JPS62141040A - Olefin resin film or sheet - Google Patents

Abstract

PURPOSE:To obtain an olefin resin film or sheet having a stable antistatic effect, by spraying water contg. a surfactant and having a specified surface tension on the surface of an olefin film or sheet contg. an antistatic agent. CONSTITUTION:A film or sheet which is obtd. by spraying water contg. a surfactant and having a surface tension of 30 dyn or below on the surface of an olefin resin film or sheet contg. 0.001-0.8wt% antistatic agent. Ethylene polymers which can be used have a density of 0.900g/cm<3> or above, pref. 0.905-0.975g/cm<3>. When the amount of the antistatic agent based on that of the olefin resin is less than 0.001wt%, any sufficient antistatic effect can not be obtd., while when the amount exceeds 0.8wt%, any improvement in the antistatic properties can not be obtd. The amount of the surfactant to be added to water is generally 0.1-5wt%.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to olefinic resins or sufficient sheets exhibiting an antistatic effect. More specifically, water containing a surfactant is sprayed onto the surface of an olefin resin film or sheet containing an antistatic agent, and the surface tension of the water containing the surfactant is 30 dynes or less. The object of the present invention is to provide an olefin resin film or notebook that exhibits a sufficient antistatic effect.

BACKGROUND ART Currently, in order to improve the charging properties of olefin resin films or notebooks, various antistatic agents are blended with olefin resin in advance, and the resulting composition is molded and used as a film or sheet. is the current situation. However, the antistatic agent bleeds onto the surface of these films or sheets, and is greatly affected by the environment, so that sufficient effects cannot always be exhibited. For example, in the case of high-density polyethylene films, kneading-in type antistatic agents are rarely effective. In addition, even if the film is effective, it will not be effective unless the antistatic agent content is changed in winter (dry season) and summer (humid season), and if the amount added is too large, There was a problem in that the antistatic agent turned into powder and blew out onto the surface.

In view of the problems to be solved by the invention, the object of the present invention is to obtain a film or sheet that does not have these drawbacks (intermediate peaks), that is, fully exhibits the ability of the antistatic agent blended, and therefore The objective is to obtain an olefin resin film or sheet with stable quality (antistatic effect).

According to the present invention, these problems can be solved by spraying water containing a surfactant onto the surface of an olefinic resin film or sheet containing 0.001 to 0.8% by weight of an antistatic agent. This problem can be solved by using an olefin resin film or sheet in which the surface tension of water containing a surfactant is 30 dynes or less. The present invention will be explained in detail below.

The olefin resins used in the present invention include ethylene homopolymers and ethylene-based copolymers with α-olefins (usually having 3 to 12 carbon atoms and a copolymerization ratio of at most 15% by weight). (hereinafter referred to as ``ethylene polymers'') and ``propylene homopolymers and zolobylene as main components, propylene and ethylene and/or α-olefins (ethylene and α-olefins)
The copolymerization ratio with olefin is generally at most 20% by weight, and the number of carbon atoms in α-olefin is 4 to 12). .

Melt flow index of ethylene polymer (JIS
Measured under condition 4 according to K7210, hereinafter r M,
1. J) is usually 0.01 to 50 g/10 minutes, preferably 0.01 to 30.9 g/10 minutes, particularly 0.
01-20 g/l 0 minutes is suitable. In addition, the melt flow rate of propylene polymer (JISK7210
(hereinafter referred to as "MFR")
is generally 0.01 to 50, li+/10 min,
0.01-30F/10 minutes is desirable, especially 0.0
1 to 20.9/10 minutes is suitable. M.I.

Alternatively, if an ethylene polymer or propylene polymer whose MFR is less than the lower limit is used, fluidity will not be good when producing the film or sheet described later.

On the other hand, if an ethylene polymer or propylene polymer exceeding the upper limit is used, the resulting film or notebook will have a large neck-in and cannot be molded.

As the ethylene polymer, any of low density polyethylene produced by a so-called high pressure method, linear low density polyethylene, and high density polyethylene may be used. The density of these ethylene polymers is 0.900
ji/cm5 or more, 0,905 fl ~0
．． 980 I/cm3 is preferred, especially 0.905~
0.975 g/cm3 is preferred.

In addition, the antistatic agents used in the present invention are anionic (e.g., fatty acid salts, higher alcohol sulfate esters, phosphate esters), cationic (e.g., ester general amines, amide general amines, antistatic agents). They are broadly classified into two types: tetraammonium salts) and nonionic systems (for example, ethylene oxide adduct systems, IJ ethyleneimine systems). 3. In carrying out the present invention, any of these antistatic agents may be used (one type alone or two or more types may be used in combination). These antistatic agents are widely used in the field of thermoplastic resins,
It is well known from pages 1 to 53 of ``Surfactant Handbook'' (Sangyo Toshosha, published in 1966).

The composition ratio of the antistatic agent to the olefin resin is 0001 to 0.8% by weight, preferably 0.002 to 0.8% by weight, and particularly preferably 0.005 to 0.6% by weight. If the composition ratio of the antistatic agent to the olefin resin is 0.00101% by weight, antistatic properties cannot be sufficiently exhibited. On the other hand, even if the amount exceeds 0.8% by weight, the antistatic properties cannot be further improved.

In producing the film or sheet of the present invention, the olefin resin and antistatic agent are uniformly mixed by a mixing method generally practiced in the field of olefin resins. Mixing method Tri-blend method using mixers such as Toshiteha Henschel mixer, extruder, roll mill, kneader and Banbury mixer
There is a method of melting and kneading using a mixer such as
Any of these methods may be used, but in order to produce a more uniform mixture, it is desirable to prepare the mixture by tri-blending in advance and then melt-knead the resulting mixture.

The film or sheet of the present invention can be obtained from the mixture (composition) thus obtained by subjecting it to the T-die method or inflation method, which is commonly practiced in the field of olefin resins. In any of the above methods, as an ethylene polymer, the density is 0.935 jj / c
If less than m3 is used, the temperature is 150 to 200°C (preferably 150 to 190°C) and the density is 0.9351/
For ethylene polymers of cm3 or more, the temperature is 160-230℃ (
Desirably 170-230°C), and 180-250°C (preferably 180-240°C) for propylene polymers.
The film or sheet may be manufactured at 0°C).

The thickness of the film and sheet is not particularly limited, but is generally 5 microns to 5 microns, and preferably 8 microns to 2 microns.

The film or sheet of the present invention can be produced by spraying water containing a surfactant having a surface tension of 30 dynes or less onto the surface of the film or sheet thus obtained.

The amount of surfactant added to water varies depending on the type of surfactant, but is generally 0.1 to 5% by weight (preferably O
12 to 5 weight ratio). In the present invention, it is important that the surface tension of the water to which the surfactant is added is 30 dynes or less (preferably 25 dynes or less).

As the surfactant, the same type of antistatic agent as mentioned above is used.

The amount of surfactant-containing water varies depending on the amount of surfactant added to the water, but is generally between 0.1 and 5 OI per square meter of film or sheet;
In particular, 0.1 to 2 g is preferable.

Spraying method 4 may be any commonly used method, including a method using an ultrasonic humidifier, but it is sufficient to spray uniformly onto the surface of the film or sheet.

EXAMPLES AND COMPARATIVE EXAMPLES The present invention will be explained in more detail with reference to Examples below.

In addition, in the examples, the surface resistivity is JISK691.
Measured according to 1.

Example 1 0.16 parts by weight of 1-hydroxy-2-alkylimidacillin ( A film with a thickness of 20 microns was produced by blow molding a mixture containing (as an antistatic agent) at a die temperature of 200°C. The surface resistivity of this film was ωΩ/L:rn.

Water (surface tension: 21 dyne) containing 3.0 weight coefficient of fluoroalkyl carboxylate (as a surfactant) was sprayed onto the surface of this film using an ultrasonic humidifier to a concentration of 0.2/m2. An extremely thin film was formed on the surface of the film. The surface resistivity of the sprayed film is 101
It was 0Ω・picture.

Example 2 100 parts by weight of low density polyethylene (M, 1.3.09/10 min) with a density of 0.921 g/cm3
．． A 40 micron thick film was produced by blow molding a mixture containing 12 parts by weight of alkanol amide (as an antistatic agent) at a die temperature of 150°C. The surface specific resistance of this film is 1
o14Ω/L:rn. 2 on the surface of this film
．． Example 1: Water (surface tension: 21 dynes) containing 8% by weight of fluoroalkyl phosphate (as a surfactant)
Sprayed in the same way.

The surface resistivity of the sprayed film was 109Ω·α.

Example 3 Low density polyethylene with short chain branches (M,!, 3.0 g/10 with density 0.922 g/cm3
A mixture containing 0.20 parts by weight of alkyl/allylsulfonic acid (as an antistatic agent) in 100 parts by weight of the average short chain branched carbon is inflation molded at a die temperature of 160°C. This produced a film with a thickness of 30 microns. The surface resistivity of this film was 1014 Ω·α.

The surface of this film was sprayed with 32 weight percent alkyl noe similar to Example 1, and the surface resistivity of the sprayed film was 10+0 Ω.

Example ・1 0.20% by weight of polyoxyethylene fatty acid ester (antistatic agent) in 100 parts by weight of propylene-ethylene random copolymer (■I9.2, 9/10 minutes) containing 2.0% more ethylene by weight A film with a thickness of 60 microns was produced by inflation molding a mixture containing (as) at a Gooey temperature of 210°C. The surface resistivity of the obtained film was 1016 Ω. As in Example 3, water containing a surfactant was sprayed onto the surface of the obtained film. The surface resistivity of the sprayed film was 109Ω.

Effects of the Invention The olefin resin film or sheet of the invention exhibits the following effects.

(1) Dust can be prevented from adhering to the surface.

(2) Excellent snow-proofing effect.

The olefin resin film or sheet of the present invention can be used in a wide variety of ways, exhibiting the above-mentioned effects. Typical uses are shown below.

(1) Packaging of electronic materials and components (2) Packaging of pharmaceuticals (3) Display packaging for foods, etc. (4)' Packaging for clothing, etc. (5) Album binder patent applicant Showa Denko K.K. representative Patent attorney Kikuchi spirit

Claims (1)

[Claims] Water containing a surfactant is sprayed onto the surface of an olefin resin film or sheet containing 0.001 to 0.8% by weight of an antistatic agent, and the surface tension of the water containing the surfactant is 30%. An olefin resin film or sheet that is less than dyne.