminating a layer made of a polylactic acid-based resin and a biodegradable resin other than the polylactic acid-based resin, and It was found that a molded product using the sheet was obtained, and the present invention was completed.
[0009]
The invention related to the laminated sheet with a folded crease according to the present application is a sheet provided with a folded crease in a biodegradable laminated sheet having an unstretched polylactic acid-based resin layer and a layer made of a biodegradable resin other than the polylactic acid-based resin. It depends on.
[0010]
Furthermore, the biodegradable resin other than the polylactic acid-based resin can be a biodegradable aliphatic polyester other than the polylactic acid-based resin having a glass transition temperature of 0 ° C. or lower and a melting point of 80 ° C. or higher.
[0011]
Further, the crystallinity of the unstretched polylactic acid-based resin layer can be set to 20% or less.
[0012]
Further, a layer formed of at least three layers and made of a biodegradable resin other than the polylactic acid-based resin constitutes both outer layers, and at least one layer of the unstretched polylactic acid-based resin layer sandwiched between both outer layers. Certain biodegradable laminate sheets can be provided with folding ruled lines.
[0013]
Furthermore, the value of the haze measured by the measuring method of JIS K7105 can be set to 40% or less.
[0014]
Further, the undrawn polylactic acid-based resin and a biodegradable resin other than the polylactic acid-based resin can be laminated by co-extrusion.
[0015]
Furthermore, a molded product can be obtained by folding and assembling the laminated sheet with the folding ruled line according to any of the above-mentioned along the folding ruled line.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described.
The laminated sheet with a folded crease according to the present invention is a laminated sheet provided with a folded crease on a biodegradable laminated sheet having a layer made of an unstretched polylactic acid-based resin and a layer made of a biodegradable resin other than the polylactic acid-based resin. It is.
[0017]
The polylactic acid-based resin used in the present invention is composed of a polylactic acid-based polymer. As the polylactic acid-based polymer, a homopolymer having a structural unit of L-lactic acid or D-lactic acid, that is, poly (L-lactic acid) or poly (D-lactic acid), and structural units of L-lactic acid and D-lactic acid And poly (DL-lactic acid) and a mixture thereof, and may be a copolymer with α-hydroxycarboxylic acid or diol / dicarboxylic acid.
[0018]
As a polymerization method of the polylactic acid-based polymer, any known method such as a condensation polymerization method and a ring-opening polymerization method can be adopted. For example, in the polycondensation method, L-lactic acid or D-lactic acid, or a mixture thereof can be directly dehydrated and polycondensed to obtain a polylactic acid-based polymer having an arbitrary composition.
[0019]
In the ring-opening polymerization method, a polylactic acid-based polymer can be obtained from lactide, which is a cyclic dimer of lactic acid, by using a selected catalyst while using a polymerization regulator and the like as necessary. Lactide includes L-lactide which is a dimer of L-lactic acid, D-lactide which is a dimer of D-lactic acid, and DL-lactide composed of L-lactic acid and D-lactic acid. By mixing and polymerizing, a polylactic acid-based polymer having an arbitrary composition and crystallinity can be obtained.
[0020]
Further, as necessary, a non-aliphatic dicarboxylic acid such as terephthalic acid, a non-aliphatic diol such as an ethylene oxide adduct of bisphenol A, or the like may be used as a small amount of a copolymer component as needed to improve heat resistance.
Furthermore, a small amount of a chain extender, for example, a diisocyanate compound, an epoxy compound, an acid anhydride or the like can be used for the purpose of increasing the molecular weight.
[0021]
The other hydroxy-carboxylic acid units copolymerized with the polylactic acid-based polymer include optical isomers of lactic acid (D-lactic acid for L-lactic acid and L-lactic acid for D-lactic acid). ), Glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxy-n-butyric acid, 2-hydroxy-3,3-dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, 2-methyllactic acid, 2-hydroxycaprol Examples include bifunctional aliphatic hydroxy-carboxylic acids such as acids and lactones such as caprolactone, butyrolactone and valerolactone.
[0022]
Examples of the aliphatic diol copolymerized with the polylactic acid-based polymer include ethylene glycol, 1,4-butanediol, and 1,4-cyclohexanedimethanol. Examples of the aliphatic dicarboxylic acids include succinic acid, adipic acid, suberic acid, sebacic acid, dodecandioic acid, and the like.
However, in these cases, the composition ratio in the polylactic acid-based resin is mainly polylactic acid, and the mol% is lactic acid: 50 mol% or more.
[0023]
The preferred range of the weight-average molecular weight of the polylactic acid-based polymer is 50,000 to 400,000, preferably 100,000 to 250,000. Melt viscosity is too high and molding processability is poor.
[0024]
The biodegradable resin other than the polylactic acid-based resin is a component for imparting heat resistance and proper crease processing to the obtained biodegradable laminated sheet and a molded product thereof.
[0025]
Examples of the biodegradable resin other than the polylactic acid resin include a polyesteramide resin, a cellulose resin, a biodegradable aliphatic polyester other than the polylactic acid resin, polyvinyl alcohol, and polyurethane.
[0026]
Examples of the polyesteramide-based resin include a copolymer of caprolactone and caprolactam, and examples of the cellulose-based resin include cellulose acetate.
[0027]
Examples of the biodegradable aliphatic polyester other than the polylactic acid-based resin include polyhydroxycarboxylic acid, aliphatic polyester or aliphatic aromatic polyester obtained by condensing aliphatic diol and aliphatic dicarboxylic acid or aromatic dicarboxylic acid, Aliphatic diols and aliphatic dicarboxylic acids, and aliphatic polyester copolymers obtained from hydroxycarboxylic acids, aliphatic polyesters obtained by ring-opening polymerization of cyclic lactones, synthetic aliphatic polyesters, aliphatics biosynthesized in cells Polyester and the like.
[0028]
Examples of polyhydroxycarboxylic acids include 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxy-n-butyric acid, 2-hydroxy-3,3-dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, 2-methyllactic acid, Examples thereof include homopolymers and copolymers of hydroxycarboxylic acids such as 2-hydroxycaproic acid.
[0029]
Examples of the aliphatic diol include ethylene glycol, 1,4-butanediol, and 1,4-cyclohexanedimethanol. Examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, suberic acid, sebacic acid, dodecandioic acid, and the like.
Examples of the aromatic dicarboxylic acid include terephthalic acid and isophthalic acid.
[0030]
Aliphatic polyesters obtained by condensing these aliphatic diols and aliphatic dicarboxylic acids, and aliphatic aromatic polyesters obtained by condensing aliphatic diols, aliphatic dicarboxylic acids and aromatic dicarboxylic acids are those described above. One or more compounds are each selected from the compounds, polycondensed, and, if necessary, jumped up with an isocyanate compound or the like to obtain a desired polymer.
[0031]
Aliphatic diols and aliphatic dicarboxylic acids, and aliphatic diols used in the aliphatic polyester copolymer obtained from hydroxycarboxylic acid, aliphatic carboxylic acids include the same as those described above, and also for hydroxycarboxylic acid L-lactic acid, D-lactic acid, DL-lactic acid, glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxy-n-butyric acid, 2-hydroxy-3,3-dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, -Methyl lactic acid, 2-hydroxycaproic acid and the like, such as polybutylene succinate lactic acid and polybutylene succinate adipate lactic acid.
[0032]
However, the composition ratio in this case is mainly composed of an aliphatic diol and an aliphatic dicarboxylic acid, and the mol% is aliphatic diol: 35 to 49.99 mol%, aliphatic dicarboxylic acid: 35 to 49.99 mol%. , Hydroxycarboxylic acid: 0.02 to 30 mol%.
[0033]
The aliphatic polyester obtained by ring-opening polymerization of the above-mentioned cyclic lactones can be obtained by polymerizing one or more kinds of cyclic monomers such as ε-caprolactone, δ-valerolactone, β-methyl-δ-valerolactone, and the like.
[0034]
Examples of the synthetic aliphatic polyester include a cyclic acid anhydride and an oxirane, for example, a copolymer of succinic anhydride and ethylene oxide, propylene oxide, or the like.
[0035]
Examples of the aliphatic polyester biosynthesized in the cells include aliphatic polyesters biosynthesized by acetyl coenzyme A (acetyl CoA) in cells such as alkaligenes eutrophus. The aliphatic polyester biosynthesized in the cells is mainly poly-β-hydroxybutyric acid (poly 3HB). To improve practical properties as plastics, hydroxyvaleric acid (HV) is copolymerized. It is industrially advantageous to use a poly (3HB-CO-3HV) copolymer. Generally, the HV copolymerization ratio is preferably from 0 to 40 mol%. Further, instead of hydroxyvaleric acid, a long-chain hydroxyalkanoate such as 3-hydroxyhexanoate, 3-hydroxyoctanoate, or 3-hydroxyoctadecanoate may be copolymerized.
[0036]
Preferred specific examples of the biodegradable aliphatic polyester other than the polylactic acid-based resin include polybutylene succinate, polybutylene succinate adipate, polybutylene adipate terephthalate, polybutylene succinate adipate terephthalate, polybutylene succinate lactic acid, At least one selected from the group consisting of polybutylene succinate adipate lactic acid, polyester carbonate, a copolymer of polyhydroxybutyrate and polyhydroxyvalerate, and a copolymer of polyhydroxybutyrate and polyhydroxyhexanoate be able to.
[0037]
In the case where transparency (visibility of contents) is required for a molded product obtained from the laminated sheet with the folded ruled line of the present invention, the unstretched polylactic acid-based component constituting one layer of the laminated sheet of the present invention is used. The crystallinity of the resin is preferably 20% or less, more preferably 15% or less, and further preferably 10% or less.
[0038]
The method for suppressing the crystallinity of the unstretched polylactic acid-based resin to 20% or less is not particularly limited. For example, a method in which a sheet extruded by an extruder is rapidly cooled by a cooling roll such as a casting roll to suppress crystallization, A method of adjusting the ratio of D-lactic acid and L-lactic acid in the lactic acid-based resin to lower the crystallinity of the polylactic acid-based resin itself, and the like.
[0039]
If the crystallinity of the unstretched polylactic acid-based resin layer exceeds 20%, the transparency may be reduced due to the growth of spherulites, and the visibility of the contents may be deteriorated.
When transparency (visibility of contents) is also required, the value of haze measured by the measuring method of JIS K7105 is preferably 40% or less. If the haze exceeds 40%, the visibility of the contents deteriorates.
The lower limit of the crystallinity of the polylactic acid resin is not limited as long as it is 20% or less, and may be 0%.
[0040]
The unstretched polylactic acid-based resin layer is preferably unstretched. When a sheet obtained by stretching a polylactic acid-based resin is used, in order to obtain a molded body, for example, 9 kg / cm ² An excessively large pressure is required, and it is difficult to perform molding at a low pressure such as vacuum molding. Further, the stretched sheet is disadvantageous in terms of cost because an extra stretching step is required as compared with an unstretched sheet.
[0041]
The glass transition temperature of the biodegradable resin other than the polylactic acid-based resin which is a component of the other layer of the laminated sheet of the present invention is preferably 0 ° C or lower, more preferably -20 ° C or lower. If the temperature is higher than 0 ° C., the effect of improving the impact resistance becomes insufficient, and the workability of the crease may become a problem. The lower limit of the glass transition temperature is not particularly limited, but is preferably -60 ° C or higher in practice. Materials having a glass transition temperature lower than -60 ° C may have a melting point lower than 80 ° C and insufficient heat resistance.
[0042]
Further, the melting point of the biodegradable resin other than the polylactic acid-based resin needs to be 80 ° C. or higher. When the melting point is 80 ° C. or less, the heat resistance of the molded body may be insufficient. The upper limit of the melting point is not particularly limited, but is preferably 170 ° C. from the viewpoint of moldability.
[0043]
The layer made of a biodegradable resin other than the polylactic acid-based resin may be stretched or unstretched, but as described above, unstretched is more preferable in terms of cost. preferable.
[0044]
The thickness of the layer made of a biodegradable resin other than the polylactic acid-based resin is preferably 2 μm or more. If the thickness is less than 2 μm, the effect of improving the impact resistance becomes insufficient, and there is a case where the ruled line workability becomes a problem.
[0045]
The thickness of the laminated sheet of the present invention is not particularly limited as long as it is a thickness that can be used for ordinary ruled line processing, but the total thickness is usually in the range of 0.1 to 1.0 mm.
[0046]
The relationship between the thickness of the layer made of a biodegradable resin other than the polylactic acid resin and the total thickness of the layer is not particularly limited as long as there is no practical problem. The layer thickness ratio of the resin layer is 0.005 to 0.7 with respect to the total layer thickness.
[0047]
The thickness of the layer of the polylactic acid-based resin is a thickness obtained by subtracting the thickness of the layer made of a biodegradable resin other than the polylactic acid-based resin from the thickness of the entire layer.
[0048]
The biodegradable laminated sheet of the present invention may include at least two layers of the predetermined unstretched polylactic acid-based resin layer and a layer made of a biodegradable resin other than the predetermined polylactic acid-based resin. What is necessary is just to be formed from two layers.
[0049]
In particular, when the biodegradable laminated sheet of the present invention is formed of at least three layers, a layer made of a biodegradable resin other than the polylactic acid-based resin constitutes both outer layers, and the unstretched polylactic acid-based resin is formed. The case where the layer is at least one of the layers sandwiched between the outer layers is preferable from the viewpoint of heat resistance.
[0050]
In addition, scraps generated during the manufacturing process may be recycled into the other layer as long as the object of the present invention is not impaired.
[0051]
The method for producing a laminated sheet of the present invention is not particularly limited as long as the object of the present invention is not impaired. For example, (1) a polylactic acid-based resin layer and a layer made of a biodegradable resin other than the polylactic acid-based resin may be used. A co-extrusion method in which two or more extruders are used and laminated with a multi-manifold or feed block type die and extruded as a molten sheet, (2) one of the unwound layers is coated with another resin Methods, (3) a method of thermocompression bonding each layer at an appropriate temperature using a roll or a press, or (4) a method of laminating using an adhesive, etc. Considering the simplicity and cost of the manufacturing process, Coextrusion is preferred.
[0052]
Further, the laminated sheet of the present invention can be subjected to various modifications by adding a secondary additive. Examples of secondary additives include stabilizers, antioxidants, ultraviolet absorbers, pigments, electrostatic agents, conductive agents, mold release agents, plasticizers, fragrances, antibacterial agents, nucleating agents, and the like. No.
[0053]
The laminated sheet of the present invention is provided with a folding ruled line having a predetermined shape. Examples of the shape of the folding ruled line include the shapes shown in FIGS.
[0054]
The folding ruled line shown in FIG. 1 is a ruled line formed by providing a concave groove 2 a having a V-shaped cross section in the laminated sheet 1 of the present invention.
[0055]
The folding ruled line shown in FIG. 2 is formed by providing a concave groove 2b having a W-shaped cross section, and the folding ruled line shown in FIG. 3 is formed by providing a concave groove 2c having a trapezoidal cross section. It is the formed ruled line. These folded ruled lines are formed by pressing the blade edges 12a, 12b, 12c of the ruled line blades 11a, 11b, 11c shown in FIGS.
[0056]
The folded ruled lines shown in FIGS. 4A and 4B are ruled lines in which a V-shaped concave groove 2d is provided in the laminated sheet 1 of the present invention, and irregularities are formed at the bottom of the concave groove along the length direction thereof. .
[0057]
The concave portion of this unevenness is formed from the bottom of the concave groove 2d, and the concave portion exerts flexibility when bending the laminated sheet 1 of the present invention. In addition, the strength of the laminated sheet 1 of the present invention when folded can be maintained by the convex portions 3a of the irregularities. By providing the irregularities, it is possible to prevent the occurrence of cracks or the like when bending the laminated sheet of the present invention. In addition, the concave groove 2d of the folding ruled line is not limited to the V-shape, and may have any shape such as a trapezoidal shape or a U-shape.
[0058]
The folded ruled lines shown in FIGS. 4A and 4B are formed by pressing the cutting edge 12d of the ruled line blade 11d shown in FIG. The cutting edge 12 d has a recess 14 a intermittently provided in a part of the protruding portion 13.
[0059]
The folded ruled lines shown in FIGS. 5A and 5B are formed by pressing the cutting edge 12e of the ruled line blade 11e shown in FIG. The cutting edge 12e is provided with arc-shaped concave portions 14b at regular intervals.
[0060]
6A and 6B, the laminated sheet 1 of the present invention is provided with a V-shaped or U-shaped concave groove 2f in the laminated sheet 1 and intermittently formed at the bottom of the concave groove along its length direction. This is a ruled line in which a deep groove 4 is provided and an intermittent hole 5 is formed in the deep groove 4. When this folding ruled line is provided, unevenness is formed by the concave groove 2f and the deep groove 4, and as in the case of the folding ruled line shown in FIG. 4, flexibility is exhibited and strength is maintained, and the laminated sheet 1 of the present invention is folded. The occurrence of cracks or the like can be prevented. In addition, since the intermittent hole 5 is provided, the distortion and elasticity generated when the laminated sheet 1 of the present invention is folded along the folding ruled line is dispersed and uniform in the length direction of the concave groove 2e and becomes smaller. The angle becomes accurate, and the flatness after assembly is improved.
[0061]
The folding ruled lines shown in FIGS. 6A and 6B are formed by pressing the cutting edge 12f of the ruled line blade 11f shown in FIG. The cutting edge 12f has a protruding portion 16 intermittently protruding from a part of the protruding portion 15.
[0062]
7 (a) to 7 (c) are the ruled lines in which the laminated sheet 1 of the present invention is provided with the V-shaped deep groove portions 6 and the extending portions 7 formed by grooves shallower than the deep groove portions 6 alternately. It is. When this folding ruled line is provided, even if the average thickness of the entire folded ruled line portion is reduced, the strength of this portion is particularly increased by the extending portion 7, so that when the laminated sheet 1 of the present invention is folded along the folded ruled line, Sheet cracking is suppressed. For this reason, a thin and sharp bent portion can be obtained.
[0063]
The folded creases are formed by pressing the intermittently provided cutting edge 12g of the protruding crease blade 11g shown in FIGS. Is formed, and the plastic sheet portion between the cutting edges 12g is stretched in the width direction by the above-mentioned spreading, so that a stretched portion 7 is formed between the deep groove portions 6. By forming the projections 17 having saddle-shaped upper surfaces between the ruled-line blades 11g, the shape of the upper surface of the extending portion 7 of the obtained folded crease becomes saddle-shaped.
[0064]
The haze value of the entire laminated sheet with folded creases according to the present invention is preferably 40% or less, and more preferably 30% or less. If it exceeds 40%, the articles stored in the container obtained from the folded creased laminated sheet are difficult to see from the outside, which is not preferable. Incidentally, the haze value is not particularly limited as long as it is 40% or less, and may be 0%.
The haze value can be measured by a measuring method according to JIS K7105.
[0065]
The laminated sheet with a folding ruled line according to the present invention can be assembled into a molded product by folding the sheet along the folding ruled line. Examples of the molded product include a plastic case for storing cosmetics, fragrances, stationery, miscellaneous goods, etc., a case for storing a desktop calendar, an advertising panel and an external POP stored in a vending machine, and a storefront. Swing POP or various bending plates used in the above.
[0066]
【Example】
Hereinafter, the present invention will be described in detail with reference to Production Examples, Examples, and Comparative Examples, but the present invention is not limited by these. The physical property values in the examples and comparative examples were measured and evaluated by the following methods.
[0067]
◆ Crease processing
The sheet was subjected to crease processing using a predetermined crease blade, and the presence or absence of cracks in the sheet during the crease processing was visually checked, and a determination was made based on the following criteria.
：: A ruled line was formed on 10 sheets, and no crack was generated.
X: A ruled line was formed on 10 sheets, and even one sheet was cracked.
[0068]
◆ Folding resistance of ruled line
The sheet with the ruled line is first folded 180 ° with the side with the ruled line outside, then returned to the original state, and then folded 180 ° with the side with the ruled line inside. The above operation was performed once, and it was visually confirmed how many times the ruled line portion was cracked, and the determination was made according to the following criteria.
：: No cracks occurred in the ruled line portion even after repeated 10 times or more. (Are better)
Δ: Cracks occurred in the ruled line portion after 5 to 10 operations. (Practical level)
×: A crack occurred in the ruled line portion by 5 or less operations. (There is a problem in practical use)
[0069]
◆ Heat resistance
Ten sheets with ruled lines were stacked and treated for 24 hours under the conditions of 60 ° C. × 90% RH. The appearance change and blocking of the sheet were confirmed, and the judgment was made according to the following criteria.
：: No change in appearance or blocking between sheets.
×: Changes in appearance and / or blocking between sheets were observed.
[0070]
◆ Crystallization temperature
Based on JIS-K-7121, ΔHm and ΔHc attributable to the polylactic acid-based resin in the biodegradable sheet were measured by differential scanning calorimetry (DSC) at a heating rate of 10 ° C./min. Was used to calculate the degree of crystallinity of the polylactic acid-based resin.
Crystallinity: Δc% = (ΔHm−ΔHc) / (92.8 × Ratio of polylactic acid-based resin in sheet) × 100
[0071]
◆ Shock resistance
Using a Toyo Seiki hydro shot impact tester (model HTM-1), a hammer having a diameter of 1/2 inch was made to collide with the biodegradable sheet at a temperature of 23 ° C. at a speed of 3 m / sec and required for destruction. Energy was calculated.
[0072]
◆ Melting point
Based on JIS-K-7121, the melting point was measured at a heating rate of 10 ° C./min by differential scanning calorimetry (DSC).
[0073]
◆ Haze
The haze of the folded ruled sheet obtained in the examples and comparative examples was measured based on JIS-K-7105.
[0074]
[Example 1]
15 ppm of tin octylate was added to 100 kg of L-lactide (trade name: PURASORB L) manufactured by Purak Japan, and the mixture was placed in a 500-liter batch polymerization tank equipped with a stirrer and a heating device. After nitrogen substitution, polymerization was carried out at 185 ° C. and a stirring speed of 100 rpm for 60 minutes. The obtained melt is supplied to a Mitsubishi Heavy Industries 40 mmφ co-axial twin-screw extruder equipped with three stages of vacuum vents, extruded into a strand at 200 ° C. while devolatilizing at a vent pressure of 4 torr, and pelletized at 70 ° C. × 24 hours. Let dry.
The weight average molecular weight of the obtained polylactic acid-based resin was 200,000, and the L-form content was 99.5%. The melting point by DSC was 171 ° C. This pellet was supplied to a φ65 mm single screw extruder, and extruded at 200 ° C. from a multi-manifold type die as an intermediate layer.
At the same time, dry pellets of polybutylene succinate adipate (Bionole 3003 manufactured by Showa Polymer, melting point: 95 ° C, glass transition point: -40 ° C) as a biodegradable resin other than the polylactic acid resin are supplied to a φ32 single screw extruder. Then, it was extruded at 190 ° C. from a multi-manifold type die for the front and back layers. At this time, the extrusion rate was adjusted so that the thickness ratio of the surface layer, the intermediate layer, and the back layer was approximately 1: 28: 1.
The extruded molten sheet was brought into contact with a cast roll at 40 ° C. to obtain a biodegradable laminated sheet having a thickness of 300 μm. The crystallinity of the polylactic acid-based resin in the obtained biodegradable laminated sheet was 9%.
Next, the ruled line blades 11a, 11b, 11d, 11f, and 11g shown in FIGS. 8, 9, 11, 13, and 14 are pressed against the sheet, and FIG. 1, FIG. 2, FIG. 4, FIG. A sheet with a folding ruled line shown in No. 7 was produced. The resulting creased sheet was evaluated for crease workability, crease resistance, heat resistance, impact resistance, and haze of the crease portion. Table 1 shows the results.
[0075]
[Example 2]
A biodegradable laminated sheet was obtained in the same manner as in Example 1 except that the thickness ratio of the surface layer, the intermediate layer, and the back layer was changed to 1: 8: 1. The crystallinity of the polylactic acid-based resin in the obtained biodegradable laminated sheet was 8%.
Further, using the obtained biodegradable laminated sheet, crease processing was performed in the same manner as in Example 1 to obtain a sheet with a folded crease.
The same evaluation as in Example 1 was performed on the obtained sheet. Table 1 shows the results.
[0076]
[Example 3]
A biodegradable laminated sheet was obtained in the same manner as in Example 1 except that the thickness ratio of the surface layer, the intermediate layer, and the back layer was changed to 1: 4: 1. The crystallinity of the polylactic acid-based resin in the obtained biodegradable laminated sheet was 8%.
In addition, using the obtained biodegradable laminated sheet, crease processing was performed in the same manner as in Example 1 to obtain a folded crease-lined sheet.
The same evaluation as in Example 1 was performed on the obtained sheet. Table 1 shows the results.
[0077]
[Example 4]
Biodegradation was performed in the same manner as in Example 1 except that polybutylene succinate (Bionole 1001, manufactured by Showa Kobunshi, melting point: 111 ° C, glass transition point: -40 ° C) was used as a biodegradable resin other than the polylactic acid-based resin. A laminated sheet was obtained. The crystallinity of the polylactic acid-based resin in the obtained biodegradable laminated sheet was 8%.
In addition, using the obtained biodegradable laminated sheet, crease processing was performed in the same manner as in Example 1 to obtain a folded crease-lined sheet.
The same evaluation as in Example 1 was performed on the obtained sheet. Table 1 shows the results.
[0078]
[Example 5]
The biodegradable laminated sheet obtained in Example 1 was subjected to a heat treatment in a hot air oven at 80 ° C. for 24 hours. The crystallinity of the polylactic acid-based resin in the biodegradable laminated sheet obtained after the heat treatment was 33%.
In addition, using the obtained biodegradable laminated sheet, crease processing was performed in the same manner as in Example 1 to obtain a folded crease-lined sheet.
The same evaluation as in Example 1 was performed on the obtained sheet. Table 1 shows the results.
[0079]
[Example 6]
To 500 kg of L-lactide (trade name: PURASORB L) manufactured by Purak Japan and 10 kg of DL-lactide (trade name: PURASORB DL) manufactured by the company, 15 ppm of tin octylate was added, and a 500-liter batch polymerization equipped with a stirrer and a heating device was added. Put in the tank. After nitrogen substitution, polymerization was carried out at 185 ° C. and a stirring speed of 100 rpm for 60 minutes. The obtained melt is supplied to a Mitsubishi Heavy Industries 40 mmφ co-axial twin-screw extruder equipped with three stages of vacuum vents, extruded into a strand at 200 ° C. while devolatilizing at a vent pressure of 4 torr, pelletized, and 70 ° C. × Dry for 24 hr. The weight average molecular weight of the obtained lactic acid-based resin was 200,000, and the L-form content was 94.8%. The melting point by DSC was 165 ° C.
A biodegradable laminated sheet was obtained in the same manner as in Example 1 except that the above pellets were used. The crystallinity of the polylactic acid-based resin in the obtained biodegradable laminated sheet was 4%.
In addition, using the obtained biodegradable laminated sheet, crease processing was performed in the same manner as in Example 1 to obtain a folded crease-lined sheet.
The same evaluation as in Example 1 was performed on the obtained sheet. Table 1 shows the results.
[0080]
[Comparative Example 1]
The polylactic acid-based resin used in Example 1 was supplied to a φ65 mm single screw extruder, and extruded at 200 ° C. from a single-layer die. The extruded molten sheet was brought into contact with a cast roll at 40 ° C. to obtain a 300 μm-thick polylactic acid-based resin single layer sheet.
The crystallinity of the polylactic acid-based resin in the obtained biodegradable sheet was 8%.
In addition, using the obtained biodegradable laminated sheet, crease processing was performed in the same manner as in Example 1 to obtain a folded crease-lined sheet.
The same evaluation as in Example 1 was performed on the obtained sheet. Table 1 shows the results.
[0081]
[Comparative Example 2]
The biodegradable sheet obtained in Comparative Example 1 was heat-treated in a hot-air oven at 80 ° C. for 24 hours. The crystallinity of the polylactic acid-based resin in the biodegradable sheet obtained after the heat treatment was 35%.
In addition, using the obtained biodegradable sheet, a crease process was performed in the same manner as in Example 1 to obtain a folded crease sheet.
The same evaluation as in Example 1 was performed on the obtained sheet. Table 1 shows the results.
[0082]
[Comparative Example 3]
The polylactic acid-based resin used in Example 6 was extruded in the same manner as in Comparative Example 1 to obtain a 300 μm-thick polylactic acid-based resin single-layer sheet. The crystallinity of the polylactic acid-based resin in the obtained biodegradable sheet was 4%.
In addition, using the obtained biodegradable sheet, a crease process was performed in the same manner as in Example 1 to obtain a folded crease sheet.
The same evaluation as in Example 1 was performed on the obtained sheet. Table 1 shows the results.
[0083]
[Table 1]

[0084]
[result]
As shown in Table 1, in Examples 1 to 6, even if the crease processing was performed with any of the crease processing blades, there was no problem in the crease processing property, the folding resistance of the crease portion, and the heat resistance, and the sheet with a good creased crease was provided. , And molded products were obtained. Further, those having a small ratio of a layer made of a biodegradable resin other than the polylactic acid-based resin and those having a low crystallinity of the polylactic acid-based resin also had good transparency.
On the other hand, in Comparative Example 1, since there was no layer made of a biodegradable resin other than the polylactic acid-based resin, about several cracks were generated at the time of crease processing. In the evaluation of the folding resistance, even when the ruled line was formed with any ruled line blade, cracks occurred in the ruled line portion by one or two operations.
Further, in the sheet of Comparative Example 1, blocking between the sheets was observed in the heat resistance test, and the sheet was also deformed.
Although there was no problem with the heat resistance in Comparative Example 2, the results were substantially the same as those in Comparative Example 1 with regard to the ruled line workability and the folding resistance of the ruled line portion.
In Comparative Example 3, the results were almost the same as those of Comparative Example 1 in any of the tests of the ruled line workability, the folding resistance of the ruled line portion, and the heat resistance.
[0085]
【The invention's effect】
As described above, in the present invention, by using a laminated sheet of a polylactic acid-based resin and a biodegradable resin other than the polylactic acid-based resin, heat resistance, a folded creased laminated sheet excellent in crease processing, and a molded product thereof. Can be provided.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an example of a sheet provided with folding ruled lines.
FIG. 2 is a perspective view showing another example of a sheet provided with folding ruled lines.
FIG. 3 is a perspective view showing another example of a sheet provided with folding ruled lines.
FIG. 4A is a perspective view showing another example of a sheet provided with folding ruled lines.
(B) AA sectional view of (a)
FIG. 5A is a perspective view showing another example of a sheet provided with folding ruled lines.
(B) EE sectional view of (a)
FIG. 6A is a perspective view showing another example of a sheet provided with folding ruled lines.
(B) BB sectional view of (a)
FIG. 7A is a perspective view showing another example of a sheet provided with folding ruled lines.
(B) CC sectional view of (a)
(C) DD sectional view of (a)
FIG. 8 is a perspective view showing an example of a ruled line blade.
FIG. 9 is a perspective view showing another example of the ruled line blade.
FIG. 10 is a perspective view showing another example of the ruled line blade.
FIG. 11 is a perspective view showing another example of a ruled line blade.
FIG. 12 is a perspective view showing another example of a ruled line blade.
FIG. 13 is a perspective view showing another example of the ruled line blade.
FIG. 14A is a perspective view showing another example of the ruled line blade.
(B) Front view of (a)
(C) Side view of (a)
[Explanation of symbols]
1 sheet
2a, 2b, 2c, 2d, 2e, 2f Groove
3a convex part
3b Arc-shaped convex
4 Deep groove
5 Intermittent hole
6 Deep groove
7 Extension section
11a, 11b, 11c, 11d, 11e, 11f, 11g Ruled line blade
12a, 12b, 12c, 12d, 12e, 12f, 12g
13 Projection
14a recess
14b Arc-shaped recess
15 Projection
16 Projection
17 Convex part

Claims (7)

A laminated sheet having a folding ruled line provided with a folding rule in a biodegradable laminated sheet having an unstretched polylactic acid-based resin layer and a layer made of a biodegradable resin other than the polylactic acid-based resin. The biodegradable resin according to claim 1, wherein the biodegradable resin other than the polylactic acid-based resin is a biodegradable aliphatic polyester other than the polylactic acid-based resin having a glass transition temperature of 0 ° C or lower and a melting point of 80 ° C or higher. Laminated sheet. The laminated sheet with a folded crease according to claim 1 or 2, wherein the unstretched polylactic acid-based resin layer has a crystallinity of 20% or less. A layer formed of at least three layers and made of a biodegradable resin other than the polylactic acid-based resin constitutes both outer layers, and the unstretched polylactic acid-based resin layer is at least one layer sandwiched between both outer layers. The laminated sheet with a folded ruled line according to any one of claims 1 to 3, wherein the degradable laminated sheet is provided with a folded ruled line. The laminated sheet with a folded crease according to any one of claims 1 to 4, wherein the value of the haze measured by the measuring method according to JIS K7105 is 40% or less. The laminated sheet with a folded crease according to any one of claims 1 to 5, wherein the unstretched polylactic acid-based resin and a biodegradable resin other than the polylactic acid-based resin are laminated by coextrusion. A molded product obtained by folding the laminated sheet with a folding ruled line according to any one of claims 1 to 6 along the folding ruled line.

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