JP2017205933A - Olefin resin sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an olefin resin sheet which is excellent in winding property, lubricity, transparency and high frequency weldability in sheet molding, and is suitable as an application requiring secondary working such as a nameplate case or a clear file.SOLUTION: An olefin resin sheet is formed of an intermediate layer formed of an ethylenic copolymer and a surface layer formed of random polypropylene and a crystal nucleus agent formed on both surfaces thereof, where a content of the crystal nucleus agent is 0.01-1 pts.wt. with respect to 100 pts.wt. of the random polypropylene. The crystal nucleus agent is selected from a nonitole nucleus agent, a sorbitol nucleus agent, a phosphate nucleus agent, a triaminobenzene derivative nucleus agent, a carboxylic acid metal salt nucleus agent and a xylitol nucleus agent.SELECTED DRAWING: None

Description

  The present invention relates to an olefin resin sheet suitable for uses such as a name tag case and a clear file, and more specifically, an olefin resin excellent in winding property, slipperiness, transparency and high frequency welder weldability during sheet molding. Regarding the sheet.

When processing the original sheet into a name tag case or clear file, the original sheet is cut or die-cut into a specific shape, and the overlapped end is bonded with an adhesive, or is welded by heat sealing or high-frequency welder processing ( Process).
When pasting with an adhesive, there is a problem that the transparency of the bonded part is impaired or the bonded part becomes hard, and in heat sealing, depending on the heat conduction of the heated object, the heated object It takes a long time to heat the inside of the steel, and there is a problem that the heat affects the part that is not welded.

  On the other hand, since the high-frequency welding process is to heat only the welded portion of the article to be heated, it can be welded in a short time without affecting the portion to be welded. In addition, since it is heated uniformly from the inside of the object to be heated, it has excellent welding strength and can perform welding with stable quality in an application time of only a few seconds. Because it is a very clean processing method that does not occur, it can be said that it is an excellent processing method for name tag cases and clear files.

  By the way, when processing into a name tag case or a clear file, there is a problem that the work is very difficult if the raw sheet is not slippery. In order to impart lubricity to an original fabric sheet, conventionally, powder was sprinkled during sheet molding. However, when powdering is performed, the transparency of the sheet is deteriorated, and the sheet is wound while holding the powder on the surface. Furthermore, there is also a problem that production in a clean room cannot be performed because dusting causes contamination of the molding line.

  As a method for imparting lubricity to a sheet, in addition to powdering, a method of adding an organic lubricant or inorganic particles to a resin composition constituting the sheet is also known (Patent Document 1, etc.).

JP 2009-265499 A

However, since organic lubricants provide lubricity by being exposed to the surface of the sheet over time, there is no immediate effect, and when processing the raw sheet into a name tag case or a clear file, In many cases, sex is not imparted. Sufficient lubricity can be obtained after the lubricant is exposed on the surface of the sheet, but this time there is a problem of poor printability and it is difficult to use.
Further, when inorganic particles are added, it is difficult to maintain the original transparency of the sheet, and it is not suitable for applications such as name tag cases and clear files.

Furthermore, in the said use, since it is excellent in transparency, use of a random polypropylene is suitable, However, When it uses a mirror surface design, there exists a problem which is easy to block at the time of winding of a sheet | seat. If it is blocked, it will be wrinkled because the distortion of the sheet cannot be eliminated.
Such a problem can be solved by making a concavo-convex design or by adding the above-mentioned dusting, organic lubricant or inorganic particles, but it has been difficult to satisfy transparency and printability.

The present invention has been made under such knowledge, and the gist thereof is as follows.
(1) An olefin-based resin sheet composed of an intermediate layer composed of an ethylene-based copolymer and a surface layer composed of random polypropylene and a crystal nucleating agent formed on both surfaces thereof, and the content of the crystal nucleating agent These are 0.01-1 weight part with respect to 100 weight part of said random polypropylene, The olefin resin sheet characterized by the above-mentioned.
(2) The crystal nucleating agent is selected from the group consisting of a nonitol nucleating agent, a sorbitol nucleating agent, a phosphate ester nucleating agent, a triaminobenzene derivative nucleating agent, a carboxylic acid metal salt nucleating agent, and a xylitol nucleating agent. The olefin resin sheet according to (1), wherein

  According to the present invention, it is possible to provide an olefin-based resin sheet that is excellent in winding property and slipperiness during sheet molding without impairing transparency. Moreover, the olefin resin sheet of the present invention is also excellent in high frequency welder weldability.

Hereinafter, the present invention will be described in detail.
The olefin resin sheet of the present invention comprises an intermediate layer composed of an ethylene copolymer, and a surface layer composed of random polypropylene and a crystal nucleating agent formed on both surfaces of the intermediate layer.

The surface layer is composed of random polypropylene and a crystal nucleating agent.
By constituting the surface layer with random polypropylene, the olefin resin sheet of the present invention is excellent in transparency.
Various random polypropylenes can be used, but random polypropylene polymerized with a metallocene catalyst is preferably used. Random polypropylene polymerized with a metallocene catalyst has higher transparency than random polypropylene or homopolypropylene polymerized with other catalysts, and is therefore advantageous for producing an olefin resin sheet having excellent transparency.
In addition, it is preferable that the random polypropylene polymerized by the metallocene catalyst has a melt flow rate at 230 ° C. × 2.16 kgf of 3 g / 10 min or more.

  The olefin resin sheet of the present invention comprises a crystal nucleating agent in the surface layer. When a crystal nucleating agent is contained in the surface layer, blocking does not occur at the time of winding the sheet without adding an antiblocking agent or a lubricant.

  The crystal nucleating agent is preferably selected from nonitol nucleating agent, sorbitol nucleating agent, phosphate ester nucleating agent, triaminobenzene derivative nucleating agent, carboxylate metal salt nucleating agent and xylitol nucleating agent.

An example of a crystal nucleating agent having a nonitol-based structure is 1,2,3-trideoxy-4,6: 5,7-bis-[(4-propylphenyl) methylene] -nonitol.
Among these, as commercially available crystal nucleating agents, for example, Millad NX8000, NX8000K, NX8000J (including 1,2,3-trideoxy-4,6: 5,7-bis-[(4-propylphenyl) methylene] -nonitol) ( And the like.

Examples of crystal nucleating agents having a sorbitol structure include, for example, bis-1,3: 2,4- (4′-ethylbenzylidene) 1-allyl sorbitol, bis-1,3: 2,4- (3′-methyl). -4′-fluoro-benzylidene) 1-propyl sorbitol, bis-1,3: 2,4- (3 ′, 4′-dimethylbenzylidene) 1′-methyl-2′-propenylsorbitol, bis-1,3 2,4-dibenzylidene 2 ′, 3′-dibromopropyl sorbitol, bis-1,3,2,4-dibenzylidene 2′-bromo-3′-hydroxypropyl sorbitol, bis-1,3: 2,4- (3′-bromo-4′-ethylbenzylidene) -1-allyl sorbitol, mono 2,4- (3′-bromo-4′-ethylbenzylidene) -1-allyl sorbitol, bis-1,3: 2,4 -(4'- Ethylbenzylidene) 1-allylsorbitol, bis-1,3: 2,4- (3 ′, 4′-dimethylbenzylidene) 1-methylsorbitol, bis (p-methylbenzylidene) sorbitol, 1,3: 2,4- Bis-o- (4-methylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-o- (benzylidene) -D-sorbitol, 1,3: 2,4-bis-o- (3 4-dimethylbenzylidene) -D-sorbitol and the like.
Among these, commercially available crystal nucleating agents include RiKAFAST R-1 (manufactured by Shin Nippon Rika Co., Ltd.), Millad 3988 (manufactured by Milliken Japan Co., Ltd.), Gel All E-200 (manufactured by Shin Nippon Rika Co., Ltd.), Gel All MD ( New Nippon Rika Co., Ltd.).

  As phosphate crystal nucleating agents, aluminum-bis (4,4 ′, 6,6′-tetra-tert-butyl-2,2′-methylenediphenyl-phosphate) -hydroxide, phosphoric acid-2,2 ′ -Methylenebis (4,6-di-tert-butylphenyl) lithium salt compound and the like. Examples of commercially available phosphate ester crystal nucleating agents include ADK STAB NA-21 (manufactured by ADEKA Corporation), ADK STAB NA-71 (manufactured by ADEKA Corporation), and the like.

  Examples of the triaminobenzene derivative crystal nucleating agent include 1,3,5-tris (2,2-dimethylpropanamide) benzene. Examples of commercially available triaminobenzene derivative crystal nucleating agents include IRGACLEAR XT386 (manufactured by BASF Japan Ltd.).

  Examples of the carboxylic acid metal salt nucleating agent include 1,2-cyclohexanedicarboxylic acid calcium salt. Examples of commercially available carboxylic acid metal salt nucleating agents include Hyperform HPN-20E (manufactured by Milliken Japan Co., Ltd.).

  Examples of the crystal nucleating agent having a xylitol structure include bis-1,3: 2,4- (5 ′, 6 ′, 7 ′, 8′-tetrahydro-2-naphthaldehydebenzylidene) 1-allylxylitol, bis -1,3: 2,4- (3 ′, 4′-dimethylbenzylidene) 1-propylxylitol.

  Among these, in order to maintain transparency after secondary processing, it is preferable to use a nonitol nucleating agent or a sorbitol nucleating agent.

  These crystal nucleating agents can be used alone or in combination of two or more.

The compounding amount of the crystal nucleating agent is 0.01 to 1 part by weight with respect to 100 parts by weight of the resin constituting the surface layer.
If it is less than 0.01 parts by weight, blocking during sheet molding cannot be suppressed, and winding of the sheet becomes difficult. On the other hand, when it exceeds 1 part by weight, the transparency of the olefin-based resin sheet tends to be impaired.

  The surface layer may contain a resin other than the random polypropylene as long as the effects of the present invention are not impaired. Other resins include, for example, low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, ethylene copolymer such as ethylene copolymer, homopolypropylene, block polypropylene, polybutene, olefin rubber, Examples include olefin-based elastomers.

  Moreover, you may add various additives, such as an antistatic agent, antioxidant, a light stabilizer, a ultraviolet absorber, an inorganic filler, and a pigment, to a surface layer as needed.

The intermediate layer of the olefin resin sheet of the present invention is made of an ethylene copolymer.
The ethylene copolymer is not particularly limited as long as it is an ethylene copolymer having high-frequency welder weldability, and examples thereof include an ethylene-vinyl acetate copolymer and an ethylene-methyl methacrylate copolymer. A flexible and highly polar ethylene-vinyl acetate copolymer is preferred. The vinyl acetate content of the ethylene-vinyl acetate copolymer is preferably 10% by weight or more, particularly preferably in the range of 10 to 35% by weight.

  In the intermediate layer, a polymer other than the above-mentioned ethylene copolymer, specifically, low density polyethylene, linear low density polyethylene, medium density, as long as the properties of the resulting olefin resin sheet are not impaired. Polyethylene, polyethylene such as high-density polyethylene, homopolypropylene, isotactic or syndiotactic polypropylene (including random propylene and ethylene, including block copolymers, ie, random polypropylene and block polypropylene), polybutene, olefin rubber, olefin It is possible to mix a base elastomer.

  Moreover, you may add various additives, such as an antistatic agent, antioxidant, a light stabilizer, a ultraviolet absorber, an inorganic filler, and a pigment, to an intermediate | middle layer like a surface layer as needed.

  The olefin-based resin sheet of the present invention is formed by forming a surface layer on both surfaces of the intermediate layer, and preferably a coextrusion method or a coextrusion inflation method with a simple manufacturing process. Of course, the intermediate layer and the surface layer can be separately formed by means of a calendering method, an extrusion method, an inflation method, or the like, and they can also be obtained by heat lamination or bonding with an adhesive or the like. The olefin resin sheet of the present invention also has an advantage of excellent interlayer adhesion without interposing an adhesive layer between the surface layers of the intermediate layer.

  Although it does not specifically limit about the thickness of the olefin resin sheet of this invention, Generally as said use, it is 0.03-2.0 mm.

  The ratio of the thickness of the intermediate layer and the surface layer in the olefin resin sheet of the present invention is in the range of 1: 2: 1 to 1: 20: 1 in the surface layer: intermediate layer: surface layer, preferably 1 : 4: 1 to 1: 16: 1.

  The olefin-based resin sheet of the present invention is excellent in winding property, slipperiness, transparency and high frequency welder weldability at the time of sheet molding, so it is used in applications that require secondary processing such as name tag cases and clear files. It is suitable for.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited by these Examples.

<Examples 1-6, Comparative Examples 1-4>
The resin composition having the formulation shown in Table 1 was T-die coextruded (two types and three layers) to produce an olefin resin sheet having a layer ratio of 1/8/1 and a total thickness of 300 μm.

In the table;
・ Random polypropylene 1
Wintech WFX4T, manufactured by Nippon Polypro Co., Ltd.
・ Random polypropylene 2
Nippon Polypro Co., Ltd., FX4G
・ Homopolypropylene Prime Polymer Co., Ltd., J105G
・ Crystal nucleating agent 1
Phosphate ester nucleating agent, manufactured by ADEKA Corporation, ADK STAB NA-71
・ Crystal nucleating agent 2
Sorbitol nucleating agent, Shin Nippon Chemical Co., Ltd., Gelol DXR
・ Lubricant Nippon Kasei Co., Ltd., L-200 (erucic acid amide)
・ Ethylene copolymer 1
Ethylene-vinyl acetate copolymer, manufactured by Mitsui DuPont Polychemical Co., Ltd., EVAFLEX EV360RC
・ Ethylene copolymer 2
Ethylene-methyl methacrylate copolymer, manufactured by Sumitomo Chemical Co., Ltd., ACLIFT WH 206F

  The following evaluation was performed about the mode at the time of shaping | molding of the sheet | seat of each Example and a comparative example, and the sheet | seat obtained by shaping | molding.

<Transparency>
The haze value was measured with a haze meter and evaluated according to the following criteria.
○ ・ ・ ・ Haze value 3 or less × ・ ・ ・ Over haze value 3

<Winding property>
The rolled-up shape at the time of sheet forming was confirmed and evaluated according to the following criteria.
○ ・ ・ ・ No problem × ・ ・ ・ Wrinkles

<High frequency welder weldability>
Using a high-frequency welder device with an output of 4 W, the synchronization rate and welding time when two sheets were stacked and welded were measured and evaluated according to the following criteria.
◎ ... Welding at a synchronization rate of 70 and transmission time of 5 seconds ○ ... Welding at a synchronization rate of 80 and transmission time of 5 seconds

<Printability>
Immediately after forming the sheet, it was subjected to corona treatment, allowed to stand at room temperature for 6 days, and evaluated the wetting index after standing using a wetting index standard solution (manufactured by Wako Pure Chemical Industries, Ltd.) 48 dynes).
○ ・ ・ ・ Wetting index is 45 dynes or more × ・ ・ ・ Wetting index is less than 45 dynes

  The sheets of Examples 1 to 6 are excellent in winding property, slipperiness, transparency, and high-frequency welder weldability at the time of sheet forming, and are therefore suitable for applications that require secondary processing such as name tag cases and clear files.

Claims (2)

An olefin-based resin sheet composed of an intermediate layer composed of an ethylene-based copolymer and a surface layer composed of random polypropylene and a crystal nucleating agent formed on both sides thereof, wherein the content of the crystal nucleating agent is An olefin-based resin sheet, which is 0.01 to 1 part by weight with respect to 100 parts by weight of random polypropylene. The crystal nucleating agent is selected from the group consisting of a nonitol nucleating agent, a sorbitol nucleating agent, a phosphate ester nucleating agent, a triaminobenzene derivative nucleating agent, a carboxylate metal salt nucleating agent, and a xylitol nucleating agent. The olefin resin sheet according to claim 1.