JP6540524B2 - Translucent wood grain oriented film - Google Patents

Description

  The present invention relates to a wood grain oriented film having translucency and having a fibrous design appearance.

  Conventionally, translucent paper such as transparencies, glassine paper, paraffin paper and sulfuric acid paper can be printed with letters, patterns, etc. on its surface to enhance the sense of luxury and design, and the contents It is also used for food packaging etc. because it is possible to confirm However, such paper loses translucency when the thickness is increased and mechanical strength is insufficient when the thickness is decreased. In addition, paper dust is generated at the time of printing, cutting, packaging, etc., which causes problems such as deterioration of printability and cutting workability, and contamination of packages. Furthermore, compared with plastic films, they are low in moisture resistance, water resistance and oil resistance, and can not be used for packaging of food and the like containing water and oil. In addition, paper generally does not have heat sealability, and can not be used for packaging forms that require heat sealability.

  On the other hand, plastic films are excellent in moisture resistance, water resistance and oil resistance, and have good mechanical strength, and thus they are used as packaging paper for food, medicine and the like. However, a plastic film has high transparency, and if it is not printed on the entire surface, it is difficult to visually recognize characters, patterns and the like, and moreover, since the texture is uniform, it is difficult to obtain high-class feeling and design. For this reason, plastic films have a problem that it is difficult to attract the attention of consumers.

  Patent Document 1 proposes a polypropylene biaxially stretched film having a pearly luster formed from a polypropylene resin composition containing polypropylene and a specific calcium carbonate powder.

  Patent Document 2 proposes an opaque polyolefin resin film containing a petroleum resin having a polar group and / or a hydride thereof.

  Patent Document 3 proposes an opaque polyolefin-based film composed of a crystalline polyolefin and a cyclic olefin-based resin.

Japanese Patent Application Laid-Open No. 11-005852 JP, 2001-019808, A Japanese Patent Application Laid-Open No. 8-73618

However, regarding the above-mentioned patent documents 1, calcium carbonate used for the above-mentioned polypropylene biaxial drawing film is opaque, and a translucent film is not obtained. Also, the above polypropylene-based opaque film does not have the wood grain appearance of the film of the present invention. In addition, contamination of the package due to the falling off of the particles and contamination of the printing plate in printing applications may occur, and it can not be said that cutting workability is also good.
Moreover, regarding the said patent document 2, since the said polyolefin-type opaque film does not necessarily have a high softening point, it may be inferior to heat resistance. Therefore, the film is not suitable for use in heat drying as a printing substrate or recording paper substrate. Also, the above-mentioned polyolefin-based opaque film does not have the wood grain appearance of the film of the present invention.
Moreover, regarding the said patent document 3, since the dispersibility of the said crystalline olefin and the said cyclic olefin resin is not necessarily favorable, a cyclic olefin resin is not finely dispersed, but the appearance becomes opaque. Moreover, the said opaque polyolefin-type film does not have the wood grain appearance of the film of this invention.
Under these circumstances, it is desirable to have a film made of plastic that has higher moisture resistance, water resistance, oil resistance and mechanical strength than paper, but also has translucency and has an appearance with excellent design. ing.
Therefore, an object of the present invention is to provide a stretched film which is translucent and has a woodgrain appearance.

  The present inventors have one or more layers containing at least a crystalline polypropylene resin A and an amorphous cyclic olefin resin B having a Tg of 142 ° C. or more and 185 ° C. or less as a resin component, and the above layers The above-mentioned problem can be solved by a translucent wood grain stretched film containing 70% by weight or more of crystalline polypropylene resin A and 25% by weight or less of amorphous cyclic olefin resin B based on the resin component. The present invention has been completed.

That is, the present invention includes the following.
[1] A translucent wood grain having one or more layers containing at least a crystalline polypropylene resin A and an amorphous cyclic olefin resin B as a resin component, and having a total light transmittance of 35% to 85%. A stretched film, wherein the layer contains 70% by weight or more of a crystalline polypropylene resin A and 25% by weight or less of an amorphous cyclic olefin resin B based on the resin component, and the amorphous cyclic ring The olefin resin B is a translucent wood grain stretched film having a glass transition temperature of 142 ° C. or more and 185 ° C. or less.
[2] The translucent wood grain oriented stretched film according to [1], wherein the non-crystalline cyclic olefin resin B is a copolymer of ethylene and norbornene.
[3] The translucent wood grain oriented stretched film according to [1] or [2], wherein the polypropylene resin A has a melting point of 155 ° C. or more and 170 ° C. or less.
[4] The translucent wood grain stretched film according to any one of [1] to [3], having a total light transmittance of more than 50%.
[5] The translucent wood grain stretched film according to any one of [1] to [4], which is a biaxially stretched film.
[6] The translucent wood grain oriented stretched film according to any one of [1] to [5], wherein the ash content in the film is 1% by weight or less based on the film.
[7] The translucent wood grain oriented film according to any one of [1] to [6], further having a gloss reducing layer.
[8] The translucent wood grain oriented film according to any one of [1] to [7], further having a heat seal layer.
[9] A method for producing a translucent wood grain stretched film according to any one of [1] to [8], which comprises a resin composition containing a crystalline polypropylene resin A and an amorphous cyclic olefin resin B. A production method comprising the steps of feeding to an extruder, heating and melting, and then extruding into a film.
[10] The method according to [9], wherein the resin composition is extruded into a film at a cylinder temperature of an extruder at 200 to 260 ° C.
[11] The production method according to [9] or [10], wherein the resin composition is extruded into a film at a draft ratio of 0.7 to 2.0.

The translucent wood grain stretched film of the present invention (hereinafter referred to as the film of the present invention) has a unique texture of wood grain without being printed, and therefore tends to attract the attention of consumers compared to general packaging paper. In addition, since the film of the present invention is translucent, the contents can be faintly confirmed. Therefore, the film of the present invention is used, for example, for direct mail etc. for substrates and packaging, for confectionery, for food packaging, for high-grade packaging, for decoration, for substrates for labels, substrates for tapes, substrates for printing, recordings It can be suitably used as a paper substrate or the like.
In addition, in the film of the present invention, a translucent film can be obtained without using inorganic particles. Therefore, there is no dropout of particles, and there is less contamination of the plate even when used as a printing substrate. Furthermore, even when a high precision filter is used during the production, no clogging occurs, so there are few foreign substances, productivity is good, the cutting surface becomes rough at the time of cutting, and consumption of cutting blades is rapid Does not happen.

FIG. 1 shows the wood grain appearance of the film obtained in Example 1. FIG. 2 shows a view from the opposite side of the film shown in FIG. FIG. 3 is an enlarged view of a portion AA of FIG.

  The film of the present invention has one or more layers containing at least a crystalline polypropylene resin A and an amorphous cyclic olefin resin B as a resin component, and has a total light transmittance of 35% to 85%. It is a transparent wood grain stretched film, and the layer contains 70% by weight or more of crystalline polypropylene resin A and 25% by weight or less of amorphous cyclic olefin resin B based on the resin component, Crystalline cyclic olefin resin B is a translucent wood grain stretched film having a glass transition temperature of 142 ° C. or more and 185 ° C. or less.

The film of the present invention is a translucent film having a total light transmittance of 35% or more and 85% or less. If the total light transmittance is less than 35%, it becomes opaque, and when used for packaging, it becomes difficult to confirm the contents. On the other hand, if it exceeds 85%, the transparency becomes high, and the design and high-quality appearance of the film appearance are reduced.
The film of the present invention preferably has a total light transmittance of 40% or more, more preferably more than 50%, still more preferably 52% or more. The film of the present invention preferably has a total light transmittance of 80% or less, more preferably 77% or less, and still more preferably 75% or less. If it is the said total light transmittance, since a film will become moderate translucency, it is preferable. In the present invention, the total light transmittance is a value measured in accordance with JIS-K7361, and can be measured using, for example, a haze meter NDH-5000 manufactured by Nippon Denshoku Kogyo Co., Ltd.

The refractive index of the crystalline polypropylene resin A and the amorphous cyclic olefin resin B in the layer containing at least the crystalline polypropylene resin A and the amorphous cyclic olefin resin B as a resin component of the film of the present invention The transmittance of the film is lowered due to the difference or the difference in the refractive index between the resin and the void portion formed by stretching between the interfaces of the crystalline polypropylene resin A and the non-crystalline cyclic olefin resin B. In the present invention, the dispersion state of the amorphous cyclic olefin-based resin B in the crystalline polypropylene-based resin A and the voids formed around it become various sizes, so that a partial difference occurs in the transmittance. . And it is thought that the film appearance of a wood grain is exhibited by the site | part from which the transmittance | permeability differs by appearing in many streak-like patterns by being in the state of orientation by the vertical direction.
Here, crystallinity means raising temperature at a rate of 20 ° C./minute from −40 ° C. to 300 ° C. under nitrogen flow using DSC, holding for 5 minutes at 300 ° C., −40 ° C. at 20 ° C./minute It is said that a clear melting peak appears in the DSC curve when the temperature is raised to 300 ° C. at 20 ° C./min after cooling to -40 ° C. for 5 minutes. On the other hand, "amorphous" means that a clear melting peak does not appear in the above measurement using DSC.

  As the crystalline polypropylene-based resin A, a homopolymer of propylene and a copolymer of propylene and ethylene are preferable. When a homopolymer of propylene is used as the crystalline polypropylene resin A, the mechanical strength and heat resistance of the film tend to be improved. In addition, when a copolymer of propylene and ethylene is used as the crystalline polypropylene resin A, the cracking resistance at low temperature tends to be improved, and the surface glossiness tends to be reduced.

  As the crystalline polypropylene resin A, homopolymers of propylene and copolymers of propylene and ethylene can be used alone or in combination. When the film of the present invention has a multilayer structure, the type of resin used can be selected depending on the layer according to the required quality.

  As a homopolymer of propylene, crystalline isotactic polypropylene resin is preferable. In the present invention, the crystalline isotactic polypropylene resin preferably has a mesopentad fraction ([mm mm]) of 92% to 98%, which is a degree of stereoregularity determined by high temperature nuclear magnetic resonance (NMR) measurement. More preferably, it is 93% to 97%. When the mesopentad fraction [mmmm] is 92% or more, the crystallinity of the resin is improved by the high stereoregular component, and high thermal stability and mechanical strength can be obtained. On the other hand, when the mesopentad fraction [mm mm] is 98% or less, the stretchability becomes good.

The high temperature NMR apparatus for measuring the mesopentad fraction ([mm mm]) is not particularly limited, and a generally commercially available high temperature nuclear magnetic resonance (NMR) apparatus capable of measuring the degree of stereoregularity of polyolefins. For example, high temperature type Fourier transform nuclear magnetic resonance apparatus (high temperature FT-NMR) JNM-ECP500 manufactured by JEOL Ltd. can be used. The observed nucleus is ¹³ C (125 MHz), the measurement temperature is 135 ° C., and ortho-dichlorobenzene (ODCB: mixed solvent of ODCB and deuterated ODCB (volume mixing ratio = 4/1)) is used as a solvent. The method by high temperature NMR can be carried out by a known method, for example, the method described in “Japan Analytical Chemistry / Polymer Analysis Research Conference Edition, New edition of Polymer Analysis Handbook, Kinokuniya Bookstore, 1995, p. 610”. . The measurement mode is single pulse proton broadband decoupling, pulse width 9.1 μsec (45 ° pulse), pulse interval 5.5 sec, integration number 4500 times, shift standard is CH ₃ (mm mm) = 21.7 ppm.

  The pentad fraction representing the degree of stereoregularity is a combination (mm mm or mrrm) of a quint on the same direction alignment “meso (m)” and a different direction alignment “Lasemo (r)” Etc. is calculated in percentage from the intensity integral value of each signal derived from Regarding the assignment of each signal derived from mmmm, mrrm, etc., the description of the spectrum, such as "T. Hayashi et al., Polymer, vol. 29, p. 138 (1988)", is referred to. The mesopentad fraction ([mm mm]) can be controlled by appropriately adjusting the polymerization conditions such as the polymerization conditions of the polypropylene resin, the type of the catalyst, and the amount of the catalyst.

  As a homopolymer of propylene, a known method, for example, a method of polymerizing propylene in a hydrocarbon solvent using a Ziegler catalyst system comprising titanium and an aluminum compound, a method of polymerizing in liquid propylene (bulk polymerization), and a gas phase What was manufactured by the method of polymerizing etc. can be used. Alternatively, commercially available products can be used. Typical commercial products include, for example, homopolymers of Prime Polypro (registered trademark) series manufactured by Prime Polymer Co., Ltd., PC412A manufactured by Sun Aroma Co., Ltd., and Novatec (registered trademark) series manufactured by Japan Polypropylene Corporation. Among them, homopolymers, Daploy series manufactured by Borealis, 5014L series manufactured by Korea Oil Chemical Industry Co., Ltd., and homopolymers among Sumitomo Nobrene (registered trademark) series manufactured by Sumitomo Chemical Co., Ltd. can be mentioned.

  As a copolymer of propylene and ethylene, both a random copolymer of propylene and ethylene and a block copolymer of propylene and ethylene are preferably used, and ethylene is contained at 50% by weight or less in the copolymer. Is more preferred. Typical commercial products include, for example, those of Copolymer in Prime Polypro (registered trademark) series manufactured by Prime Polymer Co., Ltd., those of Copolymer in Novatec (registered trademark) series manufactured by Japan Polypropylene Corporation, and Wine. Among them, those of Coc (registered trademark) series, and those of copolymers of Sumitomo Nobrene (registered trademark) series manufactured by Sumitomo Chemical Co., Ltd. are listed.

  The melting point of the crystalline polypropylene resin A is preferably 155 ° C. or more and 170 ° C. or less, more preferably 157 ° C. or more and 165 ° C. or less. When the melting point of the crystalline resin A is in the above range, the productivity of the stretched film and the heat resistance of the resulting stretched film become good, and the amorphous cyclic olefin resin in the crystalline polypropylene resin A It becomes easy to control the dispersion state of B, and the desired total light transmittance and wood grain appearance can be obtained.

  50 degrees C or less is preferable, and, as for the glass transition temperature of crystalline polypropylene resin A, -30 degreeC-30 degreeC are more preferable. When the crystalline polypropylene resin A is in the above range, an appropriate gap is formed between the interface of the crystalline polypropylene resin A and the amorphous cyclic olefin resin B when the film is stretched. Preferred for obtaining. Moreover, since the productivity of a drawn film, the heat resistance of the obtained drawn film, flexibility, low temperature fragility, etc. become favorable, it is preferable.

  The melt mass flow rate of crystalline polypropylene resin A measured at 230 ° C. and 21.18 N according to JIS-K 7210 is preferably 0.5 g / 10 min to 8 g / 10 min, more preferably 1 g / 10 min 6 g / 10 min. By setting the melt mass flow rate in the above range, the flowability of the resin becomes an appropriate range, and the thickness of the stretched film can be accurately controlled. In addition, it becomes easy to control the finely dispersed state of the amorphous cyclic olefin resin B in the crystalline polypropylene resin A, and a desired total light transmittance and a wood grain film appearance can be obtained.

  The crystalline polypropylene resin A is used in an amount of 70% by weight or more, preferably 75% by weight or more, more preferably 80% by weight or more, particularly preferably 85% by weight or more based on the resin component contained in the layer. Can. The crystalline polypropylene resin A can be used in an amount of preferably 98% by weight or less, preferably 95% by weight or less, more preferably 92% by weight or less, based on the resin component contained in the layer. By using the crystalline polypropylene resin A in an amount within the above range, a film excellent in stretchability and mechanical strength can be obtained. On the other hand, when the crystalline polypropylene resin A is less than 70% by weight based on the resin component contained in the layer, a film having sufficient stretchability and mechanical strength can not be obtained.

  Next, the amorphous cyclic olefin resin B will be described. The amorphous cyclic olefin resin B used for the film of the present invention has a glass transition temperature of 142 ° C. or more and 185 ° C. or less. When the non-crystalline cyclic olefin resin B has a glass transition temperature within the above range, it is suitable for the interface between the crystalline polypropylene resin A and the non-crystalline cyclic olefin resin B when stretching the film. An air gap is formed, and a translucent wood grain film is obtained. The glass transition temperature of the amorphous cyclic olefin resin B is preferably 146 ° C. or more, more preferably 150 ° C. or more, and still more preferably 154 ° C. or more. Further, the glass transition temperature of the amorphous cyclic olefin resin B is preferably 179 ° C. or less, more preferably 173 ° C. or less, and still more preferably 167 ° C. or less. If the glass transition temperature of the non-crystalline cyclic olefin resin B is a glass transition temperature within the above-mentioned preferable range, an appropriate gap between the interface of the crystalline polypropylene resin A and the non-crystalline cyclic olefin resin B Can be easily formed, and the desired total light transmittance and film appearance can be obtained.

  As the amorphous cyclic olefin resin B, a copolymer of cyclic olefin and linear olefin can be used. The non-crystalline cyclic olefin copolymer can be suitably used in the present invention since it is finely dispersed in the crystalline polypropylene resin A well. Amorphous cyclic olefin copolymers may be used alone or in combination of two or more. When the film of the present invention has a multilayer structure, the type of resin used can be selected depending on the layer according to the required quality.

  As the amorphous cyclic olefin copolymer, at least one cyclic olefin selected from the group consisting of cycloalkene, bicycloalkene, tricycloalkene and tetracycloalkene, and at least one group selected from the group consisting of ethylene and propylene The copolymer which consists of 1 type of linear olefins is mentioned.

Specific examples of cyclic olefins include bicyclo [2.2.1] hept-2-ene (norbornene), 6-methylbicyclo [2.2.1] hept-2-ene, 5,6-dimethylbicyclo [2 .2.1] Hept-2-ene, 1-methylbicyclo [2.2.1] hept-2-ene, 6-ethylbicyclo [2.2.1] hept-2-ene, 6-n-butyl Bicyclo [2.2.1] hept-2-ene, 6-i-butylbicyclo [2.2.1] hept-2-ene, 7-methylbicyclo [2.2.1] hept-2-ene, tricyclo ^[4.3.0.1 2.5]-3-decene, 2-methyl - tricyclo ^[4.3.0.1 2.5]-3-decene, 5-methyl - tricyclo [4.3. 0.1 ^2.5] -3-decene, tricyclo ^[4.4.0.1 2.5] -3 Sen, 10-methyl - tricyclo ^[4.4.0.1 2.5] -3- decene, tetracyclo [4.4.0.1 ^{2, 5.} 1 ^7,10 ] Dodec-3-ene and the like.

  The glass transition temperature of the amorphous cyclic olefin copolymer is, for example, by increasing the content of the cyclic olefin component in the amorphous cyclic olefin copolymer and reducing the content of the linear olefin component such as ethylene. , Can be adjusted within the above range. Preferably, the content of the cyclic olefin component in the amorphous cyclic olefin copolymer is 70 to 90% by weight, and the content of the linear olefin component such as ethylene is 30 to 10% by weight. More preferably, the content of the cyclic olefin component in the amorphous cyclic olefin copolymer is 75 to 85% by weight, and the content of a linear olefin component such as ethylene is 25 to 15% by weight. More preferably, the content of the cyclic olefin component in the amorphous cyclic olefin copolymer is 77 to 83% by weight, and the content of the linear olefin component such as ethylene is 23 to 17% by weight.

  As the cyclic olefin component, norbornene and its derivatives are preferable from the viewpoints of productivity, transparency and easy high glass transition temperature. Ethylene is preferable as the linear olefin component from the viewpoint of reactivity. Therefore, the amorphous cyclic olefin copolymer is preferably a copolymer of norbornene and ethylene.

  In addition to cyclic olefins and linear olefins, other copolymerizable unsaturated monomer components can also be copolymerized as needed, as long as the object of the present invention is not impaired. Such copolymerizable unsaturated monomers may act as molecular weight regulators, such as, for example, α-olefins having 3 to 20 carbon atoms, such as propylene, 1-butene, 4-methyl. -1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene etc., cyclopentene, cyclohexene, 3-methylcyclohexene, cyclooctene, 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 1,7-octadiene, dicyclopentadiene, 5-ethylidene-2-norbornene, 5-vinyl-2- Norbornel, tetracyclododecene, 2-methyltetracyclododecene, 2-ethyltetracyclododecene It can be mentioned.

  Furthermore, as the amorphous cyclic olefin resin B, a hydrogenated product of an amorphous cyclic olefin copolymer can also be used. From the viewpoint of providing improved thermal degradation resistance and weather degradation resistance, a hydrogen additive in which almost all double bonds are saturated by hydrogenation is preferred. The hydrogenation rate of the hydrogenated substance is preferably 90% or more, more preferably 99% or more.

  In the present invention, a commercially available non-crystalline cyclic olefin copolymer may be used as the non-crystalline cyclic olefin resin B. Typical commercial products include, for example, TOPAS (registered trademark) 6015S-04, 6017S-04 and the like manufactured by Polyplastics Co., Ltd., APEL (registered trademark) 6015T and the like manufactured by Mitsui Chemicals, Inc., and the like.

  The amorphous cyclic olefin resin B can be used in an amount of 25% by weight or less, preferably 20% by weight or less, more preferably 16% by weight or less based on the resin component contained in the layer. The amorphous cyclic olefin resin B is preferably used in an amount of 2% by weight or more, more preferably 5% by weight or more, still more preferably 8% by weight or more, based on the resin component contained in the layer. Can. By using the amorphous cyclic olefin resin B in an amount within the above range, a desired total light transmittance and a wood grain film appearance can be obtained. On the other hand, when the content of the amorphous cyclic olefin resin B exceeds 25% by weight based on the resin component contained in the layer, the total light transmittance is too low and desired translucency can not be obtained. And it is not possible to obtain a wood grain film appearance.

  In the layer containing at least the crystalline polypropylene resin A and the amorphous cyclic olefin resin B constituting the film of the present invention as the resin component, the crystalline polypropylene resin A and the amorphous cyclic olefin resin as the resin component Adjustment of stretchability, adjustment of low-temperature impact resistance, adjustment of surface roughness, crystalline resin or amorphous resin (hereinafter referred to as another resin) having a melting point or glass transition temperature different from that of resin B For the purpose of adjustment of various physical properties such as rigidity, strength, elongation and the like, it may be contained in an amount within the range that does not impair the effect of the present invention.

  The other resin is not particularly limited, and conventionally known resins which are considered to be suitable for stretched film applications can be appropriately used in the present invention. Examples thereof include polyolefin resins such as polyethylene, polypropylene, poly (1-butene), polyisobutene, poly (1-pentene) and poly (4-methyl-1-pentene) and copolymer resins thereof, such as ethylene -Copolymers of α-olefins such as propylene copolymer, propylene-butene copolymer, ethylene-butene copolymer and the like can be mentioned. In addition, styrene resin, vinyl resin, polyester resin, polyurethane resin, nylon resin and copolymer thereof, for example, vinyl monomer-diene monomer copolymer such as styrene-butadiene copolymer, styrene -Vinyl monomers such as-butadiene-styrene copolymer, diene monomer-vinyl monomer copolymer, etc. may be mentioned.

  The content of such other resin is 15% by weight or less based on the resin component contained in the layer containing at least the crystalline polypropylene resin A and the amorphous cyclic olefin resin B as a resin component. Preferably, it is 10% by weight or less.

  The film of the present invention can be produced using a conventionally known method. For example, a crystalline polypropylene resin A and an amorphous cyclic olefin resin B are blended with other resins and / or additives as required to obtain a resin composition, which is then melted using an extruder. Producing a film of the present invention having at least one layer containing at least a crystalline polypropylene resin A and an amorphous cyclic olefin resin B as a resin component by stretching an original sheet obtained by extrusion. it can.

  Examples of the additive include a heat stabilizer, an antioxidant, an organic and inorganic lubricant, a chlorine capture agent, an antistatic agent, a colorant and the like. Such additives can be added to the resin composition in an amount that does not impair the effects of the present invention.

  Examples of heat stabilizers and antioxidants include phenol type, hindered amine type, phosphite type, lactone type and tocopherol type heat stabilizers and antioxidants. More specifically, dibutyl hydroxytoluene, pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] ("Irganox (registered trademark) 1010" manufactured by BASF Japan Ltd.), 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4hydroxy) benzene ("Irganox (registered trademark) 1330" manufactured by BASF Japan Ltd.), tris (2, 4-di-t-butylphenyl) phosphite ("Irgafos (registered trademark) 168" manufactured by BASF Japan Ltd.) and the like. Among these, at least one selected from phenolic antioxidants or a combination thereof, a combination of a phenolic and a phosphite, a combination of a phenolic and a lactone, a phenolic and a phosphite and a lactone The combination of is preferred from the viewpoint of imparting chemical stability of the film.

  Examples of lubricants include, as organic lubricants, stearic acid amides, erucic acid amides such as fatty amides, lauric acid diethanolamide, alkyl diethanolamines, aliphatic monoglycerides, aliphatic diglycerides, silicone cross-linked polymers, and inorganic lubricants, silicas. And alumina, etc., but organic lubricants with little contamination of the printing plate in printing applications are preferred.

  Examples of chlorine capture agents include calcium stearate, metal soaps, hydrotalcite and the like.

Examples of the antistatic agent include alkylmethyl dibetaine, alkylamine diethanol and / or alkylamine ethanol ester and / or alkylamine diethanol diester, and the like. Among these, two or more types of antistatic agents may be used in combination, and an aliphatic alcohol may be used in combination.
Among them, it is preferable to use stearyldiethanolamine monostearate and stearyldiethanolamine in combination because they are excellent in antistatic performance and the printability is improved.
As an example of a typical commercial item of antistatic agent, Kao Corporation electro stripper series etc. are mentioned.

  By using a coloring agent, woodgrain films of various colors can be obtained. The colorant is not particularly limited as long as it is commonly used for polypropylene. Examples of coloring agents include cadmium, chromium-containing inorganic compounds, azo, quinacridone organic pigments and the like. In addition, commercially available dyes and colored pigments may be used. For example, color master batch or dry color manufactured by Tokyo Ink Co., Ltd., Hyconmaster or color compound manufactured by Dainichi Seika Kogyo Co., Ltd. can be suitably used.

  As a method for blending the crystalline polypropylene resin A and the amorphous cyclic olefin resin B, and, if necessary, other resins and / or additives, for example, the crystalline polypropylene resin A and the amorphous cyclic olefin resin B The dry blend resin using a batch type mixing device such as a tumbler or a mixer, or a continuous metering type mixing device together with the pellet, powder, etc. of the resin together with other resin pellets, powder and / or additives as necessary. Method for obtaining the composition, and pellets or powders of crystalline polypropylene resin A and non-crystalline cyclic olefin resin B, optionally with pellets, powders and / or additives of other resins The method etc. of supplying, melt-kneading, and obtaining a melt blend resin composition are mentioned.

  In the present invention, the method of using the dry blend resin composition is preferable in that the dispersion diameter of the non-crystalline cyclic olefin resin B in the crystalline polypropylene resin A is easily made uneven and the wood grain appearance is obtained.

The method for producing a translucent wood grain stretched film of the present invention comprises one or more layers containing at least a crystalline polypropylene resin A and an amorphous cyclic olefin resin B as a resin component, and has a total light transmittance of It is a translucent wood grain stretched film which is 35% or more and 85% or less, and said layer is 70% or more by weight of crystalline polypropylene resin A and 25% or less by weight of amorphous cyclic olefin based on the resin component. A method for producing a translucent wood grain oriented stretched film, which comprises a resin B, and the amorphous cyclic olefin resin B has a glass transition temperature of 142 ° C. or more and 185 ° C. or less,
A resin composition containing a crystalline polypropylene resin A and an amorphous cyclic olefin resin B is supplied to an extruder, heated and melted, and then extruded into a film.
That is, the resin composition obtained as described above can be fed to an extruder, heated and melted, and then extruded into a film. In the heat-melted resin composition, if necessary, minute foreign substances and the like can be removed by a filter or the like. Extrusion can usually be performed using a T-die.

  There is no restriction on the screw type of the extruder, and a single screw type, a twin screw type or a multi-screw type or more may be used. Furthermore, in the case of a screw type having two or more shafts, co-rotation, different direction Although any kneading type of rotation may be used, single screw type and co-rotating twin screw type kneaders are preferred because a film having a fibrous wood grain appearance is easily obtained.

  When extruding the resin composition into a film, the cylinder temperature of the extruder is preferably 200 to 260 ° C., more preferably 210 to 250 ° C. When the cylinder temperature of the extruder exceeds 260 ° C., the transmittance of the obtained film is high, and the film appearance does not have a fibrous feel, and it is difficult to obtain a wood grain appearance. In addition, when the cylinder temperature of the extruder is less than 200 ° C., the transmittance of the obtained film is low, and it approaches a white film, so that it is difficult to obtain a wood grain appearance. Therefore, a preferred embodiment of the method for producing a film of the present invention comprises the step of extruding the resin composition into a film at a cylinder temperature of an extruder of 200 to 260 ° C. Moreover, you may purge inert gas, such as nitrogen, in order to prevent the thermal deterioration of resin in the case of extrusion.

  The draft ratio, which is the ratio of the drawing speed to the extrusion speed, is preferably 0.7 to 2.0, more preferably 0.8 to 1.5. If the draft ratio is less than 0.7, the raw sheet is difficult to form. When the draft ratio exceeds 2.0, the transmittance of the obtained film tends to be high, and breakage at the time of stretching tends to occur, and the productivity may be deteriorated. Therefore, a preferred embodiment of the method for producing a film of the present invention comprises the step of extruding the resin composition into a film at a draft ratio of 0.7 to 2.0.

  The resin sheet extruded from the extruder is formed into a sheet, for example, by a known method in which it is adhered to at least one or more metal drums set at a temperature of 25 to 120 ° C. by an air knife or another roll, or electrostatics. It is molded into a raw sheet. If the temperature of the metal drum is within the above range, it is possible to control the crystal growth of the crystalline polypropylene resin A, the deformation during stretching is controlled, and the desired total light transmittance and wood grain appearance are easily obtained. Become. The preferred temperature range of the metal drum is 30-80 ° C.

  The film of the present invention may be a stretched single layer film obtained by extruding a dry blend and / or melt blend resin composition from a single layer die, but for the purpose of obtaining a desired film thickness, etc. It may be a multilayer film obtained by laminating a plurality of layers and / or films using a conventionally known lamination method such as co-extrusion method, lamination method, heat seal method and the like. The multilayer film has, for example, a three-layer structure of layer b / layer a / layer b consisting of a surface layer (skin layer: layer b) and a core layer (layer a), and one surface layer is another layer (layer c) Layer structure of layer b / layer a / layer c, layer b / layer a / layer a / layer a / layer c with two core layers, and one core layer as another core layer A four-layer configuration of layer b / layer a / layer a ′ / layer c, etc. can be used as (layer a ′).

  As the co-extrusion method, the pre-die lamination method in which the molten resin is brought into contact in the feed block in front of the mold, the in-die lamination method in which the molten resin is contacted in the route inside the mold Law etc. are mentioned. For example, in the case of the in-die lamination method, a multilayer die such as a three-layer multi-manifold die can be used.

  Examples of the laminating method include an extrusion laminating method of forming a laminated film by extruding a film of a molten resin directly onto another film using equipment of a melt extrusion molding method used for the T-die method.

  As a heat sealing method, an external heating method in which a metal body heated to a plurality of bonded films is pressed from the outside of the film and conducted heat melts and bonds the film, and heats the film by high frequency radio waves or ultrasonic waves. Internal heat generation method etc. which generate | occur | produce and join.

  In the present invention, the above-described lamination methods can be used alone or in combination.

The surface layer (skin layer) may be a layer containing at least a crystalline polypropylene resin A and an amorphous cyclic olefin resin B as a resin component, and may be a gloss reduction layer or a heat seal layer. When a gloss reduction layer is provided, it is easy to obtain a matte texture different from a print film that normally has high gloss, and a high-class feeling is easily obtained, which is preferable. The gloss reduction layer may have heat sealability.
In the surface layer, layers of different types may be laminated on each side of the present film, or layers of the same type may be laminated on both sides. When the film of the present invention is used for packaging and the like, the film of the present invention preferably has a heat seal layer on at least one side.

  When laminating a layer containing at least a crystalline polypropylene resin A and an amorphous cyclic olefin resin B as a resin component as a surface layer, types of the crystalline polypropylene resin A and the amorphous cyclic olefin resin B in each layer and The amount of addition may be the same as or different from that of the core layer. By laminating a layer containing at least a crystalline polypropylene resin A and an amorphous cyclic olefin resin B as a resin component as a surface layer, it becomes easy to obtain a wood grain appearance.

  The translucent stretched film of the present invention may further have one or more layers containing at least a crystalline polypropylene resin A and an amorphous cyclic olefin resin B as a resin component. As the crystalline polypropylene resin A and the amorphous cyclic olefin resin B, the resins described above may be used. The types and amounts of the crystalline polypropylene resin A and the amorphous cyclic olefin resin B in each layer may be the same or different. When different, it is easy to obtain the desired total light transmittance with a layer containing a large amount of amorphous cyclic olefin resin B, and to improve the stretchability with a layer containing a large amount of crystalline polypropylene resin A, etc. And it is easy to make productivity compatible. When two or more layers are laminated, at least one layer contains 70% by weight or more of crystalline polypropylene resin A based on the resin component contained in the layer, and at least one layer contains crystalline polypropylene resin A It is preferable to contain 85% by weight or more based on the resin component contained in

  Examples of resins used for the gloss reduction layer include polyolefin resins such as polyethylene, polypropylene, poly (1-butene), polyisobutene, poly (1-pentene), poly (4-methyl-1-pentene) and copolymers thereof Examples of the resin include copolymers of α-olefins such as ethylene-propylene copolymer, propylene-butene copolymer, and ethylene-butene copolymer. In addition, styrene resin, vinyl resin, polyester resin, polyurethane resin, nylon resin and copolymer thereof, for example, vinyl monomer-diene monomer copolymer such as styrene-butadiene copolymer, styrene -It is preferable to use combining 2 or more types among vinyl monomers, such as-butadiene-a styrene copolymer, a diene monomer-vinyl monomer copolymer, etc. In addition, an amorphous cyclic olefin resin B may be used for the gloss reduction layer. Among these, since the good gloss reduction effect is obtained, the combination of the ethylene-propylene copolymer and the polyethylene, and the combination of the ethylene-propylene copolymer and the polyethylene and the amorphous cyclic olefin resin B have the gloss reduction effect. High and preferred.

  The resin used for the heat seal layer is a thermoplastic resin having a melting point of 150 ° C. or less, and is selected from α-olefin monomers having 2 to 10 carbon atoms such as ethylene, propylene, butene, pentene, hexene, octene and decene. Preferred are random copolymers or block copolymers obtained by polymerizing two or more of the above. These copolymers can be used alone or in combination.

  Particularly preferred are crystalline propylene-α-olefin random copolymers, and examples of α-olefins include ethylene and α-olefins having 4 to 20 carbon atoms, such as ethylene, butene-1, hexene-1 and octene-. It is preferable to use 1 etc., and it is particularly preferable to use a copolymer or terpolymer using ethylene or butylene. For example, a propylene-ethylene-butene copolymer (FL6741G manufactured by Sumitomo Chemical Co., Ltd.) and / or a propylene-butene copolymer is preferable. The propylene-ethylene-butene copolymer is preferably a random copolymer.

  The surface layer can contain other resins and additives described above, as needed. Such other resins and additives can be used in amounts that do not impair the intended effect of the surface layer. In addition, the surface layer may contain an anti-blocking agent such as acrylic resin fine particles and silica within a range not impairing the effects of the present invention.

  The thickness of the surface layer is not particularly limited, but is preferably 1 μm to 10 μm, and more preferably 3 μm to 9 μm.

  As a stretching method for obtaining the film of the present invention, a known method such as a method of stretching between rolls provided with a peripheral speed difference, a tenter method, a tubular method and the like can be used. As the stretching direction, uniaxial stretching, biaxial stretching, biaxial stretching in an oblique direction, and the like are possible, and in the stretching of two or more axes, both sequential stretching and simultaneous stretching can be applied. Among them, from the viewpoint that a film having a woodgrain appearance is easily obtained, the simultaneous biaxial stretching method by the tenter, the sequential biaxial stretching method by the tenter, and the longitudinal between the rolls provided with the peripheral speed difference (flow, MD 2.) A sequential biaxial stretching method in which the film is stretched and then stretched horizontally (width, TD) by tenter method is preferred, and after stretching longitudinally (flow, MD) between rolls provided with a peripheral speed difference, width (width, Particularly preferred is a sequential biaxial stretching method in which the TD) is stretched.

Stretching is usually performed such that the film temperature (Ts) is a temperature between the melting point Tm (A) of the crystalline polypropylene resin A as the main resin and the glass transition temperature Tg (A). Here, the film temperature Ts is the temperature of the film at the time when the film starts to be stretched, but when the film temperature in each stage is different in multi-stage stretching such as sequential biaxial stretching, the lowest film temperature Ts.
When Ts is less than the glass transition temperature Tg (B) of the non-crystalline cyclic olefin resin B, the non-crystalline cyclic olefin resin B can not be deformed during drawing, and a fibrous wood grain appearance is obtained It will be easier.
Thus, in the present invention, the following relationship:
Tg (B)>Ts> Tg (A)
Is preferable because a translucent stretched wood grain film having a desired total light transmittance and a wood grain appearance can be obtained.

  Ts is more preferable when it is higher by at least 100 ° C. than Tg (A), and more preferable when it is higher by 110 to 150 ° C. than Tg (A). In this case, the crystalline polypropylene resin A at the time of stretching is appropriately deformed, and it becomes easy to obtain a translucent film having a desired total light transmittance. In addition, when Ts is preferably lower by 5 ° C. or more than Tg (B), more preferably by 10 to 50 ° C., a film having a fibrous wood grain appearance exhibiting a desired total light transmittance can be easily obtained. preferable.

  As the sequential biaxial stretching method, it is necessary to adjust the stretching temperature and the stretching ratio according to the melting point and the glass transition temperature of the resin used, but first, the raw sheet is preferably 100 to 155 ° C., more preferably 110 to 145 The film is maintained at a temperature of deg. C and passed between rolls provided with a peripheral speed difference or in the tenter method, preferably 3 to 6 times, more preferably 3.5 to 5.5 times, still more preferably 3 in the longitudinal direction. Stretch 8 to 5.2 times. Subsequently, the stretched film is subjected to a tenter method at a temperature of preferably 110 to 160 ° C., more preferably 120 to 155 ° C., preferably 7 to 11 times in the transverse direction, more preferably 7.5 to 10.5 times More preferably, after stretching by 8 to 10 times, it is relaxed, heat set and wound up.

  The wound film can be cut into a desired product width after being subjected to an aging treatment preferably in an atmosphere of about 20 to 45 ° C. Thus, a stretched film excellent in mechanical strength and rigidity is obtained. When the temperature during stretching is increased, the total light transmittance is likely to be increased, and when the temperature is decreased, the total light transmittance is easily reduced.

The film may be subjected to corona treatment, plasma treatment, flame treatment and the like on-line or off-line as required. In particular, when the present film is used for printing, on one side and / or both sides of the present film, a treatment such as corona treatment, plasma treatment, flame treatment, etc. for the purpose of improving wet ink spreading and adhesion of printing ink. It is preferable to In the present invention, the wetting tension of K6768: 1999 on the film surface is preferably 36 to 45 mN / m, and more preferably 38 to 44 mN / m.
Alternatively, a printability imparting layer having similar wetting tension and further smoothness may be provided.

  The film of the present invention may have a 60 degree specular gloss of 5% to 160% on at least one surface. In the present invention, the 60 degree specular gloss is a value measured in accordance with JIS-Z8741 (method 3).

  The film of the present invention has an ash content to prevent problems such as contamination of the package due to falling off of the inorganic substance, contamination of the printing plate in printing applications, roughening of the cut surface at cutting, and rapid consumption of the cutting blade. Preferably, it is at most 1% by weight, more preferably at most 0.5% by weight, still more preferably at most 0.1% by weight, based on the film. The lower limit of the ash content is not particularly limited, but is preferably as small as possible, and is, for example, 0.01% by mass, 0% by mass or the like. In the present invention, the ash content can be measured according to JIS-K 7250-1 (2006) A method.

  The thickness of the film of the present invention is preferably 10 μm to 150 μm, more preferably 15 to 100 μm, still more preferably 20 to 60 μm, and particularly preferably 25 to 45 μm, although it depends on the use application. Is 25 to 40 μm. When the thickness of the film is 10 μm or more, sufficient strength is easily obtained. Moreover, it is excellent in a ductility and productivity as the thickness of a film is 150 micrometers or less.

  The film of the present invention preferably has heat sealability. When the translucent stretched film of the present invention has heat sealability, it can be preferably used for food packaging applications. In this case, the heat seal layer described above is preferably provided on at least one side of the film.

  The film of the present invention is used for substrates such as direct mail, for packaging, for packaging of confectionery and food, for pharmaceutical packaging, for decoration, for labels, for tapes, for substrates for printing, poster paper, thermal paper It can be suitably used as a substrate, recording paper substrate and the like.

  Hereinafter, the present invention will be more specifically described by way of examples, but the present invention is not limited to these examples.

[Melt mass flow rate of resin (MFR)]
According to JIS K-7210 (1999), using a melt indexer manufactured by Toyo Seiki Seisaku-sho, Ltd., measurement was performed under the conditions of a measurement temperature of 230 ° C. and a load of 21.18 N.

[Melting point of resin, glass transition temperature]
It calculated according to the following procedures using Perkin-Elmer Inc. input compensation type | mold DSC and Diamond DSC. Each resin was weighed to 5 mg, packed into an aluminum sample holder, and set in a DSC. The temperature was increased from -40 ° C to 260 ° C at a rate of 20 ° C / minute under nitrogen flow, held at 260 ° C for 5 minutes, cooled to -40 ° C at 20 ° C / minute, and held at -40 ° C for 5 minutes. Thereafter, the melting point and the glass transition temperature were determined from the DSC curve when the temperature was raised again to 260 ° C. at 20 ° C./min. With the melting peak defined in 9.1 (1) of JIS-K7121 (the maximum melting peak in the case of showing a plurality of melting peaks) as the melting point, the midpoint glass transition temperature defined in 9.3 (1) of JIS-K7121 is It was a glass transition temperature.

[Total light transmittance of film]
It measured based on JIS-K7361 using Nippon Denshoku Industries Co., Ltd. make haze meter NDH-5000.

[Thickness of film]
It measured based on JIS-C2330 using a Citizen Seimitsu Co., Ltd. paper-paper thickness measuring device MEI-11.

[60 degree specular gloss of film]
The specular glossiness at 60 degrees was measured in accordance with JIS-Z8741 (Method 3) using a variable angle gloss meter Model GM-3D manufactured by Murakami Color Research Laboratory. In addition, a measurement is measured about the longitudinal direction and horizontal direction of a film, and it is the value which averaged both.

[Appearance (Fibrous Woodgrain Appearance)]
The light of the fluorescent lamp was penetrated to visually observe the film, and the appearance was evaluated as follows.
◎: The appearance of woodgrain can be clearly confirmed.
○: The appearance of wood grain can be confirmed in part.
X: A fibrous wood grain appearance can not be confirmed.

[Film ash content]
According to JIS-K7250-1 (2006) A method, it measured by 200 g of measurement sample quantities.

Example 1
Prime Polypro (registered trademark) F-300SP (product of Prime Polymer Co., Ltd., crystalline polypropylene homopolymer, MFR = 3 g / 10 min, melting point 160 ° C, glass transition temperature-17 ° C) as crystalline polyprepylene resin A, TOPAS (registered trademark) 6015 S-04 (Amorphous norbornene-ethylene copolymer manufactured by Polyplastics Co., Ltd., amorphous norbornene-ethylene copolymer, glass transition temperature: 158 ° C., MFR = 0.4 g / 10 min) as amorphous cyclic olefin resin B The mixed raw material pellet was prepared by dry-blending the pellet of each with a mixer by the ratio shown in Table 1, respectively.

  The mixed raw material pellet was charged into a single screw type extruder a from a hopper and melted, and was extruded from a single layer die at a cylinder temperature of 230 ° C. and a draft ratio of 0.9. The extruded resin layer was cooled and solidified while being pressed by a pneumatic blade on a cooling drum controlled to 70 ° C. using an air knife to obtain an original sheet.

  The obtained original sheet was stretched using a batch type biaxial stretching machine KARO manufactured by Bruckner. The stretching method was carried out by a sequential biaxial stretching method of stretching in the longitudinal direction and then stretching in the lateral direction. The film temperature (Ts) was preheated to 130 ° C. in an oven at a set temperature of 150 ° C., and first stretched in the longitudinal direction to 5 times at a stretching rate of 6 times / sec. Next, the film temperature was preheated to 145 ° C. in an oven at a set temperature of 165 ° C., and stretched in the lateral direction to 10 times at a stretching speed of 1 / sec. Next, in the same oven, relax the transverse direction to 9.5 times at a relaxation rate of 0.5 times / sec, then heat set for 10 seconds, drain from the oven, cool to room temperature, and stretch 30 μm thick I got a film.

Example 2
A stretched film was obtained in the same manner as in Example 1 except that the cylinder temperature during extrusion was changed to 255 ° C.

[Example 3]
A stretched film was obtained in the same manner as in Example 1 except that the cylinder temperature during extrusion was changed to 205 ° C.

Example 4
A stretched film was obtained in the same manner as in Example 1 except that the draft ratio in extrusion was changed to 1.7.

[Example 5]
A stretched film was obtained in the same manner as in Example 1, except that the number of parts of the crystalline polypropylene resin A and the amorphous cyclic olefin resin B was changed to the values shown in Table 1.

[Example 6]
As the non-crystalline cyclic olefin resin B, APEL (registered trademark) APL 6015 T (a non-crystalline norbornene-ethylene copolymer manufactured by Mitsui Chemicals, Inc., glass transition temperature 145 ° C.) is used in parts shown in Table 1 and extruded A stretched film was obtained in the same manner as in Example 1 except that the cylinder temperature was changed to 220 ° C.

[Example 7]
As the non-crystalline cyclic olefin resin B, TOPAS (registered trademark) 6017S-04 (manufactured by Polyplastics Co., Ltd., non-crystalline norbornene-ethylene copolymer, glass transition temperature 178 ° C.) is used in the number of parts shown in Table 1 A stretched film was obtained in the same manner as in Example 1 except that the cylinder temperature was changed to 245 ° C.

Example 8
A stretched film was obtained in the same manner as in Example 7, except that the number of parts of the crystalline polypropylene resin A and the amorphous cyclic olefin resin B was used in the number shown in Table 1.

[Example 9]
85 parts by weight of WINTEC (registered trademark) WFW 5 T (ethylene-propylene copolymer resin manufactured by Japan Polypropylene Corp., melting point 143 ° C.) as a resin for gloss reduction layer having heat sealability, Hyzex (registered trademark) 7700 F (prime polymer stock 10 parts by weight of polyethylene resin, melting point 131 ° C.), and 5 parts by weight of TOPAS (registered trademark) 6015S-04 as the amorphous cyclic olefin resin B are dry-blended with a mixer to prepare a mixed material for gloss reduction layer Was prepared.
As a resin for high gloss heat seal (HS) layer, 90 parts by weight of propylene-ethylene-butene random copolymer (manufactured by Sumitomo Chemical Co., Ltd., FL6741G, melting point 130 ° C.), and propylene-butene copolymer (Mitsui Chemical Co., Ltd.) Product, Toughmer MX 7070, melting point 75 ° C., 10 parts by weight, and 0.2 parts by weight of amorphous silica (Fuji Silysia Chemical Co., Ltd., Phylysia 730) as an antiblocking agent are dry-blended with a mixer to make a high gloss heat seal A mixed material for layer was prepared.

  Example 1 A single screw type extruder for forming the main layer with the mixed raw material pellet similar to Example 1, a single screw type extruder b for forming the skin layer 1 with the mixed raw material for gloss reduction layer The raw materials for the glossy heat seal layer are charged from the hopper into the single screw type extruder c for forming the skin layer 2 and melted, and these are melted in the 3-layer multi manifold die inside the skin layer 1-main layer- It laminated | stacked on 3 layer structure of the skin layer 2, and extruded as a 3 layer lamination | stacking resin layer. The ratio of the extruded resin amount of the single screw type extruder a, the single screw type extruder b, and the single screw type extruder c was 1: 10: 1. The skin layer 2 side of the extruded resin layer was solidified by cooling while being pressed with air pressure on a cooling drum controlled to 45 ° C. using an air knife to obtain an original sheet.

  With respect to the obtained original fabric sheet, it extended | stretched similarly to Example 1, and obtained the 36-micrometer-thick stretched film.

[Example 10]
A stretched film was obtained in the same manner as in Example 9 except that the mixed raw material for high gloss heat seal layer of Example 9 was used as a raw material of the skin layer 1.

Comparative Example 1
A stretched film was obtained in the same manner as in Example 1 except that Prime Polypro (registered trademark) F-300SP as crystalline polypropylene resin A was used alone without performing dry blending and melt mixing.

Comparative Example 2
A stretched film was obtained in the same manner as in Example 1, except that the number of parts of the crystalline polypropylene resin A and the amorphous cyclic olefin resin B was changed to the values shown in Table 1.

Comparative Example 3
TOPAS (registered trademark) 5013F-04 (manufactured by Polyplastics Co., Ltd., amorphous norbornene-ethylene copolymer, as amorphous non-crystalline cyclic olefin resin B, glass transition temperature 134 ° C., MFR = 9.2 g / 10 min A stretched film was obtained in the same manner as in Example 1 except that the number of parts shown in Table 1 was used, and the cylinder temperature was changed to 210 ° C.

Comparative Example 4
TOPAS (registered trademark) E-140 (Polyplastics Co., Ltd., crystalline norbornene-ethylene copolymer, melting point 84 as a crystalline cyclic olefin resin instead of using the amorphous cyclic olefin resin B C., glass transition temperature -6.degree. C., MFR = 4.4 g / 10 min) was used in the same manner as in Example 1 except that the cylinder temperature was changed to 200.degree. The

Comparative Example 5
Instead of using amorphous cyclic olefin resin B, dry blending light calcium carbonate powder (Cartex 5 manufactured by Maruo Calcium Co., Ltd., average particle diameter 0.9 μm) which is inorganic particles in the number shown in Table 1 A stretched film was obtained in the same manner as in Example 1 except that the prepared mixed raw material was used.

  As shown in Table 1, the stretched films obtained in Examples 1 to 10 were translucent stretched films having a total light transmittance of between 35 and 85% and a wood grain appearance. On the other hand, in Comparative Example 1 in which the crystalline resin was used alone, the total light transmittance was high, and a wood grain film appearance was not obtained. In Comparative Example 2 in which the amount of the amorphous cyclic olefin resin B was 30 parts, the total light transmittance was low, and a wood grain film appearance was not obtained. In Comparative Example 3 in which the glass transition temperature of the amorphous cyclic olefin resin B was 134 ° C., the total light transmittance was high, and a wood grain film appearance was not obtained. In Comparative Example 4 in which the crystalline cyclic olefin resin was used without using the amorphous cyclic olefin resin B, the total light transmittance was low, and a wood grain film appearance was not obtained. Therefore, it is understood that according to the present invention, a translucent stretched film having a wood grain film appearance is obtained.

Claims (10)

A translucent wood grain stretched film having one or more layers containing at least a crystalline polypropylene resin A and an amorphous cyclic olefin resin B as a resin component and having a total light transmittance of 35% to 85%. The layer contains 70% by weight or more of the crystalline polypropylene resin A and 25% by weight or less of the amorphous cyclic olefin resin B based on the resin component, and the amorphous cyclic olefin resin B has a glass transition temperature of Ri der 142 ° C. or higher 185 ° C. or less, the amorphous cyclic olefin resin B, Ru copolymer der of norbornene and ethylene, translucency wood stretched film. The translucent wood grain stretched film according to claim 1, wherein the polypropylene resin A has a melting point of 155 ° C. or more and 170 ° C. or less. The translucent wood grain oriented film according to claim 1 or 2 having a total light transmittance of more than 50%. The translucent wood grain stretched film according to any one of claims 1 to 3 , which is a biaxially stretched film. The translucent wood grain oriented film according to any one of claims 1 to 4 , wherein the ash content in the film is 1% by weight or less based on the film. The translucent wood grain oriented film according to any one of claims 1 to 5 , further comprising a gloss reducing layer. The translucent wood grain oriented film according to any one of claims 1 to 6 , further comprising a heat seal layer. The method for producing a translucent wood grain oriented stretched film according to any one of claims 1 to 7 , wherein a resin composition containing a crystalline polypropylene resin A and an amorphous cyclic olefin resin B is supplied to an extruder. A method of manufacturing, comprising the steps of heating, melting and then extruding into a film. The method according to claim 8 , wherein the resin composition is extruded into a film at an extruder cylinder temperature of 200 to 260C. The method according to claim 8 or 9 , wherein the resin composition is extruded into a film at a draft ratio of 0.7 to 2.0.