JP2005113104A - Anti-static polyolefin-based resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyolefin-based resin composition excellent in anti-static property, transparency and aqueous ink-printing adaptability. <P>SOLUTION: This polyolefin-based resin composition excellent in anti-static property, transparency and aqueous ink-printing adaptability contains 0.05-2.00 wt.% polyoxyethylene alkylamine or a polyoxyethylene alkenylamine, capable of being obtained by adding X moles of ethylene oxide in 2<X≤10 range to 1 mole of an 8-22C alkylamine or alkenylamine. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is an antistatic polyolefin-based resin composition that can be printed favorably in a water-based ink having a hydrophilic liquid property, has little bleed whitening over time, and has excellent transparency, and is particularly printed with a water-based ink. The present invention relates to resin molded products such as polyolefin films and sheets.

  Polyolefin films are widely used for product packaging and are very important for product manufacturers, and it is required to increase the value of products such as making the contents easier to see by improving the transparency of the film. ing.

  In such applications, the surface is usually used by printing with printing ink on the surface, and methods such as screen printing, flexographic printing, offset printing, and gravure printing are used for printing on the polyolefin film surface. .

  Conventionally, printing on the surface of polyolefin film was performed using organic solvent ink. However, the organic solvent used is generally volatile and flammable, so there is a risk of ignition and explosion. Inhalation of materials is highly toxic to the human body and leads to environmental destruction. In recent years, printing with aqueous ink in which the amount of organic solvent in the ink is adjusted to 30% by weight or less has been performed.

  Normally, polyolefin film is generally pre-added with antistatic agent to prevent dust adhesion and static electricity during film processing, but antistatic agent bleeds on the film surface. Otherwise, the effect will not be obtained, and since the bleed antistatic agent exists between the printing ink and the film, it may cause deterioration in printability and cause deterioration in the transparency of the film due to excessive bleed. There is a case.

  Polyoxyethylene alkylamines and polyoxyethylene alkenylamines having an average addition mole number of ethylene oxide of 2 mol or less are known as antistatic agents used to solve such problems, but these amine-based antistatic agents are organic. Unlike the case of solvent-based inks, it was poorly compatible with water-based inks, resulting in problems such as adhesion failure between the ink and the film surface and poor transfer, making it difficult to print clearly.

  As a method for improving the printability of these polyolefin films with water-based inks, Patent Document 1 discloses a polypropylene resin suitable for printing by adding a nonionic surfactant containing an aliphatic amide to the polypropylene resin. It has been shown that a composition is obtained. Patent Document 2 shows that the adhesion of water-based ink is improved by containing N-ethanolic acid amide in a polyolefin polymer. Patent Document 3 discloses a polyolefin film containing an acid amide compound having a characteristic structure and having water-based ink printed on one side. Patent Document 4 discloses a polyolefin film containing an acid amide compound having a characteristic structure and a fatty acid ester of a polyhydric alcohol and having water-based ink printed on one side.

  However, it cannot be said that these conventional technologies have obtained satisfactory performance for all the bleed whitening resistance, antistatic performance, and printability for water-based inks required for polyolefin films, and further improvements are required. It was.

      JP-A-1-287157 (pages 1-7)       JP-A-6-345904 (page 1-9)       JP-A-7-164608 (page 1-6)       JP-A-10-235816 (pages 1-7)

  An object of the present invention is to provide a polyolefin-based resin composition that can be suitably printed with water-based ink, has excellent antistatic properties, has little bleed whitening with time, and has excellent transparency, and an antistatic agent that enables it. Furthermore, it is to provide a resin-molded article such as an antistatic polyolefin film or sheet having at least one surface printed with water-based ink.

  As a result of diligent research to solve the above problems, the present inventors have found that polyolefin-based resins have a polyolefin resin, in order to impart printability such as adhesion to water-based ink and transferability to resin molded products such as sheets. On the other hand, when polyoxyethylene alkylamine or polyoxyethylene alkenylamine which can be obtained by adding X mole of ethylene oxide in the range of 2 <X ≦ 10 is used, an amine having an ethylene oxide average addition mole number of 2 moles or less is used. Compared with the compound, the obtained resin molded products such as films and sheets have an effective result in printability, and further have excellent antistatic properties, less bleed whitening over time, and excellent transparency. The present invention has been found and completed.

  That is, the present invention provides the following general formula (A) that can be obtained by adding X moles of ethylene oxide in the range of 2 <X ≦ 10 to 1 mole of alkylamine or alkenylamine having 8 to 22 carbon atoms. The polyoxyethylene alkylamine or polyoxyethylene alkenylamine represented is contained in an amount of 0.05 to 2.00% by weight with respect to the polyolefin-based resin, and printing suitable for water-based ink is possible. The present invention provides a polyolefin resin composition and a resin molded product such as a polyolefin film and a sheet that are less likely to be whitened over time and have excellent transparency.

（Ｒは直鎖または分岐鎖である炭素数８〜２２のアルキル基又はアルケニル基を示し、ｍ＋ｎの数平均Ｘは２＜Ｘ≦１０の関係を満たす。）で表される。

(R represents a linear or branched alkyl group or alkenyl group having 8 to 22 carbon atoms, and the number average X of m + n satisfies the relationship 2 <X ≦ 10).

  When the polyoxyethylene alkylamine or polyoxyethylene alkenylamine according to the present invention is used, it is far superior to conventional resin molded products such as polyolefin films and sheets, and is excellent in printability with water-based ink, that is, fixability, and further charged. It has been found that it is excellent in prevention, exhibits little bleed whitening over time, and exhibits excellent performance in transparency.

  Although the mechanism of this effect has not been clearly clarified, the amine compound of the present invention adds a large amount of polyoxyethylene to improve the affinity with water, and resin molding of polyolefin films, sheets, etc. When a bleed layer is formed on the surface of the product, it is presumed that the improved affinity between the bleed layer and the water-based ink contributes greatly to the printability of the water-based ink, and this forms the basis of the present invention. is there.

Hereinafter, the present invention will be described in detail.
The amine compound used in the present invention is a polyoxyethylene alkylamine or polyoxyethylene alkenylamine that can be obtained by adding X moles of ethylene oxide in the range of 2 <X ≦ 10, and has the general formula (A ).

  The amine compound of the present invention is synthesized by a known addition reaction of ethylene oxide. For example, an amine compound represented by the general formula (A) of the present invention can be synthesized by adding 3 mol of ethylene oxide to 1 mol of alkylamine or alkenylamine.

  R in the general formula (A) represents an alkyl group or alkenyl group having 8 to 22 carbon atoms. This is because if the number of carbon atoms is less than 8, blocking tends to occur, while if it exceeds 22, bleed whitening occurs over time, and transparency is impaired. In addition, the number average X of m + n in the general formula (A) satisfies the relationship 2 <X ≦ 10. If X is 2 or less, the suitability for water-based ink printing is impaired, and if X exceeds 10, bleed whitening occurs with time and transparency is impaired.

  Specific examples of the amine compound include polyoxyethylene (3) laurylamine, polyoxyethylene (4) myristylamine, polyoxyethylene (6) myristylamine, polyoxyethylene (5) palmitylamine, polyoxyethylene (2 .7) Stearylamine, polyoxyethylene (8) oleylamine, polyoxyethylene (3) behenylamine and the like can be exemplified, but are not limited thereto. Moreover, even if it mixes and uses 2 or more types of amine compounds represented by general formula (A), there will be no trouble.

  The amine compound of the present invention may contain a known antistatic agent other than the present invention, if necessary, as long as the object of the present invention is not impaired. Known antistatic agents other than the present invention include glycerin fatty acid ester, polyglycerin fatty acid ester, polyoxyethylene glycerin fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyethylene glycol fatty acid ester, polypropylene glycol fatty acid ester, poly Examples thereof include, but are not limited to, oxyethylene aliphatic alcohol ethers, condensates of fatty acids and diethanolamine, and the like.

  Specifically, glycerol monostearate, glycerol monooleate, polyglycerol monostearate, polyglycerol monooleate, sorbitan monooleate, sorbitan monoelcate, polyoxyethylene glycerol monooleate, polyoxyethylene sorbitan monooleate, polyethylene glycol Examples include monooleate, polypropylene glycol monooleate, polyoxyethylene oleyl alcohol ether, and oleyl diethanolamide. These may be used alone or in combination of two or more.

  The amount of the amine compound of the present invention added to the polyolefin resin is 0.05 to 2.00% by weight, more preferably 0.10 to 1.50% by weight. When the addition amount is less than 0.05% by weight, the antistatic performance is impaired, and when it exceeds 2.00% by weight, bleeding whitening occurs with time and transparency is impaired.

  The addition method of the amine compound of this invention is performed by a well-known method. That is, a high-concentration master batch is prepared separately, and this may be mixed in an arbitrary process until a resin molded product such as a film or sheet is obtained, or may be mixed in advance with polyolefin powder.

  In the polyolefin-based resin composition of the present invention, various additives used for resin molded products such as antioxidants, lubricants, colorants, ultraviolet absorbers and usually polyolefin films, sheets and the like within a range not impairing the object of the present invention. A filler can be added as an additional component.

  The polyolefin of the present invention is not particularly limited, and known ones are used. For example, homopolymers of α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, copolymers of the α-olefins, the α-olefins and the like Copolymers of monomers other than copolymerizable α-olefins and α-olefins, and mixtures thereof. Examples of the monomer other than the α-olefin copolymerizable with the α-olefin include vinyl acetate, maleic acid, vinyl alcohol, methacrylic acid, methyl methacrylate, and ethyl methacrylate.

  The resin molded product such as polyolefin film and sheet of the present invention may be used as a single layer or may be used by laminating two or more kinds of resins.

  At least one surface of the resin molded product such as polyolefin film or sheet of the present invention is printed with water-based ink. Printing on the surface can be performed by commonly used methods such as screen printing, flexographic printing, offset printing, and gravure printing.

  In addition, when printing on resin molded products such as polyolefin films and sheets of the present invention, if the surface is activated by a commonly used method such as corona discharge treatment prior to printing, ink familiarity and adhesion will be improved. Therefore, it is desirable to perform surface activation treatment by some method.

  EXAMPLES Next, although an Example demonstrates this invention in detail, this invention is not limited to a following example, unless the meaning is exceeded. In particular, a film will be described as a preferred example of the polyolefin-based resin molded body according to the present invention, but the polyolefin-based resin molded body in the present invention is not limited to a film.

<Synthesis Example of the Compound of the Present Invention>
1. Synthesis of amine compound A A glass autoclave equipped with a temperature controller, a nitrogen inlet tube, and a stirrer was charged with 1.0 mol of laurylamine, and after N ₂ substitution, 3.0 mol of ethylene oxide required 155 ° C. for 2 hours. Addition gave polyoxyethylene (3) laurylamine.

2. Synthesis of Amine Compounds B to H and Comparative Amine Compounds A ′ to D ′ As in A, synthesis of amine compounds B to H and comparative amine compounds A ′ to D ′ was carried out as shown in Table 1. About obtained amine compound BH and comparative amine compound A'-D ', it uses for a test of a postscript.

<Production of evaluation film>
Examples 1-8, Comparative Examples 1-5
Amine polypropylene A to H and comparative amine compounds A ′ to D ′ shown in Table 1 are blended in crystalline polypropylene having a melt flow rate of 3.0 g / 10 min and a crystallinity of 97% in the addition amounts shown in Table 2. Further, 0.1% by weight of silica having a particle size of 2.0 μm was added as an antiblocking agent and dissolved and mixed. This resin was extruded from a T-die, and a stretched film having a thickness of 20 μm was obtained using a tenter biaxial stretching machine. The surface was subjected to corona discharge treatment according to a conventional method so that the Nule index was 40 mN / m. Table 2 shows the evaluation results of the obtained film.

<Evaluation method>
The film was evaluated by the following method.
1. Bleed whitening, transparency evaluation A test piece was cut out from a film subjected to corona discharge treatment and left to stand for 14 days under constant temperature and humidity conditions at a temperature of 23 ° C. and a relative humidity of 50%. The HAZE value was measured by Denshoku).
The target for the HAZE value is 6 or less.

2. Evaluation of antistatic property A predetermined test piece was prepared from a pre-printed film subjected to corona discharge treatment, and the surface specific resistance value of the corona discharge treatment surface of the test piece was measured according to JIS-K-6911.
The target is Log (surface resistivity Ω) of 13 or less.

3. Evaluation of printability Using a gravure printer on the corona discharge treated surface of the film, water-based ink was printed to evaluate the transferability and adhesion to the film surface.
As the water-based ink, “Aqua Ecole” manufactured by Toyo Ink Mfg. Co., Ltd. was used to dilute it to a solid concentration of 20 to 30% by weight and an alcohol concentration of 30% or less using a dedicated diluent solvent.

{Circle around (1)} Transferability Evaluation The transferability evaluation was performed by observing the printed surface with an optical microscope and evaluating the transfer amount of repelling ink.
Evaluation standard ◎: No repelling is observed and the amount of transferred ink is large. ○: Almost no repelling is observed and the amount of transferred ink is large. Many, small amount of ink transferred XX: Very high repellency and small amount of ink transferred

(2) Adhesive evaluation Adhesive evaluation was performed by a peel test using a cellophane tape.
On the printed surface, make 11 100 mm square grids with 11 razors cut vertically and horizontally at a width of 1 mm. Thereafter, the cellophane tape was adhered to the grid and then peeled off, and the adhesiveness was evaluated from the ink remaining state on the printed surface.
Evaluation criteria A: The remaining area of the ink is 95% or more. B: The remaining area of the ink is 90 to 95%.
Δ: Ink remaining area of 70 to 90%
X: Ink remaining area is 50 to 70%
XX: Residual area of ink is 50% or less

  As shown in Examples 1 to 8 in Table 2, the film added with the amine compounds A to H of the present invention can be suitably printed with water-based ink, has excellent antistatic properties, and has little bleed whitening over time. Moreover, the performance excellent in transparency can be exhibited.

Claims (3)

A polyoxy compound represented by the following general formula (A) that can be obtained by adding X moles of ethylene oxide in the range of 2 <X ≦ 10 to 1 mole of alkylamine or alkenylamine having 8 to 22 carbon atoms. A polyolefin-based resin composition containing 0.05 to 2.00% by weight of ethylene alkylamine or polyoxyethylene alkenylamine.

(R represents a linear or branched alkyl group or alkenyl group having 8 to 22 carbon atoms, and the number average X of m + n satisfies the relationship 2 <X ≦ 10.)   The polyolefin resin composition according to claim 1, which is excellent in antistatic properties, transparency, and water-based ink printability.   A resin molded article such as a film or sheet comprising the polyolefin resin composition according to claim 1 or 2, wherein at least one surface is printed with water-based ink.